//===- TargetPassConfig.cpp - Target independent code generation passes ---===// // // 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 // //===----------------------------------------------------------------------===// // // This file defines interfaces to access the target independent code // generation passes provided by the LLVM backend. // //===---------------------------------------------------------------------===// #include "llvm/CodeGen/TargetPassConfig.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringRef.h" #include "llvm/Analysis/BasicAliasAnalysis.h" #include "llvm/Analysis/CallGraphSCCPass.h" #include "llvm/Analysis/ScopedNoAliasAA.h" #include "llvm/Analysis/TargetTransformInfo.h" #include "llvm/Analysis/TypeBasedAliasAnalysis.h" #include "llvm/CodeGen/BasicBlockSectionsProfileReader.h" #include "llvm/CodeGen/CSEConfigBase.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/MachinePassRegistry.h" #include "llvm/CodeGen/Passes.h" #include "llvm/CodeGen/RegAllocRegistry.h" #include "llvm/IR/IRPrintingPasses.h" #include "llvm/IR/LegacyPassManager.h" #include "llvm/IR/PassInstrumentation.h" #include "llvm/IR/Verifier.h" #include "llvm/InitializePasses.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCTargetOptions.h" #include "llvm/Pass.h" #include "llvm/Support/CodeGen.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Discriminator.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/SaveAndRestore.h" #include "llvm/Support/Threading.h" #include "llvm/Support/VirtualFileSystem.h" #include "llvm/Support/WithColor.h" #include "llvm/Target/CGPassBuilderOption.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils.h" #include #include #include using namespace llvm; static cl::opt EnableIPRA("enable-ipra", cl::init(false), cl::Hidden, cl::desc("Enable interprocedural register allocation " "to reduce load/store at procedure calls.")); static cl::opt DisablePostRASched("disable-post-ra", cl::Hidden, cl::desc("Disable Post Regalloc Scheduler")); static cl::opt DisableBranchFold("disable-branch-fold", cl::Hidden, cl::desc("Disable branch folding")); static cl::opt DisableTailDuplicate("disable-tail-duplicate", cl::Hidden, cl::desc("Disable tail duplication")); static cl::opt DisableEarlyTailDup("disable-early-taildup", cl::Hidden, cl::desc("Disable pre-register allocation tail duplication")); static cl::opt DisableBlockPlacement("disable-block-placement", cl::Hidden, cl::desc("Disable probability-driven block placement")); static cl::opt EnableBlockPlacementStats("enable-block-placement-stats", cl::Hidden, cl::desc("Collect probability-driven block placement stats")); static cl::opt DisableSSC("disable-ssc", cl::Hidden, cl::desc("Disable Stack Slot Coloring")); static cl::opt DisableMachineDCE("disable-machine-dce", cl::Hidden, cl::desc("Disable Machine Dead Code Elimination")); static cl::opt DisableEarlyIfConversion("disable-early-ifcvt", cl::Hidden, cl::desc("Disable Early If-conversion")); static cl::opt DisableMachineLICM("disable-machine-licm", cl::Hidden, cl::desc("Disable Machine LICM")); static cl::opt DisableMachineCSE("disable-machine-cse", cl::Hidden, cl::desc("Disable Machine Common Subexpression Elimination")); static cl::opt OptimizeRegAlloc( "optimize-regalloc", cl::Hidden, cl::desc("Enable optimized register allocation compilation path.")); static cl::opt DisablePostRAMachineLICM("disable-postra-machine-licm", cl::Hidden, cl::desc("Disable Machine LICM")); static cl::opt DisableMachineSink("disable-machine-sink", cl::Hidden, cl::desc("Disable Machine Sinking")); static cl::opt DisablePostRAMachineSink("disable-postra-machine-sink", cl::Hidden, cl::desc("Disable PostRA Machine Sinking")); static cl::opt DisableLSR("disable-lsr", cl::Hidden, cl::desc("Disable Loop Strength Reduction Pass")); static cl::opt DisableConstantHoisting("disable-constant-hoisting", cl::Hidden, cl::desc("Disable ConstantHoisting")); static cl::opt DisableCGP("disable-cgp", cl::Hidden, cl::desc("Disable Codegen Prepare")); static cl::opt DisableCopyProp("disable-copyprop", cl::Hidden, cl::desc("Disable Copy Propagation pass")); static cl::opt DisablePartialLibcallInlining("disable-partial-libcall-inlining", cl::Hidden, cl::desc("Disable Partial Libcall Inlining")); static cl::opt DisableAtExitBasedGlobalDtorLowering( "disable-atexit-based-global-dtor-lowering", cl::Hidden, cl::desc("For MachO, disable atexit()-based global destructor lowering")); static cl::opt EnableImplicitNullChecks( "enable-implicit-null-checks", cl::desc("Fold null checks into faulting memory operations"), cl::init(false), cl::Hidden); static cl::opt DisableMergeICmps("disable-mergeicmps", cl::desc("Disable MergeICmps Pass"), cl::init(false), cl::Hidden); static cl::opt PrintLSR("print-lsr-output", cl::Hidden, cl::desc("Print LLVM IR produced by the loop-reduce pass")); static cl::opt PrintISelInput("print-isel-input", cl::Hidden, cl::desc("Print LLVM IR input to isel pass")); static cl::opt PrintGCInfo("print-gc", cl::Hidden, cl::desc("Dump garbage collector data")); static cl::opt VerifyMachineCode("verify-machineinstrs", cl::Hidden, cl::desc("Verify generated machine code")); static cl::opt DebugifyAndStripAll("debugify-and-strip-all-safe", cl::Hidden, cl::desc("Debugify MIR before and Strip debug after " "each pass except those known to be unsafe " "when debug info is present")); static cl::opt DebugifyCheckAndStripAll( "debugify-check-and-strip-all-safe", cl::Hidden, cl::desc( "Debugify MIR before, by checking and stripping the debug info after, " "each pass except those known to be unsafe when debug info is " "present")); // Enable or disable the MachineOutliner. static cl::opt EnableMachineOutliner( "enable-machine-outliner", cl::desc("Enable the machine outliner"), cl::Hidden, cl::ValueOptional, cl::init(RunOutliner::TargetDefault), cl::values(clEnumValN(RunOutliner::AlwaysOutline, "always", "Run on all functions guaranteed to be beneficial"), clEnumValN(RunOutliner::NeverOutline, "never", "Disable all outlining"), // Sentinel value for unspecified option. clEnumValN(RunOutliner::AlwaysOutline, "", ""))); // Disable the pass to fix unwind information. Whether the pass is included in // the pipeline is controlled via the target options, this option serves as // manual override. static cl::opt DisableCFIFixup("disable-cfi-fixup", cl::Hidden, cl::desc("Disable the CFI fixup pass")); // Enable or disable FastISel. Both options are needed, because // FastISel is enabled by default with -fast, and we wish to be // able to enable or disable fast-isel independently from -O0. static cl::opt EnableFastISelOption("fast-isel", cl::Hidden, cl::desc("Enable the \"fast\" instruction selector")); static cl::opt EnableGlobalISelOption( "global-isel", cl::Hidden, cl::desc("Enable the \"global\" instruction selector")); // FIXME: remove this after switching to NPM or GlobalISel, whichever gets there // first... static