#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/CaptureTracking.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Type.h"
#include "llvm/Pass.h"
-#include "llvm/Target/TargetLibraryInfo.h"
using namespace llvm;
// Register the AliasAnalysis interface, providing a nice name to refer to.
AA->addEscapingUse(U);
}
+AliasAnalysis::ModRefResult
+AliasAnalysis::getModRefInfo(Instruction *I, ImmutableCallSite Call) {
+ // We may have two calls
+ if (auto CS = ImmutableCallSite(I)) {
+ // Check if the two calls modify the same memory
+ return getModRefInfo(Call, CS);
+ } else {
+ // Otherwise, check if the call modifies or references the
+ // location this memory access defines. The best we can say
+ // is that if the call references what this instruction
+ // defines, it must be clobbered by this location.
+ const AliasAnalysis::Location DefLoc = AA->getLocation(I);
+ if (getModRefInfo(Call, DefLoc) != AliasAnalysis::NoModRef)
+ return AliasAnalysis::ModRef;
+ }
+ return AliasAnalysis::NoModRef;
+}
AliasAnalysis::ModRefResult
AliasAnalysis::getModRefInfo(ImmutableCallSite CS,
if (!Arg->getType()->isPointerTy())
continue;
ModRefResult ArgMask;
- Location CS1Loc =
- getArgLocation(CS1, (unsigned) std::distance(CS1.arg_begin(), I),
- ArgMask);
- // 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.
+ Location CS1Loc = getArgLocation(
+ CS1, (unsigned)std::distance(CS1.arg_begin(), I), ArgMask);
+ // 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))
//===----------------------------------------------------------------------===//
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
+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
+ // memcpy/memmove can have AA tags. For memcpy, they apply
// to both the source and the destination.
- MDNode *TBAATag = MTI->getMetadata(LLVMContext::MD_tbaa);
+ AAMDNodes AATags;
+ MTI->getAAMetadata(AATags);
- return Location(MTI->getRawSource(), Size, TBAATag);
+ return Location(MTI->getRawSource(), Size, AATags);
}
-AliasAnalysis::Location
+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
+ // 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->getAAMetadata(AATags);
+
+ return Location(MTI->getRawDest(), Size, AATags);
}
// If the load address doesn't alias the given address, it doesn't read
// or write the specified memory.
- if (!alias(getLocation(L), Loc))
+ if (Loc.Ptr && !alias(getLocation(L), Loc))
return NoModRef;
// Otherwise, a load just reads.
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(getLocation(S), Loc))
- return NoModRef;
+ if (Loc.Ptr) {
+ // If the store address cannot alias the pointer in question, then the
+ // specified memory cannot be modified by the store.
+ 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(Loc))
- return NoModRef;
+ // If the pointer is a pointer to constant memory, then it could not have
+ // been modified by this store.
+ if (pointsToConstantMemory(Loc))
+ return NoModRef;
+
+ }
// Otherwise, a store just writes.
return Mod;
AliasAnalysis::ModRefResult
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(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(Loc))
- return NoModRef;
+ if (Loc.Ptr) {
+ // If the va_arg address cannot alias the pointer in question, then the
+ // specified memory cannot be accessed by the va_arg.
+ 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(Loc))
+ return NoModRef;
+ }
// Otherwise, a va_arg reads and writes.
return ModRef;
return ModRef;
// If the cmpxchg address does not alias the location, it does not access it.
- if (!alias(getLocation(CX), Loc))
+ if (Loc.Ptr && !alias(getLocation(CX), Loc))
return NoModRef;
return ModRef;
return ModRef;
// If the atomicrmw address does not alias the location, it does not access it.
- if (!alias(getLocation(RMW), Loc))
+ if (Loc.Ptr && !alias(getLocation(RMW), Loc))
return NoModRef;
return ModRef;
AliasAnalysis::callCapturesBefore(const Instruction *I,
const AliasAnalysis::Location &MemLoc,
DominatorTree *DT) {
- if (!DT || !DL) return AliasAnalysis::ModRef;
+ if (!DT)
+ return AliasAnalysis::ModRef;
- const Value *Object = GetUnderlyingObject(MemLoc.Ptr, DL);
+ const Value *Object = GetUnderlyingObject(MemLoc.Ptr, *DL);
if (!isIdentifiedObject(Object) || isa<GlobalValue>(Object) ||
isa<Constant>(Object))
return AliasAnalysis::ModRef;
// assume that the call could touch the pointer, even though it doesn't
// escape.
if (isNoAlias(AliasAnalysis::Location(*CI),
- AliasAnalysis::Location(Object)))
+ AliasAnalysis::Location(Object)))
continue;
if (CS.doesNotAccessMemory(ArgNo))
continue;
/// InitializeAliasAnalysis - Subclasses must call this method to initialize the
/// AliasAnalysis interface before any other methods are called.
///
-void AliasAnalysis::InitializeAliasAnalysis(Pass *P) {
- DataLayoutPass *DLP = P->getAnalysisIfAvailable<DataLayoutPass>();
- DL = DLP ? &DLP->getDataLayout() : nullptr;
- TLI = P->getAnalysisIfAvailable<TargetLibraryInfo>();
+void AliasAnalysis::InitializeAliasAnalysis(Pass *P, const DataLayout *NewDL) {
+ DL = NewDL;
+ auto *TLIP = P->getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
+ TLI = TLIP ? &TLIP->getTLI() : nullptr;
AA = &P->getAnalysis<AliasAnalysis>();
}
}
/// canBasicBlockModify - Return true if it is possible for execution of the
-/// specified basic block to modify the value pointed to by Ptr.
+/// specified basic block to modify the location Loc.
///
bool AliasAnalysis::canBasicBlockModify(const BasicBlock &BB,
const Location &Loc) {
- return canInstructionRangeModify(BB.front(), BB.back(), Loc);
+ return canInstructionRangeModRef(BB.front(), BB.back(), Loc, Mod);
}
-/// canInstructionRangeModify - Return true if it is possible for the execution
-/// of the specified instructions to modify the value pointed to by Ptr. The
-/// instructions to consider are all of the instructions in the range of [I1,I2]
-/// INCLUSIVE. I1 and I2 must be in the same basic block.
-///
-bool AliasAnalysis::canInstructionRangeModify(const Instruction &I1,
+/// canInstructionRangeModRef - Return true if it is possible for the
+/// execution of the specified instructions to mod\ref (according to the
+/// mode) the location Loc. The instructions to consider are all
+/// of the instructions in the range of [I1,I2] INCLUSIVE.
+/// I1 and I2 must be in the same basic block.
+bool AliasAnalysis::canInstructionRangeModRef(const Instruction &I1,
const Instruction &I2,
- const Location &Loc) {
+ const Location &Loc,
+ const ModRefResult Mode) {
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, Loc) & Mod)
+ if (getModRefInfo(I, Loc) & Mode)
return true;
return false;
}
{
return isa<AllocaInst>(V) || isNoAliasCall(V) || isNoAliasArgument(V);
}
-