Pass.h revision c7fe32e840758baa9ce4f93c321b508a69b98262
1//===- llvm/Pass.h - Base class for 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 a base class that indicates that a specified class is a 11// transformation pass implementation. 12// 13// Passes are designed this way so that it is possible to run passes in a cache 14// and organizationally optimal order without having to specify it at the front 15// end. This allows arbitrary passes to be strung together and have them 16// executed as effeciently as possible. 17// 18// Passes should extend one of the classes below, depending on the guarantees 19// that it can make about what will be modified as it is run. For example, most 20// global optimizations should derive from FunctionPass, because they do not add 21// or delete functions, they operate on the internals of the function. 22// 23// Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the 24// bottom), so the APIs exposed by these files are also automatically available 25// to all users of this file. 26// 27//===----------------------------------------------------------------------===// 28 29#ifndef LLVM_PASS_H 30#define LLVM_PASS_H 31 32#include "llvm/Support/DataTypes.h" 33#include "llvm/Support/Streams.h" 34#include <vector> 35#include <map> 36#include <iosfwd> 37#include <cassert> 38 39namespace llvm { 40 41class Value; 42class BasicBlock; 43class Function; 44class Module; 45class AnalysisUsage; 46class PassInfo; 47class ImmutablePass; 48class PMStack; 49class AnalysisResolver; 50class PMDataManager; 51 52// AnalysisID - Use the PassInfo to identify a pass... 53typedef const PassInfo* AnalysisID; 54 55/// Different types of internal pass managers. External pass managers 56/// (PassManager and FunctionPassManager) are not represented here. 57/// Ordering of pass manager types is important here. 58enum PassManagerType { 59 PMT_Unknown = 0, 60 PMT_ModulePassManager = 1, /// MPPassManager 61 PMT_CallGraphPassManager, /// CGPassManager 62 PMT_FunctionPassManager, /// FPPassManager 63 PMT_LoopPassManager, /// LPPassManager 64 PMT_BasicBlockPassManager, /// BBPassManager 65 PMT_Last 66}; 67 68//===----------------------------------------------------------------------===// 69/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 70/// interprocedural optimization or you do not fit into any of the more 71/// constrained passes described below. 72/// 73class Pass { 74 AnalysisResolver *Resolver; // Used to resolve analysis 75 intptr_t PassID; 76 bool isAnalysisPass; // True if this pass is an analysis pass. 77 // AnalysisImpls - This keeps track of which passes implement the interfaces 78 // that are required by the current pass (to implement getAnalysis()). 79 // 80 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls; 81 82 void operator=(const Pass&); // DO NOT IMPLEMENT 83 Pass(const Pass &); // DO NOT IMPLEMENT 84public: 85 explicit Pass(intptr_t pid, bool AP = false) : Resolver(0), PassID(pid), 86 isAnalysisPass(AP) {} 87 explicit Pass(const void *pid, bool AP = false) : Resolver(0), 88 PassID((intptr_t)pid), 89 isAnalysisPass(AP) {} 90 virtual ~Pass(); 91 92 bool isAnalysis() const { return isAnalysisPass; } 93 /// getPassName - Return a nice clean name for a pass. This usually 94 /// implemented in terms of the name that is registered by one of the 95 /// Registration templates, but can be overloaded directly. 96 /// 97 virtual const char *getPassName() const; 98 99 /// getPassInfo - Return the PassInfo data structure that corresponds to this 100 /// pass... If the pass has not been registered, this will return null. 101 /// 102 const PassInfo *getPassInfo() const; 103 104 /// print - Print out the internal state of the pass. This is called by 105 /// Analyze to print out the contents of an analysis. Otherwise it is not 106 /// necessary to implement this method. Beware that the module pointer MAY be 107 /// null. This automatically forwards to a virtual function that does not 108 /// provide the Module* in case the analysis doesn't need it it can just be 109 /// ignored. 110 /// 111 virtual void print(std::ostream &O, const Module *M) const; 112 void print(std::ostream *O, const Module *M) const { if (O) print(*O, M); } 113 void dump() const; // dump - call print(std::cerr, 0); 114 115 /// Each pass is responsible for assigning a pass manager to itself. 116 /// PMS is the stack of available pass manager. 117 virtual void assignPassManager(PMStack &PMS, 118 PassManagerType T = PMT_Unknown) {} 119 /// Check if available pass managers are suitable for this pass or not. 120 virtual void preparePassManager(PMStack &PMS) {} 121 122 /// Return what kind of Pass Manager can manage this pass. 123 virtual PassManagerType getPotentialPassManagerType() const { 124 return PMT_Unknown; 125 } 126 127 // Access AnalysisResolver 128 inline void setResolver(AnalysisResolver *AR) { 129 assert (!Resolver && "Resolver is already set"); 130 Resolver = AR; 131 } 132 inline AnalysisResolver *getResolver() { 133 assert (Resolver && "Resolver is not set"); 134 return Resolver; 135 } 136 137 /// getAnalysisUsage - This function should be overriden by passes that need 138 /// analysis information to do their job. If a pass specifies that it uses a 139 /// particular analysis result to this function, it can then use the 140 /// getAnalysis<AnalysisType>() function, below. 