Bug Summary

File:llvm/lib/Transforms/Scalar/SROA.cpp
Warning:line 2956, column 54
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 -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-14~++20210828111110+16086d47c0d0/build-llvm/lib/Transforms/Scalar -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/lib/Transforms/Scalar -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0=. -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-2021-08-28-193554-24367-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/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 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!")(static_cast <bool> (BeginOffset < EndOffset &&
"Partitions must span some bytes!") ? void (0) : __assert_fail
("BeginOffset < EndOffset && \"Partitions must span some bytes!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 389, __extension__ __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()) &&(static_cast <bool> ((P.SI != SE || !P.SplitTails.empty
()) && "Cannot advance past the end of the slices!") ?
void (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 458, __extension__ __PRETTY_FUNCTION__))
458 "Cannot advance past the end of the slices!")(static_cast <bool> ((P.SI != SE || !P.SplitTails.empty
()) && "Cannot advance past the end of the slices!") ?
void (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 458, __extension__ __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,(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __extension__ __PRETTY_FUNCTION__))
473 [&](Slice *S) {(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __extension__ __PRETTY_FUNCTION__))
474 return S->endOffset() == MaxSplitSliceEndOffset;(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __extension__ __PRETTY_FUNCTION__))
475 }) &&(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __extension__ __PRETTY_FUNCTION__))
476 "Could not find the current max split slice offset!")(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 476, __extension__ __PRETTY_FUNCTION__))
;
477 assert(llvm::all_of(P.SplitTails,(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __extension__ __PRETTY_FUNCTION__))
478 [&](Slice *S) {(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __extension__ __PRETTY_FUNCTION__))
479 return S->endOffset() <= MaxSplitSliceEndOffset;(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __extension__ __PRETTY_FUNCTION__))
480 }) &&(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __extension__ __PRETTY_FUNCTION__))
481 "Max split slice end offset is not actually the max!")(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 481, __extension__ __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!")(static_cast <bool> (P.SplitTails.empty() && "Failed to clear the split slices!"
) ? void (0) : __assert_fail ("P.SplitTails.empty() && \"Failed to clear the split slices!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 488, __extension__ __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())(static_cast <bool> (P.BeginOffset == P.SI->beginOffset
()) ? void (0) : __assert_fail ("P.BeginOffset == P.SI->beginOffset()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 539, __extension__ __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!")(static_cast <bool> (P.SI->isSplittable() &&
"Forming a splittable partition!") ? void (0) : __assert_fail
("P.SI->isSplittable() && \"Forming a splittable partition!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 557, __extension__ __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())(static_cast <bool> (!P.SJ->isSplittable()) ? void (
0) : __assert_fail ("!P.SJ->isSplittable()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 570, __extension__ __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 &&(static_cast <bool> (SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? void (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 578, __extension__ __PRETTY_FUNCTION__))
578 "End iterators don't match between compared partition iterators!")(static_cast <bool> (SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? void (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 578, __extension__ __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 &&(static_cast <bool> (P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? void (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 587, __extension__ __PRETTY_FUNCTION__))
587 "Same set of slices formed two different sized partitions!")(static_cast <bool> (P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? void (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 587, __extension__ __PRETTY_FUNCTION__))
;
588 assert(P.SplitTails.size() == RHS.P.SplitTails.size() &&(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __extension__ __PRETTY_FUNCTION__))
589 "Same slice position with differently sized non-empty split "(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __extension__ __PRETTY_FUNCTION__))
590 "slice tails!")(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 590, __extension__ __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)(static_cast <bool> (AllocSize >= BeginOffset) ? void
(0) : __assert_fail ("AllocSize >= BeginOffset", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 691, __extension__ __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 =
772 Ty->isIntegerTy() && !IsVolatile && DL.typeSizeEqualsStoreSize(Ty);
773
774 insertUse(I, Offset, Size, IsSplittable);
775 }
776
777 void visitLoadInst(LoadInst &LI) {
778 assert((!LI.isSimple() || LI.getType()->isSingleValueType()) &&(static_cast <bool> ((!LI.isSimple() || LI.getType()->
isSingleValueType()) && "All simple FCA loads should have been pre-split"
) ? void (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 779, __extension__ __PRETTY_FUNCTION__))
779 "All simple FCA loads should have been pre-split")(static_cast <bool> ((!LI.isSimple() || LI.getType()->
isSingleValueType()) && "All simple FCA loads should have been pre-split"
) ? void (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 779, __extension__ __PRETTY_FUNCTION__))
;
780
781 if (!IsOffsetKnown)
782 return PI.setAborted(&LI);
783
784 if (LI.isVolatile() &&
785 LI.getPointerAddressSpace() != DL.getAllocaAddrSpace())
786 return PI.setAborted(&LI);
787
788 if (isa<ScalableVectorType>(LI.getType()))
789 return PI.setAborted(&LI);
790
791 uint64_t Size = DL.getTypeStoreSize(LI.getType()).getFixedSize();
792 return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
793 }
794
795 void visitStoreInst(StoreInst &SI) {
796 Value *ValOp = SI.getValueOperand();
797 if (ValOp == *U)
798 return PI.setEscapedAndAborted(&SI);
799 if (!IsOffsetKnown)
800 return PI.setAborted(&SI);
801
802 if (SI.isVolatile() &&
803 SI.getPointerAddressSpace() != DL.getAllocaAddrSpace())
804 return PI.setAborted(&SI);
805
806 if (isa<ScalableVectorType>(ValOp->getType()))
807 return PI.setAborted(&SI);
808
809 uint64_t Size = DL.getTypeStoreSize(ValOp->getType()).getFixedSize();
810
811 // If this memory access can be shown to *statically* extend outside the
812 // bounds of the allocation, it's behavior is undefined, so simply
813 // ignore it. Note that this is more strict than the generic clamping
814 // behavior of insertUse. We also try to handle cases which might run the
815 // risk of overflow.
816 // FIXME: We should instead consider the pointer to have escaped if this
817 // function is being instrumented for addressing bugs or race conditions.
818 if (Size > AllocSize || Offset.ugt(AllocSize - Size)) {
819 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)
820 << 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)
821 << 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)
822 << " 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)
823 << " 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)
;
824 return markAsDead(SI);
825 }
826
827 assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&(static_cast <bool> ((!SI.isSimple() || ValOp->getType
()->isSingleValueType()) && "All simple FCA stores should have been pre-split"
) ? void (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 828, __extension__ __PRETTY_FUNCTION__))
828 "All simple FCA stores should have been pre-split")(static_cast <bool> ((!SI.isSimple() || ValOp->getType
()->isSingleValueType()) && "All simple FCA stores should have been pre-split"
) ? void (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 828, __extension__ __PRETTY_FUNCTION__))
;
829 handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
830 }
831
832 void visitMemSetInst(MemSetInst &II) {
833 assert(II.getRawDest() == *U && "Pointer use is not the destination?")(static_cast <bool> (II.getRawDest() == *U && "Pointer use is not the destination?"
) ? void (0) : __assert_fail ("II.getRawDest() == *U && \"Pointer use is not the destination?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 833, __extension__ __PRETTY_FUNCTION__))
;
834 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
835 if ((Length && Length->getValue() == 0) ||
836 (IsOffsetKnown && Offset.uge(AllocSize)))
837 // Zero-length mem transfer intrinsics can be ignored entirely.
838 return markAsDead(II);
839
840 if (!IsOffsetKnown)
841 return PI.setAborted(&II);
842
843 // Don't replace this with a store with a different address space. TODO:
844 // Use a store with the casted new alloca?
845 if (II.isVolatile() && II.getDestAddressSpace() != DL.getAllocaAddrSpace())
846 return PI.setAborted(&II);
847
848 insertUse(II, Offset, Length ? Length->getLimitedValue()
849 : AllocSize - Offset.getLimitedValue(),
850 (bool)Length);
851 }
852
853 void visitMemTransferInst(MemTransferInst &II) {
854 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
855 if (Length && Length->getValue() == 0)
856 // Zero-length mem transfer intrinsics can be ignored entirely.
857 return markAsDead(II);
858
859 // Because we can visit these intrinsics twice, also check to see if the
860 // first time marked this instruction as dead. If so, skip it.
861 if (VisitedDeadInsts.count(&II))
862 return;
863
864 if (!IsOffsetKnown)
865 return PI.setAborted(&II);
866
867 // Don't replace this with a load/store with a different address space.
868 // TODO: Use a store with the casted new alloca?
869 if (II.isVolatile() &&
870 (II.getDestAddressSpace() != DL.getAllocaAddrSpace() ||
871 II.getSourceAddressSpace() != DL.getAllocaAddrSpace()))
872 return PI.setAborted(&II);
873
874 // This side of the transfer is completely out-of-bounds, and so we can
875 // nuke the entire transfer. However, we also need to nuke the other side
876 // if already added to our partitions.
877 // FIXME: Yet another place we really should bypass this when
878 // instrumenting for ASan.
879 if (Offset.uge(AllocSize)) {
880 SmallDenseMap<Instruction *, unsigned>::iterator MTPI =
881 MemTransferSliceMap.find(&II);
882 if (MTPI != MemTransferSliceMap.end())
883 AS.Slices[MTPI->second].kill();
884 return markAsDead(II);
885 }
886
887 uint64_t RawOffset = Offset.getLimitedValue();
888 uint64_t Size = Length ? Length->getLimitedValue() : AllocSize - RawOffset;
889
890 // Check for the special case where the same exact value is used for both
891 // source and dest.
892 if (*U == II.getRawDest() && *U == II.getRawSource()) {
893 // For non-volatile transfers this is a no-op.
894 if (!II.isVolatile())
895 return markAsDead(II);
896
897 return insertUse(II, Offset, Size, /*IsSplittable=*/false);
898 }
899
900 // If we have seen both source and destination for a mem transfer, then
901 // they both point to the same alloca.
902 bool Inserted;
903 SmallDenseMap<Instruction *, unsigned>::iterator MTPI;
904 std::tie(MTPI, Inserted) =
905 MemTransferSliceMap.insert(std::make_pair(&II, AS.Slices.size()));
906 unsigned PrevIdx = MTPI->second;
907 if (!Inserted) {
908 Slice &PrevP = AS.Slices[PrevIdx];
909
910 // Check if the begin offsets match and this is a non-volatile transfer.
911 // In that case, we can completely elide the transfer.
912 if (!II.isVolatile() && PrevP.beginOffset() == RawOffset) {
913 PrevP.kill();
914 return markAsDead(II);
915 }
916
917 // Otherwise we have an offset transfer within the same alloca. We can't
918 // split those.
919 PrevP.makeUnsplittable();
920 }
921
922 // Insert the use now that we've fixed up the splittable nature.
923 insertUse(II, Offset, Size, /*IsSplittable=*/Inserted && Length);
924
925 // Check that we ended up with a valid index in the map.
926 assert(AS.Slices[PrevIdx].getUse()->getUser() == &II &&(static_cast <bool> (AS.Slices[PrevIdx].getUse()->getUser
() == &II && "Map index doesn't point back to a slice with this user."
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 927, __extension__ __PRETTY_FUNCTION__))
927 "Map index doesn't point back to a slice with this user.")(static_cast <bool> (AS.Slices[PrevIdx].getUse()->getUser
() == &II && "Map index doesn't point back to a slice with this user."
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 927, __extension__ __PRETTY_FUNCTION__))
;
928 }
929
930 // Disable SRoA for any intrinsics except for lifetime invariants and
931 // invariant group.
932 // FIXME: What about debug intrinsics? This matches old behavior, but
933 // doesn't make sense.
934 void visitIntrinsicInst(IntrinsicInst &II) {
935 if (II.isDroppable()) {
936 AS.DeadUseIfPromotable.push_back(U);
937 return;
938 }
939
940 if (!IsOffsetKnown)
941 return PI.setAborted(&II);
942
943 if (II.isLifetimeStartOrEnd()) {
944 ConstantInt *Length = cast<ConstantInt>(II.getArgOperand(0));
945 uint64_t Size = std::min(AllocSize - Offset.getLimitedValue(),
946 Length->getLimitedValue());
947 insertUse(II, Offset, Size, true);
948 return;
949 }
950
951 if (II.isLaunderOrStripInvariantGroup()) {
952 enqueueUsers(II);
953 return;
954 }
955
956 Base::visitIntrinsicInst(II);
957 }
958
959 Instruction *hasUnsafePHIOrSelectUse(Instruction *Root, uint64_t &Size) {
960 // We consider any PHI or select that results in a direct load or store of
961 // the same offset to be a viable use for slicing purposes. These uses
962 // are considered unsplittable and the size is the maximum loaded or stored
963 // size.
964 SmallPtrSet<Instruction *, 4> Visited;
965 SmallVector<std::pair<Instruction *, Instruction *>, 4> Uses;
966 Visited.insert(Root);
967 Uses.push_back(std::make_pair(cast<Instruction>(*U), Root));
968 const DataLayout &DL = Root->getModule()->getDataLayout();
969 // If there are no loads or stores, the access is dead. We mark that as
970 // a size zero access.
971 Size = 0;
972 do {
973 Instruction *I, *UsedI;
974 std::tie(UsedI, I) = Uses.pop_back_val();
975
976 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
977 Size = std::max(Size,
978 DL.getTypeStoreSize(LI->getType()).getFixedSize());
979 continue;
980 }
981 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
982 Value *Op = SI->getOperand(0);
983 if (Op == UsedI)
984 return SI;
985 Size = std::max(Size,
986 DL.getTypeStoreSize(Op->getType()).getFixedSize());
987 continue;
988 }
989
990 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
991 if (!GEP->hasAllZeroIndices())
992 return GEP;
993 } else if (!isa<BitCastInst>(I) && !isa<PHINode>(I) &&
994 !isa<SelectInst>(I) && !isa<AddrSpaceCastInst>(I)) {
995 return I;
996 }
997
998 for (User *U : I->users())
999 if (Visited.insert(cast<Instruction>(U)).second)
1000 Uses.push_back(std::make_pair(I, cast<Instruction>(U)));
1001 } while (!Uses.empty());
1002
1003 return nullptr;
1004 }
1005
1006 void visitPHINodeOrSelectInst(Instruction &I) {
1007 assert(isa<PHINode>(I) || isa<SelectInst>(I))(static_cast <bool> (isa<PHINode>(I) || isa<SelectInst
>(I)) ? void (0) : __assert_fail ("isa<PHINode>(I) || isa<SelectInst>(I)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1007, __extension__ __PRETTY_FUNCTION__))
;
1008 if (I.use_empty())
1009 return markAsDead(I);
1010
1011 // TODO: We could use SimplifyInstruction here to fold PHINodes and
1012 // SelectInsts. However, doing so requires to change the current
1013 // dead-operand-tracking mechanism. For instance, suppose neither loading
1014 // from %U nor %other traps. Then "load (select undef, %U, %other)" does not
1015 // trap either. However, if we simply replace %U with undef using the
1016 // current dead-operand-tracking mechanism, "load (select undef, undef,
1017 // %other)" may trap because the select may return the first operand
1018 // "undef".
1019 if (Value *Result = foldPHINodeOrSelectInst(I)) {
1020 if (Result == *U)
1021 // If the result of the constant fold will be the pointer, recurse
1022 // through the PHI/select as if we had RAUW'ed it.
1023 enqueueUsers(I);
1024 else
1025 // Otherwise the operand to the PHI/select is dead, and we can replace
1026 // it with undef.
1027 AS.DeadOperands.push_back(U);
1028
1029 return;
1030 }
1031
1032 if (!IsOffsetKnown)
1033 return PI.setAborted(&I);
1034
1035 // See if we already have computed info on this node.
1036 uint64_t &Size = PHIOrSelectSizes[&I];
1037 if (!Size) {
1038 // This is a new PHI/Select, check for an unsafe use of it.
1039 if (Instruction *UnsafeI = hasUnsafePHIOrSelectUse(&I, Size))
1040 return PI.setAborted(UnsafeI);
1041 }
1042
1043 // For PHI and select operands outside the alloca, we can't nuke the entire
1044 // phi or select -- the other side might still be relevant, so we special
1045 // case them here and use a separate structure to track the operands
1046 // themselves which should be replaced with undef.
1047 // FIXME: This should instead be escaped in the event we're instrumenting
1048 // for address sanitization.
1049 if (Offset.uge(AllocSize)) {
1050 AS.DeadOperands.push_back(U);
1051 return;
1052 }
1053
1054 insertUse(I, Offset, Size);
1055 }
1056
1057 void visitPHINode(PHINode &PN) { visitPHINodeOrSelectInst(PN); }
1058
1059 void visitSelectInst(SelectInst &SI) { visitPHINodeOrSelectInst(SI); }
1060
1061 /// Disable SROA entirely if there are unhandled users of the alloca.
1062 void visitInstruction(Instruction &I) { PI.setAborted(&I); }
1063};
1064
1065AllocaSlices::AllocaSlices(const DataLayout &DL, AllocaInst &AI)
1066 :
1067#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1068 AI(AI),
1069#endif
1070 PointerEscapingInstr(nullptr) {
1071 SliceBuilder PB(DL, AI, *this);
1072 SliceBuilder::PtrInfo PtrI = PB.visitPtr(AI);
1073 if (PtrI.isEscaped() || PtrI.isAborted()) {
1074 // FIXME: We should sink the escape vs. abort info into the caller nicely,
1075 // possibly by just storing the PtrInfo in the AllocaSlices.
1076 PointerEscapingInstr = PtrI.getEscapingInst() ? PtrI.getEscapingInst()
1077 : PtrI.getAbortingInst();
1078 assert(PointerEscapingInstr && "Did not track a bad instruction")(static_cast <bool> (PointerEscapingInstr && "Did not track a bad instruction"
) ? void (0) : __assert_fail ("PointerEscapingInstr && \"Did not track a bad instruction\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1078, __extension__ __PRETTY_FUNCTION__))
;
1079 return;
1080 }
1081
1082 llvm::erase_if(Slices, [](const Slice &S) { return S.isDead(); });
1083
1084 // Sort the uses. This arranges for the offsets to be in ascending order,
1085 // and the sizes to be in descending order.
1086 llvm::stable_sort(Slices);
1087}
1088
1089#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1090
1091void AllocaSlices::print(raw_ostream &OS, const_iterator I,
1092 StringRef Indent) const {
1093 printSlice(OS, I, Indent);
1094 OS << "\n";
1095 printUse(OS, I, Indent);
1096}
1097
1098void AllocaSlices::printSlice(raw_ostream &OS, const_iterator I,
1099 StringRef Indent) const {
1100 OS << Indent << "[" << I->beginOffset() << "," << I->endOffset() << ")"
1101 << " slice #" << (I - begin())
1102 << (I->isSplittable() ? " (splittable)" : "");
1103}
1104
1105void AllocaSlices::printUse(raw_ostream &OS, const_iterator I,
1106 StringRef Indent) const {
1107 OS << Indent << " used by: " << *I->getUse()->getUser() << "\n";
1108}
1109
1110void AllocaSlices::print(raw_ostream &OS) const {
1111 if (PointerEscapingInstr) {
1112 OS << "Can't analyze slices for alloca: " << AI << "\n"
1113 << " A pointer to this alloca escaped by:\n"
1114 << " " << *PointerEscapingInstr << "\n";
1115 return;
1116 }
1117
1118 OS << "Slices of alloca: " << AI << "\n";
1119 for (const_iterator I = begin(), E = end(); I != E; ++I)
1120 print(OS, I);
1121}
1122
1123LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump(const_iterator I) const {
1124 print(dbgs(), I);
1125}
1126LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump() const { print(dbgs()); }
1127
1128#endif // !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1129
1130/// Walk the range of a partitioning looking for a common type to cover this
1131/// sequence of slices.
1132static std::pair<Type *, IntegerType *>
1133findCommonType(AllocaSlices::const_iterator B, AllocaSlices::const_iterator E,
1134 uint64_t EndOffset) {
1135 Type *Ty = nullptr;
1136 bool TyIsCommon = true;
1137 IntegerType *ITy = nullptr;
1138
1139 // Note that we need to look at *every* alloca slice's Use to ensure we
1140 // always get consistent results regardless of the order of slices.
1141 for (AllocaSlices::const_iterator I = B; I != E; ++I) {
1142 Use *U = I->getUse();
1143 if (isa<IntrinsicInst>(*U->getUser()))
1144 continue;
1145 if (I->beginOffset() != B->beginOffset() || I->endOffset() != EndOffset)
1146 continue;
1147
1148 Type *UserTy = nullptr;
1149 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1150 UserTy = LI->getType();
1151 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1152 UserTy = SI->getValueOperand()->getType();
1153 }
1154
1155 if (IntegerType *UserITy = dyn_cast_or_null<IntegerType>(UserTy)) {
1156 // If the type is larger than the partition, skip it. We only encounter
1157 // this for split integer operations where we want to use the type of the
1158 // entity causing the split. Also skip if the type is not a byte width
1159 // multiple.
1160 if (UserITy->getBitWidth() % 8 != 0 ||
1161 UserITy->getBitWidth() / 8 > (EndOffset - B->beginOffset()))
1162 continue;
1163
1164 // Track the largest bitwidth integer type used in this way in case there
1165 // is no common type.
1166 if (!ITy || ITy->getBitWidth() < UserITy->getBitWidth())
1167 ITy = UserITy;
1168 }
1169
1170 // To avoid depending on the order of slices, Ty and TyIsCommon must not
1171 // depend on types skipped above.
1172 if (!UserTy || (Ty && Ty != UserTy))
1173 TyIsCommon = false; // Give up on anything but an iN type.
1174 else
1175 Ty = UserTy;
1176 }
1177
1178 return {TyIsCommon ? Ty : nullptr, ITy};
1179}
1180
1181/// PHI instructions that use an alloca and are subsequently loaded can be
1182/// rewritten to load both input pointers in the pred blocks and then PHI the
1183/// results, allowing the load of the alloca to be promoted.
1184/// From this:
1185/// %P2 = phi [i32* %Alloca, i32* %Other]
1186/// %V = load i32* %P2
1187/// to:
1188/// %V1 = load i32* %Alloca -> will be mem2reg'd
1189/// ...
1190/// %V2 = load i32* %Other
1191/// ...
1192/// %V = phi [i32 %V1, i32 %V2]
1193///
1194/// We can do this to a select if its only uses are loads and if the operands
1195/// to the select can be loaded unconditionally.
1196///
1197/// FIXME: This should be hoisted into a generic utility, likely in
1198/// Transforms/Util/Local.h
1199static bool isSafePHIToSpeculate(PHINode &PN) {
1200 const DataLayout &DL = PN.getModule()->getDataLayout();
1201
1202 // For now, we can only do this promotion if the load is in the same block
1203 // as the PHI, and if there are no stores between the phi and load.
1204 // TODO: Allow recursive phi users.
1205 // TODO: Allow stores.
1206 BasicBlock *BB = PN.getParent();
1207 Align MaxAlign;
1208 uint64_t APWidth = DL.getIndexTypeSizeInBits(PN.getType());
1209 APInt MaxSize(APWidth, 0);
1210 bool HaveLoad = false;
1211 for (User *U : PN.users()) {
1212 LoadInst *LI = dyn_cast<LoadInst>(U);
1213 if (!LI || !LI->isSimple())
1214 return false;
1215
1216 // For now we only allow loads in the same block as the PHI. This is
1217 // a common case that happens when instcombine merges two loads through
1218 // a PHI.
1219 if (LI->getParent() != BB)
1220 return false;
1221
1222 // Ensure that there are no instructions between the PHI and the load that
1223 // could store.
1224 for (BasicBlock::iterator BBI(PN); &*BBI != LI; ++BBI)
1225 if (BBI->mayWriteToMemory())
1226 return false;
1227
1228 uint64_t Size = DL.getTypeStoreSize(LI->getType()).getFixedSize();
1229 MaxAlign = std::max(MaxAlign, LI->getAlign());
1230 MaxSize = MaxSize.ult(Size) ? APInt(APWidth, Size) : MaxSize;
1231 HaveLoad = true;
1232 }
1233
1234 if (!HaveLoad)
1235 return false;
1236
1237 // We can only transform this if it is safe to push the loads into the
1238 // predecessor blocks. The only thing to watch out for is that we can't put
1239 // a possibly trapping load in the predecessor if it is a critical edge.
1240 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1241 Instruction *TI = PN.getIncomingBlock(Idx)->getTerminator();
1242 Value *InVal = PN.getIncomingValue(Idx);
1243
1244 // If the value is produced by the terminator of the predecessor (an
1245 // invoke) or it has side-effects, there is no valid place to put a load
1246 // in the predecessor.
1247 if (TI == InVal || TI->mayHaveSideEffects())
1248 return false;
1249
1250 // If the predecessor has a single successor, then the edge isn't
1251 // critical.
1252 if (TI->getNumSuccessors() == 1)
1253 continue;
1254
1255 // If this pointer is always safe to load, or if we can prove that there
1256 // is already a load in the block, then we can move the load to the pred
1257 // block.
1258 if (isSafeToLoadUnconditionally(InVal, MaxAlign, MaxSize, DL, TI))
1259 continue;
1260
1261 return false;
1262 }
1263
1264 return true;
1265}
1266
1267static void speculatePHINodeLoads(PHINode &PN) {
1268 LLVM_DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
1269
1270 LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
1271 Type *LoadTy = SomeLoad->getType();
1272 IRBuilderTy PHIBuilder(&PN);
1273 PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
1274 PN.getName() + ".sroa.speculated");
1275
1276 // Get the AA tags and alignment to use from one of the loads. It does not
1277 // matter which one we get and if any differ.
1278 AAMDNodes AATags;
1279 SomeLoad->getAAMetadata(AATags);
1280 Align Alignment = SomeLoad->getAlign();
1281
1282 // Rewrite all loads of the PN to use the new PHI.
1283 while (!PN.use_empty()) {
1284 LoadInst *LI = cast<LoadInst>(PN.user_back());
1285 LI->replaceAllUsesWith(NewPN);
1286 LI->eraseFromParent();
1287 }
1288
1289 // Inject loads into all of the pred blocks.
1290 DenseMap<BasicBlock*, Value*> InjectedLoads;
1291 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1292 BasicBlock *Pred = PN.getIncomingBlock(Idx);
1293 Value *InVal = PN.getIncomingValue(Idx);
1294
1295 // A PHI node is allowed to have multiple (duplicated) entries for the same
1296 // basic block, as long as the value is the same. So if we already injected
1297 // a load in the predecessor, then we should reuse the same load for all
1298 // duplicated entries.
