Google Git
Sign in
rust / rust-lang / llvm-project / dccf183bb26073c6b818ea24ec31ff87563d73e2 / . / llvm / lib / Passes / PassBuilderPipelines.cpp
blob: 660cb2e974d781608cb683dfbb05b61251db4e32 [file] [log] [blame]
//===- Construction of pass pipelines -------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file provides the implementation of the PassBuilder based on our
/// static pass registry as well as related functionality. It also provides
/// helpers to aid in analyzing, debugging, and testing passes and pass
/// pipelines.
///
//===----------------------------------------------------------------------===//
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/CGSCCPassManager.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/InlineAdvisor.h"
#include "llvm/Analysis/ProfileSummaryInfo.h"
#include "llvm/Analysis/ScopedNoAliasAA.h"
#include "llvm/Analysis/TypeBasedAliasAnalysis.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Passes/OptimizationLevel.h"
#include "llvm/Passes/PassBuilder.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/PGOOptions.h"
#include "llvm/Support/VirtualFileSystem.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/AggressiveInstCombine/AggressiveInstCombine.h"
#include "llvm/Transforms/Coroutines/CoroCleanup.h"
#include "llvm/Transforms/Coroutines/CoroConditionalWrapper.h"
#include "llvm/Transforms/Coroutines/CoroEarly.h"
#include "llvm/Transforms/Coroutines/CoroElide.h"
#include "llvm/Transforms/Coroutines/CoroSplit.h"
#include "llvm/Transforms/IPO/AlwaysInliner.h"
#include "llvm/Transforms/IPO/Annotation2Metadata.h"
#include "llvm/Transforms/IPO/ArgumentPromotion.h"
#include "llvm/Transforms/IPO/Attributor.h"
#include "llvm/Transforms/IPO/CalledValuePropagation.h"
#include "llvm/Transforms/IPO/ConstantMerge.h"
#include "llvm/Transforms/IPO/CrossDSOCFI.h"
#include "llvm/Transforms/IPO/DeadArgumentElimination.h"
#include "llvm/Transforms/IPO/ElimAvailExtern.h"
#include "llvm/Transforms/IPO/EmbedBitcodePass.h"
#include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
#include "llvm/Transforms/IPO/FunctionAttrs.h"
#include "llvm/Transforms/IPO/GlobalDCE.h"
#include "llvm/Transforms/IPO/GlobalOpt.h"
#include "llvm/Transforms/IPO/GlobalSplit.h"
#include "llvm/Transforms/IPO/HotColdSplitting.h"
#include "llvm/Transforms/IPO/IROutliner.h"
#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
#include "llvm/Transforms/IPO/Inliner.h"
#include "llvm/Transforms/IPO/LowerTypeTests.h"
#include "llvm/Transforms/IPO/MemProfContextDisambiguation.h"
#include "llvm/Transforms/IPO/MergeFunctions.h"
#include "llvm/Transforms/IPO/ModuleInliner.h"
#include "llvm/Transforms/IPO/OpenMPOpt.h"
#include "llvm/Transforms/IPO/PartialInlining.h"
#include "llvm/Transforms/IPO/SCCP.h"
#include "llvm/Transforms/IPO/SampleProfile.h"
#include "llvm/Transforms/IPO/SampleProfileProbe.h"
#include "llvm/Transforms/IPO/SyntheticCountsPropagation.h"
#include "llvm/Transforms/IPO/WholeProgramDevirt.h"
#include "llvm/Transforms/InstCombine/InstCombine.h"
#include "llvm/Transforms/Instrumentation/CGProfile.h"
#include "llvm/Transforms/Instrumentation/ControlHeightReduction.h"
#include "llvm/Transforms/Instrumentation/InstrOrderFile.h"
#include "llvm/Transforms/Instrumentation/InstrProfiling.h"
#include "llvm/Transforms/Instrumentation/MemProfiler.h"
#include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
#include "llvm/Transforms/Scalar/ADCE.h"
#include "llvm/Transforms/Scalar/AlignmentFromAssumptions.h"
#include "llvm/Transforms/Scalar/AnnotationRemarks.h"
#include "llvm/Transforms/Scalar/BDCE.h"
#include "llvm/Transforms/Scalar/CallSiteSplitting.h"
#include "llvm/Transforms/Scalar/ConstraintElimination.h"
#include "llvm/Transforms/Scalar/CorrelatedValuePropagation.h"
#include "llvm/Transforms/Scalar/DFAJumpThreading.h"
#include "llvm/Transforms/Scalar/DeadStoreElimination.h"
#include "llvm/Transforms/Scalar/DivRemPairs.h"
#include "llvm/Transforms/Scalar/EarlyCSE.h"
#include "llvm/Transforms/Scalar/Float2Int.h"
#include "llvm/Transforms/Scalar/GVN.h"
#include "llvm/Transforms/Scalar/IndVarSimplify.h"
#include "llvm/Transforms/Scalar/InstSimplifyPass.h"
#include "llvm/Transforms/Scalar/JumpThreading.h"
#include "llvm/Transforms/Scalar/LICM.h"
#include "llvm/Transforms/Scalar/LoopDeletion.h"
#include "llvm/Transforms/Scalar/LoopDistribute.h"
#include "llvm/Transforms/Scalar/LoopFlatten.h"
#include "llvm/Transforms/Scalar/LoopIdiomRecognize.h"
#include "llvm/Transforms/Scalar/LoopInstSimplify.h"
#include "llvm/Transforms/Scalar/LoopInterchange.h"
#include "llvm/Transforms/Scalar/LoopLoadElimination.h"
#include "llvm/Transforms/Scalar/LoopPassManager.h"
#include "llvm/Transforms/Scalar/LoopRotation.h"
#include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
#include "llvm/Transforms/Scalar/LoopSink.h"
#include "llvm/Transforms/Scalar/LoopUnrollAndJamPass.h"
#include "llvm/Transforms/Scalar/LoopUnrollPass.h"
#include "llvm/Transforms/Scalar/LowerConstantIntrinsics.h"
#include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
#include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
#include "llvm/Transforms/Scalar/MemCpyOptimizer.h"
#include "llvm/Transforms/Scalar/MergedLoadStoreMotion.h"
#include "llvm/Transforms/Scalar/NewGVN.h"
#include "llvm/Transforms/Scalar/Reassociate.h"
#include "llvm/Transforms/Scalar/SCCP.h"
#include "llvm/Transforms/Scalar/SROA.h"
#include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
#include "llvm/Transforms/Scalar/SimplifyCFG.h"
#include "llvm/Transforms/Scalar/SpeculativeExecution.h"
#include "llvm/Transforms/Scalar/TailRecursionElimination.h"
#include "llvm/Transforms/Scalar/WarnMissedTransforms.h"
#include "llvm/Transforms/Utils/AddDiscriminators.h"
#include "llvm/Transforms/Utils/AssumeBundleBuilder.h"
#include "llvm/Transforms/Utils/CanonicalizeAliases.h"
#include "llvm/Transforms/Utils/CountVisits.h"
#include "llvm/Transforms/Utils/InjectTLIMappings.h"
#include "llvm/Transforms/Utils/LibCallsShrinkWrap.h"
#include "llvm/Transforms/Utils/Mem2Reg.h"
#include "llvm/Transforms/Utils/MoveAutoInit.h"
#include "llvm/Transforms/Utils/NameAnonGlobals.h"
#include "llvm/Transforms/Utils/RelLookupTableConverter.h"
#include "llvm/Transforms/Utils/SimplifyCFGOptions.h"
#include "llvm/Transforms/Vectorize/LoopVectorize.h"
#include "llvm/Transforms/Vectorize/SLPVectorizer.h"
#include "llvm/Transforms/Vectorize/VectorCombine.h"
using namespace llvm;
static cl::opt<InliningAdvisorMode> UseInlineAdvisor(
"enable-ml-inliner", cl::init(InliningAdvisorMode::Default), cl::Hidden,
cl::desc("Enable ML policy for inliner. Currently trained for -Oz only"),
cl::values(clEnumValN(InliningAdvisorMode::Default, "default",
"Heuristics-based inliner version"),
clEnumValN(InliningAdvisorMode::Development, "development",
"Use development mode (runtime-loadable model)"),
clEnumValN(InliningAdvisorMode::Release, "release",
"Use release mode (AOT-compiled model)")));
static cl::opt<bool> EnableSyntheticCounts(
"enable-npm-synthetic-counts", cl::Hidden,
cl::desc("Run synthetic function entry count generation "
"pass"));
/// Flag to enable inline deferral during PGO.
static cl::opt<bool>
EnablePGOInlineDeferral("enable-npm-pgo-inline-deferral", cl::init(true),
cl::Hidden,
cl::desc("Enable inline deferral during PGO"));
static cl::opt<bool> EnableModuleInliner("enable-module-inliner",
cl::init(false), cl::Hidden,
cl::desc("Enable module inliner"));
static cl::opt<bool> PerformMandatoryInliningsFirst(
"mandatory-inlining-first", cl::init(true), cl::Hidden,
cl::desc("Perform mandatory inlinings module-wide, before performing "
"inlining"));
static cl::opt<bool> EnableEagerlyInvalidateAnalyses(
"eagerly-invalidate-analyses", cl::init(true), cl::Hidden,
cl::desc("Eagerly invalidate more analyses in default pipelines"));
static cl::opt<bool> EnableMergeFunctions(
"enable-merge-functions", cl::init(false), cl::Hidden,
cl::desc("Enable function merging as part of the optimization pipeline"));
static cl::opt<bool> EnablePostPGOLoopRotation(
"enable-post-pgo-loop-rotation", cl::init(true), cl::Hidden,
cl::desc("Run the loop rotation transformation after PGO instrumentation"));
static cl::opt<bool> EnableGlobalAnalyses(
"enable-global-analyses", cl::init(true), cl::Hidden,
cl::desc("Enable inter-procedural analyses"));
static cl::opt<bool>
RunPartialInlining("enable-partial-inlining", cl::init(false), cl::Hidden,
cl::desc("Run Partial inlinining pass"));
static cl::opt<bool> ExtraVectorizerPasses(
"extra-vectorizer-passes", cl::init(false), cl::Hidden,
cl::desc("Run cleanup optimization passes after vectorization"));
static cl::opt<bool> RunNewGVN("enable-newgvn", cl::init(false), cl::Hidden,
cl::desc("Run the NewGVN pass"));
static cl::opt<bool> EnableLoopInterchange(
"enable-loopinterchange", cl::init(false), cl::Hidden,
cl::desc("Enable the experimental LoopInterchange Pass"));
static cl::opt<bool> EnableUnrollAndJam("enable-unroll-and-jam",
cl::init(false), cl::Hidden,
cl::desc("Enable Unroll And Jam Pass"));
static cl::opt<bool> EnableLoopFlatten("enable-loop-flatten", cl::init(false),
cl::Hidden,
cl::desc("Enable the LoopFlatten Pass"));
static cl::opt<bool>
EnableDFAJumpThreading("enable-dfa-jump-thread",
cl::desc("Enable DFA jump threading"),
cl::init(false), cl::Hidden);
static cl::opt<bool>
EnableHotColdSplit("hot-cold-split",
cl::desc("Enable hot-cold splitting pass"));
static cl::opt<bool> EnableIROutliner("ir-outliner", cl::init(false),
cl::Hidden,
cl::desc("Enable ir outliner pass"));
static cl::opt<bool>
DisablePreInliner("disable-preinline", cl::init(false), cl::Hidden,
cl::desc("Disable pre-instrumentation inliner"));
static cl::opt<int> PreInlineThreshold(
"preinline-threshold", cl::Hidden, cl::init(75),
cl::desc("Control the amount of inlining in pre-instrumentation inliner "
"(default = 75)"));
static cl::opt<bool>
EnableGVNHoist("enable-gvn-hoist",
cl::desc("Enable the GVN hoisting pass (default = off)"));
static cl::opt<bool>
EnableGVNSink("enable-gvn-sink",
cl::desc("Enable the GVN sinking pass (default = off)"));
// This option is used in simplifying testing SampleFDO optimizations for
// profile loading.
