Add a comment, add a new testcase

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19179 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll b/test/Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll
index c28e79e5542f8d9c62901e766d14ef6d8296f7bc..d9160e5222f785887d303b62b7da562d41e7c501 100644 (file)
--- a/test/Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll
+++ b/test/Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll
@@ -1,5 +1,7 @@
 ; RUN: llvm-as < %s | opt -dse | llvm-dis | grep 'store int 1234567'
 
+; Do not delete stores that are only partially killed.
+
 int %test() {
        %V = alloca int
        store int 1234567, int* %V

diff --git a/test/Transforms/DeadStoreElimination/PartialStore.ll b/test/Transforms/DeadStoreElimination/PartialStore.ll
new file mode 100644 (file)
index 0000000..bc8fd3a
--- /dev/null
+++ b/test/Transforms/DeadStoreElimination/PartialStore.ll
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | opt -dse | llvm-dis | not grep 'store sbyte'
+; Ensure that the dead store is deleted in this case.  It is wholely
+; overwritten by the second store.
+int %test() {
+       %V = alloca int
+       %V2 = cast int* %V to sbyte*
+       store sbyte 0, sbyte* %V2
+       store int 1234567, int* %V
+       %X = load int* %V
+       ret int %X
+}