1299 if (Value* V = InjectedLoads.lookup(Pred)) {
1300 NewPN->addIncoming(V, Pred);
1301 continue;
1302 }
1303
1304 Instruction *TI = Pred->getTerminator();
1305 IRBuilderTy PredBuilder(TI);
1306
1307 LoadInst *Load = PredBuilder.CreateAlignedLoad(
1308 LoadTy, InVal, Alignment,
1309 (PN.getName() + ".sroa.speculate.load." + Pred->getName()));
1310 ++NumLoadsSpeculated;
1311 if (AATags)
1312 Load->setAAMetadata(AATags);
1313 NewPN->addIncoming(Load, Pred);
1314 InjectedLoads[Pred] = Load;
1315 }
1316
1317 LLVM_DEBUG(dbgs() << " speculated to: " << *NewPN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*NewPN << "\n"; } } while (false)
;
1318 PN.eraseFromParent();
1319}
1320
1321/// Select instructions that use an alloca and are subsequently loaded can be
1322/// rewritten to load both input pointers and then select between the result,
1323/// allowing the load of the alloca to be promoted.
1324/// From this:
1325/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
1326/// %V = load i32* %P2
1327/// to:
1328/// %V1 = load i32* %Alloca -> will be mem2reg'd
1329/// %V2 = load i32* %Other
1330/// %V = select i1 %cond, i32 %V1, i32 %V2
1331///
1332/// We can do this to a select if its only uses are loads and if the operand
1333/// to the select can be loaded unconditionally. If found an intervening bitcast
1334/// with a single use of the load, allow the promotion.
1335static bool isSafeSelectToSpeculate(SelectInst &SI) {
1336 Value *TValue = SI.getTrueValue();
1337 Value *FValue = SI.getFalseValue();
1338 const DataLayout &DL = SI.getModule()->getDataLayout();
1339
1340 for (User *U : SI.users()) {
1341 LoadInst *LI;
1342 BitCastInst *BC = dyn_cast<BitCastInst>(U);
1343 if (BC && BC->hasOneUse())
1344 LI = dyn_cast<LoadInst>(*BC->user_begin());
1345 else
1346 LI = dyn_cast<LoadInst>(U);
1347
1348 if (!LI || !LI->isSimple())
1349 return false;
1350
1351 // Both operands to the select need to be dereferenceable, either
1352 // absolutely (e.g. allocas) or at this point because we can see other
1353 // accesses to it.
1354 if (!isSafeToLoadUnconditionally(TValue, LI->getType(),
1355 LI->getAlign(), DL, LI))
1356 return false;
1357 if (!isSafeToLoadUnconditionally(FValue, LI->getType(),
1358 LI->getAlign(), DL, LI))
1359 return false;
1360 }
1361
1362 return true;
1363}
1364
1365static void speculateSelectInstLoads(SelectInst &SI) {
1366 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
1367
1368 IRBuilderTy IRB(&SI);
1369 Value *TV = SI.getTrueValue();
1370 Value *FV = SI.getFalseValue();
1371 // Replace the loads of the select with a select of two loads.
1372 while (!SI.use_empty()) {
1373 LoadInst *LI;
1374 BitCastInst *BC = dyn_cast<BitCastInst>(SI.user_back());
1375 if (BC) {
1376 assert(BC->hasOneUse() && "Bitcast should have a single use.")(static_cast <bool> (BC->hasOneUse() && "Bitcast should have a single use."
) ? void (0) : __assert_fail ("BC->hasOneUse() && \"Bitcast should have a single use.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1376, __extension__ __PRETTY_FUNCTION__))
;
1377 LI = cast<LoadInst>(BC->user_back());
1378 } else {
1379 LI = cast<LoadInst>(SI.user_back());
1380 }
1381
1382 assert(LI->isSimple() && "We only speculate simple loads")(static_cast <bool> (LI->isSimple() && "We only speculate simple loads"
) ? void (0) : __assert_fail ("LI->isSimple() && \"We only speculate simple loads\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1382, __extension__ __PRETTY_FUNCTION__))
;
1383
1384 IRB.SetInsertPoint(LI);
1385 Value *NewTV =
1386 BC ? IRB.CreateBitCast(TV, BC->getType(), TV->getName() + ".sroa.cast")
1387 : TV;
1388 Value *NewFV =
1389 BC ? IRB.CreateBitCast(FV, BC->getType(), FV->getName() + ".sroa.cast")
1390 : FV;
1391 LoadInst *TL = IRB.CreateLoad(LI->getType(), NewTV,
1392 LI->getName() + ".sroa.speculate.load.true");
1393 LoadInst *FL = IRB.CreateLoad(LI->getType(), NewFV,
1394 LI->getName() + ".sroa.speculate.load.false");
1395 NumLoadsSpeculated += 2;
1396
1397 // Transfer alignment and AA info if present.
1398 TL->setAlignment(LI->getAlign());
1399 FL->setAlignment(LI->getAlign());
1400
1401 AAMDNodes Tags;
1402 LI->getAAMetadata(Tags);
1403 if (Tags) {
1404 TL->setAAMetadata(Tags);
1405 FL->setAAMetadata(Tags);
1406 }
1407
1408 Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
1409 LI->getName() + ".sroa.speculated");
1410
1411 LLVM_DEBUG(dbgs() << " speculated to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*V << "\n"; } } while (false)
;
1412 LI->replaceAllUsesWith(V);
1413 LI->eraseFromParent();
1414 if (BC)
1415 BC->eraseFromParent();
1416 }
1417 SI.eraseFromParent();
1418}
1419
1420/// Build a GEP out of a base pointer and indices.
1421///
1422/// This will return the BasePtr if that is valid, or build a new GEP
1423/// instruction using the IRBuilder if GEP-ing is needed.
1424static Value *buildGEP(IRBuilderTy &IRB, Value *BasePtr,
1425 SmallVectorImpl<Value *> &Indices,
1426 const Twine &NamePrefix) {
1427 if (Indices.empty())
1428 return BasePtr;
1429
1430 // A single zero index is a no-op, so check for this and avoid building a GEP
1431 // in that case.
1432 if (Indices.size() == 1 && cast<ConstantInt>(Indices.back())->isZero())
1433 return BasePtr;
1434
1435 return IRB.CreateInBoundsGEP(BasePtr->getType()->getPointerElementType(),
1436 BasePtr, Indices, NamePrefix + "sroa_idx");
1437}
1438
1439/// Get a natural GEP off of the BasePtr walking through Ty toward
1440/// TargetTy without changing the offset of the pointer.
1441///
1442/// This routine assumes we've already established a properly offset GEP with
1443/// Indices, and arrived at the Ty type. The goal is to continue to GEP with
1444/// zero-indices down through type layers until we find one the same as
1445/// TargetTy. If we can't find one with the same type, we at least try to use
1446/// one with the same size. If none of that works, we just produce the GEP as
1447/// indicated by Indices to have the correct offset.
1448static Value *getNaturalGEPWithType(IRBuilderTy &IRB, const DataLayout &DL,
1449 Value *BasePtr, Type *Ty, Type *TargetTy,
1450 SmallVectorImpl<Value *> &Indices,
1451 const Twine &NamePrefix) {
1452 if (Ty == TargetTy)
1453 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1454
1455 // Offset size to use for the indices.
1456 unsigned OffsetSize = DL.getIndexTypeSizeInBits(BasePtr->getType());
1457
1458 // See if we can descend into a struct and locate a field with the correct
1459 // type.
1460 unsigned NumLayers = 0;
1461 Type *ElementTy = Ty;
1462 do {
1463 if (ElementTy->isPointerTy())
1464 break;
1465
1466 if (ArrayType *ArrayTy = dyn_cast<ArrayType>(ElementTy)) {
1467 ElementTy = ArrayTy->getElementType();
1468 Indices.push_back(IRB.getIntN(OffsetSize, 0));
1469 } else if (VectorType *VectorTy = dyn_cast<VectorType>(ElementTy)) {
1470 ElementTy = VectorTy->getElementType();
1471 Indices.push_back(IRB.getInt32(0));
1472 } else if (StructType *STy = dyn_cast<StructType>(ElementTy)) {
1473 if (STy->element_begin() == STy->element_end())
1474 break; // Nothing left to descend into.
1475 ElementTy = *STy->element_begin();
1476 Indices.push_back(IRB.getInt32(0));
1477 } else {
1478 break;
1479 }
1480 ++NumLayers;
1481 } while (ElementTy != TargetTy);
1482 if (ElementTy != TargetTy)
1483 Indices.erase(Indices.end() - NumLayers, Indices.end());
1484
1485 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1486}
1487
1488/// Recursively compute indices for a natural GEP.
1489///
1490/// This is the recursive step for getNaturalGEPWithOffset that walks down the
1491/// element types adding appropriate indices for the GEP.
1492static Value *getNaturalGEPRecursively(IRBuilderTy &IRB, const DataLayout &DL,
1493 Value *Ptr, Type *Ty, APInt &Offset,
1494 Type *TargetTy,
1495 SmallVectorImpl<Value *> &Indices,
1496 const Twine &NamePrefix) {
1497 if (Offset == 0)
1498 return getNaturalGEPWithType(IRB, DL, Ptr, Ty, TargetTy, Indices,
1499 NamePrefix);
1500
1501 // We can't recurse through pointer types.
1502 if (Ty->isPointerTy())
1503 return nullptr;
1504
1505 // We try to analyze GEPs over vectors here, but note that these GEPs are
1506 // extremely poorly defined currently. The long-term goal is to remove GEPing
1507 // over a vector from the IR completely.
1508 if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
1509 unsigned ElementSizeInBits =
1510 DL.getTypeSizeInBits(VecTy->getScalarType()).getFixedSize();
1511 if (ElementSizeInBits % 8 != 0) {
1512 // GEPs over non-multiple of 8 size vector elements are invalid.
1513 return nullptr;
1514 }
1515 APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
1516 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1517 if (NumSkippedElements.ugt(cast<FixedVectorType>(VecTy)->getNumElements()))
1518 return nullptr;
1519 Offset -= NumSkippedElements * ElementSize;
1520 Indices.push_back(IRB.getInt(NumSkippedElements));
1521 return getNaturalGEPRecursively(IRB, DL, Ptr, VecTy->getElementType(),
1522 Offset, TargetTy, Indices, NamePrefix);
1523 }
1524
1525 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
1526 Type *ElementTy = ArrTy->getElementType();
1527 APInt ElementSize(Offset.getBitWidth(),
1528 DL.getTypeAllocSize(ElementTy).getFixedSize());
1529 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1530 if (NumSkippedElements.ugt(ArrTy->getNumElements()))
1531 return nullptr;
1532
1533 Offset -= NumSkippedElements * ElementSize;
1534 Indices.push_back(IRB.getInt(NumSkippedElements));
1535 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1536 Indices, NamePrefix);
1537 }
1538
1539 StructType *STy = dyn_cast<StructType>(Ty);
1540 if (!STy)
1541 return nullptr;
1542
1543 const StructLayout *SL = DL.getStructLayout(STy);
1544 uint64_t StructOffset = Offset.getZExtValue();
1545 if (StructOffset >= SL->getSizeInBytes())
1546 return nullptr;
1547 unsigned Index = SL->getElementContainingOffset(StructOffset);
1548 Offset -= APInt(Offset.getBitWidth(), SL->getElementOffset(Index));
1549 Type *ElementTy = STy->getElementType(Index);
1550 if (Offset.uge(DL.getTypeAllocSize(ElementTy).getFixedSize()))
1551 return nullptr; // The offset points into alignment padding.
1552
1553 Indices.push_back(IRB.getInt32(Index));
1554 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1555 Indices, NamePrefix);
1556}
1557
1558/// Get a natural GEP from a base pointer to a particular offset and
1559/// resulting in a particular type.
1560///
1561/// The goal is to produce a "natural" looking GEP that works with the existing
1562/// composite types to arrive at the appropriate offset and element type for
1563/// a pointer. TargetTy is the element type the returned GEP should point-to if
1564/// possible. We recurse by decreasing Offset, adding the appropriate index to
1565/// Indices, and setting Ty to the result subtype.
1566///
1567/// If no natural GEP can be constructed, this function returns null.
1568static Value *getNaturalGEPWithOffset(IRBuilderTy &IRB, const DataLayout &DL,
1569 Value *Ptr, APInt Offset, Type *TargetTy,
1570 SmallVectorImpl<Value *> &Indices,
1571 const Twine &NamePrefix) {
1572 PointerType *Ty = cast<PointerType>(Ptr->getType());
1573
1574 // Don't consider any GEPs through an i8* as natural unless the TargetTy is
1575 // an i8.
1576 if (Ty == IRB.getInt8PtrTy(Ty->getAddressSpace()) && TargetTy->isIntegerTy(8))
1577 return nullptr;
1578
1579 Type *ElementTy = Ty->getElementType();
1580 if (!ElementTy->isSized())
1581 return nullptr; // We can't GEP through an unsized element.
1582 if (isa<ScalableVectorType>(ElementTy))
1583 return nullptr;
1584 APInt ElementSize(Offset.getBitWidth(),
1585 DL.getTypeAllocSize(ElementTy).getFixedSize());
1586 if (ElementSize == 0)
1587 return nullptr; // Zero-length arrays can't help us build a natural GEP.
1588 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1589
1590 Offset -= NumSkippedElements * ElementSize;
1591 Indices.push_back(IRB.getInt(NumSkippedElements));
1592 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1593 Indices, NamePrefix);
1594}
1595
1596/// Compute an adjusted pointer from Ptr by Offset bytes where the
1597/// resulting pointer has PointerTy.
1598///
1599/// This tries very hard to compute a "natural" GEP which arrives at the offset
1600/// and produces the pointer type desired. Where it cannot, it will try to use
1601/// the natural GEP to arrive at the offset and bitcast to the type. Where that
1602/// fails, it will try to use an existing i8* and GEP to the byte offset and
1603/// bitcast to the type.
1604///
1605/// The strategy for finding the more natural GEPs is to peel off layers of the
1606/// pointer, walking back through bit casts and GEPs, searching for a base
1607/// pointer from which we can compute a natural GEP with the desired
1608/// properties. The algorithm tries to fold as many constant indices into
1609/// a single GEP as possible, thus making each GEP more independent of the
1610/// surrounding code.
1611static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
1612 APInt Offset, Type *PointerTy,
1613 const Twine &NamePrefix) {
1614 // Even though we don't look through PHI nodes, we could be called on an
1615 // instruction in an unreachable block, which may be on a cycle.
1616 SmallPtrSet<Value *, 4> Visited;
1617 Visited.insert(Ptr);
1618 SmallVector<Value *, 4> Indices;
1619
1620 // We may end up computing an offset pointer that has the wrong type. If we
1621 // never are able to compute one directly that has the correct type, we'll
1622 // fall back to it, so keep it and the base it was computed from around here.
1623 Value *OffsetPtr = nullptr;
1624 Value *OffsetBasePtr;
1625
1626 // Remember any i8 pointer we come across to re-use if we need to do a raw
1627 // byte offset.
1628 Value *Int8Ptr = nullptr;
1629 APInt Int8PtrOffset(Offset.getBitWidth(), 0);
1630
1631 PointerType *TargetPtrTy = cast<PointerType>(PointerTy);
1632 Type *TargetTy = TargetPtrTy->getElementType();
1633
1634 // As `addrspacecast` is , `Ptr` (the storage pointer) may have different
1635 // address space from the expected `PointerTy` (the pointer to be used).
1636 // Adjust the pointer type based the original storage pointer.
1637 auto AS = cast<PointerType>(Ptr->getType())->getAddressSpace();
1638 PointerTy = TargetTy->getPointerTo(AS);
1639
1640 do {
1641 // First fold any existing GEPs into the offset.
1642 while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
1643 APInt GEPOffset(Offset.getBitWidth(), 0);
1644 if (!GEP->accumulateConstantOffset(DL, GEPOffset))
1645 break;
1646 Offset += GEPOffset;
1647 Ptr = GEP->getPointerOperand();
1648 if (!Visited.insert(Ptr).second)
1649 break;
1650 }
1651
1652 // See if we can perform a natural GEP here.
1653 Indices.clear();
1654 if (Value *P = getNaturalGEPWithOffset(IRB, DL, Ptr, Offset, TargetTy,
1655 Indices, NamePrefix)) {
1656 // If we have a new natural pointer at the offset, clear out any old
1657 // offset pointer we computed. Unless it is the base pointer or
1658 // a non-instruction, we built a GEP we don't need. Zap it.
1659 if (OffsetPtr && OffsetPtr != OffsetBasePtr)
1660 if (Instruction *I = dyn_cast<Instruction>(OffsetPtr)) {
1661 assert(I->use_empty() && "Built a GEP with uses some how!")(static_cast <bool> (I->use_empty() && "Built a GEP with uses some how!"
) ? void (0) : __assert_fail ("I->use_empty() && \"Built a GEP with uses some how!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1661, __extension__ __PRETTY_FUNCTION__))
;
1662 I->eraseFromParent();
1663 }
1664 OffsetPtr = P;
1665 OffsetBasePtr = Ptr;
1666 // If we also found a pointer of the right type, we're done.
1667 if (P->getType() == PointerTy)
1668 break;
1669 }
1670
1671 // Stash this pointer if we've found an i8*.
1672 if (Ptr->getType()->isIntegerTy(8)) {
1673 Int8Ptr = Ptr;
1674 Int8PtrOffset = Offset;
1675 }
1676
1677 // Peel off a layer of the pointer and update the offset appropriately.
1678 if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
1679 Ptr = cast<Operator>(Ptr)->getOperand(0);
1680 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(Ptr)) {
1681 if (GA->isInterposable())
1682 break;
1683 Ptr = GA->getAliasee();
1684 } else {
1685 break;
1686 }
1687 assert(Ptr->getType()->isPointerTy() && "Unexpected operand type!")(static_cast <bool> (Ptr->getType()->isPointerTy(
) && "Unexpected operand type!") ? void (0) : __assert_fail
("Ptr->getType()->isPointerTy() && \"Unexpected operand type!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1687, __extension__ __PRETTY_FUNCTION__))
;
1688 } while (Visited.insert(Ptr).second);
1689
1690 if (!OffsetPtr) {
1691 if (!Int8Ptr) {
1692 Int8Ptr = IRB.CreateBitCast(
1693 Ptr, IRB.getInt8PtrTy(PointerTy->getPointerAddressSpace()),
1694 NamePrefix + "sroa_raw_cast");
1695 Int8PtrOffset = Offset;
1696 }
1697
1698 OffsetPtr = Int8PtrOffset == 0
1699 ? Int8Ptr
1700 : IRB.CreateInBoundsGEP(IRB.getInt8Ty(), Int8Ptr,
1701 IRB.getInt(Int8PtrOffset),
1702 NamePrefix + "sroa_raw_idx");
1703 }
1704 Ptr = OffsetPtr;
1705
1706 // On the off chance we were targeting i8*, guard the bitcast here.
1707 if (cast<PointerType>(Ptr->getType()) != TargetPtrTy) {
1708 Ptr = IRB.CreatePointerBitCastOrAddrSpaceCast(Ptr,
1709 TargetPtrTy,
1710 NamePrefix + "sroa_cast");
1711 }
1712
1713 return Ptr;
1714}
1715
1716/// Compute the adjusted alignment for a load or store from an offset.
1717static Align getAdjustedAlignment(Instruction *I, uint64_t Offset) {
1718 return commonAlignment(getLoadStoreAlignment(I), Offset);
1719}
1720
1721/// Test whether we can convert a value from the old to the new type.
1722///
1723/// This predicate should be used to guard calls to convertValue in order to
1724/// ensure that we only try to convert viable values. The strategy is that we
1725/// will peel off single element struct and array wrappings to get to an
1726/// underlying value, and convert that value.
1727static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
1728 if (OldTy == NewTy)
1729 return true;
1730
1731 // For integer types, we can't handle any bit-width differences. This would
1732 // break both vector conversions with extension and introduce endianness
1733 // issues when in conjunction with loads and stores.
1734 if (isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) {
1735 assert(cast<IntegerType>(OldTy)->getBitWidth() !=(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1737, __extension__ __PRETTY_FUNCTION__))
1736 cast<IntegerType>(NewTy)->getBitWidth() &&(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1737, __extension__ __PRETTY_FUNCTION__))
1737 "We can't have the same bitwidth for different int types")(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1737, __extension__ __PRETTY_FUNCTION__))
;
1738 return false;
1739 }
1740
1741 if (DL.getTypeSizeInBits(NewTy).getFixedSize() !=
1742 DL.getTypeSizeInBits(OldTy).getFixedSize())
1743 return false;
1744 if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
1745 return false;
1746
1747 // We can convert pointers to integers and vice-versa. Same for vectors
1748 // of pointers and integers.
1749 OldTy = OldTy->getScalarType();
1750 NewTy = NewTy->getScalarType();
1751 if (NewTy->isPointerTy() || OldTy->isPointerTy()) {
1752 if (NewTy->isPointerTy() && OldTy->isPointerTy()) {
1753 unsigned OldAS = OldTy->getPointerAddressSpace();
1754 unsigned NewAS = NewTy->getPointerAddressSpace();
1755 // Convert pointers if they are pointers from the same address space or
1756 // different integral (not non-integral) address spaces with the same
1757 // pointer size.
1758 return OldAS == NewAS ||
1759 (!DL.isNonIntegralAddressSpace(OldAS) &&
1760 !DL.isNonIntegralAddressSpace(NewAS) &&
1761 DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS));
1762 }
1763
1764 // We can convert integers to integral pointers, but not to non-integral
1765 // pointers.
1766 if (OldTy->isIntegerTy())
1767 return !DL.isNonIntegralPointerType(NewTy);
1768
1769 // We can convert integral pointers to integers, but non-integral pointers
1770 // need to remain pointers.
1771 if (!DL.isNonIntegralPointerType(OldTy))
1772 return NewTy->isIntegerTy();
1773
1774 return false;
1775 }
1776
1777 return true;
1778}
1779
1780/// Generic routine to convert an SSA value to a value of a different
1781/// type.
1782///
1783/// This will try various different casting techniques, such as bitcasts,
1784/// inttoptr, and ptrtoint casts. Use the \c canConvertValue predicate to test
1785/// two types for viability with this routine.
1786static Value *convertValue(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
1787 Type *NewTy) {
1788 Type *OldTy = V->getType();
1789 assert(canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type")(static_cast <bool> (canConvertValue(DL, OldTy, NewTy) &&
"Value not convertable to type") ? void (0) : __assert_fail (
"canConvertValue(DL, OldTy, NewTy) && \"Value not convertable to type\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1789, __extension__ __PRETTY_FUNCTION__))
;
1790
1791 if (OldTy == NewTy)
1792 return V;
1793
1794 assert(!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) &&(static_cast <bool> (!(isa<IntegerType>(OldTy) &&
isa<IntegerType>(NewTy)) && "Integer types must be the exact same to convert."
) ? void (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1795, __extension__ __PRETTY_FUNCTION__))
1795 "Integer types must be the exact same to convert.")(static_cast <bool> (!(isa<IntegerType>(OldTy) &&
isa<IntegerType>(NewTy)) && "Integer types must be the exact same to convert."
) ? void (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1795, __extension__ __PRETTY_FUNCTION__))
;
1796
1797 // See if we need inttoptr for this type pair. May require additional bitcast.
1798 if (OldTy->isIntOrIntVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
1799 // Expand <2 x i32> to i8* --> <2 x i32> to i64 to i8*
1800 // Expand i128 to <2 x i8*> --> i128 to <2 x i64> to <2 x i8*>
1801 // Expand <4 x i32> to <2 x i8*> --> <4 x i32> to <2 x i64> to <2 x i8*>
1802 // Directly handle i64 to i8*
1803 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1804 NewTy);
1805 }
1806
1807 // See if we need ptrtoint for this type pair. May require additional bitcast.
1808 if (OldTy->isPtrOrPtrVectorTy() && NewTy->isIntOrIntVectorTy()) {
1809 // Expand <2 x i8*> to i128 --> <2 x i8*> to <2 x i64> to i128
1810 // Expand i8* to <2 x i32> --> i8* to i64 to <2 x i32>
1811 // Expand <2 x i8*> to <4 x i32> --> <2 x i8*> to <2 x i64> to <4 x i32>
1812 // Expand i8* to i64 --> i8* to i64 to i64
1813 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1814 NewTy);
1815 }
1816
1817 if (OldTy->isPtrOrPtrVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
1818 unsigned OldAS = OldTy->getPointerAddressSpace();
1819 unsigned NewAS = NewTy->getPointerAddressSpace();
1820 // To convert pointers with different address spaces (they are already
1821 // checked convertible, i.e. they have the same pointer size), so far we
1822 // cannot use `bitcast` (which has restrict on the same address space) or
1823 // `addrspacecast` (which is not always no-op casting). Instead, use a pair
1824 // of no-op `ptrtoint`/`inttoptr` casts through an integer with the same bit
1825 // size.
1826 if (OldAS != NewAS) {
1827 assert(DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS))(static_cast <bool> (DL.getPointerSize(OldAS) == DL.getPointerSize
(NewAS)) ? void (0) : __assert_fail ("DL.getPointerSize(OldAS) == DL.getPointerSize(NewAS)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1827, __extension__ __PRETTY_FUNCTION__))
;
1828 return IRB.CreateIntToPtr(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1829 NewTy);
1830 }
1831 }
1832
1833 return IRB.CreateBitCast(V, NewTy);
1834}
1835
1836/// Test whether the given slice use can be promoted to a vector.
1837///
1838/// This function is called to test each entry in a partition which is slated
1839/// for a single slice.
1840static bool isVectorPromotionViableForSlice(Partition &P, const Slice &S,
1841 VectorType *Ty,
1842 uint64_t ElementSize,
1843 const DataLayout &DL) {
1844 // First validate the slice offsets.
