return isNoAlias(Location(V1, V1Size), Location(V2, V2Size));
}
- /// pointsToConstantMemory - If the specified memory location is known to be
- /// constant, return true. This allows disambiguation of store
- /// instructions from constant pointers.
- ///
- virtual bool pointsToConstantMemory(const Location &Loc);
+ /// pointsToConstantMemory - If the specified memory location is
+ /// known to be constant, return true. If OrLocal is true and the
+ /// specified memory location is known to be "local" (derived from
+ /// an alloca), return true. Otherwise return false.
+ virtual bool pointsToConstantMemory(const Location &Loc,
+ bool OrLocal = false);
/// pointsToConstantMemory - A convenient wrapper.
- bool pointsToConstantMemory(const Value *P) {
- return pointsToConstantMemory(Location(P));
+ bool pointsToConstantMemory(const Value *P, bool OrLocal = false) {
+ return pointsToConstantMemory(Location(P), OrLocal);
}
//===--------------------------------------------------------------------===//
return AA->alias(LocA, LocB);
}
-bool AliasAnalysis::pointsToConstantMemory(const Location &Loc) {
+bool AliasAnalysis::pointsToConstantMemory(const Location &Loc,
+ bool OrLocal) {
assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
- return AA->pointsToConstantMemory(Loc);
+ return AA->pointsToConstantMemory(Loc, OrLocal);
}
void AliasAnalysis::deleteValue(Value *V) {
}
// FIXME: We could count these too...
- bool pointsToConstantMemory(const Location &Loc) {
- return getAnalysis<AliasAnalysis>().pointsToConstantMemory(Loc);
+ bool pointsToConstantMemory(const Location &Loc, bool OrLocal) {
+ return getAnalysis<AliasAnalysis>().pointsToConstantMemory(Loc, OrLocal);
}
// Forwarding functions: just delegate to a real AA implementation, counting
return AliasAnalysis::getModRefInfo(CS1,CS2);
}
- bool pointsToConstantMemory(const Location &Loc) {
+ bool pointsToConstantMemory(const Location &Loc, bool OrLocal) {
assert(Vals.find(Loc.Ptr) != Vals.end() && "Never seen value in AA before");
- return AliasAnalysis::pointsToConstantMemory(Loc);
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
}
virtual void deleteValue(Value *V) {
/// pointsToConstantMemory - Chase pointers until we find a (constant
/// global) or not.
- virtual bool pointsToConstantMemory(const Location &Loc);
+ virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal);
/// getModRefBehavior - Return the behavior when calling the given
/// call site.
return new BasicAliasAnalysis();
}
+/// pointsToConstantMemory - Returns whether the given pointer value
+/// points to memory that is local to the function, with global constants being
+/// considered local to all functions.
+bool
+BasicAliasAnalysis::pointsToConstantMemory(const Location &Loc, bool OrLocal) {
+ assert(Visited.empty() && "Visited must be cleared after use!");
-/// pointsToConstantMemory - Chase pointers until we find a (constant
-/// global) or not.
-bool BasicAliasAnalysis::pointsToConstantMemory(const Location &Loc) {
- if (const GlobalVariable *GV =
- dyn_cast<GlobalVariable>(Loc.Ptr->getUnderlyingObject()))
- // Note: this doesn't require GV to be "ODR" because it isn't legal for a
- // global to be marked constant in some modules and non-constant in others.
- // GV may even be a declaration, not a definition.
- return GV->isConstant();
+ SmallVector<const Value *, 16> Worklist;
+ Worklist.push_back(Loc.Ptr);
+ do {
+ const Value *V = Worklist.pop_back_val()->getUnderlyingObject();
+ if (!Visited.insert(V)) {
+ Visited.clear();
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
+ }
+
+ // An alloca instruction defines local memory.
+ if (OrLocal && isa<AllocaInst>(V))
+ continue;
+
+ // A global constant counts as local memory for our purposes.
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
+ // Note: this doesn't require GV to be "ODR" because it isn't legal for a
+ // global to be marked constant in some modules and non-constant in
+ // others. GV may even be a declaration, not a definition.
+ if (!GV->isConstant()) {
+ Visited.clear();
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
+ }
+ continue;
+ }
+
+ // If both select values point to local memory, then so does the select.
+ if (const SelectInst *SI = dyn_cast<SelectInst>(V)) {
+ Worklist.push_back(SI->getTrueValue());
+ Worklist.push_back(SI->getFalseValue());
+ continue;
+ }
+
+ // If all values incoming to a phi node point to local memory, then so does
+ // the phi.
