Bug Summary

File:lib/Transforms/Scalar/SROA.cpp
Warning:line 2453, column 5
Use of memory after it is freed

Annotated Source Code

1//===- SROA.cpp - Scalar Replacement Of Aggregates ------------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9/// \file
10/// This transformation implements the well known scalar replacement of
11/// aggregates transformation. It tries to identify promotable elements of an
12/// aggregate alloca, and promote them to registers. It will also try to
13/// convert uses of an element (or set of elements) of an alloca into a vector
14/// or bitfield-style integer scalar if appropriate.
15///
16/// It works to do this with minimal slicing of the alloca so that regions
17/// which are merely transferred in and out of external memory remain unchanged
18/// and are not decomposed to scalar code.
19///
20/// Because this also performs alloca promotion, it can be thought of as also
21/// serving the purpose of SSA formation. The algorithm iterates on the
22/// function until all opportunities for promotion have been realized.
23///
24//===----------------------------------------------------------------------===//
25
26#include "llvm/Transforms/Scalar/SROA.h"
27#include "llvm/ADT/STLExtras.h"
28#include "llvm/ADT/SetVector.h"
29#include "llvm/ADT/SmallVector.h"
30#include "llvm/ADT/Statistic.h"
31#include "llvm/Analysis/AssumptionCache.h"
32#include "llvm/Analysis/GlobalsModRef.h"
33#include "llvm/Analysis/Loads.h"
34#include "llvm/Analysis/PtrUseVisitor.h"
35#include "llvm/Analysis/ValueTracking.h"
36#include "llvm/IR/Constants.h"
37#include "llvm/IR/DIBuilder.h"
38#include "llvm/IR/DataLayout.h"
39#include "llvm/IR/DebugInfo.h"
40#include "llvm/IR/DerivedTypes.h"
41#include "llvm/IR/IRBuilder.h"
42#include "llvm/IR/InstVisitor.h"
43#include "llvm/IR/Instructions.h"
44#include "llvm/IR/IntrinsicInst.h"
45#include "llvm/IR/LLVMContext.h"
46#include "llvm/IR/Operator.h"
47#include "llvm/Pass.h"
48#include "llvm/Support/Chrono.h"
49#include "llvm/Support/CommandLine.h"
50#include "llvm/Support/Compiler.h"
51#include "llvm/Support/Debug.h"
52#include "llvm/Support/ErrorHandling.h"
53#include "llvm/Support/MathExtras.h"
54#include "llvm/Support/raw_ostream.h"
55#include "llvm/Transforms/Scalar.h"
56#include "llvm/Transforms/Utils/Local.h"
57#include "llvm/Transforms/Utils/PromoteMemToReg.h"
58
59#ifndef NDEBUG
60// We only use this for a debug check.
61#include <random>
62#endif
63
64using namespace llvm;
65using namespace llvm::sroa;
66
67#define DEBUG_TYPE"sroa" "sroa"
68
69STATISTIC(NumAllocasAnalyzed, "Number of allocas analyzed for replacement")static llvm::Statistic NumAllocasAnalyzed = {"sroa", "NumAllocasAnalyzed"
, "Number of allocas analyzed for replacement", {0}, false}
;
70STATISTIC(NumAllocaPartitions, "Number of alloca partitions formed")static llvm::Statistic NumAllocaPartitions = {"sroa", "NumAllocaPartitions"
, "Number of alloca partitions formed", {0}, false}
;
71STATISTIC(MaxPartitionsPerAlloca, "Maximum number of partitions per alloca")static llvm::Statistic MaxPartitionsPerAlloca = {"sroa", "MaxPartitionsPerAlloca"
, "Maximum number of partitions per alloca", {0}, false}
;
72STATISTIC(NumAllocaPartitionUses, "Number of alloca partition uses rewritten")static llvm::Statistic NumAllocaPartitionUses = {"sroa", "NumAllocaPartitionUses"
, "Number of alloca partition uses rewritten", {0}, false}
;
73STATISTIC(MaxUsesPerAllocaPartition, "Maximum number of uses of a partition")static llvm::Statistic MaxUsesPerAllocaPartition = {"sroa", "MaxUsesPerAllocaPartition"
, "Maximum number of uses of a partition", {0}, false}
;
74STATISTIC(NumNewAllocas, "Number of new, smaller allocas introduced")static llvm::Statistic NumNewAllocas = {"sroa", "NumNewAllocas"
, "Number of new, smaller allocas introduced", {0}, false}
;
75STATISTIC(NumPromoted, "Number of allocas promoted to SSA values")static llvm::Statistic NumPromoted = {"sroa", "NumPromoted", "Number of allocas promoted to SSA values"
, {0}, false}
;
76STATISTIC(NumLoadsSpeculated, "Number of loads speculated to allow promotion")static llvm::Statistic NumLoadsSpeculated = {"sroa", "NumLoadsSpeculated"
, "Number of loads speculated to allow promotion", {0}, false
}
;
77STATISTIC(NumDeleted, "Number of instructions deleted")static llvm::Statistic NumDeleted = {"sroa", "NumDeleted", "Number of instructions deleted"
, {0}, false}
;
78STATISTIC(NumVectorized, "Number of vectorized aggregates")static llvm::Statistic NumVectorized = {"sroa", "NumVectorized"
, "Number of vectorized aggregates", {0}, false}
;
79
80/// Hidden option to enable randomly shuffling the slices to help uncover
81/// instability in their order.
82static cl::opt<bool> SROARandomShuffleSlices("sroa-random-shuffle-slices",
83 cl::init(false), cl::Hidden);
84
85/// Hidden option to experiment with completely strict handling of inbounds
86/// GEPs.
87static cl::opt<bool> SROAStrictInbounds("sroa-strict-inbounds", cl::init(false),
88 cl::Hidden);
89
90namespace {
91/// \brief A custom IRBuilder inserter which prefixes all names, but only in
92/// Assert builds.
93class IRBuilderPrefixedInserter : public IRBuilderDefaultInserter {
94 std::string Prefix;
95 const Twine getNameWithPrefix(const Twine &Name) const {
96 return Name.isTriviallyEmpty() ? Name : Prefix + Name;
97 }
98
99public:
100 void SetNamePrefix(const Twine &P) { Prefix = P.str(); }
101
102protected:
103 void InsertHelper(Instruction *I, const Twine &Name, BasicBlock *BB,
104 BasicBlock::iterator InsertPt) const {
105 IRBuilderDefaultInserter::InsertHelper(I, getNameWithPrefix(Name), BB,
106 InsertPt);
107 }
108};
109
110/// \brief Provide a typedef for IRBuilder that drops names in release builds.
111using IRBuilderTy = llvm::IRBuilder<ConstantFolder, IRBuilderPrefixedInserter>;
112}
113
114namespace {
115/// \brief A used slice of an alloca.
116///
117/// This structure represents a slice of an alloca used by some instruction. It
118/// stores both the begin and end offsets of this use, a pointer to the use
119/// itself, and a flag indicating whether we can classify the use as splittable
120/// or not when forming partitions of the alloca.
121class Slice {
122 /// \brief The beginning offset of the range.
123 uint64_t BeginOffset;
124
125 /// \brief The ending offset, not included in the range.
126 uint64_t EndOffset;
127
128 /// \brief Storage for both the use of this slice and whether it can be
129 /// split.
130 PointerIntPair<Use *, 1, bool> UseAndIsSplittable;
131
132public:
133 Slice() : BeginOffset(), EndOffset() {}
134 Slice(uint64_t BeginOffset, uint64_t EndOffset, Use *U, bool IsSplittable)
135 : BeginOffset(BeginOffset), EndOffset(EndOffset),
136 UseAndIsSplittable(U, IsSplittable) {}
137
138 uint64_t beginOffset() const { return BeginOffset; }
139 uint64_t endOffset() const { return EndOffset; }
140
141 bool isSplittable() const { return UseAndIsSplittable.getInt(); }
142 void makeUnsplittable() { UseAndIsSplittable.setInt(false); }
143
144 Use *getUse() const { return UseAndIsSplittable.getPointer(); }
145
146 bool isDead() const { return getUse() == nullptr; }
147 void kill() { UseAndIsSplittable.setPointer(nullptr); }
148
149 /// \brief Support for ordering ranges.
150 ///
151 /// This provides an ordering over ranges such that start offsets are
152 /// always increasing, and within equal start offsets, the end offsets are
153 /// decreasing. Thus the spanning range comes first in a cluster with the
154 /// same start position.
155 bool operator<(const Slice &RHS) const {
156 if (beginOffset() < RHS.beginOffset())
157 return true;
158 if (beginOffset() > RHS.beginOffset())
159 return false;
160 if (isSplittable() != RHS.isSplittable())
161 return !isSplittable();
162 if (endOffset() > RHS.endOffset())
163 return true;
164 return false;
165 }
166
167 /// \brief Support comparison with a single offset to allow binary searches.
168 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(const Slice &LHS,
169 uint64_t RHSOffset) {
170 return LHS.beginOffset() < RHSOffset;
171 }
172 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(uint64_t LHSOffset,
173 const Slice &RHS) {
174 return LHSOffset < RHS.beginOffset();
175 }
176
177 bool operator==(const Slice &RHS) const {
178 return isSplittable() == RHS.isSplittable() &&
179 beginOffset() == RHS.beginOffset() && endOffset() == RHS.endOffset();
180 }
181 bool operator!=(const Slice &RHS) const { return !operator==(RHS); }
182};
183} // end anonymous namespace
184
185namespace llvm {
186template <typename T> struct isPodLike;
187template <> struct isPodLike<Slice> { static const bool value = true; };
188}
189
190/// \brief Representation of the alloca slices.
191///
192/// This class represents the slices of an alloca which are formed by its
193/// various uses. If a pointer escapes, we can't fully build a representation
194/// for the slices used and we reflect that in this structure. The uses are
195/// stored, sorted by increasing beginning offset and with unsplittable slices
196/// starting at a particular offset before splittable slices.
197class llvm::sroa::AllocaSlices {
198public:
199 /// \brief Construct the slices of a particular alloca.
200 AllocaSlices(const DataLayout &DL, AllocaInst &AI);
201
202 /// \brief Test whether a pointer to the allocation escapes our analysis.
203 ///
204 /// If this is true, the slices are never fully built and should be
205 /// ignored.
206 bool isEscaped() const { return PointerEscapingInstr; }
207
208 /// \brief Support for iterating over the slices.
209 /// @{
210 typedef SmallVectorImpl<Slice>::iterator iterator;
211 typedef iterator_range<iterator> range;
212 iterator begin() { return Slices.begin(); }
213 iterator end() { return Slices.end(); }
214
215 typedef SmallVectorImpl<Slice>::const_iterator const_iterator;
216 typedef iterator_range<const_iterator> const_range;
217 const_iterator begin() const { return Slices.begin(); }
218 const_iterator end() const { return Slices.end(); }
219 /// @}
220
221 /// \brief Erase a range of slices.
222 void erase(iterator Start, iterator Stop) { Slices.erase(Start, Stop); }
223
224 /// \brief Insert new slices for this alloca.
225 ///
226 /// This moves the slices into the alloca's slices collection, and re-sorts
227 /// everything so that the usual ordering properties of the alloca's slices
228 /// hold.
229 void insert(ArrayRef<Slice> NewSlices) {
230 int OldSize = Slices.size();
231 Slices.append(NewSlices.begin(), NewSlices.end());
232 auto SliceI = Slices.begin() + OldSize;
233 std::sort(SliceI, Slices.end());
234 std::inplace_merge(Slices.begin(), SliceI, Slices.end());
235 }
236
237 // Forward declare the iterator and range accessor for walking the
238 // partitions.
239 class partition_iterator;
240 iterator_range<partition_iterator> partitions();
241
242 /// \brief Access the dead users for this alloca.
243 ArrayRef<Instruction *> getDeadUsers() const { return DeadUsers; }
244
245 /// \brief Access the dead operands referring to this alloca.
246 ///
247 /// These are operands which have cannot actually be used to refer to the
248 /// alloca as they are outside its range and the user doesn't correct for
249 /// that. These mostly consist of PHI node inputs and the like which we just
250 /// need to replace with undef.
251 ArrayRef<Use *> getDeadOperands() const { return DeadOperands; }
252
253#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
254 void print(raw_ostream &OS, const_iterator I, StringRef Indent = " ") const;
255 void printSlice(raw_ostream &OS, const_iterator I,
256 StringRef Indent = " ") const;
257 void printUse(raw_ostream &OS, const_iterator I,
258 StringRef Indent = " ") const;
259 void print(raw_ostream &OS) const;
260 void dump(const_iterator I) const;
261 void dump() const;
262#endif
263
264private:
265 template <typename DerivedT, typename RetT = void> class BuilderBase;
266 class SliceBuilder;
267 friend class AllocaSlices::SliceBuilder;
268
269#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
270 /// \brief Handle to alloca instruction to simplify method interfaces.
271 AllocaInst &AI;
272#endif
273
274 /// \brief The instruction responsible for this alloca not having a known set
275 /// of slices.
276 ///
277 /// When an instruction (potentially) escapes the pointer to the alloca, we
278 /// store a pointer to that here and abort trying to form slices of the
279 /// alloca. This will be null if the alloca slices are analyzed successfully.
280 Instruction *PointerEscapingInstr;
281
282 /// \brief The slices of the alloca.
283 ///
284 /// We store a vector of the slices formed by uses of the alloca here. This
285 /// vector is sorted by increasing begin offset, and then the unsplittable
286 /// slices before the splittable ones. See the Slice inner class for more
287 /// details.
288 SmallVector<Slice, 8> Slices;
289
290 /// \brief Instructions which will become dead if we rewrite the alloca.
291 ///
292 /// Note that these are not separated by slice. This is because we expect an
293 /// alloca to be completely rewritten or not rewritten at all. If rewritten,
294 /// all these instructions can simply be removed and replaced with undef as
295 /// they come from outside of the allocated space.
296 SmallVector<Instruction *, 8> DeadUsers;
297
298 /// \brief Operands which will become dead if we rewrite the alloca.
299 ///
300 /// These are operands that in their particular use can be replaced with
301 /// undef when we rewrite the alloca. These show up in out-of-bounds inputs
302 /// to PHI nodes and the like. They aren't entirely dead (there might be
303 /// a GEP back into the bounds using it elsewhere) and nor is the PHI, but we
304 /// want to swap this particular input for undef to simplify the use lists of
305 /// the alloca.
306 SmallVector<Use *, 8> DeadOperands;
307};
308
309/// \brief A partition of the slices.
310///
311/// An ephemeral representation for a range of slices which can be viewed as
312/// a partition of the alloca. This range represents a span of the alloca's
313/// memory which cannot be split, and provides access to all of the slices
314/// overlapping some part of the partition.
315///
316/// Objects of this type are produced by traversing the alloca's slices, but
317/// are only ephemeral and not persistent.
318class llvm::sroa::Partition {
319private:
320 friend class AllocaSlices;
321 friend class AllocaSlices::partition_iterator;
322
323 typedef AllocaSlices::iterator iterator;
324
325 /// \brief The beginning and ending offsets of the alloca for this
326 /// partition.
327 uint64_t BeginOffset, EndOffset;
328
329 /// \brief The start end end iterators of this partition.
330 iterator SI, SJ;
331
332 /// \brief A collection of split slice tails overlapping the partition.
333 SmallVector<Slice *, 4> SplitTails;
334
335 /// \brief Raw constructor builds an empty partition starting and ending at
336 /// the given iterator.
337 Partition(iterator SI) : SI(SI), SJ(SI) {}
338
339public:
340 /// \brief The start offset of this partition.
341 ///
342 /// All of the contained slices start at or after this offset.
343 uint64_t beginOffset() const { return BeginOffset; }
344
345 /// \brief The end offset of this partition.
346 ///
347 /// All of the contained slices end at or before this offset.
348 uint64_t endOffset() const { return EndOffset; }
349
350 /// \brief The size of the partition.
351 ///
352 /// Note that this can never be zero.
353 uint64_t size() const {
354 assert(BeginOffset < EndOffset && "Partitions must span some bytes!")((BeginOffset < EndOffset && "Partitions must span some bytes!"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset < EndOffset && \"Partitions must span some bytes!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 354, __PRETTY_FUNCTION__))
;
355 return EndOffset - BeginOffset;
356 }
357
358 /// \brief Test whether this partition contains no slices, and merely spans
359 /// a region occupied by split slices.
360 bool empty() const { return SI == SJ; }
361
362 /// \name Iterate slices that start within the partition.
363 /// These may be splittable or unsplittable. They have a begin offset >= the
364 /// partition begin offset.
365 /// @{
366 // FIXME: We should probably define a "concat_iterator" helper and use that
367 // to stitch together pointee_iterators over the split tails and the
368 // contiguous iterators of the partition. That would give a much nicer
369 // interface here. We could then additionally expose filtered iterators for
370 // split, unsplit, and unsplittable splices based on the usage patterns.
371 iterator begin() const { return SI; }
372 iterator end() const { return SJ; }
373 /// @}
374
375 /// \brief Get the sequence of split slice tails.
376 ///
377 /// These tails are of slices which start before this partition but are
378 /// split and overlap into the partition. We accumulate these while forming
379 /// partitions.
380 ArrayRef<Slice *> splitSliceTails() const { return SplitTails; }
381};
382
383/// \brief An iterator over partitions of the alloca's slices.
384///
385/// This iterator implements the core algorithm for partitioning the alloca's
386/// slices. It is a forward iterator as we don't support backtracking for
387/// efficiency reasons, and re-use a single storage area to maintain the
388/// current set of split slices.
389///
390/// It is templated on the slice iterator type to use so that it can operate
391/// with either const or non-const slice iterators.
392class AllocaSlices::partition_iterator
393 : public iterator_facade_base<partition_iterator, std::forward_iterator_tag,
394 Partition> {
395 friend class AllocaSlices;
396
397 /// \brief Most of the state for walking the partitions is held in a class
398 /// with a nice interface for examining them.
399 Partition P;
400
401 /// \brief We need to keep the end of the slices to know when to stop.
402 AllocaSlices::iterator SE;
403
404 /// \brief We also need to keep track of the maximum split end offset seen.
405 /// FIXME: Do we really?
406 uint64_t MaxSplitSliceEndOffset;
407
408 /// \brief Sets the partition to be empty at given iterator, and sets the
409 /// end iterator.
410 partition_iterator(AllocaSlices::iterator SI, AllocaSlices::iterator SE)
411 : P(SI), SE(SE), MaxSplitSliceEndOffset(0) {
412 // If not already at the end, advance our state to form the initial
413 // partition.
414 if (SI != SE)
415 advance();
416 }
417
418 /// \brief Advance the iterator to the next partition.
419 ///
420 /// Requires that the iterator not be at the end of the slices.
421 void advance() {
422 assert((P.SI != SE || !P.SplitTails.empty()) &&(((P.SI != SE || !P.SplitTails.empty()) && "Cannot advance past the end of the slices!"
) ? static_cast<void> (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 423, __PRETTY_FUNCTION__))
423 "Cannot advance past the end of the slices!")(((P.SI != SE || !P.SplitTails.empty()) && "Cannot advance past the end of the slices!"
) ? static_cast<void> (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 423, __PRETTY_FUNCTION__))
;
424
425 // Clear out any split uses which have ended.
426 if (!P.SplitTails.empty()) {
427 if (P.EndOffset >= MaxSplitSliceEndOffset) {
428 // If we've finished all splits, this is easy.
429 P.SplitTails.clear();
430 MaxSplitSliceEndOffset = 0;
431 } else {
432 // Remove the uses which have ended in the prior partition. This
433 // cannot change the max split slice end because we just checked that
434 // the prior partition ended prior to that max.
435 P.SplitTails.erase(
436 remove_if(P.SplitTails,
437 [&](Slice *S) { return S->endOffset() <= P.EndOffset; }),
438 P.SplitTails.end());
439 assert(any_of(P.SplitTails,((any_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 443, __PRETTY_FUNCTION__))
440 [&](Slice *S) {((any_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 443, __PRETTY_FUNCTION__))
441 return S->endOffset() == MaxSplitSliceEndOffset;((any_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 443, __PRETTY_FUNCTION__))
442 }) &&((any_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 443, __PRETTY_FUNCTION__))
443 "Could not find the current max split slice offset!")((any_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() == MaxSplitSliceEndOffset; }) && "Could not find the current max split slice offset!"
) ? static_cast<void> (0) : __assert_fail ("any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 443, __PRETTY_FUNCTION__))
;
444 assert(all_of(P.SplitTails,((all_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 448, __PRETTY_FUNCTION__))
445 [&](Slice *S) {((all_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 448, __PRETTY_FUNCTION__))
446 return S->endOffset() <= MaxSplitSliceEndOffset;((all_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 448, __PRETTY_FUNCTION__))
447 }) &&((all_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 448, __PRETTY_FUNCTION__))
448 "Max split slice end offset is not actually the max!")((all_of(P.SplitTails, [&](Slice *S) { return S->endOffset
() <= MaxSplitSliceEndOffset; }) && "Max split slice end offset is not actually the max!"
) ? static_cast<void> (0) : __assert_fail ("all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 448, __PRETTY_FUNCTION__))
;
449 }
450 }
451
452 // If P.SI is already at the end, then we've cleared the split tail and
453 // now have an end iterator.
454 if (P.SI == SE) {
455 assert(P.SplitTails.empty() && "Failed to clear the split slices!")((P.SplitTails.empty() && "Failed to clear the split slices!"
) ? static_cast<void> (0) : __assert_fail ("P.SplitTails.empty() && \"Failed to clear the split slices!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 455, __PRETTY_FUNCTION__))
;
456 return;
457 }
458
459 // If we had a non-empty partition previously, set up the state for
460 // subsequent partitions.
461 if (P.SI != P.SJ) {
462 // Accumulate all the splittable slices which started in the old
463 // partition into the split list.
464 for (Slice &S : P)
465 if (S.isSplittable() && S.endOffset() > P.EndOffset) {
466 P.SplitTails.push_back(&S);
467 MaxSplitSliceEndOffset =
468 std::max(S.endOffset(), MaxSplitSliceEndOffset);
469 }
470
471 // Start from the end of the previous partition.
472 P.SI = P.SJ;
473
474 // If P.SI is now at the end, we at most have a tail of split slices.
475 if (P.SI == SE) {
476 P.BeginOffset = P.EndOffset;
477 P.EndOffset = MaxSplitSliceEndOffset;
478 return;
479 }
480
481 // If the we have split slices and the next slice is after a gap and is
482 // not splittable immediately form an empty partition for the split
483 // slices up until the next slice begins.
484 if (!P.SplitTails.empty() && P.SI->beginOffset() != P.EndOffset &&
485 !P.SI->isSplittable()) {
486 P.BeginOffset = P.EndOffset;
487 P.EndOffset = P.SI->beginOffset();
488 return;
489 }
490 }
491
492 // OK, we need to consume new slices. Set the end offset based on the
493 // current slice, and step SJ past it. The beginning offset of the
494 // partition is the beginning offset of the next slice unless we have
495 // pre-existing split slices that are continuing, in which case we begin
496 // at the prior end offset.
497 P.BeginOffset = P.SplitTails.empty() ? P.SI->beginOffset() : P.EndOffset;
498 P.EndOffset = P.SI->endOffset();
499 ++P.SJ;
500
501 // There are two strategies to form a partition based on whether the
502 // partition starts with an unsplittable slice or a splittable slice.
503 if (!P.SI->isSplittable()) {
504 // When we're forming an unsplittable region, it must always start at
505 // the first slice and will extend through its end.
506 assert(P.BeginOffset == P.SI->beginOffset())((P.BeginOffset == P.SI->beginOffset()) ? static_cast<void
> (0) : __assert_fail ("P.BeginOffset == P.SI->beginOffset()"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 506, __PRETTY_FUNCTION__))
;
507
508 // Form a partition including all of the overlapping slices with this
509 // unsplittable slice.
510 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
511 if (!P.SJ->isSplittable())
512 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
513 ++P.SJ;
514 }
515
516 // We have a partition across a set of overlapping unsplittable
517 // partitions.
518 return;
519 }
520
521 // If we're starting with a splittable slice, then we need to form
522 // a synthetic partition spanning it and any other overlapping splittable
523 // splices.
524 assert(P.SI->isSplittable() && "Forming a splittable partition!")((P.SI->isSplittable() && "Forming a splittable partition!"
) ? static_cast<void> (0) : __assert_fail ("P.SI->isSplittable() && \"Forming a splittable partition!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 524, __PRETTY_FUNCTION__))
;
525
526 // Collect all of the overlapping splittable slices.
527 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset &&
528 P.SJ->isSplittable()) {
529 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
530 ++P.SJ;
531 }
532
533 // Back upiP.EndOffset if we ended the span early when encountering an
534 // unsplittable slice. This synthesizes the early end offset of
535 // a partition spanning only splittable slices.
536 if (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
537 assert(!P.SJ->isSplittable())((!P.SJ->isSplittable()) ? static_cast<void> (0) : __assert_fail
("!P.SJ->isSplittable()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 537, __PRETTY_FUNCTION__))
;
538 P.EndOffset = P.SJ->beginOffset();
539 }
540 }
541
542public:
543 bool operator==(const partition_iterator &RHS) const {
544 assert(SE == RHS.SE &&((SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? static_cast<void> (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 545, __PRETTY_FUNCTION__))
545 "End iterators don't match between compared partition iterators!")((SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? static_cast<void> (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 545, __PRETTY_FUNCTION__))
;
546
547 // The observed positions of partitions is marked by the P.SI iterator and
548 // the emptiness of the split slices. The latter is only relevant when
549 // P.SI == SE, as the end iterator will additionally have an empty split
550 // slices list, but the prior may have the same P.SI and a tail of split
551 // slices.
