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
| ; RUN: opt %s -S -simplifycfg | FileCheck %s
; Check for when one branch implies the value of a successors conditional and
; it's not simply the same conditional repeated.
define void @test(i32 %length.i, i32 %i) {
; CHECK-LABEL: @test
%iplus1 = add nsw i32 %i, 1
%var29 = icmp slt i32 %iplus1, %length.i
; CHECK: br i1 %var29, label %in_bounds, label %out_of_bounds
br i1 %var29, label %next, label %out_of_bounds
next:
; CHECK-LABEL: in_bounds:
; CHECK-NEXT: ret void
%var30 = icmp slt i32 %i, %length.i
br i1 %var30, label %in_bounds, label %out_of_bounds2
in_bounds:
ret void
out_of_bounds:
call void @foo(i64 0)
unreachable
out_of_bounds2:
call void @foo(i64 1)
unreachable
}
; If the add is not nsw, it's not safe to use the fact about i+1 to imply the
; i condition since it could have overflowed.
define void @test_neg(i32 %length.i, i32 %i) {
; CHECK-LABEL: @test_neg
%iplus1 = add i32 %i, 1
%var29 = icmp slt i32 %iplus1, %length.i
; CHECK: br i1 %var29, label %next, label %out_of_bounds
br i1 %var29, label %next, label %out_of_bounds
next:
%var30 = icmp slt i32 %i, %length.i
; CHECK: br i1 %var30, label %in_bounds, label %out_of_bounds2
br i1 %var30, label %in_bounds, label %out_of_bounds2
in_bounds:
ret void
out_of_bounds:
call void @foo(i64 0)
unreachable
out_of_bounds2:
call void @foo(i64 1)
unreachable
}
define void @test2(i32 %length.i, i32 %i) {
; CHECK-LABEL: @test2
%iplus100 = add nsw i32 %i, 100
%var29 = icmp slt i32 %iplus100, %length.i
; CHECK: br i1 %var29, label %in_bounds, label %out_of_bounds
br i1 %var29, label %next, label %out_of_bounds
next:
%var30 = icmp slt i32 %i, %length.i
br i1 %var30, label %in_bounds, label %out_of_bounds2
in_bounds:
ret void
out_of_bounds:
call void @foo(i64 0)
unreachable
out_of_bounds2:
call void @foo(i64 1)
unreachable
}
declare void @foo(i64)
|