xref: /llvm-project/llvm/test/Transforms/InstCombine/shufflevector-div-rem.ll (revision 9d4557920f1008b64300928c4696bf22e923f71f) 
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instcombine -S -o - | FileCheck %s
3
4; This test case was added as a reproducer for a miscompile, where instcombine
5; introduced an
6;   srem <2 x i16> %1, <i16 undef, i16 2>
7; instruction, which makes the whole srem undefined (even if we only end up
8; extracting the second element in the vector).
9define i16 @test_srem_orig(i16 %a, i1 %cmp) {
10; CHECK-LABEL: @test_srem_orig(
11; CHECK-NEXT:    [[TMP1:%.*]] = srem i16 [[A:%.*]], 2
12; CHECK-NEXT:    [[T3:%.*]] = select i1 [[CMP:%.*]], i16 1, i16 [[TMP1]]
13; CHECK-NEXT:    ret i16 [[T3]]
14;
15  %splatinsert = insertelement <2 x i16> undef, i16 %a, i32 0
16  %splat = shufflevector <2 x i16> %splatinsert, <2 x i16> undef, <2 x i32> zeroinitializer
17  %t1 = select i1 %cmp, <2 x i16> <i16 1, i16 1>, <2 x i16> %splat
18  %t2 = srem <2 x i16> %t1, <i16 2, i16 2>
19  %t3 = extractelement <2 x i16> %t2, i32 1
20  ret i16 %t3
21}
22
23; This is basically a reduced version of test_srem_orig (based on what the
24; code would look like after a few iterations of instcombine, just before we
25; try to transform the shufflevector by doing
26; "evaluateInDifferentElementOrder".
27define <2 x i16> @test_srem(i16 %a, i1 %cmp) {
28; CHECK-LABEL: @test_srem(
29; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> <i16 poison, i16 undef>, i16 [[A:%.*]], i64 0
30; CHECK-NEXT:    [[T1:%.*]] = srem <2 x i16> [[SPLATINSERT]], <i16 2, i16 1>
31; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[T1]], <2 x i16> poison, <2 x i32> <i32 poison, i32 0>
32; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 77, i16 99>, <2 x i16> [[SPLAT_OP]]
33; CHECK-NEXT:    ret <2 x i16> [[T2]]
34;
35  %splatinsert = insertelement <2 x i16> undef, i16 %a, i32 0
36  %t1 = srem <2 x i16> %splatinsert, <i16 2, i16 1>
37  %splat.op = shufflevector <2 x i16> %t1, <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
38  %t2 = select i1 %cmp, <2 x i16> <i16 77, i16 99>, <2 x i16> %splat.op
39  ret <2 x i16> %t2
40}
41
42define <2 x i16> @test_urem(i16 %a, i1 %cmp) {
43; CHECK-LABEL: @test_urem(
44; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> <i16 poison, i16 undef>, i16 [[A:%.*]], i64 0
45; CHECK-NEXT:    [[T1:%.*]] = urem <2 x i16> [[SPLATINSERT]], <i16 3, i16 1>
46; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[T1]], <2 x i16> poison, <2 x i32> <i32 poison, i32 0>
47; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 77, i16 99>, <2 x i16> [[SPLAT_OP]]
48; CHECK-NEXT:    ret <2 x i16> [[T2]]
49;
50  %splatinsert = insertelement <2 x i16> undef, i16 %a, i32 0
51  %t1 = urem <2 x i16> %splatinsert, <i16 3, i16 1>
52  %splat.op = shufflevector <2 x i16> %t1, <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
53  %t2 = select i1 %cmp, <2 x i16> <i16 77, i16 99>, <2 x i16> %splat.op
54  ret <2 x i16> %t2
55}
56
57define <2 x i16> @test_sdiv(i16 %a, i1 %cmp) {
58; CHECK-LABEL: @test_sdiv(
59; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> <i16 poison, i16 undef>, i16 [[A:%.*]], i64 0
60; CHECK-NEXT:    [[T1:%.*]] = sdiv <2 x i16> [[SPLATINSERT]], <i16 2, i16 1>
61; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[T1]], <2 x i16> poison, <2 x i32> <i32 poison, i32 0>
62; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 77, i16 99>, <2 x i16> [[SPLAT_OP]]
63; CHECK-NEXT:    ret <2 x i16> [[T2]]
64;
65  %splatinsert = insertelement <2 x i16> undef, i16 %a, i32 0
66  %t1 = sdiv <2 x i16> %splatinsert, <i16 2, i16 1>
67  %splat.op = shufflevector <2 x i16> %t1, <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
68  %t2 = select i1 %cmp, <2 x i16> <i16 77, i16 99>, <2 x i16> %splat.op
69  ret <2 x i16> %t2
70}
71
72define <2 x i16> @test_udiv(i16 %a, i1 %cmp) {
73; CHECK-LABEL: @test_udiv(
74; CHECK-NEXT:    [[SPLATINSERT:%.*]] = insertelement <2 x i16> <i16 poison, i16 undef>, i16 [[A:%.*]], i64 0
75; CHECK-NEXT:    [[T1:%.*]] = udiv <2 x i16> [[SPLATINSERT]], <i16 3, i16 1>
76; CHECK-NEXT:    [[SPLAT_OP:%.*]] = shufflevector <2 x i16> [[T1]], <2 x i16> poison, <2 x i32> <i32 poison, i32 0>
77; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x i16> <i16 77, i16 99>, <2 x i16> [[SPLAT_OP]]
78; CHECK-NEXT:    ret <2 x i16> [[T2]]
79;
80  %splatinsert = insertelement <2 x i16> undef, i16 %a, i32 0
81  %t1 = udiv <2 x i16> %splatinsert, <i16 3, i16 1>
82  %splat.op = shufflevector <2 x i16> %t1, <2 x i16> undef, <2 x i32> <i32 undef, i32 0>
83  %t2 = select i1 %cmp, <2 x i16> <i16 77, i16 99>, <2 x i16> %splat.op
84  ret <2 x i16> %t2
85}
86
87; For fdiv we do not need to worry about div by undef. Verify that the
88; shufflevector is eliminated here.
89define <2 x float> @test_fdiv(float %a, float %b, i1 %cmp) {
90; CHECK-LABEL: @test_fdiv(
91; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x float> poison, float [[A:%.*]], i64 1
92; CHECK-NEXT:    [[SPLAT_OP:%.*]] = fdiv <2 x float> [[TMP1]], <float undef, float 3.000000e+00>
93; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x float> <float 7.700000e+01, float 9.900000e+01>, <2 x float> [[SPLAT_OP]]
94; CHECK-NEXT:    ret <2 x float> [[T2]]
95;
96  %splatinsert = insertelement <2 x float> undef, float %a, i32 0
97  %denom = insertelement <2 x float> <float 3.0, float undef>, float 1.0, i32 1
98  %t1 = fdiv <2 x float> %splatinsert, %denom
99  %splat.op = shufflevector <2 x float> %t1, <2 x float> undef, <2 x i32> <i32 undef, i32 0>
100  %t2 = select i1 %cmp, <2 x float> <float 77.0, float 99.0>, <2 x float> %splat.op
101  ret <2 x float> %t2
102}
103
104; For frem we do not need to worry about div by undef. Verify that the
105; shufflevector is eliminated here.
106define <2 x float> @test_frem(float %a, float %b, i1 %cmp) {
107; CHECK-LABEL: @test_frem(
108; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x float> poison, float [[A:%.*]], i64 1
109; CHECK-NEXT:    [[SPLAT_OP:%.*]] = frem <2 x float> [[TMP1]], <float undef, float 3.000000e+00>
110; CHECK-NEXT:    [[T2:%.*]] = select i1 [[CMP:%.*]], <2 x float> <float 7.700000e+01, float 9.900000e+01>, <2 x float> [[SPLAT_OP]]
111; CHECK-NEXT:    ret <2 x float> [[T2]]
112;
113  %splatinsert = insertelement <2 x float> undef, float %a, i32 0
114  %denom = insertelement <2 x float> <float 3.0, float undef>, float 1.0, i32 1
115  %t1 = frem <2 x float> %splatinsert, %denom
116  %splat.op = shufflevector <2 x float> %t1, <2 x float> undef, <2 x i32> <i32 undef, i32 0>
117  %t2 = select i1 %cmp, <2 x float> <float 77.0, float 99.0>, <2 x float> %splat.op
118  ret <2 x float> %t2
119}
120