1845 uint64_t BeginOffset =
1846 std::max(S.beginOffset(), P.beginOffset()) - P.beginOffset();
1847 uint64_t BeginIndex = BeginOffset / ElementSize;
1848 if (BeginIndex * ElementSize != BeginOffset ||
1849 BeginIndex >= cast<FixedVectorType>(Ty)->getNumElements())
1850 return false;
1851 uint64_t EndOffset =
1852 std::min(S.endOffset(), P.endOffset()) - P.beginOffset();
1853 uint64_t EndIndex = EndOffset / ElementSize;
1854 if (EndIndex * ElementSize != EndOffset ||
1855 EndIndex > cast<FixedVectorType>(Ty)->getNumElements())
1856 return false;
1857
1858 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1858, __extension__ __PRETTY_FUNCTION__))
;
1859 uint64_t NumElements = EndIndex - BeginIndex;
1860 Type *SliceTy = (NumElements == 1)
1861 ? Ty->getElementType()
1862 : FixedVectorType::get(Ty->getElementType(), NumElements);
1863
1864 Type *SplitIntTy =
1865 Type::getIntNTy(Ty->getContext(), NumElements * ElementSize * 8);
1866
1867 Use *U = S.getUse();
1868
1869 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
1870 if (MI->isVolatile())
1871 return false;
1872 if (!S.isSplittable())
1873 return false; // Skip any unsplittable intrinsics.
1874 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
1875 if (!II->isLifetimeStartOrEnd() && !II->isDroppable())
1876 return false;
1877 } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
1878 // Disable vector promotion when there are loads or stores of an FCA.
1879 return false;
1880 } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1881 if (LI->isVolatile())
1882 return false;
1883 Type *LTy = LI->getType();
1884 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1885 assert(LTy->isIntegerTy())(static_cast <bool> (LTy->isIntegerTy()) ? void (0) :
__assert_fail ("LTy->isIntegerTy()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1885, __extension__ __PRETTY_FUNCTION__))
;
1886 LTy = SplitIntTy;
1887 }
1888 if (!canConvertValue(DL, SliceTy, LTy))
1889 return false;
1890 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1891 if (SI->isVolatile())
1892 return false;
1893 Type *STy = SI->getValueOperand()->getType();
1894 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1895 assert(STy->isIntegerTy())(static_cast <bool> (STy->isIntegerTy()) ? void (0) :
__assert_fail ("STy->isIntegerTy()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
;
1896 STy = SplitIntTy;
1897 }
1898 if (!canConvertValue(DL, STy, SliceTy))
1899 return false;
1900 } else {
1901 return false;
1902 }
1903
1904 return true;
1905}
1906
1907/// Test whether the given alloca partitioning and range of slices can be
1908/// promoted to a vector.
1909///
1910/// This is a quick test to check whether we can rewrite a particular alloca
1911/// partition (and its newly formed alloca) into a vector alloca with only
1912/// whole-vector loads and stores such that it could be promoted to a vector
1913/// SSA value. We only can ensure this for a limited set of operations, and we
1914/// don't want to do the rewrites unless we are confident that the result will
1915/// be promotable, so we have an early test here.
1916static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
1917 // Collect the candidate types for vector-based promotion. Also track whether
1918 // we have different element types.
1919 SmallVector<VectorType *, 4> CandidateTys;
1920 Type *CommonEltTy = nullptr;
1921 bool HaveCommonEltTy = true;
1922 auto CheckCandidateType = [&](Type *Ty) {
1923 if (auto *VTy = dyn_cast<VectorType>(Ty)) {
1924 // Return if bitcast to vectors is different for total size in bits.
1925 if (!CandidateTys.empty()) {
1926 VectorType *V = CandidateTys[0];
1927 if (DL.getTypeSizeInBits(VTy).getFixedSize() !=
1928 DL.getTypeSizeInBits(V).getFixedSize()) {
1929 CandidateTys.clear();
1930 return;
1931 }
1932 }
1933 CandidateTys.push_back(VTy);
1934 if (!CommonEltTy)
1935 CommonEltTy = VTy->getElementType();
1936 else if (CommonEltTy != VTy->getElementType())
1937 HaveCommonEltTy = false;
1938 }
1939 };
1940 // Consider any loads or stores that are the exact size of the slice.
1941 for (const Slice &S : P)
1942 if (S.beginOffset() == P.beginOffset() &&
1943 S.endOffset() == P.endOffset()) {
1944 if (auto *LI = dyn_cast<LoadInst>(S.getUse()->getUser()))
1945 CheckCandidateType(LI->getType());
1946 else if (auto *SI = dyn_cast<StoreInst>(S.getUse()->getUser()))
1947 CheckCandidateType(SI->getValueOperand()->getType());
1948 }
1949
1950 // If we didn't find a vector type, nothing to do here.
1951 if (CandidateTys.empty())
1952 return nullptr;
1953
1954 // Remove non-integer vector types if we had multiple common element types.
1955 // FIXME: It'd be nice to replace them with integer vector types, but we can't
1956 // do that until all the backends are known to produce good code for all
1957 // integer vector types.
1958 if (!HaveCommonEltTy) {
1959 llvm::erase_if(CandidateTys, [](VectorType *VTy) {
1960 return !VTy->getElementType()->isIntegerTy();
1961 });
1962
1963 // If there were no integer vector types, give up.
1964 if (CandidateTys.empty())
1965 return nullptr;
1966
1967 // Rank the remaining candidate vector types. This is easy because we know
1968 // they're all integer vectors. We sort by ascending number of elements.
1969 auto RankVectorTypes = [&DL](VectorType *RHSTy, VectorType *LHSTy) {
1970 (void)DL;
1971 assert(DL.getTypeSizeInBits(RHSTy).getFixedSize() ==(static_cast <bool> (DL.getTypeSizeInBits(RHSTy).getFixedSize
() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? void (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1973, __extension__ __PRETTY_FUNCTION__))
1972 DL.getTypeSizeInBits(LHSTy).getFixedSize() &&(static_cast <bool> (DL.getTypeSizeInBits(RHSTy).getFixedSize
() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? void (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1973, __extension__ __PRETTY_FUNCTION__))
1973 "Cannot have vector types of different sizes!")(static_cast <bool> (DL.getTypeSizeInBits(RHSTy).getFixedSize
() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && "Cannot have vector types of different sizes!"
) ? void (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy).getFixedSize() == DL.getTypeSizeInBits(LHSTy).getFixedSize() && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1973, __extension__ __PRETTY_FUNCTION__))
;
1974 assert(RHSTy->getElementType()->isIntegerTy() &&(static_cast <bool> (RHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1975, __extension__ __PRETTY_FUNCTION__))
1975 "All non-integer types eliminated!")(static_cast <bool> (RHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1975, __extension__ __PRETTY_FUNCTION__))
;
1976 assert(LHSTy->getElementType()->isIntegerTy() &&(static_cast <bool> (LHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1977, __extension__ __PRETTY_FUNCTION__))
1977 "All non-integer types eliminated!")(static_cast <bool> (LHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1977, __extension__ __PRETTY_FUNCTION__))
;
1978 return cast<FixedVectorType>(RHSTy)->getNumElements() <
1979 cast<FixedVectorType>(LHSTy)->getNumElements();
1980 };
1981 llvm::sort(CandidateTys, RankVectorTypes);
1982 CandidateTys.erase(
1983 std::unique(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes),
1984 CandidateTys.end());
1985 } else {
1986// The only way to have the same element type in every vector type is to
1987// have the same vector type. Check that and remove all but one.
1988#ifndef NDEBUG
1989 for (VectorType *VTy : CandidateTys) {
1990 assert(VTy->getElementType() == CommonEltTy &&(static_cast <bool> (VTy->getElementType() == CommonEltTy
&& "Unaccounted for element type!") ? void (0) : __assert_fail
("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1991, __extension__ __PRETTY_FUNCTION__))
1991 "Unaccounted for element type!")(static_cast <bool> (VTy->getElementType() == CommonEltTy
&& "Unaccounted for element type!") ? void (0) : __assert_fail
("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1991, __extension__ __PRETTY_FUNCTION__))
;
1992 assert(VTy == CandidateTys[0] &&(static_cast <bool> (VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? void (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1993, __extension__ __PRETTY_FUNCTION__))
1993 "Different vector types with the same element type!")(static_cast <bool> (VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? void (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 1993, __extension__ __PRETTY_FUNCTION__))
;
1994 }
1995#endif
1996 CandidateTys.resize(1);
1997 }
1998
1999 // Try each vector type, and return the one which works.
2000 auto CheckVectorTypeForPromotion = [&](VectorType *VTy) {
2001 uint64_t ElementSize =
2002 DL.getTypeSizeInBits(VTy->getElementType()).getFixedSize();
2003
2004 // While the definition of LLVM vectors is bitpacked, we don't support sizes
2005 // that aren't byte sized.
2006 if (ElementSize % 8)
2007 return false;
2008 assert((DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 &&(static_cast <bool> ((DL.getTypeSizeInBits(VTy).getFixedSize
() % 8) == 0 && "vector size not a multiple of element size?"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2009, __extension__ __PRETTY_FUNCTION__))
2009 "vector size not a multiple of element size?")(static_cast <bool> ((DL.getTypeSizeInBits(VTy).getFixedSize
() % 8) == 0 && "vector size not a multiple of element size?"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy).getFixedSize() % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2009, __extension__ __PRETTY_FUNCTION__))
;
2010 ElementSize /= 8;
2011
2012 for (const Slice &S : P)
2013 if (!isVectorPromotionViableForSlice(P, S, VTy, ElementSize, DL))
2014 return false;
2015
2016 for (const Slice *S : P.splitSliceTails())
2017 if (!isVectorPromotionViableForSlice(P, *S, VTy, ElementSize, DL))
2018 return false;
2019
2020 return true;
2021 };
2022 for (VectorType *VTy : CandidateTys)
2023 if (CheckVectorTypeForPromotion(VTy))
2024 return VTy;
2025
2026 return nullptr;
2027}
2028
2029/// Test whether a slice of an alloca is valid for integer widening.
2030///
2031/// This implements the necessary checking for the \c isIntegerWideningViable
2032/// test below on a single slice of the alloca.
2033static bool isIntegerWideningViableForSlice(const Slice &S,
2034 uint64_t AllocBeginOffset,
2035 Type *AllocaTy,
2036 const DataLayout &DL,
2037 bool &WholeAllocaOp) {
2038 uint64_t Size = DL.getTypeStoreSize(AllocaTy).getFixedSize();
2039
2040 uint64_t RelBegin = S.beginOffset() - AllocBeginOffset;
2041 uint64_t RelEnd = S.endOffset() - AllocBeginOffset;
2042
2043 // We can't reasonably handle cases where the load or store extends past
2044 // the end of the alloca's type and into its padding.
2045 if (RelEnd > Size)
2046 return false;
2047
2048 Use *U = S.getUse();
2049
2050 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
2051 if (LI->isVolatile())
2052 return false;
2053 // We can't handle loads that extend past the allocated memory.
2054 if (DL.getTypeStoreSize(LI->getType()).getFixedSize() > Size)
2055 return false;
2056 // So far, AllocaSliceRewriter does not support widening split slice tails
2057 // in rewriteIntegerLoad.
2058 if (S.beginOffset() < AllocBeginOffset)
2059 return false;
2060 // Note that we don't count vector loads or stores as whole-alloca
2061 // operations which enable integer widening because we would prefer to use
2062 // vector widening instead.
2063 if (!isa<VectorType>(LI->getType()) && RelBegin == 0 && RelEnd == Size)
2064 WholeAllocaOp = true;
2065 if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType())) {
2066 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy).getFixedSize())
2067 return false;
2068 } else if (RelBegin != 0 || RelEnd != Size ||
2069 !canConvertValue(DL, AllocaTy, LI->getType())) {
2070 // Non-integer loads need to be convertible from the alloca type so that
2071 // they are promotable.
2072 return false;
2073 }
2074 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
2075 Type *ValueTy = SI->getValueOperand()->getType();
2076 if (SI->isVolatile())
2077 return false;
2078 // We can't handle stores that extend past the allocated memory.
2079 if (DL.getTypeStoreSize(ValueTy).getFixedSize() > Size)
2080 return false;
2081 // So far, AllocaSliceRewriter does not support widening split slice tails
2082 // in rewriteIntegerStore.
2083 if (S.beginOffset() < AllocBeginOffset)
2084 return false;
2085 // Note that we don't count vector loads or stores as whole-alloca
2086 // operations which enable integer widening because we would prefer to use
2087 // vector widening instead.
2088 if (!isa<VectorType>(ValueTy) && RelBegin == 0 && RelEnd == Size)
2089 WholeAllocaOp = true;
2090 if (IntegerType *ITy = dyn_cast<IntegerType>(ValueTy)) {
2091 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy).getFixedSize())
2092 return false;
2093 } else if (RelBegin != 0 || RelEnd != Size ||
2094 !canConvertValue(DL, ValueTy, AllocaTy)) {
2095 // Non-integer stores need to be convertible to the alloca type so that
2096 // they are promotable.
2097 return false;
2098 }
2099 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
2100 if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
2101 return false;
2102 if (!S.isSplittable())
2103 return false; // Skip any unsplittable intrinsics.
2104 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
2105 if (!II->isLifetimeStartOrEnd() && !II->isDroppable())
2106 return false;
2107 } else {
2108 return false;
2109 }
2110
2111 return true;
2112}
2113
2114/// Test whether the given alloca partition's integer operations can be
2115/// widened to promotable ones.
2116///
2117/// This is a quick test to check whether we can rewrite the integer loads and
2118/// stores to a particular alloca into wider loads and stores and be able to
2119/// promote the resulting alloca.
2120static bool isIntegerWideningViable(Partition &P, Type *AllocaTy,
2121 const DataLayout &DL) {
2122 uint64_t SizeInBits = DL.getTypeSizeInBits(AllocaTy).getFixedSize();
2123 // Don't create integer types larger than the maximum bitwidth.
2124 if (SizeInBits > IntegerType::MAX_INT_BITS)
2125 return false;
2126
2127 // Don't try to handle allocas with bit-padding.
2128 if (SizeInBits != DL.getTypeStoreSizeInBits(AllocaTy).getFixedSize())
2129 return false;
2130
2131 // We need to ensure that an integer type with the appropriate bitwidth can
2132 // be converted to the alloca type, whatever that is. We don't want to force
2133 // the alloca itself to have an integer type if there is a more suitable one.
2134 Type *IntTy = Type::getIntNTy(AllocaTy->getContext(), SizeInBits);
2135 if (!canConvertValue(DL, AllocaTy, IntTy) ||
2136 !canConvertValue(DL, IntTy, AllocaTy))
2137 return false;
2138
2139 // While examining uses, we ensure that the alloca has a covering load or
2140 // store. We don't want to widen the integer operations only to fail to
2141 // promote due to some other unsplittable entry (which we may make splittable
2142 // later). However, if there are only splittable uses, go ahead and assume
2143 // that we cover the alloca.
2144 // FIXME: We shouldn't consider split slices that happen to start in the
2145 // partition here...
2146 bool WholeAllocaOp = P.empty() && DL.isLegalInteger(SizeInBits);
2147
2148 for (const Slice &S : P)
2149 if (!isIntegerWideningViableForSlice(S, P.beginOffset(), AllocaTy, DL,
2150 WholeAllocaOp))
2151 return false;
2152
2153 for (const Slice *S : P.splitSliceTails())
2154 if (!isIntegerWideningViableForSlice(*S, P.beginOffset(), AllocaTy, DL,
2155 WholeAllocaOp))
2156 return false;
2157
2158 return WholeAllocaOp;
2159}
2160
2161static Value *extractInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
2162 IntegerType *Ty, uint64_t Offset,
2163 const Twine &Name) {
2164 LLVM_DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2165 IntegerType *IntTy = cast<IntegerType>(V->getType());
2166 assert(DL.getTypeStoreSize(Ty).getFixedSize() + Offset <=(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element extends past full value") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2168, __extension__ __PRETTY_FUNCTION__))
2167 DL.getTypeStoreSize(IntTy).getFixedSize() &&(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element extends past full value") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2168, __extension__ __PRETTY_FUNCTION__))
2168 "Element extends past full value")(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element extends past full value") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2168, __extension__ __PRETTY_FUNCTION__))
;
2169 uint64_t ShAmt = 8 * Offset;
2170 if (DL.isBigEndian())
2171 ShAmt = 8 * (DL.getTypeStoreSize(IntTy).getFixedSize() -
2172 DL.getTypeStoreSize(Ty).getFixedSize() - Offset);
2173 if (ShAmt) {
2174 V = IRB.CreateLShr(V, ShAmt, Name + ".shift");
2175 LLVM_DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2176 }
2177 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot extract to a larger integer!"
) ? void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2178, __extension__ __PRETTY_FUNCTION__))
2178 "Cannot extract to a larger integer!")(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot extract to a larger integer!"
) ? void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2178, __extension__ __PRETTY_FUNCTION__))
;
2179 if (Ty != IntTy) {
2180 V = IRB.CreateTrunc(V, Ty, Name + ".trunc");
2181 LLVM_DEBUG(dbgs() << " trunced: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " trunced: " << *V <<
"\n"; } } while (false)
;
2182 }
2183 return V;
2184}
2185
2186static Value *insertInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *Old,
2187 Value *V, uint64_t Offset, const Twine &Name) {
2188 IntegerType *IntTy = cast<IntegerType>(Old->getType());
2189 IntegerType *Ty = cast<IntegerType>(V->getType());
2190 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot insert a larger integer!") ?
void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2191, __extension__ __PRETTY_FUNCTION__))
2191 "Cannot insert a larger integer!")(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot insert a larger integer!") ?
void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2191, __extension__ __PRETTY_FUNCTION__))
;
2192 LLVM_DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2193 if (Ty != IntTy) {
2194 V = IRB.CreateZExt(V, IntTy, Name + ".ext");
2195 LLVM_DEBUG(dbgs() << " extended: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extended: " << *V <<
"\n"; } } while (false)
;
2196 }
2197 assert(DL.getTypeStoreSize(Ty).getFixedSize() + Offset <=(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element store outside of alloca store") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2199, __extension__ __PRETTY_FUNCTION__))
2198 DL.getTypeStoreSize(IntTy).getFixedSize() &&(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element store outside of alloca store") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2199, __extension__ __PRETTY_FUNCTION__))
2199 "Element store outside of alloca store")(static_cast <bool> (DL.getTypeStoreSize(Ty).getFixedSize
() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() &&
"Element store outside of alloca store") ? void (0) : __assert_fail
("DL.getTypeStoreSize(Ty).getFixedSize() + Offset <= DL.getTypeStoreSize(IntTy).getFixedSize() && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2199, __extension__ __PRETTY_FUNCTION__))
;
2200 uint64_t ShAmt = 8 * Offset;
2201 if (DL.isBigEndian())
2202 ShAmt = 8 * (DL.getTypeStoreSize(IntTy).getFixedSize() -
2203 DL.getTypeStoreSize(Ty).getFixedSize() - Offset);
2204 if (ShAmt) {
2205 V = IRB.CreateShl(V, ShAmt, Name + ".shift");
2206 LLVM_DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2207 }
2208
2209 if (ShAmt || Ty->getBitWidth() < IntTy->getBitWidth()) {
2210 APInt Mask = ~Ty->getMask().zext(IntTy->getBitWidth()).shl(ShAmt);
2211 Old = IRB.CreateAnd(Old, Mask, Name + ".mask");
2212 LLVM_DEBUG(dbgs() << " masked: " << *Old << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " masked: " << *Old <<
"\n"; } } while (false)
;
2213 V = IRB.CreateOr(Old, V, Name + ".insert");
2214 LLVM_DEBUG(dbgs() << " inserted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " inserted: " << *V <<
"\n"; } } while (false)
;
2215 }
2216 return V;
2217}
2218
2219static Value *extractVector(IRBuilderTy &IRB, Value *V, unsigned BeginIndex,
2220 unsigned EndIndex, const Twine &Name) {
2221 auto *VecTy = cast<FixedVectorType>(V->getType());
2222 unsigned NumElements = EndIndex - BeginIndex;
2223 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")(static_cast <bool> (NumElements <= VecTy->getNumElements
() && "Too many elements!") ? void (0) : __assert_fail
("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2223, __extension__ __PRETTY_FUNCTION__))
;
2224
2225 if (NumElements == VecTy->getNumElements())
2226 return V;
2227
2228 if (NumElements == 1) {
2229 V = IRB.CreateExtractElement(V, IRB.getInt32(BeginIndex),
2230 Name + ".extract");
2231 LLVM_DEBUG(dbgs() << " extract: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extract: " << *V <<
"\n"; } } while (false)
;
2232 return V;
2233 }
2234
2235 SmallVector<int, 8> Mask;
2236 Mask.reserve(NumElements);
2237 for (unsigned i = BeginIndex; i != EndIndex; ++i)
2238 Mask.push_back(i);
2239 V = IRB.CreateShuffleVector(V, Mask, Name + ".extract");
2240 LLVM_DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2241 return V;
2242}
2243
2244static Value *insertVector(IRBuilderTy &IRB, Value *Old, Value *V,
2245 unsigned BeginIndex, const Twine &Name) {
2246 VectorType *VecTy = cast<VectorType>(Old->getType());
2247 assert(VecTy && "Can only insert a vector into a vector")(static_cast <bool> (VecTy && "Can only insert a vector into a vector"
) ? void (0) : __assert_fail ("VecTy && \"Can only insert a vector into a vector\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2247, __extension__ __PRETTY_FUNCTION__))
;
2248
2249 VectorType *Ty = dyn_cast<VectorType>(V->getType());
2250 if (!Ty) {
2251 // Single element to insert.
2252 V = IRB.CreateInsertElement(Old, V, IRB.getInt32(BeginIndex),
2253 Name + ".insert");
2254 LLVM_DEBUG(dbgs() << " insert: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " insert: " << *V <<
"\n"; } } while (false)
;
2255 return V;
2256 }
2257
2258 assert(cast<FixedVectorType>(Ty)->getNumElements() <=(static_cast <bool> (cast<FixedVectorType>(Ty)->
getNumElements() <= cast<FixedVectorType>(VecTy)->
getNumElements() && "Too many elements!") ? void (0) :
__assert_fail ("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2260, __extension__ __PRETTY_FUNCTION__))
2259 cast<FixedVectorType>(VecTy)->getNumElements() &&(static_cast <bool> (cast<FixedVectorType>(Ty)->
getNumElements() <= cast<FixedVectorType>(VecTy)->
getNumElements() && "Too many elements!") ? void (0) :
__assert_fail ("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2260, __extension__ __PRETTY_FUNCTION__))
2260 "Too many elements!")(static_cast <bool> (cast<FixedVectorType>(Ty)->
getNumElements() <= cast<FixedVectorType>(VecTy)->
getNumElements() && "Too many elements!") ? void (0) :
__assert_fail ("cast<FixedVectorType>(Ty)->getNumElements() <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2260, __extension__ __PRETTY_FUNCTION__))
;
2261 if (cast<FixedVectorType>(Ty)->getNumElements() ==
2262 cast<FixedVectorType>(VecTy)->getNumElements()) {
2263 assert(V->getType() == VecTy && "Vector type mismatch")(static_cast <bool> (V->getType() == VecTy &&
"Vector type mismatch") ? void (0) : __assert_fail ("V->getType() == VecTy && \"Vector type mismatch\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2263, __extension__ __PRETTY_FUNCTION__))
;
2264 return V;
2265 }
2266 unsigned EndIndex = BeginIndex + cast<FixedVectorType>(Ty)->getNumElements();
2267
2268 // When inserting a smaller vector into the larger to store, we first
2269 // use a shuffle vector to widen it with undef elements, and then
2270 // a second shuffle vector to select between the loaded vector and the
2271 // incoming vector.
2272 SmallVector<int, 8> Mask;
2273 Mask.reserve(cast<FixedVectorType>(VecTy)->getNumElements());
2274 for (unsigned i = 0; i != cast<FixedVectorType>(VecTy)->getNumElements(); ++i)
2275 if (i >= BeginIndex && i < EndIndex)
2276 Mask.push_back(i - BeginIndex);
2277 else
2278 Mask.push_back(-1);
2279 V = IRB.CreateShuffleVector(V, Mask, Name + ".expand");
2280 LLVM_DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2281
2282 SmallVector<Constant *, 8> Mask2;
2283 Mask2.reserve(cast<FixedVectorType>(VecTy)->getNumElements());
2284 for (unsigned i = 0; i != cast<FixedVectorType>(VecTy)->getNumElements(); ++i)
2285 Mask2.push_back(IRB.getInt1(i >= BeginIndex && i < EndIndex));
2286
2287 V = IRB.CreateSelect(ConstantVector::get(Mask2), V, Old, Name + "blend");
2288
2289 LLVM_DEBUG(dbgs() << " blend: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " blend: " << *V <<
"\n"; } } while (false)
;
2290 return V;
2291}
2292
2293/// Visitor to rewrite instructions using p particular slice of an alloca
2294/// to use a new alloca.
2295///
2296/// Also implements the rewriting to vector-based accesses when the partition
2297/// passes the isVectorPromotionViable predicate. Most of the rewriting logic
2298/// lives here.
2299class llvm::sroa::AllocaSliceRewriter
2300 : public InstVisitor<AllocaSliceRewriter, bool> {
2301 // Befriend the base class so it can delegate to private visit methods.
2302 friend class InstVisitor<AllocaSliceRewriter, bool>;
2303
2304 using Base = InstVisitor<AllocaSliceRewriter, bool>;
2305
2306 const DataLayout &DL;
2307 AllocaSlices &AS;
2308 SROA &Pass;
2309 AllocaInst &OldAI, &NewAI;
2310 const uint64_t NewAllocaBeginOffset, NewAllocaEndOffset;
2311 Type *NewAllocaTy;
2312
2313 // This is a convenience and flag variable that will be null unless the new
2314 // alloca's integer operations should be widened to this integer type due to
2315 // passing isIntegerWideningViable above. If it is non-null, the desired
2316 // integer type will be stored here for easy access during rewriting.
2317 IntegerType *IntTy;
2318
2319 // If we are rewriting an alloca partition which can be written as pure
2320 // vector operations, we stash extra information here. When VecTy is
2321 // non-null, we have some strict guarantees about the rewritten alloca:
2322 // - The new alloca is exactly the size of the vector type here.
2323 // - The accesses all either map to the entire vector or to a single
2324 // element.
2325 // - The set of accessing instructions is only one of those handled above
2326 // in isVectorPromotionViable. Generally these are the same access kinds
2327 // which are promotable via mem2reg.
2328 VectorType *VecTy;
2329 Type *ElementTy;
2330 uint64_t ElementSize;
2331
2332 // The original offset of the slice currently being rewritten relative to
2333 // the original alloca.
