Remove the experimental AliasAnalysis::getDependency interface, which
isn't a good level of abstraction for memdep. Instead, generalize
AliasAnalysis::alias and related interfaces with a new Location
class for describing a memory location. For now, this is the same
Pointer and Size as before, plus an additional field for a TBAA tag.
Also, introduce a fixed MD_tbaa metadata tag kind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113858 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 93597ca..b9cd5a6 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -30,6 +30,7 @@
#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;
@@ -43,15 +44,14 @@
//===----------------------------------------------------------------------===//
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) {
assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
- return AA->pointsToConstantMemory(P);
+ return AA->pointsToConstantMemory(Loc);
}
void AliasAnalysis::deleteValue(Value *V) {
@@ -66,7 +66,7 @@
AliasAnalysis::ModRefResult
AliasAnalysis::getModRefInfo(ImmutableCallSite CS,
- const Value *P, unsigned Size) {
+ const Location &Loc) {
// Don't assert AA because BasicAA calls us in order to make use of the
// logic here.
@@ -81,7 +81,7 @@
bool doesAlias = false;
for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
AI != AE; ++AI)
- if (!isNoAlias(*AI, ~0U, P, Size)) {
+ if (!isNoAlias(Location(*AI), Loc)) {
doesAlias = true;
break;
}
@@ -90,9 +90,9 @@
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.
@@ -100,7 +100,7 @@
// 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
@@ -188,31 +188,22 @@
return AA->getModRefBehavior(F);
}
-AliasAnalysis::DependenceResult
-AliasAnalysis::getDependence(const Instruction *First,
- const Value *FirstPHITranslatedAddr,
- DependenceQueryFlags FirstFlags,
- const Instruction *Second,
- const Value *SecondPHITranslatedAddr,
- DependenceQueryFlags SecondFlags) {
- assert(AA && "AA didn't call InitializeAliasAnalyais in its run method!");
- return AA->getDependence(First, FirstPHITranslatedAddr, FirstFlags,
- Second, SecondPHITranslatedAddr, SecondFlags);
-}
-
//===----------------------------------------------------------------------===//
// AliasAnalysis non-virtual helper method implementation
//===----------------------------------------------------------------------===//
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(Location(L->getOperand(0),
+ getTypeStoreSize(L->getType()),
+ L->getMetadata(LLVMContext::MD_tbaa)),
+ Loc))
return NoModRef;
// Otherwise, a load just reads.
@@ -220,20 +211,22 @@
}
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(Location(S->getOperand(1),
+ getTypeStoreSize(S->getOperand(0)->getType()),
+ S->getMetadata(LLVMContext::MD_tbaa)),
+ 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.
@@ -241,240 +234,24 @@
}
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(Location(V->getOperand(0),
+ UnknownSize,
+ V->getMetadata(LLVMContext::MD_tbaa)),
+ 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::DependenceResult
-AliasAnalysis::getDependenceViaModRefInfo(const Instruction *First,
- const Value *FirstPHITranslatedAddr,
- DependenceQueryFlags FirstFlags,
- const Instruction *Second,
- const Value *SecondPHITranslatedAddr,
- DependenceQueryFlags SecondFlags) {
- if (const LoadInst *L = dyn_cast<LoadInst>(First)) {
- // Be over-conservative with volatile for now.
- if (L->isVolatile())
- return Unknown;
-
- // If we don't have a phi-translated address, use the actual one.
- if (!FirstPHITranslatedAddr)
- FirstPHITranslatedAddr = L->getPointerOperand();
-
- // Forward this query to getModRefInfo.
- switch (getModRefInfo(Second,
- FirstPHITranslatedAddr,
- getTypeStoreSize(L->getType()))) {
- case NoModRef:
- // Second doesn't reference First's memory, so they're independent.
- return Independent;
-
- case Ref:
- // Second only reads from the memory read from by First. If it
- // also writes to any other memory, be conservative.
- if (Second->mayWriteToMemory())
- return Unknown;
-
- // If it's loading the same size from the same address, we can
- // give a more precise result.
- if (const LoadInst *SecondL = dyn_cast<LoadInst>(Second)) {
- // If we don't have a phi-translated address, use the actual one.
- if (!SecondPHITranslatedAddr)
- SecondPHITranslatedAddr = SecondL->getPointerOperand();
-
- unsigned LSize = getTypeStoreSize(L->getType());
- unsigned SecondLSize = getTypeStoreSize(SecondL->getType());
- if (alias(FirstPHITranslatedAddr, LSize,
- SecondPHITranslatedAddr, SecondLSize) ==
- MustAlias) {
- // If the loads are the same size, it's ReadThenRead.
- if (LSize == SecondLSize)
- return ReadThenRead;
-
- // If the second load is smaller, it's only ReadThenReadSome.
- if (LSize > SecondLSize)
- return ReadThenReadSome;
- }
- }
-
- // Otherwise it's just two loads.
- return Independent;
-
- case Mod:
- // Second only writes to the memory read from by First. If it
- // also reads from any other memory, be conservative.
- if (Second->mayReadFromMemory())
- return Unknown;
-
- // If it's storing the same size to the same address, we can
- // give a more precise result.
- if (const StoreInst *SecondS = dyn_cast<StoreInst>(Second)) {
- // If we don't have a phi-translated address, use the actual one.
- if (!SecondPHITranslatedAddr)
- SecondPHITranslatedAddr = SecondS->getPointerOperand();
-
- unsigned LSize = getTypeStoreSize(L->getType());
- unsigned SecondSSize = getTypeStoreSize(SecondS->getType());
- if (alias(FirstPHITranslatedAddr, LSize,
- SecondPHITranslatedAddr, SecondSSize) ==
- MustAlias) {
- // If the load and the store are the same size, it's ReadThenWrite.