552 if (P.SI == RHS.P.SI && P.SplitTails.empty() == RHS.P.SplitTails.empty()) {
553 assert(P.SJ == RHS.P.SJ &&((P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? static_cast<void> (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 554, __PRETTY_FUNCTION__))
554 "Same set of slices formed two different sized partitions!")((P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? static_cast<void> (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 554, __PRETTY_FUNCTION__))
;
555 assert(P.SplitTails.size() == RHS.P.SplitTails.size() &&((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 557, __PRETTY_FUNCTION__))
556 "Same slice position with differently sized non-empty split "((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 557, __PRETTY_FUNCTION__))
557 "slice tails!")((P.SplitTails.size() == RHS.P.SplitTails.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? static_cast<void> (0) : __assert_fail
("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 557, __PRETTY_FUNCTION__))
;
558 return true;
559 }
560 return false;
561 }
562
563 partition_iterator &operator++() {
564 advance();
565 return *this;
566 }
567
568 Partition &operator*() { return P; }
569};
570
571/// \brief A forward range over the partitions of the alloca's slices.
572///
573/// This accesses an iterator range over the partitions of the alloca's
574/// slices. It computes these partitions on the fly based on the overlapping
575/// offsets of the slices and the ability to split them. It will visit "empty"
576/// partitions to cover regions of the alloca only accessed via split
577/// slices.
578iterator_range<AllocaSlices::partition_iterator> AllocaSlices::partitions() {
579 return make_range(partition_iterator(begin(), end()),
580 partition_iterator(end(), end()));
581}
582
583static Value *foldSelectInst(SelectInst &SI) {
584 // If the condition being selected on is a constant or the same value is
585 // being selected between, fold the select. Yes this does (rarely) happen
586 // early on.
587 if (ConstantInt *CI = dyn_cast<ConstantInt>(SI.getCondition()))
588 return SI.getOperand(1 + CI->isZero());
589 if (SI.getOperand(1) == SI.getOperand(2))
590 return SI.getOperand(1);
591
592 return nullptr;
593}
594
595/// \brief A helper that folds a PHI node or a select.
596static Value *foldPHINodeOrSelectInst(Instruction &I) {
597 if (PHINode *PN = dyn_cast<PHINode>(&I)) {
598 // If PN merges together the same value, return that value.
599 return PN->hasConstantValue();
600 }
601 return foldSelectInst(cast<SelectInst>(I));
602}
603
604/// \brief Builder for the alloca slices.
605///
606/// This class builds a set of alloca slices by recursively visiting the uses
607/// of an alloca and making a slice for each load and store at each offset.
608class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
609 friend class PtrUseVisitor<SliceBuilder>;
610 friend class InstVisitor<SliceBuilder>;
611 typedef PtrUseVisitor<SliceBuilder> Base;
612
613 const uint64_t AllocSize;
614 AllocaSlices &AS;
615
616 SmallDenseMap<Instruction *, unsigned> MemTransferSliceMap;
617 SmallDenseMap<Instruction *, uint64_t> PHIOrSelectSizes;
618
619 /// \brief Set to de-duplicate dead instructions found in the use walk.
620 SmallPtrSet<Instruction *, 4> VisitedDeadInsts;
621
622public:
623 SliceBuilder(const DataLayout &DL, AllocaInst &AI, AllocaSlices &AS)
624 : PtrUseVisitor<SliceBuilder>(DL),
625 AllocSize(DL.getTypeAllocSize(AI.getAllocatedType())), AS(AS) {}
626
627private:
628 void markAsDead(Instruction &I) {
629 if (VisitedDeadInsts.insert(&I).second)
630 AS.DeadUsers.push_back(&I);
631 }
632
633 void insertUse(Instruction &I, const APInt &Offset, uint64_t Size,
634 bool IsSplittable = false) {
635 // Completely skip uses which have a zero size or start either before or
636 // past the end of the allocation.
637 if (Size == 0 || Offset.uge(AllocSize)) {
638 DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte use @" << 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)
639 << " 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)
640 << 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)
641 << " 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)
642 << " 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)
;
643 return markAsDead(I);
644 }
645
646 uint64_t BeginOffset = Offset.getZExtValue();
647 uint64_t EndOffset = BeginOffset + Size;
648
649 // Clamp the end offset to the end of the allocation. Note that this is
650 // formulated to handle even the case where "BeginOffset + Size" overflows.
651 // This may appear superficially to be something we could ignore entirely,
652 // but that is not so! There may be widened loads or PHI-node uses where
653 // some instructions are dead but not others. We can't completely ignore
654 // them, and so have to record at least the information here.
655 assert(AllocSize >= BeginOffset)((AllocSize >= BeginOffset) ? static_cast<void> (0) :
__assert_fail ("AllocSize >= BeginOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 655, __PRETTY_FUNCTION__))
; // Established above.
656 if (Size > AllocSize - BeginOffset) {
657 DEBUG(dbgs() << "WARNING: Clamping a " << Size << " byte use @" << Offsetdo { 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)
658 << " to remain within the " << AllocSize << " 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)
659 << " 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)
660 << " 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)
;
661 EndOffset = AllocSize;
662 }
663
664 AS.Slices.push_back(Slice(BeginOffset, EndOffset, U, IsSplittable));
665 }
666
667 void visitBitCastInst(BitCastInst &BC) {
668 if (BC.use_empty())
669 return markAsDead(BC);
670
671 return Base::visitBitCastInst(BC);
672 }
673
674 void visitGetElementPtrInst(GetElementPtrInst &GEPI) {
675 if (GEPI.use_empty())
676 return markAsDead(GEPI);
677
678 if (SROAStrictInbounds && GEPI.isInBounds()) {
679 // FIXME: This is a manually un-factored variant of the basic code inside
680 // of GEPs with checking of the inbounds invariant specified in the
681 // langref in a very strict sense. If we ever want to enable
682 // SROAStrictInbounds, this code should be factored cleanly into
683 // PtrUseVisitor, but it is easier to experiment with SROAStrictInbounds
684 // by writing out the code here where we have the underlying allocation
685 // size readily available.
686 APInt GEPOffset = Offset;
687 const DataLayout &DL = GEPI.getModule()->getDataLayout();
688 for (gep_type_iterator GTI = gep_type_begin(GEPI),
689 GTE = gep_type_end(GEPI);
690 GTI != GTE; ++GTI) {
691 ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
692 if (!OpC)
693 break;
694
695 // Handle a struct index, which adds its field offset to the pointer.
696 if (StructType *STy = GTI.getStructTypeOrNull()) {
697 unsigned ElementIdx = OpC->getZExtValue();
698 const StructLayout *SL = DL.getStructLayout(STy);
699 GEPOffset +=
700 APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx));
701 } else {
702 // For array or vector indices, scale the index by the size of the
703 // type.
704 APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth());
705 GEPOffset += Index * APInt(Offset.getBitWidth(),
706 DL.getTypeAllocSize(GTI.getIndexedType()));
707 }
708
709 // If this index has computed an intermediate pointer which is not
710 // inbounds, then the result of the GEP is a poison value and we can
711 // delete it and all uses.
712 if (GEPOffset.ugt(AllocSize))
713 return markAsDead(GEPI);
714 }
715 }
716
717 return Base::visitGetElementPtrInst(GEPI);
718 }
719
720 void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset,
721 uint64_t Size, bool IsVolatile) {
722 // We allow splitting of non-volatile loads and stores where the type is an
723 // integer type. These may be used to implement 'memcpy' or other "transfer
724 // of bits" patterns.
725 bool IsSplittable = Ty->isIntegerTy() && !IsVolatile;
726
727 insertUse(I, Offset, Size, IsSplittable);
728 }
729
730 void visitLoadInst(LoadInst &LI) {
731 assert((!LI.isSimple() || LI.getType()->isSingleValueType()) &&(((!LI.isSimple() || LI.getType()->isSingleValueType()) &&
"All simple FCA loads should have been pre-split") ? static_cast
<void> (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 732, __PRETTY_FUNCTION__))
732 "All simple FCA loads should have been pre-split")(((!LI.isSimple() || LI.getType()->isSingleValueType()) &&
"All simple FCA loads should have been pre-split") ? static_cast
<void> (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 732, __PRETTY_FUNCTION__))
;
733
734 if (!IsOffsetKnown)
735 return PI.setAborted(&LI);
736
737 const DataLayout &DL = LI.getModule()->getDataLayout();
738 uint64_t Size = DL.getTypeStoreSize(LI.getType());
739 return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
740 }
741
742 void visitStoreInst(StoreInst &SI) {
743 Value *ValOp = SI.getValueOperand();
744 if (ValOp == *U)
745 return PI.setEscapedAndAborted(&SI);
746 if (!IsOffsetKnown)
747 return PI.setAborted(&SI);
748
749 const DataLayout &DL = SI.getModule()->getDataLayout();
750 uint64_t Size = DL.getTypeStoreSize(ValOp->getType());
751
752 // If this memory access can be shown to *statically* extend outside the
753 // bounds of of the allocation, it's behavior is undefined, so simply
754 // ignore it. Note that this is more strict than the generic clamping
755 // behavior of insertUse. We also try to handle cases which might run the
756 // risk of overflow.
757 // FIXME: We should instead consider the pointer to have escaped if this
758 // function is being instrumented for addressing bugs or race conditions.
759 if (Size > AllocSize || Offset.ugt(AllocSize - Size)) {
760 DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte store @" << Offsetdo { 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)
761 << " which extends past the end of the " << AllocSizedo { 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)
762 << " 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)
763 << " 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)
764 << " 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)
;
765 return markAsDead(SI);
766 }
767
768 assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&(((!SI.isSimple() || ValOp->getType()->isSingleValueType
()) && "All simple FCA stores should have been pre-split"
) ? static_cast<void> (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 769, __PRETTY_FUNCTION__))
769 "All simple FCA stores should have been pre-split")(((!SI.isSimple() || ValOp->getType()->isSingleValueType
()) && "All simple FCA stores should have been pre-split"
) ? static_cast<void> (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 769, __PRETTY_FUNCTION__))
;
770 handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
771 }
772
773 void visitMemSetInst(MemSetInst &II) {
774 assert(II.getRawDest() == *U && "Pointer use is not the destination?")((II.getRawDest() == *U && "Pointer use is not the destination?"
) ? static_cast<void> (0) : __assert_fail ("II.getRawDest() == *U && \"Pointer use is not the destination?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 774, __PRETTY_FUNCTION__))
;
775 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
776 if ((Length && Length->getValue() == 0) ||
777 (IsOffsetKnown && Offset.uge(AllocSize)))
778 // Zero-length mem transfer intrinsics can be ignored entirely.
779 return markAsDead(II);
780
781 if (!IsOffsetKnown)
782 return PI.setAborted(&II);
783
784 insertUse(II, Offset, Length ? Length->getLimitedValue()
785 : AllocSize - Offset.getLimitedValue(),
786 (bool)Length);
787 }
788
789 void visitMemTransferInst(MemTransferInst &II) {
790 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
791 if (Length && Length->getValue() == 0)
792 // Zero-length mem transfer intrinsics can be ignored entirely.
793 return markAsDead(II);
794
795 // Because we can visit these intrinsics twice, also check to see if the
796 // first time marked this instruction as dead. If so, skip it.
797 if (VisitedDeadInsts.count(&II))
798 return;
799
800 if (!IsOffsetKnown)
801 return PI.setAborted(&II);
802
803 // This side of the transfer is completely out-of-bounds, and so we can
804 // nuke the entire transfer. However, we also need to nuke the other side
805 // if already added to our partitions.
806 // FIXME: Yet another place we really should bypass this when
807 // instrumenting for ASan.
808 if (Offset.uge(AllocSize)) {
809 SmallDenseMap<Instruction *, unsigned>::iterator MTPI =
810 MemTransferSliceMap.find(&II);
811 if (MTPI != MemTransferSliceMap.end())
812 AS.Slices[MTPI->second].kill();
813 return markAsDead(II);
814 }
815
816 uint64_t RawOffset = Offset.getLimitedValue();
817 uint64_t Size = Length ? Length->getLimitedValue() : AllocSize - RawOffset;
818
819 // Check for the special case where the same exact value is used for both
820 // source and dest.
821 if (*U == II.getRawDest() && *U == II.getRawSource()) {
822 // For non-volatile transfers this is a no-op.
823 if (!II.isVolatile())
824 return markAsDead(II);
825
826 return insertUse(II, Offset, Size, /*IsSplittable=*/false);
827 }
828
829 // If we have seen both source and destination for a mem transfer, then
830 // they both point to the same alloca.
831 bool Inserted;
832 SmallDenseMap<Instruction *, unsigned>::iterator MTPI;
833 std::tie(MTPI, Inserted) =
834 MemTransferSliceMap.insert(std::make_pair(&II, AS.Slices.size()));
835 unsigned PrevIdx = MTPI->second;
836 if (!Inserted) {
837 Slice &PrevP = AS.Slices[PrevIdx];
838
839 // Check if the begin offsets match and this is a non-volatile transfer.
840 // In that case, we can completely elide the transfer.
841 if (!II.isVolatile() && PrevP.beginOffset() == RawOffset) {
842 PrevP.kill();
843 return markAsDead(II);
844 }
845
846 // Otherwise we have an offset transfer within the same alloca. We can't
847 // split those.
848 PrevP.makeUnsplittable();
849 }
850
851 // Insert the use now that we've fixed up the splittable nature.
852 insertUse(II, Offset, Size, /*IsSplittable=*/Inserted && Length);
853
854 // Check that we ended up with a valid index in the map.
855 assert(AS.Slices[PrevIdx].getUse()->getUser() == &II &&((AS.Slices[PrevIdx].getUse()->getUser() == &II &&
"Map index doesn't point back to a slice with this user.") ?
static_cast<void> (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 856, __PRETTY_FUNCTION__))
856 "Map index doesn't point back to a slice with this user.")((AS.Slices[PrevIdx].getUse()->getUser() == &II &&
"Map index doesn't point back to a slice with this user.") ?
static_cast<void> (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 856, __PRETTY_FUNCTION__))
;
857 }
858
859 // Disable SRoA for any intrinsics except for lifetime invariants.
860 // FIXME: What about debug intrinsics? This matches old behavior, but
861 // doesn't make sense.
862 void visitIntrinsicInst(IntrinsicInst &II) {
863 if (!IsOffsetKnown)
864 return PI.setAborted(&II);
865
866 if (II.getIntrinsicID() == Intrinsic::lifetime_start ||
867 II.getIntrinsicID() == Intrinsic::lifetime_end) {
868 ConstantInt *Length = cast<ConstantInt>(II.getArgOperand(0));
869 uint64_t Size = std::min(AllocSize - Offset.getLimitedValue(),
870 Length->getLimitedValue());
871 insertUse(II, Offset, Size, true);
872 return;
873 }
874
875 Base::visitIntrinsicInst(II);
876 }
877
878 Instruction *hasUnsafePHIOrSelectUse(Instruction *Root, uint64_t &Size) {
879 // We consider any PHI or select that results in a direct load or store of
880 // the same offset to be a viable use for slicing purposes. These uses
881 // are considered unsplittable and the size is the maximum loaded or stored
882 // size.
883 SmallPtrSet<Instruction *, 4> Visited;
884 SmallVector<std::pair<Instruction *, Instruction *>, 4> Uses;
885 Visited.insert(Root);
886 Uses.push_back(std::make_pair(cast<Instruction>(*U), Root));
887 const DataLayout &DL = Root->getModule()->getDataLayout();
888 // If there are no loads or stores, the access is dead. We mark that as
889 // a size zero access.
890 Size = 0;
891 do {
892 Instruction *I, *UsedI;
893 std::tie(UsedI, I) = Uses.pop_back_val();
894
895 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
896 Size = std::max(Size, DL.getTypeStoreSize(LI->getType()));
897 continue;
898 }
899 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
900 Value *Op = SI->getOperand(0);
901 if (Op == UsedI)
902 return SI;
903 Size = std::max(Size, DL.getTypeStoreSize(Op->getType()));
904 continue;
905 }
906
907 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
908 if (!GEP->hasAllZeroIndices())
909 return GEP;
910 } else if (!isa<BitCastInst>(I) && !isa<PHINode>(I) &&
911 !isa<SelectInst>(I)) {
912 return I;
913 }
914
915 for (User *U : I->users())
916 if (Visited.insert(cast<Instruction>(U)).second)
917 Uses.push_back(std::make_pair(I, cast<Instruction>(U)));
918 } while (!Uses.empty());
919
920 return nullptr;
921 }
922
923 void visitPHINodeOrSelectInst(Instruction &I) {
924 assert(isa<PHINode>(I) || isa<SelectInst>(I))((isa<PHINode>(I) || isa<SelectInst>(I)) ? static_cast
<void> (0) : __assert_fail ("isa<PHINode>(I) || isa<SelectInst>(I)"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 924, __PRETTY_FUNCTION__))
;
925 if (I.use_empty())
926 return markAsDead(I);
927
928 // TODO: We could use SimplifyInstruction here to fold PHINodes and
929 // SelectInsts. However, doing so requires to change the current
930 // dead-operand-tracking mechanism. For instance, suppose neither loading
931 // from %U nor %other traps. Then "load (select undef, %U, %other)" does not
932 // trap either. However, if we simply replace %U with undef using the
933 // current dead-operand-tracking mechanism, "load (select undef, undef,
934 // %other)" may trap because the select may return the first operand
935 // "undef".
936 if (Value *Result = foldPHINodeOrSelectInst(I)) {
937 if (Result == *U)
938 // If the result of the constant fold will be the pointer, recurse
939 // through the PHI/select as if we had RAUW'ed it.
940 enqueueUsers(I);
941 else
942 // Otherwise the operand to the PHI/select is dead, and we can replace
943 // it with undef.
944 AS.DeadOperands.push_back(U);
945
946 return;
947 }
948
949 if (!IsOffsetKnown)
950 return PI.setAborted(&I);
951
952 // See if we already have computed info on this node.
953 uint64_t &Size = PHIOrSelectSizes[&I];
954 if (!Size) {
955 // This is a new PHI/Select, check for an unsafe use of it.
956 if (Instruction *UnsafeI = hasUnsafePHIOrSelectUse(&I, Size))
957 return PI.setAborted(UnsafeI);
958 }
959
960 // For PHI and select operands outside the alloca, we can't nuke the entire
961 // phi or select -- the other side might still be relevant, so we special
962 // case them here and use a separate structure to track the operands
963 // themselves which should be replaced with undef.
964 // FIXME: This should instead be escaped in the event we're instrumenting
965 // for address sanitization.
966 if (Offset.uge(AllocSize)) {
967 AS.DeadOperands.push_back(U);
968 return;
969 }
970
971 insertUse(I, Offset, Size);
972 }
973
974 void visitPHINode(PHINode &PN) { visitPHINodeOrSelectInst(PN); }
975
976 void visitSelectInst(SelectInst &SI) { visitPHINodeOrSelectInst(SI); }
977
978 /// \brief Disable SROA entirely if there are unhandled users of the alloca.
979 void visitInstruction(Instruction &I) { PI.setAborted(&I); }
980};
981
982AllocaSlices::AllocaSlices(const DataLayout &DL, AllocaInst &AI)
983 :
984#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
985 AI(AI),
986#endif
987 PointerEscapingInstr(nullptr) {
988 SliceBuilder PB(DL, AI, *this);
989 SliceBuilder::PtrInfo PtrI = PB.visitPtr(AI);
990 if (PtrI.isEscaped() || PtrI.isAborted()) {
991 // FIXME: We should sink the escape vs. abort info into the caller nicely,
992 // possibly by just storing the PtrInfo in the AllocaSlices.
993 PointerEscapingInstr = PtrI.getEscapingInst() ? PtrI.getEscapingInst()
994 : PtrI.getAbortingInst();
995 assert(PointerEscapingInstr && "Did not track a bad instruction")((PointerEscapingInstr && "Did not track a bad instruction"
) ? static_cast<void> (0) : __assert_fail ("PointerEscapingInstr && \"Did not track a bad instruction\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 995, __PRETTY_FUNCTION__))
;
996 return;
997 }
998
999 Slices.erase(remove_if(Slices, [](const Slice &S) { return S.isDead(); }),
1000 Slices.end());
1001
1002#ifndef NDEBUG
1003 if (SROARandomShuffleSlices) {
1004 std::mt19937 MT(static_cast<unsigned>(
1005 std::chrono::system_clock::now().time_since_epoch().count()));
1006 std::shuffle(Slices.begin(), Slices.end(), MT);
1007 }
1008#endif
1009
1010 // Sort the uses. This arranges for the offsets to be in ascending order,
1011 // and the sizes to be in descending order.
1012 std::sort(Slices.begin(), Slices.end());
1013}
1014
1015#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1016
1017void AllocaSlices::print(raw_ostream &OS, const_iterator I,
1018 StringRef Indent) const {
1019 printSlice(OS, I, Indent);
1020 OS << "\n";
1021 printUse(OS, I, Indent);
1022}
1023
1024void AllocaSlices::printSlice(raw_ostream &OS, const_iterator I,
1025 StringRef Indent) const {
1026 OS << Indent << "[" << I->beginOffset() << "," << I->endOffset() << ")"
1027 << " slice #" << (I - begin())
1028 << (I->isSplittable() ? " (splittable)" : "");
1029}
1030
1031void AllocaSlices::printUse(raw_ostream &OS, const_iterator I,
1032 StringRef Indent) const {
1033 OS << Indent << " used by: " << *I->getUse()->getUser() << "\n";
1034}
1035
1036void AllocaSlices::print(raw_ostream &OS) const {
1037 if (PointerEscapingInstr) {
1038 OS << "Can't analyze slices for alloca: " << AI << "\n"
1039 << " A pointer to this alloca escaped by:\n"
1040 << " " << *PointerEscapingInstr << "\n";
1041 return;
1042 }
1043
1044 OS << "Slices of alloca: " << AI << "\n";
1045 for (const_iterator I = begin(), E = end(); I != E; ++I)
1046 print(OS, I);
1047}
1048
1049LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump(const_iterator I) const {
1050 print(dbgs(), I);
1051}
1052LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump() const { print(dbgs()); }
1053
1054#endif // !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1055
1056/// Walk the range of a partitioning looking for a common type to cover this
1057/// sequence of slices.
1058static Type *findCommonType(AllocaSlices::const_iterator B,
1059 AllocaSlices::const_iterator E,
1060 uint64_t EndOffset) {
1061 Type *Ty = nullptr;
1062 bool TyIsCommon = true;
1063 IntegerType *ITy = nullptr;
1064
1065 // Note that we need to look at *every* alloca slice's Use to ensure we
1066 // always get consistent results regardless of the order of slices.
1067 for (AllocaSlices::const_iterator I = B; I != E; ++I) {
1068 Use *U = I->getUse();
1069 if (isa<IntrinsicInst>(*U->getUser()))
1070 continue;
1071 if (I->beginOffset() != B->beginOffset() || I->endOffset() != EndOffset)
1072 continue;
1073
1074 Type *UserTy = nullptr;
1075 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1076 UserTy = LI->getType();
1077 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1078 UserTy = SI->getValueOperand()->getType();
1079 }
1080
1081 if (IntegerType *UserITy = dyn_cast_or_null<IntegerType>(UserTy)) {
1082 // If the type is larger than the partition, skip it. We only encounter
1083 // this for split integer operations where we want to use the type of the
1084 // entity causing the split. Also skip if the type is not a byte width
1085 // multiple.
1086 if (UserITy->getBitWidth() % 8 != 0 ||
1087 UserITy->getBitWidth() / 8 > (EndOffset - B->beginOffset()))
1088 continue;
1089
1090 // Track the largest bitwidth integer type used in this way in case there
1091 // is no common type.
1092 if (!ITy || ITy->getBitWidth() < UserITy->getBitWidth())
1093 ITy = UserITy;
1094 }
1095
1096 // To avoid depending on the order of slices, Ty and TyIsCommon must not
1097 // depend on types skipped above.
1098 if (!UserTy || (Ty && Ty != UserTy))
1099 TyIsCommon = false; // Give up on anything but an iN type.
1100 else
1101 Ty = UserTy;
1102 }
1103
1104 return TyIsCommon ? Ty : ITy;
1105}
1106
1107/// PHI instructions that use an alloca and are subsequently loaded can be
1108/// rewritten to load both input pointers in the pred blocks and then PHI the
1109/// results, allowing the load of the alloca to be promoted.
1110/// From this:
1111/// %P2 = phi [i32* %Alloca, i32* %Other]
1112/// %V = load i32* %P2
1113/// to:
1114/// %V1 = load i32* %Alloca -> will be mem2reg'd
1115/// ...
1116/// %V2 = load i32* %Other
1117/// ...
1118/// %V = phi [i32 %V1, i32 %V2]
1119///
1120/// We can do this to a select if its only uses are loads and if the operands
1121/// to the select can be loaded unconditionally.
1122///
1123/// FIXME: This should be hoisted into a generic utility, likely in
1124/// Transforms/Util/Local.h
1125static bool isSafePHIToSpeculate(PHINode &PN) {
1126 // For now, we can only do this promotion if the load is in the same block
1127 // as the PHI, and if there are no stores between the phi and load.
1128 // TODO: Allow recursive phi users.
1129 // TODO: Allow stores.
1130 BasicBlock *BB = PN.getParent();
1131 unsigned MaxAlign = 0;
1132 bool HaveLoad = false;
1133 for (User *U : PN.users()) {
1134 LoadInst *LI = dyn_cast<LoadInst>(U);
1135 if (!LI || !LI->isSimple())
1136 return false;
1137
1138 // For now we only allow loads in the same block as the PHI. This is
1139 // a common case that happens when instcombine merges two loads through
1140 // a PHI.
1141 if (LI->getParent() != BB)
1142 return false;
1143
1144 // Ensure that there are no instructions between the PHI and the load that
1145 // could store.
1146 for (BasicBlock::iterator BBI(PN); &*BBI != LI; ++BBI)
1147 if (BBI->mayWriteToMemory())
1148 return false;
1149
1150 MaxAlign = std::max(MaxAlign, LI->getAlignment());
1151 HaveLoad = true;
1152 }
1153
1154 if (!HaveLoad)
1155 return false;
1156
1157 const DataLayout &DL = PN.getModule()->getDataLayout();
1158
1159 // We can only transform this if it is safe to push the loads into the
1160 // predecessor blocks. The only thing to watch out for is that we can't put
1161 // a possibly trapping load in the predecessor if it is a critical edge.
1162 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1163 TerminatorInst *TI = PN.getIncomingBlock(Idx)->getTerminator();
1164 Value *InVal = PN.getIncomingValue(Idx);
1165
1166 // If the value is produced by the terminator of the predecessor (an
1167 // invoke) or it has side-effects, there is no valid place to put a load
1168 // in the predecessor.
