| //===- TargetPassConfig.h - Code Generation pass options --------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// Target-Independent Code Generator Pass Configuration Options pass. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_TARGETPASSCONFIG_H |
| #define LLVM_CODEGEN_TARGETPASSCONFIG_H |
| |
| #include "llvm/Pass.h" |
| #include "llvm/Support/CodeGen.h" |
| #include <cassert> |
| #include <string> |
| |
| namespace llvm { |
| |
| class LLVMTargetMachine; |
| struct MachineSchedContext; |
| class PassConfigImpl; |
| class ScheduleDAGInstrs; |
| class CSEConfigBase; |
| |
| // The old pass manager infrastructure is hidden in a legacy namespace now. |
| namespace legacy { |
| |
| class PassManagerBase; |
| |
| } // end namespace legacy |
| |
| using legacy::PassManagerBase; |
| |
| /// Discriminated union of Pass ID types. |
| /// |
| /// The PassConfig API prefers dealing with IDs because they are safer and more |
| /// efficient. IDs decouple configuration from instantiation. This way, when a |
| /// pass is overriden, it isn't unnecessarily instantiated. It is also unsafe to |
| /// refer to a Pass pointer after adding it to a pass manager, which deletes |
| /// redundant pass instances. |
| /// |
| /// However, it is convient to directly instantiate target passes with |
| /// non-default ctors. These often don't have a registered PassInfo. Rather than |
| /// force all target passes to implement the pass registry boilerplate, allow |
| /// the PassConfig API to handle either type. |
| /// |
| /// AnalysisID is sadly char*, so PointerIntPair won't work. |
| class IdentifyingPassPtr { |
| union { |
| AnalysisID ID; |
| Pass *P; |
| }; |
| bool IsInstance = false; |
| |
| public: |
| IdentifyingPassPtr() : P(nullptr) {} |
| IdentifyingPassPtr(AnalysisID IDPtr) : ID(IDPtr) {} |
| IdentifyingPassPtr(Pass *InstancePtr) : P(InstancePtr), IsInstance(true) {} |
| |
| bool isValid() const { return P; } |
| bool isInstance() const { return IsInstance; } |
| |
| AnalysisID getID() const { |
| assert(!IsInstance && "Not a Pass ID"); |
| return ID; |
| } |
| |
| Pass *getInstance() const { |
| assert(IsInstance && "Not a Pass Instance"); |
| return P; |
| } |
| }; |
| |
| |
| /// Target-Independent Code Generator Pass Configuration Options. |
| /// |
| /// This is an ImmutablePass solely for the purpose of exposing CodeGen options |
| /// to the internals of other CodeGen passes. |
| class TargetPassConfig : public ImmutablePass { |
| private: |
| PassManagerBase *PM = nullptr; |
| AnalysisID StartBefore = nullptr; |
| AnalysisID StartAfter = nullptr; |
| AnalysisID StopBefore = nullptr; |
| AnalysisID StopAfter = nullptr; |
| |
| unsigned StartBeforeInstanceNum = 0; |
| unsigned StartBeforeCount = 0; |
| |
| unsigned StartAfterInstanceNum = 0; |
| unsigned StartAfterCount = 0; |
| |
| unsigned StopBeforeInstanceNum = 0; |
| unsigned StopBeforeCount = 0; |
| |
| unsigned StopAfterInstanceNum = 0; |
| unsigned StopAfterCount = 0; |
| |
| bool Started = true; |
| bool Stopped = false; |
| bool AddingMachinePasses = false; |
| |
| /// Set the StartAfter, StartBefore and StopAfter passes to allow running only |
| /// a portion of the normal code-gen pass sequence. |
| /// |
| /// If the StartAfter and StartBefore pass ID is zero, then compilation will |
| /// begin at the normal point; otherwise, clear the Started flag to indicate |
| /// that passes should not be added until the starting pass is seen. If the |
| /// Stop pass ID is zero, then compilation will continue to the end. |
| /// |
| /// This function expects that at least one of the StartAfter or the |
| /// StartBefore pass IDs is null. |
| void setStartStopPasses(); |
| |
| protected: |
| LLVMTargetMachine *TM; |
| PassConfigImpl *Impl = nullptr; // Internal data structures |
| bool Initialized = false; // Flagged after all passes are configured. |
| |
| // Target Pass Options |
| // Targets provide a default setting, user flags override. |
| bool DisableVerify = false; |
| |
| /// Default setting for -enable-tail-merge on this target. |
| bool EnableTailMerge = true; |
| |
| /// Require processing of functions such that callees are generated before |
| /// callers. |
| bool RequireCodeGenSCCOrder = false; |
| |
| /// Add the actual instruction selection passes. This does not include |
| /// preparation passes on IR. |
| bool addCoreISelPasses(); |
| |
| public: |
| TargetPassConfig(LLVMTargetMachine &TM, PassManagerBase &pm); |
| // Dummy constructor. |
| TargetPassConfig(); |
| |
| ~TargetPassConfig() override; |
| |
