Pass.h revision 202878
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#include <cassert> 34#include <utility> 35#include <vector> 36 37namespace llvm { 38 39class BasicBlock; 40class Function; 41class Module; 42class AnalysisUsage; 43class PassInfo; 44class ImmutablePass; 45class PMStack; 46class AnalysisResolver; 47class PMDataManager; 48class raw_ostream; 49class StringRef; 50 51// AnalysisID - Use the PassInfo to identify a pass... 52typedef const PassInfo* AnalysisID; 53 54/// Different types of internal pass managers. External pass managers 55/// (PassManager and FunctionPassManager) are not represented here. 56/// Ordering of pass manager types is important here. 57enum PassManagerType { 58 PMT_Unknown = 0, 59 PMT_ModulePassManager = 1, /// MPPassManager 60 PMT_CallGraphPassManager, /// CGPassManager 61 PMT_FunctionPassManager, /// FPPassManager 62 PMT_LoopPassManager, /// LPPassManager 63 PMT_BasicBlockPassManager, /// BBPassManager 64 PMT_Last 65}; 66 67// Different types of passes. 68enum PassKind { 69 PT_BasicBlock, 70 PT_Loop, 71 PT_Function, 72 PT_CallGraphSCC, 73 PT_Module, 74 PT_PassManager 75}; 76 77//===----------------------------------------------------------------------===// 78/// Pass interface - Implemented by all 'passes'. Subclass this if you are an 79/// interprocedural optimization or you do not fit into any of the more 80/// constrained passes described below. 81/// 82class Pass { 83 AnalysisResolver *Resolver; // Used to resolve analysis 84 intptr_t PassID; 85 PassKind Kind; 86 void operator=(const Pass&); // DO NOT IMPLEMENT 87 Pass(const Pass &); // DO NOT IMPLEMENT 88 89public: 90 explicit Pass(PassKind K, intptr_t pid) : Resolver(0), PassID(pid), Kind(K) { 91 assert(pid && "pid cannot be 0"); 92 } 93 explicit Pass(PassKind K, const void *pid) 94 : Resolver(0), PassID((intptr_t)pid), Kind(K) { 95 assert(pid && "pid cannot be 0"); 96 } 97 virtual ~Pass(); 98 99 100 PassKind getPassKind() const { return Kind; } 101 102 /// getPassName - Return a nice clean name for a pass. This usually 103 /// implemented in terms of the name that is registered by one of the 104 /// Registration templates, but can be overloaded directly. 105 /// 106 virtual const char *getPassName() const; 107 108 /// getPassInfo - Return the PassInfo data structure that corresponds to this 109 /// pass... If the pass has not been registered, this will return null. 110 /// 111 const PassInfo *getPassInfo() const; 112 113 /// print - Print out the internal state of the pass. This is called by 114 /// Analyze to print out the contents of an analysis. Otherwise it is not 115 /// necessary to implement this method. Beware that the module pointer MAY be 116 /// null. This automatically forwards to a virtual function that does not 117 /// provide the Module* in case the analysis doesn't need it it can just be 118 /// ignored. 119 /// 120 virtual void print(raw_ostream &O, const Module *M) const; 121 void dump() const; // dump - Print to stderr. 122 123 /// Each pass is responsible for assigning a pass manager to itself. 124 /// PMS is the stack of available pass manager. 125 virtual void assignPassManager(PMStack &, 126 PassManagerType = PMT_Unknown) {} 127 /// Check if available pass managers are suitable for this pass or not. 128 virtual void preparePassManager(PMStack &); 129 130 /// Return what kind of Pass Manager can manage this pass. 131 virtual PassManagerType getPotentialPassManagerType() const; 132 133 // Access AnalysisResolver 134 inline void setResolver(AnalysisResolver *AR) { 135 assert(!Resolver && "Resolver is already set"); 136 Resolver = AR; 137 } 138 inline AnalysisResolver *getResolver() { 139 return Resolver; 140 } 141 142 /// getAnalysisUsage - This function should be overriden by passes that need 143 /// analysis information to do their job. If a pass specifies that it uses a 144 /// particular analysis result to this function, it can then use the 145 /// getAnalysis<AnalysisType>() function, below. 146 /// 147 virtual void getAnalysisUsage(AnalysisUsage &) const; 148 149 /// releaseMemory() - This member can be implemented by a pass if it wants to 150 /// be able to release its memory when it is no longer needed. The default 151 /// behavior of passes is to hold onto memory for the entire duration of their 152 /// lifetime (which is the entire compile time). For pipelined passes, this 153 /// is not a big deal because that memory gets recycled every time the pass is 154 /// invoked on another program unit. For IP passes, it is more important to 155 /// free memory when it is unused. 