xref: /llvm-project/llvm/test/CodeGen/AArch64/icmp-shift-opt.ll (revision 8eeabf674ca0f71aaf8120ebe387ea8e8f4e686c)
1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
2; RUN: llc < %s -mtriple=arm64-eabi | FileCheck %s
3
4; Optimize expanded SRL/SHL used as an input of
5; SETCC comparing it with zero by removing rotation.
6;
7; See https://bugs.llvm.org/show_bug.cgi?id=50197
8define i128 @opt_setcc_lt_power_of_2(i128 %a) nounwind {
9; CHECK-LABEL: opt_setcc_lt_power_of_2:
10; CHECK:       // %bb.0:
11; CHECK-NEXT:  .LBB0_1: // %loop
12; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
13; CHECK-NEXT:    adds x0, x0, #1
14; CHECK-NEXT:    cinc x1, x1, hs
15; CHECK-NEXT:    orr x8, x1, x0, lsr #60
16; CHECK-NEXT:    cbnz x8, .LBB0_1
17; CHECK-NEXT:  // %bb.2: // %exit
18; CHECK-NEXT:    ret
19  br label %loop
20
21loop:
22  %phi.a = phi i128 [ %a, %0 ], [ %inc, %loop ]
23  %inc = add i128 %phi.a, 1
24  %cmp = icmp ult i128 %inc, 1152921504606846976
25  br i1 %cmp, label %exit, label %loop
26
27exit:
28  ret i128 %inc
29}
30
31define i1 @opt_setcc_srl_eq_zero(i128 %a) nounwind {
32; CHECK-LABEL: opt_setcc_srl_eq_zero:
33; CHECK:       // %bb.0:
34; CHECK-NEXT:    orr x8, x1, x0, lsr #17
35; CHECK-NEXT:    cmp x8, #0
36; CHECK-NEXT:    cset w0, eq
37; CHECK-NEXT:    ret
38   %srl = lshr i128 %a, 17
39   %cmp = icmp eq i128 %srl, 0
40   ret i1 %cmp
41}
42
43define i1 @opt_setcc_srl_ne_zero(i128 %a) nounwind {
44; CHECK-LABEL: opt_setcc_srl_ne_zero:
45; CHECK:       // %bb.0:
46; CHECK-NEXT:    orr x8, x1, x0, lsr #17
47; CHECK-NEXT:    cmp x8, #0
48; CHECK-NEXT:    cset w0, ne
49; CHECK-NEXT:    ret
50   %srl = lshr i128 %a, 17
51   %cmp = icmp ne i128 %srl, 0
52   ret i1 %cmp
53}
54
55define i1 @opt_setcc_shl_eq_zero(i128 %a) nounwind {
56; CHECK-LABEL: opt_setcc_shl_eq_zero:
57; CHECK:       // %bb.0:
58; CHECK-NEXT:    orr x8, x0, x1, lsl #17
59; CHECK-NEXT:    cmp x8, #0
60; CHECK-NEXT:    cset w0, eq
61; CHECK-NEXT:    ret
62   %shl = shl i128 %a, 17
63   %cmp = icmp eq i128 %shl, 0
64   ret i1 %cmp
65}
66
67define i1 @opt_setcc_shl_ne_zero(i128 %a) nounwind {
68; CHECK-LABEL: opt_setcc_shl_ne_zero:
69; CHECK:       // %bb.0:
70; CHECK-NEXT:    orr x8, x0, x1, lsl #17
71; CHECK-NEXT:    cmp x8, #0
72; CHECK-NEXT:    cset w0, ne
73; CHECK-NEXT:    ret
74   %shl = shl i128 %a, 17
75   %cmp = icmp ne i128 %shl, 0
76   ret i1 %cmp
77}
78
79; Negative test: optimization should not be applied if shift has multiple users.
80define i1 @opt_setcc_shl_eq_zero_multiple_shl_users(i128 %a) nounwind {
81; CHECK-LABEL: opt_setcc_shl_eq_zero_multiple_shl_users:
82; CHECK:       // %bb.0:
83; CHECK-NEXT:    stp x30, x19, [sp, #-16]! // 16-byte Folded Spill
84; CHECK-NEXT:    extr x1, x1, x0, #47
85; CHECK-NEXT:    lsl x0, x0, #17
86; CHECK-NEXT:    orr x8, x0, x1
87; CHECK-NEXT:    cmp x8, #0
88; CHECK-NEXT:    cset w19, eq
89; CHECK-NEXT:    bl use
90; CHECK-NEXT:    mov w0, w19
91; CHECK-NEXT:    ldp x30, x19, [sp], #16 // 16-byte Folded Reload
92; CHECK-NEXT:    ret
93   %shl = shl i128 %a, 17
94   %cmp = icmp eq i128 %shl, 0
95   call void @use(i128 %shl)
96   ret i1 %cmp
97}
98
99; Check that optimization is applied to DAG having appropriate shape
100; even if there were no actual shift's expansion.
101define i1 @opt_setcc_expanded_shl_correct_shifts(i64 %a, i64 %b) nounwind {
102; CHECK-LABEL: opt_setcc_expanded_shl_correct_shifts:
103; CHECK:       // %bb.0:
104; CHECK-NEXT:    orr x8, x1, x0, lsl #17
105; CHECK-NEXT:    cmp x8, #0
106; CHECK-NEXT:    cset w0, eq
107; CHECK-NEXT:    ret
108  %shl.a = shl i64 %a, 17
109  %srl.b = lshr i64 %b, 47
110  %or.0 = or i64 %shl.a, %srl.b
111  %shl.b = shl i64 %b, 17
112  %or.1 = or i64 %or.0, %shl.b
113  %cmp = icmp eq i64 %or.1, 0
114  ret i1 %cmp
115}
116
117; Negative test: optimization should not be applied as
118; constants used in shifts do not match.
119define i1 @opt_setcc_expanded_shl_wrong_shifts(i64 %a, i64 %b) nounwind {
120; CHECK-LABEL: opt_setcc_expanded_shl_wrong_shifts:
121; CHECK:       // %bb.0:
122; CHECK-NEXT:    extr x8, x0, x1, #47
123; CHECK-NEXT:    orr x8, x8, x1, lsl #18
124; CHECK-NEXT:    cmp x8, #0
125; CHECK-NEXT:    cset w0, eq
126; CHECK-NEXT:    ret
127  %shl.a = shl i64 %a, 17
128  %srl.b = lshr i64 %b, 47
129  %or.0 = or i64 %shl.a, %srl.b
130  %shl.b = shl i64 %b, 18
131  %or.1 = or i64 %or.0, %shl.b
132  %cmp = icmp eq i64 %or.1, 0
133  ret i1 %cmp
134}
135
136define i1 @opt_setcc_shl_ne_zero_i256(i256 %a) nounwind {
137; CHECK-LABEL: opt_setcc_shl_ne_zero_i256:
138; CHECK:       // %bb.0:
139; CHECK-NEXT:    orr x8, x2, x0
140; CHECK-NEXT:    orr x8, x1, x8
141; CHECK-NEXT:    orr x8, x8, x3, lsl #17
142; CHECK-NEXT:    cmp x8, #0
143; CHECK-NEXT:    cset w0, ne
144; CHECK-NEXT:    ret
145  %shl = shl i256 %a, 17
146  %cmp = icmp ne i256 %shl, 0
147  ret i1 %cmp
148}
149
150declare void @use(i128 %a)
151