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
|
; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/calls.prof | opt -analyze -branch-prob | FileCheck %s
; Original C++ test case
;
; #include <stdio.h>
;
; int sum(int x, int y) {
; return x + y;
; }
;
; int main() {
; int s, i = 0;
; while (i++ < 20000 * 20000)
; if (i != 100) s = sum(i, s); else s = 30;
; printf("sum is %d\n", s);
; return 0;
; }
;
; Note that this test is missing the llvm.dbg.cu annotation. This emulates
; the effect of the user having only used -fprofile-sample-use without
; -gmlt when invoking the driver. In those cases, we need to track source
; location information but we do not have to generate debug info in the
; final binary.
@.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1
; Function Attrs: nounwind uwtable
define i32 @_Z3sumii(i32 %x, i32 %y) {
entry:
%x.addr = alloca i32, align 4
%y.addr = alloca i32, align 4
store i32 %x, i32* %x.addr, align 4
store i32 %y, i32* %y.addr, align 4
%0 = load i32* %x.addr, align 4, !dbg !11
%1 = load i32* %y.addr, align 4, !dbg !11
%add = add nsw i32 %0, %1, !dbg !11
ret i32 %add, !dbg !11
}
; Function Attrs: uwtable
define i32 @main() {
entry:
%retval = alloca i32, align 4
%s = alloca i32, align 4
%i = alloca i32, align 4
store i32 0, i32* %retval
store i32 0, i32* %i, align 4, !dbg !12
br label %while.cond, !dbg !13
while.cond: ; preds = %if.end, %entry
%0 = load i32* %i, align 4, !dbg !14
%inc = add nsw i32 %0, 1, !dbg !14
store i32 %inc, i32* %i, align 4, !dbg !14
%cmp = icmp slt i32 %0, 400000000, !dbg !14
br i1 %cmp, label %while.body, label %while.end, !dbg !14
; CHECK: edge while.cond -> while.body probability is 5391 / 5392 = 99.9815% [HOT edge]
; CHECK: edge while.cond -> while.end probability is 1 / 5392 = 0.018546%
while.body: ; preds = %while.cond
%1 = load i32* %i, align 4, !dbg !16
%cmp1 = icmp ne i32 %1, 100, !dbg !16
br i1 %cmp1, label %if.then, label %if.else, !dbg !16
; Without discriminator information, the profiler used to think that
; both branches out of while.body had the same weight. In reality,
; the edge while.body->if.then is taken most of the time.
;
; CHECK: edge while.body -> if.then probability is 5752 / 5753 = 99.9826% [HOT edge]
; CHECK: edge while.body -> if.else probability is 1 / 5753 = 0.0173822%
if.then: ; preds = %while.body
%2 = load i32* %i, align 4, !dbg !18
%3 = load i32* %s, align 4, !dbg !18
%call = call i32 @_Z3sumii(i32 %2, i32 %3), !dbg !18
store i32 %call, i32* %s, align 4, !dbg !18
br label %if.end, !dbg !18
if.else: ; preds = %while.body
store i32 30, i32* %s, align 4, !dbg !20
br label %if.end
if.end: ; preds = %if.else, %if.then
br label %while.cond, !dbg !22
while.end: ; preds = %while.cond
%4 = load i32* %s, align 4, !dbg !24
%call2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i32 %4), !dbg !24
ret i32 0, !dbg !25
}
declare i32 @printf(i8*, ...) #2
!llvm.module.flags = !{!8, !9}
!llvm.ident = !{!10}
!0 = !{!"0x11\004\00clang version 3.5 \000\00\000\00\000", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [./calls.cc] [DW_LANG_C_plus_plus]
!1 = !{!"calls.cc", !"."}
!2 = !{}
!3 = !{!4, !7}
!4 = !{!"0x2e\00sum\00sum\00\003\000\001\000\006\00256\000\003", !1, !5, !6, null, i32 (i32, i32)* @_Z3sumii, null, null, !2} ; [ DW_TAG_subprogram ] [line 3] [def] [sum]
!5 = !{!"0x29", !1} ; [ DW_TAG_file_type ] [./calls.cc]
!6 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !2, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!7 = !{!"0x2e\00main\00main\00\007\000\001\000\006\00256\000\007", !1, !5, !6, null, i32 ()* @main, null, null, !2} ; [ DW_TAG_subprogram ] [line 7] [def] [main]
!8 = !{i32 2, !"Dwarf Version", i32 4}
!9 = !{i32 1, !"Debug Info Version", i32 2}
!10 = !{!"clang version 3.5 "}
!11 = !MDLocation(line: 4, scope: !4)
!12 = !MDLocation(line: 8, scope: !7)
!13 = !MDLocation(line: 9, scope: !7)
!14 = !MDLocation(line: 9, scope: !15)
!15 = !{!"0xb\001", !1, !7} ; [ DW_TAG_lexical_block ] [./calls.cc]
!16 = !MDLocation(line: 10, scope: !17)
!17 = !{!"0xb\0010\000\000", !1, !7} ; [ DW_TAG_lexical_block ] [./calls.cc]
!18 = !MDLocation(line: 10, scope: !19)
!19 = !{!"0xb\001", !1, !17} ; [ DW_TAG_lexical_block ] [./calls.cc]
!20 = !MDLocation(line: 10, scope: !21)
!21 = !{!"0xb\002", !1, !17} ; [ DW_TAG_lexical_block ] [./calls.cc]
!22 = !MDLocation(line: 10, scope: !23)
!23 = !{!"0xb\003", !1, !17} ; [ DW_TAG_lexical_block ] [./calls.cc]
!24 = !MDLocation(line: 11, scope: !7)
!25 = !MDLocation(line: 12, scope: !7)
|
