[llvm] r312194 - [MachineOutliner] Add missed optimization remarks for the outliner.
Jessica Paquette via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 31 10:37:37 PDT 2017
Thanks Hans!
We think the issue might be that in DiagnosticInfo.h, we have
```
struct Argument {
StringRef Key;
std::string Val;
…
```
It looks like the Key that should be OtherStartLoc1 is being freed before the call to emit. Adam Nemet suggested changing Key to a std::string. Since the issue didn’t show up in Val at all, it seems like that should work. Once I’m done running the regression tests I’ll commit that fix (assuming it passes everything) and then recommit my patch.
- Jessica
> On Aug 31, 2017, at 9:45 AM, Hans Wennborg <hans at chromium.org> wrote:
>
> It reproduces locally for me as well, on a regular x86 Linux build.
>
> Attaching the machine-outliner-remarks.ll.tmp.yaml file.
>
> On Thu, Aug 31, 2017 at 9:32 AM, Jessica Paquette <jpaquette at apple.com> wrote:
>> Sorry for getting back to this so late. I didn’t see this until now.
>>
>> Is the output YAML from this bot lying around anywhere? Also, what’s the
>> configuration for this bot? Just x86 linux? The test passes on my Apple
>> machine, so this is kind of curious, considering it’s failing on the YAML.
>>
>> Thanks!
>>
>> - Jessica
>>
>> On Aug 30, 2017, at 11:23 PM, Daniel Jasper <djasper at google.com> wrote:
>>
>> Reverted in r312219.
>>
>> On Thu, Aug 31, 2017 at 1:38 AM, Hans Wennborg via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>>>
>>> Sad buildbot:
>>> http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/6026/steps/test_llvm/logs/LLVM%20%3A%3A%20CodeGen__AArch64__machine-outliner-remarks.ll
>>>
>>> On Wed, Aug 30, 2017 at 4:31 PM, Jessica Paquette via llvm-commits
>>> <llvm-commits at lists.llvm.org> wrote:
>>>> Author: paquette
>>>> Date: Wed Aug 30 16:31:49 2017
>>>> New Revision: 312194
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=312194&view=rev
>>>> Log:
>>>> [MachineOutliner] Add missed optimization remarks for the outliner.
>>>>
>>>> This adds missed optimization remarks which report viable candidates
>>>> that
>>>> were not outlined because they would increase code size.
>>>>
>>>> Other remarks will come in separate commits.
>>>>
>>>> This will help to diagnose code size regressions and changes in outliner
>>>> behaviour in projects using the outliner.
>>>>
>>>> https://reviews.llvm.org/D37085
>>>>
>>>> Added:
>>>> llvm/trunk/test/CodeGen/AArch64/machine-outliner-remarks.ll
>>>> Modified:
>>>> llvm/trunk/lib/CodeGen/MachineOutliner.cpp
>>>>
>>>> Modified: llvm/trunk/lib/CodeGen/MachineOutliner.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineOutliner.cpp?rev=312194&r1=312193&r2=312194&view=diff
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/lib/CodeGen/MachineOutliner.cpp (original)
>>>> +++ llvm/trunk/lib/CodeGen/MachineOutliner.cpp Wed Aug 30 16:31:49 2017
>>>> @@ -46,6 +46,7 @@
>>>> #include "llvm/CodeGen/MachineFunction.h"
>>>> #include "llvm/CodeGen/MachineInstrBuilder.h"
>>>> #include "llvm/CodeGen/MachineModuleInfo.h"
>>>> +#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
>>>> #include "llvm/CodeGen/Passes.h"
>>>> #include "llvm/IR/IRBuilder.h"
>>>> #include "llvm/Support/Allocator.h"
>>>> @@ -64,6 +65,7 @@
>>>> #define DEBUG_TYPE "machine-outliner"
>>>>
>>>> using namespace llvm;
>>>> +using namespace ore;
>>>>
>>>> STATISTIC(NumOutlined, "Number of candidates outlined");
>>>> STATISTIC(FunctionsCreated, "Number of functions created");
>>>> @@ -895,8 +897,41 @@ MachineOutliner::findCandidates(SuffixTr
>>>> size_t OutliningCost = CallOverhead + FrameOverhead +
>>>> SequenceOverhead;
>>>> size_t NotOutliningCost = SequenceOverhead *
>>>> Parent.OccurrenceCount;
>>>>
>>>> - if (NotOutliningCost <= OutliningCost)
>>>> + // Is it better to outline this candidate than not?
