Bug Summary

File:llvm/lib/Transforms/Scalar/SROA.cpp
Warning:line 2153, column 3
Called C++ object pointer is null

Annotated Source Code

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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 SROA.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 -fhalf-no-semantic-interposition -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~++20210413100635+64c24f493e5f/build-llvm/lib/Transforms/Scalar -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~++20210413100635+64c24f493e5f/build-llvm/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/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/6.3.0/../../../../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-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/build-llvm/lib/Transforms/Scalar -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f=. -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-2021-04-14-063029-18377-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp
1//===- SROA.cpp - Scalar Replacement Of Aggregates ------------------------===//
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/// \file
9/// This transformation implements the well known scalar replacement of
10/// aggregates transformation. It tries to identify promotable elements of an
11/// aggregate alloca, and promote them to registers. It will also try to
12/// convert uses of an element (or set of elements) of an alloca into a vector
13/// or bitfield-style integer scalar if appropriate.
14///
15/// It works to do this with minimal slicing of the alloca so that regions
16/// which are merely transferred in and out of external memory remain unchanged
17/// and are not decomposed to scalar code.
18///
19/// Because this also performs alloca promotion, it can be thought of as also
20/// serving the purpose of SSA formation. The algorithm iterates on the
21/// function until all opportunities for promotion have been realized.
22///
23//===----------------------------------------------------------------------===//
24
25#include "llvm/Transforms/Scalar/SROA.h"
26#include "llvm/ADT/APInt.h"
27#include "llvm/ADT/ArrayRef.h"
28#include "llvm/ADT/DenseMap.h"
29#include "llvm/ADT/PointerIntPair.h"
30#include "llvm/ADT/STLExtras.h"
31#include "llvm/ADT/SetVector.h"
32#include "llvm/ADT/SmallBitVector.h"
33#include "llvm/ADT/SmallPtrSet.h"
34#include "llvm/ADT/SmallVector.h"
35#include "llvm/ADT/Statistic.h"
36#include "llvm/ADT/StringRef.h"
37#include "llvm/ADT/Twine.h"
38#include "llvm/ADT/iterator.h"
39#include "llvm/ADT/iterator_range.h"
40#include "llvm/Analysis/AssumptionCache.h"
41#include "llvm/Analysis/GlobalsModRef.h"
42#include "llvm/Analysis/Loads.h"
43#include "llvm/Analysis/PtrUseVisitor.h"
44#include "llvm/Config/llvm-config.h"
45#include "llvm/IR/BasicBlock.h"
46#include "llvm/IR/Constant.h"
47#include "llvm/IR/ConstantFolder.h"
48#include "llvm/IR/Constants.h"
49#include "llvm/IR/DIBuilder.h"
50#include "llvm/IR/DataLayout.h"
51#include "llvm/IR/DebugInfoMetadata.h"
52#include "llvm/IR/DerivedTypes.h"
53#include "llvm/IR/Dominators.h"
54#include "llvm/IR/Function.h"
55#include "llvm/IR/GetElementPtrTypeIterator.h"
56#include "llvm/IR/GlobalAlias.h"
57#include "llvm/IR/IRBuilder.h"
58#include "llvm/IR/InstVisitor.h"
59#include "llvm/IR/InstrTypes.h"
60#include "llvm/IR/Instruction.h"
61#include "llvm/IR/Instructions.h"
62#include "llvm/IR/IntrinsicInst.h"
63#include "llvm/IR/Intrinsics.h"
64#include "llvm/IR/LLVMContext.h"
65#include "llvm/IR/Metadata.h"
66#include "llvm/IR/Module.h"
67#include "llvm/IR/Operator.h"
68#include "llvm/IR/PassManager.h"
69#include "llvm/IR/Type.h"
70#include "llvm/IR/Use.h"
71#include "llvm/IR/User.h"
72#include "llvm/IR/Value.h"
73#include "llvm/InitializePasses.h"
74#include "llvm/Pass.h"
75#include "llvm/Support/Casting.h"
76#include "llvm/Support/CommandLine.h"
77#include "llvm/Support/Compiler.h"
78#include "llvm/Support/Debug.h"
79#include "llvm/Support/ErrorHandling.h"
80#include "llvm/Support/MathExtras.h"
81#include "llvm/Support/raw_ostream.h"
82#include "llvm/Transforms/Scalar.h"
83#include "llvm/Transforms/Utils/Local.h"
84#include "llvm/Transforms/Utils/PromoteMemToReg.h"
85#include <algorithm>
86#include <cassert>
87#include <chrono>
88#include <cstddef>
89#include <cstdint>
90#include <cstring>
91#include <iterator>
92#include <string>
93#include <tuple>
94#include <utility>
95#include <vector>
96
97using namespace llvm;
98using namespace llvm::sroa;
99
100#define DEBUG_TYPE"sroa" "sroa"
101
102STATISTIC(NumAllocasAnalyzed, "Number of allocas analyzed for replacement")static llvm::Statistic NumAllocasAnalyzed = {"sroa", "NumAllocasAnalyzed"
, "Number of allocas analyzed for replacement"}
;
103STATISTIC(NumAllocaPartitions, "Number of alloca partitions formed")static llvm::Statistic NumAllocaPartitions = {"sroa", "NumAllocaPartitions"
, "Number of alloca partitions formed"}
;
104STATISTIC(MaxPartitionsPerAlloca, "Maximum number of partitions per alloca")static llvm::Statistic MaxPartitionsPerAlloca = {"sroa", "MaxPartitionsPerAlloca"
, "Maximum number of partitions per alloca"}
;
105STATISTIC(NumAllocaPartitionUses, "Number of alloca partition uses rewritten")static llvm::Statistic NumAllocaPartitionUses = {"sroa", "NumAllocaPartitionUses"
, "Number of alloca partition uses rewritten"}
;
106STATISTIC(MaxUsesPerAllocaPartition, "Maximum number of uses of a partition")static llvm::Statistic MaxUsesPerAllocaPartition = {"sroa", "MaxUsesPerAllocaPartition"
, "Maximum number of uses of a partition"}
;
107STATISTIC(NumNewAllocas, "Number of new, smaller allocas introduced")static llvm::Statistic NumNewAllocas = {"sroa", "NumNewAllocas"
, "Number of new, smaller allocas introduced"}
;
108STATISTIC(NumPromoted, "Number of allocas promoted to SSA values")static llvm::Statistic NumPromoted = {"sroa", "NumPromoted", "Number of allocas promoted to SSA values"
}
;
109STATISTIC(NumLoadsSpeculated, "Number of loads speculated to allow promotion")static llvm::Statistic NumLoadsSpeculated = {"sroa", "NumLoadsSpeculated"
, "Number of loads speculated to allow promotion"}
;
110STATISTIC(NumDeleted, "Number of instructions deleted")static llvm::Statistic NumDeleted = {"sroa", "NumDeleted", "Number of instructions deleted"
}
;
111STATISTIC(NumVectorized, "Number of vectorized aggregates")static llvm::Statistic NumVectorized = {"sroa", "NumVectorized"
, "Number of vectorized aggregates"}
;
112
113/// Hidden option to experiment with completely strict handling of inbounds
114/// GEPs.
115static cl::opt<bool> SROAStrictInbounds("sroa-strict-inbounds", cl::init(false),
116 cl::Hidden);
117
118namespace {
119
120/// A custom IRBuilder inserter which prefixes all names, but only in
121/// Assert builds.
122class IRBuilderPrefixedInserter final : public IRBuilderDefaultInserter {
123 std::string Prefix;
124
125 const Twine getNameWithPrefix(const Twine &Name) const {
126 return Name.isTriviallyEmpty() ? Name : Prefix + Name;
127 }
128
129public:
130 void SetNamePrefix(const Twine &P) { Prefix = P.str(); }
131
132 void InsertHelper(Instruction *I, const Twine &Name, BasicBlock *BB,
133 BasicBlock::iterator InsertPt) const override {
134 IRBuilderDefaultInserter::InsertHelper(I, getNameWithPrefix(Name), BB,
135 InsertPt);
136 }
137};
138
139/// Provide a type for IRBuilder that drops names in release builds.
140using IRBuilderTy = IRBuilder<ConstantFolder, IRBuilderPrefixedInserter>;
141
142/// A used slice of an alloca.
143///
144/// This structure represents a slice of an alloca used by some instruction. It
145/// stores both the begin and end offsets of this use, a pointer to the use
146/// itself, and a flag indicating whether we can classify the use as splittable
147/// or not when forming partitions of the alloca.
148class Slice {
149 /// The beginning offset of the range.
150 uint64_t BeginOffset = 0;
151
152 /// The ending offset, not included in the range.
153 uint64_t EndOffset = 0;
154
155 /// Storage for both the use of this slice and whether it can be
156 /// split.
157 PointerIntPair<Use *, 1, bool> UseAndIsSplittable;
158
159public:
160 Slice() = default;
161
162 Slice(uint64_t BeginOffset, uint64_t EndOffset, Use *U, bool IsSplittable)
163 : BeginOffset(BeginOffset), EndOffset(EndOffset),
164 UseAndIsSplittable(U, IsSplittable) {}
165
166 uint64_t beginOffset() const { return BeginOffset; }
167 uint64_t endOffset() const { return EndOffset; }
168
169 bool isSplittable() const { return UseAndIsSplittable.getInt(); }
170 void makeUnsplittable() { UseAndIsSplittable.setInt(false); }
171
172 Use *getUse() const { return UseAndIsSplittable.getPointer(); }
173
174 bool isDead() const { return getUse() == nullptr; }
175 void kill() { UseAndIsSplittable.setPointer(nullptr); }
176
177 /// Support for ordering ranges.
178 ///
179 /// This provides an ordering over ranges such that start offsets are
180 /// always increasing, and within equal start offsets, the end offsets are
181 /// decreasing. Thus the spanning range comes first in a cluster with the
182 /// same start position.
183 bool operator<(const Slice &RHS) const {
184 if (beginOffset() < RHS.beginOffset())
185 return true;
186 if (beginOffset() > RHS.beginOffset())
187 return false;
188 if (isSplittable() != RHS.isSplittable())
189 return !isSplittable();
190 if (endOffset() > RHS.endOffset())
191 return true;
192 return false;
193 }
194
195 /// Support comparison with a single offset to allow binary searches.
196 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(const Slice &LHS,
197 uint64_t RHSOffset) {
198 return LHS.beginOffset() < RHSOffset;
199 }
200 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(uint64_t LHSOffset,
201 const Slice &RHS) {
202 return LHSOffset < RHS.beginOffset();
203 }
204
205 bool operator==(const Slice &RHS) const {
206 return isSplittable() == RHS.isSplittable() &&
207 beginOffset() == RHS.beginOffset() && endOffset() == RHS.endOffset();
208 }
209 bool operator!=(const Slice &RHS) const { return !operator==(RHS); }
210};
211
212} // end anonymous namespace
213
214/// Representation of the alloca slices.
215///
216/// This class represents the slices of an alloca which are formed by its
217/// various uses. If a pointer escapes, we can't fully build a representation
218/// for the slices used and we reflect that in this structure. The uses are
219/// stored, sorted by increasing beginning offset and with unsplittable slices
220/// starting at a particular offset before splittable slices.
221class llvm::sroa::AllocaSlices {
222public:
223 /// Construct the slices of a particular alloca.
224 AllocaSlices(const DataLayout &DL, AllocaInst &AI);
225
226 /// Test whether a pointer to the allocation escapes our analysis.
227 ///
228 /// If this is true, the slices are never fully built and should be
229 /// ignored.
230 bool isEscaped() const { return PointerEscapingInstr; }
231
232 /// Support for iterating over the slices.
233 /// @{
234 using iterator = SmallVectorImpl<Slice>::iterator;
235 using range = iterator_range<iterator>;
236
237 iterator begin() { return Slices.begin(); }
238 iterator end() { return Slices.end(); }
239
240 using const_iterator = SmallVectorImpl<Slice>::const_iterator;
241 using const_range = iterator_range<const_iterator>;
242
243 const_iterator begin() const { return Slices.begin(); }
244 const_iterator end() const { return Slices.end(); }
245 /// @}
246
247 /// Erase a range of slices.
248 void erase(iterator Start, iterator Stop) { Slices.erase(Start, Stop); }
249
250 /// Insert new slices for this alloca.
251 ///
252 /// This moves the slices into the alloca's slices collection, and re-sorts
253 /// everything so that the usual ordering properties of the alloca's slices
254 /// hold.
255 void insert(ArrayRef<Slice> NewSlices) {
256 int OldSize = Slices.size();
257 Slices.append(NewSlices.begin(), NewSlices.end());
258 auto SliceI = Slices.begin() + OldSize;
259 llvm::sort(SliceI, Slices.end());
260 std::inplace_merge(Slices.begin(), SliceI, Slices.end());
261 }
262
263 // Forward declare the iterator and range accessor for walking the
264 // partitions.
265 class partition_iterator;
266 iterator_range<partition_iterator> partitions();
267
268 /// Access the dead users for this alloca.
269 ArrayRef<Instruction *> getDeadUsers() const { return DeadUsers; }
270
271 /// Access Uses that should be dropped if the alloca is promotable.
272 ArrayRef<Use *> getDeadUsesIfPromotable() const {
273 return DeadUseIfPromotable;
274 }
275
276 /// Access the dead operands referring to this alloca.
277 ///
278 /// These are operands which have cannot actually be used to refer to the
279 /// alloca as they are outside its range and the user doesn't correct for
280 /// that. These mostly consist of PHI node inputs and the like which we just
281 /// need to replace with undef.
282 ArrayRef<Use *> getDeadOperands() const { return DeadOperands; }
283
284#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
285 void print(raw_ostream &OS, const_iterator I, StringRef Indent = " ") const;
286 void printSlice(raw_ostream &OS, const_iterator I,
287 StringRef Indent = " ") const;
288 void printUse(raw_ostream &OS, const_iterator I,
289 StringRef Indent = " ") const;
290 void print(raw_ostream &OS) const;
291 void dump(const_iterator I) const;
292 void dump() const;
293#endif
294
295private:
296 template <typename DerivedT, typename RetT = void> class BuilderBase;
297 class SliceBuilder;
298
299 friend class AllocaSlices::SliceBuilder;
300
301#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
302 /// Handle to alloca instruction to simplify method interfaces.
303 AllocaInst &AI;
304#endif
305
306 /// The instruction responsible for this alloca not having a known set
307 /// of slices.
308 ///
309 /// When an instruction (potentially) escapes the pointer to the alloca, we
310 /// store a pointer to that here and abort trying to form slices of the
311 /// alloca. This will be null if the alloca slices are analyzed successfully.
312 Instruction *PointerEscapingInstr;
313
314 /// The slices of the alloca.
315 ///
316 /// We store a vector of the slices formed by uses of the alloca here. This
317 /// vector is sorted by increasing begin offset, and then the unsplittable
318 /// slices before the splittable ones. See the Slice inner class for more
319 /// details.
320 SmallVector<Slice, 8> Slices;
321
322 /// Instructions which will become dead if we rewrite the alloca.
323 ///
324 /// Note that these are not separated by slice. This is because we expect an
325 /// alloca to be completely rewritten or not rewritten at all. If rewritten,
326 /// all these instructions can simply be removed and replaced with undef as
327 /// they come from outside of the allocated space.
328 SmallVector<Instruction *, 8> DeadUsers;
329
330 /// Uses which will become dead if can promote the alloca.
331 SmallVector<Use *, 8> DeadUseIfPromotable;
332
333 /// Operands which will become dead if we rewrite the alloca.
334 ///
335 /// These are operands that in their particular use can be replaced with
336 /// undef when we rewrite the alloca. These show up in out-of-bounds inputs
337 /// to PHI nodes and the like. They aren't entirely dead (there might be
338 /// a GEP back into the bounds using it elsewhere) and nor is the PHI, but we
339 /// want to swap this particular input for undef to simplify the use lists of
340 /// the alloca.
341 SmallVector<Use *, 8> DeadOperands;
342};
343
344/// A partition of the slices.
345///
346/// An ephemeral representation for a range of slices which can be viewed as
347/// a partition of the alloca. This range represents a span of the alloca's
348/// memory which cannot be split, and provides access to all of the slices
349/// overlapping some part of the partition.
350///
351/// Objects of this type are produced by traversing the alloca's slices, but
352/// are only ephemeral and not persistent.
353class llvm::sroa::Partition {
354private:
355 friend class AllocaSlices;
356 friend class AllocaSlices::partition_iterator;
357
358 using iterator = AllocaSlices::iterator;
359
360 /// The beginning and ending offsets of the alloca for this
361 /// partition.
362 uint64_t BeginOffset = 0, EndOffset = 0;
363
364 /// The start and end iterators of this partition.
365 iterator SI, SJ;
366
367 /// A collection of split slice tails overlapping the partition.
368 SmallVector<Slice *, 4> SplitTails;
369
370 /// Raw constructor builds an empty partition starting and ending at
371 /// the given iterator.
372 Partition(iterator SI) : SI(SI), SJ(SI) {}
373
374public:
375 /// The start offset of this partition.
376 ///
377 /// All of the contained slices start at or after this offset.
378 uint64_t beginOffset() const { return BeginOffset; }
379
380 /// The end offset of this partition.
381 ///
382 /// All of the contained slices end at or before this offset.
383 uint64_t endOffset() const { return EndOffset; }
384
385 /// The size of the partition.
386 ///
387 /// Note that this can never be zero.
388 uint64_t size() const {
389 assert(BeginOffset < EndOffset && "Partitions must span some bytes!")((BeginOffset < EndOffset && "Partitions must span some bytes!"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset < EndOffset && \"Partitions must span some bytes!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 389, __PRETTY_FUNCTION__))
;
390 return EndOffset - BeginOffset;
391 }
392
393 /// Test whether this partition contains no slices, and merely spans
394 /// a region occupied by split slices.
395 bool empty() const { return SI == SJ; }
396
397 /// \name Iterate slices that start within the partition.
398 /// These may be splittable or unsplittable. They have a begin offset >= the
399 /// partition begin offset.
400 /// @{
401 // FIXME: We should probably define a "concat_iterator" helper and use that
402 // to stitch together pointee_iterators over the split tails and the
403 // contiguous iterators of the partition. That would give a much nicer
404 // interface here. We could then additionally expose filtered iterators for
405 // split, unsplit, and unsplittable splices based on the usage patterns.
406 iterator begin() const { return SI; }
407 iterator end() const { return SJ; }
408 /// @}
409
410 /// Get the sequence of split slice tails.
411 ///
412 /// These tails are of slices which start before this partition but are
413 /// split and overlap into the partition. We accumulate these while forming
414 /// partitions.
415 ArrayRef<Slice *> splitSliceTails() const { return SplitTails; }
416};
417
418/// An iterator over partitions of the alloca's slices.
419///
420/// This iterator implements the core algorithm for partitioning the alloca's
421/// slices. It is a forward iterator as we don't support backtracking for
422/// efficiency reasons, and re-use a single storage area to maintain the
423/// current set of split slices.
424///
425/// It is templated on the slice iterator type to use so that it can operate
426/// with either const or non-const slice iterators.
427class AllocaSlices::partition_iterator
428 : public iterator_facade_base<partition_iterator, std::forward_iterator_tag,
429 Partition> {
430 friend class AllocaSlices;
431
432 /// Most of the state for walking the partitions is held in a class
433 /// with a nice interface for examining them.
434 Partition P;
435
436 /// We need to keep the end of the slices to know when to stop.
437 AllocaSlices::iterator SE;
438
439 /// We also need to keep track of the maximum split end offset seen.
440 /// FIXME: Do we really?
441 uint64_t MaxSplitSliceEndOffset = 0;
442
443 /// Sets the partition to be empty at given iterator, and sets the
444 /// end iterator.
445 partition_iterator(AllocaSlices::iterator SI, AllocaSlices::iterator SE)
446 : P(SI), SE(SE) {
447 // If not already at the end, advance our state to form the initial
448 // partition.
449 if (SI != SE)
450 advance();
451 }
452
453 /// Advance the iterator to the next partition.
454 ///
455 /// Requires that the iterator not be at the end of the slices.
456 void advance() {
457 assert((P.SI != SE || !P.SplitTails.empty()) &&(((P.SI != SE || !P.SplitTails.empty()) && "Cannot advance past the end of the slices!"
) ? static_cast<void> (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 458, __PRETTY_FUNCTION__))
458 "Cannot advance past the end of the slices!")(((P.SI != SE || !P.SplitTails.empty()) && "Cannot advance past the end of the slices!"
) ? static_cast<void> (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 458, __PRETTY_FUNCTION__))
;
459
460 // Clear out any split uses which have ended.
461 if (!P.SplitTails.empty()) {
462 if (P.EndOffset >= MaxSplitSliceEndOffset) {
463 // If we've finished all splits, this is easy.
464 P.SplitTails.clear();
465 MaxSplitSliceEndOffset = 0;
466 } else {
467 // Remove the uses which have ended in the prior partition. This
468 // cannot change the max split slice end because we just checked that
469 // the prior partition ended prior to that max.
470 llvm::erase_if(P.SplitTails,
471 [&](Slice *S) { return S->endOffset() <= P.EndOffset; });
472 assert(llvm::any_of(P.SplitTails,((llvm::any_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __PRETTY_FUNCTION__))
473 [&](Slice *S) {((llvm::any_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __PRETTY_FUNCTION__))
474 return S->endOffset() == MaxSplitSliceEndOffset;((llvm::any_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __PRETTY_FUNCTION__))
475 }) &&((llvm::any_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __PRETTY_FUNCTION__))
476 "Could not find the current max split slice offset!")((llvm::any_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __PRETTY_FUNCTION__))
;
477 assert(llvm::all_of(P.SplitTails,((llvm::all_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __PRETTY_FUNCTION__))
478 [&](Slice *S) {((llvm::all_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __PRETTY_FUNCTION__))
479 return S->endOffset() <= MaxSplitSliceEndOffset;((llvm::all_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __PRETTY_FUNCTION__))
480 }) &&((llvm::all_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __PRETTY_FUNCTION__))
481 "Max split slice end offset is not actually the max!")((llvm::all_of(P.SplitTails, [&](Slice *S) { return S->
endOffset() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __PRETTY_FUNCTION__))
;
482 }
483 }
484
485 // If P.SI is already at the end, then we've cleared the split tail and
486 // now have an end iterator.
487 if (P.SI == SE) {
488 assert(P.SplitTails.empty() && "Failed to clear the split slices!")((P.SplitTails.empty() && "Failed to clear the split slices!"
) ? static_cast<void> (0) : __assert_fail ("P.SplitTails.empty() && \"Failed to clear the split slices!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 488, __PRETTY_FUNCTION__))
;
489 return;
490 }
491
492 // If we had a non-empty partition previously, set up the state for
493 // subsequent partitions.
494 if (P.SI != P.SJ) {
495 // Accumulate all the splittable slices which started in the old
496 // partition into the split list.
497 for (Slice &S : P)
498 if (S.isSplittable() && S.endOffset() > P.EndOffset) {
499 P.SplitTails.push_back(&S);
500 MaxSplitSliceEndOffset =
501 std::max(S.endOffset(), MaxSplitSliceEndOffset);
502 }
503
504 // Start from the end of the previous partition.
505 P.SI = P.SJ;
506
507 // If P.SI is now at the end, we at most have a tail of split slices.
508 if (P.SI == SE) {
509 P.BeginOffset = P.EndOffset;
510 P.EndOffset = MaxSplitSliceEndOffset;
511 return;
512 }
513
514 // If the we have split slices and the next slice is after a gap and is
515 // not splittable immediately form an empty partition for the split
516 // slices up until the next slice begins.
517 if (!P.SplitTails.empty() && P.SI->beginOffset() != P.EndOffset &&
518 !P.SI->isSplittable()) {
519 P.BeginOffset = P.EndOffset;
520 P.EndOffset = P.SI->beginOffset();
521 return;
522 }
523 }
524
525 // OK, we need to consume new slices. Set the end offset based on the
526 // current slice, and step SJ past it. The beginning offset of the
527 // partition is the beginning offset of the next slice unless we have
528 // pre-existing split slices that are continuing, in which case we begin
529 // at the prior end offset.
530 P.BeginOffset = P.SplitTails.empty() ? P.SI->beginOffset() : P.EndOffset;
531 P.EndOffset = P.SI->endOffset();
532 ++P.SJ;
533
534 // There are two strategies to form a partition based on whether the
535 // partition starts with an unsplittable slice or a splittable slice.
536 if (!P.SI->isSplittable()) {
537 // When we're forming an unsplittable region, it must always start at
538 // the first slice and will extend through its end.
539 assert(P.BeginOffset == P.SI->beginOffset())((P.BeginOffset == P.SI->beginOffset()) ? static_cast<void
> (0) : __assert_fail ("P.BeginOffset == P.SI->beginOffset()"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 539, __PRETTY_FUNCTION__))
;
540
541 // Form a partition including all of the overlapping slices with this
542 // unsplittable slice.
543 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
544 if (!P.SJ->isSplittable())
545 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
546 ++P.SJ;
547 }
548
549 // We have a partition across a set of overlapping unsplittable
550 // partitions.
551 return;
552 }
553
554 // If we're starting with a splittable slice, then we need to form
555 // a synthetic partition spanning it and any other overlapping splittable
556 // splices.
557 assert(P.SI->isSplittable() && "Forming a splittable partition!")((P.SI->isSplittable() && "Forming a splittable partition!"
) ? static_cast<void> (0) : __assert_fail ("P.SI->isSplittable() && \"Forming a splittable partition!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 557, __PRETTY_FUNCTION__))
;
558
559 // Collect all of the overlapping splittable slices.
560 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset &&
561 P.SJ->isSplittable()) {
562 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
563 ++P.SJ;
564 }
565
566 // Back upiP.EndOffset if we ended the span early when encountering an
567 // unsplittable slice. This synthesizes the early end offset of
568 // a partition spanning only splittable slices.
569 if (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
570 assert(!P.SJ->isSplittable())((!P.SJ->isSplittable()) ? static_cast<void> (0) : __assert_fail
("!P.SJ->isSplittable()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 570, __PRETTY_FUNCTION__))
;
571 P.EndOffset = P.SJ->beginOffset();
572 }
573 }
574
575public:
576 bool operator==(const partition_iterator &RHS) const {
577 assert(SE == RHS.SE &&((SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? static_cast<void> (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 578, __PRETTY_FUNCTION__))
578 "End iterators don't match between compared partition iterators!")((SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? static_cast<void> (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 578, __PRETTY_FUNCTION__))
;
579
580 // The observed positions of partitions is marked by the P.SI iterator and
581 // the emptiness of the split slices. The latter is only relevant when
582 // P.SI == SE, as the end iterator will additionally have an empty split
583 // slices list, but the prior may have the same P.SI and a tail of split
584 // slices.
585 if (P.SI == RHS.P.SI && P.SplitTails.empty() == RHS.P.SplitTails.empty()) {
586 assert(P.SJ == RHS.P.SJ &&((P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? static_cast<void> (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 587, __PRETTY_FUNCTION__))
587 "Same set of slices formed two different sized partitions!")((P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? static_cast<void> (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 587, __PRETTY_FUNCTION__))
;
588 assert(P.SplitTails.size() == RHS.P.SplitTails.size() &&((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __PRETTY_FUNCTION__))
589 "Same slice position with differently sized non-empty split "((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __PRETTY_FUNCTION__))
590 "slice tails!")((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __PRETTY_FUNCTION__))
;
591 return true;
592 }
593 return false;
594 }
595
596 partition_iterator &operator++() {
597 advance();
598 return *this;
599 }
600
601 Partition &operator*() { return P; }
602};
603
604/// A forward range over the partitions of the alloca's slices.
605///
606/// This accesses an iterator range over the partitions of the alloca's
607/// slices. It computes these partitions on the fly based on the overlapping
608/// offsets of the slices and the ability to split them. It will visit "empty"
609/// partitions to cover regions of the alloca only accessed via split
610/// slices.
611iterator_range<AllocaSlices::partition_iterator> AllocaSlices::partitions() {
612 return make_range(partition_iterator(begin(), end()),
613 partition_iterator(end(), end()));
614}
615
616static Value *foldSelectInst(SelectInst &SI) {
617 // If the condition being selected on is a constant or the same value is
618 // being selected between, fold the select. Yes this does (rarely) happen
619 // early on.
620 if (ConstantInt *CI = dyn_cast<ConstantInt>(SI.getCondition()))
621 return SI.getOperand(1 + CI->isZero());
622 if (SI.getOperand(1) == SI.getOperand(2))
623 return SI.getOperand(1);
624
625 return nullptr;
626}
627
628/// A helper that folds a PHI node or a select.
629static Value *foldPHINodeOrSelectInst(Instruction &I) {
630 if (PHINode *PN = dyn_cast<PHINode>(&I)) {
631 // If PN merges together the same value, return that value.
632 return PN->hasConstantValue();
633 }
634 return foldSelectInst(cast<SelectInst>(I));
635}
636
637/// Builder for the alloca slices.
638///
639/// This class builds a set of alloca slices by recursively visiting the uses
640/// of an alloca and making a slice for each load and store at each offset.
641class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
642 friend class PtrUseVisitor<SliceBuilder>;
643 friend class InstVisitor<SliceBuilder>;
644
645 using Base = PtrUseVisitor<SliceBuilder>;
646
647 const uint64_t AllocSize;
648 AllocaSlices &AS;
649
650 SmallDenseMap<Instruction *, unsigned> MemTransferSliceMap;
651 SmallDenseMap<Instruction *, uint64_t> PHIOrSelectSizes;
652
653 /// Set to de-duplicate dead instructions found in the use walk.
