aboutsummaryrefslogtreecommitdiff
path: root/lib/Transforms/Utils/CodeExtractor.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Transforms/Utils/CodeExtractor.cpp')
-rw-r--r--lib/Transforms/Utils/CodeExtractor.cpp309
1 files changed, 181 insertions, 128 deletions
diff --git a/lib/Transforms/Utils/CodeExtractor.cpp b/lib/Transforms/Utils/CodeExtractor.cpp
index fa6d3f8ae873..0298ff9a395f 100644
--- a/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/lib/Transforms/Utils/CodeExtractor.cpp
@@ -293,10 +293,8 @@ static BasicBlock *getCommonExitBlock(const SetVector<BasicBlock *> &Blocks) {
CommonExitBlock = Succ;
continue;
}
- if (CommonExitBlock == Succ)
- continue;
-
- return true;
+ if (CommonExitBlock != Succ)
+ return true;
}
return false;
};
@@ -307,52 +305,79 @@ static BasicBlock *getCommonExitBlock(const SetVector<BasicBlock *> &Blocks) {
return CommonExitBlock;
}
-bool CodeExtractor::isLegalToShrinkwrapLifetimeMarkers(
- Instruction *Addr) const {
- AllocaInst *AI = cast<AllocaInst>(Addr->stripInBoundsConstantOffsets());
- Function *Func = (*Blocks.begin())->getParent();
- for (BasicBlock &BB : *Func) {
- if (Blocks.count(&BB))
- continue;
- for (Instruction &II : BB) {
- if (isa<DbgInfoIntrinsic>(II))
- continue;
+CodeExtractorAnalysisCache::CodeExtractorAnalysisCache(Function &F) {
+ for (BasicBlock &BB : F) {
+ for (Instruction &II : BB.instructionsWithoutDebug())
+ if (auto *AI = dyn_cast<AllocaInst>(&II))
+ Allocas.push_back(AI);
- unsigned Opcode = II.getOpcode();
- Value *MemAddr = nullptr;
- switch (Opcode) {
- case Instruction::Store:
- case Instruction::Load: {
- if (Opcode == Instruction::Store) {
- StoreInst *SI = cast<StoreInst>(&II);
- MemAddr = SI->getPointerOperand();
- } else {
- LoadInst *LI = cast<LoadInst>(&II);
- MemAddr = LI->getPointerOperand();
- }
- // Global variable can not be aliased with locals.
- if (dyn_cast<Constant>(MemAddr))
- break;
- Value *Base = MemAddr->stripInBoundsConstantOffsets();
- if (!isa<AllocaInst>(Base) || Base == AI)
- return false;
+ findSideEffectInfoForBlock(BB);
+ }
+}
+
+void CodeExtractorAnalysisCache::findSideEffectInfoForBlock(BasicBlock &BB) {
+ for (Instruction &II : BB.instructionsWithoutDebug()) {
+ unsigned Opcode = II.getOpcode();
+ Value *MemAddr = nullptr;
+ switch (Opcode) {
+ case Instruction::Store:
+ case Instruction::Load: {
+ if (Opcode == Instruction::Store) {
+ StoreInst *SI = cast<StoreInst>(&II);
+ MemAddr = SI->getPointerOperand();
+ } else {
+ LoadInst *LI = cast<LoadInst>(&II);
+ MemAddr = LI->getPointerOperand();
+ }
+ // Global variable can not be aliased with locals.
+ if (dyn_cast<Constant>(MemAddr))
break;
+ Value *Base = MemAddr->stripInBoundsConstantOffsets();
+ if (!isa<AllocaInst>(Base)) {
+ SideEffectingBlocks.insert(&BB);
+ return;
}
- default: {
- IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(&II);
- if (IntrInst) {
- if (IntrInst->isLifetimeStartOrEnd())
- break;
- return false;
- }
- // Treat all the other cases conservatively if it has side effects.
- if (II.mayHaveSideEffects())
- return false;
+ BaseMemAddrs[&BB].insert(Base);
+ break;
+ }
+ default: {
+ IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(&II);
+ if (IntrInst) {
+ if (IntrInst->isLifetimeStartOrEnd())
+ break;
+ SideEffectingBlocks.insert(&BB);
+ return;
}
+ // Treat all the other cases conservatively if it has side effects.