2334 uint64_t BeginOffset = 0;
2335 uint64_t EndOffset = 0;
2336
2337 // The new offsets of the slice currently being rewritten relative to the
2338 // original alloca.
2339 uint64_t NewBeginOffset = 0, NewEndOffset = 0;
2340
2341 uint64_t SliceSize = 0;
2342 bool IsSplittable = false;
2343 bool IsSplit = false;
2344 Use *OldUse = nullptr;
2345 Instruction *OldPtr = nullptr;
2346
2347 // Track post-rewrite users which are PHI nodes and Selects.
2348 SmallSetVector<PHINode *, 8> &PHIUsers;
2349 SmallSetVector<SelectInst *, 8> &SelectUsers;
2350
2351 // Utility IR builder, whose name prefix is setup for each visited use, and
2352 // the insertion point is set to point to the user.
2353 IRBuilderTy IRB;
2354
2355public:
2356 AllocaSliceRewriter(const DataLayout &DL, AllocaSlices &AS, SROA &Pass,
2357 AllocaInst &OldAI, AllocaInst &NewAI,
2358 uint64_t NewAllocaBeginOffset,
2359 uint64_t NewAllocaEndOffset, bool IsIntegerPromotable,
2360 VectorType *PromotableVecTy,
2361 SmallSetVector<PHINode *, 8> &PHIUsers,
2362 SmallSetVector<SelectInst *, 8> &SelectUsers)
2363 : DL(DL), AS(AS), Pass(Pass), OldAI(OldAI), NewAI(NewAI),
2364 NewAllocaBeginOffset(NewAllocaBeginOffset),
2365 NewAllocaEndOffset(NewAllocaEndOffset),
2366 NewAllocaTy(NewAI.getAllocatedType()),
2367 IntTy(
2368 IsIntegerPromotable
2369 ? Type::getIntNTy(NewAI.getContext(),
2370 DL.getTypeSizeInBits(NewAI.getAllocatedType())
2371 .getFixedSize())
2372 : nullptr),
2373 VecTy(PromotableVecTy),
2374 ElementTy(VecTy ? VecTy->getElementType() : nullptr),
2375 ElementSize(VecTy ? DL.getTypeSizeInBits(ElementTy).getFixedSize() / 8
2376 : 0),
2377 PHIUsers(PHIUsers), SelectUsers(SelectUsers),
2378 IRB(NewAI.getContext(), ConstantFolder()) {
2379 if (VecTy) {
2380 assert((DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 &&(static_cast <bool> ((DL.getTypeSizeInBits(ElementTy).getFixedSize
() % 8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2381, __extension__ __PRETTY_FUNCTION__))
2381 "Only multiple-of-8 sized vector elements are viable")(static_cast <bool> ((DL.getTypeSizeInBits(ElementTy).getFixedSize
() % 8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy).getFixedSize() % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2381, __extension__ __PRETTY_FUNCTION__))
;
2382 ++NumVectorized;
2383 }
2384 assert((!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy))(static_cast <bool> ((!IntTy && !VecTy) || (IntTy
&& !VecTy) || (!IntTy && VecTy)) ? void (0) :
__assert_fail ("(!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2384, __extension__ __PRETTY_FUNCTION__))
;
2385 }
2386
2387 bool visit(AllocaSlices::const_iterator I) {
2388 bool CanSROA = true;
2389 BeginOffset = I->beginOffset();
2390 EndOffset = I->endOffset();
2391 IsSplittable = I->isSplittable();
2392 IsSplit =
2393 BeginOffset < NewAllocaBeginOffset || EndOffset > NewAllocaEndOffset;
2394 LLVM_DEBUG(dbgs() << " rewriting " << (IsSplit ? "split " : ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " rewriting " << (IsSplit ?
"split " : ""); } } while (false)
;
2395 LLVM_DEBUG(AS.printSlice(dbgs(), I, ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.printSlice(dbgs(), I, ""); } } while (false)
;
2396 LLVM_DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n"; } } while (false)
;
2397
2398 // Compute the intersecting offset range.
2399 assert(BeginOffset < NewAllocaEndOffset)(static_cast <bool> (BeginOffset < NewAllocaEndOffset
) ? void (0) : __assert_fail ("BeginOffset < NewAllocaEndOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2399, __extension__ __PRETTY_FUNCTION__))
;
2400 assert(EndOffset > NewAllocaBeginOffset)(static_cast <bool> (EndOffset > NewAllocaBeginOffset
) ? void (0) : __assert_fail ("EndOffset > NewAllocaBeginOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2400, __extension__ __PRETTY_FUNCTION__))
;
2401 NewBeginOffset = std::max(BeginOffset, NewAllocaBeginOffset);
2402 NewEndOffset = std::min(EndOffset, NewAllocaEndOffset);
2403
2404 SliceSize = NewEndOffset - NewBeginOffset;
2405
2406 OldUse = I->getUse();
2407 OldPtr = cast<Instruction>(OldUse->get());
2408
2409 Instruction *OldUserI = cast<Instruction>(OldUse->getUser());
2410 IRB.SetInsertPoint(OldUserI);
2411 IRB.SetCurrentDebugLocation(OldUserI->getDebugLoc());
2412 IRB.getInserter().SetNamePrefix(
2413 Twine(NewAI.getName()) + "." + Twine(BeginOffset) + ".");
2414
2415 CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
2416 if (VecTy || IntTy)
2417 assert(CanSROA)(static_cast <bool> (CanSROA) ? void (0) : __assert_fail
("CanSROA", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2417, __extension__ __PRETTY_FUNCTION__))
;
2418 return CanSROA;
2419 }
2420
2421private:
2422 // Make sure the other visit overloads are visible.
2423 using Base::visit;
2424
2425 // Every instruction which can end up as a user must have a rewrite rule.
2426 bool visitInstruction(Instruction &I) {
2427 LLVM_DEBUG(dbgs() << " !!!! Cannot rewrite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " !!!! Cannot rewrite: " <<
I << "\n"; } } while (false)
;
2428 llvm_unreachable("No rewrite rule for this instruction!")::llvm::llvm_unreachable_internal("No rewrite rule for this instruction!"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2428)
;
2429 }
2430
2431 Value *getNewAllocaSlicePtr(IRBuilderTy &IRB, Type *PointerTy) {
2432 // Note that the offset computation can use BeginOffset or NewBeginOffset
2433 // interchangeably for unsplit slices.
2434 assert(IsSplit || BeginOffset == NewBeginOffset)(static_cast <bool> (IsSplit || BeginOffset == NewBeginOffset
) ? void (0) : __assert_fail ("IsSplit || BeginOffset == NewBeginOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2434, __extension__ __PRETTY_FUNCTION__))
;
2435 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2436
2437#ifndef NDEBUG
2438 StringRef OldName = OldPtr->getName();
2439 // Skip through the last '.sroa.' component of the name.
2440 size_t LastSROAPrefix = OldName.rfind(".sroa.");
2441 if (LastSROAPrefix != StringRef::npos) {
2442 OldName = OldName.substr(LastSROAPrefix + strlen(".sroa."));
2443 // Look for an SROA slice index.
2444 size_t IndexEnd = OldName.find_first_not_of("0123456789");
2445 if (IndexEnd != StringRef::npos && OldName[IndexEnd] == '.') {
2446 // Strip the index and look for the offset.
2447 OldName = OldName.substr(IndexEnd + 1);
2448 size_t OffsetEnd = OldName.find_first_not_of("0123456789");
2449 if (OffsetEnd != StringRef::npos && OldName[OffsetEnd] == '.')
2450 // Strip the offset.
2451 OldName = OldName.substr(OffsetEnd + 1);
2452 }
2453 }
2454 // Strip any SROA suffixes as well.
2455 OldName = OldName.substr(0, OldName.find(".sroa_"));
2456#endif
2457
2458 return getAdjustedPtr(IRB, DL, &NewAI,
2459 APInt(DL.getIndexTypeSizeInBits(PointerTy), Offset),
2460 PointerTy,
2461#ifndef NDEBUG
2462 Twine(OldName) + "."
2463#else
2464 Twine()
2465#endif
2466 );
2467 }
2468
2469 /// Compute suitable alignment to access this slice of the *new*
2470 /// alloca.
2471 ///
2472 /// You can optionally pass a type to this routine and if that type's ABI
2473 /// alignment is itself suitable, this will return zero.
2474 Align getSliceAlign() {
2475 return commonAlignment(NewAI.getAlign(),
2476 NewBeginOffset - NewAllocaBeginOffset);
2477 }
2478
2479 unsigned getIndex(uint64_t Offset) {
2480 assert(VecTy && "Can only call getIndex when rewriting a vector")(static_cast <bool> (VecTy && "Can only call getIndex when rewriting a vector"
) ? void (0) : __assert_fail ("VecTy && \"Can only call getIndex when rewriting a vector\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2480, __extension__ __PRETTY_FUNCTION__))
;
2481 uint64_t RelOffset = Offset - NewAllocaBeginOffset;
2482 assert(RelOffset / ElementSize < UINT32_MAX && "Index out of bounds")(static_cast <bool> (RelOffset / ElementSize < (4294967295U
) && "Index out of bounds") ? void (0) : __assert_fail
("RelOffset / ElementSize < UINT32_MAX && \"Index out of bounds\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2482, __extension__ __PRETTY_FUNCTION__))
;
2483 uint32_t Index = RelOffset / ElementSize;
2484 assert(Index * ElementSize == RelOffset)(static_cast <bool> (Index * ElementSize == RelOffset) ?
void (0) : __assert_fail ("Index * ElementSize == RelOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2484, __extension__ __PRETTY_FUNCTION__))
;
2485 return Index;
2486 }
2487
2488 void deleteIfTriviallyDead(Value *V) {
2489 Instruction *I = cast<Instruction>(V);
2490 if (isInstructionTriviallyDead(I))
2491 Pass.DeadInsts.push_back(I);
2492 }
2493
2494 Value *rewriteVectorizedLoadInst(LoadInst &LI) {
2495 unsigned BeginIndex = getIndex(NewBeginOffset);
2496 unsigned EndIndex = getIndex(NewEndOffset);
2497 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2497, __extension__ __PRETTY_FUNCTION__))
;
2498
2499 LoadInst *Load = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2500 NewAI.getAlign(), "load");
2501
2502 Load->copyMetadata(LI, {LLVMContext::MD_mem_parallel_loop_access,
2503 LLVMContext::MD_access_group});
2504 return extractVector(IRB, Load, BeginIndex, EndIndex, "vec");
2505 }
2506
2507 Value *rewriteIntegerLoad(LoadInst &LI) {
2508 assert(IntTy && "We cannot insert an integer to the alloca")(static_cast <bool> (IntTy && "We cannot insert an integer to the alloca"
) ? void (0) : __assert_fail ("IntTy && \"We cannot insert an integer to the alloca\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2508, __extension__ __PRETTY_FUNCTION__))
;
2509 assert(!LI.isVolatile())(static_cast <bool> (!LI.isVolatile()) ? void (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2509, __extension__ __PRETTY_FUNCTION__))
;
2510 Value *V = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2511 NewAI.getAlign(), "load");
2512 V = convertValue(DL, IRB, V, IntTy);
2513 assert(NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")(static_cast <bool> (NewBeginOffset >= NewAllocaBeginOffset
&& "Out of bounds offset") ? void (0) : __assert_fail
("NewBeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2513, __extension__ __PRETTY_FUNCTION__))
;
2514 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2515 if (Offset > 0 || NewEndOffset < NewAllocaEndOffset) {
2516 IntegerType *ExtractTy = Type::getIntNTy(LI.getContext(), SliceSize * 8);
2517 V = extractInteger(DL, IRB, V, ExtractTy, Offset, "extract");
2518 }
2519 // It is possible that the extracted type is not the load type. This
2520 // happens if there is a load past the end of the alloca, and as
2521 // a consequence the slice is narrower but still a candidate for integer
2522 // lowering. To handle this case, we just zero extend the extracted
2523 // integer.
2524 assert(cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 &&(static_cast <bool> (cast<IntegerType>(LI.getType
())->getBitWidth() >= SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2525, __extension__ __PRETTY_FUNCTION__))
2525 "Can only handle an extract for an overly wide load")(static_cast <bool> (cast<IntegerType>(LI.getType
())->getBitWidth() >= SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2525, __extension__ __PRETTY_FUNCTION__))
;
2526 if (cast<IntegerType>(LI.getType())->getBitWidth() > SliceSize * 8)
2527 V = IRB.CreateZExt(V, LI.getType());
2528 return V;
2529 }
2530
2531 bool visitLoadInst(LoadInst &LI) {
2532 LLVM_DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
2533 Value *OldOp = LI.getOperand(0);
2534 assert(OldOp == OldPtr)(static_cast <bool> (OldOp == OldPtr) ? void (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2534, __extension__ __PRETTY_FUNCTION__))
;
2535
2536 AAMDNodes AATags;
2537 LI.getAAMetadata(AATags);
2538
2539 unsigned AS = LI.getPointerAddressSpace();
2540
2541 Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), SliceSize * 8)
2542 : LI.getType();
2543 const bool IsLoadPastEnd =
2544 DL.getTypeStoreSize(TargetTy).getFixedSize() > SliceSize;
2545 bool IsPtrAdjusted = false;
2546 Value *V;
2547 if (VecTy) {
2548 V = rewriteVectorizedLoadInst(LI);
2549 } else if (IntTy && LI.getType()->isIntegerTy()) {
2550 V = rewriteIntegerLoad(LI);
2551 } else if (NewBeginOffset == NewAllocaBeginOffset &&
2552 NewEndOffset == NewAllocaEndOffset &&
2553 (canConvertValue(DL, NewAllocaTy, TargetTy) ||
2554 (IsLoadPastEnd && NewAllocaTy->isIntegerTy() &&
2555 TargetTy->isIntegerTy()))) {
2556 LoadInst *NewLI = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2557 NewAI.getAlign(), LI.isVolatile(),
2558 LI.getName());
2559 if (AATags)
2560 NewLI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2561 if (LI.isVolatile())
2562 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2563 if (NewLI->isAtomic())
2564 NewLI->setAlignment(LI.getAlign());
2565
2566 // Any !nonnull metadata or !range metadata on the old load is also valid
2567 // on the new load. This is even true in some cases even when the loads
2568 // are different types, for example by mapping !nonnull metadata to
2569 // !range metadata by modeling the null pointer constant converted to the
2570 // integer type.
2571 // FIXME: Add support for range metadata here. Currently the utilities
2572 // for this don't propagate range metadata in trivial cases from one
2573 // integer load to another, don't handle non-addrspace-0 null pointers
2574 // correctly, and don't have any support for mapping ranges as the
2575 // integer type becomes winder or narrower.
2576 if (MDNode *N = LI.getMetadata(LLVMContext::MD_nonnull))
2577 copyNonnullMetadata(LI, N, *NewLI);
2578
2579 // Try to preserve nonnull metadata
2580 V = NewLI;
2581
2582 // If this is an integer load past the end of the slice (which means the
2583 // bytes outside the slice are undef or this load is dead) just forcibly
2584 // fix the integer size with correct handling of endianness.
2585 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2586 if (auto *TITy = dyn_cast<IntegerType>(TargetTy))
2587 if (AITy->getBitWidth() < TITy->getBitWidth()) {
2588 V = IRB.CreateZExt(V, TITy, "load.ext");
2589 if (DL.isBigEndian())
2590 V = IRB.CreateShl(V, TITy->getBitWidth() - AITy->getBitWidth(),
2591 "endian_shift");
2592 }
2593 } else {
2594 Type *LTy = TargetTy->getPointerTo(AS);
2595 LoadInst *NewLI =
2596 IRB.CreateAlignedLoad(TargetTy, getNewAllocaSlicePtr(IRB, LTy),
2597 getSliceAlign(), LI.isVolatile(), LI.getName());
2598 if (AATags)
2599 NewLI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2600 if (LI.isVolatile())
2601 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2602 NewLI->copyMetadata(LI, {LLVMContext::MD_mem_parallel_loop_access,
2603 LLVMContext::MD_access_group});
2604
2605 V = NewLI;
2606 IsPtrAdjusted = true;
2607 }
2608 V = convertValue(DL, IRB, V, TargetTy);
2609
2610 if (IsSplit) {
2611 assert(!LI.isVolatile())(static_cast <bool> (!LI.isVolatile()) ? void (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2611, __extension__ __PRETTY_FUNCTION__))
;
2612 assert(LI.getType()->isIntegerTy() &&(static_cast <bool> (LI.getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2613, __extension__ __PRETTY_FUNCTION__))
2613 "Only integer type loads and stores are split")(static_cast <bool> (LI.getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2613, __extension__ __PRETTY_FUNCTION__))
;
2614 assert(SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() &&(static_cast <bool> (SliceSize < DL.getTypeStoreSize
(LI.getType()).getFixedSize() && "Split load isn't smaller than original load"
) ? void (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2615, __extension__ __PRETTY_FUNCTION__))
2615 "Split load isn't smaller than original load")(static_cast <bool> (SliceSize < DL.getTypeStoreSize
(LI.getType()).getFixedSize() && "Split load isn't smaller than original load"
) ? void (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()).getFixedSize() && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2615, __extension__ __PRETTY_FUNCTION__))
;
2616 assert(DL.typeSizeEqualsStoreSize(LI.getType()) &&(static_cast <bool> (DL.typeSizeEqualsStoreSize(LI.getType
()) && "Non-byte-multiple bit width") ? void (0) : __assert_fail
("DL.typeSizeEqualsStoreSize(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2617, __extension__ __PRETTY_FUNCTION__))
2617 "Non-byte-multiple bit width")(static_cast <bool> (DL.typeSizeEqualsStoreSize(LI.getType
()) && "Non-byte-multiple bit width") ? void (0) : __assert_fail
("DL.typeSizeEqualsStoreSize(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2617, __extension__ __PRETTY_FUNCTION__))
;
2618 // Move the insertion point just past the load so that we can refer to it.
2619 IRB.SetInsertPoint(&*std::next(BasicBlock::iterator(&LI)));
2620 // Create a placeholder value with the same type as LI to use as the
2621 // basis for the new value. This allows us to replace the uses of LI with
2622 // the computed value, and then replace the placeholder with LI, leaving
2623 // LI only used for this computation.
2624 Value *Placeholder = new LoadInst(
2625 LI.getType(), UndefValue::get(LI.getType()->getPointerTo(AS)), "",
2626 false, Align(1));
2627 V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
2628 "insert");
2629 LI.replaceAllUsesWith(V);
2630 Placeholder->replaceAllUsesWith(&LI);
2631 Placeholder->deleteValue();
2632 } else {
2633 LI.replaceAllUsesWith(V);
2634 }
2635
2636 Pass.DeadInsts.push_back(&LI);
2637 deleteIfTriviallyDead(OldOp);
2638 LLVM_DEBUG(dbgs() << " to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *V <<
"\n"; } } while (false)
;
2639 return !LI.isVolatile() && !IsPtrAdjusted;
2640 }
2641
2642 bool rewriteVectorizedStoreInst(Value *V, StoreInst &SI, Value *OldOp,
2643 AAMDNodes AATags) {
2644 if (V->getType() != VecTy) {
2645 unsigned BeginIndex = getIndex(NewBeginOffset);
2646 unsigned EndIndex = getIndex(NewEndOffset);
2647 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2647, __extension__ __PRETTY_FUNCTION__))
;
2648 unsigned NumElements = EndIndex - BeginIndex;
2649 assert(NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() &&(static_cast <bool> (NumElements <= cast<FixedVectorType
>(VecTy)->getNumElements() && "Too many elements!"
) ? void (0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2650, __extension__ __PRETTY_FUNCTION__))
2650 "Too many elements!")(static_cast <bool> (NumElements <= cast<FixedVectorType
>(VecTy)->getNumElements() && "Too many elements!"
) ? void (0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2650, __extension__ __PRETTY_FUNCTION__))
;
2651 Type *SliceTy = (NumElements == 1)
2652 ? ElementTy
2653 : FixedVectorType::get(ElementTy, NumElements);
2654 if (V->getType() != SliceTy)
2655 V = convertValue(DL, IRB, V, SliceTy);
2656
2657 // Mix in the existing elements.
2658 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2659 NewAI.getAlign(), "load");
2660 V = insertVector(IRB, Old, V, BeginIndex, "vec");
2661 }
2662 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign());
2663 Store->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
2664 LLVMContext::MD_access_group});
2665 if (AATags)
2666 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2667 Pass.DeadInsts.push_back(&SI);
2668
2669 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2670 return true;
2671 }
2672
2673 bool rewriteIntegerStore(Value *V, StoreInst &SI, AAMDNodes AATags) {
2674 assert(IntTy && "We cannot extract an integer from the alloca")(static_cast <bool> (IntTy && "We cannot extract an integer from the alloca"
) ? void (0) : __assert_fail ("IntTy && \"We cannot extract an integer from the alloca\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2674, __extension__ __PRETTY_FUNCTION__))
;
2675 assert(!SI.isVolatile())(static_cast <bool> (!SI.isVolatile()) ? void (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2675, __extension__ __PRETTY_FUNCTION__))
;
2676 if (DL.getTypeSizeInBits(V->getType()).getFixedSize() !=
2677 IntTy->getBitWidth()) {
2678 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2679 NewAI.getAlign(), "oldload");
2680 Old = convertValue(DL, IRB, Old, IntTy);
2681 assert(BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "Out of bounds offset") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2681, __extension__ __PRETTY_FUNCTION__))
;
2682 uint64_t Offset = BeginOffset - NewAllocaBeginOffset;
2683 V = insertInteger(DL, IRB, Old, SI.getValueOperand(), Offset, "insert");
2684 }
2685 V = convertValue(DL, IRB, V, NewAllocaTy);
2686 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign());
2687 Store->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
2688 LLVMContext::MD_access_group});
2689 if (AATags)
2690 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2691 Pass.DeadInsts.push_back(&SI);
2692 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2693 return true;
2694 }
2695
2696 bool visitStoreInst(StoreInst &SI) {
2697 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
2698 Value *OldOp = SI.getOperand(1);
2699 assert(OldOp == OldPtr)(static_cast <bool> (OldOp == OldPtr) ? void (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2699, __extension__ __PRETTY_FUNCTION__))
;
2700
2701 AAMDNodes AATags;
2702 SI.getAAMetadata(AATags);
2703
2704 Value *V = SI.getValueOperand();
2705
2706 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2707 // alloca that should be re-examined after promoting this alloca.
2708 if (V->getType()->isPointerTy())
2709 if (AllocaInst *AI = dyn_cast<AllocaInst>(V->stripInBoundsOffsets()))
2710 Pass.PostPromotionWorklist.insert(AI);
2711
2712 if (SliceSize < DL.getTypeStoreSize(V->getType()).getFixedSize()) {
2713 assert(!SI.isVolatile())(static_cast <bool> (!SI.isVolatile()) ? void (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2713, __extension__ __PRETTY_FUNCTION__))
;
2714 assert(V->getType()->isIntegerTy() &&(static_cast <bool> (V->getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2715, __extension__ __PRETTY_FUNCTION__))
2715 "Only integer type loads and stores are split")(static_cast <bool> (V->getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2715, __extension__ __PRETTY_FUNCTION__))
;
2716 assert(DL.typeSizeEqualsStoreSize(V->getType()) &&(static_cast <bool> (DL.typeSizeEqualsStoreSize(V->getType
()) && "Non-byte-multiple bit width") ? void (0) : __assert_fail
("DL.typeSizeEqualsStoreSize(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2717, __extension__ __PRETTY_FUNCTION__))
2717 "Non-byte-multiple bit width")(static_cast <bool> (DL.typeSizeEqualsStoreSize(V->getType
()) && "Non-byte-multiple bit width") ? void (0) : __assert_fail
("DL.typeSizeEqualsStoreSize(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2717, __extension__ __PRETTY_FUNCTION__))
;
2718 IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), SliceSize * 8);
2719 V = extractInteger(DL, IRB, V, NarrowTy, NewBeginOffset - BeginOffset,
2720 "extract");
2721 }
2722
2723 if (VecTy)
2724 return rewriteVectorizedStoreInst(V, SI, OldOp, AATags);
2725 if (IntTy && V->getType()->isIntegerTy())
2726 return rewriteIntegerStore(V, SI, AATags);
2727
2728 const bool IsStorePastEnd =
2729 DL.getTypeStoreSize(V->getType()).getFixedSize() > SliceSize;
2730 StoreInst *NewSI;
2731 if (NewBeginOffset == NewAllocaBeginOffset &&
2732 NewEndOffset == NewAllocaEndOffset &&
2733 (canConvertValue(DL, V->getType(), NewAllocaTy) ||
2734 (IsStorePastEnd && NewAllocaTy->isIntegerTy() &&
2735 V->getType()->isIntegerTy()))) {
2736 // If this is an integer store past the end of slice (and thus the bytes
2737 // past that point are irrelevant or this is unreachable), truncate the
2738 // value prior to storing.
2739 if (auto *VITy = dyn_cast<IntegerType>(V->getType()))
2740 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2741 if (VITy->getBitWidth() > AITy->getBitWidth()) {
2742 if (DL.isBigEndian())
2743 V = IRB.CreateLShr(V, VITy->getBitWidth() - AITy->getBitWidth(),
2744 "endian_shift");
2745 V = IRB.CreateTrunc(V, AITy, "load.trunc");
2746 }
2747
2748 V = convertValue(DL, IRB, V, NewAllocaTy);
2749 NewSI =
2750 IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign(), SI.isVolatile());
2751 } else {
2752 unsigned AS = SI.getPointerAddressSpace();
2753 Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
2754 NewSI =
2755 IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(), SI.isVolatile());
2756 }
2757 NewSI->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
2758 LLVMContext::MD_access_group});
2759 if (AATags)
2760 NewSI->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2761 if (SI.isVolatile())
2762 NewSI->setAtomic(SI.getOrdering(), SI.getSyncScopeID());
2763 if (NewSI->isAtomic())
2764 NewSI->setAlignment(SI.getAlign());
2765 Pass.DeadInsts.push_back(&SI);
2766 deleteIfTriviallyDead(OldOp);
2767
2768 LLVM_DEBUG(dbgs() << " to: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *NewSI <<
"\n"; } } while (false)
;
2769 return NewSI->getPointerOperand() == &NewAI && !SI.isVolatile();
2770 }
2771
2772 /// Compute an integer value from splatting an i8 across the given
2773 /// number of bytes.