156 /// 157 /// Optionally implement this function to release pass memory when it is no 158 /// longer used. 159 /// 160 virtual void releaseMemory(); 161 162 /// getAdjustedAnalysisPointer - This method is used when a pass implements 163 /// an analysis interface through multiple inheritance. If needed, it should 164 /// override this to adjust the this pointer as needed for the specified pass 165 /// info. 166 virtual void *getAdjustedAnalysisPointer(const PassInfo *PI) { 167 return this; 168 } 169 virtual ImmutablePass *getAsImmutablePass() { return 0; } 170 virtual PMDataManager *getAsPMDataManager() { return 0; } 171 172 /// verifyAnalysis() - This member can be implemented by a analysis pass to 173 /// check state of analysis information. 174 virtual void verifyAnalysis() const; 175 176 // dumpPassStructure - Implement the -debug-passes=PassStructure option 177 virtual void dumpPassStructure(unsigned Offset = 0); 178 179 template<typename AnalysisClass> 180 static const PassInfo *getClassPassInfo() { 181 return lookupPassInfo(intptr_t(&AnalysisClass::ID)); 182 } 183 184 // lookupPassInfo - Return the pass info object for the specified pass class, 185 // or null if it is not known. 186 static const PassInfo *lookupPassInfo(intptr_t TI); 187 188 // lookupPassInfo - Return the pass info object for the pass with the given 189 // argument string, or null if it is not known. 190 static const PassInfo *lookupPassInfo(StringRef Arg); 191 192 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to 193 /// get analysis information that might be around, for example to update it. 194 /// This is different than getAnalysis in that it can fail (if the analysis 195 /// results haven't been computed), so should only be used if you can handle 196 /// the case when the analysis is not available. This method is often used by 197 /// transformation APIs to update analysis results for a pass automatically as 198 /// the transform is performed. 199 /// 200 template<typename AnalysisType> AnalysisType * 201 getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h 202 203 /// mustPreserveAnalysisID - This method serves the same function as 204 /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This 205 /// obviously cannot give you a properly typed instance of the class if you 206 /// don't have the class name available (use getAnalysisIfAvailable if you 207 /// do), but it can tell you if you need to preserve the pass at least. 208 /// 209 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const; 210 211 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get 212 /// to the analysis information that they claim to use by overriding the 213 /// getAnalysisUsage function. 214 /// 215 template<typename AnalysisType> 216 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h 217 218 template<typename AnalysisType> 219 AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h 220 221 template<typename AnalysisType> 222 AnalysisType &getAnalysisID(const PassInfo *PI) const; 223 224 template<typename AnalysisType> 225 AnalysisType &getAnalysisID(const PassInfo *PI, Function &F); 226}; 227 228 229//===----------------------------------------------------------------------===// 230/// ModulePass class - This class is used to implement unstructured 231/// interprocedural optimizations and analyses. ModulePasses may do anything 232/// they want to the program. 233/// 234class ModulePass : public Pass { 235public: 236 /// runOnModule - Virtual method overriden by subclasses to process the module 237 /// being operated on. 238 virtual bool runOnModule(Module &M) = 0; 239 240 virtual void assignPassManager(PMStack &PMS, 241 PassManagerType T = PMT_ModulePassManager); 242 243 /// Return what kind of Pass Manager can manage this pass. 244 virtual PassManagerType getPotentialPassManagerType() const; 245 246 explicit ModulePass(intptr_t pid) : Pass(PT_Module, pid) {} 247 explicit ModulePass(const void *pid) : Pass(PT_Module, pid) {} 248 // Force out-of-line virtual method. 249 virtual ~ModulePass(); 250}; 251 252 253//===----------------------------------------------------------------------===// 254/// ImmutablePass class - This class is used to provide information that does 255/// not need to be run. This is useful for things like target information and 256/// "basic" versions of AnalysisGroups. 257/// 258class ImmutablePass : public ModulePass { 259public: 260 /// initializePass - This method may be overriden by immutable passes to allow 261 /// them to perform various initialization actions they require. This is 262 /// primarily because an ImmutablePass can "require" another ImmutablePass, 263 /// and if it does, the overloaded version of initializePass may get access to 264 /// these passes with getAnalysis<>. 