diff options
author | dim <dim@FreeBSD.org> | 2011-06-12 18:01:31 +0000 |
---|---|---|
committer | dim <dim@FreeBSD.org> | 2011-06-12 18:01:31 +0000 |
commit | d4c7939beafe09c033866ebd290e274af0cc826d (patch) | |
tree | a9b264321873e7d25e69b8671c9f705ebc6d30ee /contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp | |
parent | b164882ef981a8ed5c085469231831e221fa1323 (diff) | |
parent | ece02cd5829cea836e9365b0845a8ef042d17b0a (diff) | |
download | FreeBSD-src-d4c7939beafe09c033866ebd290e274af0cc826d.zip FreeBSD-src-d4c7939beafe09c033866ebd290e274af0cc826d.tar.gz |
Upgrade our copy of llvm/clang to r132879, from upstream's trunk.
Diffstat (limited to 'contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp | 563 |
1 files changed, 501 insertions, 62 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp b/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp index 7d17909..8416170 100644 --- a/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp +++ b/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp @@ -10,6 +10,13 @@ // This file implements inlining of a function into a call site, resolving // parameters and the return value as appropriate. // +// The code in this file for handling inlines through invoke +// instructions preserves semantics only under some assumptions about +// the behavior of unwinders which correspond to gcc-style libUnwind +// exception personality functions. Eventually the IR will be +// improved to make this unnecessary, but until then, this code is +// marked [LIBUNWIND]. +// //===----------------------------------------------------------------------===// #include "llvm/Transforms/Utils/Cloning.h" @@ -28,6 +35,7 @@ #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Support/CallSite.h" +#include "llvm/Support/IRBuilder.h" using namespace llvm; bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI) { @@ -37,6 +45,372 @@ bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI) { return InlineFunction(CallSite(II), IFI); } +/// [LIBUNWIND] Look for an llvm.eh.exception call in the given block. +static EHExceptionInst *findExceptionInBlock(BasicBlock *bb) { + for (BasicBlock::iterator i = bb->begin(), e = bb->end(); i != e; i++) { + EHExceptionInst *exn = dyn_cast<EHExceptionInst>(i); + if (exn) return exn; + } + + return 0; +} + +/// [LIBUNWIND] Look for the 'best' llvm.eh.selector instruction for +/// the given llvm.eh.exception call. +static EHSelectorInst *findSelectorForException(EHExceptionInst *exn) { + BasicBlock *exnBlock = exn->getParent(); + + EHSelectorInst *outOfBlockSelector = 0; + for (Instruction::use_iterator + ui = exn->use_begin(), ue = exn->use_end(); ui != ue; ++ui) { + EHSelectorInst *sel = dyn_cast<EHSelectorInst>(*ui); + if (!sel) continue; + + // Immediately accept an eh.selector in the same block as the + // excepton call. + if (sel->getParent() == exnBlock) return sel; + + // Otherwise, use the first selector we see. + if (!outOfBlockSelector) outOfBlockSelector = sel; + } + + return outOfBlockSelector; +} + +/// [LIBUNWIND] Find the (possibly absent) call to @llvm.eh.selector +/// in the given landing pad. In principle, llvm.eh.exception is +/// required to be in the landing pad; in practice, SplitCriticalEdge +/// can break that invariant, and then inlining can break it further. +/// There's a real need for a reliable solution here, but until that +/// happens, we have some fragile workarounds here. +static EHSelectorInst *findSelectorForLandingPad(BasicBlock *lpad) { + // Look for an exception call in the actual landing pad. + EHExceptionInst *exn = findExceptionInBlock(lpad); + if (exn) return findSelectorForException(exn); + + // Okay, if that failed, look for one in an obvious successor. If + // we find one, we'll fix the IR by moving things back to the + // landing pad. + + bool dominates = true; // does the lpad dominate the exn call + BasicBlock *nonDominated = 0; // if not, the first non-dominated block + BasicBlock *lastDominated = 0; // and the block which branched to it + + BasicBlock *exnBlock = lpad; + + // We need to protect against lpads that lead into infinite loops. + SmallPtrSet<BasicBlock*,4> visited; + visited.insert(exnBlock); + + do { + // We're not going to apply this hack to anything more complicated + // than a