Pass.h revision 5c8aa950fe3484b6e115647328c196f8be64f9ed
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/System/DataTypes.h" 33 34#include <cassert> 35#include <string> 36#include <utility> 37#include <vector> 38 39namespace llvm { 40 41class BasicBlock; 42class Function; 43class Module; 44class AnalysisUsage; 45class PassInfo; 46class ImmutablePass; 47class PMStack; 48class AnalysisResolver; 49class PMDataManager; 50class raw_ostream; 51class StringRef; 52 53// AnalysisID - Use the PassInfo to identify a pass... 54typedef const PassInfo* AnalysisID; 55 56/// Different types of internal pass managers. External pass managers 57/// (PassManager and FunctionPassManager) are not represented here. 58/// Ordering of pass manager types is important here. 59enum PassManagerType { 60 PMT_Unknown = 0, 61 PMT_ModulePassManager = 1, ///< MPPassManager 62 PMT_CallGraphPassManager, ///< CGPassManager 63 PMT_FunctionPassManager, ///< FPPassManager 64 PMT_LoopPassManager, ///< LPPassManager 65 PMT_BasicBlockPassManager, ///< BBPassManager 66 PMT_Last 67}; 68 69// Different types of passes. 70enum PassKind { 71 PT_BasicBlock, 72 PT_Loop, 73 PT_Function, 74 PT_CallGraphSCC, 75 PT_Module, 76 PT_PassManager 77}; 78 79//===----------------------------------------------------------------------===// 80/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 81/// interprocedural optimization or you do not fit into any of the more 82/// constrained passes described below. 83/// 84class Pass { 85 AnalysisResolver *Resolver; // Used to resolve analysis 86 intptr_t PassID; 87 PassKind Kind; 88 void operator=(const Pass&); // DO NOT IMPLEMENT 89 Pass(const Pass &); // DO NOT IMPLEMENT 90 91public: 92 explicit Pass(PassKind K, intptr_t pid) : Resolver(0), PassID(pid), Kind(K) { 93 assert(pid && "pid cannot be 0"); 94 } 95 explicit Pass(PassKind K, const void *pid) 96 : Resolver(0), PassID((intptr_t)pid), Kind(K) { 97 assert(pid && "pid cannot be 0"); 98 } 99 virtual ~Pass(); 100 101 102 PassKind getPassKind() const { return Kind; } 103 104 /// getPassName - Return a nice clean name for a pass. This usually 105 /// implemented in terms of the name that is registered by one of the 106 /// Registration templates, but can be overloaded directly. 107 /// 108 virtual const char *getPassName() const; 109 110 /// getPassInfo - Return the PassInfo data structure that corresponds to this 111 /// pass... If the pass has not been registered, this will return null. 112 /// 113 const PassInfo *getPassInfo() const; 114 115 /// print - Print out the internal state of the pass. This is called by 116 /// Analyze to print out the contents of an analysis. Otherwise it is not 117 /// necessary to implement this method. Beware that the module pointer MAY be 118 /// null. This automatically forwards to a virtual function that does not 119 /// provide the Module* in case the analysis doesn't need it it can just be 120 /// ignored. 121 /// 122 virtual void print(raw_ostream &O, const Module *M) const; 123 void dump() const; // dump - Print to stderr. 124 125 /// createPrinterPass - Get a Pass appropriate to print the IR this 126 /// pass operates one (Module, Function or MachineFunction). 127 virtual Pass *createPrinterPass(raw_ostream &O, 128 const std::string &Banner) const = 0; 129 130 /// Each pass is responsible for assigning a pass manager to itself. 131 /// PMS is the stack of available pass manager. 132 virtual void assignPassManager(PMStack &, 133 PassManagerType = PMT_Unknown) {} 134 /// Check if available pass managers are suitable for this pass or not. 135 virtual void preparePassManager(PMStack &); 136 137 /// Return what kind of Pass Manager can manage this pass. 138 virtual PassManagerType getPotentialPassManagerType() const; 139 140 // Access AnalysisResolver 141 inline void setResolver(AnalysisResolver *AR) { 142 assert(!Resolver && "Resolver is already set"); 143 Resolver = AR; 144 } 145 inline AnalysisResolver *getResolver() { 146 return Resolver; 147 } 148 149 /// getAnalysisUsage - This function should be overriden by passes that need 150 /// analysis information to do their job. If a pass specifies that it uses a 151 /// particular analysis result to this function, it can then use the 152 /// getAnalysis<AnalysisType>() function, below. 153 /// 154 virtual void getAnalysisUsage(AnalysisUsage &) const; 155 156 /// releaseMemory() - This member can be implemented by a pass if it wants to 157 /// be able to release its memory when it is no longer needed. The default 158 /// behavior of passes is to hold onto memory for the entire duration of their 159 /// lifetime (which is the entire compile time). For pipelined passes, this 160 /// is not a big deal because that memory gets recycled every time the pass is 161 /// invoked on another program unit. For IP passes, it is more important to 162 /// free memory when it is unused. 