654 SmallPtrSet<Instruction *, 4> VisitedDeadInsts;
655
656public:
657 SliceBuilder(const DataLayout &DL, AllocaInst &AI, AllocaSlices &AS)
658 : PtrUseVisitor<SliceBuilder>(DL),
659 AllocSize(DL.getTypeAllocSize(AI.getAllocatedType()).getFixedSize()),
660 AS(AS) {}
661
662private:
663 void markAsDead(Instruction &I) {
664 if (VisitedDeadInsts.insert(&I).second)
665 AS.DeadUsers.push_back(&I);
666 }
667
668 void insertUse(Instruction &I, const APInt &Offset, uint64_t Size,
669 bool IsSplittable = false) {
670 // Completely skip uses which have a zero size or start either before or
671 // past the end of the allocation.
672 if (Size == 0 || Offset.uge(AllocSize)) {
673 LLVM_DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte use @"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
674 << Offsetdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
675 << " which has zero size or starts outside of the "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
676 << AllocSize << " byte alloca:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
677 << " alloca: " << AS.AI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
678 << " use: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte use @" << Offset << " which has zero size or starts outside of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
;
679 return markAsDead(I);
680 }
681
682 uint64_t BeginOffset = Offset.getZExtValue();
683 uint64_t EndOffset = BeginOffset + Size;
684
685 // Clamp the end offset to the end of the allocation. Note that this is
686 // formulated to handle even the case where "BeginOffset + Size" overflows.
687 // This may appear superficially to be something we could ignore entirely,
688 // but that is not so! There may be widened loads or PHI-node uses where
689 // some instructions are dead but not others. We can't completely ignore
690 // them, and so have to record at least the information here.
691 assert(AllocSize >= BeginOffset)((AllocSize >= BeginOffset) ? static_cast<void> (0) :
__assert_fail ("AllocSize >= BeginOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 691, __PRETTY_FUNCTION__))
; // Established above.
692 if (Size > AllocSize - BeginOffset) {
693 LLVM_DEBUG(dbgs() << "WARNING: Clamping a " << Size << " byte use @"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Clamping a " << Size
<< " byte use @" << Offset << " to remain within the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
694 << Offset << " to remain within the " << AllocSizedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Clamping a " << Size
<< " byte use @" << Offset << " to remain within the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
695 << " byte alloca:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Clamping a " << Size
<< " byte use @" << Offset << " to remain within the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
696 << " alloca: " << AS.AI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Clamping a " << Size
<< " byte use @" << Offset << " to remain within the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
697 << " use: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Clamping a " << Size
<< " byte use @" << Offset << " to remain within the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
I << "\n"; } } while (false)
;
698 EndOffset = AllocSize;
699 }
700
701 AS.Slices.push_back(Slice(BeginOffset, EndOffset, U, IsSplittable));
702 }
703
704 void visitBitCastInst(BitCastInst &BC) {
705 if (BC.use_empty())
706 return markAsDead(BC);
707
708 return Base::visitBitCastInst(BC);
709 }
710
711 void visitAddrSpaceCastInst(AddrSpaceCastInst &ASC) {
712 if (ASC.use_empty())
713 return markAsDead(ASC);
714
715 return Base::visitAddrSpaceCastInst(ASC);
716 }
717
718 void visitGetElementPtrInst(GetElementPtrInst &GEPI) {
719 if (GEPI.use_empty())
720 return markAsDead(GEPI);
721
722 if (SROAStrictInbounds && GEPI.isInBounds()) {
723 // FIXME: This is a manually un-factored variant of the basic code inside
724 // of GEPs with checking of the inbounds invariant specified in the
725 // langref in a very strict sense. If we ever want to enable
726 // SROAStrictInbounds, this code should be factored cleanly into
727 // PtrUseVisitor, but it is easier to experiment with SROAStrictInbounds
728 // by writing out the code here where we have the underlying allocation
729 // size readily available.
730 APInt GEPOffset = Offset;
731 const DataLayout &DL = GEPI.getModule()->getDataLayout();
732 for (gep_type_iterator GTI = gep_type_begin(GEPI),
733 GTE = gep_type_end(GEPI);
734 GTI != GTE; ++GTI) {
735 ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
736 if (!OpC)
737 break;
738
739 // Handle a struct index, which adds its field offset to the pointer.
740 if (StructType *STy = GTI.getStructTypeOrNull()) {
741 unsigned ElementIdx = OpC->getZExtValue();
742 const StructLayout *SL = DL.getStructLayout(STy);
743 GEPOffset +=
744 APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx));
745 } else {
746 // For array or vector indices, scale the index by the size of the
747 // type.
748 APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth());
749 GEPOffset +=
750 Index *
751 APInt(Offset.getBitWidth(),
752 DL.getTypeAllocSize(GTI.getIndexedType()).getFixedSize());
753 }
754
755 // If this index has computed an intermediate pointer which is not
756 // inbounds, then the result of the GEP is a poison value and we can
757 // delete it and all uses.
758 if (GEPOffset.ugt(AllocSize))
759 return markAsDead(GEPI);
760 }
761 }
762
763 return Base::visitGetElementPtrInst(GEPI);
764 }
765
766 void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset,
767 uint64_t Size, bool IsVolatile) {
768 // We allow splitting of non-volatile loads and stores where the type is an
769 // integer type. These may be used to implement 'memcpy' or other "transfer
770 // of bits" patterns.
771 bool IsSplittable = Ty->isIntegerTy() && !IsVolatile;
772
773 insertUse(I, Offset, Size, IsSplittable);
774 }
775
776 void visitLoadInst(LoadInst &LI) {
777 assert((!LI.isSimple() || LI.getType()->isSingleValueType()) &&(((!LI.isSimple() || LI.getType()->isSingleValueType()) &&
"All simple FCA loads should have been pre-split") ? static_cast
<void> (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 778, __PRETTY_FUNCTION__))
778 "All simple FCA loads should have been pre-split")(((!LI.isSimple() || LI.getType()->isSingleValueType()) &&
"All simple FCA loads should have been pre-split") ? static_cast
<void> (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 778, __PRETTY_FUNCTION__))
;
779
780 if (!IsOffsetKnown)
781 return PI.setAborted(&LI);
782
783 if (LI.isVolatile() &&
784 LI.getPointerAddressSpace() != DL.getAllocaAddrSpace())
785 return PI.setAborted(&LI);
786
787 if (isa<ScalableVectorType>(LI.getType()))
788 return PI.setAborted(&LI);
789
790 uint64_t Size = DL.getTypeStoreSize(LI.getType()).getFixedSize();
791 return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
792 }
793
794 void visitStoreInst(StoreInst &SI) {
795 Value *ValOp = SI.getValueOperand();
796 if (ValOp == *U)
797 return PI.setEscapedAndAborted(&SI);
798 if (!IsOffsetKnown)
799 return PI.setAborted(&SI);
800
801 if (SI.isVolatile() &&
802 SI.getPointerAddressSpace() != DL.getAllocaAddrSpace())
803 return PI.setAborted(&SI);
804
805 if (isa<ScalableVectorType>(ValOp->getType()))
806 return PI.setAborted(&SI);
807
808 uint64_t Size = DL.getTypeStoreSize(ValOp->getType()).getFixedSize();
809
810 // If this memory access can be shown to *statically* extend outside the
811 // bounds of the allocation, it's behavior is undefined, so simply
812 // ignore it. Note that this is more strict than the generic clamping
813 // behavior of insertUse. We also try to handle cases which might run the
814 // risk of overflow.
815 // FIXME: We should instead consider the pointer to have escaped if this
816 // function is being instrumented for addressing bugs or race conditions.
817 if (Size > AllocSize || Offset.ugt(AllocSize - Size)) {
818 LLVM_DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte store @"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte store @" << Offset << " which extends past the end of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
SI << "\n"; } } while (false)
819 << Offset << " which extends past the end of the "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte store @" << Offset << " which extends past the end of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
SI << "\n"; } } while (false)
820 << AllocSize << " byte alloca:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte store @" << Offset << " which extends past the end of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
SI << "\n"; } } while (false)
821 << " alloca: " << AS.AI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte store @" << Offset << " which extends past the end of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
SI << "\n"; } } while (false)
822 << " use: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "WARNING: Ignoring " << Size
<< " byte store @" << Offset << " which extends past the end of the "
<< AllocSize << " byte alloca:\n" << " alloca: "
<< AS.AI << "\n" << " use: " <<
SI << "\n"; } } while (false)
;
823 return markAsDead(SI);
824 }
825
826 assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&(((!SI.isSimple() || ValOp->getType()->isSingleValueType
()) && "All simple FCA stores should have been pre-split"
) ? static_cast<void> (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 827, __PRETTY_FUNCTION__))
827 "All simple FCA stores should have been pre-split")(((!SI.isSimple() || ValOp->getType()->isSingleValueType
()) && "All simple FCA stores should have been pre-split"
) ? static_cast<void> (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 827, __PRETTY_FUNCTION__))
;
828 handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
829 }
830
831 void visitMemSetInst(MemSetInst &II) {
832 assert(II.getRawDest() == *U && "Pointer use is not the destination?")((II.getRawDest() == *U && "Pointer use is not the destination?"
) ? static_cast<void> (0) : __assert_fail ("II.getRawDest() == *U && \"Pointer use is not the destination?\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 832, __PRETTY_FUNCTION__))
;
833 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
834 if ((Length && Length->getValue() == 0) ||
835 (IsOffsetKnown && Offset.uge(AllocSize)))
836 // Zero-length mem transfer intrinsics can be ignored entirely.
837 return markAsDead(II);
838
839 if (!IsOffsetKnown)
840 return PI.setAborted(&II);
841
842 // Don't replace this with a store with a different address space. TODO:
843 // Use a store with the casted new alloca?
844 if (II.isVolatile() && II.getDestAddressSpace() != DL.getAllocaAddrSpace())
845 return PI.setAborted(&II);
846
847 insertUse(II, Offset, Length ? Length->getLimitedValue()
848 : AllocSize - Offset.getLimitedValue(),
849 (bool)Length);
850 }
851
852 void visitMemTransferInst(MemTransferInst &II) {
853 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
854 if (Length && Length->getValue() == 0)
855 // Zero-length mem transfer intrinsics can be ignored entirely.
856 return markAsDead(II);
857
858 // Because we can visit these intrinsics twice, also check to see if the
859 // first time marked this instruction as dead. If so, skip it.
860 if (VisitedDeadInsts.count(&II))
861 return;
862
863 if (!IsOffsetKnown)
864 return PI.setAborted(&II);
865
866 // Don't replace this with a load/store with a different address space.
867 // TODO: Use a store with the casted new alloca?
868 if (II.isVolatile() &&
869 (II.getDestAddressSpace() != DL.getAllocaAddrSpace() ||
870 II.getSourceAddressSpace() != DL.getAllocaAddrSpace()))
871 return PI.setAborted(&II);
872
873 // This side of the transfer is completely out-of-bounds, and so we can
874 // nuke the entire transfer. However, we also need to nuke the other side
875 // if already added to our partitions.
876 // FIXME: Yet another place we really should bypass this when
877 // instrumenting for ASan.
878 if (Offset.uge(AllocSize)) {
879 SmallDenseMap<Instruction *, unsigned>::iterator MTPI =
880 MemTransferSliceMap.find(&II);
881 if (MTPI != MemTransferSliceMap.end())
882 AS.Slices[MTPI->second].kill();
883 return markAsDead(II);
884 }
885
886 uint64_t RawOffset = Offset.getLimitedValue();
887 uint64_t Size = Length ? Length->getLimitedValue() : AllocSize - RawOffset;
888
889 // Check for the special case where the same exact value is used for both
890 // source and dest.
891 if (*U == II.getRawDest() && *U == II.getRawSource()) {
892 // For non-volatile transfers this is a no-op.
893 if (!II.isVolatile())
894 return markAsDead(II);
895
896 return insertUse(II, Offset, Size, /*IsSplittable=*/false);
897 }
898
899 // If we have seen both source and destination for a mem transfer, then
900 // they both point to the same alloca.
901 bool Inserted;
902 SmallDenseMap<Instruction *, unsigned>::iterator MTPI;
903 std::tie(MTPI, Inserted) =
904 MemTransferSliceMap.insert(std::make_pair(&II, AS.Slices.size()));
905 unsigned PrevIdx = MTPI->second;
906 if (!Inserted) {
907 Slice &PrevP = AS.Slices[PrevIdx];
908
909 // Check if the begin offsets match and this is a non-volatile transfer.
910 // In that case, we can completely elide the transfer.
911 if (!II.isVolatile() && PrevP.beginOffset() == RawOffset) {
912 PrevP.kill();
913 return markAsDead(II);
914 }
915
916 // Otherwise we have an offset transfer within the same alloca. We can't
917 // split those.
918 PrevP.makeUnsplittable();
919 }
920
921 // Insert the use now that we've fixed up the splittable nature.
922 insertUse(II, Offset, Size, /*IsSplittable=*/Inserted && Length);
923
924 // Check that we ended up with a valid index in the map.
925 assert(AS.Slices[PrevIdx].getUse()->getUser() == &II &&((AS.Slices[PrevIdx].getUse()->getUser() == &II &&
"Map index doesn't point back to a slice with this user.") ?
static_cast<void> (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 926, __PRETTY_FUNCTION__))
926 "Map index doesn't point back to a slice with this user.")((AS.Slices[PrevIdx].getUse()->getUser() == &II &&
"Map index doesn't point back to a slice with this user.") ?
static_cast<void> (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 926, __PRETTY_FUNCTION__))
;
927 }
928
929 // Disable SRoA for any intrinsics except for lifetime invariants and
930 // invariant group.
931 // FIXME: What about debug intrinsics? This matches old behavior, but
932 // doesn't make sense.
933 void visitIntrinsicInst(IntrinsicInst &II) {
934 if (II.isDroppable()) {
935 AS.DeadUseIfPromotable.push_back(U);
936 return;
937 }
938
939 if (!IsOffsetKnown)
940 return PI.setAborted(&II);
941
942 if (II.isLifetimeStartOrEnd()) {
943 ConstantInt *Length = cast<ConstantInt>(II.getArgOperand(0));
944 uint64_t Size = std::min(AllocSize - Offset.getLimitedValue(),
945 Length->getLimitedValue());
946 insertUse(II, Offset, Size, true);
947 return;
948 }
949
950 if (II.isLaunderOrStripInvariantGroup()) {
951 enqueueUsers(II);
952 return;
953 }
954
955 Base::visitIntrinsicInst(II);
956 }
957
958 Instruction *hasUnsafePHIOrSelectUse(Instruction *Root, uint64_t &Size) {
959 // We consider any PHI or select that results in a direct load or store of
960 // the same offset to be a viable use for slicing purposes. These uses
961 // are considered unsplittable and the size is the maximum loaded or stored
962 // size.
963 SmallPtrSet<Instruction *, 4> Visited;
964 SmallVector<std::pair<Instruction *, Instruction *>, 4> Uses;
965 Visited.insert(Root);
966 Uses.push_back(std::make_pair(cast<Instruction>(*U), Root));
967 const DataLayout &DL = Root->getModule()->getDataLayout();
968 // If there are no loads or stores, the access is dead. We mark that as
969 // a size zero access.
970 Size = 0;
971 do {
972 Instruction *I, *UsedI;
973 std::tie(UsedI, I) = Uses.pop_back_val();
974
975 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
976 Size = std::max(Size,
977 DL.getTypeStoreSize(LI->getType()).getFixedSize());
978 continue;
979 }
980 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
981 Value *Op = SI->getOperand(0);
982 if (Op == UsedI)
983 return SI;
984 Size = std::max(Size,
985 DL.getTypeStoreSize(Op->getType()).getFixedSize());
986 continue;
987 }
988
989 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
990 if (!GEP->hasAllZeroIndices())
991 return GEP;
992 } else if (!isa<BitCastInst>(I) && !isa<PHINode>(I) &&
993 !isa<SelectInst>(I) && !isa<AddrSpaceCastInst>(I)) {
994 return I;
995 }
996
997 for (User *U : I->users())
998 if (Visited.insert(cast<Instruction>(U)).second)
999 Uses.push_back(std::make_pair(I, cast<Instruction>(U)));
1000 } while (!Uses.empty());
1001
1002 return nullptr;
1003 }
1004
1005 void visitPHINodeOrSelectInst(Instruction &I) {
1006 assert(isa<PHINode>(I) || isa<SelectInst>(I))((isa<PHINode>(I) || isa<SelectInst>(I)) ? static_cast
<void> (0) : __assert_fail ("isa<PHINode>(I) || isa<SelectInst>(I)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1006, __PRETTY_FUNCTION__))
;
1007 if (I.use_empty())
1008 return markAsDead(I);
1009
1010 // TODO: We could use SimplifyInstruction here to fold PHINodes and
1011 // SelectInsts. However, doing so requires to change the current
1012 // dead-operand-tracking mechanism. For instance, suppose neither loading
1013 // from %U nor %other traps. Then "load (select undef, %U, %other)" does not
1014 // trap either. However, if we simply replace %U with undef using the
1015 // current dead-operand-tracking mechanism, "load (select undef, undef,
1016 // %other)" may trap because the select may return the first operand
1017 // "undef".
1018 if (Value *Result = foldPHINodeOrSelectInst(I)) {
1019 if (Result == *U)
1020 // If the result of the constant fold will be the pointer, recurse
1021 // through the PHI/select as if we had RAUW'ed it.
1022 enqueueUsers(I);
1023 else
1024 // Otherwise the operand to the PHI/select is dead, and we can replace
1025 // it with undef.
1026 AS.DeadOperands.push_back(U);
1027
1028 return;
1029 }
1030
1031 if (!IsOffsetKnown)
1032 return PI.setAborted(&I);
1033
1034 // See if we already have computed info on this node.
1035 uint64_t &Size = PHIOrSelectSizes[&I];
1036 if (!Size) {
1037 // This is a new PHI/Select, check for an unsafe use of it.
1038 if (Instruction *UnsafeI = hasUnsafePHIOrSelectUse(&I, Size))
1039 return PI.setAborted(UnsafeI);
1040 }
1041
1042 // For PHI and select operands outside the alloca, we can't nuke the entire
1043 // phi or select -- the other side might still be relevant, so we special
1044 // case them here and use a separate structure to track the operands
1045 // themselves which should be replaced with undef.
1046 // FIXME: This should instead be escaped in the event we're instrumenting
1047 // for address sanitization.
1048 if (Offset.uge(AllocSize)) {
1049 AS.DeadOperands.push_back(U);
1050 return;
1051 }
1052
1053 insertUse(I, Offset, Size);
1054 }
1055
1056 void visitPHINode(PHINode &PN) { visitPHINodeOrSelectInst(PN); }
1057
1058 void visitSelectInst(SelectInst &SI) { visitPHINodeOrSelectInst(SI); }
1059
1060 /// Disable SROA entirely if there are unhandled users of the alloca.
1061 void visitInstruction(Instruction &I) { PI.setAborted(&I); }
1062};
1063
1064AllocaSlices::AllocaSlices(const DataLayout &DL, AllocaInst &AI)
1065 :
1066#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1067 AI(AI),
1068#endif
1069 PointerEscapingInstr(nullptr) {
1070 SliceBuilder PB(DL, AI, *this);
1071 SliceBuilder::PtrInfo PtrI = PB.visitPtr(AI);
1072 if (PtrI.isEscaped() || PtrI.isAborted()) {
1073 // FIXME: We should sink the escape vs. abort info into the caller nicely,
1074 // possibly by just storing the PtrInfo in the AllocaSlices.
1075 PointerEscapingInstr = PtrI.getEscapingInst() ? PtrI.getEscapingInst()
1076 : PtrI.getAbortingInst();
1077 assert(PointerEscapingInstr && "Did not track a bad instruction")((PointerEscapingInstr && "Did not track a bad instruction"
) ? static_cast<void> (0) : __assert_fail ("PointerEscapingInstr && \"Did not track a bad instruction\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1077, __PRETTY_FUNCTION__))
;
1078 return;
1079 }
1080
1081 llvm::erase_if(Slices, [](const Slice &S) { return S.isDead(); });
1082
1083 // Sort the uses. This arranges for the offsets to be in ascending order,
1084 // and the sizes to be in descending order.
1085 llvm::stable_sort(Slices);
1086}
1087
1088#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1089
1090void AllocaSlices::print(raw_ostream &OS, const_iterator I,
1091 StringRef Indent) const {
1092 printSlice(OS, I, Indent);
1093 OS << "\n";
1094 printUse(OS, I, Indent);
1095}
1096
1097void AllocaSlices::printSlice(raw_ostream &OS, const_iterator I,
1098 StringRef Indent) const {
1099 OS << Indent << "[" << I->beginOffset() << "," << I->endOffset() << ")"
1100 << " slice #" << (I - begin())
1101 << (I->isSplittable() ? " (splittable)" : "");
1102}
1103
1104void AllocaSlices::printUse(raw_ostream &OS, const_iterator I,
1105 StringRef Indent) const {
1106 OS << Indent << " used by: " << *I->getUse()->getUser() << "\n";
1107}
1108
1109void AllocaSlices::print(raw_ostream &OS) const {
1110 if (PointerEscapingInstr) {
1111 OS << "Can't analyze slices for alloca: " << AI << "\n"
1112 << " A pointer to this alloca escaped by:\n"
1113 << " " << *PointerEscapingInstr << "\n";
1114 return;
1115 }
1116
1117 OS << "Slices of alloca: " << AI << "\n";
1118 for (const_iterator I = begin(), E = end(); I != E; ++I)
1119 print(OS, I);
1120}
1121
1122LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump(const_iterator I) const {
1123 print(dbgs(), I);
1124}
1125LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump() const { print(dbgs()); }
1126
1127#endif // !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1128
1129/// Walk the range of a partitioning looking for a common type to cover this
1130/// sequence of slices.
1131static std::pair<Type *, IntegerType *>
1132findCommonType(AllocaSlices::const_iterator B, AllocaSlices::const_iterator E,
1133 uint64_t EndOffset) {
1134 Type *Ty = nullptr;
1135 bool TyIsCommon = true;
1136 IntegerType *ITy = nullptr;
1137
1138 // Note that we need to look at *every* alloca slice's Use to ensure we
1139 // always get consistent results regardless of the order of slices.
1140 for (AllocaSlices::const_iterator I = B; I != E; ++I) {
1141 Use *U = I->getUse();
1142 if (isa<IntrinsicInst>(*U->getUser()))
1143 continue;
1144 if (I->beginOffset() != B->beginOffset() || I->endOffset() != EndOffset)
1145 continue;
1146
1147 Type *UserTy = nullptr;
1148 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1149 UserTy = LI->getType();
1150 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1151 UserTy = SI->getValueOperand()->getType();
1152 }
1153
1154 if (IntegerType *UserITy = dyn_cast_or_null<IntegerType>(UserTy)) {
1155 // If the type is larger than the partition, skip it. We only encounter
1156 // this for split integer operations where we want to use the type of the
1157 // entity causing the split. Also skip if the type is not a byte width
1158 // multiple.
1159 if (UserITy->getBitWidth() % 8 != 0 ||
1160 UserITy->getBitWidth() / 8 > (EndOffset - B->beginOffset()))
1161 continue;
1162
1163 // Track the largest bitwidth integer type used in this way in case there
1164 // is no common type.
1165 if (!ITy || ITy->getBitWidth() < UserITy->getBitWidth())
1166 ITy = UserITy;
1167 }
1168
1169 // To avoid depending on the order of slices, Ty and TyIsCommon must not
1170 // depend on types skipped above.
1171 if (!UserTy || (Ty && Ty != UserTy))
1172 TyIsCommon = false; // Give up on anything but an iN type.
1173 else
1174 Ty = UserTy;
1175 }
1176
1177 return {TyIsCommon ? Ty : nullptr, ITy};
1178}
1179
1180/// PHI instructions that use an alloca and are subsequently loaded can be
1181/// rewritten to load both input pointers in the pred blocks and then PHI the
1182/// results, allowing the load of the alloca to be promoted.
1183/// From this:
1184/// %P2 = phi [i32* %Alloca, i32* %Other]
1185/// %V = load i32* %P2
1186/// to:
1187/// %V1 = load i32* %Alloca -> will be mem2reg'd
1188/// ...
1189/// %V2 = load i32* %Other
1190/// ...
1191/// %V = phi [i32 %V1, i32 %V2]
1192///
1193/// We can do this to a select if its only uses are loads and if the operands
1194/// to the select can be loaded unconditionally.
1195///
1196/// FIXME: This should be hoisted into a generic utility, likely in
1197/// Transforms/Util/Local.h
1198static bool isSafePHIToSpeculate(PHINode &PN) {
1199 const DataLayout &DL = PN.getModule()->getDataLayout();
1200
1201 // For now, we can only do this promotion if the load is in the same block
1202 // as the PHI, and if there are no stores between the phi and load.
1203 // TODO: Allow recursive phi users.
1204 // TODO: Allow stores.
1205 BasicBlock *BB = PN.getParent();
1206 Align MaxAlign;
1207 uint64_t APWidth = DL.getIndexTypeSizeInBits(PN.getType());
1208 APInt MaxSize(APWidth, 0);
1209 bool HaveLoad = false;
1210 for (User *U : PN.users()) {
1211 LoadInst *LI = dyn_cast<LoadInst>(U);
1212 if (!LI || !LI->isSimple())
1213 return false;
1214
1215 // For now we only allow loads in the same block as the PHI. This is
1216 // a common case that happens when instcombine merges two loads through
1217 // a PHI.
1218 if (LI->getParent() != BB)
1219 return false;
1220
1221 // Ensure that there are no instructions between the PHI and the load that
1222 // could store.
1223 for (BasicBlock::iterator BBI(PN); &*BBI != LI; ++BBI)
1224 if (BBI->mayWriteToMemory())
1225 return false;
1226
1227 uint64_t Size = DL.getTypeStoreSize(LI->getType()).getFixedSize();
1228 MaxAlign = std::max(MaxAlign, LI->getAlign());
1229 MaxSize = MaxSize.ult(Size) ? APInt(APWidth, Size) : MaxSize;
1230 HaveLoad = true;
1231 }
1232
1233 if (!HaveLoad)
1234 return false;
1235
1236 // We can only transform this if it is safe to push the loads into the
1237 // predecessor blocks. The only thing to watch out for is that we can't put
1238 // a possibly trapping load in the predecessor if it is a critical edge.
1239 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1240 Instruction *TI = PN.getIncomingBlock(Idx)->getTerminator();
1241 Value *InVal = PN.getIncomingValue(Idx);
1242
1243 // If the value is produced by the terminator of the predecessor (an
1244 // invoke) or it has side-effects, there is no valid place to put a load
1245 // in the predecessor.
1246 if (TI == InVal || TI->mayHaveSideEffects())
1247 return false;
1248
1249 // If the predecessor has a single successor, then the edge isn't
1250 // critical.
1251 if (TI->getNumSuccessors() == 1)
1252 continue;
1253
1254 // If this pointer is always safe to load, or if we can prove that there
1255 // is already a load in the block, then we can move the load to the pred
1256 // block.
1257 if (isSafeToLoadUnconditionally(InVal, MaxAlign, MaxSize, DL, TI))
1258 continue;
1259
1260 return false;
1261 }
1262
1263 return true;
1264}
1265
1266static void speculatePHINodeLoads(PHINode &PN) {
1267 LLVM_DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
1268
1269 LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
1270 Type *LoadTy = SomeLoad->getType();
1271 IRBuilderTy PHIBuilder(&PN);
1272 PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
1273 PN.getName() + ".sroa.speculated");
1274
1275 // Get the AA tags and alignment to use from one of the loads. It does not
1276 // matter which one we get and if any differ.
1277 AAMDNodes AATags;
1278 SomeLoad->getAAMetadata(AATags);
1279 Align Alignment = SomeLoad->getAlign();
1280
1281 // Rewrite all loads of the PN to use the new PHI.
1282 while (!PN.use_empty()) {
1283 LoadInst *LI = cast<LoadInst>(PN.user_back());
1284 LI->replaceAllUsesWith(NewPN);
1285 LI->eraseFromParent();
1286 }
1287
1288 // Inject loads into all of the pred blocks.
1289 DenseMap<BasicBlock*, Value*> InjectedLoads;
1290 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1291 BasicBlock *Pred = PN.getIncomingBlock(Idx);
1292 Value *InVal = PN.getIncomingValue(Idx);
1293
1294 // A PHI node is allowed to have multiple (duplicated) entries for the same
1295 // basic block, as long as the value is the same. So if we already injected
1296 // a load in the predecessor, then we should reuse the same load for all
1297 // duplicated entries.
1298 if (Value* V = InjectedLoads.lookup(Pred)) {
1299 NewPN->addIncoming(V, Pred);
1300 continue;
1301 }
1302
1303 Instruction *TI = Pred->getTerminator();
1304 IRBuilderTy PredBuilder(TI);
1305
1306 LoadInst *Load = PredBuilder.CreateAlignedLoad(
1307 LoadTy, InVal, Alignment,
1308 (PN.getName() + ".sroa.speculate.load." + Pred->getName()));
1309 ++NumLoadsSpeculated;
1310 if (AATags)
1311 Load->setAAMetadata(AATags);
1312 NewPN->addIncoming(Load, Pred);
1313 InjectedLoads[Pred] = Load;
1314 }
1315
1316 LLVM_DEBUG(dbgs() << " speculated to: " << *NewPN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*NewPN << "\n"; } } while (false)
;
1317 PN.eraseFromParent();
1318}
1319
1320/// Select instructions that use an alloca and are subsequently loaded can be
1321/// rewritten to load both input pointers and then select between the result,
1322/// allowing the load of the alloca to be promoted.
1323/// From this:
1324/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
1325/// %V = load i32* %P2
1326/// to:
1327/// %V1 = load i32* %Alloca -> will be mem2reg'd
1328/// %V2 = load i32* %Other
1329/// %V = select i1 %cond, i32 %V1, i32 %V2
1330///
1331/// We can do this to a select if its only uses are loads and if the operand
1332/// to the select can be loaded unconditionally.