cl::opt PrintAfterISel("print-after-isel", cl::init(false), cl::Hidden, cl::desc("Print machine instrs after ISel")); static cl::opt EnableGlobalISelAbort( "global-isel-abort", cl::Hidden, cl::desc("Enable abort calls when \"global\" instruction selection " "fails to lower/select an instruction"), cl::values( clEnumValN(GlobalISelAbortMode::Disable, "0", "Disable the abort"), clEnumValN(GlobalISelAbortMode::Enable, "1", "Enable the abort"), clEnumValN(GlobalISelAbortMode::DisableWithDiag, "2", "Disable the abort but emit a diagnostic on failure"))); // Disable MIRProfileLoader before RegAlloc. This is for for debugging and // tuning purpose. static cl::opt DisableRAFSProfileLoader( "disable-ra-fsprofile-loader", cl::init(false), cl::Hidden, cl::desc("Disable MIRProfileLoader before RegAlloc")); // Disable MIRProfileLoader before BloackPlacement. This is for for debugging // and tuning purpose. static cl::opt DisableLayoutFSProfileLoader( "disable-layout-fsprofile-loader", cl::init(false), cl::Hidden, cl::desc("Disable MIRProfileLoader before BlockPlacement")); // Specify FSProfile file name. static cl::opt FSProfileFile("fs-profile-file", cl::init(""), cl::value_desc("filename"), cl::desc("Flow Sensitive profile file name."), cl::Hidden); // Specify Remapping file for FSProfile. static cl::opt FSRemappingFile( "fs-remapping-file", cl::init(""), cl::value_desc("filename"), cl::desc("Flow Sensitive profile remapping file name."), cl::Hidden); // Temporary option to allow experimenting with MachineScheduler as a post-RA // scheduler. Targets can "properly" enable this with // substitutePass(&PostRASchedulerID, &PostMachineSchedulerID). // Targets can return true in targetSchedulesPostRAScheduling() and // insert a PostRA scheduling pass wherever it wants. static cl::opt MISchedPostRA( "misched-postra", cl::Hidden, cl::desc( "Run MachineScheduler post regalloc (independent of preRA sched)")); // Experimental option to run live interval analysis early. static cl::opt EarlyLiveIntervals("early-live-intervals", cl::Hidden, cl::desc("Run live interval analysis earlier in the pipeline")); /// Option names for limiting the codegen pipeline. /// Those are used in error reporting and we didn't want /// to duplicate their names all over the place. static const char StartAfterOptName[] = "start-after"; static const char StartBeforeOptName[] = "start-before"; static const char StopAfterOptName[] = "stop-after"; static const char StopBeforeOptName[] = "stop-before"; static cl::opt StartAfterOpt(StringRef(StartAfterOptName), cl::desc("Resume compilation after a specific pass"), cl::value_desc("pass-name"), cl::init(""), cl::Hidden); static cl::opt StartBeforeOpt(StringRef(StartBeforeOptName), cl::desc("Resume compilation before a specific pass"), cl::value_desc("pass-name"), cl::init(""), cl::Hidden); static cl::opt StopAfterOpt(StringRef(StopAfterOptName), cl::desc("Stop compilation after a specific pass"), cl::value_desc("pass-name"), cl::init(""), cl::Hidden); static cl::opt StopBeforeOpt(StringRef(StopBeforeOptName), cl::desc("Stop compilation before a specific pass"), cl::value_desc("pass-name"), cl::init(""), cl::Hidden); /// Enable the machine function splitter pass. static cl::opt EnableMachineFunctionSplitter( "enable-split-machine-functions", cl::Hidden, cl::desc("Split out cold blocks from machine functions based on profile " "information.")); /// Disable the expand reductions pass for testing. static cl::opt DisableExpandReductions( "disable-expand-reductions", cl::init(false), cl::Hidden, cl::desc("Disable the expand reduction intrinsics pass from running")); /// Disable the select optimization pass. static cl::opt DisableSelectOptimize( "disable-select-optimize", cl::init(true), cl::Hidden, cl::desc("Disable the select-optimization pass from running")); /// Allow standard passes to be disabled by command line options. This supports /// simple binary flags that either suppress the pass or do nothing. /// i.e. -disable-mypass=false has no effect. /// These should be converted to boolOrDefault in order to use applyOverride. static IdentifyingPassPtr applyDisable(IdentifyingPassPtr PassID, bool Override) { if (Override) return IdentifyingPassPtr(); return PassID; } /// Allow standard passes to be disabled by the command line, regardless of who /// is adding the pass. /// /// StandardID is the pass identified in the standard pass pipeline and provided /// to addPass(). It may be a target-specific ID in the case that the target /// directly adds its own pass, but in that case we harmlessly fall through. /// /// TargetID is the pass that the target has configured to override StandardID. /// /// StandardID may be a pseudo ID. In that case TargetID is the name of the real /// pass to run. This allows multiple options to control a single pass depending /// on where in the pipeline that pass is added. static IdentifyingPassPtr overridePass(AnalysisID StandardID, IdentifyingPassPtr TargetID) { if (StandardID == &PostRASchedulerID) return applyDisable(TargetID, DisablePostRASched); if (StandardID == &BranchFolderPassID) return applyDisable(TargetID, DisableBranchFold); if (StandardID == &TailDuplicateID) return applyDisable(TargetID, DisableTailDuplicate); if (StandardID == &EarlyTailDuplicateID) return applyDisable(TargetID, DisableEarlyTailDup); if (StandardID == &MachineBlockPlacementID) return applyDisable(TargetID, DisableBlockPlacement); if (StandardID == &StackSlotColoringID) return applyDisable(TargetID, DisableSSC); if (StandardID == &DeadMachineInstructionElimID) return applyDisable(TargetID, DisableMachineDCE); if (StandardID == &EarlyIfConverterID) return applyDisable(TargetID, DisableEarlyIfConversion); if (StandardID == &EarlyMachineLICMID) return applyDisable(TargetID, DisableMachineLICM); if (StandardID == &MachineCSEID) return applyDisable(TargetID, DisableMachineCSE); if (StandardID == &MachineLICMID) return applyDisable(TargetID, DisablePostRAMachineLICM); if (StandardID == &MachineSinkingID) return applyDisable(TargetID, DisableMachineSink); if (StandardID == &PostRAMachineSinkingID) return applyDisable(TargetID, DisablePostRAMachineSink); if (StandardID == &MachineCopyPropagationID) return applyDisable(TargetID, DisableCopyProp); return TargetID; } // Find the FSProfile file name. The internal option takes the precedence // before getting from TargetMachine. static std::string getFSProfileFile(const TargetMachine *TM) { if (!FSProfileFile.empty()) return FSProfileFile.getValue(); const std::optional &PGOOpt = TM->getPGOOption(); if (PGOOpt == std::nullopt || PGOOpt->Action != PGOOptions::SampleUse) return std::string(); return PGOOpt->ProfileFile; } // Find the Profile remapping file name. The internal option takes the // precedence before getting from TargetMachine. static std::string getFSRemappingFile(const TargetMachine *TM) { if (!FSRemappingFile.empty()) return