xref: /llvm-project/llvm/test/Transforms/InstCombine/zext-ctlz-trunc-to-ctlz-add.ll (revision 56c091ea7106507b36015297ee9005c9d5fab0bf)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3
4declare i3 @llvm.ctlz.i3 (i3 , i1)
5declare i32 @llvm.ctlz.i32 (i32, i1)
6declare i34 @llvm.ctlz.i34 (i34, i1)
7declare <2 x i33> @llvm.ctlz.v2i33 (<2 x i33>, i1)
8declare <2 x i32> @llvm.ctlz.v2i32 (<2 x i32>, i1)
9declare <vscale x 2 x i64> @llvm.ctlz.nxv2i64 (<vscale x 2 x i64>, i1)
10declare <vscale x 2 x i63> @llvm.ctlz.nxv2i63 (<vscale x 2 x i63>, i1)
11declare void @use(<2 x i32>)
12declare void @use1(<vscale x 2 x i63>)
13
14define i16 @trunc_ctlz_zext_i16_i32(i16 %x) {
15; CHECK-LABEL: @trunc_ctlz_zext_i16_i32(
16; CHECK-NEXT:    [[TMP1:%.*]] = call range(i16 0, 17) i16 @llvm.ctlz.i16(i16 [[X:%.*]], i1 false)
17; CHECK-NEXT:    [[ZZ:%.*]] = add nuw nsw i16 [[TMP1]], 16
18; CHECK-NEXT:    ret i16 [[ZZ]]
19;
20  %z = zext i16 %x to i32
21  %p = call i32 @llvm.ctlz.i32(i32 %z, i1 false)
22  %zz = trunc i32 %p to i16
23  ret i16 %zz
24}
25
26; Fixed vector case
27
28define <2 x i8> @trunc_ctlz_zext_v2i8_v2i33(<2 x i8> %x) {
29; CHECK-LABEL: @trunc_ctlz_zext_v2i8_v2i33(
30; CHECK-NEXT:    [[TMP1:%.*]] = call range(i8 0, 9) <2 x i8> @llvm.ctlz.v2i8(<2 x i8> [[X:%.*]], i1 true)
31; CHECK-NEXT:    [[ZZ:%.*]] = add nuw nsw <2 x i8> [[TMP1]], splat (i8 25)
32; CHECK-NEXT:    ret <2 x i8> [[ZZ]]
33;
34  %z = zext <2 x i8> %x to <2 x i33>
35  %p = call <2 x i33> @llvm.ctlz.v2i33(<2 x i33> %z, i1 true)
36  %zz = trunc <2 x i33> %p to <2 x i8>
37  ret <2 x i8> %zz
38}
39
40; Scalable vector case
41
42define <vscale x 2 x i16> @trunc_ctlz_zext_nxv2i16_nxv2i64(<vscale x 2 x i16> %x) {
43; CHECK-LABEL: @trunc_ctlz_zext_nxv2i16_nxv2i64(
44; CHECK-NEXT:    [[TMP1:%.*]] = call range(i16 0, 17) <vscale x 2 x i16> @llvm.ctlz.nxv2i16(<vscale x 2 x i16> [[X:%.*]], i1 false)
45; CHECK-NEXT:    [[ZZ:%.*]] = add nuw nsw <vscale x 2 x i16> [[TMP1]], splat (i16 48)
46; CHECK-NEXT:    ret <vscale x 2 x i16> [[ZZ]]
47;
48  %z = zext <vscale x 2 x i16> %x to <vscale x 2 x i64>
49  %p = call <vscale x 2 x i64> @llvm.ctlz.nxv2i64(<vscale x 2 x i64> %z, i1 false)
50  %zz = trunc <vscale x 2 x i64> %p to <vscale x 2 x i16>
51  ret <vscale x 2 x i16> %zz
52}
53
54; Multiple uses of ctlz for which the opt is disabled
55
56define <2 x i17> @trunc_ctlz_zext_v2i17_v2i32_multiple_uses(<2 x i17> %x) {
57; CHECK-LABEL: @trunc_ctlz_zext_v2i17_v2i32_multiple_uses(
58; CHECK-NEXT:    [[Z:%.*]] = zext <2 x i17> [[X:%.*]] to <2 x i32>
59; CHECK-NEXT:    [[P:%.*]] = call range(i32 15, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[Z]], i1 false)
