Bug Summary

File:lib/Transforms/Scalar/SROA.cpp
Warning:line 2821, column 54
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SROA.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn329677/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/Transforms/Scalar -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-04-11-031539-24776-1 -x c++ /build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp
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/APInt.h"
28#include "llvm/ADT/ArrayRef.h"
29#include "llvm/ADT/DenseMap.h"
30#include "llvm/ADT/PointerIntPair.h"
31#include "llvm/ADT/STLExtras.h"
32#include "llvm/ADT/SetVector.h"
33#include "llvm/ADT/SmallBitVector.h"
34#include "llvm/ADT/SmallPtrSet.h"
35#include "llvm/ADT/SmallVector.h"
36#include "llvm/ADT/Statistic.h"
37#include "llvm/ADT/StringRef.h"
38#include "llvm/ADT/Twine.h"
39#include "llvm/ADT/iterator.h"
40#include "llvm/ADT/iterator_range.h"
41#include "llvm/Analysis/AssumptionCache.h"
42#include "llvm/Analysis/GlobalsModRef.h"
43#include "llvm/Analysis/Loads.h"
44#include "llvm/Analysis/PtrUseVisitor.h"
45#include "llvm/Analysis/Utils/Local.h"
46#include "llvm/IR/BasicBlock.h"
47#include "llvm/IR/Constant.h"
48#include "llvm/IR/ConstantFolder.h"
49#include "llvm/IR/Constants.h"
50#include "llvm/IR/DIBuilder.h"
51#include "llvm/IR/DataLayout.h"
52#include "llvm/IR/DebugInfoMetadata.h"
53#include "llvm/IR/DerivedTypes.h"
54#include "llvm/IR/Dominators.h"
55#include "llvm/IR/Function.h"
56#include "llvm/IR/GetElementPtrTypeIterator.h"
57#include "llvm/IR/GlobalAlias.h"
58#include "llvm/IR/IRBuilder.h"
59#include "llvm/IR/InstVisitor.h"
60#include "llvm/IR/InstrTypes.h"
61#include "llvm/IR/Instruction.h"
62#include "llvm/IR/Instructions.h"
63#include "llvm/IR/IntrinsicInst.h"
64#include "llvm/IR/Intrinsics.h"
65#include "llvm/IR/LLVMContext.h"
66#include "llvm/IR/Metadata.h"
67#include "llvm/IR/Module.h"
68#include "llvm/IR/Operator.h"
69#include "llvm/IR/PassManager.h"
70#include "llvm/IR/Type.h"
71#include "llvm/IR/Use.h"
72#include "llvm/IR/User.h"
73#include "llvm/IR/Value.h"
74#include "llvm/Pass.h"
75#include "llvm/Support/Casting.h"
76#include "llvm/Support/CommandLine.h"
77#include "llvm/Support/Compiler.h"
78#include "llvm/Support/Debug.h"
79#include "llvm/Support/ErrorHandling.h"
80#include "llvm/Support/MathExtras.h"
81#include "llvm/Support/raw_ostream.h"
82#include "llvm/Transforms/Scalar.h"
83#include "llvm/Transforms/Utils/PromoteMemToReg.h"
84#include <algorithm>
85#include <cassert>
86#include <chrono>
87#include <cstddef>
88#include <cstdint>
89#include <cstring>
90#include <iterator>
91#include <string>
92#include <tuple>
93#include <utility>
94#include <vector>
95
96#ifndef NDEBUG
97// We only use this for a debug check.
98#include <random>
99#endif
100
101using namespace llvm;
102using namespace llvm::sroa;
103
104#define DEBUG_TYPE"sroa" "sroa"
105
106STATISTIC(NumAllocasAnalyzed, "Number of allocas analyzed for replacement")static llvm::Statistic NumAllocasAnalyzed = {"sroa", "NumAllocasAnalyzed"
, "Number of allocas analyzed for replacement", {0}, {false}}
;
107STATISTIC(NumAllocaPartitions, "Number of alloca partitions formed")static llvm::Statistic NumAllocaPartitions = {"sroa", "NumAllocaPartitions"
, "Number of alloca partitions formed", {0}, {false}}
;
108STATISTIC(MaxPartitionsPerAlloca, "Maximum number of partitions per alloca")static llvm::Statistic MaxPartitionsPerAlloca = {"sroa", "MaxPartitionsPerAlloca"
, "Maximum number of partitions per alloca", {0}, {false}}
;
109STATISTIC(NumAllocaPartitionUses, "Number of alloca partition uses rewritten")static llvm::Statistic NumAllocaPartitionUses = {"sroa", "NumAllocaPartitionUses"
, "Number of alloca partition uses rewritten", {0}, {false}}
;
110STATISTIC(MaxUsesPerAllocaPartition, "Maximum number of uses of a partition")static llvm::Statistic MaxUsesPerAllocaPartition = {"sroa", "MaxUsesPerAllocaPartition"
, "Maximum number of uses of a partition", {0}, {false}}
;
111STATISTIC(NumNewAllocas, "Number of new, smaller allocas introduced")static llvm::Statistic NumNewAllocas = {"sroa", "NumNewAllocas"
, "Number of new, smaller allocas introduced", {0}, {false}}
;
112STATISTIC(NumPromoted, "Number of allocas promoted to SSA values")static llvm::Statistic NumPromoted = {"sroa", "NumPromoted", "Number of allocas promoted to SSA values"
, {0}, {false}}
;
113STATISTIC(NumLoadsSpeculated, "Number of loads speculated to allow promotion")static llvm::Statistic NumLoadsSpeculated = {"sroa", "NumLoadsSpeculated"
, "Number of loads speculated to allow promotion", {0}, {false
}}
;
114STATISTIC(NumDeleted, "Number of instructions deleted")static llvm::Statistic NumDeleted = {"sroa", "NumDeleted", "Number of instructions deleted"
, {0}, {false}}
;
115STATISTIC(NumVectorized, "Number of vectorized aggregates")static llvm::Statistic NumVectorized = {"sroa", "NumVectorized"
, "Number of vectorized aggregates", {0}, {false}}
;
116
117/// Hidden option to enable randomly shuffling the slices to help uncover
118/// instability in their order.
119static cl::opt<bool> SROARandomShuffleSlices("sroa-random-shuffle-slices",
120 cl::init(false), cl::Hidden);
121
122/// Hidden option to experiment with completely strict handling of inbounds
123/// GEPs.
124static cl::opt<bool> SROAStrictInbounds("sroa-strict-inbounds", cl::init(false),
125 cl::Hidden);
126
127namespace {
128
129/// \brief A custom IRBuilder inserter which prefixes all names, but only in
130/// Assert builds.
131class IRBuilderPrefixedInserter : public IRBuilderDefaultInserter {
132 std::string Prefix;
133
134 const Twine getNameWithPrefix(const Twine &Name) const {
135 return Name.isTriviallyEmpty() ? Name : Prefix + Name;
136 }
137
138public:
139 void SetNamePrefix(const Twine &P) { Prefix = P.str(); }
140
141protected:
142 void InsertHelper(Instruction *I, const Twine &Name, BasicBlock *BB,
143 BasicBlock::iterator InsertPt) const {
144 IRBuilderDefaultInserter::InsertHelper(I, getNameWithPrefix(Name), BB,
145 InsertPt);
146 }
147};
148
149/// \brief Provide a type for IRBuilder that drops names in release builds.
150using IRBuilderTy = IRBuilder<ConstantFolder, IRBuilderPrefixedInserter>;
151
152/// \brief A used slice of an alloca.
153///
154/// This structure represents a slice of an alloca used by some instruction. It
155/// stores both the begin and end offsets of this use, a pointer to the use
156/// itself, and a flag indicating whether we can classify the use as splittable
157/// or not when forming partitions of the alloca.
158class Slice {
159 /// \brief The beginning offset of the range.
160 uint64_t BeginOffset = 0;
161
162 /// \brief The ending offset, not included in the range.
163 uint64_t EndOffset = 0;
164
165 /// \brief Storage for both the use of this slice and whether it can be
166 /// split.
167 PointerIntPair<Use *, 1, bool> UseAndIsSplittable;
168
169public:
170 Slice() = default;
171
172 Slice(uint64_t BeginOffset, uint64_t EndOffset, Use *U, bool IsSplittable)
173 : BeginOffset(BeginOffset), EndOffset(EndOffset),
174 UseAndIsSplittable(U, IsSplittable) {}
175
176 uint64_t beginOffset() const { return BeginOffset; }
177 uint64_t endOffset() const { return EndOffset; }
178
179 bool isSplittable() const { return UseAndIsSplittable.getInt(); }
180 void makeUnsplittable() { UseAndIsSplittable.setInt(false); }
181
182 Use *getUse() const { return UseAndIsSplittable.getPointer(); }
183
184 bool isDead() const { return getUse() == nullptr; }
185 void kill() { UseAndIsSplittable.setPointer(nullptr); }
186
187 /// \brief Support for ordering ranges.
188 ///
189 /// This provides an ordering over ranges such that start offsets are
190 /// always increasing, and within equal start offsets, the end offsets are
191 /// decreasing. Thus the spanning range comes first in a cluster with the
192 /// same start position.
193 bool operator<(const Slice &RHS) const {
194 if (beginOffset() < RHS.beginOffset())
195 return true;
196 if (beginOffset() > RHS.beginOffset())
197 return false;
198 if (isSplittable() != RHS.isSplittable())
199 return !isSplittable();
200 if (endOffset() > RHS.endOffset())
201 return true;
202 return false;
203 }
204
205 /// \brief Support comparison with a single offset to allow binary searches.
206 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(const Slice &LHS,
207 uint64_t RHSOffset) {
208 return LHS.beginOffset() < RHSOffset;
209 }
210 friend LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) bool operator<(uint64_t LHSOffset,
211 const Slice &RHS) {
212 return LHSOffset < RHS.beginOffset();
213 }
214
215 bool operator==(const Slice &RHS) const {
216 return isSplittable() == RHS.isSplittable() &&
217 beginOffset() == RHS.beginOffset() && endOffset() == RHS.endOffset();
218 }
219 bool operator!=(const Slice &RHS) const { return !operator==(RHS); }
220};
221
222} // end anonymous namespace
223
224namespace llvm {
225
226template <typename T> struct isPodLike;
227template <> struct isPodLike<Slice> { static const bool value = true; };
228
229} // end namespace llvm
230
231/// \brief Representation of the alloca slices.
232///
233/// This class represents the slices of an alloca which are formed by its
234/// various uses. If a pointer escapes, we can't fully build a representation
235/// for the slices used and we reflect that in this structure. The uses are
236/// stored, sorted by increasing beginning offset and with unsplittable slices
237/// starting at a particular offset before splittable slices.
238class llvm::sroa::AllocaSlices {
239public:
240 /// \brief Construct the slices of a particular alloca.
241 AllocaSlices(const DataLayout &DL, AllocaInst &AI);
242
243 /// \brief Test whether a pointer to the allocation escapes our analysis.
244 ///
245 /// If this is true, the slices are never fully built and should be
246 /// ignored.
247 bool isEscaped() const { return PointerEscapingInstr; }
248
249 /// \brief Support for iterating over the slices.
250 /// @{
251 using iterator = SmallVectorImpl<Slice>::iterator;
252 using range = iterator_range<iterator>;
253
254 iterator begin() { return Slices.begin(); }
255 iterator end() { return Slices.end(); }
256
257 using const_iterator = SmallVectorImpl<Slice>::const_iterator;
258 using const_range = iterator_range<const_iterator>;
259
260 const_iterator begin() const { return Slices.begin(); }
261 const_iterator end() const { return Slices.end(); }
262 /// @}
263
264 /// \brief Erase a range of slices.
265 void erase(iterator Start, iterator Stop) { Slices.erase(Start, Stop); }
266
267 /// \brief Insert new slices for this alloca.
268 ///
269 /// This moves the slices into the alloca's slices collection, and re-sorts
270 /// everything so that the usual ordering properties of the alloca's slices
271 /// hold.
272 void insert(ArrayRef<Slice> NewSlices) {
273 int OldSize = Slices.size();
274 Slices.append(NewSlices.begin(), NewSlices.end());
275 auto SliceI = Slices.begin() + OldSize;
276 std::sort(SliceI, Slices.end());
277 std::inplace_merge(Slices.begin(), SliceI, Slices.end());
278 }
279
280 // Forward declare the iterator and range accessor for walking the
281 // partitions.
282 class partition_iterator;
283 iterator_range<partition_iterator> partitions();
284
285 /// \brief Access the dead users for this alloca.
286 ArrayRef<Instruction *> getDeadUsers() const { return DeadUsers; }
287
288 /// \brief Access the dead operands referring to this alloca.
289 ///
290 /// These are operands which have cannot actually be used to refer to the
291 /// alloca as they are outside its range and the user doesn't correct for
292 /// that. These mostly consist of PHI node inputs and the like which we just
293 /// need to replace with undef.
294 ArrayRef<Use *> getDeadOperands() const { return DeadOperands; }
295
296#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
297 void print(raw_ostream &OS, const_iterator I, StringRef Indent = " ") const;
298 void printSlice(raw_ostream &OS, const_iterator I,
299 StringRef Indent = " ") const;
300 void printUse(raw_ostream &OS, const_iterator I,
301 StringRef Indent = " ") const;
302 void print(raw_ostream &OS) const;
303 void dump(const_iterator I) const;
304 void dump() const;
305#endif
306
307private:
308 template <typename DerivedT, typename RetT = void> class BuilderBase;
309 class SliceBuilder;
310
311 friend class AllocaSlices::SliceBuilder;
312
313#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
314 /// \brief Handle to alloca instruction to simplify method interfaces.
315 AllocaInst &AI;
316#endif
317
318 /// \brief The instruction responsible for this alloca not having a known set
319 /// of slices.
320 ///
321 /// When an instruction (potentially) escapes the pointer to the alloca, we
322 /// store a pointer to that here and abort trying to form slices of the
323 /// alloca. This will be null if the alloca slices are analyzed successfully.
324 Instruction *PointerEscapingInstr;
325
326 /// \brief The slices of the alloca.
327 ///
328 /// We store a vector of the slices formed by uses of the alloca here. This
329 /// vector is sorted by increasing begin offset, and then the unsplittable
330 /// slices before the splittable ones. See the Slice inner class for more
331 /// details.
332 SmallVector<Slice, 8> Slices;
333
334 /// \brief Instructions which will become dead if we rewrite the alloca.
335 ///
336 /// Note that these are not separated by slice. This is because we expect an
337 /// alloca to be completely rewritten or not rewritten at all. If rewritten,
338 /// all these instructions can simply be removed and replaced with undef as
339 /// they come from outside of the allocated space.
340 SmallVector<Instruction *, 8> DeadUsers;
341
342 /// \brief Operands which will become dead if we rewrite the alloca.
343 ///
344 /// These are operands that in their particular use can be replaced with
345 /// undef when we rewrite the alloca. These show up in out-of-bounds inputs
346 /// to PHI nodes and the like. They aren't entirely dead (there might be
347 /// a GEP back into the bounds using it elsewhere) and nor is the PHI, but we
348 /// want to swap this particular input for undef to simplify the use lists of
349 /// the alloca.
350 SmallVector<Use *, 8> DeadOperands;
351};
352
353/// \brief A partition of the slices.
354///
355/// An ephemeral representation for a range of slices which can be viewed as
356/// a partition of the alloca. This range represents a span of the alloca's
357/// memory which cannot be split, and provides access to all of the slices
358/// overlapping some part of the partition.
359///
360/// Objects of this type are produced by traversing the alloca's slices, but
361/// are only ephemeral and not persistent.
362class llvm::sroa::Partition {
363private:
364 friend class AllocaSlices;
365 friend class AllocaSlices::partition_iterator;
366
367 using iterator = AllocaSlices::iterator;
368
369 /// \brief The beginning and ending offsets of the alloca for this
370 /// partition.
371 uint64_t BeginOffset, EndOffset;
372
373 /// \brief The start and end iterators of this partition.
374 iterator SI, SJ;
375
376 /// \brief A collection of split slice tails overlapping the partition.
377 SmallVector<Slice *, 4> SplitTails;
378
379 /// \brief Raw constructor builds an empty partition starting and ending at
380 /// the given iterator.
381 Partition(iterator SI) : SI(SI), SJ(SI) {}
382
383public:
384 /// \brief The start offset of this partition.
385 ///
386 /// All of the contained slices start at or after this offset.
387 uint64_t beginOffset() const { return BeginOffset; }
388
389 /// \brief The end offset of this partition.
390 ///
391 /// All of the contained slices end at or before this offset.
392 uint64_t endOffset() const { return EndOffset; }
393
394 /// \brief The size of the partition.
395 ///
396 /// Note that this can never be zero.
397 uint64_t size() const {
398 assert(BeginOffset < EndOffset && "Partitions must span some bytes!")(static_cast <bool> (BeginOffset < EndOffset &&
"Partitions must span some bytes!") ? void (0) : __assert_fail
("BeginOffset < EndOffset && \"Partitions must span some bytes!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 398, __extension__ __PRETTY_FUNCTION__))
;
399 return EndOffset - BeginOffset;
400 }
401
402 /// \brief Test whether this partition contains no slices, and merely spans
403 /// a region occupied by split slices.
404 bool empty() const { return SI == SJ; }
405
406 /// \name Iterate slices that start within the partition.
407 /// These may be splittable or unsplittable. They have a begin offset >= the
408 /// partition begin offset.
409 /// @{
410 // FIXME: We should probably define a "concat_iterator" helper and use that
411 // to stitch together pointee_iterators over the split tails and the
412 // contiguous iterators of the partition. That would give a much nicer
413 // interface here. We could then additionally expose filtered iterators for
414 // split, unsplit, and unsplittable splices based on the usage patterns.
415 iterator begin() const { return SI; }
416 iterator end() const { return SJ; }
417 /// @}
418
419 /// \brief Get the sequence of split slice tails.
420 ///
421 /// These tails are of slices which start before this partition but are
422 /// split and overlap into the partition. We accumulate these while forming
423 /// partitions.
424 ArrayRef<Slice *> splitSliceTails() const { return SplitTails; }
425};
426
427/// \brief An iterator over partitions of the alloca's slices.
428///
429/// This iterator implements the core algorithm for partitioning the alloca's
430/// slices. It is a forward iterator as we don't support backtracking for
431/// efficiency reasons, and re-use a single storage area to maintain the
432/// current set of split slices.
433///
434/// It is templated on the slice iterator type to use so that it can operate
435/// with either const or non-const slice iterators.
436class AllocaSlices::partition_iterator
437 : public iterator_facade_base<partition_iterator, std::forward_iterator_tag,
438 Partition> {
439 friend class AllocaSlices;
440
441 /// \brief Most of the state for walking the partitions is held in a class
442 /// with a nice interface for examining them.
443 Partition P;
444
445 /// \brief We need to keep the end of the slices to know when to stop.
446 AllocaSlices::iterator SE;
447
448 /// \brief We also need to keep track of the maximum split end offset seen.
449 /// FIXME: Do we really?
450 uint64_t MaxSplitSliceEndOffset = 0;
451
452 /// \brief Sets the partition to be empty at given iterator, and sets the
453 /// end iterator.
454 partition_iterator(AllocaSlices::iterator SI, AllocaSlices::iterator SE)
455 : P(SI), SE(SE) {
456 // If not already at the end, advance our state to form the initial
457 // partition.
458 if (SI != SE)
459 advance();
460 }
461
462 /// \brief Advance the iterator to the next partition.
463 ///
464 /// Requires that the iterator not be at the end of the slices.
465 void advance() {
466 assert((P.SI != SE || !P.SplitTails.empty()) &&(static_cast <bool> ((P.SI != SE || !P.SplitTails.empty
()) && "Cannot advance past the end of the slices!") ?
void (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 467, __extension__ __PRETTY_FUNCTION__))
467 "Cannot advance past the end of the slices!")(static_cast <bool> ((P.SI != SE || !P.SplitTails.empty
()) && "Cannot advance past the end of the slices!") ?
void (0) : __assert_fail ("(P.SI != SE || !P.SplitTails.empty()) && \"Cannot advance past the end of the slices!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 467, __extension__ __PRETTY_FUNCTION__))
;
468
469 // Clear out any split uses which have ended.
470 if (!P.SplitTails.empty()) {
471 if (P.EndOffset >= MaxSplitSliceEndOffset) {
472 // If we've finished all splits, this is easy.
473 P.SplitTails.clear();
474 MaxSplitSliceEndOffset = 0;
475 } else {
476 // Remove the uses which have ended in the prior partition. This
477 // cannot change the max split slice end because we just checked that
478 // the prior partition ended prior to that max.
479 P.SplitTails.erase(llvm::remove_if(P.SplitTails,
480 [&](Slice *S) {
481 return S->endOffset() <=
482 P.EndOffset;
483 }),
484 P.SplitTails.end());
485 assert(llvm::any_of(P.SplitTails,(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? void (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
486 [&](Slice *S) {(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? void (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
487 return S->endOffset() == MaxSplitSliceEndOffset;(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? void (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
488 }) &&(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? void (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
489 "Could not find the current max split slice offset!")(static_cast <bool> (llvm::any_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset
; }) && "Could not find the current max split slice offset!"
) ? void (0) : __assert_fail ("llvm::any_of(P.SplitTails, [&](Slice *S) { return S->endOffset() == MaxSplitSliceEndOffset; }) && \"Could not find the current max split slice offset!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
;
490 assert(llvm::all_of(P.SplitTails,(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? void (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 494, __extension__ __PRETTY_FUNCTION__))
491 [&](Slice *S) {(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? void (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 494, __extension__ __PRETTY_FUNCTION__))
492 return S->endOffset() <= MaxSplitSliceEndOffset;(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? void (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 494, __extension__ __PRETTY_FUNCTION__))
493 }) &&(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? void (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 494, __extension__ __PRETTY_FUNCTION__))
494 "Max split slice end offset is not actually the max!")(static_cast <bool> (llvm::all_of(P.SplitTails, [&]
(Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset
; }) && "Max split slice end offset is not actually the max!"
) ? void (0) : __assert_fail ("llvm::all_of(P.SplitTails, [&](Slice *S) { return S->endOffset() <= MaxSplitSliceEndOffset; }) && \"Max split slice end offset is not actually the max!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 494, __extension__ __PRETTY_FUNCTION__))
;
495 }
496 }
497
498 // If P.SI is already at the end, then we've cleared the split tail and
499 // now have an end iterator.
500 if (P.SI == SE) {
501 assert(P.SplitTails.empty() && "Failed to clear the split slices!")(static_cast <bool> (P.SplitTails.empty() && "Failed to clear the split slices!"
) ? void (0) : __assert_fail ("P.SplitTails.empty() && \"Failed to clear the split slices!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 501, __extension__ __PRETTY_FUNCTION__))
;
502 return;
503 }
504
505 // If we had a non-empty partition previously, set up the state for
506 // subsequent partitions.
507 if (P.SI != P.SJ) {
508 // Accumulate all the splittable slices which started in the old
509 // partition into the split list.
510 for (Slice &S : P)
511 if (S.isSplittable() && S.endOffset() > P.EndOffset) {
512 P.SplitTails.push_back(&S);
513 MaxSplitSliceEndOffset =
514 std::max(S.endOffset(), MaxSplitSliceEndOffset);
515 }
516
517 // Start from the end of the previous partition.
518 P.SI = P.SJ;
519
520 // If P.SI is now at the end, we at most have a tail of split slices.
521 if (P.SI == SE) {
522 P.BeginOffset = P.EndOffset;
523 P.EndOffset = MaxSplitSliceEndOffset;
524 return;
525 }
526
527 // If the we have split slices and the next slice is after a gap and is
528 // not splittable immediately form an empty partition for the split
529 // slices up until the next slice begins.
530 if (!P.SplitTails.empty() && P.SI->beginOffset() != P.EndOffset &&
531 !P.SI->isSplittable()) {
532 P.BeginOffset = P.EndOffset;
533 P.EndOffset = P.SI->beginOffset();
534 return;
535 }
536 }
537
538 // OK, we need to consume new slices. Set the end offset based on the
539 // current slice, and step SJ past it. The beginning offset of the
540 // partition is the beginning offset of the next slice unless we have
541 // pre-existing split slices that are continuing, in which case we begin
542 // at the prior end offset.
543 P.BeginOffset = P.SplitTails.empty() ? P.SI->beginOffset() : P.EndOffset;
544 P.EndOffset = P.SI->endOffset();
545 ++P.SJ;
546
547 // There are two strategies to form a partition based on whether the
548 // partition starts with an unsplittable slice or a splittable slice.
549 if (!P.SI->isSplittable()) {
550 // When we're forming an unsplittable region, it must always start at
551 // the first slice and will extend through its end.
552 assert(P.BeginOffset == P.SI->beginOffset())(static_cast <bool> (P.BeginOffset == P.SI->beginOffset
()) ? void (0) : __assert_fail ("P.BeginOffset == P.SI->beginOffset()"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 552, __extension__ __PRETTY_FUNCTION__))
;
553
554 // Form a partition including all of the overlapping slices with this
555 // unsplittable slice.
556 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
557 if (!P.SJ->isSplittable())
558 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
559 ++P.SJ;
560 }
561
562 // We have a partition across a set of overlapping unsplittable
563 // partitions.
564 return;
565 }
566
567 // If we're starting with a splittable slice, then we need to form
568 // a synthetic partition spanning it and any other overlapping splittable
569 // splices.
570 assert(P.SI->isSplittable() && "Forming a splittable partition!")(static_cast <bool> (P.SI->isSplittable() &&
"Forming a splittable partition!") ? void (0) : __assert_fail
("P.SI->isSplittable() && \"Forming a splittable partition!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 570, __extension__ __PRETTY_FUNCTION__))
;
571
572 // Collect all of the overlapping splittable slices.
573 while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset &&
574 P.SJ->isSplittable()) {
575 P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
576 ++P.SJ;
577 }
578
579 // Back upiP.EndOffset if we ended the span early when encountering an
580 // unsplittable slice. This synthesizes the early end offset of
581 // a partition spanning only splittable slices.
582 if (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
583 assert(!P.SJ->isSplittable())(static_cast <bool> (!P.SJ->isSplittable()) ? void (
0) : __assert_fail ("!P.SJ->isSplittable()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 583, __extension__ __PRETTY_FUNCTION__))
;
584 P.EndOffset = P.SJ->beginOffset();
585 }
586 }
587
588public:
589 bool operator==(const partition_iterator &RHS) const {
590 assert(SE == RHS.SE &&(static_cast <bool> (SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? void (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 591, __extension__ __PRETTY_FUNCTION__))
591 "End iterators don't match between compared partition iterators!")(static_cast <bool> (SE == RHS.SE && "End iterators don't match between compared partition iterators!"
) ? void (0) : __assert_fail ("SE == RHS.SE && \"End iterators don't match between compared partition iterators!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 591, __extension__ __PRETTY_FUNCTION__))
;
592
593 // The observed positions of partitions is marked by the P.SI iterator and
594 // the emptiness of the split slices. The latter is only relevant when
595 // P.SI == SE, as the end iterator will additionally have an empty split
596 // slices list, but the prior may have the same P.SI and a tail of split
597 // slices.
598 if (P.SI == RHS.P.SI && P.SplitTails.empty() == RHS.P.SplitTails.empty()) {
599 assert(P.SJ == RHS.P.SJ &&(static_cast <bool> (P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? void (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 600, __extension__ __PRETTY_FUNCTION__))
600 "Same set of slices formed two different sized partitions!")(static_cast <bool> (P.SJ == RHS.P.SJ && "Same set of slices formed two different sized partitions!"
) ? void (0) : __assert_fail ("P.SJ == RHS.P.SJ && \"Same set of slices formed two different sized partitions!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 600, __extension__ __PRETTY_FUNCTION__))
;
601 assert(P.SplitTails.size() == RHS.P.SplitTails.size() &&(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? void (0) : __assert_fail ("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 603, __extension__ __PRETTY_FUNCTION__))
602 "Same slice position with differently sized non-empty split "(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? void (0) : __assert_fail ("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 603, __extension__ __PRETTY_FUNCTION__))
603 "slice tails!")(static_cast <bool> (P.SplitTails.size() == RHS.P.SplitTails
.size() && "Same slice position with differently sized non-empty split "
"slice tails!") ? void (0) : __assert_fail ("P.SplitTails.size() == RHS.P.SplitTails.size() && \"Same slice position with differently sized non-empty split \" \"slice tails!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 603, __extension__ __PRETTY_FUNCTION__))
;
604 return true;
605 }
606 return false;
607 }
608
609 partition_iterator &operator++() {
610 advance();
611 return *this;
612 }
613
614 Partition &operator*() { return P; }
615};
616
617/// \brief A forward range over the partitions of the alloca's slices.