FSRemappingFile.getValue(); const std::optional &PGOOpt = TM->getPGOOption(); if (PGOOpt == std::nullopt || PGOOpt->Action != PGOOptions::SampleUse) return std::string(); return PGOOpt->ProfileRemappingFile; } //===---------------------------------------------------------------------===// /// TargetPassConfig //===---------------------------------------------------------------------===// INITIALIZE_PASS(TargetPassConfig, "targetpassconfig", "Target Pass Configuration", false, false) char TargetPassConfig::ID = 0; namespace { struct InsertedPass { AnalysisID TargetPassID; IdentifyingPassPtr InsertedPassID; InsertedPass(AnalysisID TargetPassID, IdentifyingPassPtr InsertedPassID) : TargetPassID(TargetPassID), InsertedPassID(InsertedPassID) {} Pass *getInsertedPass() const { assert(InsertedPassID.isValid() && "Illegal Pass ID!"); if (InsertedPassID.isInstance()) return InsertedPassID.getInstance(); Pass *NP = Pass::createPass(InsertedPassID.getID()); assert(NP && "Pass ID not registered"); return NP; } }; } // end anonymous namespace namespace llvm { extern cl::opt EnableFSDiscriminator; class PassConfigImpl { public: // List of passes explicitly substituted by this target. Normally this is // empty, but it is a convenient way to suppress or replace specific passes // that are part of a standard pass pipeline without overridding the entire // pipeline. This mechanism allows target options to inherit a standard pass's // user interface. For example, a target may disable a standard pass by // default by substituting a pass ID of zero, and the user may still enable // that standard pass with an explicit command line option. DenseMap TargetPasses; /// Store the pairs of of which the second pass /// is inserted after each instance of the first one. SmallVector InsertedPasses; }; } // end namespace llvm // Out of line virtual method. TargetPassConfig::~TargetPassConfig() { delete Impl; } static const PassInfo *getPassInfo(StringRef PassName) { if (PassName.empty()) return nullptr; const PassRegistry &PR = *PassRegistry::getPassRegistry(); const PassInfo *PI = PR.getPassInfo(PassName); if (!PI) report_fatal_error(Twine('\"') + Twine(PassName) + Twine("\" pass is not registered.")); return PI; } static AnalysisID getPassIDFromName(StringRef PassName) { const PassInfo *PI = getPassInfo(PassName); return PI ? PI->getTypeInfo() : nullptr; } static std::pair getPassNameAndInstanceNum(StringRef PassName) { StringRef Name, InstanceNumStr; std::tie(Name, InstanceNumStr) = PassName.split(','); unsigned InstanceNum = 0; if (!InstanceNumStr.empty() && InstanceNumStr.getAsInteger(10, InstanceNum)) report_fatal_error("invalid pass instance specifier " + PassName); return std::make_pair(Name, InstanceNum); } void TargetPassConfig::setStartStopPasses() { StringRef StartBeforeName; std::tie(StartBeforeName, StartBeforeInstanceNum) = getPassNameAndInstanceNum(StartBeforeOpt); StringRef StartAfterName; std::tie(StartAfterName, StartAfterInstanceNum) = getPassNameAndInstanceNum(StartAfterOpt); StringRef StopBeforeName; std::tie(StopBeforeName, StopBeforeInstanceNum) = getPassNameAndInstanceNum(StopBeforeOpt); StringRef StopAfterName; std::tie(StopAfterName, StopAfterInstanceNum) = getPassNameAndInstanceNum(StopAfterOpt); StartBefore = getPassIDFromName(StartBeforeName); StartAfter = getPassIDFromName(StartAfterName); StopBefore = getPassIDFromName(StopBeforeName); StopAfter = getPassIDFromName(StopAfterName); if (StartBefore && StartAfter) report_fatal_error(Twine(StartBeforeOptName) + Twine(" and ") + Twine(StartAfterOptName) + Twine(" specified!")); if (StopBefore && StopAfter) report_fatal_error(Twine(StopBeforeOptName) + Twine(" and ") + Twine(StopAfterOptName) + Twine(" specified!")); Started = (StartAfter == nullptr) && (StartBefore == nullptr); } CGPassBuilderOption llvm::getCGPassBuilderOption() { CGPassBuilderOption Opt; #define SET_OPTION(Option) \ if (Option.getNumOccurrences()) \ Opt.Option = Option; SET_OPTION(EnableFastISelOption) SET_OPTION(EnableGlobalISelAbort) SET_OPTION(EnableGlobalISelOption) SET_OPTION(EnableIPRA) SET_OPTION(OptimizeRegAlloc) SET_OPTION(VerifyMachineCode) #define SET_BOOLEAN_OPTION(Option) Opt.Option = Option; SET_BOOLEAN_OPTION(EarlyLiveIntervals) SET_BOOLEAN_OPTION(EnableBlockPlacementStats) SET_BOOLEAN_OPTION(EnableImplicitNullChecks) SET_BOOLEAN_OPTION(EnableMachineOutliner) SET_BOOLEAN_OPTION(MISchedPostRA) SET_BOOLEAN_OPTION(DisableMergeICmps) SET_BOOLEAN_OPTION(DisableLSR) SET_BOOLEAN_OPTION(DisableConstantHoisting) SET_BOOLEAN_OPTION(DisableCGP) SET_BOOLEAN_OPTION(DisablePartialLibcallInlining) SET_BOOLEAN_OPTION(DisableSelectOptimize) SET_BOOLEAN_OPTION(PrintLSR) SET_BOOLEAN_OPTION(PrintISelInput) SET_BOOLEAN_OPTION(PrintGCInfo) return Opt; } static void registerPartialPipelineCallback(PassInstrumentationCallbacks &PIC, LLVMTargetMachine &LLVMTM) { StringRef StartBefore; StringRef StartAfter; StringRef StopBefore; StringRef StopAfter; unsigned StartBeforeInstanceNum = 0; unsigned StartAfterInstanceNum = 0; unsigned StopBeforeInstanceNum = 0; unsigned StopAfterInstanceNum = 0; std::tie(StartBefore, StartBeforeInstanceNum) = getPassNameAndInstanceNum(StartBeforeOpt); std::tie(StartAfter, StartAfterInstanceNum) = getPassNameAndInstanceNum(StartAfterOpt); std::tie(StopBefore, StopBeforeInstanceNum) = getPassNameAndInstanceNum(StopBeforeOpt); std::tie(StopAfter, StopAfterInstanceNum) = getPassNameAndInstanceNum(StopAfterOpt); if (StartBefore.empty() && StartAfter.empty() && StopBefore.empty() && StopAfter.empty()) return; std::tie(StartBefore, std::ignore) = LLVMTM.getPassNameFromLegacyName(StartBefore); std::tie(StartAfter, std::ignore) = LLVMTM.getPassNameFromLegacyName(StartAfter); std::tie(StopBefore, std::ignore) = LLVMTM.getPassNameFromLegacyName(StopBefore); std::tie(StopAfter, std::ignore) = LLVMTM.getPassNameFromLegacyName(StopAfter); if (!StartBefore.empty() && !StartAfter.empty()) report_fatal_error(Twine(StartBeforeOptName) + Twine(" and ") + Twine(StartAfterOptName) + Twine(" specified!")); if (!StopBefore.empty() && !StopAfter.empty()) report_fatal_error(Twine(StopBeforeOptName) + Twine(" and ") + Twine(StopAfterOptName) + Twine(" specified!")); PIC.registerShouldRunOptionalPassCallback( [=, EnableCurrent = StartBefore.empty() && StartAfter.empty(), EnableNext = std::optional(), StartBeforeCount = 0u, StartAfterCount = 0u, StopBeforeCount = 0u, StopAfterCount = 0u](StringRef P, Any) mutable { bool StartBeforePass = !StartBefore.empty() && P.contains(StartBefore); bool StartAfterPass = !StartAfter.empty() && P.contains(StartAfter); bool StopBeforePass = !StopBefore.empty() && P.contains(StopBefore); bool StopAfterPass = !StopAfter.empty() && P.contains(StopAfter); // Implement -start-after/-stop-after if (EnableNext) { EnableCurrent = *EnableNext; EnableNext.reset(); } // Using PIC.registerAfterPassCallback won't work because if this // callback returns false, AfterPassCallback