1 //===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a base class that indicates that a specified class is a
11 // transformation pass implementation.
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.
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.
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.
27 //===----------------------------------------------------------------------===//
32 #include "llvm/System/DataTypes.h"
48 class AnalysisResolver;
53 // AnalysisID - Use the PassInfo to identify a pass...
54 typedef const StaticPassInfo* AnalysisID;
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.
59 enum PassManagerType {
61 PMT_ModulePassManager = 1, ///< MPPassManager
62 PMT_CallGraphPassManager, ///< CGPassManager
63 PMT_FunctionPassManager, ///< FPPassManager
64 PMT_LoopPassManager, ///< LPPassManager
65 PMT_BasicBlockPassManager, ///< BBPassManager
69 // Different types of passes.
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.
85 AnalysisResolver *Resolver; // Used to resolve analysis
88 void operator=(const Pass&); // DO NOT IMPLEMENT
89 Pass(const Pass &); // DO NOT IMPLEMENT
92 explicit Pass(PassKind K, intptr_t pid);
93 explicit Pass(PassKind K, const void *pid);
97 PassKind getPassKind() const { return Kind; }
99 /// getPassName - Return a nice clean name for a pass. This usually
100 /// implemented in terms of the name that is registered by one of the
101 /// Registration templates, but can be overloaded directly.
103 virtual const char *getPassName() const;
105 /// getPassInfo - Return the PassInfo data structure that corresponds to this
106 /// pass... If the pass has not been registered, this will return null.
108 const StaticPassInfo *getPassInfo() const;
110 /// print - Print out the internal state of the pass. This is called by
111 /// Analyze to print out the contents of an analysis. Otherwise it is not
112 /// necessary to implement this method. Beware that the module pointer MAY be
113 /// null. This automatically forwards to a virtual function that does not
114 /// provide the Module* in case the analysis doesn't need it it can just be
117 virtual void print(raw_ostream &O, const Module *M) const;
118 void dump() const; // dump - Print to stderr.
120 /// createPrinterPass - Get a Pass appropriate to print the IR this
121 /// pass operates one (Module, Function or MachineFunction).
122 virtual Pass *createPrinterPass(raw_ostream &O,
123 const std::string &Banner) const = 0;
125 /// Each pass is responsible for assigning a pass manager to itself.
126 /// PMS is the stack of available pass manager.
127 virtual void assignPassManager(PMStack &,
128 PassManagerType = PMT_Unknown) {}
129 /// Check if available pass managers are suitable for this pass or not.
130 virtual void preparePassManager(PMStack &);
132 /// Return what kind of Pass Manager can manage this pass.
133 virtual PassManagerType getPotentialPassManagerType() const;
135 // Access AnalysisResolver
136 void setResolver(AnalysisResolver *AR);
137 AnalysisResolver *getResolver() const { return Resolver; }
139 /// getAnalysisUsage - This function should be overriden by passes that need
140 /// analysis information to do their job. If a pass specifies that it uses a
141 /// particular analysis result to this function, it can then use the
142 /// getAnalysis<AnalysisType>() function, below.
144 virtual void getAnalysisUsage(AnalysisUsage &) const;
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.
154 /// Optionally implement this function to release pass memory when it is no
157 virtual void releaseMemory();
159 /// getAdjustedAnalysisPointer - This method is used when a pass implements
160 /// an analysis interface through multiple inheritance. If needed, it should
161 /// override this to adjust the this pointer as needed for the specified pass
163 virtual void *getAdjustedAnalysisPointer(const StaticPassInfo *);
164 virtual ImmutablePass *getAsImmutablePass();
165 virtual PMDataManager *getAsPMDataManager();
167 /// verifyAnalysis() - This member can be implemented by a analysis pass to
168 /// check state of analysis information.
169 virtual void verifyAnalysis() const;
171 // dumpPassStructure - Implement the -debug-passes=PassStructure option
172 virtual void dumpPassStructure(unsigned Offset = 0);
174 template<typename AnalysisClass>
175 static const StaticPassInfo *getClassPassInfo() {
176 return lookupPassInfo(intptr_t(&AnalysisClass::ID));
179 // lookupPassInfo - Return the pass info object for the specified pass class,
180 // or null if it is not known.
181 static const StaticPassInfo *lookupPassInfo(intptr_t TI);
183 // lookupPassInfo - Return the pass info object for the pass with the given
184 // argument string, or null if it is not known.
185 static const StaticPassInfo *lookupPassInfo(StringRef Arg);
187 /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to
188 /// get analysis information that might be around, for example to update it.
189 /// This is different than getAnalysis in that it can fail (if the analysis
190 /// results haven't been computed), so should only be used if you can handle
191 /// the case when the analysis is not available. This method is often used by
192 /// transformation APIs to update analysis results for a pass automatically as
193 /// the transform is performed.
195 template<typename AnalysisType> AnalysisType *
196 getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h
198 /// mustPreserveAnalysisID - This method serves the same function as
199 /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This
200 /// obviously cannot give you a properly typed instance of the class if you
201 /// don't have the class name available (use getAnalysisIfAvailable if you
202 /// do), but it can tell you if you need to preserve the pass at least.
204 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const;
206 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
207 /// to the analysis information that they claim to use by overriding the
208 /// getAnalysisUsage function.
210 template<typename AnalysisType>
211 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h
213 template<typename AnalysisType>
214 AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h
216 template<typename AnalysisType>
217 AnalysisType &getAnalysisID(const StaticPassInfo *PI) const;
219 template<typename AnalysisType>
220 AnalysisType &getAnalysisID(const StaticPassInfo *PI, Function &F);
224 //===----------------------------------------------------------------------===//
225 /// ModulePass class - This class is used to implement unstructured
226 /// interprocedural optimizations and analyses. ModulePasses may do anything
227 /// they want to the program.
