diff options
Diffstat (limited to 'test/Transforms/InstSimplify/shift-knownbits.ll')
| -rw-r--r-- | test/Transforms/InstSimplify/shift-knownbits.ll | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/test/Transforms/InstSimplify/shift-knownbits.ll b/test/Transforms/InstSimplify/shift-knownbits.ll index f50ea0582c6c..63b9b76fd22f 100644 --- a/test/Transforms/InstSimplify/shift-knownbits.ll +++ b/test/Transforms/InstSimplify/shift-knownbits.ll @@ -145,3 +145,46 @@ define i1 @shl_i1(i1 %a, i1 %b) { ret i1 %shl } +; Simplify count leading/trailing zeros to zero if all valid bits are shifted out. + +declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone +declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone +declare <2 x i8> @llvm.cttz.v2i8(<2 x i8>, i1) nounwind readnone +declare <2 x i8> @llvm.ctlz.v2i8(<2 x i8>, i1) nounwind readnone + +define i32 @lshr_ctlz_zero_is_undef(i32 %x) { +; CHECK-LABEL: @lshr_ctlz_zero_is_undef( +; CHECK-NEXT: ret i32 0 +; + %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 true) + %sh = lshr i32 %ct, 5 + ret i32 %sh +} + +define i32 @lshr_cttz_zero_is_undef(i32 %x) { +; CHECK-LABEL: @lshr_cttz_zero_is_undef( +; CHECK-NEXT: ret i32 0 +; + %ct = call i32 @llvm.cttz.i32(i32 %x, i1 true) + %sh = lshr i32 %ct, 5 + ret i32 %sh +} + +define <2 x i8> @lshr_ctlz_zero_is_undef_splat_vec(<2 x i8> %x) { +; CHECK-LABEL: @lshr_ctlz_zero_is_undef_splat_vec( +; CHECK-NEXT: ret <2 x i8> zeroinitializer +; + %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true) + %sh = lshr <2 x i8> %ct, <i8 3, i8 3> + ret <2 x i8> %sh +} + +define <2 x i8> @lshr_cttz_zero_is_undef_splat_vec(<2 x i8> %x) { +; CHECK-LABEL: @lshr_cttz_zero_is_undef_splat_vec( +; CHECK-NEXT: ret <2 x i8> zeroinitializer +; + %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true) + %sh = lshr <2 x i8> %ct, <i8 3, i8 3> + ret <2 x i8> %sh +} + |