Bug Summary

File:lib/Analysis/MemorySSA.cpp
Warning:line 879, column 37
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 MemorySSA.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~svn373386/build-llvm/lib/Analysis -I /build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis -I /build/llvm-toolchain-snapshot-10~svn373386/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn373386/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/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++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~svn373386/build-llvm/lib/Analysis -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn373386=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-10-02-042503-23017-1 -x c++ /build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp

/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp

→
1//===- MemorySSA.cpp - Memory SSA Builder ---------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the MemorySSA class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/Analysis/MemorySSA.h"
14#include "llvm/ADT/DenseMap.h"
15#include "llvm/ADT/DenseMapInfo.h"
16#include "llvm/ADT/DenseSet.h"
17#include "llvm/ADT/DepthFirstIterator.h"
18#include "llvm/ADT/Hashing.h"
19#include "llvm/ADT/None.h"
20#include "llvm/ADT/Optional.h"
21#include "llvm/ADT/STLExtras.h"
22#include "llvm/ADT/SmallPtrSet.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/ADT/iterator.h"
25#include "llvm/ADT/iterator_range.h"
26#include "llvm/Analysis/AliasAnalysis.h"
27#include "llvm/Analysis/IteratedDominanceFrontier.h"
28#include "llvm/Analysis/MemoryLocation.h"
29#include "llvm/Config/llvm-config.h"
30#include "llvm/IR/AssemblyAnnotationWriter.h"
31#include "llvm/IR/BasicBlock.h"
32#include "llvm/IR/Dominators.h"
33#include "llvm/IR/Function.h"
34#include "llvm/IR/Instruction.h"
35#include "llvm/IR/Instructions.h"
36#include "llvm/IR/IntrinsicInst.h"
37#include "llvm/IR/Intrinsics.h"
38#include "llvm/IR/LLVMContext.h"
39#include "llvm/IR/PassManager.h"
40#include "llvm/IR/Use.h"
41#include "llvm/Pass.h"
42#include "llvm/Support/AtomicOrdering.h"
43#include "llvm/Support/Casting.h"
44#include "llvm/Support/CommandLine.h"
45#include "llvm/Support/Compiler.h"
46#include "llvm/Support/Debug.h"
47#include "llvm/Support/ErrorHandling.h"
48#include "llvm/Support/FormattedStream.h"
49#include "llvm/Support/raw_ostream.h"
50#include <algorithm>
51#include <cassert>
52#include <cstdlib>
53#include <iterator>
54#include <memory>
55#include <utility>
56
57using namespace llvm;
58
59#define DEBUG_TYPE"memoryssa" "memoryssa"
60
61INITIALIZE_PASS_BEGIN(MemorySSAWrapperPass, "memoryssa", "Memory SSA", false,static void *initializeMemorySSAWrapperPassPassOnce(PassRegistry
&Registry) {
62 true)static void *initializeMemorySSAWrapperPassPassOnce(PassRegistry
&Registry) {
63INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry);
64INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry);
65INITIALIZE_PASS_END(MemorySSAWrapperPass, "memoryssa", "Memory SSA", false,PassInfo *PI = new PassInfo( "Memory SSA", "memoryssa", &
MemorySSAWrapperPass::ID, PassInfo::NormalCtor_t(callDefaultCtor
<MemorySSAWrapperPass>), false, true); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeMemorySSAWrapperPassPassFlag
; void llvm::initializeMemorySSAWrapperPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySSAWrapperPassPassFlag
, initializeMemorySSAWrapperPassPassOnce, std::ref(Registry))
; }
66 true)PassInfo *PI = new PassInfo( "Memory SSA", "memoryssa", &
MemorySSAWrapperPass::ID, PassInfo::NormalCtor_t(callDefaultCtor
<MemorySSAWrapperPass>), false, true); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeMemorySSAWrapperPassPassFlag
; void llvm::initializeMemorySSAWrapperPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySSAWrapperPassPassFlag
, initializeMemorySSAWrapperPassPassOnce, std::ref(Registry))
; }
67
68INITIALIZE_PASS_BEGIN(MemorySSAPrinterLegacyPass, "print-memoryssa",static void *initializeMemorySSAPrinterLegacyPassPassOnce(PassRegistry
&Registry) {
69 "Memory SSA Printer", false, false)static void *initializeMemorySSAPrinterLegacyPassPassOnce(PassRegistry
&Registry) {
70INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)initializeMemorySSAWrapperPassPass(Registry);
71INITIALIZE_PASS_END(MemorySSAPrinterLegacyPass, "print-memoryssa",PassInfo *PI = new PassInfo( "Memory SSA Printer", "print-memoryssa"
, &MemorySSAPrinterLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<MemorySSAPrinterLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeMemorySSAPrinterLegacyPassPassFlag; void
llvm::initializeMemorySSAPrinterLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySSAPrinterLegacyPassPassFlag
, initializeMemorySSAPrinterLegacyPassPassOnce, std::ref(Registry
)); }
72 "Memory SSA Printer", false, false)PassInfo *PI = new PassInfo( "Memory SSA Printer", "print-memoryssa"
, &MemorySSAPrinterLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<MemorySSAPrinterLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeMemorySSAPrinterLegacyPassPassFlag; void
llvm::initializeMemorySSAPrinterLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySSAPrinterLegacyPassPassFlag
, initializeMemorySSAPrinterLegacyPassPassOnce, std::ref(Registry
)); }
73
74static cl::opt<unsigned> MaxCheckLimit(
75 "memssa-check-limit", cl::Hidden, cl::init(100),
76 cl::desc("The maximum number of stores/phis MemorySSA"
77 "will consider trying to walk past (default = 100)"));
78
79// Always verify MemorySSA if expensive checking is enabled.
80#ifdef EXPENSIVE_CHECKS
81bool llvm::VerifyMemorySSA = true;
82#else
83bool llvm::VerifyMemorySSA = false;
84#endif
85/// Enables memory ssa as a dependency for loop passes in legacy pass manager.
86cl::opt<bool> llvm::EnableMSSALoopDependency(
87 "enable-mssa-loop-dependency", cl::Hidden, cl::init(true),
88 cl::desc("Enable MemorySSA dependency for loop pass manager"));
89
90static cl::opt<bool, true>
91 VerifyMemorySSAX("verify-memoryssa", cl::location(VerifyMemorySSA),
92 cl::Hidden, cl::desc("Enable verification of MemorySSA."));
93
94namespace llvm {
95
96/// An assembly annotator class to print Memory SSA information in
97/// comments.
98class MemorySSAAnnotatedWriter : public AssemblyAnnotationWriter {
99 friend class MemorySSA;
100
101 const MemorySSA *MSSA;
102
103public:
104 MemorySSAAnnotatedWriter(const MemorySSA *M) : MSSA(M) {}
105
106 void emitBasicBlockStartAnnot(const BasicBlock *BB,
107 formatted_raw_ostream &OS) override {
108 if (MemoryAccess *MA = MSSA->getMemoryAccess(BB))
109 OS << "; " << *MA << "\n";
110 }
111
112 void emitInstructionAnnot(const Instruction *I,
113 formatted_raw_ostream &OS) override {
114 if (MemoryAccess *MA = MSSA->getMemoryAccess(I))
115 OS << "; " << *MA << "\n";
116 }
117};
118
119} // end namespace llvm
120
121namespace {
122
123/// Our current alias analysis API differentiates heavily between calls and
124/// non-calls, and functions called on one usually assert on the other.
125/// This class encapsulates the distinction to simplify other code that wants
126/// "Memory affecting instructions and related data" to use as a key.
127/// For example, this class is used as a densemap key in the use optimizer.
128class MemoryLocOrCall {
129public:
130 bool IsCall = false;
131
132 MemoryLocOrCall(MemoryUseOrDef *MUD)
133 : MemoryLocOrCall(MUD->getMemoryInst()) {}
134 MemoryLocOrCall(const MemoryUseOrDef *MUD)
135 : MemoryLocOrCall(MUD->getMemoryInst()) {}
136
137 MemoryLocOrCall(Instruction *Inst) {
138 if (auto *C = dyn_cast<CallBase>(Inst)) {
139 IsCall = true;
140 Call = C;
141 } else {
142 IsCall = false;
143 // There is no such thing as a memorylocation for a fence inst, and it is
144 // unique in that regard.
145 if (!isa<FenceInst>(Inst))
146 Loc = MemoryLocation::get(Inst);
147 }
148 }
149
150 explicit MemoryLocOrCall(const MemoryLocation &Loc) : Loc(Loc) {}
151
152 const CallBase *getCall() const {
153 assert(IsCall)((IsCall) ? static_cast<void> (0) : __assert_fail ("IsCall"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 153, __PRETTY_FUNCTION__));
154 return Call;
155 }
156
157 MemoryLocation getLoc() const {
158 assert(!IsCall)((!IsCall) ? static_cast<void> (0) : __assert_fail ("!IsCall"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 158, __PRETTY_FUNCTION__));
159 return Loc;
160 }
161
162 bool operator==(const MemoryLocOrCall &Other) const {
163 if (IsCall != Other.IsCall)
164 return false;
165
166 if (!IsCall)
167 return Loc == Other.Loc;
168
169 if (Call->getCalledValue() != Other.Call->getCalledValue())
170 return false;
171
172 return Call->arg_size() == Other.Call->arg_size() &&
173 std::equal(Call->arg_begin(), Call->arg_end(),
174 Other.Call->arg_begin());
175 }
176
177private:
178 union {
179 const CallBase *Call;
180 MemoryLocation Loc;
181 };
182};
183
184} // end anonymous namespace
185
186namespace llvm {
187
188template <> struct DenseMapInfo<MemoryLocOrCall> {
189 static inline MemoryLocOrCall getEmptyKey() {
190 return MemoryLocOrCall(DenseMapInfo<MemoryLocation>::getEmptyKey());
191 }
192
193 static inline MemoryLocOrCall getTombstoneKey() {
194 return MemoryLocOrCall(DenseMapInfo<MemoryLocation>::getTombstoneKey());
195 }
196
197 static unsigned getHashValue(const MemoryLocOrCall &MLOC) {
198 if (!MLOC.IsCall)
199 return hash_combine(
200 MLOC.IsCall,
201 DenseMapInfo<MemoryLocation>::getHashValue(MLOC.getLoc()));
202
203 hash_code hash =
204 hash_combine(MLOC.IsCall, DenseMapInfo<const Value *>::getHashValue(
205 MLOC.getCall()->getCalledValue()));
206
207 for (const Value *Arg : MLOC.getCall()->args())
208 hash = hash_combine(hash, DenseMapInfo<const Value *>::getHashValue(Arg));
209 return hash;
210 }
211
212 static bool isEqual(const MemoryLocOrCall &LHS, const MemoryLocOrCall &RHS) {
213 return LHS == RHS;
214 }
215};
216
217} // end namespace llvm
218
219/// This does one-way checks to see if Use could theoretically be hoisted above
220/// MayClobber. This will not check the other way around.
221///
222/// This assumes that, for the purposes of MemorySSA, Use comes directly after
223/// MayClobber, with no potentially clobbering operations in between them.
224/// (Where potentially clobbering ops are memory barriers, aliased stores, etc.)
225static bool areLoadsReorderable(const LoadInst *Use,
226 const LoadInst *MayClobber) {
227 bool VolatileUse = Use->isVolatile();
228 bool VolatileClobber = MayClobber->isVolatile();
229 // Volatile operations may never be reordered with other volatile operations.
230 if (VolatileUse && VolatileClobber)
231 return false;
232 // Otherwise, volatile doesn't matter here. From the language reference:
233 // 'optimizers may change the order of volatile operations relative to
234 // non-volatile operations.'"
235
236 // If a load is seq_cst, it cannot be moved above other loads. If its ordering
237 // is weaker, it can be moved above other loads. We just need to be sure that
238 // MayClobber isn't an acquire load, because loads can't be moved above
239 // acquire loads.
240 //
241 // Note that this explicitly *does* allow the free reordering of monotonic (or
242 // weaker) loads of the same address.
243 bool SeqCstUse = Use->getOrdering() == AtomicOrdering::SequentiallyConsistent;
244 bool MayClobberIsAcquire = isAtLeastOrStrongerThan(MayClobber->getOrdering(),
245 AtomicOrdering::Acquire);
246 return !(SeqCstUse || MayClobberIsAcquire);
247}
248
249namespace {
250
251struct ClobberAlias {
252 bool IsClobber;
253 Optional<AliasResult> AR;
254};
255
256} // end anonymous namespace
257
258// Return a pair of {IsClobber (bool), AR (AliasResult)}. It relies on AR being
259// ignored if IsClobber = false.
260template <typename AliasAnalysisType>
261static ClobberAlias
262instructionClobbersQuery(const MemoryDef *MD, const MemoryLocation &UseLoc,
263 const Instruction *UseInst, AliasAnalysisType &AA) {
264 Instruction *DefInst = MD->getMemoryInst();
265 assert(DefInst && "Defining instruction not actually an instruction")((DefInst && "Defining instruction not actually an instruction"
) ? static_cast<void> (0) : __assert_fail ("DefInst && \"Defining instruction not actually an instruction\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 265, __PRETTY_FUNCTION__));
266 const auto *UseCall = dyn_cast<CallBase>(UseInst);
267 Optional<AliasResult> AR;
268
269 if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(DefInst)) {
270 // These intrinsics will show up as affecting memory, but they are just
271 // markers, mostly.
272 //
273 // FIXME: We probably don't actually want MemorySSA to model these at all
274 // (including creating MemoryAccesses for them): we just end up inventing
275 // clobbers where they don't really exist at all. Please see D43269 for
276 // context.
277 switch (II->getIntrinsicID()) {
278 case Intrinsic::lifetime_start:
279 if (UseCall)
280 return {false, NoAlias};
281 AR = AA.alias(MemoryLocation(II->getArgOperand(1)), UseLoc);
282 return {AR != NoAlias, AR};
283 case Intrinsic::lifetime_end:
284 case Intrinsic::invariant_start:
285 case Intrinsic::invariant_end:
286 case Intrinsic::assume:
287 return {false, NoAlias};
288 case Intrinsic::dbg_addr:
289 case Intrinsic::dbg_declare:
290 case Intrinsic::dbg_label:
291 case Intrinsic::dbg_value:
292 llvm_unreachable("debuginfo shouldn't have associated defs!")::llvm::llvm_unreachable_internal("debuginfo shouldn't have associated defs!"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 292);
293 default:
294 break;
295 }
296 }
297
298 if (UseCall) {
299 ModRefInfo I = AA.getModRefInfo(DefInst, UseCall);
300 AR = isMustSet(I) ? MustAlias : MayAlias;
301 return {isModOrRefSet(I), AR};
302 }
303
304 if (auto *DefLoad = dyn_cast<LoadInst>(DefInst))
305 if (auto *UseLoad = dyn_cast<LoadInst>(UseInst))
306 return {!areLoadsReorderable(UseLoad, DefLoad), MayAlias};
307
308 ModRefInfo I = AA.getModRefInfo(DefInst, UseLoc);
309 AR = isMustSet(I) ? MustAlias : MayAlias;
310 return {isModSet(I), AR};
311}
312
313template <typename AliasAnalysisType>
314static ClobberAlias instructionClobbersQuery(MemoryDef *MD,
315 const MemoryUseOrDef *MU,
316 const MemoryLocOrCall &UseMLOC,
317 AliasAnalysisType &AA) {
318 // FIXME: This is a temporary hack to allow a single instructionClobbersQuery
319 // to exist while MemoryLocOrCall is pushed through places.
320 if (UseMLOC.IsCall)
321 return instructionClobbersQuery(MD, MemoryLocation(), MU->getMemoryInst(),
322 AA);
323 return instructionClobbersQuery(MD, UseMLOC.getLoc(), MU->getMemoryInst(),
324 AA);
325}
326
327// Return true when MD may alias MU, return false otherwise.
328bool MemorySSAUtil::defClobbersUseOrDef(MemoryDef *MD, const MemoryUseOrDef *MU,
329 AliasAnalysis &AA) {
330 return instructionClobbersQuery(MD, MU, MemoryLocOrCall(MU), AA).IsClobber;
331}
332
333namespace {
334
335struct UpwardsMemoryQuery {
336 // True if our original query started off as a call
337 bool IsCall = false;
338 // The pointer location we started the query with. This will be empty if
339 // IsCall is true.
340 MemoryLocation StartingLoc;
341 // This is the instruction we were querying about.
342 const Instruction *Inst = nullptr;
343 // The MemoryAccess we actually got called with, used to test local domination
344 const MemoryAccess *OriginalAccess = nullptr;
345 Optional<AliasResult> AR = MayAlias;
346 bool SkipSelfAccess = false;
347
348 UpwardsMemoryQuery() = default;
349
350 UpwardsMemoryQuery(const Instruction *Inst, const MemoryAccess *Access)
351 : IsCall(isa<CallBase>(Inst)), Inst(Inst), OriginalAccess(Access) {
352 if (!IsCall)
353 StartingLoc = MemoryLocation::get(Inst);
354 }
355};
356
357} // end anonymous namespace
358
359static bool lifetimeEndsAt(MemoryDef *MD, const MemoryLocation &Loc,
360 BatchAAResults &AA) {
361 Instruction *Inst = MD->getMemoryInst();
362 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
363 switch (II->getIntrinsicID()) {
364 case Intrinsic::lifetime_end:
365 return AA.alias(MemoryLocation(II->getArgOperand(1)), Loc) == MustAlias;
366 default:
367 return false;
368 }
369 }
370 return false;
371}
372
373template <typename AliasAnalysisType>
374static bool isUseTriviallyOptimizableToLiveOnEntry(AliasAnalysisType &AA,
375 const Instruction *I) {
376 // If the memory can't be changed, then loads of the memory can't be
377 // clobbered.
378 return isa<LoadInst>(I) && (I->hasMetadata(LLVMContext::MD_invariant_load) ||
379 AA.pointsToConstantMemory(MemoryLocation(
380 cast<LoadInst>(I)->getPointerOperand())));
381}
382
383/// Verifies that `Start` is clobbered by `ClobberAt`, and that nothing
384/// inbetween `Start` and `ClobberAt` can clobbers `Start`.
385///
386/// This is meant to be as simple and self-contained as possible. Because it
387/// uses no cache, etc., it can be relatively expensive.
388///
389/// \param Start The MemoryAccess that we want to walk from.
390/// \param ClobberAt A clobber for Start.
391/// \param StartLoc The MemoryLocation for Start.
392/// \param MSSA The MemorySSA instance that Start and ClobberAt belong to.
393/// \param Query The UpwardsMemoryQuery we used for our search.
394/// \param AA The AliasAnalysis we used for our search.
395/// \param AllowImpreciseClobber Always false, unless we do relaxed verify.
396
397template <typename AliasAnalysisType>
398LLVM_ATTRIBUTE_UNUSED__attribute__((__unused__)) static void
399checkClobberSanity(const MemoryAccess *Start, MemoryAccess *ClobberAt,
400 const MemoryLocation &StartLoc, const MemorySSA &MSSA,
401 const UpwardsMemoryQuery &Query, AliasAnalysisType &AA,
402 bool AllowImpreciseClobber = false) {
403 assert(MSSA.dominates(ClobberAt, Start) && "Clobber doesn't dominate start?")((MSSA.dominates(ClobberAt, Start) && "Clobber doesn't dominate start?"
) ? static_cast<void> (0) : __assert_fail ("MSSA.dominates(ClobberAt, Start) && \"Clobber doesn't dominate start?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 403, __PRETTY_FUNCTION__));
404
405 if (MSSA.isLiveOnEntryDef(Start)) {
406 assert(MSSA.isLiveOnEntryDef(ClobberAt) &&((MSSA.isLiveOnEntryDef(ClobberAt) && "liveOnEntry must clobber itself"
) ? static_cast<void> (0) : __assert_fail ("MSSA.isLiveOnEntryDef(ClobberAt) && \"liveOnEntry must clobber itself\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 407, __PRETTY_FUNCTION__))
407 "liveOnEntry must clobber itself")((MSSA.isLiveOnEntryDef(ClobberAt) && "liveOnEntry must clobber itself"
) ? static_cast<void> (0) : __assert_fail ("MSSA.isLiveOnEntryDef(ClobberAt) && \"liveOnEntry must clobber itself\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 407, __PRETTY_FUNCTION__));
408 return;
409 }
410
411 bool FoundClobber = false;
412 DenseSet<ConstMemoryAccessPair> VisitedPhis;
413 SmallVector<ConstMemoryAccessPair, 8> Worklist;
414 Worklist.emplace_back(Start, StartLoc);
415 // Walk all paths from Start to ClobberAt, while looking for clobbers. If one
416 // is found, complain.
417 while (!Worklist.empty()) {
418 auto MAP = Worklist.pop_back_val();
419 // All we care about is that nothing from Start to ClobberAt clobbers Start.
420 // We learn nothing from revisiting nodes.
421 if (!VisitedPhis.insert(MAP).second)
422 continue;
423
424 for (const auto *MA : def_chain(MAP.first)) {
425 if (MA == ClobberAt) {
426 if (const auto *MD = dyn_cast<MemoryDef>(MA)) {
427 // instructionClobbersQuery isn't essentially free, so don't use `|=`,
428 // since it won't let us short-circuit.
429 //
430 // Also, note that this can't be hoisted out of the `Worklist` loop,
431 // since MD may only act as a clobber for 1 of N MemoryLocations.
432 FoundClobber = FoundClobber || MSSA.isLiveOnEntryDef(MD);
433 if (!FoundClobber) {
434 ClobberAlias CA =
435 instructionClobbersQuery(MD, MAP.second, Query.Inst, AA);
436 if (CA.IsClobber) {
437 FoundClobber = true;
438 // Not used: CA.AR;
439 }
440 }
441 }
442 break;
443 }
444
445 // We should never hit liveOnEntry, unless it's the clobber.
446 assert(!MSSA.isLiveOnEntryDef(MA) && "Hit liveOnEntry before clobber?")((!MSSA.isLiveOnEntryDef(MA) && "Hit liveOnEntry before clobber?"
) ? static_cast<void> (0) : __assert_fail ("!MSSA.isLiveOnEntryDef(MA) && \"Hit liveOnEntry before clobber?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 446, __PRETTY_FUNCTION__));
447
448 if (const auto *MD = dyn_cast<MemoryDef>(MA)) {
449 // If Start is a Def, skip self.
450 if (MD == Start)
451 continue;
452
453 assert(!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA)((!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .
IsClobber && "Found clobber before reaching ClobberAt!"
) ? static_cast<void> (0) : __assert_fail ("!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .IsClobber && \"Found clobber before reaching ClobberAt!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 455, __PRETTY_FUNCTION__))
454 .IsClobber &&((!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .
IsClobber && "Found clobber before reaching ClobberAt!"
) ? static_cast<void> (0) : __assert_fail ("!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .IsClobber && \"Found clobber before reaching ClobberAt!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 455, __PRETTY_FUNCTION__))
455 "Found clobber before reaching ClobberAt!")((!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .
IsClobber && "Found clobber before reaching ClobberAt!"