1333static bool isSafeSelectToSpeculate(SelectInst &SI) {
1334 Value *TValue = SI.getTrueValue();
1335 Value *FValue = SI.getFalseValue();
1336 const DataLayout &DL = SI.getModule()->getDataLayout();
1337
1338 for (User *U : SI.users()) {
1339 LoadInst *LI = dyn_cast<LoadInst>(U);
1340 if (!LI || !LI->isSimple())
1341 return false;
1342
1343 // Both operands to the select need to be dereferenceable, either
1344 // absolutely (e.g. allocas) or at this point because we can see other
1345 // accesses to it.
1346 if (!isSafeToLoadUnconditionally(TValue, LI->getType(),
1347 LI->getAlign(), DL, LI))
1348 return false;
1349 if (!isSafeToLoadUnconditionally(FValue, LI->getType(),
1350 LI->getAlign(), DL, LI))
1351 return false;
1352 }
1353
1354 return true;
1355}
1356
1357static void speculateSelectInstLoads(SelectInst &SI) {
1358 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
1359
1360 IRBuilderTy IRB(&SI);
1361 Value *TV = SI.getTrueValue();
1362 Value *FV = SI.getFalseValue();
1363 // Replace the loads of the select with a select of two loads.
1364 while (!SI.use_empty()) {
1365 LoadInst *LI = cast<LoadInst>(SI.user_back());
1366 assert(LI->isSimple() && "We only speculate simple loads")((LI->isSimple() && "We only speculate simple loads"
) ? static_cast<void> (0) : __assert_fail ("LI->isSimple() && \"We only speculate simple loads\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1366, __PRETTY_FUNCTION__))
;
1367
1368 IRB.SetInsertPoint(LI);
1369 LoadInst *TL = IRB.CreateLoad(LI->getType(), TV,
1370 LI->getName() + ".sroa.speculate.load.true");
1371 LoadInst *FL = IRB.CreateLoad(LI->getType(), FV,
1372 LI->getName() + ".sroa.speculate.load.false");
1373 NumLoadsSpeculated += 2;
1374
1375 // Transfer alignment and AA info if present.
1376 TL->setAlignment(LI->getAlign());
1377 FL->setAlignment(LI->getAlign());
1378
1379 AAMDNodes Tags;
1380 LI->getAAMetadata(Tags);
1381 if (Tags) {
1382 TL->setAAMetadata(Tags);
1383 FL->setAAMetadata(Tags);
1384 }
1385
1386 Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
1387 LI->getName() + ".sroa.speculated");
1388
1389 LLVM_DEBUG(dbgs() << " speculated to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*V << "\n"; } } while (false)
;
1390 LI->replaceAllUsesWith(V);
1391 LI->eraseFromParent();
1392 }
1393 SI.eraseFromParent();
1394}
1395
1396/// Build a GEP out of a base pointer and indices.
1397///
1398/// This will return the BasePtr if that is valid, or build a new GEP
1399/// instruction using the IRBuilder if GEP-ing is needed.
1400static Value *buildGEP(IRBuilderTy &IRB, Value *BasePtr,
1401 SmallVectorImpl<Value *> &Indices,
1402 const Twine &NamePrefix) {
1403 if (Indices.empty())
1404 return BasePtr;
1405
1406 // A single zero index is a no-op, so check for this and avoid building a GEP
1407 // in that case.
1408 if (Indices.size() == 1 && cast<ConstantInt>(Indices.back())->isZero())
1409 return BasePtr;
1410
1411 return IRB.CreateInBoundsGEP(BasePtr->getType()->getPointerElementType(),
1412 BasePtr, Indices, NamePrefix + "sroa_idx");
1413}
1414
1415/// Get a natural GEP off of the BasePtr walking through Ty toward
1416/// TargetTy without changing the offset of the pointer.
1417///
1418/// This routine assumes we've already established a properly offset GEP with
1419/// Indices, and arrived at the Ty type. The goal is to continue to GEP with
1420/// zero-indices down through type layers until we find one the same as
1421/// TargetTy. If we can't find one with the same type, we at least try to use
1422/// one with the same size. If none of that works, we just produce the GEP as
1423/// indicated by Indices to have the correct offset.
1424static Value *getNaturalGEPWithType(IRBuilderTy &IRB, const DataLayout &DL,
1425 Value *BasePtr, Type *Ty, Type *TargetTy,
1426 SmallVectorImpl<Value *> &Indices,
1427 const Twine &NamePrefix) {
1428 if (Ty == TargetTy)
1429 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1430
1431 // Offset size to use for the indices.
1432 unsigned OffsetSize = DL.getIndexTypeSizeInBits(BasePtr->getType());
1433
1434 // See if we can descend into a struct and locate a field with the correct
1435 // type.
1436 unsigned NumLayers = 0;
1437 Type *ElementTy = Ty;
1438 do {
1439 if (ElementTy->isPointerTy())
1440 break;
1441
1442 if (ArrayType *ArrayTy = dyn_cast<ArrayType>(ElementTy)) {
1443 ElementTy = ArrayTy->getElementType();
1444 Indices.push_back(IRB.getIntN(OffsetSize, 0));
1445 } else if (VectorType *VectorTy = dyn_cast<VectorType>(ElementTy)) {
1446 ElementTy = VectorTy->getElementType();
1447 Indices.push_back(IRB.getInt32(0));
1448 } else if (StructType *STy = dyn_cast<StructType>(ElementTy)) {
1449 if (STy->element_begin() == STy->element_end())
1450 break; // Nothing left to descend into.
1451 ElementTy = *STy->element_begin();
1452 Indices.push_back(IRB.getInt32(0));
1453 } else {
1454 break;
1455 }
1456 ++NumLayers;
1457 } while (ElementTy != TargetTy);
1458 if (ElementTy != TargetTy)
1459 Indices.erase(Indices.end() - NumLayers, Indices.end());
1460
1461 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1462}
1463
1464/// Recursively compute indices for a natural GEP.
1465///
1466/// This is the recursive step for getNaturalGEPWithOffset that walks down the
1467/// element types adding appropriate indices for the GEP.
1468static Value *getNaturalGEPRecursively(IRBuilderTy &IRB, const DataLayout &DL,
1469 Value *Ptr, Type *Ty, APInt &Offset,
1470 Type *TargetTy,
1471 SmallVectorImpl<Value *> &Indices,
1472 const Twine &NamePrefix) {
1473 if (Offset == 0)
1474 return getNaturalGEPWithType(IRB, DL, Ptr, Ty, TargetTy, Indices,
1475 NamePrefix);
1476
1477 // We can't recurse through pointer types.
1478 if (Ty->isPointerTy())
1479 return nullptr;
1480
1481 // We try to analyze GEPs over vectors here, but note that these GEPs are
1482 // extremely poorly defined currently. The long-term goal is to remove GEPing
1483 // over a vector from the IR completely.
1484 if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
1485 unsigned ElementSizeInBits =
1486 DL.getTypeSizeInBits(VecTy->getScalarType()).getFixedSize();
1487 if (ElementSizeInBits % 8 != 0) {
1488 // GEPs over non-multiple of 8 size vector elements are invalid.
1489 return nullptr;
1490 }
1491 APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
1492 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1493 if (NumSkippedElements.ugt(cast<FixedVectorType>(VecTy)->getNumElements()))
1494 return nullptr;
1495 Offset -= NumSkippedElements * ElementSize;
1496 Indices.push_back(IRB.getInt(NumSkippedElements));
1497 return getNaturalGEPRecursively(IRB, DL, Ptr, VecTy->getElementType(),
1498 Offset, TargetTy, Indices, NamePrefix);
1499 }
1500
1501 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
1502 Type *ElementTy = ArrTy->getElementType();
1503 APInt ElementSize(Offset.getBitWidth(),
1504 DL.getTypeAllocSize(ElementTy).getFixedSize());
1505 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1506 if (NumSkippedElements.ugt(ArrTy->getNumElements()))
1507 return nullptr;
1508
1509 Offset -= NumSkippedElements * ElementSize;
1510 Indices.push_back(IRB.getInt(NumSkippedElements));
1511 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1512 Indices, NamePrefix);
1513 }
1514
1515 StructType *STy = dyn_cast<StructType>(Ty);
1516 if (!STy)
1517 return nullptr;
1518
1519 const StructLayout *SL = DL.getStructLayout(STy);
1520 uint64_t StructOffset = Offset.getZExtValue();
1521 if (StructOffset >= SL->getSizeInBytes())
1522 return nullptr;
1523 unsigned Index = SL->getElementContainingOffset(StructOffset);
1524 Offset -= APInt(Offset.getBitWidth(), SL->getElementOffset(Index));
1525 Type *ElementTy = STy->getElementType(Index);
1526 if (Offset.uge(DL.getTypeAllocSize(ElementTy).getFixedSize()))
1527 return nullptr; // The offset points into alignment padding.
1528
1529 Indices.push_back(IRB.getInt32(Index));
1530 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1531 Indices, NamePrefix);
1532}
1533
1534/// Get a natural GEP from a base pointer to a particular offset and
1535/// resulting in a particular type.
1536///
1537/// The goal is to produce a "natural" looking GEP that works with the existing
1538/// composite types to arrive at the appropriate offset and element type for
1539/// a pointer. TargetTy is the element type the returned GEP should point-to if
1540/// possible. We recurse by decreasing Offset, adding the appropriate index to
1541/// Indices, and setting Ty to the result subtype.
1542///
1543/// If no natural GEP can be constructed, this function returns null.
1544static Value *getNaturalGEPWithOffset(IRBuilderTy &IRB, const DataLayout &DL,
1545 Value *Ptr, APInt Offset, Type *TargetTy,
1546 SmallVectorImpl<Value *> &Indices,
1547 const Twine &NamePrefix) {
1548 PointerType *Ty = cast<PointerType>(Ptr->getType());
29
The object is a 'PointerType'
1549
1550 // Don't consider any GEPs through an i8* as natural unless the TargetTy is
1551 // an i8.
1552 if (Ty == IRB.getInt8PtrTy(Ty->getAddressSpace()) && TargetTy->isIntegerTy(8))
30
Assuming the condition is false
1553 return nullptr;
1554
1555 Type *ElementTy = Ty->getElementType();
1556 if (!ElementTy->isSized())
31
Assuming the condition is false
32
Taking false branch
1557 return nullptr; // We can't GEP through an unsized element.
1558 if (isa<ScalableVectorType>(ElementTy))
33
Assuming 'ElementTy' is not a 'ScalableVectorType'
34
Taking false branch
1559 return nullptr;
1560 APInt ElementSize(Offset.getBitWidth(),
1561 DL.getTypeAllocSize(ElementTy).getFixedSize());
1562 if (ElementSize == 0)
35
Taking false branch
1563 return nullptr; // Zero-length arrays can't help us build a natural GEP.
1564 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1565
1566 Offset -= NumSkippedElements * ElementSize;
1567 Indices.push_back(IRB.getInt(NumSkippedElements));
1568 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
36
Value assigned to field 'VecTy', which participates in a condition later
37
Value assigned to field 'IntTy', which participates in a condition later
1569 Indices, NamePrefix);
1570}
1571
1572/// Compute an adjusted pointer from Ptr by Offset bytes where the
1573/// resulting pointer has PointerTy.
1574///
1575/// This tries very hard to compute a "natural" GEP which arrives at the offset
1576/// and produces the pointer type desired. Where it cannot, it will try to use
1577/// the natural GEP to arrive at the offset and bitcast to the type. Where that
1578/// fails, it will try to use an existing i8* and GEP to the byte offset and
1579/// bitcast to the type.
1580///
1581/// The strategy for finding the more natural GEPs is to peel off layers of the
1582/// pointer, walking back through bit casts and GEPs, searching for a base
1583/// pointer from which we can compute a natural GEP with the desired
1584/// properties. The algorithm tries to fold as many constant indices into
1585/// a single GEP as possible, thus making each GEP more independent of the
1586/// surrounding code.
1587static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
1588 APInt Offset, Type *PointerTy,
1589 const Twine &NamePrefix) {
1590 // Even though we don't look through PHI nodes, we could be called on an
1591 // instruction in an unreachable block, which may be on a cycle.
1592 SmallPtrSet<Value *, 4> Visited;
1593 Visited.insert(Ptr);
1594 SmallVector<Value *, 4> Indices;
1595
1596 // We may end up computing an offset pointer that has the wrong type. If we
1597 // never are able to compute one directly that has the correct type, we'll
1598 // fall back to it, so keep it and the base it was computed from around here.
1599 Value *OffsetPtr = nullptr;
1600 Value *OffsetBasePtr;
1601
1602 // Remember any i8 pointer we come across to re-use if we need to do a raw
1603 // byte offset.
1604 Value *Int8Ptr = nullptr;
1605 APInt Int8PtrOffset(Offset.getBitWidth(), 0);
1606
1607 PointerType *TargetPtrTy = cast<PointerType>(PointerTy);
24
'PointerTy' is a 'PointerType'
1608 Type *TargetTy = TargetPtrTy->getElementType();
1609
1610 // As `addrspacecast` is , `Ptr` (the storage pointer) may have different
1611 // address space from the expected `PointerTy` (the pointer to be used).
1612 // Adjust the pointer type based the original storage pointer.
1613 auto AS = cast<PointerType>(Ptr->getType())->getAddressSpace();
25
The object is a 'PointerType'
1614 PointerTy = TargetTy->getPointerTo(AS);
1615
1616 do {
1617 // First fold any existing GEPs into the offset.
1618 while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
26
Assuming 'Ptr' is not a 'GEPOperator'
27
Loop condition is false. Execution continues on line 1629
1619 APInt GEPOffset(Offset.getBitWidth(), 0);
1620 if (!GEP->accumulateConstantOffset(DL, GEPOffset))
1621 break;
1622 Offset += GEPOffset;
1623 Ptr = GEP->getPointerOperand();
1624 if (!Visited.insert(Ptr).second)
1625 break;
1626 }
1627
1628 // See if we can perform a natural GEP here.
1629 Indices.clear();
1630 if (Value *P = getNaturalGEPWithOffset(IRB, DL, Ptr, Offset, TargetTy,
28
Calling 'getNaturalGEPWithOffset'
38
Returning from 'getNaturalGEPWithOffset'
39
Assuming 'P' is null
40
Taking false branch
1631 Indices, NamePrefix)) {
1632 // If we have a new natural pointer at the offset, clear out any old
1633 // offset pointer we computed. Unless it is the base pointer or
1634 // a non-instruction, we built a GEP we don't need. Zap it.
1635 if (OffsetPtr && OffsetPtr != OffsetBasePtr)
1636 if (Instruction *I = dyn_cast<Instruction>(OffsetPtr)) {
1637 assert(I->use_empty() && "Built a GEP with uses some how!")((I->use_empty() && "Built a GEP with uses some how!"
) ? static_cast<void> (0) : __assert_fail ("I->use_empty() && \"Built a GEP with uses some how!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1637, __PRETTY_FUNCTION__))
;
1638 I->eraseFromParent();
1639 }
1640 OffsetPtr = P;
1641 OffsetBasePtr = Ptr;
1642 // If we also found a pointer of the right type, we're done.
1643 if (P->getType() == PointerTy)
1644 break;
1645 }
1646
1647 // Stash this pointer if we've found an i8*.
1648 if (Ptr->getType()->isIntegerTy(8)) {
41
Assuming the condition is false
42
Taking false branch
1649 Int8Ptr = Ptr;
1650 Int8PtrOffset = Offset;
1651 }
1652
1653 // Peel off a layer of the pointer and update the offset appropriately.
1654 if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
43
Taking false branch
1655 Ptr = cast<Operator>(Ptr)->getOperand(0);
1656 } else if (GlobalAlias *GA
44.1
'GA' is null
= dyn_cast<GlobalAlias>(Ptr)) {
44
Assuming 'Ptr' is not a 'GlobalAlias'
45
Taking false branch
1657 if (GA->isInterposable())
1658 break;
1659 Ptr = GA->getAliasee();
1660 } else {
1661 break;
46
Execution continues on line 1666
1662 }
1663 assert(Ptr->getType()->isPointerTy() && "Unexpected operand type!")((Ptr->getType()->isPointerTy() && "Unexpected operand type!"
) ? static_cast<void> (0) : __assert_fail ("Ptr->getType()->isPointerTy() && \"Unexpected operand type!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1663, __PRETTY_FUNCTION__))
;
1664 } while (Visited.insert(Ptr).second);
1665
1666 if (!OffsetPtr
46.1
'OffsetPtr' is null
) {
47
Taking true branch
1667 if (!Int8Ptr
47.1
'Int8Ptr' is null
) {
48
Taking true branch
1668 Int8Ptr = IRB.CreateBitCast(
1669 Ptr, IRB.getInt8PtrTy(PointerTy->getPointerAddressSpace()),
1670 NamePrefix + "sroa_raw_cast");
1671 Int8PtrOffset = Offset;
1672 }
1673
1674 OffsetPtr = Int8PtrOffset == 0
49
'?' condition is false
1675 ? Int8Ptr
1676 : IRB.CreateInBoundsGEP(IRB.getInt8Ty(), Int8Ptr,
1677 IRB.getInt(Int8PtrOffset),
1678 NamePrefix + "sroa_raw_idx");
1679 }
1680 Ptr = OffsetPtr;
1681
1682 // On the off chance we were targeting i8*, guard the bitcast here.
1683 if (cast<PointerType>(Ptr->getType()) != TargetPtrTy) {
50
The object is a 'PointerType'
51
Assuming the condition is false
52
Taking false branch
1684 Ptr = IRB.CreatePointerBitCastOrAddrSpaceCast(Ptr,
1685 TargetPtrTy,
1686 NamePrefix + "sroa_cast");
1687 }
1688
1689 return Ptr;
1690}
1691
1692/// Compute the adjusted alignment for a load or store from an offset.
1693static Align getAdjustedAlignment(Instruction *I, uint64_t Offset) {
1694 return commonAlignment(getLoadStoreAlignment(I), Offset);
1695}
1696
1697/// Test whether we can convert a value from the old to the new type.
1698///
1699/// This predicate should be used to guard calls to convertValue in order to
1700/// ensure that we only try to convert viable values. The strategy is that we
1701/// will peel off single element struct and array wrappings to get to an
1702/// underlying value, and convert that value.
1703static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
1704 if (OldTy == NewTy)
1705 return true;
1706
1707 // For integer types, we can't handle any bit-width differences. This would
1708 // break both vector conversions with extension and introduce endianness
1709 // issues when in conjunction with loads and stores.
1710 if (isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) {
1711 assert(cast<IntegerType>(OldTy)->getBitWidth() !=((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1713, __PRETTY_FUNCTION__))
1712 cast<IntegerType>(NewTy)->getBitWidth() &&((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1713, __PRETTY_FUNCTION__))
1713 "We can't have the same bitwidth for different int types")((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1713, __PRETTY_FUNCTION__))
;
1714 return false;
1715 }
1716
1717 if (DL.getTypeSizeInBits(NewTy).getFixedSize() !=
1718 DL.getTypeSizeInBits(OldTy).getFixedSize())
1719 return false;
1720 if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
1721 return false;
1722
1723 // We can convert pointers to integers and vice-versa. Same for vectors
1724 // of pointers and integers.
1725 OldTy = OldTy->getScalarType();
1726 NewTy = NewTy->getScalarType();
1727 if (NewTy->isPointerTy() || OldTy->isPointerTy()) {
1728 if (NewTy->isPointerTy() && OldTy->isPointerTy()) {
1729 unsigned OldAS = OldTy->getPointerAddressSpace();
1730 unsigned NewAS = NewTy->getPointerAddressSpace();
1731 // Convert pointers if they are pointers from the same address space or
1732 // different integral (not non-integral) address spaces with the same
1733 // pointer size.
1734 return OldAS == NewAS ||
1735 (!DL.isNonIntegralAddressSpace(OldAS) &&
1736 !DL.isNonIntegralAddressSpace(NewAS) &&
1737 DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS));
1738 }
1739
1740 // We can convert integers to integral pointers, but not to non-integral
1741 // pointers.
1742 if (OldTy->isIntegerTy())
1743 return !DL.isNonIntegralPointerType(NewTy);
1744
1745 // We can convert integral pointers to integers, but non-integral pointers
1746 // need to remain pointers.
1747 if (!DL.isNonIntegralPointerType(OldTy))
1748 return NewTy->isIntegerTy();
1749
1750 return false;
1751 }
1752
1753 return true;
1754}
1755
1756/// Generic routine to convert an SSA value to a value of a different
1757/// type.
1758///
1759/// This will try various different casting techniques, such as bitcasts,
1760/// inttoptr, and ptrtoint casts. Use the \c canConvertValue predicate to test
1761/// two types for viability with this routine.
1762static Value *convertValue(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
1763 Type *NewTy) {
1764 Type *OldTy = V->getType();
1765 assert(canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type")((canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type"
) ? static_cast<void> (0) : __assert_fail ("canConvertValue(DL, OldTy, NewTy) && \"Value not convertable to type\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1765, __PRETTY_FUNCTION__))
;
1766
1767 if (OldTy == NewTy)
1768 return V;
1769
1770 assert(!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) &&((!(isa<IntegerType>(OldTy) && isa<IntegerType
>(NewTy)) && "Integer types must be the exact same to convert."
) ? static_cast<void> (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1771, __PRETTY_FUNCTION__))
1771 "Integer types must be the exact same to convert.")((!(isa<IntegerType>(OldTy) && isa<IntegerType
>(NewTy)) && "Integer types must be the exact same to convert."
) ? static_cast<void> (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1771, __PRETTY_FUNCTION__))
;
1772
1773 // See if we need inttoptr for this type pair. May require additional bitcast.
1774 if (OldTy->isIntOrIntVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
1775 // Expand <2 x i32> to i8* --> <2 x i32> to i64 to i8*
1776 // Expand i128 to <2 x i8*> --> i128 to <2 x i64> to <2 x i8*>
1777 // Expand <4 x i32> to <2 x i8*> --> <4 x i32> to <2 x i64> to <2 x i8*>
1778 // Directly handle i64 to i8*
1779 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1780 NewTy);
1781 }
1782
1783 // See if we need ptrtoint for this type pair. May require additional bitcast.
1784 if (OldTy->isPtrOrPtrVectorTy() && NewTy->isIntOrIntVectorTy()) {
1785 // Expand <2 x i8*> to i128 --> <2 x i8*> to <2 x i64> to i128
1786 // Expand i8* to <2 x i32> --> i8* to i64 to <2 x i32>
1787 // Expand <2 x i8*> to <4 x i32> --> <2 x i8*> to <2 x i64> to <4 x i32>
1788 // Expand i8* to i64 --> i8* to i64 to i64
1789 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1790 NewTy);
1791 }
1792
1793 if (OldTy->isPtrOrPtrVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
1794 unsigned OldAS = OldTy->getPointerAddressSpace();
1795 unsigned NewAS = NewTy->getPointerAddressSpace();
1796 // To convert pointers with different address spaces (they are already
1797 // checked convertible, i.e. they have the same pointer size), so far we
1798 // cannot use `bitcast` (which has restrict on the same address space) or
1799 // `addrspacecast` (which is not always no-op casting). Instead, use a pair
1800 // of no-op `ptrtoint`/`inttoptr` casts through an integer with the same bit
1801 // size.
1802 if (OldAS != NewAS) {
1803 assert(DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS))((DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS)) ? static_cast
<void> (0) : __assert_fail ("DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1803, __PRETTY_FUNCTION__))
;
1804 return IRB.CreateIntToPtr(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1805 NewTy);
1806 }
1807 }
1808
1809 return IRB.CreateBitCast(V, NewTy);
1810}
1811
1812/// Test whether the given slice use can be promoted to a vector.
1813///
1814/// This function is called to test each entry in a partition which is slated
1815/// for a single slice.
1816static bool isVectorPromotionViableForSlice(Partition &P, const Slice &S,
1817 VectorType *Ty,
1818 uint64_t ElementSize,
1819 const DataLayout &DL) {
1820 // First validate the slice offsets.
1821 uint64_t BeginOffset =
1822 std::max(S.beginOffset(), P.beginOffset()) - P.beginOffset();
1823 uint64_t BeginIndex = BeginOffset / ElementSize;
1824 if (BeginIndex * ElementSize != BeginOffset ||
1825 BeginIndex >= cast<FixedVectorType>(Ty)->getNumElements())
1826 return false;
1827 uint64_t EndOffset =
1828 std::min(S.endOffset(), P.endOffset()) - P.beginOffset();
1829 uint64_t EndIndex = EndOffset / ElementSize;
1830 if (EndIndex * ElementSize != EndOffset ||
1831 EndIndex > cast<FixedVectorType>(Ty)->getNumElements())
1832 return false;
1833
1834 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1834, __PRETTY_FUNCTION__))
;
1835 uint64_t NumElements = EndIndex - BeginIndex;
1836 Type *SliceTy = (NumElements == 1)
1837 ? Ty->getElementType()
1838 : FixedVectorType::get(Ty->getElementType(), NumElements);
1839
1840 Type *SplitIntTy =
1841 Type::getIntNTy(Ty->getContext(), NumElements * ElementSize * 8);
1842
1843 Use *U = S.getUse();
1844
1845 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
1846 if (MI->isVolatile())
1847 return false;
1848 if (!S.isSplittable())
1849 return false; // Skip any unsplittable intrinsics.
1850 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
1851 if (!II->isLifetimeStartOrEnd() && !II->isDroppable())
1852 return false;
1853 } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
1854 // Disable vector promotion when there are loads or stores of an FCA.
1855 return false;
1856 } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1857 if (LI->isVolatile())
1858 return false;
1859 Type *LTy = LI->getType();
1860 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1861 assert(LTy->isIntegerTy())((LTy->isIntegerTy()) ? static_cast<void> (0) : __assert_fail
("LTy->isIntegerTy()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1861, __PRETTY_FUNCTION__))
;
1862 LTy = SplitIntTy;
1863 }
1864 if (!canConvertValue(DL, SliceTy, LTy))
1865 return false;
1866 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1867 if (SI->isVolatile())
1868 return false;
1869 Type *STy = SI->getValueOperand()->getType();
1870 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1871 assert(STy->isIntegerTy())((STy->isIntegerTy()) ? static_cast<void> (0) : __assert_fail
("STy->isIntegerTy()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1871, __PRETTY_FUNCTION__))
;
1872 STy = SplitIntTy;
1873 }
1874 if (!canConvertValue(DL, STy, SliceTy))
1875 return false;
1876 } else {
1877 return false;
1878 }
1879
1880 return true;
1881}
1882
1883/// Test whether the given alloca partitioning and range of slices can be
1884/// promoted to a vector.
1885///
1886/// This is a quick test to check whether we can rewrite a particular alloca
1887/// partition (and its newly formed alloca) into a vector alloca with only
1888/// whole-vector loads and stores such that it could be promoted to a vector
1889/// SSA value. We only can ensure this for a limited set of operations, and we
1890/// don't want to do the rewrites unless we are confident that the result will
1891/// be promotable, so we have an early test here.
1892static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
1893 // Collect the candidate types for vector-based promotion. Also track whether
1894 // we have different element types.
1895 SmallVector<VectorType *, 4> CandidateTys;
1896 Type *CommonEltTy = nullptr;
1897 bool HaveCommonEltTy = true;
1898 auto CheckCandidateType = [&](Type *Ty) {
1899 if (auto *VTy = dyn_cast<VectorType>(Ty)) {
1900 // Return if bitcast to vectors is different for total size in bits.
1901 if (!CandidateTys.empty()) {
1902 VectorType *V = CandidateTys[0];
1903 if (DL.getTypeSizeInBits(VTy).getFixedSize() !=
1904 DL.getTypeSizeInBits(V).getFixedSize()) {
1905 CandidateTys.clear();
1906 return;
1907 }
1908 }
1909 CandidateTys.push_back(VTy);
1910 if (!CommonEltTy)
1911 CommonEltTy = VTy->getElementType();
1912 else if (CommonEltTy != VTy->getElementType())
1913 HaveCommonEltTy = false;
1914 }
1915 };
1916 // Consider any loads or stores that are the exact size of the slice.
1917 for (const Slice &S : P)
1918 if (S.beginOffset() == P.beginOffset() &&
1919 S.endOffset() == P.endOffset()) {
1920 if (auto *LI = dyn_cast<LoadInst>(S.getUse()->getUser()))
1921 CheckCandidateType(LI->getType());
1922 else if (auto *SI = dyn_cast<StoreInst>(S.getUse()->getUser()))
1923 CheckCandidateType(SI->getValueOperand()->getType());
1924 }
1925
1926 // If we didn't find a vector type, nothing to do here.
1927 if (CandidateTys.empty())
1928 return nullptr;
1929
1930 // Remove non-integer vector types if we had multiple common element types.
1931 // FIXME: It'd be nice to replace them with integer vector types, but we can't
1932 // do that until all the backends are known to produce good code for all
1933 // integer vector types.
1934 if (!HaveCommonEltTy) {
1935 llvm::erase_if(CandidateTys, [](VectorType *VTy) {
1936 return !VTy->getElementType()->isIntegerTy();
1937 });
1938
1939 // If there were no integer vector types, give up.
1940 if (CandidateTys.empty())
1941 return nullptr;
1942
1943 // Rank the remaining candidate vector types. This is easy because we know
1944 // they're all integer vectors. We sort by ascending number of elements.
1945 auto RankVectorTypes = [&DL](VectorType *RHSTy, VectorType *LHSTy) {
1946 (void)DL;
1947 assert(DL.getTypeSizeInBits(RHSTy).getFixedSize() ==((DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits
(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1949, __PRETTY_FUNCTION__))
1948 DL.getTypeSizeInBits(LHSTy).getFixedSize() &&((DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits
(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1949, __PRETTY_FUNCTION__))
1949 "Cannot have vector types of different sizes!")((DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits
(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1949, __PRETTY_FUNCTION__))
;
1950 assert(RHSTy->getElementType()->isIntegerTy() &&((RHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1951, __PRETTY_FUNCTION__))
1951 "All non-integer types eliminated!")((RHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1951, __PRETTY_FUNCTION__))
;
1952 assert(LHSTy->getElementType()->isIntegerTy() &&((LHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1953, __PRETTY_FUNCTION__))
1953 "All non-integer types eliminated!")((LHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1953, __PRETTY_FUNCTION__))
;
1954 return cast<FixedVectorType>(RHSTy)->getNumElements() <
1955 cast<FixedVectorType>(LHSTy)->getNumElements();
1956 };
1957 llvm::sort(CandidateTys, RankVectorTypes);
1958 CandidateTys.erase(
1959 std::unique(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes),
1960 CandidateTys.end());
1961 } else {
1962// The only way to have the same element type in every vector type is to
1963// have the same vector type. Check that and remove all but one.