2774 ///
2775 /// Note that this routine assumes an i8 is a byte. If that isn't true, don't
2776 /// call this routine.
2777 /// FIXME: Heed the advice above.
2778 ///
2779 /// \param V The i8 value to splat.
2780 /// \param Size The number of bytes in the output (assuming i8 is one byte)
2781 Value *getIntegerSplat(Value *V, unsigned Size) {
2782 assert(Size > 0 && "Expected a positive number of bytes.")(static_cast <bool> (Size > 0 && "Expected a positive number of bytes."
) ? void (0) : __assert_fail ("Size > 0 && \"Expected a positive number of bytes.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2782, __extension__ __PRETTY_FUNCTION__))
;
2783 IntegerType *VTy = cast<IntegerType>(V->getType());
2784 assert(VTy->getBitWidth() == 8 && "Expected an i8 value for the byte")(static_cast <bool> (VTy->getBitWidth() == 8 &&
"Expected an i8 value for the byte") ? void (0) : __assert_fail
("VTy->getBitWidth() == 8 && \"Expected an i8 value for the byte\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2784, __extension__ __PRETTY_FUNCTION__))
;
2785 if (Size == 1)
2786 return V;
2787
2788 Type *SplatIntTy = Type::getIntNTy(VTy->getContext(), Size * 8);
2789 V = IRB.CreateMul(
2790 IRB.CreateZExt(V, SplatIntTy, "zext"),
2791 ConstantExpr::getUDiv(
2792 Constant::getAllOnesValue(SplatIntTy),
2793 ConstantExpr::getZExt(Constant::getAllOnesValue(V->getType()),
2794 SplatIntTy)),
2795 "isplat");
2796 return V;
2797 }
2798
2799 /// Compute a vector splat for a given element value.
2800 Value *getVectorSplat(Value *V, unsigned NumElements) {
2801 V = IRB.CreateVectorSplat(NumElements, V, "vsplat");
2802 LLVM_DEBUG(dbgs() << " splat: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " splat: " << *V <<
"\n"; } } while (false)
;
2803 return V;
2804 }
2805
2806 bool visitMemSetInst(MemSetInst &II) {
2807 LLVM_DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2808 assert(II.getRawDest() == OldPtr)(static_cast <bool> (II.getRawDest() == OldPtr) ? void (
0) : __assert_fail ("II.getRawDest() == OldPtr", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2808, __extension__ __PRETTY_FUNCTION__))
;
2809
2810 AAMDNodes AATags;
2811 II.getAAMetadata(AATags);
2812
2813 // If the memset has a variable size, it cannot be split, just adjust the
2814 // pointer to the new alloca.
2815 if (!isa<ConstantInt>(II.getLength())) {
2816 assert(!IsSplit)(static_cast <bool> (!IsSplit) ? void (0) : __assert_fail
("!IsSplit", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2816, __extension__ __PRETTY_FUNCTION__))
;
2817 assert(NewBeginOffset == BeginOffset)(static_cast <bool> (NewBeginOffset == BeginOffset) ? void
(0) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2817, __extension__ __PRETTY_FUNCTION__))
;
2818 II.setDest(getNewAllocaSlicePtr(IRB, OldPtr->getType()));
2819 II.setDestAlignment(getSliceAlign());
2820
2821 deleteIfTriviallyDead(OldPtr);
2822 return false;
2823 }
2824
2825 // Record this instruction for deletion.
2826 Pass.DeadInsts.push_back(&II);
2827
2828 Type *AllocaTy = NewAI.getAllocatedType();
2829 Type *ScalarTy = AllocaTy->getScalarType();
2830
2831 const bool CanContinue = [&]() {
2832 if (VecTy || IntTy)
2833 return true;
2834 if (BeginOffset > NewAllocaBeginOffset ||
2835 EndOffset < NewAllocaEndOffset)
2836 return false;
2837 // Length must be in range for FixedVectorType.
2838 auto *C = cast<ConstantInt>(II.getLength());
2839 const uint64_t Len = C->getLimitedValue();
2840 if (Len > std::numeric_limits<unsigned>::max())
2841 return false;
2842 auto *Int8Ty = IntegerType::getInt8Ty(NewAI.getContext());
2843 auto *SrcTy = FixedVectorType::get(Int8Ty, Len);
2844 return canConvertValue(DL, SrcTy, AllocaTy) &&
2845 DL.isLegalInteger(DL.getTypeSizeInBits(ScalarTy).getFixedSize());
2846 }();
2847
2848 // If this doesn't map cleanly onto the alloca type, and that type isn't
2849 // a single value type, just emit a memset.
2850 if (!CanContinue) {
2851 Type *SizeTy = II.getLength()->getType();
2852 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2853 CallInst *New = IRB.CreateMemSet(
2854 getNewAllocaSlicePtr(IRB, OldPtr->getType()), II.getValue(), Size,
2855 MaybeAlign(getSliceAlign()), II.isVolatile());
2856 if (AATags)
2857 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2858 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2859 return false;
2860 }
2861
2862 // If we can represent this as a simple value, we have to build the actual
2863 // value to store, which requires expanding the byte present in memset to
2864 // a sensible representation for the alloca type. This is essentially
2865 // splatting the byte to a sufficiently wide integer, splatting it across
2866 // any desired vector width, and bitcasting to the final type.
2867 Value *V;
2868
2869 if (VecTy) {
2870 // If this is a memset of a vectorized alloca, insert it.
2871 assert(ElementTy == ScalarTy)(static_cast <bool> (ElementTy == ScalarTy) ? void (0) :
__assert_fail ("ElementTy == ScalarTy", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2871, __extension__ __PRETTY_FUNCTION__))
;
2872
2873 unsigned BeginIndex = getIndex(NewBeginOffset);
2874 unsigned EndIndex = getIndex(NewEndOffset);
2875 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2875, __extension__ __PRETTY_FUNCTION__))
;
2876 unsigned NumElements = EndIndex - BeginIndex;
2877 assert(NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() &&(static_cast <bool> (NumElements <= cast<FixedVectorType
>(VecTy)->getNumElements() && "Too many elements!"
) ? void (0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2878, __extension__ __PRETTY_FUNCTION__))
2878 "Too many elements!")(static_cast <bool> (NumElements <= cast<FixedVectorType
>(VecTy)->getNumElements() && "Too many elements!"
) ? void (0) : __assert_fail ("NumElements <= cast<FixedVectorType>(VecTy)->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2878, __extension__ __PRETTY_FUNCTION__))
;
2879
2880 Value *Splat = getIntegerSplat(
2881 II.getValue(), DL.getTypeSizeInBits(ElementTy).getFixedSize() / 8);
2882 Splat = convertValue(DL, IRB, Splat, ElementTy);
2883 if (NumElements > 1)
2884 Splat = getVectorSplat(Splat, NumElements);
2885
2886 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2887 NewAI.getAlign(), "oldload");
2888 V = insertVector(IRB, Old, Splat, BeginIndex, "vec");
2889 } else if (IntTy) {
2890 // If this is a memset on an alloca where we can widen stores, insert the
2891 // set integer.
2892 assert(!II.isVolatile())(static_cast <bool> (!II.isVolatile()) ? void (0) : __assert_fail
("!II.isVolatile()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2892, __extension__ __PRETTY_FUNCTION__))
;
2893
2894 uint64_t Size = NewEndOffset - NewBeginOffset;
2895 V = getIntegerSplat(II.getValue(), Size);
2896
2897 if (IntTy && (BeginOffset != NewAllocaBeginOffset ||
2898 EndOffset != NewAllocaBeginOffset)) {
2899 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
2900 NewAI.getAlign(), "oldload");
2901 Old = convertValue(DL, IRB, Old, IntTy);
2902 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2903 V = insertInteger(DL, IRB, Old, V, Offset, "insert");
2904 } else {
2905 assert(V->getType() == IntTy &&(static_cast <bool> (V->getType() == IntTy &&
"Wrong type for an alloca wide integer!") ? void (0) : __assert_fail
("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2906, __extension__ __PRETTY_FUNCTION__))
2906 "Wrong type for an alloca wide integer!")(static_cast <bool> (V->getType() == IntTy &&
"Wrong type for an alloca wide integer!") ? void (0) : __assert_fail
("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2906, __extension__ __PRETTY_FUNCTION__))
;
2907 }
2908 V = convertValue(DL, IRB, V, AllocaTy);
2909 } else {
2910 // Established these invariants above.
2911 assert(NewBeginOffset == NewAllocaBeginOffset)(static_cast <bool> (NewBeginOffset == NewAllocaBeginOffset
) ? void (0) : __assert_fail ("NewBeginOffset == NewAllocaBeginOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2911, __extension__ __PRETTY_FUNCTION__))
;
2912 assert(NewEndOffset == NewAllocaEndOffset)(static_cast <bool> (NewEndOffset == NewAllocaEndOffset
) ? void (0) : __assert_fail ("NewEndOffset == NewAllocaEndOffset"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2912, __extension__ __PRETTY_FUNCTION__))
;
2913
2914 V = getIntegerSplat(II.getValue(),
2915 DL.getTypeSizeInBits(ScalarTy).getFixedSize() / 8);
2916 if (VectorType *AllocaVecTy = dyn_cast<VectorType>(AllocaTy))
2917 V = getVectorSplat(
2918 V, cast<FixedVectorType>(AllocaVecTy)->getNumElements());
2919
2920 V = convertValue(DL, IRB, V, AllocaTy);
2921 }
2922
2923 StoreInst *New =
2924 IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlign(), II.isVolatile());
2925 New->copyMetadata(II, {LLVMContext::MD_mem_parallel_loop_access,
2926 LLVMContext::MD_access_group});
2927 if (AATags)
2928 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
2929 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2930 return !II.isVolatile();
2931 }
2932
2933 bool visitMemTransferInst(MemTransferInst &II) {
2934 // Rewriting of memory transfer instructions can be a bit tricky. We break
2935 // them into two categories: split intrinsics and unsplit intrinsics.
2936
2937 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
2938
2939 AAMDNodes AATags;
2940 II.getAAMetadata(AATags);
2941
2942 bool IsDest = &II.getRawDestUse() == OldUse;
2943 assert((IsDest && II.getRawDest() == OldPtr) ||(static_cast <bool> ((IsDest && II.getRawDest()
== OldPtr) || (!IsDest && II.getRawSource() == OldPtr
)) ? void (0) : __assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2944, __extension__ __PRETTY_FUNCTION__))
3
Assuming 'IsDest' is false
4
Assuming pointer value is null
5
'?' condition is true
2944 (!IsDest && II.getRawSource() == OldPtr))(static_cast <bool> ((IsDest && II.getRawDest()
== OldPtr) || (!IsDest && II.getRawSource() == OldPtr
)) ? void (0) : __assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2944, __extension__ __PRETTY_FUNCTION__))
;
2945
2946 MaybeAlign SliceAlign = getSliceAlign();
2947
2948 // For unsplit intrinsics, we simply modify the source and destination
2949 // pointers in place. This isn't just an optimization, it is a matter of
2950 // correctness. With unsplit intrinsics we may be dealing with transfers
2951 // within a single alloca before SROA ran, or with transfers that have
2952 // a variable length. We may also be dealing with memmove instead of
2953 // memcpy, and so simply updating the pointers is the necessary for us to
2954 // update both source and dest of a single call.
2955 if (!IsSplittable) {
6
Assuming field 'IsSplittable' is false
7
Taking true branch
2956 Value *AdjustedPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
8
Called C++ object pointer is null
2957 if (IsDest) {
2958 II.setDest(AdjustedPtr);
2959 II.setDestAlignment(SliceAlign);
2960 }
2961 else {
2962 II.setSource(AdjustedPtr);
2963 II.setSourceAlignment(SliceAlign);
2964 }
2965
2966 LLVM_DEBUG(dbgs() << " to: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << II <<
"\n"; } } while (false)
;
2967 deleteIfTriviallyDead(OldPtr);
2968 return false;
2969 }
2970 // For split transfer intrinsics we have an incredibly useful assurance:
2971 // the source and destination do not reside within the same alloca, and at
2972 // least one of them does not escape. This means that we can replace
2973 // memmove with memcpy, and we don't need to worry about all manner of
2974 // downsides to splitting and transforming the operations.
2975
2976 // If this doesn't map cleanly onto the alloca type, and that type isn't
2977 // a single value type, just emit a memcpy.
2978 bool EmitMemCpy =
2979 !VecTy && !IntTy &&
2980 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2981 SliceSize !=
2982 DL.getTypeStoreSize(NewAI.getAllocatedType()).getFixedSize() ||
2983 !NewAI.getAllocatedType()->isSingleValueType());
2984
2985 // If we're just going to emit a memcpy, the alloca hasn't changed, and the
2986 // size hasn't been shrunk based on analysis of the viable range, this is
2987 // a no-op.
2988 if (EmitMemCpy && &OldAI == &NewAI) {
2989 // Ensure the start lines up.
2990 assert(NewBeginOffset == BeginOffset)(static_cast <bool> (NewBeginOffset == BeginOffset) ? void
(0) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 2990, __extension__ __PRETTY_FUNCTION__))
;
2991
2992 // Rewrite the size as needed.
2993 if (NewEndOffset != EndOffset)
2994 II.setLength(ConstantInt::get(II.getLength()->getType(),
2995 NewEndOffset - NewBeginOffset));
2996 return false;
2997 }
2998 // Record this instruction for deletion.
2999 Pass.DeadInsts.push_back(&II);
3000
3001 // Strip all inbounds GEPs and pointer casts to try to dig out any root
3002 // alloca that should be re-examined after rewriting this instruction.
3003 Value *OtherPtr = IsDest ? II.getRawSource() : II.getRawDest();
3004 if (AllocaInst *AI =
3005 dyn_cast<AllocaInst>(OtherPtr->stripInBoundsOffsets())) {
3006 assert(AI != &OldAI && AI != &NewAI &&(static_cast <bool> (AI != &OldAI && AI != &
NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? void (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3007, __extension__ __PRETTY_FUNCTION__))
3007 "Splittable transfers cannot reach the same alloca on both ends.")(static_cast <bool> (AI != &OldAI && AI != &
NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? void (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3007, __extension__ __PRETTY_FUNCTION__))
;
3008 Pass.Worklist.insert(AI);
3009 }
3010
3011 Type *OtherPtrTy = OtherPtr->getType();
3012 unsigned OtherAS = OtherPtrTy->getPointerAddressSpace();
3013
3014 // Compute the relative offset for the other pointer within the transfer.
3015 unsigned OffsetWidth = DL.getIndexSizeInBits(OtherAS);
3016 APInt OtherOffset(OffsetWidth, NewBeginOffset - BeginOffset);
3017 Align OtherAlign =
3018 (IsDest ? II.getSourceAlign() : II.getDestAlign()).valueOrOne();
3019 OtherAlign =
3020 commonAlignment(OtherAlign, OtherOffset.zextOrTrunc(64).getZExtValue());
3021
3022 if (EmitMemCpy) {
3023 // Compute the other pointer, folding as much as possible to produce
3024 // a single, simple GEP in most cases.
3025 OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
3026 OtherPtr->getName() + ".");
3027
3028 Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3029 Type *SizeTy = II.getLength()->getType();
3030 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
3031
3032 Value *DestPtr, *SrcPtr;
3033 MaybeAlign DestAlign, SrcAlign;
3034 // Note: IsDest is true iff we're copying into the new alloca slice
3035 if (IsDest) {
3036 DestPtr = OurPtr;
3037 DestAlign = SliceAlign;
3038 SrcPtr = OtherPtr;
3039 SrcAlign = OtherAlign;
3040 } else {
3041 DestPtr = OtherPtr;
3042 DestAlign = OtherAlign;
3043 SrcPtr = OurPtr;
3044 SrcAlign = SliceAlign;
3045 }
3046 CallInst *New = IRB.CreateMemCpy(DestPtr, DestAlign, SrcPtr, SrcAlign,
3047 Size, II.isVolatile());
3048 if (AATags)
3049 New->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3050 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
3051 return false;
3052 }
3053
3054 bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
3055 NewEndOffset == NewAllocaEndOffset;
3056 uint64_t Size = NewEndOffset - NewBeginOffset;
3057 unsigned BeginIndex = VecTy ? getIndex(NewBeginOffset) : 0;
3058 unsigned EndIndex = VecTy ? getIndex(NewEndOffset) : 0;
3059 unsigned NumElements = EndIndex - BeginIndex;
3060 IntegerType *SubIntTy =
3061 IntTy ? Type::getIntNTy(IntTy->getContext(), Size * 8) : nullptr;
3062
3063 // Reset the other pointer type to match the register type we're going to
3064 // use, but using the address space of the original other pointer.
3065 Type *OtherTy;
3066 if (VecTy && !IsWholeAlloca) {
3067 if (NumElements == 1)
3068 OtherTy = VecTy->getElementType();
3069 else
3070 OtherTy = FixedVectorType::get(VecTy->getElementType(), NumElements);
3071 } else if (IntTy && !IsWholeAlloca) {
3072 OtherTy = SubIntTy;
3073 } else {
3074 OtherTy = NewAllocaTy;
3075 }
3076 OtherPtrTy = OtherTy->getPointerTo(OtherAS);
3077
3078 Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
3079 OtherPtr->getName() + ".");
3080 MaybeAlign SrcAlign = OtherAlign;
3081 Value *DstPtr = &NewAI;
3082 MaybeAlign DstAlign = SliceAlign;
3083 if (!IsDest) {
3084 std::swap(SrcPtr, DstPtr);
3085 std::swap(SrcAlign, DstAlign);
3086 }
3087
3088 Value *Src;
3089 if (VecTy && !IsWholeAlloca && !IsDest) {
3090 Src = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3091 NewAI.getAlign(), "load");
3092 Src = extractVector(IRB, Src, BeginIndex, EndIndex, "vec");
3093 } else if (IntTy && !IsWholeAlloca && !IsDest) {
3094 Src = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3095 NewAI.getAlign(), "load");
3096 Src = convertValue(DL, IRB, Src, IntTy);
3097 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
3098 Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract");
3099 } else {
3100 LoadInst *Load = IRB.CreateAlignedLoad(OtherTy, SrcPtr, SrcAlign,
3101 II.isVolatile(), "copyload");
3102 Load->copyMetadata(II, {LLVMContext::MD_mem_parallel_loop_access,
3103 LLVMContext::MD_access_group});
3104 if (AATags)
3105 Load->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3106 Src = Load;
3107 }
3108
3109 if (VecTy && !IsWholeAlloca && IsDest) {
3110 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3111 NewAI.getAlign(), "oldload");
3112 Src = insertVector(IRB, Old, Src, BeginIndex, "vec");
3113 } else if (IntTy && !IsWholeAlloca && IsDest) {
3114 Value *Old = IRB.CreateAlignedLoad(NewAI.getAllocatedType(), &NewAI,
3115 NewAI.getAlign(), "oldload");
3116 Old = convertValue(DL, IRB, Old, IntTy);
3117 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
3118 Src = insertInteger(DL, IRB, Old, Src, Offset, "insert");
3119 Src = convertValue(DL, IRB, Src, NewAllocaTy);
3120 }
3121
3122 StoreInst *Store = cast<StoreInst>(
3123 IRB.CreateAlignedStore(Src, DstPtr, DstAlign, II.isVolatile()));
3124 Store->copyMetadata(II, {LLVMContext::MD_mem_parallel_loop_access,
3125 LLVMContext::MD_access_group});
3126 if (AATags)
3127 Store->setAAMetadata(AATags.shift(NewBeginOffset - BeginOffset));
3128 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3129 return !II.isVolatile();
3130 }
3131
3132 bool visitIntrinsicInst(IntrinsicInst &II) {
3133 assert((II.isLifetimeStartOrEnd() || II.isDroppable()) &&(static_cast <bool> ((II.isLifetimeStartOrEnd() || II.isDroppable
()) && "Unexpected intrinsic!") ? void (0) : __assert_fail
("(II.isLifetimeStartOrEnd() || II.isDroppable()) && \"Unexpected intrinsic!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3134, __extension__ __PRETTY_FUNCTION__))
3134 "Unexpected intrinsic!")(static_cast <bool> ((II.isLifetimeStartOrEnd() || II.isDroppable
()) && "Unexpected intrinsic!") ? void (0) : __assert_fail
("(II.isLifetimeStartOrEnd() || II.isDroppable()) && \"Unexpected intrinsic!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3134, __extension__ __PRETTY_FUNCTION__))
;
3135 LLVM_DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
3136
3137 // Record this instruction for deletion.
3138 Pass.DeadInsts.push_back(&II);
3139
3140 if (II.isDroppable()) {
3141 assert(II.getIntrinsicID() == Intrinsic::assume && "Expected assume")(static_cast <bool> (II.getIntrinsicID() == Intrinsic::
assume && "Expected assume") ? void (0) : __assert_fail
("II.getIntrinsicID() == Intrinsic::assume && \"Expected assume\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3141, __extension__ __PRETTY_FUNCTION__))
;
3142 // TODO For now we forget assumed information, this can be improved.
3143 OldPtr->dropDroppableUsesIn(II);
3144 return true;
3145 }
3146
3147 assert(II.getArgOperand(1) == OldPtr)(static_cast <bool> (II.getArgOperand(1) == OldPtr) ? void
(0) : __assert_fail ("II.getArgOperand(1) == OldPtr", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3147, __extension__ __PRETTY_FUNCTION__))
;
3148 // Lifetime intrinsics are only promotable if they cover the whole alloca.
3149 // Therefore, we drop lifetime intrinsics which don't cover the whole
3150 // alloca.
3151 // (In theory, intrinsics which partially cover an alloca could be
3152 // promoted, but PromoteMemToReg doesn't handle that case.)
3153 // FIXME: Check whether the alloca is promotable before dropping the
3154 // lifetime intrinsics?
3155 if (NewBeginOffset != NewAllocaBeginOffset ||
3156 NewEndOffset != NewAllocaEndOffset)
3157 return true;
3158
3159 ConstantInt *Size =
3160 ConstantInt::get(cast<IntegerType>(II.getArgOperand(0)->getType()),
3161 NewEndOffset - NewBeginOffset);
3162 // Lifetime intrinsics always expect an i8* so directly get such a pointer
3163 // for the new alloca slice.
3164 Type *PointerTy = IRB.getInt8PtrTy(OldPtr->getType()->getPointerAddressSpace());
3165 Value *Ptr = getNewAllocaSlicePtr(IRB, PointerTy);
3166 Value *New;
3167 if (II.getIntrinsicID() == Intrinsic::lifetime_start)
3168 New = IRB.CreateLifetimeStart(Ptr, Size);
3169 else
3170 New = IRB.CreateLifetimeEnd(Ptr, Size);
3171
3172 (void)New;
3173 LLVM_DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
3174
3175 return true;
3176 }
3177
3178 void fixLoadStoreAlign(Instruction &Root) {
3179 // This algorithm implements the same visitor loop as
3180 // hasUnsafePHIOrSelectUse, and fixes the alignment of each load
3181 // or store found.
3182 SmallPtrSet<Instruction *, 4> Visited;
3183 SmallVector<Instruction *, 4> Uses;
3184 Visited.insert(&Root);
3185 Uses.push_back(&Root);
3186 do {
3187 Instruction *I = Uses.pop_back_val();
3188
3189 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
3190 LI->setAlignment(std::min(LI->getAlign(), getSliceAlign()));
3191 continue;
3192 }
3193 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
3194 SI->setAlignment(std::min(SI->getAlign(), getSliceAlign()));
3195 continue;
3196 }
3197
3198 assert(isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) ||(static_cast <bool> (isa<BitCastInst>(I) || isa<
AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst
>(I) || isa<GetElementPtrInst>(I)) ? void (0) : __assert_fail
("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3200, __extension__ __PRETTY_FUNCTION__))
3199 isa<PHINode>(I) || isa<SelectInst>(I) ||(static_cast <bool> (isa<BitCastInst>(I) || isa<
AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst
>(I) || isa<GetElementPtrInst>(I)) ? void (0) : __assert_fail
("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3200, __extension__ __PRETTY_FUNCTION__))
3200 isa<GetElementPtrInst>(I))(static_cast <bool> (isa<BitCastInst>(I) || isa<
AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst
>(I) || isa<GetElementPtrInst>(I)) ? void (0) : __assert_fail
("isa<BitCastInst>(I) || isa<AddrSpaceCastInst>(I) || isa<PHINode>(I) || isa<SelectInst>(I) || isa<GetElementPtrInst>(I)"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3200, __extension__ __PRETTY_FUNCTION__))
;
3201 for (User *U : I->users())
3202 if (Visited.insert(cast<Instruction>(U)).second)
3203 Uses.push_back(cast<Instruction>(U));
3204 } while (!Uses.empty());
3205 }
3206
3207 bool visitPHINode(PHINode &PN) {
3208 LLVM_DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
3209 assert(BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "PHIs are unsplittable") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3209, __extension__ __PRETTY_FUNCTION__))
;
3210 assert(EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable")(static_cast <bool> (EndOffset <= NewAllocaEndOffset
&& "PHIs are unsplittable") ? void (0) : __assert_fail
("EndOffset <= NewAllocaEndOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3210, __extension__ __PRETTY_FUNCTION__))
;
3211
3212 // We would like to compute a new pointer in only one place, but have it be
3213 // as local as possible to the PHI. To do that, we re-use the location of
3214 // the old pointer, which necessarily must be in the right position to
3215 // dominate the PHI.
3216 IRBuilderBase::InsertPointGuard Guard(IRB);
3217 if (isa<PHINode>(OldPtr))
3218 IRB.SetInsertPoint(&*OldPtr->getParent()->getFirstInsertionPt());
3219 else
3220 IRB.SetInsertPoint(OldPtr);
3221 IRB.SetCurrentDebugLocation(OldPtr->getDebugLoc());
3222
3223 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3224 // Replace the operands which were using the old pointer.
3225 std::replace(PN.op_begin(), PN.op_end(), cast<Value>(OldPtr), NewPtr);
3226
3227 LLVM_DEBUG(dbgs() << " to: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << PN <<
"\n"; } } while (false)
;
3228 deleteIfTriviallyDead(OldPtr);
3229
3230 // Fix the alignment of any loads or stores using this PHI node.