is also skipped. if (StartAfterPass && StartAfterCount++ == StartAfterInstanceNum) { assert(!EnableNext && "Error: assign to EnableNext more than once"); EnableNext = true; } if (StopAfterPass && StopAfterCount++ == StopAfterInstanceNum) { assert(!EnableNext && "Error: assign to EnableNext more than once"); EnableNext = false; } if (StartBeforePass && StartBeforeCount++ == StartBeforeInstanceNum) EnableCurrent = true; if (StopBeforePass && StopBeforeCount++ == StopBeforeInstanceNum) EnableCurrent = false; return EnableCurrent; }); } void llvm::registerCodeGenCallback(PassInstrumentationCallbacks &PIC, LLVMTargetMachine &LLVMTM) { // Register a callback for disabling passes. PIC.registerShouldRunOptionalPassCallback([](StringRef P, Any) { #define DISABLE_PASS(Option, Name) \ if (Option && P.contains(#Name)) \ return false; DISABLE_PASS(DisableBlockPlacement, MachineBlockPlacementPass) DISABLE_PASS(DisableBranchFold, BranchFolderPass) DISABLE_PASS(DisableCopyProp, MachineCopyPropagationPass) DISABLE_PASS(DisableEarlyIfConversion, EarlyIfConverterPass) DISABLE_PASS(DisableEarlyTailDup, EarlyTailDuplicatePass) DISABLE_PASS(DisableMachineCSE, MachineCSEPass) DISABLE_PASS(DisableMachineDCE, DeadMachineInstructionElimPass) DISABLE_PASS(DisableMachineLICM, EarlyMachineLICMPass) DISABLE_PASS(DisableMachineSink, MachineSinkingPass) DISABLE_PASS(DisablePostRAMachineLICM, MachineLICMPass) DISABLE_PASS(DisablePostRAMachineSink, PostRAMachineSinkingPass) DISABLE_PASS(DisablePostRASched, PostRASchedulerPass) DISABLE_PASS(DisableSSC, StackSlotColoringPass) DISABLE_PASS(DisableTailDuplicate, TailDuplicatePass) return true; }); registerPartialPipelineCallback(PIC, LLVMTM); } // Out of line constructor provides default values for pass options and // registers all common codegen passes. TargetPassConfig::TargetPassConfig(LLVMTargetMachine &TM, PassManagerBase &pm) : ImmutablePass(ID), PM(&pm), TM(&TM) { Impl = new PassConfigImpl(); // Register all target independent codegen passes to activate their PassIDs, // including this pass itself. initializeCodeGen(*PassRegistry::getPassRegistry()); // Also register alias analysis passes required by codegen passes. initializeBasicAAWrapperPassPass(*PassRegistry::getPassRegistry()); initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry()); if (EnableIPRA.getNumOccurrences()) TM.Options.EnableIPRA = EnableIPRA; else { // If not explicitly specified, use target default. TM.Options.EnableIPRA |= TM.useIPRA(); } if (TM.Options.EnableIPRA) setRequiresCodeGenSCCOrder(); if (EnableGlobalISelAbort.getNumOccurrences()) TM.Options.GlobalISelAbort = EnableGlobalISelAbort; setStartStopPasses(); } CodeGenOpt::Level TargetPassConfig::getOptLevel() const { return TM->getOptLevel(); } /// Insert InsertedPassID pass after TargetPassID. void TargetPassConfig::insertPass(AnalysisID TargetPassID, IdentifyingPassPtr InsertedPassID) { assert(((!InsertedPassID.isInstance() && TargetPassID != InsertedPassID.getID()) || (InsertedPassID.isInstance() && TargetPassID != InsertedPassID.getInstance()->getPassID())) && "Insert a pass after itself!"); Impl->InsertedPasses.emplace_back(TargetPassID, InsertedPassID); } /// createPassConfig - Create a pass configuration object to be used by /// addPassToEmitX methods for generating a pipeline of CodeGen passes. /// /// Targets may override this to extend TargetPassConfig. TargetPassConfig *LLVMTargetMachine::createPassConfig(PassManagerBase &PM) { return new TargetPassConfig(*this, PM); } TargetPassConfig::TargetPassConfig() : ImmutablePass(ID) { report_fatal_error("Trying to construct TargetPassConfig without a target " "machine. Scheduling a CodeGen pass without a target " "triple set?"); } bool TargetPassConfig::willCompleteCodeGenPipeline() { return StopBeforeOpt.empty() && StopAfterOpt.empty(); } bool TargetPassConfig::hasLimitedCodeGenPipeline() { return !StartBeforeOpt.empty() || !StartAfterOpt.empty() || !willCompleteCodeGenPipeline(); } std::string TargetPassConfig::getLimitedCodeGenPipelineReason(const char *Separator) { if (!hasLimitedCodeGenPipeline()) return std::string(); std::string Res; static cl::opt *PassNames[] = {&StartAfterOpt, &StartBeforeOpt, &StopAfterOpt, &StopBeforeOpt}; static const char *OptNames[] = {StartAfterOptName, StartBeforeOptName, StopAfterOptName, StopBeforeOptName}; bool IsFirst = true; for (int Idx = 0; Idx < 4; ++Idx) if (!PassNames[Idx]->empty()) { if (!IsFirst) Res += Separator; IsFirst = false; Res += OptNames[Idx]; } return Res; } // Helper to verify the analysis is really immutable. void TargetPassConfig::setOpt(bool &Opt, bool Val) { assert(!Initialized && "PassConfig is immutable"); Opt = Val; } void TargetPassConfig::substitutePass(AnalysisID StandardID, IdentifyingPassPtr TargetID) { Impl->TargetPasses[StandardID] = TargetID; } IdentifyingPassPtr TargetPassConfig::getPassSubstitution(AnalysisID ID) const { DenseMap::const_iterator I = Impl->TargetPasses.find(ID); if (I == Impl->TargetPasses.end()) return ID; return I->second; } bool TargetPassConfig::isPassSubstitutedOrOverridden(AnalysisID ID) const { IdentifyingPassPtr TargetID = getPassSubstitution(ID); IdentifyingPassPtr FinalPtr = overridePass(ID, TargetID); return !FinalPtr.isValid() || FinalPtr.isInstance() || FinalPtr.getID() != ID; } /// Add a pass to the PassManager if that pass is supposed to be run. If the /// Started/Stopped flags indicate either that the compilation should start at /// a later pass or that it should stop after an earlier pass, then do not add /// the pass. Finally, compare the current pass against the StartAfter /// and StopAfter options and change the Started/Stopped flags accordingly. void TargetPassConfig::addPass(Pass *P) { assert(!Initialized && "PassConfig is immutable"); // Cache the Pass ID here in case the pass manager finds this pass is // redundant with ones already scheduled / available, and deletes it. // Fundamentally, once we add the pass to the manager, we no longer own it // and shouldn't reference it. AnalysisID PassID = P->getPassID(); if (StartBefore == PassID && StartBeforeCount++ == StartBeforeInstanceNum) Started = true; if (StopBefore == PassID && StopBeforeCount++ == StopBeforeInstanceNum) Stopped = true; if (Started && !Stopped) { if (AddingMachinePasses) { // Construct banner message before PM->add() as that may delete the pass. std::string Banner = std::string("After ") + std::string(P->getPassName()); addMachinePrePasses(); PM->add(P); addMachinePostPasses(Banner); } else { PM->add(P); } // Add the passes after the pass P if there is any. for (const auto &IP : Impl->InsertedPasses) if (IP.TargetPassID == PassID) addPass(IP.getInsertedPass()); } else { delete P; } if (StopAfter == PassID && StopAfterCount++ == StopAfterInstanceNum) Stopped = true; if (StartAfter == PassID && StartAfterCount++ == StartAfterInstanceNum) Started = true; if (Stopped && !Started) report_fatal_error("Cannot