//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines a base class that indicates that a specified class is a // transformation pass implementation. // // Passes are designed this way so that it is possible to run passes in a cache // and organizationally optimal order without having to specify it at the front // end. This allows arbitrary passes to be strung together and have them // executed as effeciently as possible. // // Passes should extend one of the classes below, depending on the guarantees // that it can make about what will be modified as it is run. For example, most // global optimizations should derive from FunctionPass, because they do not add // or delete functions, they operate on the internals of the function. // // Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the // bottom), so the APIs exposed by these files are also automatically available // to all users of this file. // //===----------------------------------------------------------------------===// #ifndef LLVM_PASS_H #define LLVM_PASS_H #include "llvm/Support/Streams.h" #include <vector> #include <deque> #include <map> #include <iosfwd> #include <cassert> namespace llvm { class Value; class BasicBlock; class Function; class Module; class AnalysisUsage; class PassInfo; class ImmutablePass; class PMStack; class AnalysisResolver; class PMDataManager; // AnalysisID - Use the PassInfo to identify a pass... typedef const PassInfo* AnalysisID; /// Different types of internal pass managers. External pass managers /// (PassManager and FunctionPassManager) are not represented here. /// Ordering of pass manager types is important here. enum PassManagerType { PMT_Unknown = 0, PMT_ModulePassManager = 1, /// MPPassManager PMT_CallGraphPassManager, /// CGPassManager PMT_FunctionPassManager, /// FPPassManager PMT_LoopPassManager, /// LPPassManager PMT_BasicBlockPassManager, /// BBPassManager PMT_Last }; typedef enum PassManagerType PassManagerType; //===----------------------------------------------------------------------===// /// Pass interface - Implemented by all 'passes'. Subclass this if you are an /// interprocedural optimization or you do not fit into any of the more /// constrained passes described below. /// class Pass { AnalysisResolver *Resolver; // Used to resolve analysis intptr_t PassID; // AnalysisImpls - This keeps track of which passes implement the interfaces // that are required by the current pass (to implement getAnalysis()). // std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls; void operator=(const Pass&); // DO NOT IMPLEMENT Pass(const Pass &); // DO NOT IMPLEMENT public: explicit Pass(intptr_t pid) : Resolver(0), PassID(pid) {} virtual ~Pass(); /// getPassName - Return a nice clean name for a pass. This usually /// implemented in terms of the name that is registered by one of the /// Registration templates, but can be overloaded directly, and if nothing /// else is available, C++ RTTI will be consulted to get a SOMEWHAT /// intelligible name for the pass. /// virtual const char *getPassName() const; /// getPassInfo - Return the PassInfo data structure that corresponds to this /// pass... If the pass has not been registered, this will return null. /// const PassInfo *getPassInfo() const; /// runPass - Run this pass, returning true if a modification was made to the /// module argument. This should be implemented by all concrete subclasses. /// virtual bool runPass(Module &M) { return false; } virtual bool runPass(BasicBlock&) { return false; } /// print - Print out the internal state of the pass. This is called by /// Analyze to print out the contents of an analysis. Otherwise it is not /// necessary to implement this method. Beware that the module pointer MAY be /// null. This automatically forwards to a virtual function that does not /// provide the Module* in case the analysis doesn't need it it can just be /// ignored. /// virtual void print(std::ostream &O, const Module *M) const; void print(std::ostream *O, const Module *M) const { if (O) print(*O, M); } void dump() const; // dump - call print(std::cerr, 0); /// Each pass is responsible for assigning a pass manager to itself. /// PMS is the stack of available pass manager. virtual void assignPassManager(PMStack &PMS, PassManagerType T = PMT_Unknown) {} /// Check if available pass managers are suitable for this pass or not. virtual void preparePassManager(PMStack &PMS) {} /// Return what kind of Pass Manager can manage this pass. virtual PassManagerType getPotentialPassManagerType() const { return PMT_Unknown; } // Access AnalysisResolver inline void setResolver(AnalysisResolver *AR) { Resolver = AR; } inline AnalysisResolver *getResolver() { return Resolver; } /// getAnalysisUsage - This function should be overriden by passes that need /// analysis information to do their job. If a pass specifies that it uses a /// particular