3231 fixLoadStoreAlign(PN);
3232
3233 // PHIs can't be promoted on their own, but often can be speculated. We
3234 // check the speculation outside of the rewriter so that we see the
3235 // fully-rewritten alloca.
3236 PHIUsers.insert(&PN);
3237 return true;
3238 }
3239
3240 bool visitSelectInst(SelectInst &SI) {
3241 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3242 assert((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) &&(static_cast <bool> ((SI.getTrueValue() == OldPtr || SI
.getFalseValue() == OldPtr) && "Pointer isn't an operand!"
) ? void (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3243, __extension__ __PRETTY_FUNCTION__))
3243 "Pointer isn't an operand!")(static_cast <bool> ((SI.getTrueValue() == OldPtr || SI
.getFalseValue() == OldPtr) && "Pointer isn't an operand!"
) ? void (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3243, __extension__ __PRETTY_FUNCTION__))
;
3244 assert(BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "Selects are unsplittable") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3244, __extension__ __PRETTY_FUNCTION__))
;
3245 assert(EndOffset <= NewAllocaEndOffset && "Selects are unsplittable")(static_cast <bool> (EndOffset <= NewAllocaEndOffset
&& "Selects are unsplittable") ? void (0) : __assert_fail
("EndOffset <= NewAllocaEndOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3245, __extension__ __PRETTY_FUNCTION__))
;
3246
3247 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3248 // Replace the operands which were using the old pointer.
3249 if (SI.getOperand(1) == OldPtr)
3250 SI.setOperand(1, NewPtr);
3251 if (SI.getOperand(2) == OldPtr)
3252 SI.setOperand(2, NewPtr);
3253
3254 LLVM_DEBUG(dbgs() << " to: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << SI <<
"\n"; } } while (false)
;
3255 deleteIfTriviallyDead(OldPtr);
3256
3257 // Fix the alignment of any loads or stores using this select.
3258 fixLoadStoreAlign(SI);
3259
3260 // Selects can't be promoted on their own, but often can be speculated. We
3261 // check the speculation outside of the rewriter so that we see the
3262 // fully-rewritten alloca.
3263 SelectUsers.insert(&SI);
3264 return true;
3265 }
3266};
3267
3268namespace {
3269
3270/// Visitor to rewrite aggregate loads and stores as scalar.
3271///
3272/// This pass aggressively rewrites all aggregate loads and stores on
3273/// a particular pointer (or any pointer derived from it which we can identify)
3274/// with scalar loads and stores.
3275class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
3276 // Befriend the base class so it can delegate to private visit methods.
3277 friend class InstVisitor<AggLoadStoreRewriter, bool>;
3278
3279 /// Queue of pointer uses to analyze and potentially rewrite.
3280 SmallVector<Use *, 8> Queue;
3281
3282 /// Set to prevent us from cycling with phi nodes and loops.
3283 SmallPtrSet<User *, 8> Visited;
3284
3285 /// The current pointer use being rewritten. This is used to dig up the used
3286 /// value (as opposed to the user).
3287 Use *U = nullptr;
3288
3289 /// Used to calculate offsets, and hence alignment, of subobjects.
3290 const DataLayout &DL;
3291
3292public:
3293 AggLoadStoreRewriter(const DataLayout &DL) : DL(DL) {}
3294
3295 /// Rewrite loads and stores through a pointer and all pointers derived from
3296 /// it.
3297 bool rewrite(Instruction &I) {
3298 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)
;
3299 enqueueUsers(I);
3300 bool Changed = false;
3301 while (!Queue.empty()) {
3302 U = Queue.pop_back_val();
3303 Changed |= visit(cast<Instruction>(U->getUser()));
3304 }
3305 return Changed;
3306 }
3307
3308private:
3309 /// Enqueue all the users of the given instruction for further processing.
3310 /// This uses a set to de-duplicate users.
3311 void enqueueUsers(Instruction &I) {
3312 for (Use &U : I.uses())
3313 if (Visited.insert(U.getUser()).second)
3314 Queue.push_back(&U);
3315 }
3316
3317 // Conservative default is to not rewrite anything.
3318 bool visitInstruction(Instruction &I) { return false; }
3319
3320 /// Generic recursive split emission class.
3321 template <typename Derived> class OpSplitter {
3322 protected:
3323 /// The builder used to form new instructions.
3324 IRBuilderTy IRB;
3325
3326 /// The indices which to be used with insert- or extractvalue to select the
3327 /// appropriate value within the aggregate.
3328 SmallVector<unsigned, 4> Indices;
3329
3330 /// The indices to a GEP instruction which will move Ptr to the correct slot
3331 /// within the aggregate.
3332 SmallVector<Value *, 4> GEPIndices;
3333
3334 /// The base pointer of the original op, used as a base for GEPing the
3335 /// split operations.
3336 Value *Ptr;
3337
3338 /// The base pointee type being GEPed into.
3339 Type *BaseTy;
3340
3341 /// Known alignment of the base pointer.
3342 Align BaseAlign;
3343
3344 /// To calculate offset of each component so we can correctly deduce
3345 /// alignments.
3346 const DataLayout &DL;
3347
3348 /// Initialize the splitter with an insertion point, Ptr and start with a
3349 /// single zero GEP index.
3350 OpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3351 Align BaseAlign, const DataLayout &DL)
3352 : IRB(InsertionPoint), GEPIndices(1, IRB.getInt32(0)), Ptr(Ptr),
3353 BaseTy(BaseTy), BaseAlign(BaseAlign), DL(DL) {}
3354
3355 public:
3356 /// Generic recursive split emission routine.
3357 ///
3358 /// This method recursively splits an aggregate op (load or store) into
3359 /// scalar or vector ops. It splits recursively until it hits a single value
3360 /// and emits that single value operation via the template argument.
3361 ///
3362 /// The logic of this routine relies on GEPs and insertvalue and
3363 /// extractvalue all operating with the same fundamental index list, merely
3364 /// formatted differently (GEPs need actual values).
3365 ///
3366 /// \param Ty The type being split recursively into smaller ops.
3367 /// \param Agg The aggregate value being built up or stored, depending on
3368 /// whether this is splitting a load or a store respectively.
3369 void emitSplitOps(Type *Ty, Value *&Agg, const Twine &Name) {
3370 if (Ty->isSingleValueType()) {
3371 unsigned Offset = DL.getIndexedOffsetInType(BaseTy, GEPIndices);
3372 return static_cast<Derived *>(this)->emitFunc(
3373 Ty, Agg, commonAlignment(BaseAlign, Offset), Name);
3374 }
3375
3376 if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
3377 unsigned OldSize = Indices.size();
3378 (void)OldSize;
3379 for (unsigned Idx = 0, Size = ATy->getNumElements(); Idx != Size;
3380 ++Idx) {
3381 assert(Indices.size() == OldSize && "Did not return to the old size")(static_cast <bool> (Indices.size() == OldSize &&
"Did not return to the old size") ? void (0) : __assert_fail
("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3381, __extension__ __PRETTY_FUNCTION__))
;
3382 Indices.push_back(Idx);
3383 GEPIndices.push_back(IRB.getInt32(Idx));
3384 emitSplitOps(ATy->getElementType(), Agg, Name + "." + Twine(Idx));
3385 GEPIndices.pop_back();
3386 Indices.pop_back();
3387 }
3388 return;
3389 }
3390
3391 if (StructType *STy = dyn_cast<StructType>(Ty)) {
3392 unsigned OldSize = Indices.size();
3393 (void)OldSize;
3394 for (unsigned Idx = 0, Size = STy->getNumElements(); Idx != Size;
3395 ++Idx) {
3396 assert(Indices.size() == OldSize && "Did not return to the old size")(static_cast <bool> (Indices.size() == OldSize &&
"Did not return to the old size") ? void (0) : __assert_fail
("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3396, __extension__ __PRETTY_FUNCTION__))
;
3397 Indices.push_back(Idx);
3398 GEPIndices.push_back(IRB.getInt32(Idx));
3399 emitSplitOps(STy->getElementType(Idx), Agg, Name + "." + Twine(Idx));
3400 GEPIndices.pop_back();
3401 Indices.pop_back();
3402 }
3403 return;
3404 }
3405
3406 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3406)
;
3407 }
3408 };
3409
3410 struct LoadOpSplitter : public OpSplitter<LoadOpSplitter> {
3411 AAMDNodes AATags;
3412
3413 LoadOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3414 AAMDNodes AATags, Align BaseAlign, const DataLayout &DL)
3415 : OpSplitter<LoadOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
3416 DL),
3417 AATags(AATags) {}
3418
3419 /// Emit a leaf load of a single value. This is called at the leaves of the
3420 /// recursive emission to actually load values.
3421 void emitFunc(Type *Ty, Value *&Agg, Align Alignment, const Twine &Name) {
3422 assert(Ty->isSingleValueType())(static_cast <bool> (Ty->isSingleValueType()) ? void
(0) : __assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3422, __extension__ __PRETTY_FUNCTION__))
;
3423 // Load the single value and insert it using the indices.
3424 Value *GEP =
3425 IRB.CreateInBoundsGEP(BaseTy, Ptr, GEPIndices, Name + ".gep");
3426 LoadInst *Load =
3427 IRB.CreateAlignedLoad(Ty, GEP, Alignment, Name + ".load");
3428
3429 APInt Offset(
3430 DL.getIndexSizeInBits(Ptr->getType()->getPointerAddressSpace()), 0);
3431 if (AATags &&
3432 GEPOperator::accumulateConstantOffset(BaseTy, GEPIndices, DL, Offset))
3433 Load->setAAMetadata(AATags.shift(Offset.getZExtValue()));
3434
3435 Agg = IRB.CreateInsertValue(Agg, Load, Indices, Name + ".insert");
3436 LLVM_DEBUG(dbgs() << " to: " << *Load << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Load <<
"\n"; } } while (false)
;
3437 }
3438 };
3439
3440 bool visitLoadInst(LoadInst &LI) {
3441 assert(LI.getPointerOperand() == *U)(static_cast <bool> (LI.getPointerOperand() == *U) ? void
(0) : __assert_fail ("LI.getPointerOperand() == *U", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3441, __extension__ __PRETTY_FUNCTION__))
;
3442 if (!LI.isSimple() || LI.getType()->isSingleValueType())
3443 return false;
3444
3445 // We have an aggregate being loaded, split it apart.
3446 LLVM_DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
3447 AAMDNodes AATags;
3448 LI.getAAMetadata(AATags);
3449 LoadOpSplitter Splitter(&LI, *U, LI.getType(), AATags,
3450 getAdjustedAlignment(&LI, 0), DL);
3451 Value *V = UndefValue::get(LI.getType());
3452 Splitter.emitSplitOps(LI.getType(), V, LI.getName() + ".fca");
3453 Visited.erase(&LI);
3454 LI.replaceAllUsesWith(V);
3455 LI.eraseFromParent();
3456 return true;
3457 }
3458
3459 struct StoreOpSplitter : public OpSplitter<StoreOpSplitter> {
3460 StoreOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
3461 AAMDNodes AATags, Align BaseAlign, const DataLayout &DL)
3462 : OpSplitter<StoreOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
3463 DL),
3464 AATags(AATags) {}
3465 AAMDNodes AATags;
3466 /// Emit a leaf store of a single value. This is called at the leaves of the
3467 /// recursive emission to actually produce stores.
3468 void emitFunc(Type *Ty, Value *&Agg, Align Alignment, const Twine &Name) {
3469 assert(Ty->isSingleValueType())(static_cast <bool> (Ty->isSingleValueType()) ? void
(0) : __assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3469, __extension__ __PRETTY_FUNCTION__))
;
3470 // Extract the single value and store it using the indices.
3471 //
3472 // The gep and extractvalue values are factored out of the CreateStore
3473 // call to make the output independent of the argument evaluation order.
3474 Value *ExtractValue =
3475 IRB.CreateExtractValue(Agg, Indices, Name + ".extract");
3476 Value *InBoundsGEP =
3477 IRB.CreateInBoundsGEP(BaseTy, Ptr, GEPIndices, Name + ".gep");
3478 StoreInst *Store =
3479 IRB.CreateAlignedStore(ExtractValue, InBoundsGEP, Alignment);
3480
3481 APInt Offset(
3482 DL.getIndexSizeInBits(Ptr->getType()->getPointerAddressSpace()), 0);
3483 if (AATags &&
3484 GEPOperator::accumulateConstantOffset(BaseTy, GEPIndices, DL, Offset))
3485 Store->setAAMetadata(AATags.shift(Offset.getZExtValue()));
3486
3487 LLVM_DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3488 }
3489 };
3490
3491 bool visitStoreInst(StoreInst &SI) {
3492 if (!SI.isSimple() || SI.getPointerOperand() != *U)
3493 return false;
3494 Value *V = SI.getValueOperand();
3495 if (V->getType()->isSingleValueType())
3496 return false;
3497
3498 // We have an aggregate being stored, split it apart.
3499 LLVM_DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3500 AAMDNodes AATags;
3501 SI.getAAMetadata(AATags);
3502 StoreOpSplitter Splitter(&SI, *U, V->getType(), AATags,
3503 getAdjustedAlignment(&SI, 0), DL);
3504 Splitter.emitSplitOps(V->getType(), V, V->getName() + ".fca");
3505 Visited.erase(&SI);
3506 SI.eraseFromParent();
3507 return true;
3508 }
3509
3510 bool visitBitCastInst(BitCastInst &BC) {
3511 enqueueUsers(BC);
3512 return false;
3513 }
3514
3515 bool visitAddrSpaceCastInst(AddrSpaceCastInst &ASC) {
3516 enqueueUsers(ASC);
3517 return false;
3518 }
3519
3520 // Fold gep (select cond, ptr1, ptr2) => select cond, gep(ptr1), gep(ptr2)
3521 bool foldGEPSelect(GetElementPtrInst &GEPI) {
3522 if (!GEPI.hasAllConstantIndices())
3523 return false;
3524
3525 SelectInst *Sel = cast<SelectInst>(GEPI.getPointerOperand());
3526
3527 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)
3528 << "\n original: " << *Seldo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(select) -> select(gep):"
<< "\n original: " << *Sel << "\n "
<< GEPI; } } while (false)
3529 << "\n " << GEPI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(select) -> select(gep):"
<< "\n original: " << *Sel << "\n "
<< GEPI; } } while (false)
;
3530
3531 IRBuilderTy Builder(&GEPI);
3532 SmallVector<Value *, 4> Index(GEPI.indices());
3533 bool IsInBounds = GEPI.isInBounds();
3534
3535 Type *Ty = GEPI.getSourceElementType();
3536 Value *True = Sel->getTrueValue();
3537 Value *NTrue =
3538 IsInBounds
3539 ? Builder.CreateInBoundsGEP(Ty, True, Index,
3540 True->getName() + ".sroa.gep")
3541 : Builder.CreateGEP(Ty, True, Index, True->getName() + ".sroa.gep");
3542
3543 Value *False = Sel->getFalseValue();
3544
3545 Value *NFalse =
3546 IsInBounds
3547 ? Builder.CreateInBoundsGEP(Ty, False, Index,
3548 False->getName() + ".sroa.gep")
3549 : Builder.CreateGEP(Ty, False, Index,
3550 False->getName() + ".sroa.gep");
3551
3552 Value *NSel = Builder.CreateSelect(Sel->getCondition(), NTrue, NFalse,
3553 Sel->getName() + ".sroa.sel");
3554 Visited.erase(&GEPI);
3555 GEPI.replaceAllUsesWith(NSel);
3556 GEPI.eraseFromParent();
3557 Instruction *NSelI = cast<Instruction>(NSel);
3558 Visited.insert(NSelI);
3559 enqueueUsers(*NSelI);
3560
3561 LLVM_DEBUG(dbgs() << "\n to: " << *NTruedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
3562 << "\n " << *NFalsedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
3563 << "\n " << *NSel << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n to: " << *NTrue
<< "\n " << *NFalse << "\n "
<< *NSel << '\n'; } } while (false)
;
3564
3565 return true;
3566 }
3567
3568 // Fold gep (phi ptr1, ptr2) => phi gep(ptr1), gep(ptr2)
3569 bool foldGEPPhi(GetElementPtrInst &GEPI) {
3570 if (!GEPI.hasAllConstantIndices())
3571 return false;
3572
3573 PHINode *PHI = cast<PHINode>(GEPI.getPointerOperand());
3574 if (GEPI.getParent() != PHI->getParent() ||
3575 llvm::any_of(PHI->incoming_values(), [](Value *In)
3576 { Instruction *I = dyn_cast<Instruction>(In);
3577 return !I || isa<GetElementPtrInst>(I) || isa<PHINode>(I) ||
3578 succ_empty(I->getParent()) ||
3579 !I->getParent()->isLegalToHoistInto();
3580 }))
3581 return false;
3582
3583 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)
3584 << "\n original: " << *PHIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
3585 << "\n " << GEPIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
3586 << "\n to: ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting gep(phi) -> phi(gep):"
<< "\n original: " << *PHI << "\n "
<< GEPI << "\n to: "; } } while (false)
;
3587
3588 SmallVector<Value *, 4> Index(GEPI.indices());
3589 bool IsInBounds = GEPI.isInBounds();
3590 IRBuilderTy PHIBuilder(GEPI.getParent()->getFirstNonPHI());
3591 PHINode *NewPN = PHIBuilder.CreatePHI(GEPI.getType(),
3592 PHI->getNumIncomingValues(),
3593 PHI->getName() + ".sroa.phi");
3594 for (unsigned I = 0, E = PHI->getNumIncomingValues(); I != E; ++I) {
3595 BasicBlock *B = PHI->getIncomingBlock(I);
3596 Value *NewVal = nullptr;
3597 int Idx = NewPN->getBasicBlockIndex(B);
3598 if (Idx >= 0) {
3599 NewVal = NewPN->getIncomingValue(Idx);
3600 } else {
3601 Instruction *In = cast<Instruction>(PHI->getIncomingValue(I));
3602
3603 IRBuilderTy B(In->getParent(), std::next(In->getIterator()));
3604 Type *Ty = GEPI.getSourceElementType();
3605 NewVal = IsInBounds
3606 ? B.CreateInBoundsGEP(Ty, In, Index, In->getName() + ".sroa.gep")
3607 : B.CreateGEP(Ty, In, Index, In->getName() + ".sroa.gep");
3608 }
3609 NewPN->addIncoming(NewVal, B);
3610 }
3611
3612 Visited.erase(&GEPI);
3613 GEPI.replaceAllUsesWith(NewPN);
3614 GEPI.eraseFromParent();
3615 Visited.insert(NewPN);
3616 enqueueUsers(*NewPN);
3617
3618 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)
3619 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)
3620 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)
;
3621
3622 return true;
3623 }
3624
3625 bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
3626 if (isa<SelectInst>(GEPI.getPointerOperand()) &&
3627 foldGEPSelect(GEPI))
3628 return true;
3629
3630 if (isa<PHINode>(GEPI.getPointerOperand()) &&
3631 foldGEPPhi(GEPI))
3632 return true;
3633
3634 enqueueUsers(GEPI);
3635 return false;
3636 }
3637
3638 bool visitPHINode(PHINode &PN) {
3639 enqueueUsers(PN);
3640 return false;
3641 }
3642
3643 bool visitSelectInst(SelectInst &SI) {
3644 enqueueUsers(SI);
3645 return false;
3646 }
3647};
3648
3649} // end anonymous namespace
3650
3651/// Strip aggregate type wrapping.
3652///
3653/// This removes no-op aggregate types wrapping an underlying type. It will
3654/// strip as many layers of types as it can without changing either the type
3655/// size or the allocated size.
3656static Type *stripAggregateTypeWrapping(const DataLayout &DL, Type *Ty) {
3657 if (Ty->isSingleValueType())
3658 return Ty;
3659
3660 uint64_t AllocSize = DL.getTypeAllocSize(Ty).getFixedSize();
3661 uint64_t TypeSize = DL.getTypeSizeInBits(Ty).getFixedSize();
3662
3663 Type *InnerTy;
3664 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
3665 InnerTy = ArrTy->getElementType();
3666 } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
3667 const StructLayout *SL = DL.getStructLayout(STy);
3668 unsigned Index = SL->getElementContainingOffset(0);
3669 InnerTy = STy->getElementType(Index);
3670 } else {
3671 return Ty;
3672 }
3673
3674 if (AllocSize > DL.getTypeAllocSize(InnerTy).getFixedSize() ||
3675 TypeSize > DL.getTypeSizeInBits(InnerTy).getFixedSize())
3676 return Ty;
3677
3678 return stripAggregateTypeWrapping(DL, InnerTy);
3679}
3680
3681/// Try to find a partition of the aggregate type passed in for a given
3682/// offset and size.
3683///
3684/// This recurses through the aggregate type and tries to compute a subtype
3685/// based on the offset and size. When the offset and size span a sub-section
3686/// of an array, it will even compute a new array type for that sub-section,
3687/// and the same for structs.
3688///
3689/// Note that this routine is very strict and tries to find a partition of the
3690/// type which produces the *exact* right offset and size. It is not forgiving
3691/// when the size or offset cause either end of type-based partition to be off.
3692/// Also, this is a best-effort routine. It is reasonable to give up and not
3693/// return a type if necessary.
3694static Type *getTypePartition(const DataLayout &DL, Type *Ty, uint64_t Offset,
3695 uint64_t Size) {
3696 if (Offset == 0 && DL.getTypeAllocSize(Ty).getFixedSize() == Size)
3697 return stripAggregateTypeWrapping(DL, Ty);
3698 if (Offset > DL.getTypeAllocSize(Ty).getFixedSize() ||
3699 (DL.getTypeAllocSize(Ty).getFixedSize() - Offset) < Size)
3700 return nullptr;
3701
3702 if (isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
3703 Type *ElementTy;
3704 uint64_t TyNumElements;
3705 if (auto *AT = dyn_cast<ArrayType>(Ty)) {
3706 ElementTy = AT->getElementType();
3707 TyNumElements = AT->getNumElements();
3708 } else {
3709 // FIXME: This isn't right for vectors with non-byte-sized or
3710 // non-power-of-two sized elements.
3711 auto *VT = cast<FixedVectorType>(Ty);
3712 ElementTy = VT->getElementType();
3713 TyNumElements = VT->getNumElements();
3714 }
3715 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy).getFixedSize();
3716 uint64_t NumSkippedElements = Offset / ElementSize;
3717 if (NumSkippedElements >= TyNumElements)
3718 return nullptr;
3719 Offset -= NumSkippedElements * ElementSize;
3720
3721 // First check if we need to recurse.
3722 if (Offset > 0 || Size < ElementSize) {
3723 // Bail if the partition ends in a different array element.
3724 if ((Offset + Size) > ElementSize)
3725 return nullptr;
3726 // Recurse through the element type trying to peel off offset bytes.
3727 return getTypePartition(DL, ElementTy, Offset, Size);
3728 }
3729 assert(Offset == 0)(static_cast <bool> (Offset == 0) ? void (0) : __assert_fail
("Offset == 0", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3729, __extension__ __PRETTY_FUNCTION__))
;
3730
3731 if (Size == ElementSize)
3732 return stripAggregateTypeWrapping(DL, ElementTy);
3733 assert(Size > ElementSize)(static_cast <bool> (Size > ElementSize) ? void (0) :
__assert_fail ("Size > ElementSize", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3733, __extension__ __PRETTY_FUNCTION__))
;
3734 uint64_t NumElements = Size / ElementSize;
3735 if (NumElements * ElementSize != Size)
3736 return nullptr;
3737 return ArrayType::get(ElementTy, NumElements);
3738 }
3739
3740 StructType *STy = dyn_cast<StructType>(Ty);
3741 if (!STy)
3742 return nullptr;
3743
3744 const StructLayout *SL = DL.getStructLayout(STy);
3745 if (Offset >= SL->getSizeInBytes())
3746 return nullptr;
3747 uint64_t EndOffset = Offset + Size;
3748 if (EndOffset > SL->getSizeInBytes())
3749 return nullptr;
3750
3751 unsigned Index = SL->getElementContainingOffset(Offset);
3752 Offset -= SL->getElementOffset(Index);
3753
3754 Type *ElementTy = STy->getElementType(Index);
3755 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy).getFixedSize();
3756 if (Offset >= ElementSize)
3757 return nullptr; // The offset points into alignment padding.
3758
3759 // See if any partition must be contained by the element.
3760 if (Offset > 0 || Size < ElementSize) {
3761 if ((Offset + Size) > ElementSize)
3762 return nullptr;
3763 return getTypePartition(DL, ElementTy, Offset, Size);
3764 }
3765 assert(Offset == 0)(static_cast <bool> (Offset == 0) ? void (0) : __assert_fail
("Offset == 0", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3765, __extension__ __PRETTY_FUNCTION__))
;
3766
3767 if (Size == ElementSize)
3768 return stripAggregateTypeWrapping(DL, ElementTy);
3769
3770 StructType::element_iterator EI = STy->element_begin() + Index,
3771 EE = STy->element_end();
3772 if (EndOffset < SL->getSizeInBytes()) {
3773 unsigned EndIndex = SL->getElementContainingOffset(EndOffset);
3774 if (Index == EndIndex)
3775 return nullptr; // Within a single element and its padding.
3776
3777 // Don't try to form "natural" types if the elements don't line up with the
3778 // expected size.
3779 // FIXME: We could potentially recurse down through the last element in the
3780 // sub-struct to find a natural end point.
3781 if (SL->getElementOffset(EndIndex) != EndOffset)
3782 return nullptr;
3783
3784 assert(Index < EndIndex)(static_cast <bool> (Index < EndIndex) ? void (0) : __assert_fail
("Index < EndIndex", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3784, __extension__ __PRETTY_FUNCTION__))
;
3785 EE = STy->element_begin() + EndIndex;
3786 }
3787
3788 // Try to build up a sub-structure.
3789 StructType *SubTy =
3790 StructType::get(STy->getContext(), makeArrayRef(EI, EE), STy->isPacked());
3791 const StructLayout *SubSL = DL.getStructLayout(SubTy);
3792 if (Size != SubSL->getSizeInBytes())
3793 return nullptr; // The sub-struct doesn't have quite the size needed.
3794
3795 return SubTy;
3796}
3797
3798/// Pre-split loads and stores to simplify rewriting.