stop compilation after pass that is not run"); } /// Add a CodeGen pass at this point in the pipeline after checking for target /// and command line overrides. /// /// addPass cannot return a pointer to the pass instance because is internal the /// PassManager and the instance we create here may already be freed. AnalysisID TargetPassConfig::addPass(AnalysisID PassID) { IdentifyingPassPtr TargetID = getPassSubstitution(PassID); IdentifyingPassPtr FinalPtr = overridePass(PassID, TargetID); if (!FinalPtr.isValid()) return nullptr; Pass *P; if (FinalPtr.isInstance()) P = FinalPtr.getInstance(); else { P = Pass::createPass(FinalPtr.getID()); if (!P) llvm_unreachable("Pass ID not registered"); } AnalysisID FinalID = P->getPassID(); addPass(P); // Ends the lifetime of P. return FinalID; } void TargetPassConfig::printAndVerify(const std::string &Banner) { addPrintPass(Banner); addVerifyPass(Banner); } void TargetPassConfig::addPrintPass(const std::string &Banner) { if (PrintAfterISel) PM->add(createMachineFunctionPrinterPass(dbgs(), Banner)); } void TargetPassConfig::addVerifyPass(const std::string &Banner) { bool Verify = VerifyMachineCode == cl::BOU_TRUE; #ifdef EXPENSIVE_CHECKS if (VerifyMachineCode == cl::BOU_UNSET) Verify = TM->isMachineVerifierClean(); #endif if (Verify) PM->add(createMachineVerifierPass(Banner)); } void TargetPassConfig::addDebugifyPass() { PM->add(createDebugifyMachineModulePass()); } void TargetPassConfig::addStripDebugPass() { PM->add(createStripDebugMachineModulePass(/*OnlyDebugified=*/true)); } void TargetPassConfig::addCheckDebugPass() { PM->add(createCheckDebugMachineModulePass()); } void TargetPassConfig::addMachinePrePasses(bool AllowDebugify) { if (AllowDebugify && DebugifyIsSafe && (DebugifyAndStripAll == cl::BOU_TRUE || DebugifyCheckAndStripAll == cl::BOU_TRUE)) addDebugifyPass(); } void TargetPassConfig::addMachinePostPasses(const std::string &Banner) { if (DebugifyIsSafe) { if (DebugifyCheckAndStripAll == cl::BOU_TRUE) { addCheckDebugPass(); addStripDebugPass(); } else if (DebugifyAndStripAll == cl::BOU_TRUE) addStripDebugPass(); } addVerifyPass(Banner); } /// Add common target configurable passes that perform LLVM IR to IR transforms /// following machine independent optimization. void TargetPassConfig::addIRPasses() { // Before running any passes, run the verifier to determine if the input // coming from the front-end and/or optimizer is valid. if (!DisableVerify) addPass(createVerifierPass()); if (getOptLevel() != CodeGenOpt::None) { // Basic AliasAnalysis support. // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that // BasicAliasAnalysis wins if they disagree. This is intended to help // support "obvious" type-punning idioms. addPass(createTypeBasedAAWrapperPass()); addPass(createScopedNoAliasAAWrapperPass()); addPass(createBasicAAWrapperPass()); // Run loop strength reduction before anything else. if (!DisableLSR) { addPass(createCanonicalizeFreezeInLoopsPass()); addPass(createLoopStrengthReducePass()); if (PrintLSR) addPass(createPrintFunctionPass(dbgs(), "\n\n*** Code after LSR ***\n")); } // The MergeICmpsPass tries to create memcmp calls by grouping sequences of // loads and compares. ExpandMemCmpPass then tries to expand those calls // into optimally-sized loads and compares. The transforms are enabled by a // target lowering hook. if (!DisableMergeICmps) addPass(createMergeICmpsLegacyPass()); addPass(createExpandMemCmpPass()); } // Run GC lowering passes for builtin collectors // TODO: add a pass insertion point here addPass(&GCLoweringID); addPass(&ShadowStackGCLoweringID); addPass(createLowerConstantIntrinsicsPass()); // For MachO, lower @llvm.global_dtors into @llvm.global_ctors with // __cxa_atexit() calls to avoid emitting the deprecated __mod_term_func. if (TM->getTargetTriple().isOSBinFormatMachO() && !DisableAtExitBasedGlobalDtorLowering) addPass(createLowerGlobalDtorsLegacyPass()); // Make sure that no unreachable blocks are instruction selected. addPass(createUnreachableBlockEliminationPass()); // Prepare expensive constants for SelectionDAG. if (getOptLevel() != CodeGenOpt::None && !DisableConstantHoisting) addPass(createConstantHoistingPass()); if (getOptLevel() != CodeGenOpt::None) addPass(createReplaceWithVeclibLegacyPass()); if (getOptLevel() != CodeGenOpt::None && !DisablePartialLibcallInlining) addPass(createPartiallyInlineLibCallsPass()); // Expand vector predication intrinsics into standard IR instructions. // This pass has to run before ScalarizeMaskedMemIntrin and ExpandReduction // passes since it emits those kinds of intrinsics. addPass(createExpandVectorPredicationPass()); // Add scalarization of target's unsupported masked memory intrinsics pass. // the unsupported intrinsic will be replaced with a chain of basic blocks, // that stores/loads element one-by-one if the appropriate mask bit is set. addPass(createScalarizeMaskedMemIntrinLegacyPass()); // Expand reduction intrinsics into shuffle sequences if the target wants to. // Allow disabling it for testing purposes. if (!DisableExpandReductions) addPass(createExpandReductionsPass()); if (getOptLevel() != CodeGenOpt::None) addPass(createTLSVariableHoistPass()); // Convert conditional moves to conditional jumps when profitable. if (getOptLevel() != CodeGenOpt::None && !DisableSelectOptimize) addPass(createSelectOptimizePass()); } /// Turn exception handling constructs into something the code generators can /// handle. void TargetPassConfig::addPassesToHandleExceptions() { const MCAsmInfo *MCAI = TM->getMCAsmInfo(); assert(MCAI && "No MCAsmInfo"); switch (MCAI->getExceptionHandlingType()) { case ExceptionHandling::SjLj: // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both // Dwarf EH prepare needs to be run after SjLj prepare. Otherwise, // catch info can get misplaced when a selector ends up more than one block // removed from the parent invoke(s). This could happen when a landing // pad is shared by multiple invokes and is also a target of a normal // edge from elsewhere. addPass(createSjLjEHPreparePass(TM)); [[fallthrough]]; case ExceptionHandling::DwarfCFI: case ExceptionHandling::ARM: case ExceptionHandling::AIX: addPass(createDwarfEHPass(getOptLevel())); break; case ExceptionHandling::WinEH: // We support using both GCC-style and MSVC-style exceptions on Windows, so // add both preparation passes. Each pass will only actually run if it // recognizes the personality function. addPass(createWinEHPass()); addPass(createDwarfEHPass(getOptLevel())); break; case ExceptionHandling::Wasm: // Wasm EH uses Windows EH instructions, but it does not need to demote PHIs // on catchpads and cleanuppads because it does not outline them into // funclets. Catchswitch blocks are not lowered in SelectionDAG, so we // should remove PHIs there. addPass(createWinEHPass(/*DemoteCatchSwitchPHIOnly=*/false)); addPass(createWasmEHPass()); break; case ExceptionHandling::None: addPass(createLowerInvokePass()); // The lower invoke pass may create unreachable code. Remove it. addPass(createUnreachableBlockEliminationPass()); break; } } /// Add pass to prepare the LLVM IR for code generation. This should be done /// before exception handling preparation passes. void TargetPassConfig::addCodeGenPrepare() { if (getOptLevel() != CodeGenOpt::None && !DisableCGP) addPass(createCodeGenPreparePass()); } /// Add common passes that perform LLVM IR to IR transforms in preparation for /// instruction selection. void TargetPassConfig::addISelPrepare() { addPreISel(); // Force codegen to run according to the callgraph. if (requiresCodeGenSCCOrder()) addPass(new DummyCGSCCPass); addPass(createCallBrPass()); // Add both the safe stack and the stack protection passes: each of them will // only protect functions that have corresponding attributes. addPass(createSafeStackPass()); addPass(createStackProtectorPass()); if (PrintISelInput) addPass(createPrintFunctionPass( dbgs(), "\n\n*** Final LLVM Code input to ISel ***\n")); // All passes which modify the LLVM IR are now complete; run the verifier // to ensure that the IR is valid. if (!DisableVerify) addPass(createVerifierPass()); } bool TargetPassConfig::addCoreISelPasses() { // Enable FastISel with -fast-isel, but allow that to be overridden. TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE); // Determine an instruction selector. enum class SelectorType { SelectionDAG, FastISel, GlobalISel }; SelectorType Selector; if (EnableFastISelOption == cl::BOU_TRUE) Selector = SelectorType::FastISel; else if (EnableGlobalISelOption == cl::BOU_TRUE || (TM->Options.EnableGlobalISel && EnableGlobalISelOption != cl::BOU_FALSE)) Selector = SelectorType::GlobalISel; else if (TM->getOptLevel() == CodeGenOpt::None && TM->getO0WantsFastISel()) Selector = SelectorType::FastISel; else Selector = SelectorType::SelectionDAG; // Set consistently TM->Options.EnableFastISel and EnableGlobalISel. if (Selector == SelectorType::FastISel) { TM->setFastISel(true); TM->setGlobalISel(false); } else if (Selector == SelectorType::GlobalISel) { TM->setFastISel(false); TM->setGlobalISel(true); } // FIXME: Injecting into the DAGISel pipeline seems to cause issues with // analyses needing to be re-run. This can result in being unable to // schedule passes (particularly with 'Function Alias Analysis // Results'). It's not entirely clear why but AFAICT this seems to be // due to one FunctionPassManager not being able to use analyses from a // previous one. As we're injecting a ModulePass we break the usual // pass manager into two. GlobalISel with the fallback path disabled // and -run-pass seem to be unaffected. The majority of GlobalISel // testing uses -run-pass so this probably isn't too bad. SaveAndRestore SavedDebugifyIsSafe(DebugifyIsSafe); if (Selector != SelectorType::GlobalISel || !isGlobalISelAbortEnabled()) DebugifyIsSafe = false; // Add instruction selector passes. if (Selector == SelectorType::GlobalISel) { SaveAndRestore SavedAddingMachinePasses(AddingMachinePasses, true); if (addIRTranslator()) return true; addPreLegalizeMachineIR(); if (addLegalizeMachineIR()) return true; // Before running the register bank selector, ask the target if it // wants to run some passes. addPreRegBankSelect(); if (addRegBankSelect()) return true; addPreGlobalInstructionSelect(); if (addGlobalInstructionSelect()) return true; // Pass to reset the MachineFunction if the ISel failed. addPass(createResetMachineFunctionPass( reportDiagnosticWhenGlobalISelFallback(), isGlobalISelAbortEnabled())); // Provide a fallback path when we do not want to abort on // not-yet-supported input. if (!isGlobalISelAbortEnabled() && addInstSelector()) return true; } else if (addInstSelector()) return true; // Expand pseudo-instructions emitted by ISel. Don't run the verifier before // FinalizeISel. addPass(&FinalizeISelID); // Print the instruction selected machine code... printAndVerify("After Instruction Selection"); return false; } bool TargetPassConfig::addISelPasses() { if (TM->useEmulatedTLS()) addPass(createLowerEmuTLSPass()); PM->add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis())); addPass(createPreISelIntrinsicLoweringPass()); addPass(createExpandLargeDivRemPass()); addPass(createExpandLargeFpConvertPass()); addIRPasses(); addCodeGenPrepare(); addPassesToHandleExceptions(); addISelPrepare(); return addCoreISelPasses(); } /// -regalloc=... command line option. static FunctionPass *useDefaultRegisterAllocator() { return nullptr; } static cl::opt> RegAlloc("regalloc", cl::Hidden, cl::init(&useDefaultRegisterAllocator), cl::desc("Register allocator to use")); /// Add the complete set of target-independent postISel code generator passes. /// /// This can be read as the standard order of major LLVM CodeGen stages. Stages /// with nontrivial configuration or multiple passes are broken out below in /// add%Stage routines. /// /// Any TargetPassConfig::addXX routine may be overriden by the Target. The /// addPre/Post methods with empty header implementations allow injecting /// target-specific fixups just before or after major stages. Additionally, /// targets have the flexibility to change pass order within a stage by /// overriding default implementation of add%Stage routines below. Each /// technique has maintainability tradeoffs because alternate pass orders are /// not well supported. addPre/Post works better if the target pass is easily /// tied to a common pass. But if it has subtle dependencies on multiple passes, /// the target should override the stage instead. /// /// TODO: We could use a single addPre/Post(ID) hook to allow pass injection /// before/after any target-independent pass. But it's currently overkill. void TargetPassConfig::addMachinePasses() { AddingMachinePasses = true; // Add passes that optimize machine instructions in SSA form. if (getOptLevel() != CodeGenOpt::None) { addMachineSSAOptimization(); } else { // If the target requests it, assign local variables to stack slots relative // to one another and simplify frame index references where possible. addPass(&LocalStackSlotAllocationID); } if (TM->Options.EnableIPRA) addPass(createRegUsageInfoPropPass()); // Run pre-ra passes. addPreRegAlloc(); // Debugifying the register allocator passes seems to provoke some // non-determinism that affects CodeGen and there doesn't seem to be a point // where it becomes safe again so stop debugifying here. DebugifyIsSafe = false; // Add a FSDiscriminator pass right before RA, so that we could get // more precise SampleFDO profile for RA. if (EnableFSDiscriminator) { addPass(createMIRAddFSDiscriminatorsPass( sampleprof::FSDiscriminatorPass::Pass1)); const std::string ProfileFile = getFSProfileFile(TM); if (!ProfileFile.empty() && !DisableRAFSProfileLoader) addPass(createMIRProfileLoaderPass(ProfileFile, getFSRemappingFile(TM), sampleprof::FSDiscriminatorPass::Pass1, nullptr)); } // Run