[Analysis] bitreverse(undef) returns undef
Summary:
The reverse of an artbitrary bitpattern is also an arbitrary
bitpattern.
Reviewers: trentxintong, arsenm, majnemer
Reviewed By: majnemer
Subscribers: majnemer, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D31118
llvm-svn: 298201
diff --git a/llvm/test/Transforms/InstCombine/bitreverse-fold.ll b/llvm/test/Transforms/InstCombine/bitreverse-fold.ll
index ecdfbc8..b798ad3 100644
--- a/llvm/test/Transforms/InstCombine/bitreverse-fold.ll
+++ b/llvm/test/Transforms/InstCombine/bitreverse-fold.ll
@@ -37,6 +37,13 @@
ret i32 %x
}
+; CHECK-LABEL: @reverse_undef_i32(
+; CHECK-NEXT: ret i32 undef
+define i32 @reverse_undef_i32() {
+ %x = call i32 @llvm.bitreverse.i32(i32 undef)
+ ret i32 %x
+}
+
; CHECK-LABEL: @reverse_false_i1(
; CHECK-NEXT: ret i1 false
define i1 @reverse_false_i1() {
@@ -51,6 +58,13 @@
ret i1 %x
}
+; CHECK-LABEL: @reverse_undef_i1(
+; CHECK-NEXT: ret i1 undef
+define i1 @reverse_undef_i1() {
+ %x = call i1 @llvm.bitreverse.i1(i1 undef)
+ ret i1 %x
+}
+
; CHECK-LABEL: @reverse_false_v2i1(
; CHECK-NEXT: ret <2 x i1> zeroinitializer
define <2 x i1> @reverse_false_v2i1() {