+ if (II.mayHaveSideEffects()) {
+ SideEffectingBlocks.insert(&BB);
+ return;
}
}
+ }
}
+}
+bool CodeExtractorAnalysisCache::doesBlockContainClobberOfAddr(
+ BasicBlock &BB, AllocaInst *Addr) const {
+ if (SideEffectingBlocks.count(&BB))
+ return true;
+ auto It = BaseMemAddrs.find(&BB);
+ if (It != BaseMemAddrs.end())
+ return It->second.count(Addr);
+ return false;
+}
+
+bool CodeExtractor::isLegalToShrinkwrapLifetimeMarkers(
+ const CodeExtractorAnalysisCache &CEAC, Instruction *Addr) const {
+ AllocaInst *AI = cast<AllocaInst>(Addr->stripInBoundsConstantOffsets());
+ Function *Func = (*Blocks.begin())->getParent();
+ for (BasicBlock &BB : *Func) {
+ if (Blocks.count(&BB))
+ continue;
+ if (CEAC.doesBlockContainClobberOfAddr(BB, AI))
+ return false;
+ }
return true;
}
@@ -415,7 +440,8 @@ CodeExtractor::findOrCreateBlockForHoisting(BasicBlock *CommonExitBlock) {
// outline region. If there are not other untracked uses of the address, return
// the pair of markers if found; otherwise return a pair of nullptr.
CodeExtractor::LifetimeMarkerInfo
-CodeExtractor::getLifetimeMarkers(Instruction *Addr,
+CodeExtractor::getLifetimeMarkers(const CodeExtractorAnalysisCache &CEAC,
+ Instruction *Addr,
BasicBlock *ExitBlock) const {
LifetimeMarkerInfo Info;
@@ -447,7 +473,7 @@ CodeExtractor::getLifetimeMarkers(Instruction *Addr,
Info.HoistLifeEnd = !definedInRegion(Blocks, Info.LifeEnd);
// Do legality check.
if ((Info.SinkLifeStart || Info.HoistLifeEnd) &&
- !isLegalToShrinkwrapLifetimeMarkers(Addr))
+ !isLegalToShrinkwrapLifetimeMarkers(CEAC, Addr))
return {};
// Check to see if we have a place to do hoisting, if not, bail.
@@ -457,7 +483,8 @@ CodeExtractor::getLifetimeMarkers(Instruction *Addr,
return Info;
}
-void CodeExtractor::findAllocas(ValueSet &SinkCands, ValueSet &HoistCands,
+void CodeExtractor::findAllocas(const CodeExtractorAnalysisCache &CEAC,
+ ValueSet &SinkCands, ValueSet &HoistCands,
BasicBlock *&ExitBlock) const {
Function *Func = (*Blocks.begin())->getParent();
ExitBlock = getCommonExitBlock(Blocks);
@@ -478,74 +505,104 @@ void CodeExtractor::findAllocas(ValueSet &SinkCands, ValueSet &HoistCands,
return true;
};
- for (BasicBlock &BB : *Func) {
- if (Blocks.count(&BB))
+ // Look up allocas in the original function in CodeExtractorAnalysisCache, as
+ // this is much faster than walking all the instructions.
+ for (AllocaInst *AI : CEAC.getAllocas()) {
+ BasicBlock *BB = AI->getParent();
+ if (Blocks.count(BB))
continue;
- for (Instruction &II : BB) {
- auto *AI = dyn_cast<AllocaInst>(&II);
- if (!AI)
- continue;
- LifetimeMarkerInfo MarkerInfo = getLifetimeMarkers(AI, ExitBlock);
- bool Moved = moveOrIgnoreLifetimeMarkers(MarkerInfo);
- if (Moved) {
- LLVM_DEBUG(dbgs() << "Sinking alloca: " << *AI << "\n");
- SinkCands.insert(AI);
- continue;
- }
+ // As a prior call to extractCodeRegion() may have shrinkwrapped the alloca,
+ // check whether it is actually still in the original function.
+ Function *AIFunc = BB->getParent();
+ if (AIFunc != Func)
+ continue;
- // Follow any bitcasts.
- SmallVector<Instruction *, 2> Bitcasts;
- SmallVector<LifetimeMarkerInfo, 2> BitcastLifetimeInfo;
- for (User *U : AI->users()) {
- if (U->stripInBoundsConstantOffsets() == AI) {
- Instruction *Bitcast = cast<Instruction>(U);
- LifetimeMarkerInfo LMI = getLifetimeMarkers(Bitcast, ExitBlock);
- if (LMI.LifeStart) {
- Bitcasts.push_back(Bitcast);
- BitcastLifetimeInfo.push_back(LMI);
- continue;
- }
- }
+ LifetimeMarkerInfo MarkerInfo = getLifetimeMarkers(CEAC, AI, ExitBlock);
+ bool Moved = moveOrIgnoreLifetimeMarkers(MarkerInfo);
+ if (Moved) {
+ LLVM_DEBUG(dbgs() << "Sinking alloca: " << *AI << "\n");
+ SinkCands.insert(AI);
+ continue;
+ }
- // Found unknown use of AI.