1169 if (TI == InVal || TI->mayHaveSideEffects())
1170 return false;
1171
1172 // If the predecessor has a single successor, then the edge isn't
1173 // critical.
1174 if (TI->getNumSuccessors() == 1)
1175 continue;
1176
1177 // If this pointer is always safe to load, or if we can prove that there
1178 // is already a load in the block, then we can move the load to the pred
1179 // block.
1180 if (isSafeToLoadUnconditionally(InVal, MaxAlign, DL, TI))
1181 continue;
1182
1183 return false;
1184 }
1185
1186 return true;
1187}
1188
1189static void speculatePHINodeLoads(PHINode &PN) {
1190 DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
1191
1192 Type *LoadTy = cast<PointerType>(PN.getType())->getElementType();
1193 IRBuilderTy PHIBuilder(&PN);
1194 PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
1195 PN.getName() + ".sroa.speculated");
1196
1197 // Get the AA tags and alignment to use from one of the loads. It doesn't
1198 // matter which one we get and if any differ.
1199 LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
1200
1201 AAMDNodes AATags;
1202 SomeLoad->getAAMetadata(AATags);
1203 unsigned Align = SomeLoad->getAlignment();
1204
1205 // Rewrite all loads of the PN to use the new PHI.
1206 while (!PN.use_empty()) {
1207 LoadInst *LI = cast<LoadInst>(PN.user_back());
1208 LI->replaceAllUsesWith(NewPN);
1209 LI->eraseFromParent();
1210 }
1211
1212 // Inject loads into all of the pred blocks.
1213 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1214 BasicBlock *Pred = PN.getIncomingBlock(Idx);
1215 TerminatorInst *TI = Pred->getTerminator();
1216 Value *InVal = PN.getIncomingValue(Idx);
1217 IRBuilderTy PredBuilder(TI);
1218
1219 LoadInst *Load = PredBuilder.CreateLoad(
1220 InVal, (PN.getName() + ".sroa.speculate.load." + Pred->getName()));
1221 ++NumLoadsSpeculated;
1222 Load->setAlignment(Align);
1223 if (AATags)
1224 Load->setAAMetadata(AATags);
1225 NewPN->addIncoming(Load, Pred);
1226 }
1227
1228 DEBUG(dbgs() << " speculated to: " << *NewPN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*NewPN << "\n"; } } while (false)
;
1229 PN.eraseFromParent();
1230}
1231
1232/// Select instructions that use an alloca and are subsequently loaded can be
1233/// rewritten to load both input pointers and then select between the result,
1234/// allowing the load of the alloca to be promoted.
1235/// From this:
1236/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
1237/// %V = load i32* %P2
1238/// to:
1239/// %V1 = load i32* %Alloca -> will be mem2reg'd
1240/// %V2 = load i32* %Other
1241/// %V = select i1 %cond, i32 %V1, i32 %V2
1242///
1243/// We can do this to a select if its only uses are loads and if the operand
1244/// to the select can be loaded unconditionally.
1245static bool isSafeSelectToSpeculate(SelectInst &SI) {
1246 Value *TValue = SI.getTrueValue();
1247 Value *FValue = SI.getFalseValue();
1248 const DataLayout &DL = SI.getModule()->getDataLayout();
1249
1250 for (User *U : SI.users()) {
1251 LoadInst *LI = dyn_cast<LoadInst>(U);
1252 if (!LI || !LI->isSimple())
1253 return false;
1254
1255 // Both operands to the select need to be dereferencable, either
1256 // absolutely (e.g. allocas) or at this point because we can see other
1257 // accesses to it.
1258 if (!isSafeToLoadUnconditionally(TValue, LI->getAlignment(), DL, LI))
1259 return false;
1260 if (!isSafeToLoadUnconditionally(FValue, LI->getAlignment(), DL, LI))
1261 return false;
1262 }
1263
1264 return true;
1265}
1266
1267static void speculateSelectInstLoads(SelectInst &SI) {
1268 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
1269
1270 IRBuilderTy IRB(&SI);
1271 Value *TV = SI.getTrueValue();
1272 Value *FV = SI.getFalseValue();
1273 // Replace the loads of the select with a select of two loads.
1274 while (!SI.use_empty()) {
1275 LoadInst *LI = cast<LoadInst>(SI.user_back());
1276 assert(LI->isSimple() && "We only speculate simple loads")((LI->isSimple() && "We only speculate simple loads"
) ? static_cast<void> (0) : __assert_fail ("LI->isSimple() && \"We only speculate simple loads\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1276, __PRETTY_FUNCTION__))
;
1277
1278 IRB.SetInsertPoint(LI);
1279 LoadInst *TL =
1280 IRB.CreateLoad(TV, LI->getName() + ".sroa.speculate.load.true");
1281 LoadInst *FL =
1282 IRB.CreateLoad(FV, LI->getName() + ".sroa.speculate.load.false");
1283 NumLoadsSpeculated += 2;
1284
1285 // Transfer alignment and AA info if present.
1286 TL->setAlignment(LI->getAlignment());
1287 FL->setAlignment(LI->getAlignment());
1288
1289 AAMDNodes Tags;
1290 LI->getAAMetadata(Tags);
1291 if (Tags) {
1292 TL->setAAMetadata(Tags);
1293 FL->setAAMetadata(Tags);
1294 }
1295
1296 Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
1297 LI->getName() + ".sroa.speculated");
1298
1299 DEBUG(dbgs() << " speculated to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*V << "\n"; } } while (false)
;
1300 LI->replaceAllUsesWith(V);
1301 LI->eraseFromParent();
1302 }
1303 SI.eraseFromParent();
1304}
1305
1306/// \brief Build a GEP out of a base pointer and indices.
1307///
1308/// This will return the BasePtr if that is valid, or build a new GEP
1309/// instruction using the IRBuilder if GEP-ing is needed.
1310static Value *buildGEP(IRBuilderTy &IRB, Value *BasePtr,
1311 SmallVectorImpl<Value *> &Indices, Twine NamePrefix) {
1312 if (Indices.empty())
1313 return BasePtr;
1314
1315 // A single zero index is a no-op, so check for this and avoid building a GEP
1316 // in that case.
1317 if (Indices.size() == 1 && cast<ConstantInt>(Indices.back())->isZero())
1318 return BasePtr;
1319
1320 return IRB.CreateInBoundsGEP(nullptr, BasePtr, Indices,
1321 NamePrefix + "sroa_idx");
1322}
1323
1324/// \brief Get a natural GEP off of the BasePtr walking through Ty toward
1325/// TargetTy without changing the offset of the pointer.
1326///
1327/// This routine assumes we've already established a properly offset GEP with
1328/// Indices, and arrived at the Ty type. The goal is to continue to GEP with
1329/// zero-indices down through type layers until we find one the same as
1330/// TargetTy. If we can't find one with the same type, we at least try to use
1331/// one with the same size. If none of that works, we just produce the GEP as
1332/// indicated by Indices to have the correct offset.
1333static Value *getNaturalGEPWithType(IRBuilderTy &IRB, const DataLayout &DL,
1334 Value *BasePtr, Type *Ty, Type *TargetTy,
1335 SmallVectorImpl<Value *> &Indices,
1336 Twine NamePrefix) {
1337 if (Ty == TargetTy)
1338 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1339
1340 // Pointer size to use for the indices.
1341 unsigned PtrSize = DL.getPointerTypeSizeInBits(BasePtr->getType());
1342
1343 // See if we can descend into a struct and locate a field with the correct
1344 // type.
1345 unsigned NumLayers = 0;
1346 Type *ElementTy = Ty;
1347 do {
1348 if (ElementTy->isPointerTy())
1349 break;
1350
1351 if (ArrayType *ArrayTy = dyn_cast<ArrayType>(ElementTy)) {
1352 ElementTy = ArrayTy->getElementType();
1353 Indices.push_back(IRB.getIntN(PtrSize, 0));
1354 } else if (VectorType *VectorTy = dyn_cast<VectorType>(ElementTy)) {
1355 ElementTy = VectorTy->getElementType();
1356 Indices.push_back(IRB.getInt32(0));
1357 } else if (StructType *STy = dyn_cast<StructType>(ElementTy)) {
1358 if (STy->element_begin() == STy->element_end())
1359 break; // Nothing left to descend into.
1360 ElementTy = *STy->element_begin();
1361 Indices.push_back(IRB.getInt32(0));
1362 } else {
1363 break;
1364 }
1365 ++NumLayers;
1366 } while (ElementTy != TargetTy);
1367 if (ElementTy != TargetTy)
1368 Indices.erase(Indices.end() - NumLayers, Indices.end());
1369
1370 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1371}
1372
1373/// \brief Recursively compute indices for a natural GEP.
1374///
1375/// This is the recursive step for getNaturalGEPWithOffset that walks down the
1376/// element types adding appropriate indices for the GEP.
1377static Value *getNaturalGEPRecursively(IRBuilderTy &IRB, const DataLayout &DL,
1378 Value *Ptr, Type *Ty, APInt &Offset,
1379 Type *TargetTy,
1380 SmallVectorImpl<Value *> &Indices,
1381 Twine NamePrefix) {
1382 if (Offset == 0)
1383 return getNaturalGEPWithType(IRB, DL, Ptr, Ty, TargetTy, Indices,
1384 NamePrefix);
1385
1386 // We can't recurse through pointer types.
1387 if (Ty->isPointerTy())
1388 return nullptr;
1389
1390 // We try to analyze GEPs over vectors here, but note that these GEPs are
1391 // extremely poorly defined currently. The long-term goal is to remove GEPing
1392 // over a vector from the IR completely.
1393 if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
1394 unsigned ElementSizeInBits = DL.getTypeSizeInBits(VecTy->getScalarType());
1395 if (ElementSizeInBits % 8 != 0) {
1396 // GEPs over non-multiple of 8 size vector elements are invalid.
1397 return nullptr;
1398 }
1399 APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
1400 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1401 if (NumSkippedElements.ugt(VecTy->getNumElements()))
1402 return nullptr;
1403 Offset -= NumSkippedElements * ElementSize;
1404 Indices.push_back(IRB.getInt(NumSkippedElements));
1405 return getNaturalGEPRecursively(IRB, DL, Ptr, VecTy->getElementType(),
1406 Offset, TargetTy, Indices, NamePrefix);
1407 }
1408
1409 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
1410 Type *ElementTy = ArrTy->getElementType();
1411 APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
1412 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1413 if (NumSkippedElements.ugt(ArrTy->getNumElements()))
1414 return nullptr;
1415
1416 Offset -= NumSkippedElements * ElementSize;
1417 Indices.push_back(IRB.getInt(NumSkippedElements));
1418 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1419 Indices, NamePrefix);
1420 }
1421
1422 StructType *STy = dyn_cast<StructType>(Ty);
1423 if (!STy)
1424 return nullptr;
1425
1426 const StructLayout *SL = DL.getStructLayout(STy);
1427 uint64_t StructOffset = Offset.getZExtValue();
1428 if (StructOffset >= SL->getSizeInBytes())
1429 return nullptr;
1430 unsigned Index = SL->getElementContainingOffset(StructOffset);
1431 Offset -= APInt(Offset.getBitWidth(), SL->getElementOffset(Index));
1432 Type *ElementTy = STy->getElementType(Index);
1433 if (Offset.uge(DL.getTypeAllocSize(ElementTy)))
1434 return nullptr; // The offset points into alignment padding.
1435
1436 Indices.push_back(IRB.getInt32(Index));
1437 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1438 Indices, NamePrefix);
1439}
1440
1441/// \brief Get a natural GEP from a base pointer to a particular offset and
1442/// resulting in a particular type.
1443///
1444/// The goal is to produce a "natural" looking GEP that works with the existing
1445/// composite types to arrive at the appropriate offset and element type for
1446/// a pointer. TargetTy is the element type the returned GEP should point-to if
1447/// possible. We recurse by decreasing Offset, adding the appropriate index to
1448/// Indices, and setting Ty to the result subtype.
1449///
1450/// If no natural GEP can be constructed, this function returns null.
1451static Value *getNaturalGEPWithOffset(IRBuilderTy &IRB, const DataLayout &DL,
1452 Value *Ptr, APInt Offset, Type *TargetTy,
1453 SmallVectorImpl<Value *> &Indices,
1454 Twine NamePrefix) {
1455 PointerType *Ty = cast<PointerType>(Ptr->getType());
1456
1457 // Don't consider any GEPs through an i8* as natural unless the TargetTy is
1458 // an i8.
1459 if (Ty == IRB.getInt8PtrTy(Ty->getAddressSpace()) && TargetTy->isIntegerTy(8))
1460 return nullptr;
1461
1462 Type *ElementTy = Ty->getElementType();
1463 if (!ElementTy->isSized())
1464 return nullptr; // We can't GEP through an unsized element.
1465 APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
1466 if (ElementSize == 0)
1467 return nullptr; // Zero-length arrays can't help us build a natural GEP.
1468 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1469
1470 Offset -= NumSkippedElements * ElementSize;
1471 Indices.push_back(IRB.getInt(NumSkippedElements));
1472 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1473 Indices, NamePrefix);
1474}
1475
1476/// \brief Compute an adjusted pointer from Ptr by Offset bytes where the
1477/// resulting pointer has PointerTy.
1478///
1479/// This tries very hard to compute a "natural" GEP which arrives at the offset
1480/// and produces the pointer type desired. Where it cannot, it will try to use
1481/// the natural GEP to arrive at the offset and bitcast to the type. Where that
1482/// fails, it will try to use an existing i8* and GEP to the byte offset and
1483/// bitcast to the type.
1484///
1485/// The strategy for finding the more natural GEPs is to peel off layers of the
1486/// pointer, walking back through bit casts and GEPs, searching for a base
1487/// pointer from which we can compute a natural GEP with the desired
1488/// properties. The algorithm tries to fold as many constant indices into
1489/// a single GEP as possible, thus making each GEP more independent of the
1490/// surrounding code.
1491static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
1492 APInt Offset, Type *PointerTy, Twine NamePrefix) {
1493 // Even though we don't look through PHI nodes, we could be called on an
1494 // instruction in an unreachable block, which may be on a cycle.
1495 SmallPtrSet<Value *, 4> Visited;
1496 Visited.insert(Ptr);
1497 SmallVector<Value *, 4> Indices;
1498
1499 // We may end up computing an offset pointer that has the wrong type. If we
1500 // never are able to compute one directly that has the correct type, we'll
1501 // fall back to it, so keep it and the base it was computed from around here.
1502 Value *OffsetPtr = nullptr;
1503 Value *OffsetBasePtr;
1504
1505 // Remember any i8 pointer we come across to re-use if we need to do a raw
1506 // byte offset.
1507 Value *Int8Ptr = nullptr;
1508 APInt Int8PtrOffset(Offset.getBitWidth(), 0);
1509
1510 Type *TargetTy = PointerTy->getPointerElementType();
1511
1512 do {
1513 // First fold any existing GEPs into the offset.
1514 while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
1515 APInt GEPOffset(Offset.getBitWidth(), 0);
1516 if (!GEP->accumulateConstantOffset(DL, GEPOffset))
1517 break;
1518 Offset += GEPOffset;
1519 Ptr = GEP->getPointerOperand();
1520 if (!Visited.insert(Ptr).second)
1521 break;
1522 }
1523
1524 // See if we can perform a natural GEP here.
1525 Indices.clear();
1526 if (Value *P = getNaturalGEPWithOffset(IRB, DL, Ptr, Offset, TargetTy,
1527 Indices, NamePrefix)) {
1528 // If we have a new natural pointer at the offset, clear out any old
1529 // offset pointer we computed. Unless it is the base pointer or
1530 // a non-instruction, we built a GEP we don't need. Zap it.
1531 if (OffsetPtr && OffsetPtr != OffsetBasePtr)
1532 if (Instruction *I = dyn_cast<Instruction>(OffsetPtr)) {
1533 assert(I->use_empty() && "Built a GEP with uses some how!")((I->use_empty() && "Built a GEP with uses some how!"
) ? static_cast<void> (0) : __assert_fail ("I->use_empty() && \"Built a GEP with uses some how!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1533, __PRETTY_FUNCTION__))
;
1534 I->eraseFromParent();
1535 }
1536 OffsetPtr = P;
1537 OffsetBasePtr = Ptr;
1538 // If we also found a pointer of the right type, we're done.
1539 if (P->getType() == PointerTy)
1540 return P;
1541 }
1542
1543 // Stash this pointer if we've found an i8*.
1544 if (Ptr->getType()->isIntegerTy(8)) {
1545 Int8Ptr = Ptr;
1546 Int8PtrOffset = Offset;
1547 }
1548
1549 // Peel off a layer of the pointer and update the offset appropriately.
1550 if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
1551 Ptr = cast<Operator>(Ptr)->getOperand(0);
1552 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(Ptr)) {
1553 if (GA->isInterposable())
1554 break;
1555 Ptr = GA->getAliasee();
1556 } else {
1557 break;
1558 }
1559 assert(Ptr->getType()->isPointerTy() && "Unexpected operand type!")((Ptr->getType()->isPointerTy() && "Unexpected operand type!"
) ? static_cast<void> (0) : __assert_fail ("Ptr->getType()->isPointerTy() && \"Unexpected operand type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1559, __PRETTY_FUNCTION__))
;
1560 } while (Visited.insert(Ptr).second);
1561
1562 if (!OffsetPtr) {
1563 if (!Int8Ptr) {
1564 Int8Ptr = IRB.CreateBitCast(
1565 Ptr, IRB.getInt8PtrTy(PointerTy->getPointerAddressSpace()),
1566 NamePrefix + "sroa_raw_cast");
1567 Int8PtrOffset = Offset;
1568 }
1569
1570 OffsetPtr = Int8PtrOffset == 0
1571 ? Int8Ptr
1572 : IRB.CreateInBoundsGEP(IRB.getInt8Ty(), Int8Ptr,
1573 IRB.getInt(Int8PtrOffset),
1574 NamePrefix + "sroa_raw_idx");
1575 }
1576 Ptr = OffsetPtr;
1577
1578 // On the off chance we were targeting i8*, guard the bitcast here.
1579 if (Ptr->getType() != PointerTy)
1580 Ptr = IRB.CreateBitCast(Ptr, PointerTy, NamePrefix + "sroa_cast");
1581
1582 return Ptr;
1583}
1584
1585/// \brief Compute the adjusted alignment for a load or store from an offset.
1586static unsigned getAdjustedAlignment(Instruction *I, uint64_t Offset,
1587 const DataLayout &DL) {
1588 unsigned Alignment;
1589 Type *Ty;
1590 if (auto *LI = dyn_cast<LoadInst>(I)) {
1591 Alignment = LI->getAlignment();
1592 Ty = LI->getType();
1593 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
1594 Alignment = SI->getAlignment();
1595 Ty = SI->getValueOperand()->getType();
1596 } else {
1597 llvm_unreachable("Only loads and stores are allowed!")::llvm::llvm_unreachable_internal("Only loads and stores are allowed!"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1597)
;
1598 }
1599
1600 if (!Alignment)
1601 Alignment = DL.getABITypeAlignment(Ty);
1602
1603 return MinAlign(Alignment, Offset);
1604}
1605
1606/// \brief Test whether we can convert a value from the old to the new type.
1607///
1608/// This predicate should be used to guard calls to convertValue in order to
1609/// ensure that we only try to convert viable values. The strategy is that we
1610/// will peel off single element struct and array wrappings to get to an
1611/// underlying value, and convert that value.
1612static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
1613 if (OldTy == NewTy)
1614 return true;
1615
1616 // For integer types, we can't handle any bit-width differences. This would
1617 // break both vector conversions with extension and introduce endianness
1618 // issues when in conjunction with loads and stores.
1619 if (isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) {
1620 assert(cast<IntegerType>(OldTy)->getBitWidth() !=((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1622, __PRETTY_FUNCTION__))
1621 cast<IntegerType>(NewTy)->getBitWidth() &&((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1622, __PRETTY_FUNCTION__))
1622 "We can't have the same bitwidth for different int types")((cast<IntegerType>(OldTy)->getBitWidth() != cast<
IntegerType>(NewTy)->getBitWidth() && "We can't have the same bitwidth for different int types"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1622, __PRETTY_FUNCTION__))
;
1623 return false;
1624 }
1625
1626 if (DL.getTypeSizeInBits(NewTy) != DL.getTypeSizeInBits(OldTy))
1627 return false;
1628 if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
1629 return false;
1630
1631 // We can convert pointers to integers and vice-versa. Same for vectors
1632 // of pointers and integers.
1633 OldTy = OldTy->getScalarType();
1634 NewTy = NewTy->getScalarType();
1635 if (NewTy->isPointerTy() || OldTy->isPointerTy()) {
1636 if (NewTy->isPointerTy() && OldTy->isPointerTy()) {
1637 return cast<PointerType>(NewTy)->getPointerAddressSpace() ==
1638 cast<PointerType>(OldTy)->getPointerAddressSpace();
1639 }
1640 if (NewTy->isIntegerTy() || OldTy->isIntegerTy())
1641 return true;
1642 return false;
1643 }
1644
1645 return true;
1646}
1647
1648/// \brief Generic routine to convert an SSA value to a value of a different
1649/// type.
1650///
1651/// This will try various different casting techniques, such as bitcasts,
1652/// inttoptr, and ptrtoint casts. Use the \c canConvertValue predicate to test
1653/// two types for viability with this routine.
1654static Value *convertValue(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
1655 Type *NewTy) {
1656 Type *OldTy = V->getType();
1657 assert(canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type")((canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type"
) ? static_cast<void> (0) : __assert_fail ("canConvertValue(DL, OldTy, NewTy) && \"Value not convertable to type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1657, __PRETTY_FUNCTION__))
;
1658
1659 if (OldTy == NewTy)
1660 return V;
1661
1662 assert(!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) &&((!(isa<IntegerType>(OldTy) && isa<IntegerType
>(NewTy)) && "Integer types must be the exact same to convert."
) ? static_cast<void> (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1663, __PRETTY_FUNCTION__))
1663 "Integer types must be the exact same to convert.")((!(isa<IntegerType>(OldTy) && isa<IntegerType
>(NewTy)) && "Integer types must be the exact same to convert."
) ? static_cast<void> (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1663, __PRETTY_FUNCTION__))
;
1664
1665 // See if we need inttoptr for this type pair. A cast involving both scalars
1666 // and vectors requires and additional bitcast.
1667 if (OldTy->getScalarType()->isIntegerTy() &&
1668 NewTy->getScalarType()->isPointerTy()) {
1669 // Expand <2 x i32> to i8* --> <2 x i32> to i64 to i8*
1670 if (OldTy->isVectorTy() && !NewTy->isVectorTy())
1671 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1672 NewTy);
1673
1674 // Expand i128 to <2 x i8*> --> i128 to <2 x i64> to <2 x i8*>
1675 if (!OldTy->isVectorTy() && NewTy->isVectorTy())
1676 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1677 NewTy);
1678
1679 return IRB.CreateIntToPtr(V, NewTy);
1680 }
1681
1682 // See if we need ptrtoint for this type pair. A cast involving both scalars
1683 // and vectors requires and additional bitcast.
1684 if (OldTy->getScalarType()->isPointerTy() &&
1685 NewTy->getScalarType()->isIntegerTy()) {
1686 // Expand <2 x i8*> to i128 --> <2 x i8*> to <2 x i64> to i128
1687 if (OldTy->isVectorTy() && !NewTy->isVectorTy())
1688 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1689 NewTy);
1690
1691 // Expand i8* to <2 x i32> --> i8* to i64 to <2 x i32>
1692 if (!OldTy->isVectorTy() && NewTy->isVectorTy())
1693 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1694 NewTy);
1695
1696 return IRB.CreatePtrToInt(V, NewTy);
1697 }
1698
1699 return IRB.CreateBitCast(V, NewTy);
1700}
1701
1702/// \brief Test whether the given slice use can be promoted to a vector.
1703///
1704/// This function is called to test each entry in a partition which is slated
1705/// for a single slice.
1706static bool isVectorPromotionViableForSlice(Partition &P, const Slice &S,
1707 VectorType *Ty,
1708 uint64_t ElementSize,
1709 const DataLayout &DL) {
1710 // First validate the slice offsets.
1711 uint64_t BeginOffset =
1712 std::max(S.beginOffset(), P.beginOffset()) - P.beginOffset();
1713 uint64_t BeginIndex = BeginOffset / ElementSize;
1714 if (BeginIndex * ElementSize != BeginOffset ||
1715 BeginIndex >= Ty->getNumElements())
1716 return false;
1717 uint64_t EndOffset =
1718 std::min(S.endOffset(), P.endOffset()) - P.beginOffset();
1719 uint64_t EndIndex = EndOffset / ElementSize;
1720 if (EndIndex * ElementSize != EndOffset || EndIndex > Ty->getNumElements())
1721 return false;
1722
1723 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1723, __PRETTY_FUNCTION__))
;
1724 uint64_t NumElements = EndIndex - BeginIndex;
1725 Type *SliceTy = (NumElements == 1)
1726 ? Ty->getElementType()
1727 : VectorType::get(Ty->getElementType(), NumElements);
1728
1729 Type *SplitIntTy =
1730 Type::getIntNTy(Ty->getContext(), NumElements * ElementSize * 8);
1731
1732 Use *U = S.getUse();
1733
1734 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
1735 if (MI->isVolatile())
1736 return false;
1737 if (!S.isSplittable())
1738 return false; // Skip any unsplittable intrinsics.
1739 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
1740 if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
1741 II->getIntrinsicID() != Intrinsic::lifetime_end)
1742 return false;
1743 } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
1744 // Disable vector promotion when there are loads or stores of an FCA.
1745 return false;
1746 } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1747 if (LI->isVolatile())
1748 return false;
1749 Type *LTy = LI->getType();
1750 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1751 assert(LTy->isIntegerTy())((LTy->isIntegerTy()) ? static_cast<void> (0) : __assert_fail
("LTy->isIntegerTy()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1751, __PRETTY_FUNCTION__))
;
1752 LTy = SplitIntTy;
1753 }
1754 if (!canConvertValue(DL, SliceTy, LTy))
1755 return false;
1756 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1757 if (SI->isVolatile())
1758 return false;
1759 Type *STy = SI->getValueOperand()->getType();
1760 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1761 assert(STy->isIntegerTy())((STy->isIntegerTy()) ? static_cast<void> (0) : __assert_fail
("STy->isIntegerTy()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1761, __PRETTY_FUNCTION__))
;
1762 STy = SplitIntTy;
1763 }
1764 if (!canConvertValue(DL, STy, SliceTy))
1765 return false;
1766 } else {
1767 return false;
1768 }
1769
1770 return true;
1771}
1772
1773/// \brief Test whether the given alloca partitioning and range of slices can be
1774/// promoted to a vector.