) ? static_cast<void> (0) : __assert_fail ("!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA) .IsClobber && \"Found clobber before reaching ClobberAt!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 455, __PRETTY_FUNCTION__));
456 continue;
457 }
458
459 if (const auto *MU = dyn_cast<MemoryUse>(MA)) {
460 (void)MU;
461 assert (MU == Start &&((MU == Start && "Can only find use in def chain if Start is a use"
) ? static_cast<void> (0) : __assert_fail ("MU == Start && \"Can only find use in def chain if Start is a use\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 462, __PRETTY_FUNCTION__))
462 "Can only find use in def chain if Start is a use")((MU == Start && "Can only find use in def chain if Start is a use"
) ? static_cast<void> (0) : __assert_fail ("MU == Start && \"Can only find use in def chain if Start is a use\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 462, __PRETTY_FUNCTION__));
463 continue;
464 }
465
466 assert(isa<MemoryPhi>(MA))((isa<MemoryPhi>(MA)) ? static_cast<void> (0) : __assert_fail
("isa<MemoryPhi>(MA)", "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 466, __PRETTY_FUNCTION__));
467 Worklist.append(
468 upward_defs_begin({const_cast<MemoryAccess *>(MA), MAP.second}),
469 upward_defs_end());
470 }
471 }
472
473 // If the verify is done following an optimization, it's possible that
474 // ClobberAt was a conservative clobbering, that we can now infer is not a
475 // true clobbering access. Don't fail the verify if that's the case.
476 // We do have accesses that claim they're optimized, but could be optimized
477 // further. Updating all these can be expensive, so allow it for now (FIXME).
478 if (AllowImpreciseClobber)
479 return;
480
481 // If ClobberAt is a MemoryPhi, we can assume something above it acted as a
482 // clobber. Otherwise, `ClobberAt` should've acted as a clobber at some point.
483 assert((isa<MemoryPhi>(ClobberAt) || FoundClobber) &&(((isa<MemoryPhi>(ClobberAt) || FoundClobber) &&
"ClobberAt never acted as a clobber") ? static_cast<void>
(0) : __assert_fail ("(isa<MemoryPhi>(ClobberAt) || FoundClobber) && \"ClobberAt never acted as a clobber\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 484, __PRETTY_FUNCTION__))
484 "ClobberAt never acted as a clobber")(((isa<MemoryPhi>(ClobberAt) || FoundClobber) &&
"ClobberAt never acted as a clobber") ? static_cast<void>
(0) : __assert_fail ("(isa<MemoryPhi>(ClobberAt) || FoundClobber) && \"ClobberAt never acted as a clobber\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 484, __PRETTY_FUNCTION__));
485}
486
487namespace {
488
489/// Our algorithm for walking (and trying to optimize) clobbers, all wrapped up
490/// in one class.
491template <class AliasAnalysisType> class ClobberWalker {
492 /// Save a few bytes by using unsigned instead of size_t.
493 using ListIndex = unsigned;
494
495 /// Represents a span of contiguous MemoryDefs, potentially ending in a
496 /// MemoryPhi.
497 struct DefPath {
498 MemoryLocation Loc;
499 // Note that, because we always walk in reverse, Last will always dominate
500 // First. Also note that First and Last are inclusive.
501 MemoryAccess *First;
502 MemoryAccess *Last;
503 Optional<ListIndex> Previous;
504
505 DefPath(const MemoryLocation &Loc, MemoryAccess *First, MemoryAccess *Last,
506 Optional<ListIndex> Previous)
507 : Loc(Loc), First(First), Last(Last), Previous(Previous) {}
508
509 DefPath(const MemoryLocation &Loc, MemoryAccess *Init,
510 Optional<ListIndex> Previous)
511 : DefPath(Loc, Init, Init, Previous) {}
512 };
513
514 const MemorySSA &MSSA;
515 AliasAnalysisType &AA;
516 DominatorTree &DT;
517 UpwardsMemoryQuery *Query;
518 unsigned *UpwardWalkLimit;
519
520 // Phi optimization bookkeeping
521 SmallVector<DefPath, 32> Paths;
522 DenseSet<ConstMemoryAccessPair> VisitedPhis;
523
524 /// Find the nearest def or phi that `From` can legally be optimized to.
525 const MemoryAccess *getWalkTarget(const MemoryPhi *From) const {
526 assert(From->getNumOperands() && "Phi with no operands?")((From->getNumOperands() && "Phi with no operands?"
) ? static_cast<void> (0) : __assert_fail ("From->getNumOperands() && \"Phi with no operands?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 526, __PRETTY_FUNCTION__));
527
528 BasicBlock *BB = From->getBlock();
529 MemoryAccess *Result = MSSA.getLiveOnEntryDef();
530 DomTreeNode *Node = DT.getNode(BB);
531 while ((Node = Node->getIDom())) {
532 auto *Defs = MSSA.getBlockDefs(Node->getBlock());
533 if (Defs)
534 return &*Defs->rbegin();
535 }
536 return Result;
537 }
538
539 /// Result of calling walkToPhiOrClobber.
540 struct UpwardsWalkResult {
541 /// The "Result" of the walk. Either a clobber, the last thing we walked, or
542 /// both. Include alias info when clobber found.
543 MemoryAccess *Result;
544 bool IsKnownClobber;
545 Optional<AliasResult> AR;
546 };
547
548 /// Walk to the next Phi or Clobber in the def chain starting at Desc.Last.
549 /// This will update Desc.Last as it walks. It will (optionally) also stop at
550 /// StopAt.
551 ///
552 /// This does not test for whether StopAt is a clobber
553 UpwardsWalkResult
554 walkToPhiOrClobber(DefPath &Desc, const MemoryAccess *StopAt = nullptr,
555 const MemoryAccess *SkipStopAt = nullptr) const {
556 assert(!isa<MemoryUse>(Desc.Last) && "Uses don't exist in my world")((!isa<MemoryUse>(Desc.Last) && "Uses don't exist in my world"
) ? static_cast<void> (0) : __assert_fail ("!isa<MemoryUse>(Desc.Last) && \"Uses don't exist in my world\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 556, __PRETTY_FUNCTION__));
557 assert(UpwardWalkLimit && "Need a valid walk limit")((UpwardWalkLimit && "Need a valid walk limit") ? static_cast
<void> (0) : __assert_fail ("UpwardWalkLimit && \"Need a valid walk limit\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 557, __PRETTY_FUNCTION__));
558 bool LimitAlreadyReached = false;
559 // (*UpwardWalkLimit) may be 0 here, due to the loop in tryOptimizePhi. Set
560 // it to 1. This will not do any alias() calls. It either returns in the
561 // first iteration in the loop below, or is set back to 0 if all def chains
562 // are free of MemoryDefs.
563 if (!*UpwardWalkLimit) {
564 *UpwardWalkLimit = 1;
565 LimitAlreadyReached = true;
566 }
567
568 for (MemoryAccess *Current : def_chain(Desc.Last)) {
569 Desc.Last = Current;
570 if (Current == StopAt || Current == SkipStopAt)
571 return {Current, false, MayAlias};
572
573 if (auto *MD = dyn_cast<MemoryDef>(Current)) {
574 if (MSSA.isLiveOnEntryDef(MD))
575 return {MD, true, MustAlias};
576
577 if (!--*UpwardWalkLimit)
578 return {Current, true, MayAlias};
579
580 ClobberAlias CA =
581 instructionClobbersQuery(MD, Desc.Loc, Query->Inst, AA);
582 if (CA.IsClobber)
583 return {MD, true, CA.AR};
584 }
585 }
586
587 if (LimitAlreadyReached)
588 *UpwardWalkLimit = 0;
589
590 assert(isa<MemoryPhi>(Desc.Last) &&((isa<MemoryPhi>(Desc.Last) && "Ended at a non-clobber that's not a phi?"
) ? static_cast<void> (0) : __assert_fail ("isa<MemoryPhi>(Desc.Last) && \"Ended at a non-clobber that's not a phi?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 591, __PRETTY_FUNCTION__))
591 "Ended at a non-clobber that's not a phi?")((isa<MemoryPhi>(Desc.Last) && "Ended at a non-clobber that's not a phi?"
) ? static_cast<void> (0) : __assert_fail ("isa<MemoryPhi>(Desc.Last) && \"Ended at a non-clobber that's not a phi?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 591, __PRETTY_FUNCTION__));
592 return {Desc.Last, false, MayAlias};
593 }
594
595 void addSearches(MemoryPhi *Phi, SmallVectorImpl<ListIndex> &PausedSearches,
596 ListIndex PriorNode) {
597 auto UpwardDefs = make_range(upward_defs_begin({Phi, Paths[PriorNode].Loc}),
598 upward_defs_end());
599 for (const MemoryAccessPair &P : UpwardDefs) {
600 PausedSearches.push_back(Paths.size());
601 Paths.emplace_back(P.second, P.first, PriorNode);
602 }
603 }
604
605 /// Represents a search that terminated after finding a clobber. This clobber
606 /// may or may not be present in the path of defs from LastNode..SearchStart,
607 /// since it may have been retrieved from cache.
608 struct TerminatedPath {
609 MemoryAccess *Clobber;
610 ListIndex LastNode;
611 };
612
613 /// Get an access that keeps us from optimizing to the given phi.
614 ///
615 /// PausedSearches is an array of indices into the Paths array. Its incoming
616 /// value is the indices of searches that stopped at the last phi optimization
617 /// target. It's left in an unspecified state.
618 ///
619 /// If this returns None, NewPaused is a vector of searches that terminated
620 /// at StopWhere. Otherwise, NewPaused is left in an unspecified state.
621 Optional<TerminatedPath>
622 getBlockingAccess(const MemoryAccess *StopWhere,
623 SmallVectorImpl<ListIndex> &PausedSearches,
624 SmallVectorImpl<ListIndex> &NewPaused,
625 SmallVectorImpl<TerminatedPath> &Terminated) {
626 assert(!PausedSearches.empty() && "No searches to continue?")((!PausedSearches.empty() && "No searches to continue?"
) ? static_cast<void> (0) : __assert_fail ("!PausedSearches.empty() && \"No searches to continue?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 626, __PRETTY_FUNCTION__));
25
←
'?' condition is true
→
627
628 // BFS vs DFS really doesn't make a difference here, so just do a DFS with
629 // PausedSearches as our stack.
630 while (!PausedSearches.empty()) {
26
←
Loop condition is true. Entering loop body
→
36
←
Loop condition is false. Execution continues on line 692
→
631 ListIndex PathIndex = PausedSearches.pop_back_val();
632 DefPath &Node = Paths[PathIndex];
633
634 // If we've already visited this path with this MemoryLocation, we don't
635 // need to do so again.
636 //
637 // NOTE: That we just drop these paths on the ground makes caching
638 // behavior sporadic. e.g. given a diamond:
639 // A
640 // B C
641 // D
642 //
643 // ...If we walk D, B, A, C, we'll only cache the result of phi
644 // optimization for A, B, and D; C will be skipped because it dies here.
645 // This arguably isn't the worst thing ever, since:
646 // - We generally query things in a top-down order, so if we got below D
647 // without needing cache entries for {C, MemLoc}, then chances are
648 // that those cache entries would end up ultimately unused.
649 // - We still cache things for A, so C only needs to walk up a bit.
650 // If this behavior becomes problematic, we can fix without a ton of extra
651 // work.
652 if (!VisitedPhis.insert({Node.Last, Node.Loc}).second)
27
←
Assuming field 'second' is true
→
28
←
Taking false branch
→
653 continue;
654
655 const MemoryAccess *SkipStopWhere = nullptr;
656 if (Query->SkipSelfAccess && Node.Loc == Query->StartingLoc) {
29
←
Assuming field 'SkipSelfAccess' is false
→
657 assert(isa<MemoryDef>(Query->OriginalAccess))((isa<MemoryDef>(Query->OriginalAccess)) ? static_cast
<void> (0) : __assert_fail ("isa<MemoryDef>(Query->OriginalAccess)"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 657, __PRETTY_FUNCTION__));
658 SkipStopWhere = Query->OriginalAccess;
659 }
660
661 UpwardsWalkResult Res = walkToPhiOrClobber(Node,
662 /*StopAt=*/StopWhere,
663 /*SkipStopAt=*/SkipStopWhere);
664 if (Res.IsKnownClobber
29.1
Field 'IsKnownClobber' is false
29.1
Field 'IsKnownClobber' is false
29.1
Field 'IsKnownClobber' is false
) {
30
←
Taking false branch
→
665 assert(Res.Result != StopWhere && Res.Result != SkipStopWhere)((Res.Result != StopWhere && Res.Result != SkipStopWhere
) ? static_cast<void> (0) : __assert_fail ("Res.Result != StopWhere && Res.Result != SkipStopWhere"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 665, __PRETTY_FUNCTION__));
666
667 // If this wasn't a cache hit, we hit a clobber when walking. That's a
668 // failure.
669 TerminatedPath Term{Res.Result, PathIndex};
670 if (!MSSA.dominates(Res.Result, StopWhere))
671 return Term;
672
673 // Otherwise, it's a valid thing to potentially optimize to.
674 Terminated.push_back(Term);
675 continue;
676 }
677
678 if (Res.Result == StopWhere || Res.Result == SkipStopWhere) {
31
←
Assuming 'StopWhere' is not equal to field 'Result'
→
32
←
Assuming 'SkipStopWhere' is not equal to field 'Result'
→
33
←
Taking false branch
→
679 // We've hit our target. Save this path off for if we want to continue
680 // walking. If we are in the mode of skipping the OriginalAccess, and
681 // we've reached back to the OriginalAccess, do not save path, we've
682 // just looped back to self.
683 if (Res.Result != SkipStopWhere)
684 NewPaused.push_back(PathIndex);
685 continue;
686 }
687
688 assert(!MSSA.isLiveOnEntryDef(Res.Result) && "liveOnEntry is a clobber")((!MSSA.isLiveOnEntryDef(Res.Result) && "liveOnEntry is a clobber"
) ? static_cast<void> (0) : __assert_fail ("!MSSA.isLiveOnEntryDef(Res.Result) && \"liveOnEntry is a clobber\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 688, __PRETTY_FUNCTION__));
34
←
'?' condition is true
→
689 addSearches(cast<MemoryPhi>(Res.Result), PausedSearches, PathIndex);
35
←
Field 'Result' is a 'MemoryPhi'
→
690 }
691
692 return None;
37
←
Returning without writing to 'NewPaused.Size', which participates in a condition later
→
38
←
Returning without writing to 'Terminated.Size', which participates in a condition later
→
693 }
694
695 template <typename T, typename Walker>
696 struct generic_def_path_iterator
697 : public iterator_facade_base<generic_def_path_iterator<T, Walker>,
698 std::forward_iterator_tag, T *> {
699 generic_def_path_iterator() {}
700 generic_def_path_iterator(Walker *W, ListIndex N) : W(W), N(N) {}
701
702 T &operator*() const { return curNode(); }
703
704 generic_def_path_iterator &operator++() {
705 N = curNode().Previous;
706 return *this;
707 }
708
709 bool operator==(const generic_def_path_iterator &O) const {
710 if (N.hasValue() != O.N.hasValue())
711 return false;
712 return !N.hasValue() || *N == *O.N;
713 }
714
715 private:
716 T &curNode() const { return W->Paths[*N]; }
717
718 Walker *W = nullptr;
719 Optional<ListIndex> N = None;
720 };
721
722 using def_path_iterator = generic_def_path_iterator<DefPath, ClobberWalker>;
723 using const_def_path_iterator =
724 generic_def_path_iterator<const DefPath, const ClobberWalker>;
725
726 iterator_range<def_path_iterator> def_path(ListIndex From) {
727 return make_range(def_path_iterator(this, From), def_path_iterator());
728 }
729
730 iterator_range<const_def_path_iterator> const_def_path(ListIndex From) const {
731 return make_range(const_def_path_iterator(this, From),
732 const_def_path_iterator());
733 }
734
735 struct OptznResult {
736 /// The path that contains our result.
737 TerminatedPath PrimaryClobber;
738 /// The paths that we can legally cache back from, but that aren't
739 /// necessarily the result of the Phi optimization.
740 SmallVector<TerminatedPath, 4> OtherClobbers;
741 };
742
743 ListIndex defPathIndex(const DefPath &N) const {
744 // The assert looks nicer if we don't need to do &N
745 const DefPath *NP = &N;
746 assert(!Paths.empty() && NP >= &Paths.front() && NP <= &Paths.back() &&((!Paths.empty() && NP >= &Paths.front() &&
NP <= &Paths.back() && "Out of bounds DefPath!"
) ? static_cast<void> (0) : __assert_fail ("!Paths.empty() && NP >= &Paths.front() && NP <= &Paths.back() && \"Out of bounds DefPath!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 747, __PRETTY_FUNCTION__))
747 "Out of bounds DefPath!")((!Paths.empty() && NP >= &Paths.front() &&
NP <= &Paths.back() && "Out of bounds DefPath!"
) ? static_cast<void> (0) : __assert_fail ("!Paths.empty() && NP >= &Paths.front() && NP <= &Paths.back() && \"Out of bounds DefPath!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 747, __PRETTY_FUNCTION__));
748 return NP - &Paths.front();
749 }
750
751 /// Try to optimize a phi as best as we can. Returns a SmallVector of Paths
752 /// that act as legal clobbers. Note that this won't return *all* clobbers.
753 ///
754 /// Phi optimization algorithm tl;dr:
755 /// - Find the earliest def/phi, A, we can optimize to
756 /// - Find if all paths from the starting memory access ultimately reach A
757 /// - If not, optimization isn't possible.
758 /// - Otherwise, walk from A to another clobber or phi, A'.
759 /// - If A' is a def, we're done.
760 /// - If A' is a phi, try to optimize it.
761 ///
762 /// A path is a series of {MemoryAccess, MemoryLocation} pairs. A path
763 /// terminates when a MemoryAccess that clobbers said MemoryLocation is found.
764 OptznResult tryOptimizePhi(MemoryPhi *Phi, MemoryAccess *Start,
765 const MemoryLocation &Loc) {
766 assert(Paths.empty() && VisitedPhis.empty() &&((Paths.empty() && VisitedPhis.empty() && "Reset the optimization state."
) ? static_cast<void> (0) : __assert_fail ("Paths.empty() && VisitedPhis.empty() && \"Reset the optimization state.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 767, __PRETTY_FUNCTION__))
19
←
Assuming the condition is true
→
20
←
'?' condition is true
→
767 "Reset the optimization state.")((Paths.empty() && VisitedPhis.empty() && "Reset the optimization state."
) ? static_cast<void> (0) : __assert_fail ("Paths.empty() && VisitedPhis.empty() && \"Reset the optimization state.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 767, __PRETTY_FUNCTION__));
768
769 Paths.emplace_back(Loc, Start, Phi, None);
770 // Stores how many "valid" optimization nodes we had prior to calling
771 // addSearches/getBlockingAccess. Necessary for caching if we had a blocker.
772 auto PriorPathsSize = Paths.size();
773
774 SmallVector<ListIndex, 16> PausedSearches;
775 SmallVector<ListIndex, 8> NewPaused;
776 SmallVector<TerminatedPath, 4> TerminatedPaths;
777
778 addSearches(Phi, PausedSearches, 0);
779
780 // Moves the TerminatedPath with the "most dominated" Clobber to the end of
781 // Paths.
782 auto MoveDominatedPathToEnd = [&](SmallVectorImpl<TerminatedPath> &Paths) {
783 assert(!Paths.empty() && "Need a path to move")((!Paths.empty() && "Need a path to move") ? static_cast
<void> (0) : __assert_fail ("!Paths.empty() && \"Need a path to move\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 783, __PRETTY_FUNCTION__));
784 auto Dom = Paths.begin();
785 for (auto I = std::next(Dom), E = Paths.end(); I != E; ++I)
786 if (!MSSA.dominates(I->Clobber, Dom->Clobber))
787 Dom = I;
788 auto Last = Paths.end() - 1;
789 if (Last != Dom)
790 std::iter_swap(Last, Dom);
791 };
792
793 MemoryPhi *Current = Phi;
794 while (true) {
21
←
Loop condition is true. Entering loop body
→
795 assert(!MSSA.isLiveOnEntryDef(Current) &&((!MSSA.isLiveOnEntryDef(Current) && "liveOnEntry wasn't treated as a clobber?"
) ? static_cast<void> (0) : __assert_fail ("!MSSA.isLiveOnEntryDef(Current) && \"liveOnEntry wasn't treated as a clobber?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 796, __PRETTY_FUNCTION__))
22
←
'?' condition is true
→
796 "liveOnEntry wasn't treated as a clobber?")((!MSSA.isLiveOnEntryDef(Current) && "liveOnEntry wasn't treated as a clobber?"
) ? static_cast<void> (0) : __assert_fail ("!MSSA.isLiveOnEntryDef(Current) && \"liveOnEntry wasn't treated as a clobber?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 796, __PRETTY_FUNCTION__));
797
798 const auto *Target = getWalkTarget(Current);
799 // If a TerminatedPath doesn't dominate Target, then it wasn't a legal
800 // optimization for the prior phi.
801 assert(all_of(TerminatedPaths, [&](const TerminatedPath &P) {((all_of(TerminatedPaths, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, Target); })) ? static_cast
<void> (0) : __assert_fail ("all_of(TerminatedPaths, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, Target); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 803, __PRETTY_FUNCTION__))
23
←
'?' condition is true
→
802 return MSSA.dominates(P.Clobber, Target);((all_of(TerminatedPaths, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, Target); })) ? static_cast
<void> (0) : __assert_fail ("all_of(TerminatedPaths, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, Target); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 803, __PRETTY_FUNCTION__))
803 }))((all_of(TerminatedPaths, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, Target); })) ? static_cast
<void> (0) : __assert_fail ("all_of(TerminatedPaths, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, Target); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 803, __PRETTY_FUNCTION__));
804
805 // FIXME: This is broken, because the Blocker may be reported to be
806 // liveOnEntry, and we'll happily wait for that to disappear (read: never)
807 // For the moment, this is fine, since we do nothing with blocker info.
808 if (Optional<TerminatedPath> Blocker = getBlockingAccess(
24
←
Calling 'ClobberWalker::getBlockingAccess'
→
39
←
Returning from 'ClobberWalker::getBlockingAccess'
→
40
←
Calling 'Optional::operator bool'
→
48
←
Returning from 'Optional::operator bool'
→
49
←
Taking false branch
→
809 Target, PausedSearches, NewPaused, TerminatedPaths)) {
810
811 // Find the node we started at. We can't search based on N->Last, since
812 // we may have gone around a loop with a different MemoryLocation.
813 auto Iter = find_if(def_path(Blocker->LastNode), [&](const DefPath &N) {
814 return defPathIndex(N) < PriorPathsSize;
815 });
816 assert(Iter != def_path_iterator())((Iter != def_path_iterator()) ? static_cast<void> (0) :
__assert_fail ("Iter != def_path_iterator()", "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 816, __PRETTY_FUNCTION__));
817
818 DefPath &CurNode = *Iter;
819 assert(CurNode.Last == Current)((CurNode.Last == Current) ? static_cast<void> (0) : __assert_fail
("CurNode.Last == Current", "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 819, __PRETTY_FUNCTION__));
820
821 // Two things:
822 // A. We can't reliably cache all of NewPaused back. Consider a case
823 // where we have two paths in NewPaused; one of which can't optimize
824 // above this phi, whereas the other can. If we cache the second path
825 // back, we'll end up with suboptimal cache entries. We can handle
826 // cases like this a bit better when we either try to find all
827 // clobbers that block phi optimization, or when our cache starts
828 // supporting unfinished searches.
