Improve mod/ref information based on the pointsToConstantMemory method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11021 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-01-30 22:16:42 +00:00
parent 762e8e846f
commit f4d904d7e3

View File

@ -44,8 +44,15 @@ AliasAnalysis::getModRefInfo(LoadInst *L, Value *P, unsigned Size) {
AliasAnalysis::ModRefResult
AliasAnalysis::getModRefInfo(StoreInst *S, Value *P, unsigned Size) {
return alias(S->getOperand(1), TD->getTypeSize(S->getOperand(0)->getType()),
P, Size) ? Mod : NoModRef;
// If the stored address cannot alias the pointer in question, then the
// pointer cannot be modified by the store.
if (!alias(S->getOperand(1), TD->getTypeSize(S->getOperand(0)->getType()),
P, Size))
return NoModRef;
// If the pointer is a pointer to constant memory, then it could not have been
// modified by this store.
return pointsToConstantMemory(P) ? NoModRef : Mod;
}