618///
619/// This accesses an iterator range over the partitions of the alloca's
620/// slices. It computes these partitions on the fly based on the overlapping
621/// offsets of the slices and the ability to split them. It will visit "empty"
622/// partitions to cover regions of the alloca only accessed via split
623/// slices.
624iterator_range<AllocaSlices::partition_iterator> AllocaSlices::partitions() {
625 return make_range(partition_iterator(begin(), end()),
626 partition_iterator(end(), end()));
627}
628
629static Value *foldSelectInst(SelectInst &SI) {
630 // If the condition being selected on is a constant or the same value is
631 // being selected between, fold the select. Yes this does (rarely) happen
632 // early on.
633 if (ConstantInt *CI = dyn_cast<ConstantInt>(SI.getCondition()))
634 return SI.getOperand(1 + CI->isZero());
635 if (SI.getOperand(1) == SI.getOperand(2))
636 return SI.getOperand(1);
637
638 return nullptr;
639}
640
641/// \brief A helper that folds a PHI node or a select.
642static Value *foldPHINodeOrSelectInst(Instruction &I) {
643 if (PHINode *PN = dyn_cast<PHINode>(&I)) {
644 // If PN merges together the same value, return that value.
645 return PN->hasConstantValue();
646 }
647 return foldSelectInst(cast<SelectInst>(I));
648}
649
650/// \brief Builder for the alloca slices.
651///
652/// This class builds a set of alloca slices by recursively visiting the uses
653/// of an alloca and making a slice for each load and store at each offset.
654class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
655 friend class PtrUseVisitor<SliceBuilder>;
656 friend class InstVisitor<SliceBuilder>;
657
658 using Base = PtrUseVisitor<SliceBuilder>;
659
660 const uint64_t AllocSize;
661 AllocaSlices &AS;
662
663 SmallDenseMap<Instruction *, unsigned> MemTransferSliceMap;
664 SmallDenseMap<Instruction *, uint64_t> PHIOrSelectSizes;
665
666 /// \brief Set to de-duplicate dead instructions found in the use walk.
667 SmallPtrSet<Instruction *, 4> VisitedDeadInsts;
668
669public:
670 SliceBuilder(const DataLayout &DL, AllocaInst &AI, AllocaSlices &AS)
671 : PtrUseVisitor<SliceBuilder>(DL),
672 AllocSize(DL.getTypeAllocSize(AI.getAllocatedType())), AS(AS) {}
673
674private:
675 void markAsDead(Instruction &I) {
676 if (VisitedDeadInsts.insert(&I).second)
677 AS.DeadUsers.push_back(&I);
678 }
679
680 void insertUse(Instruction &I, const APInt &Offset, uint64_t Size,
681 bool IsSplittable = false) {
682 // Completely skip uses which have a zero size or start either before or
683 // past the end of the allocation.
684 if (Size == 0 || Offset.uge(AllocSize)) {
685 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)
686 << " 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)
687 << 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)
688 << " 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)
689 << " 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)
;
690 return markAsDead(I);
691 }
692
693 uint64_t BeginOffset = Offset.getZExtValue();
694 uint64_t EndOffset = BeginOffset + Size;
695
696 // Clamp the end offset to the end of the allocation. Note that this is
697 // formulated to handle even the case where "BeginOffset + Size" overflows.
698 // This may appear superficially to be something we could ignore entirely,
699 // but that is not so! There may be widened loads or PHI-node uses where
700 // some instructions are dead but not others. We can't completely ignore
701 // them, and so have to record at least the information here.
702 assert(AllocSize >= BeginOffset)(static_cast <bool> (AllocSize >= BeginOffset) ? void
(0) : __assert_fail ("AllocSize >= BeginOffset", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 702, __extension__ __PRETTY_FUNCTION__))
; // Established above.
703 if (Size > AllocSize - BeginOffset) {
704 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)
705 << " 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)
706 << " 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)
707 << " 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)
;
708 EndOffset = AllocSize;
709 }
710
711 AS.Slices.push_back(Slice(BeginOffset, EndOffset, U, IsSplittable));
712 }
713
714 void visitBitCastInst(BitCastInst &BC) {
715 if (BC.use_empty())
716 return markAsDead(BC);
717
718 return Base::visitBitCastInst(BC);
719 }
720
721 void visitGetElementPtrInst(GetElementPtrInst &GEPI) {
722 if (GEPI.use_empty())
723 return markAsDead(GEPI);
724
725 if (SROAStrictInbounds && GEPI.isInBounds()) {
726 // FIXME: This is a manually un-factored variant of the basic code inside
727 // of GEPs with checking of the inbounds invariant specified in the
728 // langref in a very strict sense. If we ever want to enable
729 // SROAStrictInbounds, this code should be factored cleanly into
730 // PtrUseVisitor, but it is easier to experiment with SROAStrictInbounds
731 // by writing out the code here where we have the underlying allocation
732 // size readily available.
733 APInt GEPOffset = Offset;
734 const DataLayout &DL = GEPI.getModule()->getDataLayout();
735 for (gep_type_iterator GTI = gep_type_begin(GEPI),
736 GTE = gep_type_end(GEPI);
737 GTI != GTE; ++GTI) {
738 ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
739 if (!OpC)
740 break;
741
742 // Handle a struct index, which adds its field offset to the pointer.
743 if (StructType *STy = GTI.getStructTypeOrNull()) {
744 unsigned ElementIdx = OpC->getZExtValue();
745 const StructLayout *SL = DL.getStructLayout(STy);
746 GEPOffset +=
747 APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx));
748 } else {
749 // For array or vector indices, scale the index by the size of the
750 // type.
751 APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth());
752 GEPOffset += Index * APInt(Offset.getBitWidth(),
753 DL.getTypeAllocSize(GTI.getIndexedType()));
754 }
755
756 // If this index has computed an intermediate pointer which is not
757 // inbounds, then the result of the GEP is a poison value and we can
758 // delete it and all uses.
759 if (GEPOffset.ugt(AllocSize))
760 return markAsDead(GEPI);
761 }
762 }
763
764 return Base::visitGetElementPtrInst(GEPI);
765 }
766
767 void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset,
768 uint64_t Size, bool IsVolatile) {
769 // We allow splitting of non-volatile loads and stores where the type is an
770 // integer type. These may be used to implement 'memcpy' or other "transfer
771 // of bits" patterns.
772 bool IsSplittable = Ty->isIntegerTy() && !IsVolatile;
773
774 insertUse(I, Offset, Size, IsSplittable);
775 }
776
777 void visitLoadInst(LoadInst &LI) {
778 assert((!LI.isSimple() || LI.getType()->isSingleValueType()) &&(static_cast <bool> ((!LI.isSimple() || LI.getType()->
isSingleValueType()) && "All simple FCA loads should have been pre-split"
) ? void (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 779, __extension__ __PRETTY_FUNCTION__))
779 "All simple FCA loads should have been pre-split")(static_cast <bool> ((!LI.isSimple() || LI.getType()->
isSingleValueType()) && "All simple FCA loads should have been pre-split"
) ? void (0) : __assert_fail ("(!LI.isSimple() || LI.getType()->isSingleValueType()) && \"All simple FCA loads should have been pre-split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 779, __extension__ __PRETTY_FUNCTION__))
;
780
781 if (!IsOffsetKnown)
782 return PI.setAborted(&LI);
783
784 const DataLayout &DL = LI.getModule()->getDataLayout();
785 uint64_t Size = DL.getTypeStoreSize(LI.getType());
786 return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
787 }
788
789 void visitStoreInst(StoreInst &SI) {
790 Value *ValOp = SI.getValueOperand();
791 if (ValOp == *U)
792 return PI.setEscapedAndAborted(&SI);
793 if (!IsOffsetKnown)
794 return PI.setAborted(&SI);
795
796 const DataLayout &DL = SI.getModule()->getDataLayout();
797 uint64_t Size = DL.getTypeStoreSize(ValOp->getType());
798
799 // If this memory access can be shown to *statically* extend outside the
800 // bounds of the allocation, it's behavior is undefined, so simply
801 // ignore it. Note that this is more strict than the generic clamping
802 // behavior of insertUse. We also try to handle cases which might run the
803 // risk of overflow.
804 // FIXME: We should instead consider the pointer to have escaped if this
805 // function is being instrumented for addressing bugs or race conditions.
806 if (Size > AllocSize || Offset.ugt(AllocSize - Size)) {
807 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)
808 << " 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)
809 << " 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)
810 << " 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)
811 << " 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)
;
812 return markAsDead(SI);
813 }
814
815 assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&(static_cast <bool> ((!SI.isSimple() || ValOp->getType
()->isSingleValueType()) && "All simple FCA stores should have been pre-split"
) ? void (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 816, __extension__ __PRETTY_FUNCTION__))
816 "All simple FCA stores should have been pre-split")(static_cast <bool> ((!SI.isSimple() || ValOp->getType
()->isSingleValueType()) && "All simple FCA stores should have been pre-split"
) ? void (0) : __assert_fail ("(!SI.isSimple() || ValOp->getType()->isSingleValueType()) && \"All simple FCA stores should have been pre-split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 816, __extension__ __PRETTY_FUNCTION__))
;
817 handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
818 }
819
820 void visitMemSetInst(MemSetInst &II) {
821 assert(II.getRawDest() == *U && "Pointer use is not the destination?")(static_cast <bool> (II.getRawDest() == *U && "Pointer use is not the destination?"
) ? void (0) : __assert_fail ("II.getRawDest() == *U && \"Pointer use is not the destination?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 821, __extension__ __PRETTY_FUNCTION__))
;
822 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
823 if ((Length && Length->getValue() == 0) ||
824 (IsOffsetKnown && Offset.uge(AllocSize)))
825 // Zero-length mem transfer intrinsics can be ignored entirely.
826 return markAsDead(II);
827
828 if (!IsOffsetKnown)
829 return PI.setAborted(&II);
830
831 insertUse(II, Offset, Length ? Length->getLimitedValue()
832 : AllocSize - Offset.getLimitedValue(),
833 (bool)Length);
834 }
835
836 void visitMemTransferInst(MemTransferInst &II) {
837 ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
838 if (Length && Length->getValue() == 0)
839 // Zero-length mem transfer intrinsics can be ignored entirely.
840 return markAsDead(II);
841
842 // Because we can visit these intrinsics twice, also check to see if the
843 // first time marked this instruction as dead. If so, skip it.
844 if (VisitedDeadInsts.count(&II))
845 return;
846
847 if (!IsOffsetKnown)
848 return PI.setAborted(&II);
849
850 // This side of the transfer is completely out-of-bounds, and so we can
851 // nuke the entire transfer. However, we also need to nuke the other side
852 // if already added to our partitions.
853 // FIXME: Yet another place we really should bypass this when
854 // instrumenting for ASan.
855 if (Offset.uge(AllocSize)) {
856 SmallDenseMap<Instruction *, unsigned>::iterator MTPI =
857 MemTransferSliceMap.find(&II);
858 if (MTPI != MemTransferSliceMap.end())
859 AS.Slices[MTPI->second].kill();
860 return markAsDead(II);
861 }
862
863 uint64_t RawOffset = Offset.getLimitedValue();
864 uint64_t Size = Length ? Length->getLimitedValue() : AllocSize - RawOffset;
865
866 // Check for the special case where the same exact value is used for both
867 // source and dest.
868 if (*U == II.getRawDest() && *U == II.getRawSource()) {
869 // For non-volatile transfers this is a no-op.
870 if (!II.isVolatile())
871 return markAsDead(II);
872
873 return insertUse(II, Offset, Size, /*IsSplittable=*/false);
874 }
875
876 // If we have seen both source and destination for a mem transfer, then
877 // they both point to the same alloca.
878 bool Inserted;
879 SmallDenseMap<Instruction *, unsigned>::iterator MTPI;
880 std::tie(MTPI, Inserted) =
881 MemTransferSliceMap.insert(std::make_pair(&II, AS.Slices.size()));
882 unsigned PrevIdx = MTPI->second;
883 if (!Inserted) {
884 Slice &PrevP = AS.Slices[PrevIdx];
885
886 // Check if the begin offsets match and this is a non-volatile transfer.
887 // In that case, we can completely elide the transfer.
888 if (!II.isVolatile() && PrevP.beginOffset() == RawOffset) {
889 PrevP.kill();
890 return markAsDead(II);
891 }
892
893 // Otherwise we have an offset transfer within the same alloca. We can't
894 // split those.
895 PrevP.makeUnsplittable();
896 }
897
898 // Insert the use now that we've fixed up the splittable nature.
899 insertUse(II, Offset, Size, /*IsSplittable=*/Inserted && Length);
900
901 // Check that we ended up with a valid index in the map.
902 assert(AS.Slices[PrevIdx].getUse()->getUser() == &II &&(static_cast <bool> (AS.Slices[PrevIdx].getUse()->getUser
() == &II && "Map index doesn't point back to a slice with this user."
) ? void (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 903, __extension__ __PRETTY_FUNCTION__))
903 "Map index doesn't point back to a slice with this user.")(static_cast <bool> (AS.Slices[PrevIdx].getUse()->getUser
() == &II && "Map index doesn't point back to a slice with this user."
) ? void (0) : __assert_fail ("AS.Slices[PrevIdx].getUse()->getUser() == &II && \"Map index doesn't point back to a slice with this user.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 903, __extension__ __PRETTY_FUNCTION__))
;
904 }
905
906 // Disable SRoA for any intrinsics except for lifetime invariants.
907 // FIXME: What about debug intrinsics? This matches old behavior, but
908 // doesn't make sense.
909 void visitIntrinsicInst(IntrinsicInst &II) {
910 if (!IsOffsetKnown)
911 return PI.setAborted(&II);
912
913 if (II.getIntrinsicID() == Intrinsic::lifetime_start ||
914 II.getIntrinsicID() == Intrinsic::lifetime_end) {
915 ConstantInt *Length = cast<ConstantInt>(II.getArgOperand(0));
916 uint64_t Size = std::min(AllocSize - Offset.getLimitedValue(),
917 Length->getLimitedValue());
918 insertUse(II, Offset, Size, true);
919 return;
920 }
921
922 Base::visitIntrinsicInst(II);
923 }
924
925 Instruction *hasUnsafePHIOrSelectUse(Instruction *Root, uint64_t &Size) {
926 // We consider any PHI or select that results in a direct load or store of
927 // the same offset to be a viable use for slicing purposes. These uses
928 // are considered unsplittable and the size is the maximum loaded or stored
929 // size.
930 SmallPtrSet<Instruction *, 4> Visited;
931 SmallVector<std::pair<Instruction *, Instruction *>, 4> Uses;
932 Visited.insert(Root);
933 Uses.push_back(std::make_pair(cast<Instruction>(*U), Root));
934 const DataLayout &DL = Root->getModule()->getDataLayout();
935 // If there are no loads or stores, the access is dead. We mark that as
936 // a size zero access.
937 Size = 0;
938 do {
939 Instruction *I, *UsedI;
940 std::tie(UsedI, I) = Uses.pop_back_val();
941
942 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
943 Size = std::max(Size, DL.getTypeStoreSize(LI->getType()));
944 continue;
945 }
946 if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
947 Value *Op = SI->getOperand(0);
948 if (Op == UsedI)
949 return SI;
950 Size = std::max(Size, DL.getTypeStoreSize(Op->getType()));
951 continue;
952 }
953
954 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
955 if (!GEP->hasAllZeroIndices())
956 return GEP;
957 } else if (!isa<BitCastInst>(I) && !isa<PHINode>(I) &&
958 !isa<SelectInst>(I)) {
959 return I;
960 }
961
962 for (User *U : I->users())
963 if (Visited.insert(cast<Instruction>(U)).second)
964 Uses.push_back(std::make_pair(I, cast<Instruction>(U)));
965 } while (!Uses.empty());
966
967 return nullptr;
968 }
969
970 void visitPHINodeOrSelectInst(Instruction &I) {
971 assert(isa<PHINode>(I) || isa<SelectInst>(I))(static_cast <bool> (isa<PHINode>(I) || isa<SelectInst
>(I)) ? void (0) : __assert_fail ("isa<PHINode>(I) || isa<SelectInst>(I)"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 971, __extension__ __PRETTY_FUNCTION__))
;
972 if (I.use_empty())
973 return markAsDead(I);
974
975 // TODO: We could use SimplifyInstruction here to fold PHINodes and
976 // SelectInsts. However, doing so requires to change the current
977 // dead-operand-tracking mechanism. For instance, suppose neither loading
978 // from %U nor %other traps. Then "load (select undef, %U, %other)" does not
979 // trap either. However, if we simply replace %U with undef using the
980 // current dead-operand-tracking mechanism, "load (select undef, undef,
981 // %other)" may trap because the select may return the first operand
982 // "undef".
983 if (Value *Result = foldPHINodeOrSelectInst(I)) {
984 if (Result == *U)
985 // If the result of the constant fold will be the pointer, recurse
986 // through the PHI/select as if we had RAUW'ed it.
987 enqueueUsers(I);
988 else
989 // Otherwise the operand to the PHI/select is dead, and we can replace
990 // it with undef.
991 AS.DeadOperands.push_back(U);
992
993 return;
994 }
995
996 if (!IsOffsetKnown)
997 return PI.setAborted(&I);
998
999 // See if we already have computed info on this node.
1000 uint64_t &Size = PHIOrSelectSizes[&I];
1001 if (!Size) {
1002 // This is a new PHI/Select, check for an unsafe use of it.
1003 if (Instruction *UnsafeI = hasUnsafePHIOrSelectUse(&I, Size))
1004 return PI.setAborted(UnsafeI);
1005 }
1006
1007 // For PHI and select operands outside the alloca, we can't nuke the entire
1008 // phi or select -- the other side might still be relevant, so we special
1009 // case them here and use a separate structure to track the operands
1010 // themselves which should be replaced with undef.
1011 // FIXME: This should instead be escaped in the event we're instrumenting
1012 // for address sanitization.
1013 if (Offset.uge(AllocSize)) {
1014 AS.DeadOperands.push_back(U);
1015 return;
1016 }
1017
1018 insertUse(I, Offset, Size);
1019 }
1020
1021 void visitPHINode(PHINode &PN) { visitPHINodeOrSelectInst(PN); }
1022
1023 void visitSelectInst(SelectInst &SI) { visitPHINodeOrSelectInst(SI); }
1024
1025 /// \brief Disable SROA entirely if there are unhandled users of the alloca.
1026 void visitInstruction(Instruction &I) { PI.setAborted(&I); }
1027};
1028
1029AllocaSlices::AllocaSlices(const DataLayout &DL, AllocaInst &AI)
1030 :
1031#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1032 AI(AI),
1033#endif
1034 PointerEscapingInstr(nullptr) {
1035 SliceBuilder PB(DL, AI, *this);
1036 SliceBuilder::PtrInfo PtrI = PB.visitPtr(AI);
1037 if (PtrI.isEscaped() || PtrI.isAborted()) {
1038 // FIXME: We should sink the escape vs. abort info into the caller nicely,
1039 // possibly by just storing the PtrInfo in the AllocaSlices.
1040 PointerEscapingInstr = PtrI.getEscapingInst() ? PtrI.getEscapingInst()
1041 : PtrI.getAbortingInst();
1042 assert(PointerEscapingInstr && "Did not track a bad instruction")(static_cast <bool> (PointerEscapingInstr && "Did not track a bad instruction"
) ? void (0) : __assert_fail ("PointerEscapingInstr && \"Did not track a bad instruction\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1042, __extension__ __PRETTY_FUNCTION__))
;
1043 return;
1044 }
1045
1046 Slices.erase(
1047 llvm::remove_if(Slices, [](const Slice &S) { return S.isDead(); }),
1048 Slices.end());
1049
1050#ifndef NDEBUG
1051 if (SROARandomShuffleSlices) {
1052 std::mt19937 MT(static_cast<unsigned>(
1053 std::chrono::system_clock::now().time_since_epoch().count()));
1054 std::shuffle(Slices.begin(), Slices.end(), MT);
1055 }
1056#endif
1057
1058 // Sort the uses. This arranges for the offsets to be in ascending order,
1059 // and the sizes to be in descending order.
1060 std::sort(Slices.begin(), Slices.end());
1061}
1062
1063#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1064
1065void AllocaSlices::print(raw_ostream &OS, const_iterator I,
1066 StringRef Indent) const {
1067 printSlice(OS, I, Indent);
1068 OS << "\n";
1069 printUse(OS, I, Indent);
1070}
1071
1072void AllocaSlices::printSlice(raw_ostream &OS, const_iterator I,
1073 StringRef Indent) const {
1074 OS << Indent << "[" << I->beginOffset() << "," << I->endOffset() << ")"
1075 << " slice #" << (I - begin())
1076 << (I->isSplittable() ? " (splittable)" : "");
1077}
1078
1079void AllocaSlices::printUse(raw_ostream &OS, const_iterator I,
1080 StringRef Indent) const {
1081 OS << Indent << " used by: " << *I->getUse()->getUser() << "\n";
1082}
1083
1084void AllocaSlices::print(raw_ostream &OS) const {
1085 if (PointerEscapingInstr) {
1086 OS << "Can't analyze slices for alloca: " << AI << "\n"
1087 << " A pointer to this alloca escaped by:\n"
1088 << " " << *PointerEscapingInstr << "\n";
1089 return;
1090 }
1091
1092 OS << "Slices of alloca: " << AI << "\n";
1093 for (const_iterator I = begin(), E = end(); I != E; ++I)
1094 print(OS, I);
1095}
1096
1097LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump(const_iterator I) const {
1098 print(dbgs(), I);
1099}
1100LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void AllocaSlices::dump() const { print(dbgs()); }
1101
1102#endif // !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1103
1104/// Walk the range of a partitioning looking for a common type to cover this
1105/// sequence of slices.
1106static Type *findCommonType(AllocaSlices::const_iterator B,
1107 AllocaSlices::const_iterator E,
1108 uint64_t EndOffset) {
1109 Type *Ty = nullptr;
1110 bool TyIsCommon = true;
1111 IntegerType *ITy = nullptr;
1112
1113 // Note that we need to look at *every* alloca slice's Use to ensure we
1114 // always get consistent results regardless of the order of slices.
1115 for (AllocaSlices::const_iterator I = B; I != E; ++I) {
1116 Use *U = I->getUse();
1117 if (isa<IntrinsicInst>(*U->getUser()))
1118 continue;
1119 if (I->beginOffset() != B->beginOffset() || I->endOffset() != EndOffset)
1120 continue;
1121
1122 Type *UserTy = nullptr;
1123 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1124 UserTy = LI->getType();
1125 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1126 UserTy = SI->getValueOperand()->getType();
1127 }
1128
1129 if (IntegerType *UserITy = dyn_cast_or_null<IntegerType>(UserTy)) {
1130 // If the type is larger than the partition, skip it. We only encounter
1131 // this for split integer operations where we want to use the type of the
1132 // entity causing the split. Also skip if the type is not a byte width
1133 // multiple.
1134 if (UserITy->getBitWidth() % 8 != 0 ||
1135 UserITy->getBitWidth() / 8 > (EndOffset - B->beginOffset()))
1136 continue;
1137
1138 // Track the largest bitwidth integer type used in this way in case there
1139 // is no common type.
1140 if (!ITy || ITy->getBitWidth() < UserITy->getBitWidth())
1141 ITy = UserITy;
1142 }
1143
1144 // To avoid depending on the order of slices, Ty and TyIsCommon must not
1145 // depend on types skipped above.
1146 if (!UserTy || (Ty && Ty != UserTy))
1147 TyIsCommon = false; // Give up on anything but an iN type.
1148 else
1149 Ty = UserTy;
1150 }
1151
1152 return TyIsCommon ? Ty : ITy;
1153}
1154
1155/// PHI instructions that use an alloca and are subsequently loaded can be
1156/// rewritten to load both input pointers in the pred blocks and then PHI the
1157/// results, allowing the load of the alloca to be promoted.
1158/// From this:
1159/// %P2 = phi [i32* %Alloca, i32* %Other]
1160/// %V = load i32* %P2
1161/// to:
1162/// %V1 = load i32* %Alloca -> will be mem2reg'd
1163/// ...
1164/// %V2 = load i32* %Other
1165/// ...
1166/// %V = phi [i32 %V1, i32 %V2]
1167///
1168/// We can do this to a select if its only uses are loads and if the operands
1169/// to the select can be loaded unconditionally.
1170///
1171/// FIXME: This should be hoisted into a generic utility, likely in
1172/// Transforms/Util/Local.h
1173static bool isSafePHIToSpeculate(PHINode &PN) {
1174 // For now, we can only do this promotion if the load is in the same block
1175 // as the PHI, and if there are no stores between the phi and load.
1176 // TODO: Allow recursive phi users.
1177 // TODO: Allow stores.
1178 BasicBlock *BB = PN.getParent();
1179 unsigned MaxAlign = 0;
1180 bool HaveLoad = false;
1181 for (User *U : PN.users()) {
1182 LoadInst *LI = dyn_cast<LoadInst>(U);
1183 if (!LI || !LI->isSimple())
1184 return false;
1185
1186 // For now we only allow loads in the same block as the PHI. This is
1187 // a common case that happens when instcombine merges two loads through
1188 // a PHI.
1189 if (LI->getParent() != BB)
1190 return false;
1191
1192 // Ensure that there are no instructions between the PHI and the load that
1193 // could store.
1194 for (BasicBlock::iterator BBI(PN); &*BBI != LI; ++BBI)
1195 if (BBI->mayWriteToMemory())
1196 return false;
1197
1198 MaxAlign = std::max(MaxAlign, LI->getAlignment());
1199 HaveLoad = true;
1200 }
1201
1202 if (!HaveLoad)
1203 return false;
1204
1205 const DataLayout &DL = PN.getModule()->getDataLayout();
1206
1207 // We can only transform this if it is safe to push the loads into the
1208 // predecessor blocks. The only thing to watch out for is that we can't put
1209 // a possibly trapping load in the predecessor if it is a critical edge.
1210 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1211 TerminatorInst *TI = PN.getIncomingBlock(Idx)->getTerminator();
1212 Value *InVal = PN.getIncomingValue(Idx);
1213
1214 // If the value is produced by the terminator of the predecessor (an
1215 // invoke) or it has side-effects, there is no valid place to put a load
1216 // in the predecessor.
1217 if (TI == InVal || TI->mayHaveSideEffects())
1218 return false;
1219
1220 // If the predecessor has a single successor, then the edge isn't
1221 // critical.
1222 if (TI->getNumSuccessors() == 1)
1223 continue;
1224
1225 // If this pointer is always safe to load, or if we can prove that there
1226 // is already a load in the block, then we can move the load to the pred
1227 // block.
1228 if (isSafeToLoadUnconditionally(InVal, MaxAlign, DL, TI))
1229 continue;
1230
1231 return false;
1232 }
1233
1234 return true;
1235}
1236
1237static void speculatePHINodeLoads(PHINode &PN) {
1238 DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
1239
1240 Type *LoadTy = cast<PointerType>(PN.getType())->getElementType();
1241 IRBuilderTy PHIBuilder(&PN);
1242 PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
1243 PN.getName() + ".sroa.speculated");
1244
1245 // Get the AA tags and alignment to use from one of the loads. It doesn't
1246 // matter which one we get and if any differ.
1247 LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
1248
1249 AAMDNodes AATags;
1250 SomeLoad->getAAMetadata(AATags);
1251 unsigned Align = SomeLoad->getAlignment();
1252
1253 // Rewrite all loads of the PN to use the new PHI.
1254 while (!PN.use_empty()) {
1255 LoadInst *LI = cast<LoadInst>(PN.user_back());
1256 LI->replaceAllUsesWith(NewPN);
1257 LI->eraseFromParent();
1258 }
1259
1260 // Inject loads into all of the pred blocks.