829 // B. We can't reliably cache TerminatedPaths back here without doing
830 // extra checks; consider a case like:
831 // T
832 // / \
833 // D C
834 // \ /
835 // S
836 // Where T is our target, C is a node with a clobber on it, D is a
837 // diamond (with a clobber *only* on the left or right node, N), and
838 // S is our start. Say we walk to D, through the node opposite N
839 // (read: ignoring the clobber), and see a cache entry in the top
840 // node of D. That cache entry gets put into TerminatedPaths. We then
841 // walk up to C (N is later in our worklist), find the clobber, and
842 // quit. If we append TerminatedPaths to OtherClobbers, we'll cache
843 // the bottom part of D to the cached clobber, ignoring the clobber
844 // in N. Again, this problem goes away if we start tracking all
845 // blockers for a given phi optimization.
846 TerminatedPath Result{CurNode.Last, defPathIndex(CurNode)};
847 return {Result, {}};
848 }
849
850 // If there's nothing left to search, then all paths led to valid clobbers
851 // that we got from our cache; pick the nearest to the start, and allow
852 // the rest to be cached back.
853 if (NewPaused.empty()) {
50
←
Calling 'SmallVectorBase::empty'
→
53
←
Returning from 'SmallVectorBase::empty'
→
54
←
Taking false branch
→
854 MoveDominatedPathToEnd(TerminatedPaths);
855 TerminatedPath Result = TerminatedPaths.pop_back_val();
856 return {Result, std::move(TerminatedPaths)};
857 }
858
859 MemoryAccess *DefChainEnd = nullptr;
55
←
'DefChainEnd' initialized to a null pointer value
→
860 SmallVector<TerminatedPath, 4> Clobbers;
861 for (ListIndex Paused : NewPaused) {
56
←
Assuming '__begin3' is equal to '__end3'
→
862 UpwardsWalkResult WR = walkToPhiOrClobber(Paths[Paused]);
863 if (WR.IsKnownClobber)
864 Clobbers.push_back({WR.Result, Paused});
865 else
866 // Micro-opt: If we hit the end of the chain, save it.
867 DefChainEnd = WR.Result;
868 }
869
870 if (!TerminatedPaths.empty()) {
57
←
Calling 'SmallVectorBase::empty'
→
60
←
Returning from 'SmallVectorBase::empty'
→
61
←
Taking true branch
→
871 // If we couldn't find the dominating phi/liveOnEntry in the above loop,
872 // do it now.
873 if (!DefChainEnd
61.1
'DefChainEnd' is null
61.1
'DefChainEnd' is null
61.1
'DefChainEnd' is null
)
62
←
Taking true branch
→
874 for (auto *MA : def_chain(const_cast<MemoryAccess *>(Target)))
875 DefChainEnd = MA;
876
877 // If any of the terminated paths don't dominate the phi we'll try to
878 // optimize, we need to figure out what they are and quit.
879 const BasicBlock *ChainBB = DefChainEnd->getBlock();
63
←
Called C++ object pointer is null
880 for (const TerminatedPath &TP : TerminatedPaths) {
881 // Because we know that DefChainEnd is as "high" as we can go, we
882 // don't need local dominance checks; BB dominance is sufficient.
883 if (DT.dominates(ChainBB, TP.Clobber->getBlock()))
884 Clobbers.push_back(TP);
885 }
886 }
887
888 // If we have clobbers in the def chain, find the one closest to Current
889 // and quit.
890 if (!Clobbers.empty()) {
891 MoveDominatedPathToEnd(Clobbers);
892 TerminatedPath Result = Clobbers.pop_back_val();
893 return {Result, std::move(Clobbers)};
894 }
895
896 assert(all_of(NewPaused,((all_of(NewPaused, [&](ListIndex I) { return Paths[I].Last
== DefChainEnd; })) ? static_cast<void> (0) : __assert_fail
("all_of(NewPaused, [&](ListIndex I) { return Paths[I].Last == DefChainEnd; })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 897, __PRETTY_FUNCTION__))
897 [&](ListIndex I) { return Paths[I].Last == DefChainEnd; }))((all_of(NewPaused, [&](ListIndex I) { return Paths[I].Last
== DefChainEnd; })) ? static_cast<void> (0) : __assert_fail
("all_of(NewPaused, [&](ListIndex I) { return Paths[I].Last == DefChainEnd; })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 897, __PRETTY_FUNCTION__));
898
899 // Because liveOnEntry is a clobber, this must be a phi.
900 auto *DefChainPhi = cast<MemoryPhi>(DefChainEnd);
901
902 PriorPathsSize = Paths.size();
903 PausedSearches.clear();
904 for (ListIndex I : NewPaused)
905 addSearches(DefChainPhi, PausedSearches, I);
906 NewPaused.clear();
907
908 Current = DefChainPhi;
909 }
910 }
911
912 void verifyOptResult(const OptznResult &R) const {
913 assert(all_of(R.OtherClobbers, [&](const TerminatedPath &P) {((all_of(R.OtherClobbers, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber
); })) ? static_cast<void> (0) : __assert_fail ("all_of(R.OtherClobbers, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 915, __PRETTY_FUNCTION__))
914 return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber);((all_of(R.OtherClobbers, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber
); })) ? static_cast<void> (0) : __assert_fail ("all_of(R.OtherClobbers, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 915, __PRETTY_FUNCTION__))
915 }))((all_of(R.OtherClobbers, [&](const TerminatedPath &P
) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber
); })) ? static_cast<void> (0) : __assert_fail ("all_of(R.OtherClobbers, [&](const TerminatedPath &P) { return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber); })"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 915, __PRETTY_FUNCTION__));
916 }
917
918 void resetPhiOptznState() {
919 Paths.clear();
920 VisitedPhis.clear();
921 }
922
923public:
924 ClobberWalker(const MemorySSA &MSSA, AliasAnalysisType &AA, DominatorTree &DT)
925 : MSSA(MSSA), AA(AA), DT(DT) {}
926
927 AliasAnalysisType *getAA() { return &AA; }
928 /// Finds the nearest clobber for the given query, optimizing phis if
929 /// possible.
930 MemoryAccess *findClobber(MemoryAccess *Start, UpwardsMemoryQuery &Q,
931 unsigned &UpWalkLimit) {
932 Query = &Q;
933 UpwardWalkLimit = &UpWalkLimit;
934 // Starting limit must be > 0.
935 if (!UpWalkLimit)
12
←
Assuming 'UpWalkLimit' is not equal to 0
→
13
←
Taking false branch
→
936 UpWalkLimit++;
937
938 MemoryAccess *Current = Start;
939 // This walker pretends uses don't exist. If we're handed one, silently grab
940 // its def. (This has the nice side-effect of ensuring we never cache uses)
941 if (auto *MU
14.1
'MU' is null
14.1
'MU' is null
14.1
'MU' is null
 = dyn_cast<MemoryUse>(Start))
14
←
Assuming 'Start' is not a 'MemoryUse'
→
15
←
Taking false branch
→
942 Current = MU->getDefiningAccess();
943
944 DefPath FirstDesc(Q.StartingLoc, Current, Current, None);
945 // Fast path for the overly-common case (no crazy phi optimization
946 // necessary)
947 UpwardsWalkResult WalkResult = walkToPhiOrClobber(FirstDesc);
948 MemoryAccess *Result;
949 if (WalkResult.IsKnownClobber
15.1
Field 'IsKnownClobber' is false
15.1
Field 'IsKnownClobber' is false
15.1
Field 'IsKnownClobber' is false
) {
16
←
Taking false branch
→
950 Result = WalkResult.Result;
951 Q.AR = WalkResult.AR;
952 } else {
953 OptznResult OptRes = tryOptimizePhi(cast<MemoryPhi>(FirstDesc.Last),
17
←
Field 'Last' is a 'MemoryPhi'
→
18
←
Calling 'ClobberWalker::tryOptimizePhi'
→
954 Current, Q.StartingLoc);
955 verifyOptResult(OptRes);
956 resetPhiOptznState();
957 Result = OptRes.PrimaryClobber.Clobber;
958 }
959
960#ifdef EXPENSIVE_CHECKS
961 if (!Q.SkipSelfAccess && *UpwardWalkLimit > 0)
962 checkClobberSanity(Current, Result, Q.StartingLoc, MSSA, Q, AA);
963#endif
964 return Result;
965 }
966};
967
968struct RenamePassData {
969 DomTreeNode *DTN;
970 DomTreeNode::const_iterator ChildIt;
971 MemoryAccess *IncomingVal;
972
973 RenamePassData(DomTreeNode *D, DomTreeNode::const_iterator It,
974 MemoryAccess *M)
975 : DTN(D), ChildIt(It), IncomingVal(M) {}
976
977 void swap(RenamePassData &RHS) {
978 std::swap(DTN, RHS.DTN);
979 std::swap(ChildIt, RHS.ChildIt);
980 std::swap(IncomingVal, RHS.IncomingVal);
981 }
982};
983
984} // end anonymous namespace
985
986namespace llvm {
987
988template <class AliasAnalysisType> class MemorySSA::ClobberWalkerBase {
989 ClobberWalker<AliasAnalysisType> Walker;
990 MemorySSA *MSSA;
991
992public:
993 ClobberWalkerBase(MemorySSA *M, AliasAnalysisType *A, DominatorTree *D)
994 : Walker(*M, *A, *D), MSSA(M) {}
995
996 MemoryAccess *getClobberingMemoryAccessBase(MemoryAccess *,
997 const MemoryLocation &,
998 unsigned &);
999 // Third argument (bool), defines whether the clobber search should skip the
1000 // original queried access. If true, there will be a follow-up query searching
1001 // for a clobber access past "self". Note that the Optimized access is not
1002 // updated if a new clobber is found by this SkipSelf search. If this
1003 // additional query becomes heavily used we may decide to cache the result.
1004 // Walker instantiations will decide how to set the SkipSelf bool.
1005 MemoryAccess *getClobberingMemoryAccessBase(MemoryAccess *, unsigned &, bool);
1006};
1007
1008/// A MemorySSAWalker that does AA walks to disambiguate accesses. It no
1009/// longer does caching on its own, but the name has been retained for the
1010/// moment.
1011template <class AliasAnalysisType>
1012class MemorySSA::CachingWalker final : public MemorySSAWalker {
1013 ClobberWalkerBase<AliasAnalysisType> *Walker;
1014
1015public:
1016 CachingWalker(MemorySSA *M, ClobberWalkerBase<AliasAnalysisType> *W)
1017 : MemorySSAWalker(M), Walker(W) {}
1018 ~CachingWalker() override = default;
1019
1020 using MemorySSAWalker::getClobberingMemoryAccess;
1021
1022 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA, unsigned &UWL) {
1023 return Walker->getClobberingMemoryAccessBase(MA, UWL, false);
1024 }
1025 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
1026 const MemoryLocation &Loc,
1027 unsigned &UWL) {
1028 return Walker->getClobberingMemoryAccessBase(MA, Loc, UWL);
1029 }
1030
1031 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA) override {
1032 unsigned UpwardWalkLimit = MaxCheckLimit;
1033 return getClobberingMemoryAccess(MA, UpwardWalkLimit);
1034 }
1035 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
1036 const MemoryLocation &Loc) override {
1037 unsigned UpwardWalkLimit = MaxCheckLimit;
1038 return getClobberingMemoryAccess(MA, Loc, UpwardWalkLimit);
1039 }
1040
1041 void invalidateInfo(MemoryAccess *MA) override {
1042 if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
1043 MUD->resetOptimized();
1044 }
1045};
1046
1047template <class AliasAnalysisType>
1048class MemorySSA::SkipSelfWalker final : public MemorySSAWalker {
1049 ClobberWalkerBase<AliasAnalysisType> *Walker;
1050
1051public:
1052 SkipSelfWalker(MemorySSA *M, ClobberWalkerBase<AliasAnalysisType> *W)
1053 : MemorySSAWalker(M), Walker(W) {}
1054 ~SkipSelfWalker() override = default;
1055
1056 using MemorySSAWalker::getClobberingMemoryAccess;
1057
1058 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA, unsigned &UWL) {
1059 return Walker->getClobberingMemoryAccessBase(MA, UWL, true);
1060 }
1061 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
1062 const MemoryLocation &Loc,
1063 unsigned &UWL) {
1064 return Walker->getClobberingMemoryAccessBase(MA, Loc, UWL);
2
←
Calling 'ClobberWalkerBase::getClobberingMemoryAccessBase'
→
1065 }
1066
1067 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA) override {
1068 unsigned UpwardWalkLimit = MaxCheckLimit;
1069 return getClobberingMemoryAccess(MA, UpwardWalkLimit);
1070 }
1071 MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
1072 const MemoryLocation &Loc) override {
1073 unsigned UpwardWalkLimit = MaxCheckLimit;
1074 return getClobberingMemoryAccess(MA, Loc, UpwardWalkLimit);
1
Calling 'SkipSelfWalker::getClobberingMemoryAccess'
→
1075 }
1076
1077 void invalidateInfo(MemoryAccess *MA) override {
1078 if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
1079 MUD->resetOptimized();
1080 }
1081};
1082
1083} // end namespace llvm
1084
1085void MemorySSA::renameSuccessorPhis(BasicBlock *BB, MemoryAccess *IncomingVal,
1086 bool RenameAllUses) {
1087 // Pass through values to our successors
1088 for (const BasicBlock *S : successors(BB)) {
1089 auto It = PerBlockAccesses.find(S);
1090 // Rename the phi nodes in our successor block
1091 if (It == PerBlockAccesses.end() || !isa<MemoryPhi>(It->second->front()))
1092 continue;
1093 AccessList *Accesses = It->second.get();
1094 auto *Phi = cast<MemoryPhi>(&Accesses->front());
1095 if (RenameAllUses) {
1096 bool ReplacementDone = false;
1097 for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I)
1098 if (Phi->getIncomingBlock(I) == BB) {
1099 Phi->setIncomingValue(I, IncomingVal);
1100 ReplacementDone = true;
1101 }
1102 (void) ReplacementDone;
1103 assert(ReplacementDone && "Incomplete phi during partial rename")((ReplacementDone && "Incomplete phi during partial rename"
) ? static_cast<void> (0) : __assert_fail ("ReplacementDone && \"Incomplete phi during partial rename\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1103, __PRETTY_FUNCTION__));
1104 } else
1105 Phi->addIncoming(IncomingVal, BB);
1106 }
1107}
1108
1109/// Rename a single basic block into MemorySSA form.
1110/// Uses the standard SSA renaming algorithm.
1111/// \returns The new incoming value.
1112MemoryAccess *MemorySSA::renameBlock(BasicBlock *BB, MemoryAccess *IncomingVal,
1113 bool RenameAllUses) {
1114 auto It = PerBlockAccesses.find(BB);
1115 // Skip most processing if the list is empty.
1116 if (It != PerBlockAccesses.end()) {
1117 AccessList *Accesses = It->second.get();
1118 for (MemoryAccess &L : *Accesses) {
1119 if (MemoryUseOrDef *MUD = dyn_cast<MemoryUseOrDef>(&L)) {
1120 if (MUD->getDefiningAccess() == nullptr || RenameAllUses)
1121 MUD->setDefiningAccess(IncomingVal);
1122 if (isa<MemoryDef>(&L))
1123 IncomingVal = &L;
1124 } else {
1125 IncomingVal = &L;
1126 }
1127 }
1128 }
1129 return IncomingVal;
1130}
1131
1132/// This is the standard SSA renaming algorithm.
1133///
1134/// We walk the dominator tree in preorder, renaming accesses, and then filling
1135/// in phi nodes in our successors.
1136void MemorySSA::renamePass(DomTreeNode *Root, MemoryAccess *IncomingVal,
1137 SmallPtrSetImpl<BasicBlock *> &Visited,
1138 bool SkipVisited, bool RenameAllUses) {
1139 assert(Root && "Trying to rename accesses in an unreachable block")((Root && "Trying to rename accesses in an unreachable block"
) ? static_cast<void> (0) : __assert_fail ("Root && \"Trying to rename accesses in an unreachable block\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1139, __PRETTY_FUNCTION__));
1140
1141 SmallVector<RenamePassData, 32> WorkStack;
1142 // Skip everything if we already renamed this block and we are skipping.
1143 // Note: You can't sink this into the if, because we need it to occur
1144 // regardless of whether we skip blocks or not.
1145 bool AlreadyVisited = !Visited.insert(Root->getBlock()).second;
1146 if (SkipVisited && AlreadyVisited)
1147 return;
1148
1149 IncomingVal = renameBlock(Root->getBlock(), IncomingVal, RenameAllUses);
1150 renameSuccessorPhis(Root->getBlock(), IncomingVal, RenameAllUses);
1151 WorkStack.push_back({Root, Root->begin(), IncomingVal});
1152
1153 while (!WorkStack.empty()) {
1154 DomTreeNode *Node = WorkStack.back().DTN;
1155 DomTreeNode::const_iterator ChildIt = WorkStack.back().ChildIt;
1156 IncomingVal = WorkStack.back().IncomingVal;
1157
1158 if (ChildIt == Node->end()) {
1159 WorkStack.pop_back();
1160 } else {
1161 DomTreeNode *Child = *ChildIt;
1162 ++WorkStack.back().ChildIt;
1163 BasicBlock *BB = Child->getBlock();
1164 // Note: You can't sink this into the if, because we need it to occur
1165 // regardless of whether we skip blocks or not.
1166 AlreadyVisited = !Visited.insert(BB).second;
1167 if (SkipVisited && AlreadyVisited) {
1168 // We already visited this during our renaming, which can happen when
1169 // being asked to rename multiple blocks. Figure out the incoming val,
1170 // which is the last def.
1171 // Incoming value can only change if there is a block def, and in that
1172 // case, it's the last block def in the list.
1173 if (auto *BlockDefs = getWritableBlockDefs(BB))
1174 IncomingVal = &*BlockDefs->rbegin();
1175 } else
1176 IncomingVal = renameBlock(BB, IncomingVal, RenameAllUses);
1177 renameSuccessorPhis(BB, IncomingVal, RenameAllUses);
1178 WorkStack.push_back({Child, Child->begin(), IncomingVal});
1179 }
1180 }
1181}
1182
1183/// This handles unreachable block accesses by deleting phi nodes in
1184/// unreachable blocks, and marking all other unreachable MemoryAccess's as
1185/// being uses of the live on entry definition.
1186void MemorySSA::markUnreachableAsLiveOnEntry(BasicBlock *BB) {
1187 assert(!DT->isReachableFromEntry(BB) &&((!DT->isReachableFromEntry(BB) && "Reachable block found while handling unreachable blocks"
) ? static_cast<void> (0) : __assert_fail ("!DT->isReachableFromEntry(BB) && \"Reachable block found while handling unreachable blocks\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1188, __PRETTY_FUNCTION__))
1188 "Reachable block found while handling unreachable blocks")((!DT->isReachableFromEntry(BB) && "Reachable block found while handling unreachable blocks"
) ? static_cast<void> (0) : __assert_fail ("!DT->isReachableFromEntry(BB) && \"Reachable block found while handling unreachable blocks\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1188, __PRETTY_FUNCTION__));
1189
1190 // Make sure phi nodes in our reachable successors end up with a
1191 // LiveOnEntryDef for our incoming edge, even though our block is forward
1192 // unreachable. We could just disconnect these blocks from the CFG fully,
1193 // but we do not right now.
1194 for (const BasicBlock *S : successors(BB)) {
1195 if (!DT->isReachableFromEntry(S))
1196 continue;
1197 auto It = PerBlockAccesses.find(S);
1198 // Rename the phi nodes in our successor block
1199 if (It == PerBlockAccesses.end() || !isa<MemoryPhi>(It->second->front()))
1200 continue;
1201 AccessList *Accesses = It->second.get();
1202 auto *Phi = cast<MemoryPhi>(&Accesses->front());
1203 Phi->addIncoming(LiveOnEntryDef.get(), BB);
1204 }
1205
1206 auto It = PerBlockAccesses.find(BB);
1207 if (It == PerBlockAccesses.end())
1208 return;
1209
1210 auto &Accesses = It->second;
1211 for (auto AI = Accesses->begin(), AE = Accesses->end(); AI != AE;) {
1212 auto Next = std::next(AI);
1213 // If we have a phi, just remove it. We are going to replace all
1214 // users with live on entry.
1215 if (auto *UseOrDef = dyn_cast<MemoryUseOrDef>(AI))
1216 UseOrDef->setDefiningAccess(LiveOnEntryDef.get());
1217 else
1218 Accesses->erase(AI);
1219 AI = Next;
1220 }
1221}
1222
1223MemorySSA::MemorySSA(Function &Func, AliasAnalysis *AA, DominatorTree *DT)
1224 : AA(nullptr), DT(DT), F(Func), LiveOnEntryDef(nullptr), Walker(nullptr),
1225 SkipWalker(nullptr), NextID(0) {
1226 // Build MemorySSA using a batch alias analysis. This reuses the internal
1227 // state that AA collects during an alias()/getModRefInfo() call. This is
1228 // safe because there are no CFG changes while building MemorySSA and can
1229 // significantly reduce the time spent by the compiler in AA, because we will
1230 // make queries about all the instructions in the Function.
1231 BatchAAResults BatchAA(*AA);
1232 buildMemorySSA(BatchAA);
1233 // Intentionally leave AA to nullptr while building so we don't accidently
1234 // use non-batch AliasAnalysis.
1235 this->AA = AA;
1236 // Also create the walker here.
1237 getWalker();
1238}
1239
1240MemorySSA::~MemorySSA() {
1241 // Drop all our references
1242 for (const auto &Pair : PerBlockAccesses)
1243 for (MemoryAccess &MA : *Pair.second)
1244 MA.dropAllReferences();
1245}
1246
1247MemorySSA::AccessList *MemorySSA::getOrCreateAccessList(const BasicBlock *BB) {
1248 auto Res = PerBlockAccesses.insert(std::make_pair(BB, nullptr));
1249
1250 if (Res.second)
1251 Res.first->second = std::make_unique<AccessList>();
1252 return Res.first->second.get();
1253}
1254
1255MemorySSA::DefsList *MemorySSA::getOrCreateDefsList(const BasicBlock *BB) {
1256 auto Res = PerBlockDefs.insert(std::make_pair(BB, nullptr));
1257
1258 if (Res.second)
1259 Res.first->second = std::make_unique<DefsList>();
1260 return Res.first->second.get();
1261}
1262
1263namespace llvm {
1264
1265/// This class is a batch walker of all MemoryUse's in the program, and points
1266/// their defining access at the thing that actually clobbers them. Because it
1267/// is a batch walker that touches everything, it does not operate like the
1268/// other walkers. This walker is basically performing a top-down SSA renaming
1269/// pass, where the version stack is used as the cache. This enables it to be
1270/// significantly more time and memory efficient than using the regular walker,
1271/// which is walking bottom-up.
1272class MemorySSA::OptimizeUses {
1273public:
1274 OptimizeUses(MemorySSA *MSSA, CachingWalker<BatchAAResults> *Walker,
1275 BatchAAResults *BAA, DominatorTree *DT)
1276 : MSSA(MSSA), Walker(Walker), AA(BAA), DT(DT) {}
1277
1278 void optimizeUses();
1279
1280private:
1281 /// This represents where a given memorylocation is in the stack.
1282 struct MemlocStackInfo {
1283 // This essentially is keeping track of versions of the stack. Whenever
1284 // the stack changes due to pushes or pops, these versions increase.