series of unconditional branches, so if the block + // doesn't terminate in an unconditional branch, just fail. More + // complicated cases can arise when, say, sinking a call into a + // split unwind edge and then inlining it; but that can do almost + // *anything* to the CFG, including leaving the selector + // completely unreachable. The only way to fix that properly is + // to (1) prohibit transforms which move the exception or selector + // values away from the landing pad, e.g. by producing them with + // instructions that are pinned to an edge like a phi, or + // producing them with not-really-instructions, and (2) making + // transforms which split edges deal with that. + BranchInst *branch = dyn_cast<BranchInst>(&exnBlock->back()); + if (!branch || branch->isConditional()) return 0; + + BasicBlock *successor = branch->getSuccessor(0); + + // Fail if we found an infinite loop. + if (!visited.insert(successor)) return 0; + + // If the successor isn't dominated by exnBlock: + if (!successor->getSinglePredecessor()) { + // We don't want to have to deal with threading the exception + // through multiple levels of phi, so give up if we've already + // followed a non-dominating edge. + if (!dominates) return 0; + + // Otherwise, remember this as a non-dominating edge. + dominates = false; + nonDominated = successor; + lastDominated = exnBlock; + } + + exnBlock = successor; + + // Can we stop here? + exn = findExceptionInBlock(exnBlock); + } while (!exn); + + // Look for a selector call for the exception we found. + EHSelectorInst *selector = findSelectorForException(exn); + if (!selector) return 0; + + // The easy case is when the landing pad still dominates the + // exception call, in which case we can just move both calls back to + // the landing pad. + if (dominates) { + selector->moveBefore(lpad->getFirstNonPHI()); + exn->moveBefore(selector); + return selector; + } + + // Otherwise, we have to split at the first non-dominating block. + // The CFG looks basically like this: + // lpad: + // phis_0 + // insnsAndBranches_1 + // br label %nonDominated + // nonDominated: + // phis_2 + // insns_3 + // %exn = call i8* @llvm.eh.exception() + // insnsAndBranches_4 + // %selector = call @llvm.eh.selector(i8* %exn, ... + // We need to turn this into: + // lpad: + // phis_0 + // %exn0 = call i8* @llvm.eh.exception() + // %selector0 = call @llvm.eh.selector(i8* %exn0, ... + // insnsAndBranches_1 + // br label %split // from lastDominated + // nonDominated: + // phis_2 (without edge from lastDominated) + // %exn1 = call i8* @llvm.eh.exception() + // %selector1 = call i8* @llvm.eh.selector(i8* %exn1, ... + // br label %split + // split: + // phis_2 (edge from lastDominated, edge from split) + // %exn = phi ... + // %selector = phi ... + // insns_3 + // insnsAndBranches_4 + + assert(nonDominated); + assert(lastDominated); + + // First, make clones of the intrinsics to go in lpad. + EHExceptionInst *lpadExn = cast<EHExceptionInst>(exn->clone()); + EHSelectorInst *lpadSelector = cast<EHSelectorInst>(selector->clone()); + lpadSelector->setArgOperand(0, lpadExn); + lpadSelector->insertBefore(lpad->getFirstNonPHI()); + lpadExn->insertBefore(lpadSelector); + + // Split the non-dominated block. + BasicBlock *split = + nonDominated->splitBasicBlock(nonDominated->getFirstNonPHI(), + nonDominated->getName() + ".lpad-fix"); + + // Redirect the last dominated branch there. + cast<BranchInst>(lastDominated->back()).setSuccessor(0, split); + + // Move the existing intrinsics to the end of the old block. + selector->moveBefore(&nonDominated->back()); + exn->moveBefore(selector); + + Instruction *splitIP = &split->front(); + + // For all the phis in nonDominated, make a new phi in split to join + // that phi with the edge from lastDominated. + for (BasicBlock::iterator + i = nonDominated->begin(), e = nonDominated->end(); i != e; ++i) { + PHINode *phi = dyn_cast<PHINode>(i); + if (!phi) break; + + PHINode *splitPhi = PHINode::Create(phi->getType(), 2, phi->getName(), + splitIP); + phi->replaceAllUsesWith(splitPhi); + splitPhi->addIncoming(phi, nonDominated); + splitPhi->addIncoming(phi->removeIncomingValue(lastDominated), + lastDominated); + } + + // Make new phis for the exception and selector. + PHINode *exnPhi = PHINode::Create(exn->getType(), 2, "", splitIP); + exn->replaceAllUsesWith(exnPhi); + selector->setArgOperand(0, exn); // except for this use + exnPhi->addIncoming(exn, nonDominated); + exnPhi->addIncoming(lpadExn, lastDominated); + + PHINode *selectorPhi = PHINode::Create(selector->getType(), 2, "", splitIP); + selector->replaceAllUsesWith(selectorPhi); + selectorPhi->addIncoming(selector, nonDominated); + selectorPhi->addIncoming(lpadSelector, lastDominated); + + return lpadSelector; +} + +namespace { + /// A class for recording information about inlining through an invoke. + class InvokeInliningInfo { + BasicBlock *OuterUnwindDest; + EHSelectorInst *OuterSelector; + BasicBlock *InnerUnwindDest; + PHINode *InnerExceptionPHI; + PHINode *InnerSelectorPHI; + SmallVector<Value*, 8> UnwindDestPHIValues; + + public: + InvokeInliningInfo(InvokeInst *II) : + OuterUnwindDest(II->getUnwindDest()), OuterSelector(0), + InnerUnwindDest(0), InnerExceptionPHI(0), InnerSelectorPHI(0) { + + // If there are PHI nodes in the unwind destination block, we + // need to keep track of which values came into them from the + // invoke before removing the edge from this block. + llvm::BasicBlock *invokeBB = II->getParent(); + for (BasicBlock::iterator I = OuterUnwindDest->begin(); + isa<PHINode>(I); ++I) { + // Save the value to use for this edge. + PHINode *phi = cast<PHINode>(I); + UnwindDestPHIValues.push_back(phi->getIncomingValueForBlock(invokeBB)); + } + } + + /// The outer unwind destination is the target of unwind edges + /// introduced for calls within the inlined function. + BasicBlock *getOuterUnwindDest() const { + return OuterUnwindDest; + } + + EHSelectorInst *getOuterSelector() { + if (!OuterSelector) + OuterSelector = findSelectorForLandingPad(OuterUnwindDest); + return OuterSelector; + } + + BasicBlock *getInnerUnwindDest(); + + bool forwardEHResume(CallInst *call, BasicBlock *src); + + /// Add incoming-PHI values to the unwind destination block for + /// the given basic block, using the values for the original + /// invoke's source block. + void addIncomingPHIValuesFor(BasicBlock *BB) const { + addIncomingPHIValuesForInto(BB, OuterUnwindDest); + } + + void addIncomingPHIValuesForInto(BasicBlock *src, BasicBlock *dest) const { + BasicBlock::iterator I = dest->begin(); + for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) { + PHINode *phi = cast<PHINode>(I); + phi->addIncoming(UnwindDestPHIValues[i], src); + } + } + }; +} + +/// Get or create a target for the branch out of rewritten calls to +/// llvm.eh.resume. +BasicBlock *InvokeInliningInfo::getInnerUnwindDest() { + if (InnerUnwindDest) return InnerUnwindDest; + + // Find and hoist the llvm.eh.exception and llvm.eh.selector calls + // in the outer landing pad to immediately following the phis. + EHSelectorInst *selector = getOuterSelector(); + if (!selector) return 0; + + // The call to llvm.eh.exception *must* be in the landing pad. + Instruction *exn = cast<Instruction>(selector->getArgOperand(0)); + assert(exn->getParent() == OuterUnwindDest); + + // TODO: recognize when we've already done this, so that we don't + // get a linear number of these when inlining calls into lots of + // invokes with the same landing pad. + + // Do the hoisting. + Instruction *splitPoint = exn->getParent()->getFirstNonPHI(); + assert(splitPoint != selector && "selector-on-exception dominance broken!"); + if (splitPoint == exn) { + selector->removeFromParent(); + selector->insertAfter(exn); + splitPoint = selector->getNextNode(); + } else { + exn->moveBefore(splitPoint); + selector->moveBefore(splitPoint); + } + + // Split the landing pad. + InnerUnwindDest = OuterUnwindDest->splitBasicBlock(splitPoint, + OuterUnwindDest->getName() + ".body"); + + // The number of incoming edges we expect to the inner landing pad. + const unsigned phiCapacity = 2; + + // Create corresponding new phis for all the phis in the outer landing pad. + BasicBlock::iterator insertPoint = InnerUnwindDest->begin(); + BasicBlock::iterator I = OuterUnwindDest->begin(); + for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) { + PHINode *outerPhi = cast<PHINode>(I); + PHINode *innerPhi = PHINode::Create(outerPhi->getType(), phiCapacity, + outerPhi->getName() + ".lpad-body", + insertPoint); + outerPhi->replaceAllUsesWith(innerPhi); + innerPhi->addIncoming(outerPhi, OuterUnwindDest); + } + + // Create