| static char ID; |
| |
| /// Get the right type of TargetMachine for this target. |
| template<typename TMC> TMC &getTM() const { |
| return *static_cast<TMC*>(TM); |
| } |
| |
| // |
| void setInitialized() { Initialized = true; } |
| |
| CodeGenOpt::Level getOptLevel() const; |
| |
| /// Returns true if one of the `-start-after`, `-start-before`, `-stop-after` |
| /// or `-stop-before` options is set. |
| static bool hasLimitedCodeGenPipeline(); |
| |
| /// Returns true if none of the `-stop-before` and `-stop-after` options is |
| /// set. |
| static bool willCompleteCodeGenPipeline(); |
| |
| /// If hasLimitedCodeGenPipeline is true, this method |
| /// returns a string with the name of the options, separated |
| /// by \p Separator that caused this pipeline to be limited. |
| std::string |
| getLimitedCodeGenPipelineReason(const char *Separator = "/") const; |
| |
| void setDisableVerify(bool Disable) { setOpt(DisableVerify, Disable); } |
| |
| bool getEnableTailMerge() const { return EnableTailMerge; } |
| void setEnableTailMerge(bool Enable) { setOpt(EnableTailMerge, Enable); } |
| |
| bool requiresCodeGenSCCOrder() const { return RequireCodeGenSCCOrder; } |
| void setRequiresCodeGenSCCOrder(bool Enable = true) { |
| setOpt(RequireCodeGenSCCOrder, Enable); |
| } |
| |
| /// Allow the target to override a specific pass without overriding the pass |
| /// pipeline. When passes are added to the standard pipeline at the |
| /// point where StandardID is expected, add TargetID in its place. |
| void substitutePass(AnalysisID StandardID, IdentifyingPassPtr TargetID); |
| |
| /// Insert InsertedPassID pass after TargetPassID pass. |
| void insertPass(AnalysisID TargetPassID, IdentifyingPassPtr InsertedPassID, |
| bool VerifyAfter = true, bool PrintAfter = true); |
| |
| /// Allow the target to enable a specific standard pass by default. |
| void enablePass(AnalysisID PassID) { substitutePass(PassID, PassID); } |
| |
| /// Allow the target to disable a specific standard pass by default. |
| void disablePass(AnalysisID PassID) { |
| substitutePass(PassID, IdentifyingPassPtr()); |
| } |
| |
| /// Return the pass substituted for StandardID by the target. |
| /// If no substitution exists, return StandardID. |
| IdentifyingPassPtr getPassSubstitution(AnalysisID StandardID) const; |
| |
| /// Return true if the pass has been substituted by the target or |
| /// overridden on the command line. |
| bool isPassSubstitutedOrOverridden(AnalysisID ID) const; |
| |
| /// Return true if the optimized regalloc pipeline is enabled. |
| bool getOptimizeRegAlloc() const; |
| |
| /// Return true if the default global register allocator is in use and |
| /// has not be overriden on the command line with '-regalloc=...' |
| bool usingDefaultRegAlloc() const; |
| |
| /// High level function that adds all passes necessary to go from llvm IR |
| /// representation to the MI representation. |
| /// Adds IR based lowering and target specific optimization passes and finally |
| /// the core instruction selection passes. |
| /// \returns true if an error occurred, false otherwise. |
| bool addISelPasses(); |
| |
| /// Add common target configurable passes that perform LLVM IR to IR |
| /// transforms following machine independent optimization. |
| virtual void addIRPasses(); |
| |
| /// Add passes to lower exception handling for the code generator. |
| void addPassesToHandleExceptions(); |
| |
| /// Add pass to prepare the LLVM IR for code generation. This should be done |
| /// before exception handling preparation passes. |
| virtual void addCodeGenPrepare(); |
| |
| /// Add common passes that perform LLVM IR to IR transforms in preparation for |
| /// instruction selection. |
| virtual void addISelPrepare(); |
| |
| /// addInstSelector - This method should install an instruction selector pass, |
| /// which converts from LLVM code to machine instructions. |
| virtual bool addInstSelector() { |
| return true; |
| } |
| |
| /// This method should install an IR translator pass, which converts from |
| /// LLVM code to machine instructions with possibly generic opcodes. |
| virtual bool addIRTranslator() { return true; } |
| |
| /// This method may be implemented by targets that want to run passes |
| /// immediately before legalization. |
| virtual void addPreLegalizeMachineIR() {} |
| |
| /// This method should install a legalize pass, which converts the instruction |
| /// sequence into one that can be selected by the target. |
| virtual bool addLegalizeMachineIR() { return true; } |
| |
