xref: /llvm-project/llvm/test/Analysis/ValueTracking/knownzero-shift.ll (revision 38fffa630ee80163dc65e759392ad29798905679) 
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -passes=instsimplify -S < %s | FileCheck %s
3
4define i1 @test(i8 %p, ptr %pq) {
5; CHECK-LABEL: @test(
6; CHECK-NEXT:    ret i1 false
7;
8  %q = load i8, ptr %pq, !range !0 ; %q is known nonzero; no known bits
9  %1 = or i8 %p, 2                 ; %1[1] = 1
10  %2 = and i8 %1, 254              ; %2[0] = 0, %2[1] = 1
11  %A = lshr i8 %2, 1               ; We should know that %A is nonzero.
12  %x = icmp eq i8 %A, 0
13  ret i1 %x
14}
15
16!0 = !{ i8 1, i8 5 }
17
18; The following cases only get folded by InstCombine,
19; see InstCombine/shift-shift.ll. If we wanted to,
20; we could explicitly handle them in InstSimplify as well.
21
22define i32 @shl_shl(i32 %A) {
23; CHECK-LABEL: @shl_shl(
24; CHECK-NEXT:    [[B:%.*]] = shl i32 [[A:%.*]], 6
25; CHECK-NEXT:    [[C:%.*]] = shl i32 [[B]], 28
26; CHECK-NEXT:    ret i32 [[C]]
27;
28  %B = shl i32 %A, 6
29  %C = shl i32 %B, 28
30  ret i32 %C
31}
32
33define <2 x i33> @shl_shl_splat_vec(<2 x i33> %A) {
34; CHECK-LABEL: @shl_shl_splat_vec(
35; CHECK-NEXT:    [[B:%.*]] = shl <2 x i33> [[A:%.*]], splat (i33 5)
36; CHECK-NEXT:    [[C:%.*]] = shl <2 x i33> [[B]], splat (i33 28)
37; CHECK-NEXT:    ret <2 x i33> [[C]]
38;
39  %B = shl <2 x i33> %A, <i33 5, i33 5>
40  %C = shl <2 x i33> %B, <i33 28, i33 28>
41  ret <2 x i33> %C
42}
43
44; FIXME
45
46define <2 x i33> @shl_shl_vec(<2 x i33> %A) {
47; CHECK-LABEL: @shl_shl_vec(
48; CHECK-NEXT:    [[B:%.*]] = shl <2 x i33> [[A:%.*]], <i33 6, i33 5>
49; CHECK-NEXT:    [[C:%.*]] = shl <2 x i33> [[B]], <i33 27, i33 28>
50; CHECK-NEXT:    ret <2 x i33> [[C]]
51;
52  %B = shl <2 x i33> %A, <i33 6, i33 5>
53  %C = shl <2 x i33> %B, <i33 27, i33 28>
54  ret <2 x i33> %C
55}
56
57define i232 @lshr_lshr(i232 %A) {
58; CHECK-LABEL: @lshr_lshr(
59; CHECK-NEXT:    [[B:%.*]] = lshr i232 [[A:%.*]], 231
60; CHECK-NEXT:    [[C:%.*]] = lshr i232 [[B]], 1
61; CHECK-NEXT:    ret i232 [[C]]
62;
63  %B = lshr i232 %A, 231
64  %C = lshr i232 %B, 1
65  ret i232 %C
66}
67
68define <2 x i32> @lshr_lshr_splat_vec(<2 x i32> %A) {
69; CHECK-LABEL: @lshr_lshr_splat_vec(
70; CHECK-NEXT:    [[B:%.*]] = lshr <2 x i32> [[A:%.*]], splat (i32 28)
71; CHECK-NEXT:    [[C:%.*]] = lshr <2 x i32> [[B]], splat (i32 4)
72; CHECK-NEXT:    ret <2 x i32> [[C]]
73;
74  %B = lshr <2 x i32> %A, <i32 28, i32 28>
75  %C = lshr <2 x i32> %B, <i32 4, i32 4>
76  ret <2 x i32> %C
77}
78
79define <2 x i32> @lshr_lshr_vec(<2 x i32> %A) {
80; CHECK-LABEL: @lshr_lshr_vec(
81; CHECK-NEXT:    [[B:%.*]] = lshr <2 x i32> [[A:%.*]], <i32 29, i32 28>
82; CHECK-NEXT:    [[C:%.*]] = lshr <2 x i32> [[B]], <i32 4, i32 5>
83; CHECK-NEXT:    ret <2 x i32> [[C]]
84;
85  %B = lshr <2 x i32> %A, <i32 29, i32 28>
86  %C = lshr <2 x i32> %B, <i32 4, i32 5>
87  ret <2 x i32> %C
88}
89
90