163 /// 164 /// Optionally implement this function to release pass memory when it is no 165 /// longer used. 166 /// 167 virtual void releaseMemory(); 168 169 /// getAdjustedAnalysisPointer - This method is used when a pass implements 170 /// an analysis interface through multiple inheritance. If needed, it should 171 /// override this to adjust the this pointer as needed for the specified pass 172 /// info. 173 virtual void *getAdjustedAnalysisPointer(const PassInfo *) { 174 return this; 175 } 176 virtual ImmutablePass *getAsImmutablePass() { return 0; } 177 virtual PMDataManager *getAsPMDataManager() { return 0; } 178 179 /// verifyAnalysis() - This member can be implemented by a analysis pass to 180 /// check state of analysis information. 181 virtual void verifyAnalysis() const; 182 183 // dumpPassStructure - Implement the -debug-passes=PassStructure option 184 virtual void dumpPassStructure(unsigned Offset = 0); 185 186 template<typename AnalysisClass> 187 static const PassInfo *getClassPassInfo() { 188 return lookupPassInfo(intptr_t(&AnalysisClass::ID)); 189 } 190 191 // lookupPassInfo - Return the pass info object for the specified pass class, 192 // or null if it is not known. 193 static const PassInfo *lookupPassInfo(intptr_t TI); 194 195 // lookupPassInfo - Return the pass info object for the pass with the given 196 // argument string, or null if it is not known. 197 static const PassInfo *lookupPassInfo(StringRef Arg); 198 199 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to 200 /// get analysis information that might be around, for example to update it. 201 /// This is different than getAnalysis in that it can fail (if the analysis 202 /// results haven't been computed), so should only be used if you can handle 203 /// the case when the analysis is not available. This method is often used by 204 /// transformation APIs to update analysis results for a pass automatically as 205 /// the transform is performed. 206 /// 207 template<typename AnalysisType> AnalysisType * 208 getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h 209 210 /// mustPreserveAnalysisID - This method serves the same function as 211 /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This 212 /// obviously cannot give you a properly typed instance of the class if you 213 /// don't have the class name available (use getAnalysisIfAvailable if you 214 /// do), but it can tell you if you need to preserve the pass at least. 215 /// 216 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; 217 218 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 219 /// to the analysis information that they claim to use by overriding the 220 /// getAnalysisUsage function. 221 /// 222 template<typename AnalysisType> 223 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 224 225 template<typename AnalysisType> 226 AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h 227 228 template<typename AnalysisType> 229 AnalysisType &getAnalysisID(const PassInfo *PI) const; 230 231 template<typename AnalysisType> 232 AnalysisType &getAnalysisID(const PassInfo *PI, Function &F); 233}; 234 235 236//===----------------------------------------------------------------------===// 237/// ModulePass class - This class is used to implement unstructured 238/// interprocedural optimizations and analyses. ModulePasses may do anything 239/// they want to the program. 240/// 241class ModulePass : public Pass { 242public: 243 /// createPrinterPass - Get a module printer pass. 244 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 245 246 /// runOnModule - Virtual method overriden by subclasses to process the module 247 /// being operated on. 248 virtual bool runOnModule(Module &M) = 0; 249 250 virtual void assignPassManager(PMStack &PMS, 251 PassManagerType T = PMT_ModulePassManager); 252 253 /// Return what kind of Pass Manager can manage this pass. 254 virtual PassManagerType getPotentialPassManagerType() const; 255 256 explicit ModulePass(intptr_t pid) : Pass(PT_Module, pid) {} 257 explicit ModulePass(const void *pid) : Pass(PT_Module, pid) {} 258 // Force out-of-line virtual method. 259 virtual ~ModulePass(); 260}; 261 262 263//===----------------------------------------------------------------------===// 264/// ImmutablePass class - This class is used to provide information that does 265/// not need to be run. This is useful for things like target information and 266/// "basic" versions of AnalysisGroups. 267/// 268class ImmutablePass : public ModulePass { 269public: 270 /// initializePass - This method may be overriden by immutable passes to allow 271 /// them to perform various initialization actions they require. This is 272 /// primarily because an ImmutablePass can "require" another ImmutablePass, 273 /// and if it does, the overloaded version of initializePass may get access to 274 /// these passes with getAnalysis<>. 