1775///
1776/// This is a quick test to check whether we can rewrite a particular alloca
1777/// partition (and its newly formed alloca) into a vector alloca with only
1778/// whole-vector loads and stores such that it could be promoted to a vector
1779/// SSA value. We only can ensure this for a limited set of operations, and we
1780/// don't want to do the rewrites unless we are confident that the result will
1781/// be promotable, so we have an early test here.
1782static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
1783 // Collect the candidate types for vector-based promotion. Also track whether
1784 // we have different element types.
1785 SmallVector<VectorType *, 4> CandidateTys;
1786 Type *CommonEltTy = nullptr;
1787 bool HaveCommonEltTy = true;
1788 auto CheckCandidateType = [&](Type *Ty) {
1789 if (auto *VTy = dyn_cast<VectorType>(Ty)) {
1790 CandidateTys.push_back(VTy);
1791 if (!CommonEltTy)
1792 CommonEltTy = VTy->getElementType();
1793 else if (CommonEltTy != VTy->getElementType())
1794 HaveCommonEltTy = false;
1795 }
1796 };
1797 // Consider any loads or stores that are the exact size of the slice.
1798 for (const Slice &S : P)
1799 if (S.beginOffset() == P.beginOffset() &&
1800 S.endOffset() == P.endOffset()) {
1801 if (auto *LI = dyn_cast<LoadInst>(S.getUse()->getUser()))
1802 CheckCandidateType(LI->getType());
1803 else if (auto *SI = dyn_cast<StoreInst>(S.getUse()->getUser()))
1804 CheckCandidateType(SI->getValueOperand()->getType());
1805 }
1806
1807 // If we didn't find a vector type, nothing to do here.
1808 if (CandidateTys.empty())
1809 return nullptr;
1810
1811 // Remove non-integer vector types if we had multiple common element types.
1812 // FIXME: It'd be nice to replace them with integer vector types, but we can't
1813 // do that until all the backends are known to produce good code for all
1814 // integer vector types.
1815 if (!HaveCommonEltTy) {
1816 CandidateTys.erase(remove_if(CandidateTys,
1817 [](VectorType *VTy) {
1818 return !VTy->getElementType()->isIntegerTy();
1819 }),
1820 CandidateTys.end());
1821
1822 // If there were no integer vector types, give up.
1823 if (CandidateTys.empty())
1824 return nullptr;
1825
1826 // Rank the remaining candidate vector types. This is easy because we know
1827 // they're all integer vectors. We sort by ascending number of elements.
1828 auto RankVectorTypes = [&DL](VectorType *RHSTy, VectorType *LHSTy) {
1829 (void)DL;
1830 assert(DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) &&((DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) &&
"Cannot have vector types of different sizes!") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) && \"Cannot have vector types of different sizes!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1831, __PRETTY_FUNCTION__))
1831 "Cannot have vector types of different sizes!")((DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) &&
"Cannot have vector types of different sizes!") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) && \"Cannot have vector types of different sizes!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1831, __PRETTY_FUNCTION__))
;
1832 assert(RHSTy->getElementType()->isIntegerTy() &&((RHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1833, __PRETTY_FUNCTION__))
1833 "All non-integer types eliminated!")((RHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1833, __PRETTY_FUNCTION__))
;
1834 assert(LHSTy->getElementType()->isIntegerTy() &&((LHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1835, __PRETTY_FUNCTION__))
1835 "All non-integer types eliminated!")((LHSTy->getElementType()->isIntegerTy() && "All non-integer types eliminated!"
) ? static_cast<void> (0) : __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1835, __PRETTY_FUNCTION__))
;
1836 return RHSTy->getNumElements() < LHSTy->getNumElements();
1837 };
1838 std::sort(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes);
1839 CandidateTys.erase(
1840 std::unique(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes),
1841 CandidateTys.end());
1842 } else {
1843// The only way to have the same element type in every vector type is to
1844// have the same vector type. Check that and remove all but one.
1845#ifndef NDEBUG
1846 for (VectorType *VTy : CandidateTys) {
1847 assert(VTy->getElementType() == CommonEltTy &&((VTy->getElementType() == CommonEltTy && "Unaccounted for element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1848, __PRETTY_FUNCTION__))
1848 "Unaccounted for element type!")((VTy->getElementType() == CommonEltTy && "Unaccounted for element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1848, __PRETTY_FUNCTION__))
;
1849 assert(VTy == CandidateTys[0] &&((VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1850, __PRETTY_FUNCTION__))
1850 "Different vector types with the same element type!")((VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? static_cast<void> (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1850, __PRETTY_FUNCTION__))
;
1851 }
1852#endif
1853 CandidateTys.resize(1);
1854 }
1855
1856 // Try each vector type, and return the one which works.
1857 auto CheckVectorTypeForPromotion = [&](VectorType *VTy) {
1858 uint64_t ElementSize = DL.getTypeSizeInBits(VTy->getElementType());
1859
1860 // While the definition of LLVM vectors is bitpacked, we don't support sizes
1861 // that aren't byte sized.
1862 if (ElementSize % 8)
1863 return false;
1864 assert((DL.getTypeSizeInBits(VTy) % 8) == 0 &&(((DL.getTypeSizeInBits(VTy) % 8) == 0 && "vector size not a multiple of element size?"
) ? static_cast<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy) % 8) == 0 && \"vector size not a multiple of element size?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1865, __PRETTY_FUNCTION__))
1865 "vector size not a multiple of element size?")(((DL.getTypeSizeInBits(VTy) % 8) == 0 && "vector size not a multiple of element size?"
) ? static_cast<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy) % 8) == 0 && \"vector size not a multiple of element size?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 1865, __PRETTY_FUNCTION__))
;
1866 ElementSize /= 8;
1867
1868 for (const Slice &S : P)
1869 if (!isVectorPromotionViableForSlice(P, S, VTy, ElementSize, DL))
1870 return false;
1871
1872 for (const Slice *S : P.splitSliceTails())
1873 if (!isVectorPromotionViableForSlice(P, *S, VTy, ElementSize, DL))
1874 return false;
1875
1876 return true;
1877 };
1878 for (VectorType *VTy : CandidateTys)
1879 if (CheckVectorTypeForPromotion(VTy))
1880 return VTy;
1881
1882 return nullptr;
1883}
1884
1885/// \brief Test whether a slice of an alloca is valid for integer widening.
1886///
1887/// This implements the necessary checking for the \c isIntegerWideningViable
1888/// test below on a single slice of the alloca.
1889static bool isIntegerWideningViableForSlice(const Slice &S,
1890 uint64_t AllocBeginOffset,
1891 Type *AllocaTy,
1892 const DataLayout &DL,
1893 bool &WholeAllocaOp) {
1894 uint64_t Size = DL.getTypeStoreSize(AllocaTy);
1895
1896 uint64_t RelBegin = S.beginOffset() - AllocBeginOffset;
1897 uint64_t RelEnd = S.endOffset() - AllocBeginOffset;
1898
1899 // We can't reasonably handle cases where the load or store extends past
1900 // the end of the alloca's type and into its padding.
1901 if (RelEnd > Size)
1902 return false;
1903
1904 Use *U = S.getUse();
1905
1906 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1907 if (LI->isVolatile())
1908 return false;
1909 // We can't handle loads that extend past the allocated memory.
1910 if (DL.getTypeStoreSize(LI->getType()) > Size)
1911 return false;
1912 // Note that we don't count vector loads or stores as whole-alloca
1913 // operations which enable integer widening because we would prefer to use
1914 // vector widening instead.
1915 if (!isa<VectorType>(LI->getType()) && RelBegin == 0 && RelEnd == Size)
1916 WholeAllocaOp = true;
1917 if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType())) {
1918 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
1919 return false;
1920 } else if (RelBegin != 0 || RelEnd != Size ||
1921 !canConvertValue(DL, AllocaTy, LI->getType())) {
1922 // Non-integer loads need to be convertible from the alloca type so that
1923 // they are promotable.
1924 return false;
1925 }
1926 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1927 Type *ValueTy = SI->getValueOperand()->getType();
1928 if (SI->isVolatile())
1929 return false;
1930 // We can't handle stores that extend past the allocated memory.
1931 if (DL.getTypeStoreSize(ValueTy) > Size)
1932 return false;
1933 // Note that we don't count vector loads or stores as whole-alloca
1934 // operations which enable integer widening because we would prefer to use
1935 // vector widening instead.
1936 if (!isa<VectorType>(ValueTy) && RelBegin == 0 && RelEnd == Size)
1937 WholeAllocaOp = true;
1938 if (IntegerType *ITy = dyn_cast<IntegerType>(ValueTy)) {
1939 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
1940 return false;
1941 } else if (RelBegin != 0 || RelEnd != Size ||
1942 !canConvertValue(DL, ValueTy, AllocaTy)) {
1943 // Non-integer stores need to be convertible to the alloca type so that
1944 // they are promotable.
1945 return false;
1946 }
1947 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
1948 if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
1949 return false;
1950 if (!S.isSplittable())
1951 return false; // Skip any unsplittable intrinsics.
1952 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
1953 if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
1954 II->getIntrinsicID() != Intrinsic::lifetime_end)
1955 return false;
1956 } else {
1957 return false;
1958 }
1959
1960 return true;
1961}
1962
1963/// \brief Test whether the given alloca partition's integer operations can be
1964/// widened to promotable ones.
1965///
1966/// This is a quick test to check whether we can rewrite the integer loads and
1967/// stores to a particular alloca into wider loads and stores and be able to
1968/// promote the resulting alloca.
1969static bool isIntegerWideningViable(Partition &P, Type *AllocaTy,
1970 const DataLayout &DL) {
1971 uint64_t SizeInBits = DL.getTypeSizeInBits(AllocaTy);
1972 // Don't create integer types larger than the maximum bitwidth.
1973 if (SizeInBits > IntegerType::MAX_INT_BITS)
1974 return false;
1975
1976 // Don't try to handle allocas with bit-padding.
1977 if (SizeInBits != DL.getTypeStoreSizeInBits(AllocaTy))
1978 return false;
1979
1980 // We need to ensure that an integer type with the appropriate bitwidth can
1981 // be converted to the alloca type, whatever that is. We don't want to force
1982 // the alloca itself to have an integer type if there is a more suitable one.
1983 Type *IntTy = Type::getIntNTy(AllocaTy->getContext(), SizeInBits);
1984 if (!canConvertValue(DL, AllocaTy, IntTy) ||
1985 !canConvertValue(DL, IntTy, AllocaTy))
1986 return false;
1987
1988 // While examining uses, we ensure that the alloca has a covering load or
1989 // store. We don't want to widen the integer operations only to fail to
1990 // promote due to some other unsplittable entry (which we may make splittable
1991 // later). However, if there are only splittable uses, go ahead and assume
1992 // that we cover the alloca.
1993 // FIXME: We shouldn't consider split slices that happen to start in the
1994 // partition here...
1995 bool WholeAllocaOp =
1996 P.begin() != P.end() ? false : DL.isLegalInteger(SizeInBits);
1997
1998 for (const Slice &S : P)
1999 if (!isIntegerWideningViableForSlice(S, P.beginOffset(), AllocaTy, DL,
2000 WholeAllocaOp))
2001 return false;
2002
2003 for (const Slice *S : P.splitSliceTails())
2004 if (!isIntegerWideningViableForSlice(*S, P.beginOffset(), AllocaTy, DL,
2005 WholeAllocaOp))
2006 return false;
2007
2008 return WholeAllocaOp;
2009}
2010
2011static Value *extractInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
2012 IntegerType *Ty, uint64_t Offset,
2013 const Twine &Name) {
2014 DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2015 IntegerType *IntTy = cast<IntegerType>(V->getType());
2016 assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&((DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(
IntTy) && "Element extends past full value") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element extends past full value\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2017, __PRETTY_FUNCTION__))
2017 "Element extends past full value")((DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(
IntTy) && "Element extends past full value") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element extends past full value\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2017, __PRETTY_FUNCTION__))
;
2018 uint64_t ShAmt = 8 * Offset;
2019 if (DL.isBigEndian())
2020 ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
2021 if (ShAmt) {
2022 V = IRB.CreateLShr(V, ShAmt, Name + ".shift");
2023 DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2024 }
2025 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot extract to a larger integer!") ? static_cast<void
> (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2026, __PRETTY_FUNCTION__))
2026 "Cannot extract to a larger integer!")((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot extract to a larger integer!") ? static_cast<void
> (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2026, __PRETTY_FUNCTION__))
;
2027 if (Ty != IntTy) {
2028 V = IRB.CreateTrunc(V, Ty, Name + ".trunc");
2029 DEBUG(dbgs() << " trunced: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " trunced: " << *V <<
"\n"; } } while (false)
;
2030 }
2031 return V;
2032}
2033
2034static Value *insertInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *Old,
2035 Value *V, uint64_t Offset, const Twine &Name) {
2036 IntegerType *IntTy = cast<IntegerType>(Old->getType());
2037 IntegerType *Ty = cast<IntegerType>(V->getType());
2038 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot insert a larger integer!") ? static_cast<void>
(0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2039, __PRETTY_FUNCTION__))
2039 "Cannot insert a larger integer!")((Ty->getBitWidth() <= IntTy->getBitWidth() &&
"Cannot insert a larger integer!") ? static_cast<void>
(0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2039, __PRETTY_FUNCTION__))
;
2040 DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2041 if (Ty != IntTy) {
2042 V = IRB.CreateZExt(V, IntTy, Name + ".ext");
2043 DEBUG(dbgs() << " extended: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extended: " << *V <<
"\n"; } } while (false)
;
2044 }
2045 assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&((DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(
IntTy) && "Element store outside of alloca store") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element store outside of alloca store\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2046, __PRETTY_FUNCTION__))
2046 "Element store outside of alloca store")((DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(
IntTy) && "Element store outside of alloca store") ? static_cast
<void> (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element store outside of alloca store\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2046, __PRETTY_FUNCTION__))
;
2047 uint64_t ShAmt = 8 * Offset;
2048 if (DL.isBigEndian())
2049 ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
2050 if (ShAmt) {
2051 V = IRB.CreateShl(V, ShAmt, Name + ".shift");
2052 DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2053 }
2054
2055 if (ShAmt || Ty->getBitWidth() < IntTy->getBitWidth()) {
2056 APInt Mask = ~Ty->getMask().zext(IntTy->getBitWidth()).shl(ShAmt);
2057 Old = IRB.CreateAnd(Old, Mask, Name + ".mask");
2058 DEBUG(dbgs() << " masked: " << *Old << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " masked: " << *Old <<
"\n"; } } while (false)
;
2059 V = IRB.CreateOr(Old, V, Name + ".insert");
2060 DEBUG(dbgs() << " inserted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " inserted: " << *V <<
"\n"; } } while (false)
;
2061 }
2062 return V;
2063}
2064
2065static Value *extractVector(IRBuilderTy &IRB, Value *V, unsigned BeginIndex,
2066 unsigned EndIndex, const Twine &Name) {
2067 VectorType *VecTy = cast<VectorType>(V->getType());
2068 unsigned NumElements = EndIndex - BeginIndex;
2069 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")((NumElements <= VecTy->getNumElements() && "Too many elements!"
) ? static_cast<void> (0) : __assert_fail ("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2069, __PRETTY_FUNCTION__))
;
2070
2071 if (NumElements == VecTy->getNumElements())
2072 return V;
2073
2074 if (NumElements == 1) {
2075 V = IRB.CreateExtractElement(V, IRB.getInt32(BeginIndex),
2076 Name + ".extract");
2077 DEBUG(dbgs() << " extract: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extract: " << *V <<
"\n"; } } while (false)
;
2078 return V;
2079 }
2080
2081 SmallVector<Constant *, 8> Mask;
2082 Mask.reserve(NumElements);
2083 for (unsigned i = BeginIndex; i != EndIndex; ++i)
2084 Mask.push_back(IRB.getInt32(i));
2085 V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
2086 ConstantVector::get(Mask), Name + ".extract");
2087 DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2088 return V;
2089}
2090
2091static Value *insertVector(IRBuilderTy &IRB, Value *Old, Value *V,
2092 unsigned BeginIndex, const Twine &Name) {
2093 VectorType *VecTy = cast<VectorType>(Old->getType());
2094 assert(VecTy && "Can only insert a vector into a vector")((VecTy && "Can only insert a vector into a vector") ?
static_cast<void> (0) : __assert_fail ("VecTy && \"Can only insert a vector into a vector\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2094, __PRETTY_FUNCTION__))
;
2095
2096 VectorType *Ty = dyn_cast<VectorType>(V->getType());
2097 if (!Ty) {
2098 // Single element to insert.
2099 V = IRB.CreateInsertElement(Old, V, IRB.getInt32(BeginIndex),
2100 Name + ".insert");
2101 DEBUG(dbgs() << " insert: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " insert: " << *V <<
"\n"; } } while (false)
;
2102 return V;
2103 }
2104
2105 assert(Ty->getNumElements() <= VecTy->getNumElements() &&((Ty->getNumElements() <= VecTy->getNumElements() &&
"Too many elements!") ? static_cast<void> (0) : __assert_fail
("Ty->getNumElements() <= VecTy->getNumElements() && \"Too many elements!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2106, __PRETTY_FUNCTION__))
2106 "Too many elements!")((Ty->getNumElements() <= VecTy->getNumElements() &&
"Too many elements!") ? static_cast<void> (0) : __assert_fail
("Ty->getNumElements() <= VecTy->getNumElements() && \"Too many elements!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2106, __PRETTY_FUNCTION__))
;
2107 if (Ty->getNumElements() == VecTy->getNumElements()) {
2108 assert(V->getType() == VecTy && "Vector type mismatch")((V->getType() == VecTy && "Vector type mismatch")
? static_cast<void> (0) : __assert_fail ("V->getType() == VecTy && \"Vector type mismatch\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2108, __PRETTY_FUNCTION__))
;
2109 return V;
2110 }
2111 unsigned EndIndex = BeginIndex + Ty->getNumElements();
2112
2113 // When inserting a smaller vector into the larger to store, we first
2114 // use a shuffle vector to widen it with undef elements, and then
2115 // a second shuffle vector to select between the loaded vector and the
2116 // incoming vector.
2117 SmallVector<Constant *, 8> Mask;
2118 Mask.reserve(VecTy->getNumElements());
2119 for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
2120 if (i >= BeginIndex && i < EndIndex)
2121 Mask.push_back(IRB.getInt32(i - BeginIndex));
2122 else
2123 Mask.push_back(UndefValue::get(IRB.getInt32Ty()));
2124 V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
2125 ConstantVector::get(Mask), Name + ".expand");
2126 DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2127
2128 Mask.clear();
2129 for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
2130 Mask.push_back(IRB.getInt1(i >= BeginIndex && i < EndIndex));
2131
2132 V = IRB.CreateSelect(ConstantVector::get(Mask), V, Old, Name + "blend");
2133
2134 DEBUG(dbgs() << " blend: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " blend: " << *V <<
"\n"; } } while (false)
;
2135 return V;
2136}
2137
2138/// \brief Visitor to rewrite instructions using p particular slice of an alloca
2139/// to use a new alloca.
2140///
2141/// Also implements the rewriting to vector-based accesses when the partition
2142/// passes the isVectorPromotionViable predicate. Most of the rewriting logic
2143/// lives here.
2144class llvm::sroa::AllocaSliceRewriter
2145 : public InstVisitor<AllocaSliceRewriter, bool> {
2146 // Befriend the base class so it can delegate to private visit methods.
2147 friend class llvm::InstVisitor<AllocaSliceRewriter, bool>;
2148 typedef llvm::InstVisitor<AllocaSliceRewriter, bool> Base;
2149
2150 const DataLayout &DL;
2151 AllocaSlices &AS;
2152 SROA &Pass;
2153 AllocaInst &OldAI, &NewAI;
2154 const uint64_t NewAllocaBeginOffset, NewAllocaEndOffset;
2155 Type *NewAllocaTy;
2156
2157 // This is a convenience and flag variable that will be null unless the new
2158 // alloca's integer operations should be widened to this integer type due to
2159 // passing isIntegerWideningViable above. If it is non-null, the desired
2160 // integer type will be stored here for easy access during rewriting.
2161 IntegerType *IntTy;
2162
2163 // If we are rewriting an alloca partition which can be written as pure
2164 // vector operations, we stash extra information here. When VecTy is
2165 // non-null, we have some strict guarantees about the rewritten alloca:
2166 // - The new alloca is exactly the size of the vector type here.
2167 // - The accesses all either map to the entire vector or to a single
2168 // element.
2169 // - The set of accessing instructions is only one of those handled above
2170 // in isVectorPromotionViable. Generally these are the same access kinds
2171 // which are promotable via mem2reg.
2172 VectorType *VecTy;
2173 Type *ElementTy;
2174 uint64_t ElementSize;
2175
2176 // The original offset of the slice currently being rewritten relative to
2177 // the original alloca.
2178 uint64_t BeginOffset, EndOffset;
2179 // The new offsets of the slice currently being rewritten relative to the
2180 // original alloca.
2181 uint64_t NewBeginOffset, NewEndOffset;
2182
2183 uint64_t SliceSize;
2184 bool IsSplittable;
2185 bool IsSplit;
2186 Use *OldUse;
2187 Instruction *OldPtr;
2188
2189 // Track post-rewrite users which are PHI nodes and Selects.
2190 SmallSetVector<PHINode *, 8> &PHIUsers;
2191 SmallSetVector<SelectInst *, 8> &SelectUsers;
2192
2193 // Utility IR builder, whose name prefix is setup for each visited use, and
2194 // the insertion point is set to point to the user.
2195 IRBuilderTy IRB;
2196
2197public:
2198 AllocaSliceRewriter(const DataLayout &DL, AllocaSlices &AS, SROA &Pass,
2199 AllocaInst &OldAI, AllocaInst &NewAI,
2200 uint64_t NewAllocaBeginOffset,
2201 uint64_t NewAllocaEndOffset, bool IsIntegerPromotable,
2202 VectorType *PromotableVecTy,
2203 SmallSetVector<PHINode *, 8> &PHIUsers,
2204 SmallSetVector<SelectInst *, 8> &SelectUsers)
2205 : DL(DL), AS(AS), Pass(Pass), OldAI(OldAI), NewAI(NewAI),
2206 NewAllocaBeginOffset(NewAllocaBeginOffset),
2207 NewAllocaEndOffset(NewAllocaEndOffset),
2208 NewAllocaTy(NewAI.getAllocatedType()),
2209 IntTy(IsIntegerPromotable
2210 ? Type::getIntNTy(
2211 NewAI.getContext(),
2212 DL.getTypeSizeInBits(NewAI.getAllocatedType()))
2213 : nullptr),
2214 VecTy(PromotableVecTy),
2215 ElementTy(VecTy ? VecTy->getElementType() : nullptr),
2216 ElementSize(VecTy ? DL.getTypeSizeInBits(ElementTy) / 8 : 0),
2217 BeginOffset(), EndOffset(), IsSplittable(), IsSplit(), OldUse(),
2218 OldPtr(), PHIUsers(PHIUsers), SelectUsers(SelectUsers),
2219 IRB(NewAI.getContext(), ConstantFolder()) {
2220 if (VecTy) {
2221 assert((DL.getTypeSizeInBits(ElementTy) % 8) == 0 &&(((DL.getTypeSizeInBits(ElementTy) % 8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? static_cast<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy) % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2222, __PRETTY_FUNCTION__))
2222 "Only multiple-of-8 sized vector elements are viable")(((DL.getTypeSizeInBits(ElementTy) % 8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? static_cast<void> (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy) % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2222, __PRETTY_FUNCTION__))
;
2223 ++NumVectorized;
2224 }
2225 assert((!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy))(((!IntTy && !VecTy) || (IntTy && !VecTy) || (
!IntTy && VecTy)) ? static_cast<void> (0) : __assert_fail
("(!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy)"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2225, __PRETTY_FUNCTION__))
;
2226 }
2227
2228 bool visit(AllocaSlices::const_iterator I) {
2229 bool CanSROA = true;
2230 BeginOffset = I->beginOffset();
2231 EndOffset = I->endOffset();
2232 IsSplittable = I->isSplittable();
2233 IsSplit =
2234 BeginOffset < NewAllocaBeginOffset || EndOffset > NewAllocaEndOffset;
2235 DEBUG(dbgs() << " rewriting " << (IsSplit ? "split " : ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " rewriting " << (IsSplit ?
"split " : ""); } } while (false)
;
2236 DEBUG(AS.printSlice(dbgs(), I, ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.printSlice(dbgs(), I, ""); } } while (false)
;
2237 DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n"; } } while (false)
;
2238
2239 // Compute the intersecting offset range.
2240 assert(BeginOffset < NewAllocaEndOffset)((BeginOffset < NewAllocaEndOffset) ? static_cast<void>
(0) : __assert_fail ("BeginOffset < NewAllocaEndOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2240, __PRETTY_FUNCTION__))
;
2241 assert(EndOffset > NewAllocaBeginOffset)((EndOffset > NewAllocaBeginOffset) ? static_cast<void>
(0) : __assert_fail ("EndOffset > NewAllocaBeginOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2241, __PRETTY_FUNCTION__))
;
2242 NewBeginOffset = std::max(BeginOffset, NewAllocaBeginOffset);
2243 NewEndOffset = std::min(EndOffset, NewAllocaEndOffset);
2244
2245 SliceSize = NewEndOffset - NewBeginOffset;
2246
2247 OldUse = I->getUse();
2248 OldPtr = cast<Instruction>(OldUse->get());
2249
2250 Instruction *OldUserI = cast<Instruction>(OldUse->getUser());
2251 IRB.SetInsertPoint(OldUserI);
2252 IRB.SetCurrentDebugLocation(OldUserI->getDebugLoc());
2253 IRB.SetNamePrefix(Twine(NewAI.getName()) + "." + Twine(BeginOffset) + ".");
2254
2255 CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
2256 if (VecTy || IntTy)
2257 assert(CanSROA)((CanSROA) ? static_cast<void> (0) : __assert_fail ("CanSROA"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2257, __PRETTY_FUNCTION__))
;
2258 return CanSROA;
2259 }
2260
2261private:
2262 // Make sure the other visit overloads are visible.