- if (!definedInRegion(Blocks, U)) {
- Bitcasts.clear();
- break;
+ // Follow any bitcasts.
+ SmallVector<Instruction *, 2> Bitcasts;
+ SmallVector<LifetimeMarkerInfo, 2> BitcastLifetimeInfo;
+ for (User *U : AI->users()) {
+ if (U->stripInBoundsConstantOffsets() == AI) {
+ Instruction *Bitcast = cast<Instruction>(U);
+ LifetimeMarkerInfo LMI = getLifetimeMarkers(CEAC, Bitcast, ExitBlock);
+ if (LMI.LifeStart) {
+ Bitcasts.push_back(Bitcast);
+ BitcastLifetimeInfo.push_back(LMI);
+ continue;
}
}
- // Either no bitcasts reference the alloca or there are unknown uses.
- if (Bitcasts.empty())
- continue;
+ // Found unknown use of AI.
+ if (!definedInRegion(Blocks, U)) {
+ Bitcasts.clear();
+ break;
+ }
+ }
- LLVM_DEBUG(dbgs() << "Sinking alloca (via bitcast): " << *AI << "\n");
- SinkCands.insert(AI);
- for (unsigned I = 0, E = Bitcasts.size(); I != E; ++I) {
- Instruction *BitcastAddr = Bitcasts[I];
- const LifetimeMarkerInfo &LMI = BitcastLifetimeInfo[I];
- assert(LMI.LifeStart &&
- "Unsafe to sink bitcast without lifetime markers");
- moveOrIgnoreLifetimeMarkers(LMI);
- if (!definedInRegion(Blocks, BitcastAddr)) {
- LLVM_DEBUG(dbgs() << "Sinking bitcast-of-alloca: " << *BitcastAddr
- << "\n");
- SinkCands.insert(BitcastAddr);
- }
+ // Either no bitcasts reference the alloca or there are unknown uses.
+ if (Bitcasts.empty())
+ continue;
+
+ LLVM_DEBUG(dbgs() << "Sinking alloca (via bitcast): " << *AI << "\n");
+ SinkCands.insert(AI);
+ for (unsigned I = 0, E = Bitcasts.size(); I != E; ++I) {
+ Instruction *BitcastAddr = Bitcasts[I];
+ const LifetimeMarkerInfo &LMI = BitcastLifetimeInfo[I];
+ assert(LMI.LifeStart &&
+ "Unsafe to sink bitcast without lifetime markers");
+ moveOrIgnoreLifetimeMarkers(LMI);
+ if (!definedInRegion(Blocks, BitcastAddr)) {
+ LLVM_DEBUG(dbgs() << "Sinking bitcast-of-alloca: " << *BitcastAddr
+ << "\n");
+ SinkCands.insert(BitcastAddr);
}
}
}
}
+bool CodeExtractor::isEligible() const {
+ if (Blocks.empty())
+ return false;
+ BasicBlock *Header = *Blocks.begin();
+ Function *F = Header->getParent();
+
+ // For functions with varargs, check that varargs handling is only done in the
+ // outlined function, i.e vastart and vaend are only used in outlined blocks.
+ if (AllowVarArgs && F->getFunctionType()->isVarArg()) {
+ auto containsVarArgIntrinsic = [](const Instruction &I) {
+ if (const CallInst *CI = dyn_cast<CallInst>(&I))
+ if (const Function *Callee = CI->getCalledFunction())
+ return Callee->getIntrinsicID() == Intrinsic::vastart ||
+ Callee->getIntrinsicID() == Intrinsic::vaend;
+ return false;
+ };
+
+ for (auto &BB : *F) {
+ if (Blocks.count(&BB))
+ continue;
+ if (llvm::any_of(BB, containsVarArgIntrinsic))
+ return false;
+ }
+ }
+ return true;
+}
+
void CodeExtractor::findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
const ValueSet &SinkCands) const {
for (BasicBlock *BB : Blocks) {
// If a used value is defined outside the region, it's an input. If an
// instruction is used outside the region, it's an output.
for (Instruction &II : *BB) {
- for (User::op_iterator OI = II.op_begin(), OE = II.op_end(); OI != OE;
- ++OI) {
- Value *V = *OI;
+ for (auto &OI : II.operands()) {
+ Value *V = OI;
if (!SinkCands.count(V) && definedInCaller(Blocks, V))
Inputs.insert(V);
}
@@ -904,12 +961,12 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
// within the new function. This must be done before we lose track of which
// blocks were originally in the code region.