static cl::opt<bool>
EnableCHR("enable-chr", cl::init(true), cl::Hidden,
cl::desc("Enable control height reduction optimization (CHR)"));
static cl::opt<bool> FlattenedProfileUsed(
"flattened-profile-used", cl::init(false), cl::Hidden,
cl::desc("Indicate the sample profile being used is flattened, i.e., "
"no inline hierachy exists in the profile"));
static cl::opt<bool> EnableOrderFileInstrumentation(
"enable-order-file-instrumentation", cl::init(false), cl::Hidden,
cl::desc("Enable order file instrumentation (default = off)"));
static cl::opt<bool>
EnableMatrix("enable-matrix", cl::init(false), cl::Hidden,
cl::desc("Enable lowering of the matrix intrinsics"));
static cl::opt<bool> EnableConstraintElimination(
"enable-constraint-elimination", cl::init(true), cl::Hidden,
cl::desc(
"Enable pass to eliminate conditions based on linear constraints"));
static cl::opt<AttributorRunOption> AttributorRun(
"attributor-enable", cl::Hidden, cl::init(AttributorRunOption::NONE),
cl::desc("Enable the attributor inter-procedural deduction pass"),
cl::values(clEnumValN(AttributorRunOption::ALL, "all",
"enable all attributor runs"),
clEnumValN(AttributorRunOption::MODULE, "module",
"enable module-wide attributor runs"),
clEnumValN(AttributorRunOption::CGSCC, "cgscc",
"enable call graph SCC attributor runs"),
clEnumValN(AttributorRunOption::NONE, "none",
"disable attributor runs")));
cl::opt<bool> EnableMemProfContextDisambiguation(
"enable-memprof-context-disambiguation", cl::init(false), cl::Hidden,
cl::ZeroOrMore, cl::desc("Enable MemProf context disambiguation"));
PipelineTuningOptions::PipelineTuningOptions() {
LoopInterleaving = true;
LoopVectorization = true;
SLPVectorization = false;
LoopUnrolling = true;
ForgetAllSCEVInLoopUnroll = ForgetSCEVInLoopUnroll;
LicmMssaOptCap = SetLicmMssaOptCap;
LicmMssaNoAccForPromotionCap = SetLicmMssaNoAccForPromotionCap;
CallGraphProfile = true;
UnifiedLTO = false;
MergeFunctions = EnableMergeFunctions;
InlinerThreshold = -1;
EagerlyInvalidateAnalyses = EnableEagerlyInvalidateAnalyses;
}
namespace llvm {
extern cl::opt<unsigned> MaxDevirtIterations;
extern cl::opt<bool> EnableKnowledgeRetention;
} // namespace llvm
void PassBuilder::invokePeepholeEPCallbacks(FunctionPassManager &FPM,
OptimizationLevel Level) {
for (auto &C : PeepholeEPCallbacks)
C(FPM, Level);
}
void PassBuilder::invokeLateLoopOptimizationsEPCallbacks(
LoopPassManager &LPM, OptimizationLevel Level) {
for (auto &C : LateLoopOptimizationsEPCallbacks)
C(LPM, Level);
}
void PassBuilder::invokeLoopOptimizerEndEPCallbacks(LoopPassManager &LPM,
OptimizationLevel Level) {
for (auto &C : LoopOptimizerEndEPCallbacks)
C(LPM, Level);
}
void PassBuilder::invokeScalarOptimizerLateEPCallbacks(
FunctionPassManager &FPM, OptimizationLevel Level) {
for (auto &C : ScalarOptimizerLateEPCallbacks)
C(FPM, Level);
}
void PassBuilder::invokeCGSCCOptimizerLateEPCallbacks(CGSCCPassManager &CGPM,
OptimizationLevel Level) {
for (auto &C : CGSCCOptimizerLateEPCallbacks)
C(CGPM, Level);
}
void PassBuilder::invokeVectorizerStartEPCallbacks(FunctionPassManager &FPM,
OptimizationLevel Level) {
for (auto &C : VectorizerStartEPCallbacks)
C(FPM, Level);
}
void PassBuilder::invokeOptimizerEarlyEPCallbacks(ModulePassManager &MPM,
OptimizationLevel Level) {
for (auto &C : OptimizerEarlyEPCallbacks)
C(MPM, Level);
}
void PassBuilder::invokeOptimizerLastEPCallbacks(ModulePassManager &MPM,
OptimizationLevel Level) {
for (auto &C : OptimizerLastEPCallbacks)
C(MPM, Level);
}
void PassBuilder::invokeFullLinkTimeOptimizationEarlyEPCallbacks(
ModulePassManager &MPM, OptimizationLevel Level) {
for (auto &C : FullLinkTimeOptimizationEarlyEPCallbacks)
C(MPM, Level);
}
void PassBuilder::invokeFullLinkTimeOptimizationLastEPCallbacks(
ModulePassManager &MPM, OptimizationLevel Level) {
for (auto &C : FullLinkTimeOptimizationLastEPCallbacks)
C(MPM, Level);
}
void PassBuilder::invokePipelineStartEPCallbacks(ModulePassManager &MPM,
OptimizationLevel Level) {
for (auto &C : PipelineStartEPCallbacks)
C(MPM, Level);
}
void PassBuilder::invokePipelineEarlySimplificationEPCallbacks(
ModulePassManager &MPM, OptimizationLevel Level) {
for (auto &C : PipelineEarlySimplificationEPCallbacks)
C(MPM, Level);
}
// Helper to add AnnotationRemarksPass.
static void addAnnotationRemarksPass(ModulePassManager &MPM) {
MPM.addPass(createModuleToFunctionPassAdaptor(AnnotationRemarksPass()));
}
// Helper to check if the current compilation phase is preparing for LTO
static bool isLTOPreLink(ThinOrFullLTOPhase Phase) {
return Phase == ThinOrFullLTOPhase::ThinLTOPreLink ||
Phase == ThinOrFullLTOPhase::FullLTOPreLink;
}
// TODO: Investigate the cost/benefit of tail call elimination on debugging.
FunctionPassManager
PassBuilder::buildO1FunctionSimplificationPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase Phase) {
FunctionPassManager FPM;
if (AreStatisticsEnabled())
FPM.addPass(CountVisitsPass());
// Form SSA out of local memory accesses after breaking apart aggregates into
// scalars.
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
// Catch trivial redundancies
FPM.addPass(EarlyCSEPass(true /* Enable mem-ssa. */));
// Hoisting of scalars and load expressions.
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
FPM.addPass(InstCombinePass());
FPM.addPass(LibCallsShrinkWrapPass());
invokePeepholeEPCallbacks(FPM, Level);
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
// Form canonically associated expression trees, and simplify the trees using
// basic mathematical properties. For example, this will form (nearly)
// minimal multiplication trees.
FPM.addPass(ReassociatePass());
// Add the primary loop simplification pipeline.
// FIXME: Currently this is split into two loop pass pipelines because we run
// some function passes in between them. These can and should be removed
// and/or replaced by scheduling the loop pass equivalents in the correct
// positions. But those equivalent passes aren't powerful enough yet.
// Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
// used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet to
// fully replace `SimplifyCFGPass`, and the closest to the other we have is
// `LoopInstSimplify`.
LoopPassManager LPM1, LPM2;
// Simplify the loop body. We do this initially to clean up after other loop
// passes run, either when iterating on a loop or on inner loops with
// implications on the outer loop.
LPM1.addPass(LoopInstSimplifyPass());
LPM1.addPass(LoopSimplifyCFGPass());
// Try to remove as much code from the loop header as possible,
// to reduce amount of IR that will have to be duplicated. However,
// do not perform speculative hoisting the first time as LICM
// will destroy metadata that may not need to be destroyed if run
// after loop rotation.
// TODO: Investigate promotion cap for O1.
LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/false));
LPM1.addPass(LoopRotatePass(/* Disable header duplication */ true,
isLTOPreLink(Phase)));
// TODO: Investigate promotion cap for O1.
LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true));
LPM1.addPass(SimpleLoopUnswitchPass());
if (EnableLoopFlatten)
LPM1.addPass(LoopFlattenPass());
LPM2.addPass(LoopIdiomRecognizePass());
LPM2.addPass(IndVarSimplifyPass());
invokeLateLoopOptimizationsEPCallbacks(LPM2, Level);
LPM2.addPass(LoopDeletionPass());
if (EnableLoopInterchange)
LPM2.addPass(LoopInterchangePass());
// Do not enable unrolling in PreLinkThinLTO phase during sample PGO
// because it changes IR to makes profile annotation in back compile
// inaccurate. The normal unroller doesn't pay attention to forced full unroll
// attributes so we need to make sure and allow the full unroll pass to pay
// attention to it.
if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
PGOOpt->Action != PGOOptions::SampleUse)
LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
/* OnlyWhenForced= */ !PTO.LoopUnrolling,
PTO.ForgetAllSCEVInLoopUnroll));
invokeLoopOptimizerEndEPCallbacks(LPM2, Level);
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1),
/*UseMemorySSA=*/true,
/*UseBlockFrequencyInfo=*/true));
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
FPM.addPass(InstCombinePass());
// The loop passes in LPM2 (LoopFullUnrollPass) do not preserve MemorySSA.
