1 //===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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/Support/Streams.h"
39 #define USE_OLD_PASSMANAGER 1
50 template<class Trait> class PassManagerT;
51 class BasicBlockPassManager;
52 class FunctionPassManagerT;
53 class ModulePassManager;
54 struct AnalysisResolver;
55 class AnalysisResolver_New;
57 // AnalysisID - Use the PassInfo to identify a pass...
58 typedef const PassInfo* AnalysisID;
60 //===----------------------------------------------------------------------===//
61 /// Pass interface - Implemented by all 'passes'. Subclass this if you are an
62 /// interprocedural optimization or you do not fit into any of the more
63 /// constrained passes described below.
66 friend struct AnalysisResolver;
67 AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by...
68 AnalysisResolver_New *Resolver_New; // Used to resolve analysis
69 const PassInfo *PassInfoCache;
71 // AnalysisImpls - This keeps track of which passes implement the interfaces
72 // that are required by the current pass (to implement getAnalysis()).
74 std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls;
76 void operator=(const Pass&); // DO NOT IMPLEMENT
77 Pass(const Pass &); // DO NOT IMPLEMENT
79 Pass() : Resolver(0), Resolver_New(0), PassInfoCache(0) {}
80 virtual ~Pass() {} // Destructor is virtual so we can be subclassed
82 /// getPassName - Return a nice clean name for a pass. This usually
83 /// implemented in terms of the name that is registered by one of the
84 /// Registration templates, but can be overloaded directly, and if nothing
85 /// else is available, C++ RTTI will be consulted to get a SOMEWHAT
86 /// intelligible name for the pass.
88 virtual const char *getPassName() const;
90 /// getPassInfo - Return the PassInfo data structure that corresponds to this
91 /// pass... If the pass has not been registered, this will return null.
93 const PassInfo *getPassInfo() const;
95 /// runPass - Run this pass, returning true if a modification was made to the
96 /// module argument. This should be implemented by all concrete subclasses.
98 virtual bool runPass(Module &M) { return false; }
99 virtual bool runPass(BasicBlock&) { return false; }
101 /// print - Print out the internal state of the pass. This is called by
102 /// Analyze to print out the contents of an analysis. Otherwise it is not
103 /// necessary to implement this method. Beware that the module pointer MAY be
104 /// null. This automatically forwards to a virtual function that does not
105 /// provide the Module* in case the analysis doesn't need it it can just be
108 void print(OStream &O, const Module *M) const {
109 if (O.stream()) print(*O.stream(), M);
111 virtual void print(std::ostream &O, const Module *M) const;
112 void dump() const; // dump - call print(std::cerr, 0);
114 // Access AnalysisResolver_New
115 inline void setResolver(AnalysisResolver_New *AR) { Resolver_New = AR; }
116 inline AnalysisResolver_New *getResolver() { return Resolver_New; }
118 /// getAnalysisUsage - This function should be overriden by passes that need
119 /// analysis information to do their job. If a pass specifies that it uses a
120 /// particular analysis result to this function, it can then use the
121 /// getAnalysis<AnalysisType>() function, below.
123 virtual void getAnalysisUsage(AnalysisUsage &Info) const {
124 // By default, no analysis results are used, all are invalidated.
127 /// releaseMemory() - This member can be implemented by a pass if it wants to
128 /// be able to release its memory when it is no longer needed. The default
129 /// behavior of passes is to hold onto memory for the entire duration of their
130 /// lifetime (which is the entire compile time). For pipelined passes, this
131 /// is not a big deal because that memory gets recycled every time the pass is
132 /// invoked on another program unit. For IP passes, it is more important to
133 /// free memory when it is unused.
135 /// Optionally implement this function to release pass memory when it is no
138 virtual void releaseMemory() {}
140 // dumpPassStructure - Implement the -debug-passes=PassStructure option
141 virtual void dumpPassStructure(unsigned Offset = 0);
144 // getPassInfo - Static method to get the pass information from a class name.
145 template<typename AnalysisClass>
146 static const PassInfo *getClassPassInfo() {
147 return lookupPassInfo(typeid(AnalysisClass));
150 // lookupPassInfo - Return the pass info object for the specified pass class,
151 // or null if it is not known.
152 static const PassInfo *lookupPassInfo(const std::type_info &TI);
154 /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
155 /// to get to the analysis information that might be around that needs to be
156 /// updated. This is different than getAnalysis in that it can fail (ie the
157 /// analysis results haven't been computed), so should only be used if you
158 /// provide the capability to update an analysis that exists. This method is
159 /// often used by transformation APIs to update analysis results for a pass
160 /// automatically as the transform is performed.
162 template<typename AnalysisType>
163 AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h
165 /// mustPreserveAnalysisID - This method serves the same function as
166 /// getAnalysisToUpdate, but works if you just have an AnalysisID. This
167 /// obviously cannot give you a properly typed instance of the class if you
168 /// don't have the class name available (use getAnalysisToUpdate if you do),
169 /// but it can tell you if you need to preserve the pass at least.
171 bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const;
173 /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
174 /// to the analysis information that they claim to use by overriding the
175 /// getAnalysisUsage function.
