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      1 //===-- Passes.h - Target independent code generation passes ----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines interfaces to access the target independent code generation
     11 // passes provided by the LLVM backend.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_CODEGEN_PASSES_H
     16 #define LLVM_CODEGEN_PASSES_H
     17 
     18 #include "llvm/Pass.h"
     19 #include "llvm/Target/TargetMachine.h"
     20 #include <functional>
     21 #include <string>
     22 
     23 namespace llvm {
     24 
     25 class MachineFunctionPass;
     26 class PassConfigImpl;
     27 class PassInfo;
     28 class ScheduleDAGInstrs;
     29 class TargetLowering;
     30 class TargetLoweringBase;
     31 class TargetRegisterClass;
     32 class raw_ostream;
     33 struct MachineSchedContext;
     34 
     35 // The old pass manager infrastructure is hidden in a legacy namespace now.
     36 namespace legacy {
     37 class PassManagerBase;
     38 }
     39 using legacy::PassManagerBase;
     40 
     41 /// Discriminated union of Pass ID types.
     42 ///
     43 /// The PassConfig API prefers dealing with IDs because they are safer and more
     44 /// efficient. IDs decouple configuration from instantiation. This way, when a
     45 /// pass is overriden, it isn't unnecessarily instantiated. It is also unsafe to
     46 /// refer to a Pass pointer after adding it to a pass manager, which deletes
     47 /// redundant pass instances.
     48 ///
     49 /// However, it is convient to directly instantiate target passes with
     50 /// non-default ctors. These often don't have a registered PassInfo. Rather than
     51 /// force all target passes to implement the pass registry boilerplate, allow
     52 /// the PassConfig API to handle either type.
     53 ///
     54 /// AnalysisID is sadly char*, so PointerIntPair won't work.
     55 class IdentifyingPassPtr {
     56   union {
     57     AnalysisID ID;
     58     Pass *P;
     59   };
     60   bool IsInstance;
     61 public:
     62   IdentifyingPassPtr() : P(nullptr), IsInstance(false) {}
     63   IdentifyingPassPtr(AnalysisID IDPtr) : ID(IDPtr), IsInstance(false) {}
     64   IdentifyingPassPtr(Pass *InstancePtr) : P(InstancePtr), IsInstance(true) {}
     65 
     66   bool isValid() const { return P; }
     67   bool isInstance() const { return IsInstance; }
     68 
     69   AnalysisID getID() const {
     70     assert(!IsInstance && "Not a Pass ID");
     71     return ID;
     72   }
     73   Pass *getInstance() const {
     74     assert(IsInstance && "Not a Pass Instance");
     75     return P;
     76   }
     77 };
     78 
     79 template <> struct isPodLike<IdentifyingPassPtr> {
     80   static const bool value = true;
     81 };
     82 
     83 /// Target-Independent Code Generator Pass Configuration Options.
     84 ///
     85 /// This is an ImmutablePass solely for the purpose of exposing CodeGen options
     86 /// to the internals of other CodeGen passes.
     87 class TargetPassConfig : public ImmutablePass {
     88 public:
     89   /// Pseudo Pass IDs. These are defined within TargetPassConfig because they
     90   /// are unregistered pass IDs. They are only useful for use with
     91   /// TargetPassConfig APIs to identify multiple occurrences of the same pass.
     92   ///
     93 
     94   /// EarlyTailDuplicate - A clone of the TailDuplicate pass that runs early
     95   /// during codegen, on SSA form.
     96   static char EarlyTailDuplicateID;
     97 
     98   /// PostRAMachineLICM - A clone of the LICM pass that runs during late machine
     99   /// optimization after regalloc.
    100   static char PostRAMachineLICMID;
    101 
    102 private:
    103   PassManagerBase *PM;
    104   AnalysisID StartBefore, StartAfter;
    105   AnalysisID StopAfter;
    106   bool Started;
    107   bool Stopped;
    108   bool AddingMachinePasses;
    109 
    110 protected:
    111   TargetMachine *TM;
    112   PassConfigImpl *Impl; // Internal data structures
    113   bool Initialized;     // Flagged after all passes are configured.
    114 
    115   // Target Pass Options
    116   // Targets provide a default setting, user flags override.
    117   //
    118   bool DisableVerify;
    119 
    120   /// Default setting for -enable-tail-merge on this target.