60; CHECK-NEXT:    [[ZZ:%.*]] = trunc nuw nsw <2 x i32> [[P]] to <2 x i17>
61; CHECK-NEXT:    call void @use(<2 x i32> [[P]])
62; CHECK-NEXT:    ret <2 x i17> [[ZZ]]
63;
64  %z = zext <2 x i17> %x to <2 x i32>
65  %p = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %z, i1 false)
66  %zz = trunc <2 x i32> %p to <2 x i17>
67  call void @use(<2 x i32> %p)
68  ret <2 x i17> %zz
69}
70
71; Multiple uses of zext
72
73define <vscale x 2 x i16> @trunc_ctlz_zext_nxv2i16_nxv2i63_multiple_uses(<vscale x 2 x i16> %x) {
74; CHECK-LABEL: @trunc_ctlz_zext_nxv2i16_nxv2i63_multiple_uses(
75; CHECK-NEXT:    [[Z:%.*]] = zext <vscale x 2 x i16> [[X:%.*]] to <vscale x 2 x i63>
76; CHECK-NEXT:    [[TMP1:%.*]] = call range(i16 0, 17) <vscale x 2 x i16> @llvm.ctlz.nxv2i16(<vscale x 2 x i16> [[X]], i1 true)
77; CHECK-NEXT:    [[ZZ:%.*]] = add nuw nsw <vscale x 2 x i16> [[TMP1]], splat (i16 47)
78; CHECK-NEXT:    call void @use1(<vscale x 2 x i63> [[Z]])
79; CHECK-NEXT:    ret <vscale x 2 x i16> [[ZZ]]
80;
81  %z = zext <vscale x 2 x i16> %x to <vscale x 2 x i63>
82  %p = call <vscale x 2 x i63> @llvm.ctlz.nxv2i63(<vscale x 2 x i63> %z, i1 true)
83  %zz = trunc <vscale x 2 x i63> %p to <vscale x 2 x i16>
84  call void @use1(<vscale x 2 x i63> %z)
85  ret <vscale x 2 x i16> %zz
86}
87
88; Negative case where types of x and zz don't match
89
90define i16 @trunc_ctlz_zext_i10_i32(i10 %x) {
91; CHECK-LABEL: @trunc_ctlz_zext_i10_i32(
92; CHECK-NEXT:    [[Z:%.*]] = zext i10 [[X:%.*]] to i32
93; CHECK-NEXT:    [[P:%.*]] = call range(i32 22, 33) i32 @llvm.ctlz.i32(i32 [[Z]], i1 false)
94; CHECK-NEXT:    [[ZZ:%.*]] = trunc nuw nsw i32 [[P]] to i16
95; CHECK-NEXT:    ret i16 [[ZZ]]
96;
97  %z = zext i10 %x to i32
98  %p = call i32 @llvm.ctlz.i32(i32 %z, i1 false)
99  %zz = trunc i32 %p to i16
100  ret i16 %zz
101}
102
103; Test width difference of more than log2 between x and t
104; TODO: Enable the opt for this case if it is proved that the
105; opt works for all combinations of bitwidth of zext src and dst.
106; Refer : https://reviews.llvm.org/D103788
107
108define i3 @trunc_ctlz_zext_i3_i34(i3 %x) {
109; CHECK-LABEL: @trunc_ctlz_zext_i3_i34(
110; CHECK-NEXT:    [[Z:%.*]] = zext i3 [[X:%.*]] to i34
111; CHECK-NEXT:    [[P:%.*]] = call range(i34 31, 35) i34 @llvm.ctlz.i34(i34 [[Z]], i1 false)
112; CHECK-NEXT:    [[T:%.*]] = trunc i34 [[P]] to i3
113; CHECK-NEXT:    ret i3 [[T]]
114;
115  %z = zext i3 %x to i34
116  %p = call i34 @llvm.ctlz.i34(i34 %z, i1 false)
117  %t = trunc i34 %p to i3
118  ret i3 %t
119}
120