2263 using Base::visit;
2264
2265 // Every instruction which can end up as a user must have a rewrite rule.
2266 bool visitInstruction(Instruction &I) {
2267 DEBUG(dbgs() << " !!!! Cannot rewrite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " !!!! Cannot rewrite: " <<
I << "\n"; } } while (false)
;
2268 llvm_unreachable("No rewrite rule for this instruction!")::llvm::llvm_unreachable_internal("No rewrite rule for this instruction!"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2268)
;
2269 }
2270
2271 Value *getNewAllocaSlicePtr(IRBuilderTy &IRB, Type *PointerTy) {
2272 // Note that the offset computation can use BeginOffset or NewBeginOffset
2273 // interchangeably for unsplit slices.
2274 assert(IsSplit || BeginOffset == NewBeginOffset)((IsSplit || BeginOffset == NewBeginOffset) ? static_cast<
void> (0) : __assert_fail ("IsSplit || BeginOffset == NewBeginOffset"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2274, __PRETTY_FUNCTION__))
;
2275 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2276
2277#ifndef NDEBUG
2278 StringRef OldName = OldPtr->getName();
2279 // Skip through the last '.sroa.' component of the name.
2280 size_t LastSROAPrefix = OldName.rfind(".sroa.");
2281 if (LastSROAPrefix != StringRef::npos) {
2282 OldName = OldName.substr(LastSROAPrefix + strlen(".sroa."));
2283 // Look for an SROA slice index.
2284 size_t IndexEnd = OldName.find_first_not_of("0123456789");
2285 if (IndexEnd != StringRef::npos && OldName[IndexEnd] == '.') {
2286 // Strip the index and look for the offset.
2287 OldName = OldName.substr(IndexEnd + 1);
2288 size_t OffsetEnd = OldName.find_first_not_of("0123456789");
2289 if (OffsetEnd != StringRef::npos && OldName[OffsetEnd] == '.')
2290 // Strip the offset.
2291 OldName = OldName.substr(OffsetEnd + 1);
2292 }
2293 }
2294 // Strip any SROA suffixes as well.
2295 OldName = OldName.substr(0, OldName.find(".sroa_"));
2296#endif
2297
2298 return getAdjustedPtr(IRB, DL, &NewAI,
2299 APInt(DL.getPointerTypeSizeInBits(PointerTy), Offset),
2300 PointerTy,
2301#ifndef NDEBUG
2302 Twine(OldName) + "."
2303#else
2304 Twine()
2305#endif
2306 );
2307 }
2308
2309 /// \brief Compute suitable alignment to access this slice of the *new*
2310 /// alloca.
2311 ///
2312 /// You can optionally pass a type to this routine and if that type's ABI
2313 /// alignment is itself suitable, this will return zero.
2314 unsigned getSliceAlign(Type *Ty = nullptr) {
2315 unsigned NewAIAlign = NewAI.getAlignment();
2316 if (!NewAIAlign)
2317 NewAIAlign = DL.getABITypeAlignment(NewAI.getAllocatedType());
2318 unsigned Align =
2319 MinAlign(NewAIAlign, NewBeginOffset - NewAllocaBeginOffset);
2320 return (Ty && Align == DL.getABITypeAlignment(Ty)) ? 0 : Align;
2321 }
2322
2323 unsigned getIndex(uint64_t Offset) {
2324 assert(VecTy && "Can only call getIndex when rewriting a vector")((VecTy && "Can only call getIndex when rewriting a vector"
) ? static_cast<void> (0) : __assert_fail ("VecTy && \"Can only call getIndex when rewriting a vector\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2324, __PRETTY_FUNCTION__))
;
2325 uint64_t RelOffset = Offset - NewAllocaBeginOffset;
2326 assert(RelOffset / ElementSize < UINT32_MAX && "Index out of bounds")((RelOffset / ElementSize < (4294967295U) && "Index out of bounds"
) ? static_cast<void> (0) : __assert_fail ("RelOffset / ElementSize < UINT32_MAX && \"Index out of bounds\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2326, __PRETTY_FUNCTION__))
;
2327 uint32_t Index = RelOffset / ElementSize;
2328 assert(Index * ElementSize == RelOffset)((Index * ElementSize == RelOffset) ? static_cast<void>
(0) : __assert_fail ("Index * ElementSize == RelOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2328, __PRETTY_FUNCTION__))
;
2329 return Index;
2330 }
2331
2332 void deleteIfTriviallyDead(Value *V) {
2333 Instruction *I = cast<Instruction>(V);
2334 if (isInstructionTriviallyDead(I))
2335 Pass.DeadInsts.insert(I);
2336 }
2337
2338 Value *rewriteVectorizedLoadInst() {
2339 unsigned BeginIndex = getIndex(NewBeginOffset);
2340 unsigned EndIndex = getIndex(NewEndOffset);
2341 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2341, __PRETTY_FUNCTION__))
;
2342
2343 Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2344 return extractVector(IRB, V, BeginIndex, EndIndex, "vec");
2345 }
2346
2347 Value *rewriteIntegerLoad(LoadInst &LI) {
2348 assert(IntTy && "We cannot insert an integer to the alloca")((IntTy && "We cannot insert an integer to the alloca"
) ? static_cast<void> (0) : __assert_fail ("IntTy && \"We cannot insert an integer to the alloca\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2348, __PRETTY_FUNCTION__))
;
2349 assert(!LI.isVolatile())((!LI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!LI.isVolatile()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2349, __PRETTY_FUNCTION__))
;
2350 Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2351 V = convertValue(DL, IRB, V, IntTy);
2352 assert(NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")((NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset"
) ? static_cast<void> (0) : __assert_fail ("NewBeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2352, __PRETTY_FUNCTION__))
;
2353 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2354 if (Offset > 0 || NewEndOffset < NewAllocaEndOffset) {
2355 IntegerType *ExtractTy = Type::getIntNTy(LI.getContext(), SliceSize * 8);
2356 V = extractInteger(DL, IRB, V, ExtractTy, Offset, "extract");
2357 }
2358 // It is possible that the extracted type is not the load type. This
2359 // happens if there is a load past the end of the alloca, and as
2360 // a consequence the slice is narrower but still a candidate for integer
2361 // lowering. To handle this case, we just zero extend the extracted
2362 // integer.
2363 assert(cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 &&((cast<IntegerType>(LI.getType())->getBitWidth() >=
SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2364, __PRETTY_FUNCTION__))
2364 "Can only handle an extract for an overly wide load")((cast<IntegerType>(LI.getType())->getBitWidth() >=
SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? static_cast<void> (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2364, __PRETTY_FUNCTION__))
;
2365 if (cast<IntegerType>(LI.getType())->getBitWidth() > SliceSize * 8)
2366 V = IRB.CreateZExt(V, LI.getType());
2367 return V;
2368 }
2369
2370 bool visitLoadInst(LoadInst &LI) {
2371 DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
2372 Value *OldOp = LI.getOperand(0);
2373 assert(OldOp == OldPtr)((OldOp == OldPtr) ? static_cast<void> (0) : __assert_fail
("OldOp == OldPtr", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2373, __PRETTY_FUNCTION__))
;
2374
2375 unsigned AS = LI.getPointerAddressSpace();
2376
2377 Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), SliceSize * 8)
1
Assuming the condition is false
2
'?' condition is false
2378 : LI.getType();
2379 const bool IsLoadPastEnd = DL.getTypeStoreSize(TargetTy) > SliceSize;
2380 bool IsPtrAdjusted = false;
2381 Value *V;
2382 if (VecTy) {
3
Assuming the condition is false
4
Taking false branch
2383 V = rewriteVectorizedLoadInst();
2384 } else if (IntTy && LI.getType()->isIntegerTy()) {
5
Assuming the condition is false
2385 V = rewriteIntegerLoad(LI);
2386 } else if (NewBeginOffset == NewAllocaBeginOffset &&
2387 NewEndOffset == NewAllocaEndOffset &&
2388 (canConvertValue(DL, NewAllocaTy, TargetTy) ||
2389 (IsLoadPastEnd && NewAllocaTy->isIntegerTy() &&
2390 TargetTy->isIntegerTy()))) {
2391 LoadInst *NewLI = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(),
2392 LI.isVolatile(), LI.getName());
2393 if (LI.isVolatile())
2394 NewLI->setAtomic(LI.getOrdering(), LI.getSynchScope());
2395
2396 // Try to preserve nonnull metadata
2397 if (TargetTy->isPointerTy())
2398 NewLI->copyMetadata(LI, LLVMContext::MD_nonnull);
2399 V = NewLI;
2400
2401 // If this is an integer load past the end of the slice (which means the
2402 // bytes outside the slice are undef or this load is dead) just forcibly
2403 // fix the integer size with correct handling of endianness.
2404 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2405 if (auto *TITy = dyn_cast<IntegerType>(TargetTy))
2406 if (AITy->getBitWidth() < TITy->getBitWidth()) {
2407 V = IRB.CreateZExt(V, TITy, "load.ext");
2408 if (DL.isBigEndian())
2409 V = IRB.CreateShl(V, TITy->getBitWidth() - AITy->getBitWidth(),
2410 "endian_shift");
2411 }
2412 } else {
2413 Type *LTy = TargetTy->getPointerTo(AS);
2414 LoadInst *NewLI = IRB.CreateAlignedLoad(getNewAllocaSlicePtr(IRB, LTy),
2415 getSliceAlign(TargetTy),
2416 LI.isVolatile(), LI.getName());
2417 if (LI.isVolatile())
6
Assuming the condition is false
7
Taking false branch
2418 NewLI->setAtomic(LI.getOrdering(), LI.getSynchScope());
2419
2420 V = NewLI;
2421 IsPtrAdjusted = true;
2422 }
2423 V = convertValue(DL, IRB, V, TargetTy);
2424
2425 if (IsSplit) {
8
Assuming the condition is true
9
Taking true branch
2426 assert(!LI.isVolatile())((!LI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!LI.isVolatile()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2426, __PRETTY_FUNCTION__))
;
2427 assert(LI.getType()->isIntegerTy() &&((LI.getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2428, __PRETTY_FUNCTION__))
2428 "Only integer type loads and stores are split")((LI.getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2428, __PRETTY_FUNCTION__))
;
2429 assert(SliceSize < DL.getTypeStoreSize(LI.getType()) &&((SliceSize < DL.getTypeStoreSize(LI.getType()) &&
"Split load isn't smaller than original load") ? static_cast
<void> (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()) && \"Split load isn't smaller than original load\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2430, __PRETTY_FUNCTION__))
2430 "Split load isn't smaller than original load")((SliceSize < DL.getTypeStoreSize(LI.getType()) &&
"Split load isn't smaller than original load") ? static_cast
<void> (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()) && \"Split load isn't smaller than original load\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2430, __PRETTY_FUNCTION__))
;
2431 assert(LI.getType()->getIntegerBitWidth() ==((LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(LI.getType()) && "Non-byte-multiple bit width") ? static_cast
<void> (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2433, __PRETTY_FUNCTION__))
2432 DL.getTypeStoreSizeInBits(LI.getType()) &&((LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(LI.getType()) && "Non-byte-multiple bit width") ? static_cast
<void> (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2433, __PRETTY_FUNCTION__))
2433 "Non-byte-multiple bit width")((LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(LI.getType()) && "Non-byte-multiple bit width") ? static_cast
<void> (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2433, __PRETTY_FUNCTION__))
;
2434 // Move the insertion point just past the load so that we can refer to it.
2435 IRB.SetInsertPoint(&*std::next(BasicBlock::iterator(&LI)));
2436 // Create a placeholder value with the same type as LI to use as the
2437 // basis for the new value. This allows us to replace the uses of LI with
2438 // the computed value, and then replace the placeholder with LI, leaving
2439 // LI only used for this computation.
2440 Value *Placeholder =
2441 new LoadInst(UndefValue::get(LI.getType()->getPointerTo(AS)));
2442 V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
2443 "insert");
2444 LI.replaceAllUsesWith(V);
2445 Placeholder->replaceAllUsesWith(&LI);
2446 delete Placeholder;
10
Memory is released
2447 } else {
2448 LI.replaceAllUsesWith(V);
2449 }
2450
2451 Pass.DeadInsts.insert(&LI);
2452 deleteIfTriviallyDead(OldOp);
2453 DEBUG(dbgs() << " to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *V <<
"\n"; } } while (false)
;
11
Within the expansion of the macro 'DEBUG':
a
Assuming 'DebugFlag' is not equal to 0
b
Assuming the condition is true
c
Use of memory after it is freed
2454 return !LI.isVolatile() && !IsPtrAdjusted;
2455 }
2456
2457 bool rewriteVectorizedStoreInst(Value *V, StoreInst &SI, Value *OldOp) {
2458 if (V->getType() != VecTy) {
2459 unsigned BeginIndex = getIndex(NewBeginOffset);
2460 unsigned EndIndex = getIndex(NewEndOffset);
2461 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2461, __PRETTY_FUNCTION__))
;
2462 unsigned NumElements = EndIndex - BeginIndex;
2463 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")((NumElements <= VecTy->getNumElements() && "Too many elements!"
) ? static_cast<void> (0) : __assert_fail ("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2463, __PRETTY_FUNCTION__))
;
2464 Type *SliceTy = (NumElements == 1)
2465 ? ElementTy
2466 : VectorType::get(ElementTy, NumElements);
2467 if (V->getType() != SliceTy)
2468 V = convertValue(DL, IRB, V, SliceTy);
2469
2470 // Mix in the existing elements.
2471 Value *Old = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2472 V = insertVector(IRB, Old, V, BeginIndex, "vec");
2473 }
2474 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
2475 Pass.DeadInsts.insert(&SI);
2476
2477 (void)Store;
2478 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2479 return true;
2480 }
2481
2482 bool rewriteIntegerStore(Value *V, StoreInst &SI) {
2483 assert(IntTy && "We cannot extract an integer from the alloca")((IntTy && "We cannot extract an integer from the alloca"
) ? static_cast<void> (0) : __assert_fail ("IntTy && \"We cannot extract an integer from the alloca\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2483, __PRETTY_FUNCTION__))
;
2484 assert(!SI.isVolatile())((!SI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!SI.isVolatile()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2484, __PRETTY_FUNCTION__))
;
2485 if (DL.getTypeSizeInBits(V->getType()) != IntTy->getBitWidth()) {
2486 Value *Old =
2487 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2488 Old = convertValue(DL, IRB, Old, IntTy);
2489 assert(BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")((BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2489, __PRETTY_FUNCTION__))
;
2490 uint64_t Offset = BeginOffset - NewAllocaBeginOffset;
2491 V = insertInteger(DL, IRB, Old, SI.getValueOperand(), Offset, "insert");
2492 }
2493 V = convertValue(DL, IRB, V, NewAllocaTy);
2494 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
2495 Store->copyMetadata(SI, LLVMContext::MD_mem_parallel_loop_access);
2496 Pass.DeadInsts.insert(&SI);
2497 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2498 return true;
2499 }
2500
2501 bool visitStoreInst(StoreInst &SI) {
2502 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
2503 Value *OldOp = SI.getOperand(1);
2504 assert(OldOp == OldPtr)((OldOp == OldPtr) ? static_cast<void> (0) : __assert_fail
("OldOp == OldPtr", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2504, __PRETTY_FUNCTION__))
;
2505
2506 Value *V = SI.getValueOperand();
2507
2508 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2509 // alloca that should be re-examined after promoting this alloca.
2510 if (V->getType()->isPointerTy())
2511 if (AllocaInst *AI = dyn_cast<AllocaInst>(V->stripInBoundsOffsets()))
2512 Pass.PostPromotionWorklist.insert(AI);
2513
2514 if (SliceSize < DL.getTypeStoreSize(V->getType())) {
2515 assert(!SI.isVolatile())((!SI.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!SI.isVolatile()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2515, __PRETTY_FUNCTION__))
;
2516 assert(V->getType()->isIntegerTy() &&((V->getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2517, __PRETTY_FUNCTION__))
2517 "Only integer type loads and stores are split")((V->getType()->isIntegerTy() && "Only integer type loads and stores are split"
) ? static_cast<void> (0) : __assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2517, __PRETTY_FUNCTION__))
;
2518 assert(V->getType()->getIntegerBitWidth() ==((V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(V->getType()) && "Non-byte-multiple bit width") ?
static_cast<void> (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2520, __PRETTY_FUNCTION__))
2519 DL.getTypeStoreSizeInBits(V->getType()) &&((V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(V->getType()) && "Non-byte-multiple bit width") ?
static_cast<void> (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2520, __PRETTY_FUNCTION__))
2520 "Non-byte-multiple bit width")((V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits
(V->getType()) && "Non-byte-multiple bit width") ?
static_cast<void> (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2520, __PRETTY_FUNCTION__))
;
2521 IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), SliceSize * 8);
2522 V = extractInteger(DL, IRB, V, NarrowTy, NewBeginOffset - BeginOffset,
2523 "extract");
2524 }
2525
2526 if (VecTy)
2527 return rewriteVectorizedStoreInst(V, SI, OldOp);
2528 if (IntTy && V->getType()->isIntegerTy())
2529 return rewriteIntegerStore(V, SI);
2530
2531 const bool IsStorePastEnd = DL.getTypeStoreSize(V->getType()) > SliceSize;
2532 StoreInst *NewSI;
2533 if (NewBeginOffset == NewAllocaBeginOffset &&
2534 NewEndOffset == NewAllocaEndOffset &&
2535 (canConvertValue(DL, V->getType(), NewAllocaTy) ||
2536 (IsStorePastEnd && NewAllocaTy->isIntegerTy() &&
2537 V->getType()->isIntegerTy()))) {
2538 // If this is an integer store past the end of slice (and thus the bytes
2539 // past that point are irrelevant or this is unreachable), truncate the
2540 // value prior to storing.
2541 if (auto *VITy = dyn_cast<IntegerType>(V->getType()))
2542 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2543 if (VITy->getBitWidth() > AITy->getBitWidth()) {
2544 if (DL.isBigEndian())
2545 V = IRB.CreateLShr(V, VITy->getBitWidth() - AITy->getBitWidth(),
2546 "endian_shift");
2547 V = IRB.CreateTrunc(V, AITy, "load.trunc");
2548 }
2549
2550 V = convertValue(DL, IRB, V, NewAllocaTy);
2551 NewSI = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
2552 SI.isVolatile());
2553 } else {
2554 unsigned AS = SI.getPointerAddressSpace();
2555 Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
2556 NewSI = IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(V->getType()),
2557 SI.isVolatile());
2558 }
2559 NewSI->copyMetadata(SI, LLVMContext::MD_mem_parallel_loop_access);
2560 if (SI.isVolatile())
2561 NewSI->setAtomic(SI.getOrdering(), SI.getSynchScope());
2562 Pass.DeadInsts.insert(&SI);
2563 deleteIfTriviallyDead(OldOp);
2564
2565 DEBUG(dbgs() << " to: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *NewSI <<
"\n"; } } while (false)
;
2566 return NewSI->getPointerOperand() == &NewAI && !SI.isVolatile();
2567 }
2568
2569 /// \brief Compute an integer value from splatting an i8 across the given
2570 /// number of bytes.
2571 ///
2572 /// Note that this routine assumes an i8 is a byte. If that isn't true, don't
2573 /// call this routine.
2574 /// FIXME: Heed the advice above.
2575 ///
2576 /// \param V The i8 value to splat.
2577 /// \param Size The number of bytes in the output (assuming i8 is one byte)
2578 Value *getIntegerSplat(Value *V, unsigned Size) {
2579 assert(Size > 0 && "Expected a positive number of bytes.")((Size > 0 && "Expected a positive number of bytes."
) ? static_cast<void> (0) : __assert_fail ("Size > 0 && \"Expected a positive number of bytes.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2579, __PRETTY_FUNCTION__))
;
2580 IntegerType *VTy = cast<IntegerType>(V->getType());
2581 assert(VTy->getBitWidth() == 8 && "Expected an i8 value for the byte")((VTy->getBitWidth() == 8 && "Expected an i8 value for the byte"
) ? static_cast<void> (0) : __assert_fail ("VTy->getBitWidth() == 8 && \"Expected an i8 value for the byte\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2581, __PRETTY_FUNCTION__))
;
2582 if (Size == 1)
2583 return V;
2584
2585 Type *SplatIntTy = Type::getIntNTy(VTy->getContext(), Size * 8);
2586 V = IRB.CreateMul(
2587 IRB.CreateZExt(V, SplatIntTy, "zext"),
2588 ConstantExpr::getUDiv(
2589 Constant::getAllOnesValue(SplatIntTy),
2590 ConstantExpr::getZExt(Constant::getAllOnesValue(V->getType()),
2591 SplatIntTy)),
2592 "isplat");
2593 return V;
2594 }
2595
2596 /// \brief Compute a vector splat for a given element value.
2597 Value *getVectorSplat(Value *V, unsigned NumElements) {
2598 V = IRB.CreateVectorSplat(NumElements, V, "vsplat");
2599 DEBUG(dbgs() << " splat: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " splat: " << *V <<
"\n"; } } while (false)
;
2600 return V;
2601 }
2602
2603 bool visitMemSetInst(MemSetInst &II) {
2604 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2605 assert(II.getRawDest() == OldPtr)((II.getRawDest() == OldPtr) ? static_cast<void> (0) : __assert_fail
("II.getRawDest() == OldPtr", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2605, __PRETTY_FUNCTION__))
;
2606
2607 // If the memset has a variable size, it cannot be split, just adjust the
2608 // pointer to the new alloca.
2609 if (!isa<Constant>(II.getLength())) {
2610 assert(!IsSplit)((!IsSplit) ? static_cast<void> (0) : __assert_fail ("!IsSplit"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2610, __PRETTY_FUNCTION__))
;
2611 assert(NewBeginOffset == BeginOffset)((NewBeginOffset == BeginOffset) ? static_cast<void> (0
) : __assert_fail ("NewBeginOffset == BeginOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2611, __PRETTY_FUNCTION__))
;
2612 II.setDest(getNewAllocaSlicePtr(IRB, OldPtr->getType()));
2613 Type *CstTy = II.getAlignmentCst()->getType();
2614 II.setAlignment(ConstantInt::get(CstTy, getSliceAlign()));
2615
2616 deleteIfTriviallyDead(OldPtr);
2617 return false;
2618 }
2619
2620 // Record this instruction for deletion.
2621 Pass.DeadInsts.insert(&II);
2622
2623 Type *AllocaTy = NewAI.getAllocatedType();
2624 Type *ScalarTy = AllocaTy->getScalarType();
2625
2626 // If this doesn't map cleanly onto the alloca type, and that type isn't
2627 // a single value type, just emit a memset.
2628 if (!VecTy && !IntTy &&
2629 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2630 SliceSize != DL.getTypeStoreSize(AllocaTy) ||
2631 !AllocaTy->isSingleValueType() ||
2632 !DL.isLegalInteger(DL.getTypeSizeInBits(ScalarTy)) ||
2633 DL.getTypeSizeInBits(ScalarTy) % 8 != 0)) {
2634 Type *SizeTy = II.getLength()->getType();
2635 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2636 CallInst *New = IRB.CreateMemSet(
2637 getNewAllocaSlicePtr(IRB, OldPtr->getType()), II.getValue(), Size,
2638 getSliceAlign(), II.isVolatile());
2639 (void)New;
2640 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2641 return false;
2642 }
2643
2644 // If we can represent this as a simple value, we have to build the actual
2645 // value to store, which requires expanding the byte present in memset to
2646 // a sensible representation for the alloca type. This is essentially
2647 // splatting the byte to a sufficiently wide integer, splatting it across
2648 // any desired vector width, and bitcasting to the final type.
2649 Value *V;
2650
2651 if (VecTy) {
2652 // If this is a memset of a vectorized alloca, insert it.
2653 assert(ElementTy == ScalarTy)((ElementTy == ScalarTy) ? static_cast<void> (0) : __assert_fail
("ElementTy == ScalarTy", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2653, __PRETTY_FUNCTION__))
;
2654
2655 unsigned BeginIndex = getIndex(NewBeginOffset);
2656 unsigned EndIndex = getIndex(NewEndOffset);
2657 assert(EndIndex > BeginIndex && "Empty vector!")((EndIndex > BeginIndex && "Empty vector!") ? static_cast
<void> (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2657, __PRETTY_FUNCTION__))
;
2658 unsigned NumElements = EndIndex - BeginIndex;
2659 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")((NumElements <= VecTy->getNumElements() && "Too many elements!"
) ? static_cast<void> (0) : __assert_fail ("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2659, __PRETTY_FUNCTION__))
;
2660
2661 Value *Splat =
2662 getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ElementTy) / 8);
2663 Splat = convertValue(DL, IRB, Splat, ElementTy);
2664 if (NumElements > 1)
2665 Splat = getVectorSplat(Splat, NumElements);
2666
2667 Value *Old =
2668 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2669 V = insertVector(IRB, Old, Splat, BeginIndex, "vec");
2670 } else if (IntTy) {
2671 // If this is a memset on an alloca where we can widen stores, insert the
2672 // set integer.
2673 assert(!II.isVolatile())((!II.isVolatile()) ? static_cast<void> (0) : __assert_fail
("!II.isVolatile()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2673, __PRETTY_FUNCTION__))
;
2674
2675 uint64_t Size = NewEndOffset - NewBeginOffset;
2676 V = getIntegerSplat(II.getValue(), Size);
2677
2678 if (IntTy && (BeginOffset != NewAllocaBeginOffset ||
2679 EndOffset != NewAllocaBeginOffset)) {
2680 Value *Old =
2681 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2682 Old = convertValue(DL, IRB, Old, IntTy);
2683 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2684 V = insertInteger(DL, IRB, Old, V, Offset, "insert");
2685 } else {
2686 assert(V->getType() == IntTy &&((V->getType() == IntTy && "Wrong type for an alloca wide integer!"
