Bug Summary

File:llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
Warning:line 4803, column 22
Forming reference to null pointer

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name LoopVectorize.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/build-llvm/lib/Transforms/Vectorize -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/build-llvm/lib/Transforms/Vectorize -I /build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize -I /build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/build-llvm/lib/Transforms/Vectorize -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-06-27-034459-32599-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

1//===- LoopVectorize.cpp - A Loop Vectorizer ------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops
10// and generates target-independent LLVM-IR.
11// The vectorizer uses the TargetTransformInfo analysis to estimate the costs
12// of instructions in order to estimate the profitability of vectorization.
13//
14// The loop vectorizer combines consecutive loop iterations into a single
15// 'wide' iteration. After this transformation the index is incremented
16// by the SIMD vector width, and not by one.
17//
18// This pass has three parts:
19// 1. The main loop pass that drives the different parts.
20// 2. LoopVectorizationLegality - A unit that checks for the legality
21// of the vectorization.
22// 3. InnerLoopVectorizer - A unit that performs the actual
23// widening of instructions.
24// 4. LoopVectorizationCostModel - A unit that checks for the profitability
25// of vectorization. It decides on the optimal vector width, which
26// can be one, if vectorization is not profitable.
27//
28// There is a development effort going on to migrate loop vectorizer to the
29// VPlan infrastructure and to introduce outer loop vectorization support (see
30// docs/Proposal/VectorizationPlan.rst and
31// http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html). For this
32// purpose, we temporarily introduced the VPlan-native vectorization path: an
33// alternative vectorization path that is natively implemented on top of the
34// VPlan infrastructure. See EnableVPlanNativePath for enabling.
35//
36//===----------------------------------------------------------------------===//
37//
38// The reduction-variable vectorization is based on the paper:
39// D. Nuzman and R. Henderson. Multi-platform Auto-vectorization.
40//
41// Variable uniformity checks are inspired by:
42// Karrenberg, R. and Hack, S. Whole Function Vectorization.
43//
44// The interleaved access vectorization is based on the paper:
45// Dorit Nuzman, Ira Rosen and Ayal Zaks. Auto-Vectorization of Interleaved
46// Data for SIMD
47//
48// Other ideas/concepts are from:
49// A. Zaks and D. Nuzman. Autovectorization in GCC-two years later.
50//
51// S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of
52// Vectorizing Compilers.
53//
54//===----------------------------------------------------------------------===//
55
56#include "llvm/Transforms/Vectorize/LoopVectorize.h"
57#include "LoopVectorizationPlanner.h"
58#include "VPRecipeBuilder.h"
59#include "VPlan.h"
60#include "VPlanHCFGBuilder.h"
61#include "VPlanPredicator.h"
62#include "VPlanTransforms.h"
63#include "llvm/ADT/APInt.h"
64#include "llvm/ADT/ArrayRef.h"
65#include "llvm/ADT/DenseMap.h"
66#include "llvm/ADT/DenseMapInfo.h"
67#include "llvm/ADT/Hashing.h"
68#include "llvm/ADT/MapVector.h"
69#include "llvm/ADT/None.h"
70#include "llvm/ADT/Optional.h"
71#include "llvm/ADT/STLExtras.h"
72#include "llvm/ADT/SmallPtrSet.h"
73#include "llvm/ADT/SmallSet.h"
74#include "llvm/ADT/SmallVector.h"
75#include "llvm/ADT/Statistic.h"
76#include "llvm/ADT/StringRef.h"
77#include "llvm/ADT/Twine.h"
78#include "llvm/ADT/iterator_range.h"
79#include "llvm/Analysis/AssumptionCache.h"
80#include "llvm/Analysis/BasicAliasAnalysis.h"
81#include "llvm/Analysis/BlockFrequencyInfo.h"
82#include "llvm/Analysis/CFG.h"
83#include "llvm/Analysis/CodeMetrics.h"
84#include "llvm/Analysis/DemandedBits.h"
85#include "llvm/Analysis/GlobalsModRef.h"
86#include "llvm/Analysis/LoopAccessAnalysis.h"
87#include "llvm/Analysis/LoopAnalysisManager.h"
88#include "llvm/Analysis/LoopInfo.h"
89#include "llvm/Analysis/LoopIterator.h"
90#include "llvm/Analysis/MemorySSA.h"
91#include "llvm/Analysis/OptimizationRemarkEmitter.h"
92#include "llvm/Analysis/ProfileSummaryInfo.h"
93#include "llvm/Analysis/ScalarEvolution.h"
94#include "llvm/Analysis/ScalarEvolutionExpressions.h"
95#include "llvm/Analysis/TargetLibraryInfo.h"
96#include "llvm/Analysis/TargetTransformInfo.h"
97#include "llvm/Analysis/VectorUtils.h"
98#include "llvm/IR/Attributes.h"
99#include "llvm/IR/BasicBlock.h"
100#include "llvm/IR/CFG.h"
101#include "llvm/IR/Constant.h"
102#include "llvm/IR/Constants.h"
103#include "llvm/IR/DataLayout.h"
104#include "llvm/IR/DebugInfoMetadata.h"
105#include "llvm/IR/DebugLoc.h"
106#include "llvm/IR/DerivedTypes.h"
107#include "llvm/IR/DiagnosticInfo.h"
108#include "llvm/IR/Dominators.h"
109#include "llvm/IR/Function.h"
110#include "llvm/IR/IRBuilder.h"
111#include "llvm/IR/InstrTypes.h"
112#include "llvm/IR/Instruction.h"
113#include "llvm/IR/Instructions.h"
114#include "llvm/IR/IntrinsicInst.h"
115#include "llvm/IR/Intrinsics.h"
116#include "llvm/IR/LLVMContext.h"
117#include "llvm/IR/Metadata.h"
118#include "llvm/IR/Module.h"
119#include "llvm/IR/Operator.h"
120#include "llvm/IR/PatternMatch.h"
121#include "llvm/IR/Type.h"
122#include "llvm/IR/Use.h"
123#include "llvm/IR/User.h"
124#include "llvm/IR/Value.h"
125#include "llvm/IR/ValueHandle.h"
126#include "llvm/IR/Verifier.h"
127#include "llvm/InitializePasses.h"
128#include "llvm/Pass.h"
129#include "llvm/Support/Casting.h"
130#include "llvm/Support/CommandLine.h"
131#include "llvm/Support/Compiler.h"
132#include "llvm/Support/Debug.h"
133#include "llvm/Support/ErrorHandling.h"
134#include "llvm/Support/InstructionCost.h"
135#include "llvm/Support/MathExtras.h"
136#include "llvm/Support/raw_ostream.h"
137#include "llvm/Transforms/Utils/BasicBlockUtils.h"
138#include "llvm/Transforms/Utils/InjectTLIMappings.h"
139#include "llvm/Transforms/Utils/LoopSimplify.h"
140#include "llvm/Transforms/Utils/LoopUtils.h"
141#include "llvm/Transforms/Utils/LoopVersioning.h"
142#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
143#include "llvm/Transforms/Utils/SizeOpts.h"
144#include "llvm/Transforms/Vectorize/LoopVectorizationLegality.h"
145#include <algorithm>
146#include <cassert>
147#include <cstdint>
148#include <cstdlib>
149#include <functional>
150#include <iterator>
151#include <limits>
152#include <memory>
153#include <string>
154#include <tuple>
155#include <utility>
156
157using namespace llvm;
158
159#define LV_NAME"loop-vectorize" "loop-vectorize"
160#define DEBUG_TYPE"loop-vectorize" LV_NAME"loop-vectorize"
161
162#ifndef NDEBUG
163const char VerboseDebug[] = DEBUG_TYPE"loop-vectorize" "-verbose";
164#endif
165
166/// @{
167/// Metadata attribute names
168const char LLVMLoopVectorizeFollowupAll[] = "llvm.loop.vectorize.followup_all";
169const char LLVMLoopVectorizeFollowupVectorized[] =
170 "llvm.loop.vectorize.followup_vectorized";
171const char LLVMLoopVectorizeFollowupEpilogue[] =
172 "llvm.loop.vectorize.followup_epilogue";
173/// @}
174
175STATISTIC(LoopsVectorized, "Number of loops vectorized")static llvm::Statistic LoopsVectorized = {"loop-vectorize", "LoopsVectorized"
, "Number of loops vectorized"}
;
176STATISTIC(LoopsAnalyzed, "Number of loops analyzed for vectorization")static llvm::Statistic LoopsAnalyzed = {"loop-vectorize", "LoopsAnalyzed"
, "Number of loops analyzed for vectorization"}
;
177STATISTIC(LoopsEpilogueVectorized, "Number of epilogues vectorized")static llvm::Statistic LoopsEpilogueVectorized = {"loop-vectorize"
, "LoopsEpilogueVectorized", "Number of epilogues vectorized"
}
;
178
179static cl::opt<bool> EnableEpilogueVectorization(
180 "enable-epilogue-vectorization", cl::init(true), cl::Hidden,
181 cl::desc("Enable vectorization of epilogue loops."));
182
183static cl::opt<unsigned> EpilogueVectorizationForceVF(
184 "epilogue-vectorization-force-VF", cl::init(1), cl::Hidden,
185 cl::desc("When epilogue vectorization is enabled, and a value greater than "
186 "1 is specified, forces the given VF for all applicable epilogue "
187 "loops."));
188
189static cl::opt<unsigned> EpilogueVectorizationMinVF(
190 "epilogue-vectorization-minimum-VF", cl::init(16), cl::Hidden,
191 cl::desc("Only loops with vectorization factor equal to or larger than "
192 "the specified value are considered for epilogue vectorization."));
193
194/// Loops with a known constant trip count below this number are vectorized only
195/// if no scalar iteration overheads are incurred.
196static cl::opt<unsigned> TinyTripCountVectorThreshold(
197 "vectorizer-min-trip-count", cl::init(16), cl::Hidden,
198 cl::desc("Loops with a constant trip count that is smaller than this "
199 "value are vectorized only if no scalar iteration overheads "
200 "are incurred."));
201
202static cl::opt<unsigned> PragmaVectorizeMemoryCheckThreshold(
203 "pragma-vectorize-memory-check-threshold", cl::init(128), cl::Hidden,
204 cl::desc("The maximum allowed number of runtime memory checks with a "
205 "vectorize(enable) pragma."));
206
207// Option prefer-predicate-over-epilogue indicates that an epilogue is undesired,
208// that predication is preferred, and this lists all options. I.e., the
209// vectorizer will try to fold the tail-loop (epilogue) into the vector body
210// and predicate the instructions accordingly. If tail-folding fails, there are
211// different fallback strategies depending on these values:
212namespace PreferPredicateTy {
213 enum Option {
214 ScalarEpilogue = 0,
215 PredicateElseScalarEpilogue,
216 PredicateOrDontVectorize
217 };
218} // namespace PreferPredicateTy
219
220static cl::opt<PreferPredicateTy::Option> PreferPredicateOverEpilogue(
221 "prefer-predicate-over-epilogue",
222 cl::init(PreferPredicateTy::ScalarEpilogue),
223 cl::Hidden,
224 cl::desc("Tail-folding and predication preferences over creating a scalar "
225 "epilogue loop."),
226 cl::values(clEnumValN(PreferPredicateTy::ScalarEpilogue,llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy
::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue"
}
227 "scalar-epilogue",llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy
::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue"
}
228 "Don't tail-predicate loops, create scalar epilogue")llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy
::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue"
}
,
229 clEnumValN(PreferPredicateTy::PredicateElseScalarEpilogue,llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue",
int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail "
"folding fails." }
230 "predicate-else-scalar-epilogue",llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue",
int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail "
"folding fails." }
231 "prefer tail-folding, create scalar epilogue if tail "llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue",
int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail "
"folding fails." }
232 "folding fails.")llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue",
int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail "
"folding fails." }
,
233 clEnumValN(PreferPredicateTy::PredicateOrDontVectorize,llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy
::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if "
"tail-folding fails." }
234 "predicate-dont-vectorize",llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy
::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if "
"tail-folding fails." }
235 "prefers tail-folding, don't attempt vectorization if "llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy
::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if "
"tail-folding fails." }
236 "tail-folding fails.")llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy
::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if "
"tail-folding fails." }
));
237
238static cl::opt<bool> MaximizeBandwidth(
239 "vectorizer-maximize-bandwidth", cl::init(false), cl::Hidden,
240 cl::desc("Maximize bandwidth when selecting vectorization factor which "
241 "will be determined by the smallest type in loop."));
242
243static cl::opt<bool> EnableInterleavedMemAccesses(
244 "enable-interleaved-mem-accesses", cl::init(false), cl::Hidden,
245 cl::desc("Enable vectorization on interleaved memory accesses in a loop"));
246
247/// An interleave-group may need masking if it resides in a block that needs
248/// predication, or in order to mask away gaps.
249static cl::opt<bool> EnableMaskedInterleavedMemAccesses(
250 "enable-masked-interleaved-mem-accesses", cl::init(false), cl::Hidden,
251 cl::desc("Enable vectorization on masked interleaved memory accesses in a loop"));
252
253static cl::opt<unsigned> TinyTripCountInterleaveThreshold(
254 "tiny-trip-count-interleave-threshold", cl::init(128), cl::Hidden,
255 cl::desc("We don't interleave loops with a estimated constant trip count "
256 "below this number"));
257
258static cl::opt<unsigned> ForceTargetNumScalarRegs(
259 "force-target-num-scalar-regs", cl::init(0), cl::Hidden,
260 cl::desc("A flag that overrides the target's number of scalar registers."));
261
262static cl::opt<unsigned> ForceTargetNumVectorRegs(
263 "force-target-num-vector-regs", cl::init(0), cl::Hidden,
264 cl::desc("A flag that overrides the target's number of vector registers."));
265
266static cl::opt<unsigned> ForceTargetMaxScalarInterleaveFactor(
267 "force-target-max-scalar-interleave", cl::init(0), cl::Hidden,
268 cl::desc("A flag that overrides the target's max interleave factor for "
269 "scalar loops."));
270
271static cl::opt<unsigned> ForceTargetMaxVectorInterleaveFactor(
272 "force-target-max-vector-interleave", cl::init(0), cl::Hidden,
273 cl::desc("A flag that overrides the target's max interleave factor for "
274 "vectorized loops."));
275
276static cl::opt<unsigned> ForceTargetInstructionCost(
277 "force-target-instruction-cost", cl::init(0), cl::Hidden,
278 cl::desc("A flag that overrides the target's expected cost for "
279 "an instruction to a single constant value. Mostly "
280 "useful for getting consistent testing."));
281
282static cl::opt<bool> ForceTargetSupportsScalableVectors(
283 "force-target-supports-scalable-vectors", cl::init(false), cl::Hidden,
284 cl::desc(
285 "Pretend that scalable vectors are supported, even if the target does "
286 "not support them. This flag should only be used for testing."));
287
288static cl::opt<unsigned> SmallLoopCost(
289 "small-loop-cost", cl::init(20), cl::Hidden,
290 cl::desc(
291 "The cost of a loop that is considered 'small' by the interleaver."));
292
293static cl::opt<bool> LoopVectorizeWithBlockFrequency(
294 "loop-vectorize-with-block-frequency", cl::init(true), cl::Hidden,
295 cl::desc("Enable the use of the block frequency analysis to access PGO "
296 "heuristics minimizing code growth in cold regions and being more "
297 "aggressive in hot regions."));
298
299// Runtime interleave loops for load/store throughput.
300static cl::opt<bool> EnableLoadStoreRuntimeInterleave(
301 "enable-loadstore-runtime-interleave", cl::init(true), cl::Hidden,
302 cl::desc(
303 "Enable runtime interleaving until load/store ports are saturated"));
304
305/// Interleave small loops with scalar reductions.
306static cl::opt<bool> InterleaveSmallLoopScalarReduction(
307 "interleave-small-loop-scalar-reduction", cl::init(false), cl::Hidden,
308 cl::desc("Enable interleaving for loops with small iteration counts that "
309 "contain scalar reductions to expose ILP."));
310
311/// The number of stores in a loop that are allowed to need predication.
312static cl::opt<unsigned> NumberOfStoresToPredicate(
313 "vectorize-num-stores-pred", cl::init(1), cl::Hidden,
314 cl::desc("Max number of stores to be predicated behind an if."));
315
316static cl::opt<bool> EnableIndVarRegisterHeur(
317 "enable-ind-var-reg-heur", cl::init(true), cl::Hidden,
318 cl::desc("Count the induction variable only once when interleaving"));
319
320static cl::opt<bool> EnableCondStoresVectorization(
321 "enable-cond-stores-vec", cl::init(true), cl::Hidden,
322 cl::desc("Enable if predication of stores during vectorization."));
323
324static cl::opt<unsigned> MaxNestedScalarReductionIC(
325 "max-nested-scalar-reduction-interleave", cl::init(2), cl::Hidden,
326 cl::desc("The maximum interleave count to use when interleaving a scalar "
327 "reduction in a nested loop."));
328
329static cl::opt<bool>
330 PreferInLoopReductions("prefer-inloop-reductions", cl::init(false),
331 cl::Hidden,
332 cl::desc("Prefer in-loop vector reductions, "
333 "overriding the targets preference."));
334
335cl::opt<bool> EnableStrictReductions(
336 "enable-strict-reductions", cl::init(false), cl::Hidden,
337 cl::desc("Enable the vectorisation of loops with in-order (strict) "
338 "FP reductions"));
339
340static cl::opt<bool> PreferPredicatedReductionSelect(
341 "prefer-predicated-reduction-select", cl::init(false), cl::Hidden,
342 cl::desc(
343 "Prefer predicating a reduction operation over an after loop select."));
344
345cl::opt<bool> EnableVPlanNativePath(
346 "enable-vplan-native-path", cl::init(false), cl::Hidden,
347 cl::desc("Enable VPlan-native vectorization path with "
348 "support for outer loop vectorization."));
349
350// FIXME: Remove this switch once we have divergence analysis. Currently we
351// assume divergent non-backedge branches when this switch is true.
352cl::opt<bool> EnableVPlanPredication(
353 "enable-vplan-predication", cl::init(false), cl::Hidden,
354 cl::desc("Enable VPlan-native vectorization path predicator with "
355 "support for outer loop vectorization."));
356
357// This flag enables the stress testing of the VPlan H-CFG construction in the
358// VPlan-native vectorization path. It must be used in conjuction with
359// -enable-vplan-native-path. -vplan-verify-hcfg can also be used to enable the
360// verification of the H-CFGs built.
361static cl::opt<bool> VPlanBuildStressTest(
362 "vplan-build-stress-test", cl::init(false), cl::Hidden,
363 cl::desc(
364 "Build VPlan for every supported loop nest in the function and bail "
365 "out right after the build (stress test the VPlan H-CFG construction "
366 "in the VPlan-native vectorization path)."));
367
368cl::opt<bool> llvm::EnableLoopInterleaving(
369 "interleave-loops", cl::init(true), cl::Hidden,
370 cl::desc("Enable loop interleaving in Loop vectorization passes"));
371cl::opt<bool> llvm::EnableLoopVectorization(
372 "vectorize-loops", cl::init(true), cl::Hidden,
373 cl::desc("Run the Loop vectorization passes"));
374
375cl::opt<bool> PrintVPlansInDotFormat(
376 "vplan-print-in-dot-format", cl::init(false), cl::Hidden,
377 cl::desc("Use dot format instead of plain text when dumping VPlans"));
378
379/// A helper function that returns true if the given type is irregular. The
380/// type is irregular if its allocated size doesn't equal the store size of an
381/// element of the corresponding vector type.
382static bool hasIrregularType(Type *Ty, const DataLayout &DL) {
383 // Determine if an array of N elements of type Ty is "bitcast compatible"
384 // with a <N x Ty> vector.
385 // This is only true if there is no padding between the array elements.
386 return DL.getTypeAllocSizeInBits(Ty) != DL.getTypeSizeInBits(Ty);
387}
388
389/// A helper function that returns the reciprocal of the block probability of
390/// predicated blocks. If we return X, we are assuming the predicated block
391/// will execute once for every X iterations of the loop header.
392///
393/// TODO: We should use actual block probability here, if available. Currently,
394/// we always assume predicated blocks have a 50% chance of executing.
395static unsigned getReciprocalPredBlockProb() { return 2; }
396
397/// A helper function that returns an integer or floating-point constant with
398/// value C.
399static Constant *getSignedIntOrFpConstant(Type *Ty, int64_t C) {
400 return Ty->isIntegerTy() ? ConstantInt::getSigned(Ty, C)
401 : ConstantFP::get(Ty, C);
402}
403
404/// Returns "best known" trip count for the specified loop \p L as defined by
405/// the following procedure:
406/// 1) Returns exact trip count if it is known.
407/// 2) Returns expected trip count according to profile data if any.
408/// 3) Returns upper bound estimate if it is known.
409/// 4) Returns None if all of the above failed.
410static Optional<unsigned> getSmallBestKnownTC(ScalarEvolution &SE, Loop *L) {
411 // Check if exact trip count is known.
412 if (unsigned ExpectedTC = SE.getSmallConstantTripCount(L))
413 return ExpectedTC;
414
415 // Check if there is an expected trip count available from profile data.
416 if (LoopVectorizeWithBlockFrequency)
417 if (auto EstimatedTC = getLoopEstimatedTripCount(L))
418 return EstimatedTC;
419
420 // Check if upper bound estimate is known.
421 if (unsigned ExpectedTC = SE.getSmallConstantMaxTripCount(L))
422 return ExpectedTC;
423
424 return None;
425}
426
427// Forward declare GeneratedRTChecks.
428class GeneratedRTChecks;
429
430namespace llvm {
431
432/// InnerLoopVectorizer vectorizes loops which contain only one basic
433/// block to a specified vectorization factor (VF).
434/// This class performs the widening of scalars into vectors, or multiple
435/// scalars. This class also implements the following features:
436/// * It inserts an epilogue loop for handling loops that don't have iteration
437/// counts that are known to be a multiple of the vectorization factor.
438/// * It handles the code generation for reduction variables.
439/// * Scalarization (implementation using scalars) of un-vectorizable
440/// instructions.
441/// InnerLoopVectorizer does not perform any vectorization-legality
442/// checks, and relies on the caller to check for the different legality
443/// aspects. The InnerLoopVectorizer relies on the
444/// LoopVectorizationLegality class to provide information about the induction
445/// and reduction variables that were found to a given vectorization factor.
446class InnerLoopVectorizer {
447public:
448 InnerLoopVectorizer(Loop *OrigLoop, PredicatedScalarEvolution &PSE,
449 LoopInfo *LI, DominatorTree *DT,
450 const TargetLibraryInfo *TLI,
451 const TargetTransformInfo *TTI, AssumptionCache *AC,
452 OptimizationRemarkEmitter *ORE, ElementCount VecWidth,
453 unsigned UnrollFactor, LoopVectorizationLegality *LVL,
454 LoopVectorizationCostModel *CM, BlockFrequencyInfo *BFI,
455 ProfileSummaryInfo *PSI, GeneratedRTChecks &RTChecks)
456 : OrigLoop(OrigLoop), PSE(PSE), LI(LI), DT(DT), TLI(TLI), TTI(TTI),
457 AC(AC), ORE(ORE), VF(VecWidth), UF(UnrollFactor),
458 Builder(PSE.getSE()->getContext()), Legal(LVL), Cost(CM), BFI(BFI),
459 PSI(PSI), RTChecks(RTChecks) {
460 // Query this against the original loop and save it here because the profile
461 // of the original loop header may change as the transformation happens.
462 OptForSizeBasedOnProfile = llvm::shouldOptimizeForSize(
463 OrigLoop->getHeader(), PSI, BFI, PGSOQueryType::IRPass);
464 }
465
466 virtual ~InnerLoopVectorizer() = default;
467
468 /// Create a new empty loop that will contain vectorized instructions later
469 /// on, while the old loop will be used as the scalar remainder. Control flow
470 /// is generated around the vectorized (and scalar epilogue) loops consisting
471 /// of various checks and bypasses. Return the pre-header block of the new
472 /// loop.
473 /// In the case of epilogue vectorization, this function is overriden to
474 /// handle the more complex control flow around the loops.
475 virtual BasicBlock *createVectorizedLoopSkeleton();
476
477 /// Widen a single instruction within the innermost loop.
478 void widenInstruction(Instruction &I, VPValue *Def, VPUser &Operands,
479 VPTransformState &State);
480
481 /// Widen a single call instruction within the innermost loop.
482 void widenCallInstruction(CallInst &I, VPValue *Def, VPUser &ArgOperands,
483 VPTransformState &State);
484
485 /// Widen a single select instruction within the innermost loop.
486 void widenSelectInstruction(SelectInst &I, VPValue *VPDef, VPUser &Operands,
487 bool InvariantCond, VPTransformState &State);
488
489 /// Fix the vectorized code, taking care of header phi's, live-outs, and more.
490 void fixVectorizedLoop(VPTransformState &State);
491
492 // Return true if any runtime check is added.
493 bool areSafetyChecksAdded() { return AddedSafetyChecks; }
494
495 /// A type for vectorized values in the new loop. Each value from the
496 /// original loop, when vectorized, is represented by UF vector values in the
497 /// new unrolled loop, where UF is the unroll factor.
498 using VectorParts = SmallVector<Value *, 2>;
499
500 /// Vectorize a single GetElementPtrInst based on information gathered and
501 /// decisions taken during planning.
502 void widenGEP(GetElementPtrInst *GEP, VPValue *VPDef, VPUser &Indices,
503 unsigned UF, ElementCount VF, bool IsPtrLoopInvariant,
504 SmallBitVector &IsIndexLoopInvariant, VPTransformState &State);
505
506 /// Vectorize a single PHINode in a block. This method handles the induction
507 /// variable canonicalization. It supports both VF = 1 for unrolled loops and
508 /// arbitrary length vectors.
509 void widenPHIInstruction(Instruction *PN, RecurrenceDescriptor *RdxDesc,
510 VPWidenPHIRecipe *PhiR, VPTransformState &State);
511
512 /// A helper function to scalarize a single Instruction in the innermost loop.
513 /// Generates a sequence of scalar instances for each lane between \p MinLane
514 /// and \p MaxLane, times each part between \p MinPart and \p MaxPart,
515 /// inclusive. Uses the VPValue operands from \p Operands instead of \p
516 /// Instr's operands.
517 void scalarizeInstruction(Instruction *Instr, VPValue *Def, VPUser &Operands,
518 const VPIteration &Instance, bool IfPredicateInstr,
519 VPTransformState &State);
520
521 /// Widen an integer or floating-point induction variable \p IV. If \p Trunc
522 /// is provided, the integer induction variable will first be truncated to
523 /// the corresponding type.
524 void widenIntOrFpInduction(PHINode *IV, Value *Start, TruncInst *Trunc,
525 VPValue *Def, VPValue *CastDef,
526 VPTransformState &State);
527
528 /// Construct the vector value of a scalarized value \p V one lane at a time.
529 void packScalarIntoVectorValue(VPValue *Def, const VPIteration &Instance,
530 VPTransformState &State);
531
532 /// Try to vectorize interleaved access group \p Group with the base address
533 /// given in \p Addr, optionally masking the vector operations if \p
534 /// BlockInMask is non-null. Use \p State to translate given VPValues to IR
535 /// values in the vectorized loop.
536 void vectorizeInterleaveGroup(const InterleaveGroup<Instruction> *Group,
537 ArrayRef<VPValue *> VPDefs,
538 VPTransformState &State, VPValue *Addr,
539 ArrayRef<VPValue *> StoredValues,
540 VPValue *BlockInMask = nullptr);
541
542 /// Vectorize Load and Store instructions with the base address given in \p
543 /// Addr, optionally masking the vector operations if \p BlockInMask is
544 /// non-null. Use \p State to translate given VPValues to IR values in the
545 /// vectorized loop.
546 void vectorizeMemoryInstruction(Instruction *Instr, VPTransformState &State,
547 VPValue *Def, VPValue *Addr,
548 VPValue *StoredValue, VPValue *BlockInMask);
549
550 /// Set the debug location in the builder using the debug location in
551 /// the instruction.
552 void setDebugLocFromInst(IRBuilder<> &B, const Value *Ptr);
553
554 /// Fix the non-induction PHIs in the OrigPHIsToFix vector.
555 void fixNonInductionPHIs(VPTransformState &State);
556
557 /// Returns true if the reordering of FP operations is not allowed, but we are
558 /// able to vectorize with strict in-order reductions for the given RdxDesc.
559 bool useOrderedReductions(RecurrenceDescriptor &RdxDesc);
560
561 /// Create a broadcast instruction. This method generates a broadcast
562 /// instruction (shuffle) for loop invariant values and for the induction
563 /// value. If this is the induction variable then we extend it to N, N+1, ...
564 /// this is needed because each iteration in the loop corresponds to a SIMD
565 /// element.
566 virtual Value *getBroadcastInstrs(Value *V);
567
568protected:
569 friend class LoopVectorizationPlanner;
570
571 /// A small list of PHINodes.
572 using PhiVector = SmallVector<PHINode *, 4>;
573
574 /// A type for scalarized values in the new loop. Each value from the
575 /// original loop, when scalarized, is represented by UF x VF scalar values
576 /// in the new unrolled loop, where UF is the unroll factor and VF is the
577 /// vectorization factor.
578 using ScalarParts = SmallVector<SmallVector<Value *, 4>, 2>;
579
580 /// Set up the values of the IVs correctly when exiting the vector loop.
581 void fixupIVUsers(PHINode *OrigPhi, const InductionDescriptor &II,
582 Value *CountRoundDown, Value *EndValue,
583 BasicBlock *MiddleBlock);
584
585 /// Create a new induction variable inside L.
586 PHINode *createInductionVariable(Loop *L, Value *Start, Value *End,
587 Value *Step, Instruction *DL);
588
589 /// Handle all cross-iteration phis in the header.
590 void fixCrossIterationPHIs(VPTransformState &State);
591
592 /// Fix a first-order recurrence. This is the second phase of vectorizing
593 /// this phi node.
594 void fixFirstOrderRecurrence(PHINode *Phi, VPTransformState &State);
595
596 /// Fix a reduction cross-iteration phi. This is the second phase of
597 /// vectorizing this phi node.
598 void fixReduction(VPWidenPHIRecipe *Phi, VPTransformState &State);
599
600 /// Clear NSW/NUW flags from reduction instructions if necessary.
601 void clearReductionWrapFlags(const RecurrenceDescriptor &RdxDesc,
602 VPTransformState &State);
603
604 /// Fixup the LCSSA phi nodes in the unique exit block. This simply
605 /// means we need to add the appropriate incoming value from the middle
606 /// block as exiting edges from the scalar epilogue loop (if present) are
607 /// already in place, and we exit the vector loop exclusively to the middle
608 /// block.
609 void fixLCSSAPHIs(VPTransformState &State);
610
611 /// Iteratively sink the scalarized operands of a predicated instruction into
612 /// the block that was created for it.
613 void sinkScalarOperands(Instruction *PredInst);
614
615 /// Shrinks vector element sizes to the smallest bitwidth they can be legally
616 /// represented as.
617 void truncateToMinimalBitwidths(VPTransformState &State);
618
619 /// This function adds
620 /// (StartIdx * Step, (StartIdx + 1) * Step, (StartIdx + 2) * Step, ...)
621 /// to each vector element of Val. The sequence starts at StartIndex.
622 /// \p Opcode is relevant for FP induction variable.
623 virtual Value *getStepVector(Value *Val, int StartIdx, Value *Step,
624 Instruction::BinaryOps Opcode =
625 Instruction::BinaryOpsEnd);
626
627 /// Compute scalar induction steps. \p ScalarIV is the scalar induction
628 /// variable on which to base the steps, \p Step is the size of the step, and
629 /// \p EntryVal is the value from the original loop that maps to the steps.
630 /// Note that \p EntryVal doesn't have to be an induction variable - it
631 /// can also be a truncate instruction.
632 void buildScalarSteps(Value *ScalarIV, Value *Step, Instruction *EntryVal,
633 const InductionDescriptor &ID, VPValue *Def,
634 VPValue *CastDef, VPTransformState &State);
635
636 /// Create a vector induction phi node based on an existing scalar one. \p
637 /// EntryVal is the value from the original loop that maps to the vector phi
638 /// node, and \p Step is the loop-invariant step. If \p EntryVal is a
639 /// truncate instruction, instead of widening the original IV, we widen a
640 /// version of the IV truncated to \p EntryVal's type.
641 void createVectorIntOrFpInductionPHI(const InductionDescriptor &II,
642 Value *Step, Value *Start,
643 Instruction *EntryVal, VPValue *Def,
644 VPValue *CastDef,
645 VPTransformState &State);
646
647 /// Returns true if an instruction \p I should be scalarized instead of
648 /// vectorized for the chosen vectorization factor.
649 bool shouldScalarizeInstruction(Instruction *I) const;
650
651 /// Returns true if we should generate a scalar version of \p IV.
652 bool needsScalarInduction(Instruction *IV) const;
653
654 /// If there is a cast involved in the induction variable \p ID, which should
655 /// be ignored in the vectorized loop body, this function records the
656 /// VectorLoopValue of the respective Phi also as the VectorLoopValue of the
657 /// cast. We had already proved that the casted Phi is equal to the uncasted
658 /// Phi in the vectorized loop (under a runtime guard), and therefore
659 /// there is no need to vectorize the cast - the same value can be used in the
660 /// vector loop for both the Phi and the cast.
661 /// If \p VectorLoopValue is a scalarized value, \p Lane is also specified,
662 /// Otherwise, \p VectorLoopValue is a widened/vectorized value.
663 ///
664 /// \p EntryVal is the value from the original loop that maps to the vector
665 /// phi node and is used to distinguish what is the IV currently being
666 /// processed - original one (if \p EntryVal is a phi corresponding to the
667 /// original IV) or the "newly-created" one based on the proof mentioned above
668 /// (see also buildScalarSteps() and createVectorIntOrFPInductionPHI()). In the
669 /// latter case \p EntryVal is a TruncInst and we must not record anything for
670 /// that IV, but it's error-prone to expect callers of this routine to care
671 /// about that, hence this explicit parameter.
672 void recordVectorLoopValueForInductionCast(
673 const InductionDescriptor &ID, const Instruction *EntryVal,
674 Value *VectorLoopValue, VPValue *CastDef, VPTransformState &State,
675 unsigned Part, unsigned Lane = UINT_MAX(2147483647 *2U +1U));
676
677 /// Generate a shuffle sequence that will reverse the vector Vec.
678 virtual Value *reverseVector(Value *Vec);
679
680 /// Returns (and creates if needed) the original loop trip count.
681 Value *getOrCreateTripCount(Loop *NewLoop);
682
683 /// Returns (and creates if needed) the trip count of the widened loop.
684 Value *getOrCreateVectorTripCount(Loop *NewLoop);
685
686 /// Returns a bitcasted value to the requested vector type.
687 /// Also handles bitcasts of vector<float> <-> vector<pointer> types.
688 Value *createBitOrPointerCast(Value *V, VectorType *DstVTy,
689 const DataLayout &DL);
690
691 /// Emit a bypass check to see if the vector trip count is zero, including if
692 /// it overflows.
693 void emitMinimumIterationCountCheck(Loop *L, BasicBlock *Bypass);
694
695 /// Emit a bypass check to see if all of the SCEV assumptions we've
696 /// had to make are correct. Returns the block containing the checks or
697 /// nullptr if no checks have been added.
698 BasicBlock *emitSCEVChecks(Loop *L, BasicBlock *Bypass);
699
700 /// Emit bypass checks to check any memory assumptions we may have made.
701 /// Returns the block containing the checks or nullptr if no checks have been
702 /// added.
703 BasicBlock *emitMemRuntimeChecks(Loop *L, BasicBlock *Bypass);
704
705 /// Compute the transformed value of Index at offset StartValue using step
706 /// StepValue.
707 /// For integer induction, returns StartValue + Index * StepValue.
708 /// For pointer induction, returns StartValue[Index * StepValue].
709 /// FIXME: The newly created binary instructions should contain nsw/nuw
710 /// flags, which can be found from the original scalar operations.
711 Value *emitTransformedIndex(IRBuilder<> &B, Value *Index, ScalarEvolution *SE,
712 const DataLayout &DL,
713 const InductionDescriptor &ID) const;
714
715 /// Emit basic blocks (prefixed with \p Prefix) for the iteration check,
716 /// vector loop preheader, middle block and scalar preheader. Also
717 /// allocate a loop object for the new vector loop and return it.
718 Loop *createVectorLoopSkeleton(StringRef Prefix);
719
720 /// Create new phi nodes for the induction variables to resume iteration count
721 /// in the scalar epilogue, from where the vectorized loop left off (given by
722 /// \p VectorTripCount).
723 /// In cases where the loop skeleton is more complicated (eg. epilogue
724 /// vectorization) and the resume values can come from an additional bypass
725 /// block, the \p AdditionalBypass pair provides information about the bypass
726 /// block and the end value on the edge from bypass to this loop.
727 void createInductionResumeValues(
728 Loop *L, Value *VectorTripCount,
729 std::pair<BasicBlock *, Value *> AdditionalBypass = {nullptr, nullptr});
730
731 /// Complete the loop skeleton by adding debug MDs, creating appropriate
732 /// conditional branches in the middle block, preparing the builder and
733 /// running the verifier. Take in the vector loop \p L as argument, and return
734 /// the preheader of the completed vector loop.
735 BasicBlock *completeLoopSkeleton(Loop *L, MDNode *OrigLoopID);
736
737 /// Add additional metadata to \p To that was not present on \p Orig.
738 ///
739 /// Currently this is used to add the noalias annotations based on the
740 /// inserted memchecks. Use this for instructions that are *cloned* into the
741 /// vector loop.
742 void addNewMetadata(Instruction *To, const Instruction *Orig);
743
744 /// Add metadata from one instruction to another.
745 ///
746 /// This includes both the original MDs from \p From and additional ones (\see
747 /// addNewMetadata). Use this for *newly created* instructions in the vector
748 /// loop.
749 void addMetadata(Instruction *To, Instruction *From);
750
751 /// Similar to the previous function but it adds the metadata to a
752 /// vector of instructions.
753 void addMetadata(ArrayRef<Value *> To, Instruction *From);
754
755 /// Allow subclasses to override and print debug traces before/after vplan
756 /// execution, when trace information is requested.
757 virtual void printDebugTracesAtStart(){};
758 virtual void printDebugTracesAtEnd(){};
759
760 /// The original loop.
761 Loop *OrigLoop;
762
763 /// A wrapper around ScalarEvolution used to add runtime SCEV checks. Applies
764 /// dynamic knowledge to simplify SCEV expressions and converts them to a
765 /// more usable form.
766 PredicatedScalarEvolution &PSE;
767
768 /// Loop Info.
769 LoopInfo *LI;
770
771 /// Dominator Tree.
772 DominatorTree *DT;
773
774 /// Alias Analysis.
775 AAResults *AA;
776
777 /// Target Library Info.
778 const TargetLibraryInfo *TLI;
779
780 /// Target Transform Info.
781 const TargetTransformInfo *TTI;
782
783 /// Assumption Cache.
784 AssumptionCache *AC;
785
786 /// Interface to emit optimization remarks.
787 OptimizationRemarkEmitter *ORE;
788
789 /// LoopVersioning. It's only set up (non-null) if memchecks were
790 /// used.
791 ///
792 /// This is currently only used to add no-alias metadata based on the
793 /// memchecks. The actually versioning is performed manually.
794 std::unique_ptr<LoopVersioning> LVer;
795
796 /// The vectorization SIMD factor to use. Each vector will have this many
797 /// vector elements.
798 ElementCount VF;
799
800 /// The vectorization unroll factor to use. Each scalar is vectorized to this
801 /// many different vector instructions.
802 unsigned UF;
803
804 /// The builder that we use
805 IRBuilder<> Builder;
806
807 // --- Vectorization state ---
808
809 /// The vector-loop preheader.
810 BasicBlock *LoopVectorPreHeader;
811
812 /// The scalar-loop preheader.
813 BasicBlock *LoopScalarPreHeader;
814
815 /// Middle Block between the vector and the scalar.
816 BasicBlock *LoopMiddleBlock;
817
818 /// The (unique) ExitBlock of the scalar loop. Note that
819 /// there can be multiple exiting edges reaching this block.
820 BasicBlock *LoopExitBlock;
821
822 /// The vector loop body.
823 BasicBlock *LoopVectorBody;
824
825 /// The scalar loop body.
826 BasicBlock *LoopScalarBody;
827
828 /// A list of all bypass blocks. The first block is the entry of the loop.
829 SmallVector<BasicBlock *, 4> LoopBypassBlocks;
830
831 /// The new Induction variable which was added to the new block.
832 PHINode *Induction = nullptr;
833
834 /// The induction variable of the old basic block.
835 PHINode *OldInduction = nullptr;
836
837 /// Store instructions that were predicated.
838 SmallVector<Instruction *, 4> PredicatedInstructions;
839
840 /// Trip count of the original loop.
841 Value *TripCount = nullptr;
842
843 /// Trip count of the widened loop (TripCount - TripCount % (VF*UF))
844 Value *VectorTripCount = nullptr;
845
846 /// The legality analysis.
847 LoopVectorizationLegality *Legal;
848
849 /// The profitablity analysis.
850 LoopVectorizationCostModel *Cost;
851
852 // Record whether runtime checks are added.
853 bool AddedSafetyChecks = false;
854
855 // Holds the end values for each induction variable. We save the end values
856 // so we can later fix-up the external users of the induction variables.
857 DenseMap<PHINode *, Value *> IVEndValues;
858
859 // Vector of original scalar PHIs whose corresponding widened PHIs need to be
860 // fixed up at the end of vector code generation.
861 SmallVector<PHINode *, 8> OrigPHIsToFix;
862
863 /// BFI and PSI are used to check for profile guided size optimizations.
864 BlockFrequencyInfo *BFI;
865 ProfileSummaryInfo *PSI;
866
867 // Whether this loop should be optimized for size based on profile guided size
868 // optimizatios.
869 bool OptForSizeBasedOnProfile;
870
871 /// Structure to hold information about generated runtime checks, responsible
872 /// for cleaning the checks, if vectorization turns out unprofitable.
873 GeneratedRTChecks &RTChecks;
874};
875
876class InnerLoopUnroller : public InnerLoopVectorizer {
877public:
878 InnerLoopUnroller(Loop *OrigLoop, PredicatedScalarEvolution &PSE,
879 LoopInfo *LI, DominatorTree *DT,
880 const TargetLibraryInfo *TLI,
881 const TargetTransformInfo *TTI, AssumptionCache *AC,
882 OptimizationRemarkEmitter *ORE, unsigned UnrollFactor,
883 LoopVectorizationLegality *LVL,
884 LoopVectorizationCostModel *CM, BlockFrequencyInfo *BFI,
885 ProfileSummaryInfo *PSI, GeneratedRTChecks &Check)
886 : InnerLoopVectorizer(OrigLoop, PSE, LI, DT, TLI, TTI, AC, ORE,
887 ElementCount::getFixed(1), UnrollFactor, LVL, CM,
888 BFI, PSI, Check) {}
889
890private:
891 Value *getBroadcastInstrs(Value *V) override;
892 Value *getStepVector(Value *Val, int StartIdx, Value *Step,
893 Instruction::BinaryOps Opcode =
894 Instruction::BinaryOpsEnd) override;
895 Value *reverseVector(Value *Vec) override;
896};
897
898/// Encapsulate information regarding vectorization of a loop and its epilogue.
899/// This information is meant to be updated and used across two stages of
900/// epilogue vectorization.
901struct EpilogueLoopVectorizationInfo {
902 ElementCount MainLoopVF = ElementCount::getFixed(0);
903 unsigned MainLoopUF = 0;
904 ElementCount EpilogueVF = ElementCount::getFixed(0);
905 unsigned EpilogueUF = 0;
906 BasicBlock *MainLoopIterationCountCheck = nullptr;
907 BasicBlock *EpilogueIterationCountCheck = nullptr;
908 BasicBlock *SCEVSafetyCheck = nullptr;
909 BasicBlock *MemSafetyCheck = nullptr;
910 Value *TripCount = nullptr;
911 Value *VectorTripCount = nullptr;
912
913 EpilogueLoopVectorizationInfo(unsigned MVF, unsigned MUF, unsigned EVF,
914 unsigned EUF)
915 : MainLoopVF(ElementCount::getFixed(MVF)), MainLoopUF(MUF),
916 EpilogueVF(ElementCount::getFixed(EVF)), EpilogueUF(EUF) {
917 assert(EUF == 1 &&(static_cast <bool> (EUF == 1 && "A high UF for the epilogue loop is likely not beneficial."
) ? void (0) : __assert_fail ("EUF == 1 && \"A high UF for the epilogue loop is likely not beneficial.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 918, __extension__ __PRETTY_FUNCTION__))
918 "A high UF for the epilogue loop is likely not beneficial.")(static_cast <bool> (EUF == 1 && "A high UF for the epilogue loop is likely not beneficial."
) ? void (0) : __assert_fail ("EUF == 1 && \"A high UF for the epilogue loop is likely not beneficial.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 918, __extension__ __PRETTY_FUNCTION__))
;
919 }
920};
921
922/// An extension of the inner loop vectorizer that creates a skeleton for a
923/// vectorized loop that has its epilogue (residual) also vectorized.
924/// The idea is to run the vplan on a given loop twice, firstly to setup the
925/// skeleton and vectorize the main loop, and secondly to complete the skeleton
926/// from the first step and vectorize the epilogue. This is achieved by
927/// deriving two concrete strategy classes from this base class and invoking
928/// them in succession from the loop vectorizer planner.
929class InnerLoopAndEpilogueVectorizer : public InnerLoopVectorizer {
930public:
931 InnerLoopAndEpilogueVectorizer(
932 Loop *OrigLoop, PredicatedScalarEvolution &PSE, LoopInfo *LI,
933 DominatorTree *DT, const TargetLibraryInfo *TLI,
934 const TargetTransformInfo *TTI, AssumptionCache *AC,
935 OptimizationRemarkEmitter *ORE, EpilogueLoopVectorizationInfo &EPI,
936 LoopVectorizationLegality *LVL, llvm::LoopVectorizationCostModel *CM,
937 BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
938 GeneratedRTChecks &Checks)
939 : InnerLoopVectorizer(OrigLoop, PSE, LI, DT, TLI, TTI, AC, ORE,
940 EPI.MainLoopVF, EPI.MainLoopUF, LVL, CM, BFI, PSI,
941 Checks),
942 EPI(EPI) {}
943
944 // Override this function to handle the more complex control flow around the
945 // three loops.
946 BasicBlock *createVectorizedLoopSkeleton() final override {
947 return createEpilogueVectorizedLoopSkeleton();
948 }
949
950 /// The interface for creating a vectorized skeleton using one of two
951 /// different strategies, each corresponding to one execution of the vplan
952 /// as described above.
953 virtual BasicBlock *createEpilogueVectorizedLoopSkeleton() = 0;
954
955 /// Holds and updates state information required to vectorize the main loop
956 /// and its epilogue in two separate passes. This setup helps us avoid
957 /// regenerating and recomputing runtime safety checks. It also helps us to
958 /// shorten the iteration-count-check path length for the cases where the
959 /// iteration count of the loop is so small that the main vector loop is
960 /// completely skipped.
961 EpilogueLoopVectorizationInfo &EPI;
962};
963
964/// A specialized derived class of inner loop vectorizer that performs
965/// vectorization of *main* loops in the process of vectorizing loops and their
966/// epilogues.
967class EpilogueVectorizerMainLoop : public InnerLoopAndEpilogueVectorizer {
968public:
969 EpilogueVectorizerMainLoop(
970 Loop *OrigLoop, PredicatedScalarEvolution &PSE, LoopInfo *LI,
971 DominatorTree *DT, const TargetLibraryInfo *TLI,
972 const TargetTransformInfo *TTI, AssumptionCache *AC,
973 OptimizationRemarkEmitter *ORE, EpilogueLoopVectorizationInfo &EPI,
974 LoopVectorizationLegality *LVL, llvm::LoopVectorizationCostModel *CM,
975 BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
976 GeneratedRTChecks &Check)
977 : InnerLoopAndEpilogueVectorizer(OrigLoop, PSE, LI, DT, TLI, TTI, AC, ORE,
978 EPI, LVL, CM, BFI, PSI, Check) {}
979 /// Implements the interface for creating a vectorized skeleton using the
980 /// *main loop* strategy (ie the first pass of vplan execution).
981 BasicBlock *createEpilogueVectorizedLoopSkeleton() final override;
982
983protected:
984 /// Emits an iteration count bypass check once for the main loop (when \p
985 /// ForEpilogue is false) and once for the epilogue loop (when \p
986 /// ForEpilogue is true).
987 BasicBlock *emitMinimumIterationCountCheck(Loop *L, BasicBlock *Bypass,
988 bool ForEpilogue);
989 void printDebugTracesAtStart() override;
990 void printDebugTracesAtEnd() override;
991};
992
993// A specialized derived class of inner loop vectorizer that performs
994// vectorization of *epilogue* loops in the process of vectorizing loops and
995// their epilogues.
996class EpilogueVectorizerEpilogueLoop : public InnerLoopAndEpilogueVectorizer {
997public:
998 EpilogueVectorizerEpilogueLoop(
999 Loop *OrigLoop, PredicatedScalarEvolution &PSE, LoopInfo *LI,
1000 DominatorTree *DT, const TargetLibraryInfo *TLI,
1001 const TargetTransformInfo *TTI, AssumptionCache *AC,
1002 OptimizationRemarkEmitter *ORE, EpilogueLoopVectorizationInfo &EPI,
1003 LoopVectorizationLegality *LVL, llvm::LoopVectorizationCostModel *CM,
1004 BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
1005 GeneratedRTChecks &Checks)
1006 : InnerLoopAndEpilogueVectorizer(OrigLoop, PSE, LI, DT, TLI, TTI, AC, ORE,
1007 EPI, LVL, CM, BFI, PSI, Checks) {}
1008 /// Implements the interface for creating a vectorized skeleton using the
1009 /// *epilogue loop* strategy (ie the second pass of vplan execution).
1010 BasicBlock *createEpilogueVectorizedLoopSkeleton() final override;
1011
1012protected:
1013 /// Emits an iteration count bypass check after the main vector loop has
1014 /// finished to see if there are any iterations left to execute by either
1015 /// the vector epilogue or the scalar epilogue.
1016 BasicBlock *emitMinimumVectorEpilogueIterCountCheck(Loop *L,
1017 BasicBlock *Bypass,
1018 BasicBlock *Insert);
1019 void printDebugTracesAtStart() override;
1020 void printDebugTracesAtEnd() override;
1021};
1022} // end namespace llvm
1023
1024/// Look for a meaningful debug location on the instruction or it's
1025/// operands.
1026static Instruction *getDebugLocFromInstOrOperands(Instruction *I) {
1027 if (!I)
1028 return I;
1029
1030 DebugLoc Empty;
1031 if (I->getDebugLoc() != Empty)
1032 return I;
1033
1034 for (Use &Op : I->operands()) {
1035 if (Instruction *OpInst = dyn_cast<Instruction>(Op))
1036 if (OpInst->getDebugLoc() != Empty)
1037 return OpInst;
1038 }
1039
1040 return I;
1041}
1042
1043void InnerLoopVectorizer::setDebugLocFromInst(IRBuilder<> &B, const Value *Ptr) {
1044 if (const Instruction *Inst = dyn_cast_or_null<Instruction>(Ptr)) {
1045 const DILocation *DIL = Inst->getDebugLoc();
1046
1047 // When a FSDiscriminator is enabled, we don't need to add the multiply
1048 // factors to the discriminators.
1049 if (DIL && Inst->getFunction()->isDebugInfoForProfiling() &&
1050 !isa<DbgInfoIntrinsic>(Inst) && !EnableFSDiscriminator) {
1051 // FIXME: For scalable vectors, assume vscale=1.
1052 auto NewDIL =
1053 DIL->cloneByMultiplyingDuplicationFactor(UF * VF.getKnownMinValue());
1054 if (NewDIL)
1055 B.SetCurrentDebugLocation(NewDIL.getValue());
1056 else
1057 LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Failed to create new discriminator: "
<< DIL->getFilename() << " Line: " << DIL
->getLine(); } } while (false)
1058 << "Failed to create new discriminator: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Failed to create new discriminator: "
<< DIL->getFilename() << " Line: " << DIL
->getLine(); } } while (false)
1059 << DIL->getFilename() << " Line: " << DIL->getLine())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Failed to create new discriminator: "
<< DIL->getFilename() << " Line: " << DIL
->getLine(); } } while (false)
;
1060 } else
1061 B.SetCurrentDebugLocation(DIL);
1062 } else
1063 B.SetCurrentDebugLocation(DebugLoc());
1064}
1065
1066/// Write a \p DebugMsg about vectorization to the debug output stream. If \p I
1067/// is passed, the message relates to that particular instruction.
1068#ifndef NDEBUG
1069static void debugVectorizationMessage(const StringRef Prefix,
1070 const StringRef DebugMsg,
1071 Instruction *I) {
1072 dbgs() << "LV: " << Prefix << DebugMsg;
1073 if (I != nullptr)
1074 dbgs() << " " << *I;
1075 else
1076 dbgs() << '.';
1077 dbgs() << '\n';
1078}
1079#endif
1080
1081/// Create an analysis remark that explains why vectorization failed
1082///
1083/// \p PassName is the name of the pass (e.g. can be AlwaysPrint). \p
1084/// RemarkName is the identifier for the remark. If \p I is passed it is an
1085/// instruction that prevents vectorization. Otherwise \p TheLoop is used for
1086/// the location of the remark. \return the remark object that can be
1087/// streamed to.
1088static OptimizationRemarkAnalysis createLVAnalysis(const char *PassName,
1089 StringRef RemarkName, Loop *TheLoop, Instruction *I) {
1090 Value *CodeRegion = TheLoop->getHeader();
1091 DebugLoc DL = TheLoop->getStartLoc();
1092
1093 if (I) {
1094 CodeRegion = I->getParent();
1095 // If there is no debug location attached to the instruction, revert back to
1096 // using the loop's.
1097 if (I->getDebugLoc())
1098 DL = I->getDebugLoc();
1099 }
1100
1101 return OptimizationRemarkAnalysis(PassName, RemarkName, DL, CodeRegion);
1102}
1103
1104/// Return a value for Step multiplied by VF.
1105static Value *createStepForVF(IRBuilder<> &B, Constant *Step, ElementCount VF) {
1106 assert(isa<ConstantInt>(Step) && "Expected an integer step")(static_cast <bool> (isa<ConstantInt>(Step) &&
"Expected an integer step") ? void (0) : __assert_fail ("isa<ConstantInt>(Step) && \"Expected an integer step\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1106, __extension__ __PRETTY_FUNCTION__))
;
1107 Constant *StepVal = ConstantInt::get(
1108 Step->getType(),
1109 cast<ConstantInt>(Step)->getSExtValue() * VF.getKnownMinValue());
1110 return VF.isScalable() ? B.CreateVScale(StepVal) : StepVal;
1111}
1112
1113namespace llvm {
1114
1115/// Return the runtime value for VF.
1116Value *getRuntimeVF(IRBuilder<> &B, Type *Ty, ElementCount VF) {
1117 Constant *EC = ConstantInt::get(Ty, VF.getKnownMinValue());
1118 return VF.isScalable() ? B.CreateVScale(EC) : EC;
1119}
1120
1121void reportVectorizationFailure(const StringRef DebugMsg,
1122 const StringRef OREMsg, const StringRef ORETag,
1123 OptimizationRemarkEmitter *ORE, Loop *TheLoop,
1124 Instruction *I) {
1125 LLVM_DEBUG(debugVectorizationMessage("Not vectorizing: ", DebugMsg, I))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { debugVectorizationMessage("Not vectorizing: "
, DebugMsg, I); } } while (false)
;
1126 LoopVectorizeHints Hints(TheLoop, true /* doesn't matter */, *ORE);
1127 ORE->emit(
1128 createLVAnalysis(Hints.vectorizeAnalysisPassName(), ORETag, TheLoop, I)
1129 << "loop not vectorized: " << OREMsg);
1130}
1131
1132void reportVectorizationInfo(const StringRef Msg, const StringRef ORETag,
1133 OptimizationRemarkEmitter *ORE, Loop *TheLoop,
1134 Instruction *I) {
1135 LLVM_DEBUG(debugVectorizationMessage("", Msg, I))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { debugVectorizationMessage("", Msg, I); }
} while (false)
;
1136 LoopVectorizeHints Hints(TheLoop, true /* doesn't matter */, *ORE);
1137 ORE->emit(
1138 createLVAnalysis(Hints.vectorizeAnalysisPassName(), ORETag, TheLoop, I)
1139 << Msg);
1140}
1141
1142} // end namespace llvm
1143
1144#ifndef NDEBUG
1145/// \return string containing a file name and a line # for the given loop.
1146static std::string getDebugLocString(const Loop *L) {
1147 std::string Result;
1148 if (L) {
1149 raw_string_ostream OS(Result);
1150 if (const DebugLoc LoopDbgLoc = L->getStartLoc())
1151 LoopDbgLoc.print(OS);
1152 else
1153 // Just print the module name.
1154 OS << L->getHeader()->getParent()->getParent()->getModuleIdentifier();
1155 OS.flush();
1156 }
1157 return Result;
1158}
1159#endif
1160
1161void InnerLoopVectorizer::addNewMetadata(Instruction *To,
1162 const Instruction *Orig) {
1163 // If the loop was versioned with memchecks, add the corresponding no-alias
1164 // metadata.
1165 if (LVer && (isa<LoadInst>(Orig) || isa<StoreInst>(Orig)))
1166 LVer->annotateInstWithNoAlias(To, Orig);
1167}
1168
1169void InnerLoopVectorizer::addMetadata(Instruction *To,
1170 Instruction *From) {
1171 propagateMetadata(To, From);
1172 addNewMetadata(To, From);
1173}
1174
1175void InnerLoopVectorizer::addMetadata(ArrayRef<Value *> To,
1176 Instruction *From) {
1177 for (Value *V : To) {
1178 if (Instruction *I = dyn_cast<Instruction>(V))
1179 addMetadata(I, From);
1180 }
1181}
1182
1183namespace llvm {
1184
1185// Loop vectorization cost-model hints how the scalar epilogue loop should be
1186// lowered.
1187enum ScalarEpilogueLowering {
1188
1189 // The default: allowing scalar epilogues.
1190 CM_ScalarEpilogueAllowed,
1191
1192 // Vectorization with OptForSize: don't allow epilogues.
1193 CM_ScalarEpilogueNotAllowedOptSize,
1194
1195 // A special case of vectorisation with OptForSize: loops with a very small
1196 // trip count are considered for vectorization under OptForSize, thereby
1197 // making sure the cost of their loop body is dominant, free of runtime
1198 // guards and scalar iteration overheads.
1199 CM_ScalarEpilogueNotAllowedLowTripLoop,
1200
1201 // Loop hint predicate indicating an epilogue is undesired.
1202 CM_ScalarEpilogueNotNeededUsePredicate,
1203
1204 // Directive indicating we must either tail fold or not vectorize
1205 CM_ScalarEpilogueNotAllowedUsePredicate
1206};
1207
1208/// ElementCountComparator creates a total ordering for ElementCount
1209/// for the purposes of using it in a set structure.
1210struct ElementCountComparator {
1211 bool operator()(const ElementCount &LHS, const ElementCount &RHS) const {
1212 return std::make_tuple(LHS.isScalable(), LHS.getKnownMinValue()) <
1213 std::make_tuple(RHS.isScalable(), RHS.getKnownMinValue());
1214 }
1215};
1216using ElementCountSet = SmallSet<ElementCount, 16, ElementCountComparator>;
1217
1218/// LoopVectorizationCostModel - estimates the expected speedups due to
1219/// vectorization.
1220/// In many cases vectorization is not profitable. This can happen because of
1221/// a number of reasons. In this class we mainly attempt to predict the
1222/// expected speedup/slowdowns due to the supported instruction set. We use the
1223/// TargetTransformInfo to query the different backends for the cost of
1224/// different operations.
1225class LoopVectorizationCostModel {
1226public:
1227 LoopVectorizationCostModel(ScalarEpilogueLowering SEL, Loop *L,
1228 PredicatedScalarEvolution &PSE, LoopInfo *LI,
1229 LoopVectorizationLegality *Legal,
1230 const TargetTransformInfo &TTI,
1231 const TargetLibraryInfo *TLI, DemandedBits *DB,
1232 AssumptionCache *AC,
1233 OptimizationRemarkEmitter *ORE, const Function *F,
1234 const LoopVectorizeHints *Hints,
1235 InterleavedAccessInfo &IAI)
1236 : ScalarEpilogueStatus(SEL), TheLoop(L), PSE(PSE), LI(LI), Legal(Legal),
1237 TTI(TTI), TLI(TLI), DB(DB), AC(AC), ORE(ORE), TheFunction(F),
1238 Hints(Hints), InterleaveInfo(IAI) {}
1239
1240 /// \return An upper bound for the vectorization factors (both fixed and
1241 /// scalable). If the factors are 0, vectorization and interleaving should be
1242 /// avoided up front.
1243 FixedScalableVFPair computeMaxVF(ElementCount UserVF, unsigned UserIC);
1244
1245 /// \return True if runtime checks are required for vectorization, and false
1246 /// otherwise.
1247 bool runtimeChecksRequired();
1248
1249 /// \return The most profitable vectorization factor and the cost of that VF.
1250 /// This method checks every VF in \p CandidateVFs. If UserVF is not ZERO
1251 /// then this vectorization factor will be selected if vectorization is
1252 /// possible.
1253 VectorizationFactor
1254 selectVectorizationFactor(const ElementCountSet &CandidateVFs);
1255
1256 VectorizationFactor
1257 selectEpilogueVectorizationFactor(const ElementCount MaxVF,
1258 const LoopVectorizationPlanner &LVP);
1259
1260 /// Setup cost-based decisions for user vectorization factor.
1261 void selectUserVectorizationFactor(ElementCount UserVF) {
1262 collectUniformsAndScalars(UserVF);
1263 collectInstsToScalarize(UserVF);
1264 }
1265
1266 /// \return The size (in bits) of the smallest and widest types in the code
1267 /// that needs to be vectorized. We ignore values that remain scalar such as
1268 /// 64 bit loop indices.
1269 std::pair<unsigned, unsigned> getSmallestAndWidestTypes();
1270
1271 /// \return The desired interleave count.
1272 /// If interleave count has been specified by metadata it will be returned.
1273 /// Otherwise, the interleave count is computed and returned. VF and LoopCost
1274 /// are the selected vectorization factor and the cost of the selected VF.
1275 unsigned selectInterleaveCount(ElementCount VF, unsigned LoopCost);
1276
1277 /// Memory access instruction may be vectorized in more than one way.
1278 /// Form of instruction after vectorization depends on cost.
1279 /// This function takes cost-based decisions for Load/Store instructions
1280 /// and collects them in a map. This decisions map is used for building
1281 /// the lists of loop-uniform and loop-scalar instructions.
1282 /// The calculated cost is saved with widening decision in order to
1283 /// avoid redundant calculations.
1284 void setCostBasedWideningDecision(ElementCount VF);
1285
1286 /// A struct that represents some properties of the register usage
1287 /// of a loop.
1288 struct RegisterUsage {
1289 /// Holds the number of loop invariant values that are used in the loop.
1290 /// The key is ClassID of target-provided register class.
1291 SmallMapVector<unsigned, unsigned, 4> LoopInvariantRegs;
1292 /// Holds the maximum number of concurrent live intervals in the loop.
1293 /// The key is ClassID of target-provided register class.
1294 SmallMapVector<unsigned, unsigned, 4> MaxLocalUsers;
1295 };
1296
1297 /// \return Returns information about the register usages of the loop for the
1298 /// given vectorization factors.
1299 SmallVector<RegisterUsage, 8>
1300 calculateRegisterUsage(ArrayRef<ElementCount> VFs);
1301
1302 /// Collect values we want to ignore in the cost model.
1303 void collectValuesToIgnore();
1304
1305 /// Split reductions into those that happen in the loop, and those that happen
1306 /// outside. In loop reductions are collected into InLoopReductionChains.
1307 void collectInLoopReductions();
1308
1309 /// Returns true if we should use strict in-order reductions for the given
1310 /// RdxDesc. This is true if the -enable-strict-reductions flag is passed,
1311 /// the IsOrdered flag of RdxDesc is set and we do not allow reordering
1312 /// of FP operations.
1313 bool useOrderedReductions(const RecurrenceDescriptor &RdxDesc) {
1314 return EnableStrictReductions && !Hints->allowReordering() &&
1315 RdxDesc.isOrdered();
1316 }
1317
1318 /// \returns The smallest bitwidth each instruction can be represented with.
1319 /// The vector equivalents of these instructions should be truncated to this
1320 /// type.
1321 const MapVector<Instruction *, uint64_t> &getMinimalBitwidths() const {
1322 return MinBWs;
1323 }
1324
1325 /// \returns True if it is more profitable to scalarize instruction \p I for
1326 /// vectorization factor \p VF.
1327 bool isProfitableToScalarize(Instruction *I, ElementCount VF) const {
1328 assert(VF.isVector() &&(static_cast <bool> (VF.isVector() && "Profitable to scalarize relevant only for VF > 1."
) ? void (0) : __assert_fail ("VF.isVector() && \"Profitable to scalarize relevant only for VF > 1.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1329, __extension__ __PRETTY_FUNCTION__))
1329 "Profitable to scalarize relevant only for VF > 1.")(static_cast <bool> (VF.isVector() && "Profitable to scalarize relevant only for VF > 1."
) ? void (0) : __assert_fail ("VF.isVector() && \"Profitable to scalarize relevant only for VF > 1.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1329, __extension__ __PRETTY_FUNCTION__))
;
1330
1331 // Cost model is not run in the VPlan-native path - return conservative
1332 // result until this changes.
1333 if (EnableVPlanNativePath)
1334 return false;
1335
1336 auto Scalars = InstsToScalarize.find(VF);
1337 assert(Scalars != InstsToScalarize.end() &&(static_cast <bool> (Scalars != InstsToScalarize.end() &&
"VF not yet analyzed for scalarization profitability") ? void
(0) : __assert_fail ("Scalars != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
1338 "VF not yet analyzed for scalarization profitability")(static_cast <bool> (Scalars != InstsToScalarize.end() &&
"VF not yet analyzed for scalarization profitability") ? void
(0) : __assert_fail ("Scalars != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
;
1339 return Scalars->second.find(I) != Scalars->second.end();
1340 }
1341
1342 /// Returns true if \p I is known to be uniform after vectorization.
1343 bool isUniformAfterVectorization(Instruction *I, ElementCount VF) const {
1344 if (VF.isScalar())
1345 return true;
1346
1347 // Cost model is not run in the VPlan-native path - return conservative
1348 // result until this changes.
1349 if (EnableVPlanNativePath)
1350 return false;
1351
1352 auto UniformsPerVF = Uniforms.find(VF);
1353 assert(UniformsPerVF != Uniforms.end() &&(static_cast <bool> (UniformsPerVF != Uniforms.end() &&
"VF not yet analyzed for uniformity") ? void (0) : __assert_fail
("UniformsPerVF != Uniforms.end() && \"VF not yet analyzed for uniformity\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1354, __extension__ __PRETTY_FUNCTION__))
1354 "VF not yet analyzed for uniformity")(static_cast <bool> (UniformsPerVF != Uniforms.end() &&
"VF not yet analyzed for uniformity") ? void (0) : __assert_fail
("UniformsPerVF != Uniforms.end() && \"VF not yet analyzed for uniformity\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1354, __extension__ __PRETTY_FUNCTION__))
;
1355 return UniformsPerVF->second.count(I);
1356 }
1357
1358 /// Returns true if \p I is known to be scalar after vectorization.
1359 bool isScalarAfterVectorization(Instruction *I, ElementCount VF) const {
1360 if (VF.isScalar())
1361 return true;
1362
1363 // Cost model is not run in the VPlan-native path - return conservative
1364 // result until this changes.
1365 if (EnableVPlanNativePath)
1366 return false;
1367
1368 auto ScalarsPerVF = Scalars.find(VF);
1369 assert(ScalarsPerVF != Scalars.end() &&(static_cast <bool> (ScalarsPerVF != Scalars.end() &&
"Scalar values are not calculated for VF") ? void (0) : __assert_fail
("ScalarsPerVF != Scalars.end() && \"Scalar values are not calculated for VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1370, __extension__ __PRETTY_FUNCTION__))
1370 "Scalar values are not calculated for VF")(static_cast <bool> (ScalarsPerVF != Scalars.end() &&
"Scalar values are not calculated for VF") ? void (0) : __assert_fail
("ScalarsPerVF != Scalars.end() && \"Scalar values are not calculated for VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1370, __extension__ __PRETTY_FUNCTION__))
;
1371 return ScalarsPerVF->second.count(I);
1372 }
1373
1374 /// \returns True if instruction \p I can be truncated to a smaller bitwidth
1375 /// for vectorization factor \p VF.
1376 bool canTruncateToMinimalBitwidth(Instruction *I, ElementCount VF) const {
1377 return VF.isVector() && MinBWs.find(I) != MinBWs.end() &&
1378 !isProfitableToScalarize(I, VF) &&
1379 !isScalarAfterVectorization(I, VF);
1380 }
1381
1382 /// Decision that was taken during cost calculation for memory instruction.
1383 enum InstWidening {
1384 CM_Unknown,
1385 CM_Widen, // For consecutive accesses with stride +1.
1386 CM_Widen_Reverse, // For consecutive accesses with stride -1.
1387 CM_Interleave,
1388 CM_GatherScatter,
1389 CM_Scalarize
1390 };
1391
1392 /// Save vectorization decision \p W and \p Cost taken by the cost model for
1393 /// instruction \p I and vector width \p VF.
1394 void setWideningDecision(Instruction *I, ElementCount VF, InstWidening W,
1395 InstructionCost Cost) {
1396 assert(VF.isVector() && "Expected VF >=2")(static_cast <bool> (VF.isVector() && "Expected VF >=2"
) ? void (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1396, __extension__ __PRETTY_FUNCTION__))
;
1397 WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, Cost);
1398 }
1399
1400 /// Save vectorization decision \p W and \p Cost taken by the cost model for
1401 /// interleaving group \p Grp and vector width \p VF.
1402 void setWideningDecision(const InterleaveGroup<Instruction> *Grp,
1403 ElementCount VF, InstWidening W,
1404 InstructionCost Cost) {
1405 assert(VF.isVector() && "Expected VF >=2")(static_cast <bool> (VF.isVector() && "Expected VF >=2"
) ? void (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1405, __extension__ __PRETTY_FUNCTION__))
;
1406 /// Broadcast this decicion to all instructions inside the group.
1407 /// But the cost will be assigned to one instruction only.
1408 for (unsigned i = 0; i < Grp->getFactor(); ++i) {
1409 if (auto *I = Grp->getMember(i)) {
1410 if (Grp->getInsertPos() == I)
1411 WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, Cost);
1412 else
1413 WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, 0);
1414 }
1415 }
1416 }
1417
1418 /// Return the cost model decision for the given instruction \p I and vector
1419 /// width \p VF. Return CM_Unknown if this instruction did not pass
1420 /// through the cost modeling.
1421 InstWidening getWideningDecision(Instruction *I, ElementCount VF) const {
1422 assert(VF.isVector() && "Expected VF to be a vector VF")(static_cast <bool> (VF.isVector() && "Expected VF to be a vector VF"
) ? void (0) : __assert_fail ("VF.isVector() && \"Expected VF to be a vector VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1422, __extension__ __PRETTY_FUNCTION__))
;
1423 // Cost model is not run in the VPlan-native path - return conservative
1424 // result until this changes.
1425 if (EnableVPlanNativePath)
1426 return CM_GatherScatter;
1427
1428 std::pair<Instruction *, ElementCount> InstOnVF = std::make_pair(I, VF);
1429 auto Itr = WideningDecisions.find(InstOnVF);
1430 if (Itr == WideningDecisions.end())
1431 return CM_Unknown;
1432 return Itr->second.first;
1433 }
1434
1435 /// Return the vectorization cost for the given instruction \p I and vector
1436 /// width \p VF.
1437 InstructionCost getWideningCost(Instruction *I, ElementCount VF) {
1438 assert(VF.isVector() && "Expected VF >=2")(static_cast <bool> (VF.isVector() && "Expected VF >=2"
) ? void (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1438, __extension__ __PRETTY_FUNCTION__))
;
1439 std::pair<Instruction *, ElementCount> InstOnVF = std::make_pair(I, VF);
1440 assert(WideningDecisions.find(InstOnVF) != WideningDecisions.end() &&(static_cast <bool> (WideningDecisions.find(InstOnVF) !=
WideningDecisions.end() && "The cost is not calculated"
) ? void (0) : __assert_fail ("WideningDecisions.find(InstOnVF) != WideningDecisions.end() && \"The cost is not calculated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1441, __extension__ __PRETTY_FUNCTION__))
1441 "The cost is not calculated")(static_cast <bool> (WideningDecisions.find(InstOnVF) !=
WideningDecisions.end() && "The cost is not calculated"
) ? void (0) : __assert_fail ("WideningDecisions.find(InstOnVF) != WideningDecisions.end() && \"The cost is not calculated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1441, __extension__ __PRETTY_FUNCTION__))
;
1442 return WideningDecisions[InstOnVF].second;
1443 }
1444
1445 /// Return True if instruction \p I is an optimizable truncate whose operand
1446 /// is an induction variable. Such a truncate will be removed by adding a new
1447 /// induction variable with the destination type.
1448 bool isOptimizableIVTruncate(Instruction *I, ElementCount VF) {
1449 // If the instruction is not a truncate, return false.
1450 auto *Trunc = dyn_cast<TruncInst>(I);
1451 if (!Trunc)
1452 return false;
1453
1454 // Get the source and destination types of the truncate.
1455 Type *SrcTy = ToVectorTy(cast<CastInst>(I)->getSrcTy(), VF);
1456 Type *DestTy = ToVectorTy(cast<CastInst>(I)->getDestTy(), VF);
1457
1458 // If the truncate is free for the given types, return false. Replacing a
1459 // free truncate with an induction variable would add an induction variable
1460 // update instruction to each iteration of the loop. We exclude from this
1461 // check the primary induction variable since it will need an update
1462 // instruction regardless.
1463 Value *Op = Trunc->getOperand(0);
1464 if (Op != Legal->getPrimaryInduction() && TTI.isTruncateFree(SrcTy, DestTy))
1465 return false;
1466
1467 // If the truncated value is not an induction variable, return false.
1468 return Legal->isInductionPhi(Op);
1469 }
1470
1471 /// Collects the instructions to scalarize for each predicated instruction in
1472 /// the loop.
1473 void collectInstsToScalarize(ElementCount VF);
1474
1475 /// Collect Uniform and Scalar values for the given \p VF.
1476 /// The sets depend on CM decision for Load/Store instructions
1477 /// that may be vectorized as interleave, gather-scatter or scalarized.
1478 void collectUniformsAndScalars(ElementCount VF) {
1479 // Do the analysis once.
1480 if (VF.isScalar() || Uniforms.find(VF) != Uniforms.end())
1481 return;
1482 setCostBasedWideningDecision(VF);
1483 collectLoopUniforms(VF);
1484 collectLoopScalars(VF);
1485 }
1486
1487 /// Returns true if the target machine supports masked store operation
1488 /// for the given \p DataType and kind of access to \p Ptr.
1489 bool isLegalMaskedStore(Type *DataType, Value *Ptr, Align Alignment) const {
1490 return Legal->isConsecutivePtr(Ptr) &&
1491 TTI.isLegalMaskedStore(DataType, Alignment);
1492 }
1493
1494 /// Returns true if the target machine supports masked load operation
1495 /// for the given \p DataType and kind of access to \p Ptr.
1496 bool isLegalMaskedLoad(Type *DataType, Value *Ptr, Align Alignment) const {
1497 return Legal->isConsecutivePtr(Ptr) &&
1498 TTI.isLegalMaskedLoad(DataType, Alignment);
1499 }
1500
1501 /// Returns true if the target machine can represent \p V as a masked gather
1502 /// or scatter operation.
1503 bool isLegalGatherOrScatter(Value *V) {
1504 bool LI = isa<LoadInst>(V);
1505 bool SI = isa<StoreInst>(V);
1506 if (!LI && !SI)
1507 return false;
1508 auto *Ty = getLoadStoreType(V);
1509 Align Align = getLoadStoreAlignment(V);
1510 return (LI && TTI.isLegalMaskedGather(Ty, Align)) ||
1511 (SI && TTI.isLegalMaskedScatter(Ty, Align));
1512 }
1513
1514 /// Returns true if the target machine supports all of the reduction
1515 /// variables found for the given VF.
1516 bool canVectorizeReductions(ElementCount VF) {
1517 return (all_of(Legal->getReductionVars(), [&](auto &Reduction) -> bool {
1518 const RecurrenceDescriptor &RdxDesc = Reduction.second;
1519 return TTI.isLegalToVectorizeReduction(RdxDesc, VF);
1520 }));
1521 }
1522
1523 /// Returns true if \p I is an instruction that will be scalarized with
1524 /// predication. Such instructions include conditional stores and
1525 /// instructions that may divide by zero.
1526 /// If a non-zero VF has been calculated, we check if I will be scalarized
1527 /// predication for that VF.
1528 bool isScalarWithPredication(Instruction *I) const;
1529
1530 // Returns true if \p I is an instruction that will be predicated either
1531 // through scalar predication or masked load/store or masked gather/scatter.
1532 // Superset of instructions that return true for isScalarWithPredication.
1533 bool isPredicatedInst(Instruction *I) {
1534 if (!blockNeedsPredication(I->getParent()))
1535 return false;
1536 // Loads and stores that need some form of masked operation are predicated
1537 // instructions.
1538 if (isa<LoadInst>(I) || isa<StoreInst>(I))
1539 return Legal->isMaskRequired(I);
1540 return isScalarWithPredication(I);
1541 }
1542
1543 /// Returns true if \p I is a memory instruction with consecutive memory
1544 /// access that can be widened.
1545 bool
1546 memoryInstructionCanBeWidened(Instruction *I,
1547 ElementCount VF = ElementCount::getFixed(1));
1548
1549 /// Returns true if \p I is a memory instruction in an interleaved-group
1550 /// of memory accesses that can be vectorized with wide vector loads/stores
1551 /// and shuffles.
1552 bool
1553 interleavedAccessCanBeWidened(Instruction *I,
1554 ElementCount VF = ElementCount::getFixed(1));
1555
1556 /// Check if \p Instr belongs to any interleaved access group.
1557 bool isAccessInterleaved(Instruction *Instr) {
1558 return InterleaveInfo.isInterleaved(Instr);
1559 }
1560
1561 /// Get the interleaved access group that \p Instr belongs to.
1562 const InterleaveGroup<Instruction> *
1563 getInterleavedAccessGroup(Instruction *Instr) {
1564 return InterleaveInfo.getInterleaveGroup(Instr);
1565 }
1566
1567 /// Returns true if we're required to use a scalar epilogue for at least
1568 /// the final iteration of the original loop.