1964#ifndef NDEBUG
1965 for (VectorType *VTy : CandidateTys) {
1966 assert(VTy->getElementType() == CommonEltTy &&((VTy->getElementType() == CommonEltTy && "Unaccounted for element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1967, __PRETTY_FUNCTION__))
1967 "Unaccounted for element type!")((VTy->getElementType() == CommonEltTy && "Unaccounted for element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1967, __PRETTY_FUNCTION__))
;
1968 assert(VTy == CandidateTys[0] &&((VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1969, __PRETTY_FUNCTION__))
1969 "Different vector types with the same element type!")((VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1969, __PRETTY_FUNCTION__))
;
1970 }
1971#endif
1972 CandidateTys.resize(1);
1973 }
1974
1975 // Try each vector type, and return the one which works.
1976 auto CheckVectorTypeForPromotion = [&](VectorType *VTy) {
1977 uint64_t ElementSize =
1978 DL.getTypeSizeInBits(VTy->getElementType()).getFixedSize();
1979
1980 // While the definition of LLVM vectors is bitpacked, we don't support sizes
1981 // that aren't byte sized.
1982 if (ElementSize % 8)
1983 return false;
1984 assert((DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 &&(((DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 &&
"vector size not a multiple of element size?") ? static_cast
<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1985, __PRETTY_FUNCTION__))
1985 "vector size not a multiple of element size?")(((DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 &&
"vector size not a multiple of element size?") ? static_cast
<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1985, __PRETTY_FUNCTION__))
;
1986 ElementSize /= 8;
1987
1988 for (const Slice &S : P)
1989 if (!isVectorPromotionViableForSlice(P, S, VTy, ElementSize, DL))
1990 return false;
1991
1992 for (const Slice *S : P.splitSliceTails())
1993 if (!isVectorPromotionViableForSlice(P, *S, VTy, ElementSize, DL))
1994 return false;
1995
1996 return true;
1997 };
1998 for (VectorType *VTy : CandidateTys)
1999 if (CheckVectorTypeForPromotion(VTy))
2000 return VTy;
2001
2002 return nullptr;
2003}
2004
2005/// Test whether a slice of an alloca is valid for integer widening.
2006///
2007/// This implements the necessary checking for the \c isIntegerWideningViable
2008/// test below on a single slice of the alloca.
2009static bool isIntegerWideningViableForSlice(const Slice &S,
2010 uint64_t AllocBeginOffset,
2011 Type *AllocaTy,
2012 const DataLayout &DL,
2013 bool &WholeAllocaOp) {
2014 uint64_t Size = DL.getTypeStoreSize(AllocaTy).getFixedSize();
2015
2016 uint64_t RelBegin = S.beginOffset() - AllocBeginOffset;
2017 uint64_t RelEnd = S.endOffset() - AllocBeginOffset;
2018
2019 // We can't reasonably handle cases where the load or store extends past
2020 // the end of the alloca's type and into its padding.
2021 if (RelEnd > Size)
2022 return false;
2023
2024 Use *U = S.getUse();
2025
2026 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
2027 if (LI->isVolatile())
2028 return false;
2029 // We can't handle loads that extend past the allocated memory.
2030 if (DL.getTypeStoreSize(LI->getType()).getFixedSize() > Size)
2031 return false;
2032 // So far, AllocaSliceRewriter does not support widening split slice tails
2033 // in rewriteIntegerLoad.
2034 if (S.beginOffset() < AllocBeginOffset)
2035 return false;
2036 // Note that we don't count vector loads or stores as whole-alloca
2037 // operations which enable integer widening because we would prefer to use
2038 // vector widening instead.
2039 if (!isa<VectorType>(LI->getType()) && RelBegin == 0 && RelEnd == Size)
2040 WholeAllocaOp = true;
2041 if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType())) {
2042 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy).getFixedSize())
2043 return false;
2044 } else if (RelBegin != 0 || RelEnd != Size ||
2045 !canConvertValue(DL, AllocaTy, LI->getType())) {
2046 // Non-integer loads need to be convertible from the alloca type so that
2047 // they are promotable.
2048 return false;
2049 }
2050 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
2051 Type *ValueTy = SI->getValueOperand()->getType();
2052 if (SI->isVolatile())
2053 return false;
2054 // We can't handle stores that extend past the allocated memory.
2055 if (DL.getTypeStoreSize(ValueTy).getFixedSize() > Size)
2056 return false;
2057 // So far, AllocaSliceRewriter does not support widening split slice tails
2058 // in rewriteIntegerStore.
2059 if (S.beginOffset() < AllocBeginOffset)
2060 return false;
2061 // Note that we don't count vector loads or stores as whole-alloca
2062 // operations which enable integer widening because we would prefer to use
2063 // vector widening instead.
2064 if (!isa<VectorType>(ValueTy) && RelBegin == 0 && RelEnd == Size)
2065 WholeAllocaOp = true;
2066 if (IntegerType *ITy = dyn_cast<IntegerType>(ValueTy)) {
2067 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy).getFixedSize())
2068 return false;
2069 } else if (RelBegin != 0 || RelEnd != Size ||
2070 !canConvertValue(DL, ValueTy, AllocaTy)) {
2071 // Non-integer stores need to be convertible to the alloca type so that
2072 // they are promotable.
2073 return false;
2074 }
2075 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
2076 if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
2077 return false;
2078 if (!S.isSplittable())
2079 return false; // Skip any unsplittable intrinsics.
2080 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
2081 if (!II->isLifetimeStartOrEnd() && !II->isDroppable())
2082 return false;
2083 } else {
2084 return false;
2085 }
2086
2087 return true;
2088}
2089
2090/// Test whether the given alloca partition's integer operations can be
2091/// widened to promotable ones.
2092///
2093/// This is a quick test to check whether we can rewrite the integer loads and
2094/// stores to a particular alloca into wider loads and stores and be able to
2095/// promote the resulting alloca.
2096static bool isIntegerWideningViable(Partition &P, Type *AllocaTy,
2097 const DataLayout &DL) {
2098 uint64_t SizeInBits = DL.getTypeSizeInBits(AllocaTy).getFixedSize();
2099 // Don't create integer types larger than the maximum bitwidth.
2100 if (SizeInBits > IntegerType::MAX_INT_BITS)
2101 return false;
2102
2103 // Don't try to handle allocas with bit-padding.
2104 if (SizeInBits != DL.getTypeStoreSizeInBits(AllocaTy).getFixedSize())
2105 return false;
2106
2107 // We need to ensure that an integer type with the appropriate bitwidth can
2108 // be converted to the alloca type, whatever that is. We don't want to force
2109 // the alloca itself to have an integer type if there is a more suitable one.
2110 Type *IntTy = Type::getIntNTy(AllocaTy->getContext(), SizeInBits);
2111 if (!canConvertValue(DL, AllocaTy, IntTy) ||
2112 !canConvertValue(DL, IntTy, AllocaTy))
2113 return false;
2114
2115 // While examining uses, we ensure that the alloca has a covering load or
2116 // store. We don't want to widen the integer operations only to fail to
2117 // promote due to some other unsplittable entry (which we may make splittable
2118 // later). However, if there are only splittable uses, go ahead and assume
2119 // that we cover the alloca.
2120 // FIXME: We shouldn't consider split slices that happen to start in the
2121 // partition here...
2122 bool WholeAllocaOp = P.empty() && DL.isLegalInteger(SizeInBits);
2123
2124 for (const Slice &S : P)
2125 if (!isIntegerWideningViableForSlice(S, P.beginOffset(), AllocaTy, DL,
2126 WholeAllocaOp))
2127 return false;
2128
2129 for (const Slice *S : P.splitSliceTails())
2130 if (!isIntegerWideningViableForSlice(*S, P.beginOffset(), AllocaTy, DL,
2131 WholeAllocaOp))
2132 return false;
2133
2134 return WholeAllocaOp;
2135}
2136
2137static Value *extractInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
2138 IntegerType *Ty, uint64_t Offset,
2139 const Twine &Name) {
2140 LLVM_DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
60
Assuming 'DebugFlag' is false
61
Loop condition is false. Exiting loop
2141 IntegerType *IntTy = cast<IntegerType>(V->getType());
62
The object is a 'IntegerType'
2142 assert(DL.getTypeStoreSize(Ty).getFixedSize() + Offset <=((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element extends past full value"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2144, __PRETTY_FUNCTION__))
63
Assuming the condition is true
64
'?' condition is true
2143 DL.getTypeStoreSize(IntTy).getFixedSize() &&((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element extends past full value"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2144, __PRETTY_FUNCTION__))
2144 "Element extends past full value")((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element extends past full value"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2144, __PRETTY_FUNCTION__))
;
2145 uint64_t ShAmt = 8 * Offset;
2146 if (DL.isBigEndian())
65
Assuming the condition is false
66
Taking false branch
2147 ShAmt = 8 * (DL.getTypeStoreSize(IntTy).getFixedSize() -
2148 DL.getTypeStoreSize(Ty).getFixedSize() - Offset);
2149 if (ShAmt) {
67
Assuming 'ShAmt' is 0
68
Taking false branch
2150 V = IRB.CreateLShr(V, ShAmt, Name + ".shift");
2151 LLVM_DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2152 }
2153 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot extract to a larger integer!") ? static_cast<void
> (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2154, __PRETTY_FUNCTION__))
69
Called C++ object pointer is null
2154 "Cannot extract to a larger integer!")((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot extract to a larger integer!") ? static_cast<void
> (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2154, __PRETTY_FUNCTION__))
;
2155 if (Ty != IntTy) {
2156 V = IRB.CreateTrunc(V, Ty, Name + ".trunc");
2157 LLVM_DEBUG(dbgs() << " trunced: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " trunced: " << *V <<
"\n"; } } while (false)
;
2158 }
2159 return V;
2160}
2161
2162static Value *insertInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *Old,
2163 Value *V, uint64_t Offset, const Twine &Name) {
2164 IntegerType *IntTy = cast<IntegerType>(Old->getType());
2165 IntegerType *Ty = cast<IntegerType>(V->getType());
2166 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot insert a larger integer!") ? static_cast<void>
(0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2167, __PRETTY_FUNCTION__))
2167 "Cannot insert a larger integer!")((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot insert a larger integer!") ? static_cast<void>
(0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2167, __PRETTY_FUNCTION__))
;
2168 LLVM_DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2169 if (Ty != IntTy) {
2170 V = IRB.CreateZExt(V, IntTy, Name + ".ext");
2171 LLVM_DEBUG(dbgs() << " extended: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extended: " << *V <<
"\n"; } } while (false)
;
2172 }
2173 assert(DL.getTypeStoreSize(Ty).getFixedSize() + Offset <=((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element store outside of alloca store"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2175, __PRETTY_FUNCTION__))
2174 DL.getTypeStoreSize(IntTy).getFixedSize() &&((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element store outside of alloca store"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2175, __PRETTY_FUNCTION__))
2175 "Element store outside of alloca store")((DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize
(IntTy).getFixedSize() && "Element store outside of alloca store"
) ? static_cast<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2175, __PRETTY_FUNCTION__))
;
2176 uint64_t ShAmt = 8 * Offset;
2177 if (DL.isBigEndian())
2178 ShAmt = 8 * (DL.getTypeStoreSize(IntTy).getFixedSize() -
2179 DL.getTypeStoreSize(Ty).getFixedSize() - Offset);
2180 if (ShAmt) {
2181 V = IRB.CreateShl(V, ShAmt, Name + ".shift");
2182 LLVM_DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2183 }
2184
2185 if (ShAmt || Ty->getBitWidth() < IntTy->getBitWidth()) {
2186 APInt Mask = ~Ty->getMask().zext(IntTy->getBitWidth()).shl(ShAmt);
2187 Old = IRB.CreateAnd(Old, Mask, Name + ".mask");
2188 LLVM_DEBUG(dbgs() << " masked: " << *Old << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " masked: " << *Old <<
"\n"; } } while (false)
;
2189 V = IRB.CreateOr(Old, V, Name + ".insert");
2190 LLVM_DEBUG(dbgs() << " inserted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " inserted: " << *V <<
"\n"; } } while (false)
;
2191 }
2192 return V;
2193}
2194
2195static Value *extractVector(IRBuilderTy &IRB, Value *V, unsigned BeginIndex,
2196 unsigned EndIndex, const Twine &Name) {
2197 auto *VecTy = cast<FixedVectorType>(V->getType());
2198 unsigned NumElements = EndIndex - BeginIndex;
2199 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")((NumElements <= VecTy->getNumElements() && "Too many elements!"
) ? static_cast<void> (0) : __assert_fail ("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2199, __PRETTY_FUNCTION__))
;
2200
2201 if (NumElements == VecTy->getNumElements())
2202 return V;
2203
2204 if (NumElements == 1) {
2205 V = IRB.CreateExtractElement(V, IRB.getInt32(BeginIndex),
2206 Name + ".extract");
2207 LLVM_DEBUG(dbgs() << " extract: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extract: " << *V <<
"\n"; } } while (false)
;
2208 return V;
2209 }
2210
2211 SmallVector<int, 8> Mask;
2212 Mask.reserve(NumElements);
2213 for (unsigned i = BeginIndex; i != EndIndex; ++i)
2214 Mask.push_back(i);
2215 V = IRB.CreateShuffleVector(V, Mask, Name + ".extract");
2216 LLVM_DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2217 return V;
2218}
2219
2220static Value *insertVector(IRBuilderTy &IRB, Value *Old, Value *V,
2221 unsigned BeginIndex, const Twine &Name) {
2222 VectorType *VecTy = cast<VectorType>(Old->getType());
2223 assert(VecTy && "Can only insert a vector into a vector")((VecTy && "Can only insert a vector into a vector") ?
static_cast<void> (0) : __assert_fail ("VecTy && \"Can only insert a vector into a vector\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2223, __PRETTY_FUNCTION__))
;
2224
2225 VectorType *Ty = dyn_cast<VectorType>(V->getType());
2226 if (!Ty) {
2227 // Single element to insert.
2228 V = IRB.CreateInsertElement(Old, V, IRB.getInt32(BeginIndex),
2229 Name + ".insert");
2230 LLVM_DEBUG(dbgs() << " insert: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " insert: " << *V <<
"\n"; } } while (false)
;
2231 return V;
2232 }
2233
2234 assert(cast<FixedVectorType>(Ty)->getNumElements() <=((cast<FixedVectorType>(Ty)->getNumElements() <= cast
<FixedVectorType>(VecTy)->getNumElements() &&
"Too many elements!") ? static_cast<void> (0) : __assert_fail
("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2236, __PRETTY_FUNCTION__))
2235 cast<FixedVectorType>(VecTy)->getNumElements() &&((cast<FixedVectorType>(Ty)->getNumElements() <= cast
<FixedVectorType>(VecTy)->getNumElements() &&
"Too many elements!") ? static_cast<void> (0) : __assert_fail
("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2236, __PRETTY_FUNCTION__))
2236 "Too many elements!")((cast<FixedVectorType>(Ty)->getNumElements() <= cast
<FixedVectorType>(VecTy)->getNumElements() &&
"Too many elements!") ? static_cast<void> (0) : __assert_fail
("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2236, __PRETTY_FUNCTION__))
;
2237 if (cast<FixedVectorType>(Ty)->getNumElements() ==
2238 cast<FixedVectorType>(VecTy)->getNumElements()) {
2239 assert(V->getType() == VecTy && "Vector type mismatch")((V->getType() == VecTy && "Vector type mismatch")
? static_cast<void> (0) : __assert_fail ("V->getType() == VecTy && \"Vector type mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2239, __PRETTY_FUNCTION__))
;
2240 return V;
2241 }
2242 unsigned EndIndex = BeginIndex + cast<FixedVectorType>(Ty)->getNumElements();
2243
2244 // When inserting a smaller vector into the larger to store, we first
2245 // use a shuffle vector to widen it with undef elements, and then
2246 // a second shuffle vector to select between the loaded vector and the
2247 // incoming vector.
2248 SmallVector<int, 8> Mask;
2249 Mask.reserve(cast<FixedVectorType>(VecTy)->getNumElements());
2250 for (unsigned i = 0; i != cast<FixedVectorType>(VecTy)->getNumElements(); ++i)
2251 if (i >= BeginIndex && i < EndIndex)
2252 Mask.push_back(i - BeginIndex);
2253 else
2254 Mask.push_back(-1);
2255 V = IRB.CreateShuffleVector(V, Mask, Name + ".expand");
2256 LLVM_DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2257
2258 SmallVector<Constant *, 8> Mask2;
2259 Mask2.reserve(cast<FixedVectorType>(VecTy)->getNumElements());
2260 for (unsigned i = 0; i != cast<FixedVectorType>(VecTy)->getNumElements(); ++i)
2261 Mask2.push_back(IRB.getInt1(i >= BeginIndex && i < EndIndex));
2262
2263 V = IRB.CreateSelect(ConstantVector::get(Mask2), V, Old, Name + "blend");
2264
2265 LLVM_DEBUG(dbgs() << " blend: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " blend: " << *V <<
"\n"; } } while (false)
;
2266 return V;
2267}
2268
2269/// Visitor to rewrite instructions using p particular slice of an alloca
2270/// to use a new alloca.
2271///
2272/// Also implements the rewriting to vector-based accesses when the partition
2273/// passes the isVectorPromotionViable predicate. Most of the rewriting logic
2274/// lives here.
2275class llvm::sroa::AllocaSliceRewriter
2276 : public InstVisitor<AllocaSliceRewriter, bool> {
2277 // Befriend the base class so it can delegate to private visit methods.
2278 friend class InstVisitor<AllocaSliceRewriter, bool>;
2279
2280 using Base = InstVisitor<AllocaSliceRewriter, bool>;
2281
2282 const DataLayout &DL;
2283 AllocaSlices &AS;
2284 SROA &Pass;
2285 AllocaInst &OldAI, &NewAI;
2286 const uint64_t NewAllocaBeginOffset, NewAllocaEndOffset;
2287 Type *NewAllocaTy;
2288
2289 // This is a convenience and flag variable that will be null unless the new
2290 // alloca's integer operations should be widened to this integer type due to
2291 // passing isIntegerWideningViable above. If it is non-null, the desired
2292 // integer type will be stored here for easy access during rewriting.
2293 IntegerType *IntTy;
2294
2295 // If we are rewriting an alloca partition which can be written as pure
2296 // vector operations, we stash extra information here. When VecTy is
2297 // non-null, we have some strict guarantees about the rewritten alloca:
2298 // - The new alloca is exactly the size of the vector type here.
2299 // - The accesses all either map to the entire vector or to a single
2300 // element.
2301 // - The set of accessing instructions is only one of those handled above
2302 // in isVectorPromotionViable. Generally these are the same access kinds
2303 // which are promotable via mem2reg.
2304 VectorType *VecTy;
2305 Type *ElementTy;
2306 uint64_t ElementSize;
2307
2308 // The original offset of the slice currently being rewritten relative to
2309 // the original alloca.
2310 uint64_t BeginOffset = 0;
2311 uint64_t EndOffset = 0;
2312
2313 // The new offsets of the slice currently being rewritten relative to the
2314 // original alloca.
2315 uint64_t NewBeginOffset = 0, NewEndOffset = 0;
2316
2317 uint64_t SliceSize = 0;
2318 bool IsSplittable = false;
2319 bool IsSplit = false;
2320 Use *OldUse = nullptr;
2321 Instruction *OldPtr = nullptr;
2322
2323 // Track post-rewrite users which are PHI nodes and Selects.
2324 SmallSetVector<PHINode *, 8> &PHIUsers;
2325 SmallSetVector<SelectInst *, 8> &SelectUsers;
2326
2327 // Utility IR builder, whose name prefix is setup for each visited use, and
2328 // the insertion point is set to point to the user.
2329 IRBuilderTy IRB;
2330
2331public:
2332 AllocaSliceRewriter(const DataLayout &DL, AllocaSlices &AS, SROA &Pass,
2333 AllocaInst &OldAI, AllocaInst &NewAI,
2334 uint64_t NewAllocaBeginOffset,
2335 uint64_t NewAllocaEndOffset, bool IsIntegerPromotable,
2336 VectorType *PromotableVecTy,
2337 SmallSetVector<PHINode *, 8> &PHIUsers,
2338 SmallSetVector<SelectInst *, 8> &SelectUsers)
2339 : DL(DL), AS(AS), Pass(Pass), OldAI(OldAI), NewAI(NewAI),
2340 NewAllocaBeginOffset(NewAllocaBeginOffset),
2341 NewAllocaEndOffset(NewAllocaEndOffset),
2342 NewAllocaTy(NewAI.getAllocatedType()),
2343 IntTy(
2344 IsIntegerPromotable
2345 ? Type::getIntNTy(NewAI.getContext(),
2346 DL.getTypeSizeInBits(NewAI.getAllocatedType())
2347 .getFixedSize())
2348 : nullptr),
2349 VecTy(PromotableVecTy),
2350 ElementTy(VecTy ? VecTy->getElementType() : nullptr),
2351 ElementSize(VecTy ? DL.getTypeSizeInBits(ElementTy).getFixedSize() / 8
2352 : 0),
2353 PHIUsers(PHIUsers), SelectUsers(SelectUsers),
2354 IRB(NewAI.getContext(), ConstantFolder()) {
2355 if (VecTy) {
2356 assert((DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 &&(((DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 &&
"Only multiple-of-8 sized vector elements are viable") ? static_cast
<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2357, __PRETTY_FUNCTION__))
2357 "Only multiple-of-8 sized vector elements are viable")(((DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 &&
"Only multiple-of-8 sized vector elements are viable") ? static_cast
<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2357, __PRETTY_FUNCTION__))
;
2358 ++NumVectorized;
2359 }
2360 assert((!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy))(((!IntTy && !VecTy) || (IntTy && !VecTy) || (
!IntTy && VecTy)) ? static_cast<void> (0) : __assert_fail
("(!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2360, __PRETTY_FUNCTION__))
;
2361 }
2362
2363 bool visit(AllocaSlices::const_iterator I) {
2364 bool CanSROA = true;
2365 BeginOffset = I->beginOffset();
2366 EndOffset = I->endOffset();
2367 IsSplittable = I->isSplittable();
2368 IsSplit =
2369 BeginOffset < NewAllocaBeginOffset || EndOffset > NewAllocaEndOffset;
2370 LLVM_DEBUG(dbgs() << " rewriting " << (IsSplit ? "split " : ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " rewriting " << (IsSplit ?
"split " : ""); } } while (false)
;
2371 LLVM_DEBUG(AS.printSlice(dbgs(), I, ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.printSlice(dbgs(), I, ""); } } while (false)
;
2372 LLVM_DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n"; } } while (false)
;
2373
2374 // Compute the intersecting offset range.
2375 assert(BeginOffset < NewAllocaEndOffset)((BeginOffset < NewAllocaEndOffset) ? static_cast<void>
(0) : __assert_fail ("BeginOffset < NewAllocaEndOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2375, __PRETTY_FUNCTION__))
;
2376 assert(EndOffset > NewAllocaBeginOffset)((EndOffset > NewAllocaBeginOffset) ? static_cast<void>
(0) : __assert_fail ("EndOffset > NewAllocaBeginOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2376, __PRETTY_FUNCTION__))
;
2377 NewBeginOffset = std::max(BeginOffset, NewAllocaBeginOffset);
2378 NewEndOffset = std::min(EndOffset, NewAllocaEndOffset);
2379
2380 SliceSize = NewEndOffset - NewBeginOffset;
2381
2382 OldUse = I->getUse();
2383 OldPtr = cast<Instruction>(OldUse->get());
2384
2385 Instruction *OldUserI = cast<Instruction>(OldUse->getUser());
2386 IRB.SetInsertPoint(OldUserI);
2387 IRB.SetCurrentDebugLocation(OldUserI->getDebugLoc());
2388 IRB.getInserter().SetNamePrefix(
2389 Twine(NewAI.getName()) + "." + Twine(BeginOffset) + ".");
2390
2391 CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
2392 if (VecTy || IntTy)
2393 assert(CanSROA)((CanSROA) ? static_cast<void> (0) : __assert_fail ("CanSROA"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2393, __PRETTY_FUNCTION__))
;
2394 return CanSROA;
2395 }
2396
2397private:
2398 // Make sure the other visit overloads are visible.
2399 using Base::visit;
2400
2401 // Every instruction which can end up as a user must have a rewrite rule.
2402 bool visitInstruction(Instruction &I) {
2403 LLVM_DEBUG(dbgs() << " !!!! Cannot rewrite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " !!!! Cannot rewrite: " <<
I << "\n"; } } while (false)
;
2404 llvm_unreachable("No rewrite rule for this instruction!")::llvm::llvm_unreachable_internal("No rewrite rule for this instruction!"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2404)
;
2405 }
2406
2407 Value *getNewAllocaSlicePtr(IRBuilderTy &IRB, Type *PointerTy) {
2408 // Note that the offset computation can use BeginOffset or NewBeginOffset
2409 // interchangeably for unsplit slices.
2410 assert(IsSplit || BeginOffset == NewBeginOffset)((IsSplit || BeginOffset == NewBeginOffset) ? static_cast<
void> (0) : __assert_fail ("IsSplit || BeginOffset == NewBeginOffset"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2410, __PRETTY_FUNCTION__))
;
2411 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2412
2413#ifndef NDEBUG
2414 StringRef OldName = OldPtr->getName();
2415 // Skip through the last '.sroa.' component of the name.
2416 size_t LastSROAPrefix = OldName.rfind(".sroa.");
2417 if (LastSROAPrefix != StringRef::npos) {
2418 OldName = OldName.substr(LastSROAPrefix + strlen(".sroa."));
2419 // Look for an SROA slice index.
2420 size_t IndexEnd = OldName.find_first_not_of("0123456789");
2421 if (IndexEnd != StringRef::npos && OldName[IndexEnd] == '.') {
2422 // Strip the index and look for the offset.
2423 OldName = OldName.substr(IndexEnd + 1);
2424 size_t OffsetEnd = OldName.find_first_not_of("0123456789");
2425 if (OffsetEnd != StringRef::npos && OldName[OffsetEnd] == '.')
2426 // Strip the offset.
2427 OldName = OldName.substr(OffsetEnd + 1);
2428 }
2429 }
2430 // Strip any SROA suffixes as well.
2431 OldName = OldName.substr(0, OldName.find(".sroa_"));
2432#endif
2433
2434 return getAdjustedPtr(IRB, DL, &NewAI,
2435 APInt(DL.getIndexTypeSizeInBits(PointerTy), Offset),
2436 PointerTy,
2437#ifndef NDEBUG
2438 Twine(OldName) + "."
2439#else
2440 Twine()
2441#endif
2442 );
2443 }
2444
2445 /// Compute suitable alignment to access this slice of the *new*
2446 /// alloca.
2447 ///
2448 /// You can optionally pass a type to this routine and if that type's ABI
2449 /// alignment is itself suitable, this will return zero.
2450 Align getSliceAlign() {
2451 return commonAlignment(NewAI.getAlign(),
2452 NewBeginOffset - NewAllocaBeginOffset);
2453 }
2454
2455 unsigned getIndex(uint64_t Offset) {
2456 assert(VecTy && "Can only call getIndex when rewriting a vector")((VecTy && "Can only call getIndex when rewriting a vector"
) ? static_cast<void> (0) : __assert_fail ("VecTy && \"Can only call getIndex when rewriting a vector\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2456, __PRETTY_FUNCTION__))
;
2457 uint64_t RelOffset = Offset - NewAllocaBeginOffset;
2458 assert(RelOffset / ElementSize < UINT32_MAX && "Index out of bounds")((RelOffset / ElementSize < (4294967295U) && "Index out of bounds"
) ? static_cast<void> (0) : __assert_fail ("RelOffset / ElementSize < UINT32_MAX && \"Index out of bounds\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2458, __PRETTY_FUNCTION__))
;
2459 uint32_t Index = RelOffset / ElementSize;
2460 assert(Index * ElementSize == RelOffset)((Index * ElementSize == RelOffset) ? static_cast<void>
(0) : __assert_fail ("Index * ElementSize == RelOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2460, __PRETTY_FUNCTION__))
;
2461 return Index;
2462 }
2463
2464 void deleteIfTriviallyDead(Value *V) {
2465 Instruction *I = cast<Instruction>(V);
2466 if (isInstructionTriviallyDead(I))
2467 Pass.DeadInsts.push_back(I);
2468 }
2469
2470 Value *rewriteVectorizedLoadInst() {
2471 unsigned BeginIndex = getIndex(NewBeginOffset);
2472 unsigned EndIndex = getIndex(NewEndOffset);
2473 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2473, __PRETTY_FUNCTION__))
;
2474
2475 Value *V = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2476 NewAI.getAlign(), "load");
2477 return extractVector(IRB, V, BeginIndex, EndIndex, "vec");
2478 }
2479
2480 Value *rewriteIntegerLoad(LoadInst &LI) {
2481 assert(IntTy && "We cannot insert an integer to the alloca")((IntTy && "We cannot insert an integer to the alloca"
) ? static_cast<void> (0) : __assert_fail ("IntTy && \"We cannot insert an integer to the alloca\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2481, __PRETTY_FUNCTION__))
;
2482 assert(!LI.isVolatile())((!LI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2482, __PRETTY_FUNCTION__))
;
2483 Value *V = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2484 NewAI.getAlign(), "load");
2485 V = convertValue(DL, IRB, V, IntTy);
2486 assert(NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")((NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset"
) ? static_cast<void> (0) : __assert_fail ("NewBeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2486, __PRETTY_FUNCTION__))
;
2487 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2488 if (Offset > 0 || NewEndOffset < NewAllocaEndOffset) {
2489 IntegerType *ExtractTy = Type::getIntNTy(LI.getContext(), SliceSize * 8);
2490 V = extractInteger(DL, IRB, V, ExtractTy, Offset, "extract");
2491 }
2492 // It is possible that the extracted type is not the load type. This
2493 // happens if there is a load past the end of the alloca, and as
2494 // a consequence the slice is narrower but still a candidate for integer
2495 // lowering. To handle this case, we just zero extend the extracted
2496 // integer.