// *All* loop passes must preserve it, in order to be able to use it.
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM2),
/*UseMemorySSA=*/false,
/*UseBlockFrequencyInfo=*/false));
// Delete small array after loop unroll.
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
// Specially optimize memory movement as it doesn't look like dataflow in SSA.
FPM.addPass(MemCpyOptPass());
// Sparse conditional constant propagation.
// FIXME: It isn't clear why we do this *after* loop passes rather than
// before...
FPM.addPass(SCCPPass());
// Delete dead bit computations (instcombine runs after to fold away the dead
// computations, and then ADCE will run later to exploit any new DCE
// opportunities that creates).
FPM.addPass(BDCEPass());
// Run instcombine after redundancy and dead bit elimination to exploit
// opportunities opened up by them.
FPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(FPM, Level);
FPM.addPass(CoroElidePass());
invokeScalarOptimizerLateEPCallbacks(FPM, Level);
// Finally, do an expensive DCE pass to catch all the dead code exposed by
// the simplifications and basic cleanup after all the simplifications.
// TODO: Investigate if this is too expensive.
FPM.addPass(ADCEPass());
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
FPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(FPM, Level);
return FPM;
}
FunctionPassManager
PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase Phase) {
assert(Level != OptimizationLevel::O0 && "Must request optimizations!");
// The O1 pipeline has a separate pipeline creation function to simplify
// construction readability.
if (Level.getSpeedupLevel() == 1)
return buildO1FunctionSimplificationPipeline(Level, Phase);
FunctionPassManager FPM;
if (AreStatisticsEnabled())
FPM.addPass(CountVisitsPass());
// Form SSA out of local memory accesses after breaking apart aggregates into
// scalars.
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
// Catch trivial redundancies
FPM.addPass(EarlyCSEPass(true /* Enable mem-ssa. */));
if (EnableKnowledgeRetention)
FPM.addPass(AssumeSimplifyPass());
// Hoisting of scalars and load expressions.
if (EnableGVNHoist)
FPM.addPass(GVNHoistPass());
// Global value numbering based sinking.
if (EnableGVNSink) {
FPM.addPass(GVNSinkPass());
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
}
// Speculative execution if the target has divergent branches; otherwise nop.
FPM.addPass(SpeculativeExecutionPass(/* OnlyIfDivergentTarget =*/true));
// Optimize based on known information about branches, and cleanup afterward.
FPM.addPass(JumpThreadingPass());
FPM.addPass(CorrelatedValuePropagationPass());
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
FPM.addPass(InstCombinePass());
FPM.addPass(AggressiveInstCombinePass());
if (EnableConstraintElimination)
FPM.addPass(ConstraintEliminationPass());
if (!Level.isOptimizingForSize())
FPM.addPass(LibCallsShrinkWrapPass());
invokePeepholeEPCallbacks(FPM, Level);
// For PGO use pipeline, try to optimize memory intrinsics such as memcpy
// using the size value profile. Don't perform this when optimizing for size.
if (PGOOpt && PGOOpt->Action == PGOOptions::IRUse &&
!Level.isOptimizingForSize())
FPM.addPass(PGOMemOPSizeOpt());
FPM.addPass(TailCallElimPass());
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
// Form canonically associated expression trees, and simplify the trees using
// basic mathematical properties. For example, this will form (nearly)
// minimal multiplication trees.
FPM.addPass(ReassociatePass());
// Add the primary loop simplification pipeline.
// FIXME: Currently this is split into two loop pass pipelines because we run
// some function passes in between them. These can and should be removed
// and/or replaced by scheduling the loop pass equivalents in the correct
// positions. But those equivalent passes aren't powerful enough yet.
// Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
// used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet to
// fully replace `SimplifyCFGPass`, and the closest to the other we have is
// `LoopInstSimplify`.
LoopPassManager LPM1, LPM2;
// Simplify the loop body. We do this initially to clean up after other loop
// passes run, either when iterating on a loop or on inner loops with
// implications on the outer loop.
LPM1.addPass(LoopInstSimplifyPass());
LPM1.addPass(LoopSimplifyCFGPass());
// Try to remove as much code from the loop header as possible,
// to reduce amount of IR that will have to be duplicated. However,
// do not perform speculative hoisting the first time as LICM
// will destroy metadata that may not need to be destroyed if run
// after loop rotation.
// TODO: Investigate promotion cap for O1.
LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/false));
// Disable header duplication in loop rotation at -Oz.
LPM1.addPass(
LoopRotatePass(Level != OptimizationLevel::Oz, isLTOPreLink(Phase)));
// TODO: Investigate promotion cap for O1.
LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true));
LPM1.addPass(
SimpleLoopUnswitchPass(/* NonTrivial */ Level == OptimizationLevel::O3));
if (EnableLoopFlatten)
LPM1.addPass(LoopFlattenPass());
LPM2.addPass(LoopIdiomRecognizePass());
LPM2.addPass(IndVarSimplifyPass());
invokeLateLoopOptimizationsEPCallbacks(LPM2, Level);
LPM2.addPass(LoopDeletionPass());
if (EnableLoopInterchange)
LPM2.addPass(LoopInterchangePass());
// Do not enable unrolling in PreLinkThinLTO phase during sample PGO
// because it changes IR to makes profile annotation in back compile
// inaccurate. The normal unroller doesn't pay attention to forced full unroll
// attributes so we need to make sure and allow the full unroll pass to pay
// attention to it.
if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
PGOOpt->Action != PGOOptions::SampleUse)
LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
/* OnlyWhenForced= */ !PTO.LoopUnrolling,
PTO.ForgetAllSCEVInLoopUnroll));
invokeLoopOptimizerEndEPCallbacks(LPM2, Level);
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1),
/*UseMemorySSA=*/true,
/*UseBlockFrequencyInfo=*/true));
FPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
FPM.addPass(InstCombinePass());
// The loop passes in LPM2 (LoopIdiomRecognizePass, IndVarSimplifyPass,
// LoopDeletionPass and LoopFullUnrollPass) do not preserve MemorySSA.
// *All* loop passes must preserve it, in order to be able to use it.
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM2),
/*UseMemorySSA=*/false,
/*UseBlockFrequencyInfo=*/false));
// Delete small array after loop unroll.
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
// Try vectorization/scalarization transforms that are both improvements
// themselves and can allow further folds with GVN and InstCombine.
FPM.addPass(VectorCombinePass(/*TryEarlyFoldsOnly=*/true));
// Eliminate redundancies.
FPM.addPass(MergedLoadStoreMotionPass());
if (RunNewGVN)
FPM.addPass(NewGVNPass());
else
FPM.addPass(GVNPass());
// Sparse conditional constant propagation.
// FIXME: It isn't clear why we do this *after* loop passes rather than
// before...
FPM.addPass(SCCPPass());
// Delete dead bit computations (instcombine runs after to fold away the dead
// computations, and then ADCE will run later to exploit any new DCE
// opportunities that creates).
FPM.addPass(BDCEPass());
// Run instcombine after redundancy and dead bit elimination to exploit
// opportunities opened up by them.
FPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(FPM, Level);
// Re-consider control flow based optimizations after redundancy elimination,
// redo DCE, etc.
if (EnableDFAJumpThreading && Level.getSizeLevel() == 0)
FPM.addPass(DFAJumpThreadingPass());
FPM.addPass(JumpThreadingPass());
FPM.addPass(CorrelatedValuePropagationPass());
// Finally, do an expensive DCE pass to catch all the dead code exposed by
// the simplifications and basic cleanup after all the simplifications.
// TODO: Investigate if this is too expensive.
FPM.addPass(ADCEPass());
// Specially optimize memory movement as it doesn't look like dataflow in SSA.
FPM.addPass(MemCpyOptPass());
FPM.addPass(DSEPass());
FPM.addPass(MoveAutoInitPass());
FPM.addPass(createFunctionToLoopPassAdaptor(
LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true),
/*UseMemorySSA=*/true, /*UseBlockFrequencyInfo=*/false));
FPM.addPass(CoroElidePass());
invokeScalarOptimizerLateEPCallbacks(FPM, Level);
FPM.addPass(SimplifyCFGPass(SimplifyCFGOptions()
.convertSwitchRangeToICmp(true)
.hoistCommonInsts(true)
.sinkCommonInsts(true)));
FPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(FPM, Level);
return FPM;
}
void PassBuilder::addRequiredLTOPreLinkPasses(ModulePassManager &MPM) {
MPM.addPass(CanonicalizeAliasesPass());
MPM.addPass(NameAnonGlobalPass());
}
void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM,
OptimizationLevel Level, bool RunProfileGen,
bool IsCS, std::string ProfileFile,
std::string ProfileRemappingFile,
ThinOrFullLTOPhase LTOPhase,
IntrusiveRefCntPtr<vfs::FileSystem> FS) {
assert(Level != OptimizationLevel::O0 && "Not expecting O0 here!");
if (!IsCS && !DisablePreInliner) {
InlineParams IP;
IP.DefaultThreshold = PreInlineThreshold;
// FIXME: The hint threshold has the same value used by the regular inliner
// when not optimzing for size. This should probably be lowered after
// performance testing.
// FIXME: this comment is cargo culted from the old pass manager, revisit).
IP.HintThreshold = Level.isOptimizingForSize() ? PreInlineThreshold : 325;
ModuleInlinerWrapperPass MIWP(
IP, /* MandatoryFirst */ true,
InlineContext{LTOPhase, InlinePass::EarlyInliner});
CGSCCPassManager &CGPipeline = MIWP.getPM();
FunctionPassManager FPM;
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
FPM.addPass(EarlyCSEPass()); // Catch trivial redundancies.
FPM.addPass(SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(
true))); // Merge & remove basic blocks.
FPM.addPass(InstCombinePass()); // Combine silly sequences.
invokePeepholeEPCallbacks(FPM, Level);
CGPipeline.addPass(createCGSCCToFunctionPassAdaptor(
std::move(FPM), PTO.EagerlyInvalidateAnalyses));
MPM.addPass(std::move(MIWP));
// Delete anything that is now dead to make sure that we don't instrument
// dead code. Instrumentation can end up keeping dead code around and
// dramatically increase code size.