1569 bool requiresScalarEpilogue() const {
1570 if (!isScalarEpilogueAllowed())
1571 return false;
1572 // If we might exit from anywhere but the latch, must run the exiting
1573 // iteration in scalar form.
1574 if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch())
1575 return true;
1576 return InterleaveInfo.requiresScalarEpilogue();
1577 }
1578
1579 /// Returns true if a scalar epilogue is not allowed due to optsize or a
1580 /// loop hint annotation.
1581 bool isScalarEpilogueAllowed() const {
1582 return ScalarEpilogueStatus == CM_ScalarEpilogueAllowed;
1583 }
1584
1585 /// Returns true if all loop blocks should be masked to fold tail loop.
1586 bool foldTailByMasking() const { return FoldTailByMasking; }
1587
1588 bool blockNeedsPredication(BasicBlock *BB) const {
1589 return foldTailByMasking() || Legal->blockNeedsPredication(BB);
1590 }
1591
1592 /// A SmallMapVector to store the InLoop reduction op chains, mapping phi
1593 /// nodes to the chain of instructions representing the reductions. Uses a
1594 /// MapVector to ensure deterministic iteration order.
1595 using ReductionChainMap =
1596 SmallMapVector<PHINode *, SmallVector<Instruction *, 4>, 4>;
1597
1598 /// Return the chain of instructions representing an inloop reduction.
1599 const ReductionChainMap &getInLoopReductionChains() const {
1600 return InLoopReductionChains;
1601 }
1602
1603 /// Returns true if the Phi is part of an inloop reduction.
1604 bool isInLoopReduction(PHINode *Phi) const {
1605 return InLoopReductionChains.count(Phi);
1606 }
1607
1608 /// Estimate cost of an intrinsic call instruction CI if it were vectorized
1609 /// with factor VF. Return the cost of the instruction, including
1610 /// scalarization overhead if it's needed.
1611 InstructionCost getVectorIntrinsicCost(CallInst *CI, ElementCount VF) const;
1612
1613 /// Estimate cost of a call instruction CI if it were vectorized with factor
1614 /// VF. Return the cost of the instruction, including scalarization overhead
1615 /// if it's needed. The flag NeedToScalarize shows if the call needs to be
1616 /// scalarized -
1617 /// i.e. either vector version isn't available, or is too expensive.
1618 InstructionCost getVectorCallCost(CallInst *CI, ElementCount VF,
1619 bool &NeedToScalarize) const;
1620
1621 /// Returns true if the per-lane cost of VectorizationFactor A is lower than
1622 /// that of B.
1623 bool isMoreProfitable(const VectorizationFactor &A,
1624 const VectorizationFactor &B) const;
1625
1626 /// Invalidates decisions already taken by the cost model.
1627 void invalidateCostModelingDecisions() {
1628 WideningDecisions.clear();
1629 Uniforms.clear();
1630 Scalars.clear();
1631 }
1632
1633private:
1634 unsigned NumPredStores = 0;
1635
1636 /// \return An upper bound for the vectorization factors for both
1637 /// fixed and scalable vectorization, where the minimum-known number of
1638 /// elements is a power-of-2 larger than zero. If scalable vectorization is
1639 /// disabled or unsupported, then the scalable part will be equal to
1640 /// ElementCount::getScalable(0).
1641 FixedScalableVFPair computeFeasibleMaxVF(unsigned ConstTripCount,
1642 ElementCount UserVF);
1643
1644 /// \return the maximized element count based on the targets vector
1645 /// registers and the loop trip-count, but limited to a maximum safe VF.
1646 /// This is a helper function of computeFeasibleMaxVF.
1647 /// FIXME: MaxSafeVF is currently passed by reference to avoid some obscure
1648 /// issue that occurred on one of the buildbots which cannot be reproduced
1649 /// without having access to the properietary compiler (see comments on
1650 /// D98509). The issue is currently under investigation and this workaround
1651 /// will be removed as soon as possible.
1652 ElementCount getMaximizedVFForTarget(unsigned ConstTripCount,
1653 unsigned SmallestType,
1654 unsigned WidestType,
1655 const ElementCount &MaxSafeVF);
1656
1657 /// \return the maximum legal scalable VF, based on the safe max number
1658 /// of elements.
1659 ElementCount getMaxLegalScalableVF(unsigned MaxSafeElements);
1660
1661 /// The vectorization cost is a combination of the cost itself and a boolean
1662 /// indicating whether any of the contributing operations will actually
1663 /// operate on vector values after type legalization in the backend. If this
1664 /// latter value is false, then all operations will be scalarized (i.e. no
1665 /// vectorization has actually taken place).
1666 using VectorizationCostTy = std::pair<InstructionCost, bool>;
1667
1668 /// Returns the expected execution cost. The unit of the cost does
1669 /// not matter because we use the 'cost' units to compare different
1670 /// vector widths. The cost that is returned is *not* normalized by
1671 /// the factor width.
1672 VectorizationCostTy expectedCost(ElementCount VF);
1673
1674 /// Returns the execution time cost of an instruction for a given vector
1675 /// width. Vector width of one means scalar.
1676 VectorizationCostTy getInstructionCost(Instruction *I, ElementCount VF);
1677
1678 /// The cost-computation logic from getInstructionCost which provides
1679 /// the vector type as an output parameter.
1680 InstructionCost getInstructionCost(Instruction *I, ElementCount VF,
1681 Type *&VectorTy);
1682
1683 /// Return the cost of instructions in an inloop reduction pattern, if I is
1684 /// part of that pattern.
1685 InstructionCost getReductionPatternCost(Instruction *I, ElementCount VF,
1686 Type *VectorTy,
1687 TTI::TargetCostKind CostKind);
1688
1689 /// Calculate vectorization cost of memory instruction \p I.
1690 InstructionCost getMemoryInstructionCost(Instruction *I, ElementCount VF);
1691
1692 /// The cost computation for scalarized memory instruction.
1693 InstructionCost getMemInstScalarizationCost(Instruction *I, ElementCount VF);
1694
1695 /// The cost computation for interleaving group of memory instructions.
1696 InstructionCost getInterleaveGroupCost(Instruction *I, ElementCount VF);
1697
1698 /// The cost computation for Gather/Scatter instruction.
1699 InstructionCost getGatherScatterCost(Instruction *I, ElementCount VF);
1700
1701 /// The cost computation for widening instruction \p I with consecutive
1702 /// memory access.
1703 InstructionCost getConsecutiveMemOpCost(Instruction *I, ElementCount VF);
1704
1705 /// The cost calculation for Load/Store instruction \p I with uniform pointer -
1706 /// Load: scalar load + broadcast.
1707 /// Store: scalar store + (loop invariant value stored? 0 : extract of last
1708 /// element)
1709 InstructionCost getUniformMemOpCost(Instruction *I, ElementCount VF);
1710
1711 /// Estimate the overhead of scalarizing an instruction. This is a
1712 /// convenience wrapper for the type-based getScalarizationOverhead API.
1713 InstructionCost getScalarizationOverhead(Instruction *I,
1714 ElementCount VF) const;
1715
1716 /// Returns whether the instruction is a load or store and will be a emitted
1717 /// as a vector operation.
1718 bool isConsecutiveLoadOrStore(Instruction *I);
1719
1720 /// Returns true if an artificially high cost for emulated masked memrefs
1721 /// should be used.
1722 bool useEmulatedMaskMemRefHack(Instruction *I);
1723
1724 /// Map of scalar integer values to the smallest bitwidth they can be legally
1725 /// represented as. The vector equivalents of these values should be truncated
1726 /// to this type.
1727 MapVector<Instruction *, uint64_t> MinBWs;
1728
1729 /// A type representing the costs for instructions if they were to be
1730 /// scalarized rather than vectorized. The entries are Instruction-Cost
1731 /// pairs.
1732 using ScalarCostsTy = DenseMap<Instruction *, InstructionCost>;
1733
1734 /// A set containing all BasicBlocks that are known to present after
1735 /// vectorization as a predicated block.
1736 SmallPtrSet<BasicBlock *, 4> PredicatedBBsAfterVectorization;
1737
1738 /// Records whether it is allowed to have the original scalar loop execute at
1739 /// least once. This may be needed as a fallback loop in case runtime
1740 /// aliasing/dependence checks fail, or to handle the tail/remainder
1741 /// iterations when the trip count is unknown or doesn't divide by the VF,
1742 /// or as a peel-loop to handle gaps in interleave-groups.
1743 /// Under optsize and when the trip count is very small we don't allow any
1744 /// iterations to execute in the scalar loop.
1745 ScalarEpilogueLowering ScalarEpilogueStatus = CM_ScalarEpilogueAllowed;
1746
1747 /// All blocks of loop are to be masked to fold tail of scalar iterations.
1748 bool FoldTailByMasking = false;
1749
1750 /// A map holding scalar costs for different vectorization factors. The
1751 /// presence of a cost for an instruction in the mapping indicates that the
1752 /// instruction will be scalarized when vectorizing with the associated
1753 /// vectorization factor. The entries are VF-ScalarCostTy pairs.
1754 DenseMap<ElementCount, ScalarCostsTy> InstsToScalarize;
1755
1756 /// Holds the instructions known to be uniform after vectorization.
1757 /// The data is collected per VF.
1758 DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> Uniforms;
1759
1760 /// Holds the instructions known to be scalar after vectorization.
1761 /// The data is collected per VF.
1762 DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> Scalars;
1763
1764 /// Holds the instructions (address computations) that are forced to be
1765 /// scalarized.
1766 DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> ForcedScalars;
1767
1768 /// PHINodes of the reductions that should be expanded in-loop along with
1769 /// their associated chains of reduction operations, in program order from top
1770 /// (PHI) to bottom
1771 ReductionChainMap InLoopReductionChains;
1772
1773 /// A Map of inloop reduction operations and their immediate chain operand.
1774 /// FIXME: This can be removed once reductions can be costed correctly in
1775 /// vplan. This was added to allow quick lookup to the inloop operations,
1776 /// without having to loop through InLoopReductionChains.
1777 DenseMap<Instruction *, Instruction *> InLoopReductionImmediateChains;
1778
1779 /// Returns the expected difference in cost from scalarizing the expression
1780 /// feeding a predicated instruction \p PredInst. The instructions to
1781 /// scalarize and their scalar costs are collected in \p ScalarCosts. A
1782 /// non-negative return value implies the expression will be scalarized.
1783 /// Currently, only single-use chains are considered for scalarization.
1784 int computePredInstDiscount(Instruction *PredInst, ScalarCostsTy &ScalarCosts,
1785 ElementCount VF);
1786
1787 /// Collect the instructions that are uniform after vectorization. An
1788 /// instruction is uniform if we represent it with a single scalar value in
1789 /// the vectorized loop corresponding to each vector iteration. Examples of
1790 /// uniform instructions include pointer operands of consecutive or
1791 /// interleaved memory accesses. Note that although uniformity implies an
1792 /// instruction will be scalar, the reverse is not true. In general, a
1793 /// scalarized instruction will be represented by VF scalar values in the
1794 /// vectorized loop, each corresponding to an iteration of the original
1795 /// scalar loop.
1796 void collectLoopUniforms(ElementCount VF);
1797
1798 /// Collect the instructions that are scalar after vectorization. An
1799 /// instruction is scalar if it is known to be uniform or will be scalarized
1800 /// during vectorization. Non-uniform scalarized instructions will be
1801 /// represented by VF values in the vectorized loop, each corresponding to an
1802 /// iteration of the original scalar loop.
1803 void collectLoopScalars(ElementCount VF);
1804
1805 /// Keeps cost model vectorization decision and cost for instructions.
1806 /// Right now it is used for memory instructions only.
1807 using DecisionList = DenseMap<std::pair<Instruction *, ElementCount>,
1808 std::pair<InstWidening, InstructionCost>>;
1809
1810 DecisionList WideningDecisions;
1811
1812 /// Returns true if \p V is expected to be vectorized and it needs to be
1813 /// extracted.
1814 bool needsExtract(Value *V, ElementCount VF) const {
1815 Instruction *I = dyn_cast<Instruction>(V);
1816 if (VF.isScalar() || !I || !TheLoop->contains(I) ||
1817 TheLoop->isLoopInvariant(I))
1818 return false;
1819
1820 // Assume we can vectorize V (and hence we need extraction) if the
1821 // scalars are not computed yet. This can happen, because it is called
1822 // via getScalarizationOverhead from setCostBasedWideningDecision, before
1823 // the scalars are collected. That should be a safe assumption in most
1824 // cases, because we check if the operands have vectorizable types
1825 // beforehand in LoopVectorizationLegality.
1826 return Scalars.find(VF) == Scalars.end() ||
1827 !isScalarAfterVectorization(I, VF);
1828 };
1829
1830 /// Returns a range containing only operands needing to be extracted.
1831 SmallVector<Value *, 4> filterExtractingOperands(Instruction::op_range Ops,
1832 ElementCount VF) const {
1833 return SmallVector<Value *, 4>(make_filter_range(
1834 Ops, [this, VF](Value *V) { return this->needsExtract(V, VF); }));
1835 }
1836
1837 /// Determines if we have the infrastructure to vectorize loop \p L and its
1838 /// epilogue, assuming the main loop is vectorized by \p VF.
1839 bool isCandidateForEpilogueVectorization(const Loop &L,
1840 const ElementCount VF) const;
1841
1842 /// Returns true if epilogue vectorization is considered profitable, and
1843 /// false otherwise.
1844 /// \p VF is the vectorization factor chosen for the original loop.
1845 bool isEpilogueVectorizationProfitable(const ElementCount VF) const;
1846
1847public:
1848 /// The loop that we evaluate.
1849 Loop *TheLoop;
1850
1851 /// Predicated scalar evolution analysis.
1852 PredicatedScalarEvolution &PSE;
1853
1854 /// Loop Info analysis.
1855 LoopInfo *LI;
1856
1857 /// Vectorization legality.
1858 LoopVectorizationLegality *Legal;
1859
1860 /// Vector target information.
1861 const TargetTransformInfo &TTI;
1862
1863 /// Target Library Info.
1864 const TargetLibraryInfo *TLI;
1865
1866 /// Demanded bits analysis.
1867 DemandedBits *DB;
1868
1869 /// Assumption cache.
1870 AssumptionCache *AC;
1871
1872 /// Interface to emit optimization remarks.
1873 OptimizationRemarkEmitter *ORE;
1874
1875 const Function *TheFunction;
1876
1877 /// Loop Vectorize Hint.
1878 const LoopVectorizeHints *Hints;
1879
1880 /// The interleave access information contains groups of interleaved accesses
1881 /// with the same stride and close to each other.
1882 InterleavedAccessInfo &InterleaveInfo;
1883
1884 /// Values to ignore in the cost model.
1885 SmallPtrSet<const Value *, 16> ValuesToIgnore;
1886
1887 /// Values to ignore in the cost model when VF > 1.
1888 SmallPtrSet<const Value *, 16> VecValuesToIgnore;
1889
1890 /// Profitable vector factors.
1891 SmallVector<VectorizationFactor, 8> ProfitableVFs;
1892};
1893} // end namespace llvm
1894
1895/// Helper struct to manage generating runtime checks for vectorization.
1896///
1897/// The runtime checks are created up-front in temporary blocks to allow better
1898/// estimating the cost and un-linked from the existing IR. After deciding to
1899/// vectorize, the checks are moved back. If deciding not to vectorize, the
1900/// temporary blocks are completely removed.
1901class GeneratedRTChecks {
1902 /// Basic block which contains the generated SCEV checks, if any.
1903 BasicBlock *SCEVCheckBlock = nullptr;
1904
1905 /// The value representing the result of the generated SCEV checks. If it is
1906 /// nullptr, either no SCEV checks have been generated or they have been used.
1907 Value *SCEVCheckCond = nullptr;
1908
1909 /// Basic block which contains the generated memory runtime checks, if any.
1910 BasicBlock *MemCheckBlock = nullptr;
1911
1912 /// The value representing the result of the generated memory runtime checks.
1913 /// If it is nullptr, either no memory runtime checks have been generated or
1914 /// they have been used.
1915 Instruction *MemRuntimeCheckCond = nullptr;
1916
1917 DominatorTree *DT;
1918 LoopInfo *LI;
1919
1920 SCEVExpander SCEVExp;
1921 SCEVExpander MemCheckExp;
1922
1923public:
1924 GeneratedRTChecks(ScalarEvolution &SE, DominatorTree *DT, LoopInfo *LI,
1925 const DataLayout &DL)
1926 : DT(DT), LI(LI), SCEVExp(SE, DL, "scev.check"),
1927 MemCheckExp(SE, DL, "scev.check") {}
1928
1929 /// Generate runtime checks in SCEVCheckBlock and MemCheckBlock, so we can
1930 /// accurately estimate the cost of the runtime checks. The blocks are
1931 /// un-linked from the IR and is added back during vector code generation. If
1932 /// there is no vector code generation, the check blocks are removed
1933 /// completely.
1934 void Create(Loop *L, const LoopAccessInfo &LAI,
1935 const SCEVUnionPredicate &UnionPred) {
1936
1937 BasicBlock *LoopHeader = L->getHeader();
1938 BasicBlock *Preheader = L->getLoopPreheader();
1939
1940 // Use SplitBlock to create blocks for SCEV & memory runtime checks to
1941 // ensure the blocks are properly added to LoopInfo & DominatorTree. Those
1942 // may be used by SCEVExpander. The blocks will be un-linked from their
1943 // predecessors and removed from LI & DT at the end of the function.
1944 if (!UnionPred.isAlwaysTrue()) {
1945 SCEVCheckBlock = SplitBlock(Preheader, Preheader->getTerminator(), DT, LI,
1946 nullptr, "vector.scevcheck");
1947
1948 SCEVCheckCond = SCEVExp.expandCodeForPredicate(
1949 &UnionPred, SCEVCheckBlock->getTerminator());
1950 }
1951
1952 const auto &RtPtrChecking = *LAI.getRuntimePointerChecking();
1953 if (RtPtrChecking.Need) {
1954 auto *Pred = SCEVCheckBlock ? SCEVCheckBlock : Preheader;
1955 MemCheckBlock = SplitBlock(Pred, Pred->getTerminator(), DT, LI, nullptr,
1956 "vector.memcheck");
1957
1958 std::tie(std::ignore, MemRuntimeCheckCond) =
1959 addRuntimeChecks(MemCheckBlock->getTerminator(), L,
1960 RtPtrChecking.getChecks(), MemCheckExp);
1961 assert(MemRuntimeCheckCond &&(static_cast <bool> (MemRuntimeCheckCond && "no RT checks generated although RtPtrChecking "
"claimed checks are required") ? void (0) : __assert_fail ("MemRuntimeCheckCond && \"no RT checks generated although RtPtrChecking \" \"claimed checks are required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1963, __extension__ __PRETTY_FUNCTION__))
1962 "no RT checks generated although RtPtrChecking "(static_cast <bool> (MemRuntimeCheckCond && "no RT checks generated although RtPtrChecking "
"claimed checks are required") ? void (0) : __assert_fail ("MemRuntimeCheckCond && \"no RT checks generated although RtPtrChecking \" \"claimed checks are required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1963, __extension__ __PRETTY_FUNCTION__))
1963 "claimed checks are required")(static_cast <bool> (MemRuntimeCheckCond && "no RT checks generated although RtPtrChecking "
"claimed checks are required") ? void (0) : __assert_fail ("MemRuntimeCheckCond && \"no RT checks generated although RtPtrChecking \" \"claimed checks are required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 1963, __extension__ __PRETTY_FUNCTION__))
;
1964 }
1965
1966 if (!MemCheckBlock && !SCEVCheckBlock)
1967 return;
1968
1969 // Unhook the temporary block with the checks, update various places
1970 // accordingly.
1971 if (SCEVCheckBlock)
1972 SCEVCheckBlock->replaceAllUsesWith(Preheader);
1973 if (MemCheckBlock)
1974 MemCheckBlock->replaceAllUsesWith(Preheader);
1975
1976 if (SCEVCheckBlock) {
1977 SCEVCheckBlock->getTerminator()->moveBefore(Preheader->getTerminator());
1978 new UnreachableInst(Preheader->getContext(), SCEVCheckBlock);
1979 Preheader->getTerminator()->eraseFromParent();
1980 }
1981 if (MemCheckBlock) {
1982 MemCheckBlock->getTerminator()->moveBefore(Preheader->getTerminator());
1983 new UnreachableInst(Preheader->getContext(), MemCheckBlock);
1984 Preheader->getTerminator()->eraseFromParent();
1985 }
1986
1987 DT->changeImmediateDominator(LoopHeader, Preheader);
1988 if (MemCheckBlock) {
1989 DT->eraseNode(MemCheckBlock);
1990 LI->removeBlock(MemCheckBlock);
1991 }
1992 if (SCEVCheckBlock) {
1993 DT->eraseNode(SCEVCheckBlock);
1994 LI->removeBlock(SCEVCheckBlock);
1995 }
1996 }
1997
1998 /// Remove the created SCEV & memory runtime check blocks & instructions, if
1999 /// unused.
2000 ~GeneratedRTChecks() {
2001 SCEVExpanderCleaner SCEVCleaner(SCEVExp, *DT);
2002 SCEVExpanderCleaner MemCheckCleaner(MemCheckExp, *DT);
2003 if (!SCEVCheckCond)
2004 SCEVCleaner.markResultUsed();
2005
2006 if (!MemRuntimeCheckCond)
2007 MemCheckCleaner.markResultUsed();
2008
2009 if (MemRuntimeCheckCond) {
2010 auto &SE = *MemCheckExp.getSE();
2011 // Memory runtime check generation creates compares that use expanded
2012 // values. Remove them before running the SCEVExpanderCleaners.
2013 for (auto &I : make_early_inc_range(reverse(*MemCheckBlock))) {
2014 if (MemCheckExp.isInsertedInstruction(&I))
2015 continue;
2016 SE.forgetValue(&I);
2017 SE.eraseValueFromMap(&I);
2018 I.eraseFromParent();
2019 }
2020 }
2021 MemCheckCleaner.cleanup();
2022 SCEVCleaner.cleanup();
2023
2024 if (SCEVCheckCond)
2025 SCEVCheckBlock->eraseFromParent();
2026 if (MemRuntimeCheckCond)
2027 MemCheckBlock->eraseFromParent();
2028 }
2029
2030 /// Adds the generated SCEVCheckBlock before \p LoopVectorPreHeader and
2031 /// adjusts the branches to branch to the vector preheader or \p Bypass,
2032 /// depending on the generated condition.
2033 BasicBlock *emitSCEVChecks(Loop *L, BasicBlock *Bypass,
2034 BasicBlock *LoopVectorPreHeader,
2035 BasicBlock *LoopExitBlock) {
2036 if (!SCEVCheckCond)
2037 return nullptr;
2038 if (auto *C = dyn_cast<ConstantInt>(SCEVCheckCond))
2039 if (C->isZero())
2040 return nullptr;
2041
2042 auto *Pred = LoopVectorPreHeader->getSinglePredecessor();
2043
2044 BranchInst::Create(LoopVectorPreHeader, SCEVCheckBlock);
2045 // Create new preheader for vector loop.
2046 if (auto *PL = LI->getLoopFor(LoopVectorPreHeader))
2047 PL->addBasicBlockToLoop(SCEVCheckBlock, *LI);
2048
2049 SCEVCheckBlock->getTerminator()->eraseFromParent();
2050 SCEVCheckBlock->moveBefore(LoopVectorPreHeader);
2051 Pred->getTerminator()->replaceSuccessorWith(LoopVectorPreHeader,
2052 SCEVCheckBlock);
2053
2054 DT->addNewBlock(SCEVCheckBlock, Pred);
2055 DT->changeImmediateDominator(LoopVectorPreHeader, SCEVCheckBlock);
2056
2057 ReplaceInstWithInst(
2058 SCEVCheckBlock->getTerminator(),
2059 BranchInst::Create(Bypass, LoopVectorPreHeader, SCEVCheckCond));
2060 // Mark the check as used, to prevent it from being removed during cleanup.
2061 SCEVCheckCond = nullptr;
2062 return SCEVCheckBlock;
2063 }
2064
2065 /// Adds the generated MemCheckBlock before \p LoopVectorPreHeader and adjusts
2066 /// the branches to branch to the vector preheader or \p Bypass, depending on
2067 /// the generated condition.
2068 BasicBlock *emitMemRuntimeChecks(Loop *L, BasicBlock *Bypass,
2069 BasicBlock *LoopVectorPreHeader) {
2070 // Check if we generated code that checks in runtime if arrays overlap.
2071 if (!MemRuntimeCheckCond)
2072 return nullptr;
2073
2074 auto *Pred = LoopVectorPreHeader->getSinglePredecessor();
2075 Pred->getTerminator()->replaceSuccessorWith(LoopVectorPreHeader,
2076 MemCheckBlock);
2077
2078 DT->addNewBlock(MemCheckBlock, Pred);
2079 DT->changeImmediateDominator(LoopVectorPreHeader, MemCheckBlock);
2080 MemCheckBlock->moveBefore(LoopVectorPreHeader);
2081
2082 if (auto *PL = LI->getLoopFor(LoopVectorPreHeader))
2083 PL->addBasicBlockToLoop(MemCheckBlock, *LI);
2084
2085 ReplaceInstWithInst(
2086 MemCheckBlock->getTerminator(),
2087 BranchInst::Create(Bypass, LoopVectorPreHeader, MemRuntimeCheckCond));
2088 MemCheckBlock->getTerminator()->setDebugLoc(
2089 Pred->getTerminator()->getDebugLoc());
2090
2091 // Mark the check as used, to prevent it from being removed during cleanup.
2092 MemRuntimeCheckCond = nullptr;
2093 return MemCheckBlock;
2094 }
2095};
2096
2097// Return true if \p OuterLp is an outer loop annotated with hints for explicit
2098// vectorization. The loop needs to be annotated with #pragma omp simd
2099// simdlen(#) or #pragma clang vectorize(enable) vectorize_width(#). If the
2100// vector length information is not provided, vectorization is not considered
2101// explicit. Interleave hints are not allowed either. These limitations will be
2102// relaxed in the future.
2103// Please, note that we are currently forced to abuse the pragma 'clang
2104// vectorize' semantics. This pragma provides *auto-vectorization hints*
2105// (i.e., LV must check that vectorization is legal) whereas pragma 'omp simd'
2106// provides *explicit vectorization hints* (LV can bypass legal checks and
2107// assume that vectorization is legal). However, both hints are implemented
2108// using the same metadata (llvm.loop.vectorize, processed by
2109// LoopVectorizeHints). This will be fixed in the future when the native IR
2110// representation for pragma 'omp simd' is introduced.
2111static bool isExplicitVecOuterLoop(Loop *OuterLp,
2112 OptimizationRemarkEmitter *ORE) {
2113 assert(!OuterLp->isInnermost() && "This is not an outer loop")(static_cast <bool> (!OuterLp->isInnermost() &&
"This is not an outer loop") ? void (0) : __assert_fail ("!OuterLp->isInnermost() && \"This is not an outer loop\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2113, __extension__ __PRETTY_FUNCTION__))
;
2114 LoopVectorizeHints Hints(OuterLp, true /*DisableInterleaving*/, *ORE);
2115
2116 // Only outer loops with an explicit vectorization hint are supported.
2117 // Unannotated outer loops are ignored.
2118 if (Hints.getForce() == LoopVectorizeHints::FK_Undefined)
2119 return false;
2120
2121 Function *Fn = OuterLp->getHeader()->getParent();
2122 if (!Hints.allowVectorization(Fn, OuterLp,
2123 true /*VectorizeOnlyWhenForced*/)) {
2124 LLVM_DEBUG(dbgs() << "LV: Loop hints prevent outer loop vectorization.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints prevent outer loop vectorization.\n"
; } } while (false)
;
2125 return false;
2126 }
2127
2128 if (Hints.getInterleave() > 1) {
2129 // TODO: Interleave support is future work.
2130 LLVM_DEBUG(dbgs() << "LV: Not vectorizing: Interleave is not supported for "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Interleave is not supported for "
"outer loops.\n"; } } while (false)
2131 "outer loops.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Interleave is not supported for "
"outer loops.\n"; } } while (false)
;
2132 Hints.emitRemarkWithHints();
2133 return false;
2134 }
2135
2136 return true;
2137}
2138
2139static void collectSupportedLoops(Loop &L, LoopInfo *LI,
2140 OptimizationRemarkEmitter *ORE,
2141 SmallVectorImpl<Loop *> &V) {
2142 // Collect inner loops and outer loops without irreducible control flow. For
2143 // now, only collect outer loops that have explicit vectorization hints. If we
2144 // are stress testing the VPlan H-CFG construction, we collect the outermost
2145 // loop of every loop nest.
2146 if (L.isInnermost() || VPlanBuildStressTest ||
2147 (EnableVPlanNativePath && isExplicitVecOuterLoop(&L, ORE))) {
2148 LoopBlocksRPO RPOT(&L);
2149 RPOT.perform(LI);
2150 if (!containsIrreducibleCFG<const BasicBlock *>(RPOT, *LI)) {
2151 V.push_back(&L);
2152 // TODO: Collect inner loops inside marked outer loops in case
2153 // vectorization fails for the outer loop. Do not invoke
2154 // 'containsIrreducibleCFG' again for inner loops when the outer loop is
2155 // already known to be reducible. We can use an inherited attribute for
2156 // that.
2157 return;
2158 }
2159 }
2160 for (Loop *InnerL : L)
2161 collectSupportedLoops(*InnerL, LI, ORE, V);
2162}
2163
2164namespace {
2165
2166/// The LoopVectorize Pass.
2167struct LoopVectorize : public FunctionPass {
2168 /// Pass identification, replacement for typeid
2169 static char ID;
2170
2171 LoopVectorizePass Impl;
2172
2173 explicit LoopVectorize(bool InterleaveOnlyWhenForced = false,
2174 bool VectorizeOnlyWhenForced = false)
2175 : FunctionPass(ID),
2176 Impl({InterleaveOnlyWhenForced, VectorizeOnlyWhenForced}) {
2177 initializeLoopVectorizePass(*PassRegistry::getPassRegistry());
2178 }
2179
2180 bool runOnFunction(Function &F) override {
2181 if (skipFunction(F))
2182 return false;
2183
2184 auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
2185 auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
2186 auto *TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
2187 auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
2188 auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
2189 auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
2190 auto *TLI = TLIP ? &TLIP->getTLI(F) : nullptr;
2191 auto *AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
2192 auto *AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
2193 auto *LAA = &getAnalysis<LoopAccessLegacyAnalysis>();
2194 auto *DB = &getAnalysis<DemandedBitsWrapperPass>().getDemandedBits();
2195 auto *ORE = &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
2196 auto *PSI = &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
2197
2198 std::function<const LoopAccessInfo &(Loop &)> GetLAA =
2199 [&](Loop &L) -> const LoopAccessInfo & { return LAA->getInfo(&L); };
2200
2201 return Impl.runImpl(F, *SE, *LI, *TTI, *DT, *BFI, TLI, *DB, *AA, *AC,
2202 GetLAA, *ORE, PSI).MadeAnyChange;
2203 }
2204
2205 void getAnalysisUsage(AnalysisUsage &AU) const override {
2206 AU.addRequired<AssumptionCacheTracker>();
2207 AU.addRequired<BlockFrequencyInfoWrapperPass>();
2208 AU.addRequired<DominatorTreeWrapperPass>();
2209 AU.addRequired<LoopInfoWrapperPass>();
2210 AU.addRequired<ScalarEvolutionWrapperPass>();
2211 AU.addRequired<TargetTransformInfoWrapperPass>();
2212 AU.addRequired<AAResultsWrapperPass>();
2213 AU.addRequired<LoopAccessLegacyAnalysis>();
2214 AU.addRequired<DemandedBitsWrapperPass>();
2215 AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
2216 AU.addRequired<InjectTLIMappingsLegacy>();
2217
2218 // We currently do not preserve loopinfo/dominator analyses with outer loop
2219 // vectorization. Until this is addressed, mark these analyses as preserved
2220 // only for non-VPlan-native path.
2221 // TODO: Preserve Loop and Dominator analyses for VPlan-native path.
2222 if (!EnableVPlanNativePath) {
2223 AU.addPreserved<LoopInfoWrapperPass>();
2224 AU.addPreserved<DominatorTreeWrapperPass>();
2225 }
2226
2227 AU.addPreserved<BasicAAWrapperPass>();
2228 AU.addPreserved<GlobalsAAWrapperPass>();
2229 AU.addRequired<ProfileSummaryInfoWrapperPass>();
2230 }
2231};
2232
2233} // end anonymous namespace
2234
2235//===----------------------------------------------------------------------===//
2236// Implementation of LoopVectorizationLegality, InnerLoopVectorizer and
2237// LoopVectorizationCostModel and LoopVectorizationPlanner.
2238//===----------------------------------------------------------------------===//
2239
2240Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) {
2241 // We need to place the broadcast of invariant variables outside the loop,
2242 // but only if it's proven safe to do so. Else, broadcast will be inside
2243 // vector loop body.
2244 Instruction *Instr = dyn_cast<Instruction>(V);
2245 bool SafeToHoist = OrigLoop->isLoopInvariant(V) &&
2246 (!Instr ||
2247 DT->dominates(Instr->getParent(), LoopVectorPreHeader));
2248 // Place the code for broadcasting invariant variables in the new preheader.
2249 IRBuilder<>::InsertPointGuard Guard(Builder);
2250 if (SafeToHoist)
2251 Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
2252
2253 // Broadcast the scalar into all locations in the vector.
2254 Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast");
2255
2256 return Shuf;
2257}
2258
2259void InnerLoopVectorizer::createVectorIntOrFpInductionPHI(
2260 const InductionDescriptor &II, Value *Step, Value *Start,
2261 Instruction *EntryVal, VPValue *Def, VPValue *CastDef,
2262 VPTransformState &State) {
2263 assert((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) &&(static_cast <bool> ((isa<PHINode>(EntryVal) || isa
<TruncInst>(EntryVal)) && "Expected either an induction phi-node or a truncate of it!"
) ? void (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2264, __extension__ __PRETTY_FUNCTION__))
2264 "Expected either an induction phi-node or a truncate of it!")(static_cast <bool> ((isa<PHINode>(EntryVal) || isa
<TruncInst>(EntryVal)) && "Expected either an induction phi-node or a truncate of it!"
) ? void (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2264, __extension__ __PRETTY_FUNCTION__))
;
2265
2266 // Construct the initial value of the vector IV in the vector loop preheader
2267 auto CurrIP = Builder.saveIP();
2268 Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
2269 if (isa<TruncInst>(EntryVal)) {
2270 assert(Start->getType()->isIntegerTy() &&(static_cast <bool> (Start->getType()->isIntegerTy
() && "Truncation requires an integer type") ? void (
0) : __assert_fail ("Start->getType()->isIntegerTy() && \"Truncation requires an integer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2271, __extension__ __PRETTY_FUNCTION__))
2271 "Truncation requires an integer type")(static_cast <bool> (Start->getType()->isIntegerTy
() && "Truncation requires an integer type") ? void (
0) : __assert_fail ("Start->getType()->isIntegerTy() && \"Truncation requires an integer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2271, __extension__ __PRETTY_FUNCTION__))
;
2272 auto *TruncType = cast<IntegerType>(EntryVal->getType());
2273 Step = Builder.CreateTrunc(Step, TruncType);
2274 Start = Builder.CreateCast(Instruction::Trunc, Start, TruncType);
2275 }
2276 Value *SplatStart = Builder.CreateVectorSplat(VF, Start);
2277 Value *SteppedStart =
2278 getStepVector(SplatStart, 0, Step, II.getInductionOpcode());
2279
2280 // We create vector phi nodes for both integer and floating-point induction
2281 // variables. Here, we determine the kind of arithmetic we will perform.
2282 Instruction::BinaryOps AddOp;
2283 Instruction::BinaryOps MulOp;
2284 if (Step->getType()->isIntegerTy()) {
2285 AddOp = Instruction::Add;
2286 MulOp = Instruction::Mul;
2287 } else {
2288 AddOp = II.getInductionOpcode();
2289 MulOp = Instruction::FMul;
2290 }
2291
2292 // Multiply the vectorization factor by the step using integer or
2293 // floating-point arithmetic as appropriate.
2294 Type *StepType = Step->getType();
2295 if (Step->getType()->isFloatingPointTy())
2296 StepType = IntegerType::get(StepType->getContext(),
2297 StepType->getScalarSizeInBits());
2298 Value *RuntimeVF = getRuntimeVF(Builder, StepType, VF);
2299 if (Step->getType()->isFloatingPointTy())
2300 RuntimeVF = Builder.CreateSIToFP(RuntimeVF, Step->getType());
2301 Value *Mul = Builder.CreateBinOp(MulOp, Step, RuntimeVF);
2302
2303 // Create a vector splat to use in the induction update.
2304 //
2305 // FIXME: If the step is non-constant, we create the vector splat with
2306 // IRBuilder. IRBuilder can constant-fold the multiply, but it doesn't
2307 // handle a constant vector splat.
2308 Value *SplatVF = isa<Constant>(Mul)
2309 ? ConstantVector::getSplat(VF, cast<Constant>(Mul))
2310 : Builder.CreateVectorSplat(VF, Mul);
2311 Builder.restoreIP(CurrIP);
2312
2313 // We may need to add the step a number of times, depending on the unroll
2314 // factor. The last of those goes into the PHI.
2315 PHINode *VecInd = PHINode::Create(SteppedStart->getType(), 2, "vec.ind",
2316 &*LoopVectorBody->getFirstInsertionPt());
2317 VecInd->setDebugLoc(EntryVal->getDebugLoc());
2318 Instruction *LastInduction = VecInd;
2319 for (unsigned Part = 0; Part < UF; ++Part) {
2320 State.set(Def, LastInduction, Part);
2321
2322 if (isa<TruncInst>(EntryVal))
2323 addMetadata(LastInduction, EntryVal);
2324 recordVectorLoopValueForInductionCast(II, EntryVal, LastInduction, CastDef,
2325 State, Part);
2326
2327 LastInduction = cast<Instruction>(
2328 Builder.CreateBinOp(AddOp, LastInduction, SplatVF, "step.add"));
2329 LastInduction->setDebugLoc(EntryVal->getDebugLoc());
2330 }
2331
2332 // Move the last step to the end of the latch block. This ensures consistent
2333 // placement of all induction updates.
2334 auto *LoopVectorLatch = LI->getLoopFor(LoopVectorBody)->getLoopLatch();
2335 auto *Br = cast<BranchInst>(LoopVectorLatch->getTerminator());
2336 auto *ICmp = cast<Instruction>(Br->getCondition());
2337 LastInduction->moveBefore(ICmp);
2338 LastInduction->setName("vec.ind.next");
2339
2340 VecInd->addIncoming(SteppedStart, LoopVectorPreHeader);
2341 VecInd->addIncoming(LastInduction, LoopVectorLatch);
2342}
2343
2344bool InnerLoopVectorizer::shouldScalarizeInstruction(Instruction *I) const {
2345 return Cost->isScalarAfterVectorization(I, VF) ||
2346 Cost->isProfitableToScalarize(I, VF);
2347}
2348
2349bool InnerLoopVectorizer::needsScalarInduction(Instruction *IV) const {
2350 if (shouldScalarizeInstruction(IV))
2351 return true;
2352 auto isScalarInst = [&](User *U) -> bool {
2353 auto *I = cast<Instruction>(U);
2354 return (OrigLoop->contains(I) && shouldScalarizeInstruction(I));
2355 };
2356 return llvm::any_of(IV->users(), isScalarInst);
2357}
2358
2359void InnerLoopVectorizer::recordVectorLoopValueForInductionCast(
2360 const InductionDescriptor &ID, const Instruction *EntryVal,
2361 Value *VectorLoopVal, VPValue *CastDef, VPTransformState &State,
2362 unsigned Part, unsigned Lane) {
2363 assert((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) &&(static_cast <bool> ((isa<PHINode>(EntryVal) || isa
<TruncInst>(EntryVal)) && "Expected either an induction phi-node or a truncate of it!"
) ? void (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2364, __extension__ __PRETTY_FUNCTION__))
2364 "Expected either an induction phi-node or a truncate of it!")(static_cast <bool> ((isa<PHINode>(EntryVal) || isa
<TruncInst>(EntryVal)) && "Expected either an induction phi-node or a truncate of it!"
) ? void (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2364, __extension__ __PRETTY_FUNCTION__))
;
2365
2366 // This induction variable is not the phi from the original loop but the
2367 // newly-created IV based on the proof that casted Phi is equal to the
2368 // uncasted Phi in the vectorized loop (under a runtime guard possibly). It
2369 // re-uses the same InductionDescriptor that original IV uses but we don't
2370 // have to do any recording in this case - that is done when original IV is
2371 // processed.
2372 if (isa<TruncInst>(EntryVal))
2373 return;
2374
2375 const SmallVectorImpl<Instruction *> &Casts = ID.getCastInsts();
2376 if (Casts.empty())
2377 return;
2378 // Only the first Cast instruction in the Casts vector is of interest.
2379 // The rest of the Casts (if exist) have no uses outside the
2380 // induction update chain itself.
2381 if (Lane < UINT_MAX(2147483647 *2U +1U))
2382 State.set(CastDef, VectorLoopVal, VPIteration(Part, Lane));
2383 else
2384 State.set(CastDef, VectorLoopVal, Part);
2385}
2386
2387void InnerLoopVectorizer::widenIntOrFpInduction(PHINode *IV, Value *Start,
2388 TruncInst *Trunc, VPValue *Def,
2389 VPValue *CastDef,
2390 VPTransformState &State) {
2391 assert((IV->getType()->isIntegerTy() || IV != OldInduction) &&(static_cast <bool> ((IV->getType()->isIntegerTy(
) || IV != OldInduction) && "Primary induction variable must have an integer type"
) ? void (0) : __assert_fail ("(IV->getType()->isIntegerTy() || IV != OldInduction) && \"Primary induction variable must have an integer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2392, __extension__ __PRETTY_FUNCTION__))
2392 "Primary induction variable must have an integer type")(static_cast <bool> ((IV->getType()->isIntegerTy(
) || IV != OldInduction) && "Primary induction variable must have an integer type"
) ? void (0) : __assert_fail ("(IV->getType()->isIntegerTy() || IV != OldInduction) && \"Primary induction variable must have an integer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2392, __extension__ __PRETTY_FUNCTION__))
;
2393
2394 auto II = Legal->getInductionVars().find(IV);
2395 assert(II != Legal->getInductionVars().end() && "IV is not an induction")(static_cast <bool> (II != Legal->getInductionVars()
.end() && "IV is not an induction") ? void (0) : __assert_fail
("II != Legal->getInductionVars().end() && \"IV is not an induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2395, __extension__ __PRETTY_FUNCTION__))
;
2396
2397 auto ID = II->second;
2398 assert(IV->getType() == ID.getStartValue()->getType() && "Types must match")(static_cast <bool> (IV->getType() == ID.getStartValue
()->getType() && "Types must match") ? void (0) : __assert_fail
("IV->getType() == ID.getStartValue()->getType() && \"Types must match\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2398, __extension__ __PRETTY_FUNCTION__))
;
2399
2400 // The value from the original loop to which we are mapping the new induction
2401 // variable.
2402 Instruction *EntryVal = Trunc ? cast<Instruction>(Trunc) : IV;
2403
2404 auto &DL = OrigLoop->getHeader()->getModule()->getDataLayout();
2405
2406 // Generate code for the induction step. Note that induction steps are
2407 // required to be loop-invariant
2408 auto CreateStepValue = [&](const SCEV *Step) -> Value * {
2409 assert(PSE.getSE()->isLoopInvariant(Step, OrigLoop) &&(static_cast <bool> (PSE.getSE()->isLoopInvariant(Step
, OrigLoop) && "Induction step should be loop invariant"
) ? void (0) : __assert_fail ("PSE.getSE()->isLoopInvariant(Step, OrigLoop) && \"Induction step should be loop invariant\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2410, __extension__ __PRETTY_FUNCTION__))
2410 "Induction step should be loop invariant")(static_cast <bool> (PSE.getSE()->isLoopInvariant(Step
, OrigLoop) && "Induction step should be loop invariant"
) ? void (0) : __assert_fail ("PSE.getSE()->isLoopInvariant(Step, OrigLoop) && \"Induction step should be loop invariant\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2410, __extension__ __PRETTY_FUNCTION__))
;
2411 if (PSE.getSE()->isSCEVable(IV->getType())) {
2412 SCEVExpander Exp(*PSE.getSE(), DL, "induction");
2413 return Exp.expandCodeFor(Step, Step->getType(),
2414 LoopVectorPreHeader->getTerminator());
2415 }
2416 return cast<SCEVUnknown>(Step)->getValue();
2417 };
2418
2419 // The scalar value to broadcast. This is derived from the canonical
2420 // induction variable. If a truncation type is given, truncate the canonical
2421 // induction variable and step. Otherwise, derive these values from the
2422 // induction descriptor.
2423 auto CreateScalarIV = [&](Value *&Step) -> Value * {
2424 Value *ScalarIV = Induction;
2425 if (IV != OldInduction) {
2426 ScalarIV = IV->getType()->isIntegerTy()
2427 ? Builder.CreateSExtOrTrunc(Induction, IV->getType())
2428 : Builder.CreateCast(Instruction::SIToFP, Induction,
2429 IV->getType());
2430 ScalarIV = emitTransformedIndex(Builder, ScalarIV, PSE.getSE(), DL, ID);
2431 ScalarIV->setName("offset.idx");
2432 }
2433 if (Trunc) {
2434 auto *TruncType = cast<IntegerType>(Trunc->getType());
2435 assert(Step->getType()->isIntegerTy() &&(static_cast <bool> (Step->getType()->isIntegerTy
() && "Truncation requires an integer step") ? void (
0) : __assert_fail ("Step->getType()->isIntegerTy() && \"Truncation requires an integer step\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2436, __extension__ __PRETTY_FUNCTION__))
2436 "Truncation requires an integer step")(static_cast <bool> (Step->getType()->isIntegerTy
() && "Truncation requires an integer step") ? void (
0) : __assert_fail ("Step->getType()->isIntegerTy() && \"Truncation requires an integer step\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2436, __extension__ __PRETTY_FUNCTION__))
;
2437 ScalarIV = Builder.CreateTrunc(ScalarIV, TruncType);
2438 Step = Builder.CreateTrunc(Step, TruncType);
2439 }
2440 return ScalarIV;
2441 };
2442
2443 // Create the vector values from the scalar IV, in the absence of creating a
2444 // vector IV.
2445 auto CreateSplatIV = [&](Value *ScalarIV, Value *Step) {
2446 Value *Broadcasted = getBroadcastInstrs(ScalarIV);
2447 for (unsigned Part = 0; Part < UF; ++Part) {
2448 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2448, __extension__ __PRETTY_FUNCTION__))
;
2449 Value *EntryPart =
2450 getStepVector(Broadcasted, VF.getKnownMinValue() * Part, Step,
2451 ID.getInductionOpcode());
2452 State.set(Def, EntryPart, Part);
2453 if (Trunc)
2454 addMetadata(EntryPart, Trunc);
2455 recordVectorLoopValueForInductionCast(ID, EntryVal, EntryPart, CastDef,
2456 State, Part);
2457 }
2458 };
2459
2460 // Fast-math-flags propagate from the original induction instruction.
2461 IRBuilder<>::FastMathFlagGuard FMFG(Builder);
2462 if (ID.getInductionBinOp() && isa<FPMathOperator>(ID.getInductionBinOp()))
2463 Builder.setFastMathFlags(ID.getInductionBinOp()->getFastMathFlags());
2464
2465 // Now do the actual transformations, and start with creating the step value.
2466 Value *Step = CreateStepValue(ID.getStep());
2467 if (VF.isZero() || VF.isScalar()) {
2468 Value *ScalarIV = CreateScalarIV(Step);
2469 CreateSplatIV(ScalarIV, Step);
2470 return;
2471 }
2472
2473 // Determine if we want a scalar version of the induction variable. This is
2474 // true if the induction variable itself is not widened, or if it has at
2475 // least one user in the loop that is not widened.
2476 auto NeedsScalarIV = needsScalarInduction(EntryVal);
2477 if (!NeedsScalarIV) {
2478 createVectorIntOrFpInductionPHI(ID, Step, Start, EntryVal, Def, CastDef,
2479 State);
2480 return;
2481 }
2482
2483 // Try to create a new independent vector induction variable. If we can't
2484 // create the phi node, we will splat the scalar induction variable in each
2485 // loop iteration.
2486 if (!shouldScalarizeInstruction(EntryVal)) {
2487 createVectorIntOrFpInductionPHI(ID, Step, Start, EntryVal, Def, CastDef,
2488 State);
2489 Value *ScalarIV = CreateScalarIV(Step);
2490 // Create scalar steps that can be used by instructions we will later
2491 // scalarize. Note that the addition of the scalar steps will not increase
2492 // the number of instructions in the loop in the common case prior to
2493 // InstCombine. We will be trading one vector extract for each scalar step.
2494 buildScalarSteps(ScalarIV, Step, EntryVal, ID, Def, CastDef, State);
2495 return;
2496 }
2497
2498 // All IV users are scalar instructions, so only emit a scalar IV, not a
2499 // vectorised IV. Except when we tail-fold, then the splat IV feeds the
2500 // predicate used by the masked loads/stores.
2501 Value *ScalarIV = CreateScalarIV(Step);
2502 if (!Cost->isScalarEpilogueAllowed())
2503 CreateSplatIV(ScalarIV, Step);
2504 buildScalarSteps(ScalarIV, Step, EntryVal, ID, Def, CastDef, State);
2505}
2506
2507Value *InnerLoopVectorizer::getStepVector(Value *Val, int StartIdx, Value *Step,
2508 Instruction::BinaryOps BinOp) {
2509 // Create and check the types.
2510 auto *ValVTy = cast<VectorType>(Val->getType());
2511 ElementCount VLen = ValVTy->getElementCount();
2512
2513 Type *STy = Val->getType()->getScalarType();
2514 assert((STy->isIntegerTy() || STy->isFloatingPointTy()) &&(static_cast <bool> ((STy->isIntegerTy() || STy->
isFloatingPointTy()) && "Induction Step must be an integer or FP"
) ? void (0) : __assert_fail ("(STy->isIntegerTy() || STy->isFloatingPointTy()) && \"Induction Step must be an integer or FP\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2515, __extension__ __PRETTY_FUNCTION__))
2515 "Induction Step must be an integer or FP")(static_cast <bool> ((STy->isIntegerTy() || STy->
isFloatingPointTy()) && "Induction Step must be an integer or FP"
) ? void (0) : __assert_fail ("(STy->isIntegerTy() || STy->isFloatingPointTy()) && \"Induction Step must be an integer or FP\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2515, __extension__ __PRETTY_FUNCTION__))
;
2516 assert(Step->getType() == STy && "Step has wrong type")(static_cast <bool> (Step->getType() == STy &&
"Step has wrong type") ? void (0) : __assert_fail ("Step->getType() == STy && \"Step has wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2516, __extension__ __PRETTY_FUNCTION__))
;
2517
2518 SmallVector<Constant *, 8> Indices;
2519
2520 // Create a vector of consecutive numbers from zero to VF.
2521 VectorType *InitVecValVTy = ValVTy;
2522 Type *InitVecValSTy = STy;
2523 if (STy->isFloatingPointTy()) {
2524 InitVecValSTy =
2525 IntegerType::get(STy->getContext(), STy->getScalarSizeInBits());
2526 InitVecValVTy = VectorType::get(InitVecValSTy, VLen);
2527 }
2528 Value *InitVec = Builder.CreateStepVector(InitVecValVTy);
2529
2530 // Add on StartIdx
2531 Value *StartIdxSplat = Builder.CreateVectorSplat(
2532 VLen, ConstantInt::get(InitVecValSTy, StartIdx));
2533 InitVec = Builder.CreateAdd(InitVec, StartIdxSplat);
2534
2535 if (STy->isIntegerTy()) {
2536 Step = Builder.CreateVectorSplat(VLen, Step);
2537 assert(Step->getType() == Val->getType() && "Invalid step vec")(static_cast <bool> (Step->getType() == Val->getType
() && "Invalid step vec") ? void (0) : __assert_fail (
"Step->getType() == Val->getType() && \"Invalid step vec\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2537, __extension__ __PRETTY_FUNCTION__))
;
2538 // FIXME: The newly created binary instructions should contain nsw/nuw flags,
2539 // which can be found from the original scalar operations.
2540 Step = Builder.CreateMul(InitVec, Step);
2541 return Builder.CreateAdd(Val, Step, "induction");
2542 }
2543
2544 // Floating point induction.
2545 assert((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) &&(static_cast <bool> ((BinOp == Instruction::FAdd || BinOp
== Instruction::FSub) && "Binary Opcode should be specified for FP induction"
) ? void (0) : __assert_fail ("(BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && \"Binary Opcode should be specified for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2546, __extension__ __PRETTY_FUNCTION__))
2546 "Binary Opcode should be specified for FP induction")(static_cast <bool> ((BinOp == Instruction::FAdd || BinOp
== Instruction::FSub) && "Binary Opcode should be specified for FP induction"
) ? void (0) : __assert_fail ("(BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && \"Binary Opcode should be specified for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2546, __extension__ __PRETTY_FUNCTION__))
;
2547 InitVec = Builder.CreateUIToFP(InitVec, ValVTy);
2548 Step = Builder.CreateVectorSplat(VLen, Step);
2549 Value *MulOp = Builder.CreateFMul(InitVec, Step);
2550 return Builder.CreateBinOp(BinOp, Val, MulOp, "induction");
2551}
2552
2553void InnerLoopVectorizer::buildScalarSteps(Value *ScalarIV, Value *Step,
2554 Instruction *EntryVal,
2555 const InductionDescriptor &ID,
2556 VPValue *Def, VPValue *CastDef,
2557 VPTransformState &State) {
2558 // We shouldn't have to build scalar steps if we aren't vectorizing.
2559 assert(VF.isVector() && "VF should be greater than one")(static_cast <bool> (VF.isVector() && "VF should be greater than one"
) ? void (0) : __assert_fail ("VF.isVector() && \"VF should be greater than one\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2559, __extension__ __PRETTY_FUNCTION__))
;
2560 // Get the value type and ensure it and the step have the same integer type.
2561 Type *ScalarIVTy = ScalarIV->getType()->getScalarType();
2562 assert(ScalarIVTy == Step->getType() &&(static_cast <bool> (ScalarIVTy == Step->getType() &&
"Val and Step should have the same type") ? void (0) : __assert_fail
("ScalarIVTy == Step->getType() && \"Val and Step should have the same type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2563, __extension__ __PRETTY_FUNCTION__))
2563 "Val and Step should have the same type")(static_cast <bool> (ScalarIVTy == Step->getType() &&
"Val and Step should have the same type") ? void (0) : __assert_fail
("ScalarIVTy == Step->getType() && \"Val and Step should have the same type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2563, __extension__ __PRETTY_FUNCTION__))
;
2564
2565 // We build scalar steps for both integer and floating-point induction
2566 // variables. Here, we determine the kind of arithmetic we will perform.
2567 Instruction::BinaryOps AddOp;
2568 Instruction::BinaryOps MulOp;
2569 if (ScalarIVTy->isIntegerTy()) {
2570 AddOp = Instruction::Add;
2571 MulOp = Instruction::Mul;
2572 } else {
2573 AddOp = ID.getInductionOpcode();
2574 MulOp = Instruction::FMul;
2575 }
2576
2577 // Determine the number of scalars we need to generate for each unroll
2578 // iteration. If EntryVal is uniform, we only need to generate the first
2579 // lane. Otherwise, we generate all VF values.
2580 bool IsUniform =
2581 Cost->isUniformAfterVectorization(cast<Instruction>(EntryVal), VF);
2582 unsigned Lanes = IsUniform ? 1 : VF.getKnownMinValue();
2583 // Compute the scalar steps and save the results in State.
2584 Type *IntStepTy = IntegerType::get(ScalarIVTy->getContext(),
2585 ScalarIVTy->getScalarSizeInBits());
2586 Type *VecIVTy = nullptr;
2587 Value *UnitStepVec = nullptr, *SplatStep = nullptr, *SplatIV = nullptr;
2588 if (!IsUniform && VF.isScalable()) {
2589 VecIVTy = VectorType::get(ScalarIVTy, VF);
2590 UnitStepVec = Builder.CreateStepVector(VectorType::get(IntStepTy, VF));
2591 SplatStep = Builder.CreateVectorSplat(VF, Step);
2592 SplatIV = Builder.CreateVectorSplat(VF, ScalarIV);
2593 }
2594
2595 for (unsigned Part = 0; Part < UF; ++Part) {
2596 Value *StartIdx0 =
2597 createStepForVF(Builder, ConstantInt::get(IntStepTy, Part), VF);
2598
2599 if (!IsUniform && VF.isScalable()) {
2600 auto *SplatStartIdx = Builder.CreateVectorSplat(VF, StartIdx0);
2601 auto *InitVec = Builder.CreateAdd(SplatStartIdx, UnitStepVec);
2602 if (ScalarIVTy->isFloatingPointTy())
2603 InitVec = Builder.CreateSIToFP(InitVec, VecIVTy);
2604 auto *Mul = Builder.CreateBinOp(MulOp, InitVec, SplatStep);
2605 auto *Add = Builder.CreateBinOp(AddOp, SplatIV, Mul);
2606 State.set(Def, Add, Part);
2607 recordVectorLoopValueForInductionCast(ID, EntryVal, Add, CastDef, State,
2608 Part);
2609 // It's useful to record the lane values too for the known minimum number
2610 // of elements so we do those below. This improves the code quality when
2611 // trying to extract the first element, for example.
2612 }
2613
2614 if (ScalarIVTy->isFloatingPointTy())
2615 StartIdx0 = Builder.CreateSIToFP(StartIdx0, ScalarIVTy);
2616
2617 for (unsigned Lane = 0; Lane < Lanes; ++Lane) {
2618 Value *StartIdx = Builder.CreateBinOp(
2619 AddOp, StartIdx0, getSignedIntOrFpConstant(ScalarIVTy, Lane));
2620 // The step returned by `createStepForVF` is a runtime-evaluated value
2621 // when VF is scalable. Otherwise, it should be folded into a Constant.
2622 assert((VF.isScalable() || isa<Constant>(StartIdx)) &&(static_cast <bool> ((VF.isScalable() || isa<Constant
>(StartIdx)) && "Expected StartIdx to be folded to a constant when VF is not "
"scalable") ? void (0) : __assert_fail ("(VF.isScalable() || isa<Constant>(StartIdx)) && \"Expected StartIdx to be folded to a constant when VF is not \" \"scalable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2624, __extension__ __PRETTY_FUNCTION__))
2623 "Expected StartIdx to be folded to a constant when VF is not "(static_cast <bool> ((VF.isScalable() || isa<Constant
>(StartIdx)) && "Expected StartIdx to be folded to a constant when VF is not "
"scalable") ? void (0) : __assert_fail ("(VF.isScalable() || isa<Constant>(StartIdx)) && \"Expected StartIdx to be folded to a constant when VF is not \" \"scalable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2624, __extension__ __PRETTY_FUNCTION__))
2624 "scalable")(static_cast <bool> ((VF.isScalable() || isa<Constant
>(StartIdx)) && "Expected StartIdx to be folded to a constant when VF is not "
"scalable") ? void (0) : __assert_fail ("(VF.isScalable() || isa<Constant>(StartIdx)) && \"Expected StartIdx to be folded to a constant when VF is not \" \"scalable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2624, __extension__ __PRETTY_FUNCTION__))
;
2625 auto *Mul = Builder.CreateBinOp(MulOp, StartIdx, Step);
2626 auto *Add = Builder.CreateBinOp(AddOp, ScalarIV, Mul);
2627 State.set(Def, Add, VPIteration(Part, Lane));
2628 recordVectorLoopValueForInductionCast(ID, EntryVal, Add, CastDef, State,
2629 Part, Lane);
2630 }
2631 }
2632}
2633
2634void InnerLoopVectorizer::packScalarIntoVectorValue(VPValue *Def,
2635 const VPIteration &Instance,
2636 VPTransformState &State) {
2637 Value *ScalarInst = State.get(Def, Instance);
2638 Value *VectorValue = State.get(Def, Instance.Part);
2639 VectorValue = Builder.CreateInsertElement(
2640 VectorValue, ScalarInst,
2641 Instance.Lane.getAsRuntimeExpr(State.Builder, VF));
2642 State.set(Def, VectorValue, Instance.Part);
2643}
2644
2645Value *InnerLoopVectorizer::reverseVector(Value *Vec) {
2646 assert(Vec->getType()->isVectorTy() && "Invalid type")(static_cast <bool> (Vec->getType()->isVectorTy()
&& "Invalid type") ? void (0) : __assert_fail ("Vec->getType()->isVectorTy() && \"Invalid type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2646, __extension__ __PRETTY_FUNCTION__))
;
2647 return Builder.CreateVectorReverse(Vec, "reverse");
2648}
2649
2650// Return whether we allow using masked interleave-groups (for dealing with
2651// strided loads/stores that reside in predicated blocks, or for dealing
2652// with gaps).
2653static bool useMaskedInterleavedAccesses(const TargetTransformInfo &TTI) {
2654 // If an override option has been passed in for interleaved accesses, use it.
2655 if (EnableMaskedInterleavedMemAccesses.getNumOccurrences() > 0)
2656 return EnableMaskedInterleavedMemAccesses;
2657
2658 return TTI.enableMaskedInterleavedAccessVectorization();
2659}
2660
2661// Try to vectorize the interleave group that \p Instr belongs to.
2662//
2663// E.g. Translate following interleaved load group (factor = 3):
2664// for (i = 0; i < N; i+=3) {
2665// R = Pic[i]; // Member of index 0
2666// G = Pic[i+1]; // Member of index 1
2667// B = Pic[i+2]; // Member of index 2
2668// ... // do something to R, G, B
2669// }
2670// To:
2671// %wide.vec = load <12 x i32> ; Read 4 tuples of R,G,B
2672// %R.vec = shuffle %wide.vec, poison, <0, 3, 6, 9> ; R elements
2673// %G.vec = shuffle %wide.vec, poison, <1, 4, 7, 10> ; G elements
2674// %B.vec = shuffle %wide.vec, poison, <2, 5, 8, 11> ; B elements
2675//
2676// Or translate following interleaved store group (factor = 3):
2677// for (i = 0; i < N; i+=3) {
2678// ... do something to R, G, B
2679// Pic[i] = R; // Member of index 0
2680// Pic[i+1] = G; // Member of index 1
2681// Pic[i+2] = B; // Member of index 2
2682// }
2683// To:
2684// %R_G.vec = shuffle %R.vec, %G.vec, <0, 1, 2, ..., 7>
2685// %B_U.vec = shuffle %B.vec, poison, <0, 1, 2, 3, u, u, u, u>
2686// %interleaved.vec = shuffle %R_G.vec, %B_U.vec,
2687// <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11> ; Interleave R,G,B elements
2688// store <12 x i32> %interleaved.vec ; Write 4 tuples of R,G,B
2689void InnerLoopVectorizer::vectorizeInterleaveGroup(
2690 const InterleaveGroup<Instruction> *Group, ArrayRef<VPValue *> VPDefs,
2691 VPTransformState &State, VPValue *Addr, ArrayRef<VPValue *> StoredValues,
2692 VPValue *BlockInMask) {
2693 Instruction *Instr = Group->getInsertPos();
2694 const DataLayout &DL = Instr->getModule()->getDataLayout();
2695
2696 // Prepare for the vector type of the interleaved load/store.
2697 Type *ScalarTy = getLoadStoreType(Instr);
2698 unsigned InterleaveFactor = Group->getFactor();
2699 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2699, __extension__ __PRETTY_FUNCTION__))
;
2700 auto *VecTy = VectorType::get(ScalarTy, VF * InterleaveFactor);
2701
2702 // Prepare for the new pointers.
2703 SmallVector<Value *, 2> AddrParts;
2704 unsigned Index = Group->getIndex(Instr);
2705
2706 // TODO: extend the masked interleaved-group support to reversed access.
2707 assert((!BlockInMask || !Group->isReverse()) &&(static_cast <bool> ((!BlockInMask || !Group->isReverse
()) && "Reversed masked interleave-group not supported."
) ? void (0) : __assert_fail ("(!BlockInMask || !Group->isReverse()) && \"Reversed masked interleave-group not supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2708, __extension__ __PRETTY_FUNCTION__))
2708 "Reversed masked interleave-group not supported.")(static_cast <bool> ((!BlockInMask || !Group->isReverse
()) && "Reversed masked interleave-group not supported."
) ? void (0) : __assert_fail ("(!BlockInMask || !Group->isReverse()) && \"Reversed masked interleave-group not supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2708, __extension__ __PRETTY_FUNCTION__))
;
2709
2710 // If the group is reverse, adjust the index to refer to the last vector lane
2711 // instead of the first. We adjust the index from the first vector lane,
2712 // rather than directly getting the pointer for lane VF - 1, because the
2713 // pointer operand of the interleaved access is supposed to be uniform. For
2714 // uniform instructions, we're only required to generate a value for the
2715 // first vector lane in each unroll iteration.
2716 if (Group->isReverse())
2717 Index += (VF.getKnownMinValue() - 1) * Group->getFactor();
2718
2719 for (unsigned Part = 0; Part < UF; Part++) {
2720 Value *AddrPart = State.get(Addr, VPIteration(Part, 0));
2721 setDebugLocFromInst(Builder, AddrPart);
2722
2723 // Notice current instruction could be any index. Need to adjust the address
2724 // to the member of index 0.
2725 //
2726 // E.g. a = A[i+1]; // Member of index 1 (Current instruction)
2727 // b = A[i]; // Member of index 0
2728 // Current pointer is pointed to A[i+1], adjust it to A[i].
2729 //
2730 // E.g. A[i+1] = a; // Member of index 1
2731 // A[i] = b; // Member of index 0
2732 // A[i+2] = c; // Member of index 2 (Current instruction)
2733 // Current pointer is pointed to A[i+2], adjust it to A[i].
2734
2735 bool InBounds = false;
2736 if (auto *gep = dyn_cast<GetElementPtrInst>(AddrPart->stripPointerCasts()))
2737 InBounds = gep->isInBounds();
2738 AddrPart = Builder.CreateGEP(ScalarTy, AddrPart, Builder.getInt32(-Index));
2739 cast<GetElementPtrInst>(AddrPart)->setIsInBounds(InBounds);
2740
2741 // Cast to the vector pointer type.
2742 unsigned AddressSpace = AddrPart->getType()->getPointerAddressSpace();
2743 Type *PtrTy = VecTy->getPointerTo(AddressSpace);
2744 AddrParts.push_back(Builder.CreateBitCast(AddrPart, PtrTy));
2745 }
2746
2747 setDebugLocFromInst(Builder, Instr);
2748 Value *PoisonVec = PoisonValue::get(VecTy);
2749
2750 Value *MaskForGaps = nullptr;
2751 if (Group->requiresScalarEpilogue() && !Cost->isScalarEpilogueAllowed()) {
2752 MaskForGaps = createBitMaskForGaps(Builder, VF.getKnownMinValue(), *Group);
2753 assert(MaskForGaps && "Mask for Gaps is required but it is null")(static_cast <bool> (MaskForGaps && "Mask for Gaps is required but it is null"
) ? void (0) : __assert_fail ("MaskForGaps && \"Mask for Gaps is required but it is null\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2753, __extension__ __PRETTY_FUNCTION__))
;
2754 }
2755
2756 // Vectorize the interleaved load group.
2757 if (isa<LoadInst>(Instr)) {
2758 // For each unroll part, create a wide load for the group.
2759 SmallVector<Value *, 2> NewLoads;
2760 for (unsigned Part = 0; Part < UF; Part++) {
2761 Instruction *NewLoad;
2762 if (BlockInMask || MaskForGaps) {
2763 assert(useMaskedInterleavedAccesses(*TTI) &&(static_cast <bool> (useMaskedInterleavedAccesses(*TTI)
&& "masked interleaved groups are not allowed.") ? void
(0) : __assert_fail ("useMaskedInterleavedAccesses(*TTI) && \"masked interleaved groups are not allowed.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2764, __extension__ __PRETTY_FUNCTION__))
2764 "masked interleaved groups are not allowed.")(static_cast <bool> (useMaskedInterleavedAccesses(*TTI)
&& "masked interleaved groups are not allowed.") ? void
(0) : __assert_fail ("useMaskedInterleavedAccesses(*TTI) && \"masked interleaved groups are not allowed.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2764, __extension__ __PRETTY_FUNCTION__))
;
2765 Value *GroupMask = MaskForGaps;
2766 if (BlockInMask) {
2767 Value *BlockInMaskPart = State.get(BlockInMask, Part);
2768 Value *ShuffledMask = Builder.CreateShuffleVector(
2769 BlockInMaskPart,
2770 createReplicatedMask(InterleaveFactor, VF.getKnownMinValue()),
2771 "interleaved.mask");
2772 GroupMask = MaskForGaps
2773 ? Builder.CreateBinOp(Instruction::And, ShuffledMask,
2774 MaskForGaps)
2775 : ShuffledMask;
2776 }
2777 NewLoad =
2778 Builder.CreateMaskedLoad(AddrParts[Part], Group->getAlign(),
2779 GroupMask, PoisonVec, "wide.masked.vec");
2780 }
2781 else
2782 NewLoad = Builder.CreateAlignedLoad(VecTy, AddrParts[Part],
2783 Group->getAlign(), "wide.vec");
2784 Group->addMetadata(NewLoad);
2785 NewLoads.push_back(NewLoad);
2786 }
2787
2788 // For each member in the group, shuffle out the appropriate data from the
2789 // wide loads.
2790 unsigned J = 0;
2791 for (unsigned I = 0; I < InterleaveFactor; ++I) {
2792 Instruction *Member = Group->getMember(I);
2793
2794 // Skip the gaps in the group.
2795 if (!Member)
2796 continue;
2797
2798 auto StrideMask =
2799 createStrideMask(I, InterleaveFactor, VF.getKnownMinValue());
2800 for (unsigned Part = 0; Part < UF; Part++) {
2801 Value *StridedVec = Builder.CreateShuffleVector(
2802 NewLoads[Part], StrideMask, "strided.vec");
2803
2804 // If this member has different type, cast the result type.
2805 if (Member->getType() != ScalarTy) {
2806 assert(!VF.isScalable() && "VF is assumed to be non scalable.")(static_cast <bool> (!VF.isScalable() && "VF is assumed to be non scalable."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2806, __extension__ __PRETTY_FUNCTION__))
;
2807 VectorType *OtherVTy = VectorType::get(Member->getType(), VF);
2808 StridedVec = createBitOrPointerCast(StridedVec, OtherVTy, DL);
2809 }
2810
2811 if (Group->isReverse())
2812 StridedVec = reverseVector(StridedVec);
2813
2814 State.set(VPDefs[J], StridedVec, Part);
2815 }
2816 ++J;
2817 }
2818 return;
2819 }
2820
2821 // The sub vector type for current instruction.
2822 auto *SubVT = VectorType::get(ScalarTy, VF);
2823
2824 // Vectorize the interleaved store group.
2825 for (unsigned Part = 0; Part < UF; Part++) {
2826 // Collect the stored vector from each member.
2827 SmallVector<Value *, 4> StoredVecs;
2828 for (unsigned i = 0; i < InterleaveFactor; i++) {
2829 // Interleaved store group doesn't allow a gap, so each index has a member
2830 assert(Group->getMember(i) && "Fail to get a member from an interleaved store group")(static_cast <bool> (Group->getMember(i) && "Fail to get a member from an interleaved store group"
) ? void (0) : __assert_fail ("Group->getMember(i) && \"Fail to get a member from an interleaved store group\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2830, __extension__ __PRETTY_FUNCTION__))
;
2831
2832 Value *StoredVec = State.get(StoredValues[i], Part);
2833
2834 if (Group->isReverse())
2835 StoredVec = reverseVector(StoredVec);
2836
2837 // If this member has different type, cast it to a unified type.
2838
2839 if (StoredVec->getType() != SubVT)
2840 StoredVec = createBitOrPointerCast(StoredVec, SubVT, DL);
2841
2842 StoredVecs.push_back(StoredVec);
2843 }
2844
2845 // Concatenate all vectors into a wide vector.
2846 Value *WideVec = concatenateVectors(Builder, StoredVecs);
2847
2848 // Interleave the elements in the wide vector.
2849 Value *IVec = Builder.CreateShuffleVector(
2850 WideVec, createInterleaveMask(VF.getKnownMinValue(), InterleaveFactor),
2851 "interleaved.vec");
2852
2853 Instruction *NewStoreInstr;
2854 if (BlockInMask) {
2855 Value *BlockInMaskPart = State.get(BlockInMask, Part);
2856 Value *ShuffledMask = Builder.CreateShuffleVector(
2857 BlockInMaskPart,
2858 createReplicatedMask(InterleaveFactor, VF.getKnownMinValue()),
2859 "interleaved.mask");
2860 NewStoreInstr = Builder.CreateMaskedStore(
2861 IVec, AddrParts[Part], Group->getAlign(), ShuffledMask);
2862 }
2863 else
2864 NewStoreInstr =
2865 Builder.CreateAlignedStore(IVec, AddrParts[Part], Group->getAlign());
2866
2867 Group->addMetadata(NewStoreInstr);
2868 }
2869}
2870
2871void InnerLoopVectorizer::vectorizeMemoryInstruction(
2872 Instruction *Instr, VPTransformState &State, VPValue *Def, VPValue *Addr,
2873 VPValue *StoredValue, VPValue *BlockInMask) {
2874 // Attempt to issue a wide load.
2875 LoadInst *LI = dyn_cast<LoadInst>(Instr);
2876 StoreInst *SI = dyn_cast<StoreInst>(Instr);
2877
2878 assert((LI || SI) && "Invalid Load/Store instruction")(static_cast <bool> ((LI || SI) && "Invalid Load/Store instruction"
) ? void (0) : __assert_fail ("(LI || SI) && \"Invalid Load/Store instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2878, __extension__ __PRETTY_FUNCTION__))
;
2879 assert((!SI || StoredValue) && "No stored value provided for widened store")(static_cast <bool> ((!SI || StoredValue) && "No stored value provided for widened store"
) ? void (0) : __assert_fail ("(!SI || StoredValue) && \"No stored value provided for widened store\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2879, __extension__ __PRETTY_FUNCTION__))
;
2880 assert((!LI || !StoredValue) && "Stored value provided for widened load")(static_cast <bool> ((!LI || !StoredValue) && "Stored value provided for widened load"
) ? void (0) : __assert_fail ("(!LI || !StoredValue) && \"Stored value provided for widened load\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2880, __extension__ __PRETTY_FUNCTION__))
;
2881
2882 LoopVectorizationCostModel::InstWidening Decision =
2883 Cost->getWideningDecision(Instr, VF);
2884 assert((Decision == LoopVectorizationCostModel::CM_Widen ||(static_cast <bool> ((Decision == LoopVectorizationCostModel
::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse
|| Decision == LoopVectorizationCostModel::CM_GatherScatter)
&& "CM decision is not to widen the memory instruction"
) ? void (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2887, __extension__ __PRETTY_FUNCTION__))
2885 Decision == LoopVectorizationCostModel::CM_Widen_Reverse ||(static_cast <bool> ((Decision == LoopVectorizationCostModel
::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse
|| Decision == LoopVectorizationCostModel::CM_GatherScatter)
&& "CM decision is not to widen the memory instruction"
) ? void (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2887, __extension__ __PRETTY_FUNCTION__))
2886 Decision == LoopVectorizationCostModel::CM_GatherScatter) &&(static_cast <bool> ((Decision == LoopVectorizationCostModel
::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse
|| Decision == LoopVectorizationCostModel::CM_GatherScatter)
&& "CM decision is not to widen the memory instruction"
) ? void (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2887, __extension__ __PRETTY_FUNCTION__))
2887 "CM decision is not to widen the memory instruction")(static_cast <bool> ((Decision == LoopVectorizationCostModel
::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse
|| Decision == LoopVectorizationCostModel::CM_GatherScatter)
&& "CM decision is not to widen the memory instruction"
) ? void (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2887, __extension__ __PRETTY_FUNCTION__))
;
2888
2889 Type *ScalarDataTy = getLoadStoreType(Instr);
2890
2891 auto *DataTy = VectorType::get(ScalarDataTy, VF);
2892 const Align Alignment = getLoadStoreAlignment(Instr);
2893
2894 // Determine if the pointer operand of the access is either consecutive or
2895 // reverse consecutive.
2896 bool Reverse = (Decision == LoopVectorizationCostModel::CM_Widen_Reverse);
2897 bool ConsecutiveStride =
2898 Reverse || (Decision == LoopVectorizationCostModel::CM_Widen);
2899 bool CreateGatherScatter =
2900 (Decision == LoopVectorizationCostModel::CM_GatherScatter);
2901
2902 // Either Ptr feeds a vector load/store, or a vector GEP should feed a vector
2903 // gather/scatter. Otherwise Decision should have been to Scalarize.
2904 assert((ConsecutiveStride || CreateGatherScatter) &&(static_cast <bool> ((ConsecutiveStride || CreateGatherScatter
) && "The instruction should be scalarized") ? void (
0) : __assert_fail ("(ConsecutiveStride || CreateGatherScatter) && \"The instruction should be scalarized\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2905, __extension__ __PRETTY_FUNCTION__))
2905 "The instruction should be scalarized")(static_cast <bool> ((ConsecutiveStride || CreateGatherScatter
) && "The instruction should be scalarized") ? void (
0) : __assert_fail ("(ConsecutiveStride || CreateGatherScatter) && \"The instruction should be scalarized\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2905, __extension__ __PRETTY_FUNCTION__))
;
2906 (void)ConsecutiveStride;
2907
2908 VectorParts BlockInMaskParts(UF);
2909 bool isMaskRequired = BlockInMask;
2910 if (isMaskRequired)
2911 for (unsigned Part = 0; Part < UF; ++Part)
2912 BlockInMaskParts[Part] = State.get(BlockInMask, Part);
2913
2914 const auto CreateVecPtr = [&](unsigned Part, Value *Ptr) -> Value * {
2915 // Calculate the pointer for the specific unroll-part.
2916 GetElementPtrInst *PartPtr = nullptr;
2917
2918 bool InBounds = false;
2919 if (auto *gep = dyn_cast<GetElementPtrInst>(Ptr->stripPointerCasts()))
2920 InBounds = gep->isInBounds();
2921 if (Reverse) {
2922 // If the address is consecutive but reversed, then the
2923 // wide store needs to start at the last vector element.
