Fix a bug where we didn't realize that vaarg reads memory. This fixes
Transforms/DeadStoreElimination/2005-11-30-vaarg.ll
llvm-svn: 24545
diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 07d5c65..d3f461d 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -96,6 +96,13 @@
}
if (!isa<StoreInst>(I) || cast<StoreInst>(I)->isVolatile()) {
+ // If this is a vaarg instruction, it reads its operand. We don't model
+ // it correctly, so just conservatively remove all entries.
+ if (isa<VAArgInst>(I)) {
+ KillLocs.clear();
+ continue;
+ }
+
// If this is a non-store instruction, it makes everything referenced no
// longer killed. Remove anything aliased from the alias set tracker.
KillLocs.remove(I);