MPM.addPass(GlobalDCEPass());
}
if (!RunProfileGen) {
assert(!ProfileFile.empty() && "Profile use expecting a profile file!");
MPM.addPass(
PGOInstrumentationUse(ProfileFile, ProfileRemappingFile, IsCS, FS));
// Cache ProfileSummaryAnalysis once to avoid the potential need to insert
// RequireAnalysisPass for PSI before subsequent non-module passes.
MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
return;
}
// Perform PGO instrumentation.
MPM.addPass(PGOInstrumentationGen(IsCS));
if (EnablePostPGOLoopRotation) {
// Disable header duplication in loop rotation at -Oz.
MPM.addPass(createModuleToFunctionPassAdaptor(
createFunctionToLoopPassAdaptor(
LoopRotatePass(Level != OptimizationLevel::Oz),
/*UseMemorySSA=*/false,
/*UseBlockFrequencyInfo=*/false),
PTO.EagerlyInvalidateAnalyses));
}
// Add the profile lowering pass.
InstrProfOptions Options;
if (!ProfileFile.empty())
Options.InstrProfileOutput = ProfileFile;
// Do counter promotion at Level greater than O0.
Options.DoCounterPromotion = true;
Options.UseBFIInPromotion = IsCS;
MPM.addPass(InstrProfiling(Options, IsCS));
}
void PassBuilder::addPGOInstrPassesForO0(
ModulePassManager &MPM, bool RunProfileGen, bool IsCS,
std::string ProfileFile, std::string ProfileRemappingFile,
IntrusiveRefCntPtr<vfs::FileSystem> FS) {
if (!RunProfileGen) {
assert(!ProfileFile.empty() && "Profile use expecting a profile file!");
MPM.addPass(
PGOInstrumentationUse(ProfileFile, ProfileRemappingFile, IsCS, FS));
// Cache ProfileSummaryAnalysis once to avoid the potential need to insert
// RequireAnalysisPass for PSI before subsequent non-module passes.
MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
return;
}
// Perform PGO instrumentation.
MPM.addPass(PGOInstrumentationGen(IsCS));
// Add the profile lowering pass.
InstrProfOptions Options;
if (!ProfileFile.empty())
Options.InstrProfileOutput = ProfileFile;
// Do not do counter promotion at O0.
Options.DoCounterPromotion = false;
Options.UseBFIInPromotion = IsCS;
MPM.addPass(InstrProfiling(Options, IsCS));
}
static InlineParams getInlineParamsFromOptLevel(OptimizationLevel Level) {
return getInlineParams(Level.getSpeedupLevel(), Level.getSizeLevel());
}
ModuleInlinerWrapperPass
PassBuilder::buildInlinerPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase Phase) {
InlineParams IP;
if (PTO.InlinerThreshold == -1)
IP = getInlineParamsFromOptLevel(Level);
else
IP = getInlineParams(PTO.InlinerThreshold);
// For PreLinkThinLTO + SamplePGO, set hot-caller threshold to 0 to
// disable hot callsite inline (as much as possible [1]) because it makes
// profile annotation in the backend inaccurate.
//
// [1] Note the cost of a function could be below zero due to erased
// prologue / epilogue.
if (Phase == ThinOrFullLTOPhase::ThinLTOPreLink && PGOOpt &&
PGOOpt->Action == PGOOptions::SampleUse)
IP.HotCallSiteThreshold = 0;
if (PGOOpt)
IP.EnableDeferral = EnablePGOInlineDeferral;
ModuleInlinerWrapperPass MIWP(IP, PerformMandatoryInliningsFirst,
InlineContext{Phase, InlinePass::CGSCCInliner},
UseInlineAdvisor, MaxDevirtIterations);
// Require the GlobalsAA analysis for the module so we can query it within
// the CGSCC pipeline.
MIWP.addModulePass(RequireAnalysisPass<GlobalsAA, Module>());
// Invalidate AAManager so it can be recreated and pick up the newly available
// GlobalsAA.
MIWP.addModulePass(
createModuleToFunctionPassAdaptor(InvalidateAnalysisPass<AAManager>()));
// Require the ProfileSummaryAnalysis for the module so we can query it within
// the inliner pass.
MIWP.addModulePass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
// Now begin the main postorder CGSCC pipeline.
// FIXME: The current CGSCC pipeline has its origins in the legacy pass
// manager and trying to emulate its precise behavior. Much of this doesn't
// make a lot of sense and we should revisit the core CGSCC structure.
CGSCCPassManager &MainCGPipeline = MIWP.getPM();
// Note: historically, the PruneEH pass was run first to deduce nounwind and
// generally clean up exception handling overhead. It isn't clear this is
// valuable as the inliner doesn't currently care whether it is inlining an
// invoke or a call.
if (AttributorRun & AttributorRunOption::CGSCC)
MainCGPipeline.addPass(AttributorCGSCCPass());
// Deduce function attributes. We do another run of this after the function
// simplification pipeline, so this only needs to run when it could affect the
// function simplification pipeline, which is only the case with recursive
// functions.
MainCGPipeline.addPass(PostOrderFunctionAttrsPass(/*SkipNonRecursive*/ true));
// When at O3 add argument promotion to the pass pipeline.
// FIXME: It isn't at all clear why this should be limited to O3.
if (Level == OptimizationLevel::O3)
MainCGPipeline.addPass(ArgumentPromotionPass());
// Try to perform OpenMP specific optimizations. This is a (quick!) no-op if
// there are no OpenMP runtime calls present in the module.
if (Level == OptimizationLevel::O2 || Level == OptimizationLevel::O3)
MainCGPipeline.addPass(OpenMPOptCGSCCPass());
invokeCGSCCOptimizerLateEPCallbacks(MainCGPipeline, Level);
// Add the core function simplification pipeline nested inside the
// CGSCC walk.
MainCGPipeline.addPass(createCGSCCToFunctionPassAdaptor(
buildFunctionSimplificationPipeline(Level, Phase),
PTO.EagerlyInvalidateAnalyses, /*NoRerun=*/true));
// Finally, deduce any function attributes based on the fully simplified
// function.
MainCGPipeline.addPass(PostOrderFunctionAttrsPass());
// Mark that the function is fully simplified and that it shouldn't be
// simplified again if we somehow revisit it due to CGSCC mutations unless
// it's been modified since.
MainCGPipeline.addPass(createCGSCCToFunctionPassAdaptor(
RequireAnalysisPass<ShouldNotRunFunctionPassesAnalysis, Function>()));
MainCGPipeline.addPass(CoroSplitPass(Level != OptimizationLevel::O0));
// Make sure we don't affect potential future NoRerun CGSCC adaptors.
MIWP.addLateModulePass(createModuleToFunctionPassAdaptor(
InvalidateAnalysisPass<ShouldNotRunFunctionPassesAnalysis>()));
return MIWP;
}
ModulePassManager
PassBuilder::buildModuleInlinerPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase Phase) {
ModulePassManager MPM;
InlineParams IP = getInlineParamsFromOptLevel(Level);
// For PreLinkThinLTO + SamplePGO, set hot-caller threshold to 0 to
// disable hot callsite inline (as much as possible [1]) because it makes
// profile annotation in the backend inaccurate.
//
// [1] Note the cost of a function could be below zero due to erased
// prologue / epilogue.
if (Phase == ThinOrFullLTOPhase::ThinLTOPreLink && PGOOpt &&
PGOOpt->Action == PGOOptions::SampleUse)
IP.HotCallSiteThreshold = 0;
if (PGOOpt)
IP.EnableDeferral = EnablePGOInlineDeferral;
// The inline deferral logic is used to avoid losing some
// inlining chance in future. It is helpful in SCC inliner, in which
// inlining is processed in bottom-up order.
// While in module inliner, the inlining order is a priority-based order
// by default. The inline deferral is unnecessary there. So we disable the
// inline deferral logic in module inliner.
IP.EnableDeferral = false;
MPM.addPass(ModuleInlinerPass(IP, UseInlineAdvisor, Phase));
MPM.addPass(createModuleToFunctionPassAdaptor(
buildFunctionSimplificationPipeline(Level, Phase),
PTO.EagerlyInvalidateAnalyses));
MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
CoroSplitPass(Level != OptimizationLevel::O0)));
return MPM;
}
ModulePassManager
PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase Phase) {
assert(Level != OptimizationLevel::O0 &&
"Should not be used for O0 pipeline");
assert(Phase != ThinOrFullLTOPhase::FullLTOPostLink &&
"FullLTOPostLink shouldn't call buildModuleSimplificationPipeline!");
ModulePassManager MPM;
// Place pseudo probe instrumentation as the first pass of the pipeline to
// minimize the impact of optimization changes.
if (PGOOpt && PGOOpt->PseudoProbeForProfiling &&
Phase != ThinOrFullLTOPhase::ThinLTOPostLink)
MPM.addPass(SampleProfileProbePass(TM));
bool HasSampleProfile = PGOOpt && (PGOOpt->Action == PGOOptions::SampleUse);
// In ThinLTO mode, when flattened profile is used, all the available
// profile information will be annotated in PreLink phase so there is
// no need to load the profile again in PostLink.
bool LoadSampleProfile =
HasSampleProfile &&
!(FlattenedProfileUsed && Phase == ThinOrFullLTOPhase::ThinLTOPostLink);
// During the ThinLTO backend phase we perform early indirect call promotion
// here, before globalopt. Otherwise imported available_externally functions
// look unreferenced and are removed. If we are going to load the sample
// profile then defer until later.
// TODO: See if we can move later and consolidate with the location where
// we perform ICP when we are loading a sample profile.
// TODO: We pass HasSampleProfile (whether there was a sample profile file
// passed to the compile) to the SamplePGO flag of ICP. This is used to
// determine whether the new direct calls are annotated with prof metadata.
// Ideally this should be determined from whether the IR is annotated with
// sample profile, and not whether the a sample profile was provided on the
// command line. E.g. for flattened profiles where we will not be reloading
// the sample profile in the ThinLTO backend, we ideally shouldn't have to
// provide the sample profile file.
if (Phase == ThinOrFullLTOPhase::ThinLTOPostLink && !LoadSampleProfile)
MPM.addPass(PGOIndirectCallPromotion(true /* InLTO */, HasSampleProfile));
// Create an early function pass manager to cleanup the output of the
// frontend. Not necessary with LTO post link pipelines since the pre link
// pipeline already cleaned up the frontend output.
if (Phase != ThinOrFullLTOPhase::ThinLTOPostLink) {
// Do basic inference of function attributes from known properties of system
// libraries and other oracles.