    121   bool EnableTailMerge;
    122 
    123 public:
    124   TargetPassConfig(TargetMachine *tm, PassManagerBase &pm);
    125   // Dummy constructor.
    126   TargetPassConfig();
    127 
    128   ~TargetPassConfig() override;
    129 
    130   static char ID;
    131 
    132   /// Get the right type of TargetMachine for this target.
    133   template<typename TMC> TMC &getTM() const {
    134     return *static_cast<TMC*>(TM);
    135   }
    136 
    137   //
    138   void setInitialized() { Initialized = true; }
    139 
    140   CodeGenOpt::Level getOptLevel() const { return TM->getOptLevel(); }
    141 
    142   /// Set the StartAfter, StartBefore and StopAfter passes to allow running only
    143   /// a portion of the normal code-gen pass sequence.
    144   ///
    145   /// If the StartAfter and StartBefore pass ID is zero, then compilation will
    146   /// begin at the normal point; otherwise, clear the Started flag to indicate
    147   /// that passes should not be added until the starting pass is seen.  If the
    148   /// Stop pass ID is zero, then compilation will continue to the end.
    149   ///
    150   /// This function expects that at least one of the StartAfter or the
    151   /// StartBefore pass IDs is null.
    152   void setStartStopPasses(AnalysisID StartBefore, AnalysisID StartAfter,
    153                           AnalysisID StopAfter) {
    154     if (StartAfter)
    155       assert(!StartBefore && "Start after and start before passes are given");
    156     this->StartBefore = StartBefore;
    157     this->StartAfter = StartAfter;
    158     this->StopAfter = StopAfter;
    159     Started = (StartAfter == nullptr) && (StartBefore == nullptr);
    160   }
    161 
    162   void setDisableVerify(bool Disable) { setOpt(DisableVerify, Disable); }
    163 
    164   bool getEnableTailMerge() const { return EnableTailMerge; }
    165   void setEnableTailMerge(bool Enable) { setOpt(EnableTailMerge, Enable); }
    166 
    167   /// Allow the target to override a specific pass without overriding the pass
    168   /// pipeline. When passes are added to the standard pipeline at the
    169   /// point where StandardID is expected, add TargetID in its place.
    170   void substitutePass(AnalysisID StandardID, IdentifyingPassPtr TargetID);
    171 
    172   /// Insert InsertedPassID pass after TargetPassID pass.
    173   void insertPass(AnalysisID TargetPassID, IdentifyingPassPtr InsertedPassID,
    174                   bool VerifyAfter = true, bool PrintAfter = true);
    175 
    176   /// Allow the target to enable a specific standard pass by default.
    177   void enablePass(AnalysisID PassID) { substitutePass(PassID, PassID); }
    178 
    179   /// Allow the target to disable a specific standard pass by default.
    180   void disablePass(AnalysisID PassID) {
    181     substitutePass(PassID, IdentifyingPassPtr());
    182   }
    183 
    184   /// Return the pass substituted for StandardID by the target.
    185   /// If no substitution exists, return StandardID.
    186   IdentifyingPassPtr getPassSubstitution(AnalysisID StandardID) const;
    187 
    188   /// Return true if the optimized regalloc pipeline is enabled.
    189   bool getOptimizeRegAlloc() const;
    190 
    191   /// Return true if shrink wrapping is enabled.
    192   bool getEnableShrinkWrap() const;
    193 
    194   /// Return true if the default global register allocator is in use and
    195   /// has not be overriden on the command line with '-regalloc=...'
    196   bool usingDefaultRegAlloc() const;
    197 
    198   /// Add common target configurable passes that perform LLVM IR to IR
    199   /// transforms following machine independent optimization.
    200   virtual void addIRPasses();
    201 
    202   /// Add passes to lower exception handling for the code generator.
    203   void addPassesToHandleExceptions();
    204 
    205   /// Add pass to prepare the LLVM IR for code generation. This should be done
    206   /// before exception handling preparation passes.
    207   virtual void addCodeGenPrepare();
    208 
    209   /// Add common passes that perform LLVM IR to IR transforms in preparation for
    210   /// instruction selection.
    211   virtual void addISelPrepare();
    212 
    213   /// addInstSelector - This method should install an instruction selector pass,
    214   /// which converts from LLVM code to machine instructions.
    215   virtual bool addInstSelector() {
    216     return true;
    217   }
    218 
    219   /// Add the complete, standard set of LLVM CodeGen passes.
