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 -analyze -scalar-evolution < %s | FileCheck %s
define void @u_0(i8 %rhs) {
; E.g.: %rhs = 255, %start = 99, backedge taken 156 times
entry:
%start = add i8 %rhs, 100
br label %loop
loop:
%iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
%iv.inc = add nuw i8 %iv, 1 ;; Note: this never unsigned-wraps
%iv.cmp = icmp ult i8 %iv, %rhs
br i1 %iv.cmp, label %loop, label %leave
; CHECK-LABEL: Determining loop execution counts for: @u_0
; CHECK-NEXT: Loop %loop: backedge-taken count is (-100 + (-1 * %rhs) + ((100 + %rhs) umax %rhs))
; CHECK-NEXT: Loop %loop: max backedge-taken count is -100, actual taken count either this or zero.
leave:
ret void
}
define void @u_1(i8 %start) {
entry:
; E.g.: %start = 99, %rhs = 255, backedge taken 156 times
%rhs = add i8 %start, -100
br label %loop
loop:
%iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
%iv.inc = add nuw i8 %iv, 1 ;; Note: this never unsigned-wraps
%iv.cmp = icmp ult i8 %iv, %rhs
br i1 %iv.cmp, label %loop, label %leave
; CHECK-LABEL: Determining loop execution counts for: @u_1
; CHECK-NEXT: Loop %loop: backedge-taken count is ((-1 * %start) + ((-100 + %start) umax %start))
; CHECK-NEXT: Loop %loop: max backedge-taken count is -100, actual taken count either this or zero.
leave:
ret void
}
define void @s_0(i8 %rhs) {
entry:
; E.g.: %rhs = 127, %start = -29, backedge taken 156 times
%start = add i8 %rhs, 100
br label %loop
loop:
%iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
%iv.inc = add nsw i8 %iv, 1 ;; Note: this never signed-wraps
%iv.cmp = icmp slt i8 %iv, %rhs
br i1 %iv.cmp, label %loop, label %leave
; CHECK-LABEL: Determining loop execution counts for: @s_0
; CHECK-NEXT: Loop %loop: backedge-taken count is (-100 + (-1 * %rhs) + ((100 + %rhs) smax %rhs))
; CHECK-NEXT: Loop %loop: max backedge-taken count is -100, actual taken count either this or zero.
leave:
ret void
}
define void @s_1(i8 %start) {
entry:
; E.g.: start = -29, %rhs = 127, %backedge taken 156 times
%rhs = add i8 %start, -100
br label %loop
loop:
%iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
%iv.inc = add nsw i8 %iv, 1
%iv.cmp = icmp slt i8 %iv, %rhs
br i1 %iv.cmp, label %loop, label %leave
; CHECK-LABEL: Determining loop execution counts for: @s_1
; CHECK-NEXT: Loop %loop: backedge-taken count is ((-1 * %start) + ((-100 + %start) smax %start))
; CHECK-NEXT: Loop %loop: max backedge-taken count is -100, actual taken count either this or zero.
leave:
ret void
}
|