analysis result to this function, it can then use the /// getAnalysis<AnalysisType>() function, below. /// virtual void getAnalysisUsage(AnalysisUsage &Info) const { // By default, no analysis results are used, all are invalidated. } /// releaseMemory() - This member can be implemented by a pass if it wants to /// be able to release its memory when it is no longer needed. The default /// behavior of passes is to hold onto memory for the entire duration of their /// lifetime (which is the entire compile time). For pipelined passes, this /// is not a big deal because that memory gets recycled every time the pass is /// invoked on another program unit. For IP passes, it is more important to /// free memory when it is unused. /// /// Optionally implement this function to release pass memory when it is no /// longer used. /// virtual void releaseMemory() {} // dumpPassStructure - Implement the -debug-passes=PassStructure option virtual void dumpPassStructure(unsigned Offset = 0); template<typename AnalysisClass> static const PassInfo *getClassPassInfo() { return lookupPassInfo((intptr_t)&AnalysisClass::ID); } // lookupPassInfo - Return the pass info object for the specified pass class, // or null if it is not known. static const PassInfo *lookupPassInfo(intptr_t TI); /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses /// to get to the analysis information that might be around that needs to be /// updated. This is different than getAnalysis in that it can fail (ie the /// analysis results haven't been computed), so should only be used if you /// provide the capability to update an analysis that exists. This method is /// often used by transformation APIs to update analysis results for a pass /// automatically as the transform is performed. /// template<typename AnalysisType> AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h /// mustPreserveAnalysisID - This method serves the same function as /// getAnalysisToUpdate, but works if you just have an AnalysisID. This /// obviously cannot give you a properly typed instance of the class if you /// don't have the class name available (use getAnalysisToUpdate if you do), /// but it can tell you if you need to preserve the pass at least. /// bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; /// getAnalysis<AnalysisType>() - This function is used by subclasses to get /// to the analysis information that they claim to use by overriding the /// getAnalysisUsage function. /// template<typename AnalysisType> AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h template<typename AnalysisType> AnalysisType &getAnalysis(Function &F); // Defined in PassanalysisSupport.h template<typename AnalysisType> AnalysisType &getAnalysisID(const PassInfo *PI) const; template<typename AnalysisType> AnalysisType &getAnalysisID(const PassInfo *PI, Function &F); }; inline std::ostream &operator<<(std::ostream &OS, const Pass &P) { P.print(OS, 0); return OS; } //===----------------------------------------------------------------------===// /// ModulePass class - This class is used to implement unstructured /// interprocedural optimizations and analyses. ModulePasses may do anything /// they want to the program. /// class ModulePass : public Pass { public: /// runOnModule - Virtual method overriden by subclasses to process the module /// being operated on. virtual bool runOnModule(Module &M) = 0; virtual bool runPass(Module &M) { return runOnModule(M); } virtual bool runPass(BasicBlock&) { return false; } virtual void assignPassManager(PMStack &PMS, PassManagerType T = PMT_ModulePassManager); /// Return what kind of Pass Manager can manage this pass. virtual PassManagerType getPotentialPassManagerType() const { return PMT_ModulePassManager; } explicit ModulePass(intptr_t pid) : Pass(pid) {} // Force out-of-line virtual method. virtual ~ModulePass(); }; //===----------------------------------------------------------------------===// /// ImmutablePass class - This class is used to provide information that does /// not need to be run. This is useful for things like target information and /// "basic" versions of AnalysisGroups. /// class ImmutablePass : public ModulePass { public: /// initializePass - This method may be overriden by immutable passes to allow /// them to perform various initialization actions they require. This is /// primarily because an ImmutablePass can "require" another ImmutablePass, /// and if it does, the overloaded version of initializePass may get access to /// these passes with getAnalysis<>. /// virtual void initializePass() {} /// ImmutablePasses are never run. /// virtual bool runOnModule(Module &M) { return false; } explicit ImmutablePass(intptr_t pid) : ModulePass(pid) {} // Force out-of-line virtual method. virtual ~ImmutablePass(); }; //===----------------------------------------------------------------------===// /// FunctionPass