) ? static_cast<void> (0) : __assert_fail ("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2687, __PRETTY_FUNCTION__))
2687 "Wrong type for an alloca wide integer!")((V->getType() == IntTy && "Wrong type for an alloca wide integer!"
) ? static_cast<void> (0) : __assert_fail ("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2687, __PRETTY_FUNCTION__))
;
2688 }
2689 V = convertValue(DL, IRB, V, AllocaTy);
2690 } else {
2691 // Established these invariants above.
2692 assert(NewBeginOffset == NewAllocaBeginOffset)((NewBeginOffset == NewAllocaBeginOffset) ? static_cast<void
> (0) : __assert_fail ("NewBeginOffset == NewAllocaBeginOffset"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2692, __PRETTY_FUNCTION__))
;
2693 assert(NewEndOffset == NewAllocaEndOffset)((NewEndOffset == NewAllocaEndOffset) ? static_cast<void>
(0) : __assert_fail ("NewEndOffset == NewAllocaEndOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2693, __PRETTY_FUNCTION__))
;
2694
2695 V = getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ScalarTy) / 8);
2696 if (VectorType *AllocaVecTy = dyn_cast<VectorType>(AllocaTy))
2697 V = getVectorSplat(V, AllocaVecTy->getNumElements());
2698
2699 V = convertValue(DL, IRB, V, AllocaTy);
2700 }
2701
2702 Value *New = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
2703 II.isVolatile());
2704 (void)New;
2705 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2706 return !II.isVolatile();
2707 }
2708
2709 bool visitMemTransferInst(MemTransferInst &II) {
2710 // Rewriting of memory transfer instructions can be a bit tricky. We break
2711 // them into two categories: split intrinsics and unsplit intrinsics.
2712
2713 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2714
2715 bool IsDest = &II.getRawDestUse() == OldUse;
2716 assert((IsDest && II.getRawDest() == OldPtr) ||(((IsDest && II.getRawDest() == OldPtr) || (!IsDest &&
II.getRawSource() == OldPtr)) ? static_cast<void> (0) :
__assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2717, __PRETTY_FUNCTION__))
2717 (!IsDest && II.getRawSource() == OldPtr))(((IsDest && II.getRawDest() == OldPtr) || (!IsDest &&
II.getRawSource() == OldPtr)) ? static_cast<void> (0) :
__assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2717, __PRETTY_FUNCTION__))
;
2718
2719 unsigned SliceAlign = getSliceAlign();
2720
2721 // For unsplit intrinsics, we simply modify the source and destination
2722 // pointers in place. This isn't just an optimization, it is a matter of
2723 // correctness. With unsplit intrinsics we may be dealing with transfers
2724 // within a single alloca before SROA ran, or with transfers that have
2725 // a variable length. We may also be dealing with memmove instead of
2726 // memcpy, and so simply updating the pointers is the necessary for us to
2727 // update both source and dest of a single call.
2728 if (!IsSplittable) {
2729 Value *AdjustedPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2730 if (IsDest)
2731 II.setDest(AdjustedPtr);
2732 else
2733 II.setSource(AdjustedPtr);
2734
2735 if (II.getAlignment() > SliceAlign) {
2736 Type *CstTy = II.getAlignmentCst()->getType();
2737 II.setAlignment(
2738 ConstantInt::get(CstTy, MinAlign(II.getAlignment(), SliceAlign)));
2739 }
2740
2741 DEBUG(dbgs() << " to: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << II <<
"\n"; } } while (false)
;
2742 deleteIfTriviallyDead(OldPtr);
2743 return false;
2744 }
2745 // For split transfer intrinsics we have an incredibly useful assurance:
2746 // the source and destination do not reside within the same alloca, and at
2747 // least one of them does not escape. This means that we can replace
2748 // memmove with memcpy, and we don't need to worry about all manner of
2749 // downsides to splitting and transforming the operations.
2750
2751 // If this doesn't map cleanly onto the alloca type, and that type isn't
2752 // a single value type, just emit a memcpy.
2753 bool EmitMemCpy =
2754 !VecTy && !IntTy &&
2755 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2756 SliceSize != DL.getTypeStoreSize(NewAI.getAllocatedType()) ||
2757 !NewAI.getAllocatedType()->isSingleValueType());
2758
2759 // If we're just going to emit a memcpy, the alloca hasn't changed, and the
2760 // size hasn't been shrunk based on analysis of the viable range, this is
2761 // a no-op.
2762 if (EmitMemCpy && &OldAI == &NewAI) {
2763 // Ensure the start lines up.
2764 assert(NewBeginOffset == BeginOffset)((NewBeginOffset == BeginOffset) ? static_cast<void> (0
) : __assert_fail ("NewBeginOffset == BeginOffset", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2764, __PRETTY_FUNCTION__))
;
2765
2766 // Rewrite the size as needed.
2767 if (NewEndOffset != EndOffset)
2768 II.setLength(ConstantInt::get(II.getLength()->getType(),
2769 NewEndOffset - NewBeginOffset));
2770 return false;
2771 }
2772 // Record this instruction for deletion.
2773 Pass.DeadInsts.insert(&II);
2774
2775 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2776 // alloca that should be re-examined after rewriting this instruction.
2777 Value *OtherPtr = IsDest ? II.getRawSource() : II.getRawDest();
2778 if (AllocaInst *AI =
2779 dyn_cast<AllocaInst>(OtherPtr->stripInBoundsOffsets())) {
2780 assert(AI != &OldAI && AI != &NewAI &&((AI != &OldAI && AI != &NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? static_cast<void> (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2781, __PRETTY_FUNCTION__))
2781 "Splittable transfers cannot reach the same alloca on both ends.")((AI != &OldAI && AI != &NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? static_cast<void> (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2781, __PRETTY_FUNCTION__))
;
2782 Pass.Worklist.insert(AI);
2783 }
2784
2785 Type *OtherPtrTy = OtherPtr->getType();
2786 unsigned OtherAS = OtherPtrTy->getPointerAddressSpace();
2787
2788 // Compute the relative offset for the other pointer within the transfer.
2789 unsigned IntPtrWidth = DL.getPointerSizeInBits(OtherAS);
2790 APInt OtherOffset(IntPtrWidth, NewBeginOffset - BeginOffset);
2791 unsigned OtherAlign = MinAlign(II.getAlignment() ? II.getAlignment() : 1,
2792 OtherOffset.zextOrTrunc(64).getZExtValue());
2793
2794 if (EmitMemCpy) {
2795 // Compute the other pointer, folding as much as possible to produce
2796 // a single, simple GEP in most cases.
2797 OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
2798 OtherPtr->getName() + ".");
2799
2800 Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2801 Type *SizeTy = II.getLength()->getType();
2802 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2803
2804 CallInst *New = IRB.CreateMemCpy(
2805 IsDest ? OurPtr : OtherPtr, IsDest ? OtherPtr : OurPtr, Size,
2806 MinAlign(SliceAlign, OtherAlign), II.isVolatile());
2807 (void)New;
2808 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2809 return false;
2810 }
2811
2812 bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
2813 NewEndOffset == NewAllocaEndOffset;
2814 uint64_t Size = NewEndOffset - NewBeginOffset;
2815 unsigned BeginIndex = VecTy ? getIndex(NewBeginOffset) : 0;
2816 unsigned EndIndex = VecTy ? getIndex(NewEndOffset) : 0;
2817 unsigned NumElements = EndIndex - BeginIndex;
2818 IntegerType *SubIntTy =
2819 IntTy ? Type::getIntNTy(IntTy->getContext(), Size * 8) : nullptr;
2820
2821 // Reset the other pointer type to match the register type we're going to
2822 // use, but using the address space of the original other pointer.
2823 if (VecTy && !IsWholeAlloca) {
2824 if (NumElements == 1)
2825 OtherPtrTy = VecTy->getElementType();
2826 else
2827 OtherPtrTy = VectorType::get(VecTy->getElementType(), NumElements);
2828
2829 OtherPtrTy = OtherPtrTy->getPointerTo(OtherAS);
2830 } else if (IntTy && !IsWholeAlloca) {
2831 OtherPtrTy = SubIntTy->getPointerTo(OtherAS);
2832 } else {
2833 OtherPtrTy = NewAllocaTy->getPointerTo(OtherAS);
2834 }
2835
2836 Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
2837 OtherPtr->getName() + ".");
2838 unsigned SrcAlign = OtherAlign;
2839 Value *DstPtr = &NewAI;
2840 unsigned DstAlign = SliceAlign;
2841 if (!IsDest) {
2842 std::swap(SrcPtr, DstPtr);
2843 std::swap(SrcAlign, DstAlign);
2844 }
2845
2846 Value *Src;
2847 if (VecTy && !IsWholeAlloca && !IsDest) {
2848 Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2849 Src = extractVector(IRB, Src, BeginIndex, EndIndex, "vec");
2850 } else if (IntTy && !IsWholeAlloca && !IsDest) {
2851 Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2852 Src = convertValue(DL, IRB, Src, IntTy);
2853 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2854 Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract");
2855 } else {
2856 Src =
2857 IRB.CreateAlignedLoad(SrcPtr, SrcAlign, II.isVolatile(), "copyload");
2858 }
2859
2860 if (VecTy && !IsWholeAlloca && IsDest) {
2861 Value *Old =
2862 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2863 Src = insertVector(IRB, Old, Src, BeginIndex, "vec");
2864 } else if (IntTy && !IsWholeAlloca && IsDest) {
2865 Value *Old =
2866 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2867 Old = convertValue(DL, IRB, Old, IntTy);
2868 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2869 Src = insertInteger(DL, IRB, Old, Src, Offset, "insert");
2870 Src = convertValue(DL, IRB, Src, NewAllocaTy);
2871 }
2872
2873 StoreInst *Store = cast<StoreInst>(
2874 IRB.CreateAlignedStore(Src, DstPtr, DstAlign, II.isVolatile()));
2875 (void)Store;
2876 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2877 return !II.isVolatile();
2878 }
2879
2880 bool visitIntrinsicInst(IntrinsicInst &II) {
2881 assert(II.getIntrinsicID() == Intrinsic::lifetime_start ||((II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID
() == Intrinsic::lifetime_end) ? static_cast<void> (0) :
__assert_fail ("II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2882, __PRETTY_FUNCTION__))
2882 II.getIntrinsicID() == Intrinsic::lifetime_end)((II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID
() == Intrinsic::lifetime_end) ? static_cast<void> (0) :
__assert_fail ("II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2882, __PRETTY_FUNCTION__))
;
2883 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2884 assert(II.getArgOperand(1) == OldPtr)((II.getArgOperand(1) == OldPtr) ? static_cast<void> (0
) : __assert_fail ("II.getArgOperand(1) == OldPtr", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2884, __PRETTY_FUNCTION__))
;
2885
2886 // Record this instruction for deletion.
2887 Pass.DeadInsts.insert(&II);
2888
2889 // Lifetime intrinsics are only promotable if they cover the whole alloca.
2890 // Therefore, we drop lifetime intrinsics which don't cover the whole
2891 // alloca.
2892 // (In theory, intrinsics which partially cover an alloca could be
2893 // promoted, but PromoteMemToReg doesn't handle that case.)
2894 // FIXME: Check whether the alloca is promotable before dropping the
2895 // lifetime intrinsics?
2896 if (NewBeginOffset != NewAllocaBeginOffset ||
2897 NewEndOffset != NewAllocaEndOffset)
2898 return true;
2899
2900 ConstantInt *Size =
2901 ConstantInt::get(cast<IntegerType>(II.getArgOperand(0)->getType()),
2902 NewEndOffset - NewBeginOffset);
2903 Value *Ptr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2904 Value *New;
2905 if (II.getIntrinsicID() == Intrinsic::lifetime_start)
2906 New = IRB.CreateLifetimeStart(Ptr, Size);
2907 else
2908 New = IRB.CreateLifetimeEnd(Ptr, Size);
2909
2910 (void)New;
2911 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2912
2913 return true;
2914 }
2915
2916 bool visitPHINode(PHINode &PN) {
2917 DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
2918 assert(BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable")((BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"PHIs are unsplittable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2918, __PRETTY_FUNCTION__))
;
2919 assert(EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable")((EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("EndOffset <= NewAllocaEndOffset && \"PHIs are unsplittable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2919, __PRETTY_FUNCTION__))
;
2920
2921 // We would like to compute a new pointer in only one place, but have it be
2922 // as local as possible to the PHI. To do that, we re-use the location of
2923 // the old pointer, which necessarily must be in the right position to
2924 // dominate the PHI.
2925 IRBuilderTy PtrBuilder(IRB);
2926 if (isa<PHINode>(OldPtr))
2927 PtrBuilder.SetInsertPoint(&*OldPtr->getParent()->getFirstInsertionPt());
2928 else
2929 PtrBuilder.SetInsertPoint(OldPtr);
2930 PtrBuilder.SetCurrentDebugLocation(OldPtr->getDebugLoc());
2931
2932 Value *NewPtr = getNewAllocaSlicePtr(PtrBuilder, OldPtr->getType());
2933 // Replace the operands which were using the old pointer.
2934 std::replace(PN.op_begin(), PN.op_end(), cast<Value>(OldPtr), NewPtr);
2935
2936 DEBUG(dbgs() << " to: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << PN <<
"\n"; } } while (false)
;
2937 deleteIfTriviallyDead(OldPtr);
2938
2939 // PHIs can't be promoted on their own, but often can be speculated. We
2940 // check the speculation outside of the rewriter so that we see the
2941 // fully-rewritten alloca.
2942 PHIUsers.insert(&PN);
2943 return true;
2944 }
2945
2946 bool visitSelectInst(SelectInst &SI) {
2947 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
2948 assert((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) &&(((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr
) && "Pointer isn't an operand!") ? static_cast<void
> (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2949, __PRETTY_FUNCTION__))
2949 "Pointer isn't an operand!")(((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr
) && "Pointer isn't an operand!") ? static_cast<void
> (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2949, __PRETTY_FUNCTION__))
;
2950 assert(BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable")((BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("BeginOffset >= NewAllocaBeginOffset && \"Selects are unsplittable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2950, __PRETTY_FUNCTION__))
;
2951 assert(EndOffset <= NewAllocaEndOffset && "Selects are unsplittable")((EndOffset <= NewAllocaEndOffset && "Selects are unsplittable"
) ? static_cast<void> (0) : __assert_fail ("EndOffset <= NewAllocaEndOffset && \"Selects are unsplittable\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 2951, __PRETTY_FUNCTION__))
;
2952
2953 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2954 // Replace the operands which were using the old pointer.
2955 if (SI.getOperand(1) == OldPtr)
2956 SI.setOperand(1, NewPtr);
2957 if (SI.getOperand(2) == OldPtr)
2958 SI.setOperand(2, NewPtr);
2959
2960 DEBUG(dbgs() << " to: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << SI <<
"\n"; } } while (false)
;
2961 deleteIfTriviallyDead(OldPtr);
2962
2963 // Selects can't be promoted on their own, but often can be speculated. We
2964 // check the speculation outside of the rewriter so that we see the
2965 // fully-rewritten alloca.
2966 SelectUsers.insert(&SI);
2967 return true;
2968 }
2969};
2970
2971namespace {
2972/// \brief Visitor to rewrite aggregate loads and stores as scalar.
2973///
2974/// This pass aggressively rewrites all aggregate loads and stores on
2975/// a particular pointer (or any pointer derived from it which we can identify)
2976/// with scalar loads and stores.
2977class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
2978 // Befriend the base class so it can delegate to private visit methods.
2979 friend class llvm::InstVisitor<AggLoadStoreRewriter, bool>;
2980
2981 /// Queue of pointer uses to analyze and potentially rewrite.
2982 SmallVector<Use *, 8> Queue;
2983
2984 /// Set to prevent us from cycling with phi nodes and loops.
2985 SmallPtrSet<User *, 8> Visited;
2986
2987 /// The current pointer use being rewritten. This is used to dig up the used
2988 /// value (as opposed to the user).
2989 Use *U;
2990
2991public:
2992 /// Rewrite loads and stores through a pointer and all pointers derived from
2993 /// it.
2994 bool rewrite(Instruction &I) {
2995 DEBUG(dbgs() << " Rewriting FCA loads and stores...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting FCA loads and stores...\n"
; } } while (false)
;
2996 enqueueUsers(I);
2997 bool Changed = false;
2998 while (!Queue.empty()) {
2999 U = Queue.pop_back_val();
3000 Changed |= visit(cast<Instruction>(U->getUser()));
3001 }
3002 return Changed;
3003 }
3004
3005private:
3006 /// Enqueue all the users of the given instruction for further processing.
3007 /// This uses a set to de-duplicate users.
3008 void enqueueUsers(Instruction &I) {
3009 for (Use &U : I.uses())
3010 if (Visited.insert(U.getUser()).second)
3011 Queue.push_back(&U);
3012 }
3013
3014 // Conservative default is to not rewrite anything.
3015 bool visitInstruction(Instruction &I) { return false; }
3016
3017 /// \brief Generic recursive split emission class.
3018 template <typename Derived> class OpSplitter {
3019 protected:
3020 /// The builder used to form new instructions.
3021 IRBuilderTy IRB;
3022 /// The indices which to be used with insert- or extractvalue to select the
3023 /// appropriate value within the aggregate.
3024 SmallVector<unsigned, 4> Indices;
3025 /// The indices to a GEP instruction which will move Ptr to the correct slot
3026 /// within the aggregate.
3027 SmallVector<Value *, 4> GEPIndices;
3028 /// The base pointer of the original op, used as a base for GEPing the
3029 /// split operations.
3030 Value *Ptr;
3031
3032 /// Initialize the splitter with an insertion point, Ptr and start with a
3033 /// single zero GEP index.
3034 OpSplitter(Instruction *InsertionPoint, Value *Ptr)
3035 : IRB(InsertionPoint), GEPIndices(1, IRB.getInt32(0)), Ptr(Ptr) {}
3036
3037 public:
3038 /// \brief Generic recursive split emission routine.
3039 ///
3040 /// This method recursively splits an aggregate op (load or store) into
3041 /// scalar or vector ops. It splits recursively until it hits a single value
3042 /// and emits that single value operation via the template argument.
3043 ///
3044 /// The logic of this routine relies on GEPs and insertvalue and
3045 /// extractvalue all operating with the same fundamental index list, merely
3046 /// formatted differently (GEPs need actual values).
3047 ///
3048 /// \param Ty The type being split recursively into smaller ops.
3049 /// \param Agg The aggregate value being built up or stored, depending on
3050 /// whether this is splitting a load or a store respectively.
3051 void emitSplitOps(Type *Ty, Value *&Agg, const Twine &Name) {
3052 if (Ty->isSingleValueType())
3053 return static_cast<Derived *>(this)->emitFunc(Ty, Agg, Name);
3054
3055 if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
3056 unsigned OldSize = Indices.size();
3057 (void)OldSize;
3058 for (unsigned Idx = 0, Size = ATy->getNumElements(); Idx != Size;
3059 ++Idx) {
3060 assert(Indices.size() == OldSize && "Did not return to the old size")((Indices.size() == OldSize && "Did not return to the old size"
) ? static_cast<void> (0) : __assert_fail ("Indices.size() == OldSize && \"Did not return to the old size\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3060, __PRETTY_FUNCTION__))
;
3061 Indices.push_back(Idx);
3062 GEPIndices.push_back(IRB.getInt32(Idx));
3063 emitSplitOps(ATy->getElementType(), Agg, Name + "." + Twine(Idx));
3064 GEPIndices.pop_back();
3065 Indices.pop_back();
3066 }
3067 return;
3068 }
3069
3070 if (StructType *STy = dyn_cast<StructType>(Ty)) {
3071 unsigned OldSize = Indices.size();
3072 (void)OldSize;
3073 for (unsigned Idx = 0, Size = STy->getNumElements(); Idx != Size;
3074 ++Idx) {
3075 assert(Indices.size() == OldSize && "Did not return to the old size")((Indices.size() == OldSize && "Did not return to the old size"
) ? static_cast<void> (0) : __assert_fail ("Indices.size() == OldSize && \"Did not return to the old size\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3075, __PRETTY_FUNCTION__))
;
3076 Indices.push_back(Idx);
3077 GEPIndices.push_back(IRB.getInt32(Idx));
3078 emitSplitOps(STy->getElementType(Idx), Agg, Name + "." + Twine(Idx));
3079 GEPIndices.pop_back();
3080 Indices.pop_back();
3081 }
3082 return;
3083 }
3084
3085 llvm_unreachable("Only arrays and structs are aggregate loadable types")::llvm::llvm_unreachable_internal("Only arrays and structs are aggregate loadable types"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3085)
;
3086 }
3087 };
3088
3089 struct LoadOpSplitter : public OpSplitter<LoadOpSplitter> {
3090 LoadOpSplitter(Instruction *InsertionPoint, Value *Ptr)
3091 : OpSplitter<LoadOpSplitter>(InsertionPoint, Ptr) {}
3092
3093 /// Emit a leaf load of a single value. This is called at the leaves of the
3094 /// recursive emission to actually load values.
3095 void emitFunc(Type *Ty, Value *&Agg, const Twine &Name) {
3096 assert(Ty->isSingleValueType())((Ty->isSingleValueType()) ? static_cast<void> (0) :
__assert_fail ("Ty->isSingleValueType()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3096, __PRETTY_FUNCTION__))
;
3097 // Load the single value and insert it using the indices.
3098 Value *GEP =
3099 IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
3100 Value *Load = IRB.CreateLoad(GEP, Name + ".load");
3101 Agg = IRB.CreateInsertValue(Agg, Load, Indices, Name + ".insert");
3102 DEBUG(dbgs() << " to: " << *Load << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Load <<
"\n"; } } while (false)
;
3103 }
3104 };
3105
3106 bool visitLoadInst(LoadInst &LI) {
3107 assert(LI.getPointerOperand() == *U)((LI.getPointerOperand() == *U) ? static_cast<void> (0)
: __assert_fail ("LI.getPointerOperand() == *U", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3107, __PRETTY_FUNCTION__))
;
3108 if (!LI.isSimple() || LI.getType()->isSingleValueType())
3109 return false;
3110
3111 // We have an aggregate being loaded, split it apart.
3112 DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
3113 LoadOpSplitter Splitter(&LI, *U);
3114 Value *V = UndefValue::get(LI.getType());
3115 Splitter.emitSplitOps(LI.getType(), V, LI.getName() + ".fca");
3116 LI.replaceAllUsesWith(V);
3117 LI.eraseFromParent();
3118 return true;
3119 }
3120
3121 struct StoreOpSplitter : public OpSplitter<StoreOpSplitter> {
3122 StoreOpSplitter(Instruction *InsertionPoint, Value *Ptr)
3123 : OpSplitter<StoreOpSplitter>(InsertionPoint, Ptr) {}
3124
3125 /// Emit a leaf store of a single value. This is called at the leaves of the
3126 /// recursive emission to actually produce stores.
3127 void emitFunc(Type *Ty, Value *&Agg, const Twine &Name) {
3128 assert(Ty->isSingleValueType())((Ty->isSingleValueType()) ? static_cast<void> (0) :
__assert_fail ("Ty->isSingleValueType()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3128, __PRETTY_FUNCTION__))
;
3129 // Extract the single value and store it using the indices.
3130 //
3131 // The gep and extractvalue values are factored out of the CreateStore
3132 // call to make the output independent of the argument evaluation order.
3133 Value *ExtractValue =
3134 IRB.CreateExtractValue(Agg, Indices, Name + ".extract");
3135 Value *InBoundsGEP =
3136 IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
3137 Value *Store = IRB.CreateStore(ExtractValue, InBoundsGEP);
3138 (void)Store;
3139 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3140 }
3141 };
3142
3143 bool visitStoreInst(StoreInst &SI) {
3144 if (!SI.isSimple() || SI.getPointerOperand() != *U)
3145 return false;
3146 Value *V = SI.getValueOperand();
3147 if (V->getType()->isSingleValueType())
3148 return false;
3149
3150 // We have an aggregate being stored, split it apart.
3151 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3152 StoreOpSplitter Splitter(&SI, *U);
3153 Splitter.emitSplitOps(V->getType(), V, V->getName() + ".fca");
3154 SI.eraseFromParent();
3155 return true;
3156 }
3157
3158 bool visitBitCastInst(BitCastInst &BC) {
3159 enqueueUsers(BC);
3160 return false;
3161 }
3162
3163 bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
3164 enqueueUsers(GEPI);
3165 return false;
3166 }
3167
3168 bool visitPHINode(PHINode &PN) {
3169 enqueueUsers(PN);
3170 return false;
3171 }
3172
3173 bool visitSelectInst(SelectInst &SI) {
3174 enqueueUsers(SI);
3175 return false;
3176 }
3177};
3178}
3179
3180/// \brief Strip aggregate type wrapping.
3181///
3182/// This removes no-op aggregate types wrapping an underlying type. It will
3183/// strip as many layers of types as it can without changing either the type
3184/// size or the allocated size.
3185static Type *stripAggregateTypeWrapping(const DataLayout &DL, Type *Ty) {
3186 if (Ty->isSingleValueType())
3187 return Ty;
3188
3189 uint64_t AllocSize = DL.getTypeAllocSize(Ty);
3190 uint64_t TypeSize = DL.getTypeSizeInBits(Ty);
3191
3192 Type *InnerTy;
3193 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
3194 InnerTy = ArrTy->getElementType();
3195 } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
3196 const StructLayout *SL = DL.getStructLayout(STy);
3197 unsigned Index = SL->getElementContainingOffset(0);
3198 InnerTy = STy->getElementType(Index);
3199 } else {
3200 return Ty;
3201 }
3202
3203 if (AllocSize > DL.getTypeAllocSize(InnerTy) ||
3204 TypeSize > DL.getTypeSizeInBits(InnerTy))
3205 return Ty;
3206
3207 return stripAggregateTypeWrapping(DL, InnerTy);
3208}
3209
3210/// \brief Try to find a partition of the aggregate type passed in for a given
3211/// offset and size.
3212///
3213/// This recurses through the aggregate type and tries to compute a subtype
3214/// based on the offset and size. When the offset and size span a sub-section
3215/// of an array, it will even compute a new array type for that sub-section,
3216/// and the same for structs.