    220   /// Fully developed targets will not generally override this.
    221   virtual void addMachinePasses();
    222 
    223   /// Create an instance of ScheduleDAGInstrs to be run within the standard
    224   /// MachineScheduler pass for this function and target at the current
    225   /// optimization level.
    226   ///
    227   /// This can also be used to plug a new MachineSchedStrategy into an instance
    228   /// of the standard ScheduleDAGMI:
    229   ///   return new ScheduleDAGMI(C, make_unique<MyStrategy>(C), /*RemoveKillFlags=*/false)
    230   ///
    231   /// Return NULL to select the default (generic) machine scheduler.
    232   virtual ScheduleDAGInstrs *
    233   createMachineScheduler(MachineSchedContext *C) const {
    234     return nullptr;
    235   }
    236 
    237   /// Similar to createMachineScheduler but used when postRA machine scheduling
    238   /// is enabled.
    239   virtual ScheduleDAGInstrs *
    240   createPostMachineScheduler(MachineSchedContext *C) const {
    241     return nullptr;
    242   }
    243 
    244 protected:
    245   // Helper to verify the analysis is really immutable.
    246   void setOpt(bool &Opt, bool Val);
    247 
    248   /// Methods with trivial inline returns are convenient points in the common
    249   /// codegen pass pipeline where targets may insert passes. Methods with
    250   /// out-of-line standard implementations are major CodeGen stages called by
    251   /// addMachinePasses. Some targets may override major stages when inserting
    252   /// passes is insufficient, but maintaining overriden stages is more work.
    253   ///
    254 
    255   /// addPreISelPasses - This method should add any "last minute" LLVM->LLVM
    256   /// passes (which are run just before instruction selector).
    257   virtual bool addPreISel() {
    258     return true;
    259   }
    260 
    261   /// addMachineSSAOptimization - Add standard passes that optimize machine
    262   /// instructions in SSA form.
    263   virtual void addMachineSSAOptimization();
    264 
    265   /// Add passes that optimize instruction level parallelism for out-of-order
    266   /// targets. These passes are run while the machine code is still in SSA
    267   /// form, so they can use MachineTraceMetrics to control their heuristics.
    268   ///
    269   /// All passes added here should preserve the MachineDominatorTree,
    270   /// MachineLoopInfo, and MachineTraceMetrics analyses.
    271   virtual bool addILPOpts() {
    272     return false;
    273   }
    274 
    275   /// This method may be implemented by targets that want to run passes
    276   /// immediately before register allocation.
    277   virtual void addPreRegAlloc() { }
    278 
    279   /// createTargetRegisterAllocator - Create the register allocator pass for
    280   /// this target at the current optimization level.
    281   virtual FunctionPass *createTargetRegisterAllocator(bool Optimized);
    282 
    283   /// addFastRegAlloc - Add the minimum set of target-independent passes that
    284   /// are required for fast register allocation.
    285   virtual void addFastRegAlloc(FunctionPass *RegAllocPass);
    286 
    287   /// addOptimizedRegAlloc - Add passes related to register allocation.
    288   /// LLVMTargetMachine provides standard regalloc passes for most targets.
    289   virtual void addOptimizedRegAlloc(FunctionPass *RegAllocPass);
    290 
    291   /// addPreRewrite - Add passes to the optimized register allocation pipeline
    292   /// after register allocation is complete, but before virtual registers are
    293   /// rewritten to physical registers.
    294   ///
    295   /// These passes must preserve VirtRegMap and LiveIntervals, and when running
    296   /// after RABasic or RAGreedy, they should take advantage of LiveRegMatrix.
    297   /// When these passes run, VirtRegMap contains legal physreg assignments for
    298   /// all virtual registers.
    299   virtual bool addPreRewrite() {
    300     return false;
    301   }
    302 
    303   /// This method may be implemented by targets that want to run passes after
    304   /// register allocation pass pipeline but before prolog-epilog insertion.
    305   virtual void addPostRegAlloc() { }
    306 
    307   /// Add passes that optimize machine instructions after register allocation.
    308   virtual void addMachineLateOptimization();
    309 
    310   /// This method may be implemented by targets that want to run passes after
    311   /// prolog-epilog insertion and before the second instruction scheduling pass.
