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Diffstat (limited to 'contrib/llvm/lib/CodeGen/Passes.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/Passes.cpp | 751 |
1 files changed, 751 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/Passes.cpp b/contrib/llvm/lib/CodeGen/Passes.cpp new file mode 100644 index 000000000000..f4ffd03ec3ea --- /dev/null +++ b/contrib/llvm/lib/CodeGen/Passes.cpp @@ -0,0 +1,751 @@ +//===-- Passes.cpp - Target independent code generation passes ------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines interfaces to access the target independent code +// generation passes provided by the LLVM backend. +// +//===---------------------------------------------------------------------===// + +#include "llvm/CodeGen/Passes.h" +#include "llvm/Analysis/Passes.h" +#include "llvm/Analysis/Verifier.h" +#include "llvm/Assembly/PrintModulePass.h" +#include "llvm/CodeGen/GCStrategy.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/RegAllocRegistry.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/PassManager.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetSubtargetInfo.h" +#include "llvm/Transforms/Scalar.h" + +using namespace llvm; + +static cl::opt<bool> DisablePostRA("disable-post-ra", cl::Hidden, + cl::desc("Disable Post Regalloc")); +static cl::opt<bool> DisableBranchFold("disable-branch-fold", cl::Hidden, + cl::desc("Disable branch folding")); +static cl::opt<bool> DisableTailDuplicate("disable-tail-duplicate", cl::Hidden, + cl::desc("Disable tail duplication")); +static cl::opt<bool> DisableEarlyTailDup("disable-early-taildup", cl::Hidden, + cl::desc("Disable pre-register allocation tail duplication")); +static cl::opt<bool> DisableBlockPlacement("disable-block-placement", + cl::Hidden, cl::desc("Disable probability-driven block placement")); +static cl::opt<bool> EnableBlockPlacementStats("enable-block-placement-stats", + cl::Hidden, cl::desc("Collect probability-driven block placement stats")); +static cl::opt<bool> DisableSSC("disable-ssc", cl::Hidden, + cl::desc("Disable Stack Slot Coloring")); +static cl::opt<bool> DisableMachineDCE("disable-machine-dce", cl::Hidden, + cl::desc("Disable Machine Dead Code Elimination")); +static cl::opt<bool> DisableEarlyIfConversion("disable-early-ifcvt", cl::Hidden, + cl::desc("Disable Early If-conversion")); +static cl::opt<bool> DisableMachineLICM("disable-machine-licm", cl::Hidden, + cl::desc("Disable Machine LICM")); +static cl::opt<bool> DisableMachineCSE("disable-machine-cse", cl::Hidden, + cl::desc("Disable Machine Common Subexpression Elimination")); +static cl::opt<cl::boolOrDefault> +OptimizeRegAlloc("optimize-regalloc", cl::Hidden, + cl::desc("Enable optimized register allocation compilation path.")); +static cl::opt<cl::boolOrDefault> +EnableMachineSched("enable-misched", cl::Hidden, + cl::desc("Enable the machine instruction scheduling pass.")); +static cl::opt<bool> DisablePostRAMachineLICM("disable-postra-machine-licm", + cl::Hidden, + cl::desc("Disable Machine LICM")); +static cl::opt<bool> DisableMachineSink("disable-machine-sink", cl::Hidden, + cl::desc("Disable Machine Sinking")); +static cl::opt<bool> DisableLSR("disable-lsr", cl::Hidden, + cl::desc("Disable Loop Strength Reduction Pass")); +static cl::opt<bool> DisableCGP("disable-cgp", cl::Hidden, + cl::desc("Disable Codegen Prepare")); +static cl::opt<bool> DisableCopyProp("disable-copyprop", cl::Hidden, + cl::desc("Disable Copy Propagation pass")); +static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden, + cl::desc("Print LLVM IR produced by the loop-reduce pass")); +static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden, + cl::desc("Print LLVM IR input to isel pass")); +static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden, + cl::desc("Dump garbage collector data")); +static cl::opt<bool> VerifyMachineCode("verify-machineinstrs", cl::Hidden, + cl::desc("Verify generated machine code"), + cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL)); +static cl::opt<std::string> +PrintMachineInstrs("print-machineinstrs", cl::ValueOptional, + cl::desc("Print machine instrs"), + cl::value_desc("pass-name"), cl::init("option-unspecified")); + +// Experimental option to run live interval analysis early. +static cl::opt<bool> EarlyLiveIntervals("early-live-intervals", cl::Hidden, + cl::desc("Run live interval analysis earlier in the pipeline")); + +/// 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 Pass selection to be overriden by command line options. This supports +/// flags with ternary conditions. TargetID is passed through by default. The +/// pass is suppressed