Bug Summary

File:llvm/lib/Transforms/Utils/CodeExtractor.cpp
Warning:line 1745, column 11
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 CodeExtractor.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/lib/Transforms/Utils -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/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-11/lib/clang/11.0.0/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-11~++20200309111110+2c36c23f347/build-llvm/lib/Transforms/Utils -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp

1//===- CodeExtractor.cpp - Pull code region into a new function -----------===//
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 interface to tear out a code region, such as an
10// individual loop or a parallel section, into a new function, replacing it with
11// a call to the new function.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Transforms/Utils/CodeExtractor.h"
16#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/DenseMap.h"
18#include "llvm/ADT/Optional.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/ADT/SetVector.h"
21#include "llvm/ADT/SmallPtrSet.h"
22#include "llvm/ADT/SmallVector.h"
23#include "llvm/Analysis/AssumptionCache.h"
24#include "llvm/Analysis/BlockFrequencyInfo.h"
25#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
26#include "llvm/Analysis/BranchProbabilityInfo.h"
27#include "llvm/Analysis/LoopInfo.h"
28#include "llvm/IR/Argument.h"
29#include "llvm/IR/Attributes.h"
30#include "llvm/IR/BasicBlock.h"
31#include "llvm/IR/CFG.h"
32#include "llvm/IR/Constant.h"
33#include "llvm/IR/Constants.h"
34#include "llvm/IR/DIBuilder.h"
35#include "llvm/IR/DataLayout.h"
36#include "llvm/IR/DebugInfoMetadata.h"
37#include "llvm/IR/DerivedTypes.h"
38#include "llvm/IR/Dominators.h"
39#include "llvm/IR/Function.h"
40#include "llvm/IR/GlobalValue.h"
41#include "llvm/IR/InstIterator.h"
42#include "llvm/IR/InstrTypes.h"
43#include "llvm/IR/Instruction.h"
44#include "llvm/IR/Instructions.h"
45#include "llvm/IR/IntrinsicInst.h"
46#include "llvm/IR/Intrinsics.h"
47#include "llvm/IR/LLVMContext.h"
48#include "llvm/IR/MDBuilder.h"
49#include "llvm/IR/Module.h"
50#include "llvm/IR/PatternMatch.h"
51#include "llvm/IR/Type.h"
52#include "llvm/IR/User.h"
53#include "llvm/IR/Value.h"
54#include "llvm/IR/Verifier.h"
55#include "llvm/Pass.h"
56#include "llvm/Support/BlockFrequency.h"
57#include "llvm/Support/BranchProbability.h"
58#include "llvm/Support/Casting.h"
59#include "llvm/Support/CommandLine.h"
60#include "llvm/Support/Debug.h"
61#include "llvm/Support/ErrorHandling.h"
62#include "llvm/Support/raw_ostream.h"
63#include "llvm/Transforms/Utils/BasicBlockUtils.h"
64#include "llvm/Transforms/Utils/Local.h"
65#include <cassert>
66#include <cstdint>
67#include <iterator>
68#include <map>
69#include <set>
70#include <utility>
71#include <vector>
72
73using namespace llvm;
74using namespace llvm::PatternMatch;
75using ProfileCount = Function::ProfileCount;
76
77#define DEBUG_TYPE"code-extractor" "code-extractor"
78
79// Provide a command-line option to aggregate function arguments into a struct
80// for functions produced by the code extractor. This is useful when converting
81// extracted functions to pthread-based code, as only one argument (void*) can
82// be passed in to pthread_create().
83static cl::opt<bool>
84AggregateArgsOpt("aggregate-extracted-args", cl::Hidden,
85 cl::desc("Aggregate arguments to code-extracted functions"));
86
87/// Test whether a block is valid for extraction.
88static bool isBlockValidForExtraction(const BasicBlock &BB,
89 const SetVector<BasicBlock *> &Result,
90 bool AllowVarArgs, bool AllowAlloca) {
91 // taking the address of a basic block moved to another function is illegal
92 if (BB.hasAddressTaken())
93 return false;
94
95 // don't hoist code that uses another basicblock address, as it's likely to
96 // lead to unexpected behavior, like cross-function jumps
97 SmallPtrSet<User const *, 16> Visited;
98 SmallVector<User const *, 16> ToVisit;
99
100 for (Instruction const &Inst : BB)
101 ToVisit.push_back(&Inst);
102
103 while (!ToVisit.empty()) {
104 User const *Curr = ToVisit.pop_back_val();
105 if (!Visited.insert(Curr).second)
106 continue;
107 if (isa<BlockAddress const>(Curr))
108 return false; // even a reference to self is likely to be not compatible
109
110 if (isa<Instruction>(Curr) && cast<Instruction>(Curr)->getParent() != &BB)
111 continue;
112
113 for (auto const &U : Curr->operands()) {
114 if (auto *UU = dyn_cast<User>(U))
115 ToVisit.push_back(UU);
116 }
117 }
118
119 // If explicitly requested, allow vastart and alloca. For invoke instructions
120 // verify that extraction is valid.
121 for (BasicBlock::const_iterator I = BB.begin(), E = BB.end(); I != E; ++I) {
122 if (isa<AllocaInst>(I)) {
123 if (!AllowAlloca)
124 return false;
125 continue;
126 }
127
128 if (const auto *II = dyn_cast<InvokeInst>(I)) {
129 // Unwind destination (either a landingpad, catchswitch, or cleanuppad)
130 // must be a part of the subgraph which is being extracted.
131 if (auto *UBB = II->getUnwindDest())
132 if (!Result.count(UBB))
133 return false;
134 continue;
135 }
136
137 // All catch handlers of a catchswitch instruction as well as the unwind
138 // destination must be in the subgraph.
139 if (const auto *CSI = dyn_cast<CatchSwitchInst>(I)) {
140 if (auto *UBB = CSI->getUnwindDest())
141 if (!Result.count(UBB))
142 return false;
143 for (auto *HBB : CSI->handlers())
144 if (!Result.count(const_cast<BasicBlock*>(HBB)))
145 return false;
146 continue;
147 }
148
149 // Make sure that entire catch handler is within subgraph. It is sufficient
150 // to check that catch return's block is in the list.
151 if (const auto *CPI = dyn_cast<CatchPadInst>(I)) {
152 for (const auto *U : CPI->users())
153 if (const auto *CRI = dyn_cast<CatchReturnInst>(U))
154 if (!Result.count(const_cast<BasicBlock*>(CRI->getParent())))
155 return false;
156 continue;
157 }
158
159 // And do similar checks for cleanup handler - the entire handler must be
160 // in subgraph which is going to be extracted. For cleanup return should
161 // additionally check that the unwind destination is also in the subgraph.
162 if (const auto *CPI = dyn_cast<CleanupPadInst>(I)) {
163 for (const auto *U : CPI->users())
164 if (const auto *CRI = dyn_cast<CleanupReturnInst>(U))
165 if (!Result.count(const_cast<BasicBlock*>(CRI->getParent())))
166 return false;
167 continue;
168 }
169 if (const auto *CRI = dyn_cast<CleanupReturnInst>(I)) {
170 if (auto *UBB = CRI->getUnwindDest())
171 if (!Result.count(UBB))
172 return false;
173 continue;
174 }
175
176 if (const CallInst *CI = dyn_cast<CallInst>(I)) {
177 if (const Function *F = CI->getCalledFunction()) {
178 auto IID = F->getIntrinsicID();
179 if (IID == Intrinsic::vastart) {
180 if (AllowVarArgs)
181 continue;
182 else
183 return false;
184 }
185
186 // Currently, we miscompile outlined copies of eh_typid_for. There are
187 // proposals for fixing this in llvm.org/PR39545.
188 if (IID == Intrinsic::eh_typeid_for)
189 return false;
190 }
191 }
192 }
193
194 return true;
195}
196
197/// Build a set of blocks to extract if the input blocks are viable.
198static SetVector<BasicBlock *>
199buildExtractionBlockSet(ArrayRef<BasicBlock *> BBs, DominatorTree *DT,
200 bool AllowVarArgs, bool AllowAlloca) {
201 assert(!BBs.empty() && "The set of blocks to extract must be non-empty")((!BBs.empty() && "The set of blocks to extract must be non-empty"
) ? static_cast<void> (0) : __assert_fail ("!BBs.empty() && \"The set of blocks to extract must be non-empty\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 201, __PRETTY_FUNCTION__))
;
202 SetVector<BasicBlock *> Result;
203
204 // Loop over the blocks, adding them to our set-vector, and aborting with an
205 // empty set if we encounter invalid blocks.
206 for (BasicBlock *BB : BBs) {
207 // If this block is dead, don't process it.
208 if (DT && !DT->isReachableFromEntry(BB))
209 continue;
210
211 if (!Result.insert(BB))
212 llvm_unreachable("Repeated basic blocks in extraction input")::llvm::llvm_unreachable_internal("Repeated basic blocks in extraction input"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 212)
;
213 }
214
215 LLVM_DEBUG(dbgs() << "Region front block: " << Result.front()->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Region front block: " <<
Result.front()->getName() << '\n'; } } while (false
)
216 << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Region front block: " <<
Result.front()->getName() << '\n'; } } while (false
)
;
217
218 for (auto *BB : Result) {
219 if (!isBlockValidForExtraction(*BB, Result, AllowVarArgs, AllowAlloca))
220 return {};
221
222 // Make sure that the first block is not a landing pad.
223 if (BB == Result.front()) {
224 if (BB->isEHPad()) {
225 LLVM_DEBUG(dbgs() << "The first block cannot be an unwind block\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "The first block cannot be an unwind block\n"
; } } while (false)
;
226 return {};
227 }
228 continue;
229 }
230
231 // All blocks other than the first must not have predecessors outside of
232 // the subgraph which is being extracted.
233 for (auto *PBB : predecessors(BB))
234 if (!Result.count(PBB)) {
235 LLVM_DEBUG(dbgs() << "No blocks in this region may have entries from "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "No blocks in this region may have entries from "
"outside the region except for the first block!\n" << "Problematic source BB: "
<< BB->getName() << "\n" << "Problematic destination BB: "
<< PBB->getName() << "\n"; } } while (false)
236 "outside the region except for the first block!\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "No blocks in this region may have entries from "
"outside the region except for the first block!\n" << "Problematic source BB: "
<< BB->getName() << "\n" << "Problematic destination BB: "
<< PBB->getName() << "\n"; } } while (false)
237 << "Problematic source BB: " << BB->getName() << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "No blocks in this region may have entries from "
"outside the region except for the first block!\n" << "Problematic source BB: "
<< BB->getName() << "\n" << "Problematic destination BB: "
<< PBB->getName() << "\n"; } } while (false)
238 << "Problematic destination BB: " << PBB->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "No blocks in this region may have entries from "
"outside the region except for the first block!\n" << "Problematic source BB: "
<< BB->getName() << "\n" << "Problematic destination BB: "
<< PBB->getName() << "\n"; } } while (false)
239 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "No blocks in this region may have entries from "
"outside the region except for the first block!\n" << "Problematic source BB: "
<< BB->getName() << "\n" << "Problematic destination BB: "
<< PBB->getName() << "\n"; } } while (false)
;
240 return {};
241 }
242 }
243
244 return Result;
245}
246
247CodeExtractor::CodeExtractor(ArrayRef<BasicBlock *> BBs, DominatorTree *DT,
248 bool AggregateArgs, BlockFrequencyInfo *BFI,
249 BranchProbabilityInfo *BPI, AssumptionCache *AC,
250 bool AllowVarArgs, bool AllowAlloca,
251 std::string Suffix)
252 : DT(DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
253 BPI(BPI), AC(AC), AllowVarArgs(AllowVarArgs),
254 Blocks(buildExtractionBlockSet(BBs, DT, AllowVarArgs, AllowAlloca)),
255 Suffix(Suffix) {}
256
257CodeExtractor::CodeExtractor(DominatorTree &DT, Loop &L, bool AggregateArgs,
258 BlockFrequencyInfo *BFI,
259 BranchProbabilityInfo *BPI, AssumptionCache *AC,
260 std::string Suffix)
261 : DT(&DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
262 BPI(BPI), AC(AC), AllowVarArgs(false),
263 Blocks(buildExtractionBlockSet(L.getBlocks(), &DT,
264 /* AllowVarArgs */ false,
265 /* AllowAlloca */ false)),
266 Suffix(Suffix) {}
267
268/// definedInRegion - Return true if the specified value is defined in the
269/// extracted region.
270static bool definedInRegion(const SetVector<BasicBlock *> &Blocks, Value *V) {
271 if (Instruction *I = dyn_cast<Instruction>(V))
272 if (Blocks.count(I->getParent()))
273 return true;
274 return false;
275}
276
277/// definedInCaller - Return true if the specified value is defined in the
278/// function being code extracted, but not in the region being extracted.
279/// These values must be passed in as live-ins to the function.
280static bool definedInCaller(const SetVector<BasicBlock *> &Blocks, Value *V) {
281 if (isa<Argument>(V)) return true;
282 if (Instruction *I = dyn_cast<Instruction>(V))
283 if (!Blocks.count(I->getParent()))
284 return true;
285 return false;
286}
287
288static BasicBlock *getCommonExitBlock(const SetVector<BasicBlock *> &Blocks) {
289 BasicBlock *CommonExitBlock = nullptr;
290 auto hasNonCommonExitSucc = [&](BasicBlock *Block) {
291 for (auto *Succ : successors(Block)) {
292 // Internal edges, ok.
293 if (Blocks.count(Succ))
294 continue;
295 if (!CommonExitBlock) {
296 CommonExitBlock = Succ;
297 continue;
298 }
299 if (CommonExitBlock != Succ)
300 return true;
301 }
302 return false;
303 };
304
305 if (any_of(Blocks, hasNonCommonExitSucc))
306 return nullptr;
307
308 return CommonExitBlock;
309}
310
311CodeExtractorAnalysisCache::CodeExtractorAnalysisCache(Function &F) {
312 for (BasicBlock &BB : F) {
313 for (Instruction &II : BB.instructionsWithoutDebug())
314 if (auto *AI = dyn_cast<AllocaInst>(&II))
315 Allocas.push_back(AI);
316
317 findSideEffectInfoForBlock(BB);
318 }
319}
320
321void CodeExtractorAnalysisCache::findSideEffectInfoForBlock(BasicBlock &BB) {
322 for (Instruction &II : BB.instructionsWithoutDebug()) {
323 unsigned Opcode = II.getOpcode();
324 Value *MemAddr = nullptr;
325 switch (Opcode) {
326 case Instruction::Store:
327 case Instruction::Load: {
328 if (Opcode == Instruction::Store) {
329 StoreInst *SI = cast<StoreInst>(&II);
330 MemAddr = SI->getPointerOperand();
331 } else {
332 LoadInst *LI = cast<LoadInst>(&II);
333 MemAddr = LI->getPointerOperand();
334 }
335 // Global variable can not be aliased with locals.
336 if (dyn_cast<Constant>(MemAddr))
337 break;
338 Value *Base = MemAddr->stripInBoundsConstantOffsets();
339 if (!isa<AllocaInst>(Base)) {
340 SideEffectingBlocks.insert(&BB);
341 return;
342 }
343 BaseMemAddrs[&BB].insert(Base);
344 break;
345 }
346 default: {
347 IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(&II);
348 if (IntrInst) {
349 if (IntrInst->isLifetimeStartOrEnd())
350 break;
351 SideEffectingBlocks.insert(&BB);
352 return;
353 }
354 // Treat all the other cases conservatively if it has side effects.