    312   virtual void addPreSched2() { }
    313 
    314   /// addGCPasses - Add late codegen passes that analyze code for garbage
    315   /// collection. This should return true if GC info should be printed after
    316   /// these passes.
    317   virtual bool addGCPasses();
    318 
    319   /// Add standard basic block placement passes.
    320   virtual void addBlockPlacement();
    321 
    322   /// This pass may be implemented by targets that want to run passes
    323   /// immediately before machine code is emitted.
    324   virtual void addPreEmitPass() { }
    325 
    326   /// Utilities for targets to add passes to the pass manager.
    327   ///
    328 
    329   /// Add a CodeGen pass at this point in the pipeline after checking overrides.
    330   /// Return the pass that was added, or zero if no pass was added.
    331   /// @p printAfter    if true and adding a machine function pass add an extra
    332   ///                  machine printer pass afterwards
    333   /// @p verifyAfter   if true and adding a machine function pass add an extra
    334   ///                  machine verification pass afterwards.
    335   AnalysisID addPass(AnalysisID PassID, bool verifyAfter = true,
    336                      bool printAfter = true);
    337 
    338   /// Add a pass to the PassManager if that pass is supposed to be run, as
    339   /// determined by the StartAfter and StopAfter options. Takes ownership of the
    340   /// pass.
    341   /// @p printAfter    if true and adding a machine function pass add an extra
    342   ///                  machine printer pass afterwards
    343   /// @p verifyAfter   if true and adding a machine function pass add an extra
    344   ///                  machine verification pass afterwards.
    345   void addPass(Pass *P, bool verifyAfter = true, bool printAfter = true);
    346 
    347   /// addMachinePasses helper to create the target-selected or overriden
    348   /// regalloc pass.
    349   FunctionPass *createRegAllocPass(bool Optimized);
    350 
    351   /// printAndVerify - Add a pass to dump then verify the machine function, if
    352   /// those steps are enabled.
    353   ///
    354   void printAndVerify(const std::string &Banner);
    355 
    356   /// Add a pass to print the machine function if printing is enabled.
    357   void addPrintPass(const std::string &Banner);
    358 
    359   /// Add a pass to perform basic verification of the machine function if
    360   /// verification is enabled.
    361   void addVerifyPass(const std::string &Banner);
    362 };
    363 } // namespace llvm
    364 
    365 /// List of target independent CodeGen pass IDs.
    366 namespace llvm {
    367   FunctionPass *createAtomicExpandPass(const TargetMachine *TM);
    368 
    369   /// createUnreachableBlockEliminationPass - The LLVM code generator does not
    370   /// work well with unreachable basic blocks (what live ranges make sense for a
    371   /// block that cannot be reached?).  As such, a code generator should either
    372   /// not instruction select unreachable blocks, or run this pass as its
    373   /// last LLVM modifying pass to clean up blocks that are not reachable from
    374   /// the entry block.
    375   FunctionPass *createUnreachableBlockEliminationPass();
    376 
    377   /// MachineFunctionPrinter pass - This pass prints out the machine function to
    378   /// the given stream as a debugging tool.
    379   MachineFunctionPass *
    380   createMachineFunctionPrinterPass(raw_ostream &OS,
    381                                    const std::string &Banner ="");
    382 
    383   /// MIRPrinting pass - this pass prints out the LLVM IR into the given stream
    384   /// using the MIR serialization format.
    385   MachineFunctionPass *createPrintMIRPass(raw_ostream &OS);
    386 
    387   /// createCodeGenPreparePass - Transform the code to expose more pattern
    388   /// matching during instruction selection.
    389   FunctionPass *createCodeGenPreparePass(const TargetMachine *TM = nullptr);
    390 
    391   /// AtomicExpandID -- Lowers atomic operations in terms of either cmpxchg
    392   /// load-linked/store-conditional loops.
    393   extern char &AtomicExpandID;
    394 
    395   /// MachineLoopInfo - This pass is a loop analysis pass.
    396   extern char &MachineLoopInfoID;
    397 
    398   /// MachineDominators - This pass is a machine dominators analysis pass.
    399   extern char &MachineDominatorsID;
    400 
    401 /// MachineDominanaceFrontier - This pass is a machine dominators analysis pass.
    402   extern char &MachineDominanceFrontierID;
    403 
    404   /// EdgeBundles analysis - Bundle machine CFG edges.
