Make sure scalarrepl picks the correct alloca when it rewrites a bitcast. Fixes PR11353.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144442 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index b89f730..c12f403 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -1875,8 +1875,14 @@
return;
// The bitcast references the original alloca. Replace its uses with
- // references to the first new element alloca.
- Instruction *Val = NewElts[0];
+ // references to the alloca containing offset zero (which is normally at
+ // index zero, but might not be in cases involving structs with elements
+ // of size zero).
+ Type *T = AI->getAllocatedType();
+ uint64_t EltOffset = 0;
+ Type *IdxTy;
+ uint64_t Idx = FindElementAndOffset(T, EltOffset, IdxTy);
+ Instruction *Val = NewElts[Idx];
if (Val->getType() != BC->getDestTy()) {
Val = new BitCastInst(Val, BC->getDestTy(), "", BC);
Val->takeName(BC);
@@ -2160,6 +2166,8 @@
}
unsigned EltSize = TD->getTypeAllocSize(EltTy);
+ if (!EltSize)
+ continue;
IRBuilder<> Builder(MI);