Imported Upstream version 5.18.0.205

Former-commit-id: 7f59f7e792705db773f1caecdaa823092f4e2927

external/llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll

@@ -0,0 +1,51 @@
+; RUN: opt < %s -S -instcombine | FileCheck %s
+
+declare i8 @llvm.bitreverse.i8(i8)
+declare i32 @llvm.bitreverse.i32(i32)
+
+; CHECK-LABEL: @test1
+; CHECK: ret i1 true
+define i1 @test1(i32 %arg) {
+  %a = or i32 %arg, 4294901760
+  %b = call i32 @llvm.bitreverse.i32(i32 %a)
+  %and = and i32 %b, 65535
+  %res = icmp eq i32 %and, 65535
+  ret i1 %res
+}
+
+; CHECK-LABEL: @test2
+; CHECK: ret i1 true
+define i1 @test2(i32 %arg) {
+  %a = or i32 %arg, 1
+  %b = call i32 @llvm.bitreverse.i32(i32 %a)
+  %c = and i32 %b, 2147483648
+  %d = call i32 @llvm.bitreverse.i32(i32 %c)
+  %res = icmp eq i32 %d, 1
+  ret i1 %res
+}
+
+; CHECK-LABEL: @test3
+; CHECK: ret i1 false
+define i1 @test3(i32 %arg) {
+  %a = or i32 %arg, 65536
+  %b = call i32 @llvm.bitreverse.i32(i32 %a)
+  %and = and i32 %b, 32768
+  %res = icmp eq i32 %and, 0
+  ret i1 %res
+}
+
+; CHECK-LABEL: @add_bitreverse
+; Make sure we process range metadata on bitreverse
+define i8 @add_bitreverse(i8 %a) {
+  %b = and i8 %a, 252
+  ; known bits for the bitreverse will say the result is in the range [0, 64)
+  ; but the metadata says [0, 16). So make sure the range metadata wins.
+  ;    add %reverse, 1111 0000
+  ; should become
+  ;    or  %reverse, 1111 0000
+  %reverse = call i8 @llvm.bitreverse.i8(i8 %b), !range !1
+  %c = add i8 %reverse, -16
+; CHECK: or i8 %reverse, -16
+  ret i8 %c
+}
+!1 = !{i8 0, i8 16}