1261 for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
1262 BasicBlock *Pred = PN.getIncomingBlock(Idx);
1263 TerminatorInst *TI = Pred->getTerminator();
1264 Value *InVal = PN.getIncomingValue(Idx);
1265 IRBuilderTy PredBuilder(TI);
1266
1267 LoadInst *Load = PredBuilder.CreateLoad(
1268 InVal, (PN.getName() + ".sroa.speculate.load." + Pred->getName()));
1269 ++NumLoadsSpeculated;
1270 Load->setAlignment(Align);
1271 if (AATags)
1272 Load->setAAMetadata(AATags);
1273 NewPN->addIncoming(Load, Pred);
1274 }
1275
1276 DEBUG(dbgs() << " speculated to: " << *NewPN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*NewPN << "\n"; } } while (false)
;
1277 PN.eraseFromParent();
1278}
1279
1280/// Select instructions that use an alloca and are subsequently loaded can be
1281/// rewritten to load both input pointers and then select between the result,
1282/// allowing the load of the alloca to be promoted.
1283/// From this:
1284/// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
1285/// %V = load i32* %P2
1286/// to:
1287/// %V1 = load i32* %Alloca -> will be mem2reg'd
1288/// %V2 = load i32* %Other
1289/// %V = select i1 %cond, i32 %V1, i32 %V2
1290///
1291/// We can do this to a select if its only uses are loads and if the operand
1292/// to the select can be loaded unconditionally.
1293static bool isSafeSelectToSpeculate(SelectInst &SI) {
1294 Value *TValue = SI.getTrueValue();
1295 Value *FValue = SI.getFalseValue();
1296 const DataLayout &DL = SI.getModule()->getDataLayout();
1297
1298 for (User *U : SI.users()) {
1299 LoadInst *LI = dyn_cast<LoadInst>(U);
1300 if (!LI || !LI->isSimple())
1301 return false;
1302
1303 // Both operands to the select need to be dereferenceable, either
1304 // absolutely (e.g. allocas) or at this point because we can see other
1305 // accesses to it.
1306 if (!isSafeToLoadUnconditionally(TValue, LI->getAlignment(), DL, LI))
1307 return false;
1308 if (!isSafeToLoadUnconditionally(FValue, LI->getAlignment(), DL, LI))
1309 return false;
1310 }
1311
1312 return true;
1313}
1314
1315static void speculateSelectInstLoads(SelectInst &SI) {
1316 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
1317
1318 IRBuilderTy IRB(&SI);
1319 Value *TV = SI.getTrueValue();
1320 Value *FV = SI.getFalseValue();
1321 // Replace the loads of the select with a select of two loads.
1322 while (!SI.use_empty()) {
1323 LoadInst *LI = cast<LoadInst>(SI.user_back());
1324 assert(LI->isSimple() && "We only speculate simple loads")(static_cast <bool> (LI->isSimple() && "We only speculate simple loads"
) ? void (0) : __assert_fail ("LI->isSimple() && \"We only speculate simple loads\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1324, __extension__ __PRETTY_FUNCTION__))
;
1325
1326 IRB.SetInsertPoint(LI);
1327 LoadInst *TL =
1328 IRB.CreateLoad(TV, LI->getName() + ".sroa.speculate.load.true");
1329 LoadInst *FL =
1330 IRB.CreateLoad(FV, LI->getName() + ".sroa.speculate.load.false");
1331 NumLoadsSpeculated += 2;
1332
1333 // Transfer alignment and AA info if present.
1334 TL->setAlignment(LI->getAlignment());
1335 FL->setAlignment(LI->getAlignment());
1336
1337 AAMDNodes Tags;
1338 LI->getAAMetadata(Tags);
1339 if (Tags) {
1340 TL->setAAMetadata(Tags);
1341 FL->setAAMetadata(Tags);
1342 }
1343
1344 Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
1345 LI->getName() + ".sroa.speculated");
1346
1347 DEBUG(dbgs() << " speculated to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " speculated to: " <<
*V << "\n"; } } while (false)
;
1348 LI->replaceAllUsesWith(V);
1349 LI->eraseFromParent();
1350 }
1351 SI.eraseFromParent();
1352}
1353
1354/// \brief Build a GEP out of a base pointer and indices.
1355///
1356/// This will return the BasePtr if that is valid, or build a new GEP
1357/// instruction using the IRBuilder if GEP-ing is needed.
1358static Value *buildGEP(IRBuilderTy &IRB, Value *BasePtr,
1359 SmallVectorImpl<Value *> &Indices, Twine NamePrefix) {
1360 if (Indices.empty())
1361 return BasePtr;
1362
1363 // A single zero index is a no-op, so check for this and avoid building a GEP
1364 // in that case.
1365 if (Indices.size() == 1 && cast<ConstantInt>(Indices.back())->isZero())
1366 return BasePtr;
1367
1368 return IRB.CreateInBoundsGEP(nullptr, BasePtr, Indices,
1369 NamePrefix + "sroa_idx");
1370}
1371
1372/// \brief Get a natural GEP off of the BasePtr walking through Ty toward
1373/// TargetTy without changing the offset of the pointer.
1374///
1375/// This routine assumes we've already established a properly offset GEP with
1376/// Indices, and arrived at the Ty type. The goal is to continue to GEP with
1377/// zero-indices down through type layers until we find one the same as
1378/// TargetTy. If we can't find one with the same type, we at least try to use
1379/// one with the same size. If none of that works, we just produce the GEP as
1380/// indicated by Indices to have the correct offset.
1381static Value *getNaturalGEPWithType(IRBuilderTy &IRB, const DataLayout &DL,
1382 Value *BasePtr, Type *Ty, Type *TargetTy,
1383 SmallVectorImpl<Value *> &Indices,
1384 Twine NamePrefix) {
1385 if (Ty == TargetTy)
1386 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1387
1388 // Pointer size to use for the indices.
1389 unsigned PtrSize = DL.getPointerTypeSizeInBits(BasePtr->getType());
1390
1391 // See if we can descend into a struct and locate a field with the correct
1392 // type.
1393 unsigned NumLayers = 0;
1394 Type *ElementTy = Ty;
1395 do {
1396 if (ElementTy->isPointerTy())
1397 break;
1398
1399 if (ArrayType *ArrayTy = dyn_cast<ArrayType>(ElementTy)) {
1400 ElementTy = ArrayTy->getElementType();
1401 Indices.push_back(IRB.getIntN(PtrSize, 0));
1402 } else if (VectorType *VectorTy = dyn_cast<VectorType>(ElementTy)) {
1403 ElementTy = VectorTy->getElementType();
1404 Indices.push_back(IRB.getInt32(0));
1405 } else if (StructType *STy = dyn_cast<StructType>(ElementTy)) {
1406 if (STy->element_begin() == STy->element_end())
1407 break; // Nothing left to descend into.
1408 ElementTy = *STy->element_begin();
1409 Indices.push_back(IRB.getInt32(0));
1410 } else {
1411 break;
1412 }
1413 ++NumLayers;
1414 } while (ElementTy != TargetTy);
1415 if (ElementTy != TargetTy)
1416 Indices.erase(Indices.end() - NumLayers, Indices.end());
1417
1418 return buildGEP(IRB, BasePtr, Indices, NamePrefix);
1419}
1420
1421/// \brief Recursively compute indices for a natural GEP.
1422///
1423/// This is the recursive step for getNaturalGEPWithOffset that walks down the
1424/// element types adding appropriate indices for the GEP.
1425static Value *getNaturalGEPRecursively(IRBuilderTy &IRB, const DataLayout &DL,
1426 Value *Ptr, Type *Ty, APInt &Offset,
1427 Type *TargetTy,
1428 SmallVectorImpl<Value *> &Indices,
1429 Twine NamePrefix) {
1430 if (Offset == 0)
1431 return getNaturalGEPWithType(IRB, DL, Ptr, Ty, TargetTy, Indices,
1432 NamePrefix);
1433
1434 // We can't recurse through pointer types.
1435 if (Ty->isPointerTy())
1436 return nullptr;
1437
1438 // We try to analyze GEPs over vectors here, but note that these GEPs are
1439 // extremely poorly defined currently. The long-term goal is to remove GEPing
1440 // over a vector from the IR completely.
1441 if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
1442 unsigned ElementSizeInBits = DL.getTypeSizeInBits(VecTy->getScalarType());
1443 if (ElementSizeInBits % 8 != 0) {
1444 // GEPs over non-multiple of 8 size vector elements are invalid.
1445 return nullptr;
1446 }
1447 APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
1448 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1449 if (NumSkippedElements.ugt(VecTy->getNumElements()))
1450 return nullptr;
1451 Offset -= NumSkippedElements * ElementSize;
1452 Indices.push_back(IRB.getInt(NumSkippedElements));
1453 return getNaturalGEPRecursively(IRB, DL, Ptr, VecTy->getElementType(),
1454 Offset, TargetTy, Indices, NamePrefix);
1455 }
1456
1457 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
1458 Type *ElementTy = ArrTy->getElementType();
1459 APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
1460 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1461 if (NumSkippedElements.ugt(ArrTy->getNumElements()))
1462 return nullptr;
1463
1464 Offset -= NumSkippedElements * ElementSize;
1465 Indices.push_back(IRB.getInt(NumSkippedElements));
1466 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1467 Indices, NamePrefix);
1468 }
1469
1470 StructType *STy = dyn_cast<StructType>(Ty);
1471 if (!STy)
1472 return nullptr;
1473
1474 const StructLayout *SL = DL.getStructLayout(STy);
1475 uint64_t StructOffset = Offset.getZExtValue();
1476 if (StructOffset >= SL->getSizeInBytes())
1477 return nullptr;
1478 unsigned Index = SL->getElementContainingOffset(StructOffset);
1479 Offset -= APInt(Offset.getBitWidth(), SL->getElementOffset(Index));
1480 Type *ElementTy = STy->getElementType(Index);
1481 if (Offset.uge(DL.getTypeAllocSize(ElementTy)))
1482 return nullptr; // The offset points into alignment padding.
1483
1484 Indices.push_back(IRB.getInt32(Index));
1485 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1486 Indices, NamePrefix);
1487}
1488
1489/// \brief Get a natural GEP from a base pointer to a particular offset and
1490/// resulting in a particular type.
1491///
1492/// The goal is to produce a "natural" looking GEP that works with the existing
1493/// composite types to arrive at the appropriate offset and element type for
1494/// a pointer. TargetTy is the element type the returned GEP should point-to if
1495/// possible. We recurse by decreasing Offset, adding the appropriate index to
1496/// Indices, and setting Ty to the result subtype.
1497///
1498/// If no natural GEP can be constructed, this function returns null.
1499static Value *getNaturalGEPWithOffset(IRBuilderTy &IRB, const DataLayout &DL,
1500 Value *Ptr, APInt Offset, Type *TargetTy,
1501 SmallVectorImpl<Value *> &Indices,
1502 Twine NamePrefix) {
1503 PointerType *Ty = cast<PointerType>(Ptr->getType());
1504
1505 // Don't consider any GEPs through an i8* as natural unless the TargetTy is
1506 // an i8.
1507 if (Ty == IRB.getInt8PtrTy(Ty->getAddressSpace()) && TargetTy->isIntegerTy(8))
1508 return nullptr;
1509
1510 Type *ElementTy = Ty->getElementType();
1511 if (!ElementTy->isSized())
1512 return nullptr; // We can't GEP through an unsized element.
1513 APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
1514 if (ElementSize == 0)
1515 return nullptr; // Zero-length arrays can't help us build a natural GEP.
1516 APInt NumSkippedElements = Offset.sdiv(ElementSize);
1517
1518 Offset -= NumSkippedElements * ElementSize;
1519 Indices.push_back(IRB.getInt(NumSkippedElements));
1520 return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
1521 Indices, NamePrefix);
1522}
1523
1524/// \brief Compute an adjusted pointer from Ptr by Offset bytes where the
1525/// resulting pointer has PointerTy.
1526///
1527/// This tries very hard to compute a "natural" GEP which arrives at the offset
1528/// and produces the pointer type desired. Where it cannot, it will try to use
1529/// the natural GEP to arrive at the offset and bitcast to the type. Where that
1530/// fails, it will try to use an existing i8* and GEP to the byte offset and
1531/// bitcast to the type.
1532///
1533/// The strategy for finding the more natural GEPs is to peel off layers of the
1534/// pointer, walking back through bit casts and GEPs, searching for a base
1535/// pointer from which we can compute a natural GEP with the desired
1536/// properties. The algorithm tries to fold as many constant indices into
1537/// a single GEP as possible, thus making each GEP more independent of the
1538/// surrounding code.
1539static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
1540 APInt Offset, Type *PointerTy, Twine NamePrefix) {
1541 // Even though we don't look through PHI nodes, we could be called on an
1542 // instruction in an unreachable block, which may be on a cycle.
1543 SmallPtrSet<Value *, 4> Visited;
1544 Visited.insert(Ptr);
1545 SmallVector<Value *, 4> Indices;
1546
1547 // We may end up computing an offset pointer that has the wrong type. If we
1548 // never are able to compute one directly that has the correct type, we'll
1549 // fall back to it, so keep it and the base it was computed from around here.
1550 Value *OffsetPtr = nullptr;
1551 Value *OffsetBasePtr;
1552
1553 // Remember any i8 pointer we come across to re-use if we need to do a raw
1554 // byte offset.
1555 Value *Int8Ptr = nullptr;
1556 APInt Int8PtrOffset(Offset.getBitWidth(), 0);
1557
1558 Type *TargetTy = PointerTy->getPointerElementType();
1559
1560 do {
1561 // First fold any existing GEPs into the offset.
1562 while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
1563 APInt GEPOffset(Offset.getBitWidth(), 0);
1564 if (!GEP->accumulateConstantOffset(DL, GEPOffset))
1565 break;
1566 Offset += GEPOffset;
1567 Ptr = GEP->getPointerOperand();
1568 if (!Visited.insert(Ptr).second)
1569 break;
1570 }
1571
1572 // See if we can perform a natural GEP here.
1573 Indices.clear();
1574 if (Value *P = getNaturalGEPWithOffset(IRB, DL, Ptr, Offset, TargetTy,
1575 Indices, NamePrefix)) {
1576 // If we have a new natural pointer at the offset, clear out any old
1577 // offset pointer we computed. Unless it is the base pointer or
1578 // a non-instruction, we built a GEP we don't need. Zap it.
1579 if (OffsetPtr && OffsetPtr != OffsetBasePtr)
1580 if (Instruction *I = dyn_cast<Instruction>(OffsetPtr)) {
1581 assert(I->use_empty() && "Built a GEP with uses some how!")(static_cast <bool> (I->use_empty() && "Built a GEP with uses some how!"
) ? void (0) : __assert_fail ("I->use_empty() && \"Built a GEP with uses some how!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1581, __extension__ __PRETTY_FUNCTION__))
;
1582 I->eraseFromParent();
1583 }
1584 OffsetPtr = P;
1585 OffsetBasePtr = Ptr;
1586 // If we also found a pointer of the right type, we're done.
1587 if (P->getType() == PointerTy)
1588 return P;
1589 }
1590
1591 // Stash this pointer if we've found an i8*.
1592 if (Ptr->getType()->isIntegerTy(8)) {
1593 Int8Ptr = Ptr;
1594 Int8PtrOffset = Offset;
1595 }
1596
1597 // Peel off a layer of the pointer and update the offset appropriately.
1598 if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
1599 Ptr = cast<Operator>(Ptr)->getOperand(0);
1600 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(Ptr)) {
1601 if (GA->isInterposable())
1602 break;
1603 Ptr = GA->getAliasee();
1604 } else {
1605 break;
1606 }
1607 assert(Ptr->getType()->isPointerTy() && "Unexpected operand type!")(static_cast <bool> (Ptr->getType()->isPointerTy(
) && "Unexpected operand type!") ? void (0) : __assert_fail
("Ptr->getType()->isPointerTy() && \"Unexpected operand type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1607, __extension__ __PRETTY_FUNCTION__))
;
1608 } while (Visited.insert(Ptr).second);
1609
1610 if (!OffsetPtr) {
1611 if (!Int8Ptr) {
1612 Int8Ptr = IRB.CreateBitCast(
1613 Ptr, IRB.getInt8PtrTy(PointerTy->getPointerAddressSpace()),
1614 NamePrefix + "sroa_raw_cast");
1615 Int8PtrOffset = Offset;
1616 }
1617
1618 OffsetPtr = Int8PtrOffset == 0
1619 ? Int8Ptr
1620 : IRB.CreateInBoundsGEP(IRB.getInt8Ty(), Int8Ptr,
1621 IRB.getInt(Int8PtrOffset),
1622 NamePrefix + "sroa_raw_idx");
1623 }
1624 Ptr = OffsetPtr;
1625
1626 // On the off chance we were targeting i8*, guard the bitcast here.
1627 if (Ptr->getType() != PointerTy)
1628 Ptr = IRB.CreateBitCast(Ptr, PointerTy, NamePrefix + "sroa_cast");
1629
1630 return Ptr;
1631}
1632
1633/// \brief Compute the adjusted alignment for a load or store from an offset.
1634static unsigned getAdjustedAlignment(Instruction *I, uint64_t Offset,
1635 const DataLayout &DL) {
1636 unsigned Alignment;
1637 Type *Ty;
1638 if (auto *LI = dyn_cast<LoadInst>(I)) {
1639 Alignment = LI->getAlignment();
1640 Ty = LI->getType();
1641 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
1642 Alignment = SI->getAlignment();
1643 Ty = SI->getValueOperand()->getType();
1644 } else {
1645 llvm_unreachable("Only loads and stores are allowed!")::llvm::llvm_unreachable_internal("Only loads and stores are allowed!"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1645)
;
1646 }
1647
1648 if (!Alignment)
1649 Alignment = DL.getABITypeAlignment(Ty);
1650
1651 return MinAlign(Alignment, Offset);
1652}
1653
1654/// \brief Test whether we can convert a value from the old to the new type.
1655///
1656/// This predicate should be used to guard calls to convertValue in order to
1657/// ensure that we only try to convert viable values. The strategy is that we
1658/// will peel off single element struct and array wrappings to get to an
1659/// underlying value, and convert that value.
1660static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
1661 if (OldTy == NewTy)
1662 return true;
1663
1664 // For integer types, we can't handle any bit-width differences. This would
1665 // break both vector conversions with extension and introduce endianness
1666 // issues when in conjunction with loads and stores.
1667 if (isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) {
1668 assert(cast<IntegerType>(OldTy)->getBitWidth() !=(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? void (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1670, __extension__ __PRETTY_FUNCTION__))
1669 cast<IntegerType>(NewTy)->getBitWidth() &&(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? void (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1670, __extension__ __PRETTY_FUNCTION__))
1670 "We can't have the same bitwidth for different int types")(static_cast <bool> (cast<IntegerType>(OldTy)->
getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth
() && "We can't have the same bitwidth for different int types"
) ? void (0) : __assert_fail ("cast<IntegerType>(OldTy)->getBitWidth() != cast<IntegerType>(NewTy)->getBitWidth() && \"We can't have the same bitwidth for different int types\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1670, __extension__ __PRETTY_FUNCTION__))
;
1671 return false;
1672 }
1673
1674 if (DL.getTypeSizeInBits(NewTy) != DL.getTypeSizeInBits(OldTy))
1675 return false;
1676 if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
1677 return false;
1678
1679 // We can convert pointers to integers and vice-versa. Same for vectors
1680 // of pointers and integers.
1681 OldTy = OldTy->getScalarType();
1682 NewTy = NewTy->getScalarType();
1683 if (NewTy->isPointerTy() || OldTy->isPointerTy()) {
1684 if (NewTy->isPointerTy() && OldTy->isPointerTy()) {
1685 return cast<PointerType>(NewTy)->getPointerAddressSpace() ==
1686 cast<PointerType>(OldTy)->getPointerAddressSpace();
1687 }
1688
1689 // We can convert integers to integral pointers, but not to non-integral
1690 // pointers.
1691 if (OldTy->isIntegerTy())
1692 return !DL.isNonIntegralPointerType(NewTy);
1693
1694 // We can convert integral pointers to integers, but non-integral pointers
1695 // need to remain pointers.
1696 if (!DL.isNonIntegralPointerType(OldTy))
1697 return NewTy->isIntegerTy();
1698
1699 return false;
1700 }
1701
1702 return true;
1703}
1704
1705/// \brief Generic routine to convert an SSA value to a value of a different
1706/// type.
1707///
1708/// This will try various different casting techniques, such as bitcasts,
1709/// inttoptr, and ptrtoint casts. Use the \c canConvertValue predicate to test
1710/// two types for viability with this routine.
1711static Value *convertValue(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
1712 Type *NewTy) {
1713 Type *OldTy = V->getType();
1714 assert(canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type")(static_cast <bool> (canConvertValue(DL, OldTy, NewTy) &&
"Value not convertable to type") ? void (0) : __assert_fail (
"canConvertValue(DL, OldTy, NewTy) && \"Value not convertable to type\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1714, __extension__ __PRETTY_FUNCTION__))
;
1715
1716 if (OldTy == NewTy)
1717 return V;
1718
1719 assert(!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) &&(static_cast <bool> (!(isa<IntegerType>(OldTy) &&
isa<IntegerType>(NewTy)) && "Integer types must be the exact same to convert."
) ? void (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1720, __extension__ __PRETTY_FUNCTION__))
1720 "Integer types must be the exact same to convert.")(static_cast <bool> (!(isa<IntegerType>(OldTy) &&
isa<IntegerType>(NewTy)) && "Integer types must be the exact same to convert."
) ? void (0) : __assert_fail ("!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) && \"Integer types must be the exact same to convert.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1720, __extension__ __PRETTY_FUNCTION__))
;
1721
1722 // See if we need inttoptr for this type pair. A cast involving both scalars
1723 // and vectors requires and additional bitcast.
1724 if (OldTy->isIntOrIntVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
1725 // Expand <2 x i32> to i8* --> <2 x i32> to i64 to i8*
1726 if (OldTy->isVectorTy() && !NewTy->isVectorTy())
1727 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1728 NewTy);
1729
1730 // Expand i128 to <2 x i8*> --> i128 to <2 x i64> to <2 x i8*>
1731 if (!OldTy->isVectorTy() && NewTy->isVectorTy())
1732 return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
1733 NewTy);
1734
1735 return IRB.CreateIntToPtr(V, NewTy);
1736 }
1737
1738 // See if we need ptrtoint for this type pair. A cast involving both scalars
1739 // and vectors requires and additional bitcast.
1740 if (OldTy->isPtrOrPtrVectorTy() && NewTy->isIntOrIntVectorTy()) {
1741 // Expand <2 x i8*> to i128 --> <2 x i8*> to <2 x i64> to i128
1742 if (OldTy->isVectorTy() && !NewTy->isVectorTy())
1743 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1744 NewTy);
1745
1746 // Expand i8* to <2 x i32> --> i8* to i64 to <2 x i32>
1747 if (!OldTy->isVectorTy() && NewTy->isVectorTy())
1748 return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
1749 NewTy);
1750
1751 return IRB.CreatePtrToInt(V, NewTy);
1752 }
1753
1754 return IRB.CreateBitCast(V, NewTy);
1755}
1756
1757/// \brief Test whether the given slice use can be promoted to a vector.
1758///
1759/// This function is called to test each entry in a partition which is slated
1760/// for a single slice.
1761static bool isVectorPromotionViableForSlice(Partition &P, const Slice &S,
1762 VectorType *Ty,
1763 uint64_t ElementSize,
1764 const DataLayout &DL) {
1765 // First validate the slice offsets.
1766 uint64_t BeginOffset =
1767 std::max(S.beginOffset(), P.beginOffset()) - P.beginOffset();
1768 uint64_t BeginIndex = BeginOffset / ElementSize;
1769 if (BeginIndex * ElementSize != BeginOffset ||
1770 BeginIndex >= Ty->getNumElements())
1771 return false;
1772 uint64_t EndOffset =
1773 std::min(S.endOffset(), P.endOffset()) - P.beginOffset();
1774 uint64_t EndIndex = EndOffset / ElementSize;
1775 if (EndIndex * ElementSize != EndOffset || EndIndex > Ty->getNumElements())
1776 return false;
1777
1778 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1778, __extension__ __PRETTY_FUNCTION__))
;
1779 uint64_t NumElements = EndIndex - BeginIndex;
1780 Type *SliceTy = (NumElements == 1)
1781 ? Ty->getElementType()
1782 : VectorType::get(Ty->getElementType(), NumElements);
1783
1784 Type *SplitIntTy =
1785 Type::getIntNTy(Ty->getContext(), NumElements * ElementSize * 8);
1786
1787 Use *U = S.getUse();
1788
1789 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
1790 if (MI->isVolatile())
1791 return false;
1792 if (!S.isSplittable())
1793 return false; // Skip any unsplittable intrinsics.
1794 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
1795 if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
1796 II->getIntrinsicID() != Intrinsic::lifetime_end)
1797 return false;
1798 } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
1799 // Disable vector promotion when there are loads or stores of an FCA.
1800 return false;
1801 } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1802 if (LI->isVolatile())
1803 return false;
1804 Type *LTy = LI->getType();
1805 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1806 assert(LTy->isIntegerTy())(static_cast <bool> (LTy->isIntegerTy()) ? void (0) :
__assert_fail ("LTy->isIntegerTy()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1806, __extension__ __PRETTY_FUNCTION__))
;
1807 LTy = SplitIntTy;
1808 }
1809 if (!canConvertValue(DL, SliceTy, LTy))
1810 return false;
1811 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1812 if (SI->isVolatile())
1813 return false;
1814 Type *STy = SI->getValueOperand()->getType();
1815 if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
1816 assert(STy->isIntegerTy())(static_cast <bool> (STy->isIntegerTy()) ? void (0) :
__assert_fail ("STy->isIntegerTy()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1816, __extension__ __PRETTY_FUNCTION__))
;
1817 STy = SplitIntTy;
1818 }
1819 if (!canConvertValue(DL, STy, SliceTy))
1820 return false;
1821 } else {
1822 return false;
1823 }
1824
1825 return true;
1826}
1827
1828/// \brief Test whether the given alloca partitioning and range of slices can be
1829/// promoted to a vector.
1830///
1831/// This is a quick test to check whether we can rewrite a particular alloca
1832/// partition (and its newly formed alloca) into a vector alloca with only
1833/// whole-vector loads and stores such that it could be promoted to a vector
1834/// SSA value. We only can ensure this for a limited set of operations, and we
1835/// don't want to do the rewrites unless we are confident that the result will
1836/// be promotable, so we have an early test here.
1837static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
1838 // Collect the candidate types for vector-based promotion. Also track whether
1839 // we have different element types.
1840 SmallVector<VectorType *, 4> CandidateTys;
1841 Type *CommonEltTy = nullptr;
1842 bool HaveCommonEltTy = true;
1843 auto CheckCandidateType = [&](Type *Ty) {
1844 if (auto *VTy = dyn_cast<VectorType>(Ty)) {
1845 CandidateTys.push_back(VTy);
1846 if (!CommonEltTy)
1847 CommonEltTy = VTy->getElementType();
1848 else if (CommonEltTy != VTy->getElementType())
1849 HaveCommonEltTy = false;
1850 }
1851 };
1852 // Consider any loads or stores that are the exact size of the slice.
1853 for (const Slice &S : P)
1854 if (S.beginOffset() == P.beginOffset() &&
1855 S.endOffset() == P.endOffset()) {
1856 if (auto *LI = dyn_cast<LoadInst>(S.getUse()->getUser()))
1857 CheckCandidateType(LI->getType());
1858 else if (auto *SI = dyn_cast<StoreInst>(S.getUse()->getUser()))
1859 CheckCandidateType(SI->getValueOperand()->getType());
1860 }
1861
1862 // If we didn't find a vector type, nothing to do here.
1863 if (CandidateTys.empty())
1864 return nullptr;
1865
1866 // Remove non-integer vector types if we had multiple common element types.
1867 // FIXME: It'd be nice to replace them with integer vector types, but we can't
1868 // do that until all the backends are known to produce good code for all
1869 // integer vector types.
1870 if (!HaveCommonEltTy) {
1871 CandidateTys.erase(
1872 llvm::remove_if(CandidateTys,
1873 [](VectorType *VTy) {
1874 return !VTy->getElementType()->isIntegerTy();
1875 }),
1876 CandidateTys.end());
1877
1878 // If there were no integer vector types, give up.
