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[SampleFDO] Support enabling sample loader pass in O0 mode #113985

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Merged
merged 6 commits into from
Nov 8, 2024
Merged

[SampleFDO] Support enabling sample loader pass in O0 mode #113985

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9b41a3a
[SampleFDO] Support running sample loader in O0 mode
wlei-llvm Oct 28, 2024
2d4a253
addressing comments, avoid seting global cmd var
wlei-llvm Nov 1, 2024
cde256b
Use flattened profile when sample loading inling is disablede
wlei-llvm Nov 1, 2024
efb68d2
only use flattened profile for O0 mode
wlei-llvm Nov 6, 2024
1750ff5
Merge branch 'main' into sample-O0
wlei-llvm Nov 6, 2024
eb496bd
Merge branch 'main' into sample-O0
wlei-llvm Nov 6, 2024
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4 changes: 3 additions & 1 deletion llvm/include/llvm/Transforms/IPO/SampleProfile.h
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,8 @@ class SampleProfileLoaderPass : public PassInfoMixin<SampleProfileLoaderPass> {
SampleProfileLoaderPass(
std::string File = "", std::string RemappingFile = "",
ThinOrFullLTOPhase LTOPhase = ThinOrFullLTOPhase::None,
IntrusiveRefCntPtr<vfs::FileSystem> FS = nullptr);
IntrusiveRefCntPtr<vfs::FileSystem> FS = nullptr,
bool DisableSampleProfileInlining = false);

PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);

Expand All @@ -50,6 +51,7 @@ class SampleProfileLoaderPass : public PassInfoMixin<SampleProfileLoaderPass> {
std::string ProfileRemappingFileName;
const ThinOrFullLTOPhase LTOPhase;
IntrusiveRefCntPtr<vfs::FileSystem> FS;
bool DisableSampleProfileInlining;
};

} // end namespace llvm
Expand Down
11 changes: 11 additions & 0 deletions llvm/lib/Passes/PassBuilderPipelines.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2153,6 +2153,17 @@ PassBuilder::buildO0DefaultPipeline(OptimizationLevel Level,
if (PGOOpt && PGOOpt->DebugInfoForProfiling)
MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));

if (PGOOpt && PGOOpt->Action == PGOOptions::SampleUse) {
// Explicitly disable sample loader inlining in O0 pipeline.
MPM.addPass(SampleProfileLoaderPass(PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile,
ThinOrFullLTOPhase::None, nullptr,
/*DisableSampleProfileInlining=*/true));
// Cache ProfileSummaryAnalysis once to avoid the potential need to insert
// RequireAnalysisPass for PSI before subsequent non-module passes.
MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
}

invokePipelineEarlySimplificationEPCallbacks(MPM, Level);

// Build a minimal pipeline based on the semantics required by LLVM,
Expand Down
29 changes: 20 additions & 9 deletions llvm/lib/Transforms/IPO/SampleProfile.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -195,8 +195,7 @@ static cl::opt<bool> ProfileSizeInline(
static cl::opt<bool> DisableSampleLoaderInlining(
"disable-sample-loader-inlining", cl::Hidden, cl::init(false),
cl::desc("If true, artifically skip inline transformation in sample-loader "
"pass, and merge (or scale) profiles (as configured by "
"--sample-profile-merge-inlinee)."));
"pass, and use flattened profiles to emit annotation."));

namespace llvm {
cl::opt<bool>
Expand Down Expand Up @@ -470,7 +469,7 @@ class SampleProfileLoader final : public SampleProfileLoaderBaseImpl<Function> {
std::function<AssumptionCache &(Function &)> GetAssumptionCache,
std::function<TargetTransformInfo &(Function &)> GetTargetTransformInfo,
std::function<const TargetLibraryInfo &(Function &)> GetTLI,
LazyCallGraph &CG)
LazyCallGraph &CG, bool DisableSampleProfileInlining)
: SampleProfileLoaderBaseImpl(std::string(Name), std::string(RemapName),
std::move(FS)),
GetAC(std::move(GetAssumptionCache)),
Expand All @@ -479,7 +478,8 @@ class SampleProfileLoader final : public SampleProfileLoaderBaseImpl<Function> {
AnnotatedPassName(AnnotateSampleProfileInlinePhase
? llvm::AnnotateInlinePassName(InlineContext{
LTOPhase, InlinePass::SampleProfileInliner})
: CSINLINE_DEBUG) {}
: CSINLINE_DEBUG),
DisableSampleProfileInlining(DisableSampleProfileInlining) {}