a phi for the exception value... + InnerExceptionPHI = PHINode::Create(exn->getType(), phiCapacity, + "exn.lpad-body", insertPoint); + exn->replaceAllUsesWith(InnerExceptionPHI); + selector->setArgOperand(0, exn); // restore this use + InnerExceptionPHI->addIncoming(exn, OuterUnwindDest); + + // ...and the selector. + InnerSelectorPHI = PHINode::Create(selector->getType(), phiCapacity, + "selector.lpad-body", insertPoint); + selector->replaceAllUsesWith(InnerSelectorPHI); + InnerSelectorPHI->addIncoming(selector, OuterUnwindDest); + + // All done. + return InnerUnwindDest; +} + +/// [LIBUNWIND] Try to forward the given call, which logically occurs +/// at the end of the given block, as a branch to the inner unwind +/// block. Returns true if the call was forwarded. +bool InvokeInliningInfo::forwardEHResume(CallInst *call, BasicBlock *src) { + // First, check whether this is a call to the intrinsic. + Function *fn = dyn_cast<Function>(call->getCalledValue()); + if (!fn || fn->getName() != "llvm.eh.resume") + return false; + + // At this point, we need to return true on all paths, because + // otherwise we'll construct an invoke of the intrinsic, which is + // not well-formed. + + // Try to find or make an inner unwind dest, which will fail if we + // can't find a selector call for the outer unwind dest. + BasicBlock *dest = getInnerUnwindDest(); + bool hasSelector = (dest != 0); + + // If we failed, just use the outer unwind dest, dropping the + // exception and selector on the floor. + if (!hasSelector) + dest = OuterUnwindDest; + + // Make a branch. + BranchInst::Create(dest, src); + + // Update the phis in the destination. They were inserted in an + // order which makes this work. + addIncomingPHIValuesForInto(src, dest); + + if (hasSelector) { + InnerExceptionPHI->addIncoming(call->getArgOperand(0), src); + InnerSelectorPHI->addIncoming(call->getArgOperand(1), src); + } + + return true; +} + +/// [LIBUNWIND] Check whether this selector is "only cleanups": +/// call i32 @llvm.eh.selector(blah, blah, i32 0) +static bool isCleanupOnlySelector(EHSelectorInst *selector) { + if (selector->getNumArgOperands() != 3) return false; + ConstantInt *val = dyn_cast<ConstantInt>(selector->getArgOperand(2)); + return (val && val->isZero()); +} /// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into /// an invoke, we have to turn all of the calls that can throw into @@ -44,9 +418,9 @@ bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI) { /// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI /// nodes in that block with the values specified in InvokeDestPHIValues. /// -static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, - BasicBlock *InvokeDest, - const SmallVectorImpl<Value*> &InvokeDestPHIValues) { +/// Returns true to indicate that the next block should be skipped. +static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, + InvokeInliningInfo &Invoke) { for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) { Instruction *I = BBI++; @@ -54,6 +428,38 @@ static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, // instructions require no special handling. CallInst *CI = dyn_cast<CallInst>(I); if (CI == 0) continue; + + // LIBUNWIND: merge selector instructions. + if (EHSelectorInst *Inner = dyn_cast<EHSelectorInst>(CI)) { + EHSelectorInst *Outer = Invoke.getOuterSelector(); + if (!Outer) continue; + + bool innerIsOnlyCleanup = isCleanupOnlySelector(Inner); + bool outerIsOnlyCleanup = isCleanupOnlySelector(Outer); + + // If both selectors contain only cleanups, we don't need to do + // anything. TODO: this is really just a very specific instance + // of a much more general optimization. + if (innerIsOnlyCleanup && outerIsOnlyCleanup) continue; + + // Otherwise, we just append the outer selector to the inner selector. + SmallVector<Value*, 16> NewSelector; + for (unsigned i = 0, e = Inner->getNumArgOperands(); i != e; ++i) + NewSelector.push_back(Inner->getArgOperand(i)); + for (unsigned i = 2, e = Outer->getNumArgOperands(); i != e; ++i) + NewSelector.push_back(Outer->getArgOperand(i)); + + CallInst *NewInner = CallInst::Create(Inner->getCalledValue(), + NewSelector.begin(), + NewSelector.end(), + "", + Inner); + // No