>>>> + if (NotOutliningCost <= OutliningCost) {
>>>> + // Outlining this candidate would take more instructions than not
>>>> + // outlining.
>>>> + // Emit a remark explaining why we didn't outline this candidate.
>>>> + std::pair<MachineBasicBlock::iterator,
>>>> MachineBasicBlock::iterator> C =
>>>> + CandidateClass[0];
>>>> + MachineOptimizationRemarkEmitter MORE(
>>>> + *(C.first->getParent()->getParent()), nullptr);
>>>> + MachineOptimizationRemarkMissed R(DEBUG_TYPE,
>>>> "NotOutliningCheaper",
>>>> + C.first->getDebugLoc(),
>>>> + C.first->getParent());
>>>> + R << "Did not outline " << NV("Length", StringLen) << "
>>>> instructions"
>>>> + << " from " << NV("NumOccurrences", CandidateClass.size())
>>>> + << " locations."
>>>> + << " Instructions from outlining all occurrences ("
>>>> + << NV("OutliningCost", OutliningCost) << ")"
>>>> + << " >= Unoutlined instruction count ("
>>>> + << NV("NotOutliningCost", NotOutliningCost) << ")"
>>>> + << " (Also found at: ";
>>>> +
>>>> + // Tell the user the other places the candidate was found.
>>>> + for (size_t i = 1, e = CandidateClass.size(); i < e; i++) {
>>>> + R << NV((Twine("OtherStartLoc") + Twine(i)).str(),
>>>> + CandidateClass[i].first->getDebugLoc());
>>>> + if (i != e - 1)
>>>> + R << ", ";
>>>> + }
>>>> +
>>>> + R << ")";
>>>> + MORE.emit(R);
>>>> +
>>>> + // Move to the next candidate.
>>>> continue;
>>>> + }
>>>>
>>>> size_t Benefit = NotOutliningCost - OutliningCost;
>>>>
>>>>
>>>> Added: llvm/trunk/test/CodeGen/AArch64/machine-outliner-remarks.ll
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/machine-outliner-remarks.ll?rev=312194&view=auto
>>>>
>>>> ==============================================================================
>>>> --- llvm/trunk/test/CodeGen/AArch64/machine-outliner-remarks.ll (added)
>>>> +++ llvm/trunk/test/CodeGen/AArch64/machine-outliner-remarks.ll Wed Aug
>>>> 30 16:31:49 2017
>>>> @@ -0,0 +1,73 @@
>>>> +; RUN: llc %s -enable-machine-outliner -mtriple=aarch64-unknown-unknown
>>>> -pass-remarks-missed=machine-outliner -o /dev/null 2>&1 | FileCheck %s
>>>> +; CHECK: machine-outliner-remarks.ll:5:9:
>>>> +; CHECK-SAME: Did not outline 2 instructions from 2 locations.
>>>> +; CHECK-SAME: Instructions from outlining all occurrences (9) >=
>>>> +; CHECK-SAME: Unoutlined instruction count (4)
>>>> +; CHECK-SAME: (Also found at: machine-outliner-remarks.ll:13:9)
>>>> +; RUN: llc %s -enable-machine-outliner -mtriple=aarch64-unknown-unknown
>>>> -o /dev/null -pass-remarks-missed=machine-outliner
>>>> -pass-remarks-output=%t.yaml
>>>> +; RUN: cat %t.yaml | FileCheck %s -check-prefix=YAML
>>>> +; YAML: --- !Missed
>>>> +; YAML-NEXT: Pass: machine-outliner
>>>> +; YAML-NEXT: Name: NotOutliningCheaper
>>>> +; YAML-NEXT: DebugLoc: { File: machine-outliner-remarks.ll,
>>>> Line: 5, Column: 9 }
>>>> +; YAML-NEXT: Function: dog
>>>> +; YAML-NEXT: Args:
>>>> +; YAML-NEXT: - String: 'Did not outline '
>>>> +; YAML-NEXT: - Length: '2'
>>>> +; YAML-NEXT: - String: ' instructions'
>>>> +; YAML-NEXT: - String: ' from '
>>>> +; YAML-NEXT: - NumOccurrences: '2'
>>>> +; YAML-NEXT: - String: ' locations.'