bool doInitialization(Module &M, FunctionAnalysisManager *FAM = nullptr);
bool runOnModule(Module &M, ModuleAnalysisManager *AM,
Expand Down Expand Up @@ -593,6 +593,8 @@ class SampleProfileLoader final : public SampleProfileLoaderBaseImpl<Function> {
// attribute.
bool ProfAccForSymsInList;

bool DisableSampleProfileInlining;

// External inline advisor used to replay inline decision from remarks.
std::unique_ptr<InlineAdvisor> ExternalInlineAdvisor;

Expand Down Expand Up @@ -920,7 +922,7 @@ bool SampleProfileLoader::tryPromoteAndInlineCandidate(
Function &F, InlineCandidate &Candidate, uint64_t SumOrigin, uint64_t &Sum,
SmallVector<CallBase *, 8> *InlinedCallSite) {
// Bail out early if sample-loader inliner is disabled.
if (DisableSampleLoaderInlining)
if (DisableSampleProfileInlining)
return false;

// Bail out early if MaxNumPromotions is zero.
Expand Down Expand Up @@ -1231,7 +1233,7 @@ bool SampleProfileLoader::tryInlineCandidate(
InlineCandidate &Candidate, SmallVector<CallBase *, 8> *InlinedCallSites) {
// Do not attempt to inline a candidate if
// --disable-sample-loader-inlining is true.
if (DisableSampleLoaderInlining)
if (DisableSampleProfileInlining)
return false;

CallBase &CB = *Candidate.CallInstr;
Expand Down Expand Up @@ -1975,6 +1977,13 @@ bool SampleProfileLoader::doInitialization(Module &M,

PSL = Reader->getProfileSymbolList();

if (DisableSampleLoaderInlining.getNumOccurrences())
DisableSampleProfileInlining = DisableSampleLoaderInlining;

// Use flattened profile if inlining is disabled.
if (DisableSampleProfileInlining && !Reader->profileIsCS())
ProfileConverter::flattenProfile(Reader->getProfiles());
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@WenleiHe WenleiHe Nov 3, 2024

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It makes sense to flatten profile if we are loading profile for O0. However, if we just disable sample loader inlining, but still runs O3/LTO, we may not want to flatten profile, because CGSCC inliner may have done some inlining, and we wanted to leverage context profile if possible?

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@wlei-llvm wlei-llvm Nov 6, 2024

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OK. Good point, sounds good to use flattened profile for only O0 mode.


// While profile-sample-accurate is on, ignore symbol list.
ProfAccForSymsInList =
ProfileAccurateForSymsInList && PSL && !ProfileSampleAccurate;
Expand Down Expand Up @@ -2305,9 +2314,10 @@ bool SampleProfileLoader::runOnFunction(Function &F, ModuleAnalysisManager *AM)
}
SampleProfileLoaderPass::SampleProfileLoaderPass(
std::string File, std::string RemappingFile, ThinOrFullLTOPhase LTOPhase,
IntrusiveRefCntPtr<vfs::FileSystem> FS)
IntrusiveRefCntPtr<vfs::FileSystem> FS, bool DisableSampleProfileInlining)
: ProfileFileName(File), ProfileRemappingFileName(RemappingFile),
LTOPhase(LTOPhase), FS(std::move(FS)) {}
LTOPhase(LTOPhase), FS(std::move(FS)),
DisableSampleProfileInlining(DisableSampleProfileInlining) {}