need to copy attributes, calling convention, etc. + NewInner->takeName(Inner); + Inner->replaceAllUsesWith(NewInner); + Inner->eraseFromParent(); + continue; + } // If this call cannot unwind, don't convert it to an invoke. if (CI->doesNotThrow()) @@ -62,37 +468,45 @@ static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, // Convert this function call into an invoke instruction. // First, split the basic block. BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc"); - - // Next, create the new invoke instruction, inserting it at the end - // of the old basic block. + + // Delete the unconditional branch inserted by splitBasicBlock + BB->getInstList().pop_back(); + + // LIBUNWIND: If this is a call to @llvm.eh.resume, just branch + // directly to the new landing pad. + if (Invoke.forwardEHResume(CI, BB)) { + // TODO: 'Split' is now unreachable; clean it up. + + // We want to leave the original call intact so that the call + // graph and other structures won't get misled. We also have to + // avoid processing the next block, or we'll iterate here forever. + return true; + } + + // Otherwise, create the new invoke instruction. ImmutableCallSite CS(CI); SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end()); InvokeInst *II = - InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest, + InvokeInst::Create(CI->getCalledValue(), Split, + Invoke.getOuterUnwindDest(), InvokeArgs.begin(), InvokeArgs.end(), - CI->getName(), BB->getTerminator()); + CI->getName(), BB); II->setCallingConv(CI->getCallingConv()); II->setAttributes(CI->getAttributes()); // Make sure that anything using the call now uses the invoke! This also // updates the CallGraph if present, because it uses a WeakVH. CI->replaceAllUsesWith(II); - - // Delete the unconditional branch inserted by splitBasicBlock - BB->getInstList().pop_back(); + Split->getInstList().pop_front(); // Delete the original call - + // Update any PHI nodes in the exceptional block to indicate that // there is now a new entry in them. - unsigned i = 0; - for (BasicBlock::iterator I = InvokeDest->begin(); - isa<PHINode>(I); ++I, ++i) - cast<PHINode>(I)->addIncoming(InvokeDestPHIValues[i], BB); - - // This basic block is now complete, the caller will continue scanning the - // next one. - return; + Invoke.addIncomingPHIValuesFor(BB); + return false; } + + return false; } @@ -106,17 +520,6 @@ static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock, ClonedCodeInfo &InlinedCodeInfo) { BasicBlock *InvokeDest = II->getUnwindDest(); - SmallVector<Value*, 8> InvokeDestPHIValues; - - // If there are PHI nodes in the unwind destination block, we need to - // keep track of which values came into them from this invoke, then remove - // the entry for this block. - BasicBlock *InvokeBlock = II->getParent(); - for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) { - PHINode *PN = cast<PHINode>(I); - // Save the value to use for this edge. - InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock)); - } Function *Caller = FirstNewBlock->getParent(); @@ -132,11 +535,17 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock, InvokeDest->removePredecessor(II->getParent()); return; } + + InvokeInliningInfo Invoke(II); for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){ if (InlinedCodeInfo.ContainsCalls) - HandleCallsInBlockInlinedThroughInvoke(BB, InvokeDest, - InvokeDestPHIValues); + if (HandleCallsInBlockInlinedThroughInvoke(BB, Invoke)) { + // Honor a request to skip the next block. We don't need to + // consider UnwindInsts in this case either. + ++BB; + continue; + } if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) { // An UnwindInst requires special handling when it gets inlined into an @@ -150,12 +559,7 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock, // Update any PHI nodes in the exceptional block to indicate that // there is now a new entry in them. - unsigned i = 0; - for (BasicBlock::iterator I = InvokeDest->begin(); - isa<PHINode>(I); ++I, ++i) { - PHINode *PN = cast<PHINode>(I); - PN->addIncoming(InvokeDestPHIValues[i], BB); - } + Invoke.addIncomingPHIValuesFor(BB); } } @@ -299,21 +703,48 @@ static Value *HandleByValArgument(Value *Arg, Instruction *TheCall, ConstantInt::get(Type::getInt32Ty(Context), 