1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z14 | FileCheck %s
;
; Check that signed comparisons against 0 are only eliminated if the "nsw"
; flag is present on the defining add (with register) instruction. For an
; equality comparison, add logical can be used.
define i32 @fun0(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun0:
; CHECK: jle .LBB0_2{{$}}
; CHECK: je .LBB0_4{{$}}
bb:
%tmp2 = add nsw i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = add nsw i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
; No "nsw" flag
define i32 @fun1(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun1:
; CHECK: cijle
; CHECK: alr
; CHECK: jhe
bb:
%tmp2 = add i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = add i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
; "nuw" flag
define i32 @fun2(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun2:
; CHECK: cijle
; CHECK: alr
; CHECK: jhe
bb:
%tmp2 = add nuw i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = add nuw i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
; Subtraction does not produce the value of zero in case of overflow, so
; "nsw" is not needed for the equality check against zero.
define i32 @fun3(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun3:
; CHECK: jle .LBB3_2{{$}}
; CHECK: je .LBB3_4{{$}}
bb:
%tmp2 = sub nsw i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = sub nsw i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
; No "nsw" flag
define i32 @fun4(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun4:
; CHECK: cijle
; CHECK: je .LBB4_4{{$}}
bb:
%tmp2 = sub i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = sub i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
; "nuw" flag
define i32 @fun5(i32 %arg, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: fun5:
; CHECK: cijle
; CHECK: je .LBB5_4{{$}}
bb:
%tmp2 = sub nuw i32 %arg, %arg2
%tmp3 = icmp sgt i32 %tmp2, 0
br i1 %tmp3, label %bb3, label %bb1
bb1:
%tmp4 = sub nuw i32 %arg, %arg3
%tmp5 = icmp eq i32 %tmp4, 0
br i1 %tmp5, label %bb4, label %bb2
bb2:
ret i32 0
bb3:
ret i32 1
bb4:
ret i32 2
}
|