1285 unsigned long StackEpoch;
1286 unsigned long PopEpoch;
1287 // This is the lower bound of places on the stack to check. It is equal to
1288 // the place the last stack walk ended.
1289 // Note: Correctness depends on this being initialized to 0, which densemap
1290 // does
1291 unsigned long LowerBound;
1292 const BasicBlock *LowerBoundBlock;
1293 // This is where the last walk for this memory location ended.
1294 unsigned long LastKill;
1295 bool LastKillValid;
1296 Optional<AliasResult> AR;
1297 };
1298
1299 void optimizeUsesInBlock(const BasicBlock *, unsigned long &, unsigned long &,
1300 SmallVectorImpl<MemoryAccess *> &,
1301 DenseMap<MemoryLocOrCall, MemlocStackInfo> &);
1302
1303 MemorySSA *MSSA;
1304 CachingWalker<BatchAAResults> *Walker;
1305 BatchAAResults *AA;
1306 DominatorTree *DT;
1307};
1308
1309} // end namespace llvm
1310
1311/// Optimize the uses in a given block This is basically the SSA renaming
1312/// algorithm, with one caveat: We are able to use a single stack for all
1313/// MemoryUses. This is because the set of *possible* reaching MemoryDefs is
1314/// the same for every MemoryUse. The *actual* clobbering MemoryDef is just
1315/// going to be some position in that stack of possible ones.
1316///
1317/// We track the stack positions that each MemoryLocation needs
1318/// to check, and last ended at. This is because we only want to check the
1319/// things that changed since last time. The same MemoryLocation should
1320/// get clobbered by the same store (getModRefInfo does not use invariantness or
1321/// things like this, and if they start, we can modify MemoryLocOrCall to
1322/// include relevant data)
1323void MemorySSA::OptimizeUses::optimizeUsesInBlock(
1324 const BasicBlock *BB, unsigned long &StackEpoch, unsigned long &PopEpoch,
1325 SmallVectorImpl<MemoryAccess *> &VersionStack,
1326 DenseMap<MemoryLocOrCall, MemlocStackInfo> &LocStackInfo) {
1327
1328 /// If no accesses, nothing to do.
1329 MemorySSA::AccessList *Accesses = MSSA->getWritableBlockAccesses(BB);
1330 if (Accesses == nullptr)
1331 return;
1332
1333 // Pop everything that doesn't dominate the current block off the stack,
1334 // increment the PopEpoch to account for this.
1335 while (true) {
1336 assert(((!VersionStack.empty() && "Version stack should have liveOnEntry sentinel dominating everything"
) ? static_cast<void> (0) : __assert_fail ("!VersionStack.empty() && \"Version stack should have liveOnEntry sentinel dominating everything\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1338, __PRETTY_FUNCTION__))
1337 !VersionStack.empty() &&((!VersionStack.empty() && "Version stack should have liveOnEntry sentinel dominating everything"
) ? static_cast<void> (0) : __assert_fail ("!VersionStack.empty() && \"Version stack should have liveOnEntry sentinel dominating everything\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1338, __PRETTY_FUNCTION__))
1338 "Version stack should have liveOnEntry sentinel dominating everything")((!VersionStack.empty() && "Version stack should have liveOnEntry sentinel dominating everything"
) ? static_cast<void> (0) : __assert_fail ("!VersionStack.empty() && \"Version stack should have liveOnEntry sentinel dominating everything\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1338, __PRETTY_FUNCTION__));
1339 BasicBlock *BackBlock = VersionStack.back()->getBlock();
1340 if (DT->dominates(BackBlock, BB))
1341 break;
1342 while (VersionStack.back()->getBlock() == BackBlock)
1343 VersionStack.pop_back();
1344 ++PopEpoch;
1345 }
1346
1347 for (MemoryAccess &MA : *Accesses) {
1348 auto *MU = dyn_cast<MemoryUse>(&MA);
1349 if (!MU) {
1350 VersionStack.push_back(&MA);
1351 ++StackEpoch;
1352 continue;
1353 }
1354
1355 if (isUseTriviallyOptimizableToLiveOnEntry(*AA, MU->getMemoryInst())) {
1356 MU->setDefiningAccess(MSSA->getLiveOnEntryDef(), true, None);
1357 continue;
1358 }
1359
1360 MemoryLocOrCall UseMLOC(MU);
1361 auto &LocInfo = LocStackInfo[UseMLOC];
1362 // If the pop epoch changed, it means we've removed stuff from top of
1363 // stack due to changing blocks. We may have to reset the lower bound or
1364 // last kill info.
1365 if (LocInfo.PopEpoch != PopEpoch) {
1366 LocInfo.PopEpoch = PopEpoch;
1367 LocInfo.StackEpoch = StackEpoch;
1368 // If the lower bound was in something that no longer dominates us, we
1369 // have to reset it.
1370 // We can't simply track stack size, because the stack may have had
1371 // pushes/pops in the meantime.
1372 // XXX: This is non-optimal, but only is slower cases with heavily
1373 // branching dominator trees. To get the optimal number of queries would
1374 // be to make lowerbound and lastkill a per-loc stack, and pop it until
1375 // the top of that stack dominates us. This does not seem worth it ATM.
1376 // A much cheaper optimization would be to always explore the deepest
1377 // branch of the dominator tree first. This will guarantee this resets on
1378 // the smallest set of blocks.
1379 if (LocInfo.LowerBoundBlock && LocInfo.LowerBoundBlock != BB &&
1380 !DT->dominates(LocInfo.LowerBoundBlock, BB)) {
1381 // Reset the lower bound of things to check.
1382 // TODO: Some day we should be able to reset to last kill, rather than
1383 // 0.
1384 LocInfo.LowerBound = 0;
1385 LocInfo.LowerBoundBlock = VersionStack[0]->getBlock();
1386 LocInfo.LastKillValid = false;
1387 }
1388 } else if (LocInfo.StackEpoch != StackEpoch) {
1389 // If all that has changed is the StackEpoch, we only have to check the
1390 // new things on the stack, because we've checked everything before. In
1391 // this case, the lower bound of things to check remains the same.
1392 LocInfo.PopEpoch = PopEpoch;
1393 LocInfo.StackEpoch = StackEpoch;
1394 }
1395 if (!LocInfo.LastKillValid) {
1396 LocInfo.LastKill = VersionStack.size() - 1;
1397 LocInfo.LastKillValid = true;
1398 LocInfo.AR = MayAlias;
1399 }
1400
1401 // At this point, we should have corrected last kill and LowerBound to be
1402 // in bounds.
1403 assert(LocInfo.LowerBound < VersionStack.size() &&((LocInfo.LowerBound < VersionStack.size() && "Lower bound out of range"
) ? static_cast<void> (0) : __assert_fail ("LocInfo.LowerBound < VersionStack.size() && \"Lower bound out of range\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1404, __PRETTY_FUNCTION__))
1404 "Lower bound out of range")((LocInfo.LowerBound < VersionStack.size() && "Lower bound out of range"
) ? static_cast<void> (0) : __assert_fail ("LocInfo.LowerBound < VersionStack.size() && \"Lower bound out of range\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1404, __PRETTY_FUNCTION__));
1405 assert(LocInfo.LastKill < VersionStack.size() &&((LocInfo.LastKill < VersionStack.size() && "Last kill info out of range"
) ? static_cast<void> (0) : __assert_fail ("LocInfo.LastKill < VersionStack.size() && \"Last kill info out of range\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1406, __PRETTY_FUNCTION__))
1406 "Last kill info out of range")((LocInfo.LastKill < VersionStack.size() && "Last kill info out of range"
) ? static_cast<void> (0) : __assert_fail ("LocInfo.LastKill < VersionStack.size() && \"Last kill info out of range\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1406, __PRETTY_FUNCTION__));
1407 // In any case, the new upper bound is the top of the stack.
1408 unsigned long UpperBound = VersionStack.size() - 1;
1409
1410 if (UpperBound - LocInfo.LowerBound > MaxCheckLimit) {
1411 LLVM_DEBUG(dbgs() << "MemorySSA skipping optimization of " << *MU << " ("do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "MemorySSA skipping optimization of "
<< *MU << " (" << *(MU->getMemoryInst()
) << ")" << " because there are " << UpperBound
- LocInfo.LowerBound << " stores to disambiguate\n"; }
} while (false)
1412 << *(MU->getMemoryInst()) << ")"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "MemorySSA skipping optimization of "
<< *MU << " (" << *(MU->getMemoryInst()
) << ")" << " because there are " << UpperBound
- LocInfo.LowerBound << " stores to disambiguate\n"; }
} while (false)
1413 << " because there are "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "MemorySSA skipping optimization of "
<< *MU << " (" << *(MU->getMemoryInst()
) << ")" << " because there are " << UpperBound
- LocInfo.LowerBound << " stores to disambiguate\n"; }
} while (false)
1414 << UpperBound - LocInfo.LowerBounddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "MemorySSA skipping optimization of "
<< *MU << " (" << *(MU->getMemoryInst()
) << ")" << " because there are " << UpperBound
- LocInfo.LowerBound << " stores to disambiguate\n"; }
} while (false)
1415 << " stores to disambiguate\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "MemorySSA skipping optimization of "
<< *MU << " (" << *(MU->getMemoryInst()
) << ")" << " because there are " << UpperBound
- LocInfo.LowerBound << " stores to disambiguate\n"; }
} while (false);
1416 // Because we did not walk, LastKill is no longer valid, as this may
1417 // have been a kill.
1418 LocInfo.LastKillValid = false;
1419 continue;
1420 }
1421 bool FoundClobberResult = false;
1422 unsigned UpwardWalkLimit = MaxCheckLimit;
1423 while (UpperBound > LocInfo.LowerBound) {
1424 if (isa<MemoryPhi>(VersionStack[UpperBound])) {
1425 // For phis, use the walker, see where we ended up, go there
1426 MemoryAccess *Result =
1427 Walker->getClobberingMemoryAccess(MU, UpwardWalkLimit);
1428 // We are guaranteed to find it or something is wrong
1429 while (VersionStack[UpperBound] != Result) {
1430 assert(UpperBound != 0)((UpperBound != 0) ? static_cast<void> (0) : __assert_fail
("UpperBound != 0", "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1430, __PRETTY_FUNCTION__));
1431 --UpperBound;
1432 }
1433 FoundClobberResult = true;
1434 break;
1435 }
1436
1437 MemoryDef *MD = cast<MemoryDef>(VersionStack[UpperBound]);
1438 // If the lifetime of the pointer ends at this instruction, it's live on
1439 // entry.
1440 if (!UseMLOC.IsCall && lifetimeEndsAt(MD, UseMLOC.getLoc(), *AA)) {
1441 // Reset UpperBound to liveOnEntryDef's place in the stack
1442 UpperBound = 0;
1443 FoundClobberResult = true;
1444 LocInfo.AR = MustAlias;
1445 break;
1446 }
1447 ClobberAlias CA = instructionClobbersQuery(MD, MU, UseMLOC, *AA);
1448 if (CA.IsClobber) {
1449 FoundClobberResult = true;
1450 LocInfo.AR = CA.AR;
1451 break;
1452 }
1453 --UpperBound;
1454 }
1455
1456 // Note: Phis always have AliasResult AR set to MayAlias ATM.
1457
1458 // At the end of this loop, UpperBound is either a clobber, or lower bound
1459 // PHI walking may cause it to be < LowerBound, and in fact, < LastKill.
1460 if (FoundClobberResult || UpperBound < LocInfo.LastKill) {
1461 // We were last killed now by where we got to
1462 if (MSSA->isLiveOnEntryDef(VersionStack[UpperBound]))
1463 LocInfo.AR = None;
1464 MU->setDefiningAccess(VersionStack[UpperBound], true, LocInfo.AR);
1465 LocInfo.LastKill = UpperBound;
1466 } else {
1467 // Otherwise, we checked all the new ones, and now we know we can get to
1468 // LastKill.
1469 MU->setDefiningAccess(VersionStack[LocInfo.LastKill], true, LocInfo.AR);
1470 }
1471 LocInfo.LowerBound = VersionStack.size() - 1;
1472 LocInfo.LowerBoundBlock = BB;
1473 }
1474}
1475
1476/// Optimize uses to point to their actual clobbering definitions.
1477void MemorySSA::OptimizeUses::optimizeUses() {
1478 SmallVector<MemoryAccess *, 16> VersionStack;
1479 DenseMap<MemoryLocOrCall, MemlocStackInfo> LocStackInfo;
1480 VersionStack.push_back(MSSA->getLiveOnEntryDef());
1481
1482 unsigned long StackEpoch = 1;
1483 unsigned long PopEpoch = 1;
1484 // We perform a non-recursive top-down dominator tree walk.
1485 for (const auto *DomNode : depth_first(DT->getRootNode()))
1486 optimizeUsesInBlock(DomNode->getBlock(), StackEpoch, PopEpoch, VersionStack,
1487 LocStackInfo);
1488}
1489
1490void MemorySSA::placePHINodes(
1491 const SmallPtrSetImpl<BasicBlock *> &DefiningBlocks) {
1492 // Determine where our MemoryPhi's should go
1493 ForwardIDFCalculator IDFs(*DT);
1494 IDFs.setDefiningBlocks(DefiningBlocks);
1495 SmallVector<BasicBlock *, 32> IDFBlocks;
1496 IDFs.calculate(IDFBlocks);
1497
1498 // Now place MemoryPhi nodes.
1499 for (auto &BB : IDFBlocks)
1500 createMemoryPhi(BB);
1501}
1502
1503void MemorySSA::buildMemorySSA(BatchAAResults &BAA) {
1504 // We create an access to represent "live on entry", for things like
1505 // arguments or users of globals, where the memory they use is defined before
1506 // the beginning of the function. We do not actually insert it into the IR.
1507 // We do not define a live on exit for the immediate uses, and thus our
1508 // semantics do *not* imply that something with no immediate uses can simply
1509 // be removed.
1510 BasicBlock &StartingPoint = F.getEntryBlock();
1511 LiveOnEntryDef.reset(new MemoryDef(F.getContext(), nullptr, nullptr,
1512 &StartingPoint, NextID++));
1513
1514 // We maintain lists of memory accesses per-block, trading memory for time. We
1515 // could just look up the memory access for every possible instruction in the
1516 // stream.
1517 SmallPtrSet<BasicBlock *, 32> DefiningBlocks;
1518 // Go through each block, figure out where defs occur, and chain together all
1519 // the accesses.
1520 for (BasicBlock &B : F) {
1521 bool InsertIntoDef = false;
1522 AccessList *Accesses = nullptr;
1523 DefsList *Defs = nullptr;
1524 for (Instruction &I : B) {
1525 MemoryUseOrDef *MUD = createNewAccess(&I, &BAA);
1526 if (!MUD)
1527 continue;
1528
1529 if (!Accesses)
1530 Accesses = getOrCreateAccessList(&B);
1531 Accesses->push_back(MUD);
1532 if (isa<MemoryDef>(MUD)) {
1533 InsertIntoDef = true;
1534 if (!Defs)
1535 Defs = getOrCreateDefsList(&B);
1536 Defs->push_back(*MUD);
1537 }
1538 }
1539 if (InsertIntoDef)
1540 DefiningBlocks.insert(&B);
1541 }
1542 placePHINodes(DefiningBlocks);
1543
1544 // Now do regular SSA renaming on the MemoryDef/MemoryUse. Visited will get
1545 // filled in with all blocks.
1546 SmallPtrSet<BasicBlock *, 16> Visited;
1547 renamePass(DT->getRootNode(), LiveOnEntryDef.get(), Visited);
1548
1549 ClobberWalkerBase<BatchAAResults> WalkerBase(this, &BAA, DT);
1550 CachingWalker<BatchAAResults> WalkerLocal(this, &WalkerBase);
1551 OptimizeUses(this, &WalkerLocal, &BAA, DT).optimizeUses();
1552
1553 // Mark the uses in unreachable blocks as live on entry, so that they go
1554 // somewhere.
1555 for (auto &BB : F)
1556 if (!Visited.count(&BB))
1557 markUnreachableAsLiveOnEntry(&BB);
1558}
1559
1560MemorySSAWalker *MemorySSA::getWalker() { return getWalkerImpl(); }
1561
1562MemorySSA::CachingWalker<AliasAnalysis> *MemorySSA::getWalkerImpl() {
1563 if (Walker)
1564 return Walker.get();
1565
1566 if (!WalkerBase)
1567 WalkerBase =
1568 std::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
1569
1570 Walker =
1571 std::make_unique<CachingWalker<AliasAnalysis>>(this, WalkerBase.get());
1572 return Walker.get();
1573}
1574
1575MemorySSAWalker *MemorySSA::getSkipSelfWalker() {
1576 if (SkipWalker)
1577 return SkipWalker.get();
1578
1579 if (!WalkerBase)
1580 WalkerBase =
1581 std::make_unique<ClobberWalkerBase<AliasAnalysis>>(this, AA, DT);
1582
1583 SkipWalker =
1584 std::make_unique<SkipSelfWalker<AliasAnalysis>>(this, WalkerBase.get());
1585 return SkipWalker.get();
1586 }
1587
1588
1589// This is a helper function used by the creation routines. It places NewAccess
1590// into the access and defs lists for a given basic block, at the given
1591// insertion point.
1592void MemorySSA::insertIntoListsForBlock(MemoryAccess *NewAccess,
1593 const BasicBlock *BB,
1594 InsertionPlace Point) {
1595 auto *Accesses = getOrCreateAccessList(BB);
1596 if (Point == Beginning) {
1597 // If it's a phi node, it goes first, otherwise, it goes after any phi
1598 // nodes.
1599 if (isa<MemoryPhi>(NewAccess)) {
1600 Accesses->push_front(NewAccess);
1601 auto *Defs = getOrCreateDefsList(BB);
1602 Defs->push_front(*NewAccess);
1603 } else {
1604 auto AI = find_if_not(
1605 *Accesses, [](const MemoryAccess &MA) { return isa<MemoryPhi>(MA); });
1606 Accesses->insert(AI, NewAccess);
1607 if (!isa<MemoryUse>(NewAccess)) {
1608 auto *Defs = getOrCreateDefsList(BB);
1609 auto DI = find_if_not(
1610 *Defs, [](const MemoryAccess &MA) { return isa<MemoryPhi>(MA); });
1611 Defs->insert(DI, *NewAccess);
1612 }
1613 }
1614 } else {
1615 Accesses->push_back(NewAccess);
1616 if (!isa<MemoryUse>(NewAccess)) {
1617 auto *Defs = getOrCreateDefsList(BB);
1618 Defs->push_back(*NewAccess);
1619 }
1620 }
1621 BlockNumberingValid.erase(BB);
1622}
1623
1624void MemorySSA::insertIntoListsBefore(MemoryAccess *What, const BasicBlock *BB,
1625 AccessList::iterator InsertPt) {
1626 auto *Accesses = getWritableBlockAccesses(BB);
1627 bool WasEnd = InsertPt == Accesses->end();
1628 Accesses->insert(AccessList::iterator(InsertPt), What);
1629 if (!isa<MemoryUse>(What)) {
1630 auto *Defs = getOrCreateDefsList(BB);
1631 // If we got asked to insert at the end, we have an easy job, just shove it
1632 // at the end. If we got asked to insert before an existing def, we also get
1633 // an iterator. If we got asked to insert before a use, we have to hunt for
1634 // the next def.
1635 if (WasEnd) {
1636 Defs->push_back(*What);
1637 } else if (isa<MemoryDef>(InsertPt)) {
1638 Defs->insert(InsertPt->getDefsIterator(), *What);
1639 } else {
1640 while (InsertPt != Accesses->end() && !isa<MemoryDef>(InsertPt))
1641 ++InsertPt;
1642 // Either we found a def, or we are inserting at the end
1643 if (InsertPt == Accesses->end())
1644 Defs->push_back(*What);
1645 else
1646 Defs->insert(InsertPt->getDefsIterator(), *What);
1647 }
1648 }
1649 BlockNumberingValid.erase(BB);
1650}
1651
1652void MemorySSA::prepareForMoveTo(MemoryAccess *What, BasicBlock *BB) {
1653 // Keep it in the lookup tables, remove from the lists
1654 removeFromLists(What, false);
1655
1656 // Note that moving should implicitly invalidate the optimized state of a
1657 // MemoryUse (and Phis can't be optimized). However, it doesn't do so for a
1658 // MemoryDef.
1659 if (auto *MD = dyn_cast<MemoryDef>(What))
1660 MD->resetOptimized();
1661 What->setBlock(BB);
1662}
1663
1664// Move What before Where in the IR. The end result is that What will belong to
1665// the right lists and have the right Block set, but will not otherwise be
1666// correct. It will not have the right defining access, and if it is a def,
1667// things below it will not properly be updated.
1668void MemorySSA::moveTo(MemoryUseOrDef *What, BasicBlock *BB,
1669 AccessList::iterator Where) {
1670 prepareForMoveTo(What, BB);
1671 insertIntoListsBefore(What, BB, Where);
1672}
1673
1674void MemorySSA::moveTo(MemoryAccess *What, BasicBlock *BB,
1675 InsertionPlace Point) {
1676 if (isa<MemoryPhi>(What)) {
1677 assert(Point == Beginning &&((Point == Beginning && "Can only move a Phi at the beginning of the block"
) ? static_cast<void> (0) : __assert_fail ("Point == Beginning && \"Can only move a Phi at the beginning of the block\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1678, __PRETTY_FUNCTION__))
1678 "Can only move a Phi at the beginning of the block")((Point == Beginning && "Can only move a Phi at the beginning of the block"
) ? static_cast<void> (0) : __assert_fail ("Point == Beginning && \"Can only move a Phi at the beginning of the block\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1678, __PRETTY_FUNCTION__));
1679 // Update lookup table entry
1680 ValueToMemoryAccess.erase(What->getBlock());
1681 bool Inserted = ValueToMemoryAccess.insert({BB, What}).second;
1682 (void)Inserted;
1683 assert(Inserted && "Cannot move a Phi to a block that already has one")((Inserted && "Cannot move a Phi to a block that already has one"
) ? static_cast<void> (0) : __assert_fail ("Inserted && \"Cannot move a Phi to a block that already has one\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1683, __PRETTY_FUNCTION__));
1684 }
1685
1686 prepareForMoveTo(What, BB);
1687 insertIntoListsForBlock(What, BB, Point);
1688}
1689
1690MemoryPhi *MemorySSA::createMemoryPhi(BasicBlock *BB) {
1691 assert(!getMemoryAccess(BB) && "MemoryPhi already exists for this BB")((!getMemoryAccess(BB) && "MemoryPhi already exists for this BB"
) ? static_cast<void> (0) : __assert_fail ("!getMemoryAccess(BB) && \"MemoryPhi already exists for this BB\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1691, __PRETTY_FUNCTION__));
1692 MemoryPhi *Phi = new MemoryPhi(BB->getContext(), BB, NextID++);
1693 // Phi's always are placed at the front of the block.