MPM.addPass(InferFunctionAttrsPass());
MPM.addPass(CoroEarlyPass());
FunctionPassManager EarlyFPM;
// Lower llvm.expect to metadata before attempting transforms.
// Compare/branch metadata may alter the behavior of passes like
// SimplifyCFG.
EarlyFPM.addPass(LowerExpectIntrinsicPass());
EarlyFPM.addPass(SimplifyCFGPass());
EarlyFPM.addPass(SROAPass(SROAOptions::ModifyCFG));
EarlyFPM.addPass(EarlyCSEPass());
if (Level == OptimizationLevel::O3)
EarlyFPM.addPass(CallSiteSplittingPass());
MPM.addPass(createModuleToFunctionPassAdaptor(
std::move(EarlyFPM), PTO.EagerlyInvalidateAnalyses));
}
if (LoadSampleProfile) {
// Annotate sample profile right after early FPM to ensure freshness of
// the debug info.
MPM.addPass(SampleProfileLoaderPass(PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile, Phase));
// Cache ProfileSummaryAnalysis once to avoid the potential need to insert
// RequireAnalysisPass for PSI before subsequent non-module passes.
MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
// Do not invoke ICP in the LTOPrelink phase as it makes it hard
// for the profile annotation to be accurate in the LTO backend.
if (!isLTOPreLink(Phase))
// We perform early indirect call promotion here, before globalopt.
// This is important for the ThinLTO backend phase because otherwise
// imported available_externally functions look unreferenced and are
// removed.
MPM.addPass(
PGOIndirectCallPromotion(true /* IsInLTO */, true /* SamplePGO */));
}
// Try to perform OpenMP specific optimizations on the module. This is a
// (quick!) no-op if there are no OpenMP runtime calls present in the module.
MPM.addPass(OpenMPOptPass());
if (AttributorRun & AttributorRunOption::MODULE)
MPM.addPass(AttributorPass());
// Lower type metadata and the type.test intrinsic in the ThinLTO
// post link pipeline after ICP. This is to enable usage of the type
// tests in ICP sequences.
if (Phase == ThinOrFullLTOPhase::ThinLTOPostLink)
MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
invokePipelineEarlySimplificationEPCallbacks(MPM, Level);
// Interprocedural constant propagation now that basic cleanup has occurred
// and prior to optimizing globals.
// FIXME: This position in the pipeline hasn't been carefully considered in
// years, it should be re-analyzed.
MPM.addPass(IPSCCPPass(
IPSCCPOptions(/*AllowFuncSpec=*/
Level != OptimizationLevel::Os &&
Level != OptimizationLevel::Oz &&
!isLTOPreLink(Phase))));
// Attach metadata to indirect call sites indicating the set of functions
// they may target at run-time. This should follow IPSCCP.
MPM.addPass(CalledValuePropagationPass());
// Optimize globals to try and fold them into constants.
MPM.addPass(GlobalOptPass());
// Create a small function pass pipeline to cleanup after all the global
// optimizations.
FunctionPassManager GlobalCleanupPM;
// FIXME: Should this instead by a run of SROA?
GlobalCleanupPM.addPass(PromotePass());
GlobalCleanupPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(GlobalCleanupPM, Level);
GlobalCleanupPM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM),
PTO.EagerlyInvalidateAnalyses));
// Add all the requested passes for instrumentation PGO, if requested.
if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
(PGOOpt->Action == PGOOptions::IRInstr ||
PGOOpt->Action == PGOOptions::IRUse)) {
addPGOInstrPasses(MPM, Level,
/* RunProfileGen */ PGOOpt->Action == PGOOptions::IRInstr,
/* IsCS */ false, PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile, Phase, PGOOpt->FS);
MPM.addPass(PGOIndirectCallPromotion(false, false));
}
if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
PGOOpt->CSAction == PGOOptions::CSIRInstr)
MPM.addPass(PGOInstrumentationGenCreateVar(PGOOpt->CSProfileGenFile));
if (PGOOpt && Phase != ThinOrFullLTOPhase::ThinLTOPostLink &&
!PGOOpt->MemoryProfile.empty())
MPM.addPass(MemProfUsePass(PGOOpt->MemoryProfile, PGOOpt->FS));
// Synthesize function entry counts for non-PGO compilation.
if (EnableSyntheticCounts && !PGOOpt)
MPM.addPass(SyntheticCountsPropagation());
if (EnableModuleInliner)
MPM.addPass(buildModuleInlinerPipeline(Level, Phase));
else
MPM.addPass(buildInlinerPipeline(Level, Phase));
// Remove any dead arguments exposed by cleanups, constant folding globals,
// and argument promotion.
MPM.addPass(DeadArgumentEliminationPass());
MPM.addPass(CoroCleanupPass());
// Optimize globals now that functions are fully simplified.
MPM.addPass(GlobalOptPass());
MPM.addPass(GlobalDCEPass());
return MPM;
}
/// TODO: Should LTO cause any differences to this set of passes?
void PassBuilder::addVectorPasses(OptimizationLevel Level,
FunctionPassManager &FPM, bool IsFullLTO) {
FPM.addPass(LoopVectorizePass(
LoopVectorizeOptions(!PTO.LoopInterleaving, !PTO.LoopVectorization)));
if (IsFullLTO) {
// The vectorizer may have significantly shortened a loop body; unroll
// again. Unroll small loops to hide loop backedge latency and saturate any
// parallel execution resources of an out-of-order processor. We also then
// need to clean up redundancies and loop invariant code.
// FIXME: It would be really good to use a loop-integrated instruction
// combiner for cleanup here so that the unrolling and LICM can be pipelined
// across the loop nests.
// We do UnrollAndJam in a separate LPM to ensure it happens before unroll
if (EnableUnrollAndJam && PTO.LoopUnrolling)
FPM.addPass(createFunctionToLoopPassAdaptor(
LoopUnrollAndJamPass(Level.getSpeedupLevel())));
FPM.addPass(LoopUnrollPass(LoopUnrollOptions(
Level.getSpeedupLevel(), /*OnlyWhenForced=*/!PTO.LoopUnrolling,
PTO.ForgetAllSCEVInLoopUnroll)));
FPM.addPass(WarnMissedTransformationsPass());
// Now that we are done with loop unrolling, be it either by LoopVectorizer,
// or LoopUnroll passes, some variable-offset GEP's into alloca's could have
// become constant-offset, thus enabling SROA and alloca promotion. Do so.
// NOTE: we are very late in the pipeline, and we don't have any LICM
// or SimplifyCFG passes scheduled after us, that would cleanup
// the CFG mess this may created if allowed to modify CFG, so forbid that.
FPM.addPass(SROAPass(SROAOptions::PreserveCFG));
}
if (!IsFullLTO) {
// Eliminate loads by forwarding stores from the previous iteration to loads
// of the current iteration.
FPM.addPass(LoopLoadEliminationPass());
}
// Cleanup after the loop optimization passes.
FPM.addPass(InstCombinePass());
if (Level.getSpeedupLevel() > 1 && ExtraVectorizerPasses) {
ExtraVectorPassManager ExtraPasses;
// At higher optimization levels, try to clean up any runtime overlap and
// alignment checks inserted by the vectorizer. We want to track correlated
// runtime checks for two inner loops in the same outer loop, fold any
// common computations, hoist loop-invariant aspects out of any outer loop,
// and unswitch the runtime checks if possible. Once hoisted, we may have
// dead (or speculatable) control flows or more combining opportunities.
ExtraPasses.addPass(EarlyCSEPass());
ExtraPasses.addPass(CorrelatedValuePropagationPass());
ExtraPasses.addPass(InstCombinePass());
LoopPassManager LPM;
LPM.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true));
LPM.addPass(SimpleLoopUnswitchPass(/* NonTrivial */ Level ==
OptimizationLevel::O3));
ExtraPasses.addPass(
createFunctionToLoopPassAdaptor(std::move(LPM), /*UseMemorySSA=*/true,
/*UseBlockFrequencyInfo=*/true));
ExtraPasses.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
ExtraPasses.addPass(InstCombinePass());
FPM.addPass(std::move(ExtraPasses));
}
// Now that we've formed fast to execute loop structures, we do further
// optimizations. These are run afterward as they might block doing complex
// analyses and transforms such as what are needed for loop vectorization.
// Cleanup after loop vectorization, etc. Simplification passes like CVP and
// GVN, loop transforms, and others have already run, so it's now better to
// convert to more optimized IR using more aggressive simplify CFG options.
// The extra sinking transform can create larger basic blocks, so do this
// before SLP vectorization.
FPM.addPass(SimplifyCFGPass(SimplifyCFGOptions()
.forwardSwitchCondToPhi(true)
.convertSwitchRangeToICmp(true)
.convertSwitchToLookupTable(true)
.needCanonicalLoops(false)
.hoistCommonInsts(true)
.sinkCommonInsts(true)));
if (IsFullLTO) {
FPM.addPass(SCCPPass());
FPM.addPass(InstCombinePass());
FPM.addPass(BDCEPass());
}
// Optimize parallel scalar instruction chains into SIMD instructions.
if (PTO.SLPVectorization) {
FPM.addPass(SLPVectorizerPass());
if (Level.getSpeedupLevel() > 1 && ExtraVectorizerPasses) {
FPM.addPass(EarlyCSEPass());
}
}
// Enhance/cleanup vector code.
FPM.addPass(VectorCombinePass());
if (!IsFullLTO) {
FPM.addPass(InstCombinePass());
// Unroll small loops to hide loop backedge latency and saturate any
// parallel execution resources of an out-of-order processor. We also then
// need to clean up redundancies and loop invariant code.
// FIXME: It would be really good to use a loop-integrated instruction
// combiner for cleanup here so that the unrolling and LICM can be pipelined
// across the loop nests.