    405   extern char &EdgeBundlesID;
    406 
    407   /// LiveVariables pass - This pass computes the set of blocks in which each
    408   /// variable is life and sets machine operand kill flags.
    409   extern char &LiveVariablesID;
    410 
    411   /// PHIElimination - This pass eliminates machine instruction PHI nodes
    412   /// by inserting copy instructions.  This destroys SSA information, but is the
    413   /// desired input for some register allocators.  This pass is "required" by
    414   /// these register allocator like this: AU.addRequiredID(PHIEliminationID);
    415   extern char &PHIEliminationID;
    416 
    417   /// LiveIntervals - This analysis keeps track of the live ranges of virtual
    418   /// and physical registers.
    419   extern char &LiveIntervalsID;
    420 
    421   /// LiveStacks pass. An analysis keeping track of the liveness of stack slots.
    422   extern char &LiveStacksID;
    423 
    424   /// TwoAddressInstruction - This pass reduces two-address instructions to
    425   /// use two operands. This destroys SSA information but it is desired by
    426   /// register allocators.
    427   extern char &TwoAddressInstructionPassID;
    428 
    429   /// ProcessImpicitDefs pass - This pass removes IMPLICIT_DEFs.
    430   extern char &ProcessImplicitDefsID;
    431 
    432   /// RegisterCoalescer - This pass merges live ranges to eliminate copies.
    433   extern char &RegisterCoalescerID;
    434 
    435   /// MachineScheduler - This pass schedules machine instructions.
    436   extern char &MachineSchedulerID;
    437 
    438   /// PostMachineScheduler - This pass schedules machine instructions postRA.
    439   extern char &PostMachineSchedulerID;
    440 
    441   /// SpillPlacement analysis. Suggest optimal placement of spill code between
    442   /// basic blocks.
    443   extern char &SpillPlacementID;
    444 
    445   /// ShrinkWrap pass. Look for the best place to insert save and restore
    446   // instruction and update the MachineFunctionInfo with that information.
    447   extern char &ShrinkWrapID;
    448 
    449   /// VirtRegRewriter pass. Rewrite virtual registers to physical registers as
    450   /// assigned in VirtRegMap.
    451   extern char &VirtRegRewriterID;
    452 
    453   /// UnreachableMachineBlockElimination - This pass removes unreachable
    454   /// machine basic blocks.
    455   extern char &UnreachableMachineBlockElimID;
    456 
    457   /// DeadMachineInstructionElim - This pass removes dead machine instructions.
    458   extern char &DeadMachineInstructionElimID;
    459 
    460   /// FastRegisterAllocation Pass - This pass register allocates as fast as
    461   /// possible. It is best suited for debug code where live ranges are short.
    462   ///
    463   FunctionPass *createFastRegisterAllocator();
    464 
    465   /// BasicRegisterAllocation Pass - This pass implements a degenerate global
    466   /// register allocator using the basic regalloc framework.
    467   ///
    468   FunctionPass *createBasicRegisterAllocator();
    469 
    470   /// Greedy register allocation pass - This pass implements a global register
    471   /// allocator for optimized builds.
    472   ///
    473   FunctionPass *createGreedyRegisterAllocator();
    474 
    475   /// PBQPRegisterAllocation Pass - This pass implements the Partitioned Boolean
    476   /// Quadratic Prograaming (PBQP) based register allocator.
    477   ///
    478   FunctionPass *createDefaultPBQPRegisterAllocator();
    479 
    480   /// PrologEpilogCodeInserter - This pass inserts prolog and epilog code,
    481   /// and eliminates abstract frame references.
    482   extern char &PrologEpilogCodeInserterID;
    483 
    484   /// ExpandPostRAPseudos - This pass expands pseudo instructions after
    485   /// register allocation.
    486   extern char &ExpandPostRAPseudosID;
    487 
    488   /// createPostRAScheduler - This pass performs post register allocation
    489   /// scheduling.
    490   extern char &PostRASchedulerID;
    491 
    492   /// BranchFolding - This pass performs machine code CFG based
    493   /// optimizations to delete branches to branches, eliminate branches to
    494   /// successor blocks (creating fall throughs), and eliminating branches over
    495   /// branches.
    496   extern char &BranchFolderPassID;
    497 
    498   /// MachineFunctionPrinterPass - This pass prints out MachineInstr's.
    499   extern char &MachineFunctionPrinterPassID;
    500 
    501   /// MIRPrintingPass - this pass prints out the LLVM IR using the MIR
    502   /// serialization format.
