[llvm] [nfc] Clarify when the various PGO instrumentation passes run (PR #92330)
Mircea Trofin via llvm-commits
llvm-commits at lists.llvm.org
Thu May 16 12:17:17 PDT 2024
https://github.com/mtrofin updated https://github.com/llvm/llvm-project/pull/92330
>From b719481c3c22015c69af0d949457ceb6ea47c0c0 Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Wed, 15 May 2024 17:11:56 -0700
Subject: [PATCH 1/2] [nfc] Clarify when the various PGO instrumentation passes
run
The code seems easier to read if it's centered on what the user
wants rather than combinations of whatever internal variables.
---
llvm/include/llvm/Passes/PassBuilder.h | 1 +
llvm/lib/Passes/PassBuilderPipelines.cpp | 68 ++++++++++++++----------
2 files changed, 41 insertions(+), 28 deletions(-)
diff --git a/llvm/include/llvm/Passes/PassBuilder.h b/llvm/include/llvm/Passes/PassBuilder.h
index 9b4da1c466f57..8de0f024a4b11 100644
--- a/llvm/include/llvm/Passes/PassBuilder.h
+++ b/llvm/include/llvm/Passes/PassBuilder.h
@@ -723,6 +723,7 @@ class PassBuilder {
bool AtomicCounterUpdate, std::string ProfileFile,
std::string ProfileRemappingFile,
IntrusiveRefCntPtr<vfs::FileSystem> FS);
+ void addPostPGOLoopRotation(ModulePassManager &MPM, OptimizationLevel Level);
// Extension Point callbacks
SmallVector<std::function<void(FunctionPassManager &, OptimizationLevel)>, 2>
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 72f273972f2f7..dfde877744aa6 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -803,6 +803,20 @@ void PassBuilder::addPreInlinerPasses(ModulePassManager &MPM,
MPM.addPass(GlobalDCEPass());
}
+void PassBuilder::addPostPGOLoopRotation(ModulePassManager &MPM,
+ OptimizationLevel Level) {
+ if (EnablePostPGOLoopRotation) {
+ // Disable header duplication in loop rotation at -Oz.
+ MPM.addPass(createModuleToFunctionPassAdaptor(
+ createFunctionToLoopPassAdaptor(
+ LoopRotatePass(EnableLoopHeaderDuplication ||
+ Level != OptimizationLevel::Oz),
+ /*UseMemorySSA=*/false,
+ /*UseBlockFrequencyInfo=*/false),
+ PTO.EagerlyInvalidateAnalyses));
+ }
+}
+
void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM,
OptimizationLevel Level, bool RunProfileGen,
bool IsCS, bool AtomicCounterUpdate,
@@ -824,21 +838,7 @@ void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM,
// Perform PGO instrumentation.
MPM.addPass(PGOInstrumentationGen(IsCS));
- if (EnablePostPGOLoopRotation) {
- // Disable header duplication in loop rotation at -Oz.
- MPM.addPass(createModuleToFunctionPassAdaptor(
- createFunctionToLoopPassAdaptor(
- LoopRotatePass(EnableLoopHeaderDuplication ||
- Level != OptimizationLevel::Oz),
- /*UseMemorySSA=*/false,
- /*UseBlockFrequencyInfo=*/false),
- PTO.EagerlyInvalidateAnalyses));
- }
-
- if (PGOCtxProfLoweringPass::isContextualIRPGOEnabled()) {
- MPM.addPass(PGOCtxProfLoweringPass());
- return;
- }
+ addPostPGOLoopRotation(MPM, Level);
// Add the profile lowering pass.
InstrProfOptions Options;
if (!ProfileFile.empty())
@@ -1145,29 +1145,41 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM),
PTO.EagerlyInvalidateAnalyses));
- // Invoke the pre-inliner passes for instrumentation PGO or MemProf.
- if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
- (PGOOpt->Action == PGOOptions::IRInstr ||
- PGOOpt->Action == PGOOptions::IRUse || !PGOOpt->MemoryProfile.empty()))
+ const bool IsPreLink = Phase != ThinOrFullLTOPhase::ThinLTOPostLink;
+ const bool IsPGOPreLink = PGOOpt && IsPreLink;
+ const bool IsPGOInstrGen =
+ IsPGOPreLink && PGOOpt->Action == PGOOptions::IRInstr;
+ const bool IsPGOInstrUse =
+ IsPGOPreLink && PGOOpt->Action == PGOOptions::IRUse;
+ const bool IsMemprof = IsPGOPreLink && !PGOOpt->MemoryProfile.empty();
+ // We don't want to mix pgo ctx gen and pgo gen; we also don't currently
+ // enable ctx profiling from the frontend.
+ const bool IsCtxProfGen = !IsPGOInstrGen && IsPreLink &&
+ PGOCtxProfLoweringPass::isContextualIRPGOEnabled();
+
+ if (IsPGOInstrGen || IsPGOInstrUse || IsMemprof || IsCtxProfGen)
addPreInlinerPasses(MPM, Level, Phase);
// Add all the requested passes for instrumentation PGO, if requested.