2924 // RunTimeVF = VScale * VF.getKnownMinValue()
2925 // For fixed-width VScale is 1, then RunTimeVF = VF.getKnownMinValue()
2926 Value *RunTimeVF = getRuntimeVF(Builder, Builder.getInt32Ty(), VF);
2927 // NumElt = -Part * RunTimeVF
2928 Value *NumElt = Builder.CreateMul(Builder.getInt32(-Part), RunTimeVF);
2929 // LastLane = 1 - RunTimeVF
2930 Value *LastLane = Builder.CreateSub(Builder.getInt32(1), RunTimeVF);
2931 PartPtr =
2932 cast<GetElementPtrInst>(Builder.CreateGEP(ScalarDataTy, Ptr, NumElt));
2933 PartPtr->setIsInBounds(InBounds);
2934 PartPtr = cast<GetElementPtrInst>(
2935 Builder.CreateGEP(ScalarDataTy, PartPtr, LastLane));
2936 PartPtr->setIsInBounds(InBounds);
2937 if (isMaskRequired) // Reverse of a null all-one mask is a null mask.
2938 BlockInMaskParts[Part] = reverseVector(BlockInMaskParts[Part]);
2939 } else {
2940 Value *Increment = createStepForVF(Builder, Builder.getInt32(Part), VF);
2941 PartPtr = cast<GetElementPtrInst>(
2942 Builder.CreateGEP(ScalarDataTy, Ptr, Increment));
2943 PartPtr->setIsInBounds(InBounds);
2944 }
2945
2946 unsigned AddressSpace = Ptr->getType()->getPointerAddressSpace();
2947 return Builder.CreateBitCast(PartPtr, DataTy->getPointerTo(AddressSpace));
2948 };
2949
2950 // Handle Stores:
2951 if (SI) {
2952 setDebugLocFromInst(Builder, SI);
2953
2954 for (unsigned Part = 0; Part < UF; ++Part) {
2955 Instruction *NewSI = nullptr;
2956 Value *StoredVal = State.get(StoredValue, Part);
2957 if (CreateGatherScatter) {
2958 Value *MaskPart = isMaskRequired ? BlockInMaskParts[Part] : nullptr;
2959 Value *VectorGep = State.get(Addr, Part);
2960 NewSI = Builder.CreateMaskedScatter(StoredVal, VectorGep, Alignment,
2961 MaskPart);
2962 } else {
2963 if (Reverse) {
2964 // If we store to reverse consecutive memory locations, then we need
2965 // to reverse the order of elements in the stored value.
2966 StoredVal = reverseVector(StoredVal);
2967 // We don't want to update the value in the map as it might be used in
2968 // another expression. So don't call resetVectorValue(StoredVal).
2969 }
2970 auto *VecPtr = CreateVecPtr(Part, State.get(Addr, VPIteration(0, 0)));
2971 if (isMaskRequired)
2972 NewSI = Builder.CreateMaskedStore(StoredVal, VecPtr, Alignment,
2973 BlockInMaskParts[Part]);
2974 else
2975 NewSI = Builder.CreateAlignedStore(StoredVal, VecPtr, Alignment);
2976 }
2977 addMetadata(NewSI, SI);
2978 }
2979 return;
2980 }
2981
2982 // Handle loads.
2983 assert(LI && "Must have a load instruction")(static_cast <bool> (LI && "Must have a load instruction"
) ? void (0) : __assert_fail ("LI && \"Must have a load instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 2983, __extension__ __PRETTY_FUNCTION__))
;
2984 setDebugLocFromInst(Builder, LI);
2985 for (unsigned Part = 0; Part < UF; ++Part) {
2986 Value *NewLI;
2987 if (CreateGatherScatter) {
2988 Value *MaskPart = isMaskRequired ? BlockInMaskParts[Part] : nullptr;
2989 Value *VectorGep = State.get(Addr, Part);
2990 NewLI = Builder.CreateMaskedGather(VectorGep, Alignment, MaskPart,
2991 nullptr, "wide.masked.gather");
2992 addMetadata(NewLI, LI);
2993 } else {
2994 auto *VecPtr = CreateVecPtr(Part, State.get(Addr, VPIteration(0, 0)));
2995 if (isMaskRequired)
2996 NewLI = Builder.CreateMaskedLoad(
2997 VecPtr, Alignment, BlockInMaskParts[Part], PoisonValue::get(DataTy),
2998 "wide.masked.load");
2999 else
3000 NewLI =
3001 Builder.CreateAlignedLoad(DataTy, VecPtr, Alignment, "wide.load");
3002
3003 // Add metadata to the load, but setVectorValue to the reverse shuffle.
3004 addMetadata(NewLI, LI);
3005 if (Reverse)
3006 NewLI = reverseVector(NewLI);
3007 }
3008
3009 State.set(Def, NewLI, Part);
3010 }
3011}
3012
3013void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr, VPValue *Def,
3014 VPUser &User,
3015 const VPIteration &Instance,
3016 bool IfPredicateInstr,
3017 VPTransformState &State) {
3018 assert(!Instr->getType()->isAggregateType() && "Can't handle vectors")(static_cast <bool> (!Instr->getType()->isAggregateType
() && "Can't handle vectors") ? void (0) : __assert_fail
("!Instr->getType()->isAggregateType() && \"Can't handle vectors\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3018, __extension__ __PRETTY_FUNCTION__))
;
3019
3020 // llvm.experimental.noalias.scope.decl intrinsics must only be duplicated for
3021 // the first lane and part.
3022 if (isa<NoAliasScopeDeclInst>(Instr))
3023 if (!Instance.isFirstIteration())
3024 return;
3025
3026 setDebugLocFromInst(Builder, Instr);
3027
3028 // Does this instruction return a value ?
3029 bool IsVoidRetTy = Instr->getType()->isVoidTy();
3030
3031 Instruction *Cloned = Instr->clone();
3032 if (!IsVoidRetTy)
3033 Cloned->setName(Instr->getName() + ".cloned");
3034
3035 State.Builder.SetInsertPoint(Builder.GetInsertBlock(),
3036 Builder.GetInsertPoint());
3037 // Replace the operands of the cloned instructions with their scalar
3038 // equivalents in the new loop.
3039 for (unsigned op = 0, e = User.getNumOperands(); op != e; ++op) {
3040 auto *Operand = dyn_cast<Instruction>(Instr->getOperand(op));
3041 auto InputInstance = Instance;
3042 if (!Operand || !OrigLoop->contains(Operand) ||
3043 (Cost->isUniformAfterVectorization(Operand, State.VF)))
3044 InputInstance.Lane = VPLane::getFirstLane();
3045 auto *NewOp = State.get(User.getOperand(op), InputInstance);
3046 Cloned->setOperand(op, NewOp);
3047 }
3048 addNewMetadata(Cloned, Instr);
3049
3050 // Place the cloned scalar in the new loop.
3051 Builder.Insert(Cloned);
3052
3053 State.set(Def, Cloned, Instance);
3054
3055 // If we just cloned a new assumption, add it the assumption cache.
3056 if (auto *II = dyn_cast<AssumeInst>(Cloned))
3057 AC->registerAssumption(II);
3058
3059 // End if-block.
3060 if (IfPredicateInstr)
3061 PredicatedInstructions.push_back(Cloned);
3062}
3063
3064PHINode *InnerLoopVectorizer::createInductionVariable(Loop *L, Value *Start,
3065 Value *End, Value *Step,
3066 Instruction *DL) {
3067 BasicBlock *Header = L->getHeader();
3068 BasicBlock *Latch = L->getLoopLatch();
3069 // As we're just creating this loop, it's possible no latch exists
3070 // yet. If so, use the header as this will be a single block loop.
3071 if (!Latch)
3072 Latch = Header;
3073
3074 IRBuilder<> Builder(&*Header->getFirstInsertionPt());
3075 Instruction *OldInst = getDebugLocFromInstOrOperands(OldInduction);
3076 setDebugLocFromInst(Builder, OldInst);
3077 auto *Induction = Builder.CreatePHI(Start->getType(), 2, "index");
3078
3079 Builder.SetInsertPoint(Latch->getTerminator());
3080 setDebugLocFromInst(Builder, OldInst);
3081
3082 // Create i+1 and fill the PHINode.
3083 //
3084 // If the tail is not folded, we know that End - Start >= Step (either
3085 // statically or through the minimum iteration checks). We also know that both
3086 // Start % Step == 0 and End % Step == 0. We exit the vector loop if %IV +
3087 // %Step == %End. Hence we must exit the loop before %IV + %Step unsigned
3088 // overflows and we can mark the induction increment as NUW.
3089 Value *Next =
3090 Builder.CreateAdd(Induction, Step, "index.next",
3091 /*NUW=*/!Cost->foldTailByMasking(), /*NSW=*/false);
3092 Induction->addIncoming(Start, L->getLoopPreheader());
3093 Induction->addIncoming(Next, Latch);
3094 // Create the compare.
3095 Value *ICmp = Builder.CreateICmpEQ(Next, End);
3096 Builder.CreateCondBr(ICmp, L->getUniqueExitBlock(), Header);
3097
3098 // Now we have two terminators. Remove the old one from the block.
3099 Latch->getTerminator()->eraseFromParent();
3100
3101 return Induction;
3102}
3103
3104Value *InnerLoopVectorizer::getOrCreateTripCount(Loop *L) {
3105 if (TripCount)
3106 return TripCount;
3107
3108 assert(L && "Create Trip Count for null loop.")(static_cast <bool> (L && "Create Trip Count for null loop."
) ? void (0) : __assert_fail ("L && \"Create Trip Count for null loop.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3108, __extension__ __PRETTY_FUNCTION__))
;
3109 IRBuilder<> Builder(L->getLoopPreheader()->getTerminator());
3110 // Find the loop boundaries.
3111 ScalarEvolution *SE = PSE.getSE();
3112 const SCEV *BackedgeTakenCount = PSE.getBackedgeTakenCount();
3113 assert(!isa<SCEVCouldNotCompute>(BackedgeTakenCount) &&(static_cast <bool> (!isa<SCEVCouldNotCompute>(BackedgeTakenCount
) && "Invalid loop count") ? void (0) : __assert_fail
("!isa<SCEVCouldNotCompute>(BackedgeTakenCount) && \"Invalid loop count\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3114, __extension__ __PRETTY_FUNCTION__))
3114 "Invalid loop count")(static_cast <bool> (!isa<SCEVCouldNotCompute>(BackedgeTakenCount
) && "Invalid loop count") ? void (0) : __assert_fail
("!isa<SCEVCouldNotCompute>(BackedgeTakenCount) && \"Invalid loop count\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3114, __extension__ __PRETTY_FUNCTION__))
;
3115
3116 Type *IdxTy = Legal->getWidestInductionType();
3117 assert(IdxTy && "No type for induction")(static_cast <bool> (IdxTy && "No type for induction"
) ? void (0) : __assert_fail ("IdxTy && \"No type for induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3117, __extension__ __PRETTY_FUNCTION__))
;
3118
3119 // The exit count might have the type of i64 while the phi is i32. This can
3120 // happen if we have an induction variable that is sign extended before the
3121 // compare. The only way that we get a backedge taken count is that the
3122 // induction variable was signed and as such will not overflow. In such a case
3123 // truncation is legal.
3124 if (SE->getTypeSizeInBits(BackedgeTakenCount->getType()) >
3125 IdxTy->getPrimitiveSizeInBits())
3126 BackedgeTakenCount = SE->getTruncateOrNoop(BackedgeTakenCount, IdxTy);
3127 BackedgeTakenCount = SE->getNoopOrZeroExtend(BackedgeTakenCount, IdxTy);
3128
3129 // Get the total trip count from the count by adding 1.
3130 const SCEV *ExitCount = SE->getAddExpr(
3131 BackedgeTakenCount, SE->getOne(BackedgeTakenCount->getType()));
3132
3133 const DataLayout &DL = L->getHeader()->getModule()->getDataLayout();
3134
3135 // Expand the trip count and place the new instructions in the preheader.
3136 // Notice that the pre-header does not change, only the loop body.
3137 SCEVExpander Exp(*SE, DL, "induction");
3138
3139 // Count holds the overall loop count (N).
3140 TripCount = Exp.expandCodeFor(ExitCount, ExitCount->getType(),
3141 L->getLoopPreheader()->getTerminator());
3142
3143 if (TripCount->getType()->isPointerTy())
3144 TripCount =
3145 CastInst::CreatePointerCast(TripCount, IdxTy, "exitcount.ptrcnt.to.int",
3146 L->getLoopPreheader()->getTerminator());
3147
3148 return TripCount;
3149}
3150
3151Value *InnerLoopVectorizer::getOrCreateVectorTripCount(Loop *L) {
3152 if (VectorTripCount)
3153 return VectorTripCount;
3154
3155 Value *TC = getOrCreateTripCount(L);
3156 IRBuilder<> Builder(L->getLoopPreheader()->getTerminator());
3157
3158 Type *Ty = TC->getType();
3159 // This is where we can make the step a runtime constant.
3160 Value *Step = createStepForVF(Builder, ConstantInt::get(Ty, UF), VF);
3161
3162 // If the tail is to be folded by masking, round the number of iterations N
3163 // up to a multiple of Step instead of rounding down. This is done by first
3164 // adding Step-1 and then rounding down. Note that it's ok if this addition
3165 // overflows: the vector induction variable will eventually wrap to zero given
3166 // that it starts at zero and its Step is a power of two; the loop will then
3167 // exit, with the last early-exit vector comparison also producing all-true.
3168 if (Cost->foldTailByMasking()) {
3169 assert(isPowerOf2_32(VF.getKnownMinValue() * UF) &&(static_cast <bool> (isPowerOf2_32(VF.getKnownMinValue(
) * UF) && "VF*UF must be a power of 2 when folding tail by masking"
) ? void (0) : __assert_fail ("isPowerOf2_32(VF.getKnownMinValue() * UF) && \"VF*UF must be a power of 2 when folding tail by masking\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3170, __extension__ __PRETTY_FUNCTION__))
3170 "VF*UF must be a power of 2 when folding tail by masking")(static_cast <bool> (isPowerOf2_32(VF.getKnownMinValue(
) * UF) && "VF*UF must be a power of 2 when folding tail by masking"
) ? void (0) : __assert_fail ("isPowerOf2_32(VF.getKnownMinValue() * UF) && \"VF*UF must be a power of 2 when folding tail by masking\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3170, __extension__ __PRETTY_FUNCTION__))
;
3171 assert(!VF.isScalable() &&(static_cast <bool> (!VF.isScalable() && "Tail folding not yet supported for scalable vectors"
) ? void (0) : __assert_fail ("!VF.isScalable() && \"Tail folding not yet supported for scalable vectors\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3172, __extension__ __PRETTY_FUNCTION__))
3172 "Tail folding not yet supported for scalable vectors")(static_cast <bool> (!VF.isScalable() && "Tail folding not yet supported for scalable vectors"
) ? void (0) : __assert_fail ("!VF.isScalable() && \"Tail folding not yet supported for scalable vectors\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3172, __extension__ __PRETTY_FUNCTION__))
;
3173 TC = Builder.CreateAdd(
3174 TC, ConstantInt::get(Ty, VF.getKnownMinValue() * UF - 1), "n.rnd.up");
3175 }
3176
3177 // Now we need to generate the expression for the part of the loop that the
3178 // vectorized body will execute. This is equal to N - (N % Step) if scalar
3179 // iterations are not required for correctness, or N - Step, otherwise. Step
3180 // is equal to the vectorization factor (number of SIMD elements) times the
3181 // unroll factor (number of SIMD instructions).
3182 Value *R = Builder.CreateURem(TC, Step, "n.mod.vf");
3183
3184 // There are two cases where we need to ensure (at least) the last iteration
3185 // runs in the scalar remainder loop. Thus, if the step evenly divides
3186 // the trip count, we set the remainder to be equal to the step. If the step
3187 // does not evenly divide the trip count, no adjustment is necessary since
3188 // there will already be scalar iterations. Note that the minimum iterations
3189 // check ensures that N >= Step. The cases are:
3190 // 1) If there is a non-reversed interleaved group that may speculatively
3191 // access memory out-of-bounds.
3192 // 2) If any instruction may follow a conditionally taken exit. That is, if
3193 // the loop contains multiple exiting blocks, or a single exiting block
3194 // which is not the latch.
3195 if (VF.isVector() && Cost->requiresScalarEpilogue()) {
3196 auto *IsZero = Builder.CreateICmpEQ(R, ConstantInt::get(R->getType(), 0));
3197 R = Builder.CreateSelect(IsZero, Step, R);
3198 }
3199
3200 VectorTripCount = Builder.CreateSub(TC, R, "n.vec");
3201
3202 return VectorTripCount;
3203}
3204
3205Value *InnerLoopVectorizer::createBitOrPointerCast(Value *V, VectorType *DstVTy,
3206 const DataLayout &DL) {
3207 // Verify that V is a vector type with same number of elements as DstVTy.
3208 auto *DstFVTy = cast<FixedVectorType>(DstVTy);
3209 unsigned VF = DstFVTy->getNumElements();
3210 auto *SrcVecTy = cast<FixedVectorType>(V->getType());
3211 assert((VF == SrcVecTy->getNumElements()) && "Vector dimensions do not match")(static_cast <bool> ((VF == SrcVecTy->getNumElements
()) && "Vector dimensions do not match") ? void (0) :
__assert_fail ("(VF == SrcVecTy->getNumElements()) && \"Vector dimensions do not match\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3211, __extension__ __PRETTY_FUNCTION__))
;
3212 Type *SrcElemTy = SrcVecTy->getElementType();
3213 Type *DstElemTy = DstFVTy->getElementType();
3214 assert((DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) &&(static_cast <bool> ((DL.getTypeSizeInBits(SrcElemTy) ==
DL.getTypeSizeInBits(DstElemTy)) && "Vector elements must have same size"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) && \"Vector elements must have same size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3215, __extension__ __PRETTY_FUNCTION__))
3215 "Vector elements must have same size")(static_cast <bool> ((DL.getTypeSizeInBits(SrcElemTy) ==
DL.getTypeSizeInBits(DstElemTy)) && "Vector elements must have same size"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) && \"Vector elements must have same size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3215, __extension__ __PRETTY_FUNCTION__))
;
3216
3217 // Do a direct cast if element types are castable.
3218 if (CastInst::isBitOrNoopPointerCastable(SrcElemTy, DstElemTy, DL)) {
3219 return Builder.CreateBitOrPointerCast(V, DstFVTy);
3220 }
3221 // V cannot be directly casted to desired vector type.
3222 // May happen when V is a floating point vector but DstVTy is a vector of
3223 // pointers or vice-versa. Handle this using a two-step bitcast using an
3224 // intermediate Integer type for the bitcast i.e. Ptr <-> Int <-> Float.
3225 assert((DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) &&(static_cast <bool> ((DstElemTy->isPointerTy() != SrcElemTy
->isPointerTy()) && "Only one type should be a pointer type"
) ? void (0) : __assert_fail ("(DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) && \"Only one type should be a pointer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3226, __extension__ __PRETTY_FUNCTION__))
3226 "Only one type should be a pointer type")(static_cast <bool> ((DstElemTy->isPointerTy() != SrcElemTy
->isPointerTy()) && "Only one type should be a pointer type"
) ? void (0) : __assert_fail ("(DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) && \"Only one type should be a pointer type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3226, __extension__ __PRETTY_FUNCTION__))
;
3227 assert((DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) &&(static_cast <bool> ((DstElemTy->isFloatingPointTy()
!= SrcElemTy->isFloatingPointTy()) && "Only one type should be a floating point type"
) ? void (0) : __assert_fail ("(DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) && \"Only one type should be a floating point type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3228, __extension__ __PRETTY_FUNCTION__))
3228 "Only one type should be a floating point type")(static_cast <bool> ((DstElemTy->isFloatingPointTy()
!= SrcElemTy->isFloatingPointTy()) && "Only one type should be a floating point type"
) ? void (0) : __assert_fail ("(DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) && \"Only one type should be a floating point type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3228, __extension__ __PRETTY_FUNCTION__))
;
3229 Type *IntTy =
3230 IntegerType::getIntNTy(V->getContext(), DL.getTypeSizeInBits(SrcElemTy));
3231 auto *VecIntTy = FixedVectorType::get(IntTy, VF);
3232 Value *CastVal = Builder.CreateBitOrPointerCast(V, VecIntTy);
3233 return Builder.CreateBitOrPointerCast(CastVal, DstFVTy);
3234}
3235
3236void InnerLoopVectorizer::emitMinimumIterationCountCheck(Loop *L,
3237 BasicBlock *Bypass) {
3238 Value *Count = getOrCreateTripCount(L);
3239 // Reuse existing vector loop preheader for TC checks.
3240 // Note that new preheader block is generated for vector loop.
3241 BasicBlock *const TCCheckBlock = LoopVectorPreHeader;
3242 IRBuilder<> Builder(TCCheckBlock->getTerminator());
3243
3244 // Generate code to check if the loop's trip count is less than VF * UF, or
3245 // equal to it in case a scalar epilogue is required; this implies that the
3246 // vector trip count is zero. This check also covers the case where adding one
3247 // to the backedge-taken count overflowed leading to an incorrect trip count
3248 // of zero. In this case we will also jump to the scalar loop.
3249 auto P = Cost->requiresScalarEpilogue() ? ICmpInst::ICMP_ULE
3250 : ICmpInst::ICMP_ULT;
3251
3252 // If tail is to be folded, vector loop takes care of all iterations.
3253 Value *CheckMinIters = Builder.getFalse();
3254 if (!Cost->foldTailByMasking()) {
3255 Value *Step =
3256 createStepForVF(Builder, ConstantInt::get(Count->getType(), UF), VF);
3257 CheckMinIters = Builder.CreateICmp(P, Count, Step, "min.iters.check");
3258 }
3259 // Create new preheader for vector loop.
3260 LoopVectorPreHeader =
3261 SplitBlock(TCCheckBlock, TCCheckBlock->getTerminator(), DT, LI, nullptr,
3262 "vector.ph");
3263
3264 assert(DT->properlyDominates(DT->getNode(TCCheckBlock),(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3266, __extension__ __PRETTY_FUNCTION__))
3265 DT->getNode(Bypass)->getIDom()) &&(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3266, __extension__ __PRETTY_FUNCTION__))
3266 "TC check is expected to dominate Bypass")(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3266, __extension__ __PRETTY_FUNCTION__))
;
3267
3268 // Update dominator for Bypass & LoopExit.
3269 DT->changeImmediateDominator(Bypass, TCCheckBlock);
3270 DT->changeImmediateDominator(LoopExitBlock, TCCheckBlock);
3271
3272 ReplaceInstWithInst(
3273 TCCheckBlock->getTerminator(),
3274 BranchInst::Create(Bypass, LoopVectorPreHeader, CheckMinIters));
3275 LoopBypassBlocks.push_back(TCCheckBlock);
3276}
3277
3278BasicBlock *InnerLoopVectorizer::emitSCEVChecks(Loop *L, BasicBlock *Bypass) {
3279
3280 BasicBlock *const SCEVCheckBlock =
3281 RTChecks.emitSCEVChecks(L, Bypass, LoopVectorPreHeader, LoopExitBlock);
3282 if (!SCEVCheckBlock)
3283 return nullptr;
3284
3285 assert(!(SCEVCheckBlock->getParent()->hasOptSize() ||(static_cast <bool> (!(SCEVCheckBlock->getParent()->
hasOptSize() || (OptForSizeBasedOnProfile && Cost->
Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&
"Cannot SCEV check stride or overflow when optimizing for size"
) ? void (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3288, __extension__ __PRETTY_FUNCTION__))
3286 (OptForSizeBasedOnProfile &&(static_cast <bool> (!(SCEVCheckBlock->getParent()->
hasOptSize() || (OptForSizeBasedOnProfile && Cost->
Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&
"Cannot SCEV check stride or overflow when optimizing for size"
) ? void (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3288, __extension__ __PRETTY_FUNCTION__))
3287 Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&(static_cast <bool> (!(SCEVCheckBlock->getParent()->
hasOptSize() || (OptForSizeBasedOnProfile && Cost->
Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&
"Cannot SCEV check stride or overflow when optimizing for size"
) ? void (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3288, __extension__ __PRETTY_FUNCTION__))
3288 "Cannot SCEV check stride or overflow when optimizing for size")(static_cast <bool> (!(SCEVCheckBlock->getParent()->
hasOptSize() || (OptForSizeBasedOnProfile && Cost->
Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&
"Cannot SCEV check stride or overflow when optimizing for size"
) ? void (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3288, __extension__ __PRETTY_FUNCTION__))
;
3289
3290
3291 // Update dominator only if this is first RT check.
3292 if (LoopBypassBlocks.empty()) {
3293 DT->changeImmediateDominator(Bypass, SCEVCheckBlock);
3294 DT->changeImmediateDominator(LoopExitBlock, SCEVCheckBlock);
3295 }
3296
3297 LoopBypassBlocks.push_back(SCEVCheckBlock);
3298 AddedSafetyChecks = true;
3299 return SCEVCheckBlock;
3300}
3301
3302BasicBlock *InnerLoopVectorizer::emitMemRuntimeChecks(Loop *L,
3303 BasicBlock *Bypass) {
3304 // VPlan-native path does not do any analysis for runtime checks currently.
3305 if (EnableVPlanNativePath)
3306 return nullptr;
3307
3308 BasicBlock *const MemCheckBlock =
3309 RTChecks.emitMemRuntimeChecks(L, Bypass, LoopVectorPreHeader);
3310
3311 // Check if we generated code that checks in runtime if arrays overlap. We put
3312 // the checks into a separate block to make the more common case of few
3313 // elements faster.
3314 if (!MemCheckBlock)
3315 return nullptr;
3316
3317 if (MemCheckBlock->getParent()->hasOptSize() || OptForSizeBasedOnProfile) {
3318 assert(Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled &&(static_cast <bool> (Cost->Hints->getForce() == LoopVectorizeHints
::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced "
"to vectorize.") ? void (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3320, __extension__ __PRETTY_FUNCTION__))
3319 "Cannot emit memory checks when optimizing for size, unless forced "(static_cast <bool> (Cost->Hints->getForce() == LoopVectorizeHints
::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced "
"to vectorize.") ? void (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3320, __extension__ __PRETTY_FUNCTION__))
3320 "to vectorize.")(static_cast <bool> (Cost->Hints->getForce() == LoopVectorizeHints
::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced "
"to vectorize.") ? void (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3320, __extension__ __PRETTY_FUNCTION__))
;
3321 ORE->emit([&]() {
3322 return OptimizationRemarkAnalysis(DEBUG_TYPE"loop-vectorize", "VectorizationCodeSize",
3323 L->getStartLoc(), L->getHeader())
3324 << "Code-size may be reduced by not forcing "
3325 "vectorization, or by source-code modifications "
3326 "eliminating the need for runtime checks "
3327 "(e.g., adding 'restrict').";
3328 });
3329 }
3330
3331 LoopBypassBlocks.push_back(MemCheckBlock);
3332
3333 AddedSafetyChecks = true;
3334
3335 // We currently don't use LoopVersioning for the actual loop cloning but we
3336 // still use it to add the noalias metadata.
3337 LVer = std::make_unique<LoopVersioning>(
3338 *Legal->getLAI(),
3339 Legal->getLAI()->getRuntimePointerChecking()->getChecks(), OrigLoop, LI,
3340 DT, PSE.getSE());
3341 LVer->prepareNoAliasMetadata();
3342 return MemCheckBlock;
3343}
3344
3345Value *InnerLoopVectorizer::emitTransformedIndex(
3346 IRBuilder<> &B, Value *Index, ScalarEvolution *SE, const DataLayout &DL,
3347 const InductionDescriptor &ID) const {
3348
3349 SCEVExpander Exp(*SE, DL, "induction");
3350 auto Step = ID.getStep();
3351 auto StartValue = ID.getStartValue();
3352 assert(Index->getType()->getScalarType() == Step->getType() &&(static_cast <bool> (Index->getType()->getScalarType
() == Step->getType() && "Index scalar type does not match StepValue type"
) ? void (0) : __assert_fail ("Index->getType()->getScalarType() == Step->getType() && \"Index scalar type does not match StepValue type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3353, __extension__ __PRETTY_FUNCTION__))
3353 "Index scalar type does not match StepValue type")(static_cast <bool> (Index->getType()->getScalarType
() == Step->getType() && "Index scalar type does not match StepValue type"
) ? void (0) : __assert_fail ("Index->getType()->getScalarType() == Step->getType() && \"Index scalar type does not match StepValue type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3353, __extension__ __PRETTY_FUNCTION__))
;
3354
3355 // Note: the IR at this point is broken. We cannot use SE to create any new
3356 // SCEV and then expand it, hoping that SCEV's simplification will give us
3357 // a more optimal code. Unfortunately, attempt of doing so on invalid IR may
3358 // lead to various SCEV crashes. So all we can do is to use builder and rely
3359 // on InstCombine for future simplifications. Here we handle some trivial
3360 // cases only.
3361 auto CreateAdd = [&B](Value *X, Value *Y) {
3362 assert(X->getType() == Y->getType() && "Types don't match!")(static_cast <bool> (X->getType() == Y->getType()
&& "Types don't match!") ? void (0) : __assert_fail (
"X->getType() == Y->getType() && \"Types don't match!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3362, __extension__ __PRETTY_FUNCTION__))
;
3363 if (auto *CX = dyn_cast<ConstantInt>(X))
3364 if (CX->isZero())
3365 return Y;
3366 if (auto *CY = dyn_cast<ConstantInt>(Y))
3367 if (CY->isZero())
3368 return X;
3369 return B.CreateAdd(X, Y);
3370 };
3371
3372 // We allow X to be a vector type, in which case Y will potentially be
3373 // splatted into a vector with the same element count.
3374 auto CreateMul = [&B](Value *X, Value *Y) {
3375 assert(X->getType()->getScalarType() == Y->getType() &&(static_cast <bool> (X->getType()->getScalarType(
) == Y->getType() && "Types don't match!") ? void (
0) : __assert_fail ("X->getType()->getScalarType() == Y->getType() && \"Types don't match!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3376, __extension__ __PRETTY_FUNCTION__))
3376 "Types don't match!")(static_cast <bool> (X->getType()->getScalarType(
) == Y->getType() && "Types don't match!") ? void (
0) : __assert_fail ("X->getType()->getScalarType() == Y->getType() && \"Types don't match!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3376, __extension__ __PRETTY_FUNCTION__))
;
3377 if (auto *CX = dyn_cast<ConstantInt>(X))
3378 if (CX->isOne())
3379 return Y;
3380 if (auto *CY = dyn_cast<ConstantInt>(Y))
3381 if (CY->isOne())
3382 return X;
3383 VectorType *XVTy = dyn_cast<VectorType>(X->getType());
3384 if (XVTy && !isa<VectorType>(Y->getType()))
3385 Y = B.CreateVectorSplat(XVTy->getElementCount(), Y);
3386 return B.CreateMul(X, Y);
3387 };
3388
3389 // Get a suitable insert point for SCEV expansion. For blocks in the vector
3390 // loop, choose the end of the vector loop header (=LoopVectorBody), because
3391 // the DomTree is not kept up-to-date for additional blocks generated in the
3392 // vector loop. By using the header as insertion point, we guarantee that the
3393 // expanded instructions dominate all their uses.
3394 auto GetInsertPoint = [this, &B]() {
3395 BasicBlock *InsertBB = B.GetInsertPoint()->getParent();
3396 if (InsertBB != LoopVectorBody &&
3397 LI->getLoopFor(LoopVectorBody) == LI->getLoopFor(InsertBB))
3398 return LoopVectorBody->getTerminator();
3399 return &*B.GetInsertPoint();
3400 };
3401
3402 switch (ID.getKind()) {
3403 case InductionDescriptor::IK_IntInduction: {
3404 assert(!isa<VectorType>(Index->getType()) &&(static_cast <bool> (!isa<VectorType>(Index->getType
()) && "Vector indices not supported for integer inductions yet"
) ? void (0) : __assert_fail ("!isa<VectorType>(Index->getType()) && \"Vector indices not supported for integer inductions yet\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3405, __extension__ __PRETTY_FUNCTION__))
3405 "Vector indices not supported for integer inductions yet")(static_cast <bool> (!isa<VectorType>(Index->getType
()) && "Vector indices not supported for integer inductions yet"
) ? void (0) : __assert_fail ("!isa<VectorType>(Index->getType()) && \"Vector indices not supported for integer inductions yet\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3405, __extension__ __PRETTY_FUNCTION__))
;
3406 assert(Index->getType() == StartValue->getType() &&(static_cast <bool> (Index->getType() == StartValue->
getType() && "Index type does not match StartValue type"
) ? void (0) : __assert_fail ("Index->getType() == StartValue->getType() && \"Index type does not match StartValue type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3407, __extension__ __PRETTY_FUNCTION__))
3407 "Index type does not match StartValue type")(static_cast <bool> (Index->getType() == StartValue->
getType() && "Index type does not match StartValue type"
) ? void (0) : __assert_fail ("Index->getType() == StartValue->getType() && \"Index type does not match StartValue type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3407, __extension__ __PRETTY_FUNCTION__))
;
3408 if (ID.getConstIntStepValue() && ID.getConstIntStepValue()->isMinusOne())
3409 return B.CreateSub(StartValue, Index);
3410 auto *Offset = CreateMul(
3411 Index, Exp.expandCodeFor(Step, Index->getType(), GetInsertPoint()));
3412 return CreateAdd(StartValue, Offset);
3413 }
3414 case InductionDescriptor::IK_PtrInduction: {
3415 assert(isa<SCEVConstant>(Step) &&(static_cast <bool> (isa<SCEVConstant>(Step) &&
"Expected constant step for pointer induction") ? void (0) :
__assert_fail ("isa<SCEVConstant>(Step) && \"Expected constant step for pointer induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3416, __extension__ __PRETTY_FUNCTION__))
3416 "Expected constant step for pointer induction")(static_cast <bool> (isa<SCEVConstant>(Step) &&
"Expected constant step for pointer induction") ? void (0) :
__assert_fail ("isa<SCEVConstant>(Step) && \"Expected constant step for pointer induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3416, __extension__ __PRETTY_FUNCTION__))
;
3417 return B.CreateGEP(
3418 StartValue->getType()->getPointerElementType(), StartValue,
3419 CreateMul(Index,
3420 Exp.expandCodeFor(Step, Index->getType()->getScalarType(),
3421 GetInsertPoint())));
3422 }
3423 case InductionDescriptor::IK_FpInduction: {
3424 assert(!isa<VectorType>(Index->getType()) &&(static_cast <bool> (!isa<VectorType>(Index->getType
()) && "Vector indices not supported for FP inductions yet"
) ? void (0) : __assert_fail ("!isa<VectorType>(Index->getType()) && \"Vector indices not supported for FP inductions yet\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3425, __extension__ __PRETTY_FUNCTION__))
3425 "Vector indices not supported for FP inductions yet")(static_cast <bool> (!isa<VectorType>(Index->getType
()) && "Vector indices not supported for FP inductions yet"
) ? void (0) : __assert_fail ("!isa<VectorType>(Index->getType()) && \"Vector indices not supported for FP inductions yet\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3425, __extension__ __PRETTY_FUNCTION__))
;
3426 assert(Step->getType()->isFloatingPointTy() && "Expected FP Step value")(static_cast <bool> (Step->getType()->isFloatingPointTy
() && "Expected FP Step value") ? void (0) : __assert_fail
("Step->getType()->isFloatingPointTy() && \"Expected FP Step value\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3426, __extension__ __PRETTY_FUNCTION__))
;
3427 auto InductionBinOp = ID.getInductionBinOp();
3428 assert(InductionBinOp &&(static_cast <bool> (InductionBinOp && (InductionBinOp
->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode
() == Instruction::FSub) && "Original bin op should be defined for FP induction"
) ? void (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3431, __extension__ __PRETTY_FUNCTION__))
3429 (InductionBinOp->getOpcode() == Instruction::FAdd ||(static_cast <bool> (InductionBinOp && (InductionBinOp
->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode
() == Instruction::FSub) && "Original bin op should be defined for FP induction"
) ? void (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3431, __extension__ __PRETTY_FUNCTION__))
3430 InductionBinOp->getOpcode() == Instruction::FSub) &&(static_cast <bool> (InductionBinOp && (InductionBinOp
->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode
() == Instruction::FSub) && "Original bin op should be defined for FP induction"
) ? void (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3431, __extension__ __PRETTY_FUNCTION__))
3431 "Original bin op should be defined for FP induction")(static_cast <bool> (InductionBinOp && (InductionBinOp
->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode
() == Instruction::FSub) && "Original bin op should be defined for FP induction"
) ? void (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3431, __extension__ __PRETTY_FUNCTION__))
;
3432
3433 Value *StepValue = cast<SCEVUnknown>(Step)->getValue();
3434 Value *MulExp = B.CreateFMul(StepValue, Index);
3435 return B.CreateBinOp(InductionBinOp->getOpcode(), StartValue, MulExp,
3436 "induction");
3437 }
3438 case InductionDescriptor::IK_NoInduction:
3439 return nullptr;
3440 }
3441 llvm_unreachable("invalid enum")::llvm::llvm_unreachable_internal("invalid enum", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3441)
;
3442}
3443
3444Loop *InnerLoopVectorizer::createVectorLoopSkeleton(StringRef Prefix) {
3445 LoopScalarBody = OrigLoop->getHeader();
3446 LoopVectorPreHeader = OrigLoop->getLoopPreheader();
3447 LoopExitBlock = OrigLoop->getUniqueExitBlock();
3448 assert(LoopExitBlock && "Must have an exit block")(static_cast <bool> (LoopExitBlock && "Must have an exit block"
) ? void (0) : __assert_fail ("LoopExitBlock && \"Must have an exit block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3448, __extension__ __PRETTY_FUNCTION__))
;
3449 assert(LoopVectorPreHeader && "Invalid loop structure")(static_cast <bool> (LoopVectorPreHeader && "Invalid loop structure"
) ? void (0) : __assert_fail ("LoopVectorPreHeader && \"Invalid loop structure\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3449, __extension__ __PRETTY_FUNCTION__))
;
3450
3451 LoopMiddleBlock =
3452 SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT,
3453 LI, nullptr, Twine(Prefix) + "middle.block");
3454 LoopScalarPreHeader =
3455 SplitBlock(LoopMiddleBlock, LoopMiddleBlock->getTerminator(), DT, LI,
3456 nullptr, Twine(Prefix) + "scalar.ph");
3457
3458 // Set up branch from middle block to the exit and scalar preheader blocks.
3459 // completeLoopSkeleton will update the condition to use an iteration check,
3460 // if required to decide whether to execute the remainder.
3461 BranchInst *BrInst =
3462 BranchInst::Create(LoopExitBlock, LoopScalarPreHeader, Builder.getTrue());
3463 auto *ScalarLatchTerm = OrigLoop->getLoopLatch()->getTerminator();
3464 BrInst->setDebugLoc(ScalarLatchTerm->getDebugLoc());
3465 ReplaceInstWithInst(LoopMiddleBlock->getTerminator(), BrInst);
3466
3467 // We intentionally don't let SplitBlock to update LoopInfo since
3468 // LoopVectorBody should belong to another loop than LoopVectorPreHeader.
3469 // LoopVectorBody is explicitly added to the correct place few lines later.
3470 LoopVectorBody =
3471 SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT,
3472 nullptr, nullptr, Twine(Prefix) + "vector.body");
3473
3474 // Update dominator for loop exit.
3475 DT->changeImmediateDominator(LoopExitBlock, LoopMiddleBlock);
3476
3477 // Create and register the new vector loop.
3478 Loop *Lp = LI->AllocateLoop();
3479 Loop *ParentLoop = OrigLoop->getParentLoop();
3480
3481 // Insert the new loop into the loop nest and register the new basic blocks
3482 // before calling any utilities such as SCEV that require valid LoopInfo.
3483 if (ParentLoop) {
3484 ParentLoop->addChildLoop(Lp);
3485 } else {
3486 LI->addTopLevelLoop(Lp);
3487 }
3488 Lp->addBasicBlockToLoop(LoopVectorBody, *LI);
3489 return Lp;
3490}
3491
3492void InnerLoopVectorizer::createInductionResumeValues(
3493 Loop *L, Value *VectorTripCount,
3494 std::pair<BasicBlock *, Value *> AdditionalBypass) {
3495 assert(VectorTripCount && L && "Expected valid arguments")(static_cast <bool> (VectorTripCount && L &&
"Expected valid arguments") ? void (0) : __assert_fail ("VectorTripCount && L && \"Expected valid arguments\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3495, __extension__ __PRETTY_FUNCTION__))
;
3496 assert(((AdditionalBypass.first && AdditionalBypass.second) ||(static_cast <bool> (((AdditionalBypass.first &&
AdditionalBypass.second) || (!AdditionalBypass.first &&
!AdditionalBypass.second)) && "Inconsistent information about additional bypass."
) ? void (0) : __assert_fail ("((AdditionalBypass.first && AdditionalBypass.second) || (!AdditionalBypass.first && !AdditionalBypass.second)) && \"Inconsistent information about additional bypass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3498, __extension__ __PRETTY_FUNCTION__))
3497 (!AdditionalBypass.first && !AdditionalBypass.second)) &&(static_cast <bool> (((AdditionalBypass.first &&
AdditionalBypass.second) || (!AdditionalBypass.first &&
!AdditionalBypass.second)) && "Inconsistent information about additional bypass."
) ? void (0) : __assert_fail ("((AdditionalBypass.first && AdditionalBypass.second) || (!AdditionalBypass.first && !AdditionalBypass.second)) && \"Inconsistent information about additional bypass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3498, __extension__ __PRETTY_FUNCTION__))
3498 "Inconsistent information about additional bypass.")(static_cast <bool> (((AdditionalBypass.first &&
AdditionalBypass.second) || (!AdditionalBypass.first &&
!AdditionalBypass.second)) && "Inconsistent information about additional bypass."
) ? void (0) : __assert_fail ("((AdditionalBypass.first && AdditionalBypass.second) || (!AdditionalBypass.first && !AdditionalBypass.second)) && \"Inconsistent information about additional bypass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3498, __extension__ __PRETTY_FUNCTION__))
;
3499 // We are going to resume the execution of the scalar loop.
3500 // Go over all of the induction variables that we found and fix the
3501 // PHIs that are left in the scalar version of the loop.
3502 // The starting values of PHI nodes depend on the counter of the last
3503 // iteration in the vectorized loop.
3504 // If we come from a bypass edge then we need to start from the original
3505 // start value.
3506 for (auto &InductionEntry : Legal->getInductionVars()) {
3507 PHINode *OrigPhi = InductionEntry.first;
3508 InductionDescriptor II = InductionEntry.second;
3509
3510 // Create phi nodes to merge from the backedge-taken check block.
3511 PHINode *BCResumeVal =
3512 PHINode::Create(OrigPhi->getType(), 3, "bc.resume.val",
3513 LoopScalarPreHeader->getTerminator());
3514 // Copy original phi DL over to the new one.
3515 BCResumeVal->setDebugLoc(OrigPhi->getDebugLoc());
3516 Value *&EndValue = IVEndValues[OrigPhi];
3517 Value *EndValueFromAdditionalBypass = AdditionalBypass.second;
3518 if (OrigPhi == OldInduction) {
3519 // We know what the end value is.
3520 EndValue = VectorTripCount;
3521 } else {
3522 IRBuilder<> B(L->getLoopPreheader()->getTerminator());
3523
3524 // Fast-math-flags propagate from the original induction instruction.
3525 if (II.getInductionBinOp() && isa<FPMathOperator>(II.getInductionBinOp()))
3526 B.setFastMathFlags(II.getInductionBinOp()->getFastMathFlags());
3527
3528 Type *StepType = II.getStep()->getType();
3529 Instruction::CastOps CastOp =
3530 CastInst::getCastOpcode(VectorTripCount, true, StepType, true);
3531 Value *CRD = B.CreateCast(CastOp, VectorTripCount, StepType, "cast.crd");
3532 const DataLayout &DL = LoopScalarBody->getModule()->getDataLayout();
3533 EndValue = emitTransformedIndex(B, CRD, PSE.getSE(), DL, II);
3534 EndValue->setName("ind.end");
3535
3536 // Compute the end value for the additional bypass (if applicable).
3537 if (AdditionalBypass.first) {
3538 B.SetInsertPoint(&(*AdditionalBypass.first->getFirstInsertionPt()));
3539 CastOp = CastInst::getCastOpcode(AdditionalBypass.second, true,
3540 StepType, true);
3541 CRD =
3542 B.CreateCast(CastOp, AdditionalBypass.second, StepType, "cast.crd");
3543 EndValueFromAdditionalBypass =
3544 emitTransformedIndex(B, CRD, PSE.getSE(), DL, II);
3545 EndValueFromAdditionalBypass->setName("ind.end");
3546 }
3547 }
3548 // The new PHI merges the original incoming value, in case of a bypass,
3549 // or the value at the end of the vectorized loop.
3550 BCResumeVal->addIncoming(EndValue, LoopMiddleBlock);
3551
3552 // Fix the scalar body counter (PHI node).
3553 // The old induction's phi node in the scalar body needs the truncated
3554 // value.
3555 for (BasicBlock *BB : LoopBypassBlocks)
3556 BCResumeVal->addIncoming(II.getStartValue(), BB);
3557
3558 if (AdditionalBypass.first)
3559 BCResumeVal->setIncomingValueForBlock(AdditionalBypass.first,
3560 EndValueFromAdditionalBypass);
3561
3562 OrigPhi->setIncomingValueForBlock(LoopScalarPreHeader, BCResumeVal);
3563 }
3564}
3565
3566BasicBlock *InnerLoopVectorizer::completeLoopSkeleton(Loop *L,
3567 MDNode *OrigLoopID) {
3568 assert(L && "Expected valid loop.")(static_cast <bool> (L && "Expected valid loop."
) ? void (0) : __assert_fail ("L && \"Expected valid loop.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3568, __extension__ __PRETTY_FUNCTION__))
;
3569
3570 // The trip counts should be cached by now.
3571 Value *Count = getOrCreateTripCount(L);
3572 Value *VectorTripCount = getOrCreateVectorTripCount(L);
3573
3574 auto *ScalarLatchTerm = OrigLoop->getLoopLatch()->getTerminator();
3575
3576 // Add a check in the middle block to see if we have completed
3577 // all of the iterations in the first vector loop.
3578 // If (N - N%VF) == N, then we *don't* need to run the remainder.
3579 // If tail is to be folded, we know we don't need to run the remainder.
3580 if (!Cost->foldTailByMasking()) {
3581 Instruction *CmpN = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ,
3582 Count, VectorTripCount, "cmp.n",
3583 LoopMiddleBlock->getTerminator());
3584
3585 // Here we use the same DebugLoc as the scalar loop latch terminator instead
3586 // of the corresponding compare because they may have ended up with
3587 // different line numbers and we want to avoid awkward line stepping while
3588 // debugging. Eg. if the compare has got a line number inside the loop.
3589 CmpN->setDebugLoc(ScalarLatchTerm->getDebugLoc());
3590 cast<BranchInst>(LoopMiddleBlock->getTerminator())->setCondition(CmpN);
3591 }
3592
3593 // Get ready to start creating new instructions into the vectorized body.
3594 assert(LoopVectorPreHeader == L->getLoopPreheader() &&(static_cast <bool> (LoopVectorPreHeader == L->getLoopPreheader
() && "Inconsistent vector loop preheader") ? void (0
) : __assert_fail ("LoopVectorPreHeader == L->getLoopPreheader() && \"Inconsistent vector loop preheader\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3595, __extension__ __PRETTY_FUNCTION__))
3595 "Inconsistent vector loop preheader")(static_cast <bool> (LoopVectorPreHeader == L->getLoopPreheader
() && "Inconsistent vector loop preheader") ? void (0
) : __assert_fail ("LoopVectorPreHeader == L->getLoopPreheader() && \"Inconsistent vector loop preheader\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3595, __extension__ __PRETTY_FUNCTION__))
;
3596 Builder.SetInsertPoint(&*LoopVectorBody->getFirstInsertionPt());
3597
3598 Optional<MDNode *> VectorizedLoopID =
3599 makeFollowupLoopID(OrigLoopID, {LLVMLoopVectorizeFollowupAll,
3600 LLVMLoopVectorizeFollowupVectorized});
3601 if (VectorizedLoopID.hasValue()) {
3602 L->setLoopID(VectorizedLoopID.getValue());
3603
3604 // Do not setAlreadyVectorized if loop attributes have been defined
3605 // explicitly.
3606 return LoopVectorPreHeader;
3607 }
3608
3609 // Keep all loop hints from the original loop on the vector loop (we'll
3610 // replace the vectorizer-specific hints below).
3611 if (MDNode *LID = OrigLoop->getLoopID())
3612 L->setLoopID(LID);
3613
3614 LoopVectorizeHints Hints(L, true, *ORE);
3615 Hints.setAlreadyVectorized();
3616
3617#ifdef EXPENSIVE_CHECKS
3618 assert(DT->verify(DominatorTree::VerificationLevel::Fast))(static_cast <bool> (DT->verify(DominatorTree::VerificationLevel
::Fast)) ? void (0) : __assert_fail ("DT->verify(DominatorTree::VerificationLevel::Fast)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3618, __extension__ __PRETTY_FUNCTION__))
;
3619 LI->verify(*DT);
3620#endif
3621
3622 return LoopVectorPreHeader;
3623}
3624
3625BasicBlock *InnerLoopVectorizer::createVectorizedLoopSkeleton() {
3626 /*
3627 In this function we generate a new loop. The new loop will contain
3628 the vectorized instructions while the old loop will continue to run the
3629 scalar remainder.
3630
3631 [ ] <-- loop iteration number check.
3632 / |
3633 / v
3634 | [ ] <-- vector loop bypass (may consist of multiple blocks).
3635 | / |
3636 | / v
3637 || [ ] <-- vector pre header.
3638 |/ |
3639 | v
3640 | [ ] \
3641 | [ ]_| <-- vector loop.
3642 | |
3643 | v
3644 | -[ ] <--- middle-block.
3645 | / |
3646 | / v
3647 -|- >[ ] <--- new preheader.
3648 | |
3649 | v
3650 | [ ] \
3651 | [ ]_| <-- old scalar loop to handle remainder.
3652 \ |
3653 \ v
3654 >[ ] <-- exit block.
3655 ...
3656 */
3657
3658 // Get the metadata of the original loop before it gets modified.
3659 MDNode *OrigLoopID = OrigLoop->getLoopID();
3660
3661 // Workaround! Compute the trip count of the original loop and cache it
3662 // before we start modifying the CFG. This code has a systemic problem
3663 // wherein it tries to run analysis over partially constructed IR; this is
3664 // wrong, and not simply for SCEV. The trip count of the original loop
3665 // simply happens to be prone to hitting this in practice. In theory, we
3666 // can hit the same issue for any SCEV, or ValueTracking query done during
3667 // mutation. See PR49900.
3668 getOrCreateTripCount(OrigLoop);
3669
3670 // Create an empty vector loop, and prepare basic blocks for the runtime
3671 // checks.
3672 Loop *Lp = createVectorLoopSkeleton("");
3673
3674 // Now, compare the new count to zero. If it is zero skip the vector loop and
3675 // jump to the scalar loop. This check also covers the case where the
3676 // backedge-taken count is uint##_max: adding one to it will overflow leading
3677 // to an incorrect trip count of zero. In this (rare) case we will also jump
3678 // to the scalar loop.
3679 emitMinimumIterationCountCheck(Lp, LoopScalarPreHeader);
3680
3681 // Generate the code to check any assumptions that we've made for SCEV
3682 // expressions.
3683 emitSCEVChecks(Lp, LoopScalarPreHeader);
3684
3685 // Generate the code that checks in runtime if arrays overlap. We put the
3686 // checks into a separate block to make the more common case of few elements
3687 // faster.
3688 emitMemRuntimeChecks(Lp, LoopScalarPreHeader);
3689
3690 // Some loops have a single integer induction variable, while other loops
3691 // don't. One example is c++ iterators that often have multiple pointer
3692 // induction variables. In the code below we also support a case where we
3693 // don't have a single induction variable.
3694 //
3695 // We try to obtain an induction variable from the original loop as hard
3696 // as possible. However if we don't find one that:
3697 // - is an integer
3698 // - counts from zero, stepping by one
3699 // - is the size of the widest induction variable type
3700 // then we create a new one.
3701 OldInduction = Legal->getPrimaryInduction();
3702 Type *IdxTy = Legal->getWidestInductionType();
3703 Value *StartIdx = ConstantInt::get(IdxTy, 0);
3704 // The loop step is equal to the vectorization factor (num of SIMD elements)
3705 // times the unroll factor (num of SIMD instructions).
3706 Builder.SetInsertPoint(&*Lp->getHeader()->getFirstInsertionPt());
3707 Value *Step = createStepForVF(Builder, ConstantInt::get(IdxTy, UF), VF);
3708 Value *CountRoundDown = getOrCreateVectorTripCount(Lp);
3709 Induction =
3710 createInductionVariable(Lp, StartIdx, CountRoundDown, Step,
3711 getDebugLocFromInstOrOperands(OldInduction));
3712
3713 // Emit phis for the new starting index of the scalar loop.
3714 createInductionResumeValues(Lp, CountRoundDown);
3715
3716 return completeLoopSkeleton(Lp, OrigLoopID);
3717}
3718
3719// Fix up external users of the induction variable. At this point, we are
3720// in LCSSA form, with all external PHIs that use the IV having one input value,
3721// coming from the remainder loop. We need those PHIs to also have a correct
3722// value for the IV when arriving directly from the middle block.
3723void InnerLoopVectorizer::fixupIVUsers(PHINode *OrigPhi,
3724 const InductionDescriptor &II,
3725 Value *CountRoundDown, Value *EndValue,
3726 BasicBlock *MiddleBlock) {
3727 // There are two kinds of external IV usages - those that use the value
3728 // computed in the last iteration (the PHI) and those that use the penultimate
3729 // value (the value that feeds into the phi from the loop latch).
3730 // We allow both, but they, obviously, have different values.
3731
3732 assert(OrigLoop->getUniqueExitBlock() && "Expected a single exit block")(static_cast <bool> (OrigLoop->getUniqueExitBlock() &&
"Expected a single exit block") ? void (0) : __assert_fail (
"OrigLoop->getUniqueExitBlock() && \"Expected a single exit block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3732, __extension__ __PRETTY_FUNCTION__))
;
3733
3734 DenseMap<Value *, Value *> MissingVals;
3735
3736 // An external user of the last iteration's value should see the value that
3737 // the remainder loop uses to initialize its own IV.
3738 Value *PostInc = OrigPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch());
3739 for (User *U : PostInc->users()) {
3740 Instruction *UI = cast<Instruction>(U);
3741 if (!OrigLoop->contains(UI)) {
3742 assert(isa<PHINode>(UI) && "Expected LCSSA form")(static_cast <bool> (isa<PHINode>(UI) && "Expected LCSSA form"
) ? void (0) : __assert_fail ("isa<PHINode>(UI) && \"Expected LCSSA form\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3742, __extension__ __PRETTY_FUNCTION__))
;
3743 MissingVals[UI] = EndValue;
3744 }
3745 }
3746
3747 // An external user of the penultimate value need to see EndValue - Step.
3748 // The simplest way to get this is to recompute it from the constituent SCEVs,
3749 // that is Start + (Step * (CRD - 1)).
3750 for (User *U : OrigPhi->users()) {
3751 auto *UI = cast<Instruction>(U);
3752 if (!OrigLoop->contains(UI)) {
3753 const DataLayout &DL =
3754 OrigLoop->getHeader()->getModule()->getDataLayout();
3755 assert(isa<PHINode>(UI) && "Expected LCSSA form")(static_cast <bool> (isa<PHINode>(UI) && "Expected LCSSA form"
) ? void (0) : __assert_fail ("isa<PHINode>(UI) && \"Expected LCSSA form\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3755, __extension__ __PRETTY_FUNCTION__))
;
3756
3757 IRBuilder<> B(MiddleBlock->getTerminator());
3758
3759 // Fast-math-flags propagate from the original induction instruction.
3760 if (II.getInductionBinOp() && isa<FPMathOperator>(II.getInductionBinOp()))
3761 B.setFastMathFlags(II.getInductionBinOp()->getFastMathFlags());
3762
3763 Value *CountMinusOne = B.CreateSub(
3764 CountRoundDown, ConstantInt::get(CountRoundDown->getType(), 1));
3765 Value *CMO =
3766 !II.getStep()->getType()->isIntegerTy()
3767 ? B.CreateCast(Instruction::SIToFP, CountMinusOne,
3768 II.getStep()->getType())
3769 : B.CreateSExtOrTrunc(CountMinusOne, II.getStep()->getType());
3770 CMO->setName("cast.cmo");
3771 Value *Escape = emitTransformedIndex(B, CMO, PSE.getSE(), DL, II);
3772 Escape->setName("ind.escape");
3773 MissingVals[UI] = Escape;
3774 }
3775 }
3776
3777 for (auto &I : MissingVals) {
3778 PHINode *PHI = cast<PHINode>(I.first);
3779 // One corner case we have to handle is two IVs "chasing" each-other,
3780 // that is %IV2 = phi [...], [ %IV1, %latch ]
3781 // In this case, if IV1 has an external use, we need to avoid adding both
3782 // "last value of IV1" and "penultimate value of IV2". So, verify that we
3783 // don't already have an incoming value for the middle block.
3784 if (PHI->getBasicBlockIndex(MiddleBlock) == -1)
3785 PHI->addIncoming(I.second, MiddleBlock);
3786 }
3787}
3788
3789namespace {
3790
3791struct CSEDenseMapInfo {
3792 static bool canHandle(const Instruction *I) {
3793 return isa<InsertElementInst>(I) || isa<ExtractElementInst>(I) ||
3794 isa<ShuffleVectorInst>(I) || isa<GetElementPtrInst>(I);
3795 }
3796
3797 static inline Instruction *getEmptyKey() {
3798 return DenseMapInfo<Instruction *>::getEmptyKey();
3799 }
3800
3801 static inline Instruction *getTombstoneKey() {
3802 return DenseMapInfo<Instruction *>::getTombstoneKey();
3803 }
3804
3805 static unsigned getHashValue(const Instruction *I) {
3806 assert(canHandle(I) && "Unknown instruction!")(static_cast <bool> (canHandle(I) && "Unknown instruction!"
) ? void (0) : __assert_fail ("canHandle(I) && \"Unknown instruction!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3806, __extension__ __PRETTY_FUNCTION__))
;
3807 return hash_combine(I->getOpcode(), hash_combine_range(I->value_op_begin(),
3808 I->value_op_end()));
3809 }
3810
3811 static bool isEqual(const Instruction *LHS, const Instruction *RHS) {
3812 if (LHS == getEmptyKey() || RHS == getEmptyKey() ||
3813 LHS == getTombstoneKey() || RHS == getTombstoneKey())
3814 return LHS == RHS;
3815 return LHS->isIdenticalTo(RHS);
3816 }
3817};
3818
3819} // end anonymous namespace
3820
3821///Perform cse of induction variable instructions.
3822static void cse(BasicBlock *BB) {
3823 // Perform simple cse.
3824 SmallDenseMap<Instruction *, Instruction *, 4, CSEDenseMapInfo> CSEMap;
3825 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) {
3826 Instruction *In = &*I++;
3827
3828 if (!CSEDenseMapInfo::canHandle(In))
3829 continue;
3830
3831 // Check if we can replace this instruction with any of the
3832 // visited instructions.
3833 if (Instruction *V = CSEMap.lookup(In)) {
3834 In->replaceAllUsesWith(V);
3835 In->eraseFromParent();
3836 continue;
3837 }
3838
3839 CSEMap[In] = In;
3840 }
3841}
3842
3843InstructionCost
3844LoopVectorizationCostModel::getVectorCallCost(CallInst *CI, ElementCount VF,
3845 bool &NeedToScalarize) const {
3846 Function *F = CI->getCalledFunction();
3847 Type *ScalarRetTy = CI->getType();
3848 SmallVector<Type *, 4> Tys, ScalarTys;
3849 for (auto &ArgOp : CI->arg_operands())
3850 ScalarTys.push_back(ArgOp->getType());
3851
3852 // Estimate cost of scalarized vector call. The source operands are assumed
3853 // to be vectors, so we need to extract individual elements from there,
3854 // execute VF scalar calls, and then gather the result into the vector return
3855 // value.
3856 InstructionCost ScalarCallCost =
3857 TTI.getCallInstrCost(F, ScalarRetTy, ScalarTys, TTI::TCK_RecipThroughput);
3858 if (VF.isScalar())
3859 return ScalarCallCost;
3860
3861 // Compute corresponding vector type for return value and arguments.
3862 Type *RetTy = ToVectorTy(ScalarRetTy, VF);
3863 for (Type *ScalarTy : ScalarTys)
3864 Tys.push_back(ToVectorTy(ScalarTy, VF));
3865
3866 // Compute costs of unpacking argument values for the scalar calls and
3867 // packing the return values to a vector.
3868 InstructionCost ScalarizationCost = getScalarizationOverhead(CI, VF);
3869
3870 InstructionCost Cost =
3871 ScalarCallCost * VF.getKnownMinValue() + ScalarizationCost;
3872
3873 // If we can't emit a vector call for this function, then the currently found
3874 // cost is the cost we need to return.
3875 NeedToScalarize = true;
3876 VFShape Shape = VFShape::get(*CI, VF, false /*HasGlobalPred*/);
3877 Function *VecFunc = VFDatabase(*CI).getVectorizedFunction(Shape);
3878
3879 if (!TLI || CI->isNoBuiltin() || !VecFunc)
3880 return Cost;
3881
3882 // If the corresponding vector cost is cheaper, return its cost.
3883 InstructionCost VectorCallCost =
3884 TTI.getCallInstrCost(nullptr, RetTy, Tys, TTI::TCK_RecipThroughput);
3885 if (VectorCallCost < Cost) {
3886 NeedToScalarize = false;
3887 Cost = VectorCallCost;
3888 }
3889 return Cost;
3890}
3891
3892static Type *MaybeVectorizeType(Type *Elt, ElementCount VF) {
3893 if (VF.isScalar() || (!Elt->isIntOrPtrTy() && !Elt->isFloatingPointTy()))
3894 return Elt;
3895 return VectorType::get(Elt, VF);
3896}
3897
3898InstructionCost
3899LoopVectorizationCostModel::getVectorIntrinsicCost(CallInst *CI,
3900 ElementCount VF) const {
3901 Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
3902 assert(ID && "Expected intrinsic call!")(static_cast <bool> (ID && "Expected intrinsic call!"
) ? void (0) : __assert_fail ("ID && \"Expected intrinsic call!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3902, __extension__ __PRETTY_FUNCTION__))
;
3903 Type *RetTy = MaybeVectorizeType(CI->getType(), VF);
3904 FastMathFlags FMF;
3905 if (auto *FPMO = dyn_cast<FPMathOperator>(CI))
3906 FMF = FPMO->getFastMathFlags();
3907
3908 SmallVector<const Value *> Arguments(CI->arg_begin(), CI->arg_end());
3909 FunctionType *FTy = CI->getCalledFunction()->getFunctionType();
3910 SmallVector<Type *> ParamTys;
3911 std::transform(FTy->param_begin(), FTy->param_end(),
3912 std::back_inserter(ParamTys),
3913 [&](Type *Ty) { return MaybeVectorizeType(Ty, VF); });
3914
3915 IntrinsicCostAttributes CostAttrs(ID, RetTy, Arguments, ParamTys, FMF,
3916 dyn_cast<IntrinsicInst>(CI));
3917 return TTI.getIntrinsicInstrCost(CostAttrs,
3918 TargetTransformInfo::TCK_RecipThroughput);
3919}
3920
3921static Type *smallestIntegerVectorType(Type *T1, Type *T2) {
3922 auto *I1 = cast<IntegerType>(cast<VectorType>(T1)->getElementType());
3923 auto *I2 = cast<IntegerType>(cast<VectorType>(T2)->getElementType());
3924 return I1->getBitWidth() < I2->getBitWidth() ? T1 : T2;
3925}
3926
3927static Type *largestIntegerVectorType(Type *T1, Type *T2) {
3928 auto *I1 = cast<IntegerType>(cast<VectorType>(T1)->getElementType());
3929 auto *I2 = cast<IntegerType>(cast<VectorType>(T2)->getElementType());
3930 return I1->getBitWidth() > I2->getBitWidth() ? T1 : T2;
3931}
3932
3933void InnerLoopVectorizer::truncateToMinimalBitwidths(VPTransformState &State) {
3934 // For every instruction `I` in MinBWs, truncate the operands, create a
3935 // truncated version of `I` and reextend its result. InstCombine runs
3936 // later and will remove any ext/trunc pairs.
3937 SmallPtrSet<Value *, 4> Erased;
3938 for (const auto &KV : Cost->getMinimalBitwidths()) {
3939 // If the value wasn't vectorized, we must maintain the original scalar
3940 // type. The absence of the value from State indicates that it
3941 // wasn't vectorized.
3942 VPValue *Def = State.Plan->getVPValue(KV.first);
3943 if (!State.hasAnyVectorValue(Def))
3944 continue;
3945 for (unsigned Part = 0; Part < UF; ++Part) {
3946 Value *I = State.get(Def, Part);
3947 if (Erased.count(I) || I->use_empty() || !isa<Instruction>(I))
3948 continue;
3949 Type *OriginalTy = I->getType();
3950 Type *ScalarTruncatedTy =
3951 IntegerType::get(OriginalTy->getContext(), KV.second);
3952 auto *TruncatedTy = FixedVectorType::get(
3953 ScalarTruncatedTy,
3954 cast<FixedVectorType>(OriginalTy)->getNumElements());
3955 if (TruncatedTy == OriginalTy)
3956 continue;
3957
3958 IRBuilder<> B(cast<Instruction>(I));
3959 auto ShrinkOperand = [&](Value *V) -> Value * {
3960 if (auto *ZI = dyn_cast<ZExtInst>(V))
3961 if (ZI->getSrcTy() == TruncatedTy)
3962 return ZI->getOperand(0);
3963 return B.CreateZExtOrTrunc(V, TruncatedTy);
3964 };
3965
3966 // The actual instruction modification depends on the instruction type,
3967 // unfortunately.
3968 Value *NewI = nullptr;
3969 if (auto *BO = dyn_cast<BinaryOperator>(I)) {
3970 NewI = B.CreateBinOp(BO->getOpcode(), ShrinkOperand(BO->getOperand(0)),
3971 ShrinkOperand(BO->getOperand(1)));
3972
3973 // Any wrapping introduced by shrinking this operation shouldn't be
3974 // considered undefined behavior. So, we can't unconditionally copy
3975 // arithmetic wrapping flags to NewI.
3976 cast<BinaryOperator>(NewI)->copyIRFlags(I, /*IncludeWrapFlags=*/false);
3977 } else if (auto *CI = dyn_cast<ICmpInst>(I)) {
3978 NewI =
3979 B.CreateICmp(CI->getPredicate(), ShrinkOperand(CI->getOperand(0)),
3980 ShrinkOperand(CI->getOperand(1)));
3981 } else if (auto *SI = dyn_cast<SelectInst>(I)) {
3982 NewI = B.CreateSelect(SI->getCondition(),
3983 ShrinkOperand(SI->getTrueValue()),
3984 ShrinkOperand(SI->getFalseValue()));
3985 } else if (auto *CI = dyn_cast<CastInst>(I)) {
3986 switch (CI->getOpcode()) {
3987 default:
3988 llvm_unreachable("Unhandled cast!")::llvm::llvm_unreachable_internal("Unhandled cast!", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 3988)
;
3989 case Instruction::Trunc:
3990 NewI = ShrinkOperand(CI->getOperand(0));
3991 break;
3992 case Instruction::SExt:
3993 NewI = B.CreateSExtOrTrunc(
3994 CI->getOperand(0),
3995 smallestIntegerVectorType(OriginalTy, TruncatedTy));
3996 break;
3997 case Instruction::ZExt:
3998 NewI = B.CreateZExtOrTrunc(
3999 CI->getOperand(0),
4000 smallestIntegerVectorType(OriginalTy, TruncatedTy));
4001 break;
4002 }
4003 } else if (auto *SI = dyn_cast<ShuffleVectorInst>(I)) {
4004 auto Elements0 = cast<FixedVectorType>(SI->getOperand(0)->getType())
4005 ->getNumElements();
4006 auto *O0 = B.CreateZExtOrTrunc(
4007 SI->getOperand(0),
4008 FixedVectorType::get(ScalarTruncatedTy, Elements0));
4009 auto Elements1 = cast<FixedVectorType>(SI->getOperand(1)->getType())
4010 ->getNumElements();
4011 auto *O1 = B.CreateZExtOrTrunc(
4012 SI->getOperand(1),
4013 FixedVectorType::get(ScalarTruncatedTy, Elements1));
4014
4015 NewI = B.CreateShuffleVector(O0, O1, SI->getShuffleMask());
4016 } else if (isa<LoadInst>(I) || isa<PHINode>(I)) {
4017 // Don't do anything with the operands, just extend the result.
4018 continue;
4019 } else if (auto *IE = dyn_cast<InsertElementInst>(I)) {
4020 auto Elements = cast<FixedVectorType>(IE->getOperand(0)->getType())
4021 ->getNumElements();
4022 auto *O0 = B.CreateZExtOrTrunc(
4023 IE->getOperand(0),
4024 FixedVectorType::get(ScalarTruncatedTy, Elements));
4025 auto *O1 = B.CreateZExtOrTrunc(IE->getOperand(1), ScalarTruncatedTy);
4026 NewI = B.CreateInsertElement(O0, O1, IE->getOperand(2));
4027 } else if (auto *EE = dyn_cast<ExtractElementInst>(I)) {
4028 auto Elements = cast<FixedVectorType>(EE->getOperand(0)->getType())
4029 ->getNumElements();
4030 auto *O0 = B.CreateZExtOrTrunc(
4031 EE->getOperand(0),
4032 FixedVectorType::get(ScalarTruncatedTy, Elements));
4033 NewI = B.CreateExtractElement(O0, EE->getOperand(2));
4034 } else {
4035 // If we don't know what to do, be conservative and don't do anything.
4036 continue;
4037 }
4038
4039 // Lastly, extend the result.
4040 NewI->takeName(cast<Instruction>(I));
4041 Value *Res = B.CreateZExtOrTrunc(NewI, OriginalTy);
4042 I->replaceAllUsesWith(Res);
4043 cast<Instruction>(I)->eraseFromParent();
4044 Erased.insert(I);
4045 State.reset(Def, Res, Part);
4046 }
4047 }
4048
4049 // We'll have created a bunch of ZExts that are now parentless. Clean up.
4050 for (const auto &KV : Cost->getMinimalBitwidths()) {
4051 // If the value wasn't vectorized, we must maintain the original scalar
4052 // type. The absence of the value from State indicates that it
4053 // wasn't vectorized.
4054 VPValue *Def = State.Plan->getVPValue(KV.first);
4055 if (!State.hasAnyVectorValue(Def))
4056 continue;
4057 for (unsigned Part = 0; Part < UF; ++Part) {
4058 Value *I = State.get(Def, Part);
4059 ZExtInst *Inst = dyn_cast<ZExtInst>(I);
4060 if (Inst && Inst->use_empty()) {
4061 Value *NewI = Inst->getOperand(0);
4062 Inst->eraseFromParent();
4063 State.reset(Def, NewI, Part);
4064 }
4065 }
4066 }
4067}
4068
4069void InnerLoopVectorizer::fixVectorizedLoop(VPTransformState &State) {
4070 // Insert truncates and extends for any truncated instructions as hints to
4071 // InstCombine.
4072 if (VF.isVector())
4073 truncateToMinimalBitwidths(State);
4074
4075 // Fix widened non-induction PHIs by setting up the PHI operands.
4076 if (OrigPHIsToFix.size()) {
4077 assert(EnableVPlanNativePath &&(static_cast <bool> (EnableVPlanNativePath && "Unexpected non-induction PHIs for fixup in non VPlan-native path"
) ? void (0) : __assert_fail ("EnableVPlanNativePath && \"Unexpected non-induction PHIs for fixup in non VPlan-native path\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4078, __extension__ __PRETTY_FUNCTION__))
4078 "Unexpected non-induction PHIs for fixup in non VPlan-native path")(static_cast <bool> (EnableVPlanNativePath && "Unexpected non-induction PHIs for fixup in non VPlan-native path"
) ? void (0) : __assert_fail ("EnableVPlanNativePath && \"Unexpected non-induction PHIs for fixup in non VPlan-native path\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4078, __extension__ __PRETTY_FUNCTION__))
;
4079 fixNonInductionPHIs(State);
4080 }
4081
4082 // At this point every instruction in the original loop is widened to a
4083 // vector form. Now we need to fix the recurrences in the loop. These PHI
4084 // nodes are currently empty because we did not want to introduce cycles.
4085 // This is the second stage of vectorizing recurrences.
4086 fixCrossIterationPHIs(State);
4087
4088 // Forget the original basic block.
4089 PSE.getSE()->forgetLoop(OrigLoop);
4090
4091 // Fix-up external users of the induction variables.
4092 for (auto &Entry : Legal->getInductionVars())
4093 fixupIVUsers(Entry.first, Entry.second,
4094 getOrCreateVectorTripCount(LI->getLoopFor(LoopVectorBody)),
4095 IVEndValues[Entry.first], LoopMiddleBlock);
4096
4097 fixLCSSAPHIs(State);
4098 for (Instruction *PI : PredicatedInstructions)
4099 sinkScalarOperands(&*PI);
4100
4101 // Remove redundant induction instructions.
4102 cse(LoopVectorBody);
4103
4104 // Set/update profile weights for the vector and remainder loops as original
4105 // loop iterations are now distributed among them. Note that original loop
4106 // represented by LoopScalarBody becomes remainder loop after vectorization.
4107 //
4108 // For cases like foldTailByMasking() and requiresScalarEpiloque() we may
4109 // end up getting slightly roughened result but that should be OK since
4110 // profile is not inherently precise anyway. Note also possible bypass of
4111 // vector code caused by legality checks is ignored, assigning all the weight
4112 // to the vector loop, optimistically.
4113 //
4114 // For scalable vectorization we can't know at compile time how many iterations
4115 // of the loop are handled in one vector iteration, so instead assume a pessimistic
4116 // vscale of '1'.
4117 setProfileInfoAfterUnrolling(
4118 LI->getLoopFor(LoopScalarBody), LI->getLoopFor(LoopVectorBody),
4119 LI->getLoopFor(LoopScalarBody), VF.getKnownMinValue() * UF);
4120}
4121
4122void InnerLoopVectorizer::fixCrossIterationPHIs(VPTransformState &State) {
4123 // In order to support recurrences we need to be able to vectorize Phi nodes.
4124 // Phi nodes have cycles, so we need to vectorize them in two stages. This is
4125 // stage #2: We now need to fix the recurrences by adding incoming edges to
4126 // the currently empty PHI nodes. At this point every instruction in the
4127 // original loop is widened to a vector form so we can use them to construct
4128 // the incoming edges.
4129 VPBasicBlock *Header = State.Plan->getEntry()->getEntryBasicBlock();
4130 for (VPRecipeBase &R : Header->phis()) {
4131 auto *PhiR = dyn_cast<VPWidenPHIRecipe>(&R);
4132 if (!PhiR)
4133 continue;
4134 auto *OrigPhi = cast<PHINode>(PhiR->getUnderlyingValue());
4135 if (PhiR->getRecurrenceDescriptor()) {
4136 fixReduction(PhiR, State);
4137 } else if (Legal->isFirstOrderRecurrence(OrigPhi))
4138 fixFirstOrderRecurrence(OrigPhi, State);
4139 }
4140}
4141
4142void InnerLoopVectorizer::fixFirstOrderRecurrence(PHINode *Phi,
4143 VPTransformState &State) {
4144 // This is the second phase of vectorizing first-order recurrences. An
4145 // overview of the transformation is described below. Suppose we have the
4146 // following loop.
4147 //
4148 // for (int i = 0; i < n; ++i)
4149 // b[i] = a[i] - a[i - 1];
4150 //
4151 // There is a first-order recurrence on "a". For this loop, the shorthand
4152 // scalar IR looks like:
4153 //
4154 // scalar.ph:
4155 // s_init = a[-1]
4156 // br scalar.body
4157 //
4158 // scalar.body:
4159 // i = phi [0, scalar.ph], [i+1, scalar.body]
4160 // s1 = phi [s_init, scalar.ph], [s2, scalar.body]
4161 // s2 = a[i]
4162 // b[i] = s2 - s1
4163 // br cond, scalar.body, ...
4164 //
4165 // In this example, s1 is a recurrence because it's value depends on the
4166 // previous iteration. In the first phase of vectorization, we created a
4167 // temporary value for s1. We now complete the vectorization and produce the
4168 // shorthand vector IR shown below (for VF = 4, UF = 1).
4169 //
4170 // vector.ph:
4171 // v_init = vector(..., ..., ..., a[-1])
4172 // br vector.body
4173 //
4174 // vector.body
4175 // i = phi [0, vector.ph], [i+4, vector.body]
4176 // v1 = phi [v_init, vector.ph], [v2, vector.body]
4177 // v2 = a[i, i+1, i+2, i+3];
4178 // v3 = vector(v1(3), v2(0, 1, 2))
4179 // b[i, i+1, i+2, i+3] = v2 - v3
4180 // br cond, vector.body, middle.block
4181 //
4182 // middle.block:
4183 // x = v2(3)
4184 // br scalar.ph
4185 //
4186 // scalar.ph:
4187 // s_init = phi [x, middle.block], [a[-1], otherwise]
4188 // br scalar.body
4189 //
4190 // After execution completes the vector loop, we extract the next value of
4191 // the recurrence (x) to use as the initial value in the scalar loop.
4192
4193 // Get the original loop preheader and single loop latch.
4194 auto *Preheader = OrigLoop->getLoopPreheader();
4195 auto *Latch = OrigLoop->getLoopLatch();
4196
4197 // Get the initial and previous values of the scalar recurrence.
4198 auto *ScalarInit = Phi->getIncomingValueForBlock(Preheader);
4199 auto *Previous = Phi->getIncomingValueForBlock(Latch);
4200
4201 auto *IdxTy = Builder.getInt32Ty();
4202 auto *One = ConstantInt::get(IdxTy, 1);
4203
4204 // Create a vector from the initial value.
4205 auto *VectorInit = ScalarInit;
4206 if (VF.isVector()) {
4207 Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
4208 auto *RuntimeVF = getRuntimeVF(Builder, IdxTy, VF);
4209 auto *LastIdx = Builder.CreateSub(RuntimeVF, One);
4210 VectorInit = Builder.CreateInsertElement(
4211 PoisonValue::get(VectorType::get(VectorInit->getType(), VF)),
4212 VectorInit, LastIdx, "vector.recur.init");
4213 }
4214
4215 VPValue *PhiDef = State.Plan->getVPValue(Phi);
4216 VPValue *PreviousDef = State.Plan->getVPValue(Previous);
4217 // We constructed a temporary phi node in the first phase of vectorization.
4218 // This phi node will eventually be deleted.
4219 Builder.SetInsertPoint(cast<Instruction>(State.get(PhiDef, 0)));
4220
4221 // Create a phi node for the new recurrence. The current value will either be
4222 // the initial value inserted into a vector or loop-varying vector value.