    503   extern char &MIRPrintingPassID;
    504 
    505   /// TailDuplicate - Duplicate blocks with unconditional branches
    506   /// into tails of their predecessors.
    507   extern char &TailDuplicateID;
    508 
    509   /// MachineTraceMetrics - This pass computes critical path and CPU resource
    510   /// usage in an ensemble of traces.
    511   extern char &MachineTraceMetricsID;
    512 
    513   /// EarlyIfConverter - This pass performs if-conversion on SSA form by
    514   /// inserting cmov instructions.
    515   extern char &EarlyIfConverterID;
    516 
    517   /// This pass performs instruction combining using trace metrics to estimate
    518   /// critical-path and resource depth.
    519   extern char &MachineCombinerID;
    520 
    521   /// StackSlotColoring - This pass performs stack coloring and merging.
    522   /// It merges disjoint allocas to reduce the stack size.
    523   extern char &StackColoringID;
    524 
    525   /// IfConverter - This pass performs machine code if conversion.
    526   extern char &IfConverterID;
    527 
    528   FunctionPass *createIfConverter(std::function<bool(const Function &)> Ftor);
    529 
    530   /// MachineBlockPlacement - This pass places basic blocks based on branch
    531   /// probabilities.
    532   extern char &MachineBlockPlacementID;
    533 
    534   /// MachineBlockPlacementStats - This pass collects statistics about the
    535   /// basic block placement using branch probabilities and block frequency
    536   /// information.
    537   extern char &MachineBlockPlacementStatsID;
    538 
    539   /// GCLowering Pass - Used by gc.root to perform its default lowering
    540   /// operations.
    541   FunctionPass *createGCLoweringPass();
    542 
    543   /// ShadowStackGCLowering - Implements the custom lowering mechanism
    544   /// used by the shadow stack GC.  Only runs on functions which opt in to
    545   /// the shadow stack collector.
    546   FunctionPass *createShadowStackGCLoweringPass();
    547 
    548   /// GCMachineCodeAnalysis - Target-independent pass to mark safe points
    549   /// in machine code. Must be added very late during code generation, just
    550   /// prior to output, and importantly after all CFG transformations (such as
    551   /// branch folding).
    552   extern char &GCMachineCodeAnalysisID;
    553 
    554   /// Creates a pass to print GC metadata.
    555   ///
    556   FunctionPass *createGCInfoPrinter(raw_ostream &OS);
    557 
    558   /// MachineCSE - This pass performs global CSE on machine instructions.
    559   extern char &MachineCSEID;
    560 
    561   /// ImplicitNullChecks - This pass folds null pointer checks into nearby
    562   /// memory operations.
    563   extern char &ImplicitNullChecksID;
    564 
    565   /// MachineLICM - This pass performs LICM on machine instructions.
    566   extern char &MachineLICMID;
    567 
    568   /// MachineSinking - This pass performs sinking on machine instructions.
    569   extern char &MachineSinkingID;
    570 
    571   /// MachineCopyPropagation - This pass performs copy propagation on
    572   /// machine instructions.
    573   extern char &MachineCopyPropagationID;
    574 
    575   /// PeepholeOptimizer - This pass performs peephole optimizations -
    576   /// like extension and comparison eliminations.
    577   extern char &PeepholeOptimizerID;
    578 
    579   /// OptimizePHIs - This pass optimizes machine instruction PHIs
    580   /// to take advantage of opportunities created during DAG legalization.
    581   extern char &OptimizePHIsID;
    582 
    583   /// StackSlotColoring - This pass performs stack slot coloring.
    584   extern char &StackSlotColoringID;
    585 
    586   /// \brief This pass lays out funclets contiguously.
    587   extern char &FuncletLayoutID;
    588 
    589   /// createStackProtectorPass - This pass adds stack protectors to functions.
    590   ///
    591   FunctionPass *createStackProtectorPass(const TargetMachine *TM);
    592 
    593   /// createMachineVerifierPass - This pass verifies cenerated machine code
    594   /// instructions for correctness.
    595   ///
    596   FunctionPass *createMachineVerifierPass(const std::string& Banner);
    597 
    598   /// createDwarfEHPass - This pass mulches exception handling code into a form
    599   /// adapted to code generation.  Required if using dwarf exception handling.