1879 if (CandidateTys.empty())
1880 return nullptr;
1881
1882 // Rank the remaining candidate vector types. This is easy because we know
1883 // they're all integer vectors. We sort by ascending number of elements.
1884 auto RankVectorTypes = [&DL](VectorType *RHSTy, VectorType *LHSTy) {
1885 (void)DL;
1886 assert(DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) &&(static_cast <bool> (DL.getTypeSizeInBits(RHSTy) == DL.
getTypeSizeInBits(LHSTy) && "Cannot have vector types of different sizes!"
) ? void (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1887, __extension__ __PRETTY_FUNCTION__))
1887 "Cannot have vector types of different sizes!")(static_cast <bool> (DL.getTypeSizeInBits(RHSTy) == DL.
getTypeSizeInBits(LHSTy) && "Cannot have vector types of different sizes!"
) ? void (0) : __assert_fail ("DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) && \"Cannot have vector types of different sizes!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1887, __extension__ __PRETTY_FUNCTION__))
;
1888 assert(RHSTy->getElementType()->isIntegerTy() &&(static_cast <bool> (RHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1889, __extension__ __PRETTY_FUNCTION__))
1889 "All non-integer types eliminated!")(static_cast <bool> (RHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("RHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1889, __extension__ __PRETTY_FUNCTION__))
;
1890 assert(LHSTy->getElementType()->isIntegerTy() &&(static_cast <bool> (LHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1891, __extension__ __PRETTY_FUNCTION__))
1891 "All non-integer types eliminated!")(static_cast <bool> (LHSTy->getElementType()->isIntegerTy
() && "All non-integer types eliminated!") ? void (0)
: __assert_fail ("LHSTy->getElementType()->isIntegerTy() && \"All non-integer types eliminated!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1891, __extension__ __PRETTY_FUNCTION__))
;
1892 return RHSTy->getNumElements() < LHSTy->getNumElements();
1893 };
1894 std::sort(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes);
1895 CandidateTys.erase(
1896 std::unique(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes),
1897 CandidateTys.end());
1898 } else {
1899// The only way to have the same element type in every vector type is to
1900// have the same vector type. Check that and remove all but one.
1901#ifndef NDEBUG
1902 for (VectorType *VTy : CandidateTys) {
1903 assert(VTy->getElementType() == CommonEltTy &&(static_cast <bool> (VTy->getElementType() == CommonEltTy
&& "Unaccounted for element type!") ? void (0) : __assert_fail
("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1904, __extension__ __PRETTY_FUNCTION__))
1904 "Unaccounted for element type!")(static_cast <bool> (VTy->getElementType() == CommonEltTy
&& "Unaccounted for element type!") ? void (0) : __assert_fail
("VTy->getElementType() == CommonEltTy && \"Unaccounted for element type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1904, __extension__ __PRETTY_FUNCTION__))
;
1905 assert(VTy == CandidateTys[0] &&(static_cast <bool> (VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? void (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1906, __extension__ __PRETTY_FUNCTION__))
1906 "Different vector types with the same element type!")(static_cast <bool> (VTy == CandidateTys[0] && "Different vector types with the same element type!"
) ? void (0) : __assert_fail ("VTy == CandidateTys[0] && \"Different vector types with the same element type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1906, __extension__ __PRETTY_FUNCTION__))
;
1907 }
1908#endif
1909 CandidateTys.resize(1);
1910 }
1911
1912 // Try each vector type, and return the one which works.
1913 auto CheckVectorTypeForPromotion = [&](VectorType *VTy) {
1914 uint64_t ElementSize = DL.getTypeSizeInBits(VTy->getElementType());
1915
1916 // While the definition of LLVM vectors is bitpacked, we don't support sizes
1917 // that aren't byte sized.
1918 if (ElementSize % 8)
1919 return false;
1920 assert((DL.getTypeSizeInBits(VTy) % 8) == 0 &&(static_cast <bool> ((DL.getTypeSizeInBits(VTy) % 8) ==
0 && "vector size not a multiple of element size?") ?
void (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy) % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1921, __extension__ __PRETTY_FUNCTION__))
1921 "vector size not a multiple of element size?")(static_cast <bool> ((DL.getTypeSizeInBits(VTy) % 8) ==
0 && "vector size not a multiple of element size?") ?
void (0) : __assert_fail ("(DL.getTypeSizeInBits(VTy) % 8) == 0 && \"vector size not a multiple of element size?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 1921, __extension__ __PRETTY_FUNCTION__))
;
1922 ElementSize /= 8;
1923
1924 for (const Slice &S : P)
1925 if (!isVectorPromotionViableForSlice(P, S, VTy, ElementSize, DL))
1926 return false;
1927
1928 for (const Slice *S : P.splitSliceTails())
1929 if (!isVectorPromotionViableForSlice(P, *S, VTy, ElementSize, DL))
1930 return false;
1931
1932 return true;
1933 };
1934 for (VectorType *VTy : CandidateTys)
1935 if (CheckVectorTypeForPromotion(VTy))
1936 return VTy;
1937
1938 return nullptr;
1939}
1940
1941/// \brief Test whether a slice of an alloca is valid for integer widening.
1942///
1943/// This implements the necessary checking for the \c isIntegerWideningViable
1944/// test below on a single slice of the alloca.
1945static bool isIntegerWideningViableForSlice(const Slice &S,
1946 uint64_t AllocBeginOffset,
1947 Type *AllocaTy,
1948 const DataLayout &DL,
1949 bool &WholeAllocaOp) {
1950 uint64_t Size = DL.getTypeStoreSize(AllocaTy);
1951
1952 uint64_t RelBegin = S.beginOffset() - AllocBeginOffset;
1953 uint64_t RelEnd = S.endOffset() - AllocBeginOffset;
1954
1955 // We can't reasonably handle cases where the load or store extends past
1956 // the end of the alloca's type and into its padding.
1957 if (RelEnd > Size)
1958 return false;
1959
1960 Use *U = S.getUse();
1961
1962 if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
1963 if (LI->isVolatile())
1964 return false;
1965 // We can't handle loads that extend past the allocated memory.
1966 if (DL.getTypeStoreSize(LI->getType()) > Size)
1967 return false;
1968 // Note that we don't count vector loads or stores as whole-alloca
1969 // operations which enable integer widening because we would prefer to use
1970 // vector widening instead.
1971 if (!isa<VectorType>(LI->getType()) && RelBegin == 0 && RelEnd == Size)
1972 WholeAllocaOp = true;
1973 if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType())) {
1974 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
1975 return false;
1976 } else if (RelBegin != 0 || RelEnd != Size ||
1977 !canConvertValue(DL, AllocaTy, LI->getType())) {
1978 // Non-integer loads need to be convertible from the alloca type so that
1979 // they are promotable.
1980 return false;
1981 }
1982 } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
1983 Type *ValueTy = SI->getValueOperand()->getType();
1984 if (SI->isVolatile())
1985 return false;
1986 // We can't handle stores that extend past the allocated memory.
1987 if (DL.getTypeStoreSize(ValueTy) > Size)
1988 return false;
1989 // Note that we don't count vector loads or stores as whole-alloca
1990 // operations which enable integer widening because we would prefer to use
1991 // vector widening instead.
1992 if (!isa<VectorType>(ValueTy) && RelBegin == 0 && RelEnd == Size)
1993 WholeAllocaOp = true;
1994 if (IntegerType *ITy = dyn_cast<IntegerType>(ValueTy)) {
1995 if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
1996 return false;
1997 } else if (RelBegin != 0 || RelEnd != Size ||
1998 !canConvertValue(DL, ValueTy, AllocaTy)) {
1999 // Non-integer stores need to be convertible to the alloca type so that
2000 // they are promotable.
2001 return false;
2002 }
2003 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
2004 if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
2005 return false;
2006 if (!S.isSplittable())
2007 return false; // Skip any unsplittable intrinsics.
2008 } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
2009 if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
2010 II->getIntrinsicID() != Intrinsic::lifetime_end)
2011 return false;
2012 } else {
2013 return false;
2014 }
2015
2016 return true;
2017}
2018
2019/// \brief Test whether the given alloca partition's integer operations can be
2020/// widened to promotable ones.
2021///
2022/// This is a quick test to check whether we can rewrite the integer loads and
2023/// stores to a particular alloca into wider loads and stores and be able to
2024/// promote the resulting alloca.
2025static bool isIntegerWideningViable(Partition &P, Type *AllocaTy,
2026 const DataLayout &DL) {
2027 uint64_t SizeInBits = DL.getTypeSizeInBits(AllocaTy);
2028 // Don't create integer types larger than the maximum bitwidth.
2029 if (SizeInBits > IntegerType::MAX_INT_BITS)
2030 return false;
2031
2032 // Don't try to handle allocas with bit-padding.
2033 if (SizeInBits != DL.getTypeStoreSizeInBits(AllocaTy))
2034 return false;
2035
2036 // We need to ensure that an integer type with the appropriate bitwidth can
2037 // be converted to the alloca type, whatever that is. We don't want to force
2038 // the alloca itself to have an integer type if there is a more suitable one.
2039 Type *IntTy = Type::getIntNTy(AllocaTy->getContext(), SizeInBits);
2040 if (!canConvertValue(DL, AllocaTy, IntTy) ||
2041 !canConvertValue(DL, IntTy, AllocaTy))
2042 return false;
2043
2044 // While examining uses, we ensure that the alloca has a covering load or
2045 // store. We don't want to widen the integer operations only to fail to
2046 // promote due to some other unsplittable entry (which we may make splittable
2047 // later). However, if there are only splittable uses, go ahead and assume
2048 // that we cover the alloca.
2049 // FIXME: We shouldn't consider split slices that happen to start in the
2050 // partition here...
2051 bool WholeAllocaOp =
2052 P.begin() != P.end() ? false : DL.isLegalInteger(SizeInBits);
2053
2054 for (const Slice &S : P)
2055 if (!isIntegerWideningViableForSlice(S, P.beginOffset(), AllocaTy, DL,
2056 WholeAllocaOp))
2057 return false;
2058
2059 for (const Slice *S : P.splitSliceTails())
2060 if (!isIntegerWideningViableForSlice(*S, P.beginOffset(), AllocaTy, DL,
2061 WholeAllocaOp))
2062 return false;
2063
2064 return WholeAllocaOp;
2065}
2066
2067static Value *extractInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
2068 IntegerType *Ty, uint64_t Offset,
2069 const Twine &Name) {
2070 DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2071 IntegerType *IntTy = cast<IntegerType>(V->getType());
2072 assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&(static_cast <bool> (DL.getTypeStoreSize(Ty) + Offset <=
DL.getTypeStoreSize(IntTy) && "Element extends past full value"
) ? void (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2073, __extension__ __PRETTY_FUNCTION__))
2073 "Element extends past full value")(static_cast <bool> (DL.getTypeStoreSize(Ty) + Offset <=
DL.getTypeStoreSize(IntTy) && "Element extends past full value"
) ? void (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element extends past full value\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2073, __extension__ __PRETTY_FUNCTION__))
;
2074 uint64_t ShAmt = 8 * Offset;
2075 if (DL.isBigEndian())
2076 ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
2077 if (ShAmt) {
2078 V = IRB.CreateLShr(V, ShAmt, Name + ".shift");
2079 DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2080 }
2081 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot extract to a larger integer!"
) ? void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2082, __extension__ __PRETTY_FUNCTION__))
2082 "Cannot extract to a larger integer!")(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot extract to a larger integer!"
) ? void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot extract to a larger integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2082, __extension__ __PRETTY_FUNCTION__))
;
2083 if (Ty != IntTy) {
2084 V = IRB.CreateTrunc(V, Ty, Name + ".trunc");
2085 DEBUG(dbgs() << " trunced: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " trunced: " << *V <<
"\n"; } } while (false)
;
2086 }
2087 return V;
2088}
2089
2090static Value *insertInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *Old,
2091 Value *V, uint64_t Offset, const Twine &Name) {
2092 IntegerType *IntTy = cast<IntegerType>(Old->getType());
2093 IntegerType *Ty = cast<IntegerType>(V->getType());
2094 assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot insert a larger integer!") ?
void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2095, __extension__ __PRETTY_FUNCTION__))
2095 "Cannot insert a larger integer!")(static_cast <bool> (Ty->getBitWidth() <= IntTy->
getBitWidth() && "Cannot insert a larger integer!") ?
void (0) : __assert_fail ("Ty->getBitWidth() <= IntTy->getBitWidth() && \"Cannot insert a larger integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2095, __extension__ __PRETTY_FUNCTION__))
;
2096 DEBUG(dbgs() << " start: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " start: " << *V <<
"\n"; } } while (false)
;
2097 if (Ty != IntTy) {
2098 V = IRB.CreateZExt(V, IntTy, Name + ".ext");
2099 DEBUG(dbgs() << " extended: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extended: " << *V <<
"\n"; } } while (false)
;
2100 }
2101 assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&(static_cast <bool> (DL.getTypeStoreSize(Ty) + Offset <=
DL.getTypeStoreSize(IntTy) && "Element store outside of alloca store"
) ? void (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2102, __extension__ __PRETTY_FUNCTION__))
2102 "Element store outside of alloca store")(static_cast <bool> (DL.getTypeStoreSize(Ty) + Offset <=
DL.getTypeStoreSize(IntTy) && "Element store outside of alloca store"
) ? void (0) : __assert_fail ("DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) && \"Element store outside of alloca store\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2102, __extension__ __PRETTY_FUNCTION__))
;
2103 uint64_t ShAmt = 8 * Offset;
2104 if (DL.isBigEndian())
2105 ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
2106 if (ShAmt) {
2107 V = IRB.CreateShl(V, ShAmt, Name + ".shift");
2108 DEBUG(dbgs() << " shifted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shifted: " << *V <<
"\n"; } } while (false)
;
2109 }
2110
2111 if (ShAmt || Ty->getBitWidth() < IntTy->getBitWidth()) {
2112 APInt Mask = ~Ty->getMask().zext(IntTy->getBitWidth()).shl(ShAmt);
2113 Old = IRB.CreateAnd(Old, Mask, Name + ".mask");
2114 DEBUG(dbgs() << " masked: " << *Old << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " masked: " << *Old <<
"\n"; } } while (false)
;
2115 V = IRB.CreateOr(Old, V, Name + ".insert");
2116 DEBUG(dbgs() << " inserted: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " inserted: " << *V <<
"\n"; } } while (false)
;
2117 }
2118 return V;
2119}
2120
2121static Value *extractVector(IRBuilderTy &IRB, Value *V, unsigned BeginIndex,
2122 unsigned EndIndex, const Twine &Name) {
2123 VectorType *VecTy = cast<VectorType>(V->getType());
2124 unsigned NumElements = EndIndex - BeginIndex;
2125 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")(static_cast <bool> (NumElements <= VecTy->getNumElements
() && "Too many elements!") ? void (0) : __assert_fail
("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2125, __extension__ __PRETTY_FUNCTION__))
;
2126
2127 if (NumElements == VecTy->getNumElements())
2128 return V;
2129
2130 if (NumElements == 1) {
2131 V = IRB.CreateExtractElement(V, IRB.getInt32(BeginIndex),
2132 Name + ".extract");
2133 DEBUG(dbgs() << " extract: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " extract: " << *V <<
"\n"; } } while (false)
;
2134 return V;
2135 }
2136
2137 SmallVector<Constant *, 8> Mask;
2138 Mask.reserve(NumElements);
2139 for (unsigned i = BeginIndex; i != EndIndex; ++i)
2140 Mask.push_back(IRB.getInt32(i));
2141 V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
2142 ConstantVector::get(Mask), Name + ".extract");
2143 DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2144 return V;
2145}
2146
2147static Value *insertVector(IRBuilderTy &IRB, Value *Old, Value *V,
2148 unsigned BeginIndex, const Twine &Name) {
2149 VectorType *VecTy = cast<VectorType>(Old->getType());
2150 assert(VecTy && "Can only insert a vector into a vector")(static_cast <bool> (VecTy && "Can only insert a vector into a vector"
) ? void (0) : __assert_fail ("VecTy && \"Can only insert a vector into a vector\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2150, __extension__ __PRETTY_FUNCTION__))
;
2151
2152 VectorType *Ty = dyn_cast<VectorType>(V->getType());
2153 if (!Ty) {
2154 // Single element to insert.
2155 V = IRB.CreateInsertElement(Old, V, IRB.getInt32(BeginIndex),
2156 Name + ".insert");
2157 DEBUG(dbgs() << " insert: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " insert: " << *V <<
"\n"; } } while (false)
;
2158 return V;
2159 }
2160
2161 assert(Ty->getNumElements() <= VecTy->getNumElements() &&(static_cast <bool> (Ty->getNumElements() <= VecTy
->getNumElements() && "Too many elements!") ? void
(0) : __assert_fail ("Ty->getNumElements() <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2162, __extension__ __PRETTY_FUNCTION__))
2162 "Too many elements!")(static_cast <bool> (Ty->getNumElements() <= VecTy
->getNumElements() && "Too many elements!") ? void
(0) : __assert_fail ("Ty->getNumElements() <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2162, __extension__ __PRETTY_FUNCTION__))
;
2163 if (Ty->getNumElements() == VecTy->getNumElements()) {
2164 assert(V->getType() == VecTy && "Vector type mismatch")(static_cast <bool> (V->getType() == VecTy &&
"Vector type mismatch") ? void (0) : __assert_fail ("V->getType() == VecTy && \"Vector type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2164, __extension__ __PRETTY_FUNCTION__))
;
2165 return V;
2166 }
2167 unsigned EndIndex = BeginIndex + Ty->getNumElements();
2168
2169 // When inserting a smaller vector into the larger to store, we first
2170 // use a shuffle vector to widen it with undef elements, and then
2171 // a second shuffle vector to select between the loaded vector and the
2172 // incoming vector.
2173 SmallVector<Constant *, 8> Mask;
2174 Mask.reserve(VecTy->getNumElements());
2175 for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
2176 if (i >= BeginIndex && i < EndIndex)
2177 Mask.push_back(IRB.getInt32(i - BeginIndex));
2178 else
2179 Mask.push_back(UndefValue::get(IRB.getInt32Ty()));
2180 V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
2181 ConstantVector::get(Mask), Name + ".expand");
2182 DEBUG(dbgs() << " shuffle: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " shuffle: " << *V <<
"\n"; } } while (false)
;
2183
2184 Mask.clear();
2185 for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
2186 Mask.push_back(IRB.getInt1(i >= BeginIndex && i < EndIndex));
2187
2188 V = IRB.CreateSelect(ConstantVector::get(Mask), V, Old, Name + "blend");
2189
2190 DEBUG(dbgs() << " blend: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " blend: " << *V <<
"\n"; } } while (false)
;
2191 return V;
2192}
2193
2194/// \brief Visitor to rewrite instructions using p particular slice of an alloca
2195/// to use a new alloca.
2196///
2197/// Also implements the rewriting to vector-based accesses when the partition
2198/// passes the isVectorPromotionViable predicate. Most of the rewriting logic
2199/// lives here.
2200class llvm::sroa::AllocaSliceRewriter
2201 : public InstVisitor<AllocaSliceRewriter, bool> {
2202 // Befriend the base class so it can delegate to private visit methods.
2203 friend class InstVisitor<AllocaSliceRewriter, bool>;
2204
2205 using Base = InstVisitor<AllocaSliceRewriter, bool>;
2206
2207 const DataLayout &DL;
2208 AllocaSlices &AS;
2209 SROA &Pass;
2210 AllocaInst &OldAI, &NewAI;
2211 const uint64_t NewAllocaBeginOffset, NewAllocaEndOffset;
2212 Type *NewAllocaTy;
2213
2214 // This is a convenience and flag variable that will be null unless the new
2215 // alloca's integer operations should be widened to this integer type due to
2216 // passing isIntegerWideningViable above. If it is non-null, the desired
2217 // integer type will be stored here for easy access during rewriting.
2218 IntegerType *IntTy;
2219
2220 // If we are rewriting an alloca partition which can be written as pure
2221 // vector operations, we stash extra information here. When VecTy is
2222 // non-null, we have some strict guarantees about the rewritten alloca:
2223 // - The new alloca is exactly the size of the vector type here.
2224 // - The accesses all either map to the entire vector or to a single
2225 // element.
2226 // - The set of accessing instructions is only one of those handled above
2227 // in isVectorPromotionViable. Generally these are the same access kinds
2228 // which are promotable via mem2reg.
2229 VectorType *VecTy;
2230 Type *ElementTy;
2231 uint64_t ElementSize;
2232
2233 // The original offset of the slice currently being rewritten relative to
2234 // the original alloca.
2235 uint64_t BeginOffset = 0;
2236 uint64_t EndOffset = 0;
2237
2238 // The new offsets of the slice currently being rewritten relative to the
2239 // original alloca.
2240 uint64_t NewBeginOffset, NewEndOffset;
2241
2242 uint64_t SliceSize;
2243 bool IsSplittable = false;
2244 bool IsSplit = false;
2245 Use *OldUse = nullptr;
2246 Instruction *OldPtr = nullptr;
2247
2248 // Track post-rewrite users which are PHI nodes and Selects.
2249 SmallSetVector<PHINode *, 8> &PHIUsers;
2250 SmallSetVector<SelectInst *, 8> &SelectUsers;
2251
2252 // Utility IR builder, whose name prefix is setup for each visited use, and
2253 // the insertion point is set to point to the user.
2254 IRBuilderTy IRB;
2255
2256public:
2257 AllocaSliceRewriter(const DataLayout &DL, AllocaSlices &AS, SROA &Pass,
2258 AllocaInst &OldAI, AllocaInst &NewAI,
2259 uint64_t NewAllocaBeginOffset,
2260 uint64_t NewAllocaEndOffset, bool IsIntegerPromotable,
2261 VectorType *PromotableVecTy,
2262 SmallSetVector<PHINode *, 8> &PHIUsers,
2263 SmallSetVector<SelectInst *, 8> &SelectUsers)
2264 : DL(DL), AS(AS), Pass(Pass), OldAI(OldAI), NewAI(NewAI),
2265 NewAllocaBeginOffset(NewAllocaBeginOffset),
2266 NewAllocaEndOffset(NewAllocaEndOffset),
2267 NewAllocaTy(NewAI.getAllocatedType()),
2268 IntTy(IsIntegerPromotable
2269 ? Type::getIntNTy(
2270 NewAI.getContext(),
2271 DL.getTypeSizeInBits(NewAI.getAllocatedType()))
2272 : nullptr),
2273 VecTy(PromotableVecTy),
2274 ElementTy(VecTy ? VecTy->getElementType() : nullptr),
2275 ElementSize(VecTy ? DL.getTypeSizeInBits(ElementTy) / 8 : 0),
2276 PHIUsers(PHIUsers), SelectUsers(SelectUsers),
2277 IRB(NewAI.getContext(), ConstantFolder()) {
2278 if (VecTy) {
2279 assert((DL.getTypeSizeInBits(ElementTy) % 8) == 0 &&(static_cast <bool> ((DL.getTypeSizeInBits(ElementTy) %
8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy) % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2280, __extension__ __PRETTY_FUNCTION__))
2280 "Only multiple-of-8 sized vector elements are viable")(static_cast <bool> ((DL.getTypeSizeInBits(ElementTy) %
8) == 0 && "Only multiple-of-8 sized vector elements are viable"
) ? void (0) : __assert_fail ("(DL.getTypeSizeInBits(ElementTy) % 8) == 0 && \"Only multiple-of-8 sized vector elements are viable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2280, __extension__ __PRETTY_FUNCTION__))
;
2281 ++NumVectorized;
2282 }
2283 assert((!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy))(static_cast <bool> ((!IntTy && !VecTy) || (IntTy
&& !VecTy) || (!IntTy && VecTy)) ? void (0) :
__assert_fail ("(!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy)"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2283, __extension__ __PRETTY_FUNCTION__))
;
2284 }
2285
2286 bool visit(AllocaSlices::const_iterator I) {
2287 bool CanSROA = true;
2288 BeginOffset = I->beginOffset();
2289 EndOffset = I->endOffset();
2290 IsSplittable = I->isSplittable();
2291 IsSplit =
2292 BeginOffset < NewAllocaBeginOffset || EndOffset > NewAllocaEndOffset;
2293 DEBUG(dbgs() << " rewriting " << (IsSplit ? "split " : ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " rewriting " << (IsSplit ?
"split " : ""); } } while (false)
;
2294 DEBUG(AS.printSlice(dbgs(), I, ""))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.printSlice(dbgs(), I, ""); } } while (false)
;
2295 DEBUG(dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "\n"; } } while (false)
;
2296
2297 // Compute the intersecting offset range.
2298 assert(BeginOffset < NewAllocaEndOffset)(static_cast <bool> (BeginOffset < NewAllocaEndOffset
) ? void (0) : __assert_fail ("BeginOffset < NewAllocaEndOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2298, __extension__ __PRETTY_FUNCTION__))
;
2299 assert(EndOffset > NewAllocaBeginOffset)(static_cast <bool> (EndOffset > NewAllocaBeginOffset
) ? void (0) : __assert_fail ("EndOffset > NewAllocaBeginOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2299, __extension__ __PRETTY_FUNCTION__))
;
2300 NewBeginOffset = std::max(BeginOffset, NewAllocaBeginOffset);
2301 NewEndOffset = std::min(EndOffset, NewAllocaEndOffset);
2302
2303 SliceSize = NewEndOffset - NewBeginOffset;
2304
2305 OldUse = I->getUse();
2306 OldPtr = cast<Instruction>(OldUse->get());
2307
2308 Instruction *OldUserI = cast<Instruction>(OldUse->getUser());
2309 IRB.SetInsertPoint(OldUserI);
2310 IRB.SetCurrentDebugLocation(OldUserI->getDebugLoc());
2311 IRB.SetNamePrefix(Twine(NewAI.getName()) + "." + Twine(BeginOffset) + ".");
2312
2313 CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
2314 if (VecTy || IntTy)
2315 assert(CanSROA)(static_cast <bool> (CanSROA) ? void (0) : __assert_fail
("CanSROA", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2315, __extension__ __PRETTY_FUNCTION__))
;
2316 return CanSROA;
2317 }
2318
2319private:
2320 // Make sure the other visit overloads are visible.
2321 using Base::visit;
2322
2323 // Every instruction which can end up as a user must have a rewrite rule.
2324 bool visitInstruction(Instruction &I) {
2325 DEBUG(dbgs() << " !!!! Cannot rewrite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " !!!! Cannot rewrite: " <<
I << "\n"; } } while (false)
;
2326 llvm_unreachable("No rewrite rule for this instruction!")::llvm::llvm_unreachable_internal("No rewrite rule for this instruction!"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2326)
;
2327 }
2328
2329 Value *getNewAllocaSlicePtr(IRBuilderTy &IRB, Type *PointerTy) {
2330 // Note that the offset computation can use BeginOffset or NewBeginOffset
2331 // interchangeably for unsplit slices.
2332 assert(IsSplit || BeginOffset == NewBeginOffset)(static_cast <bool> (IsSplit || BeginOffset == NewBeginOffset
) ? void (0) : __assert_fail ("IsSplit || BeginOffset == NewBeginOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2332, __extension__ __PRETTY_FUNCTION__))
;
2333 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2334
2335#ifndef NDEBUG
2336 StringRef OldName = OldPtr->getName();
2337 // Skip through the last '.sroa.' component of the name.
2338 size_t LastSROAPrefix = OldName.rfind(".sroa.");
2339 if (LastSROAPrefix != StringRef::npos) {
2340 OldName = OldName.substr(LastSROAPrefix + strlen(".sroa."));
2341 // Look for an SROA slice index.
2342 size_t IndexEnd = OldName.find_first_not_of("0123456789");
2343 if (IndexEnd != StringRef::npos && OldName[IndexEnd] == '.') {
2344 // Strip the index and look for the offset.
2345 OldName = OldName.substr(IndexEnd + 1);
2346 size_t OffsetEnd = OldName.find_first_not_of("0123456789");
2347 if (OffsetEnd != StringRef::npos && OldName[OffsetEnd] == '.')
2348 // Strip the offset.
2349 OldName = OldName.substr(OffsetEnd + 1);
2350 }
2351 }
2352 // Strip any SROA suffixes as well.