| /// This method may be implemented by targets that want to run passes |
| /// immediately before the register bank selection. |
| virtual void addPreRegBankSelect() {} |
| |
| /// This method should install a register bank selector pass, which |
| /// assigns register banks to virtual registers without a register |
| /// class or register banks. |
| virtual bool addRegBankSelect() { return true; } |
| |
| /// This method may be implemented by targets that want to run passes |
| /// immediately before the (global) instruction selection. |
| virtual void addPreGlobalInstructionSelect() {} |
| |
| /// This method should install a (global) instruction selector pass, which |
| /// converts possibly generic instructions to fully target-specific |
| /// instructions, thereby constraining all generic virtual registers to |
| /// register classes. |
| virtual bool addGlobalInstructionSelect() { return true; } |
| |
| /// Add the complete, standard set of LLVM CodeGen passes. |
| /// Fully developed targets will not generally override this. |
| virtual void addMachinePasses(); |
| |
| /// Create an instance of ScheduleDAGInstrs to be run within the standard |
| /// MachineScheduler pass for this function and target at the current |
| /// optimization level. |
| /// |
| /// This can also be used to plug a new MachineSchedStrategy into an instance |
| /// of the standard ScheduleDAGMI: |
| /// return new ScheduleDAGMI(C, make_unique<MyStrategy>(C), /*RemoveKillFlags=*/false) |
| /// |
| /// Return NULL to select the default (generic) machine scheduler. |
| virtual ScheduleDAGInstrs * |
| createMachineScheduler(MachineSchedContext *C) const { |
| return nullptr; |
| } |
| |
| /// Similar to createMachineScheduler but used when postRA machine scheduling |
| /// is enabled. |
| virtual ScheduleDAGInstrs * |
| createPostMachineScheduler(MachineSchedContext *C) const { |
| return nullptr; |
| } |
| |
| /// printAndVerify - Add a pass to dump then verify the machine function, if |
| /// those steps are enabled. |
| void printAndVerify(const std::string &Banner); |
| |
| /// Add a pass to print the machine function if printing is enabled. |
| void addPrintPass(const std::string &Banner); |
| |
| /// Add a pass to perform basic verification of the machine function if |
| /// verification is enabled. |
| void addVerifyPass(const std::string &Banner); |
| |
| /// Check whether or not GlobalISel should abort on error. |
| /// When this is disabled, GlobalISel will fall back on SDISel instead of |
| /// erroring out. |
| bool isGlobalISelAbortEnabled() const; |
| |
| /// Check whether or not a diagnostic should be emitted when GlobalISel |
| /// uses the fallback path. In other words, it will emit a diagnostic |
| /// when GlobalISel failed and isGlobalISelAbortEnabled is false. |
| virtual bool reportDiagnosticWhenGlobalISelFallback() const; |
| |
| /// Check whether continuous CSE should be enabled in GISel passes. |
| /// By default, it's enabled for non O0 levels. |
| virtual bool isGISelCSEEnabled() const; |
| |
| /// Returns the CSEConfig object to use for the current optimization level. |
| virtual std::unique_ptr<CSEConfigBase> getCSEConfig() const; |
| |
| protected: |
| // Helper to verify the analysis is really immutable. |
| void setOpt(bool &Opt, bool Val); |
| |
| /// Methods with trivial inline returns are convenient points in the common |
| /// codegen pass pipeline where targets may insert passes. Methods with |
| /// out-of-line standard implementations are major CodeGen stages called by |
| /// addMachinePasses. Some targets may override major stages when inserting |
| /// passes is insufficient, but maintaining overriden stages is more work. |
| /// |
| |
| /// addPreISelPasses - This method should add any "last minute" LLVM->LLVM |
| /// passes (which are run just before instruction selector). |
| virtual bool addPreISel() { |
| return true; |
| } |
| |
| /// addMachineSSAOptimization - Add standard passes that optimize machine |
| /// instructions in SSA form. |
| virtual void addMachineSSAOptimization(); |
| |
| /// Add passes that optimize instruction level parallelism for out-of-order |
| /// targets. These passes are run while the machine code is still in SSA |
| /// form, so they can use MachineTraceMetrics to control their heuristics. |
| /// |
| /// All passes added here should preserve the MachineDominatorTree, |
| /// MachineLoopInfo, and MachineTraceMetrics analyses. |
| virtual bool addILPOpts() { |
| return false; |
| } |
| |
| /// This method may be implemented by targets that want to run passes |