4223 auto *VecPhi = Builder.CreatePHI(VectorInit->getType(), 2, "vector.recur");
4224 VecPhi->addIncoming(VectorInit, LoopVectorPreHeader);
4225
4226 // Get the vectorized previous value of the last part UF - 1. It appears last
4227 // among all unrolled iterations, due to the order of their construction.
4228 Value *PreviousLastPart = State.get(PreviousDef, UF - 1);
4229
4230 // Find and set the insertion point after the previous value if it is an
4231 // instruction.
4232 BasicBlock::iterator InsertPt;
4233 // Note that the previous value may have been constant-folded so it is not
4234 // guaranteed to be an instruction in the vector loop.
4235 // FIXME: Loop invariant values do not form recurrences. We should deal with
4236 // them earlier.
4237 if (LI->getLoopFor(LoopVectorBody)->isLoopInvariant(PreviousLastPart))
4238 InsertPt = LoopVectorBody->getFirstInsertionPt();
4239 else {
4240 Instruction *PreviousInst = cast<Instruction>(PreviousLastPart);
4241 if (isa<PHINode>(PreviousLastPart))
4242 // If the previous value is a phi node, we should insert after all the phi
4243 // nodes in the block containing the PHI to avoid breaking basic block
4244 // verification. Note that the basic block may be different to
4245 // LoopVectorBody, in case we predicate the loop.
4246 InsertPt = PreviousInst->getParent()->getFirstInsertionPt();
4247 else
4248 InsertPt = ++PreviousInst->getIterator();
4249 }
4250 Builder.SetInsertPoint(&*InsertPt);
4251
4252 // The vector from which to take the initial value for the current iteration
4253 // (actual or unrolled). Initially, this is the vector phi node.
4254 Value *Incoming = VecPhi;
4255
4256 // Shuffle the current and previous vector and update the vector parts.
4257 for (unsigned Part = 0; Part < UF; ++Part) {
4258 Value *PreviousPart = State.get(PreviousDef, Part);
4259 Value *PhiPart = State.get(PhiDef, Part);
4260 auto *Shuffle = VF.isVector()
4261 ? Builder.CreateVectorSplice(Incoming, PreviousPart, -1)
4262 : Incoming;
4263 PhiPart->replaceAllUsesWith(Shuffle);
4264 cast<Instruction>(PhiPart)->eraseFromParent();
4265 State.reset(PhiDef, Shuffle, Part);
4266 Incoming = PreviousPart;
4267 }
4268
4269 // Fix the latch value of the new recurrence in the vector loop.
4270 VecPhi->addIncoming(Incoming, LI->getLoopFor(LoopVectorBody)->getLoopLatch());
4271
4272 // Extract the last vector element in the middle block. This will be the
4273 // initial value for the recurrence when jumping to the scalar loop.
4274 auto *ExtractForScalar = Incoming;
4275 if (VF.isVector()) {
4276 Builder.SetInsertPoint(LoopMiddleBlock->getTerminator());
4277 auto *RuntimeVF = getRuntimeVF(Builder, IdxTy, VF);
4278 auto *LastIdx = Builder.CreateSub(RuntimeVF, One);
4279 ExtractForScalar = Builder.CreateExtractElement(ExtractForScalar, LastIdx,
4280 "vector.recur.extract");
4281 }
4282 // Extract the second last element in the middle block if the
4283 // Phi is used outside the loop. We need to extract the phi itself
4284 // and not the last element (the phi update in the current iteration). This
4285 // will be the value when jumping to the exit block from the LoopMiddleBlock,
4286 // when the scalar loop is not run at all.
4287 Value *ExtractForPhiUsedOutsideLoop = nullptr;
4288 if (VF.isVector()) {
4289 auto *RuntimeVF = getRuntimeVF(Builder, IdxTy, VF);
4290 auto *Idx = Builder.CreateSub(RuntimeVF, ConstantInt::get(IdxTy, 2));
4291 ExtractForPhiUsedOutsideLoop = Builder.CreateExtractElement(
4292 Incoming, Idx, "vector.recur.extract.for.phi");
4293 } else if (UF > 1)
4294 // When loop is unrolled without vectorizing, initialize
4295 // ExtractForPhiUsedOutsideLoop with the value just prior to unrolled value
4296 // of `Incoming`. This is analogous to the vectorized case above: extracting
4297 // the second last element when VF > 1.
4298 ExtractForPhiUsedOutsideLoop = State.get(PreviousDef, UF - 2);
4299
4300 // Fix the initial value of the original recurrence in the scalar loop.
4301 Builder.SetInsertPoint(&*LoopScalarPreHeader->begin());
4302 auto *Start = Builder.CreatePHI(Phi->getType(), 2, "scalar.recur.init");
4303 for (auto *BB : predecessors(LoopScalarPreHeader)) {
4304 auto *Incoming = BB == LoopMiddleBlock ? ExtractForScalar : ScalarInit;
4305 Start->addIncoming(Incoming, BB);
4306 }
4307
4308 Phi->setIncomingValueForBlock(LoopScalarPreHeader, Start);
4309 Phi->setName("scalar.recur");
4310
4311 // Finally, fix users of the recurrence outside the loop. The users will need
4312 // either the last value of the scalar recurrence or the last value of the
4313 // vector recurrence we extracted in the middle block. Since the loop is in
4314 // LCSSA form, we just need to find all the phi nodes for the original scalar
4315 // recurrence in the exit block, and then add an edge for the middle block.
4316 // Note that LCSSA does not imply single entry when the original scalar loop
4317 // had multiple exiting edges (as we always run the last iteration in the
4318 // scalar epilogue); in that case, the exiting path through middle will be
4319 // dynamically dead and the value picked for the phi doesn't matter.
4320 for (PHINode &LCSSAPhi : LoopExitBlock->phis())
4321 if (any_of(LCSSAPhi.incoming_values(),
4322 [Phi](Value *V) { return V == Phi; }))
4323 LCSSAPhi.addIncoming(ExtractForPhiUsedOutsideLoop, LoopMiddleBlock);
4324}
4325
4326void InnerLoopVectorizer::fixReduction(VPWidenPHIRecipe *PhiR,
4327 VPTransformState &State) {
4328 PHINode *OrigPhi = cast<PHINode>(PhiR->getUnderlyingValue());
4329 // Get it's reduction variable descriptor.
4330 assert(Legal->isReductionVariable(OrigPhi) &&(static_cast <bool> (Legal->isReductionVariable(OrigPhi
) && "Unable to find the reduction variable") ? void (
0) : __assert_fail ("Legal->isReductionVariable(OrigPhi) && \"Unable to find the reduction variable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4331, __extension__ __PRETTY_FUNCTION__))
4331 "Unable to find the reduction variable")(static_cast <bool> (Legal->isReductionVariable(OrigPhi
) && "Unable to find the reduction variable") ? void (
0) : __assert_fail ("Legal->isReductionVariable(OrigPhi) && \"Unable to find the reduction variable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4331, __extension__ __PRETTY_FUNCTION__))
;
4332 const RecurrenceDescriptor &RdxDesc = *PhiR->getRecurrenceDescriptor();
4333
4334 RecurKind RK = RdxDesc.getRecurrenceKind();
4335 TrackingVH<Value> ReductionStartValue = RdxDesc.getRecurrenceStartValue();
4336 Instruction *LoopExitInst = RdxDesc.getLoopExitInstr();
4337 setDebugLocFromInst(Builder, ReductionStartValue);
4338 bool IsInLoopReductionPhi = Cost->isInLoopReduction(OrigPhi);
4339
4340 VPValue *LoopExitInstDef = State.Plan->getVPValue(LoopExitInst);
4341 // This is the vector-clone of the value that leaves the loop.
4342 Type *VecTy = State.get(LoopExitInstDef, 0)->getType();
4343
4344 // Wrap flags are in general invalid after vectorization, clear them.
4345 clearReductionWrapFlags(RdxDesc, State);
4346
4347 // Fix the vector-loop phi.
4348
4349 // Reductions do not have to start at zero. They can start with
4350 // any loop invariant values.
4351 BasicBlock *VectorLoopLatch = LI->getLoopFor(LoopVectorBody)->getLoopLatch();
4352
4353 bool IsOrdered = State.VF.isVector() && IsInLoopReductionPhi &&
4354 Cost->useOrderedReductions(RdxDesc);
4355
4356 for (unsigned Part = 0; Part < UF; ++Part) {
4357 if (IsOrdered && Part > 0)
4358 break;
4359 Value *VecRdxPhi = State.get(PhiR->getVPSingleValue(), Part);
4360 Value *Val = State.get(PhiR->getBackedgeValue(), Part);
4361 if (IsOrdered)
4362 Val = State.get(PhiR->getBackedgeValue(), UF - 1);
4363
4364 cast<PHINode>(VecRdxPhi)->addIncoming(Val, VectorLoopLatch);
4365 }
4366
4367 // Before each round, move the insertion point right between
4368 // the PHIs and the values we are going to write.
4369 // This allows us to write both PHINodes and the extractelement
4370 // instructions.
4371 Builder.SetInsertPoint(&*LoopMiddleBlock->getFirstInsertionPt());
4372
4373 setDebugLocFromInst(Builder, LoopExitInst);
4374
4375 Type *PhiTy = OrigPhi->getType();
4376 // If tail is folded by masking, the vector value to leave the loop should be
4377 // a Select choosing between the vectorized LoopExitInst and vectorized Phi,
4378 // instead of the former. For an inloop reduction the reduction will already
4379 // be predicated, and does not need to be handled here.
4380 if (Cost->foldTailByMasking() && !IsInLoopReductionPhi) {
4381 for (unsigned Part = 0; Part < UF; ++Part) {
4382 Value *VecLoopExitInst = State.get(LoopExitInstDef, Part);
4383 Value *Sel = nullptr;
4384 for (User *U : VecLoopExitInst->users()) {
4385 if (isa<SelectInst>(U)) {
4386 assert(!Sel && "Reduction exit feeding two selects")(static_cast <bool> (!Sel && "Reduction exit feeding two selects"
) ? void (0) : __assert_fail ("!Sel && \"Reduction exit feeding two selects\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4386, __extension__ __PRETTY_FUNCTION__))
;
4387 Sel = U;
4388 } else
4389 assert(isa<PHINode>(U) && "Reduction exit must feed Phi's or select")(static_cast <bool> (isa<PHINode>(U) && "Reduction exit must feed Phi's or select"
) ? void (0) : __assert_fail ("isa<PHINode>(U) && \"Reduction exit must feed Phi's or select\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4389, __extension__ __PRETTY_FUNCTION__))
;
4390 }
4391 assert(Sel && "Reduction exit feeds no select")(static_cast <bool> (Sel && "Reduction exit feeds no select"
) ? void (0) : __assert_fail ("Sel && \"Reduction exit feeds no select\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4391, __extension__ __PRETTY_FUNCTION__))
;
4392 State.reset(LoopExitInstDef, Sel, Part);
4393
4394 // If the target can create a predicated operator for the reduction at no
4395 // extra cost in the loop (for example a predicated vadd), it can be
4396 // cheaper for the select to remain in the loop than be sunk out of it,
4397 // and so use the select value for the phi instead of the old
4398 // LoopExitValue.
4399 if (PreferPredicatedReductionSelect ||
4400 TTI->preferPredicatedReductionSelect(
4401 RdxDesc.getOpcode(), PhiTy,
4402 TargetTransformInfo::ReductionFlags())) {
4403 auto *VecRdxPhi =
4404 cast<PHINode>(State.get(PhiR->getVPSingleValue(), Part));
4405 VecRdxPhi->setIncomingValueForBlock(
4406 LI->getLoopFor(LoopVectorBody)->getLoopLatch(), Sel);
4407 }
4408 }
4409 }
4410
4411 // If the vector reduction can be performed in a smaller type, we truncate
4412 // then extend the loop exit value to enable InstCombine to evaluate the
4413 // entire expression in the smaller type.
4414 if (VF.isVector() && PhiTy != RdxDesc.getRecurrenceType()) {
4415 assert(!IsInLoopReductionPhi && "Unexpected truncated inloop reduction!")(static_cast <bool> (!IsInLoopReductionPhi && "Unexpected truncated inloop reduction!"
) ? void (0) : __assert_fail ("!IsInLoopReductionPhi && \"Unexpected truncated inloop reduction!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4415, __extension__ __PRETTY_FUNCTION__))
;
4416 Type *RdxVecTy = VectorType::get(RdxDesc.getRecurrenceType(), VF);
4417 Builder.SetInsertPoint(
4418 LI->getLoopFor(LoopVectorBody)->getLoopLatch()->getTerminator());
4419 VectorParts RdxParts(UF);
4420 for (unsigned Part = 0; Part < UF; ++Part) {
4421 RdxParts[Part] = State.get(LoopExitInstDef, Part);
4422 Value *Trunc = Builder.CreateTrunc(RdxParts[Part], RdxVecTy);
4423 Value *Extnd = RdxDesc.isSigned() ? Builder.CreateSExt(Trunc, VecTy)
4424 : Builder.CreateZExt(Trunc, VecTy);
4425 for (Value::user_iterator UI = RdxParts[Part]->user_begin();
4426 UI != RdxParts[Part]->user_end();)
4427 if (*UI != Trunc) {
4428 (*UI++)->replaceUsesOfWith(RdxParts[Part], Extnd);
4429 RdxParts[Part] = Extnd;
4430 } else {
4431 ++UI;
4432 }
4433 }
4434 Builder.SetInsertPoint(&*LoopMiddleBlock->getFirstInsertionPt());
4435 for (unsigned Part = 0; Part < UF; ++Part) {
4436 RdxParts[Part] = Builder.CreateTrunc(RdxParts[Part], RdxVecTy);
4437 State.reset(LoopExitInstDef, RdxParts[Part], Part);
4438 }
4439 }
4440
4441 // Reduce all of the unrolled parts into a single vector.
4442 Value *ReducedPartRdx = State.get(LoopExitInstDef, 0);
4443 unsigned Op = RecurrenceDescriptor::getOpcode(RK);
4444
4445 // The middle block terminator has already been assigned a DebugLoc here (the
4446 // OrigLoop's single latch terminator). We want the whole middle block to
4447 // appear to execute on this line because: (a) it is all compiler generated,
4448 // (b) these instructions are always executed after evaluating the latch
4449 // conditional branch, and (c) other passes may add new predecessors which
4450 // terminate on this line. This is the easiest way to ensure we don't
4451 // accidentally cause an extra step back into the loop while debugging.
4452 setDebugLocFromInst(Builder, LoopMiddleBlock->getTerminator());
4453 if (IsOrdered)
4454 ReducedPartRdx = State.get(LoopExitInstDef, UF - 1);
4455 else {
4456 // Floating-point operations should have some FMF to enable the reduction.
4457 IRBuilderBase::FastMathFlagGuard FMFG(Builder);
4458 Builder.setFastMathFlags(RdxDesc.getFastMathFlags());
4459 for (unsigned Part = 1; Part < UF; ++Part) {
4460 Value *RdxPart = State.get(LoopExitInstDef, Part);
4461 if (Op != Instruction::ICmp && Op != Instruction::FCmp) {
4462 ReducedPartRdx = Builder.CreateBinOp(
4463 (Instruction::BinaryOps)Op, RdxPart, ReducedPartRdx, "bin.rdx");
4464 } else {
4465 ReducedPartRdx = createMinMaxOp(Builder, RK, ReducedPartRdx, RdxPart);
4466 }
4467 }
4468 }
4469
4470 // Create the reduction after the loop. Note that inloop reductions create the
4471 // target reduction in the loop using a Reduction recipe.
4472 if (VF.isVector() && !IsInLoopReductionPhi) {
4473 ReducedPartRdx =
4474 createTargetReduction(Builder, TTI, RdxDesc, ReducedPartRdx);
4475 // If the reduction can be performed in a smaller type, we need to extend
4476 // the reduction to the wider type before we branch to the original loop.
4477 if (PhiTy != RdxDesc.getRecurrenceType())
4478 ReducedPartRdx = RdxDesc.isSigned()
4479 ? Builder.CreateSExt(ReducedPartRdx, PhiTy)
4480 : Builder.CreateZExt(ReducedPartRdx, PhiTy);
4481 }
4482
4483 // Create a phi node that merges control-flow from the backedge-taken check
4484 // block and the middle block.
4485 PHINode *BCBlockPhi = PHINode::Create(PhiTy, 2, "bc.merge.rdx",
4486 LoopScalarPreHeader->getTerminator());
4487 for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I)
4488 BCBlockPhi->addIncoming(ReductionStartValue, LoopBypassBlocks[I]);
4489 BCBlockPhi->addIncoming(ReducedPartRdx, LoopMiddleBlock);
4490
4491 // Now, we need to fix the users of the reduction variable
4492 // inside and outside of the scalar remainder loop.
4493
4494 // We know that the loop is in LCSSA form. We need to update the PHI nodes
4495 // in the exit blocks. See comment on analogous loop in
4496 // fixFirstOrderRecurrence for a more complete explaination of the logic.
4497 for (PHINode &LCSSAPhi : LoopExitBlock->phis())
4498 if (any_of(LCSSAPhi.incoming_values(),
4499 [LoopExitInst](Value *V) { return V == LoopExitInst; }))
4500 LCSSAPhi.addIncoming(ReducedPartRdx, LoopMiddleBlock);
4501
4502 // Fix the scalar loop reduction variable with the incoming reduction sum
4503 // from the vector body and from the backedge value.
4504 int IncomingEdgeBlockIdx =
4505 OrigPhi->getBasicBlockIndex(OrigLoop->getLoopLatch());
4506 assert(IncomingEdgeBlockIdx >= 0 && "Invalid block index")(static_cast <bool> (IncomingEdgeBlockIdx >= 0 &&
"Invalid block index") ? void (0) : __assert_fail ("IncomingEdgeBlockIdx >= 0 && \"Invalid block index\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4506, __extension__ __PRETTY_FUNCTION__))
;
4507 // Pick the other block.
4508 int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1);
4509 OrigPhi->setIncomingValue(SelfEdgeBlockIdx, BCBlockPhi);
4510 OrigPhi->setIncomingValue(IncomingEdgeBlockIdx, LoopExitInst);
4511}
4512
4513void InnerLoopVectorizer::clearReductionWrapFlags(const RecurrenceDescriptor &RdxDesc,
4514 VPTransformState &State) {
4515 RecurKind RK = RdxDesc.getRecurrenceKind();
4516 if (RK != RecurKind::Add && RK != RecurKind::Mul)
4517 return;
4518
4519 Instruction *LoopExitInstr = RdxDesc.getLoopExitInstr();
4520 assert(LoopExitInstr && "null loop exit instruction")(static_cast <bool> (LoopExitInstr && "null loop exit instruction"
) ? void (0) : __assert_fail ("LoopExitInstr && \"null loop exit instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4520, __extension__ __PRETTY_FUNCTION__))
;
4521 SmallVector<Instruction *, 8> Worklist;
4522 SmallPtrSet<Instruction *, 8> Visited;
4523 Worklist.push_back(LoopExitInstr);
4524 Visited.insert(LoopExitInstr);
4525
4526 while (!Worklist.empty()) {
4527 Instruction *Cur = Worklist.pop_back_val();
4528 if (isa<OverflowingBinaryOperator>(Cur))
4529 for (unsigned Part = 0; Part < UF; ++Part) {
4530 Value *V = State.get(State.Plan->getVPValue(Cur), Part);
4531 cast<Instruction>(V)->dropPoisonGeneratingFlags();
4532 }
4533
4534 for (User *U : Cur->users()) {
4535 Instruction *UI = cast<Instruction>(U);
4536 if ((Cur != LoopExitInstr || OrigLoop->contains(UI->getParent())) &&
4537 Visited.insert(UI).second)
4538 Worklist.push_back(UI);
4539 }
4540 }
4541}
4542
4543void InnerLoopVectorizer::fixLCSSAPHIs(VPTransformState &State) {
4544 for (PHINode &LCSSAPhi : LoopExitBlock->phis()) {
4545 if (LCSSAPhi.getBasicBlockIndex(LoopMiddleBlock) != -1)
4546 // Some phis were already hand updated by the reduction and recurrence
4547 // code above, leave them alone.
4548 continue;
4549
4550 auto *IncomingValue = LCSSAPhi.getIncomingValue(0);
4551 // Non-instruction incoming values will have only one value.
4552
4553 VPLane Lane = VPLane::getFirstLane();
4554 if (isa<Instruction>(IncomingValue) &&
4555 !Cost->isUniformAfterVectorization(cast<Instruction>(IncomingValue),
4556 VF))
4557 Lane = VPLane::getLastLaneForVF(VF);
4558
4559 // Can be a loop invariant incoming value or the last scalar value to be
4560 // extracted from the vectorized loop.
4561 Builder.SetInsertPoint(LoopMiddleBlock->getTerminator());
4562 Value *lastIncomingValue =
4563 OrigLoop->isLoopInvariant(IncomingValue)
4564 ? IncomingValue
4565 : State.get(State.Plan->getVPValue(IncomingValue),
4566 VPIteration(UF - 1, Lane));
4567 LCSSAPhi.addIncoming(lastIncomingValue, LoopMiddleBlock);
4568 }
4569}
4570
4571void InnerLoopVectorizer::sinkScalarOperands(Instruction *PredInst) {
4572 // The basic block and loop containing the predicated instruction.
4573 auto *PredBB = PredInst->getParent();
4574 auto *VectorLoop = LI->getLoopFor(PredBB);
4575
4576 // Initialize a worklist with the operands of the predicated instruction.
4577 SetVector<Value *> Worklist(PredInst->op_begin(), PredInst->op_end());
4578
4579 // Holds instructions that we need to analyze again. An instruction may be
4580 // reanalyzed if we don't yet know if we can sink it or not.
4581 SmallVector<Instruction *, 8> InstsToReanalyze;
4582
4583 // Returns true if a given use occurs in the predicated block. Phi nodes use
4584 // their operands in their corresponding predecessor blocks.
4585 auto isBlockOfUsePredicated = [&](Use &U) -> bool {
4586 auto *I = cast<Instruction>(U.getUser());
4587 BasicBlock *BB = I->getParent();
4588 if (auto *Phi = dyn_cast<PHINode>(I))
4589 BB = Phi->getIncomingBlock(
4590 PHINode::getIncomingValueNumForOperand(U.getOperandNo()));
4591 return BB == PredBB;
4592 };
4593
4594 // Iteratively sink the scalarized operands of the predicated instruction
4595 // into the block we created for it. When an instruction is sunk, it's
4596 // operands are then added to the worklist. The algorithm ends after one pass
4597 // through the worklist doesn't sink a single instruction.
4598 bool Changed;
4599 do {
4600 // Add the instructions that need to be reanalyzed to the worklist, and
4601 // reset the changed indicator.
4602 Worklist.insert(InstsToReanalyze.begin(), InstsToReanalyze.end());
4603 InstsToReanalyze.clear();
4604 Changed = false;
4605
4606 while (!Worklist.empty()) {
4607 auto *I = dyn_cast<Instruction>(Worklist.pop_back_val());
4608
4609 // We can't sink an instruction if it is a phi node, is not in the loop,
4610 // or may have side effects.
4611 if (!I || isa<PHINode>(I) || !VectorLoop->contains(I) ||
4612 I->mayHaveSideEffects())
4613 continue;
4614
4615 // If the instruction is already in PredBB, check if we can sink its
4616 // operands. In that case, VPlan's sinkScalarOperands() succeeded in
4617 // sinking the scalar instruction I, hence it appears in PredBB; but it
4618 // may have failed to sink I's operands (recursively), which we try
4619 // (again) here.
4620 if (I->getParent() == PredBB) {
4621 Worklist.insert(I->op_begin(), I->op_end());
4622 continue;
4623 }
4624
4625 // It's legal to sink the instruction if all its uses occur in the
4626 // predicated block. Otherwise, there's nothing to do yet, and we may
4627 // need to reanalyze the instruction.
4628 if (!llvm::all_of(I->uses(), isBlockOfUsePredicated)) {
4629 InstsToReanalyze.push_back(I);
4630 continue;
4631 }
4632
4633 // Move the instruction to the beginning of the predicated block, and add
4634 // it's operands to the worklist.
4635 I->moveBefore(&*PredBB->getFirstInsertionPt());
4636 Worklist.insert(I->op_begin(), I->op_end());
4637
4638 // The sinking may have enabled other instructions to be sunk, so we will
4639 // need to iterate.
4640 Changed = true;
4641 }
4642 } while (Changed);
4643}
4644
4645void InnerLoopVectorizer::fixNonInductionPHIs(VPTransformState &State) {
4646 for (PHINode *OrigPhi : OrigPHIsToFix) {
4647 VPWidenPHIRecipe *VPPhi =
4648 cast<VPWidenPHIRecipe>(State.Plan->getVPValue(OrigPhi));
4649 PHINode *NewPhi = cast<PHINode>(State.get(VPPhi, 0));
4650 // Make sure the builder has a valid insert point.
4651 Builder.SetInsertPoint(NewPhi);
4652 for (unsigned i = 0; i < VPPhi->getNumOperands(); ++i) {
4653 VPValue *Inc = VPPhi->getIncomingValue(i);
4654 VPBasicBlock *VPBB = VPPhi->getIncomingBlock(i);
4655 NewPhi->addIncoming(State.get(Inc, 0), State.CFG.VPBB2IRBB[VPBB]);
4656 }
4657 }
4658}
4659
4660bool InnerLoopVectorizer::useOrderedReductions(RecurrenceDescriptor &RdxDesc) {
4661 return Cost->useOrderedReductions(RdxDesc);
4662}
4663
4664void InnerLoopVectorizer::widenGEP(GetElementPtrInst *GEP, VPValue *VPDef,
4665 VPUser &Operands, unsigned UF,
4666 ElementCount VF, bool IsPtrLoopInvariant,
4667 SmallBitVector &IsIndexLoopInvariant,
4668 VPTransformState &State) {
4669 // Construct a vector GEP by widening the operands of the scalar GEP as
4670 // necessary. We mark the vector GEP 'inbounds' if appropriate. A GEP
4671 // results in a vector of pointers when at least one operand of the GEP
4672 // is vector-typed. Thus, to keep the representation compact, we only use
4673 // vector-typed operands for loop-varying values.
4674
4675 if (VF.isVector() && IsPtrLoopInvariant && IsIndexLoopInvariant.all()) {
4676 // If we are vectorizing, but the GEP has only loop-invariant operands,
4677 // the GEP we build (by only using vector-typed operands for
4678 // loop-varying values) would be a scalar pointer. Thus, to ensure we
4679 // produce a vector of pointers, we need to either arbitrarily pick an
4680 // operand to broadcast, or broadcast a clone of the original GEP.
4681 // Here, we broadcast a clone of the original.
4682 //
4683 // TODO: If at some point we decide to scalarize instructions having
4684 // loop-invariant operands, this special case will no longer be
4685 // required. We would add the scalarization decision to
4686 // collectLoopScalars() and teach getVectorValue() to broadcast
4687 // the lane-zero scalar value.
4688 auto *Clone = Builder.Insert(GEP->clone());
4689 for (unsigned Part = 0; Part < UF; ++Part) {
4690 Value *EntryPart = Builder.CreateVectorSplat(VF, Clone);
4691 State.set(VPDef, EntryPart, Part);
4692 addMetadata(EntryPart, GEP);
4693 }
4694 } else {
4695 // If the GEP has at least one loop-varying operand, we are sure to
4696 // produce a vector of pointers. But if we are only unrolling, we want
4697 // to produce a scalar GEP for each unroll part. Thus, the GEP we
4698 // produce with the code below will be scalar (if VF == 1) or vector
4699 // (otherwise). Note that for the unroll-only case, we still maintain
4700 // values in the vector mapping with initVector, as we do for other
4701 // instructions.
4702 for (unsigned Part = 0; Part < UF; ++Part) {
4703 // The pointer operand of the new GEP. If it's loop-invariant, we
4704 // won't broadcast it.
4705 auto *Ptr = IsPtrLoopInvariant
4706 ? State.get(Operands.getOperand(0), VPIteration(0, 0))
4707 : State.get(Operands.getOperand(0), Part);
4708
4709 // Collect all the indices for the new GEP. If any index is
4710 // loop-invariant, we won't broadcast it.
4711 SmallVector<Value *, 4> Indices;
4712 for (unsigned I = 1, E = Operands.getNumOperands(); I < E; I++) {
4713 VPValue *Operand = Operands.getOperand(I);
4714 if (IsIndexLoopInvariant[I - 1])
4715 Indices.push_back(State.get(Operand, VPIteration(0, 0)));
4716 else
4717 Indices.push_back(State.get(Operand, Part));
4718 }
4719
4720 // Create the new GEP. Note that this GEP may be a scalar if VF == 1,
4721 // but it should be a vector, otherwise.
4722 auto *NewGEP =
4723 GEP->isInBounds()
4724 ? Builder.CreateInBoundsGEP(GEP->getSourceElementType(), Ptr,
4725 Indices)
4726 : Builder.CreateGEP(GEP->getSourceElementType(), Ptr, Indices);
4727 assert((VF.isScalar() || NewGEP->getType()->isVectorTy()) &&(static_cast <bool> ((VF.isScalar() || NewGEP->getType
()->isVectorTy()) && "NewGEP is not a pointer vector"
) ? void (0) : __assert_fail ("(VF.isScalar() || NewGEP->getType()->isVectorTy()) && \"NewGEP is not a pointer vector\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4728, __extension__ __PRETTY_FUNCTION__))
4728 "NewGEP is not a pointer vector")(static_cast <bool> ((VF.isScalar() || NewGEP->getType
()->isVectorTy()) && "NewGEP is not a pointer vector"
) ? void (0) : __assert_fail ("(VF.isScalar() || NewGEP->getType()->isVectorTy()) && \"NewGEP is not a pointer vector\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4728, __extension__ __PRETTY_FUNCTION__))
;
4729 State.set(VPDef, NewGEP, Part);
4730 addMetadata(NewGEP, GEP);
4731 }
4732 }
4733}
4734
4735void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN,
4736 RecurrenceDescriptor *RdxDesc,
4737 VPWidenPHIRecipe *PhiR,
4738 VPTransformState &State) {
4739 PHINode *P = cast<PHINode>(PN);
4
'PN' is a 'PHINode'
4740 if (EnableVPlanNativePath) {
5
Assuming the condition is false
6
Taking false branch
4741 // Currently we enter here in the VPlan-native path for non-induction
4742 // PHIs where all control flow is uniform. We simply widen these PHIs.
4743 // Create a vector phi with no operands - the vector phi operands will be
4744 // set at the end of vector code generation.
4745 Type *VecTy = (State.VF.isScalar())
4746 ? PN->getType()
4747 : VectorType::get(PN->getType(), State.VF);
4748 Value *VecPhi = Builder.CreatePHI(VecTy, PN->getNumOperands(), "vec.phi");
4749 State.set(PhiR, VecPhi, 0);
4750 OrigPHIsToFix.push_back(P);
4751
4752 return;
4753 }
4754
4755 assert(PN->getParent() == OrigLoop->getHeader() &&(static_cast <bool> (PN->getParent() == OrigLoop->
getHeader() && "Non-header phis should have been handled elsewhere"
) ? void (0) : __assert_fail ("PN->getParent() == OrigLoop->getHeader() && \"Non-header phis should have been handled elsewhere\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4756, __extension__ __PRETTY_FUNCTION__))
7
Assuming the condition is true
8
'?' condition is true
4756 "Non-header phis should have been handled elsewhere")(static_cast <bool> (PN->getParent() == OrigLoop->
getHeader() && "Non-header phis should have been handled elsewhere"
) ? void (0) : __assert_fail ("PN->getParent() == OrigLoop->getHeader() && \"Non-header phis should have been handled elsewhere\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4756, __extension__ __PRETTY_FUNCTION__))
;
4757
4758 VPValue *StartVPV = PhiR->getStartValue();
4759 Value *StartV = StartVPV
8.1
'StartVPV' is null
8.1
'StartVPV' is null
? StartVPV->getLiveInIRValue() : nullptr;
9
'?' condition is false
4760 // In order to support recurrences we need to be able to vectorize Phi nodes.
4761 // Phi nodes have cycles, so we need to vectorize them in two stages. This is
4762 // stage #1: We create a new vector PHI node with no incoming edges. We'll use
4763 // this value when we vectorize all of the instructions that use the PHI.
4764 if (RdxDesc || Legal->isFirstOrderRecurrence(P)) {
10
Assuming 'RdxDesc' is null
11
Assuming the condition is true
12
Taking true branch
4765 Value *Iden = nullptr;
4766 bool ScalarPHI =
4767 (State.VF.isScalar()) || Cost->isInLoopReduction(cast<PHINode>(PN));
13
'PN' is a 'PHINode'
4768 Type *VecTy =
4769 ScalarPHI ? PN->getType() : VectorType::get(PN->getType(), State.VF);
14
Assuming 'ScalarPHI' is true
15
'?' condition is true
4770
4771 if (RdxDesc
15.1
'RdxDesc' is null
15.1
'RdxDesc' is null
) {
16
Taking false branch
4772 assert(Legal->isReductionVariable(P) && StartV &&(static_cast <bool> (Legal->isReductionVariable(P) &&
StartV && "RdxDesc should only be set for reduction variables; in that case "
"a StartV is also required") ? void (0) : __assert_fail ("Legal->isReductionVariable(P) && StartV && \"RdxDesc should only be set for reduction variables; in that case \" \"a StartV is also required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4774, __extension__ __PRETTY_FUNCTION__))
4773 "RdxDesc should only be set for reduction variables; in that case "(static_cast <bool> (Legal->isReductionVariable(P) &&
StartV && "RdxDesc should only be set for reduction variables; in that case "
"a StartV is also required") ? void (0) : __assert_fail ("Legal->isReductionVariable(P) && StartV && \"RdxDesc should only be set for reduction variables; in that case \" \"a StartV is also required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4774, __extension__ __PRETTY_FUNCTION__))
4774 "a StartV is also required")(static_cast <bool> (Legal->isReductionVariable(P) &&
StartV && "RdxDesc should only be set for reduction variables; in that case "
"a StartV is also required") ? void (0) : __assert_fail ("Legal->isReductionVariable(P) && StartV && \"RdxDesc should only be set for reduction variables; in that case \" \"a StartV is also required\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4774, __extension__ __PRETTY_FUNCTION__))
;
4775 RecurKind RK = RdxDesc->getRecurrenceKind();
4776 if (RecurrenceDescriptor::isMinMaxRecurrenceKind(RK)) {
4777 // MinMax reduction have the start value as their identify.
4778 if (ScalarPHI) {
4779 Iden = StartV;
4780 } else {
4781 IRBuilderBase::InsertPointGuard IPBuilder(Builder);
4782 Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
4783 StartV = Iden =
4784 Builder.CreateVectorSplat(State.VF, StartV, "minmax.ident");
4785 }
4786 } else {
4787 Constant *IdenC = RecurrenceDescriptor::getRecurrenceIdentity(
4788 RK, VecTy->getScalarType(), RdxDesc->getFastMathFlags());
4789 Iden = IdenC;
4790
4791 if (!ScalarPHI) {
4792 Iden = ConstantVector::getSplat(State.VF, IdenC);
4793 IRBuilderBase::InsertPointGuard IPBuilder(Builder);
4794 Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
4795 Constant *Zero = Builder.getInt32(0);
4796 StartV = Builder.CreateInsertElement(Iden, StartV, Zero);
4797 }
4798 }
4799 }
4800
4801 bool IsOrdered = State.VF.isVector() &&
17
Calling 'ElementCount::isVector'
20
Returning from 'ElementCount::isVector'
4802 Cost->isInLoopReduction(cast<PHINode>(PN)) &&
21
'PN' is a 'PHINode'
22
Assuming the condition is true
4803 Cost->useOrderedReductions(*RdxDesc);
23
Forming reference to null pointer
4804 unsigned LastPartForNewPhi = IsOrdered ? 1 : State.UF;
4805 for (unsigned Part = 0; Part < LastPartForNewPhi; ++Part) {
4806 Value *EntryPart = PHINode::Create(
4807 VecTy, 2, "vec.phi", &*LoopVectorBody->getFirstInsertionPt());
4808 State.set(PhiR, EntryPart, Part);
4809 if (StartV) {
4810 // Make sure to add the reduction start value only to the
4811 // first unroll part.
4812 Value *StartVal = (Part == 0) ? StartV : Iden;
4813 cast<PHINode>(EntryPart)->addIncoming(StartVal, LoopVectorPreHeader);
4814 }
4815 }
4816 return;
4817 }
4818
4819 assert(!Legal->isReductionVariable(P) &&(static_cast <bool> (!Legal->isReductionVariable(P) &&
"reductions should be handled above") ? void (0) : __assert_fail
("!Legal->isReductionVariable(P) && \"reductions should be handled above\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4820, __extension__ __PRETTY_FUNCTION__))
4820 "reductions should be handled above")(static_cast <bool> (!Legal->isReductionVariable(P) &&
"reductions should be handled above") ? void (0) : __assert_fail
("!Legal->isReductionVariable(P) && \"reductions should be handled above\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4820, __extension__ __PRETTY_FUNCTION__))
;
4821
4822 setDebugLocFromInst(Builder, P);
4823
4824 // This PHINode must be an induction variable.
4825 // Make sure that we know about it.
4826 assert(Legal->getInductionVars().count(P) && "Not an induction variable")(static_cast <bool> (Legal->getInductionVars().count
(P) && "Not an induction variable") ? void (0) : __assert_fail
("Legal->getInductionVars().count(P) && \"Not an induction variable\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4826, __extension__ __PRETTY_FUNCTION__))
;
4827
4828 InductionDescriptor II = Legal->getInductionVars().lookup(P);
4829 const DataLayout &DL = OrigLoop->getHeader()->getModule()->getDataLayout();
4830
4831 // FIXME: The newly created binary instructions should contain nsw/nuw flags,
4832 // which can be found from the original scalar operations.
4833 switch (II.getKind()) {
4834 case InductionDescriptor::IK_NoInduction:
4835 llvm_unreachable("Unknown induction")::llvm::llvm_unreachable_internal("Unknown induction", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4835)
;
4836 case InductionDescriptor::IK_IntInduction:
4837 case InductionDescriptor::IK_FpInduction:
4838 llvm_unreachable("Integer/fp induction is handled elsewhere.")::llvm::llvm_unreachable_internal("Integer/fp induction is handled elsewhere."
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4838)
;
4839 case InductionDescriptor::IK_PtrInduction: {
4840 // Handle the pointer induction variable case.
4841 assert(P->getType()->isPointerTy() && "Unexpected type.")(static_cast <bool> (P->getType()->isPointerTy() &&
"Unexpected type.") ? void (0) : __assert_fail ("P->getType()->isPointerTy() && \"Unexpected type.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4841, __extension__ __PRETTY_FUNCTION__))
;
4842
4843 if (Cost->isScalarAfterVectorization(P, State.VF)) {
4844 // This is the normalized GEP that starts counting at zero.
4845 Value *PtrInd =
4846 Builder.CreateSExtOrTrunc(Induction, II.getStep()->getType());
4847 // Determine the number of scalars we need to generate for each unroll
4848 // iteration. If the instruction is uniform, we only need to generate the
4849 // first lane. Otherwise, we generate all VF values.
4850 bool IsUniform = Cost->isUniformAfterVectorization(P, State.VF);
4851 unsigned Lanes = IsUniform ? 1 : State.VF.getKnownMinValue();
4852
4853 bool NeedsVectorIndex = !IsUniform && VF.isScalable();
4854 Value *UnitStepVec = nullptr, *PtrIndSplat = nullptr;
4855 if (NeedsVectorIndex) {
4856 Type *VecIVTy = VectorType::get(PtrInd->getType(), VF);
4857 UnitStepVec = Builder.CreateStepVector(VecIVTy);
4858 PtrIndSplat = Builder.CreateVectorSplat(VF, PtrInd);
4859 }
4860
4861 for (unsigned Part = 0; Part < UF; ++Part) {
4862 Value *PartStart = createStepForVF(
4863 Builder, ConstantInt::get(PtrInd->getType(), Part), VF);
4864
4865 if (NeedsVectorIndex) {
4866 Value *PartStartSplat = Builder.CreateVectorSplat(VF, PartStart);
4867 Value *Indices = Builder.CreateAdd(PartStartSplat, UnitStepVec);
4868 Value *GlobalIndices = Builder.CreateAdd(PtrIndSplat, Indices);
4869 Value *SclrGep =
4870 emitTransformedIndex(Builder, GlobalIndices, PSE.getSE(), DL, II);
4871 SclrGep->setName("next.gep");
4872 State.set(PhiR, SclrGep, Part);
4873 // We've cached the whole vector, which means we can support the
4874 // extraction of any lane.
4875 continue;
4876 }
4877
4878 for (unsigned Lane = 0; Lane < Lanes; ++Lane) {
4879 Value *Idx = Builder.CreateAdd(
4880 PartStart, ConstantInt::get(PtrInd->getType(), Lane));
4881 Value *GlobalIdx = Builder.CreateAdd(PtrInd, Idx);
4882 Value *SclrGep =
4883 emitTransformedIndex(Builder, GlobalIdx, PSE.getSE(), DL, II);
4884 SclrGep->setName("next.gep");
4885 State.set(PhiR, SclrGep, VPIteration(Part, Lane));
4886 }
4887 }
4888 return;
4889 }
4890 assert(isa<SCEVConstant>(II.getStep()) &&(static_cast <bool> (isa<SCEVConstant>(II.getStep
()) && "Induction step not a SCEV constant!") ? void (
0) : __assert_fail ("isa<SCEVConstant>(II.getStep()) && \"Induction step not a SCEV constant!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4891, __extension__ __PRETTY_FUNCTION__))
4891 "Induction step not a SCEV constant!")(static_cast <bool> (isa<SCEVConstant>(II.getStep
()) && "Induction step not a SCEV constant!") ? void (
0) : __assert_fail ("isa<SCEVConstant>(II.getStep()) && \"Induction step not a SCEV constant!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4891, __extension__ __PRETTY_FUNCTION__))
;
4892 Type *PhiType = II.getStep()->getType();
4893
4894 // Build a pointer phi
4895 Value *ScalarStartValue = II.getStartValue();
4896 Type *ScStValueType = ScalarStartValue->getType();
4897 PHINode *NewPointerPhi =
4898 PHINode::Create(ScStValueType, 2, "pointer.phi", Induction);
4899 NewPointerPhi->addIncoming(ScalarStartValue, LoopVectorPreHeader);
4900
4901 // A pointer induction, performed by using a gep
4902 BasicBlock *LoopLatch = LI->getLoopFor(LoopVectorBody)->getLoopLatch();
4903 Instruction *InductionLoc = LoopLatch->getTerminator();
4904 const SCEV *ScalarStep = II.getStep();
4905 SCEVExpander Exp(*PSE.getSE(), DL, "induction");
4906 Value *ScalarStepValue =
4907 Exp.expandCodeFor(ScalarStep, PhiType, InductionLoc);
4908 Value *RuntimeVF = getRuntimeVF(Builder, PhiType, VF);
4909 Value *NumUnrolledElems =
4910 Builder.CreateMul(RuntimeVF, ConstantInt::get(PhiType, State.UF));
4911 Value *InductionGEP = GetElementPtrInst::Create(
4912 ScStValueType->getPointerElementType(), NewPointerPhi,
4913 Builder.CreateMul(ScalarStepValue, NumUnrolledElems), "ptr.ind",
4914 InductionLoc);
4915 NewPointerPhi->addIncoming(InductionGEP, LoopLatch);
4916
4917 // Create UF many actual address geps that use the pointer
4918 // phi as base and a vectorized version of the step value
4919 // (<step*0, ..., step*N>) as offset.
4920 for (unsigned Part = 0; Part < State.UF; ++Part) {
4921 Type *VecPhiType = VectorType::get(PhiType, State.VF);
4922 Value *StartOffsetScalar =
4923 Builder.CreateMul(RuntimeVF, ConstantInt::get(PhiType, Part));
4924 Value *StartOffset =
4925 Builder.CreateVectorSplat(State.VF, StartOffsetScalar);
4926 // Create a vector of consecutive numbers from zero to VF.
4927 StartOffset =
4928 Builder.CreateAdd(StartOffset, Builder.CreateStepVector(VecPhiType));
4929
4930 Value *GEP = Builder.CreateGEP(
4931 ScStValueType->getPointerElementType(), NewPointerPhi,
4932 Builder.CreateMul(
4933 StartOffset, Builder.CreateVectorSplat(State.VF, ScalarStepValue),
4934 "vector.gep"));
4935 State.set(PhiR, GEP, Part);
4936 }
4937 }
4938 }
4939}
4940
4941/// A helper function for checking whether an integer division-related
4942/// instruction may divide by zero (in which case it must be predicated if
4943/// executed conditionally in the scalar code).
4944/// TODO: It may be worthwhile to generalize and check isKnownNonZero().
4945/// Non-zero divisors that are non compile-time constants will not be
4946/// converted into multiplication, so we will still end up scalarizing
4947/// the division, but can do so w/o predication.
4948static bool mayDivideByZero(Instruction &I) {
4949 assert((I.getOpcode() == Instruction::UDiv ||(static_cast <bool> ((I.getOpcode() == Instruction::UDiv
|| I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction
::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction"
) ? void (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4953, __extension__ __PRETTY_FUNCTION__))
4950 I.getOpcode() == Instruction::SDiv ||(static_cast <bool> ((I.getOpcode() == Instruction::UDiv
|| I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction
::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction"
) ? void (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4953, __extension__ __PRETTY_FUNCTION__))
4951 I.getOpcode() == Instruction::URem ||(static_cast <bool> ((I.getOpcode() == Instruction::UDiv
|| I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction
::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction"
) ? void (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4953, __extension__ __PRETTY_FUNCTION__))
4952 I.getOpcode() == Instruction::SRem) &&(static_cast <bool> ((I.getOpcode() == Instruction::UDiv
|| I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction
::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction"
) ? void (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4953, __extension__ __PRETTY_FUNCTION__))
4953 "Unexpected instruction")(static_cast <bool> ((I.getOpcode() == Instruction::UDiv
|| I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction
::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction"
) ? void (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4953, __extension__ __PRETTY_FUNCTION__))
;
4954 Value *Divisor = I.getOperand(1);
4955 auto *CInt = dyn_cast<ConstantInt>(Divisor);
4956 return !CInt || CInt->isZero();
4957}
4958
4959void InnerLoopVectorizer::widenInstruction(Instruction &I, VPValue *Def,
4960 VPUser &User,
4961 VPTransformState &State) {
4962 switch (I.getOpcode()) {
4963 case Instruction::Call:
4964 case Instruction::Br:
4965 case Instruction::PHI:
4966 case Instruction::GetElementPtr:
4967 case Instruction::Select:
4968 llvm_unreachable("This instruction is handled by a different recipe.")::llvm::llvm_unreachable_internal("This instruction is handled by a different recipe."
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 4968)
;
4969 case Instruction::UDiv:
4970 case Instruction::SDiv:
4971 case Instruction::SRem:
4972 case Instruction::URem:
4973 case Instruction::Add:
4974 case Instruction::FAdd:
4975 case Instruction::Sub:
4976 case Instruction::FSub:
4977 case Instruction::FNeg:
4978 case Instruction::Mul:
4979 case Instruction::FMul:
4980 case Instruction::FDiv:
4981 case Instruction::FRem:
4982 case Instruction::Shl:
4983 case Instruction::LShr:
4984 case Instruction::AShr:
4985 case Instruction::And:
4986 case Instruction::Or:
4987 case Instruction::Xor: {
4988 // Just widen unops and binops.
4989 setDebugLocFromInst(Builder, &I);
4990
4991 for (unsigned Part = 0; Part < UF; ++Part) {
4992 SmallVector<Value *, 2> Ops;
4993 for (VPValue *VPOp : User.operands())
4994 Ops.push_back(State.get(VPOp, Part));
4995
4996 Value *V = Builder.CreateNAryOp(I.getOpcode(), Ops);
4997
4998 if (auto *VecOp = dyn_cast<Instruction>(V))
4999 VecOp->copyIRFlags(&I);
5000
5001 // Use this vector value for all users of the original instruction.
5002 State.set(Def, V, Part);
5003 addMetadata(V, &I);
5004 }
5005
5006 break;
5007 }
5008 case Instruction::ICmp:
5009 case Instruction::FCmp: {
5010 // Widen compares. Generate vector compares.
5011 bool FCmp = (I.getOpcode() == Instruction::FCmp);
5012 auto *Cmp = cast<CmpInst>(&I);
5013 setDebugLocFromInst(Builder, Cmp);
5014 for (unsigned Part = 0; Part < UF; ++Part) {
5015 Value *A = State.get(User.getOperand(0), Part);
5016 Value *B = State.get(User.getOperand(1), Part);
5017 Value *C = nullptr;
5018 if (FCmp) {
5019 // Propagate fast math flags.
5020 IRBuilder<>::FastMathFlagGuard FMFG(Builder);
5021 Builder.setFastMathFlags(Cmp->getFastMathFlags());
5022 C = Builder.CreateFCmp(Cmp->getPredicate(), A, B);
5023 } else {
5024 C = Builder.CreateICmp(Cmp->getPredicate(), A, B);
5025 }
5026 State.set(Def, C, Part);
5027 addMetadata(C, &I);
5028 }
5029
5030 break;
5031 }
5032
5033 case Instruction::ZExt:
5034 case Instruction::SExt:
5035 case Instruction::FPToUI:
5036 case Instruction::FPToSI:
5037 case Instruction::FPExt:
5038 case Instruction::PtrToInt:
5039 case Instruction::IntToPtr:
5040 case Instruction::SIToFP:
5041 case Instruction::UIToFP:
5042 case Instruction::Trunc:
5043 case Instruction::FPTrunc:
5044 case Instruction::BitCast: {
5045 auto *CI = cast<CastInst>(&I);
5046 setDebugLocFromInst(Builder, CI);
5047
5048 /// Vectorize casts.
5049 Type *DestTy =
5050 (VF.isScalar()) ? CI->getType() : VectorType::get(CI->getType(), VF);
5051
5052 for (unsigned Part = 0; Part < UF; ++Part) {
5053 Value *A = State.get(User.getOperand(0), Part);
5054 Value *Cast = Builder.CreateCast(CI->getOpcode(), A, DestTy);
5055 State.set(Def, Cast, Part);
5056 addMetadata(Cast, &I);
5057 }
5058 break;
5059 }
5060 default:
5061 // This instruction is not vectorized by simple widening.
5062 LLVM_DEBUG(dbgs() << "LV: Found an unhandled instruction: " << I)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found an unhandled instruction: "
<< I; } } while (false)
;
5063 llvm_unreachable("Unhandled instruction!")::llvm::llvm_unreachable_internal("Unhandled instruction!", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5063)
;
5064 } // end of switch.
5065}
5066
5067void InnerLoopVectorizer::widenCallInstruction(CallInst &I, VPValue *Def,
5068 VPUser &ArgOperands,
5069 VPTransformState &State) {
5070 assert(!isa<DbgInfoIntrinsic>(I) &&(static_cast <bool> (!isa<DbgInfoIntrinsic>(I) &&
"DbgInfoIntrinsic should have been dropped during VPlan construction"
) ? void (0) : __assert_fail ("!isa<DbgInfoIntrinsic>(I) && \"DbgInfoIntrinsic should have been dropped during VPlan construction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5071, __extension__ __PRETTY_FUNCTION__))
5071 "DbgInfoIntrinsic should have been dropped during VPlan construction")(static_cast <bool> (!isa<DbgInfoIntrinsic>(I) &&
"DbgInfoIntrinsic should have been dropped during VPlan construction"
) ? void (0) : __assert_fail ("!isa<DbgInfoIntrinsic>(I) && \"DbgInfoIntrinsic should have been dropped during VPlan construction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5071, __extension__ __PRETTY_FUNCTION__))
;
5072 setDebugLocFromInst(Builder, &I);
5073
5074 Module *M = I.getParent()->getParent()->getParent();
5075 auto *CI = cast<CallInst>(&I);
5076
5077 SmallVector<Type *, 4> Tys;
5078 for (Value *ArgOperand : CI->arg_operands())
5079 Tys.push_back(ToVectorTy(ArgOperand->getType(), VF.getKnownMinValue()));
5080
5081 Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
5082
5083 // The flag shows whether we use Intrinsic or a usual Call for vectorized
5084 // version of the instruction.
5085 // Is it beneficial to perform intrinsic call compared to lib call?
5086 bool NeedToScalarize = false;
5087 InstructionCost CallCost = Cost->getVectorCallCost(CI, VF, NeedToScalarize);
5088 InstructionCost IntrinsicCost = ID ? Cost->getVectorIntrinsicCost(CI, VF) : 0;
5089 bool UseVectorIntrinsic = ID && IntrinsicCost <= CallCost;
5090 assert((UseVectorIntrinsic || !NeedToScalarize) &&(static_cast <bool> ((UseVectorIntrinsic || !NeedToScalarize
) && "Instruction should be scalarized elsewhere.") ?
void (0) : __assert_fail ("(UseVectorIntrinsic || !NeedToScalarize) && \"Instruction should be scalarized elsewhere.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5091, __extension__ __PRETTY_FUNCTION__))
5091 "Instruction should be scalarized elsewhere.")(static_cast <bool> ((UseVectorIntrinsic || !NeedToScalarize
) && "Instruction should be scalarized elsewhere.") ?
void (0) : __assert_fail ("(UseVectorIntrinsic || !NeedToScalarize) && \"Instruction should be scalarized elsewhere.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5091, __extension__ __PRETTY_FUNCTION__))
;
5092 assert((IntrinsicCost.isValid() || CallCost.isValid()) &&(static_cast <bool> ((IntrinsicCost.isValid() || CallCost
.isValid()) && "Either the intrinsic cost or vector call cost must be valid"
) ? void (0) : __assert_fail ("(IntrinsicCost.isValid() || CallCost.isValid()) && \"Either the intrinsic cost or vector call cost must be valid\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5093, __extension__ __PRETTY_FUNCTION__))
5093 "Either the intrinsic cost or vector call cost must be valid")(static_cast <bool> ((IntrinsicCost.isValid() || CallCost
.isValid()) && "Either the intrinsic cost or vector call cost must be valid"
) ? void (0) : __assert_fail ("(IntrinsicCost.isValid() || CallCost.isValid()) && \"Either the intrinsic cost or vector call cost must be valid\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5093, __extension__ __PRETTY_FUNCTION__))
;
5094
5095 for (unsigned Part = 0; Part < UF; ++Part) {
5096 SmallVector<Type *, 2> TysForDecl = {CI->getType()};
5097 SmallVector<Value *, 4> Args;
5098 for (auto &I : enumerate(ArgOperands.operands())) {
5099 // Some intrinsics have a scalar argument - don't replace it with a
5100 // vector.
5101 Value *Arg;
5102 if (!UseVectorIntrinsic || !hasVectorInstrinsicScalarOpd(ID, I.index()))
5103 Arg = State.get(I.value(), Part);
5104 else {
5105 Arg = State.get(I.value(), VPIteration(0, 0));
5106 if (hasVectorInstrinsicOverloadedScalarOpd(ID, I.index()))
5107 TysForDecl.push_back(Arg->getType());
5108 }
5109 Args.push_back(Arg);
5110 }
5111
5112 Function *VectorF;
5113 if (UseVectorIntrinsic) {
5114 // Use vector version of the intrinsic.
5115 if (VF.isVector())
5116 TysForDecl[0] = VectorType::get(CI->getType()->getScalarType(), VF);
5117 VectorF = Intrinsic::getDeclaration(M, ID, TysForDecl);
5118 assert(VectorF && "Can't retrieve vector intrinsic.")(static_cast <bool> (VectorF && "Can't retrieve vector intrinsic."
) ? void (0) : __assert_fail ("VectorF && \"Can't retrieve vector intrinsic.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5118, __extension__ __PRETTY_FUNCTION__))
;
5119 } else {
5120 // Use vector version of the function call.
5121 const VFShape Shape = VFShape::get(*CI, VF, false /*HasGlobalPred*/);
5122#ifndef NDEBUG
5123 assert(VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr &&(static_cast <bool> (VFDatabase(*CI).getVectorizedFunction
(Shape) != nullptr && "Can't create vector function."
) ? void (0) : __assert_fail ("VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && \"Can't create vector function.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5124, __extension__ __PRETTY_FUNCTION__))
5124 "Can't create vector function.")(static_cast <bool> (VFDatabase(*CI).getVectorizedFunction
(Shape) != nullptr && "Can't create vector function."
) ? void (0) : __assert_fail ("VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && \"Can't create vector function.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5124, __extension__ __PRETTY_FUNCTION__))
;
5125#endif
5126 VectorF = VFDatabase(*CI).getVectorizedFunction(Shape);
5127 }
5128 SmallVector<OperandBundleDef, 1> OpBundles;
5129 CI->getOperandBundlesAsDefs(OpBundles);
5130 CallInst *V = Builder.CreateCall(VectorF, Args, OpBundles);
5131
5132 if (isa<FPMathOperator>(V))
5133 V->copyFastMathFlags(CI);
5134
5135 State.set(Def, V, Part);
5136 addMetadata(V, &I);
5137 }
5138}
5139
5140void InnerLoopVectorizer::widenSelectInstruction(SelectInst &I, VPValue *VPDef,
5141 VPUser &Operands,
5142 bool InvariantCond,
5143 VPTransformState &State) {
5144 setDebugLocFromInst(Builder, &I);
5145
5146 // The condition can be loop invariant but still defined inside the
5147 // loop. This means that we can't just use the original 'cond' value.
5148 // We have to take the 'vectorized' value and pick the first lane.
5149 // Instcombine will make this a no-op.
5150 auto *InvarCond = InvariantCond
5151 ? State.get(Operands.getOperand(0), VPIteration(0, 0))
5152 : nullptr;
5153
5154 for (unsigned Part = 0; Part < UF; ++Part) {
5155 Value *Cond =
5156 InvarCond ? InvarCond : State.get(Operands.getOperand(0), Part);
5157 Value *Op0 = State.get(Operands.getOperand(1), Part);
5158 Value *Op1 = State.get(Operands.getOperand(2), Part);
5159 Value *Sel = Builder.CreateSelect(Cond, Op0, Op1);
5160 State.set(VPDef, Sel, Part);
5161 addMetadata(Sel, &I);
5162 }
5163}
5164
5165void LoopVectorizationCostModel::collectLoopScalars(ElementCount VF) {
5166 // We should not collect Scalars more than once per VF. Right now, this
5167 // function is called from collectUniformsAndScalars(), which already does
5168 // this check. Collecting Scalars for VF=1 does not make any sense.
5169 assert(VF.isVector() && Scalars.find(VF) == Scalars.end() &&(static_cast <bool> (VF.isVector() && Scalars.find
(VF) == Scalars.end() && "This function should not be visited twice for the same VF"
) ? void (0) : __assert_fail ("VF.isVector() && Scalars.find(VF) == Scalars.end() && \"This function should not be visited twice for the same VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5170, __extension__ __PRETTY_FUNCTION__))
5170 "This function should not be visited twice for the same VF")(static_cast <bool> (VF.isVector() && Scalars.find
(VF) == Scalars.end() && "This function should not be visited twice for the same VF"
) ? void (0) : __assert_fail ("VF.isVector() && Scalars.find(VF) == Scalars.end() && \"This function should not be visited twice for the same VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5170, __extension__ __PRETTY_FUNCTION__))
;
5171
5172 SmallSetVector<Instruction *, 8> Worklist;
5173
5174 // These sets are used to seed the analysis with pointers used by memory
5175 // accesses that will remain scalar.
5176 SmallSetVector<Instruction *, 8> ScalarPtrs;
5177 SmallPtrSet<Instruction *, 8> PossibleNonScalarPtrs;
5178 auto *Latch = TheLoop->getLoopLatch();
5179
5180 // A helper that returns true if the use of Ptr by MemAccess will be scalar.
5181 // The pointer operands of loads and stores will be scalar as long as the
5182 // memory access is not a gather or scatter operation. The value operand of a
5183 // store will remain scalar if the store is scalarized.
5184 auto isScalarUse = [&](Instruction *MemAccess, Value *Ptr) {
5185 InstWidening WideningDecision = getWideningDecision(MemAccess, VF);
5186 assert(WideningDecision != CM_Unknown &&(static_cast <bool> (WideningDecision != CM_Unknown &&
"Widening decision should be ready at this moment") ? void (
0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5187, __extension__ __PRETTY_FUNCTION__))
5187 "Widening decision should be ready at this moment")(static_cast <bool> (WideningDecision != CM_Unknown &&
"Widening decision should be ready at this moment") ? void (
0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5187, __extension__ __PRETTY_FUNCTION__))
;
5188 if (auto *Store = dyn_cast<StoreInst>(MemAccess))
5189 if (Ptr == Store->getValueOperand())
5190 return WideningDecision == CM_Scalarize;
5191 assert(Ptr == getLoadStorePointerOperand(MemAccess) &&(static_cast <bool> (Ptr == getLoadStorePointerOperand(
MemAccess) && "Ptr is neither a value or pointer operand"
) ? void (0) : __assert_fail ("Ptr == getLoadStorePointerOperand(MemAccess) && \"Ptr is neither a value or pointer operand\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5192, __extension__ __PRETTY_FUNCTION__))
5192 "Ptr is neither a value or pointer operand")(static_cast <bool> (Ptr == getLoadStorePointerOperand(
MemAccess) && "Ptr is neither a value or pointer operand"
) ? void (0) : __assert_fail ("Ptr == getLoadStorePointerOperand(MemAccess) && \"Ptr is neither a value or pointer operand\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5192, __extension__ __PRETTY_FUNCTION__))
;
5193 return WideningDecision != CM_GatherScatter;
5194 };
5195
5196 // A helper that returns true if the given value is a bitcast or
5197 // getelementptr instruction contained in the loop.
5198 auto isLoopVaryingBitCastOrGEP = [&](Value *V) {
5199 return ((isa<BitCastInst>(V) && V->getType()->isPointerTy()) ||
5200 isa<GetElementPtrInst>(V)) &&
5201 !TheLoop->isLoopInvariant(V);
5202 };
5203
5204 auto isScalarPtrInduction = [&](Instruction *MemAccess, Value *Ptr) {
5205 if (!isa<PHINode>(Ptr) ||
5206 !Legal->getInductionVars().count(cast<PHINode>(Ptr)))
5207 return false;
5208 auto &Induction = Legal->getInductionVars()[cast<PHINode>(Ptr)];
5209 if (Induction.getKind() != InductionDescriptor::IK_PtrInduction)
5210 return false;
5211 return isScalarUse(MemAccess, Ptr);
5212 };
5213
5214 // A helper that evaluates a memory access's use of a pointer. If the
5215 // pointer is actually the pointer induction of a loop, it is being
5216 // inserted into Worklist. If the use will be a scalar use, and the
5217 // pointer is only used by memory accesses, we place the pointer in
5218 // ScalarPtrs. Otherwise, the pointer is placed in PossibleNonScalarPtrs.
5219 auto evaluatePtrUse = [&](Instruction *MemAccess, Value *Ptr) {
5220 if (isScalarPtrInduction(MemAccess, Ptr)) {
5221 Worklist.insert(cast<Instruction>(Ptr));
5222 Instruction *Update = cast<Instruction>(
5223 cast<PHINode>(Ptr)->getIncomingValueForBlock(Latch));
5224 Worklist.insert(Update);
5225 LLVM_DEBUG(dbgs() << "LV: Found new scalar instruction: " << *Ptrdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: "
<< *Ptr << "\n"; } } while (false)
5226 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: "
<< *Ptr << "\n"; } } while (false)
;
5227 LLVM_DEBUG(dbgs() << "LV: Found new scalar instruction: " << *Updatedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: "
<< *Update << "\n"; } } while (false)
5228 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: "
<< *Update << "\n"; } } while (false)
;
5229 return;
5230 }
5231 // We only care about bitcast and getelementptr instructions contained in
5232 // the loop.
5233 if (!isLoopVaryingBitCastOrGEP(Ptr))
5234 return;
5235
5236 // If the pointer has already been identified as scalar (e.g., if it was
5237 // also identified as uniform), there's nothing to do.
5238 auto *I = cast<Instruction>(Ptr);
5239 if (Worklist.count(I))
5240 return;
5241
5242 // If the use of the pointer will be a scalar use, and all users of the
5243 // pointer are memory accesses, place the pointer in ScalarPtrs. Otherwise,
5244 // place the pointer in PossibleNonScalarPtrs.
5245 if (isScalarUse(MemAccess, Ptr) && llvm::all_of(I->users(), [&](User *U) {
5246 return isa<LoadInst>(U) || isa<StoreInst>(U);
5247 }))
5248 ScalarPtrs.insert(I);
5249 else
5250 PossibleNonScalarPtrs.insert(I);
5251 };
5252
5253 // We seed the scalars analysis with three classes of instructions: (1)
5254 // instructions marked uniform-after-vectorization and (2) bitcast,
5255 // getelementptr and (pointer) phi instructions used by memory accesses
5256 // requiring a scalar use.
5257 //
5258 // (1) Add to the worklist all instructions that have been identified as
5259 // uniform-after-vectorization.
5260 Worklist.insert(Uniforms[VF].begin(), Uniforms[VF].end());
5261
5262 // (2) Add to the worklist all bitcast and getelementptr instructions used by
5263 // memory accesses requiring a scalar use. The pointer operands of loads and
5264 // stores will be scalar as long as the memory accesses is not a gather or
5265 // scatter operation. The value operand of a store will remain scalar if the
5266 // store is scalarized.
5267 for (auto *BB : TheLoop->blocks())
5268 for (auto &I : *BB) {
5269 if (auto *Load = dyn_cast<LoadInst>(&I)) {
5270 evaluatePtrUse(Load, Load->getPointerOperand());
5271 } else if (auto *Store = dyn_cast<StoreInst>(&I)) {
5272 evaluatePtrUse(Store, Store->getPointerOperand());
5273 evaluatePtrUse(Store, Store->getValueOperand());
5274 }
5275 }
5276 for (auto *I : ScalarPtrs)
5277 if (!PossibleNonScalarPtrs.count(I)) {
5278 LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: "
<< *I << "\n"; } } while (false)
;
5279 Worklist.insert(I);
5280 }
5281
5282 // Insert the forced scalars.
5283 // FIXME: Currently widenPHIInstruction() often creates a dead vector
5284 // induction variable when the PHI user is scalarized.
5285 auto ForcedScalar = ForcedScalars.find(VF);
5286 if (ForcedScalar != ForcedScalars.end())
5287 for (auto *I : ForcedScalar->second)
5288 Worklist.insert(I);
5289
5290 // Expand the worklist by looking through any bitcasts and getelementptr
5291 // instructions we've already identified as scalar. This is similar to the
5292 // expansion step in collectLoopUniforms(); however, here we're only
5293 // expanding to include additional bitcasts and getelementptr instructions.
5294 unsigned Idx = 0;
5295 while (Idx != Worklist.size()) {
5296 Instruction *Dst = Worklist[Idx++];
5297 if (!isLoopVaryingBitCastOrGEP(Dst->getOperand(0)))
5298 continue;
5299 auto *Src = cast<Instruction>(Dst->getOperand(0));
5300 if (llvm::all_of(Src->users(), [&](User *U) -> bool {
5301 auto *J = cast<Instruction>(U);
5302 return !TheLoop->contains(J) || Worklist.count(J) ||
5303 ((isa<LoadInst>(J) || isa<StoreInst>(J)) &&
5304 isScalarUse(J, Src));
5305 })) {
5306 Worklist.insert(Src);
5307 LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *Src << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: "
<< *Src << "\n"; } } while (false)
;
5308 }
5309 }
5310
5311 // An induction variable will remain scalar if all users of the induction
5312 // variable and induction variable update remain scalar.
5313 for (auto &Induction : Legal->getInductionVars()) {
5314 auto *Ind = Induction.first;
5315 auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch));
5316
5317 // If tail-folding is applied, the primary induction variable will be used
5318 // to feed a vector compare.
5319 if (Ind == Legal->getPrimaryInduction() && foldTailByMasking())
5320 continue;
5321
5322 // Determine if all users of the induction variable are scalar after
5323 // vectorization.
5324 auto ScalarInd = llvm::all_of(Ind->users(), [&](User *U) -> bool {
5325 auto *I = cast<Instruction>(U);
5326 return I == IndUpdate || !TheLoop->contains(I) || Worklist.count(I);
5327 });
5328 if (!ScalarInd)
5329 continue;
5330
5331 // Determine if all users of the induction variable update instruction are
5332 // scalar after vectorization.
5333 auto ScalarIndUpdate =
5334 llvm::all_of(IndUpdate->users(), [&](User *U) -> bool {
5335 auto *I = cast<Instruction>(U);
5336 return I == Ind || !TheLoop->contains(I) || Worklist.count(I);
5337 });
5338 if (!ScalarIndUpdate)
5339 continue;
5340
5341 // The induction variable and its update instruction will remain scalar.
5342 Worklist.insert(Ind);
5343 Worklist.insert(IndUpdate);
5344 LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *Ind << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: "
<< *Ind << "\n"; } } while (false)
;
5345 LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *IndUpdatedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: "
<< *IndUpdate << "\n"; } } while (false)
5346 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: "
<< *IndUpdate << "\n"; } } while (false)
;
5347 }
5348
5349 Scalars[VF].insert(Worklist.begin(), Worklist.end());
5350}
5351
5352bool LoopVectorizationCostModel::isScalarWithPredication(Instruction *I) const {
5353 if (!blockNeedsPredication(I->getParent()))
5354 return false;
5355 switch(I->getOpcode()) {
5356 default:
5357 break;
5358 case Instruction::Load:
5359 case Instruction::Store: {
5360 if (!Legal->isMaskRequired(I))
5361 return false;
5362 auto *Ptr = getLoadStorePointerOperand(I);
5363 auto *Ty = getLoadStoreType(I);
5364 const Align Alignment = getLoadStoreAlignment(I);
5365 return isa<LoadInst>(I) ? !(isLegalMaskedLoad(Ty, Ptr, Alignment) ||
5366 TTI.isLegalMaskedGather(Ty, Alignment))
5367 : !(isLegalMaskedStore(Ty, Ptr, Alignment) ||
5368 TTI.isLegalMaskedScatter(Ty, Alignment));
5369 }
5370 case Instruction::UDiv:
5371 case Instruction::SDiv:
5372 case Instruction::SRem:
5373 case Instruction::URem:
5374 return mayDivideByZero(*I);
5375 }
5376 return false;
5377}
5378
5379bool LoopVectorizationCostModel::interleavedAccessCanBeWidened(
5380 Instruction *I, ElementCount VF) {
5381 assert(isAccessInterleaved(I) && "Expecting interleaved access.")(static_cast <bool> (isAccessInterleaved(I) && "Expecting interleaved access."
) ? void (0) : __assert_fail ("isAccessInterleaved(I) && \"Expecting interleaved access.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5381, __extension__ __PRETTY_FUNCTION__))
;
5382 assert(getWideningDecision(I, VF) == CM_Unknown &&(static_cast <bool> (getWideningDecision(I, VF) == CM_Unknown
&& "Decision should not be set yet.") ? void (0) : __assert_fail
("getWideningDecision(I, VF) == CM_Unknown && \"Decision should not be set yet.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5383, __extension__ __PRETTY_FUNCTION__))
5383 "Decision should not be set yet.")(static_cast <bool> (getWideningDecision(I, VF) == CM_Unknown
&& "Decision should not be set yet.") ? void (0) : __assert_fail
("getWideningDecision(I, VF) == CM_Unknown && \"Decision should not be set yet.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5383, __extension__ __PRETTY_FUNCTION__))
;
5384 auto *Group = getInterleavedAccessGroup(I);
5385 assert(Group && "Must have a group.")(static_cast <bool> (Group && "Must have a group."
) ? void (0) : __assert_fail ("Group && \"Must have a group.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5385, __extension__ __PRETTY_FUNCTION__))
;
5386
5387 // If the instruction's allocated size doesn't equal it's type size, it
5388 // requires padding and will be scalarized.
5389 auto &DL = I->getModule()->getDataLayout();
5390 auto *ScalarTy = getLoadStoreType(I);
5391 if (hasIrregularType(ScalarTy, DL))
5392 return false;
5393
5394 // Check if masking is required.
5395 // A Group may need masking for one of two reasons: it resides in a block that
5396 // needs predication, or it was decided to use masking to deal with gaps.
5397 bool PredicatedAccessRequiresMasking =
5398 Legal->blockNeedsPredication(I->getParent()) && Legal->isMaskRequired(I);
5399 bool AccessWithGapsRequiresMasking =
5400 Group->requiresScalarEpilogue() && !isScalarEpilogueAllowed();
5401 if (!PredicatedAccessRequiresMasking && !AccessWithGapsRequiresMasking)
5402 return true;
5403
5404 // If masked interleaving is required, we expect that the user/target had
5405 // enabled it, because otherwise it either wouldn't have been created or
5406 // it should have been invalidated by the CostModel.
5407 assert(useMaskedInterleavedAccesses(TTI) &&(static_cast <bool> (useMaskedInterleavedAccesses(TTI) &&
"Masked interleave-groups for predicated accesses are not enabled."
) ? void (0) : __assert_fail ("useMaskedInterleavedAccesses(TTI) && \"Masked interleave-groups for predicated accesses are not enabled.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5408, __extension__ __PRETTY_FUNCTION__))
5408 "Masked interleave-groups for predicated accesses are not enabled.")(static_cast <bool> (useMaskedInterleavedAccesses(TTI) &&
"Masked interleave-groups for predicated accesses are not enabled."
) ? void (0) : __assert_fail ("useMaskedInterleavedAccesses(TTI) && \"Masked interleave-groups for predicated accesses are not enabled.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5408, __extension__ __PRETTY_FUNCTION__))
;
5409
5410 auto *Ty = getLoadStoreType(I);
5411 const Align Alignment = getLoadStoreAlignment(I);
5412 return isa<LoadInst>(I) ? TTI.isLegalMaskedLoad(Ty, Alignment)
5413 : TTI.isLegalMaskedStore(Ty, Alignment);
5414}
5415
5416bool LoopVectorizationCostModel::memoryInstructionCanBeWidened(
5417 Instruction *I, ElementCount VF) {
5418 // Get and ensure we have a valid memory instruction.
5419 LoadInst *LI = dyn_cast<LoadInst>(I);
5420 StoreInst *SI = dyn_cast<StoreInst>(I);
5421 assert((LI || SI) && "Invalid memory instruction")(static_cast <bool> ((LI || SI) && "Invalid memory instruction"
) ? void (0) : __assert_fail ("(LI || SI) && \"Invalid memory instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5421, __extension__ __PRETTY_FUNCTION__))
;
5422
5423 auto *Ptr = getLoadStorePointerOperand(I);
5424
5425 // In order to be widened, the pointer should be consecutive, first of all.
5426 if (!Legal->isConsecutivePtr(Ptr))
5427 return false;
5428
5429 // If the instruction is a store located in a predicated block, it will be
5430 // scalarized.
5431 if (isScalarWithPredication(I))
5432 return false;
5433
5434 // If the instruction's allocated size doesn't equal it's type size, it
5435 // requires padding and will be scalarized.
5436 auto &DL = I->getModule()->getDataLayout();
5437 auto *ScalarTy = LI ? LI->getType() : SI->getValueOperand()->getType();
5438 if (hasIrregularType(ScalarTy, DL))
5439 return false;
5440
5441 return true;
5442}
5443
5444void LoopVectorizationCostModel::collectLoopUniforms(ElementCount VF) {
5445 // We should not collect Uniforms more than once per VF. Right now,
5446 // this function is called from collectUniformsAndScalars(), which
5447 // already does this check. Collecting Uniforms for VF=1 does not make any
5448 // sense.
5449
5450 assert(VF.isVector() && Uniforms.find(VF) == Uniforms.end() &&(static_cast <bool> (VF.isVector() && Uniforms.
find(VF) == Uniforms.end() && "This function should not be visited twice for the same VF"
) ? void (0) : __assert_fail ("VF.isVector() && Uniforms.find(VF) == Uniforms.end() && \"This function should not be visited twice for the same VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5451, __extension__ __PRETTY_FUNCTION__))
5451 "This function should not be visited twice for the same VF")(static_cast <bool> (VF.isVector() && Uniforms.
find(VF) == Uniforms.end() && "This function should not be visited twice for the same VF"
) ? void (0) : __assert_fail ("VF.isVector() && Uniforms.find(VF) == Uniforms.end() && \"This function should not be visited twice for the same VF\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5451, __extension__ __PRETTY_FUNCTION__))
;
5452
5453 // Visit the list of Uniforms. If we'll not find any uniform value, we'll
5454 // not analyze again. Uniforms.count(VF) will return 1.
5455 Uniforms[VF].clear();
5456
5457 // We now know that the loop is vectorizable!
5458 // Collect instructions inside the loop that will remain uniform after
5459 // vectorization.
5460
5461 // Global values, params and instructions outside of current loop are out of
5462 // scope.
5463 auto isOutOfScope = [&](Value *V) -> bool {
5464 Instruction *I = dyn_cast<Instruction>(V);
5465 return (!I || !TheLoop->contains(I));
5466 };
5467
5468 SetVector<Instruction *> Worklist;
5469 BasicBlock *Latch = TheLoop->getLoopLatch();
5470
5471 // Instructions that are scalar with predication must not be considered
5472 // uniform after vectorization, because that would create an erroneous
5473 // replicating region where only a single instance out of VF should be formed.
5474 // TODO: optimize such seldom cases if found important, see PR40816.
5475 auto addToWorklistIfAllowed = [&](Instruction *I) -> void {
5476 if (isOutOfScope(I)) {
5477 LLVM_DEBUG(dbgs() << "LV: Found not uniform due to scope: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found not uniform due to scope: "
<< *I << "\n"; } } while (false)
5478 << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found not uniform due to scope: "
<< *I << "\n"; } } while (false)
;
5479 return;
5480 }
5481 if (isScalarWithPredication(I)) {
5482 LLVM_DEBUG(dbgs() << "LV: Found not uniform being ScalarWithPredication: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found not uniform being ScalarWithPredication: "
<< *I << "\n"; } } while (false)
5483 << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found not uniform being ScalarWithPredication: "
<< *I << "\n"; } } while (false)
;
5484 return;
5485 }
5486 LLVM_DEBUG(dbgs() << "LV: Found uniform instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found uniform instruction: "
<< *I << "\n"; } } while (false)
;
5487 Worklist.insert(I);
5488 };
5489
5490 // Start with the conditional branch. If the branch condition is an
5491 // instruction contained in the loop that is only used by the branch, it is
5492 // uniform.