// We do UnrollAndJam in a separate LPM to ensure it happens before unroll
if (EnableUnrollAndJam && PTO.LoopUnrolling) {
FPM.addPass(createFunctionToLoopPassAdaptor(
LoopUnrollAndJamPass(Level.getSpeedupLevel())));
}
FPM.addPass(LoopUnrollPass(LoopUnrollOptions(
Level.getSpeedupLevel(), /*OnlyWhenForced=*/!PTO.LoopUnrolling,
PTO.ForgetAllSCEVInLoopUnroll)));
FPM.addPass(WarnMissedTransformationsPass());
// Now that we are done with loop unrolling, be it either by LoopVectorizer,
// or LoopUnroll passes, some variable-offset GEP's into alloca's could have
// become constant-offset, thus enabling SROA and alloca promotion. Do so.
// NOTE: we are very late in the pipeline, and we don't have any LICM
// or SimplifyCFG passes scheduled after us, that would cleanup
// the CFG mess this may created if allowed to modify CFG, so forbid that.
FPM.addPass(SROAPass(SROAOptions::PreserveCFG));
}
FPM.addPass(InstCombinePass());
// This is needed for two reasons:
// 1. It works around problems that instcombine introduces, such as sinking
// expensive FP divides into loops containing multiplications using the
// divide result.
// 2. It helps to clean up some loop-invariant code created by the loop
// unroll pass when IsFullLTO=false.
FPM.addPass(createFunctionToLoopPassAdaptor(
LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true),
/*UseMemorySSA=*/true, /*UseBlockFrequencyInfo=*/false));
// Now that we've vectorized and unrolled loops, we may have more refined
// alignment information, try to re-derive it here.
FPM.addPass(AlignmentFromAssumptionsPass());
}
ModulePassManager
PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
ThinOrFullLTOPhase LTOPhase) {
const bool LTOPreLink = isLTOPreLink(LTOPhase);
ModulePassManager MPM;
// Run partial inlining pass to partially inline functions that have
// large bodies.
if (RunPartialInlining)
MPM.addPass(PartialInlinerPass());
// Remove avail extern fns and globals definitions since we aren't compiling
// an object file for later LTO. For LTO we want to preserve these so they
// are eligible for inlining at link-time. Note if they are unreferenced they
// will be removed by GlobalDCE later, so this only impacts referenced
// available externally globals. Eventually they will be suppressed during
// codegen, but eliminating here enables more opportunity for GlobalDCE as it
// may make globals referenced by available external functions dead and saves
// running remaining passes on the eliminated functions. These should be
// preserved during prelinking for link-time inlining decisions.
if (!LTOPreLink)
MPM.addPass(EliminateAvailableExternallyPass());
if (EnableOrderFileInstrumentation)
MPM.addPass(InstrOrderFilePass());
// Do RPO function attribute inference across the module to forward-propagate
// attributes where applicable.
// FIXME: Is this really an optimization rather than a canonicalization?
MPM.addPass(ReversePostOrderFunctionAttrsPass());
// Do a post inline PGO instrumentation and use pass. This is a context
// sensitive PGO pass. We don't want to do this in LTOPreLink phrase as
// cross-module inline has not been done yet. The context sensitive
// instrumentation is after all the inlines are done.
if (!LTOPreLink && PGOOpt) {
if (PGOOpt->CSAction == PGOOptions::CSIRInstr)
addPGOInstrPasses(MPM, Level, /* RunProfileGen */ true,
/* IsCS */ true, PGOOpt->CSProfileGenFile,
PGOOpt->ProfileRemappingFile, LTOPhase, PGOOpt->FS);
else if (PGOOpt->CSAction == PGOOptions::CSIRUse)
addPGOInstrPasses(MPM, Level, /* RunProfileGen */ false,
/* IsCS */ true, PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile, LTOPhase, PGOOpt->FS);
}
// Re-compute GlobalsAA here prior to function passes. This is particularly
// useful as the above will have inlined, DCE'ed, and function-attr
// propagated everything. We should at this point have a reasonably minimal
// and richly annotated call graph. By computing aliasing and mod/ref
// information for all local globals here, the late loop passes and notably
// the vectorizer will be able to use them to help recognize vectorizable
// memory operations.
MPM.addPass(RecomputeGlobalsAAPass());
invokeOptimizerEarlyEPCallbacks(MPM, Level);
FunctionPassManager OptimizePM;
OptimizePM.addPass(Float2IntPass());
OptimizePM.addPass(LowerConstantIntrinsicsPass());
if (EnableMatrix) {
OptimizePM.addPass(LowerMatrixIntrinsicsPass());
OptimizePM.addPass(EarlyCSEPass());
}
// CHR pass should only be applied with the profile information.
// The check is to check the profile summary information in CHR.
if (EnableCHR && Level == OptimizationLevel::O3)
OptimizePM.addPass(ControlHeightReductionPass());
// FIXME: We need to run some loop optimizations to re-rotate loops after
// simplifycfg and others undo their rotation.
// Optimize the loop execution. These passes operate on entire loop nests
// rather than on each loop in an inside-out manner, and so they are actually
// function passes.
invokeVectorizerStartEPCallbacks(OptimizePM, Level);
LoopPassManager LPM;
// First rotate loops that may have been un-rotated by prior passes.
// Disable header duplication at -Oz.
LPM.addPass(LoopRotatePass(Level != OptimizationLevel::Oz, LTOPreLink));
// Some loops may have become dead by now. Try to delete them.
// FIXME: see discussion in https://reviews.llvm.org/D112851,
// this may need to be revisited once we run GVN before loop deletion
// in the simplification pipeline.
LPM.addPass(LoopDeletionPass());
OptimizePM.addPass(createFunctionToLoopPassAdaptor(
std::move(LPM), /*UseMemorySSA=*/false, /*UseBlockFrequencyInfo=*/false));
// Distribute loops to allow partial vectorization. I.e. isolate dependences
// into separate loop that would otherwise inhibit vectorization. This is
// currently only performed for loops marked with the metadata
// llvm.loop.distribute=true or when -enable-loop-distribute is specified.
OptimizePM.addPass(LoopDistributePass());
// Populates the VFABI attribute with the scalar-to-vector mappings
// from the TargetLibraryInfo.
OptimizePM.addPass(InjectTLIMappings());
addVectorPasses(Level, OptimizePM, /* IsFullLTO */ false);
// LoopSink pass sinks instructions hoisted by LICM, which serves as a
// canonicalization pass that enables other optimizations. As a result,
// LoopSink pass needs to be a very late IR pass to avoid undoing LICM
// result too early.
OptimizePM.addPass(LoopSinkPass());
// And finally clean up LCSSA form before generating code.
OptimizePM.addPass(InstSimplifyPass());
// This hoists/decomposes div/rem ops. It should run after other sink/hoist
// passes to avoid re-sinking, but before SimplifyCFG because it can allow
// flattening of blocks.
OptimizePM.addPass(DivRemPairsPass());
// Try to annotate calls that were created during optimization.
OptimizePM.addPass(TailCallElimPass());
// LoopSink (and other loop passes since the last simplifyCFG) might have
// resulted in single-entry-single-exit or empty blocks. Clean up the CFG.
OptimizePM.addPass(
SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
// Add the core optimizing pipeline.
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(OptimizePM),
PTO.EagerlyInvalidateAnalyses));
invokeOptimizerLastEPCallbacks(MPM, Level);
// Split out cold code. Splitting is done late to avoid hiding context from
// other optimizations and inadvertently regressing performance. The tradeoff
// is that this has a higher code size cost than splitting early.
if (EnableHotColdSplit && !LTOPreLink)
MPM.addPass(HotColdSplittingPass());
// Search the code for similar regions of code. If enough similar regions can
// be found where extracting the regions into their own function will decrease
// the size of the program, we extract the regions, a deduplicate the
// structurally similar regions.
if (EnableIROutliner)
MPM.addPass(IROutlinerPass());
// Merge functions if requested.
if (PTO.MergeFunctions)
MPM.addPass(MergeFunctionsPass());
// Now we need to do some global optimization transforms.
// FIXME: It would seem like these should come first in the optimization
// pipeline and maybe be the bottom of the canonicalization pipeline? Weird
// ordering here.
MPM.addPass(GlobalDCEPass());
MPM.addPass(ConstantMergePass());
if (PTO.CallGraphProfile && !LTOPreLink)
MPM.addPass(CGProfilePass());
// TODO: Relative look table converter pass caused an issue when full lto is
// enabled. See https://reviews.llvm.org/D94355 for more details.
// Until the issue fixed, disable this pass during pre-linking phase.
if (!LTOPreLink)
MPM.addPass(RelLookupTableConverterPass());
return MPM;
}
ModulePassManager
PassBuilder::buildPerModuleDefaultPipeline(OptimizationLevel Level,
bool LTOPreLink) {
if (Level == OptimizationLevel::O0)
return buildO0DefaultPipeline(Level, LTOPreLink);
ModulePassManager MPM;
// Convert @llvm.global.annotations to !annotation metadata.
MPM.addPass(Annotation2MetadataPass());
// Force any function attributes we want the rest of the pipeline to observe.
MPM.addPass(ForceFunctionAttrsPass());
if (PGOOpt && PGOOpt->DebugInfoForProfiling)
MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
// Apply module pipeline start EP callback.
invokePipelineStartEPCallbacks(MPM, Level);
const ThinOrFullLTOPhase LTOPhase = LTOPreLink
? ThinOrFullLTOPhase::FullLTOPreLink
: ThinOrFullLTOPhase::None;
// Add the core simplification pipeline.
MPM.addPass(buildModuleSimplificationPipeline(Level, LTOPhase));
// Now add the optimization pipeline.
MPM.addPass(buildModuleOptimizationPipeline(Level, LTOPhase));
if (PGOOpt && PGOOpt->PseudoProbeForProfiling &&
PGOOpt->Action == PGOOptions::SampleUse)
MPM.addPass(PseudoProbeUpdatePass());
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
if (LTOPreLink)
addRequiredLTOPreLinkPasses(MPM);
return MPM;
}
ModulePassManager
PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level, bool ThinLTO,
bool EmitSummary) {
ModulePassManager MPM;
MPM.addPass(EmbedBitcodePass(ThinLTO, EmitSummary,
ThinLTO
? buildThinLTOPreLinkDefaultPipeline(Level)
: buildLTOPreLinkDefaultPipeline(Level)));
MPM.addPass(buildPerModuleDefaultPipeline(Level));
return MPM;
}
ModulePassManager
PassBuilder::buildThinLTOPreLinkDefaultPipeline(OptimizationLevel Level) {
if (Level == OptimizationLevel::O0)
return buildO0DefaultPipeline(Level, /*LTOPreLink*/true);
ModulePassManager MPM;
// Convert @llvm.global.annotations to !annotation metadata.
