InstSimplify: [al]shr exact undef, %X -> undef
Exact shifts always keep the non-zero bits of their input. This means
it keeps it's undef bits.
llvm-svn: 223923
diff --git a/llvm/test/Transforms/InstSimplify/undef.ll b/llvm/test/Transforms/InstSimplify/undef.ll
index a6ae7a9..3742d74 100644
--- a/llvm/test/Transforms/InstSimplify/undef.ll
+++ b/llvm/test/Transforms/InstSimplify/undef.ll
@@ -174,3 +174,17 @@
%b = sdiv i32 %a, 0
ret i32 %b
}
+
+; CHECK-LABEL: @test22
+; CHECK: ret i32 undef
+define i32 @test22(i32 %a) {
+ %b = ashr exact i32 undef, %a
+ ret i32 %b
+}
+
+; CHECK-LABEL: @test23
+; CHECK: ret i32 undef
+define i32 @test23(i32 %a) {
+ %b = lshr exact i32 undef, %a
+ ret i32 %b
+}