register allocation and passes that are tightly coupled with it, // including phi elimination and scheduling. if (getOptimizeRegAlloc()) addOptimizedRegAlloc(); else addFastRegAlloc(); // Run post-ra passes. addPostRegAlloc(); addPass(&RemoveRedundantDebugValuesID); addPass(&FixupStatepointCallerSavedID); // Insert prolog/epilog code. Eliminate abstract frame index references... if (getOptLevel() != CodeGenOpt::None) { addPass(&PostRAMachineSinkingID); addPass(&ShrinkWrapID); } // Prolog/Epilog inserter needs a TargetMachine to instantiate. But only // do so if it hasn't been disabled, substituted, or overridden. if (!isPassSubstitutedOrOverridden(&PrologEpilogCodeInserterID)) addPass(createPrologEpilogInserterPass()); /// Add passes that optimize machine instructions after register allocation. if (getOptLevel() != CodeGenOpt::None) addMachineLateOptimization(); // Expand pseudo instructions before second scheduling pass. addPass(&ExpandPostRAPseudosID); // Run pre-sched2 passes. addPreSched2(); if (EnableImplicitNullChecks) addPass(&ImplicitNullChecksID); // Second pass scheduler. // Let Target optionally insert this pass by itself at some other // point. if (getOptLevel() != CodeGenOpt::None && !TM->targetSchedulesPostRAScheduling()) { if (MISchedPostRA) addPass(&PostMachineSchedulerID); else addPass(&PostRASchedulerID); } // GC if (addGCPasses()) { if (PrintGCInfo) addPass(createGCInfoPrinter(dbgs())); } // Basic block placement. if (getOptLevel() != CodeGenOpt::None) addBlockPlacement(); // Insert before XRay Instrumentation. addPass(&FEntryInserterID); addPass(&XRayInstrumentationID); addPass(&PatchableFunctionID); addPreEmitPass(); if (TM->Options.EnableIPRA) // Collect register usage information and produce a register mask of // clobbered registers, to be used to optimize call sites. addPass(createRegUsageInfoCollector()); // FIXME: Some backends are incompatible with running the verifier after // addPreEmitPass. Maybe only pass "false" here for those targets? addPass(&FuncletLayoutID); addPass(&StackMapLivenessID); addPass(&LiveDebugValuesID); addPass(&MachineSanitizerBinaryMetadataID); if (TM->Options.EnableMachineOutliner && getOptLevel() != CodeGenOpt::None && EnableMachineOutliner != RunOutliner::NeverOutline) { bool RunOnAllFunctions = (EnableMachineOutliner == RunOutliner::AlwaysOutline); bool AddOutliner = RunOnAllFunctions || TM->Options.SupportsDefaultOutlining; if (AddOutliner) addPass(createMachineOutlinerPass(RunOnAllFunctions)); } if (EnableFSDiscriminator) addPass(createMIRAddFSDiscriminatorsPass( sampleprof::FSDiscriminatorPass::PassLast)); // Machine function splitter uses the basic block sections feature. Both // cannot be enabled at the same time. Basic block sections takes precedence. // FIXME: In principle, BasicBlockSection::Labels and splitting can used // together. Update this check once we have addressed any issues. if (TM->getBBSectionsType() != llvm::BasicBlockSection::None) { if (TM->getBBSectionsType() == llvm::BasicBlockSection::List) { addPass(llvm::createBasicBlockSectionsProfileReaderPass( TM->getBBSectionsFuncListBuf())); } addPass(llvm::createBasicBlockSectionsPass()); } else if (TM->Options.EnableMachineFunctionSplitter || EnableMachineFunctionSplitter) { const std::string ProfileFile = getFSProfileFile(TM); if (!ProfileFile.empty()) { if (EnableFSDiscriminator) { addPass(createMIRProfileLoaderPass( ProfileFile, getFSRemappingFile(TM), sampleprof::FSDiscriminatorPass::PassLast, nullptr)); } else { // Sample profile is given, but FSDiscriminator is not // enabled, this may result in performance regression. WithColor::warning() << "Using AutoFDO without FSDiscriminator for MFS may regress " "performance."; } } addPass(createMachineFunctionSplitterPass()); } addPostBBSections(); if (!DisableCFIFixup && TM->Options.EnableCFIFixup) addPass(createCFIFixup()); PM->add(createStackFrameLayoutAnalysisPass()); // Add passes that directly emit MI after all other MI passes. addPreEmitPass2(); AddingMachinePasses = false; } /// Add passes that optimize machine instructions in SSA form. void TargetPassConfig::addMachineSSAOptimization() { // Pre-ra tail duplication. addPass(&EarlyTailDuplicateID); // Optimize PHIs before DCE: removing dead PHI cycles may make more // instructions dead. addPass(&OptimizePHIsID); // This pass merges large allocas. StackSlotColoring is a different pass // which merges spill slots. addPass(&StackColoringID); // If the target requests it, assign local variables to stack slots relative // to one another and simplify frame index references where possible. addPass(&LocalStackSlotAllocationID); // With optimization, dead code should already be eliminated. However // there is one known exception: lowered code for arguments that are only // used by tail calls, where the tail calls reuse the incoming stack // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll). addPass(&DeadMachineInstructionElimID); // Allow targets to insert passes that improve instruction level parallelism, // like if-conversion. Such passes will typically need dominator trees and // loop info, just like LICM and CSE below. addILPOpts(); addPass(&EarlyMachineLICMID); addPass(&MachineCSEID); addPass(&MachineSinkingID); addPass(&PeepholeOptimizerID); // Clean-up the dead code that may have been generated by peephole // rewriting. addPass(&DeadMachineInstructionElimID); } //===---------------------------------------------------------------------===// /// Register Allocation Pass Configuration //===---------------------------------------------------------------------===// bool TargetPassConfig::getOptimizeRegAlloc() const { switch (OptimizeRegAlloc) { case cl::BOU_UNSET: return getOptLevel() != CodeGenOpt::None; case cl::BOU_TRUE: return true; case cl::BOU_FALSE: return false; } llvm_unreachable("Invalid optimize-regalloc state"); } /// A dummy default pass factory indicates whether the register allocator is /// overridden on the command line. static llvm::once_flag InitializeDefaultRegisterAllocatorFlag; static RegisterRegAlloc defaultRegAlloc("default", "pick register allocator based on -O option", useDefaultRegisterAllocator); static void initializeDefaultRegisterAllocatorOnce() { if (!RegisterRegAlloc::getDefault()) RegisterRegAlloc::setDefault(RegAlloc); } /// Instantiate the default register allocator pass for this target for either /// the optimized or unoptimized allocation path. This will be added to the pass /// manager by addFastRegAlloc in the unoptimized case or addOptimizedRegAlloc /// in the optimized case. /// /// A target that uses the standard regalloc pass order for fast or optimized /// allocation may still override this for per-target regalloc /// selection. But -regalloc=... always takes precedence. FunctionPass *TargetPassConfig::createTargetRegisterAllocator(bool Optimized) { if (Optimized) return createGreedyRegisterAllocator(); else