3217///
3218/// Note that this routine is very strict and tries to find a partition of the
3219/// type which produces the *exact* right offset and size. It is not forgiving
3220/// when the size or offset cause either end of type-based partition to be off.
3221/// Also, this is a best-effort routine. It is reasonable to give up and not
3222/// return a type if necessary.
3223static Type *getTypePartition(const DataLayout &DL, Type *Ty, uint64_t Offset,
3224 uint64_t Size) {
3225 if (Offset == 0 && DL.getTypeAllocSize(Ty) == Size)
3226 return stripAggregateTypeWrapping(DL, Ty);
3227 if (Offset > DL.getTypeAllocSize(Ty) ||
3228 (DL.getTypeAllocSize(Ty) - Offset) < Size)
3229 return nullptr;
3230
3231 if (SequentialType *SeqTy = dyn_cast<SequentialType>(Ty)) {
3232 Type *ElementTy = SeqTy->getElementType();
3233 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
3234 uint64_t NumSkippedElements = Offset / ElementSize;
3235 if (NumSkippedElements >= SeqTy->getNumElements())
3236 return nullptr;
3237 Offset -= NumSkippedElements * ElementSize;
3238
3239 // First check if we need to recurse.
3240 if (Offset > 0 || Size < ElementSize) {
3241 // Bail if the partition ends in a different array element.
3242 if ((Offset + Size) > ElementSize)
3243 return nullptr;
3244 // Recurse through the element type trying to peel off offset bytes.
3245 return getTypePartition(DL, ElementTy, Offset, Size);
3246 }
3247 assert(Offset == 0)((Offset == 0) ? static_cast<void> (0) : __assert_fail (
"Offset == 0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3247, __PRETTY_FUNCTION__))
;
3248
3249 if (Size == ElementSize)
3250 return stripAggregateTypeWrapping(DL, ElementTy);
3251 assert(Size > ElementSize)((Size > ElementSize) ? static_cast<void> (0) : __assert_fail
("Size > ElementSize", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3251, __PRETTY_FUNCTION__))
;
3252 uint64_t NumElements = Size / ElementSize;
3253 if (NumElements * ElementSize != Size)
3254 return nullptr;
3255 return ArrayType::get(ElementTy, NumElements);
3256 }
3257
3258 StructType *STy = dyn_cast<StructType>(Ty);
3259 if (!STy)
3260 return nullptr;
3261
3262 const StructLayout *SL = DL.getStructLayout(STy);
3263 if (Offset >= SL->getSizeInBytes())
3264 return nullptr;
3265 uint64_t EndOffset = Offset + Size;
3266 if (EndOffset > SL->getSizeInBytes())
3267 return nullptr;
3268
3269 unsigned Index = SL->getElementContainingOffset(Offset);
3270 Offset -= SL->getElementOffset(Index);
3271
3272 Type *ElementTy = STy->getElementType(Index);
3273 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
3274 if (Offset >= ElementSize)
3275 return nullptr; // The offset points into alignment padding.
3276
3277 // See if any partition must be contained by the element.
3278 if (Offset > 0 || Size < ElementSize) {
3279 if ((Offset + Size) > ElementSize)
3280 return nullptr;
3281 return getTypePartition(DL, ElementTy, Offset, Size);
3282 }
3283 assert(Offset == 0)((Offset == 0) ? static_cast<void> (0) : __assert_fail (
"Offset == 0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3283, __PRETTY_FUNCTION__))
;
3284
3285 if (Size == ElementSize)
3286 return stripAggregateTypeWrapping(DL, ElementTy);
3287
3288 StructType::element_iterator EI = STy->element_begin() + Index,
3289 EE = STy->element_end();
3290 if (EndOffset < SL->getSizeInBytes()) {
3291 unsigned EndIndex = SL->getElementContainingOffset(EndOffset);
3292 if (Index == EndIndex)
3293 return nullptr; // Within a single element and its padding.
3294
3295 // Don't try to form "natural" types if the elements don't line up with the
3296 // expected size.
3297 // FIXME: We could potentially recurse down through the last element in the
3298 // sub-struct to find a natural end point.
3299 if (SL->getElementOffset(EndIndex) != EndOffset)
3300 return nullptr;
3301
3302 assert(Index < EndIndex)((Index < EndIndex) ? static_cast<void> (0) : __assert_fail
("Index < EndIndex", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3302, __PRETTY_FUNCTION__))
;
3303 EE = STy->element_begin() + EndIndex;
3304 }
3305
3306 // Try to build up a sub-structure.
3307 StructType *SubTy =
3308 StructType::get(STy->getContext(), makeArrayRef(EI, EE), STy->isPacked());
3309 const StructLayout *SubSL = DL.getStructLayout(SubTy);
3310 if (Size != SubSL->getSizeInBytes())
3311 return nullptr; // The sub-struct doesn't have quite the size needed.
3312
3313 return SubTy;
3314}
3315
3316/// \brief Pre-split loads and stores to simplify rewriting.
3317///
3318/// We want to break up the splittable load+store pairs as much as
3319/// possible. This is important to do as a preprocessing step, as once we
3320/// start rewriting the accesses to partitions of the alloca we lose the
3321/// necessary information to correctly split apart paired loads and stores
3322/// which both point into this alloca. The case to consider is something like
3323/// the following:
3324///
3325/// %a = alloca [12 x i8]
3326/// %gep1 = getelementptr [12 x i8]* %a, i32 0, i32 0
3327/// %gep2 = getelementptr [12 x i8]* %a, i32 0, i32 4
3328/// %gep3 = getelementptr [12 x i8]* %a, i32 0, i32 8
3329/// %iptr1 = bitcast i8* %gep1 to i64*
3330/// %iptr2 = bitcast i8* %gep2 to i64*
3331/// %fptr1 = bitcast i8* %gep1 to float*
3332/// %fptr2 = bitcast i8* %gep2 to float*
3333/// %fptr3 = bitcast i8* %gep3 to float*
3334/// store float 0.0, float* %fptr1
3335/// store float 1.0, float* %fptr2
3336/// %v = load i64* %iptr1
3337/// store i64 %v, i64* %iptr2
3338/// %f1 = load float* %fptr2
3339/// %f2 = load float* %fptr3
3340///
3341/// Here we want to form 3 partitions of the alloca, each 4 bytes large, and
3342/// promote everything so we recover the 2 SSA values that should have been
3343/// there all along.
3344///
3345/// \returns true if any changes are made.
3346bool SROA::presplitLoadsAndStores(AllocaInst &AI, AllocaSlices &AS) {
3347 DEBUG(dbgs() << "Pre-splitting loads and stores\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Pre-splitting loads and stores\n"
; } } while (false)
;
3348
3349 // Track the loads and stores which are candidates for pre-splitting here, in
3350 // the order they first appear during the partition scan. These give stable
3351 // iteration order and a basis for tracking which loads and stores we
3352 // actually split.
3353 SmallVector<LoadInst *, 4> Loads;
3354 SmallVector<StoreInst *, 4> Stores;
3355
3356 // We need to accumulate the splits required of each load or store where we
3357 // can find them via a direct lookup. This is important to cross-check loads
3358 // and stores against each other. We also track the slice so that we can kill
3359 // all the slices that end up split.
3360 struct SplitOffsets {
3361 Slice *S;
3362 std::vector<uint64_t> Splits;
3363 };
3364 SmallDenseMap<Instruction *, SplitOffsets, 8> SplitOffsetsMap;
3365
3366 // Track loads out of this alloca which cannot, for any reason, be pre-split.
3367 // This is important as we also cannot pre-split stores of those loads!
3368 // FIXME: This is all pretty gross. It means that we can be more aggressive
3369 // in pre-splitting when the load feeding the store happens to come from
3370 // a separate alloca. Put another way, the effectiveness of SROA would be
3371 // decreased by a frontend which just concatenated all of its local allocas
3372 // into one big flat alloca. But defeating such patterns is exactly the job
3373 // SROA is tasked with! Sadly, to not have this discrepancy we would have
3374 // change store pre-splitting to actually force pre-splitting of the load
3375 // that feeds it *and all stores*. That makes pre-splitting much harder, but
3376 // maybe it would make it more principled?
3377 SmallPtrSet<LoadInst *, 8> UnsplittableLoads;
3378
3379 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)
;
3380 for (auto &P : AS.partitions()) {
3381 for (Slice &S : P) {
3382 Instruction *I = cast<Instruction>(S.getUse()->getUser());
3383 if (!S.isSplittable() || S.endOffset() <= P.endOffset()) {
3384 // If this is a load we have to track that it can't participate in any
3385 // pre-splitting. If this is a store of a load we have to track that
3386 // that load also can't participate in any pre-splitting.
3387 if (auto *LI = dyn_cast<LoadInst>(I))
3388 UnsplittableLoads.insert(LI);
3389 else if (auto *SI = dyn_cast<StoreInst>(I))
3390 if (auto *LI = dyn_cast<LoadInst>(SI->getValueOperand()))
3391 UnsplittableLoads.insert(LI);
3392 continue;
3393 }
3394 assert(P.endOffset() > S.beginOffset() &&((P.endOffset() > S.beginOffset() && "Empty or backwards partition!"
) ? static_cast<void> (0) : __assert_fail ("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3395, __PRETTY_FUNCTION__))
3395 "Empty or backwards partition!")((P.endOffset() > S.beginOffset() && "Empty or backwards partition!"
) ? static_cast<void> (0) : __assert_fail ("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3395, __PRETTY_FUNCTION__))
;
3396
3397 // Determine if this is a pre-splittable slice.
3398 if (auto *LI = dyn_cast<LoadInst>(I)) {
3399 assert(!LI->isVolatile() && "Cannot split volatile loads!")((!LI->isVolatile() && "Cannot split volatile loads!"
) ? static_cast<void> (0) : __assert_fail ("!LI->isVolatile() && \"Cannot split volatile loads!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3399, __PRETTY_FUNCTION__))
;
3400
3401 // The load must be used exclusively to store into other pointers for
3402 // us to be able to arbitrarily pre-split it. The stores must also be
3403 // simple to avoid changing semantics.
3404 auto IsLoadSimplyStored = [](LoadInst *LI) {
3405 for (User *LU : LI->users()) {
3406 auto *SI = dyn_cast<StoreInst>(LU);
3407 if (!SI || !SI->isSimple())
3408 return false;
3409 }
3410 return true;
3411 };
3412 if (!IsLoadSimplyStored(LI)) {
3413 UnsplittableLoads.insert(LI);
3414 continue;
3415 }
3416
3417 Loads.push_back(LI);
3418 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
3419 if (S.getUse() != &SI->getOperandUse(SI->getPointerOperandIndex()))
3420 // Skip stores *of* pointers. FIXME: This shouldn't even be possible!
3421 continue;
3422 auto *StoredLoad = dyn_cast<LoadInst>(SI->getValueOperand());
3423 if (!StoredLoad || !StoredLoad->isSimple())
3424 continue;
3425 assert(!SI->isVolatile() && "Cannot split volatile stores!")((!SI->isVolatile() && "Cannot split volatile stores!"
) ? static_cast<void> (0) : __assert_fail ("!SI->isVolatile() && \"Cannot split volatile stores!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3425, __PRETTY_FUNCTION__))
;
3426
3427 Stores.push_back(SI);
3428 } else {
3429 // Other uses cannot be pre-split.
3430 continue;
3431 }
3432
3433 // Record the initial split.
3434 DEBUG(dbgs() << " Candidate: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Candidate: " << *I <<
"\n"; } } while (false)
;
3435 auto &Offsets = SplitOffsetsMap[I];
3436 assert(Offsets.Splits.empty() &&((Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3437, __PRETTY_FUNCTION__))
3437 "Should not have splits the first time we see an instruction!")((Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3437, __PRETTY_FUNCTION__))
;
3438 Offsets.S = &S;
3439 Offsets.Splits.push_back(P.endOffset() - S.beginOffset());
3440 }
3441
3442 // Now scan the already split slices, and add a split for any of them which
3443 // we're going to pre-split.
3444 for (Slice *S : P.splitSliceTails()) {
3445 auto SplitOffsetsMapI =
3446 SplitOffsetsMap.find(cast<Instruction>(S->getUse()->getUser()));
3447 if (SplitOffsetsMapI == SplitOffsetsMap.end())
3448 continue;
3449 auto &Offsets = SplitOffsetsMapI->second;
3450
3451 assert(Offsets.S == S && "Found a mismatched slice!")((Offsets.S == S && "Found a mismatched slice!") ? static_cast
<void> (0) : __assert_fail ("Offsets.S == S && \"Found a mismatched slice!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3451, __PRETTY_FUNCTION__))
;
3452 assert(!Offsets.Splits.empty() &&((!Offsets.Splits.empty() && "Cannot have an empty set of splits on the second partition!"
) ? static_cast<void> (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3453, __PRETTY_FUNCTION__))
3453 "Cannot have an empty set of splits on the second partition!")((!Offsets.Splits.empty() && "Cannot have an empty set of splits on the second partition!"
) ? static_cast<void> (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3453, __PRETTY_FUNCTION__))
;
3454 assert(Offsets.Splits.back() ==((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3456, __PRETTY_FUNCTION__))
3455 P.beginOffset() - Offsets.S->beginOffset() &&((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3456, __PRETTY_FUNCTION__))
3456 "Previous split does not end where this one begins!")((Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset
() && "Previous split does not end where this one begins!"
) ? static_cast<void> (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3456, __PRETTY_FUNCTION__))
;
3457
3458 // Record each split. The last partition's end isn't needed as the size
3459 // of the slice dictates that.
3460 if (S->endOffset() > P.endOffset())
3461 Offsets.Splits.push_back(P.endOffset() - Offsets.S->beginOffset());
3462 }
3463 }
3464
3465 // We may have split loads where some of their stores are split stores. For
3466 // such loads and stores, we can only pre-split them if their splits exactly
3467 // match relative to their starting offset. We have to verify this prior to
3468 // any rewriting.
3469 Stores.erase(
3470 remove_if(Stores,
3471 [&UnsplittableLoads, &SplitOffsetsMap](StoreInst *SI) {
3472 // Lookup the load we are storing in our map of split
3473 // offsets.
3474 auto *LI = cast<LoadInst>(SI->getValueOperand());
3475 // If it was completely unsplittable, then we're done,
3476 // and this store can't be pre-split.
3477 if (UnsplittableLoads.count(LI))
3478 return true;
3479
3480 auto LoadOffsetsI = SplitOffsetsMap.find(LI);
3481 if (LoadOffsetsI == SplitOffsetsMap.end())
3482 return false; // Unrelated loads are definitely safe.
3483 auto &LoadOffsets = LoadOffsetsI->second;
3484
3485 // Now lookup the store's offsets.
3486 auto &StoreOffsets = SplitOffsetsMap[SI];
3487
3488 // If the relative offsets of each split in the load and
3489 // store match exactly, then we can split them and we
3490 // don't need to remove them here.
3491 if (LoadOffsets.Splits == StoreOffsets.Splits)
3492 return false;
3493
3494 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)
3495 << " " << *LI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3496 << " " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
;
3497
3498 // We've found a store and load that we need to split
3499 // with mismatched relative splits. Just give up on them
3500 // and remove both instructions from our list of
3501 // candidates.
3502 UnsplittableLoads.insert(LI);
3503 return true;
3504 }),
3505 Stores.end());
3506 // Now we have to go *back* through all the stores, because a later store may
3507 // have caused an earlier store's load to become unsplittable and if it is
3508 // unsplittable for the later store, then we can't rely on it being split in
3509 // the earlier store either.
3510 Stores.erase(remove_if(Stores,
3511 [&UnsplittableLoads](StoreInst *SI) {
3512 auto *LI = cast<LoadInst>(SI->getValueOperand());
3513 return UnsplittableLoads.count(LI);
3514 }),
3515 Stores.end());
3516 // Once we've established all the loads that can't be split for some reason,
3517 // filter any that made it into our list out.
3518 Loads.erase(remove_if(Loads,
3519 [&UnsplittableLoads](LoadInst *LI) {
3520 return UnsplittableLoads.count(LI);
3521 }),
3522 Loads.end());
3523
3524 // If no loads or stores are left, there is no pre-splitting to be done for
3525 // this alloca.
3526 if (Loads.empty() && Stores.empty())
3527 return false;
3528
3529 // From here on, we can't fail and will be building new accesses, so rig up
3530 // an IR builder.
3531 IRBuilderTy IRB(&AI);
3532
3533 // Collect the new slices which we will merge into the alloca slices.
3534 SmallVector<Slice, 4> NewSlices;
3535
3536 // Track any allocas we end up splitting loads and stores for so we iterate
3537 // on them.
3538 SmallPtrSet<AllocaInst *, 4> ResplitPromotableAllocas;
3539
3540 // At this point, we have collected all of the loads and stores we can
3541 // pre-split, and the specific splits needed for them. We actually do the
3542 // splitting in a specific order in order to handle when one of the loads in
3543 // the value operand to one of the stores.
3544 //
3545 // First, we rewrite all of the split loads, and just accumulate each split
3546 // load in a parallel structure. We also build the slices for them and append
3547 // them to the alloca slices.
3548 SmallDenseMap<LoadInst *, std::vector<LoadInst *>, 1> SplitLoadsMap;
3549 std::vector<LoadInst *> SplitLoads;
3550 const DataLayout &DL = AI.getModule()->getDataLayout();
3551 for (LoadInst *LI : Loads) {
3552 SplitLoads.clear();
3553
3554 IntegerType *Ty = cast<IntegerType>(LI->getType());
3555 uint64_t LoadSize = Ty->getBitWidth() / 8;
3556 assert(LoadSize > 0 && "Cannot have a zero-sized integer load!")((LoadSize > 0 && "Cannot have a zero-sized integer load!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize > 0 && \"Cannot have a zero-sized integer load!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3556, __PRETTY_FUNCTION__))
;
3557
3558 auto &Offsets = SplitOffsetsMap[LI];
3559 assert(LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&((LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3560, __PRETTY_FUNCTION__))
3560 "Slice size should always match load size exactly!")((LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3560, __PRETTY_FUNCTION__))
;
3561 uint64_t BaseOffset = Offsets.S->beginOffset();
3562 assert(BaseOffset + LoadSize > BaseOffset &&((BaseOffset + LoadSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3563, __PRETTY_FUNCTION__))
3563 "Cannot represent alloca access size using 64-bit integers!")((BaseOffset + LoadSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3563, __PRETTY_FUNCTION__))
;
3564
3565 Instruction *BasePtr = cast<Instruction>(LI->getPointerOperand());
3566 IRB.SetInsertPoint(LI);
3567
3568 DEBUG(dbgs() << " Splitting load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting load: " << *LI
<< "\n"; } } while (false)
;
3569
3570 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
3571 int Idx = 0, Size = Offsets.Splits.size();
3572 for (;;) {
3573 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
3574 auto *PartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
3575 LoadInst *PLoad = IRB.CreateAlignedLoad(
3576 getAdjustedPtr(IRB, DL, BasePtr,
3577 APInt(DL.getPointerSizeInBits(), PartOffset),
3578 PartPtrTy, BasePtr->getName() + "."),
3579 getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
3580 LI->getName());
3581 PLoad->copyMetadata(*LI, LLVMContext::MD_mem_parallel_loop_access);
3582
3583 // Append this load onto the list of split loads so we can find it later
3584 // to rewrite the stores.
3585 SplitLoads.push_back(PLoad);
3586
3587 // Now build a new slice for the alloca.
3588 NewSlices.push_back(
3589 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
3590 &PLoad->getOperandUse(PLoad->getPointerOperandIndex()),
3591 /*IsSplittable*/ false));
3592 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)
3593 << ", " << NewSlices.back().endOffset() << "): " << *PLoaddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
3594 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
;
3595
3596 // See if we've handled all the splits.
3597 if (Idx >= Size)
3598 break;
3599
3600 // Setup the next partition.
3601 PartOffset = Offsets.Splits[Idx];
3602 ++Idx;
3603 PartSize = (Idx < Size ? Offsets.Splits[Idx] : LoadSize) - PartOffset;
3604 }
3605
3606 // Now that we have the split loads, do the slow walk over all uses of the
3607 // load and rewrite them as split stores, or save the split loads to use
3608 // below if the store is going to be split there anyways.
3609 bool DeferredStores = false;
3610 for (User *LU : LI->users()) {
3611 StoreInst *SI = cast<StoreInst>(LU);
3612 if (!Stores.empty() && SplitOffsetsMap.count(SI)) {
3613 DeferredStores = true;
3614 DEBUG(dbgs() << " Deferred splitting of store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
;
3615 continue;
3616 }
3617
3618 Value *StoreBasePtr = SI->getPointerOperand();
3619 IRB.SetInsertPoint(SI);
3620
3621 DEBUG(dbgs() << " Splitting store of load: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store of load: " <<
*SI << "\n"; } } while (false)
;
3622
3623 for (int Idx = 0, Size = SplitLoads.size(); Idx < Size; ++Idx) {
3624 LoadInst *PLoad = SplitLoads[Idx];
3625 uint64_t PartOffset = Idx == 0 ? 0 : Offsets.Splits[Idx - 1];
3626 auto *PartPtrTy =
3627 PLoad->getType()->getPointerTo(SI->getPointerAddressSpace());
3628
3629 StoreInst *PStore = IRB.CreateAlignedStore(
3630 PLoad, getAdjustedPtr(IRB, DL, StoreBasePtr,
3631 APInt(DL.getPointerSizeInBits(), PartOffset),
3632 PartPtrTy, StoreBasePtr->getName() + "."),
3633 getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
3634 PStore->copyMetadata(*LI, LLVMContext::MD_mem_parallel_loop_access);
3635 DEBUG(dbgs() << " +" << PartOffset << ":" << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " +" << PartOffset <<
":" << *PStore << "\n"; } } while (false)
;
3636 }
3637
3638 // We want to immediately iterate on any allocas impacted by splitting
3639 // this store, and we have to track any promotable alloca (indicated by
3640 // a direct store) as needing to be resplit because it is no longer
3641 // promotable.
3642 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(StoreBasePtr)) {
3643 ResplitPromotableAllocas.insert(OtherAI);
3644 Worklist.insert(OtherAI);
3645 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
3646 StoreBasePtr->stripInBoundsOffsets())) {
3647 Worklist.insert(OtherAI);
3648 }
3649
3650 // Mark the original store as dead.
3651 DeadInsts.insert(SI);
3652 }
3653
3654 // Save the split loads if there are deferred stores among the users.
3655 if (DeferredStores)
3656 SplitLoadsMap.insert(std::make_pair(LI, std::move(SplitLoads)));
3657
3658 // Mark the original load as dead and kill the original slice.
3659 DeadInsts.insert(LI);
3660 Offsets.S->kill();
3661 }
3662
3663 // Second, we rewrite all of the split stores. At this point, we know that
3664 // all loads from this alloca have been split already. For stores of such
3665 // loads, we can simply look up the pre-existing split loads. For stores of
3666 // other loads, we split those loads first and then write split stores of
3667 // them.
3668 for (StoreInst *SI : Stores) {
3669 auto *LI = cast<LoadInst>(SI->getValueOperand());
3670 IntegerType *Ty = cast<IntegerType>(LI->getType());
3671 uint64_t StoreSize = Ty->getBitWidth() / 8;
3672 assert(StoreSize > 0 && "Cannot have a zero-sized integer store!")((StoreSize > 0 && "Cannot have a zero-sized integer store!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize > 0 && \"Cannot have a zero-sized integer store!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3672, __PRETTY_FUNCTION__))
;
3673
3674 auto &Offsets = SplitOffsetsMap[SI];
3675 assert(StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&((StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3676, __PRETTY_FUNCTION__))
3676 "Slice size should always match load size exactly!")((StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset
() && "Slice size should always match load size exactly!"
) ? static_cast<void> (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3676, __PRETTY_FUNCTION__))
;
3677 uint64_t BaseOffset = Offsets.S->beginOffset();
3678 assert(BaseOffset + StoreSize > BaseOffset &&((BaseOffset + StoreSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3679, __PRETTY_FUNCTION__))
3679 "Cannot represent alloca access size using 64-bit integers!")((BaseOffset + StoreSize > BaseOffset && "Cannot represent alloca access size using 64-bit integers!"
) ? static_cast<void> (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3679, __PRETTY_FUNCTION__))
;
3680
3681 Value *LoadBasePtr = LI->getPointerOperand();
3682 Instruction *StoreBasePtr = cast<Instruction>(SI->getPointerOperand());
3683
3684 DEBUG(dbgs() << " Splitting store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store: " << *SI
<< "\n"; } } while (false)
;
3685
3686 // Check whether we have an already split load.
3687 auto SplitLoadsMapI = SplitLoadsMap.find(LI);
3688 std::vector<LoadInst *> *SplitLoads = nullptr;
3689 if (SplitLoadsMapI != SplitLoadsMap.end()) {
3690 SplitLoads = &SplitLoadsMapI->second;
3691 assert(SplitLoads->size() == Offsets.Splits.size() + 1 &&((SplitLoads->size() == Offsets.Splits.size() + 1 &&
"Too few split loads for the number of splits in the store!"
) ? static_cast<void> (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3692, __PRETTY_FUNCTION__))
3692 "Too few split loads for the number of splits in the store!")((SplitLoads->size() == Offsets.Splits.size() + 1 &&
"Too few split loads for the number of splits in the store!"
) ? static_cast<void> (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3692, __PRETTY_FUNCTION__))
;
3693 } else {
3694 DEBUG(dbgs() << " of load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of load: " << *LI
<< "\n"; } } while (false)
;
3695 }
3696
3697 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
3698 int Idx = 0, Size = Offsets.Splits.size();
3699 for (;;) {
3700 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
3701 auto *PartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
3702
3703 // Either lookup a split load or create one.
3704 LoadInst *PLoad;
3705 if (SplitLoads) {
3706 PLoad = (*SplitLoads)[Idx];
3707 } else {
3708 IRB.SetInsertPoint(LI);
3709 PLoad = IRB.CreateAlignedLoad(
3710 getAdjustedPtr(IRB, DL, LoadBasePtr,
3711 APInt(DL.getPointerSizeInBits(), PartOffset),
3712 PartPtrTy, LoadBasePtr->getName() + "."),
3713 getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
3714 LI->getName());
3715 }
3716
3717 // And store this partition.