when the option is false. When the option is true, the +/// StandardID is selected if the target provides no default. +static IdentifyingPassPtr applyOverride(IdentifyingPassPtr TargetID, + cl::boolOrDefault Override, + AnalysisID StandardID) { + switch (Override) { + case cl::BOU_UNSET: + return TargetID; + case cl::BOU_TRUE: + if (TargetID.isValid()) + return TargetID; + if (StandardID == 0) + report_fatal_error("Target cannot enable pass"); + return StandardID; + case cl::BOU_FALSE: + return IdentifyingPassPtr(); + } + llvm_unreachable("Invalid command line option state"); +} + +/// 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, DisablePostRA); + + if (StandardID == &BranchFolderPassID) + return applyDisable(TargetID, DisableBranchFold); + + if (StandardID == &TailDuplicateID) + return applyDisable(TargetID, DisableTailDuplicate); + + if (StandardID == &TargetPassConfig::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 == &MachineLICMID) + return applyDisable(TargetID, DisableMachineLICM); + + if (StandardID == &MachineCSEID) + return applyDisable(TargetID, DisableMachineCSE); + + if (StandardID == &MachineSchedulerID) + return applyOverride(TargetID, EnableMachineSched, StandardID); + + if (StandardID == &TargetPassConfig::PostRAMachineLICMID) + return applyDisable(TargetID, DisablePostRAMachineLICM); + + if (StandardID == &MachineSinkingID) + return applyDisable(TargetID, DisableMachineSink); + + if (StandardID == &MachineCopyPropagationID) + return applyDisable(TargetID, DisableCopyProp); + + return TargetID; +} + +//===---------------------------------------------------------------------===// +/// TargetPassConfig +//===---------------------------------------------------------------------===// + +INITIALIZE_PASS(TargetPassConfig, "targetpassconfig", + "Target Pass Configuration", false, false) +char TargetPassConfig::ID = 0; + +// Pseudo Pass IDs. +char TargetPassConfig::EarlyTailDuplicateID = 0; +char TargetPassConfig::PostRAMachineLICMID = 0; + +namespace llvm { +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<AnalysisID,IdentifyingPassPtr> TargetPasses; + + /// Store the pairs of <AnalysisID, AnalysisID> of which the second pass + /// is inserted after each instance of the first one. + SmallVector<std::pair<AnalysisID, IdentifyingPassPtr>, 4> InsertedPasses; +}; +} // namespace llvm + +// Out of line virtual method. +TargetPassConfig::~TargetPassConfig() { + delete Impl; +} + +// Out of line constructor provides default values for pass options and +// registers all common codegen passes. +TargetPassConfig::TargetPassConfig(TargetMachine *tm, PassManagerBase &pm) + : ImmutablePass(ID), PM(&pm), StartAfter(0), StopAfter(0), + Started(true), Stopped(false), TM(tm), Impl(0), Initialized(false), + DisableVerify(false), + EnableTailMerge(true) { + + Impl = new PassConfigImpl(); + + // Register all target independent codegen passes to activate their PassIDs, + // including this pass itself. + initializeCodeGen(*PassRegistry::getPassRegistry()); + + // Substitute Pseudo Pass IDs for real ones. + substitutePass(&EarlyTailDuplicateID, &TailDuplicateID); + substitutePass(&PostRAMachineLICMID, &MachineLICMID); + + // Temporarily disable experimental passes. + const TargetSubtargetInfo &ST = TM->getSubtarget<TargetSubtargetInfo>(); + if (!ST.useMachineScheduler()) + disablePass(&MachineSchedulerID); +} + +/// 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!"); + std::pair<AnalysisID, IdentifyingPassPtr> P(TargetPassID, InsertedPassID); + Impl->InsertedPasses.push_back(P); +} + +/// 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), PM(0) { + llvm_unreachable("TargetPassConfig should not be constructed on-the-fly"); +} + +// 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<AnalysisID, IdentifyingPassPtr>::const_iterator + I = Impl->TargetPasses.find(ID); + if (I == Impl->TargetPasses.end()) + return ID; + return I->second; +} + +/// 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 (Started && !Stopped) + PM->add(P); + else + delete P; + if (StopAfter == PassID) + Stopped = true; + if (StartAfter == PassID) + 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 0; + + 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. + + // Add the passes after the pass P if there is any. + for (SmallVectorImpl<std::pair<AnalysisID, IdentifyingPassPtr> >::iterator + I = Impl->InsertedPasses.begin(), E = Impl->InsertedPasses.end(); + I != E; ++I) { + if ((*I).first == PassID) { + assert((*I).second.isValid() && "Illegal Pass ID!"); + Pass *NP; + if ((*I).second.isInstance()) + NP = (*I).second.getInstance(); + else { + NP = Pass::createPass((*I).second.getID()); + assert(NP && "Pass ID not registered"); + } + addPass(NP); + } + } + return FinalID; +} + +void TargetPassConfig::printAndVerify(const char *Banner) { + if (TM->shouldPrintMachineCode()) + addPass(createMachineFunctionPrinterPass(dbgs(), Banner)); + + if (VerifyMachineCode) + addPass(createMachineVerifierPass(Banner)); +} + +/// Add common target configurable passes that perform LLVM IR to IR transforms +/// following machine independent optimization. +void TargetPassConfig::addIRPasses() { + // 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(createTypeBasedAliasAnalysisPass()); + addPass(createBasicAliasAnalysisPass()); + + // 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()); + + // Run loop strength reduction before anything else. + if (getOptLevel() != CodeGenOpt::None && !DisableLSR) { + addPass(createLoopStrengthReducePass()); + if (PrintLSR) + addPass(createPrintFunctionPass("\n\n*** Code after LSR ***\n", &dbgs())); + } + + addPass(createGCLoweringPass()); + + // Make sure that no unreachable blocks are instruction selected. + addPass(createUnreachableBlockEliminationPass()); +} + +/// Turn exception handling constructs into something the code generators can +/// handle. +void TargetPassConfig::addPassesToHandleExceptions() { + switch (TM->getMCAsmInfo()->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::Win64: + addPass(createDwarfEHPass(TM)); + break; + case ExceptionHandling::None: + addPass(createLowerInvokePass(TM)); + + // 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(TM)); +} + +/// Add common passes that perform LLVM IR to IR transforms in preparation for +/// instruction selection. +void TargetPassConfig::addISelPrepare() { + addPass(createStackProtectorPass(TM)); + + addPreISel(); + + if (PrintISelInput) + addPass(createPrintFunctionPass("\n\n" + "*** Final LLVM Code input to ISel ***\n", + &dbgs())); + + // All passes which modify the LLVM IR are now complete; run the verifier + // to ensure that the IR is valid. + if (!DisableVerify) + addPass(createVerifierPass()); +} + +/// 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() { + // Insert a machine instr printer pass after the specified pass. + // If -print-machineinstrs specified, print machineinstrs after all passes. + if (StringRef(PrintMachineInstrs.getValue()).equals("")) + TM->Options.PrintMachineCode = true; + else if (!StringRef(PrintMachineInstrs.getValue()) + .equals("option-unspecified")) { + const PassRegistry *PR = PassRegistry::getPassRegistry(); + const PassInfo *TPI = PR->getPassInfo(PrintMachineInstrs.getValue()); + const PassInfo *IPI = PR->getPassInfo(StringRef("print-machineinstrs")); + assert (TPI && IPI && "Pass ID not registered!"); + const char *TID = (const char *)(TPI->getTypeInfo()); + const char *IID = (const char *)(IPI->getTypeInfo()); + insertPass(TID, IID); + } + + // Print the instruction selected machine code... + printAndVerify("After Instruction Selection"); + + // Expand pseudo-instructions emitted by ISel. + if (addPass(&ExpandISelPseudosID)) + printAndVerify("After ExpandISelPseudos"); + + // 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); + } + + // Run pre-ra passes. + if (addPreRegAlloc()) + printAndVerify("After PreRegAlloc passes"); + + // Run register allocation and passes that are tightly coupled with it, + // including phi elimination and scheduling. + if (getOptimizeRegAlloc()) + addOptimizedRegAlloc(createRegAllocPass(true)); + else + addFastRegAlloc(createRegAllocPass(false)); + + // Run post-ra passes. + if (addPostRegAlloc()) + printAndVerify("After PostRegAlloc passes"); + + // Insert prolog/epilog code. Eliminate abstract frame index references... + addPass(&PrologEpilogCodeInserterID); + printAndVerify("After PrologEpilogCodeInserter"); + + /// Add passes that optimize machine instructions after register allocation. + if (getOptLevel() != CodeGenOpt::None) + addMachineLateOptimization(); + + // Expand pseudo instructions before second scheduling pass. + addPass(&ExpandPostRAPseudosID); + printAndVerify("After ExpandPostRAPseudos"); + + // Run pre-sched2 passes. + if (addPreSched2()) + printAndVerify("After PreSched2 passes"); + + // Second pass scheduler. + if (getOptLevel() != CodeGenOpt::None) { + addPass(&PostRASchedulerID); + printAndVerify("After PostRAScheduler"); + } + + // GC + if (addGCPasses()) { + if (PrintGCInfo) + addPass(createGCInfoPrinter(dbgs())); + } + + // Basic block placement. + if (getOptLevel() != CodeGenOpt::None) + addBlockPlacement(); + + if (addPreEmitPass()) + printAndVerify("After PreEmit passes"); +} + +/// Add passes that optimize machine