diff options
Diffstat (limited to 'contrib/llvm/lib/Analysis/AliasAnalysis.cpp')
| -rw-r--r-- | contrib/llvm/lib/Analysis/AliasAnalysis.cpp | 187 |
1 files changed, 113 insertions, 74 deletions
diff --git a/contrib/llvm/lib/Analysis/AliasAnalysis.cpp b/contrib/llvm/lib/Analysis/AliasAnalysis.cpp index 1f2528f..be02ddb 100644 --- a/contrib/llvm/lib/Analysis/AliasAnalysis.cpp +++ b/contrib/llvm/lib/Analysis/AliasAnalysis.cpp @@ -30,12 +30,13 @@ #include "llvm/Function.h" #include "llvm/IntrinsicInst.h" #include "llvm/Instructions.h" +#include "llvm/LLVMContext.h" #include "llvm/Type.h" #include "llvm/Target/TargetData.h" using namespace llvm; // Register the AliasAnalysis interface, providing a nice name to refer to. -static RegisterAnalysisGroup<AliasAnalysis> Z("Alias Analysis"); +INITIALIZE_ANALYSIS_GROUP(AliasAnalysis, "Alias Analysis", NoAA) char AliasAnalysis::ID = 0; //===----------------------------------------------------------------------===// @@ -43,15 +44,15 @@ char AliasAnalysis::ID = 0; //===----------------------------------------------------------------------===// AliasAnalysis::AliasResult -AliasAnalysis::alias(const Value *V1, unsigned V1Size, - const Value *V2, unsigned V2Size) { +AliasAnalysis::alias(const Location &LocA, const Location &LocB) { assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); - return AA->alias(V1, V1Size, V2, V2Size); + return AA->alias(LocA, LocB); } -bool AliasAnalysis::pointsToConstantMemory(const Value *P) { +bool AliasAnalysis::pointsToConstantMemory(const Location &Loc, + bool OrLocal) { assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); - return AA->pointsToConstantMemory(P); + return AA->pointsToConstantMemory(Loc, OrLocal); } void AliasAnalysis::deleteValue(Value *V) { @@ -64,49 +65,55 @@ void AliasAnalysis::copyValue(Value *From, Value *To) { AA->copyValue(From, To); } +void AliasAnalysis::addEscapingUse(Use &U) { + assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); + AA->addEscapingUse(U); +} + + AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo(ImmutableCallSite CS, - const Value *P, unsigned Size) { - // Don't assert AA because BasicAA calls us in order to make use of the - // logic here. + const Location &Loc) { + assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); ModRefBehavior MRB = getModRefBehavior(CS); if (MRB == DoesNotAccessMemory) return NoModRef; ModRefResult Mask = ModRef; - if (MRB == OnlyReadsMemory) + if (onlyReadsMemory(MRB)) Mask = Ref; - else if (MRB == AliasAnalysis::AccessesArguments) { + + if (onlyAccessesArgPointees(MRB)) { bool doesAlias = false; - for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end(); - AI != AE; ++AI) - if (!isNoAlias(*AI, ~0U, P, Size)) { - doesAlias = true; - break; - } + if (doesAccessArgPointees(MRB)) + for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end(); + AI != AE; ++AI) + if (!isNoAlias(Location(*AI), Loc)) { + doesAlias = true; + break; + } if (!doesAlias) return NoModRef; } - // If P points to a constant memory location, the call definitely could not + // If Loc is a constant memory location, the call definitely could not // modify the memory location. - if ((Mask & Mod) && pointsToConstantMemory(P)) + if ((Mask & Mod) && pointsToConstantMemory(Loc)) Mask = ModRefResult(Mask & ~Mod); - // If this is BasicAA, don't forward. + // If this is the end of the chain, don't forward. if (!AA) return Mask; // Otherwise, fall back to the next AA in the chain. But we can merge // in any mask we've managed to compute. - return ModRefResult(AA->getModRefInfo(CS, P, Size) & Mask); + return ModRefResult(AA->getModRefInfo(CS, Loc) & Mask); } AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) { - // Don't assert AA because BasicAA calls us in order to make use of the - // logic here. + assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); // If CS1 or CS2 are readnone, they don't interact. ModRefBehavior CS1B = getModRefBehavior(CS1); @@ -116,45 +123,47 @@ AliasAnalysis::getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) { if (CS2B == DoesNotAccessMemory) return NoModRef; // If they both only read from memory, there is no dependence. - if (CS1B == OnlyReadsMemory && CS2B == OnlyReadsMemory) + if (onlyReadsMemory(CS1B) && onlyReadsMemory(CS2B)) return NoModRef; AliasAnalysis::ModRefResult Mask = ModRef; // If CS1 only reads memory, the only dependence on CS2 can be // from