llvm/test/Transforms/SampleProfile/calls.ll
Diego Novillo 4b2b2da9c7 Extend and simplify the sample profile input file.
1- Use the line_iterator class to read profile files.

2- Allow comments in profile file. Lines starting with '#'
   are completely ignored while reading the profile.

3- Add parsing support for discriminators and indirect call samples.

   Our external profiler can emit more profile information that we are
   currently not handling. This patch does not add new functionality to
   support this information, but it allows profile files to provide it.

   I will add actual support later on (for at least one of these
   features, I need support for DWARF discriminators in Clang).

   A sample line may contain the following additional information:

   Discriminator. This is used if the sampled program was compiled with
   DWARF discriminator support
   (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators). This
   is currently only emitted by GCC and we just ignore it.

   Potential call targets and samples. If present, this line contains a
   call instruction. This models both direct and indirect calls. Each
   called target is listed together with the number of samples. For
   example,

                    130: 7  foo:3  bar:2  baz:7

   The above means that at relative line offset 130 there is a call
   instruction that calls one of foo(), bar() and baz(). With baz()
   being the relatively more frequent call target.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2355

4- Simplify format of profile input file.

   This implements earlier suggestions to simplify the format of the
   sample profile file. The symbol table is not necessary and function
   profiles do not need to know the number of samples in advance.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2419

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198973 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-10 23:23:51 +00:00

108 lines
4.8 KiB
LLVM

; 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;
; }
@.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 !13
%inc = add nsw i32 %0, 1, !dbg !13
store i32 %inc, i32* %i, align 4, !dbg !13
%cmp = icmp slt i32 %0, 400000000, !dbg !13
br i1 %cmp, label %while.body, label %while.end, !dbg !13
; CHECK: edge while.cond -> while.body probability is 11143 / 16696 = 66.7405%
; CHECK: edge while.cond -> while.end probability is 5553 / 16696 = 33.2595%
while.body: ; preds = %while.cond
%1 = load i32* %i, align 4, !dbg !14
%cmp1 = icmp ne i32 %1, 100, !dbg !14
br i1 %cmp1, label %if.then, label %if.else, !dbg !14
; NOTE: These weights are wrong. We currently do not handle multiple
; control flow paths in the same line. The edge while.body -> if.then
; should be much heavier than the other one. Support for DWARF
; discriminators will fix this.
; CHECK: edge while.body -> if.then probability is 11143 / 22286 = 50%
; CHECK: edge while.body -> if.else probability is 11143 / 22286 = 50%
if.then: ; preds = %while.body
%2 = load i32* %i, align 4, !dbg !14
%3 = load i32* %s, align 4, !dbg !14
%call = call i32 @_Z3sumii(i32 %2, i32 %3), !dbg !14
store i32 %call, i32* %s, align 4, !dbg !14
br label %if.end, !dbg !14
if.else: ; preds = %while.body
store i32 30, i32* %s, align 4, !dbg !14
br label %if.end
if.end: ; preds = %if.else, %if.then
br label %while.cond, !dbg !14
while.end: ; preds = %while.cond
%4 = load i32* %s, align 4, !dbg !16
%call2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i32 %4), !dbg !16
ret i32 0, !dbg !17
}
declare i32 @printf(i8*, ...)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!8, !9}
!llvm.ident = !{!10}
!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [./calls.cc] [DW_LANG_C_plus_plus]
!1 = metadata !{metadata !"calls.cc", metadata !"."}
!2 = metadata !{i32 0}
!3 = metadata !{metadata !4, metadata !7}
!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"sum", metadata !"sum", metadata !"", i32 3, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32, i32)* @_Z3sumii, null, null, metadata !2, i32 3} ; [ DW_TAG_subprogram ] [line 3] [def] [sum]
!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ] [./calls.cc]
!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !2, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!7 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"main", metadata !"main", metadata !"", i32 7, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, metadata !2, i32 7} ; [ DW_TAG_subprogram ] [line 7] [def] [main]
!8 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
!9 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
!10 = metadata !{metadata !"clang version 3.5 "}
!11 = metadata !{i32 4, i32 0, metadata !4, null}
!12 = metadata !{i32 8, i32 0, metadata !7, null} ; [ DW_TAG_imported_declaration ]
!13 = metadata !{i32 9, i32 0, metadata !7, null}
!14 = metadata !{i32 10, i32 0, metadata !15, null}
!15 = metadata !{i32 786443, metadata !1, metadata !7, i32 10, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [./calls.cc]
!16 = metadata !{i32 11, i32 0, metadata !7, null}
!17 = metadata !{i32 12, i32 0, metadata !7, null}