+ if (const PHINode *PN = dyn_cast<PHINode>(V)) {
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+ Worklist.push_back(PN->getIncomingValue(i));
+ continue;
+ }
+
+ // Otherwise be conservative.
+ Visited.clear();
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
+
+ } while (!Worklist.empty());
- return AliasAnalysis::pointsToConstantMemory(Loc);
+ Visited.clear();
+ return true;
}
/// getModRefBehavior - Return the behavior when calling the given call site.
return UnknownModRefBehavior;
}
- virtual bool pointsToConstantMemory(const Location &Loc) { return false; }
+ virtual bool pointsToConstantMemory(const Location &Loc,
+ bool OrLocal) {
+ return false;
+ }
virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc) {
return ModRef;
private:
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual AliasResult alias(const Location &LocA, const Location &LocB);
- virtual bool pointsToConstantMemory(const Location &Loc);
+ virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal);
virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc);
virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
return NoAlias;
}
-bool TypeBasedAliasAnalysis::pointsToConstantMemory(const Location &Loc) {
+bool TypeBasedAliasAnalysis::pointsToConstantMemory(const Location &Loc,
+ bool OrLocal) {
if (!EnableTBAA)
- return AliasAnalysis::pointsToConstantMemory(Loc);
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
const MDNode *M = Loc.TBAATag;
- if (!M) return AliasAnalysis::pointsToConstantMemory(Loc);
+ if (!M) return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
// If this is an "immutable" type, we can assume the pointer is pointing
// to constant memory.
if (TBAANode(M).TypeIsImmutable())
return true;
- return AliasAnalysis::pointsToConstantMemory(Loc);
+ return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
}
AliasAnalysis::ModRefResult
CallGraphSCCPass::getAnalysisUsage(AU);
}
- bool PointsToLocalOrConstantMemory(Value *V);
-
private:
AliasAnalysis *AA;
};
Pass *llvm::createFunctionAttrsPass() { return new FunctionAttrs(); }
-/// PointsToLocalOrConstantMemory - Returns whether the given pointer value
-/// points to memory that is local to the function, with global constants being
-/// considered local to all functions.
-bool FunctionAttrs::PointsToLocalOrConstantMemory(Value *V) {
- SmallVector<Value*, 16> Worklist;
- unsigned MaxLookup = 8;
-
- Worklist.push_back(V);
-
- do {
- V = Worklist.pop_back_val()->getUnderlyingObject();
-
- // An alloca instruction defines local memory.
- if (isa<AllocaInst>(V))
- continue;
-
- // A global constant counts as local memory for our purposes.
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
- if (!GV->isConstant())
- return false;
- continue;
- }
-
- // If both select values point to local memory, then so does the select.
- if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
- Worklist.push_back(SI->getTrueValue());
- Worklist.push_back(SI->getFalseValue());
- continue;
- }
-
- // If all values incoming to a phi node point to local memory, then so does
- // the phi.
- if (PHINode *PN = dyn_cast<PHINode>(V)) {
- // Don't bother inspecting phi nodes with many operands.
- if (PN->getNumIncomingValues() > MaxLookup)
- return false;
- for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- Worklist.push_back(PN->getIncomingValue(i));
- continue;
- }
-
- return false;
- } while (!Worklist.empty() && --MaxLookup);
-
- return Worklist.empty();
-}
-
/// AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
SmallPtrSet<Function*, 8> SCCNodes;
CI != CE; ++CI) {
Value *Arg = *CI;
if (Arg->getType()->isPointerTy() &&
- !PointsToLocalOrConstantMemory(Arg))
+ !AA->pointsToConstantMemory(Arg, /*OrLocal=*/true))
// Writes memory. Just give up.
return false;
}
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
// Ignore non-volatile loads from local memory.
if (!LI->isVolatile() &&
- PointsToLocalOrConstantMemory(LI->getPointerOperand()))
+ AA->pointsToConstantMemory(LI->getPointerOperand(),
+ /*OrLocal=*/true))
continue;
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
// Ignore non-volatile stores to local memory.
if (!SI->isVolatile() &&
- PointsToLocalOrConstantMemory(SI->getPointerOperand()))
+ AA->pointsToConstantMemory(SI->getPointerOperand(),
+ /*OrLocal=*/true))
continue;
}
-; RUN: opt < %s -functionattrs -S | grep readnone
+; RUN: opt < %s -basicaa -functionattrs -S | grep readnone
@s = external constant i8 ; <i8*> [#uses=1]
projects / oota-llvm.git / commitdiff