- if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
- (PGOOpt->Action == PGOOptions::IRInstr ||
- PGOOpt->Action == PGOOptions::IRUse)) {
+ if (IsPGOInstrGen || IsPGOInstrUse) {
addPGOInstrPasses(MPM, Level,
- /*RunProfileGen=*/PGOOpt->Action == PGOOptions::IRInstr,
+ /*RunProfileGen=*/IsPGOInstrGen,
/*IsCS=*/false, PGOOpt->AtomicCounterUpdate,
PGOOpt->ProfileFile, PGOOpt->ProfileRemappingFile,
PGOOpt->FS);
- MPM.addPass(PGOIndirectCallPromotion(false, false));
+ } else if (IsCtxProfGen) {
+ MPM.addPass(PGOInstrumentationGen(false));
+ addPostPGOLoopRotation(MPM, Level);
+ MPM.addPass(PGOCtxProfLoweringPass());
}
- if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
- PGOOpt->CSAction == PGOOptions::CSIRInstr)
+
+ if (IsPGOInstrGen || IsPGOInstrUse || IsCtxProfGen)
+ MPM.addPass(PGOIndirectCallPromotion(false, false));
+
+ if (IsPGOPreLink && PGOOpt->CSAction == PGOOptions::CSIRInstr)
MPM.addPass(PGOInstrumentationGenCreateVar(PGOOpt->CSProfileGenFile));
- if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
- !PGOOpt->MemoryProfile.empty())
+ if (IsMemprof)
MPM.addPass(MemProfUsePass(PGOOpt->MemoryProfile, PGOOpt->FS));
// Synthesize function entry counts for non-PGO compilation.
>From 54a1c7b1ac946f4c185a63d26a807bc6925f0539 Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Thu, 16 May 2024 12:11:31 -0700
Subject: [PATCH 2/2] feedback
---
llvm/lib/Passes/PassBuilderPipelines.cpp | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index dfde877744aa6..682bdefbd5243 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -839,6 +839,10 @@ void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM,
MPM.addPass(PGOInstrumentationGen(IsCS));
addPostPGOLoopRotation(MPM, Level);
+ if (PGOCtxProfLoweringPass::isContextualIRPGOEnabled()) {
+ MPM.addPass(PGOCtxProfLoweringPass());
+ return;
+ }
// Add the profile lowering pass.
InstrProfOptions Options;
if (!ProfileFile.empty())
@@ -1145,19 +1149,16 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM),
PTO.EagerlyInvalidateAnalyses));
+ // We already asserted this happens in non-FullLTOPostLink earlier.
const bool IsPreLink = Phase != ThinOrFullLTOPhase::ThinLTOPostLink;
const bool IsPGOPreLink = PGOOpt && IsPreLink;
const bool IsPGOInstrGen =
IsPGOPreLink && PGOOpt->Action == PGOOptions::IRInstr;
const bool IsPGOInstrUse =
IsPGOPreLink && PGOOpt->Action == PGOOptions::IRUse;
- const bool IsMemprof = IsPGOPreLink && !PGOOpt->MemoryProfile.empty();
- // We don't want to mix pgo ctx gen and pgo gen; we also don't currently
- // enable ctx profiling from the frontend.
- const bool IsCtxProfGen = !IsPGOInstrGen && IsPreLink &&
- PGOCtxProfLoweringPass::isContextualIRPGOEnabled();
+ const bool IsMemprofUse = IsPGOPreLink && !PGOOpt->MemoryProfile.empty();
- if (IsPGOInstrGen || IsPGOInstrUse || IsMemprof || IsCtxProfGen)
+ if (IsPGOInstrGen || IsPGOInstrUse || IsMemprofUse)
addPreInlinerPasses(MPM, Level, Phase);
// Add all the requested passes for instrumentation PGO, if requested.
@@ -1167,19 +1168,15 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
/*IsCS=*/false, PGOOpt->AtomicCounterUpdate,
PGOOpt->ProfileFile, PGOOpt->ProfileRemappingFile,
PGOOpt->FS);
- } else if (IsCtxProfGen) {
- MPM.addPass(PGOInstrumentationGen(false));
- addPostPGOLoopRotation(MPM, Level);
- MPM.addPass(PGOCtxProfLoweringPass());
}
- if (IsPGOInstrGen || IsPGOInstrUse || IsCtxProfGen)
+ if (IsPGOInstrGen || IsPGOInstrUse)
MPM.addPass(PGOIndirectCallPromotion(false, false));
if (IsPGOPreLink && PGOOpt->CSAction == PGOOptions::CSIRInstr)
MPM.addPass(PGOInstrumentationGenCreateVar(PGOOpt->CSProfileGenFile));
- if (IsMemprof)
+ if (IsMemprofUse)
MPM.addPass(MemProfUsePass(PGOOpt->MemoryProfile, PGOOpt->FS));
// Synthesize function entry counts for non-PGO compilation.
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