New testcase

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11766 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll b/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll
new file mode 100644 (file)
index 0000000..911a73f
--- /dev/null
+++ b/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep 34
+
+int %test(int %X) {
+       ; Do not fold into shr X, 34, as this uses undefined behavior!
+       %Y = shr int %X, ubyte 17
+       %Z = shr int %Y, ubyte 17
+       ret int %Z
+}