2497 assert(cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 &&((cast<IntegerType>(LI.getType())->getBitWidth() >=
SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2498, __PRETTY_FUNCTION__))
2498 "Can only handle an extract for an overly wide load")((cast<IntegerType>(LI.getType())->getBitWidth() >=
SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2498, __PRETTY_FUNCTION__))
;
2499 if (cast<IntegerType>(LI.getType())->getBitWidth() > SliceSize * 8)
2500 V = IRB.CreateZExt(V, LI.getType());
2501 return V;
2502 }
2503
2504 bool visitLoadInst(LoadInst &LI) {
2505 LLVM_DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
2506 Value *OldOp = LI.getOperand(0);
2507 assert(OldOp == OldPtr)((OldOp == OldPtr) ? static_cast<void> (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2507, __PRETTY_FUNCTION__))
;
2508
2509 AAMDNodes AATags;
2510 LI.getAAMetadata(AATags);
2511
2512 unsigned AS = LI.getPointerAddressSpace();
2513
2514 Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), SliceSize * 8)
2515 : LI.getType();
2516 const bool IsLoadPastEnd =
2517 DL.getTypeStoreSize(TargetTy).getFixedSize() > SliceSize;
2518 bool IsPtrAdjusted = false;
2519 Value *V;
2520 if (VecTy) {
2521 V = rewriteVectorizedLoadInst();
2522 } else if (IntTy && LI.getType()->isIntegerTy()) {
2523 V = rewriteIntegerLoad(LI);
2524 } else if (NewBeginOffset == NewAllocaBeginOffset &&
2525 NewEndOffset == NewAllocaEndOffset &&
2526 (canConvertValue(DL, NewAllocaTy, TargetTy) ||
2527 (IsLoadPastEnd && NewAllocaTy->isIntegerTy() &&
2528 TargetTy->isIntegerTy()))) {
2529 LoadInst *NewLI = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2530 NewAI.getAlign(), LI.isVolatile(),
2531 LI.getName());
2532 if (AATags)
2533 NewLI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2534 if (LI.isVolatile())
2535 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2536 if (NewLI->isAtomic())
2537 NewLI->setAlignment(LI.getAlign());
2538
2539 // Any !nonnull metadata or !range metadata on the old load is also valid
2540 // on the new load. This is even true in some cases even when the loads
2541 // are different types, for example by mapping !nonnull metadata to
2542 // !range metadata by modeling the null pointer constant converted to the
2543 // integer type.
2544 // FIXME: Add support for range metadata here. Currently the utilities
2545 // for this don't propagate range metadata in trivial cases from one
2546 // integer load to another, don't handle non-addrspace-0 null pointers
2547 // correctly, and don't have any support for mapping ranges as the
2548 // integer type becomes winder or narrower.
2549 if (MDNode *N = LI.getMetadata(LLVMContext::MD_nonnull))
2550 copyNonnullMetadata(LI, N, *NewLI);
2551
2552 // Try to preserve nonnull metadata
2553 V = NewLI;
2554
2555 // If this is an integer load past the end of the slice (which means the
2556 // bytes outside the slice are undef or this load is dead) just forcibly
2557 // fix the integer size with correct handling of endianness.
2558 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2559 if (auto *TITy = dyn_cast<IntegerType>(TargetTy))
2560 if (AITy->getBitWidth() < TITy->getBitWidth()) {
2561 V = IRB.CreateZExt(V, TITy, "load.ext");
2562 if (DL.isBigEndian())
2563 V = IRB.CreateShl(V, TITy->getBitWidth() - AITy->getBitWidth(),
2564 "endian_shift");
2565 }
2566 } else {
2567 Type *LTy = TargetTy->getPointerTo(AS);
2568 LoadInst *NewLI =
2569 IRB.CreateAlignedLoad(TargetTy, getNewAllocaSlicePtr(IRB, LTy),
2570 getSliceAlign(), LI.isVolatile(), LI.getName());
2571 if (AATags)
2572 NewLI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2573 if (LI.isVolatile())
2574 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2575
2576 V = NewLI;
2577 IsPtrAdjusted = true;
2578 }
2579 V = convertValue(DL, IRB, V, TargetTy);
2580
2581 if (IsSplit) {
2582 assert(!LI.isVolatile())((!LI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2582, __PRETTY_FUNCTION__))
;
2583 assert(LI.getType()->isIntegerTy() &&((LI.getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2584, __PRETTY_FUNCTION__))
2584 "Only integer type loads and stores are split")((LI.getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2584, __PRETTY_FUNCTION__))
;
2585 assert(SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() &&((SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize
() && "Split load isn't smaller than original load") ?
static_cast<void> (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2586, __PRETTY_FUNCTION__))
2586 "Split load isn't smaller than original load")((SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize
() && "Split load isn't smaller than original load") ?
static_cast<void> (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2586, __PRETTY_FUNCTION__))
;
2587 assert(DL.typeSizeEqualsStoreSize(LI.getType()) &&((DL.typeSizeEqualsStoreSize(LI.getType()) && "Non-byte-multiple bit width"
) ? static_cast<void> (0) : __assert_fail ("DL.typeSizeEqualsStoreSize(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2588, __PRETTY_FUNCTION__))
2588 "Non-byte-multiple bit width")((DL.typeSizeEqualsStoreSize(LI.getType()) && "Non-byte-multiple bit width"
) ? static_cast<void> (0) : __assert_fail ("DL.typeSizeEqualsStoreSize(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2588, __PRETTY_FUNCTION__))
;
2589 // Move the insertion point just past the load so that we can refer to it.
2590 IRB.SetInsertPoint(&*std::next(BasicBlock::iterator(&LI)));
2591 // Create a placeholder value with the same type as LI to use as the
2592 // basis for the new value. This allows us to replace the uses of LI with
2593 // the computed value, and then replace the placeholder with LI, leaving
2594 // LI only used for this computation.
2595 Value *Placeholder = new LoadInst(
2596 LI.getType(), UndefValue::get(LI.getType()->getPointerTo(AS)), "",
2597 false, Align(1));
2598 V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
2599 "insert");
2600 LI.replaceAllUsesWith(V);
2601 Placeholder->replaceAllUsesWith(&LI);
2602 Placeholder->deleteValue();
2603 } else {
2604 LI.replaceAllUsesWith(V);
2605 }
2606
2607 Pass.DeadInsts.push_back(&LI);
2608 deleteIfTriviallyDead(OldOp);
2609 LLVM_DEBUG(dbgs() << " to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *V <<
"\n"; } } while (false)
;
2610 return !LI.isVolatile() && !IsPtrAdjusted;
2611 }
2612
2613 bool rewriteVectorizedStoreInst(Value *V, StoreInst &SI, Value *OldOp,
2614 AAMDNodes AATags) {
2615 if (V->getType() != VecTy) {
2616 unsigned BeginIndex = getIndex(NewBeginOffset);
2617 unsigned EndIndex = getIndex(NewEndOffset);
2618 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2618, __PRETTY_FUNCTION__))
;
2619 unsigned NumElements = EndIndex - BeginIndex;
2620 assert(NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() &&((NumElements <= cast<FixedVectorType>(VecTy)->getNumElements
() && "Too many elements!") ? static_cast<void>
(0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2621, __PRETTY_FUNCTION__))
2621 "Too many elements!")((NumElements <= cast<FixedVectorType>(VecTy)->getNumElements
() && "Too many elements!") ? static_cast<void>
(0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2621, __PRETTY_FUNCTION__))
;
2622 Type *SliceTy = (NumElements == 1)
2623 ? ElementTy
2624 : FixedVectorType::get(ElementTy, NumElements);
2625 if (V->getType() != SliceTy)
2626 V = convertValue(DL, IRB, V, SliceTy);
2627
2628 // Mix in the existing elements.
2629 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2630 NewAI.getAlign(), "load");
2631 V = insertVector(IRB, Old, V, BeginIndex, "vec");
2632 }
2633 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign());
2634 if (AATags)
2635 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2636 Pass.DeadInsts.push_back(&SI);
2637
2638 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2639 return true;
2640 }
2641
2642 bool rewriteIntegerStore(Value *V, StoreInst &SI, AAMDNodes AATags) {
2643 assert(IntTy && "We cannot extract an integer from the alloca")((IntTy && "We cannot extract an integer from the alloca"
) ? static_cast<void> (0) : __assert_fail ("IntTy && \"We cannot extract an integer from the alloca\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2643, __PRETTY_FUNCTION__))
;
2644 assert(!SI.isVolatile())((!SI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2644, __PRETTY_FUNCTION__))
;
2645 if (DL.getTypeSizeInBits(V->getType()).getFixedSize() !=
2646 IntTy->getBitWidth()) {
2647 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2648 NewAI.getAlign(), "oldload");
2649 Old = convertValue(DL, IRB, Old, IntTy);
2650 assert(BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")((BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2650, __PRETTY_FUNCTION__))
;
2651 uint64_t Offset = BeginOffset - NewAllocaBeginOffset;
2652 V = insertInteger(DL, IRB, Old, SI.getValueOperand(), Offset, "insert");
2653 }
2654 V = convertValue(DL, IRB, V, NewAllocaTy);
2655 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign());
2656 Store->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
2657 LLVMContext::MD_access_group});
2658 if (AATags)
2659 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2660 Pass.DeadInsts.push_back(&SI);
2661 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2662 return true;
2663 }
2664
2665 bool visitStoreInst(StoreInst &SI) {
2666 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
2667 Value *OldOp = SI.getOperand(1);
2668 assert(OldOp == OldPtr)((OldOp == OldPtr) ? static_cast<void> (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2668, __PRETTY_FUNCTION__))
;
2669
2670 AAMDNodes AATags;
2671 SI.getAAMetadata(AATags);
2672
2673 Value *V = SI.getValueOperand();
2674
2675 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2676 // alloca that should be re-examined after promoting this alloca.
2677 if (V->getType()->isPointerTy())
2678 if (AllocaInst *AI = dyn_cast<AllocaInst>(V->stripInBoundsOffsets()))
2679 Pass.PostPromotionWorklist.insert(AI);
2680
2681 if (SliceSize < DL.getTypeStoreSize(V->getType()).getFixedSize()) {
2682 assert(!SI.isVolatile())((!SI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2682, __PRETTY_FUNCTION__))
;
2683 assert(V->getType()->isIntegerTy() &&((V->getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2684, __PRETTY_FUNCTION__))
2684 "Only integer type loads and stores are split")((V->getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2684, __PRETTY_FUNCTION__))
;
2685 assert(DL.typeSizeEqualsStoreSize(V->getType()) &&((DL.typeSizeEqualsStoreSize(V->getType()) && "Non-byte-multiple bit width"
) ? static_cast<void> (0) : __assert_fail ("DL.typeSizeEqualsStoreSize(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2686, __PRETTY_FUNCTION__))
2686 "Non-byte-multiple bit width")((DL.typeSizeEqualsStoreSize(V->getType()) && "Non-byte-multiple bit width"
) ? static_cast<void> (0) : __assert_fail ("DL.typeSizeEqualsStoreSize(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2686, __PRETTY_FUNCTION__))
;
2687 IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), SliceSize * 8);
2688 V = extractInteger(DL, IRB, V, NarrowTy, NewBeginOffset - BeginOffset,
2689 "extract");
2690 }
2691
2692 if (VecTy)
2693 return rewriteVectorizedStoreInst(V, SI, OldOp, AATags);
2694 if (IntTy && V->getType()->isIntegerTy())
2695 return rewriteIntegerStore(V, SI, AATags);
2696
2697 const bool IsStorePastEnd =
2698 DL.getTypeStoreSize(V->getType()).getFixedSize() > SliceSize;
2699 StoreInst *NewSI;
2700 if (NewBeginOffset == NewAllocaBeginOffset &&
2701 NewEndOffset == NewAllocaEndOffset &&
2702 (canConvertValue(DL, V->getType(), NewAllocaTy) ||
2703 (IsStorePastEnd && NewAllocaTy->isIntegerTy() &&
2704 V->getType()->isIntegerTy()))) {
2705 // If this is an integer store past the end of slice (and thus the bytes
2706 // past that point are irrelevant or this is unreachable), truncate the
2707 // value prior to storing.
2708 if (auto *VITy = dyn_cast<IntegerType>(V->getType()))
2709 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2710 if (VITy->getBitWidth() > AITy->getBitWidth()) {
2711 if (DL.isBigEndian())
2712 V = IRB.CreateLShr(V, VITy->getBitWidth() - AITy->getBitWidth(),
2713 "endian_shift");
2714 V = IRB.CreateTrunc(V, AITy, "load.trunc");
2715 }
2716
2717 V = convertValue(DL, IRB, V, NewAllocaTy);
2718 NewSI =
2719 IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign(), SI.isVolatile());
2720 } else {
2721 unsigned AS = SI.getPointerAddressSpace();
2722 Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
2723 NewSI =
2724 IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(), SI.isVolatile());
2725 }
2726 NewSI->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
2727 LLVMContext::MD_access_group});
2728 if (AATags)
2729 NewSI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2730 if (SI.isVolatile())
2731 NewSI->setAtomic(SI.getOrdering(), SI.getSyncScopeID());
2732 if (NewSI->isAtomic())
2733 NewSI->setAlignment(SI.getAlign());
2734 Pass.DeadInsts.push_back(&SI);
2735 deleteIfTriviallyDead(OldOp);
2736
2737 LLVM_DEBUG(dbgs() << " to: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *NewSI <<
"\n"; } } while (false)
;
2738 return NewSI->getPointerOperand() == &NewAI && !SI.isVolatile();
2739 }
2740
2741 /// Compute an integer value from splatting an i8 across the given
2742 /// number of bytes.
2743 ///
2744 /// Note that this routine assumes an i8 is a byte. If that isn't true, don't
2745 /// call this routine.
2746 /// FIXME: Heed the advice above.
2747 ///
2748 /// \param V The i8 value to splat.
2749 /// \param Size The number of bytes in the output (assuming i8 is one byte)
2750 Value *getIntegerSplat(Value *V, unsigned Size) {
2751 assert(Size > 0 && "Expected a positive number of bytes.")((Size > 0 && "Expected a positive number of bytes."
) ? static_cast<void> (0) : __assert_fail ("Size > 0 && \"Expected a positive number of bytes.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2751, __PRETTY_FUNCTION__))
;
2752 IntegerType *VTy = cast<IntegerType>(V->getType());
2753 assert(VTy->getBitWidth() == 8 && "Expected an i8 value for the byte")((VTy->getBitWidth() == 8 && "Expected an i8 value for the byte"
) ? static_cast<void> (0) : __assert_fail ("VTy->getBitWidth() == 8 && \"Expected an i8 value for the byte\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2753, __PRETTY_FUNCTION__))
;
2754 if (Size == 1)
2755 return V;
2756
2757 Type *SplatIntTy = Type::getIntNTy(VTy->getContext(), Size * 8);
2758 V = IRB.CreateMul(
2759 IRB.CreateZExt(V, SplatIntTy, "zext"),
2760 ConstantExpr::getUDiv(
2761 Constant::getAllOnesValue(SplatIntTy),
2762 ConstantExpr::getZExt(Constant::getAllOnesValue(V->getType()),
2763 SplatIntTy)),
2764 "isplat");
2765 return V;
2766 }
2767
2768 /// Compute a vector splat for a given element value.
2769 Value *getVectorSplat(Value *V, unsigned NumElements) {
2770 V = IRB.CreateVectorSplat(NumElements, V, "vsplat");
2771 LLVM_DEBUG(dbgs() << " splat: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " splat: " << *V <<
"\n"; } } while (false)
;
2772 return V;
2773 }
2774
2775 bool visitMemSetInst(MemSetInst &II) {
2776 LLVM_DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2777 assert(II.getRawDest() == OldPtr)((II.getRawDest() == OldPtr) ? static_cast<void> (0) : __assert_fail
("II.getRawDest() == OldPtr", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2777, __PRETTY_FUNCTION__))
;
2778
2779 AAMDNodes AATags;
2780 II.getAAMetadata(AATags);
2781
2782 // If the memset has a variable size, it cannot be split, just adjust the
2783 // pointer to the new alloca.
2784 if (!isa<Constant>(II.getLength())) {
2785 assert(!IsSplit)((!IsSplit) ? static_cast<void> (0) : __assert_fail ("!IsSplit"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2785, __PRETTY_FUNCTION__))
;
2786 assert(NewBeginOffset == BeginOffset)((NewBeginOffset == BeginOffset) ? static_cast<void> (0
) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2786, __PRETTY_FUNCTION__))
;
2787 II.setDest(getNewAllocaSlicePtr(IRB, OldPtr->getType()));
2788 II.setDestAlignment(getSliceAlign());
2789
2790 deleteIfTriviallyDead(OldPtr);
2791 return false;
2792 }
2793
2794 // Record this instruction for deletion.
2795 Pass.DeadInsts.push_back(&II);
2796
2797 Type *AllocaTy = NewAI.getAllocatedType();
2798 Type *ScalarTy = AllocaTy->getScalarType();
2799
2800 const bool CanContinue = [&]() {
2801 if (VecTy || IntTy)
2802 return true;
2803 if (BeginOffset > NewAllocaBeginOffset ||
2804 EndOffset < NewAllocaEndOffset)
2805 return false;
2806 auto *C = cast<ConstantInt>(II.getLength());
2807 if (C->getBitWidth() > 64)
2808 return false;
2809 const auto Len = C->getZExtValue();
2810 auto *Int8Ty = IntegerType::getInt8Ty(NewAI.getContext());
2811 auto *SrcTy = FixedVectorType::get(Int8Ty, Len);
2812 return canConvertValue(DL, SrcTy, AllocaTy) &&
2813 DL.isLegalInteger(DL.getTypeSizeInBits(ScalarTy).getFixedSize());
2814 }();
2815
2816 // If this doesn't map cleanly onto the alloca type, and that type isn't
2817 // a single value type, just emit a memset.
2818 if (!CanContinue) {
2819 Type *SizeTy = II.getLength()->getType();
2820 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2821 CallInst *New = IRB.CreateMemSet(
2822 getNewAllocaSlicePtr(IRB, OldPtr->getType()), II.getValue(), Size,
2823 MaybeAlign(getSliceAlign()), II.isVolatile());
2824 if (AATags)
2825 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2826 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2827 return false;
2828 }
2829
2830 // If we can represent this as a simple value, we have to build the actual
2831 // value to store, which requires expanding the byte present in memset to
2832 // a sensible representation for the alloca type. This is essentially
2833 // splatting the byte to a sufficiently wide integer, splatting it across
2834 // any desired vector width, and bitcasting to the final type.
2835 Value *V;
2836
2837 if (VecTy) {
2838 // If this is a memset of a vectorized alloca, insert it.
2839 assert(ElementTy == ScalarTy)((ElementTy == ScalarTy) ? static_cast<void> (0) : __assert_fail
("ElementTy == ScalarTy", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2839, __PRETTY_FUNCTION__))
;
2840
2841 unsigned BeginIndex = getIndex(NewBeginOffset);
2842 unsigned EndIndex = getIndex(NewEndOffset);
2843 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2843, __PRETTY_FUNCTION__))
;
2844 unsigned NumElements = EndIndex - BeginIndex;
2845 assert(NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() &&((NumElements <= cast<FixedVectorType>(VecTy)->getNumElements
() && "Too many elements!") ? static_cast<void>
(0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2846, __PRETTY_FUNCTION__))
2846 "Too many elements!")((NumElements <= cast<FixedVectorType>(VecTy)->getNumElements
() && "Too many elements!") ? static_cast<void>
(0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2846, __PRETTY_FUNCTION__))
;
2847
2848 Value *Splat = getIntegerSplat(
2849 II.getValue(), DL.getTypeSizeInBits(ElementTy).getFixedSize() / 8);
2850 Splat = convertValue(DL, IRB, Splat, ElementTy);
2851 if (NumElements > 1)
2852 Splat = getVectorSplat(Splat, NumElements);
2853
2854 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2855 NewAI.getAlign(), "oldload");
2856 V = insertVector(IRB, Old, Splat, BeginIndex, "vec");
2857 } else if (IntTy) {
2858 // If this is a memset on an alloca where we can widen stores, insert the
2859 // set integer.
2860 assert(!II.isVolatile())((!II.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!II.isVolatile()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2860, __PRETTY_FUNCTION__))
;
2861
2862 uint64_t Size = NewEndOffset - NewBeginOffset;
2863 V = getIntegerSplat(II.getValue(), Size);
2864
2865 if (IntTy && (BeginOffset != NewAllocaBeginOffset ||
2866 EndOffset != NewAllocaBeginOffset)) {
2867 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2868 NewAI.getAlign(), "oldload");
2869 Old = convertValue(DL, IRB, Old, IntTy);
2870 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2871 V = insertInteger(DL, IRB, Old, V, Offset, "insert");
2872 } else {
2873 assert(V->getType() == IntTy &&((V->getType() == IntTy && "Wrong type for an alloca wide integer!"
) ? static_cast<void> (0) : __assert_fail ("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2874, __PRETTY_FUNCTION__))
2874 "Wrong type for an alloca wide integer!")((V->getType() == IntTy && "Wrong type for an alloca wide integer!"
) ? static_cast<void> (0) : __assert_fail ("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2874, __PRETTY_FUNCTION__))
;
2875 }
2876 V = convertValue(DL, IRB, V, AllocaTy);
2877 } else {
2878 // Established these invariants above.
2879 assert(NewBeginOffset == NewAllocaBeginOffset)((NewBeginOffset == NewAllocaBeginOffset) ? static_cast<void
> (0) : __assert_fail ("NewBeginOffset == NewAllocaBeginOffset"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2879, __PRETTY_FUNCTION__))
;
2880 assert(NewEndOffset == NewAllocaEndOffset)((NewEndOffset == NewAllocaEndOffset) ? static_cast<void>
(0) : __assert_fail ("NewEndOffset == NewAllocaEndOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2880, __PRETTY_FUNCTION__))
;
2881
2882 V = getIntegerSplat(II.getValue(),
2883 DL.getTypeSizeInBits(ScalarTy).getFixedSize() / 8);
2884 if (VectorType *AllocaVecTy = dyn_cast<VectorType>(AllocaTy))
2885 V = getVectorSplat(
2886 V, cast<FixedVectorType>(AllocaVecTy)->getNumElements());
2887
2888 V = convertValue(DL, IRB, V, AllocaTy);
2889 }
2890
2891 StoreInst *New =
2892 IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign(), II.isVolatile());
2893 if (AATags)
2894 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2895 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2896 return !II.isVolatile();
2897 }
2898
2899 bool visitMemTransferInst(MemTransferInst &II) {
2900 // Rewriting of memory transfer instructions can be a bit tricky. We break
2901 // them into two categories: split intrinsics and unsplit intrinsics.
2902
2903 LLVM_DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
1
Assuming 'DebugFlag' is false
2
Loop condition is false. Exiting loop
2904
2905 AAMDNodes AATags;
2906 II.getAAMetadata(AATags);
2907
2908 bool IsDest = &II.getRawDestUse() == OldUse;
2909 assert((IsDest && II.getRawDest() == OldPtr) ||(((IsDest && II.getRawDest() == OldPtr) || (!IsDest &&
II.getRawSource() == OldPtr)) ? static_cast<void> (0) :
__assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2910, __PRETTY_FUNCTION__))
3
Assuming 'IsDest' is false
4
Assuming the condition is true
5
'?' condition is true
2910 (!IsDest && II.getRawSource() == OldPtr))(((IsDest && II.getRawDest() == OldPtr) || (!IsDest &&
II.getRawSource() == OldPtr)) ? static_cast<void> (0) :
__assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2910, __PRETTY_FUNCTION__))
;
2911
2912 MaybeAlign SliceAlign = getSliceAlign();
2913
2914 // For unsplit intrinsics, we simply modify the source and destination
2915 // pointers in place. This isn't just an optimization, it is a matter of
2916 // correctness. With unsplit intrinsics we may be dealing with transfers
2917 // within a single alloca before SROA ran, or with transfers that have
2918 // a variable length. We may also be dealing with memmove instead of
2919 // memcpy, and so simply updating the pointers is the necessary for us to
2920 // update both source and dest of a single call.
2921 if (!IsSplittable) {
6
Assuming field 'IsSplittable' is true
7
Taking false branch
2922 Value *AdjustedPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2923 if (IsDest) {
2924 II.setDest(AdjustedPtr);
2925 II.setDestAlignment(SliceAlign);
2926 }
2927 else {
2928 II.setSource(AdjustedPtr);
2929 II.setSourceAlignment(SliceAlign);
2930 }
2931
2932 LLVM_DEBUG(dbgs() << " to: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << II <<
"\n"; } } while (false)
;
2933 deleteIfTriviallyDead(OldPtr);
2934 return false;
2935 }
2936 // For split transfer intrinsics we have an incredibly useful assurance:
2937 // the source and destination do not reside within the same alloca, and at
2938 // least one of them does not escape. This means that we can replace
2939 // memmove with memcpy, and we don't need to worry about all manner of
2940 // downsides to splitting and transforming the operations.
2941
2942 // If this doesn't map cleanly onto the alloca type, and that type isn't
2943 // a single value type, just emit a memcpy.
2944 bool EmitMemCpy =
2945 !VecTy && !IntTy &&
8
Assuming field 'VecTy' is non-null
2946 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2947 SliceSize !=
2948 DL.getTypeStoreSize(NewAI.getAllocatedType()).getFixedSize() ||
2949 !NewAI.getAllocatedType()->isSingleValueType());
2950
2951 // If we're just going to emit a memcpy, the alloca hasn't changed, and the
2952 // size hasn't been shrunk based on analysis of the viable range, this is
2953 // a no-op.
2954 if (EmitMemCpy
8.1
'EmitMemCpy' is false
&& &OldAI == &NewAI) {
2955 // Ensure the start lines up.
2956 assert(NewBeginOffset == BeginOffset)((NewBeginOffset == BeginOffset) ? static_cast<void> (0
) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2956, __PRETTY_FUNCTION__))
;
2957
2958 // Rewrite the size as needed.
2959 if (NewEndOffset != EndOffset)
2960 II.setLength(ConstantInt::get(II.getLength()->getType(),
2961 NewEndOffset - NewBeginOffset));
2962 return false;
2963 }
2964 // Record this instruction for deletion.
2965 Pass.DeadInsts.push_back(&II);
2966
2967 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2968 // alloca that should be re-examined after rewriting this instruction.
2969 Value *OtherPtr = IsDest
8.2
'IsDest' is false
? II.getRawSource() : II.getRawDest();
9
'?' condition is false
2970 if (AllocaInst *AI
10.1
'AI' is null
=
11
Taking false branch
2971 dyn_cast<AllocaInst>(OtherPtr->stripInBoundsOffsets())) {
10
Assuming the object is not a 'AllocaInst'
2972 assert(AI != &OldAI && AI != &NewAI &&((AI != &OldAI && AI != &NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? static_cast<void> (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2973, __PRETTY_FUNCTION__))
2973 "Splittable transfers cannot reach the same alloca on both ends.")((AI != &OldAI && AI != &NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? static_cast<void> (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2973, __PRETTY_FUNCTION__))
;
2974 Pass.Worklist.insert(AI);
2975 }
2976
2977 Type *OtherPtrTy = OtherPtr->getType();
2978 unsigned OtherAS = OtherPtrTy->getPointerAddressSpace();
2979
2980 // Compute the relative offset for the other pointer within the transfer.
2981 unsigned OffsetWidth = DL.getIndexSizeInBits(OtherAS);
2982 APInt OtherOffset(OffsetWidth, NewBeginOffset - BeginOffset);
2983 Align OtherAlign =
2984 (IsDest
11.1
'IsDest' is false
? II.getSourceAlign() : II.getDestAlign()).valueOrOne();
12
'?' condition is false
2985 OtherAlign =
2986 commonAlignment(OtherAlign, OtherOffset.zextOrTrunc(64).getZExtValue());
2987
2988 if (EmitMemCpy
12.1
'EmitMemCpy' is false
) {
13
Taking false branch
2989 // Compute the other pointer, folding as much as possible to produce
2990 // a single, simple GEP in most cases.
