#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;
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
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) {
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)) {
+ MDNode *CSTag = CS.getInstruction()->getMetadata(LLVMContext::MD_tbaa);
+ for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
+ AI != AE; ++AI) {
+ const Value *Arg = *AI;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ Location CSLoc(Arg, UnknownSize, CSTag);
+ if (!isNoAlias(CSLoc, 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);
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)) {
+ MDNode *CS2Tag = CS2.getInstruction()->getMetadata(LLVMContext::MD_tbaa);
+ for (ImmutableCallSite::arg_iterator
+ I = CS2.arg_begin(), E = CS2.arg_end(); I != E; ++I) {
+ const Value *Arg = *I;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ Location CS2Loc(Arg, UnknownSize, CS2Tag);
+ R = ModRefResult((R | getModRefInfo(CS1, CS2Loc)) & 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)) {
+ MDNode *CS1Tag = CS1.getInstruction()->getMetadata(LLVMContext::MD_tbaa);
+ for (ImmutableCallSite::arg_iterator
+ I = CS1.arg_begin(), E = CS1.arg_end(); I != E; ++I) {
+ const Value *Arg = *I;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ Location CS1Loc(Arg, UnknownSize, CS1Tag);
+ if (getModRefInfo(CS2, CS1Loc) != 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
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;
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
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) {
- // Be conservative in the face of volatile.
- if (L->isVolatile())
+AliasAnalysis::getModRefInfo(const LoadInst *L, const Location &Loc) {
+ // Be conservative in the face of volatile/atomic.
+ if (!L->isUnordered())
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.
}
AliasAnalysis::ModRefResult
-AliasAnalysis::getModRefInfo(const StoreInst *S, const Value *P, unsigned Size) {
- // Be conservative in the face of volatile.
- if (S->isVolatile())
+AliasAnalysis::getModRefInfo(const StoreInst *S, const Location &Loc) {
+ // Be conservative in the face of volatile/atomic.
+ if (!S->isUnordered())
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.
}
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
/// 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(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
///
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;
++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;
}
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)
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