[ValueTracking] Extend known bits to understand @llvm.bitreverse.
Differential Revision: https://reviews.llvm.org/D28780
llvm-svn: 292233
diff --git a/llvm/test/Transforms/InstSimplify/bitreverse.ll b/llvm/test/Transforms/InstSimplify/bitreverse.ll
new file mode 100644
index 0000000..d87b688
--- /dev/null
+++ b/llvm/test/Transforms/InstSimplify/bitreverse.ll
@@ -0,0 +1,31 @@
+; RUN: opt < %s -S -instsimplify | FileCheck %s
+
+declare i32 @llvm.bitreverse.i32(i32)
+
+; CHECK-LABEL: @test1(
+; CHECK: ret i1 false
+define i1 @test1(i32 %arg) {
+ %a = or i32 %arg, 1
+ %b = call i32 @llvm.bitreverse.i32(i32 %a)
+ %res = icmp eq i32 %b, 0
+ ret i1 %res
+}
+
+; CHECK-LABEL: @test2(
+; CHECK: ret i1 false
+define i1 @test2(i32 %arg) {
+ %a = or i32 %arg, 1024
+ %b = call i32 @llvm.bitreverse.i32(i32 %a)
+ %res = icmp eq i32 %b, 0
+ ret i1 %res
+}
+
+; CHECK-LABEL: @test3(
+; CHECK: ret i1 false
+define i1 @test3(i32 %arg) {
+ %a = and i32 %arg, 1
+ %b = call i32 @llvm.bitreverse.i32(i32 %a)
+ %and = and i32 %b, 1
+ %res = icmp eq i32 %and, 1
+ ret i1 %res
+}