1; RUN: opt < %s -instcombine -S | FileCheck %s
2
3; CHECK-LABEL: @sdiv1(
4; CHECK: sdiv i32 %x, 8
5define i32 @sdiv1(i32 %x) {
6  %y = sdiv i32 %x, 8
7  ret i32 %y
8}
9
10; CHECK-LABEL: @sdiv2(
11; CHECK: ashr exact i32 %x, 3
12define i32 @sdiv2(i32 %x) {
13  %y = sdiv exact i32 %x, 8
14  ret i32 %y
15}
16
17; CHECK-LABEL: @sdiv3(
18; CHECK: %y = srem i32 %x, 3
19; CHECK: %z = sub i32 %x, %y
20; CHECK: ret i32 %z
21define i32 @sdiv3(i32 %x) {
22  %y = sdiv i32 %x, 3
23  %z = mul i32 %y, 3
24  ret i32 %z
25}
26
27; CHECK-LABEL: @sdiv4(
28; CHECK: ret i32 %x
29define i32 @sdiv4(i32 %x) {
30  %y = sdiv exact i32 %x, 3
31  %z = mul i32 %y, 3
32  ret i32 %z
33}
34
35; CHECK: i32 @sdiv5
36; CHECK: %y = srem i32 %x, 3
37; CHECK: %z = sub i32 %y, %x
38; CHECK: ret i32 %z
39define i32 @sdiv5(i32 %x) {
40  %y = sdiv i32 %x, 3
41  %z = mul i32 %y, -3
42  ret i32 %z
43}
44
45; CHECK-LABEL: @sdiv6(
46; CHECK: %z = sub i32 0, %x
47; CHECK: ret i32 %z
48define i32 @sdiv6(i32 %x) {
49  %y = sdiv exact i32 %x, 3
50  %z = mul i32 %y, -3
51  ret i32 %z
52}
53
54; CHECK-LABEL: @udiv1(
55; CHECK: ret i32 %x
56define i32 @udiv1(i32 %x, i32 %w) {
57  %y = udiv exact i32 %x, %w
58  %z = mul i32 %y, %w
59  ret i32 %z
60}
61
62; CHECK-LABEL: @udiv2(
63; CHECK: %z = lshr exact i32 %x, %w
64; CHECK: ret i32 %z
65define i32 @udiv2(i32 %x, i32 %w) {
66  %y = shl i32 1, %w
67  %z = udiv exact i32 %x, %y
68  ret i32 %z
69}
70
71; CHECK-LABEL: @ashr1(
72; CHECK: %B = ashr exact i64 %A, 2
73; CHECK: ret i64 %B
74define i64 @ashr1(i64 %X) nounwind {
75  %A = shl i64 %X, 8
76  %B = ashr i64 %A, 2   ; X/4
77  ret i64 %B
78}
79
80; PR9120
81; CHECK-LABEL: @ashr_icmp1(
82; CHECK: %B = icmp eq i64 %X, 0
83; CHECK: ret i1 %B
84define i1 @ashr_icmp1(i64 %X) nounwind {
85  %A = ashr exact i64 %X, 2   ; X/4
86  %B = icmp eq i64 %A, 0
87  ret i1 %B
88}
89
90; CHECK-LABEL: @ashr_icmp2(
91; CHECK: %Z = icmp slt i64 %X, 16
92; CHECK: ret i1 %Z
93define i1 @ashr_icmp2(i64 %X) nounwind {
94 %Y = ashr exact i64 %X, 2  ; x / 4
95 %Z = icmp slt i64 %Y, 4    ; x < 16
96 ret i1 %Z
97}
98
99; PR9998
100; Make sure we don't transform the ashr here into an sdiv
101; CHECK-LABEL: @pr9998(
102; CHECK:      [[BIT:%[A-Za-z0-9.]+]] = and i32 %V, 1
103; CHECK-NEXT: [[CMP:%[A-Za-z0-9.]+]] = icmp ne i32 [[BIT]], 0
104; CHECK-NEXT: ret i1 [[CMP]]
105define i1 @pr9998(i32 %V) nounwind {
106entry:
107  %W = shl i32 %V, 31
108  %X = ashr exact i32 %W, 31
109  %Y = sext i32 %X to i64
110  %Z = icmp ugt i64 %Y, 7297771788697658747
111  ret i1 %Z
112}
113
114
115
116; CHECK-LABEL: @udiv_icmp1(
117; CHECK: icmp ne i64 %X, 0
118define i1 @udiv_icmp1(i64 %X) nounwind {
119  %A = udiv exact i64 %X, 5   ; X/5
120  %B = icmp ne i64 %A, 0
121  ret i1 %B
122}
123
124; CHECK-LABEL: @sdiv_icmp1(
125; CHECK: icmp eq i64 %X, 0
126define i1 @sdiv_icmp1(i64 %X) nounwind {
127  %A = sdiv exact i64 %X, 5   ; X/5 == 0 --> x == 0
128  %B = icmp eq i64 %A, 0
129  ret i1 %B
130}
131
132; CHECK-LABEL: @sdiv_icmp2(
133; CHECK: icmp eq i64 %X, 5
134define i1 @sdiv_icmp2(i64 %X) nounwind {
135  %A = sdiv exact i64 %X, 5   ; X/5 == 1 --> x == 5
136  %B = icmp eq i64 %A, 1
137  ret i1 %B
138}
139
140; CHECK-LABEL: @sdiv_icmp3(
141; CHECK: icmp eq i64 %X, -5
142define i1 @sdiv_icmp3(i64 %X) nounwind {
143  %A = sdiv exact i64 %X, 5   ; X/5 == -1 --> x == -5
144  %B = icmp eq i64 %A, -1
145  ret i1 %B
146}
147
148; CHECK-LABEL: @sdiv_icmp4(
149; CHECK: icmp eq i64 %X, 0
150define i1 @sdiv_icmp4(i64 %X) nounwind {
151  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
152  %B = icmp eq i64 %A, 0
153  ret i1 %B
154}
155
156; CHECK-LABEL: @sdiv_icmp5(
157; CHECK: icmp eq i64 %X, -5
158define i1 @sdiv_icmp5(i64 %X) nounwind {
159  %A = sdiv exact i64 %X, -5   ; X/-5 == 1 --> x == -5
160  %B = icmp eq i64 %A, 1
161  ret i1 %B
162}
163
164; CHECK-LABEL: @sdiv_icmp6(
165; CHECK: icmp eq i64 %X, 5
166define i1 @sdiv_icmp6(i64 %X) nounwind {
167  %A = sdiv exact i64 %X, -5   ; X/-5 == 1 --> x == 5
168  %B = icmp eq i64 %A, -1
169  ret i1 %B
170}
171
172