#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
-#include "llvm/ParameterAttributes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
return false;
}
-/// getUnderlyingObject - This traverses the use chain to figure out what object
-/// the specified value points to. If the value points to, or is derived from,
-/// a unique object or an argument, return it. This returns:
-/// Arguments, GlobalVariables, Functions, Allocas, Mallocs.
-static const Value *getUnderlyingObject(const Value *V) {
- if (!isa<PointerType>(V->getType())) return V;
-
- // If we are at some type of object, return it. GlobalValues and Allocations
- // have unique addresses.
- if (isa<GlobalValue>(V) || isa<AllocationInst>(V) || isa<Argument>(V))
- return V;
-
- // Traverse through different addressing mechanisms...
- if (const Instruction *I = dyn_cast<Instruction>(V)) {
- if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I))
- return getUnderlyingObject(I->getOperand(0));
- } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
- if (CE->getOpcode() == Instruction::BitCast ||
- CE->getOpcode() == Instruction::GetElementPtr)
- return getUnderlyingObject(CE->getOperand(0));
- }
- return V;
-}
-
static const User *isGEP(const Value *V) {
if (isa<GetElementPtrInst>(V) ||
(isa<ConstantExpr>(V) &&
return V;
}
+/// isNoAliasCall - Return true if this pointer is returned by a noalias
+/// function.
+static bool isNoAliasCall(const Value *V) {
+ if (isa<CallInst>(V) || isa<InvokeInst>(V))
+ return CallSite(const_cast<Instruction*>(cast<Instruction>(V)))
+ .paramHasAttr(0, Attribute::NoAlias);
+ return false;
+}
+
/// isIdentifiedObject - Return true if this pointer refers to a distinct and
/// identifiable object. This returns true for:
/// Global Variables and Functions
/// Allocas and Mallocs
/// ByVal and NoAlias Arguments
+/// NoAlias returns
///
static bool isIdentifiedObject(const Value *V) {
- if (isa<GlobalValue>(V) || isa<AllocationInst>(V))
+ if (isa<GlobalValue>(V) || isa<AllocationInst>(V) || isNoAliasCall(V))
return true;
if (const Argument *A = dyn_cast<Argument>(V))
return A->hasNoAliasAttr() || A->hasByValAttr();
/// object that never escapes from the function.
static bool isNonEscapingLocalObject(const Value *V) {
// If this is a local allocation, check to see if it escapes.
- if (isa<AllocationInst>(V))
+ if (isa<AllocationInst>(V) || isNoAliasCall(V))
return !AddressMightEscape(V);
// If this is an argument that corresponds to a byval or noalias argument,
///
struct VISIBILITY_HIDDEN NoAA : public ImmutablePass, public AliasAnalysis {
static char ID; // Class identification, replacement for typeinfo
- NoAA() : ImmutablePass((intptr_t)&ID) {}
- explicit NoAA(intptr_t PID) : ImmutablePass(PID) { }
+ NoAA() : ImmutablePass(&ID) {}
+ explicit NoAA(void *PID) : ImmutablePass(PID) { }
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetData>();
/// derives from the NoAA class.
struct VISIBILITY_HIDDEN BasicAliasAnalysis : public NoAA {
static char ID; // Class identification, replacement for typeinfo
- BasicAliasAnalysis() : NoAA((intptr_t)&ID) { }
+ BasicAliasAnalysis() : NoAA(&ID) {}
AliasResult alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size);
/// global) or not.
bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
if (const GlobalVariable *GV =
- dyn_cast<GlobalVariable>(getUnderlyingObject(P)))
+ dyn_cast<GlobalVariable>(P->getUnderlyingObject()))
return GV->isConstant();
return false;
}
AliasAnalysis::ModRefResult
BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
if (!isa<Constant>(P)) {
- const Value *Object = getUnderlyingObject(P);
+ const Value *Object = P->getUnderlyingObject();
// If this is a tail call and P points to a stack location, we know that
// the tail call cannot access or modify the local stack.
// Are we checking for alias of the same value?
if (V1 == V2) return MustAlias;
- if ((!isa<PointerType>(V1->getType()) || !isa<PointerType>(V2->getType())) &&
- V1->getType() != Type::Int64Ty && V2->getType() != Type::Int64Ty)
+ if (!isa<PointerType>(V1->getType()) || !isa<PointerType>(V2->getType()))
return NoAlias; // Scalars cannot alias each other
// Strip off cast instructions...
return alias(V1, V1Size, I->getOperand(0), V2Size);
// Figure out what objects these things are pointing to if we can...
- const Value *O1 = getUnderlyingObject(V1);
- const Value *O2 = getUnderlyingObject(V2);
+ const Value *O1 = V1->getUnderlyingObject();
+ const Value *O2 = V2->getUnderlyingObject();
if (O1 != O2) {
// If V1/V2 point to two different objects we know that we have no alias.
if (isIdentifiedObject(O1) && isIdentifiedObject(O2))
return NoAlias;
- // Incoming argument cannot alias locally allocated object!
- if ((isa<Argument>(O1) && isa<AllocationInst>(O2)) ||
- (isa<Argument>(O2) && isa<AllocationInst>(O1)))
+ // Arguments can't alias with local allocations or noalias calls.
+ if ((isa<Argument>(O1) && (isa<AllocationInst>(O2) || isNoAliasCall(O2))) ||
+ (isa<Argument>(O2) && (isa<AllocationInst>(O1) || isNoAliasCall(O1))))
return NoAlias;
-
+
// Most objects can't alias null.
if ((isa<ConstantPointerNull>(V2) && isKnownNonNull(O1)) ||
(isa<ConstantPointerNull>(V1) && isKnownNonNull(O2)))