new testcase miscompiled by instcombine

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28018 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/2006-04-28-ShiftShiftLongLong.ll b/test/Transforms/InstCombine/2006-04-28-ShiftShiftLongLong.ll
new file mode 100644 (file)
index 0000000..7a164dd
--- /dev/null
+++ b/test/Transforms/InstCombine/2006-04-28-ShiftShiftLongLong.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep shl &&
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep cast
+
+; This cannot be turned into a sign extending cast!
+
+long %test(long %X) {
+       %Y = shl long %X, ubyte 16
+       %Z = shr long %Y, ubyte 16
+       ret long %Z
+}