class - This class is used to implement most global /// optimizations. Optimizations should subclass this class if they meet the /// following constraints: /// /// 1. Optimizations are organized globally, i.e., a function at a time /// 2. Optimizing a function does not cause the addition or removal of any /// functions in the module /// class FunctionPass : public Pass { public: explicit FunctionPass(intptr_t pid) : Pass(pid) {} /// doInitialization - Virtual method overridden by subclasses to do /// any necessary per-module initialization. /// virtual bool doInitialization(Module &M) { return false; } /// runOnFunction - Virtual method overriden by subclasses to do the /// per-function processing of the pass. /// virtual bool runOnFunction(Function &F) = 0; /// doFinalization - Virtual method overriden by subclasses to do any post /// processing needed after all passes have run. /// virtual bool doFinalization(Module &M) { return false; } /// runOnModule - On a module, we run this pass by initializing, /// ronOnFunction'ing once for every function in the module, then by /// finalizing. /// virtual bool runOnModule(Module &M); /// run - On a function, we simply initialize, run the function, then /// finalize. /// bool run(Function &F); virtual void assignPassManager(PMStack &PMS, PassManagerType T = PMT_FunctionPassManager); /// Return what kind of Pass Manager can manage this pass. virtual PassManagerType getPotentialPassManagerType() const { return PMT_FunctionPassManager; } }; //===----------------------------------------------------------------------===// /// BasicBlockPass class - This class is used to implement most local /// optimizations. Optimizations should subclass this class if they /// meet the following constraints: /// 1. Optimizations are local, operating on either a basic block or /// instruction at a time. /// 2. Optimizations do not modify the CFG of the contained function, or any /// other basic block in the function. /// 3. Optimizations conform to all of the constraints of FunctionPasses. /// class BasicBlockPass : public Pass { public: explicit BasicBlockPass(intptr_t pid) : Pass(pid) {} /// doInitialization - Virtual method overridden by subclasses to do /// any necessary per-module initialization. /// virtual bool doInitialization(Module &M) { return false; } /// doInitialization - Virtual method overridden by BasicBlockPass subclasses /// to do any necessary per-function initialization. /// virtual bool doInitialization(Function &F) { return false; } /// runOnBasicBlock - Virtual method overriden by subclasses to do the /// per-basicblock processing of the pass. /// virtual bool runOnBasicBlock(BasicBlock &BB) = 0; /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to /// do any post processing needed after all passes have run. /// virtual bool doFinalization(Function &F) { return false; } /// doFinalization - Virtual method overriden by subclasses to do any post /// processing needed after all passes have run. /// virtual bool doFinalization(Module &M) { return false; } // To run this pass on a function, we simply call runOnBasicBlock once for // each function. // bool runOnFunction(Function &F); /// To run directly on the basic block, we initialize, runOnBasicBlock, then /// finalize. /// virtual bool runPass(Module &M) { return false; } virtual bool runPass(BasicBlock &BB); virtual void assignPassManager(PMStack &PMS, PassManagerType T = PMT_BasicBlockPassManager); /// Return what kind of Pass Manager can manage this pass. virtual PassManagerType getPotentialPassManagerType() const { return PMT_BasicBlockPassManager; } }; /// PMStack /// Top level pass manager (see PasManager.cpp) maintains active Pass Managers /// using PMStack. Each Pass implements assignPassManager() to connect itself /// with appropriate manager. assignPassManager() walks PMStack to find /// suitable manager. /// /// PMStack is just a wrapper around standard deque that overrides pop() and /// push() methods. class PMStack { public: typedef std::deque<PMDataManager *>::reverse_iterator iterator; iterator begin() { return S.rbegin(); } iterator end() { return S.rend(); } void handleLastUserOverflow(); void pop(); inline PMDataManager *top() { return S.back(); } void push(Pass *P); inline bool empty() { return S.empty(); } void dump(); private: std::deque<PMDataManager *> S; }; /// If the user specifies the -time-passes argument on an LLVM tool command line /// then the value of this boolean will be true, otherwise false. /// @brief This is the storage for the -time-passes option. extern bool TimePassesIsEnabled; } // End llvm namespace // Include support files that contain important APIs commonly used by Passes, // but that we want to separate out to make it easier to read the header files. // #include "llvm/PassSupport.h" #include "llvm/PassAnalysisSupport.h" #endif