CS1 reading memory written by CS2. - if (CS1B == OnlyReadsMemory) + if (onlyReadsMemory(CS1B)) Mask = ModRefResult(Mask & Ref); // If CS2 only access memory through arguments, accumulate the mod/ref // information from CS1's references to the memory referenced by // CS2's arguments. - if (CS2B == AccessesArguments) { + if (onlyAccessesArgPointees(CS2B)) { AliasAnalysis::ModRefResult R = NoModRef; - for (ImmutableCallSite::arg_iterator - I = CS2.arg_begin(), E = CS2.arg_end(); I != E; ++I) { - R = ModRefResult((R | getModRefInfo(CS1, *I, UnknownSize)) & Mask); - if (R == Mask) - break; - } + if (doesAccessArgPointees(CS2B)) + for (ImmutableCallSite::arg_iterator + I = CS2.arg_begin(), E = CS2.arg_end(); I != E; ++I) { + R = ModRefResult((R | getModRefInfo(CS1, *I, UnknownSize)) & Mask); + if (R == Mask) + break; + } return R; } // If CS1 only accesses memory through arguments, check if CS2 references // any of the memory referenced by CS1's arguments. If not, return NoModRef. - if (CS1B == AccessesArguments) { + if (onlyAccessesArgPointees(CS1B)) { AliasAnalysis::ModRefResult R = NoModRef; - for (ImmutableCallSite::arg_iterator - I = CS1.arg_begin(), E = CS1.arg_end(); I != E; ++I) - if (getModRefInfo(CS2, *I, UnknownSize) != NoModRef) { - R = Mask; - break; - } + if (doesAccessArgPointees(CS1B)) + for (ImmutableCallSite::arg_iterator + I = CS1.arg_begin(), E = CS1.arg_end(); I != E; ++I) + if (getModRefInfo(CS2, *I, UnknownSize) != NoModRef) { + R = Mask; + break; + } if (R == NoModRef) return R; } - // If this is BasicAA, don't forward. + // If this is the end of the chain, don't forward. if (!AA) return Mask; // Otherwise, fall back to the next AA in the chain. But we can merge @@ -164,8 +173,7 @@ AliasAnalysis::getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) { AliasAnalysis::ModRefBehavior AliasAnalysis::getModRefBehavior(ImmutableCallSite CS) { - // Don't assert AA because BasicAA calls us in order to make use of the - // logic here. + assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!"); ModRefBehavior Min = UnknownModRefBehavior; @@ -174,12 +182,12 @@ AliasAnalysis::getModRefBehavior(ImmutableCallSite CS) { if (const Function *F = CS.getCalledFunction()) Min = getModRefBehavior(F); - // If this is BasicAA, don't forward. + // If this is the end of the chain, don't forward. if (!AA) return Min; // Otherwise, fall back to the next AA in the chain. But we can merge // in any result we've managed to compute. - return std::min(AA->getModRefBehavior(CS), Min); + return ModRefBehavior(AA->getModRefBehavior(CS) & Min); } AliasAnalysis::ModRefBehavior @@ -188,20 +196,66 @@ AliasAnalysis::getModRefBehavior(const Function *F) { return AA->getModRefBehavior(F); } - //===----------------------------------------------------------------------===// // AliasAnalysis non-virtual helper method implementation //===----------------------------------------------------------------------===// +AliasAnalysis::Location AliasAnalysis::getLocation(const LoadInst *LI) { + return Location(LI->getPointerOperand(), + getTypeStoreSize(LI->getType()), + LI->getMetadata(LLVMContext::MD_tbaa)); +} + +AliasAnalysis::Location AliasAnalysis::getLocation(const StoreInst *SI) { + return Location(SI->getPointerOperand(), + getTypeStoreSize(SI->getValueOperand()->getType()), + SI->getMetadata(LLVMContext::MD_tbaa)); +} + +AliasAnalysis::Location AliasAnalysis::getLocation(const VAArgInst *VI) { + return Location(VI->getPointerOperand(), + UnknownSize, + VI->getMetadata(LLVMContext::MD_tbaa)); +} + + +AliasAnalysis::Location +AliasAnalysis::getLocationForSource(const MemTransferInst *MTI) { + uint64_t Size = UnknownSize; + if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength())) + Size = C->getValue().getZExtValue(); + + // memcpy/memmove can have TBAA 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); +} + +AliasAnalysis::Location +AliasAnalysis::getLocationForDest(const MemIntrinsic *MTI) { + uint64_t Size = UnknownSize; + if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength())) + Size = C->getValue().getZExtValue(); + + // memcpy/memmove can have TBAA 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); +} + + + AliasAnalysis::ModRefResult -AliasAnalysis::getModRefInfo(const LoadInst *L, const Value *P, unsigned Size) { +AliasAnalysis::getModRefInfo(const LoadInst *L, const Location &Loc) { // Be conservative in the face of