>>>> +; YAML-NEXT: - String: ' Instructions from outlining all
>>>> occurrences ('
>>>> +; YAML-NEXT: - OutliningCost: '9'
>>>> +; YAML-NEXT: - String: ')'
>>>> +; YAML-NEXT: - String: ' >= Unoutlined instruction count ('
>>>> +; YAML-NEXT: - NotOutliningCost: '4'
>>>> +; YAML-NEXT: - String: ')'
>>>> +; YAML-NEXT: - String: ' (Also found at: '
>>>> +; YAML-NEXT: - OtherStartLoc1: 'machine-outliner-remarks.ll:13:9'
>>>> +; YAML-NEXT: DebugLoc: { File: machine-outliner-remarks.ll,
>>>> Line: 13, Column: 9 }
>>>> +; YAML-NEXT: - String: ')'
>>>> +
>>>> +define void @dog() #0 !dbg !8 {
>>>> +entry:
>>>> + %x = alloca i32, align 4
>>>> + %y = alloca i32, align 4
>>>> + store i32 0, i32* %x, align 4, !dbg !11
>>>> + store i32 1, i32* %y, align 4, !dbg !12
>>>> + ret void, !dbg !13
>>>> +}
>>>> +
>>>> +define void @cat() #0 !dbg !14 {
>>>> +entry:
>>>> + %x = alloca i32, align 4
>>>> + %y = alloca i32, align 4
>>>> + store i32 0, i32* %x, align 4, !dbg !15
>>>> + store i32 1, i32* %y, align 4, !dbg !16
>>>> + ret void, !dbg !17
>>>> +}
>>>> +
>>>> +attributes #0 = { noredzone nounwind ssp uwtable
>>>> "no-frame-pointer-elim"="false" "target-cpu"="cyclone" }
>>>> +
>>>> +!llvm.dbg.cu = !{!0}
>>>> +!llvm.module.flags = !{!3, !4, !5, !6}
>>>> +!llvm.ident = !{!7}
>>>> +
>>>> +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1,
>>>> isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
>>>> +!1 = !DIFile(filename: "machine-outliner-remarks.ll", directory:
>>>> "/tmp")
>>>> +!2 = !{}
>>>> +!3 = !{i32 2, !"Dwarf Version", i32 4}
>>>> +!4 = !{i32 2, !"Debug Info Version", i32 3}
>>>> +!5 = !{i32 1, !"wchar_size", i32 4}
>>>> +!6 = !{i32 7, !"PIC Level", i32 2}
>>>> +!7 = !{!""}
>>>> +!8 = distinct !DISubprogram(name: "dog", scope: !1, file: !1, line: 2,
>>>> type: !9, isLocal: false, isDefinition: true, scopeLine: 3, flags:
>>>> DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
>>>> +!9 = !DISubroutineType(types: !10)
>>>> +!10 = !{null}
>>>> +!11 = !DILocation(line: 4, column: 9, scope: !8)
>>>> +!12 = !DILocation(line: 5, column: 9, scope: !8)
>>>> +!13 = !DILocation(line: 6, column: 1, scope: !8)
>>>> +!14 = distinct !DISubprogram(name: "cat", scope: !1, file: !1, line:
>>>> 10, type: !9, isLocal: false, isDefinition: true, scopeLine: 11, flags:
>>>> DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
>>>> +!15 = !DILocation(line: 12, column: 9, scope: !14)
>>>> +!16 = !DILocation(line: 13, column: 9, scope: !14)
>>>> +!17 = !DILocation(line: 14, column: 1, scope: !14)
>>>>
>>>>
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>>
>>
> <machine-outliner-remarks.ll.tmp.yaml>
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