    600   FunctionPass *createDwarfEHPass(const TargetMachine *TM);
    601 
    602   /// createWinEHPass - Prepares personality functions used by MSVC on Windows,
    603   /// in addition to the Itanium LSDA based personalities.
    604   FunctionPass *createWinEHPass(const TargetMachine *TM);
    605 
    606   /// createSjLjEHPreparePass - This pass adapts exception handling code to use
    607   /// the GCC-style builtin setjmp/longjmp (sjlj) to handling EH control flow.
    608   ///
    609   FunctionPass *createSjLjEHPreparePass();
    610 
    611   /// LocalStackSlotAllocation - This pass assigns local frame indices to stack
    612   /// slots relative to one another and allocates base registers to access them
    613   /// when it is estimated by the target to be out of range of normal frame
    614   /// pointer or stack pointer index addressing.
    615   extern char &LocalStackSlotAllocationID;
    616 
    617   /// ExpandISelPseudos - This pass expands pseudo-instructions.
    618   extern char &ExpandISelPseudosID;
    619 
    620   /// createExecutionDependencyFixPass - This pass fixes execution time
    621   /// problems with dependent instructions, such as switching execution
    622   /// domains to match.
    623   ///
    624   /// The pass will examine instructions using and defining registers in RC.
    625   ///
    626   FunctionPass *createExecutionDependencyFixPass(const TargetRegisterClass *RC);
    627 
    628   /// UnpackMachineBundles - This pass unpack machine instruction bundles.
    629   extern char &UnpackMachineBundlesID;
    630 
    631   FunctionPass *
    632   createUnpackMachineBundles(std::function<bool(const Function &)> Ftor);
    633 
    634   /// FinalizeMachineBundles - This pass finalize machine instruction
    635   /// bundles (created earlier, e.g. during pre-RA scheduling).
    636   extern char &FinalizeMachineBundlesID;
    637 
    638   /// StackMapLiveness - This pass analyses the register live-out set of
    639   /// stackmap/patchpoint intrinsics and attaches the calculated information to
    640   /// the intrinsic for later emission to the StackMap.
    641   extern char &StackMapLivenessID;
    642 
    643   /// LiveDebugValues pass
    644   extern char &LiveDebugValuesID;
    645 
    646   /// createJumpInstrTables - This pass creates jump-instruction tables.
    647   ModulePass *createJumpInstrTablesPass();
    648 
    649   /// createForwardControlFlowIntegrityPass - This pass adds control-flow
    650   /// integrity.
    651   ModulePass *createForwardControlFlowIntegrityPass();
    652 
    653   /// InterleavedAccess Pass - This pass identifies and matches interleaved
    654   /// memory accesses to target specific intrinsics.
    655   ///
    656   FunctionPass *createInterleavedAccessPass(const TargetMachine *TM);
    657 } // End llvm namespace
    658 
    659 /// Target machine pass initializer for passes with dependencies. Use with
    660 /// INITIALIZE_TM_PASS_END.
    661 #define INITIALIZE_TM_PASS_BEGIN INITIALIZE_PASS_BEGIN
    662 
    663 /// Target machine pass initializer for passes with dependencies. Use with
    664 /// INITIALIZE_TM_PASS_BEGIN.
    665 #define INITIALIZE_TM_PASS_END(passName, arg, name, cfg, analysis) \
    666     PassInfo *PI = new PassInfo(name, arg, & passName ::ID, \
    667       PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis, \
    668       PassInfo::TargetMachineCtor_t(callTargetMachineCtor< passName >)); \
    669     Registry.registerPass(*PI, true); \
    670     return PI; \
    671   } \
    672   void llvm::initialize##passName##Pass(PassRegistry &Registry) { \
    673     CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
    674   }
    675 
    676 /// This initializer registers TargetMachine constructor, so the pass being
    677 /// initialized can use target dependent interfaces. Please do not move this
    678 /// macro to be together with INITIALIZE_PASS, which is a complete target
    679 /// independent initializer, and we don't want to make libScalarOpts depend
    680 /// on libCodeGen.
    681 #define INITIALIZE_TM_PASS(passName, arg, name, cfg, analysis) \
    682     INITIALIZE_TM_PASS_BEGIN(passName, arg, name, cfg, analysis) \
    683     INITIALIZE_TM_PASS_END(passName, arg, name, cfg, analysis)
    684 
    685 #endif
    686