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:
IdentifyingPassPtr()62   IdentifyingPassPtr() : P(nullptr), IsInstance(false) {}
IdentifyingPassPtr(AnalysisID IDPtr)63   IdentifyingPassPtr(AnalysisID IDPtr) : ID(IDPtr), IsInstance(false) {}
IdentifyingPassPtr(Pass * InstancePtr)64   IdentifyingPassPtr(Pass *InstancePtr) : P(InstancePtr), IsInstance(true) {}
65 
isValid()66   bool isValid() const { return P; }
isInstance()67   bool isInstance() const { return IsInstance; }
68 
getID()69   AnalysisID getID() const {
70     assert(!IsInstance && "Not a Pass ID");
71     return ID;
72   }
getInstance()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