3799///
3800/// We want to break up the splittable load+store pairs as much as
3801/// possible. This is important to do as a preprocessing step, as once we
3802/// start rewriting the accesses to partitions of the alloca we lose the
3803/// necessary information to correctly split apart paired loads and stores
3804/// which both point into this alloca. The case to consider is something like
3805/// the following:
3806///
3807/// %a = alloca [12 x i8]
3808/// %gep1 = getelementptr [12 x i8]* %a, i32 0, i32 0
3809/// %gep2 = getelementptr [12 x i8]* %a, i32 0, i32 4
3810/// %gep3 = getelementptr [12 x i8]* %a, i32 0, i32 8
3811/// %iptr1 = bitcast i8* %gep1 to i64*
3812/// %iptr2 = bitcast i8* %gep2 to i64*
3813/// %fptr1 = bitcast i8* %gep1 to float*
3814/// %fptr2 = bitcast i8* %gep2 to float*
3815/// %fptr3 = bitcast i8* %gep3 to float*
3816/// store float 0.0, float* %fptr1
3817/// store float 1.0, float* %fptr2
3818/// %v = load i64* %iptr1
3819/// store i64 %v, i64* %iptr2
3820/// %f1 = load float* %fptr2
3821/// %f2 = load float* %fptr3
3822///
3823/// Here we want to form 3 partitions of the alloca, each 4 bytes large, and
3824/// promote everything so we recover the 2 SSA values that should have been
3825/// there all along.
3826///
3827/// \returns true if any changes are made.
3828bool SROA::presplitLoadsAndStores(AllocaInst &AI, AllocaSlices &AS) {
3829 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)
;
3830
3831 // Track the loads and stores which are candidates for pre-splitting here, in
3832 // the order they first appear during the partition scan. These give stable
3833 // iteration order and a basis for tracking which loads and stores we
3834 // actually split.
3835 SmallVector<LoadInst *, 4> Loads;
3836 SmallVector<StoreInst *, 4> Stores;
3837
3838 // We need to accumulate the splits required of each load or store where we
3839 // can find them via a direct lookup. This is important to cross-check loads
3840 // and stores against each other. We also track the slice so that we can kill
3841 // all the slices that end up split.
3842 struct SplitOffsets {
3843 Slice *S;
3844 std::vector<uint64_t> Splits;
3845 };
3846 SmallDenseMap<Instruction *, SplitOffsets, 8> SplitOffsetsMap;
3847
3848 // Track loads out of this alloca which cannot, for any reason, be pre-split.
3849 // This is important as we also cannot pre-split stores of those loads!
3850 // FIXME: This is all pretty gross. It means that we can be more aggressive
3851 // in pre-splitting when the load feeding the store happens to come from
3852 // a separate alloca. Put another way, the effectiveness of SROA would be
3853 // decreased by a frontend which just concatenated all of its local allocas
3854 // into one big flat alloca. But defeating such patterns is exactly the job
3855 // SROA is tasked with! Sadly, to not have this discrepancy we would have
3856 // change store pre-splitting to actually force pre-splitting of the load
3857 // that feeds it *and all stores*. That makes pre-splitting much harder, but
3858 // maybe it would make it more principled?
3859 SmallPtrSet<LoadInst *, 8> UnsplittableLoads;
3860
3861 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)
;
3862 for (auto &P : AS.partitions()) {
3863 for (Slice &S : P) {
3864 Instruction *I = cast<Instruction>(S.getUse()->getUser());
3865 if (!S.isSplittable() || S.endOffset() <= P.endOffset()) {
3866 // If this is a load we have to track that it can't participate in any
3867 // pre-splitting. If this is a store of a load we have to track that
3868 // that load also can't participate in any pre-splitting.
3869 if (auto *LI = dyn_cast<LoadInst>(I))
3870 UnsplittableLoads.insert(LI);
3871 else if (auto *SI = dyn_cast<StoreInst>(I))
3872 if (auto *LI = dyn_cast<LoadInst>(SI->getValueOperand()))
3873 UnsplittableLoads.insert(LI);
3874 continue;
3875 }
3876 assert(P.endOffset() > S.beginOffset() &&(static_cast <bool> (P.endOffset() > S.beginOffset()
&& "Empty or backwards partition!") ? void (0) : __assert_fail
("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3877, __extension__ __PRETTY_FUNCTION__))
3877 "Empty or backwards partition!")(static_cast <bool> (P.endOffset() > S.beginOffset()
&& "Empty or backwards partition!") ? void (0) : __assert_fail
("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3877, __extension__ __PRETTY_FUNCTION__))
;
3878
3879 // Determine if this is a pre-splittable slice.
3880 if (auto *LI = dyn_cast<LoadInst>(I)) {
3881 assert(!LI->isVolatile() && "Cannot split volatile loads!")(static_cast <bool> (!LI->isVolatile() && "Cannot split volatile loads!"
) ? void (0) : __assert_fail ("!LI->isVolatile() && \"Cannot split volatile loads!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3881, __extension__ __PRETTY_FUNCTION__))
;
3882
3883 // The load must be used exclusively to store into other pointers for
3884 // us to be able to arbitrarily pre-split it. The stores must also be
3885 // simple to avoid changing semantics.
3886 auto IsLoadSimplyStored = [](LoadInst *LI) {
3887 for (User *LU : LI->users()) {
3888 auto *SI = dyn_cast<StoreInst>(LU);
3889 if (!SI || !SI->isSimple())
3890 return false;
3891 }
3892 return true;
3893 };
3894 if (!IsLoadSimplyStored(LI)) {
3895 UnsplittableLoads.insert(LI);
3896 continue;
3897 }
3898
3899 Loads.push_back(LI);
3900 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
3901 if (S.getUse() != &SI->getOperandUse(SI->getPointerOperandIndex()))
3902 // Skip stores *of* pointers. FIXME: This shouldn't even be possible!
3903 continue;
3904 auto *StoredLoad = dyn_cast<LoadInst>(SI->getValueOperand());
3905 if (!StoredLoad || !StoredLoad->isSimple())
3906 continue;
3907 assert(!SI->isVolatile() && "Cannot split volatile stores!")(static_cast <bool> (!SI->isVolatile() && "Cannot split volatile stores!"
) ? void (0) : __assert_fail ("!SI->isVolatile() && \"Cannot split volatile stores!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3907, __extension__ __PRETTY_FUNCTION__))
;
3908
3909 Stores.push_back(SI);
3910 } else {
3911 // Other uses cannot be pre-split.
3912 continue;
3913 }
3914
3915 // Record the initial split.
3916 LLVM_DEBUG(dbgs() << " Candidate: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Candidate: " << *I <<
"\n"; } } while (false)
;
3917 auto &Offsets = SplitOffsetsMap[I];
3918 assert(Offsets.Splits.empty() &&(static_cast <bool> (Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? void (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3919, __extension__ __PRETTY_FUNCTION__))
3919 "Should not have splits the first time we see an instruction!")(static_cast <bool> (Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? void (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3919, __extension__ __PRETTY_FUNCTION__))
;
3920 Offsets.S = &S;
3921 Offsets.Splits.push_back(P.endOffset() - S.beginOffset());
3922 }
3923
3924 // Now scan the already split slices, and add a split for any of them which
3925 // we're going to pre-split.
3926 for (Slice *S : P.splitSliceTails()) {
3927 auto SplitOffsetsMapI =
3928 SplitOffsetsMap.find(cast<Instruction>(S->getUse()->getUser()));
3929 if (SplitOffsetsMapI == SplitOffsetsMap.end())
3930 continue;
3931 auto &Offsets = SplitOffsetsMapI->second;
3932
3933 assert(Offsets.S == S && "Found a mismatched slice!")(static_cast <bool> (Offsets.S == S && "Found a mismatched slice!"
) ? void (0) : __assert_fail ("Offsets.S == S && \"Found a mismatched slice!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3933, __extension__ __PRETTY_FUNCTION__))
;
3934 assert(!Offsets.Splits.empty() &&(static_cast <bool> (!Offsets.Splits.empty() &&
"Cannot have an empty set of splits on the second partition!"
) ? void (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3935, __extension__ __PRETTY_FUNCTION__))
3935 "Cannot have an empty set of splits on the second partition!")(static_cast <bool> (!Offsets.Splits.empty() &&
"Cannot have an empty set of splits on the second partition!"
) ? void (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3935, __extension__ __PRETTY_FUNCTION__))
;
3936 assert(Offsets.Splits.back() ==(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3938, __extension__ __PRETTY_FUNCTION__))
3937 P.beginOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3938, __extension__ __PRETTY_FUNCTION__))
3938 "Previous split does not end where this one begins!")(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 3938, __extension__ __PRETTY_FUNCTION__))
;
3939
3940 // Record each split. The last partition's end isn't needed as the size
3941 // of the slice dictates that.
3942 if (S->endOffset() > P.endOffset())
3943 Offsets.Splits.push_back(P.endOffset() - Offsets.S->beginOffset());
3944 }
3945 }
3946
3947 // We may have split loads where some of their stores are split stores. For
3948 // such loads and stores, we can only pre-split them if their splits exactly
3949 // match relative to their starting offset. We have to verify this prior to
3950 // any rewriting.
3951 llvm::erase_if(Stores, [&UnsplittableLoads, &SplitOffsetsMap](StoreInst *SI) {
3952 // Lookup the load we are storing in our map of split
3953 // offsets.
3954 auto *LI = cast<LoadInst>(SI->getValueOperand());
3955 // If it was completely unsplittable, then we're done,
3956 // and this store can't be pre-split.
3957 if (UnsplittableLoads.count(LI))
3958 return true;
3959
3960 auto LoadOffsetsI = SplitOffsetsMap.find(LI);
3961 if (LoadOffsetsI == SplitOffsetsMap.end())
3962 return false; // Unrelated loads are definitely safe.
3963 auto &LoadOffsets = LoadOffsetsI->second;
3964
3965 // Now lookup the store's offsets.
3966 auto &StoreOffsets = SplitOffsetsMap[SI];
3967
3968 // If the relative offsets of each split in the load and
3969 // store match exactly, then we can split them and we
3970 // don't need to remove them here.
3971 if (LoadOffsets.Splits == StoreOffsets.Splits)
3972 return false;
3973
3974 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)
3975 << " " << *LI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3976 << " " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
;
3977
3978 // We've found a store and load that we need to split
3979 // with mismatched relative splits. Just give up on them
3980 // and remove both instructions from our list of
3981 // candidates.
3982 UnsplittableLoads.insert(LI);
3983 return true;
3984 });
3985 // Now we have to go *back* through all the stores, because a later store may
3986 // have caused an earlier store's load to become unsplittable and if it is
3987 // unsplittable for the later store, then we can't rely on it being split in
3988 // the earlier store either.
3989 llvm::erase_if(Stores, [&UnsplittableLoads](StoreInst *SI) {
3990 auto *LI = cast<LoadInst>(SI->getValueOperand());
3991 return UnsplittableLoads.count(LI);
3992 });
3993 // Once we've established all the loads that can't be split for some reason,
3994 // filter any that made it into our list out.
3995 llvm::erase_if(Loads, [&UnsplittableLoads](LoadInst *LI) {
3996 return UnsplittableLoads.count(LI);
3997 });
3998
3999 // If no loads or stores are left, there is no pre-splitting to be done for
4000 // this alloca.
4001 if (Loads.empty() && Stores.empty())
4002 return false;
4003
4004 // From here on, we can't fail and will be building new accesses, so rig up
4005 // an IR builder.
4006 IRBuilderTy IRB(&AI);
4007
4008 // Collect the new slices which we will merge into the alloca slices.
4009 SmallVector<Slice, 4> NewSlices;
4010
4011 // Track any allocas we end up splitting loads and stores for so we iterate
4012 // on them.
4013 SmallPtrSet<AllocaInst *, 4> ResplitPromotableAllocas;
4014
4015 // At this point, we have collected all of the loads and stores we can
4016 // pre-split, and the specific splits needed for them. We actually do the
4017 // splitting in a specific order in order to handle when one of the loads in
4018 // the value operand to one of the stores.
4019 //
4020 // First, we rewrite all of the split loads, and just accumulate each split
4021 // load in a parallel structure. We also build the slices for them and append
4022 // them to the alloca slices.
4023 SmallDenseMap<LoadInst *, std::vector<LoadInst *>, 1> SplitLoadsMap;
4024 std::vector<LoadInst *> SplitLoads;
4025 const DataLayout &DL = AI.getModule()->getDataLayout();
4026 for (LoadInst *LI : Loads) {
4027 SplitLoads.clear();
4028
4029 IntegerType *Ty = cast<IntegerType>(LI->getType());
4030 assert(Ty->getBitWidth() % 8 == 0)(static_cast <bool> (Ty->getBitWidth() % 8 == 0) ? void
(0) : __assert_fail ("Ty->getBitWidth() % 8 == 0", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4030, __extension__ __PRETTY_FUNCTION__))
;
4031 uint64_t LoadSize = Ty->getBitWidth() / 8;
4032 assert(LoadSize > 0 && "Cannot have a zero-sized integer load!")(static_cast <bool> (LoadSize > 0 && "Cannot have a zero-sized integer load!"
) ? void (0) : __assert_fail ("LoadSize > 0 && \"Cannot have a zero-sized integer load!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4032, __extension__ __PRETTY_FUNCTION__))
;
4033
4034 auto &Offsets = SplitOffsetsMap[LI];
4035 assert(LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (LoadSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4036, __extension__ __PRETTY_FUNCTION__))
4036 "Slice size should always match load size exactly!")(static_cast <bool> (LoadSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4036, __extension__ __PRETTY_FUNCTION__))
;
4037 uint64_t BaseOffset = Offsets.S->beginOffset();
4038 assert(BaseOffset + LoadSize > BaseOffset &&(static_cast <bool> (BaseOffset + LoadSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4039, __extension__ __PRETTY_FUNCTION__))
4039 "Cannot represent alloca access size using 64-bit integers!")(static_cast <bool> (BaseOffset + LoadSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4039, __extension__ __PRETTY_FUNCTION__))
;
4040
4041 Instruction *BasePtr = cast<Instruction>(LI->getPointerOperand());
4042 IRB.SetInsertPoint(LI);
4043
4044 LLVM_DEBUG(dbgs() << " Splitting load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting load: " << *LI
<< "\n"; } } while (false)
;
4045
4046 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
4047 int Idx = 0, Size = Offsets.Splits.size();
4048 for (;;) {
4049 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
4050 auto AS = LI->getPointerAddressSpace();
4051 auto *PartPtrTy = PartTy->getPointerTo(AS);
4052 LoadInst *PLoad = IRB.CreateAlignedLoad(
4053 PartTy,
4054 getAdjustedPtr(IRB, DL, BasePtr,
4055 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4056 PartPtrTy, BasePtr->getName() + "."),
4057 getAdjustedAlignment(LI, PartOffset),
4058 /*IsVolatile*/ false, LI->getName());
4059 PLoad->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
4060 LLVMContext::MD_access_group});
4061
4062 // Append this load onto the list of split loads so we can find it later
4063 // to rewrite the stores.
4064 SplitLoads.push_back(PLoad);
4065
4066 // Now build a new slice for the alloca.
4067 NewSlices.push_back(
4068 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
4069 &PLoad->getOperandUse(PLoad->getPointerOperandIndex()),
4070 /*IsSplittable*/ false));
4071 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)
4072 << ", " << NewSlices.back().endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
4073 << "): " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
;
4074
4075 // See if we've handled all the splits.
4076 if (Idx >= Size)
4077 break;
4078
4079 // Setup the next partition.
4080 PartOffset = Offsets.Splits[Idx];
4081 ++Idx;
4082 PartSize = (Idx < Size ? Offsets.Splits[Idx] : LoadSize) - PartOffset;
4083 }
4084
4085 // Now that we have the split loads, do the slow walk over all uses of the
4086 // load and rewrite them as split stores, or save the split loads to use
4087 // below if the store is going to be split there anyways.
4088 bool DeferredStores = false;
4089 for (User *LU : LI->users()) {
4090 StoreInst *SI = cast<StoreInst>(LU);
4091 if (!Stores.empty() && SplitOffsetsMap.count(SI)) {
4092 DeferredStores = true;
4093 LLVM_DEBUG(dbgs() << " Deferred splitting of store: " << *SIdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
4094 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
;
4095 continue;
4096 }
4097
4098 Value *StoreBasePtr = SI->getPointerOperand();
4099 IRB.SetInsertPoint(SI);
4100
4101 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)
;
4102
4103 for (int Idx = 0, Size = SplitLoads.size(); Idx < Size; ++Idx) {
4104 LoadInst *PLoad = SplitLoads[Idx];
4105 uint64_t PartOffset = Idx == 0 ? 0 : Offsets.Splits[Idx - 1];
4106 auto *PartPtrTy =
4107 PLoad->getType()->getPointerTo(SI->getPointerAddressSpace());
4108
4109 auto AS = SI->getPointerAddressSpace();
4110 StoreInst *PStore = IRB.CreateAlignedStore(
4111 PLoad,
4112 getAdjustedPtr(IRB, DL, StoreBasePtr,
4113 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4114 PartPtrTy, StoreBasePtr->getName() + "."),
4115 getAdjustedAlignment(SI, PartOffset),
4116 /*IsVolatile*/ false);
4117 PStore->copyMetadata(*SI, {LLVMContext::MD_mem_parallel_loop_access,
4118 LLVMContext::MD_access_group});
4119 LLVM_DEBUG(dbgs() << " +" << PartOffset << ":" << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " +" << PartOffset <<
":" << *PStore << "\n"; } } while (false)
;
4120 }
4121
4122 // We want to immediately iterate on any allocas impacted by splitting
4123 // this store, and we have to track any promotable alloca (indicated by
4124 // a direct store) as needing to be resplit because it is no longer
4125 // promotable.
4126 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(StoreBasePtr)) {
4127 ResplitPromotableAllocas.insert(OtherAI);
4128 Worklist.insert(OtherAI);
4129 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
4130 StoreBasePtr->stripInBoundsOffsets())) {
4131 Worklist.insert(OtherAI);
4132 }
4133
4134 // Mark the original store as dead.
4135 DeadInsts.push_back(SI);
4136 }
4137
4138 // Save the split loads if there are deferred stores among the users.
4139 if (DeferredStores)
4140 SplitLoadsMap.insert(std::make_pair(LI, std::move(SplitLoads)));
4141
4142 // Mark the original load as dead and kill the original slice.
4143 DeadInsts.push_back(LI);
4144 Offsets.S->kill();
4145 }
4146
4147 // Second, we rewrite all of the split stores. At this point, we know that
4148 // all loads from this alloca have been split already. For stores of such
4149 // loads, we can simply look up the pre-existing split loads. For stores of
4150 // other loads, we split those loads first and then write split stores of
4151 // them.
4152 for (StoreInst *SI : Stores) {
4153 auto *LI = cast<LoadInst>(SI->getValueOperand());
4154 IntegerType *Ty = cast<IntegerType>(LI->getType());
4155 assert(Ty->getBitWidth() % 8 == 0)(static_cast <bool> (Ty->getBitWidth() % 8 == 0) ? void
(0) : __assert_fail ("Ty->getBitWidth() % 8 == 0", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4155, __extension__ __PRETTY_FUNCTION__))
;
4156 uint64_t StoreSize = Ty->getBitWidth() / 8;
4157 assert(StoreSize > 0 && "Cannot have a zero-sized integer store!")(static_cast <bool> (StoreSize > 0 && "Cannot have a zero-sized integer store!"
) ? void (0) : __assert_fail ("StoreSize > 0 && \"Cannot have a zero-sized integer store!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4157, __extension__ __PRETTY_FUNCTION__))
;
4158
4159 auto &Offsets = SplitOffsetsMap[SI];
4160 assert(StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (StoreSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4161, __extension__ __PRETTY_FUNCTION__))
4161 "Slice size should always match load size exactly!")(static_cast <bool> (StoreSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4161, __extension__ __PRETTY_FUNCTION__))
;
4162 uint64_t BaseOffset = Offsets.S->beginOffset();
4163 assert(BaseOffset + StoreSize > BaseOffset &&(static_cast <bool> (BaseOffset + StoreSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4164, __extension__ __PRETTY_FUNCTION__))
4164 "Cannot represent alloca access size using 64-bit integers!")(static_cast <bool> (BaseOffset + StoreSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4164, __extension__ __PRETTY_FUNCTION__))
;
4165
4166 Value *LoadBasePtr = LI->getPointerOperand();
4167 Instruction *StoreBasePtr = cast<Instruction>(SI->getPointerOperand());
4168
4169 LLVM_DEBUG(dbgs() << " Splitting store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store: " << *SI
<< "\n"; } } while (false)
;
4170
4171 // Check whether we have an already split load.
4172 auto SplitLoadsMapI = SplitLoadsMap.find(LI);
4173 std::vector<LoadInst *> *SplitLoads = nullptr;
4174 if (SplitLoadsMapI != SplitLoadsMap.end()) {
4175 SplitLoads = &SplitLoadsMapI->second;
4176 assert(SplitLoads->size() == Offsets.Splits.size() + 1 &&(static_cast <bool> (SplitLoads->size() == Offsets.Splits
.size() + 1 && "Too few split loads for the number of splits in the store!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4177, __extension__ __PRETTY_FUNCTION__))
4177 "Too few split loads for the number of splits in the store!")(static_cast <bool> (SplitLoads->size() == Offsets.Splits
.size() + 1 && "Too few split loads for the number of splits in the store!"
) ? 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-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4177, __extension__ __PRETTY_FUNCTION__))
;
4178 } else {
4179 LLVM_DEBUG(dbgs() << " of load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of load: " << *LI
<< "\n"; } } while (false)
;
4180 }
4181
4182 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
4183 int Idx = 0, Size = Offsets.Splits.size();
4184 for (;;) {
4185 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
4186 auto *LoadPartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
4187 auto *StorePartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
4188
4189 // Either lookup a split load or create one.
4190 LoadInst *PLoad;
4191 if (SplitLoads) {
4192 PLoad = (*SplitLoads)[Idx];
4193 } else {
4194 IRB.SetInsertPoint(LI);
4195 auto AS = LI->getPointerAddressSpace();
4196 PLoad = IRB.CreateAlignedLoad(
4197 PartTy,
4198 getAdjustedPtr(IRB, DL, LoadBasePtr,
4199 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4200 LoadPartPtrTy, LoadBasePtr->getName() + "."),
4201 getAdjustedAlignment(LI, PartOffset),
4202 /*IsVolatile*/ false, LI->getName());
4203 PLoad->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
4204 LLVMContext::MD_access_group});
4205 }
4206
4207 // And store this partition.
4208 IRB.SetInsertPoint(SI);
4209 auto AS = SI->getPointerAddressSpace();
4210 StoreInst *PStore = IRB.CreateAlignedStore(
4211 PLoad,
4212 getAdjustedPtr(IRB, DL, StoreBasePtr,
4213 APInt(DL.getIndexSizeInBits(AS), PartOffset),
4214 StorePartPtrTy, StoreBasePtr->getName() + "."),
4215 getAdjustedAlignment(SI, PartOffset),
4216 /*IsVolatile*/ false);
4217 PStore->copyMetadata(*SI, {LLVMContext::MD_mem_parallel_loop_access,
4218 LLVMContext::MD_access_group});
4219
4220 // Now build a new slice for the alloca.
4221 NewSlices.push_back(
4222 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
4223 &PStore->getOperandUse(PStore->getPointerOperandIndex()),
4224 /*IsSplittable*/ false));
4225 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)
4226 << ", " << NewSlices.back().endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
4227 << "): " << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
;
4228 if (!SplitLoads) {
4229 LLVM_DEBUG(dbgs() << " of split load: " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of split load: " << *
PLoad << "\n"; } } while (false)
;
4230 }
4231
4232 // See if we've finished all the splits.
4233 if (Idx >= Size)
4234 break;
4235
4236 // Setup the next partition.
4237 PartOffset = Offsets.Splits[Idx];
4238 ++Idx;
4239 PartSize = (Idx < Size ? Offsets.Splits[Idx] : StoreSize) - PartOffset;
4240 }
4241
4242 // We want to immediately iterate on any allocas impacted by splitting
4243 // this load, which is only relevant if it isn't a load of this alloca and
4244 // thus we didn't already split the loads above. We also have to keep track
4245 // of any promotable allocas we split loads on as they can no longer be
4246 // promoted.
4247 if (!SplitLoads) {
4248 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(LoadBasePtr)) {
4249 assert(OtherAI != &AI && "We can't re-split our own alloca!")(static_cast <bool> (OtherAI != &AI && "We can't re-split our own alloca!"
) ? void (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4249, __extension__ __PRETTY_FUNCTION__))
;
4250 ResplitPromotableAllocas.insert(OtherAI);
4251 Worklist.insert(OtherAI);
4252 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
4253 LoadBasePtr->stripInBoundsOffsets())) {
4254 assert(OtherAI != &AI && "We can't re-split our own alloca!")(static_cast <bool> (OtherAI != &AI && "We can't re-split our own alloca!"
) ? void (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4254, __extension__ __PRETTY_FUNCTION__))
;
4255 Worklist.insert(OtherAI);
4256 }
4257 }
4258
4259 // Mark the original store as dead now that we've split it up and kill its
4260 // slice. Note that we leave the original load in place unless this store
4261 // was its only use. It may in turn be split up if it is an alloca load
4262 // for some other alloca, but it may be a normal load. This may introduce
4263 // redundant loads, but where those can be merged the rest of the optimizer
4264 // should handle the merging, and this uncovers SSA splits which is more
4265 // important. In practice, the original loads will almost always be fully
4266 // split and removed eventually, and the splits will be merged by any
4267 // trivial CSE, including instcombine.
4268 if (LI->hasOneUse()) {
4269 assert(*LI->user_begin() == SI && "Single use isn't this store!")(static_cast <bool> (*LI->user_begin() == SI &&
"Single use isn't this store!") ? void (0) : __assert_fail (
"*LI->user_begin() == SI && \"Single use isn't this store!\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4269, __extension__ __PRETTY_FUNCTION__))
;
4270 DeadInsts.push_back(LI);
4271 }
4272 DeadInsts.push_back(SI);
4273 Offsets.S->kill();
4274 }
4275
4276 // Remove the killed slices that have ben pre-split.
4277 llvm::erase_if(AS, [](const Slice &S) { return S.isDead(); });
4278
4279 // Insert our new slices. This will sort and merge them into the sorted
4280 // sequence.