MPM.addPass(Annotation2MetadataPass());
// Force any function attributes we want the rest of the pipeline to observe.
MPM.addPass(ForceFunctionAttrsPass());
if (PGOOpt && PGOOpt->DebugInfoForProfiling)
MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
// Apply module pipeline start EP callback.
invokePipelineStartEPCallbacks(MPM, Level);
// If we are planning to perform ThinLTO later, we don't bloat the code with
// unrolling/vectorization/... now. Just simplify the module as much as we
// can.
MPM.addPass(buildModuleSimplificationPipeline(
Level, ThinOrFullLTOPhase::ThinLTOPreLink));
// Run partial inlining pass to partially inline functions that have
// large bodies.
// FIXME: It isn't clear whether this is really the right place to run this
// in ThinLTO. Because there is another canonicalization and simplification
// phase that will run after the thin link, running this here ends up with
// less information than will be available later and it may grow functions in
// ways that aren't beneficial.
if (RunPartialInlining)
MPM.addPass(PartialInlinerPass());
if (PGOOpt && PGOOpt->PseudoProbeForProfiling &&
PGOOpt->Action == PGOOptions::SampleUse)
MPM.addPass(PseudoProbeUpdatePass());
// Handle Optimizer{Early,Last}EPCallbacks added by clang on PreLink. Actual
// optimization is going to be done in PostLink stage, but clang can't add
// callbacks there in case of in-process ThinLTO called by linker.
invokeOptimizerEarlyEPCallbacks(MPM, Level);
invokeOptimizerLastEPCallbacks(MPM, Level);
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
addRequiredLTOPreLinkPasses(MPM);
return MPM;
}
ModulePassManager PassBuilder::buildThinLTODefaultPipeline(
OptimizationLevel Level, const ModuleSummaryIndex *ImportSummary) {
ModulePassManager MPM;
if (ImportSummary) {
// For ThinLTO we must apply the context disambiguation decisions early, to
// ensure we can correctly match the callsites to summary data.
if (EnableMemProfContextDisambiguation)
MPM.addPass(MemProfContextDisambiguation(ImportSummary));
// These passes import type identifier resolutions for whole-program
// devirtualization and CFI. They must run early because other passes may
// disturb the specific instruction patterns that these passes look for,
// creating dependencies on resolutions that may not appear in the summary.
//
// For example, GVN may transform the pattern assume(type.test) appearing in
// two basic blocks into assume(phi(type.test, type.test)), which would
// transform a dependency on a WPD resolution into a dependency on a type
// identifier resolution for CFI.
//
// Also, WPD has access to more precise information than ICP and can
// devirtualize more effectively, so it should operate on the IR first.
//
// The WPD and LowerTypeTest passes need to run at -O0 to lower type
// metadata and intrinsics.
MPM.addPass(WholeProgramDevirtPass(nullptr, ImportSummary));
MPM.addPass(LowerTypeTestsPass(nullptr, ImportSummary));
}
if (Level == OptimizationLevel::O0) {
// Run a second time to clean up any type tests left behind by WPD for use
// in ICP.
MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
// Drop available_externally and unreferenced globals. This is necessary
// with ThinLTO in order to avoid leaving undefined references to dead
// globals in the object file.
MPM.addPass(EliminateAvailableExternallyPass());
MPM.addPass(GlobalDCEPass());
return MPM;
}
// Add the core simplification pipeline.
MPM.addPass(buildModuleSimplificationPipeline(
Level, ThinOrFullLTOPhase::ThinLTOPostLink));
// Now add the optimization pipeline.
MPM.addPass(buildModuleOptimizationPipeline(
Level, ThinOrFullLTOPhase::ThinLTOPostLink));
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
return MPM;
}
ModulePassManager
PassBuilder::buildLTOPreLinkDefaultPipeline(OptimizationLevel Level) {
// FIXME: We should use a customized pre-link pipeline!
return buildPerModuleDefaultPipeline(Level,
/* LTOPreLink */ true);
}
ModulePassManager
PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
ModuleSummaryIndex *ExportSummary) {
ModulePassManager MPM;
invokeFullLinkTimeOptimizationEarlyEPCallbacks(MPM, Level);
// Create a function that performs CFI checks for cross-DSO calls with targets
// in the current module.
MPM.addPass(CrossDSOCFIPass());
if (Level == OptimizationLevel::O0) {
// The WPD and LowerTypeTest passes need to run at -O0 to lower type
// metadata and intrinsics.
MPM.addPass(WholeProgramDevirtPass(ExportSummary, nullptr));
MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
// Run a second time to clean up any type tests left behind by WPD for use
// in ICP.
MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
invokeFullLinkTimeOptimizationLastEPCallbacks(MPM, Level);
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
return MPM;
}
if (PGOOpt && PGOOpt->Action == PGOOptions::SampleUse) {
// Load sample profile before running the LTO optimization pipeline.
MPM.addPass(SampleProfileLoaderPass(PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile,
ThinOrFullLTOPhase::FullLTOPostLink));
// Cache ProfileSummaryAnalysis once to avoid the potential need to insert
// RequireAnalysisPass for PSI before subsequent non-module passes.
MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
}
// Try to run OpenMP optimizations, quick no-op if no OpenMP metadata present.
MPM.addPass(OpenMPOptPass(ThinOrFullLTOPhase::FullLTOPostLink));
// Remove unused virtual tables to improve the quality of code generated by
// whole-program devirtualization and bitset lowering.
MPM.addPass(GlobalDCEPass(/*InLTOPostLink=*/true));
// Do basic inference of function attributes from known properties of system
// libraries and other oracles.
MPM.addPass(InferFunctionAttrsPass());
if (Level.getSpeedupLevel() > 1) {
MPM.addPass(createModuleToFunctionPassAdaptor(
CallSiteSplittingPass(), PTO.EagerlyInvalidateAnalyses));
// Indirect call promotion. This should promote all the targets that are
// left by the earlier promotion pass that promotes intra-module targets.
// This two-step promotion is to save the compile time. For LTO, it should
// produce the same result as if we only do promotion here.
MPM.addPass(PGOIndirectCallPromotion(
true /* InLTO */, PGOOpt && PGOOpt->Action == PGOOptions::SampleUse));
// Propagate constants at call sites into the functions they call. This
// opens opportunities for globalopt (and inlining) by substituting function
// pointers passed as arguments to direct uses of functions.
MPM.addPass(IPSCCPPass(IPSCCPOptions(/*AllowFuncSpec=*/
Level != OptimizationLevel::Os &&
Level != OptimizationLevel::Oz)));
// Attach metadata to indirect call sites indicating the set of functions
// they may target at run-time. This should follow IPSCCP.
MPM.addPass(CalledValuePropagationPass());
}
// Now deduce any function attributes based in the current code.
MPM.addPass(
createModuleToPostOrderCGSCCPassAdaptor(PostOrderFunctionAttrsPass()));
// Do RPO function attribute inference across the module to forward-propagate
// attributes where applicable.
// FIXME: Is this really an optimization rather than a canonicalization?
MPM.addPass(ReversePostOrderFunctionAttrsPass());
// Use in-range annotations on GEP indices to split globals where beneficial.
MPM.addPass(GlobalSplitPass());
// Run whole program optimization of virtual call when the list of callees
// is fixed.
MPM.addPass(WholeProgramDevirtPass(ExportSummary, nullptr));
// Stop here at -O1.
if (Level == OptimizationLevel::O1) {
// The LowerTypeTestsPass needs to run to lower type metadata and the
// type.test intrinsics. The pass does nothing if CFI is disabled.
MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
// Run a second time to clean up any type tests left behind by WPD for use
// in ICP (which is performed earlier than this in the regular LTO
// pipeline).
MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
invokeFullLinkTimeOptimizationLastEPCallbacks(MPM, Level);
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
return MPM;
}
// Optimize globals to try and fold them into constants.
MPM.addPass(GlobalOptPass());
// Promote any localized globals to SSA registers.
MPM.addPass(createModuleToFunctionPassAdaptor(PromotePass()));
// Linking modules together can lead to duplicate global constant, only
// keep one copy of each constant.
MPM.addPass(ConstantMergePass());
// Remove unused arguments from functions.
MPM.addPass(DeadArgumentEliminationPass());
// Reduce the code after globalopt and ipsccp. Both can open up significant
// simplification opportunities, and both can propagate functions through
// function pointers. When this happens, we often have to resolve varargs
// calls, etc, so let instcombine do this.
FunctionPassManager PeepholeFPM;
PeepholeFPM.addPass(InstCombinePass());
if (Level.getSpeedupLevel() > 1)
PeepholeFPM.addPass(AggressiveInstCombinePass());
invokePeepholeEPCallbacks(PeepholeFPM, Level);
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(PeepholeFPM),
PTO.EagerlyInvalidateAnalyses));
// Note: historically, the PruneEH pass was run first to deduce nounwind and
// generally clean up exception handling overhead. It isn't clear this is
// valuable as the inliner doesn't currently care whether it is inlining an
// invoke or a call.
// Run the inliner now.
if (EnableModuleInliner) {
MPM.addPass(ModuleInlinerPass(getInlineParamsFromOptLevel(Level),
UseInlineAdvisor,
ThinOrFullLTOPhase::FullLTOPostLink));
} else {
MPM.addPass(ModuleInlinerWrapperPass(
getInlineParamsFromOptLevel(Level),
/* MandatoryFirst */ true,
InlineContext{ThinOrFullLTOPhase::FullLTOPostLink,
InlinePass::CGSCCInliner}));
}
// Perform context disambiguation after inlining, since that would reduce the
// amount of additional cloning required to distinguish the allocation
// contexts.
if (EnableMemProfContextDisambiguation)
MPM.addPass(MemProfContextDisambiguation());
// Optimize globals again after we ran the inliner.
MPM.addPass(GlobalOptPass());
// Run the OpenMPOpt pass again after global optimizations.
MPM.addPass(OpenMPOptPass(ThinOrFullLTOPhase::FullLTOPostLink));
// Garbage collect dead functions.
MPM.addPass(GlobalDCEPass(/*InLTOPostLink=*/true));
// If we didn't decide to inline a function, check to see if we can
// transform it to pass arguments by value instead of by reference.
MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(ArgumentPromotionPass()));
FunctionPassManager FPM;
// The IPO Passes may leave cruft around. Clean up after them.