1694 insertIntoListsForBlock(Phi, BB, Beginning);
1695 ValueToMemoryAccess[BB] = Phi;
1696 return Phi;
1697}
1698
1699MemoryUseOrDef *MemorySSA::createDefinedAccess(Instruction *I,
1700 MemoryAccess *Definition,
1701 const MemoryUseOrDef *Template,
1702 bool CreationMustSucceed) {
1703 assert(!isa<PHINode>(I) && "Cannot create a defined access for a PHI")((!isa<PHINode>(I) && "Cannot create a defined access for a PHI"
) ? static_cast<void> (0) : __assert_fail ("!isa<PHINode>(I) && \"Cannot create a defined access for a PHI\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1703, __PRETTY_FUNCTION__));
1704 MemoryUseOrDef *NewAccess = createNewAccess(I, AA, Template);
1705 if (CreationMustSucceed)
1706 assert(NewAccess != nullptr && "Tried to create a memory access for a "((NewAccess != nullptr && "Tried to create a memory access for a "
"non-memory touching instruction") ? static_cast<void>
(0) : __assert_fail ("NewAccess != nullptr && \"Tried to create a memory access for a \" \"non-memory touching instruction\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1707, __PRETTY_FUNCTION__))
1707 "non-memory touching instruction")((NewAccess != nullptr && "Tried to create a memory access for a "
"non-memory touching instruction") ? static_cast<void>
(0) : __assert_fail ("NewAccess != nullptr && \"Tried to create a memory access for a \" \"non-memory touching instruction\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1707, __PRETTY_FUNCTION__));
1708 if (NewAccess)
1709 NewAccess->setDefiningAccess(Definition);
1710 return NewAccess;
1711}
1712
1713// Return true if the instruction has ordering constraints.
1714// Note specifically that this only considers stores and loads
1715// because others are still considered ModRef by getModRefInfo.
1716static inline bool isOrdered(const Instruction *I) {
1717 if (auto *SI = dyn_cast<StoreInst>(I)) {
1718 if (!SI->isUnordered())
1719 return true;
1720 } else if (auto *LI = dyn_cast<LoadInst>(I)) {
1721 if (!LI->isUnordered())
1722 return true;
1723 }
1724 return false;
1725}
1726
1727/// Helper function to create new memory accesses
1728template <typename AliasAnalysisType>
1729MemoryUseOrDef *MemorySSA::createNewAccess(Instruction *I,
1730 AliasAnalysisType *AAP,
1731 const MemoryUseOrDef *Template) {
1732 // The assume intrinsic has a control dependency which we model by claiming
1733 // that it writes arbitrarily. Debuginfo intrinsics may be considered
1734 // clobbers when we have a nonstandard AA pipeline. Ignore these fake memory
1735 // dependencies here.
1736 // FIXME: Replace this special casing with a more accurate modelling of
1737 // assume's control dependency.
1738 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
1739 if (II->getIntrinsicID() == Intrinsic::assume)
1740 return nullptr;
1741
1742 // Using a nonstandard AA pipelines might leave us with unexpected modref
1743 // results for I, so add a check to not model instructions that may not read
1744 // from or write to memory. This is necessary for correctness.
1745 if (!I->mayReadFromMemory() && !I->mayWriteToMemory())
1746 return nullptr;
1747
1748 bool Def, Use;
1749 if (Template) {
1750 Def = dyn_cast_or_null<MemoryDef>(Template) != nullptr;
1751 Use = dyn_cast_or_null<MemoryUse>(Template) != nullptr;
1752#if !defined(NDEBUG)
1753 ModRefInfo ModRef = AAP->getModRefInfo(I, None);
1754 bool DefCheck, UseCheck;
1755 DefCheck = isModSet(ModRef) || isOrdered(I);
1756 UseCheck = isRefSet(ModRef);
1757 assert(Def == DefCheck && (Def || Use == UseCheck) && "Invalid template")((Def == DefCheck && (Def || Use == UseCheck) &&
"Invalid template") ? static_cast<void> (0) : __assert_fail
("Def == DefCheck && (Def || Use == UseCheck) && \"Invalid template\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1757, __PRETTY_FUNCTION__));
1758#endif
1759 } else {
1760 // Find out what affect this instruction has on memory.
1761 ModRefInfo ModRef = AAP->getModRefInfo(I, None);
1762 // The isOrdered check is used to ensure that volatiles end up as defs
1763 // (atomics end up as ModRef right now anyway). Until we separate the
1764 // ordering chain from the memory chain, this enables people to see at least
1765 // some relative ordering to volatiles. Note that getClobberingMemoryAccess
1766 // will still give an answer that bypasses other volatile loads. TODO:
1767 // Separate memory aliasing and ordering into two different chains so that
1768 // we can precisely represent both "what memory will this read/write/is
1769 // clobbered by" and "what instructions can I move this past".
1770 Def = isModSet(ModRef) || isOrdered(I);
1771 Use = isRefSet(ModRef);
1772 }
1773
1774 // It's possible for an instruction to not modify memory at all. During
1775 // construction, we ignore them.
1776 if (!Def && !Use)
1777 return nullptr;
1778
1779 MemoryUseOrDef *MUD;
1780 if (Def)
1781 MUD = new MemoryDef(I->getContext(), nullptr, I, I->getParent(), NextID++);
1782 else
1783 MUD = new MemoryUse(I->getContext(), nullptr, I, I->getParent());
1784 ValueToMemoryAccess[I] = MUD;
1785 return MUD;
1786}
1787
1788/// Returns true if \p Replacer dominates \p Replacee .
1789bool MemorySSA::dominatesUse(const MemoryAccess *Replacer,
1790 const MemoryAccess *Replacee) const {
1791 if (isa<MemoryUseOrDef>(Replacee))
1792 return DT->dominates(Replacer->getBlock(), Replacee->getBlock());
1793 const auto *MP = cast<MemoryPhi>(Replacee);
1794 // For a phi node, the use occurs in the predecessor block of the phi node.
1795 // Since we may occur multiple times in the phi node, we have to check each
1796 // operand to ensure Replacer dominates each operand where Replacee occurs.
1797 for (const Use &Arg : MP->operands()) {
1798 if (Arg.get() != Replacee &&
1799 !DT->dominates(Replacer->getBlock(), MP->getIncomingBlock(Arg)))
1800 return false;
1801 }
1802 return true;
1803}
1804
1805/// Properly remove \p MA from all of MemorySSA's lookup tables.
1806void MemorySSA::removeFromLookups(MemoryAccess *MA) {
1807 assert(MA->use_empty() &&((MA->use_empty() && "Trying to remove memory access that still has uses"
) ? static_cast<void> (0) : __assert_fail ("MA->use_empty() && \"Trying to remove memory access that still has uses\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1808, __PRETTY_FUNCTION__))
1808 "Trying to remove memory access that still has uses")((MA->use_empty() && "Trying to remove memory access that still has uses"
) ? static_cast<void> (0) : __assert_fail ("MA->use_empty() && \"Trying to remove memory access that still has uses\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1808, __PRETTY_FUNCTION__));
1809 BlockNumbering.erase(MA);
1810 if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
1811 MUD->setDefiningAccess(nullptr);
1812 // Invalidate our walker's cache if necessary
1813 if (!isa<MemoryUse>(MA))
1814 getWalker()->invalidateInfo(MA);
1815
1816 Value *MemoryInst;
1817 if (const auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
1818 MemoryInst = MUD->getMemoryInst();
1819 else
1820 MemoryInst = MA->getBlock();
1821
1822 auto VMA = ValueToMemoryAccess.find(MemoryInst);
1823 if (VMA->second == MA)
1824 ValueToMemoryAccess.erase(VMA);
1825}
1826
1827/// Properly remove \p MA from all of MemorySSA's lists.
1828///
1829/// Because of the way the intrusive list and use lists work, it is important to
1830/// do removal in the right order.
1831/// ShouldDelete defaults to true, and will cause the memory access to also be
1832/// deleted, not just removed.
1833void MemorySSA::removeFromLists(MemoryAccess *MA, bool ShouldDelete) {
1834 BasicBlock *BB = MA->getBlock();
1835 // The access list owns the reference, so we erase it from the non-owning list
1836 // first.
1837 if (!isa<MemoryUse>(MA)) {
1838 auto DefsIt = PerBlockDefs.find(BB);
1839 std::unique_ptr<DefsList> &Defs = DefsIt->second;
1840 Defs->remove(*MA);
1841 if (Defs->empty())
1842 PerBlockDefs.erase(DefsIt);
1843 }
1844
1845 // The erase call here will delete it. If we don't want it deleted, we call
1846 // remove instead.
1847 auto AccessIt = PerBlockAccesses.find(BB);
1848 std::unique_ptr<AccessList> &Accesses = AccessIt->second;
1849 if (ShouldDelete)
1850 Accesses->erase(MA);
1851 else
1852 Accesses->remove(MA);
1853
1854 if (Accesses->empty()) {
1855 PerBlockAccesses.erase(AccessIt);
1856 BlockNumberingValid.erase(BB);
1857 }
1858}
1859
1860void MemorySSA::print(raw_ostream &OS) const {
1861 MemorySSAAnnotatedWriter Writer(this);
1862 F.print(OS, &Writer);
1863}
1864
1865#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1866LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void MemorySSA::dump() const { print(dbgs()); }
1867#endif
1868
1869void MemorySSA::verifyMemorySSA() const {
1870 verifyDefUses(F);
1871 verifyDomination(F);
1872 verifyOrdering(F);
1873 verifyDominationNumbers(F);
1874 verifyPrevDefInPhis(F);
1875 // Previously, the verification used to also verify that the clobberingAccess
1876 // cached by MemorySSA is the same as the clobberingAccess found at a later
1877 // query to AA. This does not hold true in general due to the current fragility
1878 // of BasicAA which has arbitrary caps on the things it analyzes before giving
1879 // up. As a result, transformations that are correct, will lead to BasicAA
1880 // returning different Alias answers before and after that transformation.
1881 // Invalidating MemorySSA is not an option, as the results in BasicAA can be so
1882 // random, in the worst case we'd need to rebuild MemorySSA from scratch after
1883 // every transformation, which defeats the purpose of using it. For such an
1884 // example, see test4 added in D51960.
1885}
1886
1887void MemorySSA::verifyPrevDefInPhis(Function &F) const {
1888#if !defined(NDEBUG) && defined(EXPENSIVE_CHECKS)
1889 for (const BasicBlock &BB : F) {
1890 if (MemoryPhi *Phi = getMemoryAccess(&BB)) {
1891 for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
1892 auto *Pred = Phi->getIncomingBlock(I);
1893 auto *IncAcc = Phi->getIncomingValue(I);
1894 // If Pred has no unreachable predecessors, get last def looking at
1895 // IDoms. If, while walkings IDoms, any of these has an unreachable
1896 // predecessor, then the incoming def can be any access.
1897 if (auto *DTNode = DT->getNode(Pred)) {
1898 while (DTNode) {
1899 if (auto *DefList = getBlockDefs(DTNode->getBlock())) {
1900 auto *LastAcc = &*(--DefList->end());
1901 assert(LastAcc == IncAcc &&((LastAcc == IncAcc && "Incorrect incoming access into phi."
) ? static_cast<void> (0) : __assert_fail ("LastAcc == IncAcc && \"Incorrect incoming access into phi.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1902, __PRETTY_FUNCTION__))
1902 "Incorrect incoming access into phi.")((LastAcc == IncAcc && "Incorrect incoming access into phi."
) ? static_cast<void> (0) : __assert_fail ("LastAcc == IncAcc && \"Incorrect incoming access into phi.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1902, __PRETTY_FUNCTION__));
1903 break;
1904 }
1905 DTNode = DTNode->getIDom();
1906 }
1907 } else {
1908 // If Pred has unreachable predecessors, but has at least a Def, the
1909 // incoming access can be the last Def in Pred, or it could have been
1910 // optimized to LoE. After an update, though, the LoE may have been
1911 // replaced by another access, so IncAcc may be any access.
1912 // If Pred has unreachable predecessors and no Defs, incoming access
1913 // should be LoE; However, after an update, it may be any access.
1914 }
1915 }
1916 }
1917 }
1918#endif
1919}
1920
1921/// Verify that all of the blocks we believe to have valid domination numbers
1922/// actually have valid domination numbers.
1923void MemorySSA::verifyDominationNumbers(const Function &F) const {
1924#ifndef NDEBUG
1925 if (BlockNumberingValid.empty())
1926 return;
1927
1928 SmallPtrSet<const BasicBlock *, 16> ValidBlocks = BlockNumberingValid;
1929 for (const BasicBlock &BB : F) {
1930 if (!ValidBlocks.count(&BB))
1931 continue;
1932
1933 ValidBlocks.erase(&BB);
1934
1935 const AccessList *Accesses = getBlockAccesses(&BB);
1936 // It's correct to say an empty block has valid numbering.
1937 if (!Accesses)
1938 continue;
1939
1940 // Block numbering starts at 1.
1941 unsigned long LastNumber = 0;
1942 for (const MemoryAccess &MA : *Accesses) {
1943 auto ThisNumberIter = BlockNumbering.find(&MA);
1944 assert(ThisNumberIter != BlockNumbering.end() &&((ThisNumberIter != BlockNumbering.end() && "MemoryAccess has no domination number in a valid block!"
) ? static_cast<void> (0) : __assert_fail ("ThisNumberIter != BlockNumbering.end() && \"MemoryAccess has no domination number in a valid block!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1945, __PRETTY_FUNCTION__))
1945 "MemoryAccess has no domination number in a valid block!")((ThisNumberIter != BlockNumbering.end() && "MemoryAccess has no domination number in a valid block!"
) ? static_cast<void> (0) : __assert_fail ("ThisNumberIter != BlockNumbering.end() && \"MemoryAccess has no domination number in a valid block!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1945, __PRETTY_FUNCTION__));
1946
1947 unsigned long ThisNumber = ThisNumberIter->second;
1948 assert(ThisNumber > LastNumber &&((ThisNumber > LastNumber && "Domination numbers should be strictly increasing!"
) ? static_cast<void> (0) : __assert_fail ("ThisNumber > LastNumber && \"Domination numbers should be strictly increasing!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1949, __PRETTY_FUNCTION__))
1949 "Domination numbers should be strictly increasing!")((ThisNumber > LastNumber && "Domination numbers should be strictly increasing!"
) ? static_cast<void> (0) : __assert_fail ("ThisNumber > LastNumber && \"Domination numbers should be strictly increasing!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1949, __PRETTY_FUNCTION__));
1950 LastNumber = ThisNumber;
1951 }
1952 }
1953
1954 assert(ValidBlocks.empty() &&((ValidBlocks.empty() && "All valid BasicBlocks should exist in F -- dangling pointers?"
) ? static_cast<void> (0) : __assert_fail ("ValidBlocks.empty() && \"All valid BasicBlocks should exist in F -- dangling pointers?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1955, __PRETTY_FUNCTION__))
1955 "All valid BasicBlocks should exist in F -- dangling pointers?")((ValidBlocks.empty() && "All valid BasicBlocks should exist in F -- dangling pointers?"
) ? static_cast<void> (0) : __assert_fail ("ValidBlocks.empty() && \"All valid BasicBlocks should exist in F -- dangling pointers?\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1955, __PRETTY_FUNCTION__));
1956#endif
1957}
1958
1959/// Verify that the order and existence of MemoryAccesses matches the
1960/// order and existence of memory affecting instructions.
1961void MemorySSA::verifyOrdering(Function &F) const {
1962#ifndef NDEBUG
1963 // Walk all the blocks, comparing what the lookups think and what the access
1964 // lists think, as well as the order in the blocks vs the order in the access
1965 // lists.
1966 SmallVector<MemoryAccess *, 32> ActualAccesses;
1967 SmallVector<MemoryAccess *, 32> ActualDefs;
1968 for (BasicBlock &B : F) {
1969 const AccessList *AL = getBlockAccesses(&B);
1970 const auto *DL = getBlockDefs(&B);
1971 MemoryAccess *Phi = getMemoryAccess(&B);
1972 if (Phi) {
1973 ActualAccesses.push_back(Phi);
1974 ActualDefs.push_back(Phi);
1975 }
1976
1977 for (Instruction &I : B) {
1978 MemoryAccess *MA = getMemoryAccess(&I);
1979 assert((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&(((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&
"We have memory affecting instructions " "in this block but they are not in the "
"access list or defs list") ? static_cast<void> (0) : __assert_fail
("(!MA || (AL && (isa<MemoryUse>(MA) || DL))) && \"We have memory affecting instructions \" \"in this block but they are not in the \" \"access list or defs list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1982, __PRETTY_FUNCTION__))
1980 "We have memory affecting instructions "(((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&
"We have memory affecting instructions " "in this block but they are not in the "
"access list or defs list") ? static_cast<void> (0) : __assert_fail
("(!MA || (AL && (isa<MemoryUse>(MA) || DL))) && \"We have memory affecting instructions \" \"in this block but they are not in the \" \"access list or defs list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1982, __PRETTY_FUNCTION__))
1981 "in this block but they are not in the "(((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&
"We have memory affecting instructions " "in this block but they are not in the "
"access list or defs list") ? static_cast<void> (0) : __assert_fail
("(!MA || (AL && (isa<MemoryUse>(MA) || DL))) && \"We have memory affecting instructions \" \"in this block but they are not in the \" \"access list or defs list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1982, __PRETTY_FUNCTION__))
1982 "access list or defs list")(((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&
"We have memory affecting instructions " "in this block but they are not in the "
"access list or defs list") ? static_cast<void> (0) : __assert_fail
("(!MA || (AL && (isa<MemoryUse>(MA) || DL))) && \"We have memory affecting instructions \" \"in this block but they are not in the \" \"access list or defs list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1982, __PRETTY_FUNCTION__));
1983 if (MA) {
1984 ActualAccesses.push_back(MA);
1985 if (isa<MemoryDef>(MA))
1986 ActualDefs.push_back(MA);
1987 }
1988 }
1989 // Either we hit the assert, really have no accesses, or we have both
1990 // accesses and an access list.
1991 // Same with defs.
1992 if (!AL && !DL)
1993 continue;
1994 assert(AL->size() == ActualAccesses.size() &&((AL->size() == ActualAccesses.size() && "We don't have the same number of accesses in the block as on the "
"access list") ? static_cast<void> (0) : __assert_fail
("AL->size() == ActualAccesses.size() && \"We don't have the same number of accesses in the block as on the \" \"access list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1996, __PRETTY_FUNCTION__))
1995 "We don't have the same number of accesses in the block as on the "((AL->size() == ActualAccesses.size() && "We don't have the same number of accesses in the block as on the "
"access list") ? static_cast<void> (0) : __assert_fail
("AL->size() == ActualAccesses.size() && \"We don't have the same number of accesses in the block as on the \" \"access list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1996, __PRETTY_FUNCTION__))
1996 "access list")((AL->size() == ActualAccesses.size() && "We don't have the same number of accesses in the block as on the "
"access list") ? static_cast<void> (0) : __assert_fail
("AL->size() == ActualAccesses.size() && \"We don't have the same number of accesses in the block as on the \" \"access list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1996, __PRETTY_FUNCTION__));
1997 assert((DL || ActualDefs.size() == 0) &&(((DL || ActualDefs.size() == 0) && "Either we should have a defs list, or we should have no defs"
) ? static_cast<void> (0) : __assert_fail ("(DL || ActualDefs.size() == 0) && \"Either we should have a defs list, or we should have no defs\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1998, __PRETTY_FUNCTION__))
1998 "Either we should have a defs list, or we should have no defs")(((DL || ActualDefs.size() == 0) && "Either we should have a defs list, or we should have no defs"
) ? static_cast<void> (0) : __assert_fail ("(DL || ActualDefs.size() == 0) && \"Either we should have a defs list, or we should have no defs\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 1998, __PRETTY_FUNCTION__));
1999 assert((!DL || DL->size() == ActualDefs.size()) &&(((!DL || DL->size() == ActualDefs.size()) && "We don't have the same number of defs in the block as on the "
"def list") ? static_cast<void> (0) : __assert_fail ("(!DL || DL->size() == ActualDefs.size()) && \"We don't have the same number of defs in the block as on the \" \"def list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2001, __PRETTY_FUNCTION__))
2000 "We don't have the same number of defs in the block as on the "(((!DL || DL->size() == ActualDefs.size()) && "We don't have the same number of defs in the block as on the "
"def list") ? static_cast<void> (0) : __assert_fail ("(!DL || DL->size() == ActualDefs.size()) && \"We don't have the same number of defs in the block as on the \" \"def list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2001, __PRETTY_FUNCTION__))
2001 "def list")(((!DL || DL->size() == ActualDefs.size()) && "We don't have the same number of defs in the block as on the "
"def list") ? static_cast<void> (0) : __assert_fail ("(!DL || DL->size() == ActualDefs.size()) && \"We don't have the same number of defs in the block as on the \" \"def list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2001, __PRETTY_FUNCTION__));
2002 auto ALI = AL->begin();
2003 auto AAI = ActualAccesses.begin();
2004 while (ALI != AL->end() && AAI != ActualAccesses.end()) {
2005 assert(&*ALI == *AAI && "Not the same accesses in the same order")((&*ALI == *AAI && "Not the same accesses in the same order"
) ? static_cast<void> (0) : __assert_fail ("&*ALI == *AAI && \"Not the same accesses in the same order\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2005, __PRETTY_FUNCTION__));
2006 ++ALI;
2007 ++AAI;
2008 }
2009 ActualAccesses.clear();
2010 if (DL) {
2011 auto DLI = DL->begin();
2012 auto ADI = ActualDefs.begin();
2013 while (DLI != DL->end() && ADI != ActualDefs.end()) {
2014 assert(&*DLI == *ADI && "Not the same defs in the same order")((&*DLI == *ADI && "Not the same defs in the same order"
) ? static_cast<void> (0) : __assert_fail ("&*DLI == *ADI && \"Not the same defs in the same order\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2014, __PRETTY_FUNCTION__));
2015 ++DLI;
2016 ++ADI;
2017 }
2018 }
2019 ActualDefs.clear();
2020 }
2021#endif
2022}
2023
2024/// Verify the domination properties of MemorySSA by checking that each
2025/// definition dominates all of its uses.
2026void MemorySSA::verifyDomination(Function &F) const {
2027#ifndef NDEBUG
2028 for (BasicBlock &B : F) {
2029 // Phi nodes are attached to basic blocks
2030 if (MemoryPhi *MP = getMemoryAccess(&B))
2031 for (const Use &U : MP->uses())
2032 assert(dominates(MP, U) && "Memory PHI does not dominate it's uses")((dominates(MP, U) && "Memory PHI does not dominate it's uses"
) ? static_cast<void> (0) : __assert_fail ("dominates(MP, U) && \"Memory PHI does not dominate it's uses\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2032, __PRETTY_FUNCTION__));
2033
2034 for (Instruction &I : B) {
2035 MemoryAccess *MD = dyn_cast_or_null<MemoryDef>(getMemoryAccess(&I));
2036 if (!MD)
2037 continue;
2038
2039 for (const Use &U : MD->uses())
2040 assert(dominates(MD, U) && "Memory Def does not dominate it's uses")((dominates(MD, U) && "Memory Def does not dominate it's uses"
) ? static_cast<void> (0) : __assert_fail ("dominates(MD, U) && \"Memory Def does not dominate it's uses\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2040, __PRETTY_FUNCTION__));
2041 }
2042 }
2043#endif
2044}
2045
2046/// Verify the def-use lists in MemorySSA, by verifying that \p Use
2047/// appears in the use list of \p Def.