5493 auto *Cmp = dyn_cast<Instruction>(Latch->getTerminator()->getOperand(0));
5494 if (Cmp && TheLoop->contains(Cmp) && Cmp->hasOneUse())
5495 addToWorklistIfAllowed(Cmp);
5496
5497 auto isUniformDecision = [&](Instruction *I, ElementCount VF) {
5498 InstWidening WideningDecision = getWideningDecision(I, VF);
5499 assert(WideningDecision != CM_Unknown &&(static_cast <bool> (WideningDecision != CM_Unknown &&
"Widening decision should be ready at this moment") ? void (
0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5500, __extension__ __PRETTY_FUNCTION__))
5500 "Widening decision should be ready at this moment")(static_cast <bool> (WideningDecision != CM_Unknown &&
"Widening decision should be ready at this moment") ? void (
0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5500, __extension__ __PRETTY_FUNCTION__))
;
5501
5502 // A uniform memory op is itself uniform. We exclude uniform stores
5503 // here as they demand the last lane, not the first one.
5504 if (isa<LoadInst>(I) && Legal->isUniformMemOp(*I)) {
5505 assert(WideningDecision == CM_Scalarize)(static_cast <bool> (WideningDecision == CM_Scalarize) ?
void (0) : __assert_fail ("WideningDecision == CM_Scalarize"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5505, __extension__ __PRETTY_FUNCTION__))
;
5506 return true;
5507 }
5508
5509 return (WideningDecision == CM_Widen ||
5510 WideningDecision == CM_Widen_Reverse ||
5511 WideningDecision == CM_Interleave);
5512 };
5513
5514
5515 // Returns true if Ptr is the pointer operand of a memory access instruction
5516 // I, and I is known to not require scalarization.
5517 auto isVectorizedMemAccessUse = [&](Instruction *I, Value *Ptr) -> bool {
5518 return getLoadStorePointerOperand(I) == Ptr && isUniformDecision(I, VF);
5519 };
5520
5521 // Holds a list of values which are known to have at least one uniform use.
5522 // Note that there may be other uses which aren't uniform. A "uniform use"
5523 // here is something which only demands lane 0 of the unrolled iterations;
5524 // it does not imply that all lanes produce the same value (e.g. this is not
5525 // the usual meaning of uniform)
5526 SetVector<Value *> HasUniformUse;
5527
5528 // Scan the loop for instructions which are either a) known to have only
5529 // lane 0 demanded or b) are uses which demand only lane 0 of their operand.
5530 for (auto *BB : TheLoop->blocks())
5531 for (auto &I : *BB) {
5532 // If there's no pointer operand, there's nothing to do.
5533 auto *Ptr = getLoadStorePointerOperand(&I);
5534 if (!Ptr)
5535 continue;
5536
5537 // A uniform memory op is itself uniform. We exclude uniform stores
5538 // here as they demand the last lane, not the first one.
5539 if (isa<LoadInst>(I) && Legal->isUniformMemOp(I))
5540 addToWorklistIfAllowed(&I);
5541
5542 if (isUniformDecision(&I, VF)) {
5543 assert(isVectorizedMemAccessUse(&I, Ptr) && "consistency check")(static_cast <bool> (isVectorizedMemAccessUse(&I, Ptr
) && "consistency check") ? void (0) : __assert_fail (
"isVectorizedMemAccessUse(&I, Ptr) && \"consistency check\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5543, __extension__ __PRETTY_FUNCTION__))
;
5544 HasUniformUse.insert(Ptr);
5545 }
5546 }
5547
5548 // Add to the worklist any operands which have *only* uniform (e.g. lane 0
5549 // demanding) users. Since loops are assumed to be in LCSSA form, this
5550 // disallows uses outside the loop as well.
5551 for (auto *V : HasUniformUse) {
5552 if (isOutOfScope(V))
5553 continue;
5554 auto *I = cast<Instruction>(V);
5555 auto UsersAreMemAccesses =
5556 llvm::all_of(I->users(), [&](User *U) -> bool {
5557 return isVectorizedMemAccessUse(cast<Instruction>(U), V);
5558 });
5559 if (UsersAreMemAccesses)
5560 addToWorklistIfAllowed(I);
5561 }
5562
5563 // Expand Worklist in topological order: whenever a new instruction
5564 // is added , its users should be already inside Worklist. It ensures
5565 // a uniform instruction will only be used by uniform instructions.
5566 unsigned idx = 0;
5567 while (idx != Worklist.size()) {
5568 Instruction *I = Worklist[idx++];
5569
5570 for (auto OV : I->operand_values()) {
5571 // isOutOfScope operands cannot be uniform instructions.
5572 if (isOutOfScope(OV))
5573 continue;
5574 // First order recurrence Phi's should typically be considered
5575 // non-uniform.
5576 auto *OP = dyn_cast<PHINode>(OV);
5577 if (OP && Legal->isFirstOrderRecurrence(OP))
5578 continue;
5579 // If all the users of the operand are uniform, then add the
5580 // operand into the uniform worklist.
5581 auto *OI = cast<Instruction>(OV);
5582 if (llvm::all_of(OI->users(), [&](User *U) -> bool {
5583 auto *J = cast<Instruction>(U);
5584 return Worklist.count(J) || isVectorizedMemAccessUse(J, OI);
5585 }))
5586 addToWorklistIfAllowed(OI);
5587 }
5588 }
5589
5590 // For an instruction to be added into Worklist above, all its users inside
5591 // the loop should also be in Worklist. However, this condition cannot be
5592 // true for phi nodes that form a cyclic dependence. We must process phi
5593 // nodes separately. An induction variable will remain uniform if all users
5594 // of the induction variable and induction variable update remain uniform.
5595 // The code below handles both pointer and non-pointer induction variables.
5596 for (auto &Induction : Legal->getInductionVars()) {
5597 auto *Ind = Induction.first;
5598 auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch));
5599
5600 // Determine if all users of the induction variable are uniform after
5601 // vectorization.
5602 auto UniformInd = llvm::all_of(Ind->users(), [&](User *U) -> bool {
5603 auto *I = cast<Instruction>(U);
5604 return I == IndUpdate || !TheLoop->contains(I) || Worklist.count(I) ||
5605 isVectorizedMemAccessUse(I, Ind);
5606 });
5607 if (!UniformInd)
5608 continue;
5609
5610 // Determine if all users of the induction variable update instruction are
5611 // uniform after vectorization.
5612 auto UniformIndUpdate =
5613 llvm::all_of(IndUpdate->users(), [&](User *U) -> bool {
5614 auto *I = cast<Instruction>(U);
5615 return I == Ind || !TheLoop->contains(I) || Worklist.count(I) ||
5616 isVectorizedMemAccessUse(I, IndUpdate);
5617 });
5618 if (!UniformIndUpdate)
5619 continue;
5620
5621 // The induction variable and its update instruction will remain uniform.
5622 addToWorklistIfAllowed(Ind);
5623 addToWorklistIfAllowed(IndUpdate);
5624 }
5625
5626 Uniforms[VF].insert(Worklist.begin(), Worklist.end());
5627}
5628
5629bool LoopVectorizationCostModel::runtimeChecksRequired() {
5630 LLVM_DEBUG(dbgs() << "LV: Performing code size checks.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Performing code size checks.\n"
; } } while (false)
;
5631
5632 if (Legal->getRuntimePointerChecking()->Need) {
5633 reportVectorizationFailure("Runtime ptr check is required with -Os/-Oz",
5634 "runtime pointer checks needed. Enable vectorization of this "
5635 "loop with '#pragma clang loop vectorize(enable)' when "
5636 "compiling with -Os/-Oz",
5637 "CantVersionLoopWithOptForSize", ORE, TheLoop);
5638 return true;
5639 }
5640
5641 if (!PSE.getUnionPredicate().getPredicates().empty()) {
5642 reportVectorizationFailure("Runtime SCEV check is required with -Os/-Oz",
5643 "runtime SCEV checks needed. Enable vectorization of this "
5644 "loop with '#pragma clang loop vectorize(enable)' when "
5645 "compiling with -Os/-Oz",
5646 "CantVersionLoopWithOptForSize", ORE, TheLoop);
5647 return true;
5648 }
5649
5650 // FIXME: Avoid specializing for stride==1 instead of bailing out.
5651 if (!Legal->getLAI()->getSymbolicStrides().empty()) {
5652 reportVectorizationFailure("Runtime stride check for small trip count",
5653 "runtime stride == 1 checks needed. Enable vectorization of "
5654 "this loop without such check by compiling with -Os/-Oz",
5655 "CantVersionLoopWithOptForSize", ORE, TheLoop);
5656 return true;
5657 }
5658
5659 return false;
5660}
5661
5662ElementCount
5663LoopVectorizationCostModel::getMaxLegalScalableVF(unsigned MaxSafeElements) {
5664 if (!TTI.supportsScalableVectors() && !ForceTargetSupportsScalableVectors) {
5665 reportVectorizationInfo(
5666 "Disabling scalable vectorization, because target does not "
5667 "support scalable vectors.",
5668 "ScalableVectorsUnsupported", ORE, TheLoop);
5669 return ElementCount::getScalable(0);
5670 }
5671
5672 if (Hints->isScalableVectorizationDisabled()) {
5673 reportVectorizationInfo("Scalable vectorization is explicitly disabled",
5674 "ScalableVectorizationDisabled", ORE, TheLoop);
5675 return ElementCount::getScalable(0);
5676 }
5677
5678 auto MaxScalableVF = ElementCount::getScalable(
5679 std::numeric_limits<ElementCount::ScalarTy>::max());
5680
5681 // Disable scalable vectorization if the loop contains unsupported reductions.
5682 // Test that the loop-vectorizer can legalize all operations for this MaxVF.
5683 // FIXME: While for scalable vectors this is currently sufficient, this should
5684 // be replaced by a more detailed mechanism that filters out specific VFs,
5685 // instead of invalidating vectorization for a whole set of VFs based on the
5686 // MaxVF.
5687 if (!canVectorizeReductions(MaxScalableVF)) {
5688 reportVectorizationInfo(
5689 "Scalable vectorization not supported for the reduction "
5690 "operations found in this loop.",
5691 "ScalableVFUnfeasible", ORE, TheLoop);
5692 return ElementCount::getScalable(0);
5693 }
5694
5695 if (Legal->isSafeForAnyVectorWidth())
5696 return MaxScalableVF;
5697
5698 // Limit MaxScalableVF by the maximum safe dependence distance.
5699 Optional<unsigned> MaxVScale = TTI.getMaxVScale();
5700 MaxScalableVF = ElementCount::getScalable(
5701 MaxVScale ? (MaxSafeElements / MaxVScale.getValue()) : 0);
5702 if (!MaxScalableVF)
5703 reportVectorizationInfo(
5704 "Max legal vector width too small, scalable vectorization "
5705 "unfeasible.",
5706 "ScalableVFUnfeasible", ORE, TheLoop);
5707
5708 return MaxScalableVF;
5709}
5710
5711FixedScalableVFPair
5712LoopVectorizationCostModel::computeFeasibleMaxVF(unsigned ConstTripCount,
5713 ElementCount UserVF) {
5714 MinBWs = computeMinimumValueSizes(TheLoop->getBlocks(), *DB, &TTI);
5715 unsigned SmallestType, WidestType;
5716 std::tie(SmallestType, WidestType) = getSmallestAndWidestTypes();
5717
5718 // Get the maximum safe dependence distance in bits computed by LAA.
5719 // It is computed by MaxVF * sizeOf(type) * 8, where type is taken from
5720 // the memory accesses that is most restrictive (involved in the smallest
5721 // dependence distance).
5722 unsigned MaxSafeElements =
5723 PowerOf2Floor(Legal->getMaxSafeVectorWidthInBits() / WidestType);
5724
5725 auto MaxSafeFixedVF = ElementCount::getFixed(MaxSafeElements);
5726 auto MaxSafeScalableVF = getMaxLegalScalableVF(MaxSafeElements);
5727
5728 LLVM_DEBUG(dbgs() << "LV: The max safe fixed VF is: " << MaxSafeFixedVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The max safe fixed VF is: "
<< MaxSafeFixedVF << ".\n"; } } while (false)
5729 << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The max safe fixed VF is: "
<< MaxSafeFixedVF << ".\n"; } } while (false)
;
5730 LLVM_DEBUG(dbgs() << "LV: The max safe scalable VF is: " << MaxSafeScalableVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The max safe scalable VF is: "
<< MaxSafeScalableVF << ".\n"; } } while (false)
5731 << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The max safe scalable VF is: "
<< MaxSafeScalableVF << ".\n"; } } while (false)
;
5732
5733 // First analyze the UserVF, fall back if the UserVF should be ignored.
5734 if (UserVF) {
5735 auto MaxSafeUserVF =
5736 UserVF.isScalable() ? MaxSafeScalableVF : MaxSafeFixedVF;
5737
5738 if (ElementCount::isKnownLE(UserVF, MaxSafeUserVF))
5739 return UserVF;
5740
5741 assert(ElementCount::isKnownGT(UserVF, MaxSafeUserVF))(static_cast <bool> (ElementCount::isKnownGT(UserVF, MaxSafeUserVF
)) ? void (0) : __assert_fail ("ElementCount::isKnownGT(UserVF, MaxSafeUserVF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5741, __extension__ __PRETTY_FUNCTION__))
;
5742
5743 // Only clamp if the UserVF is not scalable. If the UserVF is scalable, it
5744 // is better to ignore the hint and let the compiler choose a suitable VF.
5745 if (!UserVF.isScalable()) {
5746 LLVM_DEBUG(dbgs() << "LV: User VF=" << UserVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: User VF=" <<
UserVF << " is unsafe, clamping to max safe VF=" <<
MaxSafeFixedVF << ".\n"; } } while (false)
5747 << " is unsafe, clamping to max safe VF="do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: User VF=" <<
UserVF << " is unsafe, clamping to max safe VF=" <<
MaxSafeFixedVF << ".\n"; } } while (false)
5748 << MaxSafeFixedVF << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: User VF=" <<
UserVF << " is unsafe, clamping to max safe VF=" <<
MaxSafeFixedVF << ".\n"; } } while (false)
;
5749 ORE->emit([&]() {
5750 return OptimizationRemarkAnalysis(DEBUG_TYPE"loop-vectorize", "VectorizationFactor",
5751 TheLoop->getStartLoc(),
5752 TheLoop->getHeader())
5753 << "User-specified vectorization factor "
5754 << ore::NV("UserVectorizationFactor", UserVF)
5755 << " is unsafe, clamping to maximum safe vectorization factor "
5756 << ore::NV("VectorizationFactor", MaxSafeFixedVF);
5757 });
5758 return MaxSafeFixedVF;
5759 }
5760
5761 LLVM_DEBUG(dbgs() << "LV: User VF=" << UserVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: User VF=" <<
UserVF << " is unsafe. Ignoring scalable UserVF.\n"; }
} while (false)
5762 << " is unsafe. Ignoring scalable UserVF.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: User VF=" <<
UserVF << " is unsafe. Ignoring scalable UserVF.\n"; }
} while (false)
;
5763 ORE->emit([&]() {
5764 return OptimizationRemarkAnalysis(DEBUG_TYPE"loop-vectorize", "VectorizationFactor",
5765 TheLoop->getStartLoc(),
5766 TheLoop->getHeader())
5767 << "User-specified vectorization factor "
5768 << ore::NV("UserVectorizationFactor", UserVF)
5769 << " is unsafe. Ignoring the hint to let the compiler pick a "
5770 "suitable VF.";
5771 });
5772 }
5773
5774 LLVM_DEBUG(dbgs() << "LV: The Smallest and Widest types: " << SmallestTypedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The Smallest and Widest types: "
<< SmallestType << " / " << WidestType <<
" bits.\n"; } } while (false)
5775 << " / " << WidestType << " bits.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The Smallest and Widest types: "
<< SmallestType << " / " << WidestType <<
" bits.\n"; } } while (false)
;
5776
5777 FixedScalableVFPair Result(ElementCount::getFixed(1),
5778 ElementCount::getScalable(0));
5779 if (auto MaxVF = getMaximizedVFForTarget(ConstTripCount, SmallestType,
5780 WidestType, MaxSafeFixedVF))
5781 Result.FixedVF = MaxVF;
5782
5783 if (auto MaxVF = getMaximizedVFForTarget(ConstTripCount, SmallestType,
5784 WidestType, MaxSafeScalableVF))
5785 if (MaxVF.isScalable()) {
5786 Result.ScalableVF = MaxVF;
5787 LLVM_DEBUG(dbgs() << "LV: Found feasible scalable VF = " << MaxVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found feasible scalable VF = "
<< MaxVF << "\n"; } } while (false)
5788 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found feasible scalable VF = "
<< MaxVF << "\n"; } } while (false)
;
5789 }
5790
5791 return Result;
5792}
5793
5794FixedScalableVFPair
5795LoopVectorizationCostModel::computeMaxVF(ElementCount UserVF, unsigned UserIC) {
5796 if (Legal->getRuntimePointerChecking()->Need && TTI.hasBranchDivergence()) {
5797 // TODO: It may by useful to do since it's still likely to be dynamically
5798 // uniform if the target can skip.
5799 reportVectorizationFailure(
5800 "Not inserting runtime ptr check for divergent target",
5801 "runtime pointer checks needed. Not enabled for divergent target",
5802 "CantVersionLoopWithDivergentTarget", ORE, TheLoop);
5803 return FixedScalableVFPair::getNone();
5804 }
5805
5806 unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop);
5807 LLVM_DEBUG(dbgs() << "LV: Found trip count: " << TC << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found trip count: "
<< TC << '\n'; } } while (false)
;
5808 if (TC == 1) {
5809 reportVectorizationFailure("Single iteration (non) loop",
5810 "loop trip count is one, irrelevant for vectorization",
5811 "SingleIterationLoop", ORE, TheLoop);
5812 return FixedScalableVFPair::getNone();
5813 }
5814
5815 switch (ScalarEpilogueStatus) {
5816 case CM_ScalarEpilogueAllowed:
5817 return computeFeasibleMaxVF(TC, UserVF);
5818 case CM_ScalarEpilogueNotAllowedUsePredicate:
5819 LLVM_FALLTHROUGH[[gnu::fallthrough]];
5820 case CM_ScalarEpilogueNotNeededUsePredicate:
5821 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n"
<< "LV: Not allowing scalar epilogue, creating predicated "
<< "vector loop.\n"; } } while (false)
5822 dbgs() << "LV: vector predicate hint/switch found.\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n"
<< "LV: Not allowing scalar epilogue, creating predicated "
<< "vector loop.\n"; } } while (false)
5823 << "LV: Not allowing scalar epilogue, creating predicated "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n"
<< "LV: Not allowing scalar epilogue, creating predicated "
<< "vector loop.\n"; } } while (false)
5824 << "vector loop.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n"
<< "LV: Not allowing scalar epilogue, creating predicated "
<< "vector loop.\n"; } } while (false)
;
5825 break;
5826 case CM_ScalarEpilogueNotAllowedLowTripLoop:
5827 // fallthrough as a special case of OptForSize
5828 case CM_ScalarEpilogueNotAllowedOptSize:
5829 if (ScalarEpilogueStatus == CM_ScalarEpilogueNotAllowedOptSize)
5830 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n"
; } } while (false)
5831 dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n"
; } } while (false)
;
5832 else
5833 LLVM_DEBUG(dbgs() << "LV: Not allowing scalar epilogue due to low trip "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to low trip "
<< "count.\n"; } } while (false)
5834 << "count.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to low trip "
<< "count.\n"; } } while (false)
;
5835
5836 // Bail if runtime checks are required, which are not good when optimising
5837 // for size.
5838 if (runtimeChecksRequired())
5839 return FixedScalableVFPair::getNone();
5840
5841 break;
5842 }
5843
5844 // The only loops we can vectorize without a scalar epilogue, are loops with
5845 // a bottom-test and a single exiting block. We'd have to handle the fact
5846 // that not every instruction executes on the last iteration. This will
5847 // require a lane mask which varies through the vector loop body. (TODO)
5848 if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) {
5849 // If there was a tail-folding hint/switch, but we can't fold the tail by
5850 // masking, fallback to a vectorization with a scalar epilogue.
5851 if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate) {
5852 LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking: vectorize with a "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a "
"scalar epilogue instead.\n"; } } while (false)
5853 "scalar epilogue instead.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a "
"scalar epilogue instead.\n"; } } while (false)
;
5854 ScalarEpilogueStatus = CM_ScalarEpilogueAllowed;
5855 return computeFeasibleMaxVF(TC, UserVF);
5856 }
5857 return FixedScalableVFPair::getNone();
5858 }
5859
5860 // Now try the tail folding
5861
5862 // Invalidate interleave groups that require an epilogue if we can't mask
5863 // the interleave-group.
5864 if (!useMaskedInterleavedAccesses(TTI)) {
5865 assert(WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() &&(static_cast <bool> (WideningDecisions.empty() &&
Uniforms.empty() && Scalars.empty() && "No decisions should have been taken at this point"
) ? void (0) : __assert_fail ("WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && \"No decisions should have been taken at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5866, __extension__ __PRETTY_FUNCTION__))
5866 "No decisions should have been taken at this point")(static_cast <bool> (WideningDecisions.empty() &&
Uniforms.empty() && Scalars.empty() && "No decisions should have been taken at this point"
) ? void (0) : __assert_fail ("WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && \"No decisions should have been taken at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5866, __extension__ __PRETTY_FUNCTION__))
;
5867 // Note: There is no need to invalidate any cost modeling decisions here, as
5868 // non where taken so far.
5869 InterleaveInfo.invalidateGroupsRequiringScalarEpilogue();
5870 }
5871
5872 FixedScalableVFPair MaxFactors = computeFeasibleMaxVF(TC, UserVF);
5873 // Avoid tail folding if the trip count is known to be a multiple of any VF
5874 // we chose.
5875 // FIXME: The condition below pessimises the case for fixed-width vectors,
5876 // when scalable VFs are also candidates for vectorization.
5877 if (MaxFactors.FixedVF.isVector() && !MaxFactors.ScalableVF) {
5878 ElementCount MaxFixedVF = MaxFactors.FixedVF;
5879 assert((UserVF.isNonZero() || isPowerOf2_32(MaxFixedVF.getFixedValue())) &&(static_cast <bool> ((UserVF.isNonZero() || isPowerOf2_32
(MaxFixedVF.getFixedValue())) && "MaxFixedVF must be a power of 2"
) ? void (0) : __assert_fail ("(UserVF.isNonZero() || isPowerOf2_32(MaxFixedVF.getFixedValue())) && \"MaxFixedVF must be a power of 2\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5880, __extension__ __PRETTY_FUNCTION__))
5880 "MaxFixedVF must be a power of 2")(static_cast <bool> ((UserVF.isNonZero() || isPowerOf2_32
(MaxFixedVF.getFixedValue())) && "MaxFixedVF must be a power of 2"
) ? void (0) : __assert_fail ("(UserVF.isNonZero() || isPowerOf2_32(MaxFixedVF.getFixedValue())) && \"MaxFixedVF must be a power of 2\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5880, __extension__ __PRETTY_FUNCTION__))
;
5881 unsigned MaxVFtimesIC = UserIC ? MaxFixedVF.getFixedValue() * UserIC
5882 : MaxFixedVF.getFixedValue();
5883 ScalarEvolution *SE = PSE.getSE();
5884 const SCEV *BackedgeTakenCount = PSE.getBackedgeTakenCount();
5885 const SCEV *ExitCount = SE->getAddExpr(
5886 BackedgeTakenCount, SE->getOne(BackedgeTakenCount->getType()));
5887 const SCEV *Rem = SE->getURemExpr(
5888 SE->applyLoopGuards(ExitCount, TheLoop),
5889 SE->getConstant(BackedgeTakenCount->getType(), MaxVFtimesIC));
5890 if (Rem->isZero()) {
5891 // Accept MaxFixedVF if we do not have a tail.
5892 LLVM_DEBUG(dbgs() << "LV: No tail will remain for any chosen VF.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: No tail will remain for any chosen VF.\n"
; } } while (false)
;
5893 return MaxFactors;
5894 }
5895 }
5896
5897 // If we don't know the precise trip count, or if the trip count that we
5898 // found modulo the vectorization factor is not zero, try to fold the tail
5899 // by masking.
5900 // FIXME: look for a smaller MaxVF that does divide TC rather than masking.
5901 if (Legal->prepareToFoldTailByMasking()) {
5902 FoldTailByMasking = true;
5903 return MaxFactors;
5904 }
5905
5906 // If there was a tail-folding hint/switch, but we can't fold the tail by
5907 // masking, fallback to a vectorization with a scalar epilogue.
5908 if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate) {
5909 LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking: vectorize with a "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a "
"scalar epilogue instead.\n"; } } while (false)
5910 "scalar epilogue instead.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a "
"scalar epilogue instead.\n"; } } while (false)
;
5911 ScalarEpilogueStatus = CM_ScalarEpilogueAllowed;
5912 return MaxFactors;
5913 }
5914
5915 if (ScalarEpilogueStatus == CM_ScalarEpilogueNotAllowedUsePredicate) {
5916 LLVM_DEBUG(dbgs() << "LV: Can't fold tail by masking: don't vectorize\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Can't fold tail by masking: don't vectorize\n"
; } } while (false)
;
5917 return FixedScalableVFPair::getNone();
5918 }
5919
5920 if (TC == 0) {
5921 reportVectorizationFailure(
5922 "Unable to calculate the loop count due to complex control flow",
5923 "unable to calculate the loop count due to complex control flow",
5924 "UnknownLoopCountComplexCFG", ORE, TheLoop);
5925 return FixedScalableVFPair::getNone();
5926 }
5927
5928 reportVectorizationFailure(
5929 "Cannot optimize for size and vectorize at the same time.",
5930 "cannot optimize for size and vectorize at the same time. "
5931 "Enable vectorization of this loop with '#pragma clang loop "
5932 "vectorize(enable)' when compiling with -Os/-Oz",
5933 "NoTailLoopWithOptForSize", ORE, TheLoop);
5934 return FixedScalableVFPair::getNone();
5935}
5936
5937ElementCount LoopVectorizationCostModel::getMaximizedVFForTarget(
5938 unsigned ConstTripCount, unsigned SmallestType, unsigned WidestType,
5939 const ElementCount &MaxSafeVF) {
5940 bool ComputeScalableMaxVF = MaxSafeVF.isScalable();
5941 TypeSize WidestRegister = TTI.getRegisterBitWidth(
5942 ComputeScalableMaxVF ? TargetTransformInfo::RGK_ScalableVector
5943 : TargetTransformInfo::RGK_FixedWidthVector);
5944
5945 // Convenience function to return the minimum of two ElementCounts.
5946 auto MinVF = [](const ElementCount &LHS, const ElementCount &RHS) {
5947 assert((LHS.isScalable() == RHS.isScalable()) &&(static_cast <bool> ((LHS.isScalable() == RHS.isScalable
()) && "Scalable flags must match") ? void (0) : __assert_fail
("(LHS.isScalable() == RHS.isScalable()) && \"Scalable flags must match\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5948, __extension__ __PRETTY_FUNCTION__))
5948 "Scalable flags must match")(static_cast <bool> ((LHS.isScalable() == RHS.isScalable
()) && "Scalable flags must match") ? void (0) : __assert_fail
("(LHS.isScalable() == RHS.isScalable()) && \"Scalable flags must match\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 5948, __extension__ __PRETTY_FUNCTION__))
;
5949 return ElementCount::isKnownLT(LHS, RHS) ? LHS : RHS;
5950 };
5951
5952 // Ensure MaxVF is a power of 2; the dependence distance bound may not be.
5953 // Note that both WidestRegister and WidestType may not be a powers of 2.
5954 auto MaxVectorElementCount = ElementCount::get(
5955 PowerOf2Floor(WidestRegister.getKnownMinSize() / WidestType),
5956 ComputeScalableMaxVF);
5957 MaxVectorElementCount = MinVF(MaxVectorElementCount, MaxSafeVF);
5958 LLVM_DEBUG(dbgs() << "LV: The Widest register safe to use is: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The Widest register safe to use is: "
<< (MaxVectorElementCount * WidestType) << " bits.\n"
; } } while (false)
5959 << (MaxVectorElementCount * WidestType) << " bits.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The Widest register safe to use is: "
<< (MaxVectorElementCount * WidestType) << " bits.\n"
; } } while (false)
;
5960
5961 if (!MaxVectorElementCount) {
5962 LLVM_DEBUG(dbgs() << "LV: The target has no "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has no "
<< (ComputeScalableMaxVF ? "scalable" : "fixed") <<
" vector registers.\n"; } } while (false)
5963 << (ComputeScalableMaxVF ? "scalable" : "fixed")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has no "
<< (ComputeScalableMaxVF ? "scalable" : "fixed") <<
" vector registers.\n"; } } while (false)
5964 << " vector registers.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has no "
<< (ComputeScalableMaxVF ? "scalable" : "fixed") <<
" vector registers.\n"; } } while (false)
;
5965 return ElementCount::getFixed(1);
5966 }
5967
5968 const auto TripCountEC = ElementCount::getFixed(ConstTripCount);
5969 if (ConstTripCount &&
5970 ElementCount::isKnownLE(TripCountEC, MaxVectorElementCount) &&
5971 isPowerOf2_32(ConstTripCount)) {
5972 // We need to clamp the VF to be the ConstTripCount. There is no point in
5973 // choosing a higher viable VF as done in the loop below. If
5974 // MaxVectorElementCount is scalable, we only fall back on a fixed VF when
5975 // the TC is less than or equal to the known number of lanes.
5976 LLVM_DEBUG(dbgs() << "LV: Clamping the MaxVF to the constant trip count: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Clamping the MaxVF to the constant trip count: "
<< ConstTripCount << "\n"; } } while (false)
5977 << ConstTripCount << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Clamping the MaxVF to the constant trip count: "
<< ConstTripCount << "\n"; } } while (false)
;
5978 return TripCountEC;
5979 }
5980
5981 ElementCount MaxVF = MaxVectorElementCount;
5982 if (TTI.shouldMaximizeVectorBandwidth() ||
5983 (MaximizeBandwidth && isScalarEpilogueAllowed())) {
5984 auto MaxVectorElementCountMaxBW = ElementCount::get(
5985 PowerOf2Floor(WidestRegister.getKnownMinSize() / SmallestType),
5986 ComputeScalableMaxVF);
5987 MaxVectorElementCountMaxBW = MinVF(MaxVectorElementCountMaxBW, MaxSafeVF);
5988
5989 // Collect all viable vectorization factors larger than the default MaxVF
5990 // (i.e. MaxVectorElementCount).
5991 SmallVector<ElementCount, 8> VFs;
5992 for (ElementCount VS = MaxVectorElementCount * 2;
5993 ElementCount::isKnownLE(VS, MaxVectorElementCountMaxBW); VS *= 2)
5994 VFs.push_back(VS);
5995
5996 // For each VF calculate its register usage.
5997 auto RUs = calculateRegisterUsage(VFs);
5998
5999 // Select the largest VF which doesn't require more registers than existing
6000 // ones.
6001 for (int i = RUs.size() - 1; i >= 0; --i) {
6002 bool Selected = true;
6003 for (auto &pair : RUs[i].MaxLocalUsers) {
6004 unsigned TargetNumRegisters = TTI.getNumberOfRegisters(pair.first);
6005 if (pair.second > TargetNumRegisters)
6006 Selected = false;
6007 }
6008 if (Selected) {
6009 MaxVF = VFs[i];
6010 break;
6011 }
6012 }
6013 if (ElementCount MinVF =
6014 TTI.getMinimumVF(SmallestType, ComputeScalableMaxVF)) {
6015 if (ElementCount::isKnownLT(MaxVF, MinVF)) {
6016 LLVM_DEBUG(dbgs() << "LV: Overriding calculated MaxVF(" << MaxVFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Overriding calculated MaxVF("
<< MaxVF << ") with target's minimum: " <<
MinVF << '\n'; } } while (false)
6017 << ") with target's minimum: " << MinVF << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Overriding calculated MaxVF("
<< MaxVF << ") with target's minimum: " <<
MinVF << '\n'; } } while (false)
;
6018 MaxVF = MinVF;
6019 }
6020 }
6021 }
6022 return MaxVF;
6023}
6024
6025bool LoopVectorizationCostModel::isMoreProfitable(
6026 const VectorizationFactor &A, const VectorizationFactor &B) const {
6027 InstructionCost::CostType CostA = *A.Cost.getValue();
6028 InstructionCost::CostType CostB = *B.Cost.getValue();
6029
6030 unsigned MaxTripCount = PSE.getSE()->getSmallConstantMaxTripCount(TheLoop);
6031
6032 if (!A.Width.isScalable() && !B.Width.isScalable() && FoldTailByMasking &&
6033 MaxTripCount) {
6034 // If we are folding the tail and the trip count is a known (possibly small)
6035 // constant, the trip count will be rounded up to an integer number of
6036 // iterations. The total cost will be PerIterationCost*ceil(TripCount/VF),
6037 // which we compare directly. When not folding the tail, the total cost will
6038 // be PerIterationCost*floor(TC/VF) + Scalar remainder cost, and so is
6039 // approximated with the per-lane cost below instead of using the tripcount
6040 // as here.
6041 int64_t RTCostA = CostA * divideCeil(MaxTripCount, A.Width.getFixedValue());
6042 int64_t RTCostB = CostB * divideCeil(MaxTripCount, B.Width.getFixedValue());
6043 return RTCostA < RTCostB;
6044 }
6045
6046 // When set to preferred, for now assume vscale may be larger than 1, so
6047 // that scalable vectorization is slightly favorable over fixed-width
6048 // vectorization.
6049 if (Hints->isScalableVectorizationPreferred())
6050 if (A.Width.isScalable() && !B.Width.isScalable())
6051 return (CostA * B.Width.getKnownMinValue()) <=
6052 (CostB * A.Width.getKnownMinValue());
6053
6054 // To avoid the need for FP division:
6055 // (CostA / A.Width) < (CostB / B.Width)
6056 // <=> (CostA * B.Width) < (CostB * A.Width)
6057 return (CostA * B.Width.getKnownMinValue()) <
6058 (CostB * A.Width.getKnownMinValue());
6059}
6060
6061VectorizationFactor LoopVectorizationCostModel::selectVectorizationFactor(
6062 const ElementCountSet &VFCandidates) {
6063 InstructionCost ExpectedCost = expectedCost(ElementCount::getFixed(1)).first;
6064 LLVM_DEBUG(dbgs() << "LV: Scalar loop costs: " << ExpectedCost << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Scalar loop costs: "
<< ExpectedCost << ".\n"; } } while (false)
;
6065 assert(ExpectedCost.isValid() && "Unexpected invalid cost for scalar loop")(static_cast <bool> (ExpectedCost.isValid() && "Unexpected invalid cost for scalar loop"
) ? void (0) : __assert_fail ("ExpectedCost.isValid() && \"Unexpected invalid cost for scalar loop\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6065, __extension__ __PRETTY_FUNCTION__))
;
6066 assert(VFCandidates.count(ElementCount::getFixed(1)) &&(static_cast <bool> (VFCandidates.count(ElementCount::getFixed
(1)) && "Expected Scalar VF to be a candidate") ? void
(0) : __assert_fail ("VFCandidates.count(ElementCount::getFixed(1)) && \"Expected Scalar VF to be a candidate\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6067, __extension__ __PRETTY_FUNCTION__))
6067 "Expected Scalar VF to be a candidate")(static_cast <bool> (VFCandidates.count(ElementCount::getFixed
(1)) && "Expected Scalar VF to be a candidate") ? void
(0) : __assert_fail ("VFCandidates.count(ElementCount::getFixed(1)) && \"Expected Scalar VF to be a candidate\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6067, __extension__ __PRETTY_FUNCTION__))
;
6068
6069 const VectorizationFactor ScalarCost(ElementCount::getFixed(1), ExpectedCost);
6070 VectorizationFactor ChosenFactor = ScalarCost;
6071
6072 bool ForceVectorization = Hints->getForce() == LoopVectorizeHints::FK_Enabled;
6073 if (ForceVectorization && VFCandidates.size() > 1) {
6074 // Ignore scalar width, because the user explicitly wants vectorization.
6075 // Initialize cost to max so that VF = 2 is, at least, chosen during cost
6076 // evaluation.
6077 ChosenFactor.Cost = std::numeric_limits<InstructionCost::CostType>::max();
6078 }
6079
6080 for (const auto &i : VFCandidates) {
6081 // The cost for scalar VF=1 is already calculated, so ignore it.
6082 if (i.isScalar())
6083 continue;
6084
6085 // Notice that the vector loop needs to be executed less times, so
6086 // we need to divide the cost of the vector loops by the width of
6087 // the vector elements.
6088 VectorizationCostTy C = expectedCost(i);
6089
6090 assert(C.first.isValid() && "Unexpected invalid cost for vector loop")(static_cast <bool> (C.first.isValid() && "Unexpected invalid cost for vector loop"
) ? void (0) : __assert_fail ("C.first.isValid() && \"Unexpected invalid cost for vector loop\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6090, __extension__ __PRETTY_FUNCTION__))
;
6091 VectorizationFactor Candidate(i, C.first);
6092 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
6093 dbgs() << "LV: Vector loop of width " << i << " costs: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
6094 << (*Candidate.Cost.getValue() /do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
6095 Candidate.Width.getKnownMinValue())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
6096 << (i.isScalable() ? " (assuming a minimum vscale of 1)" : "")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
6097 << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vector loop of width "
<< i << " costs: " << (*Candidate.Cost.getValue
() / Candidate.Width.getKnownMinValue()) << (i.isScalable
() ? " (assuming a minimum vscale of 1)" : "") << ".\n"
; } } while (false)
;
6098
6099 if (!C.second && !ForceVectorization) {
6100 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not considering vector loop of width "
<< i << " because it will not generate any vector instructions.\n"
; } } while (false)
6101 dbgs() << "LV: Not considering vector loop of width " << ido { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not considering vector loop of width "
<< i << " because it will not generate any vector instructions.\n"
; } } while (false)
6102 << " because it will not generate any vector instructions.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not considering vector loop of width "
<< i << " because it will not generate any vector instructions.\n"
; } } while (false)
;
6103 continue;
6104 }
6105
6106 // If profitable add it to ProfitableVF list.
6107 if (isMoreProfitable(Candidate, ScalarCost))
6108 ProfitableVFs.push_back(Candidate);
6109
6110 if (isMoreProfitable(Candidate, ChosenFactor))
6111 ChosenFactor = Candidate;
6112 }
6113
6114 if (!EnableCondStoresVectorization && NumPredStores) {
6115 reportVectorizationFailure("There are conditional stores.",
6116 "store that is conditionally executed prevents vectorization",
6117 "ConditionalStore", ORE, TheLoop);
6118 ChosenFactor = ScalarCost;
6119 }
6120
6121 LLVM_DEBUG(if (ForceVectorization && !ChosenFactor.Width.isScalar() &&do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { if (ForceVectorization && !ChosenFactor
.Width.isScalar() && *ChosenFactor.Cost.getValue() >=
*ScalarCost.Cost.getValue()) dbgs() << "LV: Vectorization seems to be not beneficial, "
<< "but was forced by a user.\n"; } } while (false)
6122 *ChosenFactor.Cost.getValue() >= *ScalarCost.Cost.getValue())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { if (ForceVectorization && !ChosenFactor
.Width.isScalar() && *ChosenFactor.Cost.getValue() >=
*ScalarCost.Cost.getValue()) dbgs() << "LV: Vectorization seems to be not beneficial, "
<< "but was forced by a user.\n"; } } while (false)
6123 dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { if (ForceVectorization && !ChosenFactor
.Width.isScalar() && *ChosenFactor.Cost.getValue() >=
*ScalarCost.Cost.getValue()) dbgs() << "LV: Vectorization seems to be not beneficial, "
<< "but was forced by a user.\n"; } } while (false)
6124 << "LV: Vectorization seems to be not beneficial, "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { if (ForceVectorization && !ChosenFactor
.Width.isScalar() && *ChosenFactor.Cost.getValue() >=
*ScalarCost.Cost.getValue()) dbgs() << "LV: Vectorization seems to be not beneficial, "
<< "but was forced by a user.\n"; } } while (false)
6125 << "but was forced by a user.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { if (ForceVectorization && !ChosenFactor
.Width.isScalar() && *ChosenFactor.Cost.getValue() >=
*ScalarCost.Cost.getValue()) dbgs() << "LV: Vectorization seems to be not beneficial, "
<< "but was forced by a user.\n"; } } while (false)
;
6126 LLVM_DEBUG(dbgs() << "LV: Selecting VF: " << ChosenFactor.Width << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Selecting VF: " <<
ChosenFactor.Width << ".\n"; } } while (false)
;
6127 return ChosenFactor;
6128}
6129
6130bool LoopVectorizationCostModel::isCandidateForEpilogueVectorization(
6131 const Loop &L, ElementCount VF) const {
6132 // Cross iteration phis such as reductions need special handling and are
6133 // currently unsupported.
6134 if (any_of(L.getHeader()->phis(), [&](PHINode &Phi) {
6135 return Legal->isFirstOrderRecurrence(&Phi) ||
6136 Legal->isReductionVariable(&Phi);
6137 }))
6138 return false;
6139
6140 // Phis with uses outside of the loop require special handling and are
6141 // currently unsupported.
6142 for (auto &Entry : Legal->getInductionVars()) {
6143 // Look for uses of the value of the induction at the last iteration.
6144 Value *PostInc = Entry.first->getIncomingValueForBlock(L.getLoopLatch());
6145 for (User *U : PostInc->users())
6146 if (!L.contains(cast<Instruction>(U)))
6147 return false;
6148 // Look for uses of penultimate value of the induction.
6149 for (User *U : Entry.first->users())
6150 if (!L.contains(cast<Instruction>(U)))
6151 return false;
6152 }
6153
6154 // Induction variables that are widened require special handling that is
6155 // currently not supported.
6156 if (any_of(Legal->getInductionVars(), [&](auto &Entry) {
6157 return !(this->isScalarAfterVectorization(Entry.first, VF) ||
6158 this->isProfitableToScalarize(Entry.first, VF));
6159 }))
6160 return false;
6161
6162 return true;
6163}
6164
6165bool LoopVectorizationCostModel::isEpilogueVectorizationProfitable(
6166 const ElementCount VF) const {
6167 // FIXME: We need a much better cost-model to take different parameters such
6168 // as register pressure, code size increase and cost of extra branches into
6169 // account. For now we apply a very crude heuristic and only consider loops
6170 // with vectorization factors larger than a certain value.
6171 // We also consider epilogue vectorization unprofitable for targets that don't
6172 // consider interleaving beneficial (eg. MVE).
6173 if (TTI.getMaxInterleaveFactor(VF.getKnownMinValue()) <= 1)
6174 return false;
6175 if (VF.getFixedValue() >= EpilogueVectorizationMinVF)
6176 return true;
6177 return false;
6178}
6179
6180VectorizationFactor
6181LoopVectorizationCostModel::selectEpilogueVectorizationFactor(
6182 const ElementCount MainLoopVF, const LoopVectorizationPlanner &LVP) {
6183 VectorizationFactor Result = VectorizationFactor::Disabled();
6184 if (!EnableEpilogueVectorization) {
6185 LLVM_DEBUG(dbgs() << "LEV: Epilogue vectorization is disabled.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization is disabled.\n"
;; } } while (false)
;
6186 return Result;
6187 }
6188
6189 if (!isScalarEpilogueAllowed()) {
6190 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because no epilogue is "
"allowed.\n";; } } while (false)
6191 dbgs() << "LEV: Unable to vectorize epilogue because no epilogue is "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because no epilogue is "
"allowed.\n";; } } while (false)
6192 "allowed.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because no epilogue is "
"allowed.\n";; } } while (false)
;
6193 return Result;
6194 }
6195
6196 // FIXME: This can be fixed for scalable vectors later, because at this stage
6197 // the LoopVectorizer will only consider vectorizing a loop with scalable
6198 // vectors when the loop has a hint to enable vectorization for a given VF.
6199 if (MainLoopVF.isScalable()) {
6200 LLVM_DEBUG(dbgs() << "LEV: Epilogue vectorization for scalable vectors not "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization for scalable vectors not "
"yet supported.\n"; } } while (false)
6201 "yet supported.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization for scalable vectors not "
"yet supported.\n"; } } while (false)
;
6202 return Result;
6203 }
6204
6205 // Not really a cost consideration, but check for unsupported cases here to
6206 // simplify the logic.
6207 if (!isCandidateForEpilogueVectorization(*TheLoop, MainLoopVF)) {
6208 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because the loop is "
"not a supported candidate.\n";; } } while (false)
6209 dbgs() << "LEV: Unable to vectorize epilogue because the loop is "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because the loop is "
"not a supported candidate.\n";; } } while (false)
6210 "not a supported candidate.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Unable to vectorize epilogue because the loop is "
"not a supported candidate.\n";; } } while (false)
;
6211 return Result;
6212 }
6213
6214 if (EpilogueVectorizationForceVF > 1) {
6215 LLVM_DEBUG(dbgs() << "LEV: Epilogue vectorization factor is forced.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization factor is forced.\n"
;; } } while (false)
;
6216 if (LVP.hasPlanWithVFs(
6217 {MainLoopVF, ElementCount::getFixed(EpilogueVectorizationForceVF)}))
6218 return {ElementCount::getFixed(EpilogueVectorizationForceVF), 0};
6219 else {
6220 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization forced factor is not viable.\n"
;; } } while (false)
6221 dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization forced factor is not viable.\n"
;; } } while (false)
6222 << "LEV: Epilogue vectorization forced factor is not viable.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization forced factor is not viable.\n"
;; } } while (false)
;
6223 return Result;
6224 }
6225 }
6226
6227 if (TheLoop->getHeader()->getParent()->hasOptSize() ||
6228 TheLoop->getHeader()->getParent()->hasMinSize()) {
6229 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization skipped due to opt for size.\n"
;; } } while (false)
6230 dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization skipped due to opt for size.\n"
;; } } while (false)
6231 << "LEV: Epilogue vectorization skipped due to opt for size.\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Epilogue vectorization skipped due to opt for size.\n"
;; } } while (false)
;
6232 return Result;
6233 }
6234
6235 if (!isEpilogueVectorizationProfitable(MainLoopVF))
6236 return Result;
6237
6238 for (auto &NextVF : ProfitableVFs)
6239 if (ElementCount::isKnownLT(NextVF.Width, MainLoopVF) &&
6240 (Result.Width.getFixedValue() == 1 ||
6241 isMoreProfitable(NextVF, Result)) &&
6242 LVP.hasPlanWithVFs({MainLoopVF, NextVF.Width}))
6243 Result = NextVF;
6244
6245 if (Result != VectorizationFactor::Disabled())
6246 LLVM_DEBUG(dbgs() << "LEV: Vectorizing epilogue loop with VF = "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Vectorizing epilogue loop with VF = "
<< Result.Width.getFixedValue() << "\n";; } } while
(false)
6247 << Result.Width.getFixedValue() << "\n";)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LEV: Vectorizing epilogue loop with VF = "
<< Result.Width.getFixedValue() << "\n";; } } while
(false)
;
6248 return Result;
6249}
6250
6251std::pair<unsigned, unsigned>
6252LoopVectorizationCostModel::getSmallestAndWidestTypes() {
6253 unsigned MinWidth = -1U;
6254 unsigned MaxWidth = 8;
6255 const DataLayout &DL = TheFunction->getParent()->getDataLayout();
6256
6257 // For each block.
6258 for (BasicBlock *BB : TheLoop->blocks()) {
6259 // For each instruction in the loop.
6260 for (Instruction &I : BB->instructionsWithoutDebug()) {
6261 Type *T = I.getType();
6262
6263 // Skip ignored values.
6264 if (ValuesToIgnore.count(&I))
6265 continue;
6266
6267 // Only examine Loads, Stores and PHINodes.
6268 if (!isa<LoadInst>(I) && !isa<StoreInst>(I) && !isa<PHINode>(I))
6269 continue;
6270
6271 // Examine PHI nodes that are reduction variables. Update the type to
6272 // account for the recurrence type.
6273 if (auto *PN = dyn_cast<PHINode>(&I)) {
6274 if (!Legal->isReductionVariable(PN))
6275 continue;
6276 const RecurrenceDescriptor &RdxDesc = Legal->getReductionVars()[PN];
6277 if (PreferInLoopReductions || useOrderedReductions(RdxDesc) ||
6278 TTI.preferInLoopReduction(RdxDesc.getOpcode(),
6279 RdxDesc.getRecurrenceType(),
6280 TargetTransformInfo::ReductionFlags()))
6281 continue;
6282 T = RdxDesc.getRecurrenceType();
6283 }
6284
6285 // Examine the stored values.
6286 if (auto *ST = dyn_cast<StoreInst>(&I))
6287 T = ST->getValueOperand()->getType();
6288
6289 // Ignore loaded pointer types and stored pointer types that are not
6290 // vectorizable.
6291 //
6292 // FIXME: The check here attempts to predict whether a load or store will
6293 // be vectorized. We only know this for certain after a VF has
6294 // been selected. Here, we assume that if an access can be
6295 // vectorized, it will be. We should also look at extending this
6296 // optimization to non-pointer types.
6297 //
6298 if (T->isPointerTy() && !isConsecutiveLoadOrStore(&I) &&
6299 !isAccessInterleaved(&I) && !isLegalGatherOrScatter(&I))
6300 continue;
6301
6302 MinWidth = std::min(MinWidth,
6303 (unsigned)DL.getTypeSizeInBits(T->getScalarType()));
6304 MaxWidth = std::max(MaxWidth,
6305 (unsigned)DL.getTypeSizeInBits(T->getScalarType()));
6306 }
6307 }
6308
6309 return {MinWidth, MaxWidth};
6310}
6311
6312unsigned LoopVectorizationCostModel::selectInterleaveCount(ElementCount VF,
6313 unsigned LoopCost) {
6314 // -- The interleave heuristics --
6315 // We interleave the loop in order to expose ILP and reduce the loop overhead.
6316 // There are many micro-architectural considerations that we can't predict
6317 // at this level. For example, frontend pressure (on decode or fetch) due to
6318 // code size, or the number and capabilities of the execution ports.
6319 //
6320 // We use the following heuristics to select the interleave count:
6321 // 1. If the code has reductions, then we interleave to break the cross
6322 // iteration dependency.
6323 // 2. If the loop is really small, then we interleave to reduce the loop
6324 // overhead.
6325 // 3. We don't interleave if we think that we will spill registers to memory
6326 // due to the increased register pressure.
6327
6328 if (!isScalarEpilogueAllowed())
6329 return 1;
6330
6331 // We used the distance for the interleave count.
6332 if (Legal->getMaxSafeDepDistBytes() != -1U)
6333 return 1;
6334
6335 auto BestKnownTC = getSmallBestKnownTC(*PSE.getSE(), TheLoop);
6336 const bool HasReductions = !Legal->getReductionVars().empty();
6337 // Do not interleave loops with a relatively small known or estimated trip
6338 // count. But we will interleave when InterleaveSmallLoopScalarReduction is
6339 // enabled, and the code has scalar reductions(HasReductions && VF = 1),
6340 // because with the above conditions interleaving can expose ILP and break
6341 // cross iteration dependences for reductions.
6342 if (BestKnownTC && (*BestKnownTC < TinyTripCountInterleaveThreshold) &&
6343 !(InterleaveSmallLoopScalarReduction && HasReductions && VF.isScalar()))
6344 return 1;
6345
6346 RegisterUsage R = calculateRegisterUsage({VF})[0];
6347 // We divide by these constants so assume that we have at least one
6348 // instruction that uses at least one register.
6349 for (auto& pair : R.MaxLocalUsers) {
6350 pair.second = std::max(pair.second, 1U);
6351 }
6352
6353 // We calculate the interleave count using the following formula.
6354 // Subtract the number of loop invariants from the number of available
6355 // registers. These registers are used by all of the interleaved instances.
6356 // Next, divide the remaining registers by the number of registers that is
6357 // required by the loop, in order to estimate how many parallel instances
6358 // fit without causing spills. All of this is rounded down if necessary to be
6359 // a power of two. We want power of two interleave count to simplify any
6360 // addressing operations or alignment considerations.
6361 // We also want power of two interleave counts to ensure that the induction
6362 // variable of the vector loop wraps to zero, when tail is folded by masking;
6363 // this currently happens when OptForSize, in which case IC is set to 1 above.
6364 unsigned IC = UINT_MAX(2147483647 *2U +1U);
6365
6366 for (auto& pair : R.MaxLocalUsers) {
6367 unsigned TargetNumRegisters = TTI.getNumberOfRegisters(pair.first);
6368 LLVM_DEBUG(dbgs() << "LV: The target has " << TargetNumRegistersdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has " <<
TargetNumRegisters << " registers of " << TTI.getRegisterClassName
(pair.first) << " register class\n"; } } while (false)
6369 << " registers of "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has " <<
TargetNumRegisters << " registers of " << TTI.getRegisterClassName
(pair.first) << " register class\n"; } } while (false)
6370 << TTI.getRegisterClassName(pair.first) << " register class\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: The target has " <<
TargetNumRegisters << " registers of " << TTI.getRegisterClassName
(pair.first) << " register class\n"; } } while (false)
;
6371 if (VF.isScalar()) {
6372 if (ForceTargetNumScalarRegs.getNumOccurrences() > 0)
6373 TargetNumRegisters = ForceTargetNumScalarRegs;
6374 } else {
6375 if (ForceTargetNumVectorRegs.getNumOccurrences() > 0)
6376 TargetNumRegisters = ForceTargetNumVectorRegs;
6377 }
6378 unsigned MaxLocalUsers = pair.second;
6379 unsigned LoopInvariantRegs = 0;
6380 if (R.LoopInvariantRegs.find(pair.first) != R.LoopInvariantRegs.end())
6381 LoopInvariantRegs = R.LoopInvariantRegs[pair.first];
6382
6383 unsigned TmpIC = PowerOf2Floor((TargetNumRegisters - LoopInvariantRegs) / MaxLocalUsers);
6384 // Don't count the induction variable as interleaved.
6385 if (EnableIndVarRegisterHeur) {
6386 TmpIC =
6387 PowerOf2Floor((TargetNumRegisters - LoopInvariantRegs - 1) /
6388 std::max(1U, (MaxLocalUsers - 1)));
6389 }
6390
6391 IC = std::min(IC, TmpIC);
6392 }
6393
6394 // Clamp the interleave ranges to reasonable counts.
6395 unsigned MaxInterleaveCount =
6396 TTI.getMaxInterleaveFactor(VF.getKnownMinValue());
6397
6398 // Check if the user has overridden the max.
6399 if (VF.isScalar()) {
6400 if (ForceTargetMaxScalarInterleaveFactor.getNumOccurrences() > 0)
6401 MaxInterleaveCount = ForceTargetMaxScalarInterleaveFactor;
6402 } else {
6403 if (ForceTargetMaxVectorInterleaveFactor.getNumOccurrences() > 0)
6404 MaxInterleaveCount = ForceTargetMaxVectorInterleaveFactor;
6405 }
6406
6407 // If trip count is known or estimated compile time constant, limit the
6408 // interleave count to be less than the trip count divided by VF, provided it
6409 // is at least 1.
6410 //
6411 // For scalable vectors we can't know if interleaving is beneficial. It may
6412 // not be beneficial for small loops if none of the lanes in the second vector
6413 // iterations is enabled. However, for larger loops, there is likely to be a
6414 // similar benefit as for fixed-width vectors. For now, we choose to leave
6415 // the InterleaveCount as if vscale is '1', although if some information about
6416 // the vector is known (e.g. min vector size), we can make a better decision.
6417 if (BestKnownTC) {
6418 MaxInterleaveCount =
6419 std::min(*BestKnownTC / VF.getKnownMinValue(), MaxInterleaveCount);
6420 // Make sure MaxInterleaveCount is greater than 0.
6421 MaxInterleaveCount = std::max(1u, MaxInterleaveCount);
6422 }
6423
6424 assert(MaxInterleaveCount > 0 &&(static_cast <bool> (MaxInterleaveCount > 0 &&
"Maximum interleave count must be greater than 0") ? void (0
) : __assert_fail ("MaxInterleaveCount > 0 && \"Maximum interleave count must be greater than 0\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6425, __extension__ __PRETTY_FUNCTION__))
6425 "Maximum interleave count must be greater than 0")(static_cast <bool> (MaxInterleaveCount > 0 &&
"Maximum interleave count must be greater than 0") ? void (0
) : __assert_fail ("MaxInterleaveCount > 0 && \"Maximum interleave count must be greater than 0\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6425, __extension__ __PRETTY_FUNCTION__))
;
6426
6427 // Clamp the calculated IC to be between the 1 and the max interleave count
6428 // that the target and trip count allows.
6429 if (IC > MaxInterleaveCount)
6430 IC = MaxInterleaveCount;
6431 else
6432 // Make sure IC is greater than 0.
6433 IC = std::max(1u, IC);
6434
6435 assert(IC > 0 && "Interleave count must be greater than 0.")(static_cast <bool> (IC > 0 && "Interleave count must be greater than 0."
) ? void (0) : __assert_fail ("IC > 0 && \"Interleave count must be greater than 0.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6435, __extension__ __PRETTY_FUNCTION__))
;
6436
6437 // If we did not calculate the cost for VF (because the user selected the VF)
6438 // then we calculate the cost of VF here.
6439 if (LoopCost == 0) {
6440 assert(expectedCost(VF).first.isValid() && "Expected a valid cost")(static_cast <bool> (expectedCost(VF).first.isValid() &&
"Expected a valid cost") ? void (0) : __assert_fail ("expectedCost(VF).first.isValid() && \"Expected a valid cost\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6440, __extension__ __PRETTY_FUNCTION__))
;
6441 LoopCost = *expectedCost(VF).first.getValue();
6442 }
6443
6444 assert(LoopCost && "Non-zero loop cost expected")(static_cast <bool> (LoopCost && "Non-zero loop cost expected"
) ? void (0) : __assert_fail ("LoopCost && \"Non-zero loop cost expected\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6444, __extension__ __PRETTY_FUNCTION__))
;
6445
6446 // Interleave if we vectorized this loop and there is a reduction that could
6447 // benefit from interleaving.
6448 if (VF.isVector() && HasReductions) {
6449 LLVM_DEBUG(dbgs() << "LV: Interleaving because of reductions.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving because of reductions.\n"
; } } while (false)
;
6450 return IC;
6451 }
6452
6453 // Note that if we've already vectorized the loop we will have done the
6454 // runtime check and so interleaving won't require further checks.
6455 bool InterleavingRequiresRuntimePointerCheck =
6456 (VF.isScalar() && Legal->getRuntimePointerChecking()->Need);
6457
6458 // We want to interleave small loops in order to reduce the loop overhead and
6459 // potentially expose ILP opportunities.
6460 LLVM_DEBUG(dbgs() << "LV: Loop cost is " << LoopCost << '\n'do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop cost is " <<
LoopCost << '\n' << "LV: IC is " << IC <<
'\n' << "LV: VF is " << VF << '\n'; } } while
(false)
6461 << "LV: IC is " << IC << '\n'do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop cost is " <<
LoopCost << '\n' << "LV: IC is " << IC <<
'\n' << "LV: VF is " << VF << '\n'; } } while
(false)
6462 << "LV: VF is " << VF << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop cost is " <<
LoopCost << '\n' << "LV: IC is " << IC <<
'\n' << "LV: VF is " << VF << '\n'; } } while
(false)
;
6463 const bool AggressivelyInterleaveReductions =
6464 TTI.enableAggressiveInterleaving(HasReductions);
6465 if (!InterleavingRequiresRuntimePointerCheck && LoopCost < SmallLoopCost) {
6466 // We assume that the cost overhead is 1 and we use the cost model
6467 // to estimate the cost of the loop and interleave until the cost of the
6468 // loop overhead is about 5% of the cost of the loop.
6469 unsigned SmallIC =
6470 std::min(IC, (unsigned)PowerOf2Floor(SmallLoopCost / LoopCost));
6471
6472 // Interleave until store/load ports (estimated by max interleave count) are
6473 // saturated.
6474 unsigned NumStores = Legal->getNumStores();
6475 unsigned NumLoads = Legal->getNumLoads();
6476 unsigned StoresIC = IC / (NumStores ? NumStores : 1);
6477 unsigned LoadsIC = IC / (NumLoads ? NumLoads : 1);
6478
6479 // If we have a scalar reduction (vector reductions are already dealt with
6480 // by this point), we can increase the critical path length if the loop
6481 // we're interleaving is inside another loop. Limit, by default to 2, so the
6482 // critical path only gets increased by one reduction operation.
6483 if (HasReductions && TheLoop->getLoopDepth() > 1) {
6484 unsigned F = static_cast<unsigned>(MaxNestedScalarReductionIC);
6485 SmallIC = std::min(SmallIC, F);
6486 StoresIC = std::min(StoresIC, F);
6487 LoadsIC = std::min(LoadsIC, F);
6488 }
6489
6490 if (EnableLoadStoreRuntimeInterleave &&
6491 std::max(StoresIC, LoadsIC) > SmallIC) {
6492 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving to saturate store or load ports.\n"
; } } while (false)
6493 dbgs() << "LV: Interleaving to saturate store or load ports.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving to saturate store or load ports.\n"
; } } while (false)
;
6494 return std::max(StoresIC, LoadsIC);
6495 }
6496
6497 // If there are scalar reductions and TTI has enabled aggressive
6498 // interleaving for reductions, we will interleave to expose ILP.
6499 if (InterleaveSmallLoopScalarReduction && VF.isScalar() &&
6500 AggressivelyInterleaveReductions) {
6501 LLVM_DEBUG(dbgs() << "LV: Interleaving to expose ILP.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving to expose ILP.\n"
; } } while (false)
;
6502 // Interleave no less than SmallIC but not as aggressive as the normal IC
6503 // to satisfy the rare situation when resources are too limited.
6504 return std::max(IC / 2, SmallIC);
6505 } else {
6506 LLVM_DEBUG(dbgs() << "LV: Interleaving to reduce branch cost.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving to reduce branch cost.\n"
; } } while (false)
;
6507 return SmallIC;
6508 }
6509 }
6510
6511 // Interleave if this is a large loop (small loops are already dealt with by
6512 // this point) that could benefit from interleaving.
6513 if (AggressivelyInterleaveReductions) {
6514 LLVM_DEBUG(dbgs() << "LV: Interleaving to expose ILP.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving to expose ILP.\n"
; } } while (false)
;
6515 return IC;
6516 }
6517
6518 LLVM_DEBUG(dbgs() << "LV: Not Interleaving.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not Interleaving.\n"
; } } while (false)
;
6519 return 1;
6520}
6521
6522SmallVector<LoopVectorizationCostModel::RegisterUsage, 8>
6523LoopVectorizationCostModel::calculateRegisterUsage(ArrayRef<ElementCount> VFs) {
6524 // This function calculates the register usage by measuring the highest number
6525 // of values that are alive at a single location. Obviously, this is a very
6526 // rough estimation. We scan the loop in a topological order in order and
6527 // assign a number to each instruction. We use RPO to ensure that defs are
6528 // met before their users. We assume that each instruction that has in-loop
6529 // users starts an interval. We record every time that an in-loop value is
6530 // used, so we have a list of the first and last occurrences of each
6531 // instruction. Next, we transpose this data structure into a multi map that
6532 // holds the list of intervals that *end* at a specific location. This multi
6533 // map allows us to perform a linear search. We scan the instructions linearly
6534 // and record each time that a new interval starts, by placing it in a set.
6535 // If we find this value in the multi-map then we remove it from the set.
6536 // The max register usage is the maximum size of the set.
6537 // We also search for instructions that are defined outside the loop, but are
6538 // used inside the loop. We need this number separately from the max-interval
6539 // usage number because when we unroll, loop-invariant values do not take
6540 // more register.
6541 LoopBlocksDFS DFS(TheLoop);
6542 DFS.perform(LI);
6543
6544 RegisterUsage RU;
6545
6546 // Each 'key' in the map opens a new interval. The values
6547 // of the map are the index of the 'last seen' usage of the
6548 // instruction that is the key.
6549 using IntervalMap = DenseMap<Instruction *, unsigned>;
6550
6551 // Maps instruction to its index.
6552 SmallVector<Instruction *, 64> IdxToInstr;
6553 // Marks the end of each interval.
6554 IntervalMap EndPoint;
6555 // Saves the list of instruction indices that are used in the loop.
6556 SmallPtrSet<Instruction *, 8> Ends;
6557 // Saves the list of values that are used in the loop but are
6558 // defined outside the loop, such as arguments and constants.
6559 SmallPtrSet<Value *, 8> LoopInvariants;
6560
6561 for (BasicBlock *BB : make_range(DFS.beginRPO(), DFS.endRPO())) {
6562 for (Instruction &I : BB->instructionsWithoutDebug()) {
6563 IdxToInstr.push_back(&I);
6564
6565 // Save the end location of each USE.
6566 for (Value *U : I.operands()) {
6567 auto *Instr = dyn_cast<Instruction>(U);
6568
6569 // Ignore non-instruction values such as arguments, constants, etc.
6570 if (!Instr)
6571 continue;
6572
6573 // If this instruction is outside the loop then record it and continue.
6574 if (!TheLoop->contains(Instr)) {
6575 LoopInvariants.insert(Instr);
6576 continue;
6577 }
6578
6579 // Overwrite previous end points.
6580 EndPoint[Instr] = IdxToInstr.size();
6581 Ends.insert(Instr);
6582 }
6583 }
6584 }
6585
6586 // Saves the list of intervals that end with the index in 'key'.
6587 using InstrList = SmallVector<Instruction *, 2>;
6588 DenseMap<unsigned, InstrList> TransposeEnds;
6589
6590 // Transpose the EndPoints to a list of values that end at each index.
6591 for (auto &Interval : EndPoint)
6592 TransposeEnds[Interval.second].push_back(Interval.first);
6593
6594 SmallPtrSet<Instruction *, 8> OpenIntervals;
6595 SmallVector<RegisterUsage, 8> RUs(VFs.size());
6596 SmallVector<SmallMapVector<unsigned, unsigned, 4>, 8> MaxUsages(VFs.size());
6597
6598 LLVM_DEBUG(dbgs() << "LV(REG): Calculating max register usage:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV(REG): Calculating max register usage:\n"
; } } while (false)
;
6599
6600 // A lambda that gets the register usage for the given type and VF.
6601 const auto &TTICapture = TTI;
6602 auto GetRegUsage = [&TTICapture](Type *Ty, ElementCount VF) {
6603 if (Ty->isTokenTy() || !VectorType::isValidElementType(Ty))
6604 return 0;
6605 return *TTICapture.getRegUsageForType(VectorType::get(Ty, VF)).getValue();
6606 };
6607
6608 for (unsigned int i = 0, s = IdxToInstr.size(); i < s; ++i) {
6609 Instruction *I = IdxToInstr[i];
6610
6611 // Remove all of the instructions that end at this location.
6612 InstrList &List = TransposeEnds[i];
6613 for (Instruction *ToRemove : List)
6614 OpenIntervals.erase(ToRemove);
6615
6616 // Ignore instructions that are never used within the loop.
6617 if (!Ends.count(I))
6618 continue;
6619
6620 // Skip ignored values.
6621 if (ValuesToIgnore.count(I))
6622 continue;
6623
6624 // For each VF find the maximum usage of registers.
6625 for (unsigned j = 0, e = VFs.size(); j < e; ++j) {
6626 // Count the number of live intervals.
6627 SmallMapVector<unsigned, unsigned, 4> RegUsage;
6628
6629 if (VFs[j].isScalar()) {
6630 for (auto Inst : OpenIntervals) {
6631 unsigned ClassID = TTI.getRegisterClassForType(false, Inst->getType());
6632 if (RegUsage.find(ClassID) == RegUsage.end())
6633 RegUsage[ClassID] = 1;
6634 else
6635 RegUsage[ClassID] += 1;
6636 }
6637 } else {
6638 collectUniformsAndScalars(VFs[j]);
6639 for (auto Inst : OpenIntervals) {
6640 // Skip ignored values for VF > 1.
6641 if (VecValuesToIgnore.count(Inst))
6642 continue;
6643 if (isScalarAfterVectorization(Inst, VFs[j])) {
6644 unsigned ClassID = TTI.getRegisterClassForType(false, Inst->getType());
6645 if (RegUsage.find(ClassID) == RegUsage.end())
6646 RegUsage[ClassID] = 1;
6647 else
6648 RegUsage[ClassID] += 1;
6649 } else {
6650 unsigned ClassID = TTI.getRegisterClassForType(true, Inst->getType());
6651 if (RegUsage.find(ClassID) == RegUsage.end())
6652 RegUsage[ClassID] = GetRegUsage(Inst->getType(), VFs[j]);
6653 else
6654 RegUsage[ClassID] += GetRegUsage(Inst->getType(), VFs[j]);
6655 }
6656 }
6657 }
6658
6659 for (auto& pair : RegUsage) {
6660 if (MaxUsages[j].find(pair.first) != MaxUsages[j].end())
6661 MaxUsages[j][pair.first] = std::max(MaxUsages[j][pair.first], pair.second);
6662 else
6663 MaxUsages[j][pair.first] = pair.second;
6664 }
6665 }
6666
6667 LLVM_DEBUG(dbgs() << "LV(REG): At #" << i << " Interval # "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV(REG): At #" <<
i << " Interval # " << OpenIntervals.size() <<
'\n'; } } while (false)
6668 << OpenIntervals.size() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV(REG): At #" <<
i << " Interval # " << OpenIntervals.size() <<
'\n'; } } while (false)
;
6669
6670 // Add the current instruction to the list of open intervals.
6671 OpenIntervals.insert(I);
6672 }
6673
6674 for (unsigned i = 0, e = VFs.size(); i < e; ++i) {
6675 SmallMapVector<unsigned, unsigned, 4> Invariant;
6676
6677 for (auto Inst : LoopInvariants) {
6678 unsigned Usage =
6679 VFs[i].isScalar() ? 1 : GetRegUsage(Inst->getType(), VFs[i]);
6680 unsigned ClassID =
6681 TTI.getRegisterClassForType(VFs[i].isVector(), Inst->getType());
6682 if (Invariant.find(ClassID) == Invariant.end())
6683 Invariant[ClassID] = Usage;
6684 else
6685 Invariant[ClassID] += Usage;
6686 }
6687
6688 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6689 dbgs() << "LV(REG): VF = " << VFs[i] << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6690 dbgs() << "LV(REG): Found max usage: " << MaxUsages[i].size()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6691 << " item\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6692 for (const auto &pair : MaxUsages[i]) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6693 dbgs() << "LV(REG): RegisterClass: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6694 << TTI.getRegisterClassName(pair.first) << ", " << pair.seconddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6695 << " registers\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6696 }do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6697 dbgs() << "LV(REG): Found invariant usage: " << Invariant.size()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6698 << " item\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6699 for (const auto &pair : Invariant) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6700 dbgs() << "LV(REG): RegisterClass: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6701 << TTI.getRegisterClassName(pair.first) << ", " << pair.seconddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6702 << " registers\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6703 }do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
6704 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "LV(REG): VF = " <<
VFs[i] << '\n'; dbgs() << "LV(REG): Found max usage: "
<< MaxUsages[i].size() << " item\n"; for (const auto
&pair : MaxUsages[i]) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } dbgs() << "LV(REG): Found invariant usage: "
<< Invariant.size() << " item\n"; for (const auto
&pair : Invariant) { dbgs() << "LV(REG): RegisterClass: "
<< TTI.getRegisterClassName(pair.first) << ", " <<
pair.second << " registers\n"; } }; } } while (false)
;
6705
6706 RU.LoopInvariantRegs = Invariant;
6707 RU.MaxLocalUsers = MaxUsages[i];
6708 RUs[i] = RU;
6709 }
6710
6711 return RUs;
6712}
6713
6714bool LoopVectorizationCostModel::useEmulatedMaskMemRefHack(Instruction *I){
6715 // TODO: Cost model for emulated masked load/store is completely
6716 // broken. This hack guides the cost model to use an artificially
6717 // high enough value to practically disable vectorization with such
6718 // operations, except where previously deployed legality hack allowed
6719 // using very low cost values. This is to avoid regressions coming simply
6720 // from moving "masked load/store" check from legality to cost model.
6721 // Masked Load/Gather emulation was previously never allowed.
6722 // Limited number of Masked Store/Scatter emulation was allowed.
6723 assert(isPredicatedInst(I) &&(static_cast <bool> (isPredicatedInst(I) && "Expecting a scalar emulated instruction"
) ? void (0) : __assert_fail ("isPredicatedInst(I) && \"Expecting a scalar emulated instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6724, __extension__ __PRETTY_FUNCTION__))
6724 "Expecting a scalar emulated instruction")(static_cast <bool> (isPredicatedInst(I) && "Expecting a scalar emulated instruction"
) ? void (0) : __assert_fail ("isPredicatedInst(I) && \"Expecting a scalar emulated instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6724, __extension__ __PRETTY_FUNCTION__))
;
6725 return isa<LoadInst>(I) ||
6726 (isa<StoreInst>(I) &&
6727 NumPredStores > NumberOfStoresToPredicate);
6728}
6729
6730void LoopVectorizationCostModel::collectInstsToScalarize(ElementCount VF) {
6731 // If we aren't vectorizing the loop, or if we've already collected the
6732 // instructions to scalarize, there's nothing to do. Collection may already
6733 // have occurred if we have a user-selected VF and are now computing the
6734 // expected cost for interleaving.
6735 if (VF.isScalar() || VF.isZero() ||
6736 InstsToScalarize.find(VF) != InstsToScalarize.end())
6737 return;
6738
6739 // Initialize a mapping for VF in InstsToScalalarize. If we find that it's
6740 // not profitable to scalarize any instructions, the presence of VF in the
6741 // map will indicate that we've analyzed it already.
6742 ScalarCostsTy &ScalarCostsVF = InstsToScalarize[VF];
6743
6744 // Find all the instructions that are scalar with predication in the loop and
6745 // determine if it would be better to not if-convert the blocks they are in.
6746 // If so, we also record the instructions to scalarize.
6747 for (BasicBlock *BB : TheLoop->blocks()) {
6748 if (!blockNeedsPredication(BB))
6749 continue;
6750 for (Instruction &I : *BB)
6751 if (isScalarWithPredication(&I)) {
6752 ScalarCostsTy ScalarCosts;
6753 // Do not apply discount logic if hacked cost is needed
6754 // for emulated masked memrefs.
6755 if (!useEmulatedMaskMemRefHack(&I) &&
6756 computePredInstDiscount(&I, ScalarCosts, VF) >= 0)
6757 ScalarCostsVF.insert(ScalarCosts.begin(), ScalarCosts.end());
6758 // Remember that BB will remain after vectorization.
6759 PredicatedBBsAfterVectorization.insert(BB);
6760 }
6761 }
6762}
6763
6764int LoopVectorizationCostModel::computePredInstDiscount(
6765 Instruction *PredInst, ScalarCostsTy &ScalarCosts, ElementCount VF) {
6766 assert(!isUniformAfterVectorization(PredInst, VF) &&(static_cast <bool> (!isUniformAfterVectorization(PredInst
, VF) && "Instruction marked uniform-after-vectorization will be predicated"
) ? void (0) : __assert_fail ("!isUniformAfterVectorization(PredInst, VF) && \"Instruction marked uniform-after-vectorization will be predicated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6767, __extension__ __PRETTY_FUNCTION__))
6767 "Instruction marked uniform-after-vectorization will be predicated")(static_cast <bool> (!isUniformAfterVectorization(PredInst
, VF) && "Instruction marked uniform-after-vectorization will be predicated"
) ? void (0) : __assert_fail ("!isUniformAfterVectorization(PredInst, VF) && \"Instruction marked uniform-after-vectorization will be predicated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6767, __extension__ __PRETTY_FUNCTION__))
;
6768
6769 // Initialize the discount to zero, meaning that the scalar version and the
6770 // vector version cost the same.
6771 InstructionCost Discount = 0;
6772
6773 // Holds instructions to analyze. The instructions we visit are mapped in
6774 // ScalarCosts. Those instructions are the ones that would be scalarized if
6775 // we find that the scalar version costs less.
6776 SmallVector<Instruction *, 8> Worklist;
6777
6778 // Returns true if the given instruction can be scalarized.
6779 auto canBeScalarized = [&](Instruction *I) -> bool {
6780 // We only attempt to scalarize instructions forming a single-use chain
6781 // from the original predicated block that would otherwise be vectorized.
6782 // Although not strictly necessary, we give up on instructions we know will
6783 // already be scalar to avoid traversing chains that are unlikely to be
6784 // beneficial.
6785 if (!I->hasOneUse() || PredInst->getParent() != I->getParent() ||
6786 isScalarAfterVectorization(I, VF))
6787 return false;
6788
6789 // If the instruction is scalar with predication, it will be analyzed
6790 // separately. We ignore it within the context of PredInst.
6791 if (isScalarWithPredication(I))
6792 return false;
6793
6794 // If any of the instruction's operands are uniform after vectorization,
6795 // the instruction cannot be scalarized. This prevents, for example, a
6796 // masked load from being scalarized.
6797 //
6798 // We assume we will only emit a value for lane zero of an instruction
6799 // marked uniform after vectorization, rather than VF identical values.
6800 // Thus, if we scalarize an instruction that uses a uniform, we would
6801 // create uses of values corresponding to the lanes we aren't emitting code
6802 // for. This behavior can be changed by allowing getScalarValue to clone
6803 // the lane zero values for uniforms rather than asserting.
6804 for (Use &U : I->operands())
6805 if (auto *J = dyn_cast<Instruction>(U.get()))
6806 if (isUniformAfterVectorization(J, VF))
6807 return false;
6808
6809 // Otherwise, we can scalarize the instruction.
6810 return true;
6811 };
6812
6813 // Compute the expected cost discount from scalarizing the entire expression
6814 // feeding the predicated instruction. We currently only consider expressions
6815 // that are single-use instruction chains.
6816 Worklist.push_back(PredInst);
6817 while (!Worklist.empty()) {
6818 Instruction *I = Worklist.pop_back_val();
6819
6820 // If we've already analyzed the instruction, there's nothing to do.
6821 if (ScalarCosts.find(I) != ScalarCosts.end())
6822 continue;
6823
6824 // Compute the cost of the vector instruction. Note that this cost already
6825 // includes the scalarization overhead of the predicated instruction.
6826 InstructionCost VectorCost = getInstructionCost(I, VF).first;
6827
6828 // Compute the cost of the scalarized instruction. This cost is the cost of
6829 // the instruction as if it wasn't if-converted and instead remained in the
6830 // predicated block. We will scale this cost by block probability after
6831 // computing the scalarization overhead.
6832 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6832, __extension__ __PRETTY_FUNCTION__))
;
6833 InstructionCost ScalarCost =
6834 VF.getKnownMinValue() *
6835 getInstructionCost(I, ElementCount::getFixed(1)).first;
6836
6837 // Compute the scalarization overhead of needed insertelement instructions
6838 // and phi nodes.