return createFastRegisterAllocator(); } /// Find and instantiate the register allocation pass requested by this target /// at the current optimization level. Different register allocators are /// defined as separate passes because they may require different analysis. /// /// This helper ensures that the regalloc= option is always available, /// even for targets that override the default allocator. /// /// FIXME: When MachinePassRegistry register pass IDs instead of function ptrs, /// this can be folded into addPass. FunctionPass *TargetPassConfig::createRegAllocPass(bool Optimized) { // Initialize the global default. llvm::call_once(InitializeDefaultRegisterAllocatorFlag, initializeDefaultRegisterAllocatorOnce); RegisterRegAlloc::FunctionPassCtor Ctor = RegisterRegAlloc::getDefault(); if (Ctor != useDefaultRegisterAllocator) return Ctor(); // With no -regalloc= override, ask the target for a regalloc pass. return createTargetRegisterAllocator(Optimized); } bool TargetPassConfig::isCustomizedRegAlloc() { return RegAlloc != (RegisterRegAlloc::FunctionPassCtor)&useDefaultRegisterAllocator; } bool TargetPassConfig::addRegAssignAndRewriteFast() { if (RegAlloc != (RegisterRegAlloc::FunctionPassCtor)&useDefaultRegisterAllocator && RegAlloc != (RegisterRegAlloc::FunctionPassCtor)&createFastRegisterAllocator) report_fatal_error("Must use fast (default) register allocator for unoptimized regalloc."); addPass(createRegAllocPass(false)); // Allow targets to change the register assignments after // fast register allocation. addPostFastRegAllocRewrite(); return true; } bool TargetPassConfig::addRegAssignAndRewriteOptimized() { // Add the selected register allocation pass. addPass(createRegAllocPass(true)); // Allow targets to change the register assignments before rewriting. addPreRewrite(); // Finally rewrite virtual registers. addPass(&VirtRegRewriterID); // Regalloc scoring for ML-driven eviction - noop except when learning a new // eviction policy. addPass(createRegAllocScoringPass()); return true; } /// Return true if the default global register allocator is in use and /// has not be overriden on the command line with '-regalloc=...' bool TargetPassConfig::usingDefaultRegAlloc() const { return RegAlloc.getNumOccurrences() == 0; } /// Add the minimum set of target-independent passes that are required for /// register allocation. No coalescing or scheduling. void TargetPassConfig::addFastRegAlloc() { addPass(&PHIEliminationID); addPass(&TwoAddressInstructionPassID); addRegAssignAndRewriteFast(); } /// Add standard target-independent passes that are tightly coupled with /// optimized register allocation, including coalescing, machine instruction /// scheduling, and register allocation itself. void TargetPassConfig::addOptimizedRegAlloc() { addPass(&DetectDeadLanesID); addPass(&ProcessImplicitDefsID); // LiveVariables currently requires pure SSA form. // // FIXME: Once TwoAddressInstruction pass no longer uses kill flags, // LiveVariables can be removed completely, and LiveIntervals can be directly // computed. (We still either need to regenerate kill flags after regalloc, or // preferably fix the scavenger to not depend on them). // FIXME: UnreachableMachineBlockElim is a dependant pass of LiveVariables. // When LiveVariables is removed this has to be removed/moved either. // Explicit addition of UnreachableMachineBlockElim allows stopping before or // after it with -stop-before/-stop-after. addPass(&UnreachableMachineBlockElimID); addPass(&LiveVariablesID); // Edge splitting is smarter with machine loop info. addPass(&MachineLoopInfoID); addPass(&PHIEliminationID); // Eventually, we want to run LiveIntervals before PHI elimination. if (EarlyLiveIntervals) addPass(&LiveIntervalsID); addPass(&TwoAddressInstructionPassID); addPass(&RegisterCoalescerID); // The machine scheduler may accidentally create disconnected components // when moving subregister definitions around, avoid this by splitting them to // separate vregs before. Splitting can also improve reg. allocation quality. addPass(&RenameIndependentSubregsID); // PreRA instruction scheduling. addPass(&MachineSchedulerID); if (addRegAssignAndRewriteOptimized()) { // Perform stack slot coloring and post-ra machine LICM. addPass(&StackSlotColoringID); // Allow targets to expand pseudo instructions depending on the choice of // registers before MachineCopyPropagation. addPostRewrite(); // Copy propagate to forward register uses and try to eliminate COPYs that // were not coalesced. addPass(&MachineCopyPropagationID); // Run post-ra machine LICM to hoist reloads / remats. // // FIXME: can this move into MachineLateOptimization? addPass(&MachineLICMID); } } //===---------------------------------------------------------------------===// /// Post RegAlloc Pass Configuration //===---------------------------------------------------------------------===// /// Add passes that optimize machine instructions after register allocation. void TargetPassConfig::addMachineLateOptimization() { // Cleanup of redundant immediate/address loads. addPass(&MachineLateInstrsCleanupID); // Branch folding must be run after regalloc and prolog/epilog insertion. addPass(&BranchFolderPassID); // Tail duplication. // Note that duplicating tail just increases code size and degrades // performance for targets that require Structured Control Flow. // In addition it can also make CFG irreducible. Thus we disable it. if (!TM->requiresStructuredCFG()) addPass(&TailDuplicateID); // Copy propagation. addPass(&MachineCopyPropagationID); } /// Add standard GC passes. bool TargetPassConfig::addGCPasses() { addPass(&GCMachineCodeAnalysisID); return true; } /// Add standard basic block placement passes. void TargetPassConfig::addBlockPlacement() { if (EnableFSDiscriminator) { addPass(createMIRAddFSDiscriminatorsPass( sampleprof::FSDiscriminatorPass::Pass2)); const std::string ProfileFile = getFSProfileFile(TM); if (!ProfileFile.empty() && !DisableLayoutFSProfileLoader) addPass(createMIRProfileLoaderPass(ProfileFile, getFSRemappingFile(TM), sampleprof::FSDiscriminatorPass::Pass2, nullptr)); } if (addPass(&MachineBlockPlacementID)) { // Run a separate pass to collect block placement statistics. if (EnableBlockPlacementStats) addPass(&MachineBlockPlacementStatsID); } } //===---------------------------------------------------------------------===// /// GlobalISel Configuration //===---------------------------------------------------------------------===// bool TargetPassConfig::isGlobalISelAbortEnabled() const { return TM->Options.GlobalISelAbort == GlobalISelAbortMode::Enable; } bool TargetPassConfig::reportDiagnosticWhenGlobalISelFallback() const { return TM->Options.GlobalISelAbort == GlobalISelAbortMode::DisableWithDiag; } bool TargetPassConfig::isGISelCSEEnabled() const { return true; } std::unique_ptr TargetPassConfig::getCSEConfig() const { return std::make_unique(); }