X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FAliasAnalysis.cpp;h=8aee8b1aa335dca3f10ad11bb80c93db3bc143ae;hb=1cb132f921c55f9584d06787b849ef0f255403b2;hp=5cde979ae1f65d8c07ca9cbb353c01ef63bbb76f;hpb=04fe99019022707c605ad0ab96dbd50bcad4364d;p=oota-llvm.git diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp index 5cde979ae1f..8aee8b1aa33 100644 --- a/lib/Analysis/AliasAnalysis.cpp +++ b/lib/Analysis/AliasAnalysis.cpp @@ -199,14 +199,19 @@ AliasAnalysis::getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) { Location CS1Loc = getArgLocation(CS1, (unsigned) std::distance(CS1.arg_begin(), I), ArgMask); - if ((getModRefInfo(CS2, CS1Loc) & ArgMask) != NoModRef) { - R = Mask; + // ArgMask indicates what CS1 might do to CS1Loc; if CS1 might Mod + // CS1Loc, then we care about either a Mod or a Ref by CS2. If CS1 + // might Ref, then we care only about a Mod by CS2. + ModRefResult ArgR = getModRefInfo(CS2, CS1Loc); + if (((ArgMask & Mod) != NoModRef && (ArgR & ModRef) != NoModRef) || + ((ArgMask & Ref) != NoModRef && (ArgR & Mod) != NoModRef)) + R = ModRefResult((R | ArgMask) & Mask); + + if (R == Mask) break; - } } } - if (R == NoModRef) - return R; + return R; } // If this is the end of the chain, don't forward. @@ -247,35 +252,45 @@ AliasAnalysis::getModRefBehavior(const Function *F) { //===----------------------------------------------------------------------===// AliasAnalysis::Location AliasAnalysis::getLocation(const LoadInst *LI) { + AAMDNodes AATags; + LI->getAAMetadata(AATags); + return Location(LI->getPointerOperand(), - getTypeStoreSize(LI->getType()), - LI->getMetadata(LLVMContext::MD_tbaa)); + getTypeStoreSize(LI->getType()), AATags); } AliasAnalysis::Location AliasAnalysis::getLocation(const StoreInst *SI) { + AAMDNodes AATags; + SI->getAAMetadata(AATags); + return Location(SI->getPointerOperand(), - getTypeStoreSize(SI->getValueOperand()->getType()), - SI->getMetadata(LLVMContext::MD_tbaa)); + getTypeStoreSize(SI->getValueOperand()->getType()), AATags); } AliasAnalysis::Location AliasAnalysis::getLocation(const VAArgInst *VI) { - return Location(VI->getPointerOperand(), - UnknownSize, - VI->getMetadata(LLVMContext::MD_tbaa)); + AAMDNodes AATags; + VI->getAAMetadata(AATags); + + return Location(VI->getPointerOperand(), UnknownSize, AATags); } AliasAnalysis::Location AliasAnalysis::getLocation(const AtomicCmpXchgInst *CXI) { + AAMDNodes AATags; + CXI->getAAMetadata(AATags); + return Location(CXI->getPointerOperand(), getTypeStoreSize(CXI->getCompareOperand()->getType()), - CXI->getMetadata(LLVMContext::MD_tbaa)); + AATags); } AliasAnalysis::Location AliasAnalysis::getLocation(const AtomicRMWInst *RMWI) { + AAMDNodes AATags; + RMWI->getAAMetadata(AATags); + return Location(RMWI->getPointerOperand(), - getTypeStoreSize(RMWI->getValOperand()->getType()), - RMWI->getMetadata(LLVMContext::MD_tbaa)); + getTypeStoreSize(RMWI->getValOperand()->getType()), AATags); } AliasAnalysis::Location @@ -284,11 +299,12 @@ AliasAnalysis::getLocationForSource(const MemTransferInst *MTI) { if (ConstantInt *C = dyn_cast(MTI->getLength())) Size = C->getValue().getZExtValue(); - // memcpy/memmove can have TBAA tags. For memcpy, they apply + // memcpy/memmove can have AA tags. For memcpy, they apply // to both the source and the destination. - MDNode *TBAATag = MTI->getMetadata(LLVMContext::MD_tbaa); - - return Location(MTI->getRawSource(), Size, TBAATag); + AAMDNodes AATags; + MTI->getAAMetadata(AATags); + + return Location(MTI->getRawSource(), Size, AATags); } AliasAnalysis::Location @@ -297,11 +313,12 @@ AliasAnalysis::getLocationForDest(const MemIntrinsic *MTI) { if (ConstantInt *C = dyn_cast(MTI->getLength())) Size = C->getValue().getZExtValue(); - // memcpy/memmove can have TBAA tags. For memcpy, they apply + // memcpy/memmove can have AA tags. For memcpy, they apply // to both the source and the destination. - MDNode *TBAATag = MTI->getMetadata(LLVMContext::MD_tbaa); - - return Location(MTI->getRawDest(), Size, TBAATag); + AAMDNodes AATags; + MTI->getMetadata(AATags); + + return Location(MTI->getRawDest(), Size, AATags); } @@ -383,53 +400,6 @@ AliasAnalysis::getModRefInfo(const AtomicRMWInst *RMW, const Location &Loc) { return ModRef; } -namespace { - /// Only find pointer captures which happen before the given instruction. Uses - /// the dominator tree to determine whether one instruction is before another. - /// Only support the case where the Value is defined in the same basic block - /// as the given instruction and the use. - struct CapturesBefore : public CaptureTracker { - CapturesBefore(const Instruction *I, DominatorTree *DT) - : BeforeHere(I), DT(DT), Captured(false) {} - - void tooManyUses() override { Captured = true; } - - bool shouldExplore(const Use *U) override { - Instruction *I = cast(U->getUser()); - BasicBlock *BB = I->getParent(); - // We explore this usage only if the usage can reach "BeforeHere". - // If use is not reachable from entry, there is no need to explore. - if (BeforeHere != I && !DT->isReachableFromEntry(BB)) - return false; - // If the value is defined in the same basic block as use and BeforeHere, - // there is no need to explore the use if BeforeHere dominates use. - // Check whether there is a path from I to BeforeHere. - if (BeforeHere != I && DT->dominates(BeforeHere, I) && - !isPotentiallyReachable(I, BeforeHere, DT)) - return false; - return true; - } - - bool captured(const Use *U) override { - Instruction *I = cast(U->getUser()); - BasicBlock *BB = I->getParent(); - // Same logic as in shouldExplore. - if (BeforeHere != I && !DT->isReachableFromEntry(BB)) - return false; - if (BeforeHere != I && DT->dominates(BeforeHere, I) && - !isPotentiallyReachable(I, BeforeHere, DT)) - return false; - Captured = true; - return true; - } - - const Instruction *BeforeHere; - DominatorTree *DT; - - bool Captured; - }; -} - // FIXME: this is really just shoring-up a deficiency in alias analysis. // BasicAA isn't willing to spend linear time determining whether an alloca // was captured before or after this particular call, while we are. However, @@ -449,9 +419,9 @@ AliasAnalysis::callCapturesBefore(const Instruction *I, if (!CS.getInstruction() || CS.getInstruction() == Object) return AliasAnalysis::ModRef; - CapturesBefore CB(I, DT); - llvm::PointerMayBeCaptured(Object, &CB); - if (CB.Captured) + if (llvm::PointerMayBeCapturedBefore(Object, /* ReturnCaptures */ true, + /* StoreCaptures */ true, I, DT, + /* include Object */ true)) return AliasAnalysis::ModRef; unsigned ArgNo = 0; @@ -577,3 +547,14 @@ bool llvm::isIdentifiedObject(const Value *V) { return A->hasNoAliasAttr() || A->hasByValAttr(); return false; } + +/// isIdentifiedFunctionLocal - Return true if V is umabigously identified +/// at the function-level. Different IdentifiedFunctionLocals can't alias. +/// Further, an IdentifiedFunctionLocal can not alias with any function +/// arguments other than itself, which is not necessarily true for +/// IdentifiedObjects. +bool llvm::isIdentifiedFunctionLocal(const Value *V) +{ + return isa(V) || isNoAliasCall(V) || isNoAliasArgument(V); +} +