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
|
; RUN: opt -lower-expect -S -o - < %s | FileCheck %s
; RUN: opt -S -passes='function(lower-expect)' < %s | FileCheck %s
;
; if (__builtin_expect((x > goo() || y > hoo()), 1)) {
; ..
; }
; For the above case, only the second branch should be
; annotated.
; if (__builtin_expect((x > goo() || y > hoo()), 0)) {
; ..
; }
; For the above case, two branches should be annotated.
; Function Attrs: noinline nounwind uwtable
define void @foo(i32 %arg, i32 %arg1, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: void @foo
bb:
%tmp8 = call i32 @goo()
%tmp9 = icmp slt i32 %arg, %tmp8
br i1 %tmp9, label %bb14, label %bb10
; CHECK: br i1 %tmp9
; CHECK-NOT: br i1 %tmp9{{.*}}!prof
bb10: ; preds = %bb
%tmp12 = call i32 @hoo()
%tmp13 = icmp sgt i32 %arg1, %tmp12
br label %bb14
bb14: ; preds = %bb10, %bb
%tmp15 = phi i1 [ true, %bb ], [ %tmp13, %bb10 ]
%tmp16 = zext i1 %tmp15 to i32
%tmp17 = sext i32 %tmp16 to i64
%expect = call i64 @llvm.expect.i64(i64 %tmp17, i64 1)
%tmp18 = icmp ne i64 %expect, 0
br i1 %tmp18, label %bb19, label %bb21
; CHECK: br i1 %tmp18{{.*}}!prof [[WEIGHT:![0-9]+]]
bb19: ; preds = %bb14
%tmp20 = call i32 @goo()
br label %bb23
bb21: ; preds = %bb14
%tmp22 = call i32 @hoo()
br label %bb23
bb23: ; preds = %bb21, %bb19
ret void
}
define void @foo2(i32 %arg, i32 %arg1, i32 %arg2, i32 %arg3) {
; CHECK-LABEL: void @foo2
bb:
%tmp = alloca i32, align 4
%tmp4 = alloca i32, align 4
%tmp5 = alloca i32, align 4
%tmp6 = alloca i32, align 4
store i32 %arg, i32* %tmp, align 4
store i32 %arg1, i32* %tmp4, align 4
store i32 %arg2, i32* %tmp5, align 4
store i32 %arg3, i32* %tmp6, align 4
%tmp7 = load i32, i32* %tmp, align 4
%tmp8 = call i32 @goo()
%tmp9 = icmp slt i32 %tmp7, %tmp8
br i1 %tmp9, label %bb14, label %bb10
; CHECK: br i1 %tmp9{{.*}}!prof [[WEIGHT2:![0-9]+]]
bb10: ; preds = %bb
%tmp11 = load i32, i32* %tmp5, align 4
%tmp12 = call i32 @hoo()
%tmp13 = icmp sgt i32 %tmp11, %tmp12
br label %bb14
bb14: ; preds = %bb10, %bb
%tmp15 = phi i1 [ true, %bb ], [ %tmp13, %bb10 ]
%tmp16 = zext i1 %tmp15 to i32
%tmp17 = sext i32 %tmp16 to i64
%expect = call i64 @llvm.expect.i64(i64 %tmp17, i64 0)
%tmp18 = icmp ne i64 %expect, 0
br i1 %tmp18, label %bb19, label %bb21
; CHECK: br i1 %tmp18{{.*}}!prof [[WEIGHT2]]
bb19: ; preds = %bb14
%tmp20 = call i32 @goo()
br label %bb23
bb21: ; preds = %bb14
%tmp22 = call i32 @hoo()
br label %bb23
bb23: ; preds = %bb21, %bb19
ret void
}
declare i32 @goo()
declare i32 @hoo()
declare i64 @llvm.expect.i64(i64, i64)
!llvm.ident = !{!0}
!0 = !{!"clang version 5.0.0 (trunk 302965)"}
; CHECK: [[WEIGHT]] = !{!"branch_weights", i32 2000, i32 1}
; CHECK: [[WEIGHT2]] = !{!"branch_weights", i32 1, i32 2000}
|