355 if (II.mayHaveSideEffects()) {
356 SideEffectingBlocks.insert(&BB);
357 return;
358 }
359 }
360 }
361 }
362}
363
364bool CodeExtractorAnalysisCache::doesBlockContainClobberOfAddr(
365 BasicBlock &BB, AllocaInst *Addr) const {
366 if (SideEffectingBlocks.count(&BB))
367 return true;
368 auto It = BaseMemAddrs.find(&BB);
369 if (It != BaseMemAddrs.end())
370 return It->second.count(Addr);
371 return false;
372}
373
374bool CodeExtractor::isLegalToShrinkwrapLifetimeMarkers(
375 const CodeExtractorAnalysisCache &CEAC, Instruction *Addr) const {
376 AllocaInst *AI = cast<AllocaInst>(Addr->stripInBoundsConstantOffsets());
377 Function *Func = (*Blocks.begin())->getParent();
378 for (BasicBlock &BB : *Func) {
379 if (Blocks.count(&BB))
380 continue;
381 if (CEAC.doesBlockContainClobberOfAddr(BB, AI))
382 return false;
383 }
384 return true;
385}
386
387BasicBlock *
388CodeExtractor::findOrCreateBlockForHoisting(BasicBlock *CommonExitBlock) {
389 BasicBlock *SinglePredFromOutlineRegion = nullptr;
390 assert(!Blocks.count(CommonExitBlock) &&((!Blocks.count(CommonExitBlock) && "Expect a block outside the region!"
) ? static_cast<void> (0) : __assert_fail ("!Blocks.count(CommonExitBlock) && \"Expect a block outside the region!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 391, __PRETTY_FUNCTION__))
391 "Expect a block outside the region!")((!Blocks.count(CommonExitBlock) && "Expect a block outside the region!"
) ? static_cast<void> (0) : __assert_fail ("!Blocks.count(CommonExitBlock) && \"Expect a block outside the region!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 391, __PRETTY_FUNCTION__))
;
392 for (auto *Pred : predecessors(CommonExitBlock)) {
393 if (!Blocks.count(Pred))
394 continue;
395 if (!SinglePredFromOutlineRegion) {
396 SinglePredFromOutlineRegion = Pred;
397 } else if (SinglePredFromOutlineRegion != Pred) {
398 SinglePredFromOutlineRegion = nullptr;
399 break;
400 }
401 }
402
403 if (SinglePredFromOutlineRegion)
404 return SinglePredFromOutlineRegion;
405
406#ifndef NDEBUG
407 auto getFirstPHI = [](BasicBlock *BB) {
408 BasicBlock::iterator I = BB->begin();
409 PHINode *FirstPhi = nullptr;
410 while (I != BB->end()) {
411 PHINode *Phi = dyn_cast<PHINode>(I);
412 if (!Phi)
413 break;
414 if (!FirstPhi) {
415 FirstPhi = Phi;
416 break;
417 }
418 }
419 return FirstPhi;
420 };
421 // If there are any phi nodes, the single pred either exists or has already
422 // be created before code extraction.
423 assert(!getFirstPHI(CommonExitBlock) && "Phi not expected")((!getFirstPHI(CommonExitBlock) && "Phi not expected"
) ? static_cast<void> (0) : __assert_fail ("!getFirstPHI(CommonExitBlock) && \"Phi not expected\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 423, __PRETTY_FUNCTION__))
;
424#endif
425
426 BasicBlock *NewExitBlock = CommonExitBlock->splitBasicBlock(
427 CommonExitBlock->getFirstNonPHI()->getIterator());
428
429 for (auto PI = pred_begin(CommonExitBlock), PE = pred_end(CommonExitBlock);
430 PI != PE;) {
431 BasicBlock *Pred = *PI++;
432 if (Blocks.count(Pred))
433 continue;
434 Pred->getTerminator()->replaceUsesOfWith(CommonExitBlock, NewExitBlock);
435 }
436 // Now add the old exit block to the outline region.
437 Blocks.insert(CommonExitBlock);
438 return CommonExitBlock;
439}
440
441// Find the pair of life time markers for address 'Addr' that are either
442// defined inside the outline region or can legally be shrinkwrapped into the
443// outline region. If there are not other untracked uses of the address, return
444// the pair of markers if found; otherwise return a pair of nullptr.
445CodeExtractor::LifetimeMarkerInfo
446CodeExtractor::getLifetimeMarkers(const CodeExtractorAnalysisCache &CEAC,
447 Instruction *Addr,
448 BasicBlock *ExitBlock) const {
449 LifetimeMarkerInfo Info;
450
451 for (User *U : Addr->users()) {
452 IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(U);
453 if (IntrInst) {
454 if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_start) {
455 // Do not handle the case where Addr has multiple start markers.
456 if (Info.LifeStart)
457 return {};
458 Info.LifeStart = IntrInst;
459 }
460 if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_end) {
461 if (Info.LifeEnd)
462 return {};
463 Info.LifeEnd = IntrInst;
464 }
465 continue;
466 }
467 // Find untracked uses of the address, bail.
468 if (!definedInRegion(Blocks, U))
469 return {};
470 }
471
472 if (!Info.LifeStart || !Info.LifeEnd)
473 return {};
474
475 Info.SinkLifeStart = !definedInRegion(Blocks, Info.LifeStart);
476 Info.HoistLifeEnd = !definedInRegion(Blocks, Info.LifeEnd);
477 // Do legality check.
478 if ((Info.SinkLifeStart || Info.HoistLifeEnd) &&
479 !isLegalToShrinkwrapLifetimeMarkers(CEAC, Addr))
480 return {};
481
482 // Check to see if we have a place to do hoisting, if not, bail.
483 if (Info.HoistLifeEnd && !ExitBlock)
484 return {};
485
486 return Info;
487}
488
489void CodeExtractor::findAllocas(const CodeExtractorAnalysisCache &CEAC,
490 ValueSet &SinkCands, ValueSet &HoistCands,
491 BasicBlock *&ExitBlock) const {
492 Function *Func = (*Blocks.begin())->getParent();
493 ExitBlock = getCommonExitBlock(Blocks);
494
495 auto moveOrIgnoreLifetimeMarkers =
496 [&](const LifetimeMarkerInfo &LMI) -> bool {
497 if (!LMI.LifeStart)
498 return false;
499 if (LMI.SinkLifeStart) {
500 LLVM_DEBUG(dbgs() << "Sinking lifetime.start: " << *LMI.LifeStartdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking lifetime.start: "
<< *LMI.LifeStart << "\n"; } } while (false)
501 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking lifetime.start: "
<< *LMI.LifeStart << "\n"; } } while (false)
;
502 SinkCands.insert(LMI.LifeStart);
503 }
504 if (LMI.HoistLifeEnd) {
505 LLVM_DEBUG(dbgs() << "Hoisting lifetime.end: " << *LMI.LifeEnd << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Hoisting lifetime.end: "
<< *LMI.LifeEnd << "\n"; } } while (false)
;
506 HoistCands.insert(LMI.LifeEnd);
507 }
508 return true;
509 };
510
511 // Look up allocas in the original function in CodeExtractorAnalysisCache, as
512 // this is much faster than walking all the instructions.
513 for (AllocaInst *AI : CEAC.getAllocas()) {
514 BasicBlock *BB = AI->getParent();
515 if (Blocks.count(BB))
516 continue;
517
518 // As a prior call to extractCodeRegion() may have shrinkwrapped the alloca,
519 // check whether it is actually still in the original function.
520 Function *AIFunc = BB->getParent();
521 if (AIFunc != Func)
522 continue;
523
524 LifetimeMarkerInfo MarkerInfo = getLifetimeMarkers(CEAC, AI, ExitBlock);
525 bool Moved = moveOrIgnoreLifetimeMarkers(MarkerInfo);
526 if (Moved) {
527 LLVM_DEBUG(dbgs() << "Sinking alloca: " << *AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking alloca: " <<
*AI << "\n"; } } while (false)
;
528 SinkCands.insert(AI);
529 continue;
530 }
531
532 // Follow any bitcasts.
533 SmallVector<Instruction *, 2> Bitcasts;
534 SmallVector<LifetimeMarkerInfo, 2> BitcastLifetimeInfo;
535 for (User *U : AI->users()) {
536 if (U->stripInBoundsConstantOffsets() == AI) {
537 Instruction *Bitcast = cast<Instruction>(U);
538 LifetimeMarkerInfo LMI = getLifetimeMarkers(CEAC, Bitcast, ExitBlock);
539 if (LMI.LifeStart) {
540 Bitcasts.push_back(Bitcast);
541 BitcastLifetimeInfo.push_back(LMI);
542 continue;
543 }
544 }
545
546 // Found unknown use of AI.
547 if (!definedInRegion(Blocks, U)) {
548 Bitcasts.clear();
549 break;
550 }
551 }
552
553 // Either no bitcasts reference the alloca or there are unknown uses.
554 if (Bitcasts.empty())
555 continue;
556
557 LLVM_DEBUG(dbgs() << "Sinking alloca (via bitcast): " << *AI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking alloca (via bitcast): "
<< *AI << "\n"; } } while (false)
;
558 SinkCands.insert(AI);
559 for (unsigned I = 0, E = Bitcasts.size(); I != E; ++I) {
560 Instruction *BitcastAddr = Bitcasts[I];
561 const LifetimeMarkerInfo &LMI = BitcastLifetimeInfo[I];
562 assert(LMI.LifeStart &&((LMI.LifeStart && "Unsafe to sink bitcast without lifetime markers"
) ? static_cast<void> (0) : __assert_fail ("LMI.LifeStart && \"Unsafe to sink bitcast without lifetime markers\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 563, __PRETTY_FUNCTION__))
563 "Unsafe to sink bitcast without lifetime markers")((LMI.LifeStart && "Unsafe to sink bitcast without lifetime markers"
) ? static_cast<void> (0) : __assert_fail ("LMI.LifeStart && \"Unsafe to sink bitcast without lifetime markers\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 563, __PRETTY_FUNCTION__))
;
564 moveOrIgnoreLifetimeMarkers(LMI);
565 if (!definedInRegion(Blocks, BitcastAddr)) {
566 LLVM_DEBUG(dbgs() << "Sinking bitcast-of-alloca: " << *BitcastAddrdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking bitcast-of-alloca: "
<< *BitcastAddr << "\n"; } } while (false)
567 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "Sinking bitcast-of-alloca: "
<< *BitcastAddr << "\n"; } } while (false)
;
568 SinkCands.insert(BitcastAddr);
569 }
570 }
571 }
572}
573
574bool CodeExtractor::isEligible() const {
575 if (Blocks.empty())
576 return false;
577 BasicBlock *Header = *Blocks.begin();
578 Function *F = Header->getParent();
579
580 // For functions with varargs, check that varargs handling is only done in the
581 // outlined function, i.e vastart and vaend are only used in outlined blocks.
582 if (AllowVarArgs && F->getFunctionType()->isVarArg()) {
583 auto containsVarArgIntrinsic = [](const Instruction &I) {
584 if (const CallInst *CI = dyn_cast<CallInst>(&I))
585 if (const Function *Callee = CI->getCalledFunction())
586 return Callee->getIntrinsicID() == Intrinsic::vastart ||
587 Callee->getIntrinsicID() == Intrinsic::vaend;
588 return false;
589 };
590
591 for (auto &BB : *F) {
592 if (Blocks.count(&BB))
593 continue;
594 if (llvm::any_of(BB, containsVarArgIntrinsic))
595 return false;
596 }
597 }
598 return true;
599}
600
601void CodeExtractor::findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
602 const ValueSet &SinkCands) const {
603 for (BasicBlock *BB : Blocks) {
604 // If a used value is defined outside the region, it's an input. If an
605 // instruction is used outside the region, it's an output.
606 for (Instruction &II : *BB) {
607 for (auto &OI : II.operands()) {
608 Value *V = OI;
609 if (!SinkCands.count(V) && definedInCaller(Blocks, V))
610 Inputs.insert(V);
611 }
612
613 for (User *U : II.users())
614 if (!definedInRegion(Blocks, U)) {
615 Outputs.insert(&II);
616 break;
617 }
618 }
619 }
620}
621
622/// severSplitPHINodesOfEntry - If a PHI node has multiple inputs from outside
623/// of the region, we need to split the entry block of the region so that the
624/// PHI node is easier to deal with.
625void CodeExtractor::severSplitPHINodesOfEntry(BasicBlock *&Header) {
626 unsigned NumPredsFromRegion = 0;
627 unsigned NumPredsOutsideRegion = 0;
628
629 if (Header != &Header->getParent()->getEntryBlock()) {
630 PHINode *PN = dyn_cast<PHINode>(Header->begin());
631 if (!PN) return; // No PHI nodes.
632
633 // If the header node contains any PHI nodes, check to see if there is more
634 // than one entry from outside the region. If so, we need to sever the
635 // header block into two.
636 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
637 if (Blocks.count(PN->getIncomingBlock(i)))
638 ++NumPredsFromRegion;
639 else
640 ++NumPredsOutsideRegion;
641
642 // If there is one (or fewer) predecessor from outside the region, we don't
643 // need to do anything special.
644 if (NumPredsOutsideRegion <= 1) return;
645 }
646
647 // Otherwise, we need to split the header block into two pieces: one
648 // containing PHI nodes merging values from outside of the region, and a
649 // second that contains all of the code for the block and merges back any
650 // incoming values from inside of the region.
651 BasicBlock *NewBB = SplitBlock(Header, Header->getFirstNonPHI(), DT);
652
653 // We only want to code extract the second block now, and it becomes the new
654 // header of the region.
655 BasicBlock *OldPred = Header;
656 Blocks.remove(OldPred);
657 Blocks.insert(NewBB);
658 Header = NewBB;
659
660 // Okay, now we need to adjust the PHI nodes and any branches from within the
661 // region to go to the new header block instead of the old header block.
662 if (NumPredsFromRegion) {
663 PHINode *PN = cast<PHINode>(OldPred->begin());
664 // Loop over all of the predecessors of OldPred that are in the region,
665 // changing them to branch to NewBB instead.
666 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
667 if (Blocks.count(PN->getIncomingBlock(i))) {
668 Instruction *TI = PN->getIncomingBlock(i)->getTerminator();
669 TI->replaceUsesOfWith(OldPred, NewBB);
670 }
671
672 // Okay, everything within the region is now branching to the right block, we
673 // just have to update the PHI nodes now, inserting PHI nodes into NewBB.
674 BasicBlock::iterator AfterPHIs;
675 for (AfterPHIs = OldPred->begin(); isa<PHINode>(AfterPHIs); ++AfterPHIs) {
676 PHINode *PN = cast<PHINode>(AfterPHIs);
677 // Create a new PHI node in the new region, which has an incoming value
678 // from OldPred of PN.
679 PHINode *NewPN = PHINode::Create(PN->getType(), 1 + NumPredsFromRegion,
680 PN->getName() + ".ce", &NewBB->front());
681 PN->replaceAllUsesWith(NewPN);
682 NewPN->addIncoming(PN, OldPred);
683
684 // Loop over all of the incoming value in PN, moving them to NewPN if they
685 // are from the extracted region.
686 for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) {
687 if (Blocks.count(PN->getIncomingBlock(i))) {
688 NewPN->addIncoming(PN->getIncomingValue(i), PN->getIncomingBlock(i));
689 PN->removeIncomingValue(i);
690 --i;
691 }
692 }
693 }
694 }
695}
696
697/// severSplitPHINodesOfExits - if PHI nodes in exit blocks have inputs from
698/// outlined region, we split these PHIs on two: one with inputs from region
699/// and other with remaining incoming blocks; then first PHIs are placed in
700/// outlined region.
701void CodeExtractor::severSplitPHINodesOfExits(
702 const SmallPtrSetImpl<BasicBlock *> &Exits) {
703 for (BasicBlock *ExitBB : Exits) {
704 BasicBlock *NewBB = nullptr;
705
706 for (PHINode &PN : ExitBB->phis()) {
707 // Find all incoming values from the outlining region.
708 SmallVector<unsigned, 2> IncomingVals;
709 for (unsigned i = 0; i < PN.getNumIncomingValues(); ++i)
710 if (Blocks.count(PN.getIncomingBlock(i)))
711 IncomingVals.push_back(i);
712
713 // Do not process PHI if there is one (or fewer) predecessor from region.