std::vector<User *> Users(header->user_begin(), header->user_end());
- for (unsigned i = 0, e = Users.size(); i != e; ++i)
+ for (auto &U : Users)
// The BasicBlock which contains the branch is not in the region
// modify the branch target to a new block
- if (Instruction *I = dyn_cast<Instruction>(Users[i]))
- if (I->isTerminator() && !Blocks.count(I->getParent()) &&
- I->getParent()->getParent() == oldFunction)
+ if (Instruction *I = dyn_cast<Instruction>(U))
+ if (I->isTerminator() && I->getFunction() == oldFunction &&
+ !Blocks.count(I->getParent()))
I->replaceUsesOfWith(header, newHeader);
return newFunction;
@@ -1277,13 +1334,6 @@ void CodeExtractor::moveCodeToFunction(Function *newFunction) {
// Insert this basic block into the new function
newBlocks.push_back(Block);
-
- // Remove @llvm.assume calls that were moved to the new function from the
- // old function's assumption cache.
- if (AC)
- for (auto &I : *Block)
- if (match(&I, m_Intrinsic<Intrinsic::assume>()))
- AC->unregisterAssumption(cast<CallInst>(&I));
}
}
@@ -1332,7 +1382,8 @@ void CodeExtractor::calculateNewCallTerminatorWeights(
MDBuilder(TI->getContext()).createBranchWeights(BranchWeights));
}
-Function *CodeExtractor::extractCodeRegion() {
+Function *
+CodeExtractor::extractCodeRegion(const CodeExtractorAnalysisCache &CEAC) {
if (!isEligible())
return nullptr;
@@ -1341,27 +1392,6 @@ Function *CodeExtractor::extractCodeRegion() {
BasicBlock *header = *Blocks.begin();
Function *oldFunction = header->getParent();
- // For functions with varargs, check that varargs handling is only done in the
- // outlined function, i.e vastart and vaend are only used in outlined blocks.
- if (AllowVarArgs && oldFunction->getFunctionType()->isVarArg()) {
- auto containsVarArgIntrinsic = [](Instruction &I) {
- if (const CallInst *CI = dyn_cast<CallInst>(&I))
- if (const Function *F = CI->getCalledFunction())
- return F->getIntrinsicID() == Intrinsic::vastart ||
- F->getIntrinsicID() == Intrinsic::vaend;
- return false;
- };
-
- for (auto &BB : *oldFunction) {
- if (Blocks.count(&BB))
- continue;
- if (llvm::any_of(BB, containsVarArgIntrinsic))
- return nullptr;
- }
- }
- ValueSet inputs, outputs, SinkingCands, HoistingCands;
- BasicBlock *CommonExit = nullptr;
-
// Calculate the entry frequency of the new function before we change the root
// block.
BlockFrequency EntryFreq;
@@ -1375,6 +1405,15 @@ Function *CodeExtractor::extractCodeRegion() {
}
}
+ if (AC) {
+ // Remove @llvm.assume calls that were moved to the new function from the
+ // old function's assumption cache.
+ for (BasicBlock *Block : Blocks)
+ for (auto &I : *Block)
+ if (match(&I, m_Intrinsic<Intrinsic::assume>()))
+ AC->unregisterAssumption(cast<CallInst>(&I));
+ }
+
// If we have any return instructions in the region, split those blocks so
// that the return is not in the region.
splitReturnBlocks();
@@ -1428,7 +1467,9 @@ Function *CodeExtractor::extractCodeRegion() {
}
newFuncRoot->getInstList().push_back(BranchI);
- findAllocas(SinkingCands, HoistingCands, CommonExit);
+ ValueSet inputs, outputs, SinkingCands, HoistingCands;
+ BasicBlock *CommonExit = nullptr;
+ findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
assert(HoistingCands.empty() || CommonExit);
// Find inputs to, outputs from the code region.
@@ -1563,5 +1604,17 @@ Function *CodeExtractor::extractCodeRegion() {
});
LLVM_DEBUG(if (verifyFunction(*oldFunction))
report_fatal_error("verification of oldFunction failed!"));
+ LLVM_DEBUG(if (AC && verifyAssumptionCache(*oldFunction, AC))
+ report_fatal_error("Stale Asumption cache for old Function!"));
return newFunction;
}
+
+bool CodeExtractor::verifyAssumptionCache(const Function& F,
+ AssumptionCache *AC) {
+ for (auto AssumeVH : AC->assumptions()) {
+ CallInst *I = cast<CallInst>(AssumeVH);
+ if (I->getFunction() != &F)
+ return true;
+ }
+ return false;
+}