PreservedAnalyses SampleProfileLoaderPass::run(Module &M,
ModuleAnalysisManager &AM) {
Expand All @@ -2332,7 +2342,8 @@ PreservedAnalyses SampleProfileLoaderPass::run(Module &M,
ProfileFileName.empty() ? SampleProfileFile : ProfileFileName,
ProfileRemappingFileName.empty() ? SampleProfileRemappingFile
: ProfileRemappingFileName,
LTOPhase, FS, GetAssumptionCache, GetTTI, GetTLI, CG);
LTOPhase, FS, GetAssumptionCache, GetTTI, GetTLI, CG,
DisableSampleProfileInlining);
if (!SampleLoader.doInitialization(M, &FAM))
return PreservedAnalyses::all();

Expand Down
6 changes: 5 additions & 1 deletion llvm/test/Other/new-pm-pgo-O0.ll
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Expand Up @@ -9,15 +9,19 @@
; RUN: |FileCheck %s --check-prefixes=USE_POST_LINK,USE
; RUN: opt -debug-pass-manager -passes='lto<O0>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 \
; RUN: |FileCheck %s --check-prefixes=USE_POST_LINK,USE
; RUN: opt -debug-pass-manager -passes='default<O0>' -pgo-kind=pgo-sample-use-pipeline -profile-file='%S/Inputs/new-pm-pgo.prof' %s 2>&1 \
; RUN: |FileCheck %s --check-prefixes=SAMPLE_USE

;
; GEN: Running pass: PGOInstrumentationGen
; USE_DEFAULT: Running pass: PGOInstrumentationUse
; USE_PRE_LINK: Running pass: PGOInstrumentationUse
; USE_POST_LINK-NOT: Running pass: PGOInstrumentationUse
; USE-NOT: Running pass: PGOIndirectCallPromotion
; USE-NOT: Running pass: PGOMemOPSizeOpt

; SAMPLE_USE: Running pass: AddDiscriminatorsPass
; SAMPLE_USE: Running pass: SampleProfileLoaderPass

define void @foo() {
ret void
}
12 changes: 10 additions & 2 deletions llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
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Expand Up @@ -9,8 +9,9 @@
; when the profile uses md5.
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.md5.prof -sample-profile-merge-inlinee=true -use-profiled-call-graph=0 -S | FileCheck -check-prefix=MERGE %s

; Test we properly merge not inlined profile with '--sample-profile-merge-inlinee' even if '--disable-sample-loader-inlining' is true
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.md5.prof -sample-profile-merge-inlinee=true --disable-sample-loader-inlining -use-profiled-call-graph=0 -S | FileCheck -check-prefix=MERGE %s
; Test we properly use flattened profile when using '--disable-sample-loader-inlining'.

; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=true --disable-sample-loader-inlining -use-profiled-call-graph=0 -S | FileCheck -check-prefix=FLATTEN %s

@.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1

Expand Down Expand Up @@ -103,3 +104,10 @@ declare i32 @printf(ptr, ...)
; MERGE: !{!"branch_weights", i32 10}
; MERGE: name: "sub"
; MERGE-NEXT: {!"function_entry_count", i64 3}

; FLATTEN: name: "sum"
; FLATTEN-NEXT: {!"function_entry_count", i64 35}
; FLATTEN: !{!"branch_weights", i32 13, i32 23}
; FLATTEN: !{!"branch_weights", i32 12}
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@wlei-llvm wlei-llvm Nov 2, 2024

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OK, after switch using flattened profile, it triggered a test failure, I took a deep look at this, the reason might explain the difference using flattened profile vs merging not inlined profile on-the-fly(merged profile):
Original profile (two sum are in different context)


...
 sum:46
  2:10 sub:10
...
 sum:11:22
  2: sub:2
   1: 2

The merged profile:

sum:46
 2:10 sub:10
 ...
 2: sub:2
  1: 2

For a flattened profile

sum:46
 2:12 sub:12

Then for the line 2, it gives different block count 12 vs 10, because the inlinee profile isn't counted for the block count, which I think it should be, so this seems using flattened profile makes more sense(though the difference is not big)

; FLATTEN: name: "sub"
; FLATTEN-NEXT: {!"function_entry_count", i64 3}
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