FPM.addPass(InstCombinePass());
invokePeepholeEPCallbacks(FPM, Level);
if (EnableConstraintElimination)
FPM.addPass(ConstraintEliminationPass());
FPM.addPass(JumpThreadingPass());
// Do a post inline PGO instrumentation and use pass. This is a context
// sensitive PGO pass.
if (PGOOpt) {
if (PGOOpt->CSAction == PGOOptions::CSIRInstr)
addPGOInstrPasses(MPM, Level, /* RunProfileGen */ true,
/* IsCS */ true, PGOOpt->CSProfileGenFile,
PGOOpt->ProfileRemappingFile,
ThinOrFullLTOPhase::FullLTOPostLink, PGOOpt->FS);
else if (PGOOpt->CSAction == PGOOptions::CSIRUse)
addPGOInstrPasses(MPM, Level, /* RunProfileGen */ false,
/* IsCS */ true, PGOOpt->ProfileFile,
PGOOpt->ProfileRemappingFile,
ThinOrFullLTOPhase::FullLTOPostLink, PGOOpt->FS);
}
// Break up allocas
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
// LTO provides additional opportunities for tailcall elimination due to
// link-time inlining, and visibility of nocapture attribute.
FPM.addPass(TailCallElimPass());
// Run a few AA driver optimizations here and now to cleanup the code.
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM),
PTO.EagerlyInvalidateAnalyses));
MPM.addPass(
createModuleToPostOrderCGSCCPassAdaptor(PostOrderFunctionAttrsPass()));
// Require the GlobalsAA analysis for the module so we can query it within
// MainFPM.
MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
// Invalidate AAManager so it can be recreated and pick up the newly available
// GlobalsAA.
MPM.addPass(
createModuleToFunctionPassAdaptor(InvalidateAnalysisPass<AAManager>()));
FunctionPassManager MainFPM;
MainFPM.addPass(createFunctionToLoopPassAdaptor(
LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
/*AllowSpeculation=*/true),
/*USeMemorySSA=*/true, /*UseBlockFrequencyInfo=*/false));
if (RunNewGVN)
MainFPM.addPass(NewGVNPass());
else
MainFPM.addPass(GVNPass());
// Remove dead memcpy()'s.
MainFPM.addPass(MemCpyOptPass());
// Nuke dead stores.
MainFPM.addPass(DSEPass());
MainFPM.addPass(MoveAutoInitPass());
MainFPM.addPass(MergedLoadStoreMotionPass());
LoopPassManager LPM;
if (EnableLoopFlatten && Level.getSpeedupLevel() > 1)
LPM.addPass(LoopFlattenPass());
LPM.addPass(IndVarSimplifyPass());
LPM.addPass(LoopDeletionPass());
// FIXME: Add loop interchange.
// Unroll small loops and perform peeling.
LPM.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
/* OnlyWhenForced= */ !PTO.LoopUnrolling,
PTO.ForgetAllSCEVInLoopUnroll));
// The loop passes in LPM (LoopFullUnrollPass) do not preserve MemorySSA.
// *All* loop passes must preserve it, in order to be able to use it.
MainFPM.addPass(createFunctionToLoopPassAdaptor(
std::move(LPM), /*UseMemorySSA=*/false, /*UseBlockFrequencyInfo=*/true));
MainFPM.addPass(LoopDistributePass());
addVectorPasses(Level, MainFPM, /* IsFullLTO */ true);
// Run the OpenMPOpt CGSCC pass again late.
MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(
OpenMPOptCGSCCPass(ThinOrFullLTOPhase::FullLTOPostLink)));
invokePeepholeEPCallbacks(MainFPM, Level);
MainFPM.addPass(JumpThreadingPass());
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(MainFPM),
PTO.EagerlyInvalidateAnalyses));
// Lower type metadata and the type.test intrinsic. This pass supports
// clang's control flow integrity mechanisms (-fsanitize=cfi*) and needs
// to be run at link time if CFI is enabled. This pass does nothing if
// CFI is disabled.
MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
// Run a second time to clean up any type tests left behind by WPD for use
// in ICP (which is performed earlier than this in the regular LTO pipeline).
MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
// Enable splitting late in the FullLTO post-link pipeline.
if (EnableHotColdSplit)
MPM.addPass(HotColdSplittingPass());
// Add late LTO optimization passes.
FunctionPassManager LateFPM;
// LoopSink pass sinks instructions hoisted by LICM, which serves as a
// canonicalization pass that enables other optimizations. As a result,
// LoopSink pass needs to be a very late IR pass to avoid undoing LICM
// result too early.
LateFPM.addPass(LoopSinkPass());
// This hoists/decomposes div/rem ops. It should run after other sink/hoist
// passes to avoid re-sinking, but before SimplifyCFG because it can allow
// flattening of blocks.
LateFPM.addPass(DivRemPairsPass());
// Delete basic blocks, which optimization passes may have killed.
LateFPM.addPass(SimplifyCFGPass(
SimplifyCFGOptions().convertSwitchRangeToICmp(true).hoistCommonInsts(
true)));
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(LateFPM)));
// Drop bodies of available eternally objects to improve GlobalDCE.
MPM.addPass(EliminateAvailableExternallyPass());
// Now that we have optimized the program, discard unreachable functions.
MPM.addPass(GlobalDCEPass(/*InLTOPostLink=*/true));
if (PTO.MergeFunctions)
MPM.addPass(MergeFunctionsPass());
if (PTO.CallGraphProfile)
MPM.addPass(CGProfilePass());
invokeFullLinkTimeOptimizationLastEPCallbacks(MPM, Level);
// Emit annotation remarks.
addAnnotationRemarksPass(MPM);
return MPM;
}
ModulePassManager PassBuilder::buildO0DefaultPipeline(OptimizationLevel Level,
bool LTOPreLink) {
assert(Level == OptimizationLevel::O0 &&
"buildO0DefaultPipeline should only be used with O0");
ModulePassManager MPM;
// Perform pseudo probe instrumentation in O0 mode. This is for the
// consistency between different build modes. For example, a LTO build can be
// mixed with an O0 prelink and an O2 postlink. Loading a sample profile in
// the postlink will require pseudo probe instrumentation in the prelink.
if (PGOOpt && PGOOpt->PseudoProbeForProfiling)
MPM.addPass(SampleProfileProbePass(TM));
if (PGOOpt && (PGOOpt->Action == PGOOptions::IRInstr ||
PGOOpt->Action == PGOOptions::IRUse))
addPGOInstrPassesForO0(
MPM,
/* RunProfileGen */ (PGOOpt->Action == PGOOptions::IRInstr),
/* IsCS */ false, PGOOpt->ProfileFile, PGOOpt->ProfileRemappingFile,
PGOOpt->FS);
invokePipelineStartEPCallbacks(MPM, Level);
if (PGOOpt && PGOOpt->DebugInfoForProfiling)
MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
invokePipelineEarlySimplificationEPCallbacks(MPM, Level);
// Build a minimal pipeline based on the semantics required by LLVM,
// which is just that always inlining occurs. Further, disable generating
// lifetime intrinsics to avoid enabling further optimizations during
// code generation.
MPM.addPass(AlwaysInlinerPass(
/*InsertLifetimeIntrinsics=*/false));
if (PTO.MergeFunctions)
MPM.addPass(MergeFunctionsPass());
if (EnableMatrix)
MPM.addPass(
createModuleToFunctionPassAdaptor(LowerMatrixIntrinsicsPass(true)));
if (!CGSCCOptimizerLateEPCallbacks.empty()) {
CGSCCPassManager CGPM;
invokeCGSCCOptimizerLateEPCallbacks(CGPM, Level);
if (!CGPM.isEmpty())
MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
}
if (!LateLoopOptimizationsEPCallbacks.empty()) {
LoopPassManager LPM;
invokeLateLoopOptimizationsEPCallbacks(LPM, Level);
if (!LPM.isEmpty()) {
MPM.addPass(createModuleToFunctionPassAdaptor(
createFunctionToLoopPassAdaptor(std::move(LPM))));
}
}
if (!LoopOptimizerEndEPCallbacks.empty()) {
LoopPassManager LPM;
invokeLoopOptimizerEndEPCallbacks(LPM, Level);
if (!LPM.isEmpty()) {
MPM.addPass(createModuleToFunctionPassAdaptor(
createFunctionToLoopPassAdaptor(std::move(LPM))));
}
}
if (!ScalarOptimizerLateEPCallbacks.empty()) {
FunctionPassManager FPM;
invokeScalarOptimizerLateEPCallbacks(FPM, Level);
if (!FPM.isEmpty())
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
}
invokeOptimizerEarlyEPCallbacks(MPM, Level);
if (!VectorizerStartEPCallbacks.empty()) {
FunctionPassManager FPM;
invokeVectorizerStartEPCallbacks(FPM, Level);
if (!FPM.isEmpty())
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
}
ModulePassManager CoroPM;
CoroPM.addPass(CoroEarlyPass());
CGSCCPassManager CGPM;
CGPM.addPass(CoroSplitPass());
CoroPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
CoroPM.addPass(CoroCleanupPass());
CoroPM.addPass(GlobalDCEPass());
MPM.addPass(CoroConditionalWrapper(std::move(CoroPM)));
invokeOptimizerLastEPCallbacks(MPM, Level);
if (LTOPreLink)
addRequiredLTOPreLinkPasses(MPM);
MPM.addPass(createModuleToFunctionPassAdaptor(AnnotationRemarksPass()));
return MPM;
}
AAManager PassBuilder::buildDefaultAAPipeline() {
AAManager AA;
// The order in which these are registered determines their priority when
// being queried.
// First we register the basic alias analysis that provides the majority of
// per-function local AA logic. This is a stateless, on-demand local set of
// AA techniques.
AA.registerFunctionAnalysis<BasicAA>();
// Next we query fast, specialized alias analyses that wrap IR-embedded
// information about aliasing.
AA.registerFunctionAnalysis<ScopedNoAliasAA>();
AA.registerFunctionAnalysis<TypeBasedAA>();
// Add support for querying global aliasing information when available.
// Because the `AAManager` is a function analysis and `GlobalsAA` is a module
// analysis, all that the `AAManager` can do is query for any *cached*
// results from `GlobalsAA` through a readonly proxy.
if (EnableGlobalAnalyses)
AA.registerModuleAnalysis<GlobalsAA>();
// Add target-specific alias analyses.
if (TM)
TM->registerDefaultAliasAnalyses(AA);
return AA;
}