- if (LSize == SecondSSize)
- return ReadThenWrite;
- }
- }
-
- // Otherwise we don't know if it could be writing to other memory.
- return Unknown;
-
- case ModRef:
- // Second reads and writes to the memory read from by First.
- // We don't have a way to express that.
- return Unknown;
- }
-
- } else if (const StoreInst *S = dyn_cast<StoreInst>(First)) {
- // Be over-conservative with volatile for now.
- if (S->isVolatile())
- return Unknown;
-
- // If we don't have a phi-translated address, use the actual one.
- if (!FirstPHITranslatedAddr)
- FirstPHITranslatedAddr = S->getPointerOperand();
-
- // Forward this query to getModRefInfo.
- switch (getModRefInfo(Second,
- FirstPHITranslatedAddr,
- getTypeStoreSize(S->getValueOperand()->getType()))) {
- case NoModRef:
- // Second doesn't reference First's memory, so they're independent.
- return Independent;
-
- case Ref:
- // Second only reads from the memory written to by First. If it
- // also writes to any other memory, be conservative.
- if (Second->mayWriteToMemory())
- return Unknown;
-
- // If it's loading the same size from the same address, we can
- // give a more precise result.
- if (const LoadInst *SecondL = dyn_cast<LoadInst>(Second)) {
- // If we don't have a phi-translated address, use the actual one.
- if (!SecondPHITranslatedAddr)
- SecondPHITranslatedAddr = SecondL->getPointerOperand();
-
- unsigned SSize = getTypeStoreSize(S->getValueOperand()->getType());
- unsigned SecondLSize = getTypeStoreSize(SecondL->getType());
- if (alias(FirstPHITranslatedAddr, SSize,
- SecondPHITranslatedAddr, SecondLSize) ==
- MustAlias) {
- // If the store and the load are the same size, it's WriteThenRead.
- if (SSize == SecondLSize)
- return WriteThenRead;
-
- // If the load is smaller, it's only WriteThenReadSome.
- if (SSize > SecondLSize)
- return WriteThenReadSome;
- }
- }
-
- // Otherwise we don't know if it could be reading from other memory.
- return Unknown;
-
- case Mod:
- // Second only writes to the memory written to by First. If it
- // also reads from any other memory, be conservative.
- if (Second->mayReadFromMemory())
- return Unknown;
-
- // If it's storing the same size to the same address, we can
- // give a more precise result.
- if (const StoreInst *SecondS = dyn_cast<StoreInst>(Second)) {
- // If we don't have a phi-translated address, use the actual one.
- if (!SecondPHITranslatedAddr)
- SecondPHITranslatedAddr = SecondS->getPointerOperand();
-
- unsigned SSize = getTypeStoreSize(S->getValueOperand()->getType());
- unsigned SecondSSize = getTypeStoreSize(SecondS->getType());
- if (alias(FirstPHITranslatedAddr, SSize,
- SecondPHITranslatedAddr, SecondSSize) ==
- MustAlias) {
- // If the stores are the same size, it's WriteThenWrite.
- if (SSize == SecondSSize)
- return WriteThenWrite;
-
- // If the second store is larger, it's only WriteSomeThenWrite.
- if (SSize < SecondSSize)
- return WriteSomeThenWrite;
- }
- }
-
- // Otherwise we don't know if it could be writing to other memory.
- return Unknown;
-
- case ModRef:
- // Second reads and writes to the memory written to by First.
- // We don't have a way to express that.
- return Unknown;
- }
-
- } else if (const VAArgInst *V = dyn_cast<VAArgInst>(First)) {
- // If we don't have a phi-translated address, use the actual one.
- if (!FirstPHITranslatedAddr)
- FirstPHITranslatedAddr = V->getPointerOperand();
-
- // Forward this query to getModRefInfo.
- if (getModRefInfo(Second, FirstPHITranslatedAddr, UnknownSize) == NoModRef)
- // Second doesn't reference First's memory, so they're independent.
- return Independent;
-
- } else if (ImmutableCallSite FirstCS = cast<Value>(First)) {
- assert(!FirstPHITranslatedAddr &&
- !SecondPHITranslatedAddr &&
- "PHI translation with calls not supported yet!");
-
- // If both instructions are calls/invokes we can use the two-callsite
- // form of getModRefInfo.
- if (ImmutableCallSite SecondCS = cast<Value>(Second))
- // getModRefInfo's arguments are backwards from intuition.
- switch (getModRefInfo(SecondCS, FirstCS)) {
- case NoModRef:
- // Second doesn't reference First's memory, so they're independent.
- return Independent;
-
- case Ref:
- // If they're both read-only, there's no dependence.
- if (FirstCS.onlyReadsMemory() && SecondCS.onlyReadsMemory())
- return Independent;
-
- // Otherwise it's not obvious what we can do here.
- return Unknown;
-
- case Mod:
- // It's not obvious what we can do here.
- return Unknown;
-
- case ModRef:
- // I know, right?
- return Unknown;
- }
- }
-
- // For anything else, be conservative.
- return Unknown;
-}
-
AliasAnalysis::ModRefBehavior
AliasAnalysis::getIntrinsicModRefBehavior(unsigned iid) {
#define GET_INTRINSIC_MODREF_BEHAVIOR
@@ -514,8 +291,8 @@
/// 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
@@ -525,7 +302,7 @@
///
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;
@@ -533,7 +310,7 @@
++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;
}