229 class ModulePass : public Pass {
231 /// createPrinterPass - Get a module printer pass.
232 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const;
234 /// runOnModule - Virtual method overriden by subclasses to process the module
235 /// being operated on.
236 virtual bool runOnModule(Module &M) = 0;
238 virtual void assignPassManager(PMStack &PMS,
239 PassManagerType T = PMT_ModulePassManager);
241 /// Return what kind of Pass Manager can manage this pass.
242 virtual PassManagerType getPotentialPassManagerType() const;
244 explicit ModulePass(intptr_t pid) : Pass(PT_Module, pid) {}
245 explicit ModulePass(const void *pid) : Pass(PT_Module, pid) {}
246 // Force out-of-line virtual method.
247 virtual ~ModulePass();
251 //===----------------------------------------------------------------------===//
252 /// ImmutablePass class - This class is used to provide information that does
253 /// not need to be run. This is useful for things like target information and
254 /// "basic" versions of AnalysisGroups.
256 class ImmutablePass : public ModulePass {
258 /// initializePass - This method may be overriden by immutable passes to allow
259 /// them to perform various initialization actions they require. This is
260 /// primarily because an ImmutablePass can "require" another ImmutablePass,
261 /// and if it does, the overloaded version of initializePass may get access to
262 /// these passes with getAnalysis<>.
264 virtual void initializePass();
266 virtual ImmutablePass *getAsImmutablePass() { return this; }
268 /// ImmutablePasses are never run.
270 bool runOnModule(Module &) { return false; }
272 explicit ImmutablePass(intptr_t pid) : ModulePass(pid) {}
273 explicit ImmutablePass(const void *pid)
276 // Force out-of-line virtual method.
277 virtual ~ImmutablePass();
280 //===----------------------------------------------------------------------===//
281 /// FunctionPass class - This class is used to implement most global
282 /// optimizations. Optimizations should subclass this class if they meet the
283 /// following constraints:
285 /// 1. Optimizations are organized globally, i.e., a function at a time
286 /// 2. Optimizing a function does not cause the addition or removal of any
287 /// functions in the module
289 class FunctionPass : public Pass {
291 explicit FunctionPass(intptr_t pid) : Pass(PT_Function, pid) {}
292 explicit FunctionPass(const void *pid) : Pass(PT_Function, pid) {}
294 /// createPrinterPass - Get a function printer pass.
295 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const;
297 /// doInitialization - Virtual method overridden by subclasses to do
298 /// any necessary per-module initialization.
300 virtual bool doInitialization(Module &);
302 /// runOnFunction - Virtual method overriden by subclasses to do the
303 /// per-function processing of the pass.
305 virtual bool runOnFunction(Function &F) = 0;
307 /// doFinalization - Virtual method overriden by subclasses to do any post
308 /// processing needed after all passes have run.
310 virtual bool doFinalization(Module &);
312 /// runOnModule - On a module, we run this pass by initializing,
313 /// ronOnFunction'ing once for every function in the module, then by
316 virtual bool runOnModule(Module &M);
318 /// run - On a function, we simply initialize, run the function, then
321 bool run(Function &F);
323 virtual void assignPassManager(PMStack &PMS,
324 PassManagerType T = PMT_FunctionPassManager);
326 /// Return what kind of Pass Manager can manage this pass.
327 virtual PassManagerType getPotentialPassManagerType() const;
332 //===----------------------------------------------------------------------===//
333 /// BasicBlockPass class - This class is used to implement most local
334 /// optimizations. Optimizations should subclass this class if they
335 /// meet the following constraints:
336 /// 1. Optimizations are local, operating on either a basic block or
337 /// instruction at a time.
338 /// 2. Optimizations do not modify the CFG of the contained function, or any
339 /// other basic block in the function.
340 /// 3. Optimizations conform to all of the constraints of FunctionPasses.
342 class BasicBlockPass : public Pass {
344 explicit BasicBlockPass(intptr_t pid) : Pass(PT_BasicBlock, pid) {}
345 explicit BasicBlockPass(const void *pid) : Pass(PT_BasicBlock, pid) {}
347 /// createPrinterPass - Get a function printer pass.
348 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const;
350 /// doInitialization - Virtual method overridden by subclasses to do
351 /// any necessary per-module initialization.
353 virtual bool doInitialization(Module &);
355 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
356 /// to do any necessary per-function initialization.
358 virtual bool doInitialization(Function &);
360 /// runOnBasicBlock - Virtual method overriden by subclasses to do the
361 /// per-basicblock processing of the pass.
363 virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
365 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
366 /// do any post processing needed after all passes have run.
368 virtual bool doFinalization(Function &);
370 /// doFinalization - Virtual method overriden by subclasses to do any post
371 /// processing needed after all passes have run.
373 virtual bool doFinalization(Module &);
376 // To run this pass on a function, we simply call runOnBasicBlock once for
379 bool runOnFunction(Function &F);
381 virtual void assignPassManager(PMStack &PMS,
382 PassManagerType T = PMT_BasicBlockPassManager);
384 /// Return what kind of Pass Manager can manage this pass.
385 virtual PassManagerType getPotentialPassManagerType() const;
388 /// If the user specifies the -time-passes argument on an LLVM tool command line
389 /// then the value of this boolean will be true, otherwise false.
390 /// @brief This is the storage for the -time-passes option.
391 extern bool TimePassesIsEnabled;
393 } // End llvm namespace
395 // Include support files that contain important APIs commonly used by Passes,
396 // but that we want to separate out to make it easier to read the header files.
398 #include "llvm/PassSupport.h"
399 #include "llvm/PassAnalysisSupport.h"