2048void MemorySSA::verifyUseInDefs(MemoryAccess *Def, MemoryAccess *Use) const {
2049#ifndef NDEBUG
2050 // The live on entry use may cause us to get a NULL def here
2051 if (!Def)
2052 assert(isLiveOnEntryDef(Use) &&((isLiveOnEntryDef(Use) && "Null def but use not point to live on entry def"
) ? static_cast<void> (0) : __assert_fail ("isLiveOnEntryDef(Use) && \"Null def but use not point to live on entry def\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2053, __PRETTY_FUNCTION__))
2053 "Null def but use not point to live on entry def")((isLiveOnEntryDef(Use) && "Null def but use not point to live on entry def"
) ? static_cast<void> (0) : __assert_fail ("isLiveOnEntryDef(Use) && \"Null def but use not point to live on entry def\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2053, __PRETTY_FUNCTION__));
2054 else
2055 assert(is_contained(Def->users(), Use) &&((is_contained(Def->users(), Use) && "Did not find use in def's use list"
) ? static_cast<void> (0) : __assert_fail ("is_contained(Def->users(), Use) && \"Did not find use in def's use list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2056, __PRETTY_FUNCTION__))
2056 "Did not find use in def's use list")((is_contained(Def->users(), Use) && "Did not find use in def's use list"
) ? static_cast<void> (0) : __assert_fail ("is_contained(Def->users(), Use) && \"Did not find use in def's use list\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2056, __PRETTY_FUNCTION__));
2057#endif
2058}
2059
2060/// Verify the immediate use information, by walking all the memory
2061/// accesses and verifying that, for each use, it appears in the
2062/// appropriate def's use list
2063void MemorySSA::verifyDefUses(Function &F) const {
2064#if !defined(NDEBUG) && defined(EXPENSIVE_CHECKS)
2065 for (BasicBlock &B : F) {
2066 // Phi nodes are attached to basic blocks
2067 if (MemoryPhi *Phi = getMemoryAccess(&B)) {
2068 assert(Phi->getNumOperands() == static_cast<unsigned>(std::distance(((Phi->getNumOperands() == static_cast<unsigned>(std
::distance( pred_begin(&B), pred_end(&B))) &&
"Incomplete MemoryPhi Node") ? static_cast<void> (0) :
__assert_fail ("Phi->getNumOperands() == static_cast<unsigned>(std::distance( pred_begin(&B), pred_end(&B))) && \"Incomplete MemoryPhi Node\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2070, __PRETTY_FUNCTION__))
2069 pred_begin(&B), pred_end(&B))) &&((Phi->getNumOperands() == static_cast<unsigned>(std
::distance( pred_begin(&B), pred_end(&B))) &&
"Incomplete MemoryPhi Node") ? static_cast<void> (0) :
__assert_fail ("Phi->getNumOperands() == static_cast<unsigned>(std::distance( pred_begin(&B), pred_end(&B))) && \"Incomplete MemoryPhi Node\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2070, __PRETTY_FUNCTION__))
2070 "Incomplete MemoryPhi Node")((Phi->getNumOperands() == static_cast<unsigned>(std
::distance( pred_begin(&B), pred_end(&B))) &&
"Incomplete MemoryPhi Node") ? static_cast<void> (0) :
__assert_fail ("Phi->getNumOperands() == static_cast<unsigned>(std::distance( pred_begin(&B), pred_end(&B))) && \"Incomplete MemoryPhi Node\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2070, __PRETTY_FUNCTION__));
2071 for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
2072 verifyUseInDefs(Phi->getIncomingValue(I), Phi);
2073 assert(find(predecessors(&B), Phi->getIncomingBlock(I)) !=((find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end
(&B) && "Incoming phi block not a block predecessor"
) ? static_cast<void> (0) : __assert_fail ("find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end(&B) && \"Incoming phi block not a block predecessor\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2075, __PRETTY_FUNCTION__))
2074 pred_end(&B) &&((find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end
(&B) && "Incoming phi block not a block predecessor"
) ? static_cast<void> (0) : __assert_fail ("find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end(&B) && \"Incoming phi block not a block predecessor\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2075, __PRETTY_FUNCTION__))
2075 "Incoming phi block not a block predecessor")((find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end
(&B) && "Incoming phi block not a block predecessor"
) ? static_cast<void> (0) : __assert_fail ("find(predecessors(&B), Phi->getIncomingBlock(I)) != pred_end(&B) && \"Incoming phi block not a block predecessor\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2075, __PRETTY_FUNCTION__));
2076 }
2077 }
2078
2079 for (Instruction &I : B) {
2080 if (MemoryUseOrDef *MA = getMemoryAccess(&I)) {
2081 verifyUseInDefs(MA->getDefiningAccess(), MA);
2082 }
2083 }
2084 }
2085#endif
2086}
2087
2088/// Perform a local numbering on blocks so that instruction ordering can be
2089/// determined in constant time.
2090/// TODO: We currently just number in order. If we numbered by N, we could
2091/// allow at least N-1 sequences of insertBefore or insertAfter (and at least
2092/// log2(N) sequences of mixed before and after) without needing to invalidate
2093/// the numbering.
2094void MemorySSA::renumberBlock(const BasicBlock *B) const {
2095 // The pre-increment ensures the numbers really start at 1.
2096 unsigned long CurrentNumber = 0;
2097 const AccessList *AL = getBlockAccesses(B);
2098 assert(AL != nullptr && "Asking to renumber an empty block")((AL != nullptr && "Asking to renumber an empty block"
) ? static_cast<void> (0) : __assert_fail ("AL != nullptr && \"Asking to renumber an empty block\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2098, __PRETTY_FUNCTION__));
2099 for (const auto &I : *AL)
2100 BlockNumbering[&I] = ++CurrentNumber;
2101 BlockNumberingValid.insert(B);
2102}
2103
2104/// Determine, for two memory accesses in the same block,
2105/// whether \p Dominator dominates \p Dominatee.
2106/// \returns True if \p Dominator dominates \p Dominatee.
2107bool MemorySSA::locallyDominates(const MemoryAccess *Dominator,
2108 const MemoryAccess *Dominatee) const {
2109 const BasicBlock *DominatorBlock = Dominator->getBlock();
2110
2111 assert((DominatorBlock == Dominatee->getBlock()) &&(((DominatorBlock == Dominatee->getBlock()) && "Asking for local domination when accesses are in different blocks!"
) ? static_cast<void> (0) : __assert_fail ("(DominatorBlock == Dominatee->getBlock()) && \"Asking for local domination when accesses are in different blocks!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2112, __PRETTY_FUNCTION__))
2112 "Asking for local domination when accesses are in different blocks!")(((DominatorBlock == Dominatee->getBlock()) && "Asking for local domination when accesses are in different blocks!"
) ? static_cast<void> (0) : __assert_fail ("(DominatorBlock == Dominatee->getBlock()) && \"Asking for local domination when accesses are in different blocks!\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2112, __PRETTY_FUNCTION__));
2113 // A node dominates itself.
2114 if (Dominatee == Dominator)
2115 return true;
2116
2117 // When Dominatee is defined on function entry, it is not dominated by another
2118 // memory access.
2119 if (isLiveOnEntryDef(Dominatee))
2120 return false;
2121
2122 // When Dominator is defined on function entry, it dominates the other memory
2123 // access.
2124 if (isLiveOnEntryDef(Dominator))
2125 return true;
2126
2127 if (!BlockNumberingValid.count(DominatorBlock))
2128 renumberBlock(DominatorBlock);
2129
2130 unsigned long DominatorNum = BlockNumbering.lookup(Dominator);
2131 // All numbers start with 1
2132 assert(DominatorNum != 0 && "Block was not numbered properly")((DominatorNum != 0 && "Block was not numbered properly"
) ? static_cast<void> (0) : __assert_fail ("DominatorNum != 0 && \"Block was not numbered properly\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2132, __PRETTY_FUNCTION__));
2133 unsigned long DominateeNum = BlockNumbering.lookup(Dominatee);
2134 assert(DominateeNum != 0 && "Block was not numbered properly")((DominateeNum != 0 && "Block was not numbered properly"
) ? static_cast<void> (0) : __assert_fail ("DominateeNum != 0 && \"Block was not numbered properly\""
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2134, __PRETTY_FUNCTION__));
2135 return DominatorNum < DominateeNum;
2136}
2137
2138bool MemorySSA::dominates(const MemoryAccess *Dominator,
2139 const MemoryAccess *Dominatee) const {
2140 if (Dominator == Dominatee)
2141 return true;
2142
2143 if (isLiveOnEntryDef(Dominatee))
2144 return false;
2145
2146 if (Dominator->getBlock() != Dominatee->getBlock())
2147 return DT->dominates(Dominator->getBlock(), Dominatee->getBlock());
2148 return locallyDominates(Dominator, Dominatee);
2149}
2150
2151bool MemorySSA::dominates(const MemoryAccess *Dominator,
2152 const Use &Dominatee) const {
2153 if (MemoryPhi *MP = dyn_cast<MemoryPhi>(Dominatee.getUser())) {
2154 BasicBlock *UseBB = MP->getIncomingBlock(Dominatee);
2155 // The def must dominate the incoming block of the phi.
2156 if (UseBB != Dominator->getBlock())
2157 return DT->dominates(Dominator->getBlock(), UseBB);
2158 // If the UseBB and the DefBB are the same, compare locally.
2159 return locallyDominates(Dominator, cast<MemoryAccess>(Dominatee));
2160 }
2161 // If it's not a PHI node use, the normal dominates can already handle it.
2162 return dominates(Dominator, cast<MemoryAccess>(Dominatee.getUser()));
2163}
2164
2165const static char LiveOnEntryStr[] = "liveOnEntry";
2166
2167void MemoryAccess::print(raw_ostream &OS) const {
2168 switch (getValueID()) {
2169 case MemoryPhiVal: return static_cast<const MemoryPhi *>(this)->print(OS);
2170 case MemoryDefVal: return static_cast<const MemoryDef *>(this)->print(OS);
2171 case MemoryUseVal: return static_cast<const MemoryUse *>(this)->print(OS);
2172 }
2173 llvm_unreachable("invalid value id")::llvm::llvm_unreachable_internal("invalid value id", "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2173);
2174}
2175
2176void MemoryDef::print(raw_ostream &OS) const {
2177 MemoryAccess *UO = getDefiningAccess();
2178
2179 auto printID = [&OS](MemoryAccess *A) {
2180 if (A && A->getID())
2181 OS << A->getID();
2182 else
2183 OS << LiveOnEntryStr;
2184 };
2185
2186 OS << getID() << " = MemoryDef(";
2187 printID(UO);
2188 OS << ")";
2189
2190 if (isOptimized()) {
2191 OS << "->";
2192 printID(getOptimized());
2193
2194 if (Optional<AliasResult> AR = getOptimizedAccessType())
2195 OS << " " << *AR;
2196 }
2197}
2198
2199void MemoryPhi::print(raw_ostream &OS) const {
2200 bool First = true;
2201 OS << getID() << " = MemoryPhi(";
2202 for (const auto &Op : operands()) {
2203 BasicBlock *BB = getIncomingBlock(Op);
2204 MemoryAccess *MA = cast<MemoryAccess>(Op);
2205 if (!First)
2206 OS << ',';
2207 else
2208 First = false;
2209
2210 OS << '{';
2211 if (BB->hasName())
2212 OS << BB->getName();
2213 else
2214 BB->printAsOperand(OS, false);
2215 OS << ',';
2216 if (unsigned ID = MA->getID())
2217 OS << ID;
2218 else
2219 OS << LiveOnEntryStr;
2220 OS << '}';
2221 }
2222 OS << ')';
2223}
2224
2225void MemoryUse::print(raw_ostream &OS) const {
2226 MemoryAccess *UO = getDefiningAccess();
2227 OS << "MemoryUse(";
2228 if (UO && UO->getID())
2229 OS << UO->getID();
2230 else
2231 OS << LiveOnEntryStr;
2232 OS << ')';
2233
2234 if (Optional<AliasResult> AR = getOptimizedAccessType())
2235 OS << " " << *AR;
2236}
2237
2238void MemoryAccess::dump() const {
2239// Cannot completely remove virtual function even in release mode.
2240#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2241 print(dbgs());
2242 dbgs() << "\n";
2243#endif
2244}
2245
2246char MemorySSAPrinterLegacyPass::ID = 0;
2247
2248MemorySSAPrinterLegacyPass::MemorySSAPrinterLegacyPass() : FunctionPass(ID) {
2249 initializeMemorySSAPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
2250}
2251
2252void MemorySSAPrinterLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const {
2253 AU.setPreservesAll();
2254 AU.addRequired<MemorySSAWrapperPass>();
2255}
2256
2257bool MemorySSAPrinterLegacyPass::runOnFunction(Function &F) {
2258 auto &MSSA = getAnalysis<MemorySSAWrapperPass>().getMSSA();
2259 MSSA.print(dbgs());
2260 if (VerifyMemorySSA)
2261 MSSA.verifyMemorySSA();
2262 return false;
2263}
2264
2265AnalysisKey MemorySSAAnalysis::Key;
2266
2267MemorySSAAnalysis::Result MemorySSAAnalysis::run(Function &F,
2268 FunctionAnalysisManager &AM) {
2269 auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
2270 auto &AA = AM.getResult<AAManager>(F);
2271 return MemorySSAAnalysis::Result(std::make_unique<MemorySSA>(F, &AA, &DT));
2272}
2273
2274bool MemorySSAAnalysis::Result::invalidate(
2275 Function &F, const PreservedAnalyses &PA,
2276 FunctionAnalysisManager::Invalidator &Inv) {
2277 auto PAC = PA.getChecker<MemorySSAAnalysis>();
2278 return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>()) ||
2279 Inv.invalidate<AAManager>(F, PA) ||
2280 Inv.invalidate<DominatorTreeAnalysis>(F, PA);
2281}
2282
2283PreservedAnalyses MemorySSAPrinterPass::run(Function &F,
2284 FunctionAnalysisManager &AM) {
2285 OS << "MemorySSA for function: " << F.getName() << "\n";
2286 AM.getResult<MemorySSAAnalysis>(F).getMSSA().print(OS);
2287
2288 return PreservedAnalyses::all();
2289}
2290
2291PreservedAnalyses MemorySSAVerifierPass::run(Function &F,
2292 FunctionAnalysisManager &AM) {
2293 AM.getResult<MemorySSAAnalysis>(F).getMSSA().verifyMemorySSA();
2294
2295 return PreservedAnalyses::all();
2296}
2297
2298char MemorySSAWrapperPass::ID = 0;
2299
2300MemorySSAWrapperPass::MemorySSAWrapperPass() : FunctionPass(ID) {
2301 initializeMemorySSAWrapperPassPass(*PassRegistry::getPassRegistry());
2302}
2303
2304void MemorySSAWrapperPass::releaseMemory() { MSSA.reset(); }
2305
2306void MemorySSAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
2307 AU.setPreservesAll();
2308 AU.addRequiredTransitive<DominatorTreeWrapperPass>();
2309 AU.addRequiredTransitive<AAResultsWrapperPass>();
2310}
2311
2312bool MemorySSAWrapperPass::runOnFunction(Function &F) {
2313 auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
2314 auto &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
2315 MSSA.reset(new MemorySSA(F, &AA, &DT));
2316 return false;
2317}
2318
2319void MemorySSAWrapperPass::verifyAnalysis() const { MSSA->verifyMemorySSA(); }
2320
2321void MemorySSAWrapperPass::print(raw_ostream &OS, const Module *M) const {
2322 MSSA->print(OS);
2323}
2324
2325MemorySSAWalker::MemorySSAWalker(MemorySSA *M) : MSSA(M) {}
2326
2327/// Walk the use-def chains starting at \p StartingAccess and find
2328/// the MemoryAccess that actually clobbers Loc.
2329///
2330/// \returns our clobbering memory access
2331template <typename AliasAnalysisType>
2332MemoryAccess *
2333MemorySSA::ClobberWalkerBase<AliasAnalysisType>::getClobberingMemoryAccessBase(
2334 MemoryAccess *StartingAccess, const MemoryLocation &Loc,
2335 unsigned &UpwardWalkLimit) {
2336 if (isa<MemoryPhi>(StartingAccess))
3
←
Assuming 'StartingAccess' is not a 'MemoryPhi'
→
4
←
Taking false branch
→
2337 return StartingAccess;
2338
2339 auto *StartingUseOrDef = cast<MemoryUseOrDef>(StartingAccess);
5
←
'StartingAccess' is a 'MemoryUseOrDef'
→
2340 if (MSSA->isLiveOnEntryDef(StartingUseOrDef))
6
←
Taking false branch
→
2341 return StartingUseOrDef;
2342
2343 Instruction *I = StartingUseOrDef->getMemoryInst();
2344
2345 // Conservatively, fences are always clobbers, so don't perform the walk if we
2346 // hit a fence.
2347 if (!isa<CallBase>(I) && I->isFenceLike())
7
←
Assuming 'I' is not a 'CallBase'
→
8
←
Taking false branch
→
2348 return StartingUseOrDef;
2349
2350 UpwardsMemoryQuery Q;
2351 Q.OriginalAccess = StartingUseOrDef;
2352 Q.StartingLoc = Loc;
2353 Q.Inst = I;
2354 Q.IsCall = false;
2355
2356 // Unlike the other function, do not walk to the def of a def, because we are
2357 // handed something we already believe is the clobbering access.
2358 // We never set SkipSelf to true in Q in this method.
2359 MemoryAccess *DefiningAccess = isa<MemoryUse>(StartingUseOrDef)
9
←
Assuming 'StartingUseOrDef' is not a 'MemoryUse'
→
10
←
'?' condition is false
→
2360 ? StartingUseOrDef->getDefiningAccess()
2361 : StartingUseOrDef;
2362
2363 MemoryAccess *Clobber =
2364 Walker.findClobber(DefiningAccess, Q, UpwardWalkLimit);
11
←
Calling 'ClobberWalker::findClobber'
→
2365 LLVM_DEBUG(dbgs() << "Starting Memory SSA clobber for " << *I << " is ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "Starting Memory SSA clobber for "
<< *I << " is "; } } while (false);
2366 LLVM_DEBUG(dbgs() << *StartingUseOrDef << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << *StartingUseOrDef << "\n"
; } } while (false);
2367 LLVM_DEBUG(dbgs() << "Final Memory SSA clobber for " << *I << " is ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "Final Memory SSA clobber for "
<< *I << " is "; } } while (false);
2368 LLVM_DEBUG(dbgs() << *Clobber << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << *Clobber << "\n"; } } while
(false);
2369 return Clobber;
2370}
2371
2372template <typename AliasAnalysisType>
2373MemoryAccess *
2374MemorySSA::ClobberWalkerBase<AliasAnalysisType>::getClobberingMemoryAccessBase(
2375 MemoryAccess *MA, unsigned &UpwardWalkLimit, bool SkipSelf) {
2376 auto *StartingAccess = dyn_cast<MemoryUseOrDef>(MA);
2377 // If this is a MemoryPhi, we can't do anything.
2378 if (!StartingAccess)
2379 return MA;
2380
2381 bool IsOptimized = false;
2382
2383 // If this is an already optimized use or def, return the optimized result.
2384 // Note: Currently, we store the optimized def result in a separate field,
2385 // since we can't use the defining access.
2386 if (StartingAccess->isOptimized()) {
2387 if (!SkipSelf || !isa<MemoryDef>(StartingAccess))
2388 return StartingAccess->getOptimized();
2389 IsOptimized = true;
2390 }
2391
2392 const Instruction *I = StartingAccess->getMemoryInst();
2393 // We can't sanely do anything with a fence, since they conservatively clobber
2394 // all memory, and have no locations to get pointers from to try to
2395 // disambiguate.
2396 if (!isa<CallBase>(I) && I->isFenceLike())
2397 return StartingAccess;
2398
2399 UpwardsMemoryQuery Q(I, StartingAccess);
2400
2401 if (isUseTriviallyOptimizableToLiveOnEntry(*Walker.getAA(), I)) {
2402 MemoryAccess *LiveOnEntry = MSSA->getLiveOnEntryDef();
2403 StartingAccess->setOptimized(LiveOnEntry);
2404 StartingAccess->setOptimizedAccessType(None);
2405 return LiveOnEntry;
2406 }
2407
2408 MemoryAccess *OptimizedAccess;
2409 if (!IsOptimized) {
2410 // Start with the thing we already think clobbers this location
2411 MemoryAccess *DefiningAccess = StartingAccess->getDefiningAccess();
2412
2413 // At this point, DefiningAccess may be the live on entry def.
2414 // If it is, we will not get a better result.
2415 if (MSSA->isLiveOnEntryDef(DefiningAccess)) {
2416 StartingAccess->setOptimized(DefiningAccess);
2417 StartingAccess->setOptimizedAccessType(None);
2418 return DefiningAccess;
2419 }
2420
2421 OptimizedAccess = Walker.findClobber(DefiningAccess, Q, UpwardWalkLimit);
2422 StartingAccess->setOptimized(OptimizedAccess);
2423 if (MSSA->isLiveOnEntryDef(OptimizedAccess))
2424 StartingAccess->setOptimizedAccessType(None);
2425 else if (Q.AR == MustAlias)
2426 StartingAccess->setOptimizedAccessType(MustAlias);
2427 } else
2428 OptimizedAccess = StartingAccess->getOptimized();
2429
2430 LLVM_DEBUG(dbgs() << "Starting Memory SSA clobber for " << *I << " is ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "Starting Memory SSA clobber for "
<< *I << " is "; } } while (false);
2431 LLVM_DEBUG(dbgs() << *StartingAccess << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << *StartingAccess << "\n"
; } } while (false);
2432 LLVM_DEBUG(dbgs() << "Optimized Memory SSA clobber for " << *I << " is ")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "Optimized Memory SSA clobber for "
<< *I << " is "; } } while (false);
2433 LLVM_DEBUG(dbgs() << *OptimizedAccess << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << *OptimizedAccess << "\n"
; } } while (false);
2434
2435 MemoryAccess *Result;
2436 if (SkipSelf && isa<MemoryPhi>(OptimizedAccess) &&
2437 isa<MemoryDef>(StartingAccess) && UpwardWalkLimit) {
2438 assert(isa<MemoryDef>(Q.OriginalAccess))((isa<MemoryDef>(Q.OriginalAccess)) ? static_cast<void
> (0) : __assert_fail ("isa<MemoryDef>(Q.OriginalAccess)"
, "/build/llvm-toolchain-snapshot-10~svn373386/lib/Analysis/MemorySSA.cpp"
, 2438, __PRETTY_FUNCTION__));
2439 Q.SkipSelfAccess = true;
2440 Result = Walker.findClobber(OptimizedAccess, Q, UpwardWalkLimit);
2441 } else
2442 Result = OptimizedAccess;
2443
2444 LLVM_DEBUG(dbgs() << "Result Memory SSA clobber [SkipSelf = " << SkipSelf)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "Result Memory SSA clobber [SkipSelf = "
<< SkipSelf; } } while (false);
2445 LLVM_DEBUG(dbgs() << "] for " << *I << " is " << *Result << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("memoryssa")) { dbgs() << "] for " << *I <<
" is " << *Result << "\n"; } } while (false);
2446
2447 return Result;
2448}
2449
2450MemoryAccess *
2451DoNothingMemorySSAWalker::getClobberingMemoryAccess(MemoryAccess *MA) {
2452 if (auto *Use = dyn_cast<MemoryUseOrDef>(MA))
2453 return Use->getDefiningAccess();
2454 return MA;
2455}
2456
2457MemoryAccess *DoNothingMemorySSAWalker::getClobberingMemoryAccess(
2458 MemoryAccess *StartingAccess, const MemoryLocation &) {
2459 if (auto *Use = dyn_cast<MemoryUseOrDef>(StartingAccess))
2460 return Use->getDefiningAccess();
2461 return StartingAccess;
2462}
2463
2464void MemoryPhi::deleteMe(DerivedUser *Self) {
2465 delete static_cast<MemoryPhi *>(Self);
2466}
2467
2468void MemoryDef::deleteMe(DerivedUser *Self) {
2469 delete static_cast<MemoryDef *>(Self);
2470}
2471
2472void MemoryUse::deleteMe(DerivedUser *Self) {
2473 delete static_cast<MemoryUse *>(Self);
2474}
←

/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h

→
1//===- Optional.h - Simple variant for passing optional values --*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file provides Optional, a template class modeled in the spirit of
10// OCaml's 'opt' variant. The idea is to strongly type whether or not
11// a value can be optional.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ADT_OPTIONAL_H
16#define LLVM_ADT_OPTIONAL_H
17
18#include "llvm/ADT/None.h"
19#include "llvm/Support/Compiler.h"
20#include "llvm/Support/type_traits.h"
21#include <cassert>
22#include <memory>
23#include <new>
24#include <utility>
25
26namespace llvm {
27
28class raw_ostream;
29
30namespace optional_detail {
31
32struct in_place_t {};
33
34/// Storage for any type.