2353 OldName = OldName.substr(0, OldName.find(".sroa_"));
2354#endif
2355
2356 return getAdjustedPtr(IRB, DL, &NewAI,
2357 APInt(DL.getPointerTypeSizeInBits(PointerTy), Offset),
2358 PointerTy,
2359#ifndef NDEBUG
2360 Twine(OldName) + "."
2361#else
2362 Twine()
2363#endif
2364 );
2365 }
2366
2367 /// \brief Compute suitable alignment to access this slice of the *new*
2368 /// alloca.
2369 ///
2370 /// You can optionally pass a type to this routine and if that type's ABI
2371 /// alignment is itself suitable, this will return zero.
2372 unsigned getSliceAlign(Type *Ty = nullptr) {
2373 unsigned NewAIAlign = NewAI.getAlignment();
2374 if (!NewAIAlign)
2375 NewAIAlign = DL.getABITypeAlignment(NewAI.getAllocatedType());
2376 unsigned Align =
2377 MinAlign(NewAIAlign, NewBeginOffset - NewAllocaBeginOffset);
2378 return (Ty && Align == DL.getABITypeAlignment(Ty)) ? 0 : Align;
2379 }
2380
2381 unsigned getIndex(uint64_t Offset) {
2382 assert(VecTy && "Can only call getIndex when rewriting a vector")(static_cast <bool> (VecTy && "Can only call getIndex when rewriting a vector"
) ? void (0) : __assert_fail ("VecTy && \"Can only call getIndex when rewriting a vector\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2382, __extension__ __PRETTY_FUNCTION__))
;
2383 uint64_t RelOffset = Offset - NewAllocaBeginOffset;
2384 assert(RelOffset / ElementSize < UINT32_MAX && "Index out of bounds")(static_cast <bool> (RelOffset / ElementSize < (4294967295U
) && "Index out of bounds") ? void (0) : __assert_fail
("RelOffset / ElementSize < UINT32_MAX && \"Index out of bounds\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2384, __extension__ __PRETTY_FUNCTION__))
;
2385 uint32_t Index = RelOffset / ElementSize;
2386 assert(Index * ElementSize == RelOffset)(static_cast <bool> (Index * ElementSize == RelOffset) ?
void (0) : __assert_fail ("Index * ElementSize == RelOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2386, __extension__ __PRETTY_FUNCTION__))
;
2387 return Index;
2388 }
2389
2390 void deleteIfTriviallyDead(Value *V) {
2391 Instruction *I = cast<Instruction>(V);
2392 if (isInstructionTriviallyDead(I))
2393 Pass.DeadInsts.insert(I);
2394 }
2395
2396 Value *rewriteVectorizedLoadInst() {
2397 unsigned BeginIndex = getIndex(NewBeginOffset);
2398 unsigned EndIndex = getIndex(NewEndOffset);
2399 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2399, __extension__ __PRETTY_FUNCTION__))
;
2400
2401 Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2402 return extractVector(IRB, V, BeginIndex, EndIndex, "vec");
2403 }
2404
2405 Value *rewriteIntegerLoad(LoadInst &LI) {
2406 assert(IntTy && "We cannot insert an integer to the alloca")(static_cast <bool> (IntTy && "We cannot insert an integer to the alloca"
) ? void (0) : __assert_fail ("IntTy && \"We cannot insert an integer to the alloca\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2406, __extension__ __PRETTY_FUNCTION__))
;
2407 assert(!LI.isVolatile())(static_cast <bool> (!LI.isVolatile()) ? void (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2407, __extension__ __PRETTY_FUNCTION__))
;
2408 Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2409 V = convertValue(DL, IRB, V, IntTy);
2410 assert(NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")(static_cast <bool> (NewBeginOffset >= NewAllocaBeginOffset
&& "Out of bounds offset") ? void (0) : __assert_fail
("NewBeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2410, __extension__ __PRETTY_FUNCTION__))
;
2411 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2412 if (Offset > 0 || NewEndOffset < NewAllocaEndOffset) {
2413 IntegerType *ExtractTy = Type::getIntNTy(LI.getContext(), SliceSize * 8);
2414 V = extractInteger(DL, IRB, V, ExtractTy, Offset, "extract");
2415 }
2416 // It is possible that the extracted type is not the load type. This
2417 // happens if there is a load past the end of the alloca, and as
2418 // a consequence the slice is narrower but still a candidate for integer
2419 // lowering. To handle this case, we just zero extend the extracted
2420 // integer.
2421 assert(cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 &&(static_cast <bool> (cast<IntegerType>(LI.getType
())->getBitWidth() >= SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? void (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2422, __extension__ __PRETTY_FUNCTION__))
2422 "Can only handle an extract for an overly wide load")(static_cast <bool> (cast<IntegerType>(LI.getType
())->getBitWidth() >= SliceSize * 8 && "Can only handle an extract for an overly wide load"
) ? void (0) : __assert_fail ("cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 && \"Can only handle an extract for an overly wide load\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2422, __extension__ __PRETTY_FUNCTION__))
;
2423 if (cast<IntegerType>(LI.getType())->getBitWidth() > SliceSize * 8)
2424 V = IRB.CreateZExt(V, LI.getType());
2425 return V;
2426 }
2427
2428 bool visitLoadInst(LoadInst &LI) {
2429 DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
2430 Value *OldOp = LI.getOperand(0);
2431 assert(OldOp == OldPtr)(static_cast <bool> (OldOp == OldPtr) ? void (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2431, __extension__ __PRETTY_FUNCTION__))
;
2432
2433 AAMDNodes AATags;
2434 LI.getAAMetadata(AATags);
2435
2436 unsigned AS = LI.getPointerAddressSpace();
2437
2438 Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), SliceSize * 8)
2439 : LI.getType();
2440 const bool IsLoadPastEnd = DL.getTypeStoreSize(TargetTy) > SliceSize;
2441 bool IsPtrAdjusted = false;
2442 Value *V;
2443 if (VecTy) {
2444 V = rewriteVectorizedLoadInst();
2445 } else if (IntTy && LI.getType()->isIntegerTy()) {
2446 V = rewriteIntegerLoad(LI);
2447 } else if (NewBeginOffset == NewAllocaBeginOffset &&
2448 NewEndOffset == NewAllocaEndOffset &&
2449 (canConvertValue(DL, NewAllocaTy, TargetTy) ||
2450 (IsLoadPastEnd && NewAllocaTy->isIntegerTy() &&
2451 TargetTy->isIntegerTy()))) {
2452 LoadInst *NewLI = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(),
2453 LI.isVolatile(), LI.getName());
2454 if (AATags)
2455 NewLI->setAAMetadata(AATags);
2456 if (LI.isVolatile())
2457 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2458
2459 // Any !nonnull metadata or !range metadata on the old load is also valid
2460 // on the new load. This is even true in some cases even when the loads
2461 // are different types, for example by mapping !nonnull metadata to
2462 // !range metadata by modeling the null pointer constant converted to the
2463 // integer type.
2464 // FIXME: Add support for range metadata here. Currently the utilities
2465 // for this don't propagate range metadata in trivial cases from one
2466 // integer load to another, don't handle non-addrspace-0 null pointers
2467 // correctly, and don't have any support for mapping ranges as the
2468 // integer type becomes winder or narrower.
2469 if (MDNode *N = LI.getMetadata(LLVMContext::MD_nonnull))
2470 copyNonnullMetadata(LI, N, *NewLI);
2471
2472 // Try to preserve nonnull metadata
2473 V = NewLI;
2474
2475 // If this is an integer load past the end of the slice (which means the
2476 // bytes outside the slice are undef or this load is dead) just forcibly
2477 // fix the integer size with correct handling of endianness.
2478 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2479 if (auto *TITy = dyn_cast<IntegerType>(TargetTy))
2480 if (AITy->getBitWidth() < TITy->getBitWidth()) {
2481 V = IRB.CreateZExt(V, TITy, "load.ext");
2482 if (DL.isBigEndian())
2483 V = IRB.CreateShl(V, TITy->getBitWidth() - AITy->getBitWidth(),
2484 "endian_shift");
2485 }
2486 } else {
2487 Type *LTy = TargetTy->getPointerTo(AS);
2488 LoadInst *NewLI = IRB.CreateAlignedLoad(getNewAllocaSlicePtr(IRB, LTy),
2489 getSliceAlign(TargetTy),
2490 LI.isVolatile(), LI.getName());
2491 if (AATags)
2492 NewLI->setAAMetadata(AATags);
2493 if (LI.isVolatile())
2494 NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
2495
2496 V = NewLI;
2497 IsPtrAdjusted = true;
2498 }
2499 V = convertValue(DL, IRB, V, TargetTy);
2500
2501 if (IsSplit) {
2502 assert(!LI.isVolatile())(static_cast <bool> (!LI.isVolatile()) ? void (0) : __assert_fail
("!LI.isVolatile()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2502, __extension__ __PRETTY_FUNCTION__))
;
2503 assert(LI.getType()->isIntegerTy() &&(static_cast <bool> (LI.getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2504, __extension__ __PRETTY_FUNCTION__))
2504 "Only integer type loads and stores are split")(static_cast <bool> (LI.getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("LI.getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2504, __extension__ __PRETTY_FUNCTION__))
;
2505 assert(SliceSize < DL.getTypeStoreSize(LI.getType()) &&(static_cast <bool> (SliceSize < DL.getTypeStoreSize
(LI.getType()) && "Split load isn't smaller than original load"
) ? void (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()) && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2506, __extension__ __PRETTY_FUNCTION__))
2506 "Split load isn't smaller than original load")(static_cast <bool> (SliceSize < DL.getTypeStoreSize
(LI.getType()) && "Split load isn't smaller than original load"
) ? void (0) : __assert_fail ("SliceSize < DL.getTypeStoreSize(LI.getType()) && \"Split load isn't smaller than original load\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2506, __extension__ __PRETTY_FUNCTION__))
;
2507 assert(LI.getType()->getIntegerBitWidth() ==(static_cast <bool> (LI.getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(LI.getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2509, __extension__ __PRETTY_FUNCTION__))
2508 DL.getTypeStoreSizeInBits(LI.getType()) &&(static_cast <bool> (LI.getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(LI.getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2509, __extension__ __PRETTY_FUNCTION__))
2509 "Non-byte-multiple bit width")(static_cast <bool> (LI.getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(LI.getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("LI.getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(LI.getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2509, __extension__ __PRETTY_FUNCTION__))
;
2510 // Move the insertion point just past the load so that we can refer to it.
2511 IRB.SetInsertPoint(&*std::next(BasicBlock::iterator(&LI)));
2512 // Create a placeholder value with the same type as LI to use as the
2513 // basis for the new value. This allows us to replace the uses of LI with
2514 // the computed value, and then replace the placeholder with LI, leaving
2515 // LI only used for this computation.
2516 Value *Placeholder =
2517 new LoadInst(UndefValue::get(LI.getType()->getPointerTo(AS)));
2518 V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
2519 "insert");
2520 LI.replaceAllUsesWith(V);
2521 Placeholder->replaceAllUsesWith(&LI);
2522 Placeholder->deleteValue();
2523 } else {
2524 LI.replaceAllUsesWith(V);
2525 }
2526
2527 Pass.DeadInsts.insert(&LI);
2528 deleteIfTriviallyDead(OldOp);
2529 DEBUG(dbgs() << " to: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *V <<
"\n"; } } while (false)
;
2530 return !LI.isVolatile() && !IsPtrAdjusted;
2531 }
2532
2533 bool rewriteVectorizedStoreInst(Value *V, StoreInst &SI, Value *OldOp,
2534 AAMDNodes AATags) {
2535 if (V->getType() != VecTy) {
2536 unsigned BeginIndex = getIndex(NewBeginOffset);
2537 unsigned EndIndex = getIndex(NewEndOffset);
2538 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2538, __extension__ __PRETTY_FUNCTION__))
;
2539 unsigned NumElements = EndIndex - BeginIndex;
2540 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")(static_cast <bool> (NumElements <= VecTy->getNumElements
() && "Too many elements!") ? void (0) : __assert_fail
("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2540, __extension__ __PRETTY_FUNCTION__))
;
2541 Type *SliceTy = (NumElements == 1)
2542 ? ElementTy
2543 : VectorType::get(ElementTy, NumElements);
2544 if (V->getType() != SliceTy)
2545 V = convertValue(DL, IRB, V, SliceTy);
2546
2547 // Mix in the existing elements.
2548 Value *Old = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2549 V = insertVector(IRB, Old, V, BeginIndex, "vec");
2550 }
2551 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
2552 if (AATags)
2553 Store->setAAMetadata(AATags);
2554 Pass.DeadInsts.insert(&SI);
2555
2556 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2557 return true;
2558 }
2559
2560 bool rewriteIntegerStore(Value *V, StoreInst &SI, AAMDNodes AATags) {
2561 assert(IntTy && "We cannot extract an integer from the alloca")(static_cast <bool> (IntTy && "We cannot extract an integer from the alloca"
) ? void (0) : __assert_fail ("IntTy && \"We cannot extract an integer from the alloca\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2561, __extension__ __PRETTY_FUNCTION__))
;
2562 assert(!SI.isVolatile())(static_cast <bool> (!SI.isVolatile()) ? void (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2562, __extension__ __PRETTY_FUNCTION__))
;
2563 if (DL.getTypeSizeInBits(V->getType()) != IntTy->getBitWidth()) {
2564 Value *Old =
2565 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2566 Old = convertValue(DL, IRB, Old, IntTy);
2567 assert(BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "Out of bounds offset") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"Out of bounds offset\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2567, __extension__ __PRETTY_FUNCTION__))
;
2568 uint64_t Offset = BeginOffset - NewAllocaBeginOffset;
2569 V = insertInteger(DL, IRB, Old, SI.getValueOperand(), Offset, "insert");
2570 }
2571 V = convertValue(DL, IRB, V, NewAllocaTy);
2572 StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
2573 Store->copyMetadata(SI, LLVMContext::MD_mem_parallel_loop_access);
2574 if (AATags)
2575 Store->setAAMetadata(AATags);
2576 Pass.DeadInsts.insert(&SI);
2577 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2578 return true;
2579 }
2580
2581 bool visitStoreInst(StoreInst &SI) {
2582 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
2583 Value *OldOp = SI.getOperand(1);
2584 assert(OldOp == OldPtr)(static_cast <bool> (OldOp == OldPtr) ? void (0) : __assert_fail
("OldOp == OldPtr", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2584, __extension__ __PRETTY_FUNCTION__))
;
2585
2586 AAMDNodes AATags;
2587 SI.getAAMetadata(AATags);
2588
2589 Value *V = SI.getValueOperand();
2590
2591 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2592 // alloca that should be re-examined after promoting this alloca.
2593 if (V->getType()->isPointerTy())
2594 if (AllocaInst *AI = dyn_cast<AllocaInst>(V->stripInBoundsOffsets()))
2595 Pass.PostPromotionWorklist.insert(AI);
2596
2597 if (SliceSize < DL.getTypeStoreSize(V->getType())) {
2598 assert(!SI.isVolatile())(static_cast <bool> (!SI.isVolatile()) ? void (0) : __assert_fail
("!SI.isVolatile()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2598, __extension__ __PRETTY_FUNCTION__))
;
2599 assert(V->getType()->isIntegerTy() &&(static_cast <bool> (V->getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2600, __extension__ __PRETTY_FUNCTION__))
2600 "Only integer type loads and stores are split")(static_cast <bool> (V->getType()->isIntegerTy() &&
"Only integer type loads and stores are split") ? void (0) :
__assert_fail ("V->getType()->isIntegerTy() && \"Only integer type loads and stores are split\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2600, __extension__ __PRETTY_FUNCTION__))
;
2601 assert(V->getType()->getIntegerBitWidth() ==(static_cast <bool> (V->getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(V->getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2603, __extension__ __PRETTY_FUNCTION__))
2602 DL.getTypeStoreSizeInBits(V->getType()) &&(static_cast <bool> (V->getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(V->getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2603, __extension__ __PRETTY_FUNCTION__))
2603 "Non-byte-multiple bit width")(static_cast <bool> (V->getType()->getIntegerBitWidth
() == DL.getTypeStoreSizeInBits(V->getType()) && "Non-byte-multiple bit width"
) ? void (0) : __assert_fail ("V->getType()->getIntegerBitWidth() == DL.getTypeStoreSizeInBits(V->getType()) && \"Non-byte-multiple bit width\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2603, __extension__ __PRETTY_FUNCTION__))
;
2604 IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), SliceSize * 8);
2605 V = extractInteger(DL, IRB, V, NarrowTy, NewBeginOffset - BeginOffset,
2606 "extract");
2607 }
2608
2609 if (VecTy)
2610 return rewriteVectorizedStoreInst(V, SI, OldOp, AATags);
2611 if (IntTy && V->getType()->isIntegerTy())
2612 return rewriteIntegerStore(V, SI, AATags);
2613
2614 const bool IsStorePastEnd = DL.getTypeStoreSize(V->getType()) > SliceSize;
2615 StoreInst *NewSI;
2616 if (NewBeginOffset == NewAllocaBeginOffset &&
2617 NewEndOffset == NewAllocaEndOffset &&
2618 (canConvertValue(DL, V->getType(), NewAllocaTy) ||
2619 (IsStorePastEnd && NewAllocaTy->isIntegerTy() &&
2620 V->getType()->isIntegerTy()))) {
2621 // If this is an integer store past the end of slice (and thus the bytes
2622 // past that point are irrelevant or this is unreachable), truncate the
2623 // value prior to storing.
2624 if (auto *VITy = dyn_cast<IntegerType>(V->getType()))
2625 if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
2626 if (VITy->getBitWidth() > AITy->getBitWidth()) {
2627 if (DL.isBigEndian())
2628 V = IRB.CreateLShr(V, VITy->getBitWidth() - AITy->getBitWidth(),
2629 "endian_shift");
2630 V = IRB.CreateTrunc(V, AITy, "load.trunc");
2631 }
2632
2633 V = convertValue(DL, IRB, V, NewAllocaTy);
2634 NewSI = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
2635 SI.isVolatile());
2636 } else {
2637 unsigned AS = SI.getPointerAddressSpace();
2638 Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
2639 NewSI = IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(V->getType()),
2640 SI.isVolatile());
2641 }
2642 NewSI->copyMetadata(SI, LLVMContext::MD_mem_parallel_loop_access);
2643 if (AATags)
2644 NewSI->setAAMetadata(AATags);
2645 if (SI.isVolatile())
2646 NewSI->setAtomic(SI.getOrdering(), SI.getSyncScopeID());
2647 Pass.DeadInsts.insert(&SI);
2648 deleteIfTriviallyDead(OldOp);
2649
2650 DEBUG(dbgs() << " to: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *NewSI <<
"\n"; } } while (false)
;
2651 return NewSI->getPointerOperand() == &NewAI && !SI.isVolatile();
2652 }
2653
2654 /// \brief Compute an integer value from splatting an i8 across the given
2655 /// number of bytes.
2656 ///
2657 /// Note that this routine assumes an i8 is a byte. If that isn't true, don't
2658 /// call this routine.
2659 /// FIXME: Heed the advice above.
2660 ///
2661 /// \param V The i8 value to splat.
2662 /// \param Size The number of bytes in the output (assuming i8 is one byte)
2663 Value *getIntegerSplat(Value *V, unsigned Size) {
2664 assert(Size > 0 && "Expected a positive number of bytes.")(static_cast <bool> (Size > 0 && "Expected a positive number of bytes."
) ? void (0) : __assert_fail ("Size > 0 && \"Expected a positive number of bytes.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2664, __extension__ __PRETTY_FUNCTION__))
;
2665 IntegerType *VTy = cast<IntegerType>(V->getType());
2666 assert(VTy->getBitWidth() == 8 && "Expected an i8 value for the byte")(static_cast <bool> (VTy->getBitWidth() == 8 &&
"Expected an i8 value for the byte") ? void (0) : __assert_fail
("VTy->getBitWidth() == 8 && \"Expected an i8 value for the byte\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2666, __extension__ __PRETTY_FUNCTION__))
;
2667 if (Size == 1)
2668 return V;
2669
2670 Type *SplatIntTy = Type::getIntNTy(VTy->getContext(), Size * 8);
2671 V = IRB.CreateMul(
2672 IRB.CreateZExt(V, SplatIntTy, "zext"),
2673 ConstantExpr::getUDiv(
2674 Constant::getAllOnesValue(SplatIntTy),
2675 ConstantExpr::getZExt(Constant::getAllOnesValue(V->getType()),
2676 SplatIntTy)),
2677 "isplat");
2678 return V;
2679 }
2680
2681 /// \brief Compute a vector splat for a given element value.
2682 Value *getVectorSplat(Value *V, unsigned NumElements) {
2683 V = IRB.CreateVectorSplat(NumElements, V, "vsplat");
2684 DEBUG(dbgs() << " splat: " << *V << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " splat: " << *V <<
"\n"; } } while (false)
;
2685 return V;
2686 }
2687
2688 bool visitMemSetInst(MemSetInst &II) {
2689 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2690 assert(II.getRawDest() == OldPtr)(static_cast <bool> (II.getRawDest() == OldPtr) ? void (
0) : __assert_fail ("II.getRawDest() == OldPtr", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2690, __extension__ __PRETTY_FUNCTION__))
;
2691
2692 AAMDNodes AATags;
2693 II.getAAMetadata(AATags);
2694
2695 // If the memset has a variable size, it cannot be split, just adjust the
2696 // pointer to the new alloca.
2697 if (!isa<Constant>(II.getLength())) {
2698 assert(!IsSplit)(static_cast <bool> (!IsSplit) ? void (0) : __assert_fail
("!IsSplit", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2698, __extension__ __PRETTY_FUNCTION__))
;
2699 assert(NewBeginOffset == BeginOffset)(static_cast <bool> (NewBeginOffset == BeginOffset) ? void
(0) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2699, __extension__ __PRETTY_FUNCTION__))
;
2700 II.setDest(getNewAllocaSlicePtr(IRB, OldPtr->getType()));
2701 II.setDestAlignment(getSliceAlign());
2702
2703 deleteIfTriviallyDead(OldPtr);
2704 return false;
2705 }
2706
2707 // Record this instruction for deletion.
2708 Pass.DeadInsts.insert(&II);
2709
2710 Type *AllocaTy = NewAI.getAllocatedType();
2711 Type *ScalarTy = AllocaTy->getScalarType();
2712
2713 // If this doesn't map cleanly onto the alloca type, and that type isn't
2714 // a single value type, just emit a memset.
2715 if (!VecTy && !IntTy &&
2716 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2717 SliceSize != DL.getTypeStoreSize(AllocaTy) ||
2718 !AllocaTy->isSingleValueType() ||
2719 !DL.isLegalInteger(DL.getTypeSizeInBits(ScalarTy)) ||
2720 DL.getTypeSizeInBits(ScalarTy) % 8 != 0)) {
2721 Type *SizeTy = II.getLength()->getType();
2722 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2723 CallInst *New = IRB.CreateMemSet(
2724 getNewAllocaSlicePtr(IRB, OldPtr->getType()), II.getValue(), Size,
2725 getSliceAlign(), II.isVolatile());
2726 if (AATags)
2727 New->setAAMetadata(AATags);
2728 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2729 return false;
2730 }
2731
2732 // If we can represent this as a simple value, we have to build the actual
2733 // value to store, which requires expanding the byte present in memset to
2734 // a sensible representation for the alloca type. This is essentially
2735 // splatting the byte to a sufficiently wide integer, splatting it across
2736 // any desired vector width, and bitcasting to the final type.
2737 Value *V;
2738
2739 if (VecTy) {
2740 // If this is a memset of a vectorized alloca, insert it.
2741 assert(ElementTy == ScalarTy)(static_cast <bool> (ElementTy == ScalarTy) ? void (0) :
__assert_fail ("ElementTy == ScalarTy", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2741, __extension__ __PRETTY_FUNCTION__))
;
2742
2743 unsigned BeginIndex = getIndex(NewBeginOffset);
2744 unsigned EndIndex = getIndex(NewEndOffset);
2745 assert(EndIndex > BeginIndex && "Empty vector!")(static_cast <bool> (EndIndex > BeginIndex &&
"Empty vector!") ? void (0) : __assert_fail ("EndIndex > BeginIndex && \"Empty vector!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2745, __extension__ __PRETTY_FUNCTION__))
;
2746 unsigned NumElements = EndIndex - BeginIndex;
2747 assert(NumElements <= VecTy->getNumElements() && "Too many elements!")(static_cast <bool> (NumElements <= VecTy->getNumElements
() && "Too many elements!") ? void (0) : __assert_fail
("NumElements <= VecTy->getNumElements() && \"Too many elements!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2747, __extension__ __PRETTY_FUNCTION__))
;
2748
2749 Value *Splat =
2750 getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ElementTy) / 8);
2751 Splat = convertValue(DL, IRB, Splat, ElementTy);
2752 if (NumElements > 1)
2753 Splat = getVectorSplat(Splat, NumElements);
2754
2755 Value *Old =
2756 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2757 V = insertVector(IRB, Old, Splat, BeginIndex, "vec");
2758 } else if (IntTy) {
2759 // If this is a memset on an alloca where we can widen stores, insert the
2760 // set integer.
2761 assert(!II.isVolatile())(static_cast <bool> (!II.isVolatile()) ? void (0) : __assert_fail
("!II.isVolatile()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2761, __extension__ __PRETTY_FUNCTION__))
;
2762
2763 uint64_t Size = NewEndOffset - NewBeginOffset;
2764 V = getIntegerSplat(II.getValue(), Size);
2765
2766 if (IntTy && (BeginOffset != NewAllocaBeginOffset ||
2767 EndOffset != NewAllocaBeginOffset)) {
2768 Value *Old =
2769 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2770 Old = convertValue(DL, IRB, Old, IntTy);
2771 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2772 V = insertInteger(DL, IRB, Old, V, Offset, "insert");
2773 } else {
2774 assert(V->getType() == IntTy &&(static_cast <bool> (V->getType() == IntTy &&
"Wrong type for an alloca wide integer!") ? void (0) : __assert_fail
("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2775, __extension__ __PRETTY_FUNCTION__))
2775 "Wrong type for an alloca wide integer!")(static_cast <bool> (V->getType() == IntTy &&
"Wrong type for an alloca wide integer!") ? void (0) : __assert_fail
("V->getType() == IntTy && \"Wrong type for an alloca wide integer!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2775, __extension__ __PRETTY_FUNCTION__))
;
2776 }
2777 V = convertValue(DL, IRB, V, AllocaTy);
2778 } else {
2779 // Established these invariants above.
2780 assert(NewBeginOffset == NewAllocaBeginOffset)(static_cast <bool> (NewBeginOffset == NewAllocaBeginOffset
) ? void (0) : __assert_fail ("NewBeginOffset == NewAllocaBeginOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2780, __extension__ __PRETTY_FUNCTION__))
;
2781 assert(NewEndOffset == NewAllocaEndOffset)(static_cast <bool> (NewEndOffset == NewAllocaEndOffset
) ? void (0) : __assert_fail ("NewEndOffset == NewAllocaEndOffset"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2781, __extension__ __PRETTY_FUNCTION__))
;
2782
2783 V = getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ScalarTy) / 8);
2784 if (VectorType *AllocaVecTy = dyn_cast<VectorType>(AllocaTy))
2785 V = getVectorSplat(V, AllocaVecTy->getNumElements());
2786
2787 V = convertValue(DL, IRB, V, AllocaTy);
2788 }
2789
2790 StoreInst *New = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
2791 II.isVolatile());
2792 if (AATags)
2793 New->setAAMetadata(AATags);
2794 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2795 return !II.isVolatile();
2796 }
2797
2798 bool visitMemTransferInst(MemTransferInst &II) {
2799 // Rewriting of memory transfer instructions can be a bit tricky. We break
2800 // them into two categories: split intrinsics and unsplit intrinsics.