2991 OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
2992 OtherPtr->getName() + ".");
2993
2994 Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2995 Type *SizeTy = II.getLength()->getType();
2996 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2997
2998 Value *DestPtr, *SrcPtr;
2999 MaybeAlign DestAlign, SrcAlign;
3000 // Note: IsDest is true iff we're copying into the new alloca slice
3001 if (IsDest) {
3002 DestPtr = OurPtr;
3003 DestAlign = SliceAlign;
3004 SrcPtr = OtherPtr;
3005 SrcAlign = OtherAlign;
3006 } else {
3007 DestPtr = OtherPtr;
3008 DestAlign = OtherAlign;
3009 SrcPtr = OurPtr;
3010 SrcAlign = SliceAlign;
3011 }
3012 CallInst *New = IRB.CreateMemCpy(DestPtr, DestAlign, SrcPtr, SrcAlign,
3013 Size, II.isVolatile());
3014 if (AATags)
3015 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3016 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
3017 return false;
3018 }
3019
3020 bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
14
Assuming field 'NewBeginOffset' is not equal to field 'NewAllocaBeginOffset'
3021 NewEndOffset == NewAllocaEndOffset;
3022 uint64_t Size = NewEndOffset - NewBeginOffset;
3023 unsigned BeginIndex = VecTy
14.1
Field 'VecTy' is non-null
? getIndex(NewBeginOffset) : 0;
15
'?' condition is true
3024 unsigned EndIndex = VecTy
15.1
Field 'VecTy' is non-null
? getIndex(NewEndOffset) : 0;
16
'?' condition is true
3025 unsigned NumElements = EndIndex - BeginIndex;
3026 IntegerType *SubIntTy =
19
'SubIntTy' initialized to a null pointer value
3027 IntTy ? Type::getIntNTy(IntTy->getContext(), Size * 8) : nullptr;
17
Assuming field 'IntTy' is null
18
'?' condition is false
3028
3029 // Reset the other pointer type to match the register type we're going to
3030 // use, but using the address space of the original other pointer.
3031 Type *OtherTy;
3032 if (VecTy
19.1
Field 'VecTy' is non-null
&& !IsWholeAlloca
19.2
'IsWholeAlloca' is false
) {
20
Taking true branch
3033 if (NumElements == 1)
21
Assuming 'NumElements' is not equal to 1
22
Taking false branch
3034 OtherTy = VecTy->getElementType();
3035 else
3036 OtherTy = FixedVectorType::get(VecTy->getElementType(), NumElements);
3037 } else if (IntTy && !IsWholeAlloca) {
3038 OtherTy = SubIntTy;
3039 } else {
3040 OtherTy = NewAllocaTy;
3041 }
3042 OtherPtrTy = OtherTy->getPointerTo(OtherAS);
3043
3044 Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
23
Calling 'getAdjustedPtr'
53
Returning from 'getAdjustedPtr'
3045 OtherPtr->getName() + ".");
3046 MaybeAlign SrcAlign = OtherAlign;
3047 Value *DstPtr = &NewAI;
3048 MaybeAlign DstAlign = SliceAlign;
3049 if (!IsDest
53.1
'IsDest' is false
) {
54
Taking true branch
3050 std::swap(SrcPtr, DstPtr);
3051 std::swap(SrcAlign, DstAlign);
3052 }
3053
3054 Value *Src;
3055 if (VecTy && !IsWholeAlloca && !IsDest) {
55
Assuming field 'VecTy' is null
3056 Src = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3057 NewAI.getAlign(), "load");
3058 Src = extractVector(IRB, Src, BeginIndex, EndIndex, "vec");
3059 } else if (IntTy && !IsWholeAlloca
56.1
'IsWholeAlloca' is false
&& !IsDest
56.2
'IsDest' is false
) {
56
Assuming field 'IntTy' is non-null
57
Taking true branch
3060 Src = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3061 NewAI.getAlign(), "load");
3062 Src = convertValue(DL, IRB, Src, IntTy);
3063 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
3064 Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract");
58
Passing null pointer value via 4th parameter 'Ty'
59
Calling 'extractInteger'
3065 } else {
3066 LoadInst *Load = IRB.CreateAlignedLoad(OtherTy, SrcPtr, SrcAlign,
3067 II.isVolatile(), "copyload");
3068 if (AATags)
3069 Load->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3070 Src = Load;
3071 }
3072
3073 if (VecTy && !IsWholeAlloca && IsDest) {
3074 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3075 NewAI.getAlign(), "oldload");
3076 Src = insertVector(IRB, Old, Src, BeginIndex, "vec");
3077 } else if (IntTy && !IsWholeAlloca && IsDest) {
3078 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3079 NewAI.getAlign(), "oldload");
3080 Old = convertValue(DL, IRB, Old, IntTy);
3081 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
3082 Src = insertInteger(DL, IRB, Old, Src, Offset, "insert");
3083 Src = convertValue(DL, IRB, Src, NewAllocaTy);
3084 }
3085
3086 StoreInst *Store = cast<StoreInst>(
3087 IRB.CreateAlignedStore(Src, DstPtr, DstAlign, II.isVolatile()));
3088 if (AATags)
3089 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3090 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3091 return !II.isVolatile();
3092 }
3093
3094 bool visitIntrinsicInst(IntrinsicInst &II) {
3095 assert((II.isLifetimeStartOrEnd() || II.isDroppable()) &&(((II.isLifetimeStartOrEnd() || II.isDroppable()) && "Unexpected intrinsic!"
) ? static_cast<void> (0) : __assert_fail ("(II.isLifetimeStartOrEnd() || II.isDroppable()) && \"Unexpected intrinsic!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3096, __PRETTY_FUNCTION__))
3096 "Unexpected intrinsic!")(((II.isLifetimeStartOrEnd() || II.isDroppable()) && "Unexpected intrinsic!"
) ? static_cast<void> (0) : __assert_fail ("(II.isLifetimeStartOrEnd() || II.isDroppable()) && \"Unexpected intrinsic!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3096, __PRETTY_FUNCTION__))
;
3097 LLVM_DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
3098
3099 // Record this instruction for deletion.
3100 Pass.DeadInsts.push_back(&II);
3101
3102 if (II.isDroppable()) {
3103 assert(II.getIntrinsicID() == Intrinsic::assume && "Expected assume")((II.getIntrinsicID() == Intrinsic::assume && "Expected assume"
) ? static_cast<void> (0) : __assert_fail ("II.getIntrinsicID() == Intrinsic::assume && \"Expected assume\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3103, __PRETTY_FUNCTION__))
;
3104 // TODO For now we forget assumed information, this can be improved.
3105 OldPtr->dropDroppableUsesIn(II);
3106 return true;
3107 }
3108
3109 assert(II.getArgOperand(1) == OldPtr)((II.getArgOperand(1) == OldPtr) ? static_cast<void> (0
) : __assert_fail ("II.getArgOperand(1) == OldPtr", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3109, __PRETTY_FUNCTION__))
;
3110 // Lifetime intrinsics are only promotable if they cover the whole alloca.
3111 // Therefore, we drop lifetime intrinsics which don't cover the whole
3112 // alloca.
3113 // (In theory, intrinsics which partially cover an alloca could be
3114 // promoted, but PromoteMemToReg doesn't handle that case.)
3115 // FIXME: Check whether the alloca is promotable before dropping the
3116 // lifetime intrinsics?
3117 if (NewBeginOffset != NewAllocaBeginOffset ||
3118 NewEndOffset != NewAllocaEndOffset)
3119 return true;
3120
3121 ConstantInt *Size =
3122 ConstantInt::get(cast<IntegerType>(II.getArgOperand(0)->getType()),
3123 NewEndOffset - NewBeginOffset);
3124 // Lifetime intrinsics always expect an i8* so directly get such a pointer
3125 // for the new alloca slice.
3126 Type *PointerTy = IRB.getInt8PtrTy(OldPtr->getType()->getPointerAddressSpace());
3127 Value *Ptr = getNewAllocaSlicePtr(IRB, PointerTy);
3128 Value *New;
3129 if (II.getIntrinsicID() == Intrinsic::lifetime_start)
3130 New = IRB.CreateLifetimeStart(Ptr, Size);
3131 else
3132 New = IRB.CreateLifetimeEnd(Ptr, Size);
3133
3134 (void)New;
3135 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
3136
3137 return true;
3138 }
3139
3140 void fixLoadStoreAlign(Instruction &Root) {
3141 // This algorithm implements the same visitor loop as
3142 // hasUnsafePHIOrSelectUse, and fixes the alignment of each load
3143 // or store found.
3144 SmallPtrSet<Instruction *, 4> Visited;
3145 SmallVector<Instruction *, 4> Uses;
3146 Visited.insert(&Root);
3147 Uses.push_back(&Root);
3148 do {
3149 Instruction *I = Uses.pop_back_val();
3150
3151 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
3152 LI->setAlignment(std::min(LI->getAlign(), getSliceAlign()));
3153 continue;
3154 }
3155 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
3156 SI->setAlignment(std::min(SI->getAlign(), getSliceAlign()));
3157 continue;
3158 }
3159
3160 assert(isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) ||((isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I
) || isa<PHINode>(I) || isa<SelectInst>(I) || isa
<GetElementPtrInst>(I)) ? static_cast<void> (0) :
__assert_fail ("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3162, __PRETTY_FUNCTION__))
3161 isa<PHINode>(I) || isa<SelectInst>(I) ||((isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I
) || isa<PHINode>(I) || isa<SelectInst>(I) || isa
<GetElementPtrInst>(I)) ? static_cast<void> (0) :
__assert_fail ("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3162, __PRETTY_FUNCTION__))
3162 isa<GetElementPtrInst>(I))((isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I
) || isa<PHINode>(I) || isa<SelectInst>(I) || isa
<GetElementPtrInst>(I)) ? static_cast<void> (0) :
__assert_fail ("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3162, __PRETTY_FUNCTION__))
;
3163 for (User *U : I->users())
3164 if (Visited.insert(cast<Instruction>(U)).second)
3165 Uses.push_back(cast<Instruction>(U));
3166 } while (!Uses.empty());
3167 }
3168
3169 bool visitPHINode(PHINode &PN) {
3170 LLVM_DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
3171 assert(BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable")((BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3171, __PRETTY_FUNCTION__))
;
3172 assert(EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable")((EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("EndOffset <= NewAllocaEndOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3172, __PRETTY_FUNCTION__))
;
3173
3174 // We would like to compute a new pointer in only one place, but have it be
3175 // as local as possible to the PHI. To do that, we re-use the location of
3176 // the old pointer, which necessarily must be in the right position to
3177 // dominate the PHI.
3178 IRBuilderBase::InsertPointGuard Guard(IRB);
3179 if (isa<PHINode>(OldPtr))
3180 IRB.SetInsertPoint(&*OldPtr->getParent()->getFirstInsertionPt());
3181 else
3182 IRB.SetInsertPoint(OldPtr);
3183 IRB.SetCurrentDebugLocation(OldPtr->getDebugLoc());
3184
3185 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3186 // Replace the operands which were using the old pointer.
3187 std::replace(PN.op_begin(), PN.op_end(), cast<Value>(OldPtr), NewPtr);
3188
3189 LLVM_DEBUG(dbgs() << " to: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << PN <<
"\n"; } } while (false)
;
3190 deleteIfTriviallyDead(OldPtr);
3191
3192 // Fix the alignment of any loads or stores using this PHI node.
3193 fixLoadStoreAlign(PN);
3194
3195 // PHIs can't be promoted on their own, but often can be speculated. We
3196 // check the speculation outside of the rewriter so that we see the
3197 // fully-rewritten alloca.
3198 PHIUsers.insert(&PN);
3199 return true;
3200 }
3201
3202 bool visitSelectInst(SelectInst &SI) {
3203 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3204 assert((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) &&(((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr
) && "Pointer isn't an operand!") ? static_cast<void
> (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3205, __PRETTY_FUNCTION__))
3205 "Pointer isn't an operand!")(((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr
) && "Pointer isn't an operand!") ? static_cast<void
> (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3205, __PRETTY_FUNCTION__))
;
3206 assert(BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable")((BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3206, __PRETTY_FUNCTION__))
;
3207 assert(EndOffset <= NewAllocaEndOffset && "Selects are unsplittable")((EndOffset <= NewAllocaEndOffset && "Selects are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("EndOffset <= NewAllocaEndOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3207, __PRETTY_FUNCTION__))
;
3208
3209 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3210 // Replace the operands which were using the old pointer.
3211 if (SI.getOperand(1) == OldPtr)
3212 SI.setOperand(1, NewPtr);
3213 if (SI.getOperand(2) == OldPtr)
3214 SI.setOperand(2, NewPtr);
3215
3216 LLVM_DEBUG(dbgs() << " to: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << SI <<
"\n"; } } while (false)
;
3217 deleteIfTriviallyDead(OldPtr);
3218
3219 // Fix the alignment of any loads or stores using this select.
3220 fixLoadStoreAlign(SI);
3221
3222 // Selects can't be promoted on their own, but often can be speculated. We
3223 // check the speculation outside of the rewriter so that we see the
3224 // fully-rewritten alloca.
3225 SelectUsers.insert(&SI);
3226 return true;
3227 }
3228};
3229
3230namespace {
3231
3232/// Visitor to rewrite aggregate loads and stores as scalar.
3233///
3234/// This pass aggressively rewrites all aggregate loads and stores on
3235/// a particular pointer (or any pointer derived from it which we can identify)
3236/// with scalar loads and stores.
3237class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
3238 // Befriend the base class so it can delegate to private visit methods.
3239 friend class InstVisitor<AggLoadStoreRewriter, bool>;
3240
3241 /// Queue of pointer uses to analyze and potentially rewrite.
3242 SmallVector<Use *, 8> Queue;
3243
3244 /// Set to prevent us from cycling with phi nodes and loops.
3245 SmallPtrSet<User *, 8> Visited;
3246
3247 /// The current pointer use being rewritten. This is used to dig up the used
3248 /// value (as opposed to the user).
3249 Use *U = nullptr;
3250
3251 /// Used to calculate offsets, and hence alignment, of subobjects.
3252 const DataLayout &DL;
3253
3254public:
3255 AggLoadStoreRewriter(const DataLayout &DL) : DL(DL) {}
3256
3257 /// Rewrite loads and stores through a pointer and all pointers derived from
3258 /// it.
3259 bool rewrite(Instruction &I) {
3260 LLVM_DEBUG(dbgs() << " Rewriting FCA loads and stores...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting FCA loads and stores...\n"
; } } while (false)
;
3261 enqueueUsers(I);
3262 bool Changed = false;
3263 while (!Queue.empty()) {
3264 U = Queue.pop_back_val();
3265 Changed |= visit(cast<Instruction>(U->getUser()));
3266 }
3267 return Changed;
3268 }
3269
3270private:
3271 /// Enqueue all the users of the given instruction for further processing.
3272 /// This uses a set to de-duplicate users.
3273 void enqueueUsers(Instruction &I) {
3274 for (Use &U : I.uses())
3275 if (Visited.insert(U.getUser()).second)
3276 Queue.push_back(&U);
3277 }
3278
3279 // Conservative default is to not rewrite anything.
3280 bool visitInstruction(Instruction &I) { return false; }
3281
3282 /// Generic recursive split emission class.
3283 template <typename Derived> class OpSplitter {
3284 protected:
3285 /// The builder used to form new instructions.
3286 IRBuilderTy IRB;
3287
3288 /// The indices which to be used with insert- or extractvalue to select the
3289 /// appropriate value within the aggregate.
3290 SmallVector<unsigned, 4> Indices;
3291
3292 /// The indices to a GEP instruction which will move Ptr to the correct slot
3293 /// within the aggregate.
3294 SmallVector<Value *, 4> GEPIndices;
3295
3296 /// The base pointer of the original op, used as a base for GEPing the
3297 /// split operations.
3298 Value *Ptr;
3299
3300 /// The base pointee type being GEPed into.
3301 Type *BaseTy;
3302
3303 /// Known alignment of the base pointer.
3304 Align BaseAlign;
3305
3306 /// To calculate offset of each component so we can correctly deduce
3307 /// alignments.
3308 const DataLayout &DL;
3309
3310 /// Initialize the splitter with an insertion point, Ptr and start with a
3311 /// single zero GEP index.
3312 OpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3313 Align BaseAlign, const DataLayout &DL)
3314 : IRB(InsertionPoint), GEPIndices(1, IRB.getInt32(0)), Ptr(Ptr),
3315 BaseTy(BaseTy), BaseAlign(BaseAlign), DL(DL) {}
3316
3317 public:
3318 /// Generic recursive split emission routine.
3319 ///
3320 /// This method recursively splits an aggregate op (load or store) into
3321 /// scalar or vector ops. It splits recursively until it hits a single value
3322 /// and emits that single value operation via the template argument.
3323 ///
3324 /// The logic of this routine relies on GEPs and insertvalue and
3325 /// extractvalue all operating with the same fundamental index list, merely
3326 /// formatted differently (GEPs need actual values).
3327 ///
3328 /// \param Ty The type being split recursively into smaller ops.
3329 /// \param Agg The aggregate value being built up or stored, depending on
3330 /// whether this is splitting a load or a store respectively.
3331 void emitSplitOps(Type *Ty, Value *&Agg, const Twine &Name) {
3332 if (Ty->isSingleValueType()) {
3333 unsigned Offset = DL.getIndexedOffsetInType(BaseTy, GEPIndices);
3334 return static_cast<Derived *>(this)->emitFunc(
3335 Ty, Agg, commonAlignment(BaseAlign, Offset), Name);
3336 }
3337
3338 if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
3339 unsigned OldSize = Indices.size();
3340 (void)OldSize;
3341 for (unsigned Idx = 0, Size = ATy->getNumElements(); Idx != Size;
3342 ++Idx) {
3343 assert(Indices.size() == OldSize && "Did not return to the old size")((Indices.size() == OldSize && "Did not return to the old size"
) ? static_cast<void> (0) : __assert_fail ("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3343, __PRETTY_FUNCTION__))
;
3344 Indices.push_back(Idx);
3345 GEPIndices.push_back(IRB.getInt32(Idx));
3346 emitSplitOps(ATy->getElementType(), Agg, Name + "." + Twine(Idx));
3347 GEPIndices.pop_back();
3348 Indices.pop_back();
3349 }
3350 return;
3351 }
3352
3353 if (StructType *STy = dyn_cast<StructType>(Ty)) {
3354 unsigned OldSize = Indices.size();
3355 (void)OldSize;
3356 for (unsigned Idx = 0, Size = STy->getNumElements(); Idx != Size;
3357 ++Idx) {
3358 assert(Indices.size() == OldSize && "Did not return to the old size")((Indices.size() == OldSize && "Did not return to the old size"
) ? static_cast<void> (0) : __assert_fail ("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3358, __PRETTY_FUNCTION__))
;
3359 Indices.push_back(Idx);
3360 GEPIndices.push_back(IRB.getInt32(Idx));
3361 emitSplitOps(STy->getElementType(Idx), Agg, Name + "." + Twine(Idx));
3362 GEPIndices.pop_back();
3363 Indices.pop_back();
3364 }
3365 return;
3366 }
3367
3368 llvm_unreachable("Only arrays and structs are aggregate loadable types")::llvm::llvm_unreachable_internal("Only arrays and structs are aggregate loadable types"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3368)
;
3369 }
3370 };
3371
3372 struct LoadOpSplitter : public OpSplitter<LoadOpSplitter> {
3373 AAMDNodes AATags;
3374
3375 LoadOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3376 AAMDNodes AATags, Align BaseAlign, const DataLayout &DL)
3377 : OpSplitter<LoadOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
3378 DL),
3379 AATags(AATags) {}
3380
3381 /// Emit a leaf load of a single value. This is called at the leaves of the
3382 /// recursive emission to actually load values.
3383 void emitFunc(Type *Ty, Value *&Agg, Align Alignment, const Twine &Name) {
3384 assert(Ty->isSingleValueType())((Ty->isSingleValueType()) ? static_cast<void> (0) :
__assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3384, __PRETTY_FUNCTION__))
;
3385 // Load the single value and insert it using the indices.
3386 Value *GEP =
3387 IRB.CreateInBoundsGEP(BaseTy, Ptr, GEPIndices, Name + ".gep");
3388 LoadInst *Load =
3389 IRB.CreateAlignedLoad(Ty, GEP, Alignment, Name + ".load");
3390
3391 APInt Offset(
3392 DL.getIndexSizeInBits(Ptr->getType()->getPointerAddressSpace()), 0);
3393 if (AATags &&
3394 GEPOperator::accumulateConstantOffset(BaseTy, GEPIndices, DL, Offset))
3395 Load->setAAMetadata(AATags.shift(Offset.getZExtValue()));
3396
3397 Agg = IRB.CreateInsertValue(Agg, Load, Indices, Name + ".insert");
3398 LLVM_DEBUG(dbgs() << " to: " << *Load << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Load <<
"\n"; } } while (false)
;
3399 }
3400 };
3401
3402 bool visitLoadInst(LoadInst &LI) {
3403 assert(LI.getPointerOperand() == *U)((LI.getPointerOperand() == *U) ? static_cast<void> (0)
: __assert_fail ("LI.getPointerOperand() == *U", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3403, __PRETTY_FUNCTION__))
;
3404 if (!LI.isSimple() || LI.getType()->isSingleValueType())
3405 return false;
3406
3407 // We have an aggregate being loaded, split it apart.
3408 LLVM_DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
3409 AAMDNodes AATags;
3410 LI.getAAMetadata(AATags);
3411 LoadOpSplitter Splitter(&LI, *U, LI.getType(), AATags,
3412 getAdjustedAlignment(&LI, 0), DL);
3413 Value *V = UndefValue::get(LI.getType());
3414 Splitter.emitSplitOps(LI.getType(), V, LI.getName() + ".fca");
3415 Visited.erase(&LI);
3416 LI.replaceAllUsesWith(V);
3417 LI.eraseFromParent();
3418 return true;
3419 }
3420
3421 struct StoreOpSplitter : public OpSplitter<StoreOpSplitter> {
3422 StoreOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3423 AAMDNodes AATags, Align BaseAlign, const DataLayout &DL)
3424 : OpSplitter<StoreOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
3425 DL),
3426 AATags(AATags) {}
3427 AAMDNodes AATags;
3428 /// Emit a leaf store of a single value. This is called at the leaves of the
3429 /// recursive emission to actually produce stores.
3430 void emitFunc(Type *Ty, Value *&Agg, Align Alignment, const Twine &Name) {
3431 assert(Ty->isSingleValueType())((Ty->isSingleValueType()) ? static_cast<void> (0) :
__assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3431, __PRETTY_FUNCTION__))
;
3432 // Extract the single value and store it using the indices.
3433 //
3434 // The gep and extractvalue values are factored out of the CreateStore
3435 // call to make the output independent of the argument evaluation order.
3436 Value *ExtractValue =
3437 IRB.CreateExtractValue(Agg, Indices, Name + ".extract");
3438 Value *InBoundsGEP =
3439 IRB.CreateInBoundsGEP(BaseTy, Ptr, GEPIndices, Name + ".gep");
3440 StoreInst *Store =
3441 IRB.CreateAlignedStore(ExtractValue, InBoundsGEP, Alignment);
3442
3443 APInt Offset(
3444 DL.getIndexSizeInBits(Ptr->getType()->getPointerAddressSpace()), 0);
3445 if (AATags &&
3446 GEPOperator::accumulateConstantOffset(BaseTy, GEPIndices, DL, Offset))
3447 Store->setAAMetadata(AATags.shift(Offset.getZExtValue()));
3448
3449 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3450 }
3451 };
3452
3453 bool visitStoreInst(StoreInst &SI) {
3454 if (!SI.isSimple() || SI.getPointerOperand() != *U)
3455 return false;
3456 Value *V = SI.getValueOperand();
3457 if (V->getType()->isSingleValueType())
3458 return false;
3459
3460 // We have an aggregate being stored, split it apart.
3461 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3462 AAMDNodes AATags;
3463 SI.getAAMetadata(AATags);
3464 StoreOpSplitter Splitter(&SI, *U, V->getType(), AATags,
3465 getAdjustedAlignment(&SI, 0), DL);
3466 Splitter.emitSplitOps(V->getType(), V, V->getName() + ".fca");
3467 Visited.erase(&SI);
3468 SI.eraseFromParent();
3469 return true;
3470 }
3471
3472 bool visitBitCastInst(BitCastInst &BC) {
3473 enqueueUsers(BC);
3474 return false;
3475 }
3476
3477 bool visitAddrSpaceCastInst(AddrSpaceCastInst &ASC) {
3478 enqueueUsers(ASC);
3479 return false;
3480 }
3481
3482 // Fold gep (select cond, ptr1, ptr2) => select cond, gep(ptr1), gep(ptr2)
3483 bool foldGEPSelect(GetElementPtrInst &GEPI) {
3484 if (!GEPI.hasAllConstantIndices())
3485 return false;
3486
3487 SelectInst *Sel = cast<SelectInst>(GEPI.getPointerOperand());
3488
3489 LLVM_DEBUG(dbgs() << " Rewriting gep(select) -> select(gep):"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(select) -> select(gep):"
<< "\n original: " << *Sel << "\n "
<< GEPI; } } while (false)
3490 << "\n original: " << *Seldo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(select) -> select(gep):"
<< "\n original: " << *Sel << "\n "
<< GEPI; } } while (false)
3491 << "\n " << GEPI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(select) -> select(gep):"
<< "\n original: " << *Sel << "\n "
<< GEPI; } } while (false)
;
3492
3493 IRBuilderTy Builder(&GEPI);
3494 SmallVector<Value *, 4> Index(GEPI.indices());
3495 bool IsInBounds = GEPI.isInBounds();
3496
3497 Type *Ty = GEPI.getSourceElementType();
3498 Value *True = Sel->getTrueValue();
3499 Value *NTrue =
3500 IsInBounds
3501 ? Builder.CreateInBoundsGEP(Ty, True, Index,
3502 True->getName() + ".sroa.gep")
3503 : Builder.CreateGEP(Ty, True, Index, True->getName() + ".sroa.gep");
3504
3505 Value *False = Sel->getFalseValue();
3506
3507 Value *NFalse =
3508 IsInBounds
3509 ? Builder.CreateInBoundsGEP(Ty, False, Index,
3510 False->getName() + ".sroa.gep")
3511 : Builder.CreateGEP(Ty, False, Index,
3512 False->getName() + ".sroa.gep");
3513
3514 Value *NSel = Builder.CreateSelect(Sel->getCondition(), NTrue, NFalse,
3515 Sel->getName() + ".sroa.sel");
3516 Visited.erase(&GEPI);
3517 GEPI.replaceAllUsesWith(NSel);
3518 GEPI.eraseFromParent();
3519 Instruction *NSelI = cast<Instruction>(NSel);
3520 Visited.insert(NSelI);
3521 enqueueUsers(*NSelI);
3522
3523 LLVM_DEBUG(dbgs() << "\n to: " << *NTruedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
3524 << "\n " << *NFalsedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
3525 << "\n " << *NSel << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
;
3526
3527 return true;
3528 }
3529
3530 // Fold gep (phi ptr1, ptr2) => phi gep(ptr1), gep(ptr2)
3531 bool foldGEPPhi(GetElementPtrInst &GEPI) {
3532 if (!GEPI.hasAllConstantIndices())
3533 return false;
3534
3535 PHINode *PHI = cast<PHINode>(GEPI.getPointerOperand());
3536 if (GEPI.getParent() != PHI->getParent() ||
3537 llvm::any_of(PHI->incoming_values(), [](Value *In)
3538 { Instruction *I = dyn_cast<Instruction>(In);
3539 return !I || isa<GetElementPtrInst>(I) || isa<PHINode>(I) ||
3540 succ_empty(I->getParent()) ||
3541 !I->getParent()->isLegalToHoistInto();
3542 }))
3543 return false;
3544
3545 LLVM_DEBUG(dbgs() << " Rewriting gep(phi) -> phi(gep):"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
3546 << "\n original: " << *PHIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
3547 << "\n " << GEPIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
3548 << "\n to: ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
;
3549
3550 SmallVector<Value *, 4> Index(GEPI.indices());
3551 bool IsInBounds = GEPI.isInBounds();
3552 IRBuilderTy PHIBuilder(GEPI.getParent()->getFirstNonPHI());
3553 PHINode *NewPN = PHIBuilder.CreatePHI(GEPI.getType(),
3554 PHI->getNumIncomingValues(),
3555 PHI->getName() + ".sroa.phi");
3556 for (unsigned I = 0, E = PHI->getNumIncomingValues(); I != E; ++I) {
3557 BasicBlock *B = PHI->getIncomingBlock(I);
3558 Value *NewVal = nullptr;
3559 int Idx = NewPN->getBasicBlockIndex(B);
3560 if (Idx >= 0) {
3561 NewVal = NewPN->getIncomingValue(Idx);
3562 } else {
3563 Instruction *In = cast<Instruction>(PHI->getIncomingValue(I));
3564
3565 IRBuilderTy B(In->getParent(), std::next(In->getIterator()));
3566 Type *Ty = GEPI.getSourceElementType();
3567 NewVal = IsInBounds
3568 ? B.CreateInBoundsGEP(Ty, In, Index, In->getName() + ".sroa.gep")
3569 : B.CreateGEP(Ty, In, Index, In->getName() + ".sroa.gep");
3570 }
3571 NewPN->addIncoming(NewVal, B);
3572 }
3573
3574 Visited.erase(&GEPI);
3575 GEPI.replaceAllUsesWith(NewPN);
3576 GEPI.eraseFromParent();
3577 Visited.insert(NewPN);
3578 enqueueUsers(*NewPN);
3579
3580 LLVM_DEBUG(for (Value *In : NewPN->incoming_values())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { for (Value *In : NewPN->incoming_values()) dbgs
() << "\n " << *In; dbgs() << "\n "
<< *NewPN << '\n'; } } while (false)
3581 dbgs() << "\n " << *In;do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { for (Value *In : NewPN->incoming_values()) dbgs
() << "\n " << *In; dbgs() << "\n "
<< *NewPN << '\n'; } } while (false)
3582 dbgs() << "\n " << *NewPN << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { for (Value *In : NewPN->incoming_values()) dbgs
() << "\n " << *In; dbgs() << "\n "
<< *NewPN << '\n'; } } while (false)
;
3583
3584 return true;
3585 }
3586
3587 bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
3588 if (isa<SelectInst>(GEPI.getPointerOperand()) &&
3589 foldGEPSelect(GEPI))
3590 return true;
3591
3592 if (isa<PHINode>(GEPI.getPointerOperand()) &&
3593 foldGEPPhi(GEPI))
3594 return true;
3595
3596 enqueueUsers(GEPI);
3597 return false;
3598 }
3599
3600 bool visitPHINode(PHINode &PN) {
3601 enqueueUsers(PN);
3602 return false;
3603 }
3604
3605 bool visitSelectInst(SelectInst &SI) {
3606 enqueueUsers(SI);
3607 return false;
3608 }
3609};
3610
3611} // end anonymous namespace
3612
3613/// Strip aggregate type wrapping.