141 /// 142 virtual void getAnalysisUsage(AnalysisUsage &Info) const { 143 // By default, no analysis results are used, all are invalidated. 144 } 145 146 /// releaseMemory() - This member can be implemented by a pass if it wants to 147 /// be able to release its memory when it is no longer needed. The default 148 /// behavior of passes is to hold onto memory for the entire duration of their 149 /// lifetime (which is the entire compile time). For pipelined passes, this 150 /// is not a big deal because that memory gets recycled every time the pass is 151 /// invoked on another program unit. For IP passes, it is more important to 152 /// free memory when it is unused. 153 /// 154 /// Optionally implement this function to release pass memory when it is no 155 /// longer used. 156 /// 157 virtual void releaseMemory() {} 158 159 /// verifyAnalysis() - This member can be implemented by a analysis pass to 160 /// check state of analysis information. 161 virtual void verifyAnalysis() const {} 162 163 // dumpPassStructure - Implement the -debug-passes=PassStructure option 164 virtual void dumpPassStructure(unsigned Offset = 0); 165 166 template<typename AnalysisClass> 167 static const PassInfo *getClassPassInfo() { 168 return lookupPassInfo(intptr_t(&AnalysisClass::ID)); 169 } 170 171 // lookupPassInfo - Return the pass info object for the specified pass class, 172 // or null if it is not known. 173 static const PassInfo *lookupPassInfo(intptr_t TI); 174 175 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses 176 /// to get to the analysis information that might be around that needs to be 177 /// updated. This is different than getAnalysis in that it can fail (ie the 178 /// analysis results haven't been computed), so should only be used if you 179 /// provide the capability to update an analysis that exists. This method is 180 /// often used by transformation APIs to update analysis results for a pass 181 /// automatically as the transform is performed. 182 /// 183 template<typename AnalysisType> 184 AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h 185 186 /// mustPreserveAnalysisID - This method serves the same function as 187 /// getAnalysisToUpdate, but works if you just have an AnalysisID. This 188 /// obviously cannot give you a properly typed instance of the class if you 189 /// don't have the class name available (use getAnalysisToUpdate if you do), 190 /// but it can tell you if you need to preserve the pass at least. 191 /// 192 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; 193 194 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 195 /// to the analysis information that they claim to use by overriding the 196 /// getAnalysisUsage function. 197 /// 198 template<typename AnalysisType> 199 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 200 201 template<typename AnalysisType> 202 AnalysisType &getAnalysis(Function &F); // Defined in PassanalysisSupport.h 203 204 template<typename AnalysisType> 205 AnalysisType &getAnalysisID(const PassInfo *PI) const; 206 207 template<typename AnalysisType> 208 AnalysisType &getAnalysisID(const PassInfo *PI, Function &F); 209}; 210 211inline std::ostream &operator<<(std::ostream &OS, const Pass &P) { 212 P.print(OS, 0); return OS; 213} 214 215//===----------------------------------------------------------------------===// 216/// ModulePass class - This class is used to implement unstructured 217/// interprocedural optimizations and analyses. ModulePasses may do anything 218/// they want to the program. 219/// 220class ModulePass : public Pass { 221public: 222 /// runOnModule - Virtual method overriden by subclasses to process the module 223 /// being operated on. 224 virtual bool runOnModule(Module &M) = 0; 225 226 virtual void assignPassManager(PMStack &PMS, 227 PassManagerType T = PMT_ModulePassManager); 228 229 /// Return what kind of Pass Manager can manage this pass. 230 virtual PassManagerType getPotentialPassManagerType() const { 231 return PMT_ModulePassManager; 232 } 233 234 explicit ModulePass(intptr_t pid, bool AP = false) : Pass(pid, AP) {} 235 explicit ModulePass(const void *pid, bool AP = false) : Pass(pid, AP) {} 236 // Force out-of-line virtual method. 237 virtual ~ModulePass(); 238}; 239 240 241//===----------------------------------------------------------------------===// 242/// ImmutablePass class - This class is used to provide information that does 243/// not need to be run. This is useful for things like target information and 244/// "basic" versions of AnalysisGroups. 245/// 246class ImmutablePass : public ModulePass { 247public: 248 /// initializePass - This method may be overriden by immutable passes to allow 249 /// them to perform various initialization actions they require. This is 250 /// primarily because an ImmutablePass can "require" another ImmutablePass, 251 /// and if it does, the overloaded version of initializePass may get access to 252 /// these passes with getAnalysis<>. 