Memory dependence analysis was incorrectly stopping to scan for stores to a pointer at bitcast uses of a malloc call.
It should continue scanning until the malloc call, and this patch fixes that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83931 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 97b791c..d640075 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -225,16 +225,11 @@
// the allocation, return Def. This means that there is no dependence and
// the access can be optimized based on that. For example, a load could
// turn into undef.
- if (AllocationInst *AI = dyn_cast<AllocationInst>(Inst)) {
- Value *AccessPtr = MemPtr->getUnderlyingObject();
-
- if (AccessPtr == AI ||
- AA->alias(AI, 1, AccessPtr, 1) == AliasAnalysis::MustAlias)
- return MemDepResult::getDef(AI);
- continue;
- }
-
- if (isMalloc(Inst)) {
+ // Note: Only determine this to be a malloc if Inst is the malloc call, not
+ // a subsequent bitcast of the malloc call result. There can be stores to
+ // the malloced memory between the malloc call and its bitcast uses, and we
+ // need to continue scanning until the malloc call.
+ if (isa<AllocationInst>(Inst) || extractMallocCall(Inst)) {
Value *AccessPtr = MemPtr->getUnderlyingObject();
if (AccessPtr == Inst ||