275 /// 276 virtual void initializePass(); 277 278 virtual ImmutablePass *getAsImmutablePass() { return this; } 279 280 /// ImmutablePasses are never run. 281 /// 282 bool runOnModule(Module &) { return false; } 283 284 explicit ImmutablePass(intptr_t pid) : ModulePass(pid) {} 285 explicit ImmutablePass(const void *pid) 286 : ModulePass(pid) {} 287 288 // Force out-of-line virtual method. 289 virtual ~ImmutablePass(); 290}; 291 292//===----------------------------------------------------------------------===// 293/// FunctionPass class - This class is used to implement most global 294/// optimizations. Optimizations should subclass this class if they meet the 295/// following constraints: 296/// 297/// 1. Optimizations are organized globally, i.e., a function at a time 298/// 2. Optimizing a function does not cause the addition or removal of any 299/// functions in the module 300/// 301class FunctionPass : public Pass { 302public: 303 explicit FunctionPass(intptr_t pid) : Pass(PT_Function, pid) {} 304 explicit FunctionPass(const void *pid) : Pass(PT_Function, pid) {} 305 306 /// createPrinterPass - Get a function printer pass. 307 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 308 309 /// doInitialization - Virtual method overridden by subclasses to do 310 /// any necessary per-module initialization. 311 /// 312 virtual bool doInitialization(Module &); 313 314 /// runOnFunction - Virtual method overriden by subclasses to do the 315 /// per-function processing of the pass. 316 /// 317 virtual bool runOnFunction(Function &F) = 0; 318 319 /// doFinalization - Virtual method overriden by subclasses to do any post 320 /// processing needed after all passes have run. 321 /// 322 virtual bool doFinalization(Module &); 323 324 /// runOnModule - On a module, we run this pass by initializing, 325 /// ronOnFunction'ing once for every function in the module, then by 326 /// finalizing. 327 /// 328 virtual bool runOnModule(Module &M); 329 330 /// run - On a function, we simply initialize, run the function, then 331 /// finalize. 332 /// 333 bool run(Function &F); 334 335 virtual void assignPassManager(PMStack &PMS, 336 PassManagerType T = PMT_FunctionPassManager); 337 338 /// Return what kind of Pass Manager can manage this pass. 339 virtual PassManagerType getPotentialPassManagerType() const; 340}; 341 342 343 344//===----------------------------------------------------------------------===// 345/// BasicBlockPass class - This class is used to implement most local 346/// optimizations. Optimizations should subclass this class if they 347/// meet the following constraints: 348/// 1. Optimizations are local, operating on either a basic block or 349/// instruction at a time. 350/// 2. Optimizations do not modify the CFG of the contained function, or any 351/// other basic block in the function. 352/// 3. Optimizations conform to all of the constraints of FunctionPasses. 353/// 354class BasicBlockPass : public Pass { 355public: 356 explicit BasicBlockPass(intptr_t pid) : Pass(PT_BasicBlock, pid) {} 357 explicit BasicBlockPass(const void *pid) : Pass(PT_BasicBlock, pid) {} 358 359 /// createPrinterPass - Get a function printer pass. 360 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 361 362 /// doInitialization - Virtual method overridden by subclasses to do 363 /// any necessary per-module initialization. 364 /// 365 virtual bool doInitialization(Module &); 366 367 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 368 /// to do any necessary per-function initialization. 369 /// 370 virtual bool doInitialization(Function &); 371 372 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 373 /// per-basicblock processing of the pass. 374 /// 375 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 376 377 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 378 /// do any post processing needed after all passes have run. 379 /// 380 virtual bool doFinalization(Function &); 381 382 /// doFinalization - Virtual method overriden by subclasses to do any post 383 /// processing needed after all passes have run. 384 /// 385 virtual bool doFinalization(Module &); 386 387 388 // To run this pass on a function, we simply call runOnBasicBlock once for 389 // each function. 390 // 391 bool runOnFunction(Function &F); 392 393 virtual void assignPassManager(PMStack &PMS, 394 PassManagerType T = PMT_BasicBlockPassManager); 395 396 /// Return what kind of Pass Manager can manage this pass. 397 virtual PassManagerType getPotentialPassManagerType() const; 398}; 399 400/// If the user specifies the -time-passes argument on an LLVM tool command line 401/// then the value of this boolean will be true, otherwise false. 402/// @brief This is the storage for the -time-passes option. 403extern bool TimePassesIsEnabled; 404 405} // End llvm namespace 406 407// Include support files that contain important APIs commonly used by Passes, 408// but that we want to separate out to make it easier to read the header files. 409// 410#include "llvm/PassSupport.h" 411#include "llvm/PassAnalysisSupport.h" 412 413#endif 414