6839 if (isScalarWithPredication(I) && !I->getType()->isVoidTy()) {
6840 ScalarCost += TTI.getScalarizationOverhead(
6841 cast<VectorType>(ToVectorTy(I->getType(), VF)),
6842 APInt::getAllOnesValue(VF.getKnownMinValue()), true, false);
6843 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6843, __extension__ __PRETTY_FUNCTION__))
;
6844 ScalarCost +=
6845 VF.getKnownMinValue() *
6846 TTI.getCFInstrCost(Instruction::PHI, TTI::TCK_RecipThroughput);
6847 }
6848
6849 // Compute the scalarization overhead of needed extractelement
6850 // instructions. For each of the instruction's operands, if the operand can
6851 // be scalarized, add it to the worklist; otherwise, account for the
6852 // overhead.
6853 for (Use &U : I->operands())
6854 if (auto *J = dyn_cast<Instruction>(U.get())) {
6855 assert(VectorType::isValidElementType(J->getType()) &&(static_cast <bool> (VectorType::isValidElementType(J->
getType()) && "Instruction has non-scalar type") ? void
(0) : __assert_fail ("VectorType::isValidElementType(J->getType()) && \"Instruction has non-scalar type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6856, __extension__ __PRETTY_FUNCTION__))
6856 "Instruction has non-scalar type")(static_cast <bool> (VectorType::isValidElementType(J->
getType()) && "Instruction has non-scalar type") ? void
(0) : __assert_fail ("VectorType::isValidElementType(J->getType()) && \"Instruction has non-scalar type\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6856, __extension__ __PRETTY_FUNCTION__))
;
6857 if (canBeScalarized(J))
6858 Worklist.push_back(J);
6859 else if (needsExtract(J, VF)) {
6860 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6860, __extension__ __PRETTY_FUNCTION__))
;
6861 ScalarCost += TTI.getScalarizationOverhead(
6862 cast<VectorType>(ToVectorTy(J->getType(), VF)),
6863 APInt::getAllOnesValue(VF.getKnownMinValue()), false, true);
6864 }
6865 }
6866
6867 // Scale the total scalar cost by block probability.
6868 ScalarCost /= getReciprocalPredBlockProb();
6869
6870 // Compute the discount. A non-negative discount means the vector version
6871 // of the instruction costs more, and scalarizing would be beneficial.
6872 Discount += VectorCost - ScalarCost;
6873 ScalarCosts[I] = ScalarCost;
6874 }
6875
6876 return *Discount.getValue();
6877}
6878
6879LoopVectorizationCostModel::VectorizationCostTy
6880LoopVectorizationCostModel::expectedCost(ElementCount VF) {
6881 VectorizationCostTy Cost;
6882
6883 // For each block.
6884 for (BasicBlock *BB : TheLoop->blocks()) {
6885 VectorizationCostTy BlockCost;
6886
6887 // For each instruction in the old loop.
6888 for (Instruction &I : BB->instructionsWithoutDebug()) {
6889 // Skip ignored values.
6890 if (ValuesToIgnore.count(&I) ||
6891 (VF.isVector() && VecValuesToIgnore.count(&I)))
6892 continue;
6893
6894 VectorizationCostTy C = getInstructionCost(&I, VF);
6895
6896 // Check if we should override the cost.
6897 if (ForceTargetInstructionCost.getNumOccurrences() > 0)
6898 C.first = InstructionCost(ForceTargetInstructionCost);
6899
6900 BlockCost.first += C.first;
6901 BlockCost.second |= C.second;
6902 LLVM_DEBUG(dbgs() << "LV: Found an estimated cost of " << C.firstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found an estimated cost of "
<< C.first << " for VF " << VF << " For instruction: "
<< I << '\n'; } } while (false)
6903 << " for VF " << VF << " For instruction: " << Ido { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found an estimated cost of "
<< C.first << " for VF " << VF << " For instruction: "
<< I << '\n'; } } while (false)
6904 << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found an estimated cost of "
<< C.first << " for VF " << VF << " For instruction: "
<< I << '\n'; } } while (false)
;
6905 }
6906
6907 // If we are vectorizing a predicated block, it will have been
6908 // if-converted. This means that the block's instructions (aside from
6909 // stores and instructions that may divide by zero) will now be
6910 // unconditionally executed. For the scalar case, we may not always execute
6911 // the predicated block, if it is an if-else block. Thus, scale the block's
6912 // cost by the probability of executing it. blockNeedsPredication from
6913 // Legal is used so as to not include all blocks in tail folded loops.
6914 if (VF.isScalar() && Legal->blockNeedsPredication(BB))
6915 BlockCost.first /= getReciprocalPredBlockProb();
6916
6917 Cost.first += BlockCost.first;
6918 Cost.second |= BlockCost.second;
6919 }
6920
6921 return Cost;
6922}
6923
6924/// Gets Address Access SCEV after verifying that the access pattern
6925/// is loop invariant except the induction variable dependence.
6926///
6927/// This SCEV can be sent to the Target in order to estimate the address
6928/// calculation cost.
6929static const SCEV *getAddressAccessSCEV(
6930 Value *Ptr,
6931 LoopVectorizationLegality *Legal,
6932 PredicatedScalarEvolution &PSE,
6933 const Loop *TheLoop) {
6934
6935 auto *Gep = dyn_cast<GetElementPtrInst>(Ptr);
6936 if (!Gep)
6937 return nullptr;
6938
6939 // We are looking for a gep with all loop invariant indices except for one
6940 // which should be an induction variable.
6941 auto SE = PSE.getSE();
6942 unsigned NumOperands = Gep->getNumOperands();
6943 for (unsigned i = 1; i < NumOperands; ++i) {
6944 Value *Opd = Gep->getOperand(i);
6945 if (!SE->isLoopInvariant(SE->getSCEV(Opd), TheLoop) &&
6946 !Legal->isInductionVariable(Opd))
6947 return nullptr;
6948 }
6949
6950 // Now we know we have a GEP ptr, %inv, %ind, %inv. return the Ptr SCEV.
6951 return PSE.getSCEV(Ptr);
6952}
6953
6954static bool isStrideMul(Instruction *I, LoopVectorizationLegality *Legal) {
6955 return Legal->hasStride(I->getOperand(0)) ||
6956 Legal->hasStride(I->getOperand(1));
6957}
6958
6959InstructionCost
6960LoopVectorizationCostModel::getMemInstScalarizationCost(Instruction *I,
6961 ElementCount VF) {
6962 assert(VF.isVector() &&(static_cast <bool> (VF.isVector() && "Scalarization cost of instruction implies vectorization."
) ? void (0) : __assert_fail ("VF.isVector() && \"Scalarization cost of instruction implies vectorization.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6963, __extension__ __PRETTY_FUNCTION__))
6963 "Scalarization cost of instruction implies vectorization.")(static_cast <bool> (VF.isVector() && "Scalarization cost of instruction implies vectorization."
) ? void (0) : __assert_fail ("VF.isVector() && \"Scalarization cost of instruction implies vectorization.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 6963, __extension__ __PRETTY_FUNCTION__))
;
6964 if (VF.isScalable())
6965 return InstructionCost::getInvalid();
6966
6967 Type *ValTy = getLoadStoreType(I);
6968 auto SE = PSE.getSE();
6969
6970 unsigned AS = getLoadStoreAddressSpace(I);
6971 Value *Ptr = getLoadStorePointerOperand(I);
6972 Type *PtrTy = ToVectorTy(Ptr->getType(), VF);
6973
6974 // Figure out whether the access is strided and get the stride value
6975 // if it's known in compile time
6976 const SCEV *PtrSCEV = getAddressAccessSCEV(Ptr, Legal, PSE, TheLoop);
6977
6978 // Get the cost of the scalar memory instruction and address computation.
6979 InstructionCost Cost =
6980 VF.getKnownMinValue() * TTI.getAddressComputationCost(PtrTy, SE, PtrSCEV);
6981
6982 // Don't pass *I here, since it is scalar but will actually be part of a
6983 // vectorized loop where the user of it is a vectorized instruction.
6984 const Align Alignment = getLoadStoreAlignment(I);
6985 Cost += VF.getKnownMinValue() *
6986 TTI.getMemoryOpCost(I->getOpcode(), ValTy->getScalarType(), Alignment,
6987 AS, TTI::TCK_RecipThroughput);
6988
6989 // Get the overhead of the extractelement and insertelement instructions
6990 // we might create due to scalarization.
6991 Cost += getScalarizationOverhead(I, VF);
6992
6993 // If we have a predicated load/store, it will need extra i1 extracts and
6994 // conditional branches, but may not be executed for each vector lane. Scale
6995 // the cost by the probability of executing the predicated block.
6996 if (isPredicatedInst(I)) {
6997 Cost /= getReciprocalPredBlockProb();
6998
6999 // Add the cost of an i1 extract and a branch
7000 auto *Vec_i1Ty =
7001 VectorType::get(IntegerType::getInt1Ty(ValTy->getContext()), VF);
7002 Cost += TTI.getScalarizationOverhead(
7003 Vec_i1Ty, APInt::getAllOnesValue(VF.getKnownMinValue()),
7004 /*Insert=*/false, /*Extract=*/true);
7005 Cost += TTI.getCFInstrCost(Instruction::Br, TTI::TCK_RecipThroughput);
7006
7007 if (useEmulatedMaskMemRefHack(I))
7008 // Artificially setting to a high enough value to practically disable
7009 // vectorization with such operations.
7010 Cost = 3000000;
7011 }
7012
7013 return Cost;
7014}
7015
7016InstructionCost
7017LoopVectorizationCostModel::getConsecutiveMemOpCost(Instruction *I,
7018 ElementCount VF) {
7019 Type *ValTy = getLoadStoreType(I);
7020 auto *VectorTy = cast<VectorType>(ToVectorTy(ValTy, VF));
7021 Value *Ptr = getLoadStorePointerOperand(I);
7022 unsigned AS = getLoadStoreAddressSpace(I);
7023 int ConsecutiveStride = Legal->isConsecutivePtr(Ptr);
7024 enum TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
7025
7026 assert((ConsecutiveStride == 1 || ConsecutiveStride == -1) &&(static_cast <bool> ((ConsecutiveStride == 1 || ConsecutiveStride
== -1) && "Stride should be 1 or -1 for consecutive memory access"
) ? void (0) : __assert_fail ("(ConsecutiveStride == 1 || ConsecutiveStride == -1) && \"Stride should be 1 or -1 for consecutive memory access\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7027, __extension__ __PRETTY_FUNCTION__))
7027 "Stride should be 1 or -1 for consecutive memory access")(static_cast <bool> ((ConsecutiveStride == 1 || ConsecutiveStride
== -1) && "Stride should be 1 or -1 for consecutive memory access"
) ? void (0) : __assert_fail ("(ConsecutiveStride == 1 || ConsecutiveStride == -1) && \"Stride should be 1 or -1 for consecutive memory access\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7027, __extension__ __PRETTY_FUNCTION__))
;
7028 const Align Alignment = getLoadStoreAlignment(I);
7029 InstructionCost Cost = 0;
7030 if (Legal->isMaskRequired(I))
7031 Cost += TTI.getMaskedMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS,
7032 CostKind);
7033 else
7034 Cost += TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS,
7035 CostKind, I);
7036
7037 bool Reverse = ConsecutiveStride < 0;
7038 if (Reverse)
7039 Cost +=
7040 TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy, None, 0);
7041 return Cost;
7042}
7043
7044InstructionCost
7045LoopVectorizationCostModel::getUniformMemOpCost(Instruction *I,
7046 ElementCount VF) {
7047 assert(Legal->isUniformMemOp(*I))(static_cast <bool> (Legal->isUniformMemOp(*I)) ? void
(0) : __assert_fail ("Legal->isUniformMemOp(*I)", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7047, __extension__ __PRETTY_FUNCTION__))
;
7048
7049 Type *ValTy = getLoadStoreType(I);
7050 auto *VectorTy = cast<VectorType>(ToVectorTy(ValTy, VF));
7051 const Align Alignment = getLoadStoreAlignment(I);
7052 unsigned AS = getLoadStoreAddressSpace(I);
7053 enum TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
7054 if (isa<LoadInst>(I)) {
7055 return TTI.getAddressComputationCost(ValTy) +
7056 TTI.getMemoryOpCost(Instruction::Load, ValTy, Alignment, AS,
7057 CostKind) +
7058 TTI.getShuffleCost(TargetTransformInfo::SK_Broadcast, VectorTy);
7059 }
7060 StoreInst *SI = cast<StoreInst>(I);
7061
7062 bool isLoopInvariantStoreValue = Legal->isUniform(SI->getValueOperand());
7063 return TTI.getAddressComputationCost(ValTy) +
7064 TTI.getMemoryOpCost(Instruction::Store, ValTy, Alignment, AS,
7065 CostKind) +
7066 (isLoopInvariantStoreValue
7067 ? 0
7068 : TTI.getVectorInstrCost(Instruction::ExtractElement, VectorTy,
7069 VF.getKnownMinValue() - 1));
7070}
7071
7072InstructionCost
7073LoopVectorizationCostModel::getGatherScatterCost(Instruction *I,
7074 ElementCount VF) {
7075 Type *ValTy = getLoadStoreType(I);
7076 auto *VectorTy = cast<VectorType>(ToVectorTy(ValTy, VF));
7077 const Align Alignment = getLoadStoreAlignment(I);
7078 const Value *Ptr = getLoadStorePointerOperand(I);
7079
7080 return TTI.getAddressComputationCost(VectorTy) +
7081 TTI.getGatherScatterOpCost(
7082 I->getOpcode(), VectorTy, Ptr, Legal->isMaskRequired(I), Alignment,
7083 TargetTransformInfo::TCK_RecipThroughput, I);
7084}
7085
7086InstructionCost
7087LoopVectorizationCostModel::getInterleaveGroupCost(Instruction *I,
7088 ElementCount VF) {
7089 // TODO: Once we have support for interleaving with scalable vectors
7090 // we can calculate the cost properly here.
7091 if (VF.isScalable())
7092 return InstructionCost::getInvalid();
7093
7094 Type *ValTy = getLoadStoreType(I);
7095 auto *VectorTy = cast<VectorType>(ToVectorTy(ValTy, VF));
7096 unsigned AS = getLoadStoreAddressSpace(I);
7097
7098 auto Group = getInterleavedAccessGroup(I);
7099 assert(Group && "Fail to get an interleaved access group.")(static_cast <bool> (Group && "Fail to get an interleaved access group."
) ? void (0) : __assert_fail ("Group && \"Fail to get an interleaved access group.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7099, __extension__ __PRETTY_FUNCTION__))
;
7100
7101 unsigned InterleaveFactor = Group->getFactor();
7102 auto *WideVecTy = VectorType::get(ValTy, VF * InterleaveFactor);
7103
7104 // Holds the indices of existing members in an interleaved load group.
7105 // An interleaved store group doesn't need this as it doesn't allow gaps.
7106 SmallVector<unsigned, 4> Indices;
7107 if (isa<LoadInst>(I)) {
7108 for (unsigned i = 0; i < InterleaveFactor; i++)
7109 if (Group->getMember(i))
7110 Indices.push_back(i);
7111 }
7112
7113 // Calculate the cost of the whole interleaved group.
7114 bool UseMaskForGaps =
7115 Group->requiresScalarEpilogue() && !isScalarEpilogueAllowed();
7116 InstructionCost Cost = TTI.getInterleavedMemoryOpCost(
7117 I->getOpcode(), WideVecTy, Group->getFactor(), Indices, Group->getAlign(),
7118 AS, TTI::TCK_RecipThroughput, Legal->isMaskRequired(I), UseMaskForGaps);
7119
7120 if (Group->isReverse()) {
7121 // TODO: Add support for reversed masked interleaved access.
7122 assert(!Legal->isMaskRequired(I) &&(static_cast <bool> (!Legal->isMaskRequired(I) &&
"Reverse masked interleaved access not supported.") ? void (
0) : __assert_fail ("!Legal->isMaskRequired(I) && \"Reverse masked interleaved access not supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7123, __extension__ __PRETTY_FUNCTION__))
7123 "Reverse masked interleaved access not supported.")(static_cast <bool> (!Legal->isMaskRequired(I) &&
"Reverse masked interleaved access not supported.") ? void (
0) : __assert_fail ("!Legal->isMaskRequired(I) && \"Reverse masked interleaved access not supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7123, __extension__ __PRETTY_FUNCTION__))
;
7124 Cost +=
7125 Group->getNumMembers() *
7126 TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy, None, 0);
7127 }
7128 return Cost;
7129}
7130
7131InstructionCost LoopVectorizationCostModel::getReductionPatternCost(
7132 Instruction *I, ElementCount VF, Type *Ty, TTI::TargetCostKind CostKind) {
7133 // Early exit for no inloop reductions
7134 if (InLoopReductionChains.empty() || VF.isScalar() || !isa<VectorType>(Ty))
7135 return InstructionCost::getInvalid();
7136 auto *VectorTy = cast<VectorType>(Ty);
7137
7138 // We are looking for a pattern of, and finding the minimal acceptable cost:
7139 // reduce(mul(ext(A), ext(B))) or
7140 // reduce(mul(A, B)) or
7141 // reduce(ext(A)) or
7142 // reduce(A).
7143 // The basic idea is that we walk down the tree to do that, finding the root
7144 // reduction instruction in InLoopReductionImmediateChains. From there we find
7145 // the pattern of mul/ext and test the cost of the entire pattern vs the cost
7146 // of the components. If the reduction cost is lower then we return it for the
7147 // reduction instruction and 0 for the other instructions in the pattern. If
7148 // it is not we return an invalid cost specifying the orignal cost method
7149 // should be used.
7150 Instruction *RetI = I;
7151 if ((RetI->getOpcode() == Instruction::SExt ||
7152 RetI->getOpcode() == Instruction::ZExt)) {
7153 if (!RetI->hasOneUser())
7154 return InstructionCost::getInvalid();
7155 RetI = RetI->user_back();
7156 }
7157 if (RetI->getOpcode() == Instruction::Mul &&
7158 RetI->user_back()->getOpcode() == Instruction::Add) {
7159 if (!RetI->hasOneUser())
7160 return InstructionCost::getInvalid();
7161 RetI = RetI->user_back();
7162 }
7163
7164 // Test if the found instruction is a reduction, and if not return an invalid
7165 // cost specifying the parent to use the original cost modelling.
7166 if (!InLoopReductionImmediateChains.count(RetI))
7167 return InstructionCost::getInvalid();
7168
7169 // Find the reduction this chain is a part of and calculate the basic cost of
7170 // the reduction on its own.
7171 Instruction *LastChain = InLoopReductionImmediateChains[RetI];
7172 Instruction *ReductionPhi = LastChain;
7173 while (!isa<PHINode>(ReductionPhi))
7174 ReductionPhi = InLoopReductionImmediateChains[ReductionPhi];
7175
7176 const RecurrenceDescriptor &RdxDesc =
7177 Legal->getReductionVars()[cast<PHINode>(ReductionPhi)];
7178 InstructionCost BaseCost = TTI.getArithmeticReductionCost(
7179 RdxDesc.getOpcode(), VectorTy, false, CostKind);
7180
7181 // Get the operand that was not the reduction chain and match it to one of the
7182 // patterns, returning the better cost if it is found.
7183 Instruction *RedOp = RetI->getOperand(1) == LastChain
7184 ? dyn_cast<Instruction>(RetI->getOperand(0))
7185 : dyn_cast<Instruction>(RetI->getOperand(1));
7186
7187 VectorTy = VectorType::get(I->getOperand(0)->getType(), VectorTy);
7188
7189 if (RedOp && (isa<SExtInst>(RedOp) || isa<ZExtInst>(RedOp)) &&
7190 !TheLoop->isLoopInvariant(RedOp)) {
7191 bool IsUnsigned = isa<ZExtInst>(RedOp);
7192 auto *ExtType = VectorType::get(RedOp->getOperand(0)->getType(), VectorTy);
7193 InstructionCost RedCost = TTI.getExtendedAddReductionCost(
7194 /*IsMLA=*/false, IsUnsigned, RdxDesc.getRecurrenceType(), ExtType,
7195 CostKind);
7196
7197 InstructionCost ExtCost =
7198 TTI.getCastInstrCost(RedOp->getOpcode(), VectorTy, ExtType,
7199 TTI::CastContextHint::None, CostKind, RedOp);
7200 if (RedCost.isValid() && RedCost < BaseCost + ExtCost)
7201 return I == RetI ? *RedCost.getValue() : 0;
7202 } else if (RedOp && RedOp->getOpcode() == Instruction::Mul) {
7203 Instruction *Mul = RedOp;
7204 Instruction *Op0 = dyn_cast<Instruction>(Mul->getOperand(0));
7205 Instruction *Op1 = dyn_cast<Instruction>(Mul->getOperand(1));
7206 if (Op0 && Op1 && (isa<SExtInst>(Op0) || isa<ZExtInst>(Op0)) &&
7207 Op0->getOpcode() == Op1->getOpcode() &&
7208 Op0->getOperand(0)->getType() == Op1->getOperand(0)->getType() &&
7209 !TheLoop->isLoopInvariant(Op0) && !TheLoop->isLoopInvariant(Op1)) {
7210 bool IsUnsigned = isa<ZExtInst>(Op0);
7211 auto *ExtType = VectorType::get(Op0->getOperand(0)->getType(), VectorTy);
7212 // reduce(mul(ext, ext))
7213 InstructionCost ExtCost =
7214 TTI.getCastInstrCost(Op0->getOpcode(), VectorTy, ExtType,
7215 TTI::CastContextHint::None, CostKind, Op0);
7216 InstructionCost MulCost =
7217 TTI.getArithmeticInstrCost(Mul->getOpcode(), VectorTy, CostKind);
7218
7219 InstructionCost RedCost = TTI.getExtendedAddReductionCost(
7220 /*IsMLA=*/true, IsUnsigned, RdxDesc.getRecurrenceType(), ExtType,
7221 CostKind);
7222
7223 if (RedCost.isValid() && RedCost < ExtCost * 2 + MulCost + BaseCost)
7224 return I == RetI ? *RedCost.getValue() : 0;
7225 } else {
7226 InstructionCost MulCost =
7227 TTI.getArithmeticInstrCost(Mul->getOpcode(), VectorTy, CostKind);
7228
7229 InstructionCost RedCost = TTI.getExtendedAddReductionCost(
7230 /*IsMLA=*/true, true, RdxDesc.getRecurrenceType(), VectorTy,
7231 CostKind);
7232
7233 if (RedCost.isValid() && RedCost < MulCost + BaseCost)
7234 return I == RetI ? *RedCost.getValue() : 0;
7235 }
7236 }
7237
7238 return I == RetI ? BaseCost : InstructionCost::getInvalid();
7239}
7240
7241InstructionCost
7242LoopVectorizationCostModel::getMemoryInstructionCost(Instruction *I,
7243 ElementCount VF) {
7244 // Calculate scalar cost only. Vectorization cost should be ready at this
7245 // moment.
7246 if (VF.isScalar()) {
7247 Type *ValTy = getLoadStoreType(I);
7248 const Align Alignment = getLoadStoreAlignment(I);
7249 unsigned AS = getLoadStoreAddressSpace(I);
7250
7251 return TTI.getAddressComputationCost(ValTy) +
7252 TTI.getMemoryOpCost(I->getOpcode(), ValTy, Alignment, AS,
7253 TTI::TCK_RecipThroughput, I);
7254 }
7255 return getWideningCost(I, VF);
7256}
7257
7258LoopVectorizationCostModel::VectorizationCostTy
7259LoopVectorizationCostModel::getInstructionCost(Instruction *I,
7260 ElementCount VF) {
7261 // If we know that this instruction will remain uniform, check the cost of
7262 // the scalar version.
7263 if (isUniformAfterVectorization(I, VF))
7264 VF = ElementCount::getFixed(1);
7265
7266 if (VF.isVector() && isProfitableToScalarize(I, VF))
7267 return VectorizationCostTy(InstsToScalarize[VF][I], false);
7268
7269 // Forced scalars do not have any scalarization overhead.
7270 auto ForcedScalar = ForcedScalars.find(VF);
7271 if (VF.isVector() && ForcedScalar != ForcedScalars.end()) {
7272 auto InstSet = ForcedScalar->second;
7273 if (InstSet.count(I))
7274 return VectorizationCostTy(
7275 (getInstructionCost(I, ElementCount::getFixed(1)).first *
7276 VF.getKnownMinValue()),
7277 false);
7278 }
7279
7280 Type *VectorTy;
7281 InstructionCost C = getInstructionCost(I, VF, VectorTy);
7282
7283 bool TypeNotScalarized =
7284 VF.isVector() && VectorTy->isVectorTy() &&
7285 TTI.getNumberOfParts(VectorTy) < VF.getKnownMinValue();
7286 return VectorizationCostTy(C, TypeNotScalarized);
7287}
7288
7289InstructionCost
7290LoopVectorizationCostModel::getScalarizationOverhead(Instruction *I,
7291 ElementCount VF) const {
7292
7293 if (VF.isScalable())
7294 return InstructionCost::getInvalid();
7295
7296 if (VF.isScalar())
7297 return 0;
7298
7299 InstructionCost Cost = 0;
7300 Type *RetTy = ToVectorTy(I->getType(), VF);
7301 if (!RetTy->isVoidTy() &&
7302 (!isa<LoadInst>(I) || !TTI.supportsEfficientVectorElementLoadStore()))
7303 Cost += TTI.getScalarizationOverhead(
7304 cast<VectorType>(RetTy), APInt::getAllOnesValue(VF.getKnownMinValue()),
7305 true, false);
7306
7307 // Some targets keep addresses scalar.
7308 if (isa<LoadInst>(I) && !TTI.prefersVectorizedAddressing())
7309 return Cost;
7310
7311 // Some targets support efficient element stores.
7312 if (isa<StoreInst>(I) && TTI.supportsEfficientVectorElementLoadStore())
7313 return Cost;
7314
7315 // Collect operands to consider.
7316 CallInst *CI = dyn_cast<CallInst>(I);
7317 Instruction::op_range Ops = CI ? CI->arg_operands() : I->operands();
7318
7319 // Skip operands that do not require extraction/scalarization and do not incur
7320 // any overhead.
7321 SmallVector<Type *> Tys;
7322 for (auto *V : filterExtractingOperands(Ops, VF))
7323 Tys.push_back(MaybeVectorizeType(V->getType(), VF));
7324 return Cost + TTI.getOperandsScalarizationOverhead(
7325 filterExtractingOperands(Ops, VF), Tys);
7326}
7327
7328void LoopVectorizationCostModel::setCostBasedWideningDecision(ElementCount VF) {
7329 if (VF.isScalar())
7330 return;
7331 NumPredStores = 0;
7332 for (BasicBlock *BB : TheLoop->blocks()) {
7333 // For each instruction in the old loop.
7334 for (Instruction &I : *BB) {
7335 Value *Ptr = getLoadStorePointerOperand(&I);
7336 if (!Ptr)
7337 continue;
7338
7339 // TODO: We should generate better code and update the cost model for
7340 // predicated uniform stores. Today they are treated as any other
7341 // predicated store (see added test cases in
7342 // invariant-store-vectorization.ll).
7343 if (isa<StoreInst>(&I) && isScalarWithPredication(&I))
7344 NumPredStores++;
7345
7346 if (Legal->isUniformMemOp(I)) {
7347 // TODO: Avoid replicating loads and stores instead of
7348 // relying on instcombine to remove them.
7349 // Load: Scalar load + broadcast
7350 // Store: Scalar store + isLoopInvariantStoreValue ? 0 : extract
7351 InstructionCost Cost = getUniformMemOpCost(&I, VF);
7352 setWideningDecision(&I, VF, CM_Scalarize, Cost);
7353 continue;
7354 }
7355
7356 // We assume that widening is the best solution when possible.
7357 if (memoryInstructionCanBeWidened(&I, VF)) {
7358 InstructionCost Cost = getConsecutiveMemOpCost(&I, VF);
7359 int ConsecutiveStride =
7360 Legal->isConsecutivePtr(getLoadStorePointerOperand(&I));
7361 assert((ConsecutiveStride == 1 || ConsecutiveStride == -1) &&(static_cast <bool> ((ConsecutiveStride == 1 || ConsecutiveStride
== -1) && "Expected consecutive stride.") ? void (0)
: __assert_fail ("(ConsecutiveStride == 1 || ConsecutiveStride == -1) && \"Expected consecutive stride.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7362, __extension__ __PRETTY_FUNCTION__))
7362 "Expected consecutive stride.")(static_cast <bool> ((ConsecutiveStride == 1 || ConsecutiveStride
== -1) && "Expected consecutive stride.") ? void (0)
: __assert_fail ("(ConsecutiveStride == 1 || ConsecutiveStride == -1) && \"Expected consecutive stride.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7362, __extension__ __PRETTY_FUNCTION__))
;
7363 InstWidening Decision =
7364 ConsecutiveStride == 1 ? CM_Widen : CM_Widen_Reverse;
7365 setWideningDecision(&I, VF, Decision, Cost);
7366 continue;
7367 }
7368
7369 // Choose between Interleaving, Gather/Scatter or Scalarization.
7370 InstructionCost InterleaveCost = InstructionCost::getInvalid();
7371 unsigned NumAccesses = 1;
7372 if (isAccessInterleaved(&I)) {
7373 auto Group = getInterleavedAccessGroup(&I);
7374 assert(Group && "Fail to get an interleaved access group.")(static_cast <bool> (Group && "Fail to get an interleaved access group."
) ? void (0) : __assert_fail ("Group && \"Fail to get an interleaved access group.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7374, __extension__ __PRETTY_FUNCTION__))
;
7375
7376 // Make one decision for the whole group.
7377 if (getWideningDecision(&I, VF) != CM_Unknown)
7378 continue;
7379
7380 NumAccesses = Group->getNumMembers();
7381 if (interleavedAccessCanBeWidened(&I, VF))
7382 InterleaveCost = getInterleaveGroupCost(&I, VF);
7383 }
7384
7385 InstructionCost GatherScatterCost =
7386 isLegalGatherOrScatter(&I)
7387 ? getGatherScatterCost(&I, VF) * NumAccesses
7388 : InstructionCost::getInvalid();
7389
7390 InstructionCost ScalarizationCost =
7391 getMemInstScalarizationCost(&I, VF) * NumAccesses;
7392
7393 // Choose better solution for the current VF,
7394 // write down this decision and use it during vectorization.
7395 InstructionCost Cost;
7396 InstWidening Decision;
7397 if (InterleaveCost <= GatherScatterCost &&
7398 InterleaveCost < ScalarizationCost) {
7399 Decision = CM_Interleave;
7400 Cost = InterleaveCost;
7401 } else if (GatherScatterCost < ScalarizationCost) {
7402 Decision = CM_GatherScatter;
7403 Cost = GatherScatterCost;
7404 } else {
7405 assert(!VF.isScalable() &&(static_cast <bool> (!VF.isScalable() && "We cannot yet scalarise for scalable vectors"
) ? void (0) : __assert_fail ("!VF.isScalable() && \"We cannot yet scalarise for scalable vectors\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7406, __extension__ __PRETTY_FUNCTION__))
7406 "We cannot yet scalarise for scalable vectors")(static_cast <bool> (!VF.isScalable() && "We cannot yet scalarise for scalable vectors"
) ? void (0) : __assert_fail ("!VF.isScalable() && \"We cannot yet scalarise for scalable vectors\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7406, __extension__ __PRETTY_FUNCTION__))
;
7407 Decision = CM_Scalarize;
7408 Cost = ScalarizationCost;
7409 }
7410 // If the instructions belongs to an interleave group, the whole group
7411 // receives the same decision. The whole group receives the cost, but
7412 // the cost will actually be assigned to one instruction.
7413 if (auto Group = getInterleavedAccessGroup(&I))
7414 setWideningDecision(Group, VF, Decision, Cost);
7415 else
7416 setWideningDecision(&I, VF, Decision, Cost);
7417 }
7418 }
7419
7420 // Make sure that any load of address and any other address computation
7421 // remains scalar unless there is gather/scatter support. This avoids
7422 // inevitable extracts into address registers, and also has the benefit of
7423 // activating LSR more, since that pass can't optimize vectorized
7424 // addresses.
7425 if (TTI.prefersVectorizedAddressing())
7426 return;
7427
7428 // Start with all scalar pointer uses.
7429 SmallPtrSet<Instruction *, 8> AddrDefs;
7430 for (BasicBlock *BB : TheLoop->blocks())
7431 for (Instruction &I : *BB) {
7432 Instruction *PtrDef =
7433 dyn_cast_or_null<Instruction>(getLoadStorePointerOperand(&I));
7434 if (PtrDef && TheLoop->contains(PtrDef) &&
7435 getWideningDecision(&I, VF) != CM_GatherScatter)
7436 AddrDefs.insert(PtrDef);
7437 }
7438
7439 // Add all instructions used to generate the addresses.
7440 SmallVector<Instruction *, 4> Worklist;
7441 append_range(Worklist, AddrDefs);
7442 while (!Worklist.empty()) {
7443 Instruction *I = Worklist.pop_back_val();
7444 for (auto &Op : I->operands())
7445 if (auto *InstOp = dyn_cast<Instruction>(Op))
7446 if ((InstOp->getParent() == I->getParent()) && !isa<PHINode>(InstOp) &&
7447 AddrDefs.insert(InstOp).second)
7448 Worklist.push_back(InstOp);
7449 }
7450
7451 for (auto *I : AddrDefs) {
7452 if (isa<LoadInst>(I)) {
7453 // Setting the desired widening decision should ideally be handled in
7454 // by cost functions, but since this involves the task of finding out
7455 // if the loaded register is involved in an address computation, it is
7456 // instead changed here when we know this is the case.
7457 InstWidening Decision = getWideningDecision(I, VF);
7458 if (Decision == CM_Widen || Decision == CM_Widen_Reverse)
7459 // Scalarize a widened load of address.
7460 setWideningDecision(
7461 I, VF, CM_Scalarize,
7462 (VF.getKnownMinValue() *
7463 getMemoryInstructionCost(I, ElementCount::getFixed(1))));
7464 else if (auto Group = getInterleavedAccessGroup(I)) {
7465 // Scalarize an interleave group of address loads.
7466 for (unsigned I = 0; I < Group->getFactor(); ++I) {
7467 if (Instruction *Member = Group->getMember(I))
7468 setWideningDecision(
7469 Member, VF, CM_Scalarize,
7470 (VF.getKnownMinValue() *
7471 getMemoryInstructionCost(Member, ElementCount::getFixed(1))));
7472 }
7473 }
7474 } else
7475 // Make sure I gets scalarized and a cost estimate without
7476 // scalarization overhead.
7477 ForcedScalars[VF].insert(I);
7478 }
7479}
7480
7481InstructionCost
7482LoopVectorizationCostModel::getInstructionCost(Instruction *I, ElementCount VF,
7483 Type *&VectorTy) {
7484 Type *RetTy = I->getType();
7485 if (canTruncateToMinimalBitwidth(I, VF))
7486 RetTy = IntegerType::get(RetTy->getContext(), MinBWs[I]);
7487 auto SE = PSE.getSE();
7488 TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
7489
7490 auto hasSingleCopyAfterVectorization = [this](Instruction *I,
7491 ElementCount VF) -> bool {
7492 if (VF.isScalar())
7493 return true;
7494
7495 auto Scalarized = InstsToScalarize.find(VF);
7496 assert(Scalarized != InstsToScalarize.end() &&(static_cast <bool> (Scalarized != InstsToScalarize.end
() && "VF not yet analyzed for scalarization profitability"
) ? void (0) : __assert_fail ("Scalarized != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7497, __extension__ __PRETTY_FUNCTION__))
7497 "VF not yet analyzed for scalarization profitability")(static_cast <bool> (Scalarized != InstsToScalarize.end
() && "VF not yet analyzed for scalarization profitability"
) ? void (0) : __assert_fail ("Scalarized != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7497, __extension__ __PRETTY_FUNCTION__))
;
7498 return !Scalarized->second.count(I) &&
7499 llvm::all_of(I->users(), [&](User *U) {
7500 auto *UI = cast<Instruction>(U);
7501 return !Scalarized->second.count(UI);
7502 });
7503 };
7504 (void) hasSingleCopyAfterVectorization;
7505
7506 if (isScalarAfterVectorization(I, VF)) {
7507 // With the exception of GEPs and PHIs, after scalarization there should
7508 // only be one copy of the instruction generated in the loop. This is
7509 // because the VF is either 1, or any instructions that need scalarizing
7510 // have already been dealt with by the the time we get here. As a result,
7511 // it means we don't have to multiply the instruction cost by VF.
7512 assert(I->getOpcode() == Instruction::GetElementPtr ||(static_cast <bool> (I->getOpcode() == Instruction::
GetElementPtr || I->getOpcode() == Instruction::PHI || (I->
getOpcode() == Instruction::BitCast && I->getType(
)->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF
)) ? void (0) : __assert_fail ("I->getOpcode() == Instruction::GetElementPtr || I->getOpcode() == Instruction::PHI || (I->getOpcode() == Instruction::BitCast && I->getType()->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7516, __extension__ __PRETTY_FUNCTION__))
7513 I->getOpcode() == Instruction::PHI ||(static_cast <bool> (I->getOpcode() == Instruction::
GetElementPtr || I->getOpcode() == Instruction::PHI || (I->
getOpcode() == Instruction::BitCast && I->getType(
)->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF
)) ? void (0) : __assert_fail ("I->getOpcode() == Instruction::GetElementPtr || I->getOpcode() == Instruction::PHI || (I->getOpcode() == Instruction::BitCast && I->getType()->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7516, __extension__ __PRETTY_FUNCTION__))
7514 (I->getOpcode() == Instruction::BitCast &&(static_cast <bool> (I->getOpcode() == Instruction::
GetElementPtr || I->getOpcode() == Instruction::PHI || (I->
getOpcode() == Instruction::BitCast && I->getType(
)->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF
)) ? void (0) : __assert_fail ("I->getOpcode() == Instruction::GetElementPtr || I->getOpcode() == Instruction::PHI || (I->getOpcode() == Instruction::BitCast && I->getType()->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7516, __extension__ __PRETTY_FUNCTION__))
7515 I->getType()->isPointerTy()) ||(static_cast <bool> (I->getOpcode() == Instruction::
GetElementPtr || I->getOpcode() == Instruction::PHI || (I->
getOpcode() == Instruction::BitCast && I->getType(
)->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF
)) ? void (0) : __assert_fail ("I->getOpcode() == Instruction::GetElementPtr || I->getOpcode() == Instruction::PHI || (I->getOpcode() == Instruction::BitCast && I->getType()->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7516, __extension__ __PRETTY_FUNCTION__))
7516 hasSingleCopyAfterVectorization(I, VF))(static_cast <bool> (I->getOpcode() == Instruction::
GetElementPtr || I->getOpcode() == Instruction::PHI || (I->
getOpcode() == Instruction::BitCast && I->getType(
)->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF
)) ? void (0) : __assert_fail ("I->getOpcode() == Instruction::GetElementPtr || I->getOpcode() == Instruction::PHI || (I->getOpcode() == Instruction::BitCast && I->getType()->isPointerTy()) || hasSingleCopyAfterVectorization(I, VF)"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7516, __extension__ __PRETTY_FUNCTION__))
;
7517 VectorTy = RetTy;
7518 } else
7519 VectorTy = ToVectorTy(RetTy, VF);
7520
7521 // TODO: We need to estimate the cost of intrinsic calls.
7522 switch (I->getOpcode()) {
7523 case Instruction::GetElementPtr:
7524 // We mark this instruction as zero-cost because the cost of GEPs in
7525 // vectorized code depends on whether the corresponding memory instruction
7526 // is scalarized or not. Therefore, we handle GEPs with the memory
7527 // instruction cost.
7528 return 0;
7529 case Instruction::Br: {
7530 // In cases of scalarized and predicated instructions, there will be VF
7531 // predicated blocks in the vectorized loop. Each branch around these
7532 // blocks requires also an extract of its vector compare i1 element.
7533 bool ScalarPredicatedBB = false;
7534 BranchInst *BI = cast<BranchInst>(I);
7535 if (VF.isVector() && BI->isConditional() &&
7536 (PredicatedBBsAfterVectorization.count(BI->getSuccessor(0)) ||
7537 PredicatedBBsAfterVectorization.count(BI->getSuccessor(1))))
7538 ScalarPredicatedBB = true;
7539
7540 if (ScalarPredicatedBB) {
7541 // Return cost for branches around scalarized and predicated blocks.
7542 assert(!VF.isScalable() && "scalable vectors not yet supported.")(static_cast <bool> (!VF.isScalable() && "scalable vectors not yet supported."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7542, __extension__ __PRETTY_FUNCTION__))
;
7543 auto *Vec_i1Ty =
7544 VectorType::get(IntegerType::getInt1Ty(RetTy->getContext()), VF);
7545 return (TTI.getScalarizationOverhead(
7546 Vec_i1Ty, APInt::getAllOnesValue(VF.getKnownMinValue()),
7547 false, true) +
7548 (TTI.getCFInstrCost(Instruction::Br, CostKind) *
7549 VF.getKnownMinValue()));
7550 } else if (I->getParent() == TheLoop->getLoopLatch() || VF.isScalar())
7551 // The back-edge branch will remain, as will all scalar branches.
7552 return TTI.getCFInstrCost(Instruction::Br, CostKind);
7553 else
7554 // This branch will be eliminated by if-conversion.
7555 return 0;
7556 // Note: We currently assume zero cost for an unconditional branch inside
7557 // a predicated block since it will become a fall-through, although we
7558 // may decide in the future to call TTI for all branches.
7559 }
7560 case Instruction::PHI: {
7561 auto *Phi = cast<PHINode>(I);
7562
7563 // First-order recurrences are replaced by vector shuffles inside the loop.
7564 // NOTE: Don't use ToVectorTy as SK_ExtractSubvector expects a vector type.
7565 if (VF.isVector() && Legal->isFirstOrderRecurrence(Phi))
7566 return TTI.getShuffleCost(
7567 TargetTransformInfo::SK_ExtractSubvector, cast<VectorType>(VectorTy),
7568 None, VF.getKnownMinValue() - 1, FixedVectorType::get(RetTy, 1));
7569
7570 // Phi nodes in non-header blocks (not inductions, reductions, etc.) are
7571 // converted into select instructions. We require N - 1 selects per phi
7572 // node, where N is the number of incoming values.
7573 if (VF.isVector() && Phi->getParent() != TheLoop->getHeader())
7574 return (Phi->getNumIncomingValues() - 1) *
7575 TTI.getCmpSelInstrCost(
7576 Instruction::Select, ToVectorTy(Phi->getType(), VF),
7577 ToVectorTy(Type::getInt1Ty(Phi->getContext()), VF),
7578 CmpInst::BAD_ICMP_PREDICATE, CostKind);
7579
7580 return TTI.getCFInstrCost(Instruction::PHI, CostKind);
7581 }
7582 case Instruction::UDiv:
7583 case Instruction::SDiv:
7584 case Instruction::URem:
7585 case Instruction::SRem:
7586 // If we have a predicated instruction, it may not be executed for each
7587 // vector lane. Get the scalarization cost and scale this amount by the
7588 // probability of executing the predicated block. If the instruction is not
7589 // predicated, we fall through to the next case.
7590 if (VF.isVector() && isScalarWithPredication(I)) {
7591 InstructionCost Cost = 0;
7592
7593 // These instructions have a non-void type, so account for the phi nodes
7594 // that we will create. This cost is likely to be zero. The phi node
7595 // cost, if any, should be scaled by the block probability because it
7596 // models a copy at the end of each predicated block.
7597 Cost += VF.getKnownMinValue() *
7598 TTI.getCFInstrCost(Instruction::PHI, CostKind);
7599
7600 // The cost of the non-predicated instruction.
7601 Cost += VF.getKnownMinValue() *
7602 TTI.getArithmeticInstrCost(I->getOpcode(), RetTy, CostKind);
7603
7604 // The cost of insertelement and extractelement instructions needed for
7605 // scalarization.
7606 Cost += getScalarizationOverhead(I, VF);
7607
7608 // Scale the cost by the probability of executing the predicated blocks.
7609 // This assumes the predicated block for each vector lane is equally
7610 // likely.
7611 return Cost / getReciprocalPredBlockProb();
7612 }
7613 LLVM_FALLTHROUGH[[gnu::fallthrough]];
7614 case Instruction::Add:
7615 case Instruction::FAdd:
7616 case Instruction::Sub:
7617 case Instruction::FSub:
7618 case Instruction::Mul:
7619 case Instruction::FMul:
7620 case Instruction::FDiv:
7621 case Instruction::FRem:
7622 case Instruction::Shl:
7623 case Instruction::LShr:
7624 case Instruction::AShr:
7625 case Instruction::And:
7626 case Instruction::Or:
7627 case Instruction::Xor: {
7628 // Since we will replace the stride by 1 the multiplication should go away.
7629 if (I->getOpcode() == Instruction::Mul && isStrideMul(I, Legal))
7630 return 0;
7631
7632 // Detect reduction patterns
7633 InstructionCost RedCost;
7634 if ((RedCost = getReductionPatternCost(I, VF, VectorTy, CostKind))
7635 .isValid())
7636 return RedCost;
7637
7638 // Certain instructions can be cheaper to vectorize if they have a constant
7639 // second vector operand. One example of this are shifts on x86.
7640 Value *Op2 = I->getOperand(1);
7641 TargetTransformInfo::OperandValueProperties Op2VP;
7642 TargetTransformInfo::OperandValueKind Op2VK =
7643 TTI.getOperandInfo(Op2, Op2VP);
7644 if (Op2VK == TargetTransformInfo::OK_AnyValue && Legal->isUniform(Op2))
7645 Op2VK = TargetTransformInfo::OK_UniformValue;
7646
7647 SmallVector<const Value *, 4> Operands(I->operand_values());
7648 return TTI.getArithmeticInstrCost(
7649 I->getOpcode(), VectorTy, CostKind, TargetTransformInfo::OK_AnyValue,
7650 Op2VK, TargetTransformInfo::OP_None, Op2VP, Operands, I);
7651 }
7652 case Instruction::FNeg: {
7653 return TTI.getArithmeticInstrCost(
7654 I->getOpcode(), VectorTy, CostKind, TargetTransformInfo::OK_AnyValue,
7655 TargetTransformInfo::OK_AnyValue, TargetTransformInfo::OP_None,
7656 TargetTransformInfo::OP_None, I->getOperand(0), I);
7657 }
7658 case Instruction::Select: {
7659 SelectInst *SI = cast<SelectInst>(I);
7660 const SCEV *CondSCEV = SE->getSCEV(SI->getCondition());
7661 bool ScalarCond = (SE->isLoopInvariant(CondSCEV, TheLoop));
7662
7663 const Value *Op0, *Op1;
7664 using namespace llvm::PatternMatch;
7665 if (!ScalarCond && (match(I, m_LogicalAnd(m_Value(Op0), m_Value(Op1))) ||
7666 match(I, m_LogicalOr(m_Value(Op0), m_Value(Op1))))) {
7667 // select x, y, false --> x & y
7668 // select x, true, y --> x | y
7669 TTI::OperandValueProperties Op1VP = TTI::OP_None;
7670 TTI::OperandValueProperties Op2VP = TTI::OP_None;
7671 TTI::OperandValueKind Op1VK = TTI::getOperandInfo(Op0, Op1VP);
7672 TTI::OperandValueKind Op2VK = TTI::getOperandInfo(Op1, Op2VP);
7673 assert(Op0->getType()->getScalarSizeInBits() == 1 &&(static_cast <bool> (Op0->getType()->getScalarSizeInBits
() == 1 && Op1->getType()->getScalarSizeInBits(
) == 1) ? void (0) : __assert_fail ("Op0->getType()->getScalarSizeInBits() == 1 && Op1->getType()->getScalarSizeInBits() == 1"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7674, __extension__ __PRETTY_FUNCTION__))
7674 Op1->getType()->getScalarSizeInBits() == 1)(static_cast <bool> (Op0->getType()->getScalarSizeInBits
() == 1 && Op1->getType()->getScalarSizeInBits(
) == 1) ? void (0) : __assert_fail ("Op0->getType()->getScalarSizeInBits() == 1 && Op1->getType()->getScalarSizeInBits() == 1"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7674, __extension__ __PRETTY_FUNCTION__))
;
7675
7676 SmallVector<const Value *, 2> Operands{Op0, Op1};
7677 return TTI.getArithmeticInstrCost(
7678 match(I, m_LogicalOr()) ? Instruction::Or : Instruction::And, VectorTy,
7679 CostKind, Op1VK, Op2VK, Op1VP, Op2VP, Operands, I);
7680 }
7681
7682 Type *CondTy = SI->getCondition()->getType();
7683 if (!ScalarCond)
7684 CondTy = VectorType::get(CondTy, VF);
7685 return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy,
7686 CmpInst::BAD_ICMP_PREDICATE, CostKind, I);
7687 }
7688 case Instruction::ICmp:
7689 case Instruction::FCmp: {
7690 Type *ValTy = I->getOperand(0)->getType();
7691 Instruction *Op0AsInstruction = dyn_cast<Instruction>(I->getOperand(0));
7692 if (canTruncateToMinimalBitwidth(Op0AsInstruction, VF))
7693 ValTy = IntegerType::get(ValTy->getContext(), MinBWs[Op0AsInstruction]);
7694 VectorTy = ToVectorTy(ValTy, VF);
7695 return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, nullptr,
7696 CmpInst::BAD_ICMP_PREDICATE, CostKind, I);
7697 }
7698 case Instruction::Store:
7699 case Instruction::Load: {
7700 ElementCount Width = VF;
7701 if (Width.isVector()) {
7702 InstWidening Decision = getWideningDecision(I, Width);
7703 assert(Decision != CM_Unknown &&(static_cast <bool> (Decision != CM_Unknown && "CM decision should be taken at this point"
) ? void (0) : __assert_fail ("Decision != CM_Unknown && \"CM decision should be taken at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7704, __extension__ __PRETTY_FUNCTION__))
7704 "CM decision should be taken at this point")(static_cast <bool> (Decision != CM_Unknown && "CM decision should be taken at this point"
) ? void (0) : __assert_fail ("Decision != CM_Unknown && \"CM decision should be taken at this point\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7704, __extension__ __PRETTY_FUNCTION__))
;
7705 if (Decision == CM_Scalarize)
7706 Width = ElementCount::getFixed(1);
7707 }
7708 VectorTy = ToVectorTy(getLoadStoreType(I), Width);
7709 return getMemoryInstructionCost(I, VF);
7710 }
7711 case Instruction::BitCast:
7712 if (I->getType()->isPointerTy())
7713 return 0;
7714 LLVM_FALLTHROUGH[[gnu::fallthrough]];
7715 case Instruction::ZExt:
7716 case Instruction::SExt:
7717 case Instruction::FPToUI:
7718 case Instruction::FPToSI:
7719 case Instruction::FPExt:
7720 case Instruction::PtrToInt:
7721 case Instruction::IntToPtr:
7722 case Instruction::SIToFP:
7723 case Instruction::UIToFP:
7724 case Instruction::Trunc:
7725 case Instruction::FPTrunc: {
7726 // Computes the CastContextHint from a Load/Store instruction.
7727 auto ComputeCCH = [&](Instruction *I) -> TTI::CastContextHint {
7728 assert((isa<LoadInst>(I) || isa<StoreInst>(I)) &&(static_cast <bool> ((isa<LoadInst>(I) || isa<
StoreInst>(I)) && "Expected a load or a store!") ?
void (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Expected a load or a store!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7729, __extension__ __PRETTY_FUNCTION__))
7729 "Expected a load or a store!")(static_cast <bool> ((isa<LoadInst>(I) || isa<
StoreInst>(I)) && "Expected a load or a store!") ?
void (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Expected a load or a store!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7729, __extension__ __PRETTY_FUNCTION__))
;
7730
7731 if (VF.isScalar() || !TheLoop->contains(I))
7732 return TTI::CastContextHint::Normal;
7733
7734 switch (getWideningDecision(I, VF)) {
7735 case LoopVectorizationCostModel::CM_GatherScatter:
7736 return TTI::CastContextHint::GatherScatter;
7737 case LoopVectorizationCostModel::CM_Interleave:
7738 return TTI::CastContextHint::Interleave;
7739 case LoopVectorizationCostModel::CM_Scalarize:
7740 case LoopVectorizationCostModel::CM_Widen:
7741 return Legal->isMaskRequired(I) ? TTI::CastContextHint::Masked
7742 : TTI::CastContextHint::Normal;
7743 case LoopVectorizationCostModel::CM_Widen_Reverse:
7744 return TTI::CastContextHint::Reversed;
7745 case LoopVectorizationCostModel::CM_Unknown:
7746 llvm_unreachable("Instr did not go through cost modelling?")::llvm::llvm_unreachable_internal("Instr did not go through cost modelling?"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7746)
;
7747 }
7748
7749 llvm_unreachable("Unhandled case!")::llvm::llvm_unreachable_internal("Unhandled case!", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7749)
;
7750 };
7751
7752 unsigned Opcode = I->getOpcode();
7753 TTI::CastContextHint CCH = TTI::CastContextHint::None;
7754 // For Trunc, the context is the only user, which must be a StoreInst.
7755 if (Opcode == Instruction::Trunc || Opcode == Instruction::FPTrunc) {
7756 if (I->hasOneUse())
7757 if (StoreInst *Store = dyn_cast<StoreInst>(*I->user_begin()))
7758 CCH = ComputeCCH(Store);
7759 }
7760 // For Z/Sext, the context is the operand, which must be a LoadInst.
7761 else if (Opcode == Instruction::ZExt || Opcode == Instruction::SExt ||
7762 Opcode == Instruction::FPExt) {
7763 if (LoadInst *Load = dyn_cast<LoadInst>(I->getOperand(0)))
7764 CCH = ComputeCCH(Load);
7765 }
7766
7767 // We optimize the truncation of induction variables having constant
7768 // integer steps. The cost of these truncations is the same as the scalar
7769 // operation.
7770 if (isOptimizableIVTruncate(I, VF)) {
7771 auto *Trunc = cast<TruncInst>(I);
7772 return TTI.getCastInstrCost(Instruction::Trunc, Trunc->getDestTy(),
7773 Trunc->getSrcTy(), CCH, CostKind, Trunc);
7774 }
7775
7776 // Detect reduction patterns
7777 InstructionCost RedCost;
7778 if ((RedCost = getReductionPatternCost(I, VF, VectorTy, CostKind))
7779 .isValid())
7780 return RedCost;
7781
7782 Type *SrcScalarTy = I->getOperand(0)->getType();
7783 Type *SrcVecTy =
7784 VectorTy->isVectorTy() ? ToVectorTy(SrcScalarTy, VF) : SrcScalarTy;
7785 if (canTruncateToMinimalBitwidth(I, VF)) {
7786 // This cast is going to be shrunk. This may remove the cast or it might
7787 // turn it into slightly different cast. For example, if MinBW == 16,
7788 // "zext i8 %1 to i32" becomes "zext i8 %1 to i16".
7789 //
7790 // Calculate the modified src and dest types.
7791 Type *MinVecTy = VectorTy;
7792 if (Opcode == Instruction::Trunc) {
7793 SrcVecTy = smallestIntegerVectorType(SrcVecTy, MinVecTy);
7794 VectorTy =
7795 largestIntegerVectorType(ToVectorTy(I->getType(), VF), MinVecTy);
7796 } else if (Opcode == Instruction::ZExt || Opcode == Instruction::SExt) {
7797 SrcVecTy = largestIntegerVectorType(SrcVecTy, MinVecTy);
7798 VectorTy =
7799 smallestIntegerVectorType(ToVectorTy(I->getType(), VF), MinVecTy);
7800 }
7801 }
7802
7803 return TTI.getCastInstrCost(Opcode, VectorTy, SrcVecTy, CCH, CostKind, I);
7804 }
7805 case Instruction::Call: {
7806 bool NeedToScalarize;
7807 CallInst *CI = cast<CallInst>(I);
7808 InstructionCost CallCost = getVectorCallCost(CI, VF, NeedToScalarize);
7809 if (getVectorIntrinsicIDForCall(CI, TLI)) {
7810 InstructionCost IntrinsicCost = getVectorIntrinsicCost(CI, VF);
7811 return std::min(CallCost, IntrinsicCost);
7812 }
7813 return CallCost;
7814 }
7815 case Instruction::ExtractValue:
7816 return TTI.getInstructionCost(I, TTI::TCK_RecipThroughput);
7817 default:
7818 // This opcode is unknown. Assume that it is the same as 'mul'.
7819 return TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy, CostKind);
7820 } // end of switch.
7821}
7822
7823char LoopVectorize::ID = 0;
7824
7825static const char lv_name[] = "Loop Vectorization";
7826
7827INITIALIZE_PASS_BEGIN(LoopVectorize, LV_NAME, lv_name, false, false)static void *initializeLoopVectorizePassOnce(PassRegistry &
Registry) {
7828INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)initializeTargetTransformInfoWrapperPassPass(Registry);
7829INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass)initializeBasicAAWrapperPassPass(Registry);
7830INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry);
7831INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)initializeGlobalsAAWrapperPassPass(Registry);
7832INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry);
7833INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)initializeBlockFrequencyInfoWrapperPassPass(Registry);
7834INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
7835INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)initializeScalarEvolutionWrapperPassPass(Registry);
7836INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)initializeLoopInfoWrapperPassPass(Registry);
7837INITIALIZE_PASS_DEPENDENCY(LoopAccessLegacyAnalysis)initializeLoopAccessLegacyAnalysisPass(Registry);
7838INITIALIZE_PASS_DEPENDENCY(DemandedBitsWrapperPass)initializeDemandedBitsWrapperPassPass(Registry);
7839INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)initializeOptimizationRemarkEmitterWrapperPassPass(Registry);
7840INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)initializeProfileSummaryInfoWrapperPassPass(Registry);
7841INITIALIZE_PASS_DEPENDENCY(InjectTLIMappingsLegacy)initializeInjectTLIMappingsLegacyPass(Registry);
7842INITIALIZE_PASS_END(LoopVectorize, LV_NAME, lv_name, false, false)PassInfo *PI = new PassInfo( lv_name, "loop-vectorize", &
LoopVectorize::ID, PassInfo::NormalCtor_t(callDefaultCtor<
LoopVectorize>), false, false); Registry.registerPass(*PI,
true); return PI; } static llvm::once_flag InitializeLoopVectorizePassFlag
; void llvm::initializeLoopVectorizePass(PassRegistry &Registry
) { llvm::call_once(InitializeLoopVectorizePassFlag, initializeLoopVectorizePassOnce
, std::ref(Registry)); }
7843
7844namespace llvm {
7845
7846Pass *createLoopVectorizePass() { return new LoopVectorize(); }
7847
7848Pass *createLoopVectorizePass(bool InterleaveOnlyWhenForced,
7849 bool VectorizeOnlyWhenForced) {
7850 return new LoopVectorize(InterleaveOnlyWhenForced, VectorizeOnlyWhenForced);
7851}
7852
7853} // end namespace llvm
7854
7855bool LoopVectorizationCostModel::isConsecutiveLoadOrStore(Instruction *Inst) {
7856 // Check if the pointer operand of a load or store instruction is
7857 // consecutive.
7858 if (auto *Ptr = getLoadStorePointerOperand(Inst))
7859 return Legal->isConsecutivePtr(Ptr);
7860 return false;
7861}
7862
7863void LoopVectorizationCostModel::collectValuesToIgnore() {
7864 // Ignore ephemeral values.
7865 CodeMetrics::collectEphemeralValues(TheLoop, AC, ValuesToIgnore);
7866
7867 // Ignore type-promoting instructions we identified during reduction
7868 // detection.
7869 for (auto &Reduction : Legal->getReductionVars()) {
7870 RecurrenceDescriptor &RedDes = Reduction.second;
7871 const SmallPtrSetImpl<Instruction *> &Casts = RedDes.getCastInsts();
7872 VecValuesToIgnore.insert(Casts.begin(), Casts.end());
7873 }
7874 // Ignore type-casting instructions we identified during induction
7875 // detection.
7876 for (auto &Induction : Legal->getInductionVars()) {
7877 InductionDescriptor &IndDes = Induction.second;
7878 const SmallVectorImpl<Instruction *> &Casts = IndDes.getCastInsts();
7879 VecValuesToIgnore.insert(Casts.begin(), Casts.end());
7880 }
7881}
7882
7883void LoopVectorizationCostModel::collectInLoopReductions() {
7884 for (auto &Reduction : Legal->getReductionVars()) {
7885 PHINode *Phi = Reduction.first;
7886 RecurrenceDescriptor &RdxDesc = Reduction.second;
7887
7888 // We don't collect reductions that are type promoted (yet).
7889 if (RdxDesc.getRecurrenceType() != Phi->getType())
7890 continue;
7891
7892 // If the target would prefer this reduction to happen "in-loop", then we
7893 // want to record it as such.
7894 unsigned Opcode = RdxDesc.getOpcode();
7895 if (!PreferInLoopReductions && !useOrderedReductions(RdxDesc) &&
7896 !TTI.preferInLoopReduction(Opcode, Phi->getType(),
7897 TargetTransformInfo::ReductionFlags()))
7898 continue;
7899
7900 // Check that we can correctly put the reductions into the loop, by
7901 // finding the chain of operations that leads from the phi to the loop
7902 // exit value.
7903 SmallVector<Instruction *, 4> ReductionOperations =
7904 RdxDesc.getReductionOpChain(Phi, TheLoop);
7905 bool InLoop = !ReductionOperations.empty();
7906 if (InLoop) {
7907 InLoopReductionChains[Phi] = ReductionOperations;
7908 // Add the elements to InLoopReductionImmediateChains for cost modelling.
7909 Instruction *LastChain = Phi;
7910 for (auto *I : ReductionOperations) {
7911 InLoopReductionImmediateChains[I] = LastChain;
7912 LastChain = I;
7913 }
7914 }
7915 LLVM_DEBUG(dbgs() << "LV: Using " << (InLoop ? "inloop" : "out of loop")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
InLoop ? "inloop" : "out of loop") << " reduction for phi: "
<< *Phi << "\n"; } } while (false)
7916 << " reduction for phi: " << *Phi << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
InLoop ? "inloop" : "out of loop") << " reduction for phi: "
<< *Phi << "\n"; } } while (false)
;
7917 }
7918}
7919
7920// TODO: we could return a pair of values that specify the max VF and
7921// min VF, to be used in `buildVPlans(MinVF, MaxVF)` instead of
7922// `buildVPlans(VF, VF)`. We cannot do it because VPLAN at the moment
7923// doesn't have a cost model that can choose which plan to execute if
7924// more than one is generated.
7925static unsigned determineVPlanVF(const unsigned WidestVectorRegBits,
7926 LoopVectorizationCostModel &CM) {
7927 unsigned WidestType;
7928 std::tie(std::ignore, WidestType) = CM.getSmallestAndWidestTypes();
7929 return WidestVectorRegBits / WidestType;
7930}
7931
7932VectorizationFactor
7933LoopVectorizationPlanner::planInVPlanNativePath(ElementCount UserVF) {
7934 assert(!UserVF.isScalable() && "scalable vectors not yet supported")(static_cast <bool> (!UserVF.isScalable() && "scalable vectors not yet supported"
) ? void (0) : __assert_fail ("!UserVF.isScalable() && \"scalable vectors not yet supported\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7934, __extension__ __PRETTY_FUNCTION__))
;
7935 ElementCount VF = UserVF;
7936 // Outer loop handling: They may require CFG and instruction level
7937 // transformations before even evaluating whether vectorization is profitable.
7938 // Since we cannot modify the incoming IR, we need to build VPlan upfront in
7939 // the vectorization pipeline.
7940 if (!OrigLoop->isInnermost()) {
7941 // If the user doesn't provide a vectorization factor, determine a
7942 // reasonable one.
7943 if (UserVF.isZero()) {
7944 VF = ElementCount::getFixed(determineVPlanVF(
7945 TTI->getRegisterBitWidth(TargetTransformInfo::RGK_FixedWidthVector)
7946 .getFixedSize(),
7947 CM));
7948 LLVM_DEBUG(dbgs() << "LV: VPlan computed VF " << VF << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: VPlan computed VF "
<< VF << ".\n"; } } while (false)
;
7949
7950 // Make sure we have a VF > 1 for stress testing.
7951 if (VPlanBuildStressTest && (VF.isScalar() || VF.isZero())) {
7952 LLVM_DEBUG(dbgs() << "LV: VPlan stress testing: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: VPlan stress testing: "
<< "overriding computed VF.\n"; } } while (false)
7953 << "overriding computed VF.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: VPlan stress testing: "
<< "overriding computed VF.\n"; } } while (false)
;
7954 VF = ElementCount::getFixed(4);
7955 }
7956 }
7957 assert(EnableVPlanNativePath && "VPlan-native path is not enabled.")(static_cast <bool> (EnableVPlanNativePath && "VPlan-native path is not enabled."
) ? void (0) : __assert_fail ("EnableVPlanNativePath && \"VPlan-native path is not enabled.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7957, __extension__ __PRETTY_FUNCTION__))
;
7958 assert(isPowerOf2_32(VF.getKnownMinValue()) &&(static_cast <bool> (isPowerOf2_32(VF.getKnownMinValue(
)) && "VF needs to be a power of two") ? void (0) : __assert_fail
("isPowerOf2_32(VF.getKnownMinValue()) && \"VF needs to be a power of two\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7959, __extension__ __PRETTY_FUNCTION__))
7959 "VF needs to be a power of two")(static_cast <bool> (isPowerOf2_32(VF.getKnownMinValue(
)) && "VF needs to be a power of two") ? void (0) : __assert_fail
("isPowerOf2_32(VF.getKnownMinValue()) && \"VF needs to be a power of two\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7959, __extension__ __PRETTY_FUNCTION__))
;
7960 LLVM_DEBUG(dbgs() << "LV: Using " << (!UserVF.isZero() ? "user " : "")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
!UserVF.isZero() ? "user " : "") << "VF " << VF <<
" to build VPlans.\n"; } } while (false)
7961 << "VF " << VF << " to build VPlans.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
!UserVF.isZero() ? "user " : "") << "VF " << VF <<
" to build VPlans.\n"; } } while (false)
;
7962 buildVPlans(VF, VF);
7963
7964 // For VPlan build stress testing, we bail out after VPlan construction.
7965 if (VPlanBuildStressTest)
7966 return VectorizationFactor::Disabled();
7967
7968 return {VF, 0 /*Cost*/};
7969 }
7970
7971 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing. Inner loops aren't supported in the "
"VPlan-native path.\n"; } } while (false)
7972 dbgs() << "LV: Not vectorizing. Inner loops aren't supported in the "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing. Inner loops aren't supported in the "
"VPlan-native path.\n"; } } while (false)
7973 "VPlan-native path.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing. Inner loops aren't supported in the "
"VPlan-native path.\n"; } } while (false)
;
7974 return VectorizationFactor::Disabled();
7975}
7976
7977Optional<VectorizationFactor>
7978LoopVectorizationPlanner::plan(ElementCount UserVF, unsigned UserIC) {
7979 assert(OrigLoop->isInnermost() && "Inner loop expected.")(static_cast <bool> (OrigLoop->isInnermost() &&
"Inner loop expected.") ? void (0) : __assert_fail ("OrigLoop->isInnermost() && \"Inner loop expected.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 7979, __extension__ __PRETTY_FUNCTION__))
;
7980 FixedScalableVFPair MaxFactors = CM.computeMaxVF(UserVF, UserIC);
7981 if (!MaxFactors) // Cases that should not to be vectorized nor interleaved.
7982 return None;
7983
7984 // Invalidate interleave groups if all blocks of loop will be predicated.
7985 if (CM.blockNeedsPredication(OrigLoop->getHeader()) &&
7986 !useMaskedInterleavedAccesses(*TTI)) {
7987 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Invalidate all interleaved groups due to fold-tail by masking "
"which requires masked-interleaved support.\n"; } } while (false
)
7988 dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Invalidate all interleaved groups due to fold-tail by masking "
"which requires masked-interleaved support.\n"; } } while (false
)
7989 << "LV: Invalidate all interleaved groups due to fold-tail by masking "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Invalidate all interleaved groups due to fold-tail by masking "
"which requires masked-interleaved support.\n"; } } while (false
)
7990 "which requires masked-interleaved support.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Invalidate all interleaved groups due to fold-tail by masking "
"which requires masked-interleaved support.\n"; } } while (false
)
;
7991 if (CM.InterleaveInfo.invalidateGroups())
7992 // Invalidating interleave groups also requires invalidating all decisions
7993 // based on them, which includes widening decisions and uniform and scalar
7994 // values.
7995 CM.invalidateCostModelingDecisions();
7996 }
7997
7998 ElementCount MaxUserVF =
7999 UserVF.isScalable() ? MaxFactors.ScalableVF : MaxFactors.FixedVF;
8000 bool UserVFIsLegal = ElementCount::isKnownLE(UserVF, MaxUserVF);
8001 if (!UserVF.isZero() && UserVFIsLegal) {
8002 LLVM_DEBUG(dbgs() << "LV: Using " << (UserVFIsLegal ? "user" : "max")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
UserVFIsLegal ? "user" : "max") << " VF " << UserVF
<< ".\n"; } } while (false)
8003 << " VF " << UserVF << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Using " << (
UserVFIsLegal ? "user" : "max") << " VF " << UserVF
<< ".\n"; } } while (false)
;
8004 assert(isPowerOf2_32(UserVF.getKnownMinValue()) &&(static_cast <bool> (isPowerOf2_32(UserVF.getKnownMinValue
()) && "VF needs to be a power of two") ? void (0) : __assert_fail
("isPowerOf2_32(UserVF.getKnownMinValue()) && \"VF needs to be a power of two\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8005, __extension__ __PRETTY_FUNCTION__))
8005 "VF needs to be a power of two")(static_cast <bool> (isPowerOf2_32(UserVF.getKnownMinValue
()) && "VF needs to be a power of two") ? void (0) : __assert_fail
("isPowerOf2_32(UserVF.getKnownMinValue()) && \"VF needs to be a power of two\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8005, __extension__ __PRETTY_FUNCTION__))
;
8006 // Collect the instructions (and their associated costs) that will be more
8007 // profitable to scalarize.
8008 CM.selectUserVectorizationFactor(UserVF);
8009 CM.collectInLoopReductions();
8010 buildVPlansWithVPRecipes(UserVF, UserVF);
8011 LLVM_DEBUG(printPlans(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { printPlans(dbgs()); } } while (false)
;
8012 return {{UserVF, 0}};
8013 }
8014
8015 // Populate the set of Vectorization Factor Candidates.
8016 ElementCountSet VFCandidates;
8017 for (auto VF = ElementCount::getFixed(1);
8018 ElementCount::isKnownLE(VF, MaxFactors.FixedVF); VF *= 2)
8019 VFCandidates.insert(VF);
8020 for (auto VF = ElementCount::getScalable(1);
8021 ElementCount::isKnownLE(VF, MaxFactors.ScalableVF); VF *= 2)
8022 VFCandidates.insert(VF);
8023
8024 for (const auto &VF : VFCandidates) {
8025 // Collect Uniform and Scalar instructions after vectorization with VF.
8026 CM.collectUniformsAndScalars(VF);
8027
8028 // Collect the instructions (and their associated costs) that will be more
8029 // profitable to scalarize.
8030 if (VF.isVector())
8031 CM.collectInstsToScalarize(VF);
8032 }
8033
8034 CM.collectInLoopReductions();
8035 buildVPlansWithVPRecipes(ElementCount::getFixed(1), MaxFactors.FixedVF);
8036 buildVPlansWithVPRecipes(ElementCount::getScalable(1), MaxFactors.ScalableVF);
8037
8038 LLVM_DEBUG(printPlans(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { printPlans(dbgs()); } } while (false)
;
8039 if (!MaxFactors.hasVector())
8040 return VectorizationFactor::Disabled();
8041
8042 // Select the optimal vectorization factor.
8043 auto SelectedVF = CM.selectVectorizationFactor(VFCandidates);
8044
8045 // Check if it is profitable to vectorize with runtime checks.
8046 unsigned NumRuntimePointerChecks = Requirements.getNumRuntimePointerChecks();
8047 if (SelectedVF.Width.getKnownMinValue() > 1 && NumRuntimePointerChecks) {
8048 bool PragmaThresholdReached =
8049 NumRuntimePointerChecks > PragmaVectorizeMemoryCheckThreshold;
8050 bool ThresholdReached =
8051 NumRuntimePointerChecks > VectorizerParams::RuntimeMemoryCheckThreshold;
8052 if ((ThresholdReached && !Hints.allowReordering()) ||
8053 PragmaThresholdReached) {
8054 ORE->emit([&]() {
8055 return OptimizationRemarkAnalysisAliasing(
8056 DEBUG_TYPE"loop-vectorize", "CantReorderMemOps", OrigLoop->getStartLoc(),
8057 OrigLoop->getHeader())
8058 << "loop not vectorized: cannot prove it is safe to reorder "
8059 "memory operations";
8060 });
8061 LLVM_DEBUG(dbgs() << "LV: Too many memory checks needed.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Too many memory checks needed.\n"
; } } while (false)
;
8062 Hints.emitRemarkWithHints();
8063 return VectorizationFactor::Disabled();
8064 }
8065 }
8066 return SelectedVF;
8067}
8068
8069void LoopVectorizationPlanner::setBestPlan(ElementCount VF, unsigned UF) {
8070 LLVM_DEBUG(dbgs() << "Setting best plan to VF=" << VF << ", UF=" << UFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Setting best plan to VF="
<< VF << ", UF=" << UF << '\n'; } } while
(false)
8071 << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Setting best plan to VF="
<< VF << ", UF=" << UF << '\n'; } } while
(false)
;
8072 BestVF = VF;
8073 BestUF = UF;
8074
8075 erase_if(VPlans, [VF](const VPlanPtr &Plan) {
8076 return !Plan->hasVF(VF);
8077 });
8078 assert(VPlans.size() == 1 && "Best VF has not a single VPlan.")(static_cast <bool> (VPlans.size() == 1 && "Best VF has not a single VPlan."
) ? void (0) : __assert_fail ("VPlans.size() == 1 && \"Best VF has not a single VPlan.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8078, __extension__ __PRETTY_FUNCTION__))
;
8079}
8080
8081void LoopVectorizationPlanner::executePlan(InnerLoopVectorizer &ILV,
8082 DominatorTree *DT) {
8083 // Perform the actual loop transformation.
8084
8085 // 1. Create a new empty loop. Unlink the old loop and connect the new one.
8086 assert(BestVF.hasValue() && "Vectorization Factor is missing")(static_cast <bool> (BestVF.hasValue() && "Vectorization Factor is missing"
) ? void (0) : __assert_fail ("BestVF.hasValue() && \"Vectorization Factor is missing\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8086, __extension__ __PRETTY_FUNCTION__))
;
8087 assert(VPlans.size() == 1 && "Not a single VPlan to execute.")(static_cast <bool> (VPlans.size() == 1 && "Not a single VPlan to execute."
) ? void (0) : __assert_fail ("VPlans.size() == 1 && \"Not a single VPlan to execute.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8087, __extension__ __PRETTY_FUNCTION__))
;
8088
8089 VPTransformState State{
8090 *BestVF, BestUF, LI, DT, ILV.Builder, &ILV, VPlans.front().get()};
8091 State.CFG.PrevBB = ILV.createVectorizedLoopSkeleton();
8092 State.TripCount = ILV.getOrCreateTripCount(nullptr);
8093 State.CanonicalIV = ILV.Induction;
8094
8095 ILV.printDebugTracesAtStart();
8096
8097 //===------------------------------------------------===//
8098 //
8099 // Notice: any optimization or new instruction that go
8100 // into the code below should also be implemented in
8101 // the cost-model.
8102 //
8103 //===------------------------------------------------===//
8104
8105 // 2. Copy and widen instructions from the old loop into the new loop.
8106 VPlans.front()->execute(&State);
8107
8108 // 3. Fix the vectorized code: take care of header phi's, live-outs,
8109 // predication, updating analyses.
8110 ILV.fixVectorizedLoop(State);
8111
8112 ILV.printDebugTracesAtEnd();
8113}
8114
8115#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
8116void LoopVectorizationPlanner::printPlans(raw_ostream &O) {
8117 for (const auto &Plan : VPlans)
8118 if (PrintVPlansInDotFormat)
8119 Plan->printDOT(O);
8120 else
8121 Plan->print(O);
8122}
8123#endif
8124
8125void LoopVectorizationPlanner::collectTriviallyDeadInstructions(
8126 SmallPtrSetImpl<Instruction *> &DeadInstructions) {
8127
8128 // We create new control-flow for the vectorized loop, so the original exit
8129 // conditions will be dead after vectorization if it's only used by the
8130 // terminator
8131 SmallVector<BasicBlock*> ExitingBlocks;
8132 OrigLoop->getExitingBlocks(ExitingBlocks);
8133 for (auto *BB : ExitingBlocks) {
8134 auto *Cmp = dyn_cast<Instruction>(BB->getTerminator()->getOperand(0));
8135 if (!Cmp || !Cmp->hasOneUse())
8136 continue;
8137
8138 // TODO: we should introduce a getUniqueExitingBlocks on Loop
8139 if (!DeadInstructions.insert(Cmp).second)
8140 continue;
8141
8142 // The operands of the icmp is often a dead trunc, used by IndUpdate.
8143 // TODO: can recurse through operands in general
8144 for (Value *Op : Cmp->operands()) {
8145 if (isa<TruncInst>(Op) && Op->hasOneUse())
8146 DeadInstructions.insert(cast<Instruction>(Op));
8147 }
8148 }
8149
8150 // We create new "steps" for induction variable updates to which the original
8151 // induction variables map. An original update instruction will be dead if
8152 // all its users except the induction variable are dead.
8153 auto *Latch = OrigLoop->getLoopLatch();
8154 for (auto &Induction : Legal->getInductionVars()) {
8155 PHINode *Ind = Induction.first;
8156 auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch));
8157
8158 // If the tail is to be folded by masking, the primary induction variable,
8159 // if exists, isn't dead: it will be used for masking. Don't kill it.
8160 if (CM.foldTailByMasking() && IndUpdate == Legal->getPrimaryInduction())
8161 continue;
8162
8163 if (llvm::all_of(IndUpdate->users(), [&](User *U) -> bool {
8164 return U == Ind || DeadInstructions.count(cast<Instruction>(U));
8165 }))
8166 DeadInstructions.insert(IndUpdate);
8167
8168 // We record as "Dead" also the type-casting instructions we had identified
8169 // during induction analysis. We don't need any handling for them in the
8170 // vectorized loop because we have proven that, under a proper runtime
8171 // test guarding the vectorized loop, the value of the phi, and the casted
8172 // value of the phi, are the same. The last instruction in this casting chain
8173 // will get its scalar/vector/widened def from the scalar/vector/widened def
8174 // of the respective phi node. Any other casts in the induction def-use chain
8175 // have no other uses outside the phi update chain, and will be ignored.