2801
2802 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2803
2804 AAMDNodes AATags;
2805 II.getAAMetadata(AATags);
2806
2807 bool IsDest = &II.getRawDestUse() == OldUse;
2808 assert((IsDest && II.getRawDest() == OldPtr) ||(static_cast <bool> ((IsDest && II.getRawDest()
== OldPtr) || (!IsDest && II.getRawSource() == OldPtr
)) ? void (0) : __assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2809, __extension__ __PRETTY_FUNCTION__))
1
Within the expansion of the macro 'assert':
a
Assuming 'IsDest' is 0
b
Assuming pointer value is null
2809 (!IsDest && II.getRawSource() == OldPtr))(static_cast <bool> ((IsDest && II.getRawDest()
== OldPtr) || (!IsDest && II.getRawSource() == OldPtr
)) ? void (0) : __assert_fail ("(IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2809, __extension__ __PRETTY_FUNCTION__))
;
2810
2811 unsigned SliceAlign = getSliceAlign();
2812
2813 // For unsplit intrinsics, we simply modify the source and destination
2814 // pointers in place. This isn't just an optimization, it is a matter of
2815 // correctness. With unsplit intrinsics we may be dealing with transfers
2816 // within a single alloca before SROA ran, or with transfers that have
2817 // a variable length. We may also be dealing with memmove instead of
2818 // memcpy, and so simply updating the pointers is the necessary for us to
2819 // update both source and dest of a single call.
2820 if (!IsSplittable) {
2
Assuming the condition is true
3
Taking true branch
2821 Value *AdjustedPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
4
Called C++ object pointer is null
2822 if (IsDest) {
2823 II.setDest(AdjustedPtr);
2824 II.setDestAlignment(SliceAlign);
2825 }
2826 else {
2827 II.setSource(AdjustedPtr);
2828 II.setSourceAlignment(SliceAlign);
2829 }
2830
2831 DEBUG(dbgs() << " to: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << II <<
"\n"; } } while (false)
;
2832 deleteIfTriviallyDead(OldPtr);
2833 return false;
2834 }
2835 // For split transfer intrinsics we have an incredibly useful assurance:
2836 // the source and destination do not reside within the same alloca, and at
2837 // least one of them does not escape. This means that we can replace
2838 // memmove with memcpy, and we don't need to worry about all manner of
2839 // downsides to splitting and transforming the operations.
2840
2841 // If this doesn't map cleanly onto the alloca type, and that type isn't
2842 // a single value type, just emit a memcpy.
2843 bool EmitMemCpy =
2844 !VecTy && !IntTy &&
2845 (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
2846 SliceSize != DL.getTypeStoreSize(NewAI.getAllocatedType()) ||
2847 !NewAI.getAllocatedType()->isSingleValueType());
2848
2849 // If we're just going to emit a memcpy, the alloca hasn't changed, and the
2850 // size hasn't been shrunk based on analysis of the viable range, this is
2851 // a no-op.
2852 if (EmitMemCpy && &OldAI == &NewAI) {
2853 // Ensure the start lines up.
2854 assert(NewBeginOffset == BeginOffset)(static_cast <bool> (NewBeginOffset == BeginOffset) ? void
(0) : __assert_fail ("NewBeginOffset == BeginOffset", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2854, __extension__ __PRETTY_FUNCTION__))
;
2855
2856 // Rewrite the size as needed.
2857 if (NewEndOffset != EndOffset)
2858 II.setLength(ConstantInt::get(II.getLength()->getType(),
2859 NewEndOffset - NewBeginOffset));
2860 return false;
2861 }
2862 // Record this instruction for deletion.
2863 Pass.DeadInsts.insert(&II);
2864
2865 // Strip all inbounds GEPs and pointer casts to try to dig out any root
2866 // alloca that should be re-examined after rewriting this instruction.
2867 Value *OtherPtr = IsDest ? II.getRawSource() : II.getRawDest();
2868 if (AllocaInst *AI =
2869 dyn_cast<AllocaInst>(OtherPtr->stripInBoundsOffsets())) {
2870 assert(AI != &OldAI && AI != &NewAI &&(static_cast <bool> (AI != &OldAI && AI != &
NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? void (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2871, __extension__ __PRETTY_FUNCTION__))
2871 "Splittable transfers cannot reach the same alloca on both ends.")(static_cast <bool> (AI != &OldAI && AI != &
NewAI && "Splittable transfers cannot reach the same alloca on both ends."
) ? void (0) : __assert_fail ("AI != &OldAI && AI != &NewAI && \"Splittable transfers cannot reach the same alloca on both ends.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2871, __extension__ __PRETTY_FUNCTION__))
;
2872 Pass.Worklist.insert(AI);
2873 }
2874
2875 Type *OtherPtrTy = OtherPtr->getType();
2876 unsigned OtherAS = OtherPtrTy->getPointerAddressSpace();
2877
2878 // Compute the relative offset for the other pointer within the transfer.
2879 unsigned IntPtrWidth = DL.getPointerSizeInBits(OtherAS);
2880 APInt OtherOffset(IntPtrWidth, NewBeginOffset - BeginOffset);
2881 unsigned OtherAlign =
2882 IsDest ? II.getSourceAlignment() : II.getDestAlignment();
2883 OtherAlign = MinAlign(OtherAlign ? OtherAlign : 1,
2884 OtherOffset.zextOrTrunc(64).getZExtValue());
2885
2886 if (EmitMemCpy) {
2887 // Compute the other pointer, folding as much as possible to produce
2888 // a single, simple GEP in most cases.
2889 OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
2890 OtherPtr->getName() + ".");
2891
2892 Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
2893 Type *SizeTy = II.getLength()->getType();
2894 Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
2895
2896 Value *DestPtr, *SrcPtr;
2897 unsigned DestAlign, SrcAlign;
2898 // Note: IsDest is true iff we're copying into the new alloca slice
2899 if (IsDest) {
2900 DestPtr = OurPtr;
2901 DestAlign = SliceAlign;
2902 SrcPtr = OtherPtr;
2903 SrcAlign = OtherAlign;
2904 } else {
2905 DestPtr = OtherPtr;
2906 DestAlign = OtherAlign;
2907 SrcPtr = OurPtr;
2908 SrcAlign = SliceAlign;
2909 }
2910 CallInst *New = IRB.CreateMemCpy(DestPtr, DestAlign, SrcPtr, SrcAlign,
2911 Size, II.isVolatile());
2912 if (AATags)
2913 New->setAAMetadata(AATags);
2914 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
2915 return false;
2916 }
2917
2918 bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
2919 NewEndOffset == NewAllocaEndOffset;
2920 uint64_t Size = NewEndOffset - NewBeginOffset;
2921 unsigned BeginIndex = VecTy ? getIndex(NewBeginOffset) : 0;
2922 unsigned EndIndex = VecTy ? getIndex(NewEndOffset) : 0;
2923 unsigned NumElements = EndIndex - BeginIndex;
2924 IntegerType *SubIntTy =
2925 IntTy ? Type::getIntNTy(IntTy->getContext(), Size * 8) : nullptr;
2926
2927 // Reset the other pointer type to match the register type we're going to
2928 // use, but using the address space of the original other pointer.
2929 if (VecTy && !IsWholeAlloca) {
2930 if (NumElements == 1)
2931 OtherPtrTy = VecTy->getElementType();
2932 else
2933 OtherPtrTy = VectorType::get(VecTy->getElementType(), NumElements);
2934
2935 OtherPtrTy = OtherPtrTy->getPointerTo(OtherAS);
2936 } else if (IntTy && !IsWholeAlloca) {
2937 OtherPtrTy = SubIntTy->getPointerTo(OtherAS);
2938 } else {
2939 OtherPtrTy = NewAllocaTy->getPointerTo(OtherAS);
2940 }
2941
2942 Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
2943 OtherPtr->getName() + ".");
2944 unsigned SrcAlign = OtherAlign;
2945 Value *DstPtr = &NewAI;
2946 unsigned DstAlign = SliceAlign;
2947 if (!IsDest) {
2948 std::swap(SrcPtr, DstPtr);
2949 std::swap(SrcAlign, DstAlign);
2950 }
2951
2952 Value *Src;
2953 if (VecTy && !IsWholeAlloca && !IsDest) {
2954 Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2955 Src = extractVector(IRB, Src, BeginIndex, EndIndex, "vec");
2956 } else if (IntTy && !IsWholeAlloca && !IsDest) {
2957 Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
2958 Src = convertValue(DL, IRB, Src, IntTy);
2959 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2960 Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract");
2961 } else {
2962 LoadInst *Load = IRB.CreateAlignedLoad(SrcPtr, SrcAlign, II.isVolatile(),
2963 "copyload");
2964 if (AATags)
2965 Load->setAAMetadata(AATags);
2966 Src = Load;
2967 }
2968
2969 if (VecTy && !IsWholeAlloca && IsDest) {
2970 Value *Old =
2971 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2972 Src = insertVector(IRB, Old, Src, BeginIndex, "vec");
2973 } else if (IntTy && !IsWholeAlloca && IsDest) {
2974 Value *Old =
2975 IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
2976 Old = convertValue(DL, IRB, Old, IntTy);
2977 uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
2978 Src = insertInteger(DL, IRB, Old, Src, Offset, "insert");
2979 Src = convertValue(DL, IRB, Src, NewAllocaTy);
2980 }
2981
2982 StoreInst *Store = cast<StoreInst>(
2983 IRB.CreateAlignedStore(Src, DstPtr, DstAlign, II.isVolatile()));
2984 if (AATags)
2985 Store->setAAMetadata(AATags);
2986 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
2987 return !II.isVolatile();
2988 }
2989
2990 bool visitIntrinsicInst(IntrinsicInst &II) {
2991 assert(II.getIntrinsicID() == Intrinsic::lifetime_start ||(static_cast <bool> (II.getIntrinsicID() == Intrinsic::
lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end
) ? void (0) : __assert_fail ("II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2992, __extension__ __PRETTY_FUNCTION__))
2992 II.getIntrinsicID() == Intrinsic::lifetime_end)(static_cast <bool> (II.getIntrinsicID() == Intrinsic::
lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end
) ? void (0) : __assert_fail ("II.getIntrinsicID() == Intrinsic::lifetime_start || II.getIntrinsicID() == Intrinsic::lifetime_end"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2992, __extension__ __PRETTY_FUNCTION__))
;
2993 DEBUG(dbgs() << " original: " << II << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << II <<
"\n"; } } while (false)
;
2994 assert(II.getArgOperand(1) == OldPtr)(static_cast <bool> (II.getArgOperand(1) == OldPtr) ? void
(0) : __assert_fail ("II.getArgOperand(1) == OldPtr", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 2994, __extension__ __PRETTY_FUNCTION__))
;
2995
2996 // Record this instruction for deletion.
2997 Pass.DeadInsts.insert(&II);
2998
2999 // Lifetime intrinsics are only promotable if they cover the whole alloca.
3000 // Therefore, we drop lifetime intrinsics which don't cover the whole
3001 // alloca.
3002 // (In theory, intrinsics which partially cover an alloca could be
3003 // promoted, but PromoteMemToReg doesn't handle that case.)
3004 // FIXME: Check whether the alloca is promotable before dropping the
3005 // lifetime intrinsics?
3006 if (NewBeginOffset != NewAllocaBeginOffset ||
3007 NewEndOffset != NewAllocaEndOffset)
3008 return true;
3009
3010 ConstantInt *Size =
3011 ConstantInt::get(cast<IntegerType>(II.getArgOperand(0)->getType()),
3012 NewEndOffset - NewBeginOffset);
3013 Value *Ptr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3014 Value *New;
3015 if (II.getIntrinsicID() == Intrinsic::lifetime_start)
3016 New = IRB.CreateLifetimeStart(Ptr, Size);
3017 else
3018 New = IRB.CreateLifetimeEnd(Ptr, Size);
3019
3020 (void)New;
3021 DEBUG(dbgs() << " to: " << *New << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *New <<
"\n"; } } while (false)
;
3022
3023 return true;
3024 }
3025
3026 bool visitPHINode(PHINode &PN) {
3027 DEBUG(dbgs() << " original: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << PN <<
"\n"; } } while (false)
;
3028 assert(BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "PHIs are unsplittable") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3028, __extension__ __PRETTY_FUNCTION__))
;
3029 assert(EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable")(static_cast <bool> (EndOffset <= NewAllocaEndOffset
&& "PHIs are unsplittable") ? void (0) : __assert_fail
("EndOffset <= NewAllocaEndOffset && \"PHIs are unsplittable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3029, __extension__ __PRETTY_FUNCTION__))
;
3030
3031 // We would like to compute a new pointer in only one place, but have it be
3032 // as local as possible to the PHI. To do that, we re-use the location of
3033 // the old pointer, which necessarily must be in the right position to
3034 // dominate the PHI.
3035 IRBuilderTy PtrBuilder(IRB);
3036 if (isa<PHINode>(OldPtr))
3037 PtrBuilder.SetInsertPoint(&*OldPtr->getParent()->getFirstInsertionPt());
3038 else
3039 PtrBuilder.SetInsertPoint(OldPtr);
3040 PtrBuilder.SetCurrentDebugLocation(OldPtr->getDebugLoc());
3041
3042 Value *NewPtr = getNewAllocaSlicePtr(PtrBuilder, OldPtr->getType());
3043 // Replace the operands which were using the old pointer.
3044 std::replace(PN.op_begin(), PN.op_end(), cast<Value>(OldPtr), NewPtr);
3045
3046 DEBUG(dbgs() << " to: " << PN << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << PN <<
"\n"; } } while (false)
;
3047 deleteIfTriviallyDead(OldPtr);
3048
3049 // PHIs can't be promoted on their own, but often can be speculated. We
3050 // check the speculation outside of the rewriter so that we see the
3051 // fully-rewritten alloca.
3052 PHIUsers.insert(&PN);
3053 return true;
3054 }
3055
3056 bool visitSelectInst(SelectInst &SI) {
3057 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3058 assert((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) &&(static_cast <bool> ((SI.getTrueValue() == OldPtr || SI
.getFalseValue() == OldPtr) && "Pointer isn't an operand!"
) ? void (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3059, __extension__ __PRETTY_FUNCTION__))
3059 "Pointer isn't an operand!")(static_cast <bool> ((SI.getTrueValue() == OldPtr || SI
.getFalseValue() == OldPtr) && "Pointer isn't an operand!"
) ? void (0) : __assert_fail ("(SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) && \"Pointer isn't an operand!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3059, __extension__ __PRETTY_FUNCTION__))
;
3060 assert(BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable")(static_cast <bool> (BeginOffset >= NewAllocaBeginOffset
&& "Selects are unsplittable") ? void (0) : __assert_fail
("BeginOffset >= NewAllocaBeginOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3060, __extension__ __PRETTY_FUNCTION__))
;
3061 assert(EndOffset <= NewAllocaEndOffset && "Selects are unsplittable")(static_cast <bool> (EndOffset <= NewAllocaEndOffset
&& "Selects are unsplittable") ? void (0) : __assert_fail
("EndOffset <= NewAllocaEndOffset && \"Selects are unsplittable\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3061, __extension__ __PRETTY_FUNCTION__))
;
3062
3063 Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
3064 // Replace the operands which were using the old pointer.
3065 if (SI.getOperand(1) == OldPtr)
3066 SI.setOperand(1, NewPtr);
3067 if (SI.getOperand(2) == OldPtr)
3068 SI.setOperand(2, NewPtr);
3069
3070 DEBUG(dbgs() << " to: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << SI <<
"\n"; } } while (false)
;
3071 deleteIfTriviallyDead(OldPtr);
3072
3073 // Selects can't be promoted on their own, but often can be speculated. We
3074 // check the speculation outside of the rewriter so that we see the
3075 // fully-rewritten alloca.
3076 SelectUsers.insert(&SI);
3077 return true;
3078 }
3079};
3080
3081namespace {
3082
3083/// \brief Visitor to rewrite aggregate loads and stores as scalar.
3084///
3085/// This pass aggressively rewrites all aggregate loads and stores on
3086/// a particular pointer (or any pointer derived from it which we can identify)
3087/// with scalar loads and stores.
3088class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
3089 // Befriend the base class so it can delegate to private visit methods.
3090 friend class InstVisitor<AggLoadStoreRewriter, bool>;
3091
3092 /// Queue of pointer uses to analyze and potentially rewrite.
3093 SmallVector<Use *, 8> Queue;
3094
3095 /// Set to prevent us from cycling with phi nodes and loops.
3096 SmallPtrSet<User *, 8> Visited;
3097
3098 /// The current pointer use being rewritten. This is used to dig up the used
3099 /// value (as opposed to the user).
3100 Use *U;
3101
3102public:
3103 /// Rewrite loads and stores through a pointer and all pointers derived from
3104 /// it.
3105 bool rewrite(Instruction &I) {
3106 DEBUG(dbgs() << " Rewriting FCA loads and stores...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Rewriting FCA loads and stores...\n"
; } } while (false)
;
3107 enqueueUsers(I);
3108 bool Changed = false;
3109 while (!Queue.empty()) {
3110 U = Queue.pop_back_val();
3111 Changed |= visit(cast<Instruction>(U->getUser()));
3112 }
3113 return Changed;
3114 }
3115
3116private:
3117 /// Enqueue all the users of the given instruction for further processing.
3118 /// This uses a set to de-duplicate users.
3119 void enqueueUsers(Instruction &I) {
3120 for (Use &U : I.uses())
3121 if (Visited.insert(U.getUser()).second)
3122 Queue.push_back(&U);
3123 }
3124
3125 // Conservative default is to not rewrite anything.
3126 bool visitInstruction(Instruction &I) { return false; }
3127
3128 /// \brief Generic recursive split emission class.
3129 template <typename Derived> class OpSplitter {
3130 protected:
3131 /// The builder used to form new instructions.
3132 IRBuilderTy IRB;
3133
3134 /// The indices which to be used with insert- or extractvalue to select the
3135 /// appropriate value within the aggregate.
3136 SmallVector<unsigned, 4> Indices;
3137
3138 /// The indices to a GEP instruction which will move Ptr to the correct slot
3139 /// within the aggregate.
3140 SmallVector<Value *, 4> GEPIndices;
3141
3142 /// The base pointer of the original op, used as a base for GEPing the
3143 /// split operations.
3144 Value *Ptr;
3145
3146 /// Initialize the splitter with an insertion point, Ptr and start with a
3147 /// single zero GEP index.
3148 OpSplitter(Instruction *InsertionPoint, Value *Ptr)
3149 : IRB(InsertionPoint), GEPIndices(1, IRB.getInt32(0)), Ptr(Ptr) {}
3150
3151 public:
3152 /// \brief Generic recursive split emission routine.
3153 ///
3154 /// This method recursively splits an aggregate op (load or store) into
3155 /// scalar or vector ops. It splits recursively until it hits a single value
3156 /// and emits that single value operation via the template argument.
3157 ///
3158 /// The logic of this routine relies on GEPs and insertvalue and
3159 /// extractvalue all operating with the same fundamental index list, merely
3160 /// formatted differently (GEPs need actual values).
3161 ///
3162 /// \param Ty The type being split recursively into smaller ops.
3163 /// \param Agg The aggregate value being built up or stored, depending on
3164 /// whether this is splitting a load or a store respectively.
3165 void emitSplitOps(Type *Ty, Value *&Agg, const Twine &Name) {
3166 if (Ty->isSingleValueType())
3167 return static_cast<Derived *>(this)->emitFunc(Ty, Agg, Name);
3168
3169 if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
3170 unsigned OldSize = Indices.size();
3171 (void)OldSize;
3172 for (unsigned Idx = 0, Size = ATy->getNumElements(); Idx != Size;
3173 ++Idx) {
3174 assert(Indices.size() == OldSize && "Did not return to the old size")(static_cast <bool> (Indices.size() == OldSize &&
"Did not return to the old size") ? void (0) : __assert_fail
("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3174, __extension__ __PRETTY_FUNCTION__))
;
3175 Indices.push_back(Idx);
3176 GEPIndices.push_back(IRB.getInt32(Idx));
3177 emitSplitOps(ATy->getElementType(), Agg, Name + "." + Twine(Idx));
3178 GEPIndices.pop_back();
3179 Indices.pop_back();
3180 }
3181 return;
3182 }
3183
3184 if (StructType *STy = dyn_cast<StructType>(Ty)) {
3185 unsigned OldSize = Indices.size();
3186 (void)OldSize;
3187 for (unsigned Idx = 0, Size = STy->getNumElements(); Idx != Size;
3188 ++Idx) {
3189 assert(Indices.size() == OldSize && "Did not return to the old size")(static_cast <bool> (Indices.size() == OldSize &&
"Did not return to the old size") ? void (0) : __assert_fail
("Indices.size() == OldSize && \"Did not return to the old size\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3189, __extension__ __PRETTY_FUNCTION__))
;
3190 Indices.push_back(Idx);
3191 GEPIndices.push_back(IRB.getInt32(Idx));
3192 emitSplitOps(STy->getElementType(Idx), Agg, Name + "." + Twine(Idx));
3193 GEPIndices.pop_back();
3194 Indices.pop_back();
3195 }
3196 return;
3197 }
3198
3199 llvm_unreachable("Only arrays and structs are aggregate loadable types")::llvm::llvm_unreachable_internal("Only arrays and structs are aggregate loadable types"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3199)
;
3200 }
3201 };
3202
3203 struct LoadOpSplitter : public OpSplitter<LoadOpSplitter> {
3204 AAMDNodes AATags;
3205
3206 LoadOpSplitter(Instruction *InsertionPoint, Value *Ptr, AAMDNodes AATags)
3207 : OpSplitter<LoadOpSplitter>(InsertionPoint, Ptr), AATags(AATags) {}
3208
3209 /// Emit a leaf load of a single value. This is called at the leaves of the
3210 /// recursive emission to actually load values.
3211 void emitFunc(Type *Ty, Value *&Agg, const Twine &Name) {
3212 assert(Ty->isSingleValueType())(static_cast <bool> (Ty->isSingleValueType()) ? void
(0) : __assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3212, __extension__ __PRETTY_FUNCTION__))
;
3213 // Load the single value and insert it using the indices.
3214 Value *GEP =
3215 IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
3216 LoadInst *Load = IRB.CreateLoad(GEP, Name + ".load");
3217 if (AATags)
3218 Load->setAAMetadata(AATags);
3219 Agg = IRB.CreateInsertValue(Agg, Load, Indices, Name + ".insert");
3220 DEBUG(dbgs() << " to: " << *Load << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Load <<
"\n"; } } while (false)
;
3221 }
3222 };
3223
3224 bool visitLoadInst(LoadInst &LI) {
3225 assert(LI.getPointerOperand() == *U)(static_cast <bool> (LI.getPointerOperand() == *U) ? void
(0) : __assert_fail ("LI.getPointerOperand() == *U", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3225, __extension__ __PRETTY_FUNCTION__))
;
3226 if (!LI.isSimple() || LI.getType()->isSingleValueType())
3227 return false;
3228
3229 // We have an aggregate being loaded, split it apart.
3230 DEBUG(dbgs() << " original: " << LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << LI <<
"\n"; } } while (false)
;
3231 AAMDNodes AATags;
3232 LI.getAAMetadata(AATags);
3233 LoadOpSplitter Splitter(&LI, *U, AATags);
3234 Value *V = UndefValue::get(LI.getType());
3235 Splitter.emitSplitOps(LI.getType(), V, LI.getName() + ".fca");
3236 LI.replaceAllUsesWith(V);
3237 LI.eraseFromParent();
3238 return true;
3239 }
3240
3241 struct StoreOpSplitter : public OpSplitter<StoreOpSplitter> {
3242 StoreOpSplitter(Instruction *InsertionPoint, Value *Ptr, AAMDNodes AATags)
3243 : OpSplitter<StoreOpSplitter>(InsertionPoint, Ptr), AATags(AATags) {}
3244 AAMDNodes AATags;
3245
3246 /// Emit a leaf store of a single value. This is called at the leaves of the
3247 /// recursive emission to actually produce stores.
3248 void emitFunc(Type *Ty, Value *&Agg, const Twine &Name) {
3249 assert(Ty->isSingleValueType())(static_cast <bool> (Ty->isSingleValueType()) ? void
(0) : __assert_fail ("Ty->isSingleValueType()", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3249, __extension__ __PRETTY_FUNCTION__))
;
3250 // Extract the single value and store it using the indices.
3251 //
3252 // The gep and extractvalue values are factored out of the CreateStore
3253 // call to make the output independent of the argument evaluation order.
3254 Value *ExtractValue =
3255 IRB.CreateExtractValue(Agg, Indices, Name + ".extract");
3256 Value *InBoundsGEP =
3257 IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
3258 StoreInst *Store = IRB.CreateStore(ExtractValue, InBoundsGEP);
3259 if (AATags)
3260 Store->setAAMetadata(AATags);
3261 DEBUG(dbgs() << " to: " << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " to: " << *Store <<
"\n"; } } while (false)
;
3262 }
3263 };
3264
3265 bool visitStoreInst(StoreInst &SI) {
3266 if (!SI.isSimple() || SI.getPointerOperand() != *U)
3267 return false;
3268 Value *V = SI.getValueOperand();
3269 if (V->getType()->isSingleValueType())
3270 return false;
3271
3272 // We have an aggregate being stored, split it apart.
3273 DEBUG(dbgs() << " original: " << SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " original: " << SI <<
"\n"; } } while (false)
;
3274 AAMDNodes AATags;
3275 SI.getAAMetadata(AATags);
3276 StoreOpSplitter Splitter(&SI, *U, AATags);
3277 Splitter.emitSplitOps(V->getType(), V, V->getName() + ".fca");
3278 SI.eraseFromParent();
3279 return true;
3280 }
3281
3282 bool visitBitCastInst(BitCastInst &BC) {
3283 enqueueUsers(BC);
3284 return false;
3285 }
3286
3287 bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
3288 enqueueUsers(GEPI);
3289 return false;
3290 }
3291
3292 bool visitPHINode(PHINode &PN) {
3293 enqueueUsers(PN);
3294 return false;
3295 }
3296
3297 bool visitSelectInst(SelectInst &SI) {
3298 enqueueUsers(SI);
3299 return false;
3300 }
3301};
3302
3303} // end anonymous namespace
3304
3305/// \brief Strip aggregate type wrapping.
3306///
3307/// This removes no-op aggregate types wrapping an underlying type. It will
3308/// strip as many layers of types as it can without changing either the type
3309/// size or the allocated size.
3310static Type *stripAggregateTypeWrapping(const DataLayout &DL, Type *Ty) {
3311 if (Ty->isSingleValueType())
3312 return Ty;
3313
3314 uint64_t AllocSize = DL.getTypeAllocSize(Ty);
3315 uint64_t TypeSize = DL.getTypeSizeInBits(Ty);
3316
3317 Type *InnerTy;
3318 if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
3319 InnerTy = ArrTy->getElementType();
3320 } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
3321 const StructLayout *SL = DL.getStructLayout(STy);
3322 unsigned Index = SL->getElementContainingOffset(0);
3323 InnerTy = STy->getElementType(Index);
3324 } else {
3325 return Ty;
3326 }
3327
3328 if (AllocSize > DL.getTypeAllocSize(InnerTy) ||
3329 TypeSize > DL.getTypeSizeInBits(InnerTy))
3330 return Ty;
3331
3332 return stripAggregateTypeWrapping(DL, InnerTy);
3333}
3334
3335/// \brief Try to find a partition of the aggregate type passed in for a given
3336/// offset and size.
3337///
3338/// This recurses through the aggregate type and tries to compute a subtype
3339/// based on the offset and size. When the offset and size span a sub-section
3340/// of an array, it will even compute a new array type for that sub-section,
3341/// and the same for structs.
3342///
3343/// Note that this routine is very strict and tries to find a partition of the
3344/// type which produces the *exact* right offset and size. It is not forgiving
3345/// when the size or offset cause either end of type-based partition to be off.
3346/// Also, this is a best-effort routine. It is reasonable to give up and not
3347/// return a type if necessary.
3348static Type *getTypePartition(const DataLayout &DL, Type *Ty, uint64_t Offset,
3349 uint64_t Size) {
3350 if (Offset == 0 && DL.getTypeAllocSize(Ty) == Size)
3351 return stripAggregateTypeWrapping(DL, Ty);
3352 if (Offset > DL.getTypeAllocSize(Ty) ||
3353 (DL.getTypeAllocSize(Ty) - Offset) < Size)
3354 return nullptr;
3355
3356 if (SequentialType *SeqTy = dyn_cast<SequentialType>(Ty)) {
3357 Type *ElementTy = SeqTy->getElementType();
3358 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
3359 uint64_t NumSkippedElements = Offset / ElementSize;
3360 if (NumSkippedElements >= SeqTy->getNumElements())
3361 return nullptr;
3362 Offset -= NumSkippedElements * ElementSize;
3363
3364 // First check if we need to recurse.
3365 if (Offset > 0 || Size < ElementSize) {
3366 // Bail if the partition ends in a different array element.