714 // If PHI has exactly one predecessor from region, only this one incoming
715 // will be replaced on codeRepl block, so it should be safe to skip PHI.
716 if (IncomingVals.size() <= 1)
717 continue;
718
719 // Create block for new PHIs and add it to the list of outlined if it
720 // wasn't done before.
721 if (!NewBB) {
722 NewBB = BasicBlock::Create(ExitBB->getContext(),
723 ExitBB->getName() + ".split",
724 ExitBB->getParent(), ExitBB);
725 SmallVector<BasicBlock *, 4> Preds(pred_begin(ExitBB),
726 pred_end(ExitBB));
727 for (BasicBlock *PredBB : Preds)
728 if (Blocks.count(PredBB))
729 PredBB->getTerminator()->replaceUsesOfWith(ExitBB, NewBB);
730 BranchInst::Create(ExitBB, NewBB);
731 Blocks.insert(NewBB);
732 }
733
734 // Split this PHI.
735 PHINode *NewPN =
736 PHINode::Create(PN.getType(), IncomingVals.size(),
737 PN.getName() + ".ce", NewBB->getFirstNonPHI());
738 for (unsigned i : IncomingVals)
739 NewPN->addIncoming(PN.getIncomingValue(i), PN.getIncomingBlock(i));
740 for (unsigned i : reverse(IncomingVals))
741 PN.removeIncomingValue(i, false);
742 PN.addIncoming(NewPN, NewBB);
743 }
744 }
745}
746
747void CodeExtractor::splitReturnBlocks() {
748 for (BasicBlock *Block : Blocks)
749 if (ReturnInst *RI = dyn_cast<ReturnInst>(Block->getTerminator())) {
750 BasicBlock *New =
751 Block->splitBasicBlock(RI->getIterator(), Block->getName() + ".ret");
752 if (DT) {
753 // Old dominates New. New node dominates all other nodes dominated
754 // by Old.
755 DomTreeNode *OldNode = DT->getNode(Block);
756 SmallVector<DomTreeNode *, 8> Children(OldNode->begin(),
757 OldNode->end());
758
759 DomTreeNode *NewNode = DT->addNewBlock(New, Block);
760
761 for (DomTreeNode *I : Children)
762 DT->changeImmediateDominator(I, NewNode);
763 }
764 }
765}
766
767/// constructFunction - make a function based on inputs and outputs, as follows:
768/// f(in0, ..., inN, out0, ..., outN)
769Function *CodeExtractor::constructFunction(const ValueSet &inputs,
770 const ValueSet &outputs,
771 BasicBlock *header,
772 BasicBlock *newRootNode,
773 BasicBlock *newHeader,
774 Function *oldFunction,
775 Module *M) {
776 LLVM_DEBUG(dbgs() << "inputs: " << inputs.size() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "inputs: " << inputs
.size() << "\n"; } } while (false)
;
777 LLVM_DEBUG(dbgs() << "outputs: " << outputs.size() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "outputs: " << outputs
.size() << "\n"; } } while (false)
;
778
779 // This function returns unsigned, outputs will go back by reference.
780 switch (NumExitBlocks) {
781 case 0:
782 case 1: RetTy = Type::getVoidTy(header->getContext()); break;
783 case 2: RetTy = Type::getInt1Ty(header->getContext()); break;
784 default: RetTy = Type::getInt16Ty(header->getContext()); break;
785 }
786
787 std::vector<Type *> paramTy;
788
789 // Add the types of the input values to the function's argument list
790 for (Value *value : inputs) {
791 LLVM_DEBUG(dbgs() << "value used in func: " << *value << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "value used in func: " <<
*value << "\n"; } } while (false)
;
792 paramTy.push_back(value->getType());
793 }
794
795 // Add the types of the output values to the function's argument list.
796 for (Value *output : outputs) {
797 LLVM_DEBUG(dbgs() << "instr used in func: " << *output << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { dbgs() << "instr used in func: " <<
*output << "\n"; } } while (false)
;
798 if (AggregateArgs)
799 paramTy.push_back(output->getType());
800 else
801 paramTy.push_back(PointerType::getUnqual(output->getType()));
802 }
803
804 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
805 dbgs() << "Function type: " << *RetTy << " f(";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
806 for (Type *i : paramTy)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
807 dbgs() << *i << ", ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
808 dbgs() << ")\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
809 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { { dbgs() << "Function type: " <<
*RetTy << " f("; for (Type *i : paramTy) dbgs() <<
*i << ", "; dbgs() << ")\n"; }; } } while (false
)
;
810
811 StructType *StructTy = nullptr;
812 if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
813 StructTy = StructType::get(M->getContext(), paramTy);
814 paramTy.clear();
815 paramTy.push_back(PointerType::getUnqual(StructTy));
816 }
817 FunctionType *funcType =
818 FunctionType::get(RetTy, paramTy,
819 AllowVarArgs && oldFunction->isVarArg());
820
821 std::string SuffixToUse =
822 Suffix.empty()
823 ? (header->getName().empty() ? "extracted" : header->getName().str())
824 : Suffix;
825 // Create the new function
826 Function *newFunction = Function::Create(
827 funcType, GlobalValue::InternalLinkage, oldFunction->getAddressSpace(),
828 oldFunction->getName() + "." + SuffixToUse, M);
829 // If the old function is no-throw, so is the new one.
830 if (oldFunction->doesNotThrow())
831 newFunction->setDoesNotThrow();
832
833 // Inherit the uwtable attribute if we need to.
834 if (oldFunction->hasUWTable())
835 newFunction->setHasUWTable();
836
837 // Inherit all of the target dependent attributes and white-listed
838 // target independent attributes.
839 // (e.g. If the extracted region contains a call to an x86.sse
840 // instruction we need to make sure that the extracted region has the
841 // "target-features" attribute allowing it to be lowered.
842 // FIXME: This should be changed to check to see if a specific
843 // attribute can not be inherited.
844 for (const auto &Attr : oldFunction->getAttributes().getFnAttributes()) {
845 if (Attr.isStringAttribute()) {
846 if (Attr.getKindAsString() == "thunk")
847 continue;
848 } else
849 switch (Attr.getKindAsEnum()) {
850 // Those attributes cannot be propagated safely. Explicitly list them
851 // here so we get a warning if new attributes are added. This list also
852 // includes non-function attributes.
853 case Attribute::Alignment:
854 case Attribute::AllocSize:
855 case Attribute::ArgMemOnly:
856 case Attribute::Builtin:
857 case Attribute::ByVal:
858 case Attribute::Convergent:
859 case Attribute::Dereferenceable:
860 case Attribute::DereferenceableOrNull:
861 case Attribute::InAlloca:
862 case Attribute::InReg:
863 case Attribute::InaccessibleMemOnly:
864 case Attribute::InaccessibleMemOrArgMemOnly:
865 case Attribute::JumpTable:
866 case Attribute::Naked:
867 case Attribute::Nest:
868 case Attribute::NoAlias:
869 case Attribute::NoBuiltin:
870 case Attribute::NoCapture:
871 case Attribute::NoReturn:
872 case Attribute::NoSync:
873 case Attribute::None:
874 case Attribute::NonNull:
875 case Attribute::ReadNone:
876 case Attribute::ReadOnly:
877 case Attribute::Returned:
878 case Attribute::ReturnsTwice:
879 case Attribute::SExt:
880 case Attribute::Speculatable:
881 case Attribute::StackAlignment:
882 case Attribute::StructRet:
883 case Attribute::SwiftError:
884 case Attribute::SwiftSelf:
885 case Attribute::WillReturn:
886 case Attribute::WriteOnly:
887 case Attribute::ZExt:
888 case Attribute::ImmArg:
889 case Attribute::EndAttrKinds:
890 case Attribute::EmptyKey:
891 case Attribute::TombstoneKey:
892 continue;
893 // Those attributes should be safe to propagate to the extracted function.
894 case Attribute::AlwaysInline:
895 case Attribute::Cold:
896 case Attribute::NoRecurse:
897 case Attribute::InlineHint:
898 case Attribute::MinSize:
899 case Attribute::NoDuplicate:
900 case Attribute::NoFree:
901 case Attribute::NoImplicitFloat:
902 case Attribute::NoInline:
903 case Attribute::NonLazyBind:
904 case Attribute::NoRedZone:
905 case Attribute::NoUnwind:
906 case Attribute::OptForFuzzing:
907 case Attribute::OptimizeNone:
908 case Attribute::OptimizeForSize:
909 case Attribute::SafeStack:
910 case Attribute::ShadowCallStack:
911 case Attribute::SanitizeAddress:
912 case Attribute::SanitizeMemory:
913 case Attribute::SanitizeThread:
914 case Attribute::SanitizeHWAddress:
915 case Attribute::SanitizeMemTag:
916 case Attribute::SpeculativeLoadHardening:
917 case Attribute::StackProtect:
918 case Attribute::StackProtectReq:
919 case Attribute::StackProtectStrong:
920 case Attribute::StrictFP:
921 case Attribute::UWTable:
922 case Attribute::NoCfCheck:
923 break;
924 }
925
926 newFunction->addFnAttr(Attr);
927 }
928 newFunction->getBasicBlockList().push_back(newRootNode);
929
930 // Create an iterator to name all of the arguments we inserted.
931 Function::arg_iterator AI = newFunction->arg_begin();
932
933 // Rewrite all users of the inputs in the extracted region to use the
934 // arguments (or appropriate addressing into struct) instead.
935 for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
936 Value *RewriteVal;
937 if (AggregateArgs) {
938 Value *Idx[2];
939 Idx[0] = Constant::getNullValue(Type::getInt32Ty(header->getContext()));
940 Idx[1] = ConstantInt::get(Type::getInt32Ty(header->getContext()), i);
941 Instruction *TI = newFunction->begin()->getTerminator();
942 GetElementPtrInst *GEP = GetElementPtrInst::Create(
943 StructTy, &*AI, Idx, "gep_" + inputs[i]->getName(), TI);
944 RewriteVal = new LoadInst(StructTy->getElementType(i), GEP,
945 "loadgep_" + inputs[i]->getName(), TI);
946 } else
947 RewriteVal = &*AI++;
948
949 std::vector<User *> Users(inputs[i]->user_begin(), inputs[i]->user_end());
950 for (User *use : Users)
951 if (Instruction *inst = dyn_cast<Instruction>(use))
952 if (Blocks.count(inst->getParent()))
953 inst->replaceUsesOfWith(inputs[i], RewriteVal);
954 }
955
956 // Set names for input and output arguments.
957 if (!AggregateArgs) {
958 AI = newFunction->arg_begin();
959 for (unsigned i = 0, e = inputs.size(); i != e; ++i, ++AI)
960 AI->setName(inputs[i]->getName());
961 for (unsigned i = 0, e = outputs.size(); i != e; ++i, ++AI)
962 AI->setName(outputs[i]->getName()+".out");
963 }
964
965 // Rewrite branches to basic blocks outside of the loop to new dummy blocks
966 // within the new function. This must be done before we lose track of which
967 // blocks were originally in the code region.
968 std::vector<User *> Users(header->user_begin(), header->user_end());
969 for (auto &U : Users)
970 // The BasicBlock which contains the branch is not in the region
971 // modify the branch target to a new block
972 if (Instruction *I = dyn_cast<Instruction>(U))
973 if (I->isTerminator() && I->getFunction() == oldFunction &&
974 !Blocks.count(I->getParent()))
975 I->replaceUsesOfWith(header, newHeader);
976
977 return newFunction;
978}
979
980/// Erase lifetime.start markers which reference inputs to the extraction
981/// region, and insert the referenced memory into \p LifetimesStart.
982///
983/// The extraction region is defined by a set of blocks (\p Blocks), and a set
984/// of allocas which will be moved from the caller function into the extracted
985/// function (\p SunkAllocas).
986static void eraseLifetimeMarkersOnInputs(const SetVector<BasicBlock *> &Blocks,
987 const SetVector<Value *> &SunkAllocas,
988 SetVector<Value *> &LifetimesStart) {
989 for (BasicBlock *BB : Blocks) {
990 for (auto It = BB->begin(), End = BB->end(); It != End;) {
991 auto *II = dyn_cast<IntrinsicInst>(&*It);
992 ++It;
993 if (!II || !II->isLifetimeStartOrEnd())
994 continue;
995
996 // Get the memory operand of the lifetime marker. If the underlying
997 // object is a sunk alloca, or is otherwise defined in the extraction
998 // region, the lifetime marker must not be erased.
999 Value *Mem = II->getOperand(1)->stripInBoundsOffsets();
1000 if (SunkAllocas.count(Mem) || definedInRegion(Blocks, Mem))
1001 continue;
1002
1003 if (II->getIntrinsicID() == Intrinsic::lifetime_start)
1004 LifetimesStart.insert(Mem);
1005 II->eraseFromParent();
1006 }
1007 }
1008}
1009
1010/// Insert lifetime start/end markers surrounding the call to the new function
1011/// for objects defined in the caller.
1012static void insertLifetimeMarkersSurroundingCall(
1013 Module *M, ArrayRef<Value *> LifetimesStart, ArrayRef<Value *> LifetimesEnd,
1014 CallInst *TheCall) {
1015 LLVMContext &Ctx = M->getContext();
1016 auto Int8PtrTy = Type::getInt8PtrTy(Ctx);
1017 auto NegativeOne = ConstantInt::getSigned(Type::getInt64Ty(Ctx), -1);
1018 Instruction *Term = TheCall->getParent()->getTerminator();
1019
1020 // The memory argument to a lifetime marker must be a i8*. Cache any bitcasts
1021 // needed to satisfy this requirement so they may be reused.
1022 DenseMap<Value *, Value *> Bitcasts;
1023
1024 // Emit lifetime markers for the pointers given in \p Objects. Insert the
1025 // markers before the call if \p InsertBefore, and after the call otherwise.
1026 auto insertMarkers = [&](Function *MarkerFunc, ArrayRef<Value *> Objects,
1027 bool InsertBefore) {
1028 for (Value *Mem : Objects) {
1029 assert((!isa<Instruction>(Mem) || cast<Instruction>(Mem)->getFunction() ==(((!isa<Instruction>(Mem) || cast<Instruction>(Mem
)->getFunction() == TheCall->getFunction()) && "Input memory not defined in original function"
) ? static_cast<void> (0) : __assert_fail ("(!isa<Instruction>(Mem) || cast<Instruction>(Mem)->getFunction() == TheCall->getFunction()) && \"Input memory not defined in original function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1031, __PRETTY_FUNCTION__))
1030 TheCall->getFunction()) &&(((!isa<Instruction>(Mem) || cast<Instruction>(Mem
)->getFunction() == TheCall->getFunction()) && "Input memory not defined in original function"
) ? static_cast<void> (0) : __assert_fail ("(!isa<Instruction>(Mem) || cast<Instruction>(Mem)->getFunction() == TheCall->getFunction()) && \"Input memory not defined in original function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1031, __PRETTY_FUNCTION__))
1031 "Input memory not defined in original function")(((!isa<Instruction>(Mem) || cast<Instruction>(Mem
)->getFunction() == TheCall->getFunction()) && "Input memory not defined in original function"
) ? static_cast<void> (0) : __assert_fail ("(!isa<Instruction>(Mem) || cast<Instruction>(Mem)->getFunction() == TheCall->getFunction()) && \"Input memory not defined in original function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1031, __PRETTY_FUNCTION__))
;
1032 Value *&MemAsI8Ptr = Bitcasts[Mem];
1033 if (!MemAsI8Ptr) {
1034 if (Mem->getType() == Int8PtrTy)
1035 MemAsI8Ptr = Mem;
1036 else
1037 MemAsI8Ptr =
1038 CastInst::CreatePointerCast(Mem, Int8PtrTy, "lt.cast", TheCall);
1039 }
1040
1041 auto Marker = CallInst::Create(MarkerFunc, {NegativeOne, MemAsI8Ptr});
1042 if (InsertBefore)
1043 Marker->insertBefore(TheCall);
1044 else
1045 Marker->insertBefore(Term);
1046 }
1047 };
1048
1049 if (!LifetimesStart.empty()) {
1050 auto StartFn = llvm::Intrinsic::getDeclaration(
1051 M, llvm::Intrinsic::lifetime_start, Int8PtrTy);
1052 insertMarkers(StartFn, LifetimesStart, /*InsertBefore=*/true);
1053 }
1054
1055 if (!LifetimesEnd.empty()) {
1056 auto EndFn = llvm::Intrinsic::getDeclaration(
1057 M, llvm::Intrinsic::lifetime_end, Int8PtrTy);
1058 insertMarkers(EndFn, LifetimesEnd, /*InsertBefore=*/false);
1059 }
1060}
1061
1062/// emitCallAndSwitchStatement - This method sets up the caller side by adding
1063/// the call instruction, splitting any PHI nodes in the header block as
1064/// necessary.