volatile. if (L->isVolatile()) return ModRef; // If the load address doesn't alias the given address, it doesn't read // or write the specified memory. - if (!alias(L->getOperand(0), getTypeStoreSize(L->getType()), P, Size)) + if (!alias(getLocation(L), Loc)) return NoModRef; // Otherwise, a load just reads. @@ -209,20 +263,19 @@ AliasAnalysis::getModRefInfo(const LoadInst *L, const Value *P, unsigned Size) { } AliasAnalysis::ModRefResult -AliasAnalysis::getModRefInfo(const StoreInst *S, const Value *P, unsigned Size) { +AliasAnalysis::getModRefInfo(const StoreInst *S, const Location &Loc) { // Be conservative in the face of volatile. if (S->isVolatile()) return ModRef; // If the store address cannot alias the pointer in question, then the // specified memory cannot be modified by the store. - if (!alias(S->getOperand(1), - getTypeStoreSize(S->getOperand(0)->getType()), P, Size)) + if (!alias(getLocation(S), Loc)) return NoModRef; // If the pointer is a pointer to constant memory, then it could not have been // modified by this store. - if (pointsToConstantMemory(P)) + if (pointsToConstantMemory(Loc)) return NoModRef; // Otherwise, a store just writes. @@ -230,29 +283,21 @@ AliasAnalysis::getModRefInfo(const StoreInst *S, const Value *P, unsigned Size) } AliasAnalysis::ModRefResult -AliasAnalysis::getModRefInfo(const VAArgInst *V, const Value *P, unsigned Size) { +AliasAnalysis::getModRefInfo(const VAArgInst *V, const Location &Loc) { // If the va_arg address cannot alias the pointer in question, then the // specified memory cannot be accessed by the va_arg. - if (!alias(V->getOperand(0), UnknownSize, P, Size)) + if (!alias(getLocation(V), Loc)) return NoModRef; // If the pointer is a pointer to constant memory, then it could not have been // modified by this va_arg. - if (pointsToConstantMemory(P)) + if (pointsToConstantMemory(Loc)) return NoModRef; // Otherwise, a va_arg reads and writes. return ModRef; } - -AliasAnalysis::ModRefBehavior -AliasAnalysis::getIntrinsicModRefBehavior(unsigned iid) { -#define GET_INTRINSIC_MODREF_BEHAVIOR -#include "llvm/Intrinsics.gen" -#undef GET_INTRINSIC_MODREF_BEHAVIOR -} - // AliasAnalysis destructor: DO NOT move this to the header file for // AliasAnalysis or else clients of the AliasAnalysis class may not depend on // the AliasAnalysis.o file in the current .a file, causing alias analysis @@ -277,16 +322,16 @@ void AliasAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { /// getTypeStoreSize - Return the TargetData store size for the given type, /// if known, or a conservative value otherwise. /// -unsigned AliasAnalysis::getTypeStoreSize(const Type *Ty) { - return TD ? TD->getTypeStoreSize(Ty) : ~0u; +uint64_t AliasAnalysis::getTypeStoreSize(const Type *Ty) { + return TD ? TD->getTypeStoreSize(Ty) : UnknownSize; } /// canBasicBlockModify - Return true if it is possible for execution of the /// specified basic block to modify the value pointed to by Ptr. /// bool AliasAnalysis::canBasicBlockModify(const BasicBlock &BB, - const Value *Ptr, unsigned Size) { - return canInstructionRangeModify(BB.front(), BB.back(), Ptr, Size); + const Location &Loc) { + return canInstructionRangeModify(BB.front(), BB.back(), Loc); } /// canInstructionRangeModify - Return true if it is possible for the execution @@ -296,7 +341,7 @@ bool AliasAnalysis::canBasicBlockModify(const BasicBlock &BB, /// bool AliasAnalysis::canInstructionRangeModify(const Instruction &I1, const Instruction &I2, - const Value *Ptr, unsigned Size) { + const Location &Loc) { assert(I1.getParent() == I2.getParent() && "Instructions not in same basic block!"); BasicBlock::const_iterator I = &I1; @@ -304,7 +349,7 @@ bool AliasAnalysis::canInstructionRangeModify(const Instruction &I1, ++E; // Convert from inclusive to exclusive range. for (; I != E; ++I) // Check every instruction in range - if (getModRefInfo(I, Ptr, Size) & Mod) + if (getModRefInfo(I, Loc) & Mod) return true; return false; } @@ -336,9 +381,3 @@ bool llvm::isIdentifiedObject(const Value *V) { return A->hasNoAliasAttr() || A->hasByValAttr(); return false; } - -// Because of the way .a files work, we must force the BasicAA implementation to -// be pulled in if the AliasAnalysis classes are pulled in. Otherwise we run -// the risk of AliasAnalysis being used, but the default implementation not -// being linked into the tool that uses it. -DEFINING_FILE_FOR(AliasAnalysis) |