3367 if ((Offset + Size) > ElementSize)
3368 return nullptr;
3369 // Recurse through the element type trying to peel off offset bytes.
3370 return getTypePartition(DL, ElementTy, Offset, Size);
3371 }
3372 assert(Offset == 0)(static_cast <bool> (Offset == 0) ? void (0) : __assert_fail
("Offset == 0", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3372, __extension__ __PRETTY_FUNCTION__))
;
3373
3374 if (Size == ElementSize)
3375 return stripAggregateTypeWrapping(DL, ElementTy);
3376 assert(Size > ElementSize)(static_cast <bool> (Size > ElementSize) ? void (0) :
__assert_fail ("Size > ElementSize", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3376, __extension__ __PRETTY_FUNCTION__))
;
3377 uint64_t NumElements = Size / ElementSize;
3378 if (NumElements * ElementSize != Size)
3379 return nullptr;
3380 return ArrayType::get(ElementTy, NumElements);
3381 }
3382
3383 StructType *STy = dyn_cast<StructType>(Ty);
3384 if (!STy)
3385 return nullptr;
3386
3387 const StructLayout *SL = DL.getStructLayout(STy);
3388 if (Offset >= SL->getSizeInBytes())
3389 return nullptr;
3390 uint64_t EndOffset = Offset + Size;
3391 if (EndOffset > SL->getSizeInBytes())
3392 return nullptr;
3393
3394 unsigned Index = SL->getElementContainingOffset(Offset);
3395 Offset -= SL->getElementOffset(Index);
3396
3397 Type *ElementTy = STy->getElementType(Index);
3398 uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
3399 if (Offset >= ElementSize)
3400 return nullptr; // The offset points into alignment padding.
3401
3402 // See if any partition must be contained by the element.
3403 if (Offset > 0 || Size < ElementSize) {
3404 if ((Offset + Size) > ElementSize)
3405 return nullptr;
3406 return getTypePartition(DL, ElementTy, Offset, Size);
3407 }
3408 assert(Offset == 0)(static_cast <bool> (Offset == 0) ? void (0) : __assert_fail
("Offset == 0", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3408, __extension__ __PRETTY_FUNCTION__))
;
3409
3410 if (Size == ElementSize)
3411 return stripAggregateTypeWrapping(DL, ElementTy);
3412
3413 StructType::element_iterator EI = STy->element_begin() + Index,
3414 EE = STy->element_end();
3415 if (EndOffset < SL->getSizeInBytes()) {
3416 unsigned EndIndex = SL->getElementContainingOffset(EndOffset);
3417 if (Index == EndIndex)
3418 return nullptr; // Within a single element and its padding.
3419
3420 // Don't try to form "natural" types if the elements don't line up with the
3421 // expected size.
3422 // FIXME: We could potentially recurse down through the last element in the
3423 // sub-struct to find a natural end point.
3424 if (SL->getElementOffset(EndIndex) != EndOffset)
3425 return nullptr;
3426
3427 assert(Index < EndIndex)(static_cast <bool> (Index < EndIndex) ? void (0) : __assert_fail
("Index < EndIndex", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3427, __extension__ __PRETTY_FUNCTION__))
;
3428 EE = STy->element_begin() + EndIndex;
3429 }
3430
3431 // Try to build up a sub-structure.
3432 StructType *SubTy =
3433 StructType::get(STy->getContext(), makeArrayRef(EI, EE), STy->isPacked());
3434 const StructLayout *SubSL = DL.getStructLayout(SubTy);
3435 if (Size != SubSL->getSizeInBytes())
3436 return nullptr; // The sub-struct doesn't have quite the size needed.
3437
3438 return SubTy;
3439}
3440
3441/// \brief Pre-split loads and stores to simplify rewriting.
3442///
3443/// We want to break up the splittable load+store pairs as much as
3444/// possible. This is important to do as a preprocessing step, as once we
3445/// start rewriting the accesses to partitions of the alloca we lose the
3446/// necessary information to correctly split apart paired loads and stores
3447/// which both point into this alloca. The case to consider is something like
3448/// the following:
3449///
3450/// %a = alloca [12 x i8]
3451/// %gep1 = getelementptr [12 x i8]* %a, i32 0, i32 0
3452/// %gep2 = getelementptr [12 x i8]* %a, i32 0, i32 4
3453/// %gep3 = getelementptr [12 x i8]* %a, i32 0, i32 8
3454/// %iptr1 = bitcast i8* %gep1 to i64*
3455/// %iptr2 = bitcast i8* %gep2 to i64*
3456/// %fptr1 = bitcast i8* %gep1 to float*
3457/// %fptr2 = bitcast i8* %gep2 to float*
3458/// %fptr3 = bitcast i8* %gep3 to float*
3459/// store float 0.0, float* %fptr1
3460/// store float 1.0, float* %fptr2
3461/// %v = load i64* %iptr1
3462/// store i64 %v, i64* %iptr2
3463/// %f1 = load float* %fptr2
3464/// %f2 = load float* %fptr3
3465///
3466/// Here we want to form 3 partitions of the alloca, each 4 bytes large, and
3467/// promote everything so we recover the 2 SSA values that should have been
3468/// there all along.
3469///
3470/// \returns true if any changes are made.
3471bool SROA::presplitLoadsAndStores(AllocaInst &AI, AllocaSlices &AS) {
3472 DEBUG(dbgs() << "Pre-splitting loads and stores\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Pre-splitting loads and stores\n"
; } } while (false)
;
3473
3474 // Track the loads and stores which are candidates for pre-splitting here, in
3475 // the order they first appear during the partition scan. These give stable
3476 // iteration order and a basis for tracking which loads and stores we
3477 // actually split.
3478 SmallVector<LoadInst *, 4> Loads;
3479 SmallVector<StoreInst *, 4> Stores;
3480
3481 // We need to accumulate the splits required of each load or store where we
3482 // can find them via a direct lookup. This is important to cross-check loads
3483 // and stores against each other. We also track the slice so that we can kill
3484 // all the slices that end up split.
3485 struct SplitOffsets {
3486 Slice *S;
3487 std::vector<uint64_t> Splits;
3488 };
3489 SmallDenseMap<Instruction *, SplitOffsets, 8> SplitOffsetsMap;
3490
3491 // Track loads out of this alloca which cannot, for any reason, be pre-split.
3492 // This is important as we also cannot pre-split stores of those loads!
3493 // FIXME: This is all pretty gross. It means that we can be more aggressive
3494 // in pre-splitting when the load feeding the store happens to come from
3495 // a separate alloca. Put another way, the effectiveness of SROA would be
3496 // decreased by a frontend which just concatenated all of its local allocas
3497 // into one big flat alloca. But defeating such patterns is exactly the job
3498 // SROA is tasked with! Sadly, to not have this discrepancy we would have
3499 // change store pre-splitting to actually force pre-splitting of the load
3500 // that feeds it *and all stores*. That makes pre-splitting much harder, but
3501 // maybe it would make it more principled?
3502 SmallPtrSet<LoadInst *, 8> UnsplittableLoads;
3503
3504 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)
;
3505 for (auto &P : AS.partitions()) {
3506 for (Slice &S : P) {
3507 Instruction *I = cast<Instruction>(S.getUse()->getUser());
3508 if (!S.isSplittable() || S.endOffset() <= P.endOffset()) {
3509 // If this is a load we have to track that it can't participate in any
3510 // pre-splitting. If this is a store of a load we have to track that
3511 // that load also can't participate in any pre-splitting.
3512 if (auto *LI = dyn_cast<LoadInst>(I))
3513 UnsplittableLoads.insert(LI);
3514 else if (auto *SI = dyn_cast<StoreInst>(I))
3515 if (auto *LI = dyn_cast<LoadInst>(SI->getValueOperand()))
3516 UnsplittableLoads.insert(LI);
3517 continue;
3518 }
3519 assert(P.endOffset() > S.beginOffset() &&(static_cast <bool> (P.endOffset() > S.beginOffset()
&& "Empty or backwards partition!") ? void (0) : __assert_fail
("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3520, __extension__ __PRETTY_FUNCTION__))
3520 "Empty or backwards partition!")(static_cast <bool> (P.endOffset() > S.beginOffset()
&& "Empty or backwards partition!") ? void (0) : __assert_fail
("P.endOffset() > S.beginOffset() && \"Empty or backwards partition!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3520, __extension__ __PRETTY_FUNCTION__))
;
3521
3522 // Determine if this is a pre-splittable slice.
3523 if (auto *LI = dyn_cast<LoadInst>(I)) {
3524 assert(!LI->isVolatile() && "Cannot split volatile loads!")(static_cast <bool> (!LI->isVolatile() && "Cannot split volatile loads!"
) ? void (0) : __assert_fail ("!LI->isVolatile() && \"Cannot split volatile loads!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3524, __extension__ __PRETTY_FUNCTION__))
;
3525
3526 // The load must be used exclusively to store into other pointers for
3527 // us to be able to arbitrarily pre-split it. The stores must also be
3528 // simple to avoid changing semantics.
3529 auto IsLoadSimplyStored = [](LoadInst *LI) {
3530 for (User *LU : LI->users()) {
3531 auto *SI = dyn_cast<StoreInst>(LU);
3532 if (!SI || !SI->isSimple())
3533 return false;
3534 }
3535 return true;
3536 };
3537 if (!IsLoadSimplyStored(LI)) {
3538 UnsplittableLoads.insert(LI);
3539 continue;
3540 }
3541
3542 Loads.push_back(LI);
3543 } else if (auto *SI = dyn_cast<StoreInst>(I)) {
3544 if (S.getUse() != &SI->getOperandUse(SI->getPointerOperandIndex()))
3545 // Skip stores *of* pointers. FIXME: This shouldn't even be possible!
3546 continue;
3547 auto *StoredLoad = dyn_cast<LoadInst>(SI->getValueOperand());
3548 if (!StoredLoad || !StoredLoad->isSimple())
3549 continue;
3550 assert(!SI->isVolatile() && "Cannot split volatile stores!")(static_cast <bool> (!SI->isVolatile() && "Cannot split volatile stores!"
) ? void (0) : __assert_fail ("!SI->isVolatile() && \"Cannot split volatile stores!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3550, __extension__ __PRETTY_FUNCTION__))
;
3551
3552 Stores.push_back(SI);
3553 } else {
3554 // Other uses cannot be pre-split.
3555 continue;
3556 }
3557
3558 // Record the initial split.
3559 DEBUG(dbgs() << " Candidate: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Candidate: " << *I <<
"\n"; } } while (false)
;
3560 auto &Offsets = SplitOffsetsMap[I];
3561 assert(Offsets.Splits.empty() &&(static_cast <bool> (Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? void (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3562, __extension__ __PRETTY_FUNCTION__))
3562 "Should not have splits the first time we see an instruction!")(static_cast <bool> (Offsets.Splits.empty() && "Should not have splits the first time we see an instruction!"
) ? void (0) : __assert_fail ("Offsets.Splits.empty() && \"Should not have splits the first time we see an instruction!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3562, __extension__ __PRETTY_FUNCTION__))
;
3563 Offsets.S = &S;
3564 Offsets.Splits.push_back(P.endOffset() - S.beginOffset());
3565 }
3566
3567 // Now scan the already split slices, and add a split for any of them which
3568 // we're going to pre-split.
3569 for (Slice *S : P.splitSliceTails()) {
3570 auto SplitOffsetsMapI =
3571 SplitOffsetsMap.find(cast<Instruction>(S->getUse()->getUser()));
3572 if (SplitOffsetsMapI == SplitOffsetsMap.end())
3573 continue;
3574 auto &Offsets = SplitOffsetsMapI->second;
3575
3576 assert(Offsets.S == S && "Found a mismatched slice!")(static_cast <bool> (Offsets.S == S && "Found a mismatched slice!"
) ? void (0) : __assert_fail ("Offsets.S == S && \"Found a mismatched slice!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3576, __extension__ __PRETTY_FUNCTION__))
;
3577 assert(!Offsets.Splits.empty() &&(static_cast <bool> (!Offsets.Splits.empty() &&
"Cannot have an empty set of splits on the second partition!"
) ? void (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3578, __extension__ __PRETTY_FUNCTION__))
3578 "Cannot have an empty set of splits on the second partition!")(static_cast <bool> (!Offsets.Splits.empty() &&
"Cannot have an empty set of splits on the second partition!"
) ? void (0) : __assert_fail ("!Offsets.Splits.empty() && \"Cannot have an empty set of splits on the second partition!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3578, __extension__ __PRETTY_FUNCTION__))
;
3579 assert(Offsets.Splits.back() ==(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? void (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3581, __extension__ __PRETTY_FUNCTION__))
3580 P.beginOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? void (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3581, __extension__ __PRETTY_FUNCTION__))
3581 "Previous split does not end where this one begins!")(static_cast <bool> (Offsets.Splits.back() == P.beginOffset
() - Offsets.S->beginOffset() && "Previous split does not end where this one begins!"
) ? void (0) : __assert_fail ("Offsets.Splits.back() == P.beginOffset() - Offsets.S->beginOffset() && \"Previous split does not end where this one begins!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3581, __extension__ __PRETTY_FUNCTION__))
;
3582
3583 // Record each split. The last partition's end isn't needed as the size
3584 // of the slice dictates that.
3585 if (S->endOffset() > P.endOffset())
3586 Offsets.Splits.push_back(P.endOffset() - Offsets.S->beginOffset());
3587 }
3588 }
3589
3590 // We may have split loads where some of their stores are split stores. For
3591 // such loads and stores, we can only pre-split them if their splits exactly
3592 // match relative to their starting offset. We have to verify this prior to
3593 // any rewriting.
3594 Stores.erase(
3595 llvm::remove_if(Stores,
3596 [&UnsplittableLoads, &SplitOffsetsMap](StoreInst *SI) {
3597 // Lookup the load we are storing in our map of split
3598 // offsets.
3599 auto *LI = cast<LoadInst>(SI->getValueOperand());
3600 // If it was completely unsplittable, then we're done,
3601 // and this store can't be pre-split.
3602 if (UnsplittableLoads.count(LI))
3603 return true;
3604
3605 auto LoadOffsetsI = SplitOffsetsMap.find(LI);
3606 if (LoadOffsetsI == SplitOffsetsMap.end())
3607 return false; // Unrelated loads are definitely safe.
3608 auto &LoadOffsets = LoadOffsetsI->second;
3609
3610 // Now lookup the store's offsets.
3611 auto &StoreOffsets = SplitOffsetsMap[SI];
3612
3613 // If the relative offsets of each split in the load and
3614 // store match exactly, then we can split them and we
3615 // don't need to remove them here.
3616 if (LoadOffsets.Splits == StoreOffsets.Splits)
3617 return false;
3618
3619 DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3620 << " 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)
3621 << " " << *LI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
3622 << " " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Mismatched splits for load and store:\n"
<< " " << *LI << "\n" << " "
<< *SI << "\n"; } } while (false)
;
3623
3624 // We've found a store and load that we need to split
3625 // with mismatched relative splits. Just give up on them
3626 // and remove both instructions from our list of
3627 // candidates.
3628 UnsplittableLoads.insert(LI);
3629 return true;
3630 }),
3631 Stores.end());
3632 // Now we have to go *back* through all the stores, because a later store may
3633 // have caused an earlier store's load to become unsplittable and if it is
3634 // unsplittable for the later store, then we can't rely on it being split in
3635 // the earlier store either.
3636 Stores.erase(llvm::remove_if(Stores,
3637 [&UnsplittableLoads](StoreInst *SI) {
3638 auto *LI =
3639 cast<LoadInst>(SI->getValueOperand());
3640 return UnsplittableLoads.count(LI);
3641 }),
3642 Stores.end());
3643 // Once we've established all the loads that can't be split for some reason,
3644 // filter any that made it into our list out.
3645 Loads.erase(llvm::remove_if(Loads,
3646 [&UnsplittableLoads](LoadInst *LI) {
3647 return UnsplittableLoads.count(LI);
3648 }),
3649 Loads.end());
3650
3651 // If no loads or stores are left, there is no pre-splitting to be done for
3652 // this alloca.
3653 if (Loads.empty() && Stores.empty())
3654 return false;
3655
3656 // From here on, we can't fail and will be building new accesses, so rig up
3657 // an IR builder.
3658 IRBuilderTy IRB(&AI);
3659
3660 // Collect the new slices which we will merge into the alloca slices.
3661 SmallVector<Slice, 4> NewSlices;
3662
3663 // Track any allocas we end up splitting loads and stores for so we iterate
3664 // on them.
3665 SmallPtrSet<AllocaInst *, 4> ResplitPromotableAllocas;
3666
3667 // At this point, we have collected all of the loads and stores we can
3668 // pre-split, and the specific splits needed for them. We actually do the
3669 // splitting in a specific order in order to handle when one of the loads in
3670 // the value operand to one of the stores.
3671 //
3672 // First, we rewrite all of the split loads, and just accumulate each split
3673 // load in a parallel structure. We also build the slices for them and append
3674 // them to the alloca slices.
3675 SmallDenseMap<LoadInst *, std::vector<LoadInst *>, 1> SplitLoadsMap;
3676 std::vector<LoadInst *> SplitLoads;
3677 const DataLayout &DL = AI.getModule()->getDataLayout();
3678 for (LoadInst *LI : Loads) {
3679 SplitLoads.clear();
3680
3681 IntegerType *Ty = cast<IntegerType>(LI->getType());
3682 uint64_t LoadSize = Ty->getBitWidth() / 8;
3683 assert(LoadSize > 0 && "Cannot have a zero-sized integer load!")(static_cast <bool> (LoadSize > 0 && "Cannot have a zero-sized integer load!"
) ? void (0) : __assert_fail ("LoadSize > 0 && \"Cannot have a zero-sized integer load!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3683, __extension__ __PRETTY_FUNCTION__))
;
3684
3685 auto &Offsets = SplitOffsetsMap[LI];
3686 assert(LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (LoadSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3687, __extension__ __PRETTY_FUNCTION__))
3687 "Slice size should always match load size exactly!")(static_cast <bool> (LoadSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3687, __extension__ __PRETTY_FUNCTION__))
;
3688 uint64_t BaseOffset = Offsets.S->beginOffset();
3689 assert(BaseOffset + LoadSize > BaseOffset &&(static_cast <bool> (BaseOffset + LoadSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3690, __extension__ __PRETTY_FUNCTION__))
3690 "Cannot represent alloca access size using 64-bit integers!")(static_cast <bool> (BaseOffset + LoadSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + LoadSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3690, __extension__ __PRETTY_FUNCTION__))
;
3691
3692 Instruction *BasePtr = cast<Instruction>(LI->getPointerOperand());
3693 IRB.SetInsertPoint(LI);
3694
3695 DEBUG(dbgs() << " Splitting load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting load: " << *LI
<< "\n"; } } while (false)
;
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 AS = LI->getPointerAddressSpace();
3702 auto *PartPtrTy = PartTy->getPointerTo(AS);
3703 LoadInst *PLoad = IRB.CreateAlignedLoad(
3704 getAdjustedPtr(IRB, DL, BasePtr,
3705 APInt(DL.getIndexSizeInBits(AS), PartOffset),
3706 PartPtrTy, BasePtr->getName() + "."),
3707 getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
3708 LI->getName());
3709 PLoad->copyMetadata(*LI, LLVMContext::MD_mem_parallel_loop_access);
3710
3711 // Append this load onto the list of split loads so we can find it later
3712 // to rewrite the stores.
3713 SplitLoads.push_back(PLoad);
3714
3715 // Now build a new slice for the alloca.
3716 NewSlices.push_back(
3717 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
3718 &PLoad->getOperandUse(PLoad->getPointerOperandIndex()),
3719 /*IsSplittable*/ false));
3720 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)
3721 << ", " << NewSlices.back().endOffset() << "): " << *PLoaddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
3722 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PLoad << "\n"; } }
while (false)
;
3723
3724 // See if we've handled all the splits.
3725 if (Idx >= Size)
3726 break;
3727
3728 // Setup the next partition.
3729 PartOffset = Offsets.Splits[Idx];
3730 ++Idx;
3731 PartSize = (Idx < Size ? Offsets.Splits[Idx] : LoadSize) - PartOffset;
3732 }
3733
3734 // Now that we have the split loads, do the slow walk over all uses of the
3735 // load and rewrite them as split stores, or save the split loads to use
3736 // below if the store is going to be split there anyways.
3737 bool DeferredStores = false;
3738 for (User *LU : LI->users()) {
3739 StoreInst *SI = cast<StoreInst>(LU);
3740 if (!Stores.empty() && SplitOffsetsMap.count(SI)) {
3741 DeferredStores = true;
3742 DEBUG(dbgs() << " Deferred splitting of store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Deferred splitting of store: "
<< *SI << "\n"; } } while (false)
;
3743 continue;
3744 }
3745
3746 Value *StoreBasePtr = SI->getPointerOperand();
3747 IRB.SetInsertPoint(SI);
3748
3749 DEBUG(dbgs() << " Splitting store of load: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store of load: " <<
*SI << "\n"; } } while (false)
;
3750
3751 for (int Idx = 0, Size = SplitLoads.size(); Idx < Size; ++Idx) {
3752 LoadInst *PLoad = SplitLoads[Idx];
3753 uint64_t PartOffset = Idx == 0 ? 0 : Offsets.Splits[Idx - 1];
3754 auto *PartPtrTy =
3755 PLoad->getType()->getPointerTo(SI->getPointerAddressSpace());
3756
3757 auto AS = SI->getPointerAddressSpace();
3758 StoreInst *PStore = IRB.CreateAlignedStore(
3759 PLoad,
3760 getAdjustedPtr(IRB, DL, StoreBasePtr,
3761 APInt(DL.getIndexSizeInBits(AS), PartOffset),
3762 PartPtrTy, StoreBasePtr->getName() + "."),
3763 getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
3764 PStore->copyMetadata(*LI, LLVMContext::MD_mem_parallel_loop_access);
3765 DEBUG(dbgs() << " +" << PartOffset << ":" << *PStore << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " +" << PartOffset <<
":" << *PStore << "\n"; } } while (false)
;
3766 }
3767
3768 // We want to immediately iterate on any allocas impacted by splitting
3769 // this store, and we have to track any promotable alloca (indicated by
3770 // a direct store) as needing to be resplit because it is no longer
3771 // promotable.
3772 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(StoreBasePtr)) {
3773 ResplitPromotableAllocas.insert(OtherAI);
3774 Worklist.insert(OtherAI);
3775 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
3776 StoreBasePtr->stripInBoundsOffsets())) {
3777 Worklist.insert(OtherAI);
3778 }
3779
3780 // Mark the original store as dead.
3781 DeadInsts.insert(SI);
3782 }
3783
3784 // Save the split loads if there are deferred stores among the users.
3785 if (DeferredStores)
3786 SplitLoadsMap.insert(std::make_pair(LI, std::move(SplitLoads)));
3787
3788 // Mark the original load as dead and kill the original slice.
3789 DeadInsts.insert(LI);
3790 Offsets.S->kill();
3791 }
3792
3793 // Second, we rewrite all of the split stores. At this point, we know that
3794 // all loads from this alloca have been split already. For stores of such
3795 // loads, we can simply look up the pre-existing split loads. For stores of
3796 // other loads, we split those loads first and then write split stores of
3797 // them.
3798 for (StoreInst *SI : Stores) {
3799 auto *LI = cast<LoadInst>(SI->getValueOperand());
3800 IntegerType *Ty = cast<IntegerType>(LI->getType());
3801 uint64_t StoreSize = Ty->getBitWidth() / 8;
3802 assert(StoreSize > 0 && "Cannot have a zero-sized integer store!")(static_cast <bool> (StoreSize > 0 && "Cannot have a zero-sized integer store!"
) ? void (0) : __assert_fail ("StoreSize > 0 && \"Cannot have a zero-sized integer store!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3802, __extension__ __PRETTY_FUNCTION__))
;
3803
3804 auto &Offsets = SplitOffsetsMap[SI];
3805 assert(StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&(static_cast <bool> (StoreSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3806, __extension__ __PRETTY_FUNCTION__))
3806 "Slice size should always match load size exactly!")(static_cast <bool> (StoreSize == Offsets.S->endOffset
() - Offsets.S->beginOffset() && "Slice size should always match load size exactly!"
) ? void (0) : __assert_fail ("StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() && \"Slice size should always match load size exactly!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3806, __extension__ __PRETTY_FUNCTION__))
;
3807 uint64_t BaseOffset = Offsets.S->beginOffset();
3808 assert(BaseOffset + StoreSize > BaseOffset &&(static_cast <bool> (BaseOffset + StoreSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3809, __extension__ __PRETTY_FUNCTION__))
3809 "Cannot represent alloca access size using 64-bit integers!")(static_cast <bool> (BaseOffset + StoreSize > BaseOffset
&& "Cannot represent alloca access size using 64-bit integers!"
) ? void (0) : __assert_fail ("BaseOffset + StoreSize > BaseOffset && \"Cannot represent alloca access size using 64-bit integers!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3809, __extension__ __PRETTY_FUNCTION__))
;
3810
3811 Value *LoadBasePtr = LI->getPointerOperand();
3812 Instruction *StoreBasePtr = cast<Instruction>(SI->getPointerOperand());
3813
3814 DEBUG(dbgs() << " Splitting store: " << *SI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Splitting store: " << *SI
<< "\n"; } } while (false)
;
3815
3816 // Check whether we have an already split load.
3817 auto SplitLoadsMapI = SplitLoadsMap.find(LI);
3818 std::vector<LoadInst *> *SplitLoads = nullptr;
3819 if (SplitLoadsMapI != SplitLoadsMap.end()) {
3820 SplitLoads = &SplitLoadsMapI->second;
3821 assert(SplitLoads->size() == Offsets.Splits.size() + 1 &&(static_cast <bool> (SplitLoads->size() == Offsets.Splits
.size() + 1 && "Too few split loads for the number of splits in the store!"
) ? void (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3822, __extension__ __PRETTY_FUNCTION__))
3822 "Too few split loads for the number of splits in the store!")(static_cast <bool> (SplitLoads->size() == Offsets.Splits
.size() + 1 && "Too few split loads for the number of splits in the store!"
) ? void (0) : __assert_fail ("SplitLoads->size() == Offsets.Splits.size() + 1 && \"Too few split loads for the number of splits in the store!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3822, __extension__ __PRETTY_FUNCTION__))
;
3823 } else {
3824 DEBUG(dbgs() << " of load: " << *LI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of load: " << *LI
<< "\n"; } } while (false)
;
3825 }
3826
3827 uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
3828 int Idx = 0, Size = Offsets.Splits.size();
3829 for (;;) {
3830 auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
3831 auto *LoadPartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
3832 auto *StorePartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
3833
3834 // Either lookup a split load or create one.
3835 LoadInst *PLoad;
3836 if (SplitLoads) {
3837 PLoad = (*SplitLoads)[Idx];
3838 } else {
3839 IRB.SetInsertPoint(LI);
3840 auto AS = LI->getPointerAddressSpace();
3841 PLoad = IRB.CreateAlignedLoad(
3842 getAdjustedPtr(IRB, DL, LoadBasePtr,
3843 APInt(DL.getIndexSizeInBits(AS), PartOffset),
3844 LoadPartPtrTy, LoadBasePtr->getName() + "."),
3845 getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
3846 LI->getName());
3847 }
3848
3849 // And store this partition.
3850 IRB.SetInsertPoint(SI);
3851 auto AS = SI->getPointerAddressSpace();
3852 StoreInst *PStore = IRB.CreateAlignedStore(
3853 PLoad,
3854 getAdjustedPtr(IRB, DL, StoreBasePtr,
3855 APInt(DL.getIndexSizeInBits(AS), PartOffset),
3856 StorePartPtrTy, StoreBasePtr->getName() + "."),
3857 getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
3858
3859 // Now build a new slice for the alloca.
3860 NewSlices.push_back(
3861 Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
3862 &PStore->getOperandUse(PStore->getPointerOperandIndex()),
3863 /*IsSplittable*/ false));
3864 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)
3865 << ", " << NewSlices.back().endOffset() << "): " << *PStoredo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
3866 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " new slice [" << NewSlices
.back().beginOffset() << ", " << NewSlices.back()
.endOffset() << "): " << *PStore << "\n"; }
} while (false)
;
3867 if (!SplitLoads) {
3868 DEBUG(dbgs() << " of split load: " << *PLoad << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " of split load: " << *
PLoad << "\n"; } } while (false)
;
3869 }
3870
3871 // See if we've finished all the splits.
