char MemoryDependenceAnalysis::ID = 0;
// Register this pass...
-static RegisterPass<MemoryDependenceAnalysis> X("memdep",
- "Memory Dependence Analysis", false, true);
+INITIALIZE_PASS(MemoryDependenceAnalysis, "memdep",
+ "Memory Dependence Analysis", false, true);
MemoryDependenceAnalysis::MemoryDependenceAnalysis()
-: FunctionPass(&ID), PredCache(0) {
+: FunctionPass(ID), PredCache(0) {
}
MemoryDependenceAnalysis::~MemoryDependenceAnalysis() {
}
} else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) {
Pointer = V->getOperand(0);
PointerSize = AA->getTypeStoreSize(V->getType());
- } else if (isFreeCall(Inst)) {
- Pointer = Inst->getOperand(1);
+ } else if (const CallInst *CI = isFreeCall(Inst)) {
+ Pointer = CI->getArgOperand(0);
// calls to free() erase the entire structure
PointerSize = ~0ULL;
- } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
+ } else if (CallSite InstCS = cast<Value>(Inst)) {
// Debug intrinsics don't cause dependences.
if (isa<DbgInfoIntrinsic>(Inst)) continue;
- CallSite InstCS = CallSite::get(Inst);
// If these two calls do not interfere, look past it.
switch (AA->getModRefInfo(CS, InstCS)) {
case AliasAnalysis::NoModRef:
- // If the two calls don't interact (e.g. InstCS is readnone) keep
- // scanning.
+ // If the two calls are the same, return InstCS as a Def, so that
+ // CS can be found redundant and eliminated.
+ if (isReadOnlyCall && InstCS.onlyReadsMemory() &&
+ CS.getInstruction()->isIdenticalToWhenDefined(Inst))
+ return MemDepResult::getDef(Inst);
+
+ // Otherwise if the two calls don't interact (e.g. InstCS is readnone)
+ // keep scanning.
continue;
- case AliasAnalysis::Ref:
- // If the two calls read the same memory locations and CS is a readonly
- // function, then we have two cases: 1) the calls may not interfere with
- // each other at all. 2) the calls may produce the same value. In case
- // #1 we want to ignore the values, in case #2, we want to return Inst
- // as a Def dependence. This allows us to CSE in cases like:
- // X = strlen(P);
- // memchr(...);
- // Y = strlen(P); // Y = X
- if (isReadOnlyCall) {
- if (CS.getCalledFunction() != 0 &&
- CS.getCalledFunction() == InstCS.getCalledFunction())
- return MemDepResult::getDef(Inst);
- // Ignore unrelated read/read call dependences.
- continue;
- }
- // FALL THROUGH
default:
return MemDepResult::getClobber(Inst);
}
}
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
- // Debug intrinsics don't cause dependences.
- if (isa<DbgInfoIntrinsic>(Inst)) continue;
+ // Debug intrinsics don't (and can't) cause dependences.
+ if (isa<DbgInfoIntrinsic>(II)) continue;
// If we pass an invariant-end marker, then we've just entered an
// invariant region and can start ignoring dependencies.
// FIXME: This only considers queries directly on the invariant-tagged
// pointer, not on query pointers that are indexed off of them. It'd
// be nice to handle that at some point.
- AliasAnalysis::AliasResult R =
- AA->alias(II->getOperand(3), ~0U, MemPtr, ~0U);
- if (R == AliasAnalysis::MustAlias) {
- InvariantTag = II->getOperand(1);
- continue;
- }
-
+ AliasAnalysis::AliasResult R = AA->alias(II->getArgOperand(2), MemPtr);
+ if (R == AliasAnalysis::MustAlias)
+ InvariantTag = II->getArgOperand(0);
+
+ continue;
+ }
+
// If we reach a lifetime begin or end marker, then the query ends here
// because the value is undefined.
- } else if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
+ if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
// FIXME: This only considers queries directly on the invariant-tagged
// pointer, not on query pointers that are indexed off of them. It'd
// be nice to handle that at some point.
- AliasAnalysis::AliasResult R =
- AA->alias(II->getOperand(2), ~0U, MemPtr, ~0U);
+ AliasAnalysis::AliasResult R = AA->alias(II->getArgOperand(1), MemPtr);
if (R == AliasAnalysis::MustAlias)
return MemDepResult::getDef(II);
+ continue;
}
}
// If we're querying on a load and we're in an invariant region, we're done
// at this point. Nothing a load depends on can live in an invariant region.