instructions in SSA form. +void TargetPassConfig::addMachineSSAOptimization() { + // Pre-ra tail duplication. + if (addPass(&EarlyTailDuplicateID)) + printAndVerify("After Pre-RegAlloc TailDuplicate"); + + // 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); + printAndVerify("After codegen DCE pass"); + + // 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. + if (addILPOpts()) + printAndVerify("After ILP optimizations"); + + addPass(&MachineLICMID); + addPass(&MachineCSEID); + addPass(&MachineSinkingID); + printAndVerify("After Machine LICM, CSE and Sinking passes"); + + addPass(&PeepholeOptimizerID); + printAndVerify("After codegen peephole optimization pass"); +} + +//===---------------------------------------------------------------------===// +/// 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"); +} + +/// RegisterRegAlloc's global Registry tracks allocator registration. +MachinePassRegistry RegisterRegAlloc::Registry; + +/// A dummy default pass factory indicates whether the register allocator is +/// overridden on the command line. +static FunctionPass *useDefaultRegisterAllocator() { return 0; } +static RegisterRegAlloc +defaultRegAlloc("default", + "pick register allocator based on -O option", + useDefaultRegisterAllocator); + +/// -regalloc=... command line option. +static cl::opt<RegisterRegAlloc::FunctionPassCtor, false, + RegisterPassParser<RegisterRegAlloc> > +RegAlloc("regalloc", + cl::init(&useDefaultRegisterAllocator), + cl::desc("Register allocator to use")); + + +/// 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) { + RegisterRegAlloc::FunctionPassCtor Ctor = RegisterRegAlloc::getDefault(); + + // Initialize the global default. + if (!Ctor) { + Ctor = RegAlloc; + RegisterRegAlloc::setDefault(RegAlloc); + } + if (Ctor != useDefaultRegisterAllocator) + return Ctor(); + + // With no -regalloc= override, ask the target for a regalloc pass. + return createTargetRegisterAllocator(Optimized); +} + +/// Add the minimum set of target-independent passes that are required for +/// register allocation. No coalescing or scheduling. +void TargetPassConfig::addFastRegAlloc(FunctionPass *RegAllocPass) { + addPass(&PHIEliminationID); + addPass(&TwoAddressInstructionPassID); + + addPass(RegAllocPass); + printAndVerify("After Register Allocation"); +} + +/// 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(FunctionPass *RegAllocPass) { + 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). + 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); + + // PreRA instruction scheduling. + if (addPass(&MachineSchedulerID)) + printAndVerify("After Machine Scheduling"); + + // Add the selected register allocation pass. + addPass(RegAllocPass); + printAndVerify("After Register Allocation, before rewriter"); + + // Allow targets to change the register assignments before rewriting. + if (addPreRewrite()) + printAndVerify("After pre-rewrite passes"); + + // Finally rewrite virtual registers. + addPass(&VirtRegRewriterID); + printAndVerify("After Virtual Register Rewriter"); + + // Perform stack slot coloring and post-ra machine LICM. + // + // FIXME: Re-enable coloring with register when it's capable of adding + // kill markers. + addPass(&StackSlotColoringID); + + // Run post-ra machine LICM to hoist reloads / remats. + // + // FIXME: can this move into MachineLateOptimization? + addPass(&PostRAMachineLICMID); + + printAndVerify("After StackSlotColoring and postra Machine LICM"); +} + +//===---------------------------------------------------------------------===// +/// Post RegAlloc Pass Configuration +//===---------------------------------------------------------------------===// + +/// Add passes that optimize machine instructions after register allocation. +void TargetPassConfig::addMachineLateOptimization() { + // Branch folding must be run after regalloc and prolog/epilog insertion. + if (addPass(&BranchFolderPassID)) + printAndVerify("After BranchFolding"); + + // Tail duplication. + if (addPass(&TailDuplicateID)) + printAndVerify("After TailDuplicate"); + + // Copy propagation. + if (addPass(&MachineCopyPropagationID)) + printAndVerify("After copy propagation pass"); +} + +/// Add standard GC passes. +bool TargetPassConfig::addGCPasses() { + addPass(&GCMachineCodeAnalysisID); + return true; +} + +/// Add standard basic block placement passes. +void TargetPassConfig::addBlockPlacement() { + if (addPass(&MachineBlockPlacementID)) { + // Run a separate pass to collect block placement statistics. + if (EnableBlockPlacementStats) + addPass(&MachineBlockPlacementStatsID); + + printAndVerify("After machine block placement."); + } +} |