3872 if (Idx >= Size)
3873 break;
3874
3875 // Setup the next partition.
3876 PartOffset = Offsets.Splits[Idx];
3877 ++Idx;
3878 PartSize = (Idx < Size ? Offsets.Splits[Idx] : StoreSize) - PartOffset;
3879 }
3880
3881 // We want to immediately iterate on any allocas impacted by splitting
3882 // this load, which is only relevant if it isn't a load of this alloca and
3883 // thus we didn't already split the loads above. We also have to keep track
3884 // of any promotable allocas we split loads on as they can no longer be
3885 // promoted.
3886 if (!SplitLoads) {
3887 if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(LoadBasePtr)) {
3888 assert(OtherAI != &AI && "We can't re-split our own alloca!")(static_cast <bool> (OtherAI != &AI && "We can't re-split our own alloca!"
) ? void (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3888, __extension__ __PRETTY_FUNCTION__))
;
3889 ResplitPromotableAllocas.insert(OtherAI);
3890 Worklist.insert(OtherAI);
3891 } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
3892 LoadBasePtr->stripInBoundsOffsets())) {
3893 assert(OtherAI != &AI && "We can't re-split our own alloca!")(static_cast <bool> (OtherAI != &AI && "We can't re-split our own alloca!"
) ? void (0) : __assert_fail ("OtherAI != &AI && \"We can't re-split our own alloca!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3893, __extension__ __PRETTY_FUNCTION__))
;
3894 Worklist.insert(OtherAI);
3895 }
3896 }
3897
3898 // Mark the original store as dead now that we've split it up and kill its
3899 // slice. Note that we leave the original load in place unless this store
3900 // was its only use. It may in turn be split up if it is an alloca load
3901 // for some other alloca, but it may be a normal load. This may introduce
3902 // redundant loads, but where those can be merged the rest of the optimizer
3903 // should handle the merging, and this uncovers SSA splits which is more
3904 // important. In practice, the original loads will almost always be fully
3905 // split and removed eventually, and the splits will be merged by any
3906 // trivial CSE, including instcombine.
3907 if (LI->hasOneUse()) {
3908 assert(*LI->user_begin() == SI && "Single use isn't this store!")(static_cast <bool> (*LI->user_begin() == SI &&
"Single use isn't this store!") ? void (0) : __assert_fail (
"*LI->user_begin() == SI && \"Single use isn't this store!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3908, __extension__ __PRETTY_FUNCTION__))
;
3909 DeadInsts.insert(LI);
3910 }
3911 DeadInsts.insert(SI);
3912 Offsets.S->kill();
3913 }
3914
3915 // Remove the killed slices that have ben pre-split.
3916 AS.erase(llvm::remove_if(AS, [](const Slice &S) { return S.isDead(); }),
3917 AS.end());
3918
3919 // Insert our new slices. This will sort and merge them into the sorted
3920 // sequence.
3921 AS.insert(NewSlices);
3922
3923 DEBUG(dbgs() << " Pre-split slices:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Pre-split slices:\n"; } } while
(false)
;
3924#ifndef NDEBUG
3925 for (auto I = AS.begin(), E = AS.end(); I != E; ++I)
3926 DEBUG(AS.print(dbgs(), I, " "))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs(), I, " "); } } while (false)
;
3927#endif
3928
3929 // Finally, don't try to promote any allocas that new require re-splitting.
3930 // They have already been added to the worklist above.
3931 PromotableAllocas.erase(
3932 llvm::remove_if(
3933 PromotableAllocas,
3934 [&](AllocaInst *AI) { return ResplitPromotableAllocas.count(AI); }),
3935 PromotableAllocas.end());
3936
3937 return true;
3938}
3939
3940/// \brief Rewrite an alloca partition's users.
3941///
3942/// This routine drives both of the rewriting goals of the SROA pass. It tries
3943/// to rewrite uses of an alloca partition to be conducive for SSA value
3944/// promotion. If the partition needs a new, more refined alloca, this will
3945/// build that new alloca, preserving as much type information as possible, and
3946/// rewrite the uses of the old alloca to point at the new one and have the
3947/// appropriate new offsets. It also evaluates how successful the rewrite was
3948/// at enabling promotion and if it was successful queues the alloca to be
3949/// promoted.
3950AllocaInst *SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS,
3951 Partition &P) {
3952 // Try to compute a friendly type for this partition of the alloca. This
3953 // won't always succeed, in which case we fall back to a legal integer type
3954 // or an i8 array of an appropriate size.
3955 Type *SliceTy = nullptr;
3956 const DataLayout &DL = AI.getModule()->getDataLayout();
3957 if (Type *CommonUseTy = findCommonType(P.begin(), P.end(), P.endOffset()))
3958 if (DL.getTypeAllocSize(CommonUseTy) >= P.size())
3959 SliceTy = CommonUseTy;
3960 if (!SliceTy)
3961 if (Type *TypePartitionTy = getTypePartition(DL, AI.getAllocatedType(),
3962 P.beginOffset(), P.size()))
3963 SliceTy = TypePartitionTy;
3964 if ((!SliceTy || (SliceTy->isArrayTy() &&
3965 SliceTy->getArrayElementType()->isIntegerTy())) &&
3966 DL.isLegalInteger(P.size() * 8))
3967 SliceTy = Type::getIntNTy(*C, P.size() * 8);
3968 if (!SliceTy)
3969 SliceTy = ArrayType::get(Type::getInt8Ty(*C), P.size());
3970 assert(DL.getTypeAllocSize(SliceTy) >= P.size())(static_cast <bool> (DL.getTypeAllocSize(SliceTy) >=
P.size()) ? void (0) : __assert_fail ("DL.getTypeAllocSize(SliceTy) >= P.size()"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 3970, __extension__ __PRETTY_FUNCTION__))
;
3971
3972 bool IsIntegerPromotable = isIntegerWideningViable(P, SliceTy, DL);
3973
3974 VectorType *VecTy =
3975 IsIntegerPromotable ? nullptr : isVectorPromotionViable(P, DL);
3976 if (VecTy)
3977 SliceTy = VecTy;
3978
3979 // Check for the case where we're going to rewrite to a new alloca of the
3980 // exact same type as the original, and with the same access offsets. In that
3981 // case, re-use the existing alloca, but still run through the rewriter to
3982 // perform phi and select speculation.
3983 // P.beginOffset() can be non-zero even with the same type in a case with
3984 // out-of-bounds access (e.g. @PR35657 function in SROA/basictest.ll).
3985 AllocaInst *NewAI;
3986 if (SliceTy == AI.getAllocatedType() && P.beginOffset() == 0) {
3987 NewAI = &AI;
3988 // FIXME: We should be able to bail at this point with "nothing changed".
3989 // FIXME: We might want to defer PHI speculation until after here.
3990 // FIXME: return nullptr;
3991 } else {
3992 unsigned Alignment = AI.getAlignment();
3993 if (!Alignment) {
3994 // The minimum alignment which users can rely on when the explicit
3995 // alignment is omitted or zero is that required by the ABI for this
3996 // type.
3997 Alignment = DL.getABITypeAlignment(AI.getAllocatedType());
3998 }
3999 Alignment = MinAlign(Alignment, P.beginOffset());
4000 // If we will get at least this much alignment from the type alone, leave
4001 // the alloca's alignment unconstrained.
4002 if (Alignment <= DL.getABITypeAlignment(SliceTy))
4003 Alignment = 0;
4004 NewAI = new AllocaInst(
4005 SliceTy, AI.getType()->getAddressSpace(), nullptr, Alignment,
4006 AI.getName() + ".sroa." + Twine(P.begin() - AS.begin()), &AI);
4007 ++NumNewAllocas;
4008 }
4009
4010 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)
4011 << "[" << P.beginOffset() << "," << P.endOffset()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
4012 << ") to: " << *NewAI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Rewriting alloca partition " <<
"[" << P.beginOffset() << "," << P.endOffset
() << ") to: " << *NewAI << "\n"; } } while
(false)
;
4013
4014 // Track the high watermark on the worklist as it is only relevant for
4015 // promoted allocas. We will reset it to this point if the alloca is not in
4016 // fact scheduled for promotion.
4017 unsigned PPWOldSize = PostPromotionWorklist.size();
4018 unsigned NumUses = 0;
4019 SmallSetVector<PHINode *, 8> PHIUsers;
4020 SmallSetVector<SelectInst *, 8> SelectUsers;
4021
4022 AllocaSliceRewriter Rewriter(DL, AS, *this, AI, *NewAI, P.beginOffset(),
4023 P.endOffset(), IsIntegerPromotable, VecTy,
4024 PHIUsers, SelectUsers);
4025 bool Promotable = true;
4026 for (Slice *S : P.splitSliceTails()) {
4027 Promotable &= Rewriter.visit(S);
4028 ++NumUses;
4029 }
4030 for (Slice &S : P) {
4031 Promotable &= Rewriter.visit(&S);
4032 ++NumUses;
4033 }
4034
4035 NumAllocaPartitionUses += NumUses;
4036 MaxUsesPerAllocaPartition.updateMax(NumUses);
4037
4038 // Now that we've processed all the slices in the new partition, check if any
4039 // PHIs or Selects would block promotion.
4040 for (PHINode *PHI : PHIUsers)
4041 if (!isSafePHIToSpeculate(*PHI)) {
4042 Promotable = false;
4043 PHIUsers.clear();
4044 SelectUsers.clear();
4045 break;
4046 }
4047
4048 for (SelectInst *Sel : SelectUsers)
4049 if (!isSafeSelectToSpeculate(*Sel)) {
4050 Promotable = false;
4051 PHIUsers.clear();
4052 SelectUsers.clear();
4053 break;
4054 }
4055
4056 if (Promotable) {
4057 if (PHIUsers.empty() && SelectUsers.empty()) {
4058 // Promote the alloca.
4059 PromotableAllocas.push_back(NewAI);
4060 } else {
4061 // If we have either PHIs or Selects to speculate, add them to those
4062 // worklists and re-queue the new alloca so that we promote in on the
4063 // next iteration.
4064 for (PHINode *PHIUser : PHIUsers)
4065 SpeculatablePHIs.insert(PHIUser);
4066 for (SelectInst *SelectUser : SelectUsers)
4067 SpeculatableSelects.insert(SelectUser);
4068 Worklist.insert(NewAI);
4069 }
4070 } else {
4071 // Drop any post-promotion work items if promotion didn't happen.
4072 while (PostPromotionWorklist.size() > PPWOldSize)
4073 PostPromotionWorklist.pop_back();
4074
4075 // We couldn't promote and we didn't create a new partition, nothing
4076 // happened.
4077 if (NewAI == &AI)
4078 return nullptr;
4079
4080 // If we can't promote the alloca, iterate on it to check for new
4081 // refinements exposed by splitting the current alloca. Don't iterate on an
4082 // alloca which didn't actually change and didn't get promoted.
4083 Worklist.insert(NewAI);
4084 }
4085
4086 return NewAI;
4087}
4088
4089/// \brief Walks the slices of an alloca and form partitions based on them,
4090/// rewriting each of their uses.
4091bool SROA::splitAlloca(AllocaInst &AI, AllocaSlices &AS) {
4092 if (AS.begin() == AS.end())
4093 return false;
4094
4095 unsigned NumPartitions = 0;
4096 bool Changed = false;
4097 const DataLayout &DL = AI.getModule()->getDataLayout();
4098
4099 // First try to pre-split loads and stores.
4100 Changed |= presplitLoadsAndStores(AI, AS);
4101
4102 // Now that we have identified any pre-splitting opportunities,
4103 // mark loads and stores unsplittable except for the following case.
4104 // We leave a slice splittable if all other slices are disjoint or fully
4105 // included in the slice, such as whole-alloca loads and stores.
4106 // If we fail to split these during pre-splitting, we want to force them
4107 // to be rewritten into a partition.
4108 bool IsSorted = true;
4109
4110 uint64_t AllocaSize = DL.getTypeAllocSize(AI.getAllocatedType());
4111 const uint64_t MaxBitVectorSize = 1024;
4112 if (AllocaSize <= MaxBitVectorSize) {
4113 // If a byte boundary is included in any load or store, a slice starting or
4114 // ending at the boundary is not splittable.
4115 SmallBitVector SplittableOffset(AllocaSize + 1, true);
4116 for (Slice &S : AS)
4117 for (unsigned O = S.beginOffset() + 1;
4118 O < S.endOffset() && O < AllocaSize; O++)
4119 SplittableOffset.reset(O);
4120
4121 for (Slice &S : AS) {
4122 if (!S.isSplittable())
4123 continue;
4124
4125 if ((S.beginOffset() > AllocaSize || SplittableOffset[S.beginOffset()]) &&
4126 (S.endOffset() > AllocaSize || SplittableOffset[S.endOffset()]))
4127 continue;
4128
4129 if (isa<LoadInst>(S.getUse()->getUser()) ||
4130 isa<StoreInst>(S.getUse()->getUser())) {
4131 S.makeUnsplittable();
4132 IsSorted = false;
4133 }
4134 }
4135 }
4136 else {
4137 // We only allow whole-alloca splittable loads and stores
4138 // for a large alloca to avoid creating too large BitVector.
4139 for (Slice &S : AS) {
4140 if (!S.isSplittable())
4141 continue;
4142
4143 if (S.beginOffset() == 0 && S.endOffset() >= AllocaSize)
4144 continue;
4145
4146 if (isa<LoadInst>(S.getUse()->getUser()) ||
4147 isa<StoreInst>(S.getUse()->getUser())) {
4148 S.makeUnsplittable();
4149 IsSorted = false;
4150 }
4151 }
4152 }
4153
4154 if (!IsSorted)
4155 std::sort(AS.begin(), AS.end());
4156
4157 /// Describes the allocas introduced by rewritePartition in order to migrate
4158 /// the debug info.
4159 struct Fragment {
4160 AllocaInst *Alloca;
4161 uint64_t Offset;
4162 uint64_t Size;
4163 Fragment(AllocaInst *AI, uint64_t O, uint64_t S)
4164 : Alloca(AI), Offset(O), Size(S) {}
4165 };
4166 SmallVector<Fragment, 4> Fragments;
4167
4168 // Rewrite each partition.
4169 for (auto &P : AS.partitions()) {
4170 if (AllocaInst *NewAI = rewritePartition(AI, AS, P)) {
4171 Changed = true;
4172 if (NewAI != &AI) {
4173 uint64_t SizeOfByte = 8;
4174 uint64_t AllocaSize = DL.getTypeSizeInBits(NewAI->getAllocatedType());
4175 // Don't include any padding.
4176 uint64_t Size = std::min(AllocaSize, P.size() * SizeOfByte);
4177 Fragments.push_back(Fragment(NewAI, P.beginOffset() * SizeOfByte, Size));
4178 }
4179 }
4180 ++NumPartitions;
4181 }
4182
4183 NumAllocaPartitions += NumPartitions;
4184 MaxPartitionsPerAlloca.updateMax(NumPartitions);
4185
4186 // Migrate debug information from the old alloca to the new alloca(s)
4187 // and the individual partitions.
4188 TinyPtrVector<DbgInfoIntrinsic *> DbgDeclares = FindDbgAddrUses(&AI);
4189 if (!DbgDeclares.empty()) {
4190 auto *Var = DbgDeclares.front()->getVariable();
4191 auto *Expr = DbgDeclares.front()->getExpression();
4192 auto VarSize = Var->getSizeInBits();
4193 DIBuilder DIB(*AI.getModule(), /*AllowUnresolved*/ false);
4194 uint64_t AllocaSize = DL.getTypeSizeInBits(AI.getAllocatedType());
4195 for (auto Fragment : Fragments) {
4196 // Create a fragment expression describing the new partition or reuse AI's
4197 // expression if there is only one partition.
4198 auto *FragmentExpr = Expr;
4199 if (Fragment.Size < AllocaSize || Expr->isFragment()) {
4200 // If this alloca is already a scalar replacement of a larger aggregate,
4201 // Fragment.Offset describes the offset inside the scalar.
4202 auto ExprFragment = Expr->getFragmentInfo();
4203 uint64_t Offset = ExprFragment ? ExprFragment->OffsetInBits : 0;
4204 uint64_t Start = Offset + Fragment.Offset;
4205 uint64_t Size = Fragment.Size;
4206 if (ExprFragment) {
4207 uint64_t AbsEnd =
4208 ExprFragment->OffsetInBits + ExprFragment->SizeInBits;
4209 if (Start >= AbsEnd)
4210 // No need to describe a SROAed padding.
4211 continue;
4212 Size = std::min(Size, AbsEnd - Start);
4213 }
4214 // The new, smaller fragment is stenciled out from the old fragment.
4215 if (auto OrigFragment = FragmentExpr->getFragmentInfo()) {
4216 assert(Start >= OrigFragment->OffsetInBits &&(static_cast <bool> (Start >= OrigFragment->OffsetInBits
&& "new fragment is outside of original fragment") ?
void (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 4217, __extension__ __PRETTY_FUNCTION__))
4217 "new fragment is outside of original fragment")(static_cast <bool> (Start >= OrigFragment->OffsetInBits
&& "new fragment is outside of original fragment") ?
void (0) : __assert_fail ("Start >= OrigFragment->OffsetInBits && \"new fragment is outside of original fragment\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Transforms/Scalar/SROA.cpp"
, 4217, __extension__ __PRETTY_FUNCTION__))
;
4218 Start -= OrigFragment->OffsetInBits;
4219 }
4220
4221 // The alloca may be larger than the variable.
4222 if (VarSize) {
4223 if (Size > *VarSize)
4224 Size = *VarSize;
4225 if (Size == 0 || Start + Size > *VarSize)
4226 continue;
4227 }
4228
4229 // Avoid creating a fragment expression that covers the entire variable.
4230 if (!VarSize || *VarSize != Size) {
4231 if (auto E =
4232 DIExpression::createFragmentExpression(Expr, Start, Size))
4233 FragmentExpr = *E;
4234 else
4235 continue;
4236 }
4237 }
4238
4239 // Remove any existing intrinsics describing the same alloca.
4240 for (DbgInfoIntrinsic *OldDII : FindDbgAddrUses(Fragment.Alloca))
4241 OldDII->eraseFromParent();
4242
4243 DIB.insertDeclare(Fragment.Alloca, Var, FragmentExpr,
4244 DbgDeclares.front()->getDebugLoc(), &AI);
4245 }
4246 }
4247 return Changed;
4248}
4249
4250/// \brief Clobber a use with undef, deleting the used value if it becomes dead.
4251void SROA::clobberUse(Use &U) {
4252 Value *OldV = U;
4253 // Replace the use with an undef value.
4254 U = UndefValue::get(OldV->getType());
4255
4256 // Check for this making an instruction dead. We have to garbage collect
4257 // all the dead instructions to ensure the uses of any alloca end up being
4258 // minimal.
4259 if (Instruction *OldI = dyn_cast<Instruction>(OldV))
4260 if (isInstructionTriviallyDead(OldI)) {
4261 DeadInsts.insert(OldI);
4262 }
4263}
4264
4265/// \brief Analyze an alloca for SROA.
4266///
4267/// This analyzes the alloca to ensure we can reason about it, builds
4268/// the slices of the alloca, and then hands it off to be split and
4269/// rewritten as needed.
4270bool SROA::runOnAlloca(AllocaInst &AI) {
4271 DEBUG(dbgs() << "SROA alloca: " << AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA alloca: " << AI <<
"\n"; } } while (false)
;
4272 ++NumAllocasAnalyzed;
4273
4274 // Special case dead allocas, as they're trivial.
4275 if (AI.use_empty()) {
4276 AI.eraseFromParent();
4277 return true;
4278 }
4279 const DataLayout &DL = AI.getModule()->getDataLayout();
4280
4281 // Skip alloca forms that this analysis can't handle.
4282 if (AI.isArrayAllocation() || !AI.getAllocatedType()->isSized() ||
4283 DL.getTypeAllocSize(AI.getAllocatedType()) == 0)
4284 return false;
4285
4286 bool Changed = false;
4287
4288 // First, split any FCA loads and stores touching this alloca to promote
4289 // better splitting and promotion opportunities.
4290 AggLoadStoreRewriter AggRewriter;
4291 Changed |= AggRewriter.rewrite(AI);
4292
4293 // Build the slices using a recursive instruction-visiting builder.
4294 AllocaSlices AS(DL, AI);
4295 DEBUG(AS.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { AS.print(dbgs()); } } while (false)
;
4296 if (AS.isEscaped())
4297 return Changed;
4298
4299 // Delete all the dead users of this alloca before splitting and rewriting it.
4300 for (Instruction *DeadUser : AS.getDeadUsers()) {
4301 // Free up everything used by this instruction.
4302 for (Use &DeadOp : DeadUser->operands())
4303 clobberUse(DeadOp);
4304
4305 // Now replace the uses of this instruction.
4306 DeadUser->replaceAllUsesWith(UndefValue::get(DeadUser->getType()));
4307
4308 // And mark it for deletion.
4309 DeadInsts.insert(DeadUser);
4310 Changed = true;
4311 }
4312 for (Use *DeadOp : AS.getDeadOperands()) {
4313 clobberUse(*DeadOp);
4314 Changed = true;
4315 }
4316
4317 // No slices to split. Leave the dead alloca for a later pass to clean up.
4318 if (AS.begin() == AS.end())
4319 return Changed;
4320
4321 Changed |= splitAlloca(AI, AS);
4322
4323 DEBUG(dbgs() << " Speculating PHIs\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating PHIs\n"; } } while
(false)
;
4324 while (!SpeculatablePHIs.empty())
4325 speculatePHINodeLoads(*SpeculatablePHIs.pop_back_val());
4326
4327 DEBUG(dbgs() << " Speculating Selects\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << " Speculating Selects\n"; } } while
(false)
;
4328 while (!SpeculatableSelects.empty())
4329 speculateSelectInstLoads(*SpeculatableSelects.pop_back_val());
4330
4331 return Changed;
4332}
4333
4334/// \brief Delete the dead instructions accumulated in this run.
4335///
4336/// Recursively deletes the dead instructions we've accumulated. This is done
4337/// at the very end to maximize locality of the recursive delete and to
4338/// minimize the problems of invalidated instruction pointers as such pointers
4339/// are used heavily in the intermediate stages of the algorithm.
4340///
4341/// We also record the alloca instructions deleted here so that they aren't
4342/// subsequently handed to mem2reg to promote.
4343bool SROA::deleteDeadInstructions(
4344 SmallPtrSetImpl<AllocaInst *> &DeletedAllocas) {
4345 bool Changed = false;
4346 while (!DeadInsts.empty()) {
4347 Instruction *I = DeadInsts.pop_back_val();
4348 DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Deleting dead instruction: " <<
*I << "\n"; } } while (false)
;
4349
4350 // If the instruction is an alloca, find the possible dbg.declare connected
4351 // to it, and remove it too. We must do this before calling RAUW or we will
4352 // not be able to find it.
4353 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
4354 DeletedAllocas.insert(AI);
4355 for (DbgInfoIntrinsic *OldDII : FindDbgAddrUses(AI))
4356 OldDII->eraseFromParent();
4357 }
4358
4359 I->replaceAllUsesWith(UndefValue::get(I->getType()));
4360
4361 for (Use &Operand : I->operands())
4362 if (Instruction *U = dyn_cast<Instruction>(Operand)) {
4363 // Zero out the operand and see if it becomes trivially dead.
4364 Operand = nullptr;
4365 if (isInstructionTriviallyDead(U))
4366 DeadInsts.insert(U);
4367 }
4368
4369 ++NumDeleted;
4370 I->eraseFromParent();
4371 Changed = true;
4372 }
4373 return Changed;
4374}
4375
4376/// \brief Promote the allocas, using the best available technique.
4377///
4378/// This attempts to promote whatever allocas have been identified as viable in
4379/// the PromotableAllocas list. If that list is empty, there is nothing to do.
4380/// This function returns whether any promotion occurred.
4381bool SROA::promoteAllocas(Function &F) {
4382 if (PromotableAllocas.empty())
4383 return false;
4384
4385 NumPromoted += PromotableAllocas.size();
4386
4387 DEBUG(dbgs() << "Promoting allocas with mem2reg...\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "Promoting allocas with mem2reg...\n"
; } } while (false)
;
4388 PromoteMemToReg(PromotableAllocas, *DT, AC);
4389 PromotableAllocas.clear();
4390 return true;
4391}
4392
4393PreservedAnalyses SROA::runImpl(Function &F, DominatorTree &RunDT,
4394 AssumptionCache &RunAC) {
4395 DEBUG(dbgs() << "SROA function: " << F.getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("sroa")) { dbgs() << "SROA function: " << F.getName
() << "\n"; } } while (false)
;
4396 C = &F.getContext();
4397 DT = &RunDT;
4398 AC = &RunAC;
4399
4400 BasicBlock &EntryBB = F.getEntryBlock();
4401 for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
4402 I != E; ++I) {
4403 if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
4404 Worklist.insert(AI);
4405 }
4406
4407 bool Changed = false;
4408 // A set of deleted alloca instruction pointers which should be removed from
4409 // the list of promotable allocas.
4410 SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
4411
4412 do {
4413 while (!Worklist.empty()) {
4414 Changed |= runOnAlloca(*Worklist.pop_back_val());
4415 Changed |= deleteDeadInstructions(DeletedAllocas);
4416
4417 // Remove the deleted allocas from various lists so that we don't try to
4418 // continue processing them.
4419 if (!DeletedAllocas.empty()) {
4420 auto IsInSet = [&](AllocaInst *AI) { return DeletedAllocas.count(AI); };
4421 Worklist.remove_if(IsInSet);
4422 PostPromotionWorklist.remove_if(IsInSet);
4423 PromotableAllocas.erase(llvm::remove_if(PromotableAllocas, IsInSet),
4424 PromotableAllocas.end());
4425 DeletedAllocas.clear();
4426 }
4427 }
4428
4429 Changed |= promoteAllocas(F);
4430
4431 Worklist = PostPromotionWorklist;
4432 PostPromotionWorklist.clear();
4433 } while (!Worklist.empty());
4434
4435 if (!Changed)
4436 return PreservedAnalyses::all();
4437
4438 PreservedAnalyses PA;
4439 PA.preserveSet<CFGAnalyses>();
4440 PA.preserve<GlobalsAA>();
4441 return PA;
4442}
4443
4444PreservedAnalyses SROA::run(Function &F, FunctionAnalysisManager &AM) {
4445 return runImpl(F, AM.getResult<DominatorTreeAnalysis>(F),
4446 AM.getResult<AssumptionAnalysis>(F));
4447}
4448
4449/// A legacy pass for the legacy pass manager that wraps the \c SROA pass.
4450///
4451/// This is in the llvm namespace purely to allow it to be a friend of the \c
4452/// SROA pass.
4453class llvm::sroa::SROALegacyPass : public FunctionPass {
4454 /// The SROA implementation.
4455 SROA Impl;
4456
4457public:
4458 static char ID;
4459
4460 SROALegacyPass() : FunctionPass(ID) {
4461 initializeSROALegacyPassPass(*PassRegistry::getPassRegistry());
4462 }
4463
4464 bool runOnFunction(Function &F) override {
4465 if (skipFunction(F))
4466 return false;
4467
4468 auto PA = Impl.runImpl(
4469 F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
4470 getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F));
4471 return !PA.areAllPreserved();
4472 }
4473
4474 void getAnalysisUsage(AnalysisUsage &AU) const override {
4475 AU.addRequired<AssumptionCacheTracker>();
4476 AU.addRequired<DominatorTreeWrapperPass>();
4477 AU.addPreserved<GlobalsAAWrapperPass>();
4478 AU.setPreservesCFG();
4479 }
4480
4481 StringRef getPassName() const override { return "SROA"; }
4482};
4483
4484char SROALegacyPass::ID = 0;
4485
4486FunctionPass *llvm::createSROAPass() { return new SROALegacyPass(); }
4487
4488INITIALIZE_PASS_BEGIN(SROALegacyPass, "sroa",static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4489 "Scalar Replacement Of Aggregates", false, false)static void *initializeSROALegacyPassPassOnce(PassRegistry &
Registry) {
4490INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry);
4491INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
4492INITIALIZE_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)); }
4493 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)); }