1065CallInst *CodeExtractor::emitCallAndSwitchStatement(Function *newFunction,
1066 BasicBlock *codeReplacer,
1067 ValueSet &inputs,
1068 ValueSet &outputs) {
1069 // Emit a call to the new function, passing in: *pointer to struct (if
1070 // aggregating parameters), or plan inputs and allocated memory for outputs
1071 std::vector<Value *> params, StructValues, ReloadOutputs, Reloads;
1072
1073 Module *M = newFunction->getParent();
1074 LLVMContext &Context = M->getContext();
1075 const DataLayout &DL = M->getDataLayout();
1076 CallInst *call = nullptr;
1077
1078 // Add inputs as params, or to be filled into the struct
1079 unsigned ArgNo = 0;
1080 SmallVector<unsigned, 1> SwiftErrorArgs;
1081 for (Value *input : inputs) {
1082 if (AggregateArgs)
1083 StructValues.push_back(input);
1084 else {
1085 params.push_back(input);
1086 if (input->isSwiftError())
1087 SwiftErrorArgs.push_back(ArgNo);
1088 }
1089 ++ArgNo;
1090 }
1091
1092 // Create allocas for the outputs
1093 for (Value *output : outputs) {
1094 if (AggregateArgs) {
1095 StructValues.push_back(output);
1096 } else {
1097 AllocaInst *alloca =
1098 new AllocaInst(output->getType(), DL.getAllocaAddrSpace(),
1099 nullptr, output->getName() + ".loc",
1100 &codeReplacer->getParent()->front().front());
1101 ReloadOutputs.push_back(alloca);
1102 params.push_back(alloca);
1103 }
1104 }
1105
1106 StructType *StructArgTy = nullptr;
1107 AllocaInst *Struct = nullptr;
1108 if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
1109 std::vector<Type *> ArgTypes;
1110 for (ValueSet::iterator v = StructValues.begin(),
1111 ve = StructValues.end(); v != ve; ++v)
1112 ArgTypes.push_back((*v)->getType());
1113
1114 // Allocate a struct at the beginning of this function
1115 StructArgTy = StructType::get(newFunction->getContext(), ArgTypes);
1116 Struct = new AllocaInst(StructArgTy, DL.getAllocaAddrSpace(), nullptr,
1117 "structArg",
1118 &codeReplacer->getParent()->front().front());
1119 params.push_back(Struct);
1120
1121 for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
1122 Value *Idx[2];
1123 Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1124 Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), i);
1125 GetElementPtrInst *GEP = GetElementPtrInst::Create(
1126 StructArgTy, Struct, Idx, "gep_" + StructValues[i]->getName());
1127 codeReplacer->getInstList().push_back(GEP);
1128 StoreInst *SI = new StoreInst(StructValues[i], GEP);
1129 codeReplacer->getInstList().push_back(SI);
1130 }
1131 }
1132
1133 // Emit the call to the function
1134 call = CallInst::Create(newFunction, params,
1135 NumExitBlocks > 1 ? "targetBlock" : "");
1136 // Add debug location to the new call, if the original function has debug
1137 // info. In that case, the terminator of the entry block of the extracted
1138 // function contains the first debug location of the extracted function,
1139 // set in extractCodeRegion.
1140 if (codeReplacer->getParent()->getSubprogram()) {
1141 if (auto DL = newFunction->getEntryBlock().getTerminator()->getDebugLoc())
1142 call->setDebugLoc(DL);
1143 }
1144 codeReplacer->getInstList().push_back(call);
1145
1146 // Set swifterror parameter attributes.
1147 for (unsigned SwiftErrArgNo : SwiftErrorArgs) {
1148 call->addParamAttr(SwiftErrArgNo, Attribute::SwiftError);
1149 newFunction->addParamAttr(SwiftErrArgNo, Attribute::SwiftError);
1150 }
1151
1152 Function::arg_iterator OutputArgBegin = newFunction->arg_begin();
1153 unsigned FirstOut = inputs.size();
1154 if (!AggregateArgs)
1155 std::advance(OutputArgBegin, inputs.size());
1156
1157 // Reload the outputs passed in by reference.
1158 for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
1159 Value *Output = nullptr;
1160 if (AggregateArgs) {
1161 Value *Idx[2];
1162 Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1163 Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), FirstOut + i);
1164 GetElementPtrInst *GEP = GetElementPtrInst::Create(
1165 StructArgTy, Struct, Idx, "gep_reload_" + outputs[i]->getName());
1166 codeReplacer->getInstList().push_back(GEP);
1167 Output = GEP;
1168 } else {
1169 Output = ReloadOutputs[i];
1170 }
1171 LoadInst *load = new LoadInst(outputs[i]->getType(), Output,
1172 outputs[i]->getName() + ".reload");
1173 Reloads.push_back(load);
1174 codeReplacer->getInstList().push_back(load);
1175 std::vector<User *> Users(outputs[i]->user_begin(), outputs[i]->user_end());
1176 for (unsigned u = 0, e = Users.size(); u != e; ++u) {
1177 Instruction *inst = cast<Instruction>(Users[u]);
1178 if (!Blocks.count(inst->getParent()))
1179 inst->replaceUsesOfWith(outputs[i], load);
1180 }
1181 }
1182
1183 // Now we can emit a switch statement using the call as a value.
1184 SwitchInst *TheSwitch =
1185 SwitchInst::Create(Constant::getNullValue(Type::getInt16Ty(Context)),
1186 codeReplacer, 0, codeReplacer);
1187
1188 // Since there may be multiple exits from the original region, make the new
1189 // function return an unsigned, switch on that number. This loop iterates
1190 // over all of the blocks in the extracted region, updating any terminator
1191 // instructions in the to-be-extracted region that branch to blocks that are
1192 // not in the region to be extracted.
1193 std::map<BasicBlock *, BasicBlock *> ExitBlockMap;
1194
1195 unsigned switchVal = 0;
1196 for (BasicBlock *Block : Blocks) {
1197 Instruction *TI = Block->getTerminator();
1198 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
1199 if (!Blocks.count(TI->getSuccessor(i))) {
1200 BasicBlock *OldTarget = TI->getSuccessor(i);
1201 // add a new basic block which returns the appropriate value
1202 BasicBlock *&NewTarget = ExitBlockMap[OldTarget];
1203 if (!NewTarget) {
1204 // If we don't already have an exit stub for this non-extracted
1205 // destination, create one now!
1206 NewTarget = BasicBlock::Create(Context,
1207 OldTarget->getName() + ".exitStub",
1208 newFunction);
1209 unsigned SuccNum = switchVal++;
1210
1211 Value *brVal = nullptr;
1212 switch (NumExitBlocks) {
1213 case 0:
1214 case 1: break; // No value needed.
1215 case 2: // Conditional branch, return a bool
1216 brVal = ConstantInt::get(Type::getInt1Ty(Context), !SuccNum);
1217 break;
1218 default:
1219 brVal = ConstantInt::get(Type::getInt16Ty(Context), SuccNum);
1220 break;
1221 }
1222
1223 ReturnInst::Create(Context, brVal, NewTarget);
1224
1225 // Update the switch instruction.
1226 TheSwitch->addCase(ConstantInt::get(Type::getInt16Ty(Context),
1227 SuccNum),
1228 OldTarget);
1229 }
1230
1231 // rewrite the original branch instruction with this new target
1232 TI->setSuccessor(i, NewTarget);
1233 }
1234 }
1235
1236 // Store the arguments right after the definition of output value.
1237 // This should be proceeded after creating exit stubs to be ensure that invoke
1238 // result restore will be placed in the outlined function.
1239 Function::arg_iterator OAI = OutputArgBegin;
1240 for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
1241 auto *OutI = dyn_cast<Instruction>(outputs[i]);
1242 if (!OutI)
1243 continue;
1244
1245 // Find proper insertion point.
1246 BasicBlock::iterator InsertPt;
1247 // In case OutI is an invoke, we insert the store at the beginning in the
1248 // 'normal destination' BB. Otherwise we insert the store right after OutI.
1249 if (auto *InvokeI = dyn_cast<InvokeInst>(OutI))
1250 InsertPt = InvokeI->getNormalDest()->getFirstInsertionPt();
1251 else if (auto *Phi = dyn_cast<PHINode>(OutI))
1252 InsertPt = Phi->getParent()->getFirstInsertionPt();
1253 else
1254 InsertPt = std::next(OutI->getIterator());
1255
1256 Instruction *InsertBefore = &*InsertPt;
1257 assert((InsertBefore->getFunction() == newFunction ||(((InsertBefore->getFunction() == newFunction || Blocks.count
(InsertBefore->getParent())) && "InsertPt should be in new function"
) ? static_cast<void> (0) : __assert_fail ("(InsertBefore->getFunction() == newFunction || Blocks.count(InsertBefore->getParent())) && \"InsertPt should be in new function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1259, __PRETTY_FUNCTION__))
1258 Blocks.count(InsertBefore->getParent())) &&(((InsertBefore->getFunction() == newFunction || Blocks.count
(InsertBefore->getParent())) && "InsertPt should be in new function"
) ? static_cast<void> (0) : __assert_fail ("(InsertBefore->getFunction() == newFunction || Blocks.count(InsertBefore->getParent())) && \"InsertPt should be in new function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1259, __PRETTY_FUNCTION__))
1259 "InsertPt should be in new function")(((InsertBefore->getFunction() == newFunction || Blocks.count
(InsertBefore->getParent())) && "InsertPt should be in new function"
) ? static_cast<void> (0) : __assert_fail ("(InsertBefore->getFunction() == newFunction || Blocks.count(InsertBefore->getParent())) && \"InsertPt should be in new function\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1259, __PRETTY_FUNCTION__))
;
1260 assert(OAI != newFunction->arg_end() &&((OAI != newFunction->arg_end() && "Number of output arguments should match "
"the amount of defined values") ? static_cast<void> (0
) : __assert_fail ("OAI != newFunction->arg_end() && \"Number of output arguments should match \" \"the amount of defined values\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1262, __PRETTY_FUNCTION__))
1261 "Number of output arguments should match "((OAI != newFunction->arg_end() && "Number of output arguments should match "
"the amount of defined values") ? static_cast<void> (0
) : __assert_fail ("OAI != newFunction->arg_end() && \"Number of output arguments should match \" \"the amount of defined values\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1262, __PRETTY_FUNCTION__))
1262 "the amount of defined values")((OAI != newFunction->arg_end() && "Number of output arguments should match "
"the amount of defined values") ? static_cast<void> (0
) : __assert_fail ("OAI != newFunction->arg_end() && \"Number of output arguments should match \" \"the amount of defined values\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1262, __PRETTY_FUNCTION__))
;
1263 if (AggregateArgs) {
1264 Value *Idx[2];
1265 Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1266 Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), FirstOut + i);
1267 GetElementPtrInst *GEP = GetElementPtrInst::Create(
1268 StructArgTy, &*OAI, Idx, "gep_" + outputs[i]->getName(),
1269 InsertBefore);
1270 new StoreInst(outputs[i], GEP, InsertBefore);
1271 // Since there should be only one struct argument aggregating
1272 // all the output values, we shouldn't increment OAI, which always
1273 // points to the struct argument, in this case.
1274 } else {
1275 new StoreInst(outputs[i], &*OAI, InsertBefore);
1276 ++OAI;
1277 }
1278 }
1279
1280 // Now that we've done the deed, simplify the switch instruction.
1281 Type *OldFnRetTy = TheSwitch->getParent()->getParent()->getReturnType();
1282 switch (NumExitBlocks) {
1283 case 0:
1284 // There are no successors (the block containing the switch itself), which
1285 // means that previously this was the last part of the function, and hence
1286 // this should be rewritten as a `ret'
1287
1288 // Check if the function should return a value
1289 if (OldFnRetTy->isVoidTy()) {
1290 ReturnInst::Create(Context, nullptr, TheSwitch); // Return void
1291 } else if (OldFnRetTy == TheSwitch->getCondition()->getType()) {
1292 // return what we have
1293 ReturnInst::Create(Context, TheSwitch->getCondition(), TheSwitch);
1294 } else {
1295 // Otherwise we must have code extracted an unwind or something, just
1296 // return whatever we want.
1297 ReturnInst::Create(Context,
1298 Constant::getNullValue(OldFnRetTy), TheSwitch);
1299 }
1300
1301 TheSwitch->eraseFromParent();
1302 break;
1303 case 1:
1304 // Only a single destination, change the switch into an unconditional
1305 // branch.
1306 BranchInst::Create(TheSwitch->getSuccessor(1), TheSwitch);
1307 TheSwitch->eraseFromParent();
1308 break;
1309 case 2:
1310 BranchInst::Create(TheSwitch->getSuccessor(1), TheSwitch->getSuccessor(2),
1311 call, TheSwitch);
1312 TheSwitch->eraseFromParent();
1313 break;
1314 default:
1315 // Otherwise, make the default destination of the switch instruction be one
1316 // of the other successors.
1317 TheSwitch->setCondition(call);
1318 TheSwitch->setDefaultDest(TheSwitch->getSuccessor(NumExitBlocks));
1319 // Remove redundant case
1320 TheSwitch->removeCase(SwitchInst::CaseIt(TheSwitch, NumExitBlocks-1));
1321 break;
1322 }
1323
1324 // Insert lifetime markers around the reloads of any output values. The
1325 // allocas output values are stored in are only in-use in the codeRepl block.
1326 insertLifetimeMarkersSurroundingCall(M, ReloadOutputs, ReloadOutputs, call);
1327
1328 return call;
1329}
1330
1331void CodeExtractor::moveCodeToFunction(Function *newFunction) {
1332 Function *oldFunc = (*Blocks.begin())->getParent();
1333 Function::BasicBlockListType &oldBlocks = oldFunc->getBasicBlockList();
1334 Function::BasicBlockListType &newBlocks = newFunction->getBasicBlockList();
1335
1336 for (BasicBlock *Block : Blocks) {
1337 // Delete the basic block from the old function, and the list of blocks
1338 oldBlocks.remove(Block);
1339
1340 // Insert this basic block into the new function
1341 newBlocks.push_back(Block);
1342 }
1343}
1344
1345void CodeExtractor::calculateNewCallTerminatorWeights(
1346 BasicBlock *CodeReplacer,
1347 DenseMap<BasicBlock *, BlockFrequency> &ExitWeights,
1348 BranchProbabilityInfo *BPI) {
1349 using Distribution = BlockFrequencyInfoImplBase::Distribution;
1350 using BlockNode = BlockFrequencyInfoImplBase::BlockNode;
1351
1352 // Update the branch weights for the exit block.
1353 Instruction *TI = CodeReplacer->getTerminator();
1354 SmallVector<unsigned, 8> BranchWeights(TI->getNumSuccessors(), 0);
1355
1356 // Block Frequency distribution with dummy node.
1357 Distribution BranchDist;
1358
1359 // Add each of the frequencies of the successors.
1360 for (unsigned i = 0, e = TI->getNumSuccessors(); i < e; ++i) {
1361 BlockNode ExitNode(i);
1362 uint64_t ExitFreq = ExitWeights[TI->getSuccessor(i)].getFrequency();
1363 if (ExitFreq != 0)
1364 BranchDist.addExit(ExitNode, ExitFreq);
1365 else
1366 BPI->setEdgeProbability(CodeReplacer, i, BranchProbability::getZero());
1367 }
1368
1369 // Check for no total weight.