| /// immediately before register allocation. |
| virtual void addPreRegAlloc() { } |
| |
| /// createTargetRegisterAllocator - Create the register allocator pass for |
| /// this target at the current optimization level. |
| virtual FunctionPass *createTargetRegisterAllocator(bool Optimized); |
| |
| /// addFastRegAlloc - Add the minimum set of target-independent passes that |
| /// are required for fast register allocation. |
| virtual void addFastRegAlloc(); |
| |
| /// addOptimizedRegAlloc - Add passes related to register allocation. |
| /// LLVMTargetMachine provides standard regalloc passes for most targets. |
| virtual void addOptimizedRegAlloc(); |
| |
| /// addPreRewrite - Add passes to the optimized register allocation pipeline |
| /// after register allocation is complete, but before virtual registers are |
| /// rewritten to physical registers. |
| /// |
| /// These passes must preserve VirtRegMap and LiveIntervals, and when running |
| /// after RABasic or RAGreedy, they should take advantage of LiveRegMatrix. |
| /// When these passes run, VirtRegMap contains legal physreg assignments for |
| /// all virtual registers. |
| /// |
| /// Note if the target overloads addRegAssignAndRewriteOptimized, this may not |
| /// be honored. This is also not generally used for the the fast variant, |
| /// where the allocation and rewriting are done in one pass. |
| virtual bool addPreRewrite() { |
| return false; |
| } |
| |
| /// Add passes to be run immediately after virtual registers are rewritten |
| /// to physical registers. |
| virtual void addPostRewrite() { } |
| |
| /// This method may be implemented by targets that want to run passes after |
| /// register allocation pass pipeline but before prolog-epilog insertion. |
| virtual void addPostRegAlloc() { } |
| |
| /// Add passes that optimize machine instructions after register allocation. |
| virtual void addMachineLateOptimization(); |
| |
| /// This method may be implemented by targets that want to run passes after |
| /// prolog-epilog insertion and before the second instruction scheduling pass. |
| virtual void addPreSched2() { } |
| |
| /// addGCPasses - Add late codegen passes that analyze code for garbage |
| /// collection. This should return true if GC info should be printed after |
| /// these passes. |
| virtual bool addGCPasses(); |
| |
| /// Add standard basic block placement passes. |
| virtual void addBlockPlacement(); |
| |
| /// This pass may be implemented by targets that want to run passes |
| /// immediately before machine code is emitted. |
| virtual void addPreEmitPass() { } |
| |
| /// Targets may add passes immediately before machine code is emitted in this |
| /// callback. This is called even later than `addPreEmitPass`. |
| // FIXME: Rename `addPreEmitPass` to something more sensible given its actual |
| // position and remove the `2` suffix here as this callback is what |
| // `addPreEmitPass` *should* be but in reality isn't. |
| virtual void addPreEmitPass2() {} |
| |
| /// Utilities for targets to add passes to the pass manager. |
| /// |
| |
| /// Add a CodeGen pass at this point in the pipeline after checking overrides. |
| /// Return the pass that was added, or zero if no pass was added. |
| /// @p printAfter if true and adding a machine function pass add an extra |
| /// machine printer pass afterwards |
| /// @p verifyAfter if true and adding a machine function pass add an extra |
| /// machine verification pass afterwards. |
| AnalysisID addPass(AnalysisID PassID, bool verifyAfter = true, |
| bool printAfter = true); |
| |
| /// Add a pass to the PassManager if that pass is supposed to be run, as |
| /// determined by the StartAfter and StopAfter options. Takes ownership of the |
| /// pass. |
| /// @p printAfter if true and adding a machine function pass add an extra |
| /// machine printer pass afterwards |
| /// @p verifyAfter if true and adding a machine function pass add an extra |
| /// machine verification pass afterwards. |
| void addPass(Pass *P, bool verifyAfter = true, bool printAfter = true); |
| |
| /// addMachinePasses helper to create the target-selected or overriden |
| /// regalloc pass. |
| virtual FunctionPass *createRegAllocPass(bool Optimized); |
| |
| /// Add core register alloator passes which do the actual register assignment |
| /// and rewriting. \returns true if any passes were added. |
| virtual bool addRegAssignmentFast(); |
| virtual bool addRegAssignmentOptimized(); |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_CODEGEN_TARGETPASSCONFIG_H |