llvm-mirror/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
Piotr Padlewski 3152e057e1 [thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

llvm-svn: 282437
2016-09-26 20:37:32 +00:00

99 lines
3.7 KiB
LLVM

; Test to check the callgraph in summary when there is PGO
; RUN: opt -module-summary %s -o %t.o
; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
; RUN: opt -module-summary %p/Inputs/thinlto-function-summary-callgraph-profile-summary.ll -o %t2.o
; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
; CHECK-LABEL: <GLOBALVAL_SUMMARY_BLOCK
; CHECK-NEXT: <VERSION
; See if the call to func is registered, using the expected callsite count
; and profile count, with value id matching the subsequent value symbol table.
; CHECK-NEXT: <PERMODULE_PROFILE {{.*}} op4=[[HOT1:.*]] op5=3 op6=[[HOT2:.*]] op7=3 op8=[[HOT3:.*]] op9=3 op10=[[COLD:.*]] op11=1 op12=[[NONE1:.*]] op13=2 op14=[[NONE2:.*]] op15=2 op16=[[NONE3:.*]] op17=2/>
; CHECK-NEXT: </GLOBALVAL_SUMMARY_BLOCK>
; CHECK-LABEL: <VALUE_SYMTAB
; CHECK-NEXT: <FNENTRY {{.*}} record string = 'hot_function
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[NONE1]] {{.*}} record string = 'none1'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[COLD]] {{.*}} record string = 'cold'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[NONE2]] {{.*}} record string = 'none2'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[NONE3]] {{.*}} record string = 'none3'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[HOT1]] {{.*}} record string = 'hot1'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[HOT2]] {{.*}} record string = 'hot2'
; CHECK-DAG: <ENTRY abbrevid=6 op0=[[HOT3]] {{.*}} record string = 'hot3'
; CHECK-LABEL: </VALUE_SYMTAB>
; COMBINED: <GLOBALVAL_SUMMARY_BLOCK
; COMBINED-NEXT: <VERSION
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED abbrevid=
; COMBINED-NEXT: <COMBINED_PROFILE {{.*}} op5=[[HOT1:.*]] op6=3 op7=[[HOT2:.*]] op8=3 op9=[[HOT3:.*]] op10=3 op11=[[COLD:.*]] op12=1 op13=[[NONE1:.*]] op14=2 op15=[[NONE2:.*]] op16=2 op17=[[NONE3:.*]] op18=2/>
; COMBINED_NEXT: <COMBINED abbrevid=
; COMBINED_NEXT: </GLOBALVAL_SUMMARY_BLOCK>
; ModuleID = 'thinlto-function-summary-callgraph.ll'
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; This function have high profile count, so entry block is hot.
define void @hot_function(i1 %a, i1 %a2) !prof !20 {
entry:
call void @hot1()
br i1 %a, label %Cold, label %Hot, !prof !41
Cold: ; 1/1000 goes here
call void @cold()
call void @hot2()
call void @none1()
br label %exit
Hot: ; 999/1000 goes here
call void @hot2()
call void @hot3()
br i1 %a2, label %None1, label %None2, !prof !42
None1: ; half goes here
call void @none1()
call void @none2()
br label %exit
None2: ; half goes here
call void @none3()
br label %exit
exit:
ret void
}
declare void @hot1() #1
declare void @hot2() #1
declare void @hot3() #1
declare void @cold() #1
declare void @none1() #1
declare void @none2() #1
declare void @none3() #1
!41 = !{!"branch_weights", i32 1, i32 1000}
!42 = !{!"branch_weights", i32 1, i32 1}
!llvm.module.flags = !{!1}
!20 = !{!"function_entry_count", i64 110}
!1 = !{i32 1, !"ProfileSummary", !2}
!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
!3 = !{!"ProfileFormat", !"InstrProf"}
!4 = !{!"TotalCount", i64 10000}
!5 = !{!"MaxCount", i64 10}
!6 = !{!"MaxInternalCount", i64 1}
!7 = !{!"MaxFunctionCount", i64 1000}
!8 = !{!"NumCounts", i64 3}
!9 = !{!"NumFunctions", i64 3}
!10 = !{!"DetailedSummary", !11}
!11 = !{!12, !13, !14}
!12 = !{i32 10000, i64 100, i32 1}
!13 = !{i32 999000, i64 100, i32 1}
!14 = !{i32 999999, i64 1, i32 2}