265 /// 266 virtual void initializePass(); 267 268 virtual ImmutablePass *getAsImmutablePass() { return this; } 269 270 /// ImmutablePasses are never run. 271 /// 272 bool runOnModule(Module &) { return false; } 273 274 explicit ImmutablePass(intptr_t pid) : ModulePass(pid) {} 275 explicit ImmutablePass(const void *pid) 276 : ModulePass(pid) {} 277 278 // Force out-of-line virtual method. 279 virtual ~ImmutablePass(); 280}; 281 282//===----------------------------------------------------------------------===// 283/// FunctionPass class - This class is used to implement most global 284/// optimizations. Optimizations should subclass this class if they meet the 285/// following constraints: 286/// 287/// 1. Optimizations are organized globally, i.e., a function at a time 288/// 2. Optimizing a function does not cause the addition or removal of any 289/// functions in the module 290/// 291class FunctionPass : public Pass { 292public: 293 explicit FunctionPass(intptr_t pid) : Pass(PT_Function, pid) {} 294 explicit FunctionPass(const void *pid) : Pass(PT_Function, pid) {} 295 296 /// doInitialization - Virtual method overridden by subclasses to do 297 /// any necessary per-module initialization. 298 /// 299 virtual bool doInitialization(Module &); 300 301 /// runOnFunction - Virtual method overriden by subclasses to do the 302 /// per-function processing of the pass. 303 /// 304 virtual bool runOnFunction(Function &F) = 0; 305 306 /// doFinalization - Virtual method overriden by subclasses to do any post 307 /// processing needed after all passes have run. 308 /// 309 virtual bool doFinalization(Module &); 310 311 /// runOnModule - On a module, we run this pass by initializing, 312 /// ronOnFunction'ing once for every function in the module, then by 313 /// finalizing. 314 /// 315 virtual bool runOnModule(Module &M); 316 317 /// run - On a function, we simply initialize, run the function, then 318 /// finalize. 319 /// 320 bool run(Function &F); 321 322 virtual void assignPassManager(PMStack &PMS, 323 PassManagerType T = PMT_FunctionPassManager); 324 325 /// Return what kind of Pass Manager can manage this pass. 326 virtual PassManagerType getPotentialPassManagerType() const; 327}; 328 329 330 331//===----------------------------------------------------------------------===// 332/// BasicBlockPass class - This class is used to implement most local 333/// optimizations. Optimizations should subclass this class if they 334/// meet the following constraints: 335/// 1. Optimizations are local, operating on either a basic block or 336/// instruction at a time. 337/// 2. Optimizations do not modify the CFG of the contained function, or any 338/// other basic block in the function. 339/// 3. Optimizations conform to all of the constraints of FunctionPasses. 340/// 341class BasicBlockPass : public Pass { 342public: 343 explicit BasicBlockPass(intptr_t pid) : Pass(PT_BasicBlock, pid) {} 344 explicit BasicBlockPass(const void *pid) : Pass(PT_BasicBlock, pid) {} 345 346 /// doInitialization - Virtual method overridden by subclasses to do 347 /// any necessary per-module initialization. 348 /// 349 virtual bool doInitialization(Module &); 350 351 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses 352 /// to do any necessary per-function initialization. 353 /// 354 virtual bool doInitialization(Function &); 355 356 /// runOnBasicBlock - Virtual method overriden by subclasses to do the 357 /// per-basicblock processing of the pass. 358 /// 359 virtual bool runOnBasicBlock(BasicBlock &BB) = 0; 360 361 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to 362 /// do any post processing needed after all passes have run. 363 /// 364 virtual bool doFinalization(Function &); 365 366 /// doFinalization - Virtual method overriden by subclasses to do any post 367 /// processing needed after all passes have run. 368 /// 369 virtual bool doFinalization(Module &); 370 371 372 // To run this pass on a function, we simply call runOnBasicBlock once for 373 // each function. 374 // 375 bool runOnFunction(Function &F); 376 377 virtual void assignPassManager(PMStack &PMS, 378 PassManagerType T = PMT_BasicBlockPassManager); 379 380 /// Return what kind of Pass Manager can manage this pass. 381 virtual PassManagerType getPotentialPassManagerType() const; 382}; 383 384/// If the user specifies the -time-passes argument on an LLVM tool command line 385/// then the value of this boolean will be true, otherwise false. 386/// @brief This is the storage for the -time-passes option. 387extern bool TimePassesIsEnabled; 388 389} // End llvm namespace 390 391// Include support files that contain important APIs commonly used by Passes, 392// but that we want to separate out to make it easier to read the header files. 393// 394#include "llvm/PassSupport.h" 395#include "llvm/PassAnalysisSupport.h" 396 397#endif 398