4281 AS.insert(NewSlices);
4282
4283 LLVM_DEBUG(dbgs() << " Pre-split slices:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Pre-split slices:\n"; } } while
(false)
;
4284#ifndef NDEBUG
4285 for (auto I = AS.begin(), E = AS.end(); I != E; ++I)
4286 LLVM_DEBUG(AS.print(dbgs(), I, " "))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs(), I, " "); } } while (false)
;
4287#endif
4288
4289 // Finally, don't try to promote any allocas that new require re-splitting.
4290 // They have already been added to the worklist above.
4291 llvm::erase_if(PromotableAllocas, [&](AllocaInst *AI) {
4292 return ResplitPromotableAllocas.count(AI);
4293 });
4294
4295 return true;
4296}
4297
4298/// Rewrite an alloca partition's users.
4299///
4300/// This routine drives both of the rewriting goals of the SROA pass. It tries
4301/// to rewrite uses of an alloca partition to be conducive for SSA value
4302/// promotion. If the partition needs a new, more refined alloca, this will
4303/// build that new alloca, preserving as much type information as possible, and
4304/// rewrite the uses of the old alloca to point at the new one and have the
4305/// appropriate new offsets. It also evaluates how successful the rewrite was
4306/// at enabling promotion and if it was successful queues the alloca to be
4307/// promoted.
4308AllocaInst *SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS,
4309 Partition &P) {
4310 // Try to compute a friendly type for this partition of the alloca. This
4311 // won't always succeed, in which case we fall back to a legal integer type
4312 // or an i8 array of an appropriate size.
4313 Type *SliceTy = nullptr;
4314 const DataLayout &DL = AI.getModule()->getDataLayout();
4315 std::pair<Type *, IntegerType *> CommonUseTy =
4316 findCommonType(P.begin(), P.end(), P.endOffset());
4317 // Do all uses operate on the same type?
4318 if (CommonUseTy.first)
4319 if (DL.getTypeAllocSize(CommonUseTy.first).getFixedSize() >= P.size())
4320 SliceTy = CommonUseTy.first;
4321 // If not, can we find an appropriate subtype in the original allocated type?
4322 if (!SliceTy)
4323 if (Type *TypePartitionTy = getTypePartition(DL, AI.getAllocatedType(),
4324 P.beginOffset(), P.size()))
4325 SliceTy = TypePartitionTy;
4326 // If still not, can we use the largest bitwidth integer type used?
4327 if (!SliceTy && CommonUseTy.second)
4328 if (DL.getTypeAllocSize(CommonUseTy.second).getFixedSize() >= P.size())
4329 SliceTy = CommonUseTy.second;
4330 if ((!SliceTy || (SliceTy->isArrayTy() &&
4331 SliceTy->getArrayElementType()->isIntegerTy())) &&
4332 DL.isLegalInteger(P.size() * 8))
4333 SliceTy = Type::getIntNTy(*C, P.size() * 8);
4334 if (!SliceTy)
4335 SliceTy = ArrayType::get(Type::getInt8Ty(*C), P.size());
4336 assert(DL.getTypeAllocSize(SliceTy).getFixedSize() >= P.size())(static_cast <bool> (DL.getTypeAllocSize(SliceTy).getFixedSize
() >= P.size()) ? void (0) : __assert_fail ("DL.getTypeAllocSize(SliceTy).getFixedSize() >= P.size()"
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4336, __extension__ __PRETTY_FUNCTION__))
;
4337
4338 bool IsIntegerPromotable = isIntegerWideningViable(P, SliceTy, DL);
4339
4340 VectorType *VecTy =
4341 IsIntegerPromotable ? nullptr : isVectorPromotionViable(P, DL);
4342 if (VecTy)
4343 SliceTy = VecTy;
4344
4345 // Check for the case where we're going to rewrite to a new alloca of the
4346 // exact same type as the original, and with the same access offsets. In that
4347 // case, re-use the existing alloca, but still run through the rewriter to
4348 // perform phi and select speculation.
4349 // P.beginOffset() can be non-zero even with the same type in a case with
4350 // out-of-bounds access (e.g. @PR35657 function in SROA/basictest.ll).
4351 AllocaInst *NewAI;
4352 if (SliceTy == AI.getAllocatedType() && P.beginOffset() == 0) {
4353 NewAI = &AI;
4354 // FIXME: We should be able to bail at this point with "nothing changed".
4355 // FIXME: We might want to defer PHI speculation until after here.
4356 // FIXME: return nullptr;
4357 } else {
4358 // Make sure the alignment is compatible with P.beginOffset().
4359 const Align Alignment = commonAlignment(AI.getAlign(), P.beginOffset());
4360 // If we will get at least this much alignment from the type alone, leave
4361 // the alloca's alignment unconstrained.
4362 const bool IsUnconstrained = Alignment <= DL.getABITypeAlign(SliceTy);
4363 NewAI = new AllocaInst(
4364 SliceTy, AI.getType()->getAddressSpace(), nullptr,
4365 IsUnconstrained ? DL.getPrefTypeAlign(SliceTy) : Alignment,
4366 AI.getName() + ".sroa." + Twine(P.begin() - AS.begin()), &AI);
4367 // Copy the old AI debug location over to the new one.
4368 NewAI->setDebugLoc(AI.getDebugLoc());
4369 ++NumNewAllocas;
4370 }
4371
4372 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)
4373 << "[" << P.beginOffset() << "," << P.endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
4374 << ") to: " << *NewAI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
;
4375
4376 // Track the high watermark on the worklist as it is only relevant for
4377 // promoted allocas. We will reset it to this point if the alloca is not in
4378 // fact scheduled for promotion.
4379 unsigned PPWOldSize = PostPromotionWorklist.size();
4380 unsigned NumUses = 0;
4381 SmallSetVector<PHINode *, 8> PHIUsers;
4382 SmallSetVector<SelectInst *, 8> SelectUsers;
4383
4384 AllocaSliceRewriter Rewriter(DL, AS, *this, AI, *NewAI, P.beginOffset(),
4385 P.endOffset(), IsIntegerPromotable, VecTy,
4386 PHIUsers, SelectUsers);
4387 bool Promotable = true;
4388 for (Slice *S : P.splitSliceTails()) {
4389 Promotable &= Rewriter.visit(S);
4390 ++NumUses;
4391 }
4392 for (Slice &S : P) {
4393 Promotable &= Rewriter.visit(&S);
4394 ++NumUses;
4395 }
4396
4397 NumAllocaPartitionUses += NumUses;
4398 MaxUsesPerAllocaPartition.updateMax(NumUses);
4399
4400 // Now that we've processed all the slices in the new partition, check if any
4401 // PHIs or Selects would block promotion.
4402 for (PHINode *PHI : PHIUsers)
4403 if (!isSafePHIToSpeculate(*PHI)) {
4404 Promotable = false;
4405 PHIUsers.clear();
4406 SelectUsers.clear();
4407 break;
4408 }
4409
4410 for (SelectInst *Sel : SelectUsers)
4411 if (!isSafeSelectToSpeculate(*Sel)) {
4412 Promotable = false;
4413 PHIUsers.clear();
4414 SelectUsers.clear();
4415 break;
4416 }
4417
4418 if (Promotable) {
4419 for (Use *U : AS.getDeadUsesIfPromotable()) {
4420 auto *OldInst = dyn_cast<Instruction>(U->get());
4421 Value::dropDroppableUse(*U);
4422 if (OldInst)
4423 if (isInstructionTriviallyDead(OldInst))
4424 DeadInsts.push_back(OldInst);
4425 }
4426 if (PHIUsers.empty() && SelectUsers.empty()) {
4427 // Promote the alloca.
4428 PromotableAllocas.push_back(NewAI);
4429 } else {
4430 // If we have either PHIs or Selects to speculate, add them to those
4431 // worklists and re-queue the new alloca so that we promote in on the
4432 // next iteration.
4433 for (PHINode *PHIUser : PHIUsers)
4434 SpeculatablePHIs.insert(PHIUser);
4435 for (SelectInst *SelectUser : SelectUsers)
4436 SpeculatableSelects.insert(SelectUser);
4437 Worklist.insert(NewAI);
4438 }
4439 } else {
4440 // Drop any post-promotion work items if promotion didn't happen.
4441 while (PostPromotionWorklist.size() > PPWOldSize)
4442 PostPromotionWorklist.pop_back();
4443
4444 // We couldn't promote and we didn't create a new partition, nothing
4445 // happened.
4446 if (NewAI == &AI)
4447 return nullptr;
4448
4449 // If we can't promote the alloca, iterate on it to check for new
4450 // refinements exposed by splitting the current alloca. Don't iterate on an
4451 // alloca which didn't actually change and didn't get promoted.
4452 Worklist.insert(NewAI);
4453 }
4454
4455 return NewAI;
4456}
4457
4458/// Walks the slices of an alloca and form partitions based on them,
4459/// rewriting each of their uses.
4460bool SROA::splitAlloca(AllocaInst &AI, AllocaSlices &AS) {
4461 if (AS.begin() == AS.end())
4462 return false;
4463
4464 unsigned NumPartitions = 0;
4465 bool Changed = false;
4466 const DataLayout &DL = AI.getModule()->getDataLayout();
4467
4468 // First try to pre-split loads and stores.
4469 Changed |= presplitLoadsAndStores(AI, AS);
4470
4471 // Now that we have identified any pre-splitting opportunities,
4472 // mark loads and stores unsplittable except for the following case.
4473 // We leave a slice splittable if all other slices are disjoint or fully
4474 // included in the slice, such as whole-alloca loads and stores.
4475 // If we fail to split these during pre-splitting, we want to force them
4476 // to be rewritten into a partition.
4477 bool IsSorted = true;
4478
4479 uint64_t AllocaSize =
4480 DL.getTypeAllocSize(AI.getAllocatedType()).getFixedSize();
4481 const uint64_t MaxBitVectorSize = 1024;
4482 if (AllocaSize <= MaxBitVectorSize) {
4483 // If a byte boundary is included in any load or store, a slice starting or
4484 // ending at the boundary is not splittable.
4485 SmallBitVector SplittableOffset(AllocaSize + 1, true);
4486 for (Slice &S : AS)
4487 for (unsigned O = S.beginOffset() + 1;
4488 O < S.endOffset() && O < AllocaSize; O++)
4489 SplittableOffset.reset(O);
4490
4491 for (Slice &S : AS) {
4492 if (!S.isSplittable())
4493 continue;
4494
4495 if ((S.beginOffset() > AllocaSize || SplittableOffset[S.beginOffset()]) &&
4496 (S.endOffset() > AllocaSize || SplittableOffset[S.endOffset()]))
4497 continue;
4498
4499 if (isa<LoadInst>(S.getUse()->getUser()) ||
4500 isa<StoreInst>(S.getUse()->getUser())) {
4501 S.makeUnsplittable();
4502 IsSorted = false;
4503 }
4504 }
4505 }
4506 else {
4507 // We only allow whole-alloca splittable loads and stores
4508 // for a large alloca to avoid creating too large BitVector.
4509 for (Slice &S : AS) {
4510 if (!S.isSplittable())
4511 continue;
4512
4513 if (S.beginOffset() == 0 && S.endOffset() >= AllocaSize)
4514 continue;
4515
4516 if (isa<LoadInst>(S.getUse()->getUser()) ||
4517 isa<StoreInst>(S.getUse()->getUser())) {
4518 S.makeUnsplittable();
4519 IsSorted = false;
4520 }
4521 }
4522 }
4523
4524 if (!IsSorted)
4525 llvm::sort(AS);
4526
4527 /// Describes the allocas introduced by rewritePartition in order to migrate
4528 /// the debug info.
4529 struct Fragment {
4530 AllocaInst *Alloca;
4531 uint64_t Offset;
4532 uint64_t Size;
4533 Fragment(AllocaInst *AI, uint64_t O, uint64_t S)
4534 : Alloca(AI), Offset(O), Size(S) {}
4535 };
4536 SmallVector<Fragment, 4> Fragments;
4537
4538 // Rewrite each partition.
4539 for (auto &P : AS.partitions()) {
4540 if (AllocaInst *NewAI = rewritePartition(AI, AS, P)) {
4541 Changed = true;
4542 if (NewAI != &AI) {
4543 uint64_t SizeOfByte = 8;
4544 uint64_t AllocaSize =
4545 DL.getTypeSizeInBits(NewAI->getAllocatedType()).getFixedSize();
4546 // Don't include any padding.
4547 uint64_t Size = std::min(AllocaSize, P.size() * SizeOfByte);
4548 Fragments.push_back(Fragment(NewAI, P.beginOffset() * SizeOfByte, Size));
4549 }
4550 }
4551 ++NumPartitions;
4552 }
4553
4554 NumAllocaPartitions += NumPartitions;
4555 MaxPartitionsPerAlloca.updateMax(NumPartitions);
4556
4557 // Migrate debug information from the old alloca to the new alloca(s)
4558 // and the individual partitions.
4559 TinyPtrVector<DbgVariableIntrinsic *> DbgDeclares = FindDbgAddrUses(&AI);
4560 for (DbgVariableIntrinsic *DbgDeclare : DbgDeclares) {
4561 auto *Expr = DbgDeclare->getExpression();
4562 DIBuilder DIB(*AI.getModule(), /*AllowUnresolved*/ false);
4563 uint64_t AllocaSize =
4564 DL.getTypeSizeInBits(AI.getAllocatedType()).getFixedSize();
4565 for (auto Fragment : Fragments) {
4566 // Create a fragment expression describing the new partition or reuse AI's
4567 // expression if there is only one partition.
4568 auto *FragmentExpr = Expr;
4569 if (Fragment.Size < AllocaSize || Expr->isFragment()) {
4570 // If this alloca is already a scalar replacement of a larger aggregate,
4571 // Fragment.Offset describes the offset inside the scalar.
4572 auto ExprFragment = Expr->getFragmentInfo();
4573 uint64_t Offset = ExprFragment ? ExprFragment->OffsetInBits : 0;
4574 uint64_t Start = Offset + Fragment.Offset;
4575 uint64_t Size = Fragment.Size;
4576 if (ExprFragment) {
4577 uint64_t AbsEnd =
4578 ExprFragment->OffsetInBits + ExprFragment->SizeInBits;
4579 if (Start >= AbsEnd)
4580 // No need to describe a SROAed padding.
4581 continue;
4582 Size = std::min(Size, AbsEnd - Start);
4583 }
4584 // The new, smaller fragment is stenciled out from the old fragment.
4585 if (auto OrigFragment = FragmentExpr->getFragmentInfo()) {
4586 assert(Start >= OrigFragment->OffsetInBits &&(static_cast <bool> (Start >= OrigFragment->OffsetInBits
&& "new fragment is outside of original fragment") ?
void (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4587, __extension__ __PRETTY_FUNCTION__))
4587 "new fragment is outside of original fragment")(static_cast <bool> (Start >= OrigFragment->OffsetInBits
&& "new fragment is outside of original fragment") ?
void (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Transforms/Scalar/SROA.cpp"
, 4587, __extension__ __PRETTY_FUNCTION__))
;
4588 Start -= OrigFragment->OffsetInBits;
4589 }
4590
4591 // The alloca may be larger than the variable.
4592 auto VarSize = DbgDeclare->getVariable()->getSizeInBits();
4593 if (VarSize) {
4594 if (Size > *VarSize)
4595 Size = *VarSize;
4596 if (Size == 0 || Start + Size > *VarSize)
4597 continue;
4598 }
4599
4600 // Avoid creating a fragment expression that covers the entire variable.
4601 if (!VarSize || *VarSize != Size) {
4602 if (auto E =
4603 DIExpression::createFragmentExpression(Expr, Start, Size))
4604 FragmentExpr = *E;
4605 else
4606 continue;
4607 }
4608 }
4609
4610 // Remove any existing intrinsics on the new alloca describing
4611 // the variable fragment.
4612 for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(Fragment.Alloca)) {
4613 auto SameVariableFragment = [](const DbgVariableIntrinsic *LHS,
4614 const DbgVariableIntrinsic *RHS) {
4615 return LHS->getVariable() == RHS->getVariable() &&
4616 LHS->getDebugLoc()->getInlinedAt() ==
4617 RHS->getDebugLoc()->getInlinedAt();
4618 };
4619 if (SameVariableFragment(OldDII, DbgDeclare))
4620 OldDII->eraseFromParent();
4621 }
4622
4623 DIB.insertDeclare(Fragment.Alloca, DbgDeclare->getVariable(), FragmentExpr,
4624 DbgDeclare->getDebugLoc(), &AI);
4625 }
4626 }
4627 return Changed;
4628}
4629
4630/// Clobber a use with undef, deleting the used value if it becomes dead.
4631void SROA::clobberUse(Use &U) {
4632 Value *OldV = U;
4633 // Replace the use with an undef value.
4634 U = UndefValue::get(OldV->getType());
4635
4636 // Check for this making an instruction dead. We have to garbage collect
4637 // all the dead instructions to ensure the uses of any alloca end up being
4638 // minimal.
4639 if (Instruction *OldI = dyn_cast<Instruction>(OldV))
4640 if (isInstructionTriviallyDead(OldI)) {
4641 DeadInsts.push_back(OldI);
4642 }
4643}
4644
4645/// Analyze an alloca for SROA.
4646///
4647/// This analyzes the alloca to ensure we can reason about it, builds
4648/// the slices of the alloca, and then hands it off to be split and
4649/// rewritten as needed.
4650bool SROA::runOnAlloca(AllocaInst &AI) {
4651 LLVM_DEBUG(dbgs() << "SROA alloca: " << AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA alloca: " << AI <<
"\n"; } } while (false)
;
4652 ++NumAllocasAnalyzed;
4653
4654 // Special case dead allocas, as they're trivial.
4655 if (AI.use_empty()) {
4656 AI.eraseFromParent();
4657 return true;
4658 }
4659 const DataLayout &DL = AI.getModule()->getDataLayout();
4660
4661 // Skip alloca forms that this analysis can't handle.
4662 auto *AT = AI.getAllocatedType();
4663 if (AI.isArrayAllocation() || !AT->isSized() || isa<ScalableVectorType>(AT) ||
4664 DL.getTypeAllocSize(AT).getFixedSize() == 0)
4665 return false;
4666
4667 bool Changed = false;
4668
4669 // First, split any FCA loads and stores touching this alloca to promote
4670 // better splitting and promotion opportunities.
4671 AggLoadStoreRewriter AggRewriter(DL);
4672 Changed |= AggRewriter.rewrite(AI);
4673
4674 // Build the slices using a recursive instruction-visiting builder.
4675 AllocaSlices AS(DL, AI);
4676 LLVM_DEBUG(AS.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs()); } } while (false)
;
4677 if (AS.isEscaped())
4678 return Changed;
4679
4680 // Delete all the dead users of this alloca before splitting and rewriting it.
4681 for (Instruction *DeadUser : AS.getDeadUsers()) {
4682 // Free up everything used by this instruction.
4683 for (Use &DeadOp : DeadUser->operands())
4684 clobberUse(DeadOp);
4685
4686 // Now replace the uses of this instruction.
4687 DeadUser->replaceAllUsesWith(UndefValue::get(DeadUser->getType()));
4688
4689 // And mark it for deletion.
4690 DeadInsts.push_back(DeadUser);
4691 Changed = true;
4692 }
4693 for (Use *DeadOp : AS.getDeadOperands()) {
4694 clobberUse(*DeadOp);
4695 Changed = true;
4696 }
4697
4698 // No slices to split. Leave the dead alloca for a later pass to clean up.
4699 if (AS.begin() == AS.end())
4700 return Changed;
4701
4702 Changed |= splitAlloca(AI, AS);
4703
4704 LLVM_DEBUG(dbgs() << " Speculating PHIs\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating PHIs\n"; } } while
(false)
;
4705 while (!SpeculatablePHIs.empty())
4706 speculatePHINodeLoads(*SpeculatablePHIs.pop_back_val());
4707
4708 LLVM_DEBUG(dbgs() << " Speculating Selects\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating Selects\n"; } } while
(false)
;
4709 while (!SpeculatableSelects.empty())
4710 speculateSelectInstLoads(*SpeculatableSelects.pop_back_val());
4711
4712 return Changed;
4713}
4714
4715/// Delete the dead instructions accumulated in this run.
4716///
4717/// Recursively deletes the dead instructions we've accumulated. This is done
4718/// at the very end to maximize locality of the recursive delete and to
4719/// minimize the problems of invalidated instruction pointers as such pointers
4720/// are used heavily in the intermediate stages of the algorithm.
4721///
4722/// We also record the alloca instructions deleted here so that they aren't
4723/// subsequently handed to mem2reg to promote.
4724bool SROA::deleteDeadInstructions(
4725 SmallPtrSetImpl<AllocaInst *> &DeletedAllocas) {
4726 bool Changed = false;
4727 while (!DeadInsts.empty()) {
4728 Instruction *I = dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val());
4729 if (!I) continue;
4730 LLVM_DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Deleting dead instruction: " <<
*I << "\n"; } } while (false)
;
4731
4732 // If the instruction is an alloca, find the possible dbg.declare connected
4733 // to it, and remove it too. We must do this before calling RAUW or we will
4734 // not be able to find it.
4735 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4736 DeletedAllocas.insert(AI);
4737 for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(AI))
4738 OldDII->eraseFromParent();
4739 }
4740
4741 I->replaceAllUsesWith(UndefValue::get(I->getType()));
4742
4743 for (Use &Operand : I->operands())
4744 if (Instruction *U = dyn_cast<Instruction>(Operand)) {
4745 // Zero out the operand and see if it becomes trivially dead.
4746 Operand = nullptr;
4747 if (isInstructionTriviallyDead(U))
4748 DeadInsts.push_back(U);
4749 }
4750
4751 ++NumDeleted;
4752 I->eraseFromParent();
4753 Changed = true;
4754 }
4755 return Changed;
4756}
4757
4758/// Promote the allocas, using the best available technique.
4759///
4760/// This attempts to promote whatever allocas have been identified as viable in
4761/// the PromotableAllocas list. If that list is empty, there is nothing to do.
4762/// This function returns whether any promotion occurred.
4763bool SROA::promoteAllocas(Function &F) {
4764 if (PromotableAllocas.empty())
4765 return false;
4766
4767 NumPromoted += PromotableAllocas.size();
4768
4769 LLVM_DEBUG(dbgs() << "Promoting allocas with mem2reg...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Promoting allocas with mem2reg...\n"
; } } while (false)
;
4770 PromoteMemToReg(PromotableAllocas, *DT, AC);
4771 PromotableAllocas.clear();
4772 return true;
4773}
4774
4775PreservedAnalyses SROA::runImpl(Function &F, DominatorTree &RunDT,
4776 AssumptionCache &RunAC) {
4777 LLVM_DEBUG(dbgs() << "SROA function: " << F.getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA function: " << F.getName
() << "\n"; } } while (false)
;
4778 C = &F.getContext();
4779 DT = &RunDT;
4780 AC = &RunAC;
4781
4782 BasicBlock &EntryBB = F.getEntryBlock();
4783 for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
4784 I != E; ++I) {
4785 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4786 if (isa<ScalableVectorType>(AI->getAllocatedType())) {
4787 if (isAllocaPromotable(AI))
4788 PromotableAllocas.push_back(AI);
4789 } else {
4790 Worklist.insert(AI);
4791 }
4792 }
4793 }
4794
4795 bool Changed = false;
4796 // A set of deleted alloca instruction pointers which should be removed from
4797 // the list of promotable allocas.
4798 SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
4799
4800 do {
4801 while (!Worklist.empty()) {
4802 Changed |= runOnAlloca(*Worklist.pop_back_val());
4803 Changed |= deleteDeadInstructions(DeletedAllocas);
4804
4805 // Remove the deleted allocas from various lists so that we don't try to
4806 // continue processing them.
4807 if (!DeletedAllocas.empty()) {
4808 auto IsInSet = [&](AllocaInst *AI) { return DeletedAllocas.count(AI); };
4809 Worklist.remove_if(IsInSet);
4810 PostPromotionWorklist.remove_if(IsInSet);
4811 llvm::erase_if(PromotableAllocas, IsInSet);
4812 DeletedAllocas.clear();
4813 }
4814 }
4815
4816 Changed |= promoteAllocas(F);
4817
4818 Worklist = PostPromotionWorklist;
4819 PostPromotionWorklist.clear();
4820 } while (!Worklist.empty());
4821
4822 if (!Changed)
4823 return PreservedAnalyses::all();
4824
4825 PreservedAnalyses PA;
4826 PA.preserveSet<CFGAnalyses>();
4827 return PA;
4828}
4829
4830PreservedAnalyses SROA::run(Function &F, FunctionAnalysisManager &AM) {
4831 return runImpl(F, AM.getResult<DominatorTreeAnalysis>(F),
4832 AM.getResult<AssumptionAnalysis>(F));
4833}
4834
4835/// A legacy pass for the legacy pass manager that wraps the \c SROA pass.
4836///
4837/// This is in the llvm namespace purely to allow it to be a friend of the \c
4838/// SROA pass.
4839class llvm::sroa::SROALegacyPass : public FunctionPass {
4840 /// The SROA implementation.
4841 SROA Impl;
4842
4843public:
4844 static char ID;
4845
4846 SROALegacyPass() : FunctionPass(ID) {
4847 initializeSROALegacyPassPass(*PassRegistry::getPassRegistry());
4848 }
4849
4850 bool runOnFunction(Function &F) override {
4851 if (skipFunction(F))
4852 return false;
4853
4854 auto PA = Impl.runImpl(
4855 F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
4856 getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F));
4857 return !PA.areAllPreserved();
4858 }
4859
4860 void getAnalysisUsage(AnalysisUsage &AU) const override {
4861 AU.addRequired<AssumptionCacheTracker>();
4862 AU.addRequired<DominatorTreeWrapperPass>();
4863 AU.addPreserved<GlobalsAAWrapperPass>();
4864 AU.setPreservesCFG();
4865 }
4866
4867 StringRef getPassName() const override { return "SROA"; }
4868};
4869
4870char SROALegacyPass::ID = 0;
4871
4872FunctionPass *llvm::createSROAPass() { return new SROALegacyPass(); }
4873
4874INITIALIZE_PASS_BEGIN(SROALegacyPass, "sroa",static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4875 "Scalar Replacement Of Aggregates", false, false)static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4876INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry);
4877INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
4878INITIALIZE_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)); }
4879 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)); }