35template <typename T, bool = is_trivially_copyable<T>::value>
36class OptionalStorage {
37 union {
38 char empty;
39 T value;
40 };
41 bool hasVal;
42
43public:
44 ~OptionalStorage() { reset(); }
45
46 OptionalStorage() noexcept : empty(), hasVal(false) {}
47
48 OptionalStorage(OptionalStorage const &other) : OptionalStorage() {
49 if (other.hasValue()) {
50 emplace(other.value);
51 }
52 }
53 OptionalStorage(OptionalStorage &&other) : OptionalStorage() {
54 if (other.hasValue()) {
55 emplace(std::move(other.value));
56 }
57 }
58
59 template <class... Args>
60 explicit OptionalStorage(in_place_t, Args &&... args)
61 : value(std::forward<Args>(args)...), hasVal(true) {}
62
63 void reset() noexcept {
64 if (hasVal) {
65 value.~T();
66 hasVal = false;
67 }
68 }
69
70 bool hasValue() const noexcept { return hasVal; }
71
72 T &getValue() LLVM_LVALUE_FUNCTION& noexcept {
73 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 73, __PRETTY_FUNCTION__));
74 return value;
75 }
76 T const &getValue() const LLVM_LVALUE_FUNCTION& noexcept {
77 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 77, __PRETTY_FUNCTION__));
78 return value;
79 }
80#if LLVM_HAS_RVALUE_REFERENCE_THIS1
81 T &&getValue() && noexcept {
82 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 82, __PRETTY_FUNCTION__));
83 return std::move(value);
84 }
85#endif
86
87 template <class... Args> void emplace(Args &&... args) {
88 reset();
89 ::new ((void *)std::addressof(value)) T(std::forward<Args>(args)...);
90 hasVal = true;
91 }
92
93 OptionalStorage &operator=(T const &y) {
94 if (hasValue()) {
95 value = y;
96 } else {
97 ::new ((void *)std::addressof(value)) T(y);
98 hasVal = true;
99 }
100 return *this;
101 }
102 OptionalStorage &operator=(T &&y) {
103 if (hasValue()) {
104 value = std::move(y);
105 } else {
106 ::new ((void *)std::addressof(value)) T(std::move(y));
107 hasVal = true;
108 }
109 return *this;
110 }
111
112 OptionalStorage &operator=(OptionalStorage const &other) {
113 if (other.hasValue()) {
114 if (hasValue()) {
115 value = other.value;
116 } else {
117 ::new ((void *)std::addressof(value)) T(other.value);
118 hasVal = true;
119 }
120 } else {
121 reset();
122 }
123 return *this;
124 }
125
126 OptionalStorage &operator=(OptionalStorage &&other) {
127 if (other.hasValue()) {
128 if (hasValue()) {
129 value = std::move(other.value);
130 } else {
131 ::new ((void *)std::addressof(value)) T(std::move(other.value));
132 hasVal = true;
133 }
134 } else {
135 reset();
136 }
137 return *this;
138 }
139};
140
141template <typename T> class OptionalStorage<T, true> {
142 union {
143 char empty;
144 T value;
145 };
146 bool hasVal = false;
147
148public:
149 ~OptionalStorage() = default;
150
151 OptionalStorage() noexcept : empty{} {}
152
153 OptionalStorage(OptionalStorage const &other) = default;
154 OptionalStorage(OptionalStorage &&other) = default;
155
156 OptionalStorage &operator=(OptionalStorage const &other) = default;
157 OptionalStorage &operator=(OptionalStorage &&other) = default;
158
159 template <class... Args>
160 explicit OptionalStorage(in_place_t, Args &&... args)
161 : value(std::forward<Args>(args)...), hasVal(true) {}
162
163 void reset() noexcept {
164 if (hasVal) {
165 value.~T();
166 hasVal = false;
167 }
168 }
169
170 bool hasValue() const noexcept { return hasVal; }
43
←
Returning zero, which participates in a condition later
→
171
172 T &getValue() LLVM_LVALUE_FUNCTION& noexcept {
173 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 173, __PRETTY_FUNCTION__));
174 return value;
175 }
176 T const &getValue() const LLVM_LVALUE_FUNCTION& noexcept {
177 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 177, __PRETTY_FUNCTION__));
178 return value;
179 }
180#if LLVM_HAS_RVALUE_REFERENCE_THIS1
181 T &&getValue() && noexcept {
182 assert(hasVal)((hasVal) ? static_cast<void> (0) : __assert_fail ("hasVal"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/Optional.h"
, 182, __PRETTY_FUNCTION__));
183 return std::move(value);
184 }
185#endif
186
187 template <class... Args> void emplace(Args &&... args) {
188 reset();
189 ::new ((void *)std::addressof(value)) T(std::forward<Args>(args)...);
190 hasVal = true;
191 }
192
193 OptionalStorage &operator=(T const &y) {
194 if (hasValue()) {
195 value = y;
196 } else {
197 ::new ((void *)std::addressof(value)) T(y);
198 hasVal = true;
199 }
200 return *this;
201 }
202 OptionalStorage &operator=(T &&y) {
203 if (hasValue()) {
204 value = std::move(y);
205 } else {
206 ::new ((void *)std::addressof(value)) T(std::move(y));
207 hasVal = true;
208 }
209 return *this;
210 }
211};
212
213} // namespace optional_detail
214
215template <typename T> class Optional {
216 optional_detail::OptionalStorage<T> Storage;
217
218public:
219 using value_type = T;
220
221 constexpr Optional() {}
222 constexpr Optional(NoneType) {}
223
224 Optional(const T &y) : Storage(optional_detail::in_place_t{}, y) {}
225 Optional(const Optional &O) = default;
226
227 Optional(T &&y) : Storage(optional_detail::in_place_t{}, std::move(y)) {}
228 Optional(Optional &&O) = default;
229
230 Optional &operator=(T &&y) {
231 Storage = std::move(y);
232 return *this;
233 }
234 Optional &operator=(Optional &&O) = default;
235
236 /// Create a new object by constructing it in place with the given arguments.
237 template <typename... ArgTypes> void emplace(ArgTypes &&... Args) {
238 Storage.emplace(std::forward<ArgTypes>(Args)...);
239 }
240
241 static inline Optional create(const T *y) {
242 return y ? Optional(*y) : Optional();
243 }
244
245 Optional &operator=(const T &y) {
246 Storage = y;
247 return *this;
248 }
249 Optional &operator=(const Optional &O) = default;
250
251 void reset() { Storage.reset(); }
252
253 const T *getPointer() const { return &Storage.getValue(); }
254 T *getPointer() { return &Storage.getValue(); }
255 const T &getValue() const LLVM_LVALUE_FUNCTION& { return Storage.getValue(); }
256 T &getValue() LLVM_LVALUE_FUNCTION& { return Storage.getValue(); }
257
258 explicit operator bool() const { return hasValue(); }
41
←
Calling 'Optional::hasValue'
→
46
←
Returning from 'Optional::hasValue'
→
47
←
Returning zero, which participates in a condition later
→
259 bool hasValue() const { return Storage.hasValue(); }
42
←
Calling 'OptionalStorage::hasValue'
→
44
←
Returning from 'OptionalStorage::hasValue'
→
45
←
Returning zero, which participates in a condition later
→
260 const T *operator->() const { return getPointer(); }
261 T *operator->() { return getPointer(); }
262 const T &operator*() const LLVM_LVALUE_FUNCTION& { return getValue(); }
263 T &operator*() LLVM_LVALUE_FUNCTION& { return getValue(); }
264
265 template <typename U>
266 constexpr T getValueOr(U &&value) const LLVM_LVALUE_FUNCTION& {
267 return hasValue() ? getValue() : std::forward<U>(value);
268 }
269
270#if LLVM_HAS_RVALUE_REFERENCE_THIS1
271 T &&getValue() && { return std::move(Storage.getValue()); }
272 T &&operator*() && { return std::move(Storage.getValue()); }
273
274 template <typename U>
275 T getValueOr(U &&value) && {
276 return hasValue() ? std::move(getValue()) : std::forward<U>(value);
277 }
278#endif
279};
280
281template <typename T, typename U>
282bool operator==(const Optional<T> &X, const Optional<U> &Y) {
283 if (X && Y)
284 return *X == *Y;
285 return X.hasValue() == Y.hasValue();
286}
287
288template <typename T, typename U>
289bool operator!=(const Optional<T> &X, const Optional<U> &Y) {
290 return !(X == Y);
291}
292
293template <typename T, typename U>
294bool operator<(const Optional<T> &X, const Optional<U> &Y) {
295 if (X && Y)
296 return *X < *Y;
297 return X.hasValue() < Y.hasValue();
298}
299
300template <typename T, typename U>
301bool operator<=(const Optional<T> &X, const Optional<U> &Y) {
302 return !(Y < X);
303}
304
305template <typename T, typename U>
306bool operator>(const Optional<T> &X, const Optional<U> &Y) {
307 return Y < X;
308}
309
310template <typename T, typename U>
311bool operator>=(const Optional<T> &X, const Optional<U> &Y) {
312 return !(X < Y);
313}
314
315template<typename T>
316bool operator==(const Optional<T> &X, NoneType) {
317 return !X;
318}
319
320template<typename T>
321bool operator==(NoneType, const Optional<T> &X) {
322 return X == None;
323}
324
325template<typename T>
326bool operator!=(const Optional<T> &X, NoneType) {
327 return !(X == None);
328}
329
330template<typename T>
331bool operator!=(NoneType, const Optional<T> &X) {
332 return X != None;
333}
334
335template <typename T> bool operator<(const Optional<T> &X, NoneType) {
336 return false;
337}
338
339template <typename T> bool operator<(NoneType, const Optional<T> &X) {
340 return X.hasValue();
341}
342
343template <typename T> bool operator<=(const Optional<T> &X, NoneType) {
344 return !(None < X);
345}
346
347template <typename T> bool operator<=(NoneType, const Optional<T> &X) {
348 return !(X < None);
349}
350
351template <typename T> bool operator>(const Optional<T> &X, NoneType) {
352 return None < X;
353}
354
355template <typename T> bool operator>(NoneType, const Optional<T> &X) {
356 return X < None;
357}
358
359template <typename T> bool operator>=(const Optional<T> &X, NoneType) {
360 return None <= X;
361}
362
363template <typename T> bool operator>=(NoneType, const Optional<T> &X) {
364 return X <= None;
365}
366
367template <typename T> bool operator==(const Optional<T> &X, const T &Y) {
368 return X && *X == Y;
369}
370
371template <typename T> bool operator==(const T &X, const Optional<T> &Y) {
372 return Y && X == *Y;
373}
374
375template <typename T> bool operator!=(const Optional<T> &X, const T &Y) {
376 return !(X == Y);
377}
378
379template <typename T> bool operator!=(const T &X, const Optional<T> &Y) {
380 return !(X == Y);
381}
382
383template <typename T> bool operator<(const Optional<T> &X, const T &Y) {
384 return !X || *X < Y;
385}
386
387template <typename T> bool operator<(const T &X, const Optional<T> &Y) {
388 return Y && X < *Y;
389}
390
391template <typename T> bool operator<=(const Optional<T> &X, const T &Y) {
392 return !(Y < X);
393}
394
395template <typename T> bool operator<=(const T &X, const Optional<T> &Y) {
396 return !(Y < X);
397}
398
399template <typename T> bool operator>(const Optional<T> &X, const T &Y) {
400 return Y < X;
401}
402
403template <typename T> bool operator>(const T &X, const Optional<T> &Y) {
404 return Y < X;
405}
406
407template <typename T> bool operator>=(const Optional<T> &X, const T &Y) {
408 return !(X < Y);
409}
410
411template <typename T> bool operator>=(const T &X, const Optional<T> &Y) {
412 return !(X < Y);
413}
414
415raw_ostream &operator<<(raw_ostream &OS, NoneType);
416
417template <typename T, typename = decltype(std::declval<raw_ostream &>()
418 << std::declval<const T &>())>
419raw_ostream &operator<<(raw_ostream &OS, const Optional<T> &O) {
420 if (O)
421 OS << *O;
422 else
423 OS << None;
424 return OS;
425}
426
427} // end namespace llvm
428
429#endif // LLVM_ADT_OPTIONAL_H
←

/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h

1//===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the SmallVector class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_ADT_SMALLVECTOR_H
14#define LLVM_ADT_SMALLVECTOR_H
15
16#include "llvm/ADT/iterator_range.h"
17#include "llvm/Support/AlignOf.h"
18#include "llvm/Support/Compiler.h"
19#include "llvm/Support/MathExtras.h"
20#include "llvm/Support/MemAlloc.h"
21#include "llvm/Support/type_traits.h"
22#include "llvm/Support/ErrorHandling.h"
23#include <algorithm>
24#include <cassert>
25#include <cstddef>
26#include <cstdlib>
27#include <cstring>
28#include <initializer_list>
29#include <iterator>
30#include <memory>
31#include <new>
32#include <type_traits>
33#include <utility>
34
35namespace llvm {
36
37/// This is all the non-templated stuff common to all SmallVectors.
38class SmallVectorBase {
39protected:
40 void *BeginX;
41 unsigned Size = 0, Capacity;
42
43 SmallVectorBase() = delete;
44 SmallVectorBase(void *FirstEl, size_t TotalCapacity)
45 : BeginX(FirstEl), Capacity(TotalCapacity) {}
46
47 /// This is an implementation of the grow() method which only works
48 /// on POD-like data types and is out of line to reduce code duplication.
49 void grow_pod(void *FirstEl, size_t MinCapacity, size_t TSize);
50
51public:
52 size_t size() const { return Size; }
53 size_t capacity() const { return Capacity; }
54
55 LLVM_NODISCARD[[clang::warn_unused_result]] bool empty() const { return !Size; }
51
←
Assuming field 'Size' is not equal to 0, which participates in a condition later
→
52
←
Returning zero, which participates in a condition later
→
58
←
Assuming field 'Size' is not equal to 0, which participates in a condition later
→
59
←
Returning zero, which participates in a condition later
→
56
57 /// Set the array size to \p N, which the current array must have enough
58 /// capacity for.
59 ///
60 /// This does not construct or destroy any elements in the vector.
61 ///
62 /// Clients can use this in conjunction with capacity() to write past the end
63 /// of the buffer when they know that more elements are available, and only
64 /// update the size later. This avoids the cost of value initializing elements
65 /// which will only be overwritten.
66 void set_size(size_t N) {
67 assert(N <= capacity())((N <= capacity()) ? static_cast<void> (0) : __assert_fail
("N <= capacity()", "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 67, __PRETTY_FUNCTION__));
68 Size = N;
69 }
70};
71
72/// Figure out the offset of the first element.
73template <class T, typename = void> struct SmallVectorAlignmentAndSize {
74 AlignedCharArrayUnion<SmallVectorBase> Base;
75 AlignedCharArrayUnion<T> FirstEl;
76};
77
78/// This is the part of SmallVectorTemplateBase which does not depend on whether
79/// the type T is a POD. The extra dummy template argument is used by ArrayRef
80/// to avoid unnecessarily requiring T to be complete.
81template <typename T, typename = void>
82class SmallVectorTemplateCommon : public SmallVectorBase {
83 /// Find the address of the first element. For this pointer math to be valid
84 /// with small-size of 0 for T with lots of alignment, it's important that
85 /// SmallVectorStorage is properly-aligned even for small-size of 0.
86 void *getFirstEl() const {
87 return const_cast<void *>(reinterpret_cast<const void *>(
88 reinterpret_cast<const char *>(this) +
89 offsetof(SmallVectorAlignmentAndSize<T>, FirstEl)__builtin_offsetof(SmallVectorAlignmentAndSize<T>, FirstEl
)));
90 }
91 // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
92
93protected:
94 SmallVectorTemplateCommon(size_t Size)
95 : SmallVectorBase(getFirstEl(), Size) {}
96
97 void grow_pod(size_t MinCapacity, size_t TSize) {
98 SmallVectorBase::grow_pod(getFirstEl(), MinCapacity, TSize);
99 }
100
101 /// Return true if this is a smallvector which has not had dynamic
102 /// memory allocated for it.
103 bool isSmall() const { return BeginX == getFirstEl(); }
104
105 /// Put this vector in a state of being small.
106 void resetToSmall() {
107 BeginX = getFirstEl();
108 Size = Capacity = 0; // FIXME: Setting Capacity to 0 is suspect.
109 }
110
111public:
112 using size_type = size_t;
113 using difference_type = ptrdiff_t;
114 using value_type = T;
115 using iterator = T *;
116 using const_iterator = const T *;
117
118 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
119 using reverse_iterator = std::reverse_iterator<iterator>;
120
121 using reference = T &;
122 using const_reference = const T &;
123 using pointer = T *;
124 using const_pointer = const T *;
125
126 // forward iterator creation methods.
127 iterator begin() { return (iterator)this->BeginX; }
128 const_iterator begin() const { return (const_iterator)this->BeginX; }
129 iterator end() { return begin() + size(); }
130 const_iterator end() const { return begin() + size(); }
131
132 // reverse iterator creation methods.
133 reverse_iterator rbegin() { return reverse_iterator(end()); }
134 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
135 reverse_iterator rend() { return reverse_iterator(begin()); }
136 const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
137
138 size_type size_in_bytes() const { return size() * sizeof(T); }
139 size_type max_size() const { return size_type(-1) / sizeof(T); }
140
141 size_t capacity_in_bytes() const { return capacity() * sizeof(T); }
142
143 /// Return a pointer to the vector's buffer, even if empty().
144 pointer data() { return pointer(begin()); }
145 /// Return a pointer to the vector's buffer, even if empty().
146 const_pointer data() const { return const_pointer(begin()); }
147
148 reference operator[](size_type idx) {
149 assert(idx < size())((idx < size()) ? static_cast<void> (0) : __assert_fail
("idx < size()", "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 149, __PRETTY_FUNCTION__));
150 return begin()[idx];
151 }
152 const_reference operator[](size_type idx) const {
153 assert(idx < size())((idx < size()) ? static_cast<void> (0) : __assert_fail
("idx < size()", "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 153, __PRETTY_FUNCTION__));
154 return begin()[idx];
155 }
156
157 reference front() {
158 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 158, __PRETTY_FUNCTION__));
159 return begin()[0];
160 }
161 const_reference front() const {
162 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 162, __PRETTY_FUNCTION__));
163 return begin()[0];
164 }
165
166 reference back() {
167 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 167, __PRETTY_FUNCTION__));
168 return end()[-1];
169 }
170 const_reference back() const {
171 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 171, __PRETTY_FUNCTION__));
172 return end()[-1];
173 }
174};
175
176/// SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put method
177/// implementations that are designed to work with non-POD-like T's.
178template <typename T, bool = is_trivially_copyable<T>::value>
179class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
180protected:
181 SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
182
183 static void destroy_range(T *S, T *E) {
184 while (S != E) {
185 --E;
186 E->~T();
187 }
188 }
189
190 /// Move the range [I, E) into the uninitialized memory starting with "Dest",
191 /// constructing elements as needed.
192 template<typename It1, typename It2>
193 static void uninitialized_move(It1 I, It1 E, It2 Dest) {
194 std::uninitialized_copy(std::make_move_iterator(I),
195 std::make_move_iterator(E), Dest);
196 }
197
198 /// Copy the range [I, E) onto the uninitialized memory starting with "Dest",
199 /// constructing elements as needed.
200 template<typename It1, typename It2>
201 static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
202 std::uninitialized_copy(I, E, Dest);
203 }
204
205 /// Grow the allocated memory (without initializing new elements), doubling
206 /// the size of the allocated memory. Guarantees space for at least one more
207 /// element, or MinSize more elements if specified.
208 void grow(size_t MinSize = 0);
209
210public:
211 void push_back(const T &Elt) {
212 if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity
()), false))
213 this->grow();
214 ::new ((void*) this->end()) T(Elt);
215 this->set_size(this->size() + 1);
216 }
217
218 void push_back(T &&Elt) {
219 if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity
()), false))
220 this->grow();
221 ::new ((void*) this->end()) T(::std::move(Elt));
222 this->set_size(this->size() + 1);
223 }
224
225 void pop_back() {
226 this->set_size(this->size() - 1);
227 this->end()->~T();
228 }
229};
230
231// Define this out-of-line to dissuade the C++ compiler from inlining it.
232template <typename T, bool TriviallyCopyable>
233void SmallVectorTemplateBase<T, TriviallyCopyable>::grow(size_t MinSize) {
234 if (MinSize > UINT32_MAX(4294967295U))
235 report_bad_alloc_error("SmallVector capacity overflow during allocation");
236
237 // Always grow, even from zero.
238 size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + 2));
239 NewCapacity = std::min(std::max(NewCapacity, MinSize), size_t(UINT32_MAX(4294967295U)));
240 T *NewElts = static_cast<T*>(llvm::safe_malloc(NewCapacity*sizeof(T)));
241
242 // Move the elements over.
243 this->uninitialized_move(this->begin(), this->end(), NewElts);
244
245 // Destroy the original elements.
246 destroy_range(this->begin(), this->end());
247
248 // If this wasn't grown from the inline copy, deallocate the old space.
249 if (!this->isSmall())
250 free(this->begin());
251
252 this->BeginX = NewElts;
253 this->Capacity = NewCapacity;
254}
255
256/// SmallVectorTemplateBase<TriviallyCopyable = true> - This is where we put
257/// method implementations that are designed to work with POD-like T's.
258template <typename T>
259class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> {
260protected:
261 SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
262
263 // No need to do a destroy loop for POD's.
264 static void destroy_range(T *, T *) {}
265
266 /// Move the range [I, E) onto the uninitialized memory
267 /// starting with "Dest", constructing elements into it as needed.
268 template<typename It1, typename It2>
269 static void uninitialized_move(It1 I, It1 E, It2 Dest) {
270 // Just do a copy.
271 uninitialized_copy(I, E, Dest);
272 }
273
274 /// Copy the range [I, E) onto the uninitialized memory
275 /// starting with "Dest", constructing elements into it as needed.