8176 InductionDescriptor &IndDes = Induction.second;
8177 const SmallVectorImpl<Instruction *> &Casts = IndDes.getCastInsts();
8178 DeadInstructions.insert(Casts.begin(), Casts.end());
8179 }
8180}
8181
8182Value *InnerLoopUnroller::reverseVector(Value *Vec) { return Vec; }
8183
8184Value *InnerLoopUnroller::getBroadcastInstrs(Value *V) { return V; }
8185
8186Value *InnerLoopUnroller::getStepVector(Value *Val, int StartIdx, Value *Step,
8187 Instruction::BinaryOps BinOp) {
8188 // When unrolling and the VF is 1, we only need to add a simple scalar.
8189 Type *Ty = Val->getType();
8190 assert(!Ty->isVectorTy() && "Val must be a scalar")(static_cast <bool> (!Ty->isVectorTy() && "Val must be a scalar"
) ? void (0) : __assert_fail ("!Ty->isVectorTy() && \"Val must be a scalar\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8190, __extension__ __PRETTY_FUNCTION__))
;
8191
8192 if (Ty->isFloatingPointTy()) {
8193 Constant *C = ConstantFP::get(Ty, (double)StartIdx);
8194
8195 // Floating-point operations inherit FMF via the builder's flags.
8196 Value *MulOp = Builder.CreateFMul(C, Step);
8197 return Builder.CreateBinOp(BinOp, Val, MulOp);
8198 }
8199 Constant *C = ConstantInt::get(Ty, StartIdx);
8200 return Builder.CreateAdd(Val, Builder.CreateMul(C, Step), "induction");
8201}
8202
8203static void AddRuntimeUnrollDisableMetaData(Loop *L) {
8204 SmallVector<Metadata *, 4> MDs;
8205 // Reserve first location for self reference to the LoopID metadata node.
8206 MDs.push_back(nullptr);
8207 bool IsUnrollMetadata = false;
8208 MDNode *LoopID = L->getLoopID();
8209 if (LoopID) {
8210 // First find existing loop unrolling disable metadata.
8211 for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
8212 auto *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
8213 if (MD) {
8214 const auto *S = dyn_cast<MDString>(MD->getOperand(0));
8215 IsUnrollMetadata =
8216 S && S->getString().startswith("llvm.loop.unroll.disable");
8217 }
8218 MDs.push_back(LoopID->getOperand(i));
8219 }
8220 }
8221
8222 if (!IsUnrollMetadata) {
8223 // Add runtime unroll disable metadata.
8224 LLVMContext &Context = L->getHeader()->getContext();
8225 SmallVector<Metadata *, 1> DisableOperands;
8226 DisableOperands.push_back(
8227 MDString::get(Context, "llvm.loop.unroll.runtime.disable"));
8228 MDNode *DisableNode = MDNode::get(Context, DisableOperands);
8229 MDs.push_back(DisableNode);
8230 MDNode *NewLoopID = MDNode::get(Context, MDs);
8231 // Set operand 0 to refer to the loop id itself.
8232 NewLoopID->replaceOperandWith(0, NewLoopID);
8233 L->setLoopID(NewLoopID);
8234 }
8235}
8236
8237//===--------------------------------------------------------------------===//
8238// EpilogueVectorizerMainLoop
8239//===--------------------------------------------------------------------===//
8240
8241/// This function is partially responsible for generating the control flow
8242/// depicted in https://llvm.org/docs/Vectorizers.html#epilogue-vectorization.
8243BasicBlock *EpilogueVectorizerMainLoop::createEpilogueVectorizedLoopSkeleton() {
8244 MDNode *OrigLoopID = OrigLoop->getLoopID();
8245 Loop *Lp = createVectorLoopSkeleton("");
8246
8247 // Generate the code to check the minimum iteration count of the vector
8248 // epilogue (see below).
8249 EPI.EpilogueIterationCountCheck =
8250 emitMinimumIterationCountCheck(Lp, LoopScalarPreHeader, true);
8251 EPI.EpilogueIterationCountCheck->setName("iter.check");
8252
8253 // Generate the code to check any assumptions that we've made for SCEV
8254 // expressions.
8255 EPI.SCEVSafetyCheck = emitSCEVChecks(Lp, LoopScalarPreHeader);
8256
8257 // Generate the code that checks at runtime if arrays overlap. We put the
8258 // checks into a separate block to make the more common case of few elements
8259 // faster.
8260 EPI.MemSafetyCheck = emitMemRuntimeChecks(Lp, LoopScalarPreHeader);
8261
8262 // Generate the iteration count check for the main loop, *after* the check
8263 // for the epilogue loop, so that the path-length is shorter for the case
8264 // that goes directly through the vector epilogue. The longer-path length for
8265 // the main loop is compensated for, by the gain from vectorizing the larger
8266 // trip count. Note: the branch will get updated later on when we vectorize
8267 // the epilogue.
8268 EPI.MainLoopIterationCountCheck =
8269 emitMinimumIterationCountCheck(Lp, LoopScalarPreHeader, false);
8270
8271 // Generate the induction variable.
8272 OldInduction = Legal->getPrimaryInduction();
8273 Type *IdxTy = Legal->getWidestInductionType();
8274 Value *StartIdx = ConstantInt::get(IdxTy, 0);
8275 Constant *Step = ConstantInt::get(IdxTy, VF.getKnownMinValue() * UF);
8276 Value *CountRoundDown = getOrCreateVectorTripCount(Lp);
8277 EPI.VectorTripCount = CountRoundDown;
8278 Induction =
8279 createInductionVariable(Lp, StartIdx, CountRoundDown, Step,
8280 getDebugLocFromInstOrOperands(OldInduction));
8281
8282 // Skip induction resume value creation here because they will be created in
8283 // the second pass. If we created them here, they wouldn't be used anyway,
8284 // because the vplan in the second pass still contains the inductions from the
8285 // original loop.
8286
8287 return completeLoopSkeleton(Lp, OrigLoopID);
8288}
8289
8290void EpilogueVectorizerMainLoop::printDebugTracesAtStart() {
8291 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8292 dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8293 << "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8294 << ", Main Loop UF:" << EPI.MainLoopUFdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8295 << ", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8296 << ", Epilogue Loop UF:" << EPI.EpilogueUF << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8297 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (first pass)\n"
<< "Main Loop VF:" << EPI.MainLoopVF.getKnownMinValue
() << ", Main Loop UF:" << EPI.MainLoopUF <<
", Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
;
8298}
8299
8300void EpilogueVectorizerMainLoop::printDebugTracesAtEnd() {
8301 DEBUG_WITH_TYPE(VerboseDebug, {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "intermediate fn:\n" <<
*Induction->getFunction() << "\n"; }; } } while (false
)
8302 dbgs() << "intermediate fn:\n" << *Induction->getFunction() << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "intermediate fn:\n" <<
*Induction->getFunction() << "\n"; }; } } while (false
)
8303 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "intermediate fn:\n" <<
*Induction->getFunction() << "\n"; }; } } while (false
)
;
8304}
8305
8306BasicBlock *EpilogueVectorizerMainLoop::emitMinimumIterationCountCheck(
8307 Loop *L, BasicBlock *Bypass, bool ForEpilogue) {
8308 assert(L && "Expected valid Loop.")(static_cast <bool> (L && "Expected valid Loop."
) ? void (0) : __assert_fail ("L && \"Expected valid Loop.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8308, __extension__ __PRETTY_FUNCTION__))
;
8309 assert(Bypass && "Expected valid bypass basic block.")(static_cast <bool> (Bypass && "Expected valid bypass basic block."
) ? void (0) : __assert_fail ("Bypass && \"Expected valid bypass basic block.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8309, __extension__ __PRETTY_FUNCTION__))
;
8310 unsigned VFactor =
8311 ForEpilogue ? EPI.EpilogueVF.getKnownMinValue() : VF.getKnownMinValue();
8312 unsigned UFactor = ForEpilogue ? EPI.EpilogueUF : UF;
8313 Value *Count = getOrCreateTripCount(L);
8314 // Reuse existing vector loop preheader for TC checks.
8315 // Note that new preheader block is generated for vector loop.
8316 BasicBlock *const TCCheckBlock = LoopVectorPreHeader;
8317 IRBuilder<> Builder(TCCheckBlock->getTerminator());
8318
8319 // Generate code to check if the loop's trip count is less than VF * UF of the
8320 // main vector loop.
8321 auto P =
8322 Cost->requiresScalarEpilogue() ? ICmpInst::ICMP_ULE : ICmpInst::ICMP_ULT;
8323
8324 Value *CheckMinIters = Builder.CreateICmp(
8325 P, Count, ConstantInt::get(Count->getType(), VFactor * UFactor),
8326 "min.iters.check");
8327
8328 if (!ForEpilogue)
8329 TCCheckBlock->setName("vector.main.loop.iter.check");
8330
8331 // Create new preheader for vector loop.
8332 LoopVectorPreHeader = SplitBlock(TCCheckBlock, TCCheckBlock->getTerminator(),
8333 DT, LI, nullptr, "vector.ph");
8334
8335 if (ForEpilogue) {
8336 assert(DT->properlyDominates(DT->getNode(TCCheckBlock),(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8338, __extension__ __PRETTY_FUNCTION__))
8337 DT->getNode(Bypass)->getIDom()) &&(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8338, __extension__ __PRETTY_FUNCTION__))
8338 "TC check is expected to dominate Bypass")(static_cast <bool> (DT->properlyDominates(DT->getNode
(TCCheckBlock), DT->getNode(Bypass)->getIDom()) &&
"TC check is expected to dominate Bypass") ? void (0) : __assert_fail
("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8338, __extension__ __PRETTY_FUNCTION__))
;
8339
8340 // Update dominator for Bypass & LoopExit.
8341 DT->changeImmediateDominator(Bypass, TCCheckBlock);
8342 DT->changeImmediateDominator(LoopExitBlock, TCCheckBlock);
8343
8344 LoopBypassBlocks.push_back(TCCheckBlock);
8345
8346 // Save the trip count so we don't have to regenerate it in the
8347 // vec.epilog.iter.check. This is safe to do because the trip count
8348 // generated here dominates the vector epilog iter check.
8349 EPI.TripCount = Count;
8350 }
8351
8352 ReplaceInstWithInst(
8353 TCCheckBlock->getTerminator(),
8354 BranchInst::Create(Bypass, LoopVectorPreHeader, CheckMinIters));
8355
8356 return TCCheckBlock;
8357}
8358
8359//===--------------------------------------------------------------------===//
8360// EpilogueVectorizerEpilogueLoop
8361//===--------------------------------------------------------------------===//
8362
8363/// This function is partially responsible for generating the control flow
8364/// depicted in https://llvm.org/docs/Vectorizers.html#epilogue-vectorization.
8365BasicBlock *
8366EpilogueVectorizerEpilogueLoop::createEpilogueVectorizedLoopSkeleton() {
8367 MDNode *OrigLoopID = OrigLoop->getLoopID();
8368 Loop *Lp = createVectorLoopSkeleton("vec.epilog.");
8369
8370 // Now, compare the remaining count and if there aren't enough iterations to
8371 // execute the vectorized epilogue skip to the scalar part.
8372 BasicBlock *VecEpilogueIterationCountCheck = LoopVectorPreHeader;
8373 VecEpilogueIterationCountCheck->setName("vec.epilog.iter.check");
8374 LoopVectorPreHeader =
8375 SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT,
8376 LI, nullptr, "vec.epilog.ph");
8377 emitMinimumVectorEpilogueIterCountCheck(Lp, LoopScalarPreHeader,
8378 VecEpilogueIterationCountCheck);
8379
8380 // Adjust the control flow taking the state info from the main loop
8381 // vectorization into account.
8382 assert(EPI.MainLoopIterationCountCheck && EPI.EpilogueIterationCountCheck &&(static_cast <bool> (EPI.MainLoopIterationCountCheck &&
EPI.EpilogueIterationCountCheck && "expected this to be saved from the previous pass."
) ? void (0) : __assert_fail ("EPI.MainLoopIterationCountCheck && EPI.EpilogueIterationCountCheck && \"expected this to be saved from the previous pass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8383, __extension__ __PRETTY_FUNCTION__))
8383 "expected this to be saved from the previous pass.")(static_cast <bool> (EPI.MainLoopIterationCountCheck &&
EPI.EpilogueIterationCountCheck && "expected this to be saved from the previous pass."
) ? void (0) : __assert_fail ("EPI.MainLoopIterationCountCheck && EPI.EpilogueIterationCountCheck && \"expected this to be saved from the previous pass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8383, __extension__ __PRETTY_FUNCTION__))
;
8384 EPI.MainLoopIterationCountCheck->getTerminator()->replaceUsesOfWith(
8385 VecEpilogueIterationCountCheck, LoopVectorPreHeader);
8386
8387 DT->changeImmediateDominator(LoopVectorPreHeader,
8388 EPI.MainLoopIterationCountCheck);
8389
8390 EPI.EpilogueIterationCountCheck->getTerminator()->replaceUsesOfWith(
8391 VecEpilogueIterationCountCheck, LoopScalarPreHeader);
8392
8393 if (EPI.SCEVSafetyCheck)
8394 EPI.SCEVSafetyCheck->getTerminator()->replaceUsesOfWith(
8395 VecEpilogueIterationCountCheck, LoopScalarPreHeader);
8396 if (EPI.MemSafetyCheck)
8397 EPI.MemSafetyCheck->getTerminator()->replaceUsesOfWith(
8398 VecEpilogueIterationCountCheck, LoopScalarPreHeader);
8399
8400 DT->changeImmediateDominator(
8401 VecEpilogueIterationCountCheck,
8402 VecEpilogueIterationCountCheck->getSinglePredecessor());
8403
8404 DT->changeImmediateDominator(LoopScalarPreHeader,
8405 EPI.EpilogueIterationCountCheck);
8406 DT->changeImmediateDominator(LoopExitBlock, EPI.EpilogueIterationCountCheck);
8407
8408 // Keep track of bypass blocks, as they feed start values to the induction
8409 // phis in the scalar loop preheader.
8410 if (EPI.SCEVSafetyCheck)
8411 LoopBypassBlocks.push_back(EPI.SCEVSafetyCheck);
8412 if (EPI.MemSafetyCheck)
8413 LoopBypassBlocks.push_back(EPI.MemSafetyCheck);
8414 LoopBypassBlocks.push_back(EPI.EpilogueIterationCountCheck);
8415
8416 // Generate a resume induction for the vector epilogue and put it in the
8417 // vector epilogue preheader
8418 Type *IdxTy = Legal->getWidestInductionType();
8419 PHINode *EPResumeVal = PHINode::Create(IdxTy, 2, "vec.epilog.resume.val",
8420 LoopVectorPreHeader->getFirstNonPHI());
8421 EPResumeVal->addIncoming(EPI.VectorTripCount, VecEpilogueIterationCountCheck);
8422 EPResumeVal->addIncoming(ConstantInt::get(IdxTy, 0),
8423 EPI.MainLoopIterationCountCheck);
8424
8425 // Generate the induction variable.
8426 OldInduction = Legal->getPrimaryInduction();
8427 Value *CountRoundDown = getOrCreateVectorTripCount(Lp);
8428 Constant *Step = ConstantInt::get(IdxTy, VF.getKnownMinValue() * UF);
8429 Value *StartIdx = EPResumeVal;
8430 Induction =
8431 createInductionVariable(Lp, StartIdx, CountRoundDown, Step,
8432 getDebugLocFromInstOrOperands(OldInduction));
8433
8434 // Generate induction resume values. These variables save the new starting
8435 // indexes for the scalar loop. They are used to test if there are any tail
8436 // iterations left once the vector loop has completed.
8437 // Note that when the vectorized epilogue is skipped due to iteration count
8438 // check, then the resume value for the induction variable comes from
8439 // the trip count of the main vector loop, hence passing the AdditionalBypass
8440 // argument.
8441 createInductionResumeValues(Lp, CountRoundDown,
8442 {VecEpilogueIterationCountCheck,
8443 EPI.VectorTripCount} /* AdditionalBypass */);
8444
8445 AddRuntimeUnrollDisableMetaData(Lp);
8446 return completeLoopSkeleton(Lp, OrigLoopID);
8447}
8448
8449BasicBlock *
8450EpilogueVectorizerEpilogueLoop::emitMinimumVectorEpilogueIterCountCheck(
8451 Loop *L, BasicBlock *Bypass, BasicBlock *Insert) {
8452
8453 assert(EPI.TripCount &&(static_cast <bool> (EPI.TripCount && "Expected trip count to have been safed in the first pass."
) ? void (0) : __assert_fail ("EPI.TripCount && \"Expected trip count to have been safed in the first pass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8454, __extension__ __PRETTY_FUNCTION__))
8454 "Expected trip count to have been safed in the first pass.")(static_cast <bool> (EPI.TripCount && "Expected trip count to have been safed in the first pass."
) ? void (0) : __assert_fail ("EPI.TripCount && \"Expected trip count to have been safed in the first pass.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8454, __extension__ __PRETTY_FUNCTION__))
;
8455 assert((static_cast <bool> ((!isa<Instruction>(EPI.TripCount
) || DT->dominates(cast<Instruction>(EPI.TripCount)->
getParent(), Insert)) && "saved trip count does not dominate insertion point."
) ? void (0) : __assert_fail ("(!isa<Instruction>(EPI.TripCount) || DT->dominates(cast<Instruction>(EPI.TripCount)->getParent(), Insert)) && \"saved trip count does not dominate insertion point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8458, __extension__ __PRETTY_FUNCTION__))
8456 (!isa<Instruction>(EPI.TripCount) ||(static_cast <bool> ((!isa<Instruction>(EPI.TripCount
) || DT->dominates(cast<Instruction>(EPI.TripCount)->
getParent(), Insert)) && "saved trip count does not dominate insertion point."
) ? void (0) : __assert_fail ("(!isa<Instruction>(EPI.TripCount) || DT->dominates(cast<Instruction>(EPI.TripCount)->getParent(), Insert)) && \"saved trip count does not dominate insertion point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8458, __extension__ __PRETTY_FUNCTION__))
8457 DT->dominates(cast<Instruction>(EPI.TripCount)->getParent(), Insert)) &&(static_cast <bool> ((!isa<Instruction>(EPI.TripCount
) || DT->dominates(cast<Instruction>(EPI.TripCount)->
getParent(), Insert)) && "saved trip count does not dominate insertion point."
) ? void (0) : __assert_fail ("(!isa<Instruction>(EPI.TripCount) || DT->dominates(cast<Instruction>(EPI.TripCount)->getParent(), Insert)) && \"saved trip count does not dominate insertion point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8458, __extension__ __PRETTY_FUNCTION__))
8458 "saved trip count does not dominate insertion point.")(static_cast <bool> ((!isa<Instruction>(EPI.TripCount
) || DT->dominates(cast<Instruction>(EPI.TripCount)->
getParent(), Insert)) && "saved trip count does not dominate insertion point."
) ? void (0) : __assert_fail ("(!isa<Instruction>(EPI.TripCount) || DT->dominates(cast<Instruction>(EPI.TripCount)->getParent(), Insert)) && \"saved trip count does not dominate insertion point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8458, __extension__ __PRETTY_FUNCTION__))
;
8459 Value *TC = EPI.TripCount;
8460 IRBuilder<> Builder(Insert->getTerminator());
8461 Value *Count = Builder.CreateSub(TC, EPI.VectorTripCount, "n.vec.remaining");
8462
8463 // Generate code to check if the loop's trip count is less than VF * UF of the
8464 // vector epilogue loop.
8465 auto P =
8466 Cost->requiresScalarEpilogue() ? ICmpInst::ICMP_ULE : ICmpInst::ICMP_ULT;
8467
8468 Value *CheckMinIters = Builder.CreateICmp(
8469 P, Count,
8470 ConstantInt::get(Count->getType(),
8471 EPI.EpilogueVF.getKnownMinValue() * EPI.EpilogueUF),
8472 "min.epilog.iters.check");
8473
8474 ReplaceInstWithInst(
8475 Insert->getTerminator(),
8476 BranchInst::Create(Bypass, LoopVectorPreHeader, CheckMinIters));
8477
8478 LoopBypassBlocks.push_back(Insert);
8479 return Insert;
8480}
8481
8482void EpilogueVectorizerEpilogueLoop::printDebugTracesAtStart() {
8483 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"
<< "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8484 dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"
<< "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8485 << "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"
<< "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8486 << ", Epilogue Loop UF:" << EPI.EpilogueUF << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"
<< "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
8487 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { { dbgs() << "Create Skeleton for epilogue vectorized loop (second pass)\n"
<< "Epilogue Loop VF:" << EPI.EpilogueVF.getKnownMinValue
() << ", Epilogue Loop UF:" << EPI.EpilogueUF <<
"\n"; }; } } while (false)
;
8488}
8489
8490void EpilogueVectorizerEpilogueLoop::printDebugTracesAtEnd() {
8491 DEBUG_WITH_TYPE(VerboseDebug, {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "final fn:\n" << *Induction
->getFunction() << "\n"; }; } } while (false)
8492 dbgs() << "final fn:\n" << *Induction->getFunction() << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "final fn:\n" << *Induction
->getFunction() << "\n"; }; } } while (false)
8493 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
(VerboseDebug)) { { dbgs() << "final fn:\n" << *Induction
->getFunction() << "\n"; }; } } while (false)
;
8494}
8495
8496bool LoopVectorizationPlanner::getDecisionAndClampRange(
8497 const std::function<bool(ElementCount)> &Predicate, VFRange &Range) {
8498 assert(!Range.isEmpty() && "Trying to test an empty VF range.")(static_cast <bool> (!Range.isEmpty() && "Trying to test an empty VF range."
) ? void (0) : __assert_fail ("!Range.isEmpty() && \"Trying to test an empty VF range.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8498, __extension__ __PRETTY_FUNCTION__))
;
8499 bool PredicateAtRangeStart = Predicate(Range.Start);
8500
8501 for (ElementCount TmpVF = Range.Start * 2;
8502 ElementCount::isKnownLT(TmpVF, Range.End); TmpVF *= 2)
8503 if (Predicate(TmpVF) != PredicateAtRangeStart) {
8504 Range.End = TmpVF;
8505 break;
8506 }
8507
8508 return PredicateAtRangeStart;
8509}
8510
8511/// Build VPlans for the full range of feasible VF's = {\p MinVF, 2 * \p MinVF,
8512/// 4 * \p MinVF, ..., \p MaxVF} by repeatedly building a VPlan for a sub-range
8513/// of VF's starting at a given VF and extending it as much as possible. Each
8514/// vectorization decision can potentially shorten this sub-range during
8515/// buildVPlan().
8516void LoopVectorizationPlanner::buildVPlans(ElementCount MinVF,
8517 ElementCount MaxVF) {
8518 auto MaxVFPlusOne = MaxVF.getWithIncrement(1);
8519 for (ElementCount VF = MinVF; ElementCount::isKnownLT(VF, MaxVFPlusOne);) {
8520 VFRange SubRange = {VF, MaxVFPlusOne};
8521 VPlans.push_back(buildVPlan(SubRange));
8522 VF = SubRange.End;
8523 }
8524}
8525
8526VPValue *VPRecipeBuilder::createEdgeMask(BasicBlock *Src, BasicBlock *Dst,
8527 VPlanPtr &Plan) {
8528 assert(is_contained(predecessors(Dst), Src) && "Invalid edge")(static_cast <bool> (is_contained(predecessors(Dst), Src
) && "Invalid edge") ? void (0) : __assert_fail ("is_contained(predecessors(Dst), Src) && \"Invalid edge\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8528, __extension__ __PRETTY_FUNCTION__))
;
8529
8530 // Look for cached value.
8531 std::pair<BasicBlock *, BasicBlock *> Edge(Src, Dst);
8532 EdgeMaskCacheTy::iterator ECEntryIt = EdgeMaskCache.find(Edge);
8533 if (ECEntryIt != EdgeMaskCache.end())
8534 return ECEntryIt->second;
8535
8536 VPValue *SrcMask = createBlockInMask(Src, Plan);
8537
8538 // The terminator has to be a branch inst!
8539 BranchInst *BI = dyn_cast<BranchInst>(Src->getTerminator());
8540 assert(BI && "Unexpected terminator found")(static_cast <bool> (BI && "Unexpected terminator found"
) ? void (0) : __assert_fail ("BI && \"Unexpected terminator found\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8540, __extension__ __PRETTY_FUNCTION__))
;
8541
8542 if (!BI->isConditional() || BI->getSuccessor(0) == BI->getSuccessor(1))
8543 return EdgeMaskCache[Edge] = SrcMask;
8544
8545 // If source is an exiting block, we know the exit edge is dynamically dead
8546 // in the vector loop, and thus we don't need to restrict the mask. Avoid
8547 // adding uses of an otherwise potentially dead instruction.
8548 if (OrigLoop->isLoopExiting(Src))
8549 return EdgeMaskCache[Edge] = SrcMask;
8550
8551 VPValue *EdgeMask = Plan->getOrAddVPValue(BI->getCondition());
8552 assert(EdgeMask && "No Edge Mask found for condition")(static_cast <bool> (EdgeMask && "No Edge Mask found for condition"
) ? void (0) : __assert_fail ("EdgeMask && \"No Edge Mask found for condition\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8552, __extension__ __PRETTY_FUNCTION__))
;
8553
8554 if (BI->getSuccessor(0) != Dst)
8555 EdgeMask = Builder.createNot(EdgeMask);
8556
8557 if (SrcMask) { // Otherwise block in-mask is all-one, no need to AND.
8558 // The condition is 'SrcMask && EdgeMask', which is equivalent to
8559 // 'select i1 SrcMask, i1 EdgeMask, i1 false'.
8560 // The select version does not introduce new UB if SrcMask is false and
8561 // EdgeMask is poison. Using 'and' here introduces undefined behavior.
8562 VPValue *False = Plan->getOrAddVPValue(
8563 ConstantInt::getFalse(BI->getCondition()->getType()));
8564 EdgeMask = Builder.createSelect(SrcMask, EdgeMask, False);
8565 }
8566
8567 return EdgeMaskCache[Edge] = EdgeMask;
8568}
8569
8570VPValue *VPRecipeBuilder::createBlockInMask(BasicBlock *BB, VPlanPtr &Plan) {
8571 assert(OrigLoop->contains(BB) && "Block is not a part of a loop")(static_cast <bool> (OrigLoop->contains(BB) &&
"Block is not a part of a loop") ? void (0) : __assert_fail (
"OrigLoop->contains(BB) && \"Block is not a part of a loop\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8571, __extension__ __PRETTY_FUNCTION__))
;
8572
8573 // Look for cached value.
8574 BlockMaskCacheTy::iterator BCEntryIt = BlockMaskCache.find(BB);
8575 if (BCEntryIt != BlockMaskCache.end())
8576 return BCEntryIt->second;
8577
8578 // All-one mask is modelled as no-mask following the convention for masked
8579 // load/store/gather/scatter. Initialize BlockMask to no-mask.
8580 VPValue *BlockMask = nullptr;
8581
8582 if (OrigLoop->getHeader() == BB) {
8583 if (!CM.blockNeedsPredication(BB))
8584 return BlockMaskCache[BB] = BlockMask; // Loop incoming mask is all-one.
8585
8586 // Create the block in mask as the first non-phi instruction in the block.
8587 VPBuilder::InsertPointGuard Guard(Builder);
8588 auto NewInsertionPoint = Builder.getInsertBlock()->getFirstNonPhi();
8589 Builder.setInsertPoint(Builder.getInsertBlock(), NewInsertionPoint);
8590
8591 // Introduce the early-exit compare IV <= BTC to form header block mask.
8592 // This is used instead of IV < TC because TC may wrap, unlike BTC.
8593 // Start by constructing the desired canonical IV.
8594 VPValue *IV = nullptr;
8595 if (Legal->getPrimaryInduction())
8596 IV = Plan->getOrAddVPValue(Legal->getPrimaryInduction());
8597 else {
8598 auto IVRecipe = new VPWidenCanonicalIVRecipe();
8599 Builder.getInsertBlock()->insert(IVRecipe, NewInsertionPoint);
8600 IV = IVRecipe->getVPSingleValue();
8601 }
8602 VPValue *BTC = Plan->getOrCreateBackedgeTakenCount();
8603 bool TailFolded = !CM.isScalarEpilogueAllowed();
8604
8605 if (TailFolded && CM.TTI.emitGetActiveLaneMask()) {
8606 // While ActiveLaneMask is a binary op that consumes the loop tripcount
8607 // as a second argument, we only pass the IV here and extract the
8608 // tripcount from the transform state where codegen of the VP instructions
8609 // happen.
8610 BlockMask = Builder.createNaryOp(VPInstruction::ActiveLaneMask, {IV});
8611 } else {
8612 BlockMask = Builder.createNaryOp(VPInstruction::ICmpULE, {IV, BTC});
8613 }
8614 return BlockMaskCache[BB] = BlockMask;
8615 }
8616
8617 // This is the block mask. We OR all incoming edges.
8618 for (auto *Predecessor : predecessors(BB)) {
8619 VPValue *EdgeMask = createEdgeMask(Predecessor, BB, Plan);
8620 if (!EdgeMask) // Mask of predecessor is all-one so mask of block is too.
8621 return BlockMaskCache[BB] = EdgeMask;
8622
8623 if (!BlockMask) { // BlockMask has its initialized nullptr value.
8624 BlockMask = EdgeMask;
8625 continue;
8626 }
8627
8628 BlockMask = Builder.createOr(BlockMask, EdgeMask);
8629 }
8630
8631 return BlockMaskCache[BB] = BlockMask;
8632}
8633
8634VPRecipeBase *VPRecipeBuilder::tryToWidenMemory(Instruction *I,
8635 ArrayRef<VPValue *> Operands,
8636 VFRange &Range,
8637 VPlanPtr &Plan) {
8638 assert((isa<LoadInst>(I) || isa<StoreInst>(I)) &&(static_cast <bool> ((isa<LoadInst>(I) || isa<
StoreInst>(I)) && "Must be called with either a load or store"
) ? void (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Must be called with either a load or store\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8639, __extension__ __PRETTY_FUNCTION__))
8639 "Must be called with either a load or store")(static_cast <bool> ((isa<LoadInst>(I) || isa<
StoreInst>(I)) && "Must be called with either a load or store"
) ? void (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Must be called with either a load or store\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8639, __extension__ __PRETTY_FUNCTION__))
;
8640
8641 auto willWiden = [&](ElementCount VF) -> bool {
8642 if (VF.isScalar())
8643 return false;
8644 LoopVectorizationCostModel::InstWidening Decision =
8645 CM.getWideningDecision(I, VF);
8646 assert(Decision != LoopVectorizationCostModel::CM_Unknown &&(static_cast <bool> (Decision != LoopVectorizationCostModel
::CM_Unknown && "CM decision should be taken at this point."
) ? void (0) : __assert_fail ("Decision != LoopVectorizationCostModel::CM_Unknown && \"CM decision should be taken at this point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8647, __extension__ __PRETTY_FUNCTION__))
8647 "CM decision should be taken at this point.")(static_cast <bool> (Decision != LoopVectorizationCostModel
::CM_Unknown && "CM decision should be taken at this point."
) ? void (0) : __assert_fail ("Decision != LoopVectorizationCostModel::CM_Unknown && \"CM decision should be taken at this point.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8647, __extension__ __PRETTY_FUNCTION__))
;
8648 if (Decision == LoopVectorizationCostModel::CM_Interleave)
8649 return true;
8650 if (CM.isScalarAfterVectorization(I, VF) ||
8651 CM.isProfitableToScalarize(I, VF))
8652 return false;
8653 return Decision != LoopVectorizationCostModel::CM_Scalarize;
8654 };
8655
8656 if (!LoopVectorizationPlanner::getDecisionAndClampRange(willWiden, Range))
8657 return nullptr;
8658
8659 VPValue *Mask = nullptr;
8660 if (Legal->isMaskRequired(I))
8661 Mask = createBlockInMask(I->getParent(), Plan);
8662
8663 if (LoadInst *Load = dyn_cast<LoadInst>(I))
8664 return new VPWidenMemoryInstructionRecipe(*Load, Operands[0], Mask);
8665
8666 StoreInst *Store = cast<StoreInst>(I);
8667 return new VPWidenMemoryInstructionRecipe(*Store, Operands[1], Operands[0],
8668 Mask);
8669}
8670
8671VPWidenIntOrFpInductionRecipe *
8672VPRecipeBuilder::tryToOptimizeInductionPHI(PHINode *Phi,
8673 ArrayRef<VPValue *> Operands) const {
8674 // Check if this is an integer or fp induction. If so, build the recipe that
8675 // produces its scalar and vector values.
8676 InductionDescriptor II = Legal->getInductionVars().lookup(Phi);
8677 if (II.getKind() == InductionDescriptor::IK_IntInduction ||
8678 II.getKind() == InductionDescriptor::IK_FpInduction) {
8679 assert(II.getStartValue() ==(static_cast <bool> (II.getStartValue() == Phi->getIncomingValueForBlock
(OrigLoop->getLoopPreheader())) ? void (0) : __assert_fail
("II.getStartValue() == Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8680, __extension__ __PRETTY_FUNCTION__))
8680 Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader()))(static_cast <bool> (II.getStartValue() == Phi->getIncomingValueForBlock
(OrigLoop->getLoopPreheader())) ? void (0) : __assert_fail
("II.getStartValue() == Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8680, __extension__ __PRETTY_FUNCTION__))
;
8681 const SmallVectorImpl<Instruction *> &Casts = II.getCastInsts();
8682 return new VPWidenIntOrFpInductionRecipe(
8683 Phi, Operands[0], Casts.empty() ? nullptr : Casts.front());
8684 }
8685
8686 return nullptr;
8687}
8688
8689VPWidenIntOrFpInductionRecipe *VPRecipeBuilder::tryToOptimizeInductionTruncate(
8690 TruncInst *I, ArrayRef<VPValue *> Operands, VFRange &Range,
8691 VPlan &Plan) const {
8692 // Optimize the special case where the source is a constant integer
8693 // induction variable. Notice that we can only optimize the 'trunc' case
8694 // because (a) FP conversions lose precision, (b) sext/zext may wrap, and
8695 // (c) other casts depend on pointer size.
8696
8697 // Determine whether \p K is a truncation based on an induction variable that
8698 // can be optimized.
8699 auto isOptimizableIVTruncate =
8700 [&](Instruction *K) -> std::function<bool(ElementCount)> {
8701 return [=](ElementCount VF) -> bool {
8702 return CM.isOptimizableIVTruncate(K, VF);
8703 };
8704 };
8705
8706 if (LoopVectorizationPlanner::getDecisionAndClampRange(
8707 isOptimizableIVTruncate(I), Range)) {
8708
8709 InductionDescriptor II =
8710 Legal->getInductionVars().lookup(cast<PHINode>(I->getOperand(0)));
8711 VPValue *Start = Plan.getOrAddVPValue(II.getStartValue());
8712 return new VPWidenIntOrFpInductionRecipe(cast<PHINode>(I->getOperand(0)),
8713 Start, nullptr, I);
8714 }
8715 return nullptr;
8716}
8717
8718VPRecipeOrVPValueTy VPRecipeBuilder::tryToBlend(PHINode *Phi,
8719 ArrayRef<VPValue *> Operands,
8720 VPlanPtr &Plan) {
8721 // If all incoming values are equal, the incoming VPValue can be used directly
8722 // instead of creating a new VPBlendRecipe.
8723 VPValue *FirstIncoming = Operands[0];
8724 if (all_of(Operands, [FirstIncoming](const VPValue *Inc) {
8725 return FirstIncoming == Inc;
8726 })) {
8727 return Operands[0];
8728 }
8729
8730 // We know that all PHIs in non-header blocks are converted into selects, so
8731 // we don't have to worry about the insertion order and we can just use the
8732 // builder. At this point we generate the predication tree. There may be
8733 // duplications since this is a simple recursive scan, but future
8734 // optimizations will clean it up.
8735 SmallVector<VPValue *, 2> OperandsWithMask;
8736 unsigned NumIncoming = Phi->getNumIncomingValues();
8737
8738 for (unsigned In = 0; In < NumIncoming; In++) {
8739 VPValue *EdgeMask =
8740 createEdgeMask(Phi->getIncomingBlock(In), Phi->getParent(), Plan);
8741 assert((EdgeMask || NumIncoming == 1) &&(static_cast <bool> ((EdgeMask || NumIncoming == 1) &&
"Multiple predecessors with one having a full mask") ? void (
0) : __assert_fail ("(EdgeMask || NumIncoming == 1) && \"Multiple predecessors with one having a full mask\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8742, __extension__ __PRETTY_FUNCTION__))
8742 "Multiple predecessors with one having a full mask")(static_cast <bool> ((EdgeMask || NumIncoming == 1) &&
"Multiple predecessors with one having a full mask") ? void (
0) : __assert_fail ("(EdgeMask || NumIncoming == 1) && \"Multiple predecessors with one having a full mask\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8742, __extension__ __PRETTY_FUNCTION__))
;
8743 OperandsWithMask.push_back(Operands[In]);
8744 if (EdgeMask)
8745 OperandsWithMask.push_back(EdgeMask);
8746 }
8747 return toVPRecipeResult(new VPBlendRecipe(Phi, OperandsWithMask));
8748}
8749
8750VPWidenCallRecipe *VPRecipeBuilder::tryToWidenCall(CallInst *CI,
8751 ArrayRef<VPValue *> Operands,
8752 VFRange &Range) const {
8753
8754 bool IsPredicated = LoopVectorizationPlanner::getDecisionAndClampRange(
8755 [this, CI](ElementCount VF) { return CM.isScalarWithPredication(CI); },
8756 Range);
8757
8758 if (IsPredicated)
8759 return nullptr;
8760
8761 Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
8762 if (ID && (ID == Intrinsic::assume || ID == Intrinsic::lifetime_end ||
8763 ID == Intrinsic::lifetime_start || ID == Intrinsic::sideeffect ||
8764 ID == Intrinsic::pseudoprobe ||
8765 ID == Intrinsic::experimental_noalias_scope_decl))
8766 return nullptr;
8767
8768 auto willWiden = [&](ElementCount VF) -> bool {
8769 Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI);
8770 // The following case may be scalarized depending on the VF.
8771 // The flag shows whether we use Intrinsic or a usual Call for vectorized
8772 // version of the instruction.
8773 // Is it beneficial to perform intrinsic call compared to lib call?
8774 bool NeedToScalarize = false;
8775 InstructionCost CallCost = CM.getVectorCallCost(CI, VF, NeedToScalarize);
8776 InstructionCost IntrinsicCost = ID ? CM.getVectorIntrinsicCost(CI, VF) : 0;
8777 bool UseVectorIntrinsic = ID && IntrinsicCost <= CallCost;
8778 assert((IntrinsicCost.isValid() || CallCost.isValid()) &&(static_cast <bool> ((IntrinsicCost.isValid() || CallCost
.isValid()) && "Either the intrinsic cost or vector call cost must be valid"
) ? void (0) : __assert_fail ("(IntrinsicCost.isValid() || CallCost.isValid()) && \"Either the intrinsic cost or vector call cost must be valid\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8779, __extension__ __PRETTY_FUNCTION__))
8779 "Either the intrinsic cost or vector call cost must be valid")(static_cast <bool> ((IntrinsicCost.isValid() || CallCost
.isValid()) && "Either the intrinsic cost or vector call cost must be valid"
) ? void (0) : __assert_fail ("(IntrinsicCost.isValid() || CallCost.isValid()) && \"Either the intrinsic cost or vector call cost must be valid\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8779, __extension__ __PRETTY_FUNCTION__))
;
8780 return UseVectorIntrinsic || !NeedToScalarize;
8781 };
8782
8783 if (!LoopVectorizationPlanner::getDecisionAndClampRange(willWiden, Range))
8784 return nullptr;
8785
8786 ArrayRef<VPValue *> Ops = Operands.take_front(CI->getNumArgOperands());
8787 return new VPWidenCallRecipe(*CI, make_range(Ops.begin(), Ops.end()));
8788}
8789
8790bool VPRecipeBuilder::shouldWiden(Instruction *I, VFRange &Range) const {
8791 assert(!isa<BranchInst>(I) && !isa<PHINode>(I) && !isa<LoadInst>(I) &&(static_cast <bool> (!isa<BranchInst>(I) &&
!isa<PHINode>(I) && !isa<LoadInst>(I) &&
!isa<StoreInst>(I) && "Instruction should have been handled earlier"
) ? void (0) : __assert_fail ("!isa<BranchInst>(I) && !isa<PHINode>(I) && !isa<LoadInst>(I) && !isa<StoreInst>(I) && \"Instruction should have been handled earlier\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8792, __extension__ __PRETTY_FUNCTION__))
8792 !isa<StoreInst>(I) && "Instruction should have been handled earlier")(static_cast <bool> (!isa<BranchInst>(I) &&
!isa<PHINode>(I) && !isa<LoadInst>(I) &&
!isa<StoreInst>(I) && "Instruction should have been handled earlier"
) ? void (0) : __assert_fail ("!isa<BranchInst>(I) && !isa<PHINode>(I) && !isa<LoadInst>(I) && !isa<StoreInst>(I) && \"Instruction should have been handled earlier\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8792, __extension__ __PRETTY_FUNCTION__))
;
8793 // Instruction should be widened, unless it is scalar after vectorization,
8794 // scalarization is profitable or it is predicated.
8795 auto WillScalarize = [this, I](ElementCount VF) -> bool {
8796 return CM.isScalarAfterVectorization(I, VF) ||
8797 CM.isProfitableToScalarize(I, VF) || CM.isScalarWithPredication(I);
8798 };
8799 return !LoopVectorizationPlanner::getDecisionAndClampRange(WillScalarize,
8800 Range);
8801}
8802
8803VPWidenRecipe *VPRecipeBuilder::tryToWiden(Instruction *I,
8804 ArrayRef<VPValue *> Operands) const {
8805 auto IsVectorizableOpcode = [](unsigned Opcode) {
8806 switch (Opcode) {
8807 case Instruction::Add:
8808 case Instruction::And:
8809 case Instruction::AShr:
8810 case Instruction::BitCast:
8811 case Instruction::FAdd:
8812 case Instruction::FCmp:
8813 case Instruction::FDiv:
8814 case Instruction::FMul:
8815 case Instruction::FNeg:
8816 case Instruction::FPExt:
8817 case Instruction::FPToSI:
8818 case Instruction::FPToUI:
8819 case Instruction::FPTrunc:
8820 case Instruction::FRem:
8821 case Instruction::FSub:
8822 case Instruction::ICmp:
8823 case Instruction::IntToPtr:
8824 case Instruction::LShr:
8825 case Instruction::Mul:
8826 case Instruction::Or:
8827 case Instruction::PtrToInt:
8828 case Instruction::SDiv:
8829 case Instruction::Select:
8830 case Instruction::SExt:
8831 case Instruction::Shl:
8832 case Instruction::SIToFP:
8833 case Instruction::SRem:
8834 case Instruction::Sub:
8835 case Instruction::Trunc:
8836 case Instruction::UDiv:
8837 case Instruction::UIToFP:
8838 case Instruction::URem:
8839 case Instruction::Xor:
8840 case Instruction::ZExt:
8841 return true;
8842 }
8843 return false;
8844 };
8845
8846 if (!IsVectorizableOpcode(I->getOpcode()))
8847 return nullptr;
8848
8849 // Success: widen this instruction.
8850 return new VPWidenRecipe(*I, make_range(Operands.begin(), Operands.end()));
8851}
8852
8853void VPRecipeBuilder::fixHeaderPhis() {
8854 BasicBlock *OrigLatch = OrigLoop->getLoopLatch();
8855 for (VPWidenPHIRecipe *R : PhisToFix) {
8856 auto *PN = cast<PHINode>(R->getUnderlyingValue());
8857 VPRecipeBase *IncR =
8858 getRecipe(cast<Instruction>(PN->getIncomingValueForBlock(OrigLatch)));
8859 R->addOperand(IncR->getVPSingleValue());
8860 }
8861}
8862
8863VPBasicBlock *VPRecipeBuilder::handleReplication(
8864 Instruction *I, VFRange &Range, VPBasicBlock *VPBB,
8865 VPlanPtr &Plan) {
8866 bool IsUniform = LoopVectorizationPlanner::getDecisionAndClampRange(
8867 [&](ElementCount VF) { return CM.isUniformAfterVectorization(I, VF); },
8868 Range);
8869
8870 bool IsPredicated = LoopVectorizationPlanner::getDecisionAndClampRange(
8871 [&](ElementCount VF) { return CM.isPredicatedInst(I); }, Range);
8872
8873 auto *Recipe = new VPReplicateRecipe(I, Plan->mapToVPValues(I->operands()),
8874 IsUniform, IsPredicated);
8875 setRecipe(I, Recipe);
8876 Plan->addVPValue(I, Recipe);
8877
8878 // Find if I uses a predicated instruction. If so, it will use its scalar
8879 // value. Avoid hoisting the insert-element which packs the scalar value into
8880 // a vector value, as that happens iff all users use the vector value.
8881 for (VPValue *Op : Recipe->operands()) {
8882 auto *PredR = dyn_cast_or_null<VPPredInstPHIRecipe>(Op->getDef());
8883 if (!PredR)
8884 continue;
8885 auto *RepR =
8886 cast_or_null<VPReplicateRecipe>(PredR->getOperand(0)->getDef());
8887 assert(RepR->isPredicated() &&(static_cast <bool> (RepR->isPredicated() &&
"expected Replicate recipe to be predicated") ? void (0) : __assert_fail
("RepR->isPredicated() && \"expected Replicate recipe to be predicated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8888, __extension__ __PRETTY_FUNCTION__))
8888 "expected Replicate recipe to be predicated")(static_cast <bool> (RepR->isPredicated() &&
"expected Replicate recipe to be predicated") ? void (0) : __assert_fail
("RepR->isPredicated() && \"expected Replicate recipe to be predicated\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8888, __extension__ __PRETTY_FUNCTION__))
;
8889 RepR->setAlsoPack(false);
8890 }
8891
8892 // Finalize the recipe for Instr, first if it is not predicated.
8893 if (!IsPredicated) {
8894 LLVM_DEBUG(dbgs() << "LV: Scalarizing:" << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Scalarizing:" <<
*I << "\n"; } } while (false)
;
8895 VPBB->appendRecipe(Recipe);
8896 return VPBB;
8897 }
8898 LLVM_DEBUG(dbgs() << "LV: Scalarizing and predicating:" << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Scalarizing and predicating:"
<< *I << "\n"; } } while (false)
;
8899 assert(VPBB->getSuccessors().empty() &&(static_cast <bool> (VPBB->getSuccessors().empty() &&
"VPBB has successors when handling predicated replication.")
? void (0) : __assert_fail ("VPBB->getSuccessors().empty() && \"VPBB has successors when handling predicated replication.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8900, __extension__ __PRETTY_FUNCTION__))
8900 "VPBB has successors when handling predicated replication.")(static_cast <bool> (VPBB->getSuccessors().empty() &&
"VPBB has successors when handling predicated replication.")
? void (0) : __assert_fail ("VPBB->getSuccessors().empty() && \"VPBB has successors when handling predicated replication.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8900, __extension__ __PRETTY_FUNCTION__))
;
8901 // Record predicated instructions for above packing optimizations.
8902 VPBlockBase *Region = createReplicateRegion(I, Recipe, Plan);
8903 VPBlockUtils::insertBlockAfter(Region, VPBB);
8904 auto *RegSucc = new VPBasicBlock();
8905 VPBlockUtils::insertBlockAfter(RegSucc, Region);
8906 return RegSucc;
8907}
8908
8909VPRegionBlock *VPRecipeBuilder::createReplicateRegion(Instruction *Instr,
8910 VPRecipeBase *PredRecipe,
8911 VPlanPtr &Plan) {
8912 // Instructions marked for predication are replicated and placed under an
8913 // if-then construct to prevent side-effects.
8914
8915 // Generate recipes to compute the block mask for this region.
8916 VPValue *BlockInMask = createBlockInMask(Instr->getParent(), Plan);
8917
8918 // Build the triangular if-then region.
8919 std::string RegionName = (Twine("pred.") + Instr->getOpcodeName()).str();
8920 assert(Instr->getParent() && "Predicated instruction not in any basic block")(static_cast <bool> (Instr->getParent() && "Predicated instruction not in any basic block"
) ? void (0) : __assert_fail ("Instr->getParent() && \"Predicated instruction not in any basic block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8920, __extension__ __PRETTY_FUNCTION__))
;
8921 auto *BOMRecipe = new VPBranchOnMaskRecipe(BlockInMask);
8922 auto *Entry = new VPBasicBlock(Twine(RegionName) + ".entry", BOMRecipe);
8923 auto *PHIRecipe = Instr->getType()->isVoidTy()
8924 ? nullptr
8925 : new VPPredInstPHIRecipe(Plan->getOrAddVPValue(Instr));
8926 if (PHIRecipe) {
8927 Plan->removeVPValueFor(Instr);
8928 Plan->addVPValue(Instr, PHIRecipe);
8929 }
8930 auto *Exit = new VPBasicBlock(Twine(RegionName) + ".continue", PHIRecipe);
8931 auto *Pred = new VPBasicBlock(Twine(RegionName) + ".if", PredRecipe);
8932 VPRegionBlock *Region = new VPRegionBlock(Entry, Exit, RegionName, true);
8933
8934 // Note: first set Entry as region entry and then connect successors starting
8935 // from it in order, to propagate the "parent" of each VPBasicBlock.
8936 VPBlockUtils::insertTwoBlocksAfter(Pred, Exit, BlockInMask, Entry);
8937 VPBlockUtils::connectBlocks(Pred, Exit);
8938
8939 return Region;
8940}
8941
8942VPRecipeOrVPValueTy
8943VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
8944 ArrayRef<VPValue *> Operands,
8945 VFRange &Range, VPlanPtr &Plan) {
8946 // First, check for specific widening recipes that deal with calls, memory
8947 // operations, inductions and Phi nodes.
8948 if (auto *CI = dyn_cast<CallInst>(Instr))
8949 return toVPRecipeResult(tryToWidenCall(CI, Operands, Range));
8950
8951 if (isa<LoadInst>(Instr) || isa<StoreInst>(Instr))
8952 return toVPRecipeResult(tryToWidenMemory(Instr, Operands, Range, Plan));
8953
8954 VPRecipeBase *Recipe;
8955 if (auto Phi = dyn_cast<PHINode>(Instr)) {
8956 if (Phi->getParent() != OrigLoop->getHeader())
8957 return tryToBlend(Phi, Operands, Plan);
8958 if ((Recipe = tryToOptimizeInductionPHI(Phi, Operands)))
8959 return toVPRecipeResult(Recipe);
8960
8961 if (Legal->isReductionVariable(Phi)) {
8962 RecurrenceDescriptor &RdxDesc = Legal->getReductionVars()[Phi];
8963 assert(RdxDesc.getRecurrenceStartValue() ==(static_cast <bool> (RdxDesc.getRecurrenceStartValue() ==
Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader
())) ? void (0) : __assert_fail ("RdxDesc.getRecurrenceStartValue() == Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8964, __extension__ __PRETTY_FUNCTION__))
8964 Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader()))(static_cast <bool> (RdxDesc.getRecurrenceStartValue() ==
Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader
())) ? void (0) : __assert_fail ("RdxDesc.getRecurrenceStartValue() == Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 8964, __extension__ __PRETTY_FUNCTION__))
;
8965 VPValue *StartV = Operands[0];
8966
8967 auto *PhiRecipe = new VPWidenPHIRecipe(Phi, RdxDesc, *StartV);
8968 PhisToFix.push_back(PhiRecipe);
8969 // Record the incoming value from the backedge, so we can add the incoming
8970 // value from the backedge after all recipes have been created.
8971 recordRecipeOf(cast<Instruction>(
8972 Phi->getIncomingValueForBlock(OrigLoop->getLoopLatch())));
8973 return toVPRecipeResult(PhiRecipe);
8974 }
8975
8976 return toVPRecipeResult(new VPWidenPHIRecipe(Phi));
8977 }
8978
8979 if (isa<TruncInst>(Instr) &&
8980 (Recipe = tryToOptimizeInductionTruncate(cast<TruncInst>(Instr), Operands,
8981 Range, *Plan)))
8982 return toVPRecipeResult(Recipe);
8983
8984 if (!shouldWiden(Instr, Range))
8985 return nullptr;
8986
8987 if (auto GEP = dyn_cast<GetElementPtrInst>(Instr))
8988 return toVPRecipeResult(new VPWidenGEPRecipe(
8989 GEP, make_range(Operands.begin(), Operands.end()), OrigLoop));
8990
8991 if (auto *SI = dyn_cast<SelectInst>(Instr)) {
8992 bool InvariantCond =
8993 PSE.getSE()->isLoopInvariant(PSE.getSCEV(SI->getOperand(0)), OrigLoop);
8994 return toVPRecipeResult(new VPWidenSelectRecipe(
8995 *SI, make_range(Operands.begin(), Operands.end()), InvariantCond));
8996 }
8997
8998 return toVPRecipeResult(tryToWiden(Instr, Operands));
8999}
9000
9001void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
9002 ElementCount MaxVF) {
9003 assert(OrigLoop->isInnermost() && "Inner loop expected.")(static_cast <bool> (OrigLoop->isInnermost() &&
"Inner loop expected.") ? void (0) : __assert_fail ("OrigLoop->isInnermost() && \"Inner loop expected.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9003, __extension__ __PRETTY_FUNCTION__))
;
9004
9005 // Collect instructions from the original loop that will become trivially dead
9006 // in the vectorized loop. We don't need to vectorize these instructions. For
9007 // example, original induction update instructions can become dead because we
9008 // separately emit induction "steps" when generating code for the new loop.
9009 // Similarly, we create a new latch condition when setting up the structure
9010 // of the new loop, so the old one can become dead.
9011 SmallPtrSet<Instruction *, 4> DeadInstructions;
9012 collectTriviallyDeadInstructions(DeadInstructions);
9013
9014 // Add assume instructions we need to drop to DeadInstructions, to prevent
9015 // them from being added to the VPlan.
9016 // TODO: We only need to drop assumes in blocks that get flattend. If the
9017 // control flow is preserved, we should keep them.
9018 auto &ConditionalAssumes = Legal->getConditionalAssumes();
9019 DeadInstructions.insert(ConditionalAssumes.begin(), ConditionalAssumes.end());
9020
9021 MapVector<Instruction *, Instruction *> &SinkAfter = Legal->getSinkAfter();
9022 // Dead instructions do not need sinking. Remove them from SinkAfter.
9023 for (Instruction *I : DeadInstructions)
9024 SinkAfter.erase(I);
9025
9026 auto MaxVFPlusOne = MaxVF.getWithIncrement(1);
9027 for (ElementCount VF = MinVF; ElementCount::isKnownLT(VF, MaxVFPlusOne);) {
9028 VFRange SubRange = {VF, MaxVFPlusOne};
9029 VPlans.push_back(
9030 buildVPlanWithVPRecipes(SubRange, DeadInstructions, SinkAfter));
9031 VF = SubRange.End;
9032 }
9033}
9034
9035VPlanPtr LoopVectorizationPlanner::buildVPlanWithVPRecipes(
9036 VFRange &Range, SmallPtrSetImpl<Instruction *> &DeadInstructions,
9037 const MapVector<Instruction *, Instruction *> &SinkAfter) {
9038
9039 SmallPtrSet<const InterleaveGroup<Instruction> *, 1> InterleaveGroups;
9040
9041 VPRecipeBuilder RecipeBuilder(OrigLoop, TLI, Legal, CM, PSE, Builder);
9042
9043 // ---------------------------------------------------------------------------
9044 // Pre-construction: record ingredients whose recipes we'll need to further
9045 // process after constructing the initial VPlan.
9046 // ---------------------------------------------------------------------------
9047
9048 // Mark instructions we'll need to sink later and their targets as
9049 // ingredients whose recipe we'll need to record.
9050 for (auto &Entry : SinkAfter) {
9051 RecipeBuilder.recordRecipeOf(Entry.first);
9052 RecipeBuilder.recordRecipeOf(Entry.second);
9053 }
9054 for (auto &Reduction : CM.getInLoopReductionChains()) {
9055 PHINode *Phi = Reduction.first;
9056 RecurKind Kind = Legal->getReductionVars()[Phi].getRecurrenceKind();
9057 const SmallVector<Instruction *, 4> &ReductionOperations = Reduction.second;
9058
9059 RecipeBuilder.recordRecipeOf(Phi);
9060 for (auto &R : ReductionOperations) {
9061 RecipeBuilder.recordRecipeOf(R);
9062 // For min/max reducitons, where we have a pair of icmp/select, we also
9063 // need to record the ICmp recipe, so it can be removed later.
9064 if (RecurrenceDescriptor::isMinMaxRecurrenceKind(Kind))
9065 RecipeBuilder.recordRecipeOf(cast<Instruction>(R->getOperand(0)));
9066 }
9067 }
9068
9069 // For each interleave group which is relevant for this (possibly trimmed)
9070 // Range, add it to the set of groups to be later applied to the VPlan and add
9071 // placeholders for its members' Recipes which we'll be replacing with a
9072 // single VPInterleaveRecipe.
9073 for (InterleaveGroup<Instruction> *IG : IAI.getInterleaveGroups()) {
9074 auto applyIG = [IG, this](ElementCount VF) -> bool {
9075 return (VF.isVector() && // Query is illegal for VF == 1
9076 CM.getWideningDecision(IG->getInsertPos(), VF) ==
9077 LoopVectorizationCostModel::CM_Interleave);
9078 };
9079 if (!getDecisionAndClampRange(applyIG, Range))
9080 continue;
9081 InterleaveGroups.insert(IG);
9082 for (unsigned i = 0; i < IG->getFactor(); i++)
9083 if (Instruction *Member = IG->getMember(i))
9084 RecipeBuilder.recordRecipeOf(Member);
9085 };
9086
9087 // ---------------------------------------------------------------------------
9088 // Build initial VPlan: Scan the body of the loop in a topological order to
9089 // visit each basic block after having visited its predecessor basic blocks.
9090 // ---------------------------------------------------------------------------
9091
9092 // Create a dummy pre-entry VPBasicBlock to start building the VPlan.
9093 auto Plan = std::make_unique<VPlan>();
9094 VPBasicBlock *VPBB = new VPBasicBlock("Pre-Entry");
9095 Plan->setEntry(VPBB);
9096
9097 // Scan the body of the loop in a topological order to visit each basic block
9098 // after having visited its predecessor basic blocks.
9099 LoopBlocksDFS DFS(OrigLoop);
9100 DFS.perform(LI);
9101
9102 for (BasicBlock *BB : make_range(DFS.beginRPO(), DFS.endRPO())) {
9103 // Relevant instructions from basic block BB will be grouped into VPRecipe
9104 // ingredients and fill a new VPBasicBlock.
9105 unsigned VPBBsForBB = 0;
9106 auto *FirstVPBBForBB = new VPBasicBlock(BB->getName());
9107 VPBlockUtils::insertBlockAfter(FirstVPBBForBB, VPBB);
9108 VPBB = FirstVPBBForBB;
9109 Builder.setInsertPoint(VPBB);
9110
9111 // Introduce each ingredient into VPlan.
9112 // TODO: Model and preserve debug instrinsics in VPlan.
9113 for (Instruction &I : BB->instructionsWithoutDebug()) {
9114 Instruction *Instr = &I;
9115
9116 // First filter out irrelevant instructions, to ensure no recipes are
9117 // built for them.
9118 if (isa<BranchInst>(Instr) || DeadInstructions.count(Instr))
9119 continue;
9120
9121 SmallVector<VPValue *, 4> Operands;
9122 auto *Phi = dyn_cast<PHINode>(Instr);
9123 if (Phi && Phi->getParent() == OrigLoop->getHeader()) {
9124 Operands.push_back(Plan->getOrAddVPValue(
9125 Phi->getIncomingValueForBlock(OrigLoop->getLoopPreheader())));
9126 } else {
9127 auto OpRange = Plan->mapToVPValues(Instr->operands());
9128 Operands = {OpRange.begin(), OpRange.end()};
9129 }
9130 if (auto RecipeOrValue = RecipeBuilder.tryToCreateWidenRecipe(
9131 Instr, Operands, Range, Plan)) {
9132 // If Instr can be simplified to an existing VPValue, use it.
9133 if (RecipeOrValue.is<VPValue *>()) {
9134 auto *VPV = RecipeOrValue.get<VPValue *>();
9135 Plan->addVPValue(Instr, VPV);
9136 // If the re-used value is a recipe, register the recipe for the
9137 // instruction, in case the recipe for Instr needs to be recorded.
9138 if (auto *R = dyn_cast_or_null<VPRecipeBase>(VPV->getDef()))
9139 RecipeBuilder.setRecipe(Instr, R);
9140 continue;
9141 }
9142 // Otherwise, add the new recipe.
9143 VPRecipeBase *Recipe = RecipeOrValue.get<VPRecipeBase *>();
9144 for (auto *Def : Recipe->definedValues()) {
9145 auto *UV = Def->getUnderlyingValue();
9146 Plan->addVPValue(UV, Def);
9147 }
9148
9149 RecipeBuilder.setRecipe(Instr, Recipe);
9150 VPBB->appendRecipe(Recipe);
9151 continue;
9152 }
9153
9154 // Otherwise, if all widening options failed, Instruction is to be
9155 // replicated. This may create a successor for VPBB.
9156 VPBasicBlock *NextVPBB =
9157 RecipeBuilder.handleReplication(Instr, Range, VPBB, Plan);
9158 if (NextVPBB != VPBB) {
9159 VPBB = NextVPBB;
9160 VPBB->setName(BB->hasName() ? BB->getName() + "." + Twine(VPBBsForBB++)
9161 : "");
9162 }
9163 }
9164 }
9165
9166 RecipeBuilder.fixHeaderPhis();
9167
9168 // Discard empty dummy pre-entry VPBasicBlock. Note that other VPBasicBlocks
9169 // may also be empty, such as the last one VPBB, reflecting original
9170 // basic-blocks with no recipes.
9171 VPBasicBlock *PreEntry = cast<VPBasicBlock>(Plan->getEntry());
9172 assert(PreEntry->empty() && "Expecting empty pre-entry block.")(static_cast <bool> (PreEntry->empty() && "Expecting empty pre-entry block."
) ? void (0) : __assert_fail ("PreEntry->empty() && \"Expecting empty pre-entry block.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9172, __extension__ __PRETTY_FUNCTION__))
;
9173 VPBlockBase *Entry = Plan->setEntry(PreEntry->getSingleSuccessor());
9174 VPBlockUtils::disconnectBlocks(PreEntry, Entry);
9175 delete PreEntry;
9176
9177 // ---------------------------------------------------------------------------
9178 // Transform initial VPlan: Apply previously taken decisions, in order, to
9179 // bring the VPlan to its final state.
9180 // ---------------------------------------------------------------------------
9181
9182 // Apply Sink-After legal constraints.
9183 for (auto &Entry : SinkAfter) {
9184 VPRecipeBase *Sink = RecipeBuilder.getRecipe(Entry.first);
9185 VPRecipeBase *Target = RecipeBuilder.getRecipe(Entry.second);
9186
9187 auto GetReplicateRegion = [](VPRecipeBase *R) -> VPRegionBlock * {
9188 auto *Region =
9189 dyn_cast_or_null<VPRegionBlock>(R->getParent()->getParent());
9190 if (Region && Region->isReplicator()) {
9191 assert(Region->getNumSuccessors() == 1 &&(static_cast <bool> (Region->getNumSuccessors() == 1
&& Region->getNumPredecessors() == 1 && "Expected SESE region!"
) ? void (0) : __assert_fail ("Region->getNumSuccessors() == 1 && Region->getNumPredecessors() == 1 && \"Expected SESE region!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9192, __extension__ __PRETTY_FUNCTION__))
9192 Region->getNumPredecessors() == 1 && "Expected SESE region!")(static_cast <bool> (Region->getNumSuccessors() == 1
&& Region->getNumPredecessors() == 1 && "Expected SESE region!"
) ? void (0) : __assert_fail ("Region->getNumSuccessors() == 1 && Region->getNumPredecessors() == 1 && \"Expected SESE region!\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9192, __extension__ __PRETTY_FUNCTION__))
;
9193 assert(R->getParent()->size() == 1 &&(static_cast <bool> (R->getParent()->size() == 1 &&
"A recipe in an original replicator region must be the only "
"recipe in its block") ? void (0) : __assert_fail ("R->getParent()->size() == 1 && \"A recipe in an original replicator region must be the only \" \"recipe in its block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9195, __extension__ __PRETTY_FUNCTION__))
9194 "A recipe in an original replicator region must be the only "(static_cast <bool> (R->getParent()->size() == 1 &&
"A recipe in an original replicator region must be the only "
"recipe in its block") ? void (0) : __assert_fail ("R->getParent()->size() == 1 && \"A recipe in an original replicator region must be the only \" \"recipe in its block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9195, __extension__ __PRETTY_FUNCTION__))
9195 "recipe in its block")(static_cast <bool> (R->getParent()->size() == 1 &&
"A recipe in an original replicator region must be the only "
"recipe in its block") ? void (0) : __assert_fail ("R->getParent()->size() == 1 && \"A recipe in an original replicator region must be the only \" \"recipe in its block\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9195, __extension__ __PRETTY_FUNCTION__))
;
9196 return Region;
9197 }
9198 return nullptr;
9199 };
9200 auto *TargetRegion = GetReplicateRegion(Target);
9201 auto *SinkRegion = GetReplicateRegion(Sink);
9202 if (!SinkRegion) {
9203 // If the sink source is not a replicate region, sink the recipe directly.
9204 if (TargetRegion) {
9205 // The target is in a replication region, make sure to move Sink to
9206 // the block after it, not into the replication region itself.
9207 VPBasicBlock *NextBlock =
9208 cast<VPBasicBlock>(TargetRegion->getSuccessors().front());
9209 Sink->moveBefore(*NextBlock, NextBlock->getFirstNonPhi());
9210 } else
9211 Sink->moveAfter(Target);
9212 continue;
9213 }
9214
9215 // The sink source is in a replicate region. Unhook the region from the CFG.
9216 auto *SinkPred = SinkRegion->getSinglePredecessor();
9217 auto *SinkSucc = SinkRegion->getSingleSuccessor();
9218 VPBlockUtils::disconnectBlocks(SinkPred, SinkRegion);
9219 VPBlockUtils::disconnectBlocks(SinkRegion, SinkSucc);
9220 VPBlockUtils::connectBlocks(SinkPred, SinkSucc);
9221
9222 if (TargetRegion) {
9223 // The target recipe is also in a replicate region, move the sink region
9224 // after the target region.
9225 auto *TargetSucc = TargetRegion->getSingleSuccessor();
9226 VPBlockUtils::disconnectBlocks(TargetRegion, TargetSucc);
9227 VPBlockUtils::connectBlocks(TargetRegion, SinkRegion);
9228 VPBlockUtils::connectBlocks(SinkRegion, TargetSucc);
9229 } else {
9230 // The sink source is in a replicate region, we need to move the whole
9231 // replicate region, which should only contain a single recipe in the main
9232 // block.
9233 auto *SplitBlock =
9234 Target->getParent()->splitAt(std::next(Target->getIterator()));
9235
9236 auto *SplitPred = SplitBlock->getSinglePredecessor();
9237
9238 VPBlockUtils::disconnectBlocks(SplitPred, SplitBlock);
9239 VPBlockUtils::connectBlocks(SplitPred, SinkRegion);
9240 VPBlockUtils::connectBlocks(SinkRegion, SplitBlock);
9241 if (VPBB == SplitPred)
9242 VPBB = SplitBlock;
9243 }
9244 }
9245
9246 // Interleave memory: for each Interleave Group we marked earlier as relevant
9247 // for this VPlan, replace the Recipes widening its memory instructions with a
9248 // single VPInterleaveRecipe at its insertion point.
9249 for (auto IG : InterleaveGroups) {
9250 auto *Recipe = cast<VPWidenMemoryInstructionRecipe>(
9251 RecipeBuilder.getRecipe(IG->getInsertPos()));
9252 SmallVector<VPValue *, 4> StoredValues;
9253 for (unsigned i = 0; i < IG->getFactor(); ++i)
9254 if (auto *SI = dyn_cast_or_null<StoreInst>(IG->getMember(i)))
9255 StoredValues.push_back(Plan->getOrAddVPValue(SI->getOperand(0)));
9256
9257 auto *VPIG = new VPInterleaveRecipe(IG, Recipe->getAddr(), StoredValues,
9258 Recipe->getMask());
9259 VPIG->insertBefore(Recipe);
9260 unsigned J = 0;
9261 for (unsigned i = 0; i < IG->getFactor(); ++i)
9262 if (Instruction *Member = IG->getMember(i)) {
9263 if (!Member->getType()->isVoidTy()) {
9264 VPValue *OriginalV = Plan->getVPValue(Member);
9265 Plan->removeVPValueFor(Member);
9266 Plan->addVPValue(Member, VPIG->getVPValue(J));
9267 OriginalV->replaceAllUsesWith(VPIG->getVPValue(J));
9268 J++;
9269 }
9270 RecipeBuilder.getRecipe(Member)->eraseFromParent();
9271 }
9272 }
9273
9274 // Adjust the recipes for any inloop reductions.
9275 if (Range.Start.isVector())
9276 adjustRecipesForInLoopReductions(Plan, RecipeBuilder);
9277
9278 // Finally, if tail is folded by masking, introduce selects between the phi
9279 // and the live-out instruction of each reduction, at the end of the latch.
9280 if (CM.foldTailByMasking() && !Legal->getReductionVars().empty()) {
9281 Builder.setInsertPoint(VPBB);
9282 auto *Cond = RecipeBuilder.createBlockInMask(OrigLoop->getHeader(), Plan);
9283 for (auto &Reduction : Legal->getReductionVars()) {
9284 if (CM.isInLoopReduction(Reduction.first))
9285 continue;
9286 VPValue *Phi = Plan->getOrAddVPValue(Reduction.first);
9287 VPValue *Red = Plan->getOrAddVPValue(Reduction.second.getLoopExitInstr());
9288 Builder.createNaryOp(Instruction::Select, {Cond, Red, Phi});
9289 }
9290 }
9291
9292 VPlanTransforms::sinkScalarOperands(*Plan);
9293
9294 std::string PlanName;
9295 raw_string_ostream RSO(PlanName);
9296 ElementCount VF = Range.Start;
9297 Plan->addVF(VF);
9298 RSO << "Initial VPlan for VF={" << VF;
9299 for (VF *= 2; ElementCount::isKnownLT(VF, Range.End); VF *= 2) {
9300 Plan->addVF(VF);
9301 RSO << "," << VF;
9302 }
9303 RSO << "},UF>=1";
9304 RSO.flush();
9305 Plan->setName(PlanName);
9306
9307 return Plan;
9308}
9309
9310VPlanPtr LoopVectorizationPlanner::buildVPlan(VFRange &Range) {
9311 // Outer loop handling: They may require CFG and instruction level
9312 // transformations before even evaluating whether vectorization is profitable.
9313 // Since we cannot modify the incoming IR, we need to build VPlan upfront in
9314 // the vectorization pipeline.
9315 assert(!OrigLoop->isInnermost())(static_cast <bool> (!OrigLoop->isInnermost()) ? void
(0) : __assert_fail ("!OrigLoop->isInnermost()", "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9315, __extension__ __PRETTY_FUNCTION__))
;
9316 assert(EnableVPlanNativePath && "VPlan-native path is not enabled.")(static_cast <bool> (EnableVPlanNativePath && "VPlan-native path is not enabled."
) ? void (0) : __assert_fail ("EnableVPlanNativePath && \"VPlan-native path is not enabled.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9316, __extension__ __PRETTY_FUNCTION__))
;
9317
9318 // Create new empty VPlan
9319 auto Plan = std::make_unique<VPlan>();
9320
9321 // Build hierarchical CFG
9322 VPlanHCFGBuilder HCFGBuilder(OrigLoop, LI, *Plan);
9323 HCFGBuilder.buildHierarchicalCFG();
9324
9325 for (ElementCount VF = Range.Start; ElementCount::isKnownLT(VF, Range.End);
9326 VF *= 2)
9327 Plan->addVF(VF);
9328
9329 if (EnableVPlanPredication) {
9330 VPlanPredicator VPP(*Plan);
9331 VPP.predicate();
9332
9333 // Avoid running transformation to recipes until masked code generation in
9334 // VPlan-native path is in place.
9335 return Plan;
9336 }
9337
9338 SmallPtrSet<Instruction *, 1> DeadInstructions;
9339 VPlanTransforms::VPInstructionsToVPRecipes(OrigLoop, Plan,
9340 Legal->getInductionVars(),
9341 DeadInstructions, *PSE.getSE());
9342 return Plan;
9343}
9344
9345// Adjust the recipes for any inloop reductions. The chain of instructions
9346// leading from the loop exit instr to the phi need to be converted to
9347// reductions, with one operand being vector and the other being the scalar
9348// reduction chain.
9349void LoopVectorizationPlanner::adjustRecipesForInLoopReductions(
9350 VPlanPtr &Plan, VPRecipeBuilder &RecipeBuilder) {
9351 for (auto &Reduction : CM.getInLoopReductionChains()) {
9352 PHINode *Phi = Reduction.first;
9353 RecurrenceDescriptor &RdxDesc = Legal->getReductionVars()[Phi];
9354 const SmallVector<Instruction *, 4> &ReductionOperations = Reduction.second;
9355
9356 // ReductionOperations are orders top-down from the phi's use to the
9357 // LoopExitValue. We keep a track of the previous item (the Chain) to tell
9358 // which of the two operands will remain scalar and which will be reduced.
9359 // For minmax the chain will be the select instructions.
9360 Instruction *Chain = Phi;
9361 for (Instruction *R : ReductionOperations) {
9362 VPRecipeBase *WidenRecipe = RecipeBuilder.getRecipe(R);
9363 RecurKind Kind = RdxDesc.getRecurrenceKind();
9364
9365 VPValue *ChainOp = Plan->getVPValue(Chain);
9366 unsigned FirstOpId;
9367 if (RecurrenceDescriptor::isMinMaxRecurrenceKind(Kind)) {
9368 assert(isa<VPWidenSelectRecipe>(WidenRecipe) &&(static_cast <bool> (isa<VPWidenSelectRecipe>(WidenRecipe
) && "Expected to replace a VPWidenSelectSC") ? void (
0) : __assert_fail ("isa<VPWidenSelectRecipe>(WidenRecipe) && \"Expected to replace a VPWidenSelectSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9369, __extension__ __PRETTY_FUNCTION__))
9369 "Expected to replace a VPWidenSelectSC")(static_cast <bool> (isa<VPWidenSelectRecipe>(WidenRecipe
) && "Expected to replace a VPWidenSelectSC") ? void (
0) : __assert_fail ("isa<VPWidenSelectRecipe>(WidenRecipe) && \"Expected to replace a VPWidenSelectSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9369, __extension__ __PRETTY_FUNCTION__))
;
9370 FirstOpId = 1;
9371 } else {
9372 assert(isa<VPWidenRecipe>(WidenRecipe) &&(static_cast <bool> (isa<VPWidenRecipe>(WidenRecipe
) && "Expected to replace a VPWidenSC") ? void (0) : __assert_fail
("isa<VPWidenRecipe>(WidenRecipe) && \"Expected to replace a VPWidenSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9373, __extension__ __PRETTY_FUNCTION__))
9373 "Expected to replace a VPWidenSC")(static_cast <bool> (isa<VPWidenRecipe>(WidenRecipe
) && "Expected to replace a VPWidenSC") ? void (0) : __assert_fail
("isa<VPWidenRecipe>(WidenRecipe) && \"Expected to replace a VPWidenSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9373, __extension__ __PRETTY_FUNCTION__))
;
9374 FirstOpId = 0;
9375 }
9376 unsigned VecOpId =
9377 R->getOperand(FirstOpId) == Chain ? FirstOpId + 1 : FirstOpId;
9378 VPValue *VecOp = Plan->getVPValue(R->getOperand(VecOpId));
9379
9380 auto *CondOp = CM.foldTailByMasking()
9381 ? RecipeBuilder.createBlockInMask(R->getParent(), Plan)
9382 : nullptr;
9383 VPReductionRecipe *RedRecipe = new VPReductionRecipe(
9384 &RdxDesc, R, ChainOp, VecOp, CondOp, TTI);
9385 WidenRecipe->getVPSingleValue()->replaceAllUsesWith(RedRecipe);
9386 Plan->removeVPValueFor(R);
9387 Plan->addVPValue(R, RedRecipe);
9388 WidenRecipe->getParent()->insert(RedRecipe, WidenRecipe->getIterator());
9389 WidenRecipe->getVPSingleValue()->replaceAllUsesWith(RedRecipe);
9390 WidenRecipe->eraseFromParent();
9391
9392 if (RecurrenceDescriptor::isMinMaxRecurrenceKind(Kind)) {
9393 VPRecipeBase *CompareRecipe =
9394 RecipeBuilder.getRecipe(cast<Instruction>(R->getOperand(0)));
9395 assert(isa<VPWidenRecipe>(CompareRecipe) &&(static_cast <bool> (isa<VPWidenRecipe>(CompareRecipe
) && "Expected to replace a VPWidenSC") ? void (0) : __assert_fail
("isa<VPWidenRecipe>(CompareRecipe) && \"Expected to replace a VPWidenSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9396, __extension__ __PRETTY_FUNCTION__))
9396 "Expected to replace a VPWidenSC")(static_cast <bool> (isa<VPWidenRecipe>(CompareRecipe
) && "Expected to replace a VPWidenSC") ? void (0) : __assert_fail
("isa<VPWidenRecipe>(CompareRecipe) && \"Expected to replace a VPWidenSC\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9396, __extension__ __PRETTY_FUNCTION__))
;
9397 assert(cast<VPWidenRecipe>(CompareRecipe)->getNumUsers() == 0 &&(static_cast <bool> (cast<VPWidenRecipe>(CompareRecipe
)->getNumUsers() == 0 && "Expected no remaining users"
) ? void (0) : __assert_fail ("cast<VPWidenRecipe>(CompareRecipe)->getNumUsers() == 0 && \"Expected no remaining users\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9398, __extension__ __PRETTY_FUNCTION__))
9398 "Expected no remaining users")(static_cast <bool> (cast<VPWidenRecipe>(CompareRecipe
)->getNumUsers() == 0 && "Expected no remaining users"
) ? void (0) : __assert_fail ("cast<VPWidenRecipe>(CompareRecipe)->getNumUsers() == 0 && \"Expected no remaining users\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9398, __extension__ __PRETTY_FUNCTION__))
;
9399 CompareRecipe->eraseFromParent();
9400 }
9401 Chain = R;
9402 }
9403 }
9404}
9405
9406#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
9407void VPInterleaveRecipe::print(raw_ostream &O, const Twine &Indent,
9408 VPSlotTracker &SlotTracker) const {
9409 O << Indent << "INTERLEAVE-GROUP with factor " << IG->getFactor() << " at ";
9410 IG->getInsertPos()->printAsOperand(O, false);
9411 O << ", ";
9412 getAddr()->printAsOperand(O, SlotTracker);
9413 VPValue *Mask = getMask();
9414 if (Mask) {
9415 O << ", ";
9416 Mask->printAsOperand(O, SlotTracker);
9417 }
9418 for (unsigned i = 0; i < IG->getFactor(); ++i)
9419 if (Instruction *I = IG->getMember(i))
9420 O << "\n" << Indent << " " << VPlanIngredient(I) << " " << i;
9421}
9422#endif
9423
9424void VPWidenCallRecipe::execute(VPTransformState &State) {
9425 State.ILV->widenCallInstruction(*cast<CallInst>(getUnderlyingInstr()), this,
9426 *this, State);
9427}
9428
9429void VPWidenSelectRecipe::execute(VPTransformState &State) {
9430 State.ILV->widenSelectInstruction(*cast<SelectInst>(getUnderlyingInstr()),
9431 this, *this, InvariantCond, State);
9432}
9433
9434void VPWidenRecipe::execute(VPTransformState &State) {
9435 State.ILV->widenInstruction(*getUnderlyingInstr(), this, *this, State);
9436}
9437
9438void VPWidenGEPRecipe::execute(VPTransformState &State) {
9439 State.ILV->widenGEP(cast<GetElementPtrInst>(getUnderlyingInstr()), this,
9440 *this, State.UF, State.VF, IsPtrLoopInvariant,
9441 IsIndexLoopInvariant, State);
9442}
9443
9444void VPWidenIntOrFpInductionRecipe::execute(VPTransformState &State) {
9445 assert(!State.Instance && "Int or FP induction being replicated.")(static_cast <bool> (!State.Instance && "Int or FP induction being replicated."