1), ConstantInt::getFalse(Context) // isVolatile }; - CallInst *TheMemCpy = - CallInst::Create(MemCpyFn, CallArgs, CallArgs+5, "", TheCall); - - // If we have a call graph, update it. - if (CallGraph *CG = IFI.CG) { - CallGraphNode *MemCpyCGN = CG->getOrInsertFunction(MemCpyFn); - CallGraphNode *CallerNode = (*CG)[Caller]; - CallerNode->addCalledFunction(TheMemCpy, MemCpyCGN); - } + CallInst::Create(MemCpyFn, CallArgs, CallArgs+5, "", TheCall); // Uses of the argument in the function should use our new alloca // instead. return NewAlloca; } +// isUsedByLifetimeMarker - Check whether this Value is used by a lifetime +// intrinsic. +static bool isUsedByLifetimeMarker(Value *V) { + for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE; + ++UI) { + if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*UI)) { + switch (II->getIntrinsicID()) { + default: break; + case Intrinsic::lifetime_start: + case Intrinsic::lifetime_end: + return true; + } + } + } + return false; +} + +// hasLifetimeMarkers - Check whether the given alloca already has +// lifetime.start or lifetime.end intrinsics. +static bool hasLifetimeMarkers(AllocaInst *AI) { + const Type *Int8PtrTy = Type::getInt8PtrTy(AI->getType()->getContext()); + if (AI->getType() == Int8PtrTy) + return isUsedByLifetimeMarker(AI); + + // Do a scan to find all the bitcasts to i8*. + for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); I != E; + ++I) { + if (I->getType() != Int8PtrTy) continue; + if (!isa<BitCastInst>(*I)) continue; + if (isUsedByLifetimeMarker(*I)) + return true; + } + return false; +} + // InlineFunction - This function inlines the called function into the basic // block of the caller. This returns false if it is not possible to inline this // call. The program is still in a well defined state if this occurs though. @@ -460,6 +891,26 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) { } } + // Leave lifetime markers for the static alloca's, scoping them to the + // function we just inlined. + if (!IFI.StaticAllocas.empty()) { + IRBuilder<> builder(FirstNewBlock->begin()); + for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) { + AllocaInst *AI = IFI.StaticAllocas[ai]; + + // If the alloca is already scoped to something smaller than the whole + // function then there's no need to add redundant, less accurate markers. + if (hasLifetimeMarkers(AI)) + continue; + + builder.CreateLifetimeStart(AI); + for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) { + IRBuilder<> builder(Returns[ri]); + builder.CreateLifetimeEnd(AI); + } + } + } + // If the inlined code contained dynamic alloca instructions, wrap the inlined // code with llvm.stacksave/llvm.stackrestore intrinsics. if (InlinedFunctionInfo.ContainsDynamicAllocas) { @@ -468,25 +919,14 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) { Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave); Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore); - // If we are preserving the callgraph, add edges to the stacksave/restore - // functions for the calls we insert. - CallGraphNode *StackSaveCGN = 0, *StackRestoreCGN = 0, *CallerNode = 0; - if (CallGraph *CG = IFI.CG) { - StackSaveCGN = CG->getOrInsertFunction(StackSave); - StackRestoreCGN = CG->getOrInsertFunction(StackRestore); - CallerNode = (*CG)[Caller]; - } - // Insert the llvm.stacksave. CallInst *SavedPtr = CallInst::Create(StackSave, "savedstack", FirstNewBlock->begin()); - if (IFI.CG) CallerNode->addCalledFunction(SavedPtr, StackSaveCGN); // Insert a call to llvm.stackrestore before any return instructions in the // inlined function. for (unsigned i = 0, e = Returns.size(); i != e; ++i) { - CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", Returns[i]); - if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN); + CallInst::Create(StackRestore, SavedPtr, "", Returns[i]); } // Count the number of StackRestore calls we insert. @@ -498,8 +938,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) { for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB) if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) { - CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", UI); - if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN); + CallInst::Create(StackRestore, SavedPtr, "", UI); ++NumStackRestores; } } |