The trick with globals actually works with allocas and malloc too
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18262 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 3ab2744..b195b25 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -290,13 +290,13 @@
if (!isa<Argument>(O1) && isa<ConstantPointerNull>(V2))
return NoAlias; // Unique values don't alias null
- if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(O1))
- if (GV->getType()->getElementType()->isSized()) {
+ if (isa<GlobalVariable>(O1) || isa<AllocationInst>(O1))
+ if (cast<PointerType>(O1->getType())->getElementType()->isSized()) {
// If the size of the other access is larger than the total size of the
- // global, it cannot be accessing the global (it's undefined to load or
- // store bytes after the global).
- unsigned GlobalSize =
- getTargetData().getTypeSize(GV->getType()->getElementType());
+ // global/alloca/malloc, it cannot be accessing the global (it's
+ // undefined to load or store bytes before or after an object).
+ const Type *ElTy = cast<PointerType>(O1->getType())->getElementType();
+ unsigned GlobalSize = getTargetData().getTypeSize(ElTy);
if (GlobalSize < V2Size)
return NoAlias;
}
@@ -306,13 +306,13 @@
if (!isa<Argument>(O2) && isa<ConstantPointerNull>(V1))
return NoAlias; // Unique values don't alias null
- if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(O2))
- if (GV->getType()->getElementType()->isSized()) {
+ if (isa<GlobalVariable>(O2) || isa<AllocationInst>(O2))
+ if (cast<PointerType>(O2->getType())->getElementType()->isSized()) {
// If the size of the other access is larger than the total size of the
- // global, it cannot be accessing the global (it's undefined to load or
- // store bytes after the global).
- unsigned GlobalSize =
- getTargetData().getTypeSize(GV->getType()->getElementType());
+ // global/alloca/malloc, it cannot be accessing the object (it's
+ // undefined to load or store bytes before or after an object).
+ const Type *ElTy = cast<PointerType>(O2->getType())->getElementType();
+ unsigned GlobalSize = getTargetData().getTypeSize(ElTy);
if (GlobalSize < V1Size)
return NoAlias;
}