3614///
3615/// This removes no-op aggregate types wrapping an underlying type. It will
3616/// strip as many layers of types as it can without changing either the type
3617/// size or the allocated size.
3618static Type *stripAggregateTypeWrapping(const DataLayout &DL, Type *Ty) {
3619 if (Ty->isSingleValueType())
3620 return Ty;
3621
3622 uint64_t AllocSize = DL.getTypeAllocSize(Ty).getFixedSize();
3623 uint64_t TypeSize = DL.getTypeSizeInBits(Ty).getFixedSize();
3624
3625 Type *InnerTy;
3626 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
3627 InnerTy = ArrTy->getElementType();
3628 } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
3629 const StructLayout *SL = DL.getStructLayout(STy);
3630 unsigned Index = SL->getElementContainingOffset(0);
3631 InnerTy = STy->getElementType(Index);
3632 } else {
3633 return Ty;
3634 }
3635
3636 if (AllocSize > DL.getTypeAllocSize(InnerTy).getFixedSize() ||
3637 TypeSize > DL.getTypeSizeInBits(InnerTy).getFixedSize())
3638 return Ty;
3639
3640 return stripAggregateTypeWrapping(DL, InnerTy);
3641}
3642
3643/// Try to find a partition of the aggregate type passed in for a given
3644/// offset and size.
3645///
3646/// This recurses through the aggregate type and tries to compute a subtype
3647/// based on the offset and size. When the offset and size span a sub-section
3648/// of an array, it will even compute a new array type for that sub-section,
3649/// and the same for structs.
3650///
3651/// Note that this routine is very strict and tries to find a partition of the
3652/// type which produces the *exact* right offset and size. It is not forgiving
3653/// when the size or offset cause either end of type-based partition to be off.
3654/// Also, this is a best-effort routine. It is reasonable to give up and not
3655/// return a type if necessary.
3656static Type *getTypePartition(const DataLayout &DL, Type *Ty, uint64_t Offset,
3657 uint64_t Size) {
3658 if (Offset == 0 && DL.getTypeAllocSize(Ty).getFixedSize() == Size)
3659 return stripAggregateTypeWrapping(DL, Ty);
3660 if (Offset > DL.getTypeAllocSize(Ty).getFixedSize() ||
3661 (DL.getTypeAllocSize(Ty).getFixedSize() - Offset) < Size)
3662 return nullptr;
3663
3664 if (isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
3665 Type *ElementTy;
3666 uint64_t TyNumElements;
3667 if (auto *AT = dyn_cast<ArrayType>(Ty)) {
3668 ElementTy = AT->getElementType();
3669 TyNumElements = AT->getNumElements();
3670 } else {
3671 // FIXME: This isn't right for vectors with non-byte-sized or
3672 // non-power-of-two sized elements.
3673 auto *VT = cast<FixedVectorType>(Ty);
3674 ElementTy = VT->getElementType();
3675 TyNumElements = VT->getNumElements();
3676 }
3677 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy).getFixedSize();
3678 uint64_t NumSkippedElements = Offset / ElementSize;
3679 if (NumSkippedElements >= TyNumElements)
3680 return nullptr;
3681 Offset -= NumSkippedElements * ElementSize;
3682
3683 // First check if we need to recurse.
3684 if (Offset > 0 || Size < ElementSize) {
3685 // Bail if the partition ends in a different array element.
3686 if ((Offset + Size) > ElementSize)
3687 return nullptr;
3688 // Recurse through the element type trying to peel off offset bytes.
3689 return getTypePartition(DL, ElementTy, Offset, Size);
3690 }
3691 assert(Offset == 0)((Offset == 0) ? static_cast<void> (0) : __assert_fail (
"Offset == 0", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3691, __PRETTY_FUNCTION__))
;
3692
3693 if (Size == ElementSize)
3694 return stripAggregateTypeWrapping(DL, ElementTy);
3695 assert(Size > ElementSize)((Size > ElementSize) ? static_cast<void> (0) : __assert_fail
("Size > ElementSize", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3695, __PRETTY_FUNCTION__))
;
3696 uint64_t NumElements = Size / ElementSize;
3697 if (NumElements * ElementSize != Size)
3698 return nullptr;
3699 return ArrayType::get(ElementTy, NumElements);
3700 }
3701
3702 StructType *STy = dyn_cast<StructType>(Ty);
3703 if (!STy)
3704 return nullptr;
3705
3706 const StructLayout *SL = DL.getStructLayout(STy);
3707 if (Offset >= SL->getSizeInBytes())
3708 return nullptr;
3709 uint64_t EndOffset = Offset + Size;
3710 if (EndOffset > SL->getSizeInBytes())
3711 return nullptr;
3712
3713 unsigned Index = SL->getElementContainingOffset(Offset);
3714 Offset -= SL->getElementOffset(Index);
3715
3716 Type *ElementTy = STy->getElementType(Index);
3717 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy).getFixedSize();
3718 if (Offset >= ElementSize)
3719 return nullptr; // The offset points into alignment padding.
3720
3721 // See if any partition must be contained by the element.
3722 if (Offset > 0 || Size < ElementSize) {
3723 if ((Offset + Size) > ElementSize)
3724 return nullptr;
3725 return getTypePartition(DL, ElementTy, Offset, Size);
3726 }
3727 assert(Offset == 0)((Offset == 0) ? static_cast<void> (0) : __assert_fail (
"Offset == 0", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3727, __PRETTY_FUNCTION__))
;
3728
3729 if (Size == ElementSize)
3730 return stripAggregateTypeWrapping(DL, ElementTy);
3731
3732 StructType::element_iterator EI = STy->element_begin() + Index,
3733 EE = STy->element_end();
3734 if (EndOffset < SL->getSizeInBytes()) {
3735 unsigned EndIndex = SL->getElementContainingOffset(EndOffset);
3736 if (Index == EndIndex)
3737 return nullptr; // Within a single element and its padding.
3738
3739 // Don't try to form "natural" types if the elements don't line up with the
3740 // expected size.
3741 // FIXME: We could potentially recurse down through the last element in the
3742 // sub-struct to find a natural end point.
3743 if (SL->getElementOffset(EndIndex) != EndOffset)
3744 return nullptr;
3745
3746 assert(Index < EndIndex)((Index < EndIndex) ? static_cast<void> (0) : __assert_fail
("Index < EndIndex", "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3746, __PRETTY_FUNCTION__))
;
3747 EE = STy->element_begin() + EndIndex;
3748 }
3749
3750 // Try to build up a sub-structure.
3751 StructType *SubTy =
3752 StructType::get(STy->getContext(), makeArrayRef(EI, EE), STy->isPacked());
3753 const StructLayout *SubSL = DL.getStructLayout(SubTy);
3754 if (Size != SubSL->getSizeInBytes())
3755 return nullptr; // The sub-struct doesn't have quite the size needed.
3756
3757 return SubTy;
3758}
3759
3760/// Pre-split loads and stores to simplify rewriting.
3761///
3762/// We want to break up the splittable load+store pairs as much as
3763/// possible. This is important to do as a preprocessing step, as once we
3764/// start rewriting the accesses to partitions of the alloca we lose the
3765/// necessary information to correctly split apart paired loads and stores
3766/// which both point into this alloca. The case to consider is something like
3767/// the following:
3768///
3769/// %a = alloca [12 x i8]
3770/// %gep1 = getelementptr [12 x i8]* %a, i32 0, i32 0
3771/// %gep2 = getelementptr [12 x i8]* %a, i32 0, i32 4
3772/// %gep3 = getelementptr [12 x i8]* %a, i32 0, i32 8
3773/// %iptr1 = bitcast i8* %gep1 to i64*
3774/// %iptr2 = bitcast i8* %gep2 to i64*
3775/// %fptr1 = bitcast i8* %gep1 to float*
3776/// %fptr2 = bitcast i8* %gep2 to float*
3777/// %fptr3 = bitcast i8* %gep3 to float*
3778/// store float 0.0, float* %fptr1
3779/// store float 1.0, float* %fptr2
3780/// %v = load i64* %iptr1
3781/// store i64 %v, i64* %iptr2
3782/// %f1 = load float* %fptr2
3783/// %f2 = load float* %fptr3
3784///
3785/// Here we want to form 3 partitions of the alloca, each 4 bytes large, and
3786/// promote everything so we recover the 2 SSA values that should have been
3787/// there all along.
3788///
3789/// \returns true if any changes are made.
3790bool SROA::presplitLoadsAndStores(AllocaInst &AI, AllocaSlices &AS) {
3791 LLVM_DEBUG(dbgs() << "Pre-splitting loads and stores\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Pre-splitting loads and stores\n"
; } } while (false)
;
3792
3793 // Track the loads and stores which are candidates for pre-splitting here, in
3794 // the order they first appear during the partition scan. These give stable
3795 // iteration order and a basis for tracking which loads and stores we
3796 // actually split.
3797 SmallVector<LoadInst *, 4> Loads;
3798 SmallVector<StoreInst *, 4> Stores;
3799
3800 // We need to accumulate the splits required of each load or store where we
3801 // can find them via a direct lookup. This is important to cross-check loads
3802 // and stores against each other. We also track the slice so that we can kill
3803 // all the slices that end up split.
3804 struct SplitOffsets {
3805 Slice *S;
3806 std::vector<uint64_t> Splits;
3807 };
3808 SmallDenseMap<Instruction *, SplitOffsets, 8> SplitOffsetsMap;
3809
3810 // Track loads out of this alloca which cannot, for any reason, be pre-split.
3811 // This is important as we also cannot pre-split stores of those loads!
3812 // FIXME: This is all pretty gross. It means that we can be more aggressive
3813 // in pre-splitting when the load feeding the store happens to come from
3814 // a separate alloca. Put another way, the effectiveness of SROA would be
3815 // decreased by a frontend which just concatenated all of its local allocas
3816 // into one big flat alloca. But defeating such patterns is exactly the job
3817 // SROA is tasked with! Sadly, to not have this discrepancy we would have
3818 // change store pre-splitting to actually force pre-splitting of the load
3819 // that feeds it *and all stores*. That makes pre-splitting much harder, but
3820 // maybe it would make it more principled?
3821 SmallPtrSet<LoadInst *, 8> UnsplittableLoads;
3822
3823 LLVM_DEBUG(dbgs() << " Searching for candidate loads and stores\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Searching for candidate loads and stores\n"
; } } while (false)
;
3824 for (auto &P : AS.partitions()) {
3825 for (Slice &S : P) {
3826 Instruction *I = cast<Instruction>(S.getUse()->getUser());
3827 if (!S.isSplittable() || S.endOffset() <= P.endOffset()) {
3828 // If this is a load we have to track that it can't participate in any
3829 // pre-splitting. If this is a store of a load we have to track that
3830 // that load also can't participate in any pre-splitting.
3831 if (auto *LI = dyn_cast<LoadInst>(I))
3832 UnsplittableLoads.insert(LI);
3833 else if (auto *SI = dyn_cast<StoreInst>(I))
3834 if (auto *LI = dyn_cast<LoadInst>(SI->getValueOperand()))
3835 UnsplittableLoads.insert(LI);
3836 continue;
3837 }
3838 assert(P.endOffset() > S.beginOffset() &&((P.endOffset() > S.beginOffset() && "Empty or backwards partition!"
) ? static_cast<void> (0) : __assert_fail ("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3839, __PRETTY_FUNCTION__))
3839 "Empty or backwards partition!")((P.endOffset() > S.beginOffset() && "Empty or backwards partition!"
) ? static_cast<void> (0) : __assert_fail ("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3839, __PRETTY_FUNCTION__))
;
3840
3841 // Determine if this is a pre-splittable slice.
3842 if (auto *LI = dyn_cast<LoadInst>(I)) {
3843 assert(!LI->isVolatile() && "Cannot split volatile loads!")((!LI->isVolatile() && "Cannot split volatile loads!"
) ? static_cast<void> (0) : __assert_fail ("!LI->isVolatile() && \"Cannot split volatile loads!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3843, __PRETTY_FUNCTION__))
;
3844
3845 // The load must be used exclusively to store into other pointers for
3846 // us to be able to arbitrarily pre-split it. The stores must also be
3847 // simple to avoid changing semantics.
3848 auto IsLoadSimplyStored = [](LoadInst *LI) {
3849 for (User *LU : LI->users()) {
3850 auto *SI = dyn_cast<StoreInst>(LU);
3851 if (!SI || !SI->isSimple())
3852 return false;
3853 }
3854 return true;
3855 };
3856 if (!IsLoadSimplyStored(LI)) {
3857 UnsplittableLoads.insert(LI);
3858 continue;
3859 }
3860
3861 Loads.push_back(LI);
3862 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
3863 if (S.getUse() != &SI->getOperandUse(SI->getPointerOperandIndex()))
3864 // Skip stores *of* pointers. FIXME: This shouldn't even be possible!
3865 continue;
3866 auto *StoredLoad = dyn_cast<LoadInst>(SI->getValueOperand());
3867 if (!StoredLoad || !StoredLoad->isSimple())
3868 continue;
3869 assert(!SI->isVolatile() && "Cannot split volatile stores!")((!SI->isVolatile() && "Cannot split volatile stores!"
) ? static_cast<void> (0) : __assert_fail ("!SI->isVolatile() && \"Cannot split volatile stores!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3869, __PRETTY_FUNCTION__))
;
3870
3871 Stores.push_back(SI);
3872 } else {
3873 // Other uses cannot be pre-split.
3874 continue;
3875 }
3876
3877 // Record the initial split.
3878 LLVM_DEBUG(dbgs() << " Candidate: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Candidate: " << *I <<
"\n"; } } while (false)
;
3879 auto &Offsets = SplitOffsetsMap[I];
3880 assert(Offsets.Splits.empty() &&((Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3881, __PRETTY_FUNCTION__))
3881 "Should not have splits the first time we see an instruction!")((Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3881, __PRETTY_FUNCTION__))
;
3882 Offsets.S = &S;
3883 Offsets.Splits.push_back(P.endOffset() - S.beginOffset());
3884 }
3885
3886 // Now scan the already split slices, and add a split for any of them which
3887 // we're going to pre-split.
3888 for (Slice *S : P.splitSliceTails()) {
3889 auto SplitOffsetsMapI =
3890 SplitOffsetsMap.find(cast<Instruction>(S->getUse()->getUser()));
3891 if (SplitOffsetsMapI == SplitOffsetsMap.end())
3892 continue;
3893 auto &Offsets = SplitOffsetsMapI->second;
3894
3895 assert(Offsets.S == S && "Found a mismatched slice!")((Offsets.S == S && "Found a mismatched slice!") ? static_cast
<void> (0) : __assert_fail ("Offsets.S == S && \"Found a mismatched slice!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3895, __PRETTY_FUNCTION__))
;
3896 assert(!Offsets.Splits.empty() &&((!Offsets.Splits.empty() && "Cannot have an empty set of splits on the second partition!"
) ? static_cast<void> (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3897, __PRETTY_FUNCTION__))
3897 "Cannot have an empty set of splits on the second partition!")((!Offsets.Splits.empty() && "Cannot have an empty set of splits on the second partition!"
) ? static_cast<void> (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3897, __PRETTY_FUNCTION__))
;
3898 assert(Offsets.Splits.back() ==((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3900, __PRETTY_FUNCTION__))
3899 P.beginOffset() - Offsets.S->beginOffset() &&((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3900, __PRETTY_FUNCTION__))
3900 "Previous split does not end where this one begins!")((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3900, __PRETTY_FUNCTION__))
;
3901
3902 // Record each split. The last partition's end isn't needed as the size
3903 // of the slice dictates that.
3904 if (S->endOffset() > P.endOffset())
3905 Offsets.Splits.push_back(P.endOffset() - Offsets.S->beginOffset());
3906 }
3907 }
3908
3909 // We may have split loads where some of their stores are split stores. For
3910 // such loads and stores, we can only pre-split them if their splits exactly
3911 // match relative to their starting offset. We have to verify this prior to
3912 // any rewriting.
3913 llvm::erase_if(Stores, [&UnsplittableLoads, &SplitOffsetsMap](StoreInst *SI) {
3914 // Lookup the load we are storing in our map of split
3915 // offsets.
3916 auto *LI = cast<LoadInst>(SI->getValueOperand());
3917 // If it was completely unsplittable, then we're done,
3918 // and this store can't be pre-split.
3919 if (UnsplittableLoads.count(LI))
3920 return true;
3921
3922 auto LoadOffsetsI = SplitOffsetsMap.find(LI);
3923 if (LoadOffsetsI == SplitOffsetsMap.end())
3924 return false; // Unrelated loads are definitely safe.
3925 auto &LoadOffsets = LoadOffsetsI->second;
3926
3927 // Now lookup the store's offsets.
3928 auto &StoreOffsets = SplitOffsetsMap[SI];
3929
3930 // If the relative offsets of each split in the load and
3931 // store match exactly, then we can split them and we
3932 // don't need to remove them here.
3933 if (LoadOffsets.Splits == StoreOffsets.Splits)
3934 return false;
3935
3936 LLVM_DEBUG(dbgs() << " Mismatched splits for load and store:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3937 << " " << *LI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3938 << " " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
;
3939
3940 // We've found a store and load that we need to split
3941 // with mismatched relative splits. Just give up on them
3942 // and remove both instructions from our list of
3943 // candidates.
3944 UnsplittableLoads.insert(LI);
3945 return true;
3946 });
3947 // Now we have to go *back* through all the stores, because a later store may
3948 // have caused an earlier store's load to become unsplittable and if it is
3949 // unsplittable for the later store, then we can't rely on it being split in
3950 // the earlier store either.
3951 llvm::erase_if(Stores, [&UnsplittableLoads](StoreInst *SI) {
3952 auto *LI = cast<LoadInst>(SI->getValueOperand());
3953 return UnsplittableLoads.count(LI);
3954 });
3955 // Once we've established all the loads that can't be split for some reason,
3956 // filter any that made it into our list out.
3957 llvm::erase_if(Loads, [&UnsplittableLoads](LoadInst *LI) {
3958 return UnsplittableLoads.count(LI);
3959 });
3960
3961 // If no loads or stores are left, there is no pre-splitting to be done for
3962 // this alloca.
3963 if (Loads.empty() && Stores.empty())
3964 return false;
3965
3966 // From here on, we can't fail and will be building new accesses, so rig up
3967 // an IR builder.
3968 IRBuilderTy IRB(&AI);
3969
3970 // Collect the new slices which we will merge into the alloca slices.
3971 SmallVector<Slice, 4> NewSlices;
3972
3973 // Track any allocas we end up splitting loads and stores for so we iterate
3974 // on them.
3975 SmallPtrSet<AllocaInst *, 4> ResplitPromotableAllocas;
3976
3977 // At this point, we have collected all of the loads and stores we can
3978 // pre-split, and the specific splits needed for them. We actually do the
3979 // splitting in a specific order in order to handle when one of the loads in
3980 // the value operand to one of the stores.
3981 //
3982 // First, we rewrite all of the split loads, and just accumulate each split
3983 // load in a parallel structure. We also build the slices for them and append
3984 // them to the alloca slices.
3985 SmallDenseMap<LoadInst *, std::vector<LoadInst *>, 1> SplitLoadsMap;
3986 std::vector<LoadInst *> SplitLoads;
3987 const DataLayout &DL = AI.getModule()->getDataLayout();
3988 for (LoadInst *LI : Loads) {
3989 SplitLoads.clear();
3990
3991 IntegerType *Ty = cast<IntegerType>(LI->getType());
3992 uint64_t LoadSize = Ty->getBitWidth() / 8;
3993 assert(LoadSize > 0 && "Cannot have a zero-sized integer load!")((LoadSize > 0 && "Cannot have a zero-sized integer load!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize > 0 && \"Cannot have a zero-sized integer load!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3993, __PRETTY_FUNCTION__))
;
3994
3995 auto &Offsets = SplitOffsetsMap[LI];
3996 assert(LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&((LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3997, __PRETTY_FUNCTION__))
3997 "Slice size should always match load size exactly!")((LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3997, __PRETTY_FUNCTION__))
;
3998 uint64_t BaseOffset = Offsets.S->beginOffset();
3999 assert(BaseOffset + LoadSize > BaseOffset &&((BaseOffset + LoadSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4000, __PRETTY_FUNCTION__))
4000 "Cannot represent alloca access size using 64-bit integers!")((BaseOffset + LoadSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4000, __PRETTY_FUNCTION__))
;
4001
4002 Instruction *BasePtr = cast<Instruction>(LI->getPointerOperand());
4003 IRB.SetInsertPoint(LI);
4004
4005 LLVM_DEBUG(dbgs() << " Splitting load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting load: " << *LI
<< "\n"; } } while (false)
;
4006
4007 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
4008 int Idx = 0, Size = Offsets.Splits.size();
4009 for (;;) {
4010 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
4011 auto AS = LI->getPointerAddressSpace();
4012 auto *PartPtrTy = PartTy->getPointerTo(AS);
4013 LoadInst *PLoad = IRB.CreateAlignedLoad(
4014 PartTy,
4015 getAdjustedPtr(IRB, DL, BasePtr,
4016 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4017 PartPtrTy, BasePtr->getName() + "."),
4018 getAdjustedAlignment(LI, PartOffset),
4019 /*IsVolatile*/ false, LI->getName());
4020 PLoad->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
4021 LLVMContext::MD_access_group});
4022
4023 // Append this load onto the list of split loads so we can find it later
4024 // to rewrite the stores.
4025 SplitLoads.push_back(PLoad);
4026
4027 // Now build a new slice for the alloca.
4028 NewSlices.push_back(
4029 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
4030 &PLoad->getOperandUse(PLoad->getPointerOperandIndex()),
4031 /*IsSplittable*/ false));
4032 LLVM_DEBUG(dbgs() << " new slice [" << NewSlices.back().beginOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
4033 << ", " << NewSlices.back().endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
4034 << "): " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
;
4035
4036 // See if we've handled all the splits.
4037 if (Idx >= Size)
4038 break;
4039
4040 // Setup the next partition.
4041 PartOffset = Offsets.Splits[Idx];
4042 ++Idx;
4043 PartSize = (Idx < Size ? Offsets.Splits[Idx] : LoadSize) - PartOffset;
4044 }
4045
4046 // Now that we have the split loads, do the slow walk over all uses of the
4047 // load and rewrite them as split stores, or save the split loads to use
4048 // below if the store is going to be split there anyways.
4049 bool DeferredStores = false;
4050 for (User *LU : LI->users()) {
4051 StoreInst *SI = cast<StoreInst>(LU);
4052 if (!Stores.empty() && SplitOffsetsMap.count(SI)) {
4053 DeferredStores = true;
4054 LLVM_DEBUG(dbgs() << " Deferred splitting of store: " << *SIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
4055 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
;
4056 continue;
4057 }
4058
4059 Value *StoreBasePtr = SI->getPointerOperand();
4060 IRB.SetInsertPoint(SI);
4061
4062 LLVM_DEBUG(dbgs() << " Splitting store of load: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store of load: " <<
*SI << "\n"; } } while (false)
;
4063
4064 for (int Idx = 0, Size = SplitLoads.size(); Idx < Size; ++Idx) {
4065 LoadInst *PLoad = SplitLoads[Idx];
4066 uint64_t PartOffset = Idx == 0 ? 0 : Offsets.Splits[Idx - 1];
4067 auto *PartPtrTy =
4068 PLoad->getType()->getPointerTo(SI->getPointerAddressSpace());
4069
4070 auto AS = SI->getPointerAddressSpace();
4071 StoreInst *PStore = IRB.CreateAlignedStore(
4072 PLoad,
4073 getAdjustedPtr(IRB, DL, StoreBasePtr,
4074 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4075 PartPtrTy, StoreBasePtr->getName() + "."),
4076 getAdjustedAlignment(SI, PartOffset),
4077 /*IsVolatile*/ false);
4078 PStore->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
4079 LLVMContext::MD_access_group});
4080 LLVM_DEBUG(dbgs() << " +" << PartOffset << ":" << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " +" << PartOffset <<
":" << *PStore << "\n"; } } while (false)
;
4081 }
4082
4083 // We want to immediately iterate on any allocas impacted by splitting
4084 // this store, and we have to track any promotable alloca (indicated by
4085 // a direct store) as needing to be resplit because it is no longer
4086 // promotable.
4087 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(StoreBasePtr)) {
4088 ResplitPromotableAllocas.insert(OtherAI);
4089 Worklist.insert(OtherAI);
4090 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
4091 StoreBasePtr->stripInBoundsOffsets())) {
4092 Worklist.insert(OtherAI);
4093 }
4094
4095 // Mark the original store as dead.
4096 DeadInsts.push_back(SI);
4097 }
4098
4099 // Save the split loads if there are deferred stores among the users.
4100 if (DeferredStores)
4101 SplitLoadsMap.insert(std::make_pair(LI, std::move(SplitLoads)));
4102
4103 // Mark the original load as dead and kill the original slice.
4104 DeadInsts.push_back(LI);
4105 Offsets.S->kill();
4106 }
4107
4108 // Second, we rewrite all of the split stores. At this point, we know that
4109 // all loads from this alloca have been split already. For stores of such
4110 // loads, we can simply look up the pre-existing split loads. For stores of
4111 // other loads, we split those loads first and then write split stores of
4112 // them.
4113 for (StoreInst *SI : Stores) {
4114 auto *LI = cast<LoadInst>(SI->getValueOperand());
4115 IntegerType *Ty = cast<IntegerType>(LI->getType());
4116 uint64_t StoreSize = Ty->getBitWidth() / 8;
4117 assert(StoreSize > 0 && "Cannot have a zero-sized integer store!")((StoreSize > 0 && "Cannot have a zero-sized integer store!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize > 0 && \"Cannot have a zero-sized integer store!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4117, __PRETTY_FUNCTION__))
;
4118
4119 auto &Offsets = SplitOffsetsMap[SI];
4120 assert(StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&((StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4121, __PRETTY_FUNCTION__))
4121 "Slice size should always match load size exactly!")((StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4121, __PRETTY_FUNCTION__))
;
4122 uint64_t BaseOffset = Offsets.S->beginOffset();
4123 assert(BaseOffset + StoreSize > BaseOffset &&((BaseOffset + StoreSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4124, __PRETTY_FUNCTION__))
4124 "Cannot represent alloca access size using 64-bit integers!")((BaseOffset + StoreSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4124, __PRETTY_FUNCTION__))
;
4125
4126 Value *LoadBasePtr = LI->getPointerOperand();
4127 Instruction *StoreBasePtr = cast<Instruction>(SI->getPointerOperand());
4128
4129 LLVM_DEBUG(dbgs() << " Splitting store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store: " << *SI
<< "\n"; } } while (false)
;
4130
4131 // Check whether we have an already split load.
4132 auto SplitLoadsMapI = SplitLoadsMap.find(LI);
4133 std::vector<LoadInst *> *SplitLoads = nullptr;
4134 if (SplitLoadsMapI != SplitLoadsMap.end()) {
4135 SplitLoads = &SplitLoadsMapI->second;
4136 assert(SplitLoads->size() == Offsets.Splits.size() + 1 &&((SplitLoads->size() == Offsets.Splits.size() + 1 &&
"Too few split loads for the number of splits in the store!"
) ? static_cast<void> (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4137, __PRETTY_FUNCTION__))
4137 "Too few split loads for the number of splits in the store!")((SplitLoads->size() == Offsets.Splits.size() + 1 &&
"Too few split loads for the number of splits in the store!"
) ? static_cast<void> (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4137, __PRETTY_FUNCTION__))
;
4138 } else {
4139 LLVM_DEBUG(dbgs() << " of load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of load: " << *LI
<< "\n"; } } while (false)
;
4140 }
4141
4142 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
4143 int Idx = 0, Size = Offsets.Splits.size();
4144 for (;;) {
4145 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
4146 auto *LoadPartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
4147 auto *StorePartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
4148
4149 // Either lookup a split load or create one.
4150 LoadInst *PLoad;
4151 if (SplitLoads) {
4152 PLoad = (*SplitLoads)[Idx];
4153 } else {
4154 IRB.SetInsertPoint(LI);
4155 auto AS = LI->getPointerAddressSpace();
4156 PLoad = IRB.CreateAlignedLoad(
4157 PartTy,
4158 getAdjustedPtr(IRB, DL, LoadBasePtr,
4159 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4160 LoadPartPtrTy, LoadBasePtr->getName() + "."),
4161 getAdjustedAlignment(LI, PartOffset),
4162 /*IsVolatile*/ false, LI->getName());
4163 }
4164
4165 // And store this partition.
4166 IRB.SetInsertPoint(SI);
4167 auto AS = SI->getPointerAddressSpace();
4168 StoreInst *PStore = IRB.CreateAlignedStore(
4169 PLoad,
4170 getAdjustedPtr(IRB, DL, StoreBasePtr,
4171 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4172 StorePartPtrTy, StoreBasePtr->getName() + "."),
4173 getAdjustedAlignment(SI, PartOffset),
4174 /*IsVolatile*/ false);
4175
4176 // Now build a new slice for the alloca.
4177 NewSlices.push_back(
4178 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
4179 &PStore->getOperandUse(PStore->getPointerOperandIndex()),
4180 /*IsSplittable*/ false));
4181 LLVM_DEBUG(dbgs() << " new slice [" << NewSlices.back().beginOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
4182 << ", " << NewSlices.back().endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
4183 << "): " << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
;
4184 if (!SplitLoads) {
4185 LLVM_DEBUG(dbgs() << " of split load: " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of split load: " << *
PLoad << "\n"; } } while (false)
;
4186 }
4187
4188 // See if we've finished all the splits.
4189 if (Idx >= Size)
4190 break;
4191
4192 // Setup the next partition.