) ? void (0) : __assert_fail ("!State.Instance && \"Int or FP induction being replicated.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9445, __extension__ __PRETTY_FUNCTION__))
;
9446 State.ILV->widenIntOrFpInduction(IV, getStartValue()->getLiveInIRValue(),
9447 getTruncInst(), getVPValue(0),
9448 getCastValue(), State);
9449}
9450
9451void VPWidenPHIRecipe::execute(VPTransformState &State) {
9452 State.ILV->widenPHIInstruction(cast<PHINode>(getUnderlyingValue()), RdxDesc,
1
The object is a 'PHINode'
2
Passing value via 2nd parameter 'RdxDesc'
3
Calling 'InnerLoopVectorizer::widenPHIInstruction'
9453 this, State);
9454}
9455
9456void VPBlendRecipe::execute(VPTransformState &State) {
9457 State.ILV->setDebugLocFromInst(State.Builder, Phi);
9458 // We know that all PHIs in non-header blocks are converted into
9459 // selects, so we don't have to worry about the insertion order and we
9460 // can just use the builder.
9461 // At this point we generate the predication tree. There may be
9462 // duplications since this is a simple recursive scan, but future
9463 // optimizations will clean it up.
9464
9465 unsigned NumIncoming = getNumIncomingValues();
9466
9467 // Generate a sequence of selects of the form:
9468 // SELECT(Mask3, In3,
9469 // SELECT(Mask2, In2,
9470 // SELECT(Mask1, In1,
9471 // In0)))
9472 // Note that Mask0 is never used: lanes for which no path reaches this phi and
9473 // are essentially undef are taken from In0.
9474 InnerLoopVectorizer::VectorParts Entry(State.UF);
9475 for (unsigned In = 0; In < NumIncoming; ++In) {
9476 for (unsigned Part = 0; Part < State.UF; ++Part) {
9477 // We might have single edge PHIs (blocks) - use an identity
9478 // 'select' for the first PHI operand.
9479 Value *In0 = State.get(getIncomingValue(In), Part);
9480 if (In == 0)
9481 Entry[Part] = In0; // Initialize with the first incoming value.
9482 else {
9483 // Select between the current value and the previous incoming edge
9484 // based on the incoming mask.
9485 Value *Cond = State.get(getMask(In), Part);
9486 Entry[Part] =
9487 State.Builder.CreateSelect(Cond, In0, Entry[Part], "predphi");
9488 }
9489 }
9490 }
9491 for (unsigned Part = 0; Part < State.UF; ++Part)
9492 State.set(this, Entry[Part], Part);
9493}
9494
9495void VPInterleaveRecipe::execute(VPTransformState &State) {
9496 assert(!State.Instance && "Interleave group being replicated.")(static_cast <bool> (!State.Instance && "Interleave group being replicated."
) ? void (0) : __assert_fail ("!State.Instance && \"Interleave group being replicated.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9496, __extension__ __PRETTY_FUNCTION__))
;
9497 State.ILV->vectorizeInterleaveGroup(IG, definedValues(), State, getAddr(),
9498 getStoredValues(), getMask());
9499}
9500
9501void VPReductionRecipe::execute(VPTransformState &State) {
9502 assert(!State.Instance && "Reduction being replicated.")(static_cast <bool> (!State.Instance && "Reduction being replicated."
) ? void (0) : __assert_fail ("!State.Instance && \"Reduction being replicated.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9502, __extension__ __PRETTY_FUNCTION__))
;
9503 Value *PrevInChain = State.get(getChainOp(), 0);
9504 for (unsigned Part = 0; Part < State.UF; ++Part) {
9505 RecurKind Kind = RdxDesc->getRecurrenceKind();
9506 bool IsOrdered = State.ILV->useOrderedReductions(*RdxDesc);
9507 Value *NewVecOp = State.get(getVecOp(), Part);
9508 if (VPValue *Cond = getCondOp()) {
9509 Value *NewCond = State.get(Cond, Part);
9510 VectorType *VecTy = cast<VectorType>(NewVecOp->getType());
9511 Constant *Iden = RecurrenceDescriptor::getRecurrenceIdentity(
9512 Kind, VecTy->getElementType(), RdxDesc->getFastMathFlags());
9513 Constant *IdenVec =
9514 ConstantVector::getSplat(VecTy->getElementCount(), Iden);
9515 Value *Select = State.Builder.CreateSelect(NewCond, NewVecOp, IdenVec);
9516 NewVecOp = Select;
9517 }
9518 Value *NewRed;
9519 Value *NextInChain;
9520 if (IsOrdered) {
9521 NewRed = createOrderedReduction(State.Builder, *RdxDesc, NewVecOp,
9522 PrevInChain);
9523 PrevInChain = NewRed;
9524 } else {
9525 PrevInChain = State.get(getChainOp(), Part);
9526 NewRed = createTargetReduction(State.Builder, TTI, *RdxDesc, NewVecOp);
9527 }
9528 if (RecurrenceDescriptor::isMinMaxRecurrenceKind(Kind)) {
9529 NextInChain =
9530 createMinMaxOp(State.Builder, RdxDesc->getRecurrenceKind(),
9531 NewRed, PrevInChain);
9532 } else if (IsOrdered)
9533 NextInChain = NewRed;
9534 else {
9535 NextInChain = State.Builder.CreateBinOp(
9536 (Instruction::BinaryOps)getUnderlyingInstr()->getOpcode(), NewRed,
9537 PrevInChain);
9538 }
9539 State.set(this, NextInChain, Part);
9540 }
9541}
9542
9543void VPReplicateRecipe::execute(VPTransformState &State) {
9544 if (State.Instance) { // Generate a single instance.
9545 assert(!State.VF.isScalable() && "Can't scalarize a scalable vector")(static_cast <bool> (!State.VF.isScalable() && "Can't scalarize a scalable vector"
) ? void (0) : __assert_fail ("!State.VF.isScalable() && \"Can't scalarize a scalable vector\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9545, __extension__ __PRETTY_FUNCTION__))
;
9546 State.ILV->scalarizeInstruction(getUnderlyingInstr(), this, *this,
9547 *State.Instance, IsPredicated, State);
9548 // Insert scalar instance packing it into a vector.
9549 if (AlsoPack && State.VF.isVector()) {
9550 // If we're constructing lane 0, initialize to start from poison.
9551 if (State.Instance->Lane.isFirstLane()) {
9552 assert(!State.VF.isScalable() && "VF is assumed to be non scalable.")(static_cast <bool> (!State.VF.isScalable() && "VF is assumed to be non scalable."
) ? void (0) : __assert_fail ("!State.VF.isScalable() && \"VF is assumed to be non scalable.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9552, __extension__ __PRETTY_FUNCTION__))
;
9553 Value *Poison = PoisonValue::get(
9554 VectorType::get(getUnderlyingValue()->getType(), State.VF));
9555 State.set(this, Poison, State.Instance->Part);
9556 }
9557 State.ILV->packScalarIntoVectorValue(this, *State.Instance, State);
9558 }
9559 return;
9560 }
9561
9562 // Generate scalar instances for all VF lanes of all UF parts, unless the
9563 // instruction is uniform inwhich case generate only the first lane for each
9564 // of the UF parts.
9565 unsigned EndLane = IsUniform ? 1 : State.VF.getKnownMinValue();
9566 assert((!State.VF.isScalable() || IsUniform) &&(static_cast <bool> ((!State.VF.isScalable() || IsUniform
) && "Can't scalarize a scalable vector") ? void (0) :
__assert_fail ("(!State.VF.isScalable() || IsUniform) && \"Can't scalarize a scalable vector\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9567, __extension__ __PRETTY_FUNCTION__))
9567 "Can't scalarize a scalable vector")(static_cast <bool> ((!State.VF.isScalable() || IsUniform
) && "Can't scalarize a scalable vector") ? void (0) :
__assert_fail ("(!State.VF.isScalable() || IsUniform) && \"Can't scalarize a scalable vector\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9567, __extension__ __PRETTY_FUNCTION__))
;
9568 for (unsigned Part = 0; Part < State.UF; ++Part)
9569 for (unsigned Lane = 0; Lane < EndLane; ++Lane)
9570 State.ILV->scalarizeInstruction(getUnderlyingInstr(), this, *this,
9571 VPIteration(Part, Lane), IsPredicated,
9572 State);
9573}
9574
9575void VPBranchOnMaskRecipe::execute(VPTransformState &State) {
9576 assert(State.Instance && "Branch on Mask works only on single instance.")(static_cast <bool> (State.Instance && "Branch on Mask works only on single instance."
) ? void (0) : __assert_fail ("State.Instance && \"Branch on Mask works only on single instance.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9576, __extension__ __PRETTY_FUNCTION__))
;
9577
9578 unsigned Part = State.Instance->Part;
9579 unsigned Lane = State.Instance->Lane.getKnownLane();
9580
9581 Value *ConditionBit = nullptr;
9582 VPValue *BlockInMask = getMask();
9583 if (BlockInMask) {
9584 ConditionBit = State.get(BlockInMask, Part);
9585 if (ConditionBit->getType()->isVectorTy())
9586 ConditionBit = State.Builder.CreateExtractElement(
9587 ConditionBit, State.Builder.getInt32(Lane));
9588 } else // Block in mask is all-one.
9589 ConditionBit = State.Builder.getTrue();
9590
9591 // Replace the temporary unreachable terminator with a new conditional branch,
9592 // whose two destinations will be set later when they are created.
9593 auto *CurrentTerminator = State.CFG.PrevBB->getTerminator();
9594 assert(isa<UnreachableInst>(CurrentTerminator) &&(static_cast <bool> (isa<UnreachableInst>(CurrentTerminator
) && "Expected to replace unreachable terminator with conditional branch."
) ? void (0) : __assert_fail ("isa<UnreachableInst>(CurrentTerminator) && \"Expected to replace unreachable terminator with conditional branch.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9595, __extension__ __PRETTY_FUNCTION__))
9595 "Expected to replace unreachable terminator with conditional branch.")(static_cast <bool> (isa<UnreachableInst>(CurrentTerminator
) && "Expected to replace unreachable terminator with conditional branch."
) ? void (0) : __assert_fail ("isa<UnreachableInst>(CurrentTerminator) && \"Expected to replace unreachable terminator with conditional branch.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9595, __extension__ __PRETTY_FUNCTION__))
;
9596 auto *CondBr = BranchInst::Create(State.CFG.PrevBB, nullptr, ConditionBit);
9597 CondBr->setSuccessor(0, nullptr);
9598 ReplaceInstWithInst(CurrentTerminator, CondBr);
9599}
9600
9601void VPPredInstPHIRecipe::execute(VPTransformState &State) {
9602 assert(State.Instance && "Predicated instruction PHI works per instance.")(static_cast <bool> (State.Instance && "Predicated instruction PHI works per instance."
) ? void (0) : __assert_fail ("State.Instance && \"Predicated instruction PHI works per instance.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9602, __extension__ __PRETTY_FUNCTION__))
;
9603 Instruction *ScalarPredInst =
9604 cast<Instruction>(State.get(getOperand(0), *State.Instance));
9605 BasicBlock *PredicatedBB = ScalarPredInst->getParent();
9606 BasicBlock *PredicatingBB = PredicatedBB->getSinglePredecessor();
9607 assert(PredicatingBB && "Predicated block has no single predecessor.")(static_cast <bool> (PredicatingBB && "Predicated block has no single predecessor."
) ? void (0) : __assert_fail ("PredicatingBB && \"Predicated block has no single predecessor.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9607, __extension__ __PRETTY_FUNCTION__))
;
9608 assert(isa<VPReplicateRecipe>(getOperand(0)) &&(static_cast <bool> (isa<VPReplicateRecipe>(getOperand
(0)) && "operand must be VPReplicateRecipe") ? void (
0) : __assert_fail ("isa<VPReplicateRecipe>(getOperand(0)) && \"operand must be VPReplicateRecipe\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9609, __extension__ __PRETTY_FUNCTION__))
9609 "operand must be VPReplicateRecipe")(static_cast <bool> (isa<VPReplicateRecipe>(getOperand
(0)) && "operand must be VPReplicateRecipe") ? void (
0) : __assert_fail ("isa<VPReplicateRecipe>(getOperand(0)) && \"operand must be VPReplicateRecipe\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9609, __extension__ __PRETTY_FUNCTION__))
;
9610
9611 // By current pack/unpack logic we need to generate only a single phi node: if
9612 // a vector value for the predicated instruction exists at this point it means
9613 // the instruction has vector users only, and a phi for the vector value is
9614 // needed. In this case the recipe of the predicated instruction is marked to
9615 // also do that packing, thereby "hoisting" the insert-element sequence.
9616 // Otherwise, a phi node for the scalar value is needed.
9617 unsigned Part = State.Instance->Part;
9618 if (State.hasVectorValue(getOperand(0), Part)) {
9619 Value *VectorValue = State.get(getOperand(0), Part);
9620 InsertElementInst *IEI = cast<InsertElementInst>(VectorValue);
9621 PHINode *VPhi = State.Builder.CreatePHI(IEI->getType(), 2);
9622 VPhi->addIncoming(IEI->getOperand(0), PredicatingBB); // Unmodified vector.
9623 VPhi->addIncoming(IEI, PredicatedBB); // New vector with inserted element.
9624 if (State.hasVectorValue(this, Part))
9625 State.reset(this, VPhi, Part);
9626 else
9627 State.set(this, VPhi, Part);
9628 // NOTE: Currently we need to update the value of the operand, so the next
9629 // predicated iteration inserts its generated value in the correct vector.
9630 State.reset(getOperand(0), VPhi, Part);
9631 } else {
9632 Type *PredInstType = getOperand(0)->getUnderlyingValue()->getType();
9633 PHINode *Phi = State.Builder.CreatePHI(PredInstType, 2);
9634 Phi->addIncoming(PoisonValue::get(ScalarPredInst->getType()),
9635 PredicatingBB);
9636 Phi->addIncoming(ScalarPredInst, PredicatedBB);
9637 if (State.hasScalarValue(this, *State.Instance))
9638 State.reset(this, Phi, *State.Instance);
9639 else
9640 State.set(this, Phi, *State.Instance);
9641 // NOTE: Currently we need to update the value of the operand, so the next
9642 // predicated iteration inserts its generated value in the correct vector.
9643 State.reset(getOperand(0), Phi, *State.Instance);
9644 }
9645}
9646
9647void VPWidenMemoryInstructionRecipe::execute(VPTransformState &State) {
9648 VPValue *StoredValue = isStore() ? getStoredValue() : nullptr;
9649 State.ILV->vectorizeMemoryInstruction(
9650 &Ingredient, State, StoredValue ? nullptr : getVPSingleValue(), getAddr(),
9651 StoredValue, getMask());
9652}
9653
9654// Determine how to lower the scalar epilogue, which depends on 1) optimising
9655// for minimum code-size, 2) predicate compiler options, 3) loop hints forcing
9656// predication, and 4) a TTI hook that analyses whether the loop is suitable
9657// for predication.
9658static ScalarEpilogueLowering getScalarEpilogueLowering(
9659 Function *F, Loop *L, LoopVectorizeHints &Hints, ProfileSummaryInfo *PSI,
9660 BlockFrequencyInfo *BFI, TargetTransformInfo *TTI, TargetLibraryInfo *TLI,
9661 AssumptionCache *AC, LoopInfo *LI, ScalarEvolution *SE, DominatorTree *DT,
9662 LoopVectorizationLegality &LVL) {
9663 // 1) OptSize takes precedence over all other options, i.e. if this is set,
9664 // don't look at hints or options, and don't request a scalar epilogue.
9665 // (For PGSO, as shouldOptimizeForSize isn't currently accessible from
9666 // LoopAccessInfo (due to code dependency and not being able to reliably get
9667 // PSI/BFI from a loop analysis under NPM), we cannot suppress the collection
9668 // of strides in LoopAccessInfo::analyzeLoop() and vectorize without
9669 // versioning when the vectorization is forced, unlike hasOptSize. So revert
9670 // back to the old way and vectorize with versioning when forced. See D81345.)
9671 if (F->hasOptSize() || (llvm::shouldOptimizeForSize(L->getHeader(), PSI, BFI,
9672 PGSOQueryType::IRPass) &&
9673 Hints.getForce() != LoopVectorizeHints::FK_Enabled))
9674 return CM_ScalarEpilogueNotAllowedOptSize;
9675
9676 // 2) If set, obey the directives
9677 if (PreferPredicateOverEpilogue.getNumOccurrences()) {
9678 switch (PreferPredicateOverEpilogue) {
9679 case PreferPredicateTy::ScalarEpilogue:
9680 return CM_ScalarEpilogueAllowed;
9681 case PreferPredicateTy::PredicateElseScalarEpilogue:
9682 return CM_ScalarEpilogueNotNeededUsePredicate;
9683 case PreferPredicateTy::PredicateOrDontVectorize:
9684 return CM_ScalarEpilogueNotAllowedUsePredicate;
9685 };
9686 }
9687
9688 // 3) If set, obey the hints
9689 switch (Hints.getPredicate()) {
9690 case LoopVectorizeHints::FK_Enabled:
9691 return CM_ScalarEpilogueNotNeededUsePredicate;
9692 case LoopVectorizeHints::FK_Disabled:
9693 return CM_ScalarEpilogueAllowed;
9694 };
9695
9696 // 4) if the TTI hook indicates this is profitable, request predication.
9697 if (TTI->preferPredicateOverEpilogue(L, LI, *SE, *AC, TLI, DT,
9698 LVL.getLAI()))
9699 return CM_ScalarEpilogueNotNeededUsePredicate;
9700
9701 return CM_ScalarEpilogueAllowed;
9702}
9703
9704Value *VPTransformState::get(VPValue *Def, unsigned Part) {
9705 // If Values have been set for this Def return the one relevant for \p Part.
9706 if (hasVectorValue(Def, Part))
9707 return Data.PerPartOutput[Def][Part];
9708
9709 if (!hasScalarValue(Def, {Part, 0})) {
9710 Value *IRV = Def->getLiveInIRValue();
9711 Value *B = ILV->getBroadcastInstrs(IRV);
9712 set(Def, B, Part);
9713 return B;
9714 }
9715
9716 Value *ScalarValue = get(Def, {Part, 0});
9717 // If we aren't vectorizing, we can just copy the scalar map values over
9718 // to the vector map.
9719 if (VF.isScalar()) {
9720 set(Def, ScalarValue, Part);
9721 return ScalarValue;
9722 }
9723
9724 auto *RepR = dyn_cast<VPReplicateRecipe>(Def);
9725 bool IsUniform = RepR && RepR->isUniform();
9726
9727 unsigned LastLane = IsUniform ? 0 : VF.getKnownMinValue() - 1;
9728 // Check if there is a scalar value for the selected lane.
9729 if (!hasScalarValue(Def, {Part, LastLane})) {
9730 // At the moment, VPWidenIntOrFpInductionRecipes can also be uniform.
9731 assert(isa<VPWidenIntOrFpInductionRecipe>(Def->getDef()) &&(static_cast <bool> (isa<VPWidenIntOrFpInductionRecipe
>(Def->getDef()) && "unexpected recipe found to be invariant"
) ? void (0) : __assert_fail ("isa<VPWidenIntOrFpInductionRecipe>(Def->getDef()) && \"unexpected recipe found to be invariant\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9732, __extension__ __PRETTY_FUNCTION__))
9732 "unexpected recipe found to be invariant")(static_cast <bool> (isa<VPWidenIntOrFpInductionRecipe
>(Def->getDef()) && "unexpected recipe found to be invariant"
) ? void (0) : __assert_fail ("isa<VPWidenIntOrFpInductionRecipe>(Def->getDef()) && \"unexpected recipe found to be invariant\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9732, __extension__ __PRETTY_FUNCTION__))
;
9733 IsUniform = true;
9734 LastLane = 0;
9735 }
9736
9737 auto *LastInst = cast<Instruction>(get(Def, {Part, LastLane}));
9738 // Set the insert point after the last scalarized instruction or after the
9739 // last PHI, if LastInst is a PHI. This ensures the insertelement sequence
9740 // will directly follow the scalar definitions.
9741 auto OldIP = Builder.saveIP();
9742 auto NewIP =
9743 isa<PHINode>(LastInst)
9744 ? BasicBlock::iterator(LastInst->getParent()->getFirstNonPHI())
9745 : std::next(BasicBlock::iterator(LastInst));
9746 Builder.SetInsertPoint(&*NewIP);
9747
9748 // However, if we are vectorizing, we need to construct the vector values.
9749 // If the value is known to be uniform after vectorization, we can just
9750 // broadcast the scalar value corresponding to lane zero for each unroll
9751 // iteration. Otherwise, we construct the vector values using
9752 // insertelement instructions. Since the resulting vectors are stored in
9753 // State, we will only generate the insertelements once.
9754 Value *VectorValue = nullptr;
9755 if (IsUniform) {
9756 VectorValue = ILV->getBroadcastInstrs(ScalarValue);
9757 set(Def, VectorValue, Part);
9758 } else {
9759 // Initialize packing with insertelements to start from undef.
9760 assert(!VF.isScalable() && "VF is assumed to be non scalable.")(static_cast <bool> (!VF.isScalable() && "VF is assumed to be non scalable."
) ? void (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9760, __extension__ __PRETTY_FUNCTION__))
;
9761 Value *Undef = PoisonValue::get(VectorType::get(LastInst->getType(), VF));
9762 set(Def, Undef, Part);
9763 for (unsigned Lane = 0; Lane < VF.getKnownMinValue(); ++Lane)
9764 ILV->packScalarIntoVectorValue(Def, {Part, Lane}, *this);
9765 VectorValue = get(Def, Part);
9766 }
9767 Builder.restoreIP(OldIP);
9768 return VectorValue;
9769}
9770
9771// Process the loop in the VPlan-native vectorization path. This path builds
9772// VPlan upfront in the vectorization pipeline, which allows to apply
9773// VPlan-to-VPlan transformations from the very beginning without modifying the
9774// input LLVM IR.
9775static bool processLoopInVPlanNativePath(
9776 Loop *L, PredicatedScalarEvolution &PSE, LoopInfo *LI, DominatorTree *DT,
9777 LoopVectorizationLegality *LVL, TargetTransformInfo *TTI,
9778 TargetLibraryInfo *TLI, DemandedBits *DB, AssumptionCache *AC,
9779 OptimizationRemarkEmitter *ORE, BlockFrequencyInfo *BFI,
9780 ProfileSummaryInfo *PSI, LoopVectorizeHints &Hints,
9781 LoopVectorizationRequirements &Requirements) {
9782
9783 if (isa<SCEVCouldNotCompute>(PSE.getBackedgeTakenCount())) {
9784 LLVM_DEBUG(dbgs() << "LV: cannot compute the outer-loop trip count\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: cannot compute the outer-loop trip count\n"
; } } while (false)
;
9785 return false;
9786 }
9787 assert(EnableVPlanNativePath && "VPlan-native path is disabled.")(static_cast <bool> (EnableVPlanNativePath && "VPlan-native path is disabled."
) ? void (0) : __assert_fail ("EnableVPlanNativePath && \"VPlan-native path is disabled.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9787, __extension__ __PRETTY_FUNCTION__))
;
9788 Function *F = L->getHeader()->getParent();
9789 InterleavedAccessInfo IAI(PSE, L, DT, LI, LVL->getLAI());
9790
9791 ScalarEpilogueLowering SEL = getScalarEpilogueLowering(
9792 F, L, Hints, PSI, BFI, TTI, TLI, AC, LI, PSE.getSE(), DT, *LVL);
9793
9794 LoopVectorizationCostModel CM(SEL, L, PSE, LI, LVL, *TTI, TLI, DB, AC, ORE, F,
9795 &Hints, IAI);
9796 // Use the planner for outer loop vectorization.
9797 // TODO: CM is not used at this point inside the planner. Turn CM into an
9798 // optional argument if we don't need it in the future.
9799 LoopVectorizationPlanner LVP(L, LI, TLI, TTI, LVL, CM, IAI, PSE, Hints,
9800 Requirements, ORE);
9801
9802 // Get user vectorization factor.
9803 ElementCount UserVF = Hints.getWidth();
9804
9805 // Plan how to best vectorize, return the best VF and its cost.
9806 const VectorizationFactor VF = LVP.planInVPlanNativePath(UserVF);
9807
9808 // If we are stress testing VPlan builds, do not attempt to generate vector
9809 // code. Masked vector code generation support will follow soon.
9810 // Also, do not attempt to vectorize if no vector code will be produced.
9811 if (VPlanBuildStressTest || EnableVPlanPredication ||
9812 VectorizationFactor::Disabled() == VF)
9813 return false;
9814
9815 LVP.setBestPlan(VF.Width, 1);
9816
9817 {
9818 GeneratedRTChecks Checks(*PSE.getSE(), DT, LI,
9819 F->getParent()->getDataLayout());
9820 InnerLoopVectorizer LB(L, PSE, LI, DT, TLI, TTI, AC, ORE, VF.Width, 1, LVL,
9821 &CM, BFI, PSI, Checks);
9822 LLVM_DEBUG(dbgs() << "Vectorizing outer loop in \""do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Vectorizing outer loop in \""
<< L->getHeader()->getParent()->getName() <<
"\"\n"; } } while (false)
9823 << L->getHeader()->getParent()->getName() << "\"\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "Vectorizing outer loop in \""
<< L->getHeader()->getParent()->getName() <<
"\"\n"; } } while (false)
;
9824 LVP.executePlan(LB, DT);
9825 }
9826
9827 // Mark the loop as already vectorized to avoid vectorizing again.
9828 Hints.setAlreadyVectorized();
9829 assert(!verifyFunction(*L->getHeader()->getParent(), &dbgs()))(static_cast <bool> (!verifyFunction(*L->getHeader()
->getParent(), &dbgs())) ? void (0) : __assert_fail ("!verifyFunction(*L->getHeader()->getParent(), &dbgs())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9829, __extension__ __PRETTY_FUNCTION__))
;
9830 return true;
9831}
9832
9833// Emit a remark if there are stores to floats that required a floating point
9834// extension. If the vectorized loop was generated with floating point there
9835// will be a performance penalty from the conversion overhead and the change in
9836// the vector width.
9837static void checkMixedPrecision(Loop *L, OptimizationRemarkEmitter *ORE) {
9838 SmallVector<Instruction *, 4> Worklist;
9839 for (BasicBlock *BB : L->getBlocks()) {
9840 for (Instruction &Inst : *BB) {
9841 if (auto *S = dyn_cast<StoreInst>(&Inst)) {
9842 if (S->getValueOperand()->getType()->isFloatTy())
9843 Worklist.push_back(S);
9844 }
9845 }
9846 }
9847
9848 // Traverse the floating point stores upwards searching, for floating point
9849 // conversions.
9850 SmallPtrSet<const Instruction *, 4> Visited;
9851 SmallPtrSet<const Instruction *, 4> EmittedRemark;
9852 while (!Worklist.empty()) {
9853 auto *I = Worklist.pop_back_val();
9854 if (!L->contains(I))
9855 continue;
9856 if (!Visited.insert(I).second)
9857 continue;
9858
9859 // Emit a remark if the floating point store required a floating
9860 // point conversion.
9861 // TODO: More work could be done to identify the root cause such as a
9862 // constant or a function return type and point the user to it.
9863 if (isa<FPExtInst>(I) && EmittedRemark.insert(I).second)
9864 ORE->emit([&]() {
9865 return OptimizationRemarkAnalysis(LV_NAME"loop-vectorize", "VectorMixedPrecision",
9866 I->getDebugLoc(), L->getHeader())
9867 << "floating point conversion changes vector width. "
9868 << "Mixed floating point precision requires an up/down "
9869 << "cast that will negatively impact performance.";
9870 });
9871
9872 for (Use &Op : I->operands())
9873 if (auto *OpI = dyn_cast<Instruction>(Op))
9874 Worklist.push_back(OpI);
9875 }
9876}
9877
9878LoopVectorizePass::LoopVectorizePass(LoopVectorizeOptions Opts)
9879 : InterleaveOnlyWhenForced(Opts.InterleaveOnlyWhenForced ||
9880 !EnableLoopInterleaving),
9881 VectorizeOnlyWhenForced(Opts.VectorizeOnlyWhenForced ||
9882 !EnableLoopVectorization) {}
9883
9884bool LoopVectorizePass::processLoop(Loop *L) {
9885 assert((EnableVPlanNativePath || L->isInnermost()) &&(static_cast <bool> ((EnableVPlanNativePath || L->isInnermost
()) && "VPlan-native path is not enabled. Only process inner loops."
) ? void (0) : __assert_fail ("(EnableVPlanNativePath || L->isInnermost()) && \"VPlan-native path is not enabled. Only process inner loops.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9886, __extension__ __PRETTY_FUNCTION__))
9886 "VPlan-native path is not enabled. Only process inner loops.")(static_cast <bool> ((EnableVPlanNativePath || L->isInnermost
()) && "VPlan-native path is not enabled. Only process inner loops."
) ? void (0) : __assert_fail ("(EnableVPlanNativePath || L->isInnermost()) && \"VPlan-native path is not enabled. Only process inner loops.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9886, __extension__ __PRETTY_FUNCTION__))
;
9887
9888#ifndef NDEBUG
9889 const std::string DebugLocStr = getDebugLocString(L);
9890#endif /* NDEBUG */
9891
9892 LLVM_DEBUG(dbgs() << "\nLV: Checking a loop in \""do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \""
<< L->getHeader()->getParent()->getName() <<
"\" from " << DebugLocStr << "\n"; } } while (false
)
9893 << L->getHeader()->getParent()->getName() << "\" from "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \""
<< L->getHeader()->getParent()->getName() <<
"\" from " << DebugLocStr << "\n"; } } while (false
)
9894 << DebugLocStr << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "\nLV: Checking a loop in \""
<< L->getHeader()->getParent()->getName() <<
"\" from " << DebugLocStr << "\n"; } } while (false
)
;
9895
9896 LoopVectorizeHints Hints(L, InterleaveOnlyWhenForced, *ORE);
9897
9898 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9899 dbgs() << "LV: Loop hints:"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9900 << " force="do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9901 << (Hints.getForce() == LoopVectorizeHints::FK_Disableddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9902 ? "disabled"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9903 : (Hints.getForce() == LoopVectorizeHints::FK_Enableddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9904 ? "enabled"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9905 : "?"))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9906 << " width=" << Hints.getWidth()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
9907 << " interleave=" << Hints.getInterleave() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints:" <<
" force=" << (Hints.getForce() == LoopVectorizeHints::
FK_Disabled ? "disabled" : (Hints.getForce() == LoopVectorizeHints
::FK_Enabled ? "enabled" : "?")) << " width=" << Hints
.getWidth() << " interleave=" << Hints.getInterleave
() << "\n"; } } while (false)
;
9908
9909 // Function containing loop
9910 Function *F = L->getHeader()->getParent();
9911
9912 // Looking at the diagnostic output is the only way to determine if a loop
9913 // was vectorized (other than looking at the IR or machine code), so it
9914 // is important to generate an optimization remark for each loop. Most of
9915 // these messages are generated as OptimizationRemarkAnalysis. Remarks
9916 // generated as OptimizationRemark and OptimizationRemarkMissed are
9917 // less verbose reporting vectorized loops and unvectorized loops that may
9918 // benefit from vectorization, respectively.
9919
9920 if (!Hints.allowVectorization(F, L, VectorizeOnlyWhenForced)) {
9921 LLVM_DEBUG(dbgs() << "LV: Loop hints prevent vectorization.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Loop hints prevent vectorization.\n"
; } } while (false)
;
9922 return false;
9923 }
9924
9925 PredicatedScalarEvolution PSE(*SE, *L);
9926
9927 // Check if it is legal to vectorize the loop.
9928 LoopVectorizationRequirements Requirements;
9929 LoopVectorizationLegality LVL(L, PSE, DT, TTI, TLI, AA, F, GetLAA, LI, ORE,
9930 &Requirements, &Hints, DB, AC, BFI, PSI);
9931 if (!LVL.canVectorize(EnableVPlanNativePath)) {
9932 LLVM_DEBUG(dbgs() << "LV: Not vectorizing: Cannot prove legality.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Cannot prove legality.\n"
; } } while (false)
;
9933 Hints.emitRemarkWithHints();
9934 return false;
9935 }
9936
9937 // Check the function attributes and profiles to find out if this function
9938 // should be optimized for size.
9939 ScalarEpilogueLowering SEL = getScalarEpilogueLowering(
9940 F, L, Hints, PSI, BFI, TTI, TLI, AC, LI, PSE.getSE(), DT, LVL);
9941
9942 // Entrance to the VPlan-native vectorization path. Outer loops are processed
9943 // here. They may require CFG and instruction level transformations before
9944 // even evaluating whether vectorization is profitable. Since we cannot modify
9945 // the incoming IR, we need to build VPlan upfront in the vectorization
9946 // pipeline.
9947 if (!L->isInnermost())
9948 return processLoopInVPlanNativePath(L, PSE, LI, DT, &LVL, TTI, TLI, DB, AC,
9949 ORE, BFI, PSI, Hints, Requirements);
9950
9951 assert(L->isInnermost() && "Inner loop expected.")(static_cast <bool> (L->isInnermost() && "Inner loop expected."
) ? void (0) : __assert_fail ("L->isInnermost() && \"Inner loop expected.\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 9951, __extension__ __PRETTY_FUNCTION__))
;
9952
9953 // Check the loop for a trip count threshold: vectorize loops with a tiny trip
9954 // count by optimizing for size, to minimize overheads.
9955 auto ExpectedTC = getSmallBestKnownTC(*SE, L);
9956 if (ExpectedTC && *ExpectedTC < TinyTripCountVectorThreshold) {
9957 LLVM_DEBUG(dbgs() << "LV: Found a loop with a very small trip count. "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a loop with a very small trip count. "
<< "This loop is worth vectorizing only if no scalar "
<< "iteration overheads are incurred."; } } while (false
)
9958 << "This loop is worth vectorizing only if no scalar "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a loop with a very small trip count. "
<< "This loop is worth vectorizing only if no scalar "
<< "iteration overheads are incurred."; } } while (false
)
9959 << "iteration overheads are incurred.")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a loop with a very small trip count. "
<< "This loop is worth vectorizing only if no scalar "
<< "iteration overheads are incurred."; } } while (false
)
;
9960 if (Hints.getForce() == LoopVectorizeHints::FK_Enabled)
9961 LLVM_DEBUG(dbgs() << " But vectorizing was explicitly forced.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << " But vectorizing was explicitly forced.\n"
; } } while (false)
;
9962 else {
9963 LLVM_DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "\n"; } } while (false)
;
9964 SEL = CM_ScalarEpilogueNotAllowedLowTripLoop;
9965 }
9966 }
9967
9968 // Check the function attributes to see if implicit floats are allowed.
9969 // FIXME: This check doesn't seem possibly correct -- what if the loop is
9970 // an integer loop and the vector instructions selected are purely integer
9971 // vector instructions?
9972 if (F->hasFnAttribute(Attribute::NoImplicitFloat)) {
9973 reportVectorizationFailure(
9974 "Can't vectorize when the NoImplicitFloat attribute is used",
9975 "loop not vectorized due to NoImplicitFloat attribute",
9976 "NoImplicitFloat", ORE, L);
9977 Hints.emitRemarkWithHints();
9978 return false;
9979 }
9980
9981 // Check if the target supports potentially unsafe FP vectorization.
9982 // FIXME: Add a check for the type of safety issue (denormal, signaling)
9983 // for the target we're vectorizing for, to make sure none of the
9984 // additional fp-math flags can help.
9985 if (Hints.isPotentiallyUnsafe() &&
9986 TTI->isFPVectorizationPotentiallyUnsafe()) {
9987 reportVectorizationFailure(
9988 "Potentially unsafe FP op prevents vectorization",
9989 "loop not vectorized due to unsafe FP support.",
9990 "UnsafeFP", ORE, L);
9991 Hints.emitRemarkWithHints();
9992 return false;
9993 }
9994
9995 if (!LVL.canVectorizeFPMath(EnableStrictReductions)) {
9996 ORE->emit([&]() {
9997 auto *ExactFPMathInst = Requirements.getExactFPInst();
9998 return OptimizationRemarkAnalysisFPCommute(DEBUG_TYPE"loop-vectorize", "CantReorderFPOps",
9999 ExactFPMathInst->getDebugLoc(),
10000 ExactFPMathInst->getParent())
10001 << "loop not vectorized: cannot prove it is safe to reorder "
10002 "floating-point operations";
10003 });
10004 LLVM_DEBUG(dbgs() << "LV: loop not vectorized: cannot prove it is safe to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: loop not vectorized: cannot prove it is safe to "
"reorder floating-point operations\n"; } } while (false)
10005 "reorder floating-point operations\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: loop not vectorized: cannot prove it is safe to "
"reorder floating-point operations\n"; } } while (false)
;
10006 Hints.emitRemarkWithHints();
10007 return false;
10008 }
10009
10010 bool UseInterleaved = TTI->enableInterleavedAccessVectorization();
10011 InterleavedAccessInfo IAI(PSE, L, DT, LI, LVL.getLAI());
10012
10013 // If an override option has been passed in for interleaved accesses, use it.
10014 if (EnableInterleavedMemAccesses.getNumOccurrences() > 0)
10015 UseInterleaved = EnableInterleavedMemAccesses;
10016
10017 // Analyze interleaved memory accesses.
10018 if (UseInterleaved) {
10019 IAI.analyzeInterleaving(useMaskedInterleavedAccesses(*TTI));
10020 }
10021
10022 // Use the cost model.
10023 LoopVectorizationCostModel CM(SEL, L, PSE, LI, &LVL, *TTI, TLI, DB, AC, ORE,
10024 F, &Hints, IAI);
10025 CM.collectValuesToIgnore();
10026
10027 // Use the planner for vectorization.
10028 LoopVectorizationPlanner LVP(L, LI, TLI, TTI, &LVL, CM, IAI, PSE, Hints,
10029 Requirements, ORE);
10030
10031 // Get user vectorization factor and interleave count.
10032 ElementCount UserVF = Hints.getWidth();
10033 unsigned UserIC = Hints.getInterleave();
10034
10035 // Plan how to best vectorize, return the best VF and its cost.
10036 Optional<VectorizationFactor> MaybeVF = LVP.plan(UserVF, UserIC);
10037
10038 VectorizationFactor VF = VectorizationFactor::Disabled();
10039 unsigned IC = 1;
10040
10041 if (MaybeVF) {
10042 VF = *MaybeVF;
10043 // Select the interleave count.
10044 IC = CM.selectInterleaveCount(VF.Width, *VF.Cost.getValue());
10045 }
10046
10047 // Identify the diagnostic messages that should be produced.
10048 std::pair<StringRef, std::string> VecDiagMsg, IntDiagMsg;
10049 bool VectorizeLoop = true, InterleaveLoop = true;
10050 if (VF.Width.isScalar()) {
10051 LLVM_DEBUG(dbgs() << "LV: Vectorization is possible but not beneficial.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Vectorization is possible but not beneficial.\n"
; } } while (false)
;
10052 VecDiagMsg = std::make_pair(
10053 "VectorizationNotBeneficial",
10054 "the cost-model indicates that vectorization is not beneficial");
10055 VectorizeLoop = false;
10056 }
10057
10058 if (!MaybeVF && UserIC > 1) {
10059 // Tell the user interleaving was avoided up-front, despite being explicitly
10060 // requested.
10061 LLVM_DEBUG(dbgs() << "LV: Ignoring UserIC, because vectorization and "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Ignoring UserIC, because vectorization and "
"interleaving should be avoided up front\n"; } } while (false
)
10062 "interleaving should be avoided up front\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Ignoring UserIC, because vectorization and "
"interleaving should be avoided up front\n"; } } while (false
)
;
10063 IntDiagMsg = std::make_pair(
10064 "InterleavingAvoided",
10065 "Ignoring UserIC, because interleaving was avoided up front");
10066 InterleaveLoop = false;
10067 } else if (IC == 1 && UserIC <= 1) {
10068 // Tell the user interleaving is not beneficial.
10069 LLVM_DEBUG(dbgs() << "LV: Interleaving is not beneficial.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving is not beneficial.\n"
; } } while (false)
;
10070 IntDiagMsg = std::make_pair(
10071 "InterleavingNotBeneficial",
10072 "the cost-model indicates that interleaving is not beneficial");
10073 InterleaveLoop = false;
10074 if (UserIC == 1) {
10075 IntDiagMsg.first = "InterleavingNotBeneficialAndDisabled";
10076 IntDiagMsg.second +=
10077 " and is explicitly disabled or interleave count is set to 1";
10078 }
10079 } else if (IC > 1 && UserIC == 1) {
10080 // Tell the user interleaving is beneficial, but it explicitly disabled.
10081 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving is beneficial but is explicitly disabled."
; } } while (false)
10082 dbgs() << "LV: Interleaving is beneficial but is explicitly disabled.")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleaving is beneficial but is explicitly disabled."
; } } while (false)
;
10083 IntDiagMsg = std::make_pair(
10084 "InterleavingBeneficialButDisabled",
10085 "the cost-model indicates that interleaving is beneficial "
10086 "but is explicitly disabled or interleave count is set to 1");
10087 InterleaveLoop = false;
10088 }
10089
10090 // Override IC if user provided an interleave count.
10091 IC = UserIC > 0 ? UserIC : IC;
10092
10093 // Emit diagnostic messages, if any.
10094 const char *VAPassName = Hints.vectorizeAnalysisPassName();
10095 if (!VectorizeLoop && !InterleaveLoop) {
10096 // Do not vectorize or interleaving the loop.
10097 ORE->emit([&]() {
10098 return OptimizationRemarkMissed(VAPassName, VecDiagMsg.first,
10099 L->getStartLoc(), L->getHeader())
10100 << VecDiagMsg.second;
10101 });
10102 ORE->emit([&]() {
10103 return OptimizationRemarkMissed(LV_NAME"loop-vectorize", IntDiagMsg.first,
10104 L->getStartLoc(), L->getHeader())
10105 << IntDiagMsg.second;
10106 });
10107 return false;
10108 } else if (!VectorizeLoop && InterleaveLoop) {
10109 LLVM_DEBUG(dbgs() << "LV: Interleave Count is " << IC << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleave Count is "
<< IC << '\n'; } } while (false)
;
10110 ORE->emit([&]() {
10111 return OptimizationRemarkAnalysis(VAPassName, VecDiagMsg.first,
10112 L->getStartLoc(), L->getHeader())
10113 << VecDiagMsg.second;
10114 });
10115 } else if (VectorizeLoop && !InterleaveLoop) {
10116 LLVM_DEBUG(dbgs() << "LV: Found a vectorizable loop (" << VF.Widthdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop ("
<< VF.Width << ") in " << DebugLocStr <<
'\n'; } } while (false)
10117 << ") in " << DebugLocStr << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop ("
<< VF.Width << ") in " << DebugLocStr <<
'\n'; } } while (false)
;
10118 ORE->emit([&]() {
10119 return OptimizationRemarkAnalysis(LV_NAME"loop-vectorize", IntDiagMsg.first,
10120 L->getStartLoc(), L->getHeader())
10121 << IntDiagMsg.second;
10122 });
10123 } else if (VectorizeLoop && InterleaveLoop) {
10124 LLVM_DEBUG(dbgs() << "LV: Found a vectorizable loop (" << VF.Widthdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop ("
<< VF.Width << ") in " << DebugLocStr <<
'\n'; } } while (false)
10125 << ") in " << DebugLocStr << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Found a vectorizable loop ("
<< VF.Width << ") in " << DebugLocStr <<
'\n'; } } while (false)
;
10126 LLVM_DEBUG(dbgs() << "LV: Interleave Count is " << IC << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("loop-vectorize")) { dbgs() << "LV: Interleave Count is "
<< IC << '\n'; } } while (false)
;
10127 }
10128
10129 bool DisableRuntimeUnroll = false;
10130 MDNode *OrigLoopID = L->getLoopID();
10131 {
10132 // Optimistically generate runtime checks. Drop them if they turn out to not
10133 // be profitable. Limit the scope of Checks, so the cleanup happens
10134 // immediately after vector codegeneration is done.
10135 GeneratedRTChecks Checks(*PSE.getSE(), DT, LI,
10136 F->getParent()->getDataLayout());
10137 if (!VF.Width.isScalar() || IC > 1)
10138 Checks.Create(L, *LVL.getLAI(), PSE.getUnionPredicate());
10139 LVP.setBestPlan(VF.Width, IC);
10140
10141 using namespace ore;
10142 if (!VectorizeLoop) {
10143 assert(IC > 1 && "interleave count should not be 1 or 0")(static_cast <bool> (IC > 1 && "interleave count should not be 1 or 0"
) ? void (0) : __assert_fail ("IC > 1 && \"interleave count should not be 1 or 0\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 10143, __extension__ __PRETTY_FUNCTION__))
;
10144 // If we decided that it is not legal to vectorize the loop, then
10145 // interleave it.
10146 InnerLoopUnroller Unroller(L, PSE, LI, DT, TLI, TTI, AC, ORE, IC, &LVL,
10147 &CM, BFI, PSI, Checks);
10148 LVP.executePlan(Unroller, DT);
10149
10150 ORE->emit([&]() {
10151 return OptimizationRemark(LV_NAME"loop-vectorize", "Interleaved", L->getStartLoc(),
10152 L->getHeader())
10153 << "interleaved loop (interleaved count: "
10154 << NV("InterleaveCount", IC) << ")";
10155 });
10156 } else {
10157 // If we decided that it is *legal* to vectorize the loop, then do it.
10158
10159 // Consider vectorizing the epilogue too if it's profitable.
10160 VectorizationFactor EpilogueVF =
10161 CM.selectEpilogueVectorizationFactor(VF.Width, LVP);
10162 if (EpilogueVF.Width.isVector()) {
10163
10164 // The first pass vectorizes the main loop and creates a scalar epilogue
10165 // to be vectorized by executing the plan (potentially with a different
10166 // factor) again shortly afterwards.
10167 EpilogueLoopVectorizationInfo EPI(VF.Width.getKnownMinValue(), IC,
10168 EpilogueVF.Width.getKnownMinValue(),
10169 1);
10170 EpilogueVectorizerMainLoop MainILV(L, PSE, LI, DT, TLI, TTI, AC, ORE,
10171 EPI, &LVL, &CM, BFI, PSI, Checks);
10172
10173 LVP.setBestPlan(EPI.MainLoopVF, EPI.MainLoopUF);
10174 LVP.executePlan(MainILV, DT);
10175 ++LoopsVectorized;
10176
10177 simplifyLoop(L, DT, LI, SE, AC, nullptr, false /* PreserveLCSSA */);
10178 formLCSSARecursively(*L, *DT, LI, SE);
10179
10180 // Second pass vectorizes the epilogue and adjusts the control flow
10181 // edges from the first pass.
10182 LVP.setBestPlan(EPI.EpilogueVF, EPI.EpilogueUF);
10183 EPI.MainLoopVF = EPI.EpilogueVF;
10184 EPI.MainLoopUF = EPI.EpilogueUF;
10185 EpilogueVectorizerEpilogueLoop EpilogILV(L, PSE, LI, DT, TLI, TTI, AC,
10186 ORE, EPI, &LVL, &CM, BFI, PSI,
10187 Checks);
10188 LVP.executePlan(EpilogILV, DT);
10189 ++LoopsEpilogueVectorized;
10190
10191 if (!MainILV.areSafetyChecksAdded())
10192 DisableRuntimeUnroll = true;
10193 } else {
10194 InnerLoopVectorizer LB(L, PSE, LI, DT, TLI, TTI, AC, ORE, VF.Width, IC,
10195 &LVL, &CM, BFI, PSI, Checks);
10196 LVP.executePlan(LB, DT);
10197 ++LoopsVectorized;
10198
10199 // Add metadata to disable runtime unrolling a scalar loop when there
10200 // are no runtime checks about strides and memory. A scalar loop that is
10201 // rarely used is not worth unrolling.
10202 if (!LB.areSafetyChecksAdded())
10203 DisableRuntimeUnroll = true;
10204 }
10205 // Report the vectorization decision.
10206 ORE->emit([&]() {
10207 return OptimizationRemark(LV_NAME"loop-vectorize", "Vectorized", L->getStartLoc(),
10208 L->getHeader())
10209 << "vectorized loop (vectorization width: "
10210 << NV("VectorizationFactor", VF.Width)
10211 << ", interleaved count: " << NV("InterleaveCount", IC) << ")";
10212 });
10213 }
10214
10215 if (ORE->allowExtraAnalysis(LV_NAME"loop-vectorize"))
10216 checkMixedPrecision(L, ORE);
10217 }
10218
10219 Optional<MDNode *> RemainderLoopID =
10220 makeFollowupLoopID(OrigLoopID, {LLVMLoopVectorizeFollowupAll,
10221 LLVMLoopVectorizeFollowupEpilogue});
10222 if (RemainderLoopID.hasValue()) {
10223 L->setLoopID(RemainderLoopID.getValue());
10224 } else {
10225 if (DisableRuntimeUnroll)
10226 AddRuntimeUnrollDisableMetaData(L);
10227
10228 // Mark the loop as already vectorized to avoid vectorizing again.
10229 Hints.setAlreadyVectorized();
10230 }
10231
10232 assert(!verifyFunction(*L->getHeader()->getParent(), &dbgs()))(static_cast <bool> (!verifyFunction(*L->getHeader()
->getParent(), &dbgs())) ? void (0) : __assert_fail ("!verifyFunction(*L->getHeader()->getParent(), &dbgs())"
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp"
, 10232, __extension__ __PRETTY_FUNCTION__))
;
10233 return true;
10234}
10235
10236LoopVectorizeResult LoopVectorizePass::runImpl(
10237 Function &F, ScalarEvolution &SE_, LoopInfo &LI_, TargetTransformInfo &TTI_,
10238 DominatorTree &DT_, BlockFrequencyInfo &BFI_, TargetLibraryInfo *TLI_,
10239 DemandedBits &DB_, AAResults &AA_, AssumptionCache &AC_,
10240 std::function<const LoopAccessInfo &(Loop &)> &GetLAA_,
10241 OptimizationRemarkEmitter &ORE_, ProfileSummaryInfo *PSI_) {
10242 SE = &SE_;
10243 LI = &LI_;
10244 TTI = &TTI_;
10245 DT = &DT_;
10246 BFI = &BFI_;
10247 TLI = TLI_;
10248 AA = &AA_;
10249 AC = &AC_;
10250 GetLAA = &GetLAA_;
10251 DB = &DB_;
10252 ORE = &ORE_;
10253 PSI = PSI_;
10254
10255 // Don't attempt if
10256 // 1. the target claims to have no vector registers, and
10257 // 2. interleaving won't help ILP.
10258 //
10259 // The second condition is necessary because, even if the target has no
10260 // vector registers, loop vectorization may still enable scalar
10261 // interleaving.
10262 if (!TTI->getNumberOfRegisters(TTI->getRegisterClassForType(true)) &&
10263 TTI->getMaxInterleaveFactor(1) < 2)
10264 return LoopVectorizeResult(false, false);
10265
10266 bool Changed = false, CFGChanged = false;
10267
10268 // The vectorizer requires loops to be in simplified form.
10269 // Since simplification may add new inner loops, it has to run before the
10270 // legality and profitability checks. This means running the loop vectorizer
10271 // will simplify all loops, regardless of whether anything end up being
10272 // vectorized.
10273 for (auto &L : *LI)
10274 Changed |= CFGChanged |=
10275 simplifyLoop(L, DT, LI, SE, AC, nullptr, false /* PreserveLCSSA */);
10276
10277 // Build up a worklist of inner-loops to vectorize. This is necessary as
10278 // the act of vectorizing or partially unrolling a loop creates new loops
10279 // and can invalidate iterators across the loops.
10280 SmallVector<Loop *, 8> Worklist;
10281
10282 for (Loop *L : *LI)
10283 collectSupportedLoops(*L, LI, ORE, Worklist);
10284
10285 LoopsAnalyzed += Worklist.size();
10286
10287 // Now walk the identified inner loops.
10288 while (!Worklist.empty()) {
10289 Loop *L = Worklist.pop_back_val();
10290
10291 // For the inner loops we actually process, form LCSSA to simplify the
10292 // transform.
10293 Changed |= formLCSSARecursively(*L, *DT, LI, SE);
10294
10295 Changed |= CFGChanged |= processLoop(L);
10296 }
10297
10298 // Process each loop nest in the function.
10299 return LoopVectorizeResult(Changed, CFGChanged);
10300}
10301
10302PreservedAnalyses LoopVectorizePass::run(Function &F,
10303 FunctionAnalysisManager &AM) {
10304 auto &SE = AM.getResult<ScalarEvolutionAnalysis>(F);
10305 auto &LI = AM.getResult<LoopAnalysis>(F);
10306 auto &TTI = AM.getResult<TargetIRAnalysis>(F);
10307 auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
10308 auto &BFI = AM.getResult<BlockFrequencyAnalysis>(F);
10309 auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
10310 auto &AA = AM.getResult<AAManager>(F);
10311 auto &AC = AM.getResult<AssumptionAnalysis>(F);
10312 auto &DB = AM.getResult<DemandedBitsAnalysis>(F);
10313 auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
10314 MemorySSA *MSSA = EnableMSSALoopDependency
10315 ? &AM.getResult<MemorySSAAnalysis>(F).getMSSA()
10316 : nullptr;
10317
10318 auto &LAM = AM.getResult<LoopAnalysisManagerFunctionProxy>(F).getManager();
10319 std::function<const LoopAccessInfo &(Loop &)> GetLAA =
10320 [&](Loop &L) -> const LoopAccessInfo & {
10321 LoopStandardAnalysisResults AR = {AA, AC, DT, LI, SE,
10322 TLI, TTI, nullptr, MSSA};
10323 return LAM.getResult<LoopAccessAnalysis>(L, AR);
10324 };
10325 auto &MAMProxy = AM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
10326 ProfileSummaryInfo *PSI =
10327 MAMProxy.getCachedResult<ProfileSummaryAnalysis>(*F.getParent());
10328 LoopVectorizeResult Result =
10329 runImpl(F, SE, LI, TTI, DT, BFI, &TLI, DB, AA, AC, GetLAA, ORE, PSI);
10330 if (!Result.MadeAnyChange)
10331 return PreservedAnalyses::all();
10332 PreservedAnalyses PA;
10333
10334 // We currently do not preserve loopinfo/dominator analyses with outer loop
10335 // vectorization. Until this is addressed, mark these analyses as preserved
10336 // only for non-VPlan-native path.
10337 // TODO: Preserve Loop and Dominator analyses for VPlan-native path.
10338 if (!EnableVPlanNativePath) {
10339 PA.preserve<LoopAnalysis>();
10340 PA.preserve<DominatorTreeAnalysis>();
10341 }
10342 if (!Result.MadeCFGChange)
10343 PA.preserveSet<CFGAnalyses>();
10344 return PA;
10345}

/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h

1//===- TypeSize.h - Wrapper around type sizes -------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file provides a struct that can be used to query the size of IR types
10// which may be scalable vectors. It provides convenience operators so that
11// it can be used in much the same way as a single scalar value.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_SUPPORT_TYPESIZE_H
16#define LLVM_SUPPORT_TYPESIZE_H
17
18#include "llvm/ADT/ArrayRef.h"
19#include "llvm/Support/MathExtras.h"
20#include "llvm/Support/WithColor.h"
21
22#include <algorithm>
23#include <array>
24#include <cassert>
25#include <cstdint>
26#include <type_traits>
27
28namespace llvm {
29
30/// Reports a diagnostic message to indicate an invalid size request has been
31/// done on a scalable vector. This function may not return.
32void reportInvalidSizeRequest(const char *Msg);
33
34template <typename LeafTy> struct LinearPolyBaseTypeTraits {};
35
36//===----------------------------------------------------------------------===//
37// LinearPolyBase - a base class for linear polynomials with multiple
38// dimensions. This can e.g. be used to describe offsets that are have both a
39// fixed and scalable component.
40//===----------------------------------------------------------------------===//
41
42/// LinearPolyBase describes a linear polynomial:
43/// c0 * scale0 + c1 * scale1 + ... + cK * scaleK
44/// where the scale is implicit, so only the coefficients are encoded.
45template <typename LeafTy>
46class LinearPolyBase {
47public:
48 using ScalarTy = typename LinearPolyBaseTypeTraits<LeafTy>::ScalarTy;
49 static constexpr auto Dimensions = LinearPolyBaseTypeTraits<LeafTy>::Dimensions;
50 static_assert(Dimensions != std::numeric_limits<unsigned>::max(),
51 "Dimensions out of range");
52
53private:
54 std::array<ScalarTy, Dimensions> Coefficients;
55
56protected:
57 LinearPolyBase(ArrayRef<ScalarTy> Values) {
58 std::copy(Values.begin(), Values.end(), Coefficients.begin());
59 }
60
61public:
62 friend LeafTy &operator+=(LeafTy &LHS, const LeafTy &RHS) {
63 for (unsigned I=0; I<Dimensions; ++I)
64 LHS.Coefficients[I] += RHS.Coefficients[I];
65 return LHS;
66 }
67
68 friend LeafTy &operator-=(LeafTy &LHS, const LeafTy &RHS) {
69 for (unsigned I=0; I<Dimensions; ++I)
70 LHS.Coefficients[I] -= RHS.Coefficients[I];
71 return LHS;
72 }
73
74 friend LeafTy &operator*=(LeafTy &LHS, ScalarTy RHS) {
75 for (auto &C : LHS.Coefficients)
76 C *= RHS;
77 return LHS;
78 }
79
80 friend LeafTy operator+(const LeafTy &LHS, const LeafTy &RHS) {
81 LeafTy Copy = LHS;
82 return Copy += RHS;
83 }
84
85 friend LeafTy operator-(const LeafTy &LHS, const LeafTy &RHS) {
86 LeafTy Copy = LHS;
87 return Copy -= RHS;
88 }
89
90 friend LeafTy operator*(const LeafTy &LHS, ScalarTy RHS) {
91 LeafTy Copy = LHS;
92 return Copy *= RHS;
93 }
94
95 template <typename U = ScalarTy>
96 friend typename std::enable_if_t<std::is_signed<U>::value, LeafTy>
97 operator-(const LeafTy &LHS) {
98 LeafTy Copy = LHS;
99 return Copy *= -1;
100 }
101
102 bool operator==(const LinearPolyBase &RHS) const {
103 return std::equal(Coefficients.begin(), Coefficients.end(),
104 RHS.Coefficients.begin());
105 }
106
107 bool operator!=(const LinearPolyBase &RHS) const {
108 return !(*this == RHS);
109 }
110
111 bool isZero() const {
112 return all_of(Coefficients, [](const ScalarTy &C) { return C == 0; });
113 }
114 bool isNonZero() const { return !isZero(); }
115 explicit operator bool() const { return isNonZero(); }
116
117 ScalarTy getValue(unsigned Dim) const { return Coefficients[Dim]; }
118};
119
120//===----------------------------------------------------------------------===//
121// StackOffset - Represent an offset with named fixed and scalable components.
122//===----------------------------------------------------------------------===//
123
124class StackOffset;
125template <> struct LinearPolyBaseTypeTraits<StackOffset> {
126 using ScalarTy = int64_t;
127 static constexpr unsigned Dimensions = 2;
128};
129
130/// StackOffset is a class to represent an offset with 2 dimensions,
131/// named fixed and scalable, respectively. This class allows a value for both
132/// dimensions to depict e.g. "8 bytes and 16 scalable bytes", which is needed
133/// to represent stack offsets.
134class StackOffset : public LinearPolyBase<StackOffset> {
135protected:
136 StackOffset(ScalarTy Fixed, ScalarTy Scalable)
137 : LinearPolyBase<StackOffset>({Fixed, Scalable}) {}
138
139public:
140 StackOffset() : StackOffset({0, 0}) {}
141 StackOffset(const LinearPolyBase<StackOffset> &Other)
142 : LinearPolyBase<StackOffset>(Other) {}
143 static StackOffset getFixed(ScalarTy Fixed) { return {Fixed, 0}; }
144 static StackOffset getScalable(ScalarTy Scalable) { return {0, Scalable}; }
145 static StackOffset get(ScalarTy Fixed, ScalarTy Scalable) {
146 return {Fixed, Scalable};
147 }
148
149 ScalarTy getFixed() const { return this->getValue(0); }
150 ScalarTy getScalable() const { return this->getValue(1); }
151};
152
153//===----------------------------------------------------------------------===//
154// UnivariateLinearPolyBase - a base class for linear polynomials with multiple
155// dimensions, but where only one dimension can be set at any time.
156// This can e.g. be used to describe sizes that are either fixed or scalable.
157//===----------------------------------------------------------------------===//
158
159/// UnivariateLinearPolyBase is a base class for ElementCount and TypeSize.
160/// Like LinearPolyBase it tries to represent a linear polynomial
161/// where only one dimension can be set at any time, e.g.
162/// 0 * scale0 + 0 * scale1 + ... + cJ * scaleJ + ... + 0 * scaleK
163/// The dimension that is set is the univariate dimension.
164template <typename LeafTy>
165class UnivariateLinearPolyBase {
166public:
167 using ScalarTy = typename LinearPolyBaseTypeTraits<LeafTy>::ScalarTy;
168 static constexpr auto Dimensions = LinearPolyBaseTypeTraits<LeafTy>::Dimensions;
169 static_assert(Dimensions != std::numeric_limits<unsigned>::max(),
170 "Dimensions out of range");
171
172protected:
173 ScalarTy Value; // The value at the univeriate dimension.
174 unsigned UnivariateDim; // The univeriate dimension.
175
176 UnivariateLinearPolyBase(ScalarTy Val, unsigned UnivariateDim)
177 : Value(Val), UnivariateDim(UnivariateDim) {
178 assert(UnivariateDim < Dimensions && "Dimension out of range")(static_cast <bool> (UnivariateDim < Dimensions &&
"Dimension out of range") ? void (0) : __assert_fail ("UnivariateDim < Dimensions && \"Dimension out of range\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 178, __extension__ __PRETTY_FUNCTION__))
;
179 }
180
181 friend LeafTy &operator+=(LeafTy &LHS, const LeafTy &RHS) {
182 assert(LHS.UnivariateDim == RHS.UnivariateDim && "Invalid dimensions")(static_cast <bool> (LHS.UnivariateDim == RHS.UnivariateDim
&& "Invalid dimensions") ? void (0) : __assert_fail (
"LHS.UnivariateDim == RHS.UnivariateDim && \"Invalid dimensions\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 182, __extension__ __PRETTY_FUNCTION__))
;
183 LHS.Value += RHS.Value;
184 return LHS;
185 }
186
187 friend LeafTy &operator-=(LeafTy &LHS, const LeafTy &RHS) {
188 assert(LHS.UnivariateDim == RHS.UnivariateDim && "Invalid dimensions")(static_cast <bool> (LHS.UnivariateDim == RHS.UnivariateDim
&& "Invalid dimensions") ? void (0) : __assert_fail (
"LHS.UnivariateDim == RHS.UnivariateDim && \"Invalid dimensions\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 188, __extension__ __PRETTY_FUNCTION__))
;
189 LHS.Value -= RHS.Value;
190 return LHS;
191 }
192
193 friend LeafTy &operator*=(LeafTy &LHS, ScalarTy RHS) {
194 LHS.Value *= RHS;
195 return LHS;
196 }
197
198 friend LeafTy operator+(const LeafTy &LHS, const LeafTy &RHS) {
199 LeafTy Copy = LHS;
200 return Copy += RHS;
201 }
202
203 friend LeafTy operator-(const LeafTy &LHS, const LeafTy &RHS) {
204 LeafTy Copy = LHS;
205 return Copy -= RHS;
206 }
207
208 friend LeafTy operator*(const LeafTy &LHS, ScalarTy RHS) {
209 LeafTy Copy = LHS;
210 return Copy *= RHS;
211 }
212
213 template <typename U = ScalarTy>
214 friend typename std::enable_if<std::is_signed<U>::value, LeafTy>::type
215 operator-(const LeafTy &LHS) {
216 LeafTy Copy = LHS;
217 return Copy *= -1;
218 }
219
220public:
221 bool operator==(const UnivariateLinearPolyBase &RHS) const {
222 return Value == RHS.Value && UnivariateDim == RHS.UnivariateDim;
223 }
224
225 bool operator!=(const UnivariateLinearPolyBase &RHS) const {
226 return !(*this == RHS);
227 }
228
229 bool isZero() const { return !Value; }
230 bool isNonZero() const { return !isZero(); }
231 explicit operator bool() const { return isNonZero(); }
232 ScalarTy getValue() const { return Value; }
233 ScalarTy getValue(unsigned Dim) const {
234 return Dim == UnivariateDim ? Value : 0;
235 }
236
237 /// Add \p RHS to the value at the univariate dimension.
238 LeafTy getWithIncrement(ScalarTy RHS) const {
239 return static_cast<LeafTy>(
240 UnivariateLinearPolyBase(Value + RHS, UnivariateDim));
241 }
242
243 /// Subtract \p RHS from the value at the univariate dimension.
244 LeafTy getWithDecrement(ScalarTy RHS) const {
245 return static_cast<LeafTy>(
246 UnivariateLinearPolyBase(Value - RHS, UnivariateDim));
247 }
248};
249
250
251//===----------------------------------------------------------------------===//
252// LinearPolySize - base class for fixed- or scalable sizes.
253// ^ ^
254// | |
255// | +----- ElementCount - Leaf class to represent an element count
256// | (vscale x unsigned)
257// |
258// +-------- TypeSize - Leaf class to represent a type size
259// (vscale x uint64_t)
260//===----------------------------------------------------------------------===//
261
262/// LinearPolySize is a base class to represent sizes. It is either
263/// fixed-sized or it is scalable-sized, but it cannot be both.
264template <typename LeafTy>
265class LinearPolySize : public UnivariateLinearPolyBase<LeafTy> {
266 // Make the parent class a friend, so that it can access the protected
267 // conversion/copy-constructor for UnivariatePolyBase<LeafTy> ->
268 // LinearPolySize<LeafTy>.
269 friend class UnivariateLinearPolyBase<LeafTy>;
270
271public:
272 using ScalarTy = typename UnivariateLinearPolyBase<LeafTy>::ScalarTy;
273 enum Dims : unsigned { FixedDim = 0, ScalableDim = 1 };
274
275protected:
276 LinearPolySize(ScalarTy MinVal, Dims D)
277 : UnivariateLinearPolyBase<LeafTy>(MinVal, D) {}
278
279 LinearPolySize(const UnivariateLinearPolyBase<LeafTy> &V)
280 : UnivariateLinearPolyBase<LeafTy>(V) {}
281
282public:
283
284 static LeafTy getFixed(ScalarTy MinVal) {
285 return static_cast<LeafTy>(LinearPolySize(MinVal, FixedDim));
286 }
287 static LeafTy getScalable(ScalarTy MinVal) {
288 return static_cast<LeafTy>(LinearPolySize(MinVal, ScalableDim));
289 }
290 static LeafTy get(ScalarTy MinVal, bool Scalable) {
291 return static_cast<LeafTy>(
292 LinearPolySize(MinVal, Scalable ? ScalableDim : FixedDim));
293 }
294 static LeafTy getNull() { return get(0, false); }
295
296 /// Returns the minimum value this size can represent.
297 ScalarTy getKnownMinValue() const { return this->getValue(); }
298 /// Returns whether the size is scaled by a runtime quantity (vscale).
299 bool isScalable() const { return this->UnivariateDim == ScalableDim; }
300 /// A return value of true indicates we know at compile time that the number
301 /// of elements (vscale * Min) is definitely even. However, returning false
302 /// does not guarantee that the total number of elements is odd.
303 bool isKnownEven() const { return (getKnownMinValue() & 0x1) == 0; }
304 /// This function tells the caller whether the element count is known at
305 /// compile time to be a multiple of the scalar value RHS.
306 bool isKnownMultipleOf(ScalarTy RHS) const {
307 return getKnownMinValue() % RHS == 0;
308 }
309
310 // Return the minimum value with the assumption that the count is exact.
311 // Use in places where a scalable count doesn't make sense (e.g. non-vector
312 // types, or vectors in backends which don't support scalable vectors).
313 ScalarTy getFixedValue() const {
314 assert(!isScalable() &&(static_cast <bool> (!isScalable() && "Request for a fixed element count on a scalable object"
) ? void (0) : __assert_fail ("!isScalable() && \"Request for a fixed element count on a scalable object\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 315, __extension__ __PRETTY_FUNCTION__))
315 "Request for a fixed element count on a scalable object")(static_cast <bool> (!isScalable() && "Request for a fixed element count on a scalable object"
) ? void (0) : __assert_fail ("!isScalable() && \"Request for a fixed element count on a scalable object\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 315, __extension__ __PRETTY_FUNCTION__))
;
316 return getKnownMinValue();
317 }
318
319 // For some cases, size ordering between scalable and fixed size types cannot
320 // be determined at compile time, so such comparisons aren't allowed.
321 //
322 // e.g. <vscale x 2 x i16> could be bigger than <4 x i32> with a runtime
323 // vscale >= 5, equal sized with a vscale of 4, and smaller with
324 // a vscale <= 3.
325 //
326 // All the functions below make use of the fact vscale is always >= 1, which
327 // means that <vscale x 4 x i32> is guaranteed to be >= <4 x i32>, etc.
328
329 static bool isKnownLT(const LinearPolySize &LHS, const LinearPolySize &RHS) {
330 if (!LHS.isScalable() || RHS.isScalable())
331 return LHS.getKnownMinValue() < RHS.getKnownMinValue();
332 return false;
333 }
334
335 static bool isKnownGT(const LinearPolySize &LHS, const LinearPolySize &RHS) {
336 if (LHS.isScalable() || !RHS.isScalable())
337 return LHS.getKnownMinValue() > RHS.getKnownMinValue();
338 return false;
339 }
340
341 static bool isKnownLE(const LinearPolySize &LHS, const LinearPolySize &RHS) {
342 if (!LHS.isScalable() || RHS.isScalable())
343 return LHS.getKnownMinValue() <= RHS.getKnownMinValue();
344 return false;
345 }
346
347 static bool isKnownGE(const LinearPolySize &LHS, const LinearPolySize &RHS) {
348 if (LHS.isScalable() || !RHS.isScalable())
349 return LHS.getKnownMinValue() >= RHS.getKnownMinValue();
350 return false;
351 }
352
353 /// We do not provide the '/' operator here because division for polynomial
354 /// types does not work in the same way as for normal integer types. We can
355 /// only divide the minimum value (or coefficient) by RHS, which is not the
356 /// same as
357 /// (Min * Vscale) / RHS
358 /// The caller is recommended to use this function in combination with
359 /// isKnownMultipleOf(RHS), which lets the caller know if it's possible to
360 /// perform a lossless divide by RHS.
361 LeafTy divideCoefficientBy(ScalarTy RHS) const {
362 return static_cast<LeafTy>(
363 LinearPolySize::get(getKnownMinValue() / RHS, isScalable()));
364 }
365
366 LeafTy coefficientNextPowerOf2() const {
367 return static_cast<LeafTy>(LinearPolySize::get(
368 static_cast<ScalarTy>(llvm::NextPowerOf2(getKnownMinValue())),
369 isScalable()));
370 }
371
372 /// Printing function.
373 void print(raw_ostream &OS) const {
374 if (isScalable())
375 OS << "vscale x ";
376 OS << getKnownMinValue();
377 }
378};
379
380class ElementCount;
381template <> struct LinearPolyBaseTypeTraits<ElementCount> {
382 using ScalarTy = unsigned;
383 static constexpr unsigned Dimensions = 2;
384};
385
386class ElementCount : public LinearPolySize<ElementCount> {
387public:
388 ElementCount() : LinearPolySize(LinearPolySize::getNull()) {}
389
390 ElementCount(const LinearPolySize<ElementCount> &V) : LinearPolySize(V) {}
391
392 /// Counting predicates.
393 ///
394 ///@{ Number of elements..
395 /// Exactly one element.
396 bool isScalar() const { return !isScalable() && getKnownMinValue() == 1; }
397 /// One or more elements.
398 bool isVector() const {
399 return (isScalable() && getKnownMinValue() != 0) || getKnownMinValue() > 1;
18
Assuming the condition is true
19
Returning the value 1, which participates in a condition later
400 }
401 ///@}
402};
403
404// This class is used to represent the size of types. If the type is of fixed
405class TypeSize;
406template <> struct LinearPolyBaseTypeTraits<TypeSize> {
407 using ScalarTy = uint64_t;
408 static constexpr unsigned Dimensions = 2;
409};
410
411// TODO: Most functionality in this class will gradually be phased out
412// so it will resemble LinearPolySize as much as possible.
413//
414// TypeSize is used to represent the size of types. If the type is of fixed
415// size, it will represent the exact size. If the type is a scalable vector,
416// it will represent the known minimum size.
417class TypeSize : public LinearPolySize<TypeSize> {
418public:
419 TypeSize(const LinearPolySize<TypeSize> &V) : LinearPolySize(V) {}
420 TypeSize(ScalarTy MinVal, bool IsScalable)
421 : LinearPolySize(LinearPolySize::get(MinVal, IsScalable)) {}
422
423 static TypeSize Fixed(ScalarTy MinVal) { return TypeSize(MinVal, false); }
424 static TypeSize Scalable(ScalarTy MinVal) { return TypeSize(MinVal, true); }
425
426 ScalarTy getFixedSize() const { return getFixedValue(); }
427 ScalarTy getKnownMinSize() const { return getKnownMinValue(); }
428
429 // All code for this class below this point is needed because of the
430 // temporary implicit conversion to uint64_t. The operator overloads are
431 // needed because otherwise the conversion of the parent class
432 // UnivariateLinearPolyBase -> TypeSize is ambiguous.
433 // TODO: Remove the implicit conversion.
434
435 // Casts to a uint64_t if this is a fixed-width size.
436 //
437 // This interface is deprecated and will be removed in a future version
438 // of LLVM in favour of upgrading uses that rely on this implicit conversion
439 // to uint64_t. Calls to functions that return a TypeSize should use the
440 // proper interfaces to TypeSize.
441 // In practice this is mostly calls to MVT/EVT::getSizeInBits().
442 //
443 // To determine how to upgrade the code:
444 //
445 // if (<algorithm works for both scalable and fixed-width vectors>)
446 // use getKnownMinValue()
447 // else if (<algorithm works only for fixed-width vectors>) {
448 // if <algorithm can be adapted for both scalable and fixed-width vectors>
449 // update the algorithm and use getKnownMinValue()
450 // else
451 // bail out early for scalable vectors and use getFixedValue()
452 // }
453 operator ScalarTy() const;
454
455 // Additional operators needed to avoid ambiguous parses
456 // because of the implicit conversion hack.
457 friend TypeSize operator*(const TypeSize &LHS, const int RHS) {
458 return LHS * (ScalarTy)RHS;
459 }
460 friend TypeSize operator*(const TypeSize &LHS, const unsigned RHS) {
461 return LHS * (ScalarTy)RHS;
462 }
463 friend TypeSize operator*(const TypeSize &LHS, const int64_t RHS) {
464 return LHS * (ScalarTy)RHS;
465 }
466 friend TypeSize operator*(const int LHS, const TypeSize &RHS) {
467 return RHS * LHS;
468 }
469 friend TypeSize operator*(const unsigned LHS, const TypeSize &RHS) {
470 return RHS * LHS;
471 }
472 friend TypeSize operator*(const int64_t LHS, const TypeSize &RHS) {
473 return RHS * LHS;
474 }
475 friend TypeSize operator*(const uint64_t LHS, const TypeSize &RHS) {
476 return RHS * LHS;
477 }
478};
479
480//===----------------------------------------------------------------------===//
481// Utilities
482//===----------------------------------------------------------------------===//
483
484/// Returns a TypeSize with a known minimum size that is the next integer
485/// (mod 2**64) that is greater than or equal to \p Value and is a multiple
486/// of \p Align. \p Align must be non-zero.
487///
488/// Similar to the alignTo functions in MathExtras.h
489inline TypeSize alignTo(TypeSize Size, uint64_t Align) {
490 assert(Align != 0u && "Align must be non-zero")(static_cast <bool> (Align != 0u && "Align must be non-zero"
) ? void (0) : __assert_fail ("Align != 0u && \"Align must be non-zero\""
, "/build/llvm-toolchain-snapshot-13~++20210626100611+81b2f95971ed/llvm/include/llvm/Support/TypeSize.h"
, 490, __extension__ __PRETTY_FUNCTION__))
;
491 return {(Size.getKnownMinValue() + Align - 1) / Align * Align,
492 Size.isScalable()};
493}
494
495/// Stream operator function for `LinearPolySize`.
496template <typename LeafTy>
497inline raw_ostream &operator<<(raw_ostream &OS,
498 const LinearPolySize<LeafTy> &PS) {
499 PS.print(OS);
500 return OS;
501}
502
503template <typename T> struct DenseMapInfo;
504template <> struct DenseMapInfo<ElementCount> {
505 static inline ElementCount getEmptyKey() {
506 return ElementCount::getScalable(~0U);
507 }
508 static inline ElementCount getTombstoneKey() {
509 return ElementCount::getFixed(~0U - 1);
510 }
511 static unsigned getHashValue(const ElementCount &EltCnt) {
512 unsigned HashVal = EltCnt.getKnownMinValue() * 37U;
513 if (EltCnt.isScalable())
514 return (HashVal - 1U);
515
516 return HashVal;
517 }
518
519 static bool isEqual(const ElementCount &LHS, const ElementCount &RHS) {
520 return LHS == RHS;
521 }
522};
523
524} // end namespace llvm
525
526#endif // LLVM_SUPPORT_TYPESIZE_H