253 /// 254 virtual void initializePass() {} 255 256 /// ImmutablePasses are never run. 257 /// 258 bool runOnModule(Module &M) { return false; } 259 260 explicit ImmutablePass(intptr_t pid, bool AP = false) : ModulePass(pid, AP) {} 261 explicit ImmutablePass(const void *pid, bool AP = false) 262 : ModulePass(pid, AP) {} 263 264 // Force out-of-line virtual method. 265 virtual ~ImmutablePass(); 266}; 267 268//===----------------------------------------------------------------------===// 269/// FunctionPass class - This class is used to implement most global 270/// optimizations. Optimizations should subclass this class if they meet the 271/// following constraints: 272/// 273/// 1. Optimizations are organized globally, i.e., a function at a time 274/// 2. Optimizing a function does not cause the addition or removal of any 275/// functions in the module 276/// 277class FunctionPass : public Pass { 278public: 279 explicit FunctionPass(intptr_t pid, bool AP = false) : Pass(pid, AP) {} 280 explicit FunctionPass(const void *pid, bool AP = false) : Pass(pid, AP) {} 281 282 /// doInitialization - Virtual method overridden by subclasses to do 283 /// any necessary per-module initialization. 284 /// 285 virtual bool doInitialization(Module &M) { return false; } 286 287 /// runOnFunction - Virtual method overriden by subclasses to do the 288 /// per-function processing of the pass. 289 /// 290 virtual bool runOnFunction(Function &F) = 0; 291 292 /// doFinalization - Virtual method overriden by subclasses to do any post 293 /// processing needed after all passes have run. 294 /// 295 virtual bool doFinalization(Module &M) { return false; } 296 297 /// runOnModule - On a module, we run this pass by initializing, 298 /// ronOnFunction'ing once for every function in the module, then by 299 /// finalizing. 300 /// 301 virtual bool runOnModule(Module &M); 302 303 /// run - On a function, we simply initialize, run the function, then 304 /// finalize. 305 /// 306 bool run(Function &F); 307 308 virtual void assignPassManager(PMStack &PMS, 309 PassManagerType T = PMT_FunctionPassManager); 310 311 /// Return what kind of Pass Manager can manage this pass. 312 virtual PassManagerType getPotentialPassManagerType() const { 313 return PMT_FunctionPassManager; 314 } 315}; 316 317 318 319//===----------------------------------------------------------------------===// 320/// BasicBlockPass class - This class is used to implement most local 321/// optimizations. Optimizations should subclass this class if they 322/// meet the following constraints: 323/// 1. Optimizations are local, operating on either a basic block or 324/// instruction at a time. 325/// 2. Optimizations do not modify the CFG of the contained function, or any 326/// other basic block in the function. 327/// 3. Optimizations conform to all of the constraints of FunctionPasses. 328/// 329class BasicBlockPass : public Pass { 330public: 331 explicit BasicBlockPass(intptr_t pid, bool AP = false) : Pass(pid, AP) {} 332 explicit BasicBlockPass(const void *pid, bool AP = false) : Pass(pid, AP) {} 333 334 /// doInitialization - Virtual method overridden by subclasses to do 335 /// any necessary per-module initialization. 336 /// 337 virtual bool doInitialization(Module &M) { return false; } 338 339 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 340 /// to do any necessary per-function initialization. 341 /// 342 virtual bool doInitialization(Function &F) { return false; } 343 344 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 345 /// per-basicblock processing of the pass. 346 /// 347 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 348 349 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 350 /// do any post processing needed after all passes have run. 351 /// 352 virtual bool doFinalization(Function &F) { return false; } 353 354 /// doFinalization - Virtual method overriden by subclasses to do any post 355 /// processing needed after all passes have run. 356 /// 357 virtual bool doFinalization(Module &M) { return false; } 358 359 360 // To run this pass on a function, we simply call runOnBasicBlock once for 361 // each function. 362 // 363 bool runOnFunction(Function &F); 364 365 virtual void assignPassManager(PMStack &PMS, 366 PassManagerType T = PMT_BasicBlockPassManager); 367 368 /// Return what kind of Pass Manager can manage this pass. 369 virtual PassManagerType getPotentialPassManagerType() const { 370 return PMT_BasicBlockPassManager; 371 } 372}; 373 374/// If the user specifies the -time-passes argument on an LLVM tool command line 375/// then the value of this boolean will be true, otherwise false. 376/// @brief This is the storage for the -time-passes option. 377extern bool TimePassesIsEnabled; 378 379} // End llvm namespace 380 381// Include support files that contain important APIs commonly used by Passes, 382// but that we want to separate out to make it easier to read the header files. 383// 384#include "llvm/PassSupport.h" 385#include "llvm/PassAnalysisSupport.h" 386 387#endif 388