1370 if (BranchDist.Total == 0)
1371 return;
1372
1373 // Normalize the distribution so that they can fit in unsigned.
1374 BranchDist.normalize();
1375
1376 // Create normalized branch weights and set the metadata.
1377 for (unsigned I = 0, E = BranchDist.Weights.size(); I < E; ++I) {
1378 const auto &Weight = BranchDist.Weights[I];
1379
1380 // Get the weight and update the current BFI.
1381 BranchWeights[Weight.TargetNode.Index] = Weight.Amount;
1382 BranchProbability BP(Weight.Amount, BranchDist.Total);
1383 BPI->setEdgeProbability(CodeReplacer, Weight.TargetNode.Index, BP);
1384 }
1385 TI->setMetadata(
1386 LLVMContext::MD_prof,
1387 MDBuilder(TI->getContext()).createBranchWeights(BranchWeights));
1388}
1389
1390/// Erase debug info intrinsics which refer to values in \p F but aren't in
1391/// \p F.
1392static void eraseDebugIntrinsicsWithNonLocalRefs(Function &F) {
1393 for (Instruction &I : instructions(F)) {
1394 SmallVector<DbgVariableIntrinsic *, 4> DbgUsers;
1395 findDbgUsers(DbgUsers, &I);
1396 for (DbgVariableIntrinsic *DVI : DbgUsers)
1397 if (DVI->getFunction() != &F)
1398 DVI->eraseFromParent();
1399 }
1400}
1401
1402/// Fix up the debug info in the old and new functions by pointing line
1403/// locations and debug intrinsics to the new subprogram scope, and by deleting
1404/// intrinsics which point to values outside of the new function.
1405static void fixupDebugInfoPostExtraction(Function &OldFunc, Function &NewFunc,
1406 CallInst &TheCall) {
1407 DISubprogram *OldSP = OldFunc.getSubprogram();
1408 LLVMContext &Ctx = OldFunc.getContext();
1409
1410 if (!OldSP) {
1411 // Erase any debug info the new function contains.
1412 stripDebugInfo(NewFunc);
1413 // Make sure the old function doesn't contain any non-local metadata refs.
1414 eraseDebugIntrinsicsWithNonLocalRefs(NewFunc);
1415 return;
1416 }
1417
1418 // Create a subprogram for the new function. Leave out a description of the
1419 // function arguments, as the parameters don't correspond to anything at the
1420 // source level.
1421 assert(OldSP->getUnit() && "Missing compile unit for subprogram")((OldSP->getUnit() && "Missing compile unit for subprogram"
) ? static_cast<void> (0) : __assert_fail ("OldSP->getUnit() && \"Missing compile unit for subprogram\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1421, __PRETTY_FUNCTION__))
;
1422 DIBuilder DIB(*OldFunc.getParent(), /*AllowUnresolvedNodes=*/false,
1423 OldSP->getUnit());
1424 auto SPType = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
1425 DISubprogram::DISPFlags SPFlags = DISubprogram::SPFlagDefinition |
1426 DISubprogram::SPFlagOptimized |
1427 DISubprogram::SPFlagLocalToUnit;
1428 auto NewSP = DIB.createFunction(
1429 OldSP->getUnit(), NewFunc.getName(), NewFunc.getName(), OldSP->getFile(),
1430 /*LineNo=*/0, SPType, /*ScopeLine=*/0, DINode::FlagZero, SPFlags);
1431 NewFunc.setSubprogram(NewSP);
1432
1433 // Debug intrinsics in the new function need to be updated in one of two
1434 // ways:
1435 // 1) They need to be deleted, because they describe a value in the old
1436 // function.
1437 // 2) They need to point to fresh metadata, e.g. because they currently
1438 // point to a variable in the wrong scope.
1439 SmallDenseMap<DINode *, DINode *> RemappedMetadata;
1440 SmallVector<Instruction *, 4> DebugIntrinsicsToDelete;
1441 for (Instruction &I : instructions(NewFunc)) {
1442 auto *DII = dyn_cast<DbgInfoIntrinsic>(&I);
1443 if (!DII)
1444 continue;
1445
1446 // Point the intrinsic to a fresh label within the new function.
1447 if (auto *DLI = dyn_cast<DbgLabelInst>(&I)) {
1448 DILabel *OldLabel = DLI->getLabel();
1449 DINode *&NewLabel = RemappedMetadata[OldLabel];
1450 if (!NewLabel)
1451 NewLabel = DILabel::get(Ctx, NewSP, OldLabel->getName(),
1452 OldLabel->getFile(), OldLabel->getLine());
1453 DLI->setArgOperand(0, MetadataAsValue::get(Ctx, NewLabel));
1454 continue;
1455 }
1456
1457 // If the location isn't a constant or an instruction, delete the
1458 // intrinsic.
1459 auto *DVI = cast<DbgVariableIntrinsic>(DII);
1460 Value *Location = DVI->getVariableLocation();
1461 if (!Location ||
1462 (!isa<Constant>(Location) && !isa<Instruction>(Location))) {
1463 DebugIntrinsicsToDelete.push_back(DVI);
1464 continue;
1465 }
1466
1467 // If the variable location is an instruction but isn't in the new
1468 // function, delete the intrinsic.
1469 Instruction *LocationInst = dyn_cast<Instruction>(Location);
1470 if (LocationInst && LocationInst->getFunction() != &NewFunc) {
1471 DebugIntrinsicsToDelete.push_back(DVI);
1472 continue;
1473 }
1474
1475 // Point the intrinsic to a fresh variable within the new function.
1476 DILocalVariable *OldVar = DVI->getVariable();
1477 DINode *&NewVar = RemappedMetadata[OldVar];
1478 if (!NewVar)
1479 NewVar = DIB.createAutoVariable(
1480 NewSP, OldVar->getName(), OldVar->getFile(), OldVar->getLine(),
1481 OldVar->getType(), /*AlwaysPreserve=*/false, DINode::FlagZero,
1482 OldVar->getAlignInBits());
1483 DVI->setArgOperand(1, MetadataAsValue::get(Ctx, NewVar));
1484 }
1485 for (auto *DII : DebugIntrinsicsToDelete)
1486 DII->eraseFromParent();
1487 DIB.finalizeSubprogram(NewSP);
1488
1489 // Fix up the scope information attached to the line locations in the new
1490 // function.
1491 for (Instruction &I : instructions(NewFunc)) {
1492 if (const DebugLoc &DL = I.getDebugLoc())
1493 I.setDebugLoc(DebugLoc::get(DL.getLine(), DL.getCol(), NewSP));
1494
1495 // Loop info metadata may contain line locations. Fix them up.
1496 auto updateLoopInfoLoc = [&Ctx,
1497 NewSP](const DILocation &Loc) -> DILocation * {
1498 return DILocation::get(Ctx, Loc.getLine(), Loc.getColumn(), NewSP,
1499 nullptr);
1500 };
1501 updateLoopMetadataDebugLocations(I, updateLoopInfoLoc);
1502 }
1503 if (!TheCall.getDebugLoc())
1504 TheCall.setDebugLoc(DebugLoc::get(0, 0, OldSP));
1505
1506 eraseDebugIntrinsicsWithNonLocalRefs(NewFunc);
1507}
1508
1509Function *
1510CodeExtractor::extractCodeRegion(const CodeExtractorAnalysisCache &CEAC) {
1511 if (!isEligible())
1
Taking false branch
1512 return nullptr;
1513
1514 // Assumption: this is a single-entry code region, and the header is the first
1515 // block in the region.
1516 BasicBlock *header = *Blocks.begin();
1517 Function *oldFunction = header->getParent();
1518
1519 // Calculate the entry frequency of the new function before we change the root
1520 // block.
1521 BlockFrequency EntryFreq;
1522 if (BFI) {
2
Assuming field 'BFI' is null
3
Taking false branch
1523 assert(BPI && "Both BPI and BFI are required to preserve profile info")((BPI && "Both BPI and BFI are required to preserve profile info"
) ? static_cast<void> (0) : __assert_fail ("BPI && \"Both BPI and BFI are required to preserve profile info\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1523, __PRETTY_FUNCTION__))
;
1524 for (BasicBlock *Pred : predecessors(header)) {
1525 if (Blocks.count(Pred))
1526 continue;
1527 EntryFreq +=
1528 BFI->getBlockFreq(Pred) * BPI->getEdgeProbability(Pred, header);
1529 }
1530 }
1531
1532 // Remove @llvm.assume calls that will be moved to the new function from the
1533 // old function's assumption cache.
1534 for (BasicBlock *Block : Blocks) {
1535 for (auto It = Block->begin(), End = Block->end(); It != End;) {
1536 Instruction *I = &*It;
1537 ++It;
1538
1539 if (match(I, m_Intrinsic<Intrinsic::assume>())) {
1540 if (AC)
1541 AC->unregisterAssumption(cast<CallInst>(I));
1542 I->eraseFromParent();
1543 }
1544 }
1545 }
1546
1547 // If we have any return instructions in the region, split those blocks so
1548 // that the return is not in the region.
1549 splitReturnBlocks();
1550
1551 // Calculate the exit blocks for the extracted region and the total exit
1552 // weights for each of those blocks.
1553 DenseMap<BasicBlock *, BlockFrequency> ExitWeights;
1554 SmallPtrSet<BasicBlock *, 1> ExitBlocks;
1555 for (BasicBlock *Block : Blocks) {
1556 for (succ_iterator SI = succ_begin(Block), SE = succ_end(Block); SI != SE;
1557 ++SI) {
1558 if (!Blocks.count(*SI)) {
1559 // Update the branch weight for this successor.
1560 if (BFI) {
1561 BlockFrequency &BF = ExitWeights[*SI];
1562 BF += BFI->getBlockFreq(Block) * BPI->getEdgeProbability(Block, *SI);
1563 }
1564 ExitBlocks.insert(*SI);
1565 }
1566 }
1567 }
1568 NumExitBlocks = ExitBlocks.size();
1569
1570 // If we have to split PHI nodes of the entry or exit blocks, do so now.
1571 severSplitPHINodesOfEntry(header);
1572 severSplitPHINodesOfExits(ExitBlocks);
1573
1574 // This takes place of the original loop
1575 BasicBlock *codeReplacer = BasicBlock::Create(header->getContext(),
1576 "codeRepl", oldFunction,
1577 header);
1578
1579 // The new function needs a root node because other nodes can branch to the
1580 // head of the region, but the entry node of a function cannot have preds.
1581 BasicBlock *newFuncRoot = BasicBlock::Create(header->getContext(),
1582 "newFuncRoot");
1583 auto *BranchI = BranchInst::Create(header);
1584 // If the original function has debug info, we have to add a debug location
1585 // to the new branch instruction from the artificial entry block.
1586 // We use the debug location of the first instruction in the extracted
1587 // blocks, as there is no other equivalent line in the source code.
1588 if (oldFunction->getSubprogram()) {
4
Assuming the condition is false
5
Taking false branch
1589 any_of(Blocks, [&BranchI](const BasicBlock *BB) {
1590 return any_of(*BB, [&BranchI](const Instruction &I) {
1591 if (!I.getDebugLoc())
1592 return false;
1593 BranchI->setDebugLoc(I.getDebugLoc());
1594 return true;
1595 });
1596 });
1597 }
1598 newFuncRoot->getInstList().push_back(BranchI);
1599
1600 ValueSet inputs, outputs, SinkingCands, HoistingCands;
1601 BasicBlock *CommonExit = nullptr;
1602 findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
1603 assert(HoistingCands.empty() || CommonExit)((HoistingCands.empty() || CommonExit) ? static_cast<void>
(0) : __assert_fail ("HoistingCands.empty() || CommonExit", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1603, __PRETTY_FUNCTION__))
;
6
Assuming the condition is true
1604
1605 // Find inputs to, outputs from the code region.
1606 findInputsOutputs(inputs, outputs, SinkingCands);
1607
1608 // Now sink all instructions which only have non-phi uses inside the region.
1609 // Group the allocas at the start of the block, so that any bitcast uses of
1610 // the allocas are well-defined.
1611 AllocaInst *FirstSunkAlloca = nullptr;
1612 for (auto *II : SinkingCands) {
1613 if (auto *AI = dyn_cast<AllocaInst>(II)) {
1614 AI->moveBefore(*newFuncRoot, newFuncRoot->getFirstInsertionPt());
1615 if (!FirstSunkAlloca)
1616 FirstSunkAlloca = AI;
1617 }
1618 }
1619 assert((SinkingCands.empty() || FirstSunkAlloca) &&(((SinkingCands.empty() || FirstSunkAlloca) && "Did not expect a sink candidate without any allocas"
) ? static_cast<void> (0) : __assert_fail ("(SinkingCands.empty() || FirstSunkAlloca) && \"Did not expect a sink candidate without any allocas\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1620, __PRETTY_FUNCTION__))
7
Assuming the condition is true
8
'?' condition is true
1620 "Did not expect a sink candidate without any allocas")(((SinkingCands.empty() || FirstSunkAlloca) && "Did not expect a sink candidate without any allocas"
) ? static_cast<void> (0) : __assert_fail ("(SinkingCands.empty() || FirstSunkAlloca) && \"Did not expect a sink candidate without any allocas\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1620, __PRETTY_FUNCTION__))
;
1621 for (auto *II : SinkingCands) {
1622 if (!isa<AllocaInst>(II)) {
1623 cast<Instruction>(II)->moveAfter(FirstSunkAlloca);
1624 }
1625 }
1626
1627 if (!HoistingCands.empty()) {
9
Assuming the condition is false
10
Taking false branch
1628 auto *HoistToBlock = findOrCreateBlockForHoisting(CommonExit);
1629 Instruction *TI = HoistToBlock->getTerminator();
1630 for (auto *II : HoistingCands)
1631 cast<Instruction>(II)->moveBefore(TI);
1632 }
1633
1634 // Collect objects which are inputs to the extraction region and also
1635 // referenced by lifetime start markers within it. The effects of these
1636 // markers must be replicated in the calling function to prevent the stack
1637 // coloring pass from merging slots which store input objects.
1638 ValueSet LifetimesStart;
1639 eraseLifetimeMarkersOnInputs(Blocks, SinkingCands, LifetimesStart);
1640
1641 // Construct new function based on inputs/outputs & add allocas for all defs.
1642 Function *newFunction =
1643 constructFunction(inputs, outputs, header, newFuncRoot, codeReplacer,
1644 oldFunction, oldFunction->getParent());
1645
1646 // Update the entry count of the function.
1647 if (BFI) {
11
Assuming field 'BFI' is null
12
Taking false branch
1648 auto Count = BFI->getProfileCountFromFreq(EntryFreq.getFrequency());
1649 if (Count.hasValue())
1650 newFunction->setEntryCount(
1651 ProfileCount(Count.getValue(), Function::PCT_Real)); // FIXME
1652 BFI->setBlockFreq(codeReplacer, EntryFreq.getFrequency());
1653 }
1654
1655 CallInst *TheCall =
1656 emitCallAndSwitchStatement(newFunction, codeReplacer, inputs, outputs);
1657
1658 moveCodeToFunction(newFunction);
1659
1660 // Replicate the effects of any lifetime start/end markers which referenced
1661 // input objects in the extraction region by placing markers around the call.
1662 insertLifetimeMarkersSurroundingCall(
1663 oldFunction->getParent(), LifetimesStart.getArrayRef(), {}, TheCall);
1664
1665 // Propagate personality info to the new function if there is one.
1666 if (oldFunction->hasPersonalityFn())
13
Assuming the condition is false
14
Taking false branch
1667 newFunction->setPersonalityFn(oldFunction->getPersonalityFn());
1668
1669 // Update the branch weights for the exit block.