4193 PartOffset = Offsets.Splits[Idx];
4194 ++Idx;
4195 PartSize = (Idx < Size ? Offsets.Splits[Idx] : StoreSize) - PartOffset;
4196 }
4197
4198 // We want to immediately iterate on any allocas impacted by splitting
4199 // this load, which is only relevant if it isn't a load of this alloca and
4200 // thus we didn't already split the loads above. We also have to keep track
4201 // of any promotable allocas we split loads on as they can no longer be
4202 // promoted.
4203 if (!SplitLoads) {
4204 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(LoadBasePtr)) {
4205 assert(OtherAI != &AI && "We can't re-split our own alloca!")((OtherAI != &AI && "We can't re-split our own alloca!"
) ? static_cast<void> (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4205, __PRETTY_FUNCTION__))
;
4206 ResplitPromotableAllocas.insert(OtherAI);
4207 Worklist.insert(OtherAI);
4208 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
4209 LoadBasePtr->stripInBoundsOffsets())) {
4210 assert(OtherAI != &AI && "We can't re-split our own alloca!")((OtherAI != &AI && "We can't re-split our own alloca!"
) ? static_cast<void> (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4210, __PRETTY_FUNCTION__))
;
4211 Worklist.insert(OtherAI);
4212 }
4213 }
4214
4215 // Mark the original store as dead now that we've split it up and kill its
4216 // slice. Note that we leave the original load in place unless this store
4217 // was its only use. It may in turn be split up if it is an alloca load
4218 // for some other alloca, but it may be a normal load. This may introduce
4219 // redundant loads, but where those can be merged the rest of the optimizer
4220 // should handle the merging, and this uncovers SSA splits which is more
4221 // important. In practice, the original loads will almost always be fully
4222 // split and removed eventually, and the splits will be merged by any
4223 // trivial CSE, including instcombine.
4224 if (LI->hasOneUse()) {
4225 assert(*LI->user_begin() == SI && "Single use isn't this store!")((*LI->user_begin() == SI && "Single use isn't this store!"
) ? static_cast<void> (0) : __assert_fail ("*LI->user_begin() == SI && \"Single use isn't this store!\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4225, __PRETTY_FUNCTION__))
;
4226 DeadInsts.push_back(LI);
4227 }
4228 DeadInsts.push_back(SI);
4229 Offsets.S->kill();
4230 }
4231
4232 // Remove the killed slices that have ben pre-split.
4233 llvm::erase_if(AS, [](const Slice &S) { return S.isDead(); });
4234
4235 // Insert our new slices. This will sort and merge them into the sorted
4236 // sequence.
4237 AS.insert(NewSlices);
4238
4239 LLVM_DEBUG(dbgs() << " Pre-split slices:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Pre-split slices:\n"; } } while
(false)
;
4240#ifndef NDEBUG
4241 for (auto I = AS.begin(), E = AS.end(); I != E; ++I)
4242 LLVM_DEBUG(AS.print(dbgs(), I, " "))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs(), I, " "); } } while (false)
;
4243#endif
4244
4245 // Finally, don't try to promote any allocas that new require re-splitting.
4246 // They have already been added to the worklist above.
4247 llvm::erase_if(PromotableAllocas, [&](AllocaInst *AI) {
4248 return ResplitPromotableAllocas.count(AI);
4249 });
4250
4251 return true;
4252}
4253
4254/// Rewrite an alloca partition's users.
4255///
4256/// This routine drives both of the rewriting goals of the SROA pass. It tries
4257/// to rewrite uses of an alloca partition to be conducive for SSA value
4258/// promotion. If the partition needs a new, more refined alloca, this will
4259/// build that new alloca, preserving as much type information as possible, and
4260/// rewrite the uses of the old alloca to point at the new one and have the
4261/// appropriate new offsets. It also evaluates how successful the rewrite was
4262/// at enabling promotion and if it was successful queues the alloca to be
4263/// promoted.
4264AllocaInst *SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS,
4265 Partition &P) {
4266 // Try to compute a friendly type for this partition of the alloca. This
4267 // won't always succeed, in which case we fall back to a legal integer type
4268 // or an i8 array of an appropriate size.
4269 Type *SliceTy = nullptr;
4270 const DataLayout &DL = AI.getModule()->getDataLayout();
4271 std::pair<Type *, IntegerType *> CommonUseTy =
4272 findCommonType(P.begin(), P.end(), P.endOffset());
4273 // Do all uses operate on the same type?
4274 if (CommonUseTy.first)
4275 if (DL.getTypeAllocSize(CommonUseTy.first).getFixedSize() >= P.size())
4276 SliceTy = CommonUseTy.first;
4277 // If not, can we find an appropriate subtype in the original allocated type?
4278 if (!SliceTy)
4279 if (Type *TypePartitionTy = getTypePartition(DL, AI.getAllocatedType(),
4280 P.beginOffset(), P.size()))
4281 SliceTy = TypePartitionTy;
4282 // If still not, can we use the largest bitwidth integer type used?
4283 if (!SliceTy && CommonUseTy.second)
4284 if (DL.getTypeAllocSize(CommonUseTy.second).getFixedSize() >= P.size())
4285 SliceTy = CommonUseTy.second;
4286 if ((!SliceTy || (SliceTy->isArrayTy() &&
4287 SliceTy->getArrayElementType()->isIntegerTy())) &&
4288 DL.isLegalInteger(P.size() * 8))
4289 SliceTy = Type::getIntNTy(*C, P.size() * 8);
4290 if (!SliceTy)
4291 SliceTy = ArrayType::get(Type::getInt8Ty(*C), P.size());
4292 assert(DL.getTypeAllocSize(SliceTy).getFixedSize() >= P.size())((DL.getTypeAllocSize(SliceTy).getFixedSize() >= P.size())
? static_cast<void> (0) : __assert_fail ("DL.getTypeAllocSize(SliceTy).getFixedSize() >= P.size()"
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4292, __PRETTY_FUNCTION__))
;
4293
4294 bool IsIntegerPromotable = isIntegerWideningViable(P, SliceTy, DL);
4295
4296 VectorType *VecTy =
4297 IsIntegerPromotable ? nullptr : isVectorPromotionViable(P, DL);
4298 if (VecTy)
4299 SliceTy = VecTy;
4300
4301 // Check for the case where we're going to rewrite to a new alloca of the
4302 // exact same type as the original, and with the same access offsets. In that
4303 // case, re-use the existing alloca, but still run through the rewriter to
4304 // perform phi and select speculation.
4305 // P.beginOffset() can be non-zero even with the same type in a case with
4306 // out-of-bounds access (e.g. @PR35657 function in SROA/basictest.ll).
4307 AllocaInst *NewAI;
4308 if (SliceTy == AI.getAllocatedType() && P.beginOffset() == 0) {
4309 NewAI = &AI;
4310 // FIXME: We should be able to bail at this point with "nothing changed".
4311 // FIXME: We might want to defer PHI speculation until after here.
4312 // FIXME: return nullptr;
4313 } else {
4314 // Make sure the alignment is compatible with P.beginOffset().
4315 const Align Alignment = commonAlignment(AI.getAlign(), P.beginOffset());
4316 // If we will get at least this much alignment from the type alone, leave
4317 // the alloca's alignment unconstrained.
4318 const bool IsUnconstrained = Alignment <= DL.getABITypeAlign(SliceTy);
4319 NewAI = new AllocaInst(
4320 SliceTy, AI.getType()->getAddressSpace(), nullptr,
4321 IsUnconstrained ? DL.getPrefTypeAlign(SliceTy) : Alignment,
4322 AI.getName() + ".sroa." + Twine(P.begin() - AS.begin()), &AI);
4323 // Copy the old AI debug location over to the new one.
4324 NewAI->setDebugLoc(AI.getDebugLoc());
4325 ++NumNewAllocas;
4326 }
4327
4328 LLVM_DEBUG(dbgs() << "Rewriting alloca partition "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
4329 << "[" << P.beginOffset() << "," << P.endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
4330 << ") to: " << *NewAI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
;
4331
4332 // Track the high watermark on the worklist as it is only relevant for
4333 // promoted allocas. We will reset it to this point if the alloca is not in
4334 // fact scheduled for promotion.
4335 unsigned PPWOldSize = PostPromotionWorklist.size();
4336 unsigned NumUses = 0;
4337 SmallSetVector<PHINode *, 8> PHIUsers;
4338 SmallSetVector<SelectInst *, 8> SelectUsers;
4339
4340 AllocaSliceRewriter Rewriter(DL, AS, *this, AI, *NewAI, P.beginOffset(),
4341 P.endOffset(), IsIntegerPromotable, VecTy,
4342 PHIUsers, SelectUsers);
4343 bool Promotable = true;
4344 for (Slice *S : P.splitSliceTails()) {
4345 Promotable &= Rewriter.visit(S);
4346 ++NumUses;
4347 }
4348 for (Slice &S : P) {
4349 Promotable &= Rewriter.visit(&S);
4350 ++NumUses;
4351 }
4352
4353 NumAllocaPartitionUses += NumUses;
4354 MaxUsesPerAllocaPartition.updateMax(NumUses);
4355
4356 // Now that we've processed all the slices in the new partition, check if any
4357 // PHIs or Selects would block promotion.
4358 for (PHINode *PHI : PHIUsers)
4359 if (!isSafePHIToSpeculate(*PHI)) {
4360 Promotable = false;
4361 PHIUsers.clear();
4362 SelectUsers.clear();
4363 break;
4364 }
4365
4366 for (SelectInst *Sel : SelectUsers)
4367 if (!isSafeSelectToSpeculate(*Sel)) {
4368 Promotable = false;
4369 PHIUsers.clear();
4370 SelectUsers.clear();
4371 break;
4372 }
4373
4374 if (Promotable) {
4375 for (Use *U : AS.getDeadUsesIfPromotable()) {
4376 auto *OldInst = dyn_cast<Instruction>(U->get());
4377 Value::dropDroppableUse(*U);
4378 if (OldInst)
4379 if (isInstructionTriviallyDead(OldInst))
4380 DeadInsts.push_back(OldInst);
4381 }
4382 if (PHIUsers.empty() && SelectUsers.empty()) {
4383 // Promote the alloca.
4384 PromotableAllocas.push_back(NewAI);
4385 } else {
4386 // If we have either PHIs or Selects to speculate, add them to those
4387 // worklists and re-queue the new alloca so that we promote in on the
4388 // next iteration.
4389 for (PHINode *PHIUser : PHIUsers)
4390 SpeculatablePHIs.insert(PHIUser);
4391 for (SelectInst *SelectUser : SelectUsers)
4392 SpeculatableSelects.insert(SelectUser);
4393 Worklist.insert(NewAI);
4394 }
4395 } else {
4396 // Drop any post-promotion work items if promotion didn't happen.
4397 while (PostPromotionWorklist.size() > PPWOldSize)
4398 PostPromotionWorklist.pop_back();
4399
4400 // We couldn't promote and we didn't create a new partition, nothing
4401 // happened.
4402 if (NewAI == &AI)
4403 return nullptr;
4404
4405 // If we can't promote the alloca, iterate on it to check for new
4406 // refinements exposed by splitting the current alloca. Don't iterate on an
4407 // alloca which didn't actually change and didn't get promoted.
4408 Worklist.insert(NewAI);
4409 }
4410
4411 return NewAI;
4412}
4413
4414/// Walks the slices of an alloca and form partitions based on them,
4415/// rewriting each of their uses.
4416bool SROA::splitAlloca(AllocaInst &AI, AllocaSlices &AS) {
4417 if (AS.begin() == AS.end())
4418 return false;
4419
4420 unsigned NumPartitions = 0;
4421 bool Changed = false;
4422 const DataLayout &DL = AI.getModule()->getDataLayout();
4423
4424 // First try to pre-split loads and stores.
4425 Changed |= presplitLoadsAndStores(AI, AS);
4426
4427 // Now that we have identified any pre-splitting opportunities,
4428 // mark loads and stores unsplittable except for the following case.
4429 // We leave a slice splittable if all other slices are disjoint or fully
4430 // included in the slice, such as whole-alloca loads and stores.
4431 // If we fail to split these during pre-splitting, we want to force them
4432 // to be rewritten into a partition.
4433 bool IsSorted = true;
4434
4435 uint64_t AllocaSize =
4436 DL.getTypeAllocSize(AI.getAllocatedType()).getFixedSize();
4437 const uint64_t MaxBitVectorSize = 1024;
4438 if (AllocaSize <= MaxBitVectorSize) {
4439 // If a byte boundary is included in any load or store, a slice starting or
4440 // ending at the boundary is not splittable.
4441 SmallBitVector SplittableOffset(AllocaSize + 1, true);
4442 for (Slice &S : AS)
4443 for (unsigned O = S.beginOffset() + 1;
4444 O < S.endOffset() && O < AllocaSize; O++)
4445 SplittableOffset.reset(O);
4446
4447 for (Slice &S : AS) {
4448 if (!S.isSplittable())
4449 continue;
4450
4451 if ((S.beginOffset() > AllocaSize || SplittableOffset[S.beginOffset()]) &&
4452 (S.endOffset() > AllocaSize || SplittableOffset[S.endOffset()]))
4453 continue;
4454
4455 if (isa<LoadInst>(S.getUse()->getUser()) ||
4456 isa<StoreInst>(S.getUse()->getUser())) {
4457 S.makeUnsplittable();
4458 IsSorted = false;
4459 }
4460 }
4461 }
4462 else {
4463 // We only allow whole-alloca splittable loads and stores
4464 // for a large alloca to avoid creating too large BitVector.
4465 for (Slice &S : AS) {
4466 if (!S.isSplittable())
4467 continue;
4468
4469 if (S.beginOffset() == 0 && S.endOffset() >= AllocaSize)
4470 continue;
4471
4472 if (isa<LoadInst>(S.getUse()->getUser()) ||
4473 isa<StoreInst>(S.getUse()->getUser())) {
4474 S.makeUnsplittable();
4475 IsSorted = false;
4476 }
4477 }
4478 }
4479
4480 if (!IsSorted)
4481 llvm::sort(AS);
4482
4483 /// Describes the allocas introduced by rewritePartition in order to migrate
4484 /// the debug info.
4485 struct Fragment {
4486 AllocaInst *Alloca;
4487 uint64_t Offset;
4488 uint64_t Size;
4489 Fragment(AllocaInst *AI, uint64_t O, uint64_t S)
4490 : Alloca(AI), Offset(O), Size(S) {}
4491 };
4492 SmallVector<Fragment, 4> Fragments;
4493
4494 // Rewrite each partition.
4495 for (auto &P : AS.partitions()) {
4496 if (AllocaInst *NewAI = rewritePartition(AI, AS, P)) {
4497 Changed = true;
4498 if (NewAI != &AI) {
4499 uint64_t SizeOfByte = 8;
4500 uint64_t AllocaSize =
4501 DL.getTypeSizeInBits(NewAI->getAllocatedType()).getFixedSize();
4502 // Don't include any padding.
4503 uint64_t Size = std::min(AllocaSize, P.size() * SizeOfByte);
4504 Fragments.push_back(Fragment(NewAI, P.beginOffset() * SizeOfByte, Size));
4505 }
4506 }
4507 ++NumPartitions;
4508 }
4509
4510 NumAllocaPartitions += NumPartitions;
4511 MaxPartitionsPerAlloca.updateMax(NumPartitions);
4512
4513 // Migrate debug information from the old alloca to the new alloca(s)
4514 // and the individual partitions.
4515 TinyPtrVector<DbgVariableIntrinsic *> DbgDeclares = FindDbgAddrUses(&AI);
4516 for (DbgVariableIntrinsic *DbgDeclare : DbgDeclares) {
4517 auto *Expr = DbgDeclare->getExpression();
4518 DIBuilder DIB(*AI.getModule(), /*AllowUnresolved*/ false);
4519 uint64_t AllocaSize =
4520 DL.getTypeSizeInBits(AI.getAllocatedType()).getFixedSize();
4521 for (auto Fragment : Fragments) {
4522 // Create a fragment expression describing the new partition or reuse AI's
4523 // expression if there is only one partition.
4524 auto *FragmentExpr = Expr;
4525 if (Fragment.Size < AllocaSize || Expr->isFragment()) {
4526 // If this alloca is already a scalar replacement of a larger aggregate,
4527 // Fragment.Offset describes the offset inside the scalar.
4528 auto ExprFragment = Expr->getFragmentInfo();
4529 uint64_t Offset = ExprFragment ? ExprFragment->OffsetInBits : 0;
4530 uint64_t Start = Offset + Fragment.Offset;
4531 uint64_t Size = Fragment.Size;
4532 if (ExprFragment) {
4533 uint64_t AbsEnd =
4534 ExprFragment->OffsetInBits + ExprFragment->SizeInBits;
4535 if (Start >= AbsEnd)
4536 // No need to describe a SROAed padding.
4537 continue;
4538 Size = std::min(Size, AbsEnd - Start);
4539 }
4540 // The new, smaller fragment is stenciled out from the old fragment.
4541 if (auto OrigFragment = FragmentExpr->getFragmentInfo()) {
4542 assert(Start >= OrigFragment->OffsetInBits &&((Start >= OrigFragment->OffsetInBits && "new fragment is outside of original fragment"
) ? static_cast<void> (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4543, __PRETTY_FUNCTION__))
4543 "new fragment is outside of original fragment")((Start >= OrigFragment->OffsetInBits && "new fragment is outside of original fragment"
) ? static_cast<void> (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-13~++20210413100635+64c24f493e5f/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4543, __PRETTY_FUNCTION__))
;
4544 Start -= OrigFragment->OffsetInBits;
4545 }
4546
4547 // The alloca may be larger than the variable.
4548 auto VarSize = DbgDeclare->getVariable()->getSizeInBits();
4549 if (VarSize) {
4550 if (Size > *VarSize)
4551 Size = *VarSize;
4552 if (Size == 0 || Start + Size > *VarSize)
4553 continue;
4554 }
4555
4556 // Avoid creating a fragment expression that covers the entire variable.
4557 if (!VarSize || *VarSize != Size) {
4558 if (auto E =
4559 DIExpression::createFragmentExpression(Expr, Start, Size))
4560 FragmentExpr = *E;
4561 else
4562 continue;
4563 }
4564 }
4565
4566 // Remove any existing intrinsics on the new alloca describing
4567 // the variable fragment.
4568 for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(Fragment.Alloca)) {
4569 auto SameVariableFragment = [](const DbgVariableIntrinsic *LHS,
4570 const DbgVariableIntrinsic *RHS) {
4571 return LHS->getVariable() == RHS->getVariable() &&
4572 LHS->getDebugLoc()->getInlinedAt() ==
4573 RHS->getDebugLoc()->getInlinedAt();
4574 };
4575 if (SameVariableFragment(OldDII, DbgDeclare))
4576 OldDII->eraseFromParent();
4577 }
4578
4579 DIB.insertDeclare(Fragment.Alloca, DbgDeclare->getVariable(), FragmentExpr,
4580 DbgDeclare->getDebugLoc(), &AI);
4581 }
4582 }
4583 return Changed;
4584}
4585
4586/// Clobber a use with undef, deleting the used value if it becomes dead.
4587void SROA::clobberUse(Use &U) {
4588 Value *OldV = U;
4589 // Replace the use with an undef value.
4590 U = UndefValue::get(OldV->getType());
4591
4592 // Check for this making an instruction dead. We have to garbage collect
4593 // all the dead instructions to ensure the uses of any alloca end up being
4594 // minimal.
4595 if (Instruction *OldI = dyn_cast<Instruction>(OldV))
4596 if (isInstructionTriviallyDead(OldI)) {
4597 DeadInsts.push_back(OldI);
4598 }
4599}
4600
4601/// Analyze an alloca for SROA.
4602///
4603/// This analyzes the alloca to ensure we can reason about it, builds
4604/// the slices of the alloca, and then hands it off to be split and
4605/// rewritten as needed.
4606bool SROA::runOnAlloca(AllocaInst &AI) {
4607 LLVM_DEBUG(dbgs() << "SROA alloca: " << AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA alloca: " << AI <<
"\n"; } } while (false)
;
4608 ++NumAllocasAnalyzed;
4609
4610 // Special case dead allocas, as they're trivial.
4611 if (AI.use_empty()) {
4612 AI.eraseFromParent();
4613 return true;
4614 }
4615 const DataLayout &DL = AI.getModule()->getDataLayout();
4616
4617 // Skip alloca forms that this analysis can't handle.
4618 auto *AT = AI.getAllocatedType();
4619 if (AI.isArrayAllocation() || !AT->isSized() || isa<ScalableVectorType>(AT) ||
4620 DL.getTypeAllocSize(AT).getFixedSize() == 0)
4621 return false;
4622
4623 bool Changed = false;
4624
4625 // First, split any FCA loads and stores touching this alloca to promote
4626 // better splitting and promotion opportunities.
4627 AggLoadStoreRewriter AggRewriter(DL);
4628 Changed |= AggRewriter.rewrite(AI);
4629
4630 // Build the slices using a recursive instruction-visiting builder.
4631 AllocaSlices AS(DL, AI);
4632 LLVM_DEBUG(AS.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs()); } } while (false)
;
4633 if (AS.isEscaped())
4634 return Changed;
4635
4636 // Delete all the dead users of this alloca before splitting and rewriting it.
4637 for (Instruction *DeadUser : AS.getDeadUsers()) {
4638 // Free up everything used by this instruction.
4639 for (Use &DeadOp : DeadUser->operands())
4640 clobberUse(DeadOp);
4641
4642 // Now replace the uses of this instruction.
4643 DeadUser->replaceAllUsesWith(UndefValue::get(DeadUser->getType()));
4644
4645 // And mark it for deletion.
4646 DeadInsts.push_back(DeadUser);
4647 Changed = true;
4648 }
4649 for (Use *DeadOp : AS.getDeadOperands()) {
4650 clobberUse(*DeadOp);
4651 Changed = true;
4652 }
4653
4654 // No slices to split. Leave the dead alloca for a later pass to clean up.
4655 if (AS.begin() == AS.end())
4656 return Changed;
4657
4658 Changed |= splitAlloca(AI, AS);
4659
4660 LLVM_DEBUG(dbgs() << " Speculating PHIs\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating PHIs\n"; } } while
(false)
;
4661 while (!SpeculatablePHIs.empty())
4662 speculatePHINodeLoads(*SpeculatablePHIs.pop_back_val());
4663
4664 LLVM_DEBUG(dbgs() << " Speculating Selects\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating Selects\n"; } } while
(false)
;
4665 while (!SpeculatableSelects.empty())
4666 speculateSelectInstLoads(*SpeculatableSelects.pop_back_val());
4667
4668 return Changed;
4669}
4670
4671/// Delete the dead instructions accumulated in this run.
4672///
4673/// Recursively deletes the dead instructions we've accumulated. This is done
4674/// at the very end to maximize locality of the recursive delete and to
4675/// minimize the problems of invalidated instruction pointers as such pointers
4676/// are used heavily in the intermediate stages of the algorithm.
4677///
4678/// We also record the alloca instructions deleted here so that they aren't
4679/// subsequently handed to mem2reg to promote.
4680bool SROA::deleteDeadInstructions(
4681 SmallPtrSetImpl<AllocaInst *> &DeletedAllocas) {
4682 bool Changed = false;
4683 while (!DeadInsts.empty()) {
4684 Instruction *I = dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val());
4685 if (!I) continue;
4686 LLVM_DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Deleting dead instruction: " <<
*I << "\n"; } } while (false)
;
4687
4688 // If the instruction is an alloca, find the possible dbg.declare connected
4689 // to it, and remove it too. We must do this before calling RAUW or we will
4690 // not be able to find it.
4691 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4692 DeletedAllocas.insert(AI);
4693 for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(AI))
4694 OldDII->eraseFromParent();
4695 }
4696
4697 I->replaceAllUsesWith(UndefValue::get(I->getType()));
4698
4699 for (Use &Operand : I->operands())
4700 if (Instruction *U = dyn_cast<Instruction>(Operand)) {
4701 // Zero out the operand and see if it becomes trivially dead.
4702 Operand = nullptr;
4703 if (isInstructionTriviallyDead(U))
4704 DeadInsts.push_back(U);
4705 }
4706
4707 ++NumDeleted;
4708 I->eraseFromParent();
4709 Changed = true;
4710 }
4711 return Changed;
4712}
4713
4714/// Promote the allocas, using the best available technique.
4715///
4716/// This attempts to promote whatever allocas have been identified as viable in
4717/// the PromotableAllocas list. If that list is empty, there is nothing to do.
4718/// This function returns whether any promotion occurred.
4719bool SROA::promoteAllocas(Function &F) {
4720 if (PromotableAllocas.empty())
4721 return false;
4722
4723 NumPromoted += PromotableAllocas.size();
4724
4725 LLVM_DEBUG(dbgs() << "Promoting allocas with mem2reg...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Promoting allocas with mem2reg...\n"
; } } while (false)
;
4726 PromoteMemToReg(PromotableAllocas, *DT, AC);
4727 PromotableAllocas.clear();
4728 return true;
4729}
4730
4731PreservedAnalyses SROA::runImpl(Function &F, DominatorTree &RunDT,
4732 AssumptionCache &RunAC) {
4733 LLVM_DEBUG(dbgs() << "SROA function: " << F.getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA function: " << F.getName
() << "\n"; } } while (false)
;
4734 C = &F.getContext();
4735 DT = &RunDT;
4736 AC = &RunAC;
4737
4738 BasicBlock &EntryBB = F.getEntryBlock();
4739 for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
4740 I != E; ++I) {
4741 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4742 if (isa<ScalableVectorType>(AI->getAllocatedType())) {
4743 if (isAllocaPromotable(AI))
4744 PromotableAllocas.push_back(AI);
4745 } else {
4746 Worklist.insert(AI);
4747 }
4748 }
4749 }
4750
4751 bool Changed = false;
4752 // A set of deleted alloca instruction pointers which should be removed from
4753 // the list of promotable allocas.
4754 SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
4755
4756 do {
4757 while (!Worklist.empty()) {
4758 Changed |= runOnAlloca(*Worklist.pop_back_val());
4759 Changed |= deleteDeadInstructions(DeletedAllocas);
4760
4761 // Remove the deleted allocas from various lists so that we don't try to
4762 // continue processing them.
4763 if (!DeletedAllocas.empty()) {
4764 auto IsInSet = [&](AllocaInst *AI) { return DeletedAllocas.count(AI); };
4765 Worklist.remove_if(IsInSet);
4766 PostPromotionWorklist.remove_if(IsInSet);
4767 llvm::erase_if(PromotableAllocas, IsInSet);
4768 DeletedAllocas.clear();
4769 }
4770 }
4771
4772 Changed |= promoteAllocas(F);
4773
4774 Worklist = PostPromotionWorklist;
4775 PostPromotionWorklist.clear();
4776 } while (!Worklist.empty());
4777
4778 if (!Changed)
4779 return PreservedAnalyses::all();
4780
4781 PreservedAnalyses PA;
4782 PA.preserveSet<CFGAnalyses>();
4783 PA.preserve<GlobalsAA>();
4784 return PA;
4785}
4786
4787PreservedAnalyses SROA::run(Function &F, FunctionAnalysisManager &AM) {
4788 return runImpl(F, AM.getResult<DominatorTreeAnalysis>(F),
4789 AM.getResult<AssumptionAnalysis>(F));
4790}
4791
4792/// A legacy pass for the legacy pass manager that wraps the \c SROA pass.
4793///
4794/// This is in the llvm namespace purely to allow it to be a friend of the \c
4795/// SROA pass.
4796class llvm::sroa::SROALegacyPass : public FunctionPass {
4797 /// The SROA implementation.
4798 SROA Impl;
4799
4800public:
4801 static char ID;
4802
4803 SROALegacyPass() : FunctionPass(ID) {
4804 initializeSROALegacyPassPass(*PassRegistry::getPassRegistry());
4805 }
4806
4807 bool runOnFunction(Function &F) override {
4808 if (skipFunction(F))
4809 return false;
4810
4811 auto PA = Impl.runImpl(
4812 F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
4813 getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F));
4814 return !PA.areAllPreserved();
4815 }
4816
4817 void getAnalysisUsage(AnalysisUsage &AU) const override {
4818 AU.addRequired<AssumptionCacheTracker>();
4819 AU.addRequired<DominatorTreeWrapperPass>();
4820 AU.addPreserved<GlobalsAAWrapperPass>();
4821 AU.setPreservesCFG();
4822 }
4823
4824 StringRef getPassName() const override { return "SROA"; }
4825};
4826
4827char SROALegacyPass::ID = 0;
4828
4829FunctionPass *llvm::createSROAPass() { return new SROALegacyPass(); }
4830
4831INITIALIZE_PASS_BEGIN(SROALegacyPass, "sroa",static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4832 "Scalar Replacement Of Aggregates", false, false)static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4833INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry);
4834INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
4835INITIALIZE_PASS_END(SROALegacyPass, "sroa", "Scalar Replacement Of Aggregates",PassInfo *PI = new PassInfo( "Scalar Replacement Of Aggregates"
, "sroa", &SROALegacyPass::ID, PassInfo::NormalCtor_t(callDefaultCtor
<SROALegacyPass>), false, false); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeSROALegacyPassPassFlag
; void llvm::initializeSROALegacyPassPass(PassRegistry &Registry
) { llvm::call_once(InitializeSROALegacyPassPassFlag, initializeSROALegacyPassPassOnce
, std::ref(Registry)); }
4836 false, false)PassInfo *PI = new PassInfo( "Scalar Replacement Of Aggregates"
, "sroa", &SROALegacyPass::ID, PassInfo::NormalCtor_t(callDefaultCtor
<SROALegacyPass>), false, false); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeSROALegacyPassPassFlag
; void llvm::initializeSROALegacyPassPass(PassRegistry &Registry
) { llvm::call_once(InitializeSROALegacyPassPassFlag, initializeSROALegacyPassPassOnce
, std::ref(Registry)); }