diff options
Diffstat (limited to 'llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll b/llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll new file mode 100644 index 00000000000..cd1523a3b06 --- /dev/null +++ b/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} |