+ //
+ // FIXME: this will prevent us from returning load/load must-aliases, so GVN
+ // won't remove redundant loads.
if (isLoad && InvariantTag) continue;
// Values depend on loads if the pointers are must aliased. This means that
MemPtr = LI->getPointerOperand();
MemSize = AA->getTypeStoreSize(LI->getType());
}
- } else if (isFreeCall(QueryInst)) {
- MemPtr = QueryInst->getOperand(1);
+ } else if (const CallInst *CI = isFreeCall(QueryInst)) {
+ MemPtr = CI->getArgOperand(0);
// calls to free() erase the entire structure, not just a field.
MemSize = ~0UL;
} else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) {
int IntrinsicID = 0; // Intrinsic IDs start at 1.
- if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(QueryInst))
+ IntrinsicInst *II = dyn_cast<IntrinsicInst>(QueryInst);
+ if (II)
IntrinsicID = II->getIntrinsicID();
switch (IntrinsicID) {
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end:
case Intrinsic::invariant_start:
- MemPtr = QueryInst->getOperand(2);
- MemSize = cast<ConstantInt>(QueryInst->getOperand(1))->getZExtValue();
+ MemPtr = II->getArgOperand(1);
+ MemSize = cast<ConstantInt>(II->getArgOperand(0))->getZExtValue();
break;
case Intrinsic::invariant_end:
- MemPtr = QueryInst->getOperand(3);
- MemSize = cast<ConstantInt>(QueryInst->getOperand(2))->getZExtValue();
+ MemPtr = II->getArgOperand(2);
+ MemSize = cast<ConstantInt>(II->getArgOperand(1))->getZExtValue();
break;
default:
- CallSite QueryCS = CallSite::get(QueryInst);
+ CallSite QueryCS(QueryInst);
bool isReadOnly = AA->onlyReadsMemory(QueryCS);
LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos,
QueryParent);
// Okay, we have a cache entry. If we know it is not dirty, just return it
// with no computation.
if (!CacheP.second) {
- NumCacheNonLocal++;
+ ++NumCacheNonLocal;
return Cache;
}
BasicBlock *QueryBB = QueryCS.getInstruction()->getParent();
for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI)
DirtyBlocks.push_back(*PI);
- NumUncacheNonLocal++;
+ ++NumUncacheNonLocal;
}
// isReadonlyCall - If this is a read-only call, we can be more aggressive.
void MemoryDependenceAnalysis::
getNonLocalPointerDependency(Value *Pointer, bool isLoad, BasicBlock *FromBB,
SmallVectorImpl<NonLocalDepResult> &Result) {
- assert(isa<PointerType>(Pointer->getType()) &&
+ assert(Pointer->getType()->isPointerTy() &&
"Can't get pointer deps of a non-pointer!");
Result.clear();
// Get the PHI translated pointer in this predecessor. This can fail if
// not translatable, in which case the getAddr() returns null.
PHITransAddr PredPointer(Pointer);
- PredPointer.PHITranslateValue(BB, Pred);
+ PredPointer.PHITranslateValue(BB, Pred, 0);
Value *PredPtrVal = PredPointer.getAddr();
/// in more places that cached info does not necessarily keep.
void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) {
// If Ptr isn't really a pointer, just ignore it.
- if (!isa<PointerType>(Ptr->getType())) return;
+ if (!Ptr->getType()->isPointerTy()) return;
// Flush store info for the pointer.
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
// Flush load info for the pointer.
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
}
+/// invalidateCachedPredecessors - Clear the PredIteratorCache info.
+/// This needs to be done when the CFG changes, e.g., due to splitting
+/// critical edges.
+void MemoryDependenceAnalysis::invalidateCachedPredecessors() {
+ PredCache->clear();
+}
+
/// removeInstruction - Remove an instruction from the dependence analysis,
/// updating the dependence of instructions that previously depended on it.
/// This method attempts to keep the cache coherent using the reverse map.
// Remove it from both the load info and the store info. The instruction
// can't be in either of these maps if it is non-pointer.
- if (isa<PointerType>(RemInst->getType())) {
+ if (RemInst->getType()->isPointerTy()) {
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
}
projects / oota-llvm.git / blobdiff