1670 if (BFI && NumExitBlocks > 1)
15
Assuming field 'BFI' is null
1671 calculateNewCallTerminatorWeights(codeReplacer, ExitWeights, BPI);
1672
1673 // Loop over all of the PHI nodes in the header and exit blocks, and change
1674 // any references to the old incoming edge to be the new incoming edge.
1675 for (BasicBlock::iterator I = header->begin(); isa<PHINode>(I); ++I) {
16
Assuming 'I' is not a 'PHINode'
17
Loop condition is false. Execution continues on line 1682
1676 PHINode *PN = cast<PHINode>(I);
1677 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
1678 if (!Blocks.count(PN->getIncomingBlock(i)))
1679 PN->setIncomingBlock(i, newFuncRoot);
1680 }
1681
1682 for (BasicBlock *ExitBB : ExitBlocks)
1683 for (PHINode &PN : ExitBB->phis()) {
1684 Value *IncomingCodeReplacerVal = nullptr;
1685 for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1686 // Ignore incoming values from outside of the extracted region.
1687 if (!Blocks.count(PN.getIncomingBlock(i)))
1688 continue;
1689
1690 // Ensure that there is only one incoming value from codeReplacer.
1691 if (!IncomingCodeReplacerVal) {
1692 PN.setIncomingBlock(i, codeReplacer);
1693 IncomingCodeReplacerVal = PN.getIncomingValue(i);
1694 } else
1695 assert(IncomingCodeReplacerVal == PN.getIncomingValue(i) &&((IncomingCodeReplacerVal == PN.getIncomingValue(i) &&
"PHI has two incompatbile incoming values from codeRepl") ? static_cast
<void> (0) : __assert_fail ("IncomingCodeReplacerVal == PN.getIncomingValue(i) && \"PHI has two incompatbile incoming values from codeRepl\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1696, __PRETTY_FUNCTION__))
1696 "PHI has two incompatbile incoming values from codeRepl")((IncomingCodeReplacerVal == PN.getIncomingValue(i) &&
"PHI has two incompatbile incoming values from codeRepl") ? static_cast
<void> (0) : __assert_fail ("IncomingCodeReplacerVal == PN.getIncomingValue(i) && \"PHI has two incompatbile incoming values from codeRepl\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Utils/CodeExtractor.cpp"
, 1696, __PRETTY_FUNCTION__))
;
1697 }
1698 }
1699
1700 fixupDebugInfoPostExtraction(*oldFunction, *newFunction, *TheCall);
1701
1702 // Mark the new function `noreturn` if applicable. Terminators which resume
1703 // exception propagation are treated as returning instructions. This is to
1704 // avoid inserting traps after calls to outlined functions which unwind.
1705 bool doesNotReturn = none_of(*newFunction, [](const BasicBlock &BB) {
1706 const Instruction *Term = BB.getTerminator();
1707 return isa<ReturnInst>(Term) || isa<ResumeInst>(Term);
1708 });
1709 if (doesNotReturn
17.1
'doesNotReturn' is true
17.1
'doesNotReturn' is true
17.1
'doesNotReturn' is true
)
18
Taking true branch
1710 newFunction->setDoesNotReturn();
1711
1712 LLVM_DEBUG(if (verifyFunction(*newFunction, &errs())) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*newFunction, &errs
())) { newFunction->dump(); report_fatal_error("verification of newFunction failed!"
); }; } } while (false)
19
Assuming 'DebugFlag' is true
20
Assuming the condition is false
21
Taking false branch
22
Loop condition is false. Exiting loop
1713 newFunction->dump();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*newFunction, &errs
())) { newFunction->dump(); report_fatal_error("verification of newFunction failed!"
); }; } } while (false)
1714 report_fatal_error("verification of newFunction failed!");do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*newFunction, &errs
())) { newFunction->dump(); report_fatal_error("verification of newFunction failed!"
); }; } } while (false)
1715 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*newFunction, &errs
())) { newFunction->dump(); report_fatal_error("verification of newFunction failed!"
); }; } } while (false)
;
1716 LLVM_DEBUG(if (verifyFunction(*oldFunction))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*oldFunction)) report_fatal_error
("verification of oldFunction failed!"); } } while (false)
23
Assuming 'DebugFlag' is true
24
Assuming the condition is false
25
Taking false branch
26
Loop condition is false. Exiting loop
1717 report_fatal_error("verification of oldFunction failed!"))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (verifyFunction(*oldFunction)) report_fatal_error
("verification of oldFunction failed!"); } } while (false)
;
1718 LLVM_DEBUG(if (AC && verifyAssumptionCache(*oldFunction, *newFunction, AC))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (AC && verifyAssumptionCache
(*oldFunction, *newFunction, AC)) report_fatal_error("Stale Asumption cache for old Function!"
); } } while (false)
27
Assuming 'DebugFlag' is true
28
Assuming the condition is true
29
Taking true branch
30
Assuming field 'AC' is non-null
31
Calling 'CodeExtractor::verifyAssumptionCache'
1719 report_fatal_error("Stale Asumption cache for old Function!"))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("code-extractor")) { if (AC && verifyAssumptionCache
(*oldFunction, *newFunction, AC)) report_fatal_error("Stale Asumption cache for old Function!"
); } } while (false)
;
1720 return newFunction;
1721}
1722
1723bool CodeExtractor::verifyAssumptionCache(const Function &OldFunc,
1724 const Function &NewFunc,
1725 AssumptionCache *AC) {
1726 for (auto AssumeVH : AC->assumptions()) {
32
Assuming '__begin1' is not equal to '__end1'
33
Calling copy constructor for 'WeakTrackingVH'
41
Returning from copy constructor for 'WeakTrackingVH'
1727 CallInst *I = dyn_cast_or_null<CallInst>(AssumeVH);
42
Calling 'dyn_cast_or_null<llvm::CallInst, llvm::WeakTrackingVH>'
51
Returning from 'dyn_cast_or_null<llvm::CallInst, llvm::WeakTrackingVH>'
1728 if (!I
51.1
'I' is non-null
51.1
'I' is non-null
51.1
'I' is non-null
)
52
Taking false branch
1729 continue;
1730
1731 // There shouldn't be any llvm.assume intrinsics in the new function.
1732 if (I->getFunction() != &OldFunc)
53
Assuming the condition is false
54
Taking false branch
1733 return true;
1734
1735 // There shouldn't be any stale affected values in the assumption cache
1736 // that were previously in the old function, but that have now been moved
1737 // to the new function.
1738 for (auto AffectedValVH : AC->assumptionsFor(I->getOperand(0))) {
55
Assuming '__begin2' is not equal to '__end2'
56
Calling copy constructor for 'WeakTrackingVH'
64
Returning from copy constructor for 'WeakTrackingVH'
1739 CallInst *AffectedCI = dyn_cast_or_null<CallInst>(AffectedValVH);
65
Calling 'dyn_cast_or_null<llvm::CallInst, llvm::WeakTrackingVH>'
74
Returning from 'dyn_cast_or_null<llvm::CallInst, llvm::WeakTrackingVH>'
1740 if (!AffectedCI
74.1
'AffectedCI' is non-null
74.1
'AffectedCI' is non-null
74.1
'AffectedCI' is non-null
)
75
Taking false branch
1741 continue;
1742 if (AffectedCI->getFunction() != &OldFunc)
76
Assuming the condition is false
77
Taking false branch
1743 return true;
1744 auto *AssumedInst = dyn_cast<Instruction>(AffectedCI->getOperand(0));
78
Assuming the object is not a 'Instruction'
79
'AssumedInst' initialized to a null pointer value
1745 if (AssumedInst->getFunction() != &OldFunc)
80
Called C++ object pointer is null
1746 return true;
1747 }
1748 }
1749 return false;
1750}

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h

1//===- ValueHandle.h - Value Smart Pointer classes --------------*- 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 declares the ValueHandle class and its sub-classes.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_IR_VALUEHANDLE_H
14#define LLVM_IR_VALUEHANDLE_H
15
16#include "llvm/ADT/DenseMapInfo.h"
17#include "llvm/ADT/PointerIntPair.h"
18#include "llvm/IR/Value.h"
19#include "llvm/Support/Casting.h"
20#include <cassert>
21
22namespace llvm {
23
24/// This is the common base class of value handles.
25///
26/// ValueHandle's are smart pointers to Value's that have special behavior when
27/// the value is deleted or ReplaceAllUsesWith'd. See the specific handles
28/// below for details.
29class ValueHandleBase {
30 friend class Value;
31
32protected:
33 /// This indicates what sub class the handle actually is.
34 ///
35 /// This is to avoid having a vtable for the light-weight handle pointers. The
36 /// fully general Callback version does have a vtable.
37 enum HandleBaseKind { Assert, Callback, Weak, WeakTracking };
38
39 ValueHandleBase(const ValueHandleBase &RHS)
40 : ValueHandleBase(RHS.PrevPair.getInt(), RHS) {}
41
42 ValueHandleBase(HandleBaseKind Kind, const ValueHandleBase &RHS)
43 : PrevPair(nullptr, Kind), Val(RHS.getValPtr()) {
44 if (isValid(getValPtr()))
35
Calling 'ValueHandleBase::isValid'
38
Returning from 'ValueHandleBase::isValid'
39
Taking false branch
58
Calling 'ValueHandleBase::isValid'
61
Returning from 'ValueHandleBase::isValid'
62
Taking false branch
45 AddToExistingUseList(RHS.getPrevPtr());
46 }
47
48private:
49 PointerIntPair<ValueHandleBase**, 2, HandleBaseKind> PrevPair;
50 ValueHandleBase *Next = nullptr;
51 Value *Val = nullptr;
52
53 void setValPtr(Value *V) { Val = V; }
54
55public:
56 explicit ValueHandleBase(HandleBaseKind Kind)
57 : PrevPair(nullptr, Kind) {}
58 ValueHandleBase(HandleBaseKind Kind, Value *V)
59 : PrevPair(nullptr, Kind), Val(V) {
60 if (isValid(getValPtr()))
61 AddToUseList();
62 }
63
64 ~ValueHandleBase() {
65 if (isValid(getValPtr()))
66 RemoveFromUseList();
67 }
68
69 Value *operator=(Value *RHS) {
70 if (getValPtr() == RHS)
71 return RHS;
72 if (isValid(getValPtr()))
73 RemoveFromUseList();
74 setValPtr(RHS);
75 if (isValid(getValPtr()))
76 AddToUseList();
77 return RHS;
78 }
79
80 Value *operator=(const ValueHandleBase &RHS) {
81 if (getValPtr() == RHS.getValPtr())
82 return RHS.getValPtr();
83 if (isValid(getValPtr()))
84 RemoveFromUseList();
85 setValPtr(RHS.getValPtr());
86 if (isValid(getValPtr()))
87 AddToExistingUseList(RHS.getPrevPtr());
88 return getValPtr();
89 }
90
91 Value *operator->() const { return getValPtr(); }
92 Value &operator*() const {
93 Value *V = getValPtr();
94 assert(V && "Dereferencing deleted ValueHandle")((V && "Dereferencing deleted ValueHandle") ? static_cast
<void> (0) : __assert_fail ("V && \"Dereferencing deleted ValueHandle\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 94, __PRETTY_FUNCTION__))
;
95 return *V;
96 }
97
98protected:
99 Value *getValPtr() const { return Val; }
100
101 static bool isValid(Value *V) {
102 return V &&
36
Assuming 'V' is non-null, which participates in a condition later
59
Assuming 'V' is non-null, which participates in a condition later
103 V != DenseMapInfo<Value *>::getEmptyKey() &&
37
Assuming the condition is false
60
Assuming the condition is false
104 V != DenseMapInfo<Value *>::getTombstoneKey();
105 }
106
107 /// Remove this ValueHandle from its current use list.
108 void RemoveFromUseList();
109
110 /// Clear the underlying pointer without clearing the use list.
111 ///
112 /// This should only be used if a derived class has manually removed the
113 /// handle from the use list.
114 void clearValPtr() { setValPtr(nullptr); }
115
116public:
117 // Callbacks made from Value.
118 static void ValueIsDeleted(Value *V);
119 static void ValueIsRAUWd(Value *Old, Value *New);
120
121private:
122 // Internal implementation details.
123 ValueHandleBase **getPrevPtr() const { return PrevPair.getPointer(); }
124 HandleBaseKind getKind() const { return PrevPair.getInt(); }
125 void setPrevPtr(ValueHandleBase **Ptr) { PrevPair.setPointer(Ptr); }
126
127 /// Add this ValueHandle to the use list for V.
128 ///
129 /// List is the address of either the head of the list or a Next node within
130 /// the existing use list.
131 void AddToExistingUseList(ValueHandleBase **List);
132
133 /// Add this ValueHandle to the use list after Node.
134 void AddToExistingUseListAfter(ValueHandleBase *Node);
135
136 /// Add this ValueHandle to the use list for V.
137 void AddToUseList();
138};
139
140/// A nullable Value handle that is nullable.
141///
142/// This is a value handle that points to a value, and nulls itself
143/// out if that value is deleted.
144class WeakVH : public ValueHandleBase {
145public:
146 WeakVH() : ValueHandleBase(Weak) {}
147 WeakVH(Value *P) : ValueHandleBase(Weak, P) {}
148 WeakVH(const WeakVH &RHS)
149 : ValueHandleBase(Weak, RHS) {}
150
151 WeakVH &operator=(const WeakVH &RHS) = default;
152
153 Value *operator=(Value *RHS) {
154 return ValueHandleBase::operator=(RHS);
155 }
156 Value *operator=(const ValueHandleBase &RHS) {
157 return ValueHandleBase::operator=(RHS);
158 }
159
160 operator Value*() const {
161 return getValPtr();
162 }
163};
164
165// Specialize simplify_type to allow WeakVH to participate in
166// dyn_cast, isa, etc.
167template <> struct simplify_type<WeakVH> {
168 using SimpleType = Value *;
169
170 static SimpleType getSimplifiedValue(WeakVH &WVH) { return WVH; }
171};
172template <> struct simplify_type<const WeakVH> {
173 using SimpleType = Value *;
174
175 static SimpleType getSimplifiedValue(const WeakVH &WVH) { return WVH; }
176};
177
178// Specialize DenseMapInfo to allow WeakVH to participate in DenseMap.
179template <> struct DenseMapInfo<WeakVH> {
180 static inline WeakVH getEmptyKey() {
181 return WeakVH(DenseMapInfo<Value *>::getEmptyKey());
182 }
183
184 static inline WeakVH getTombstoneKey() {
185 return WeakVH(DenseMapInfo<Value *>::getTombstoneKey());
186 }
187
188 static unsigned getHashValue(const WeakVH &Val) {
189 return DenseMapInfo<Value *>::getHashValue(Val);
190 }
191
192 static bool isEqual(const WeakVH &LHS, const WeakVH &RHS) {
193 return DenseMapInfo<Value *>::isEqual(LHS, RHS);
194 }
195};
196
197/// Value handle that is nullable, but tries to track the Value.
198///
199/// This is a value handle that tries hard to point to a Value, even across
200/// RAUW operations, but will null itself out if the value is destroyed. this
201/// is useful for advisory sorts of information, but should not be used as the
202/// key of a map (since the map would have to rearrange itself when the pointer
203/// changes).
204class WeakTrackingVH : public ValueHandleBase {
205public:
206 WeakTrackingVH() : ValueHandleBase(WeakTracking) {}
207 WeakTrackingVH(Value *P) : ValueHandleBase(WeakTracking, P) {}
208 WeakTrackingVH(const WeakTrackingVH &RHS)
209 : ValueHandleBase(WeakTracking, RHS) {}
34
Calling constructor for 'ValueHandleBase'
40
Returning from constructor for 'ValueHandleBase'
57
Calling constructor for 'ValueHandleBase'
63
Returning from constructor for 'ValueHandleBase'
210
211 WeakTrackingVH &operator=(const WeakTrackingVH &RHS) = default;
212
213 Value *operator=(Value *RHS) {
214 return ValueHandleBase::operator=(RHS);
215 }
216 Value *operator=(const ValueHandleBase &RHS) {
217 return ValueHandleBase::operator=(RHS);
218 }
219
220 operator Value*() const {
221 return getValPtr();
222 }
223
224 bool pointsToAliveValue() const {
225 return ValueHandleBase::isValid(getValPtr());
226 }
227};
228
229// Specialize simplify_type to allow WeakTrackingVH to participate in
230// dyn_cast, isa, etc.