276 template<typename It1, typename It2>
277 static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
278 // Arbitrary iterator types; just use the basic implementation.
279 std::uninitialized_copy(I, E, Dest);
280 }
281
282 /// Copy the range [I, E) onto the uninitialized memory
283 /// starting with "Dest", constructing elements into it as needed.
284 template <typename T1, typename T2>
285 static void uninitialized_copy(
286 T1 *I, T1 *E, T2 *Dest,
287 typename std::enable_if<std::is_same<typename std::remove_const<T1>::type,
288 T2>::value>::type * = nullptr) {
289 // Use memcpy for PODs iterated by pointers (which includes SmallVector
290 // iterators): std::uninitialized_copy optimizes to memmove, but we can
291 // use memcpy here. Note that I and E are iterators and thus might be
292 // invalid for memcpy if they are equal.
293 if (I != E)
294 memcpy(reinterpret_cast<void *>(Dest), I, (E - I) * sizeof(T));
295 }
296
297 /// Double the size of the allocated memory, guaranteeing space for at
298 /// least one more element or MinSize if specified.
299 void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); }
300
301public:
302 void push_back(const T &Elt) {
303 if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity
()), false))
304 this->grow();
305 memcpy(reinterpret_cast<void *>(this->end()), &Elt, sizeof(T));
306 this->set_size(this->size() + 1);
307 }
308
309 void pop_back() { this->set_size(this->size() - 1); }
310};
311
312/// This class consists of common code factored out of the SmallVector class to
313/// reduce code duplication based on the SmallVector 'N' template parameter.
314template <typename T>
315class SmallVectorImpl : public SmallVectorTemplateBase<T> {
316 using SuperClass = SmallVectorTemplateBase<T>;
317
318public:
319 using iterator = typename SuperClass::iterator;
320 using const_iterator = typename SuperClass::const_iterator;
321 using reference = typename SuperClass::reference;
322 using size_type = typename SuperClass::size_type;
323
324protected:
325 // Default ctor - Initialize to empty.
326 explicit SmallVectorImpl(unsigned N)
327 : SmallVectorTemplateBase<T>(N) {}
328
329public:
330 SmallVectorImpl(const SmallVectorImpl &) = delete;
331
332 ~SmallVectorImpl() {
333 // Subclass has already destructed this vector's elements.
334 // If this wasn't grown from the inline copy, deallocate the old space.
335 if (!this->isSmall())
336 free(this->begin());
337 }
338
339 void clear() {
340 this->destroy_range(this->begin(), this->end());
341 this->Size = 0;
342 }
343
344 void resize(size_type N) {
345 if (N < this->size()) {
346 this->destroy_range(this->begin()+N, this->end());
347 this->set_size(N);
348 } else if (N > this->size()) {
349 if (this->capacity() < N)
350 this->grow(N);
351 for (auto I = this->end(), E = this->begin() + N; I != E; ++I)
352 new (&*I) T();
353 this->set_size(N);
354 }
355 }
356
357 void resize(size_type N, const T &NV) {
358 if (N < this->size()) {
359 this->destroy_range(this->begin()+N, this->end());
360 this->set_size(N);
361 } else if (N > this->size()) {
362 if (this->capacity() < N)
363 this->grow(N);
364 std::uninitialized_fill(this->end(), this->begin()+N, NV);
365 this->set_size(N);
366 }
367 }
368
369 void reserve(size_type N) {
370 if (this->capacity() < N)
371 this->grow(N);
372 }
373
374 LLVM_NODISCARD[[clang::warn_unused_result]] T pop_back_val() {
375 T Result = ::std::move(this->back());
376 this->pop_back();
377 return Result;
378 }
379
380 void swap(SmallVectorImpl &RHS);
381
382 /// Add the specified range to the end of the SmallVector.
383 template <typename in_iter,
384 typename = typename std::enable_if<std::is_convertible<
385 typename std::iterator_traits<in_iter>::iterator_category,
386 std::input_iterator_tag>::value>::type>
387 void append(in_iter in_start, in_iter in_end) {
388 size_type NumInputs = std::distance(in_start, in_end);
389 if (NumInputs > this->capacity() - this->size())
390 this->grow(this->size()+NumInputs);
391
392 this->uninitialized_copy(in_start, in_end, this->end());
393 this->set_size(this->size() + NumInputs);
394 }
395
396 /// Append \p NumInputs copies of \p Elt to the end.
397 void append(size_type NumInputs, const T &Elt) {
398 if (NumInputs > this->capacity() - this->size())
399 this->grow(this->size()+NumInputs);
400
401 std::uninitialized_fill_n(this->end(), NumInputs, Elt);
402 this->set_size(this->size() + NumInputs);
403 }
404
405 void append(std::initializer_list<T> IL) {
406 append(IL.begin(), IL.end());
407 }
408
409 // FIXME: Consider assigning over existing elements, rather than clearing &
410 // re-initializing them - for all assign(...) variants.
411
412 void assign(size_type NumElts, const T &Elt) {
413 clear();
414 if (this->capacity() < NumElts)
415 this->grow(NumElts);
416 this->set_size(NumElts);
417 std::uninitialized_fill(this->begin(), this->end(), Elt);
418 }
419
420 template <typename in_iter,
421 typename = typename std::enable_if<std::is_convertible<
422 typename std::iterator_traits<in_iter>::iterator_category,
423 std::input_iterator_tag>::value>::type>
424 void assign(in_iter in_start, in_iter in_end) {
425 clear();
426 append(in_start, in_end);
427 }
428
429 void assign(std::initializer_list<T> IL) {
430 clear();
431 append(IL);
432 }
433
434 iterator erase(const_iterator CI) {
435 // Just cast away constness because this is a non-const member function.
436 iterator I = const_cast<iterator>(CI);
437
438 assert(I >= this->begin() && "Iterator to erase is out of bounds.")((I >= this->begin() && "Iterator to erase is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Iterator to erase is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 438, __PRETTY_FUNCTION__));
439 assert(I < this->end() && "Erasing at past-the-end iterator.")((I < this->end() && "Erasing at past-the-end iterator."
) ? static_cast<void> (0) : __assert_fail ("I < this->end() && \"Erasing at past-the-end iterator.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 439, __PRETTY_FUNCTION__));
440
441 iterator N = I;
442 // Shift all elts down one.
443 std::move(I+1, this->end(), I);
444 // Drop the last elt.
445 this->pop_back();
446 return(N);
447 }
448
449 iterator erase(const_iterator CS, const_iterator CE) {
450 // Just cast away constness because this is a non-const member function.
451 iterator S = const_cast<iterator>(CS);
452 iterator E = const_cast<iterator>(CE);
453
454 assert(S >= this->begin() && "Range to erase is out of bounds.")((S >= this->begin() && "Range to erase is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("S >= this->begin() && \"Range to erase is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 454, __PRETTY_FUNCTION__));
455 assert(S <= E && "Trying to erase invalid range.")((S <= E && "Trying to erase invalid range.") ? static_cast
<void> (0) : __assert_fail ("S <= E && \"Trying to erase invalid range.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 455, __PRETTY_FUNCTION__));
456 assert(E <= this->end() && "Trying to erase past the end.")((E <= this->end() && "Trying to erase past the end."
) ? static_cast<void> (0) : __assert_fail ("E <= this->end() && \"Trying to erase past the end.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 456, __PRETTY_FUNCTION__));
457
458 iterator N = S;
459 // Shift all elts down.
460 iterator I = std::move(E, this->end(), S);
461 // Drop the last elts.
462 this->destroy_range(I, this->end());
463 this->set_size(I - this->begin());
464 return(N);
465 }
466
467 iterator insert(iterator I, T &&Elt) {
468 if (I == this->end()) { // Important special case for empty vector.
469 this->push_back(::std::move(Elt));
470 return this->end()-1;
471 }
472
473 assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 473, __PRETTY_FUNCTION__));
474 assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector."
) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 474, __PRETTY_FUNCTION__));
475
476 if (this->size() >= this->capacity()) {
477 size_t EltNo = I-this->begin();
478 this->grow();
479 I = this->begin()+EltNo;
480 }
481
482 ::new ((void*) this->end()) T(::std::move(this->back()));
483 // Push everything else over.
484 std::move_backward(I, this->end()-1, this->end());
485 this->set_size(this->size() + 1);
486
487 // If we just moved the element we're inserting, be sure to update
488 // the reference.
489 T *EltPtr = &Elt;
490 if (I <= EltPtr && EltPtr < this->end())
491 ++EltPtr;
492
493 *I = ::std::move(*EltPtr);
494 return I;
495 }
496
497 iterator insert(iterator I, const T &Elt) {
498 if (I == this->end()) { // Important special case for empty vector.
499 this->push_back(Elt);
500 return this->end()-1;
501 }
502
503 assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 503, __PRETTY_FUNCTION__));
504 assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector."
) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 504, __PRETTY_FUNCTION__));
505
506 if (this->size() >= this->capacity()) {
507 size_t EltNo = I-this->begin();
508 this->grow();
509 I = this->begin()+EltNo;
510 }
511 ::new ((void*) this->end()) T(std::move(this->back()));
512 // Push everything else over.
513 std::move_backward(I, this->end()-1, this->end());
514 this->set_size(this->size() + 1);
515
516 // If we just moved the element we're inserting, be sure to update
517 // the reference.
518 const T *EltPtr = &Elt;
519 if (I <= EltPtr && EltPtr < this->end())
520 ++EltPtr;
521
522 *I = *EltPtr;
523 return I;
524 }
525
526 iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
527 // Convert iterator to elt# to avoid invalidating iterator when we reserve()
528 size_t InsertElt = I - this->begin();
529
530 if (I == this->end()) { // Important special case for empty vector.
531 append(NumToInsert, Elt);
532 return this->begin()+InsertElt;
533 }
534
535 assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 535, __PRETTY_FUNCTION__));
536 assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector."
) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 536, __PRETTY_FUNCTION__));
537
538 // Ensure there is enough space.
539 reserve(this->size() + NumToInsert);
540
541 // Uninvalidate the iterator.
542 I = this->begin()+InsertElt;
543
544 // If there are more elements between the insertion point and the end of the
545 // range than there are being inserted, we can use a simple approach to
546 // insertion. Since we already reserved space, we know that this won't
547 // reallocate the vector.
548 if (size_t(this->end()-I) >= NumToInsert) {
549 T *OldEnd = this->end();
550 append(std::move_iterator<iterator>(this->end() - NumToInsert),
551 std::move_iterator<iterator>(this->end()));
552
553 // Copy the existing elements that get replaced.
554 std::move_backward(I, OldEnd-NumToInsert, OldEnd);
555
556 std::fill_n(I, NumToInsert, Elt);
557 return I;
558 }
559
560 // Otherwise, we're inserting more elements than exist already, and we're
561 // not inserting at the end.
562
563 // Move over the elements that we're about to overwrite.
564 T *OldEnd = this->end();
565 this->set_size(this->size() + NumToInsert);
566 size_t NumOverwritten = OldEnd-I;
567 this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
568
569 // Replace the overwritten part.
570 std::fill_n(I, NumOverwritten, Elt);
571
572 // Insert the non-overwritten middle part.
573 std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
574 return I;
575 }
576
577 template <typename ItTy,
578 typename = typename std::enable_if<std::is_convertible<
579 typename std::iterator_traits<ItTy>::iterator_category,
580 std::input_iterator_tag>::value>::type>
581 iterator insert(iterator I, ItTy From, ItTy To) {
582 // Convert iterator to elt# to avoid invalidating iterator when we reserve()
583 size_t InsertElt = I - this->begin();
584
585 if (I == this->end()) { // Important special case for empty vector.
586 append(From, To);
587 return this->begin()+InsertElt;
588 }
589
590 assert(I >= this->begin() && "Insertion iterator is out of bounds.")((I >= this->begin() && "Insertion iterator is out of bounds."
) ? static_cast<void> (0) : __assert_fail ("I >= this->begin() && \"Insertion iterator is out of bounds.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 590, __PRETTY_FUNCTION__));
591 assert(I <= this->end() && "Inserting past the end of the vector.")((I <= this->end() && "Inserting past the end of the vector."
) ? static_cast<void> (0) : __assert_fail ("I <= this->end() && \"Inserting past the end of the vector.\""
, "/build/llvm-toolchain-snapshot-10~svn373386/include/llvm/ADT/SmallVector.h"
, 591, __PRETTY_FUNCTION__));
592
593 size_t NumToInsert = std::distance(From, To);
594
595 // Ensure there is enough space.
596 reserve(this->size() + NumToInsert);
597
598 // Uninvalidate the iterator.
599 I = this->begin()+InsertElt;
600
601 // If there are more elements between the insertion point and the end of the
602 // range than there are being inserted, we can use a simple approach to
603 // insertion. Since we already reserved space, we know that this won't
604 // reallocate the vector.
605 if (size_t(this->end()-I) >= NumToInsert) {
606 T *OldEnd = this->end();
607 append(std::move_iterator<iterator>(this->end() - NumToInsert),
608 std::move_iterator<iterator>(this->end()));
609
610 // Copy the existing elements that get replaced.
611 std::move_backward(I, OldEnd-NumToInsert, OldEnd);
612
613 std::copy(From, To, I);
614 return I;
615 }
616
617 // Otherwise, we're inserting more elements than exist already, and we're
618 // not inserting at the end.
619
620 // Move over the elements that we're about to overwrite.
621 T *OldEnd = this->end();
622 this->set_size(this->size() + NumToInsert);
623 size_t NumOverwritten = OldEnd-I;
624 this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
625
626 // Replace the overwritten part.
627 for (T *J = I; NumOverwritten > 0; --NumOverwritten) {
628 *J = *From;
629 ++J; ++From;
630 }
631
632 // Insert the non-overwritten middle part.
633 this->uninitialized_copy(From, To, OldEnd);
634 return I;
635 }
636
637 void insert(iterator I, std::initializer_list<T> IL) {
638 insert(I, IL.begin(), IL.end());
639 }
640
641 template <typename... ArgTypes> reference emplace_back(ArgTypes &&... Args) {
642 if (LLVM_UNLIKELY(this->size() >= this->capacity())__builtin_expect((bool)(this->size() >= this->capacity
()), false))
643 this->grow();
644 ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...);
645 this->set_size(this->size() + 1);
646 return this->back();
647 }
648
649 SmallVectorImpl &operator=(const SmallVectorImpl &RHS);
650
651 SmallVectorImpl &operator=(SmallVectorImpl &&RHS);
652
653 bool operator==(const SmallVectorImpl &RHS) const {
654 if (this->size() != RHS.size()) return false;
655 return std::equal(this->begin(), this->end(), RHS.begin());
656 }
657 bool operator!=(const SmallVectorImpl &RHS) const {
658 return !(*this == RHS);
659 }
660
661 bool operator<(const SmallVectorImpl &RHS) const {
662 return std::lexicographical_compare(this->begin(), this->end(),
663 RHS.begin(), RHS.end());
664 }
665};
666
667template <typename T>
668void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) {
669 if (this == &RHS) return;
670
671 // We can only avoid copying elements if neither vector is small.
672 if (!this->isSmall() && !RHS.isSmall()) {
673 std::swap(this->BeginX, RHS.BeginX);
674 std::swap(this->Size, RHS.Size);
675 std::swap(this->Capacity, RHS.Capacity);
676 return;
677 }
678 if (RHS.size() > this->capacity())
679 this->grow(RHS.size());
680 if (this->size() > RHS.capacity())
681 RHS.grow(this->size());
682
683 // Swap the shared elements.
684 size_t NumShared = this->size();
685 if (NumShared > RHS.size()) NumShared = RHS.size();
686 for (size_type i = 0; i != NumShared; ++i)
687 std::swap((*this)[i], RHS[i]);
688
689 // Copy over the extra elts.
690 if (this->size() > RHS.size()) {
691 size_t EltDiff = this->size() - RHS.size();
692 this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
693 RHS.set_size(RHS.size() + EltDiff);
694 this->destroy_range(this->begin()+NumShared, this->end());
695 this->set_size(NumShared);
696 } else if (RHS.size() > this->size()) {
697 size_t EltDiff = RHS.size() - this->size();
698 this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
699 this->set_size(this->size() + EltDiff);
700 this->destroy_range(RHS.begin()+NumShared, RHS.end());
701 RHS.set_size(NumShared);
702 }
703}
704
705template <typename T>
706SmallVectorImpl<T> &SmallVectorImpl<T>::
707 operator=(const SmallVectorImpl<T> &RHS) {
708 // Avoid self-assignment.
709 if (this == &RHS) return *this;
710
711 // If we already have sufficient space, assign the common elements, then
712 // destroy any excess.
713 size_t RHSSize = RHS.size();
714 size_t CurSize = this->size();
715 if (CurSize >= RHSSize) {
716 // Assign common elements.
717 iterator NewEnd;
718 if (RHSSize)
719 NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
720 else
721 NewEnd = this->begin();
722
723 // Destroy excess elements.
724 this->destroy_range(NewEnd, this->end());
725
726 // Trim.
727 this->set_size(RHSSize);
728 return *this;
729 }
730
731 // If we have to grow to have enough elements, destroy the current elements.
732 // This allows us to avoid copying them during the grow.
733 // FIXME: don't do this if they're efficiently moveable.
734 if (this->capacity() < RHSSize) {
735 // Destroy current elements.
736 this->destroy_range(this->begin(), this->end());
737 this->set_size(0);
738 CurSize = 0;
739 this->grow(RHSSize);
740 } else if (CurSize) {
741 // Otherwise, use assignment for the already-constructed elements.
742 std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
743 }
744
745 // Copy construct the new elements in place.
746 this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
747 this->begin()+CurSize);
748
749 // Set end.
750 this->set_size(RHSSize);
751 return *this;
752}
753
754template <typename T>
755SmallVectorImpl<T> &SmallVectorImpl<T>::operator=(SmallVectorImpl<T> &&RHS) {
756 // Avoid self-assignment.
757 if (this == &RHS) return *this;
758
759 // If the RHS isn't small, clear this vector and then steal its buffer.
760 if (!RHS.isSmall()) {
761 this->destroy_range(this->begin(), this->end());
762 if (!this->isSmall()) free(this->begin());
763 this->BeginX = RHS.BeginX;
764 this->Size = RHS.Size;
765 this->Capacity = RHS.Capacity;
766 RHS.resetToSmall();
767 return *this;
768 }
769
770 // If we already have sufficient space, assign the common elements, then
771 // destroy any excess.
772 size_t RHSSize = RHS.size();
773 size_t CurSize = this->size();
774 if (CurSize >= RHSSize) {
775 // Assign common elements.
776 iterator NewEnd = this->begin();
777 if (RHSSize)
778 NewEnd = std::move(RHS.begin(), RHS.end(), NewEnd);
779
780 // Destroy excess elements and trim the bounds.
781 this->destroy_range(NewEnd, this->end());
782 this->set_size(RHSSize);
783
784 // Clear the RHS.
785 RHS.clear();
786
787 return *this;
788 }
789
790 // If we have to grow to have enough elements, destroy the current elements.
791 // This allows us to avoid copying them during the grow.
792 // FIXME: this may not actually make any sense if we can efficiently move
793 // elements.
794 if (this->capacity() < RHSSize) {
795 // Destroy current elements.
796 this->destroy_range(this->begin(), this->end());
797 this->set_size(0);
798 CurSize = 0;
799 this->grow(RHSSize);
800 } else if (CurSize) {
801 // Otherwise, use assignment for the already-constructed elements.
802 std::move(RHS.begin(), RHS.begin()+CurSize, this->begin());
803 }
804
805 // Move-construct the new elements in place.
806 this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
807 this->begin()+CurSize);
808
809 // Set end.
810 this->set_size(RHSSize);
811
812 RHS.clear();
813 return *this;
814}
815
816/// Storage for the SmallVector elements. This is specialized for the N=0 case
817/// to avoid allocating unnecessary storage.
818template <typename T, unsigned N>
819struct SmallVectorStorage {
820 AlignedCharArrayUnion<T> InlineElts[N];
821};
822
823/// We need the storage to be properly aligned even for small-size of 0 so that
824/// the pointer math in \a SmallVectorTemplateCommon::getFirstEl() is
825/// well-defined.
826template <typename T> struct alignas(alignof(T)) SmallVectorStorage<T, 0> {};
827
828/// This is a 'vector' (really, a variable-sized array), optimized
829/// for the case when the array is small. It contains some number of elements
830/// in-place, which allows it to avoid heap allocation when the actual number of
831/// elements is below that threshold. This allows normal "small" cases to be
832/// fast without losing generality for large inputs.
833///
834/// Note that this does not attempt to be exception safe.
835///
836template <typename T, unsigned N>
837class SmallVector : public SmallVectorImpl<T>, SmallVectorStorage<T, N> {
838public:
839 SmallVector() : SmallVectorImpl<T>(N) {}
840
841 ~SmallVector() {
842 // Destroy the constructed elements in the vector.
843 this->destroy_range(this->begin(), this->end());
844 }
845
846 explicit SmallVector(size_t Size, const T &Value = T())
847 : SmallVectorImpl<T>(N) {
848 this->assign(Size, Value);
849 }
850
851 template <typename ItTy,
852 typename = typename std::enable_if<std::is_convertible<
853 typename std::iterator_traits<ItTy>::iterator_category,
854 std::input_iterator_tag>::value>::type>
855 SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
856 this->append(S, E);
857 }
858
859 template <typename RangeTy>
860 explicit SmallVector(const iterator_range<RangeTy> &R)
861 : SmallVectorImpl<T>(N) {
862 this->append(R.begin(), R.end());
863 }
864
865 SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) {
866 this->assign(IL);
867 }
868
869 SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) {
870 if (!RHS.empty())
871 SmallVectorImpl<T>::operator=(RHS);
872 }
873
874 const SmallVector &operator=(const SmallVector &RHS) {
875 SmallVectorImpl<T>::operator=(RHS);
876 return *this;
877 }
878
879 SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(N) {
880 if (!RHS.empty())
881 SmallVectorImpl<T>::operator=(::std::move(RHS));
882 }
883
884 SmallVector(SmallVectorImpl<T> &&RHS) : SmallVectorImpl<T>(N) {
885 if (!RHS.empty())
886 SmallVectorImpl<T>::operator=(::std::move(RHS));
887 }
888
889 const SmallVector &operator=(SmallVector &&RHS) {
890 SmallVectorImpl<T>::operator=(::std::move(RHS));
891 return *this;
892 }
893
894 const SmallVector &operator=(SmallVectorImpl<T> &&RHS) {
895 SmallVectorImpl<T>::operator=(::std::move(RHS));
896 return *this;
897 }
898
899 const SmallVector &operator=(std::initializer_list<T> IL) {
900 this->assign(IL);
901 return *this;
902 }
903};
904
905template <typename T, unsigned N>
906inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
907 return X.capacity_in_bytes();
908}
909
910} // end namespace llvm
911
912namespace std {
913
914 /// Implement std::swap in terms of SmallVector swap.
915 template<typename T>
916 inline void
917 swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) {
918 LHS.swap(RHS);
919 }
920
921 /// Implement std::swap in terms of SmallVector swap.
922 template<typename T, unsigned N>
923 inline void
924 swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) {
925 LHS.swap(RHS);
926 }
927
928} // end namespace std
929
930#endif // LLVM_ADT_SMALLVECTOR_H