3718 IRB.SetInsertPoint(SI);
3719 StoreInst *PStore = IRB.CreateAlignedStore(
3720 PLoad, getAdjustedPtr(IRB, DL, StoreBasePtr,
3721 APInt(DL.getPointerSizeInBits(), PartOffset),
3722 PartPtrTy, StoreBasePtr->getName() + "."),
3723 getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
3724
3725 // Now build a new slice for the alloca.
3726 NewSlices.push_back(
3727 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
3728 &PStore->getOperandUse(PStore->getPointerOperandIndex()),
3729 /*IsSplittable*/ false));
3730 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)
3731 << ", " << NewSlices.back().endOffset() << "): " << *PStoredo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
3732 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
;
3733 if (!SplitLoads) {
3734 DEBUG(dbgs() << " of split load: " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of split load: " << *
PLoad << "\n"; } } while (false)
;
3735 }
3736
3737 // See if we've finished all the splits.
3738 if (Idx >= Size)
3739 break;
3740
3741 // Setup the next partition.
3742 PartOffset = Offsets.Splits[Idx];
3743 ++Idx;
3744 PartSize = (Idx < Size ? Offsets.Splits[Idx] : StoreSize) - PartOffset;
3745 }
3746
3747 // We want to immediately iterate on any allocas impacted by splitting
3748 // this load, which is only relevant if it isn't a load of this alloca and
3749 // thus we didn't already split the loads above. We also have to keep track
3750 // of any promotable allocas we split loads on as they can no longer be
3751 // promoted.
3752 if (!SplitLoads) {
3753 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(LoadBasePtr)) {
3754 assert(OtherAI != &AI && "We can't re-split our own alloca!")((OtherAI != &AI && "We can't re-split our own alloca!"
) ? static_cast<void> (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3754, __PRETTY_FUNCTION__))
;
3755 ResplitPromotableAllocas.insert(OtherAI);
3756 Worklist.insert(OtherAI);
3757 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
3758 LoadBasePtr->stripInBoundsOffsets())) {
3759 assert(OtherAI != &AI && "We can't re-split our own alloca!")((OtherAI != &AI && "We can't re-split our own alloca!"
) ? static_cast<void> (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3759, __PRETTY_FUNCTION__))
;
3760 Worklist.insert(OtherAI);
3761 }
3762 }
3763
3764 // Mark the original store as dead now that we've split it up and kill its
3765 // slice. Note that we leave the original load in place unless this store
3766 // was its only use. It may in turn be split up if it is an alloca load
3767 // for some other alloca, but it may be a normal load. This may introduce
3768 // redundant loads, but where those can be merged the rest of the optimizer
3769 // should handle the merging, and this uncovers SSA splits which is more
3770 // important. In practice, the original loads will almost always be fully
3771 // split and removed eventually, and the splits will be merged by any
3772 // trivial CSE, including instcombine.
3773 if (LI->hasOneUse()) {
3774 assert(*LI->user_begin() == SI && "Single use isn't this store!")((*LI->user_begin() == SI && "Single use isn't this store!"
) ? static_cast<void> (0) : __assert_fail ("*LI->user_begin() == SI && \"Single use isn't this store!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3774, __PRETTY_FUNCTION__))
;
3775 DeadInsts.insert(LI);
3776 }
3777 DeadInsts.insert(SI);
3778 Offsets.S->kill();
3779 }
3780
3781 // Remove the killed slices that have ben pre-split.
3782 AS.erase(remove_if(AS, [](const Slice &S) { return S.isDead(); }), AS.end());
3783
3784 // Insert our new slices. This will sort and merge them into the sorted
3785 // sequence.
3786 AS.insert(NewSlices);
3787
3788 DEBUG(dbgs() << " Pre-split slices:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Pre-split slices:\n"; } } while
(false)
;
3789#ifndef NDEBUG
3790 for (auto I = AS.begin(), E = AS.end(); I != E; ++I)
3791 DEBUG(AS.print(dbgs(), I, " "))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs(), I, " "); } } while (false)
;
3792#endif
3793
3794 // Finally, don't try to promote any allocas that new require re-splitting.
3795 // They have already been added to the worklist above.
3796 PromotableAllocas.erase(
3797 remove_if(
3798 PromotableAllocas,
3799 [&](AllocaInst *AI) { return ResplitPromotableAllocas.count(AI); }),
3800 PromotableAllocas.end());
3801
3802 return true;
3803}
3804
3805/// \brief Rewrite an alloca partition's users.
3806///
3807/// This routine drives both of the rewriting goals of the SROA pass. It tries
3808/// to rewrite uses of an alloca partition to be conducive for SSA value
3809/// promotion. If the partition needs a new, more refined alloca, this will
3810/// build that new alloca, preserving as much type information as possible, and
3811/// rewrite the uses of the old alloca to point at the new one and have the
3812/// appropriate new offsets. It also evaluates how successful the rewrite was
3813/// at enabling promotion and if it was successful queues the alloca to be
3814/// promoted.
3815AllocaInst *SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS,
3816 Partition &P) {
3817 // Try to compute a friendly type for this partition of the alloca. This
3818 // won't always succeed, in which case we fall back to a legal integer type
3819 // or an i8 array of an appropriate size.
3820 Type *SliceTy = nullptr;
3821 const DataLayout &DL = AI.getModule()->getDataLayout();
3822 if (Type *CommonUseTy = findCommonType(P.begin(), P.end(), P.endOffset()))
3823 if (DL.getTypeAllocSize(CommonUseTy) >= P.size())
3824 SliceTy = CommonUseTy;
3825 if (!SliceTy)
3826 if (Type *TypePartitionTy = getTypePartition(DL, AI.getAllocatedType(),
3827 P.beginOffset(), P.size()))
3828 SliceTy = TypePartitionTy;
3829 if ((!SliceTy || (SliceTy->isArrayTy() &&
3830 SliceTy->getArrayElementType()->isIntegerTy())) &&
3831 DL.isLegalInteger(P.size() * 8))
3832 SliceTy = Type::getIntNTy(*C, P.size() * 8);
3833 if (!SliceTy)
3834 SliceTy = ArrayType::get(Type::getInt8Ty(*C), P.size());
3835 assert(DL.getTypeAllocSize(SliceTy) >= P.size())((DL.getTypeAllocSize(SliceTy) >= P.size()) ? static_cast<
void> (0) : __assert_fail ("DL.getTypeAllocSize(SliceTy) >= P.size()"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3835, __PRETTY_FUNCTION__))
;
3836
3837 bool IsIntegerPromotable = isIntegerWideningViable(P, SliceTy, DL);
3838
3839 VectorType *VecTy =
3840 IsIntegerPromotable ? nullptr : isVectorPromotionViable(P, DL);
3841 if (VecTy)
3842 SliceTy = VecTy;
3843
3844 // Check for the case where we're going to rewrite to a new alloca of the
3845 // exact same type as the original, and with the same access offsets. In that
3846 // case, re-use the existing alloca, but still run through the rewriter to
3847 // perform phi and select speculation.
3848 AllocaInst *NewAI;
3849 if (SliceTy == AI.getAllocatedType()) {
3850 assert(P.beginOffset() == 0 &&((P.beginOffset() == 0 && "Non-zero begin offset but same alloca type"
) ? static_cast<void> (0) : __assert_fail ("P.beginOffset() == 0 && \"Non-zero begin offset but same alloca type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3851, __PRETTY_FUNCTION__))
3851 "Non-zero begin offset but same alloca type")((P.beginOffset() == 0 && "Non-zero begin offset but same alloca type"
) ? static_cast<void> (0) : __assert_fail ("P.beginOffset() == 0 && \"Non-zero begin offset but same alloca type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn301769/lib/Transforms/Scalar/SROA.cpp"
, 3851, __PRETTY_FUNCTION__))
;
3852 NewAI = &AI;
3853 // FIXME: We should be able to bail at this point with "nothing changed".
3854 // FIXME: We might want to defer PHI speculation until after here.
3855 // FIXME: return nullptr;
3856 } else {
3857 unsigned Alignment = AI.getAlignment();
3858 if (!Alignment) {
3859 // The minimum alignment which users can rely on when the explicit
3860 // alignment is omitted or zero is that required by the ABI for this
3861 // type.
3862 Alignment = DL.getABITypeAlignment(AI.getAllocatedType());
3863 }
3864 Alignment = MinAlign(Alignment, P.beginOffset());
3865 // If we will get at least this much alignment from the type alone, leave
3866 // the alloca's alignment unconstrained.
3867 if (Alignment <= DL.getABITypeAlignment(SliceTy))
3868 Alignment = 0;
3869 NewAI = new AllocaInst(
3870 SliceTy, AI.getType()->getAddressSpace(), nullptr, Alignment,
3871 AI.getName() + ".sroa." + Twine(P.begin() - AS.begin()), &AI);
3872 ++NumNewAllocas;
3873 }
3874
3875 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)
3876 << "[" << P.beginOffset() << "," << P.endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
3877 << ") to: " << *NewAI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
;
3878
3879 // Track the high watermark on the worklist as it is only relevant for
3880 // promoted allocas. We will reset it to this point if the alloca is not in
3881 // fact scheduled for promotion.
3882 unsigned PPWOldSize = PostPromotionWorklist.size();
3883 unsigned NumUses = 0;
3884 SmallSetVector<PHINode *, 8> PHIUsers;
3885 SmallSetVector<SelectInst *, 8> SelectUsers;
3886
3887 AllocaSliceRewriter Rewriter(DL, AS, *this, AI, *NewAI, P.beginOffset(),
3888 P.endOffset(), IsIntegerPromotable, VecTy,
3889 PHIUsers, SelectUsers);
3890 bool Promotable = true;
3891 for (Slice *S : P.splitSliceTails()) {
3892 Promotable &= Rewriter.visit(S);
3893 ++NumUses;
3894 }
3895 for (Slice &S : P) {
3896 Promotable &= Rewriter.visit(&S);
3897 ++NumUses;
3898 }
3899
3900 NumAllocaPartitionUses += NumUses;
3901 MaxUsesPerAllocaPartition =
3902 std::max<unsigned>(NumUses, MaxUsesPerAllocaPartition);
3903
3904 // Now that we've processed all the slices in the new partition, check if any
3905 // PHIs or Selects would block promotion.
3906 for (PHINode *PHI : PHIUsers)
3907 if (!isSafePHIToSpeculate(*PHI)) {
3908 Promotable = false;
3909 PHIUsers.clear();
3910 SelectUsers.clear();
3911 break;
3912 }
3913
3914 for (SelectInst *Sel : SelectUsers)
3915 if (!isSafeSelectToSpeculate(*Sel)) {
3916 Promotable = false;
3917 PHIUsers.clear();
3918 SelectUsers.clear();
3919 break;
3920 }
3921
3922 if (Promotable) {
3923 if (PHIUsers.empty() && SelectUsers.empty()) {
3924 // Promote the alloca.
3925 PromotableAllocas.push_back(NewAI);
3926 } else {
3927 // If we have either PHIs or Selects to speculate, add them to those
3928 // worklists and re-queue the new alloca so that we promote in on the
3929 // next iteration.
3930 for (PHINode *PHIUser : PHIUsers)
3931 SpeculatablePHIs.insert(PHIUser);
3932 for (SelectInst *SelectUser : SelectUsers)
3933 SpeculatableSelects.insert(SelectUser);
3934 Worklist.insert(NewAI);
3935 }
3936 } else {
3937 // Drop any post-promotion work items if promotion didn't happen.
3938 while (PostPromotionWorklist.size() > PPWOldSize)
3939 PostPromotionWorklist.pop_back();
3940
3941 // We couldn't promote and we didn't create a new partition, nothing
3942 // happened.
3943 if (NewAI == &AI)
3944 return nullptr;
3945
3946 // If we can't promote the alloca, iterate on it to check for new
3947 // refinements exposed by splitting the current alloca. Don't iterate on an
3948 // alloca which didn't actually change and didn't get promoted.
3949 Worklist.insert(NewAI);
3950 }
3951
3952 return NewAI;
3953}
3954
3955/// \brief Walks the slices of an alloca and form partitions based on them,
3956/// rewriting each of their uses.
3957bool SROA::splitAlloca(AllocaInst &AI, AllocaSlices &AS) {
3958 if (AS.begin() == AS.end())
3959 return false;
3960
3961 unsigned NumPartitions = 0;
3962 bool Changed = false;
3963 const DataLayout &DL = AI.getModule()->getDataLayout();
3964
3965 // First try to pre-split loads and stores.
3966 Changed |= presplitLoadsAndStores(AI, AS);
3967
3968 // Now that we have identified any pre-splitting opportunities, mark any
3969 // splittable (non-whole-alloca) loads and stores as unsplittable. If we fail
3970 // to split these during pre-splitting, we want to force them to be
3971 // rewritten into a partition.
3972 bool IsSorted = true;
3973 for (Slice &S : AS) {
3974 if (!S.isSplittable())
3975 continue;
3976 // FIXME: We currently leave whole-alloca splittable loads and stores. This
3977 // used to be the only splittable loads and stores and we need to be
3978 // confident that the above handling of splittable loads and stores is
3979 // completely sufficient before we forcibly disable the remaining handling.
3980 if (S.beginOffset() == 0 &&
3981 S.endOffset() >= DL.getTypeAllocSize(AI.getAllocatedType()))
3982 continue;
3983 if (isa<LoadInst>(S.getUse()->getUser()) ||
3984 isa<StoreInst>(S.getUse()->getUser())) {
3985 S.makeUnsplittable();
3986 IsSorted = false;
3987 }
3988 }
3989 if (!IsSorted)
3990 std::sort(AS.begin(), AS.end());
3991
3992 /// Describes the allocas introduced by rewritePartition in order to migrate
3993 /// the debug info.
3994 struct Fragment {
3995 AllocaInst *Alloca;
3996 uint64_t Offset;
3997 uint64_t Size;
3998 Fragment(AllocaInst *AI, uint64_t O, uint64_t S)
3999 : Alloca(AI), Offset(O), Size(S) {}
4000 };
4001 SmallVector<Fragment, 4> Fragments;
4002
4003 // Rewrite each partition.
4004 for (auto &P : AS.partitions()) {
4005 if (AllocaInst *NewAI = rewritePartition(AI, AS, P)) {
4006 Changed = true;
4007 if (NewAI != &AI) {
4008 uint64_t SizeOfByte = 8;
4009 uint64_t AllocaSize = DL.getTypeSizeInBits(NewAI->getAllocatedType());
4010 // Don't include any padding.
4011 uint64_t Size = std::min(AllocaSize, P.size() * SizeOfByte);
4012 Fragments.push_back(Fragment(NewAI, P.beginOffset() * SizeOfByte, Size));
4013 }
4014 }
4015 ++NumPartitions;
4016 }
4017
4018 NumAllocaPartitions += NumPartitions;
4019 MaxPartitionsPerAlloca =
4020 std::max<unsigned>(NumPartitions, MaxPartitionsPerAlloca);
4021
4022 // Migrate debug information from the old alloca to the new alloca(s)
4023 // and the individual partitions.
4024 if (DbgDeclareInst *DbgDecl = FindAllocaDbgDeclare(&AI)) {
4025 auto *Var = DbgDecl->getVariable();
4026 auto *Expr = DbgDecl->getExpression();
4027 DIBuilder DIB(*AI.getModule(), /*AllowUnresolved*/ false);
4028 uint64_t AllocaSize = DL.getTypeSizeInBits(AI.getAllocatedType());
4029 for (auto Fragment : Fragments) {
4030 // Create a fragment expression describing the new partition or reuse AI's
4031 // expression if there is only one partition.
4032 auto *FragmentExpr = Expr;
4033 if (Fragment.Size < AllocaSize || Expr->isFragment()) {
4034 // If this alloca is already a scalar replacement of a larger aggregate,
4035 // Fragment.Offset describes the offset inside the scalar.
4036 auto ExprFragment = Expr->getFragmentInfo();
4037 uint64_t Offset = ExprFragment ? ExprFragment->OffsetInBits : 0;
4038 uint64_t Start = Offset + Fragment.Offset;
4039 uint64_t Size = Fragment.Size;
4040 if (ExprFragment) {
4041 uint64_t AbsEnd =
4042 ExprFragment->OffsetInBits + ExprFragment->SizeInBits;
4043 if (Start >= AbsEnd)
4044 // No need to describe a SROAed padding.
4045 continue;
4046 Size = std::min(Size, AbsEnd - Start);
4047 }
4048 FragmentExpr = DIB.createFragmentExpression(Start, Size);
4049 }
4050
4051 // Remove any existing dbg.declare intrinsic describing the same alloca.
4052 if (DbgDeclareInst *OldDDI = FindAllocaDbgDeclare(Fragment.Alloca))
4053 OldDDI->eraseFromParent();
4054
4055 DIB.insertDeclare(Fragment.Alloca, Var, FragmentExpr,
4056 DbgDecl->getDebugLoc(), &AI);
4057 }
4058 }
4059 return Changed;
4060}
4061
4062/// \brief Clobber a use with undef, deleting the used value if it becomes dead.
4063void SROA::clobberUse(Use &U) {
4064 Value *OldV = U;
4065 // Replace the use with an undef value.
4066 U = UndefValue::get(OldV->getType());
4067
4068 // Check for this making an instruction dead. We have to garbage collect
4069 // all the dead instructions to ensure the uses of any alloca end up being
4070 // minimal.
4071 if (Instruction *OldI = dyn_cast<Instruction>(OldV))
4072 if (isInstructionTriviallyDead(OldI)) {
4073 DeadInsts.insert(OldI);
4074 }
4075}
4076
4077/// \brief Analyze an alloca for SROA.
4078///
4079/// This analyzes the alloca to ensure we can reason about it, builds
4080/// the slices of the alloca, and then hands it off to be split and
4081/// rewritten as needed.
4082bool SROA::runOnAlloca(AllocaInst &AI) {
4083 DEBUG(dbgs() << "SROA alloca: " << AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA alloca: " << AI <<
"\n"; } } while (false)
;
4084 ++NumAllocasAnalyzed;
4085
4086 // Special case dead allocas, as they're trivial.
4087 if (AI.use_empty()) {
4088 AI.eraseFromParent();
4089 return true;
4090 }
4091 const DataLayout &DL = AI.getModule()->getDataLayout();
4092
4093 // Skip alloca forms that this analysis can't handle.
4094 if (AI.isArrayAllocation() || !AI.getAllocatedType()->isSized() ||
4095 DL.getTypeAllocSize(AI.getAllocatedType()) == 0)
4096 return false;
4097
4098 bool Changed = false;
4099
4100 // First, split any FCA loads and stores touching this alloca to promote
4101 // better splitting and promotion opportunities.
4102 AggLoadStoreRewriter AggRewriter;
4103 Changed |= AggRewriter.rewrite(AI);
4104
4105 // Build the slices using a recursive instruction-visiting builder.
4106 AllocaSlices AS(DL, AI);
4107 DEBUG(AS.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs()); } } while (false)
;
4108 if (AS.isEscaped())
4109 return Changed;
4110
4111 // Delete all the dead users of this alloca before splitting and rewriting it.
4112 for (Instruction *DeadUser : AS.getDeadUsers()) {
4113 // Free up everything used by this instruction.
4114 for (Use &DeadOp : DeadUser->operands())
4115 clobberUse(DeadOp);
4116
4117 // Now replace the uses of this instruction.
4118 DeadUser->replaceAllUsesWith(UndefValue::get(DeadUser->getType()));
4119
4120 // And mark it for deletion.
4121 DeadInsts.insert(DeadUser);
4122 Changed = true;
4123 }
4124 for (Use *DeadOp : AS.getDeadOperands()) {
4125 clobberUse(*DeadOp);
4126 Changed = true;
4127 }
4128
4129 // No slices to split. Leave the dead alloca for a later pass to clean up.
4130 if (AS.begin() == AS.end())
4131 return Changed;
4132
4133 Changed |= splitAlloca(AI, AS);
4134
4135 DEBUG(dbgs() << " Speculating PHIs\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating PHIs\n"; } } while
(false)
;
4136 while (!SpeculatablePHIs.empty())
4137 speculatePHINodeLoads(*SpeculatablePHIs.pop_back_val());
4138
4139 DEBUG(dbgs() << " Speculating Selects\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating Selects\n"; } } while
(false)
;
4140 while (!SpeculatableSelects.empty())
4141 speculateSelectInstLoads(*SpeculatableSelects.pop_back_val());
4142
4143 return Changed;
4144}
4145
4146/// \brief Delete the dead instructions accumulated in this run.
4147///
4148/// Recursively deletes the dead instructions we've accumulated. This is done
4149/// at the very end to maximize locality of the recursive delete and to
4150/// minimize the problems of invalidated instruction pointers as such pointers
4151/// are used heavily in the intermediate stages of the algorithm.
4152///
4153/// We also record the alloca instructions deleted here so that they aren't
4154/// subsequently handed to mem2reg to promote.
4155void SROA::deleteDeadInstructions(
4156 SmallPtrSetImpl<AllocaInst *> &DeletedAllocas) {
4157 while (!DeadInsts.empty()) {
4158 Instruction *I = DeadInsts.pop_back_val();
4159 DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Deleting dead instruction: " <<
*I << "\n"; } } while (false)
;
4160
4161 I->replaceAllUsesWith(UndefValue::get(I->getType()));
4162
4163 for (Use &Operand : I->operands())
4164 if (Instruction *U = dyn_cast<Instruction>(Operand)) {
4165 // Zero out the operand and see if it becomes trivially dead.
4166 Operand = nullptr;
4167 if (isInstructionTriviallyDead(U))
4168 DeadInsts.insert(U);
4169 }
4170
4171 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4172 DeletedAllocas.insert(AI);
4173 if (DbgDeclareInst *DbgDecl = FindAllocaDbgDeclare(AI))
4174 DbgDecl->eraseFromParent();
4175 }
4176
4177 ++NumDeleted;
4178 I->eraseFromParent();
4179 }
4180}
4181
4182/// \brief Promote the allocas, using the best available technique.
4183///
4184/// This attempts to promote whatever allocas have been identified as viable in
4185/// the PromotableAllocas list. If that list is empty, there is nothing to do.
4186/// This function returns whether any promotion occurred.
4187bool SROA::promoteAllocas(Function &F) {
4188 if (PromotableAllocas.empty())
4189 return false;
4190
4191 NumPromoted += PromotableAllocas.size();
4192
4193 DEBUG(dbgs() << "Promoting allocas with mem2reg...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Promoting allocas with mem2reg...\n"
; } } while (false)
;
4194 PromoteMemToReg(PromotableAllocas, *DT, AC);
4195 PromotableAllocas.clear();
4196 return true;
4197}
4198
4199PreservedAnalyses SROA::runImpl(Function &F, DominatorTree &RunDT,
4200 AssumptionCache &RunAC) {
4201 DEBUG(dbgs() << "SROA function: " << F.getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA function: " << F.getName
() << "\n"; } } while (false)
;
4202 C = &F.getContext();
4203 DT = &RunDT;
4204 AC = &RunAC;
4205
4206 BasicBlock &EntryBB = F.getEntryBlock();
4207 for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
4208 I != E; ++I) {
4209 if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
4210 Worklist.insert(AI);
4211 }
4212
4213 bool Changed = false;
4214 // A set of deleted alloca instruction pointers which should be removed from
4215 // the list of promotable allocas.
4216 SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
4217
4218 do {
4219 while (!Worklist.empty()) {
4220 Changed |= runOnAlloca(*Worklist.pop_back_val());
4221 deleteDeadInstructions(DeletedAllocas);
4222
4223 // Remove the deleted allocas from various lists so that we don't try to
4224 // continue processing them.
4225 if (!DeletedAllocas.empty()) {
4226 auto IsInSet = [&](AllocaInst *AI) { return DeletedAllocas.count(AI); };
4227 Worklist.remove_if(IsInSet);
4228 PostPromotionWorklist.remove_if(IsInSet);
4229 PromotableAllocas.erase(remove_if(PromotableAllocas, IsInSet),
4230 PromotableAllocas.end());
4231 DeletedAllocas.clear();
4232 }
4233 }
4234
4235 Changed |= promoteAllocas(F);
4236
4237 Worklist = PostPromotionWorklist;
4238 PostPromotionWorklist.clear();
4239 } while (!Worklist.empty());
4240
4241 if (!Changed)
4242 return PreservedAnalyses::all();
4243
4244 PreservedAnalyses PA;
4245 PA.preserveSet<CFGAnalyses>();
4246 PA.preserve<GlobalsAA>();
4247 return PA;
4248}
4249
4250PreservedAnalyses SROA::run(Function &F, FunctionAnalysisManager &AM) {
4251 return runImpl(F, AM.getResult<DominatorTreeAnalysis>(F),
4252 AM.getResult<AssumptionAnalysis>(F));
4253}
4254
4255/// A legacy pass for the legacy pass manager that wraps the \c SROA pass.
4256///
4257/// This is in the llvm namespace purely to allow it to be a friend of the \c
4258/// SROA pass.
4259class llvm::sroa::SROALegacyPass : public FunctionPass {
4260 /// The SROA implementation.
4261 SROA Impl;
4262
4263public:
4264 SROALegacyPass() : FunctionPass(ID) {
4265 initializeSROALegacyPassPass(*PassRegistry::getPassRegistry());
4266 }
4267 bool runOnFunction(Function &F) override {
4268 if (skipFunction(F))
4269 return false;
4270
4271 auto PA = Impl.runImpl(
4272 F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
4273 getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F));
4274 return !PA.areAllPreserved();
4275 }
4276 void getAnalysisUsage(AnalysisUsage &AU) const override {
4277 AU.addRequired<AssumptionCacheTracker>();
4278 AU.addRequired<DominatorTreeWrapperPass>();
4279 AU.addPreserved<GlobalsAAWrapperPass>();
4280 AU.setPreservesCFG();
4281 }
4282
4283 StringRef getPassName() const override { return "SROA"; }
4284 static char ID;
4285};
4286
4287char SROALegacyPass::ID = 0;
4288
4289FunctionPass *llvm::createSROAPass() { return new SROALegacyPass(); }
4290
4291INITIALIZE_PASS_BEGIN(SROALegacyPass, "sroa",static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4292 "Scalar Replacement Of Aggregates", false, false)static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4293INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry);
4294INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
4295INITIALIZE_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)); }
4296 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)); }