231template <> struct simplify_type<WeakTrackingVH> {
232 using SimpleType = Value *;
233
234 static SimpleType getSimplifiedValue(WeakTrackingVH &WVH) { return WVH; }
235};
236template <> struct simplify_type<const WeakTrackingVH> {
237 using SimpleType = Value *;
238
239 static SimpleType getSimplifiedValue(const WeakTrackingVH &WVH) {
240 return WVH;
241 }
242};
243
244/// Value handle that asserts if the Value is deleted.
245///
246/// This is a Value Handle that points to a value and asserts out if the value
247/// is destroyed while the handle is still live. This is very useful for
248/// catching dangling pointer bugs and other things which can be non-obvious.
249/// One particularly useful place to use this is as the Key of a map. Dangling
250/// pointer bugs often lead to really subtle bugs that only occur if another
251/// object happens to get allocated to the same address as the old one. Using
252/// an AssertingVH ensures that an assert is triggered as soon as the bad
253/// delete occurs.
254///
255/// Note that an AssertingVH handle does *not* follow values across RAUW
256/// operations. This means that RAUW's need to explicitly update the
257/// AssertingVH's as it moves. This is required because in non-assert mode this
258/// class turns into a trivial wrapper around a pointer.
259template <typename ValueTy>
260class AssertingVH
261#ifndef NDEBUG
262 : public ValueHandleBase
263#endif
264 {
265 friend struct DenseMapInfo<AssertingVH<ValueTy>>;
266
267#ifndef NDEBUG
268 Value *getRawValPtr() const { return ValueHandleBase::getValPtr(); }
269 void setRawValPtr(Value *P) { ValueHandleBase::operator=(P); }
270#else
271 Value *ThePtr;
272 Value *getRawValPtr() const { return ThePtr; }
273 void setRawValPtr(Value *P) { ThePtr = P; }
274#endif
275 // Convert a ValueTy*, which may be const, to the raw Value*.
276 static Value *GetAsValue(Value *V) { return V; }
277 static Value *GetAsValue(const Value *V) { return const_cast<Value*>(V); }
278
279 ValueTy *getValPtr() const { return static_cast<ValueTy *>(getRawValPtr()); }
280 void setValPtr(ValueTy *P) { setRawValPtr(GetAsValue(P)); }
281
282public:
283#ifndef NDEBUG
284 AssertingVH() : ValueHandleBase(Assert) {}
285 AssertingVH(ValueTy *P) : ValueHandleBase(Assert, GetAsValue(P)) {}
286 AssertingVH(const AssertingVH &RHS) : ValueHandleBase(Assert, RHS) {}
287#else
288 AssertingVH() : ThePtr(nullptr) {}
289 AssertingVH(ValueTy *P) : ThePtr(GetAsValue(P)) {}
290 AssertingVH(const AssertingVH<ValueTy> &) = default;
291#endif
292
293 operator ValueTy*() const {
294 return getValPtr();
295 }
296
297 ValueTy *operator=(ValueTy *RHS) {
298 setValPtr(RHS);
299 return getValPtr();
300 }
301 ValueTy *operator=(const AssertingVH<ValueTy> &RHS) {
302 setValPtr(RHS.getValPtr());
303 return getValPtr();
304 }
305
306 ValueTy *operator->() const { return getValPtr(); }
307 ValueTy &operator*() const { return *getValPtr(); }
308};
309
310// Specialize DenseMapInfo to allow AssertingVH to participate in DenseMap.
311template<typename T>
312struct DenseMapInfo<AssertingVH<T>> {
313 static inline AssertingVH<T> getEmptyKey() {
314 AssertingVH<T> Res;
315 Res.setRawValPtr(DenseMapInfo<Value *>::getEmptyKey());
316 return Res;
317 }
318
319 static inline AssertingVH<T> getTombstoneKey() {
320 AssertingVH<T> Res;
321 Res.setRawValPtr(DenseMapInfo<Value *>::getTombstoneKey());
322 return Res;
323 }
324
325 static unsigned getHashValue(const AssertingVH<T> &Val) {
326 return DenseMapInfo<Value *>::getHashValue(Val.getRawValPtr());
327 }
328
329 static bool isEqual(const AssertingVH<T> &LHS, const AssertingVH<T> &RHS) {
330 return DenseMapInfo<Value *>::isEqual(LHS.getRawValPtr(),
331 RHS.getRawValPtr());
332 }
333};
334
335/// Value handle that tracks a Value across RAUW.
336///
337/// TrackingVH is designed for situations where a client needs to hold a handle
338/// to a Value (or subclass) across some operations which may move that value,
339/// but should never destroy it or replace it with some unacceptable type.
340///
341/// It is an error to attempt to replace a value with one of a type which is
342/// incompatible with any of its outstanding TrackingVHs.
343///
344/// It is an error to read from a TrackingVH that does not point to a valid
345/// value. A TrackingVH is said to not point to a valid value if either it
346/// hasn't yet been assigned a value yet or because the value it was tracking
347/// has since been deleted.
348///
349/// Assigning a value to a TrackingVH is always allowed, even if said TrackingVH
350/// no longer points to a valid value.
351template <typename ValueTy> class TrackingVH {
352 WeakTrackingVH InnerHandle;
353
354public:
355 ValueTy *getValPtr() const {
356 assert(InnerHandle.pointsToAliveValue() &&((InnerHandle.pointsToAliveValue() && "TrackingVH must be non-null and valid on dereference!"
) ? static_cast<void> (0) : __assert_fail ("InnerHandle.pointsToAliveValue() && \"TrackingVH must be non-null and valid on dereference!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 357, __PRETTY_FUNCTION__))
357 "TrackingVH must be non-null and valid on dereference!")((InnerHandle.pointsToAliveValue() && "TrackingVH must be non-null and valid on dereference!"
) ? static_cast<void> (0) : __assert_fail ("InnerHandle.pointsToAliveValue() && \"TrackingVH must be non-null and valid on dereference!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 357, __PRETTY_FUNCTION__))
;
358
359 // Check that the value is a member of the correct subclass. We would like
360 // to check this property on assignment for better debugging, but we don't
361 // want to require a virtual interface on this VH. Instead we allow RAUW to
362 // replace this value with a value of an invalid type, and check it here.
363 assert(isa<ValueTy>(InnerHandle) &&((isa<ValueTy>(InnerHandle) && "Tracked Value was replaced by one with an invalid type!"
) ? static_cast<void> (0) : __assert_fail ("isa<ValueTy>(InnerHandle) && \"Tracked Value was replaced by one with an invalid type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 364, __PRETTY_FUNCTION__))
364 "Tracked Value was replaced by one with an invalid type!")((isa<ValueTy>(InnerHandle) && "Tracked Value was replaced by one with an invalid type!"
) ? static_cast<void> (0) : __assert_fail ("isa<ValueTy>(InnerHandle) && \"Tracked Value was replaced by one with an invalid type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 364, __PRETTY_FUNCTION__))
;
365 return cast<ValueTy>(InnerHandle);
366 }
367
368 void setValPtr(ValueTy *P) {
369 // Assigning to non-valid TrackingVH's are fine so we just unconditionally
370 // assign here.
371 InnerHandle = GetAsValue(P);
372 }
373
374 // Convert a ValueTy*, which may be const, to the type the base
375 // class expects.
376 static Value *GetAsValue(Value *V) { return V; }
377 static Value *GetAsValue(const Value *V) { return const_cast<Value*>(V); }
378
379public:
380 TrackingVH() = default;
381 TrackingVH(ValueTy *P) { setValPtr(P); }
382
383 operator ValueTy*() const {
384 return getValPtr();
385 }
386
387 ValueTy *operator=(ValueTy *RHS) {
388 setValPtr(RHS);
389 return getValPtr();
390 }
391
392 ValueTy *operator->() const { return getValPtr(); }
393 ValueTy &operator*() const { return *getValPtr(); }
394};
395
396/// Value handle with callbacks on RAUW and destruction.
397///
398/// This is a value handle that allows subclasses to define callbacks that run
399/// when the underlying Value has RAUW called on it or is destroyed. This
400/// class can be used as the key of a map, as long as the user takes it out of
401/// the map before calling setValPtr() (since the map has to rearrange itself
402/// when the pointer changes). Unlike ValueHandleBase, this class has a vtable.
403class CallbackVH : public ValueHandleBase {
404 virtual void anchor();
405protected:
406 ~CallbackVH() = default;
407 CallbackVH(const CallbackVH &) = default;
408 CallbackVH &operator=(const CallbackVH &) = default;
409
410 void setValPtr(Value *P) {
411 ValueHandleBase::operator=(P);
412 }
413
414public:
415 CallbackVH() : ValueHandleBase(Callback) {}
416 CallbackVH(Value *P) : ValueHandleBase(Callback, P) {}
417 CallbackVH(const Value *P) : CallbackVH(const_cast<Value *>(P)) {}
418
419 operator Value*() const {
420 return getValPtr();
421 }
422
423 /// Callback for Value destruction.
424 ///
425 /// Called when this->getValPtr() is destroyed, inside ~Value(), so you
426 /// may call any non-virtual Value method on getValPtr(), but no subclass
427 /// methods. If WeakTrackingVH were implemented as a CallbackVH, it would use
428 /// this
429 /// method to call setValPtr(NULL). AssertingVH would use this method to
430 /// cause an assertion failure.
431 ///
432 /// All implementations must remove the reference from this object to the
433 /// Value that's being destroyed.
434 virtual void deleted() { setValPtr(nullptr); }
435
436 /// Callback for Value RAUW.
437 ///
438 /// Called when this->getValPtr()->replaceAllUsesWith(new_value) is called,
439 /// _before_ any of the uses have actually been replaced. If WeakTrackingVH
440 /// were
441 /// implemented as a CallbackVH, it would use this method to call
442 /// setValPtr(new_value). AssertingVH would do nothing in this method.
443 virtual void allUsesReplacedWith(Value *) {}
444};
445
446/// Value handle that poisons itself if the Value is deleted.
447///
448/// This is a Value Handle that points to a value and poisons itself if the
449/// value is destroyed while the handle is still live. This is very useful for
450/// catching dangling pointer bugs where an \c AssertingVH cannot be used
451/// because the dangling handle needs to outlive the value without ever being
452/// used.
453///
454/// One particularly useful place to use this is as the Key of a map. Dangling
455/// pointer bugs often lead to really subtle bugs that only occur if another
456/// object happens to get allocated to the same address as the old one. Using
457/// a PoisoningVH ensures that an assert is triggered if looking up a new value
458/// in the map finds a handle from the old value.
459///
460/// Note that a PoisoningVH handle does *not* follow values across RAUW
461/// operations. This means that RAUW's need to explicitly update the
462/// PoisoningVH's as it moves. This is required because in non-assert mode this
463/// class turns into a trivial wrapper around a pointer.
464template <typename ValueTy>
465class PoisoningVH
466#ifndef NDEBUG
467 final : public CallbackVH
468#endif
469{
470 friend struct DenseMapInfo<PoisoningVH<ValueTy>>;
471
472 // Convert a ValueTy*, which may be const, to the raw Value*.
473 static Value *GetAsValue(Value *V) { return V; }
474 static Value *GetAsValue(const Value *V) { return const_cast<Value *>(V); }
475
476#ifndef NDEBUG
477 /// A flag tracking whether this value has been poisoned.
478 ///
479 /// On delete and RAUW, we leave the value pointer alone so that as a raw
480 /// pointer it produces the same value (and we fit into the same key of
481 /// a hash table, etc), but we poison the handle so that any top-level usage
482 /// will fail.
483 bool Poisoned = false;
484
485 Value *getRawValPtr() const { return ValueHandleBase::getValPtr(); }
486 void setRawValPtr(Value *P) { ValueHandleBase::operator=(P); }
487
488 /// Handle deletion by poisoning the handle.
489 void deleted() override {
490 assert(!Poisoned && "Tried to delete an already poisoned handle!")((!Poisoned && "Tried to delete an already poisoned handle!"
) ? static_cast<void> (0) : __assert_fail ("!Poisoned && \"Tried to delete an already poisoned handle!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 490, __PRETTY_FUNCTION__))
;
491 Poisoned = true;
492 RemoveFromUseList();
493 }
494
495 /// Handle RAUW by poisoning the handle.
496 void allUsesReplacedWith(Value *) override {
497 assert(!Poisoned && "Tried to RAUW an already poisoned handle!")((!Poisoned && "Tried to RAUW an already poisoned handle!"
) ? static_cast<void> (0) : __assert_fail ("!Poisoned && \"Tried to RAUW an already poisoned handle!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 497, __PRETTY_FUNCTION__))
;
498 Poisoned = true;
499 RemoveFromUseList();
500 }
501#else // NDEBUG
502 Value *ThePtr = nullptr;
503
504 Value *getRawValPtr() const { return ThePtr; }
505 void setRawValPtr(Value *P) { ThePtr = P; }
506#endif
507
508 ValueTy *getValPtr() const {
509 assert(!Poisoned && "Accessed a poisoned value handle!")((!Poisoned && "Accessed a poisoned value handle!") ?
static_cast<void> (0) : __assert_fail ("!Poisoned && \"Accessed a poisoned value handle!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/IR/ValueHandle.h"
, 509, __PRETTY_FUNCTION__))
;
510 return static_cast<ValueTy *>(getRawValPtr());
511 }
512 void setValPtr(ValueTy *P) { setRawValPtr(GetAsValue(P)); }
513
514public:
515 PoisoningVH() = default;
516#ifndef NDEBUG
517 PoisoningVH(ValueTy *P) : CallbackVH(GetAsValue(P)) {}
518 PoisoningVH(const PoisoningVH &RHS)
519 : CallbackVH(RHS), Poisoned(RHS.Poisoned) {}
520
521 ~PoisoningVH() {
522 if (Poisoned)
523 clearValPtr();
524 }
525
526 PoisoningVH &operator=(const PoisoningVH &RHS) {
527 if (Poisoned)
528 clearValPtr();
529 CallbackVH::operator=(RHS);
530 Poisoned = RHS.Poisoned;
531 return *this;
532 }
533#else
534 PoisoningVH(ValueTy *P) : ThePtr(GetAsValue(P)) {}
535#endif
536
537 operator ValueTy *() const { return getValPtr(); }
538
539 ValueTy *operator->() const { return getValPtr(); }
540 ValueTy &operator*() const { return *getValPtr(); }
541};
542
543// Specialize DenseMapInfo to allow PoisoningVH to participate in DenseMap.
544template <typename T> struct DenseMapInfo<PoisoningVH<T>> {
545 static inline PoisoningVH<T> getEmptyKey() {
546 PoisoningVH<T> Res;
547 Res.setRawValPtr(DenseMapInfo<Value *>::getEmptyKey());
548 return Res;
549 }
550
551 static inline PoisoningVH<T> getTombstoneKey() {
552 PoisoningVH<T> Res;
553 Res.setRawValPtr(DenseMapInfo<Value *>::getTombstoneKey());
554 return Res;
555 }
556
557 static unsigned getHashValue(const PoisoningVH<T> &Val) {
558 return DenseMapInfo<Value *>::getHashValue(Val.getRawValPtr());
559 }
560
561 static bool isEqual(const PoisoningVH<T> &LHS, const PoisoningVH<T> &RHS) {
562 return DenseMapInfo<Value *>::isEqual(LHS.getRawValPtr(),
563 RHS.getRawValPtr());
564 }
565};
566
567} // end namespace llvm
568
569#endif // LLVM_IR_VALUEHANDLE_H

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h

1//===- llvm/Support/Casting.h - Allow flexible, checked, casts --*- 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 isa<X>(), cast<X>(), dyn_cast<X>(), cast_or_null<X>(),
10// and dyn_cast_or_null<X>() templates.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_CASTING_H
15#define LLVM_SUPPORT_CASTING_H
16
17#include "llvm/Support/Compiler.h"
18#include "llvm/Support/type_traits.h"
19#include <cassert>
20#include <memory>
21#include <type_traits>
22
23namespace llvm {
24
25//===----------------------------------------------------------------------===//
26// isa<x> Support Templates
27//===----------------------------------------------------------------------===//
28
29// Define a template that can be specialized by smart pointers to reflect the
30// fact that they are automatically dereferenced, and are not involved with the
31// template selection process... the default implementation is a noop.
