xref: /llvm-project/llvm/test/CodeGen/ARM/icmp-shift-opt.ll (revision a70d5e25f32ebd5f1d1c394312036a37591e998b)
1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
2; RUN: llc -mtriple=armv7 %s -o - | 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 i64 @opt_setcc_lt_power_of_2(i64 %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 r0, r0, #1
14; CHECK-NEXT:    adc r1, r1, #0
15; CHECK-NEXT:    orrs r2, r1, r0, lsr #16
16; CHECK-NEXT:    bne .LBB0_1
17; CHECK-NEXT:  @ %bb.2: @ %exit
18; CHECK-NEXT:    bx lr
19  br label %loop
20
21loop:
22  %phi.a = phi i64 [ %a, %0 ], [ %inc, %loop ]
23  %inc = add i64 %phi.a, 1
24  %cmp = icmp ult i64 %inc, 65536
25  br i1 %cmp, label %exit, label %loop
26
27exit:
28  ret i64 %inc
29}
30
31define i1 @opt_setcc_srl_eq_zero(i64 %a) nounwind {
32; CHECK-LABEL: opt_setcc_srl_eq_zero:
33; CHECK:       @ %bb.0:
34; CHECK-NEXT:    orr r0, r1, r0, lsr #17
35; CHECK-NEXT:    clz r0, r0
36; CHECK-NEXT:    lsr r0, r0, #5
37; CHECK-NEXT:    bx lr
38   %srl = lshr i64 %a, 17
39   %cmp = icmp eq i64 %srl, 0
40   ret i1 %cmp
41}
42
43define i1 @opt_setcc_srl_ne_zero(i64 %a) nounwind {
44; CHECK-LABEL: opt_setcc_srl_ne_zero:
45; CHECK:       @ %bb.0:
46; CHECK-NEXT:    orrs r0, r1, r0, lsr #17
47; CHECK-NEXT:    movwne r0, #1
48; CHECK-NEXT:    bx lr
49   %srl = lshr i64 %a, 17
50   %cmp = icmp ne i64 %srl, 0
51   ret i1 %cmp
52}
53
54define i1 @opt_setcc_shl_eq_zero(i64 %a) nounwind {
55; CHECK-LABEL: opt_setcc_shl_eq_zero:
56; CHECK:       @ %bb.0:
57; CHECK-NEXT:    orr r0, r0, r1, lsl #17
58; CHECK-NEXT:    clz r0, r0
59; CHECK-NEXT:    lsr r0, r0, #5
60; CHECK-NEXT:    bx lr
61   %shl = shl i64 %a, 17
62   %cmp = icmp eq i64 %shl, 0
63   ret i1 %cmp
64}
65
66define i1 @opt_setcc_shl_ne_zero(i64 %a) nounwind {
67; CHECK-LABEL: opt_setcc_shl_ne_zero:
68; CHECK:       @ %bb.0:
69; CHECK-NEXT:    orrs r0, r0, r1, lsl #17
70; CHECK-NEXT:    movwne r0, #1
71; CHECK-NEXT:    bx lr
72   %shl = shl i64 %a, 17
73   %cmp = icmp ne i64 %shl, 0
74   ret i1 %cmp
75}
76
77; Negative test: optimization should not be applied if shift has multiple users.
78define i1 @opt_setcc_shl_eq_zero_multiple_shl_users(i64 %a) nounwind {
79; CHECK-LABEL: opt_setcc_shl_eq_zero_multiple_shl_users:
80; CHECK:       @ %bb.0:
81; CHECK-NEXT:    push {r4, r5, r11, lr}
82; CHECK-NEXT:    mov r4, r0
83; CHECK-NEXT:    lsl r0, r1, #17
84; CHECK-NEXT:    orr r5, r0, r4, lsr #15
85; CHECK-NEXT:    lsl r0, r4, #17
86; CHECK-NEXT:    mov r1, r5
87; CHECK-NEXT:    bl use
88; CHECK-NEXT:    orr r0, r5, r4, lsl #17
89; CHECK-NEXT:    clz r0, r0
90; CHECK-NEXT:    lsr r0, r0, #5
91; CHECK-NEXT:    pop {r4, r5, r11, pc}
92   %shl = shl i64 %a, 17
93   %cmp = icmp eq i64 %shl, 0
94   call void @use(i64 %shl)
95   ret i1 %cmp
96}
97
98; Check that optimization is applied to DAG having appropriate shape
99; even if there were no actual shift's expansion.
100define i1 @opt_setcc_expanded_shl_correct_shifts(i32 %a, i32 %b) nounwind {
101; CHECK-LABEL: opt_setcc_expanded_shl_correct_shifts:
102; CHECK:       @ %bb.0:
103; CHECK-NEXT:    orr r0, r1, r0, lsl #17
104; CHECK-NEXT:    clz r0, r0
105; CHECK-NEXT:    lsr r0, r0, #5
106; CHECK-NEXT:    bx lr
107  %shl.a = shl i32 %a, 17
108  %srl.b = lshr i32 %b, 15
109  %or.0 = or i32 %shl.a, %srl.b
110  %shl.b = shl i32 %b, 17
111  %or.1 = or i32 %or.0, %shl.b
112  %cmp = icmp eq i32 %or.1, 0
113  ret i1 %cmp
114}
115
116; Negative test: optimization should not be applied as
117; constants used in shifts do not match.
118define i1 @opt_setcc_expanded_shl_wrong_shifts(i32 %a, i32 %b) nounwind {
119; CHECK-LABEL: opt_setcc_expanded_shl_wrong_shifts:
120; CHECK:       @ %bb.0:
121; CHECK-NEXT:    lsl r0, r0, #17
122; CHECK-NEXT:    orr r0, r0, r1, lsr #15
123; CHECK-NEXT:    orr r0, r0, r1, lsl #18
124; CHECK-NEXT:    clz r0, r0
125; CHECK-NEXT:    lsr r0, r0, #5
126; CHECK-NEXT:    bx lr
127  %shl.a = shl i32 %a, 17
128  %srl.b = lshr i32 %b, 15
129  %or.0 = or i32 %shl.a, %srl.b
130  %shl.b = shl i32 %b, 18
131  %or.1 = or i32 %or.0, %shl.b
132  %cmp = icmp eq i32 %or.1, 0
133  ret i1 %cmp
134}
135
136define i1 @opt_setcc_shl_ne_zero_i128(i128 %a) nounwind {
137; CHECK-LABEL: opt_setcc_shl_ne_zero_i128:
138; CHECK:       @ %bb.0:
139; CHECK-NEXT:    orr r0, r2, r0
140; CHECK-NEXT:    orr r0, r1, r0
141; CHECK-NEXT:    orr r1, r0, r3
142; CHECK-NEXT:    lsl r1, r1, #17
143; CHECK-NEXT:    orrs r0, r1, r0, lsr #15
144; CHECK-NEXT:    movwne r0, #1
145; CHECK-NEXT:    bx lr
146  %shl = shl i128 %a, 17
147  %cmp = icmp ne i128 %shl, 0
148  ret i1 %cmp
149}
150
151declare void @use(i64 %a)
152