32//
33template<typename From> struct simplify_type {
34 using SimpleType = From; // The real type this represents...
35
36 // An accessor to get the real value...
37 static SimpleType &getSimplifiedValue(From &Val) { return Val; }
38};
39
40template<typename From> struct simplify_type<const From> {
41 using NonConstSimpleType = typename simplify_type<From>::SimpleType;
42 using SimpleType =
43 typename add_const_past_pointer<NonConstSimpleType>::type;
44 using RetType =
45 typename add_lvalue_reference_if_not_pointer<SimpleType>::type;
46
47 static RetType getSimplifiedValue(const From& Val) {
48 return simplify_type<From>::getSimplifiedValue(const_cast<From&>(Val));
49 }
50};
51
52// The core of the implementation of isa<X> is here; To and From should be
53// the names of classes. This template can be specialized to customize the
54// implementation of isa<> without rewriting it from scratch.
55template <typename To, typename From, typename Enabler = void>
56struct isa_impl {
57 static inline bool doit(const From &Val) {
58 return To::classof(&Val);
59 }
60};
61
62/// Always allow upcasts, and perform no dynamic check for them.
63template <typename To, typename From>
64struct isa_impl<To, From, std::enable_if_t<std::is_base_of<To, From>::value>> {
65 static inline bool doit(const From &) { return true; }
66};
67
68template <typename To, typename From> struct isa_impl_cl {
69 static inline bool doit(const From &Val) {
70 return isa_impl<To, From>::doit(Val);
71 }
72};
73
74template <typename To, typename From> struct isa_impl_cl<To, const From> {
75 static inline bool doit(const From &Val) {
76 return isa_impl<To, From>::doit(Val);
77 }
78};
79
80template <typename To, typename From>
81struct isa_impl_cl<To, const std::unique_ptr<From>> {
82 static inline bool doit(const std::unique_ptr<From> &Val) {
83 assert(Val && "isa<> used on a null pointer")((Val && "isa<> used on a null pointer") ? static_cast
<void> (0) : __assert_fail ("Val && \"isa<> used on a null pointer\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 83, __PRETTY_FUNCTION__))
;
84 return isa_impl_cl<To, From>::doit(*Val);
85 }
86};
87
88template <typename To, typename From> struct isa_impl_cl<To, From*> {
89 static inline bool doit(const From *Val) {
90 assert(Val && "isa<> used on a null pointer")((Val && "isa<> used on a null pointer") ? static_cast
<void> (0) : __assert_fail ("Val && \"isa<> used on a null pointer\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 90, __PRETTY_FUNCTION__))
;
91 return isa_impl<To, From>::doit(*Val);
92 }
93};
94
95template <typename To, typename From> struct isa_impl_cl<To, From*const> {
96 static inline bool doit(const From *Val) {
97 assert(Val && "isa<> used on a null pointer")((Val && "isa<> used on a null pointer") ? static_cast
<void> (0) : __assert_fail ("Val && \"isa<> used on a null pointer\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 97, __PRETTY_FUNCTION__))
;
98 return isa_impl<To, From>::doit(*Val);
99 }
100};
101
102template <typename To, typename From> struct isa_impl_cl<To, const From*> {
103 static inline bool doit(const From *Val) {
104 assert(Val && "isa<> used on a null pointer")((Val && "isa<> used on a null pointer") ? static_cast
<void> (0) : __assert_fail ("Val && \"isa<> used on a null pointer\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 104, __PRETTY_FUNCTION__))
;
105 return isa_impl<To, From>::doit(*Val);
106 }
107};
108
109template <typename To, typename From> struct isa_impl_cl<To, const From*const> {
110 static inline bool doit(const From *Val) {
111 assert(Val && "isa<> used on a null pointer")((Val && "isa<> used on a null pointer") ? static_cast
<void> (0) : __assert_fail ("Val && \"isa<> used on a null pointer\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 111, __PRETTY_FUNCTION__))
;
112 return isa_impl<To, From>::doit(*Val);
113 }
114};
115
116template<typename To, typename From, typename SimpleFrom>
117struct isa_impl_wrap {
118 // When From != SimplifiedType, we can simplify the type some more by using
119 // the simplify_type template.
120 static bool doit(const From &Val) {
121 return isa_impl_wrap<To, SimpleFrom,
122 typename simplify_type<SimpleFrom>::SimpleType>::doit(
123 simplify_type<const From>::getSimplifiedValue(Val));
124 }
125};
126
127template<typename To, typename FromTy>
128struct isa_impl_wrap<To, FromTy, FromTy> {
129 // When From == SimpleType, we are as simple as we are going to get.
130 static bool doit(const FromTy &Val) {
131 return isa_impl_cl<To,FromTy>::doit(Val);
132 }
133};
134
135// isa<X> - Return true if the parameter to the template is an instance of the
136// template type argument. Used like this:
137//
138// if (isa<Type>(myVal)) { ... }
139//
140template <class X, class Y> LLVM_NODISCARD[[clang::warn_unused_result]] inline bool isa(const Y &Val) {
141 return isa_impl_wrap<X, const Y,
142 typename simplify_type<const Y>::SimpleType>::doit(Val);
143}
144
145// isa_and_nonnull<X> - Functionally identical to isa, except that a null value
146// is accepted.
147//
148template <class X, class Y>
149LLVM_NODISCARD[[clang::warn_unused_result]] inline bool isa_and_nonnull(const Y &Val) {
150 if (!Val)
151 return false;
152 return isa<X>(Val);
153}
154
155//===----------------------------------------------------------------------===//
156// cast<x> Support Templates
157//===----------------------------------------------------------------------===//
158
159template<class To, class From> struct cast_retty;
160
161// Calculate what type the 'cast' function should return, based on a requested
162// type of To and a source type of From.
163template<class To, class From> struct cast_retty_impl {
164 using ret_type = To &; // Normal case, return Ty&
165};
166template<class To, class From> struct cast_retty_impl<To, const From> {
167 using ret_type = const To &; // Normal case, return Ty&
168};
169
170template<class To, class From> struct cast_retty_impl<To, From*> {
171 using ret_type = To *; // Pointer arg case, return Ty*
172};
173
174template<class To, class From> struct cast_retty_impl<To, const From*> {
175 using ret_type = const To *; // Constant pointer arg case, return const Ty*
176};
177
178template<class To, class From> struct cast_retty_impl<To, const From*const> {
179 using ret_type = const To *; // Constant pointer arg case, return const Ty*
180};
181
182template <class To, class From>
183struct cast_retty_impl<To, std::unique_ptr<From>> {
184private:
185 using PointerType = typename cast_retty_impl<To, From *>::ret_type;
186 using ResultType = std::remove_pointer_t<PointerType>;
187
188public:
189 using ret_type = std::unique_ptr<ResultType>;
190};
191
192template<class To, class From, class SimpleFrom>
193struct cast_retty_wrap {
194 // When the simplified type and the from type are not the same, use the type
195 // simplifier to reduce the type, then reuse cast_retty_impl to get the
196 // resultant type.
197 using ret_type = typename cast_retty<To, SimpleFrom>::ret_type;
198};
199
200template<class To, class FromTy>
201struct cast_retty_wrap<To, FromTy, FromTy> {
202 // When the simplified type is equal to the from type, use it directly.
203 using ret_type = typename cast_retty_impl<To,FromTy>::ret_type;
204};
205
206template<class To, class From>
207struct cast_retty {
208 using ret_type = typename cast_retty_wrap<
209 To, From, typename simplify_type<From>::SimpleType>::ret_type;
210};
211
212// Ensure the non-simple values are converted using the simplify_type template
213// that may be specialized by smart pointers...
214//
215template<class To, class From, class SimpleFrom> struct cast_convert_val {
216 // This is not a simple type, use the template to simplify it...
217 static typename cast_retty<To, From>::ret_type doit(From &Val) {
218 return cast_convert_val<To, SimpleFrom,
219 typename simplify_type<SimpleFrom>::SimpleType>::doit(
220 simplify_type<From>::getSimplifiedValue(Val));
221 }
222};
223
224template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> {
225 // This _is_ a simple type, just cast it.
226 static typename cast_retty<To, FromTy>::ret_type doit(const FromTy &Val) {
227 typename cast_retty<To, FromTy>::ret_type Res2
228 = (typename cast_retty<To, FromTy>::ret_type)const_cast<FromTy&>(Val);
229 return Res2;
230 }
231};
232
233template <class X> struct is_simple_type {
234 static const bool value =
235 std::is_same<X, typename simplify_type<X>::SimpleType>::value;
236};
237
238// cast<X> - Return the argument parameter cast to the specified type. This
239// casting operator asserts that the type is correct, so it does not return null
240// on failure. It does not allow a null argument (use cast_or_null for that).
241// It is typically used like this:
242//
243// cast<Instruction>(myVal)->getParent()
244//
245template <class X, class Y>
246inline std::enable_if_t<!is_simple_type<Y>::value,
247 typename cast_retty<X, const Y>::ret_type>
248cast(const Y &Val) {
249 assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 249, __PRETTY_FUNCTION__))
;
250 return cast_convert_val<
251 X, const Y, typename simplify_type<const Y>::SimpleType>::doit(Val);
252}
253
254template <class X, class Y>
255inline typename cast_retty<X, Y>::ret_type cast(Y &Val) {
256 assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 256, __PRETTY_FUNCTION__))
;
46
'Val' is a 'CallInst'
47
'?' condition is true
69
'Val' is a 'CallInst'
70
'?' condition is true
257 return cast_convert_val<X, Y,
48
Returning pointer, which participates in a condition later
71
Returning pointer, which participates in a condition later
258 typename simplify_type<Y>::SimpleType>::doit(Val);
259}
260
261template <class X, class Y>
262inline typename cast_retty<X, Y *>::ret_type cast(Y *Val) {
263 assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 263, __PRETTY_FUNCTION__))
;
264 return cast_convert_val<X, Y*,
265 typename simplify_type<Y*>::SimpleType>::doit(Val);
266}
267
268template <class X, class Y>
269inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type
270cast(std::unique_ptr<Y> &&Val) {
271 assert(isa<X>(Val.get()) && "cast<Ty>() argument of incompatible type!")((isa<X>(Val.get()) && "cast<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val.get()) && \"cast<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 271, __PRETTY_FUNCTION__))
;
272 using ret_type = typename cast_retty<X, std::unique_ptr<Y>>::ret_type;
273 return ret_type(
274 cast_convert_val<X, Y *, typename simplify_type<Y *>::SimpleType>::doit(
275 Val.release()));
276}
277
278// cast_or_null<X> - Functionally identical to cast, except that a null value is
279// accepted.
280//
281template <class X, class Y>
282LLVM_NODISCARD[[clang::warn_unused_result]] inline std::enable_if_t<
283 !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
284cast_or_null(const Y &Val) {
285 if (!Val)
286 return nullptr;
287 assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 287, __PRETTY_FUNCTION__))
;
288 return cast<X>(Val);
289}
290
291template <class X, class Y>
292LLVM_NODISCARD[[clang::warn_unused_result]] inline std::enable_if_t<!is_simple_type<Y>::value,
293 typename cast_retty<X, Y>::ret_type>
294cast_or_null(Y &Val) {
295 if (!Val)
296 return nullptr;
297 assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 297, __PRETTY_FUNCTION__))
;
298 return cast<X>(Val);
299}
300
301template <class X, class Y>
302LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type
303cast_or_null(Y *Val) {
304 if (!Val) return nullptr;
305 assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")((isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"
) ? static_cast<void> (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include/llvm/Support/Casting.h"
, 305, __PRETTY_FUNCTION__))
;
306 return cast<X>(Val);
307}
308
309template <class X, class Y>
310inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type
311cast_or_null(std::unique_ptr<Y> &&Val) {
312 if (!Val)
313 return nullptr;
314 return cast<X>(std::move(Val));
315}
316
317// dyn_cast<X> - Return the argument parameter cast to the specified type. This
318// casting operator returns null if the argument is of the wrong type, so it can
319// be used to test for a type as well as cast if successful. This should be
320// used in the context of an if statement like this:
321//
322// if (const Instruction *I = dyn_cast<Instruction>(myVal)) { ... }
323//
324
325template <class X, class Y>
326LLVM_NODISCARD[[clang::warn_unused_result]] inline std::enable_if_t<
327 !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
328dyn_cast(const Y &Val) {
329 return isa<X>(Val) ? cast<X>(Val) : nullptr;
330}
331
332template <class X, class Y>
333LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y>::ret_type dyn_cast(Y &Val) {
334 return isa<X>(Val) ? cast<X>(Val) : nullptr;
335}
336
337template <class X, class Y>
338LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type dyn_cast(Y *Val) {
339 return isa<X>(Val) ? cast<X>(Val) : nullptr;
340}
341
342// dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null
343// value is accepted.
344//
345template <class X, class Y>
346LLVM_NODISCARD[[clang::warn_unused_result]] inline std::enable_if_t<
347 !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
348dyn_cast_or_null(const Y &Val) {
349 return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
350}
351
352template <class X, class Y>
353LLVM_NODISCARD[[clang::warn_unused_result]] inline std::enable_if_t<!is_simple_type<Y>::value,
354 typename cast_retty<X, Y>::ret_type>
355dyn_cast_or_null(Y &Val) {
356 return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
43
Assuming 'Val' is a 'CallInst'
44
'?' condition is true
45
Calling 'cast<llvm::CallInst, llvm::WeakTrackingVH>'
49
Returning from 'cast<llvm::CallInst, llvm::WeakTrackingVH>'
50
Returning pointer, which participates in a condition later
66
Assuming 'Val' is a 'CallInst'
67
'?' condition is true
68
Calling 'cast<llvm::CallInst, llvm::WeakTrackingVH>'
72
Returning from 'cast<llvm::CallInst, llvm::WeakTrackingVH>'
73
Returning pointer, which participates in a condition later
357}
358
359template <class X, class Y>
360LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type
361dyn_cast_or_null(Y *Val) {
362 return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
363}
364
365// unique_dyn_cast<X> - Given a unique_ptr<Y>, try to return a unique_ptr<X>,
366// taking ownership of the input pointer iff isa<X>(Val) is true. If the
367// cast is successful, From refers to nullptr on exit and the casted value
368// is returned. If the cast is unsuccessful, the function returns nullptr
369// and From is unchanged.
370template <class X, class Y>
371LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast(std::unique_ptr<Y> &Val)
372 -> decltype(cast<X>(Val)) {
373 if (!isa<X>(Val))
374 return nullptr;
375 return cast<X>(std::move(Val));
376}
377
378template <class X, class Y>
379LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast(std::unique_ptr<Y> &&Val) {
380 return unique_dyn_cast<X, Y>(Val);
381}
382
383// dyn_cast_or_null<X> - Functionally identical to unique_dyn_cast, except that
384// a null value is accepted.
385template <class X, class Y>
386LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &Val)
387 -> decltype(cast<X>(Val)) {
388 if (!Val)
389 return nullptr;
390 return unique_dyn_cast<X, Y>(Val);
391}
392
393template <class X, class Y>
394LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &&Val) {
395 return unique_dyn_cast_or_null<X, Y>(Val);
396}
397
398} // end namespace llvm
399
400#endif // LLVM_SUPPORT_CASTING_H