177 template<typename AnalysisType>
178 AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h
180 template<typename AnalysisType>
181 AnalysisType &getAnalysisID(const PassInfo *PI) const;
184 template<typename Trait> friend class PassManagerT;
185 friend class ModulePassManager;
186 friend class FunctionPassManagerT;
187 friend class BasicBlockPassManager;
190 inline std::ostream &operator<<(std::ostream &OS, const Pass &P) {
191 P.print(OS, 0); return OS;
194 //===----------------------------------------------------------------------===//
195 /// ModulePass class - This class is used to implement unstructured
196 /// interprocedural optimizations and analyses. ModulePasses may do anything
197 /// they want to the program.
199 class ModulePass : public Pass {
201 /// runOnModule - Virtual method overriden by subclasses to process the module
202 /// being operated on.
203 virtual bool runOnModule(Module &M) = 0;
205 virtual bool runPass(Module &M) { return runOnModule(M); }
206 virtual bool runPass(BasicBlock&) { return false; }
208 #ifdef USE_OLD_PASSMANAGER
209 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
214 //===----------------------------------------------------------------------===//
215 /// ImmutablePass class - This class is used to provide information that does
216 /// not need to be run. This is useful for things like target information and
217 /// "basic" versions of AnalysisGroups.
219 class ImmutablePass : public ModulePass {
221 /// initializePass - This method may be overriden by immutable passes to allow
222 /// them to perform various initialization actions they require. This is
223 /// primarily because an ImmutablePass can "require" another ImmutablePass,
224 /// and if it does, the overloaded version of initializePass may get access to
225 /// these passes with getAnalysis<>.
227 virtual void initializePass() {}
229 /// ImmutablePasses are never run.
231 virtual bool runOnModule(Module &M) { return false; }
233 #ifdef USE_OLD_PASSMANAGER
235 template<typename Trait> friend class PassManagerT;
236 friend class ModulePassManager;
237 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
241 //===----------------------------------------------------------------------===//
242 /// FunctionPass class - This class is used to implement most global
243 /// optimizations. Optimizations should subclass this class if they meet the
244 /// following constraints:
246 /// 1. Optimizations are organized globally, i.e., a function at a time
247 /// 2. Optimizing a function does not cause the addition or removal of any
248 /// functions in the module
250 class FunctionPass : public ModulePass {
252 /// doInitialization - Virtual method overridden by subclasses to do
253 /// any necessary per-module initialization.
255 virtual bool doInitialization(Module &M) { return false; }
257 /// runOnFunction - Virtual method overriden by subclasses to do the
258 /// per-function processing of the pass.
260 virtual bool runOnFunction(Function &F) = 0;
262 /// doFinalization - Virtual method overriden by subclasses to do any post
263 /// processing needed after all passes have run.
265 virtual bool doFinalization(Module &M) { return false; }
267 /// runOnModule - On a module, we run this pass by initializing,
268 /// ronOnFunction'ing once for every function in the module, then by
271 virtual bool runOnModule(Module &M);
273 /// run - On a function, we simply initialize, run the function, then
276 bool run(Function &F);
278 #ifdef USE_OLD_PASSMANAGER
280 template<typename Trait> friend class PassManagerT;
281 friend class ModulePassManager;
282 friend class FunctionPassManagerT;
283 friend class BasicBlockPassManager;
284 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU);
285 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU);
291 //===----------------------------------------------------------------------===//
292 /// BasicBlockPass class - This class is used to implement most local
293 /// optimizations. Optimizations should subclass this class if they
294 /// meet the following constraints:
295 /// 1. Optimizations are local, operating on either a basic block or
296 /// instruction at a time.
297 /// 2. Optimizations do not modify the CFG of the contained function, or any
298 /// other basic block in the function.
299 /// 3. Optimizations conform to all of the constraints of FunctionPasses.
301 class BasicBlockPass : public FunctionPass {
303 /// doInitialization - Virtual method overridden by subclasses to do
304 /// any necessary per-module initialization.
306 virtual bool doInitialization(Module &M) { return false; }
308 /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
309 /// to do any necessary per-function initialization.
311 virtual bool doInitialization(Function &F) { return false; }
313 /// runOnBasicBlock - Virtual method overriden by subclasses to do the
314 /// per-basicblock processing of the pass.
316 virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
318 /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
319 /// do any post processing needed after all passes have run.
321 virtual bool doFinalization(Function &F) { return false; }
323 /// doFinalization - Virtual method overriden by subclasses to do any post
324 /// processing needed after all passes have run.
326 virtual bool doFinalization(Module &M) { return false; }
329 // To run this pass on a function, we simply call runOnBasicBlock once for
332 bool runOnFunction(Function &F);
334 /// To run directly on the basic block, we initialize, runOnBasicBlock, then
337 virtual bool runPass(Module &M) { return false; }
338 virtual bool runPass(BasicBlock &BB);
340 #ifdef USE_OLD_PASSMANAGER
342 template<typename Trait> friend class PassManagerT;
343 friend class FunctionPassManagerT;
344 friend class BasicBlockPassManager;
345 virtual void addToPassManager(ModulePassManager *PM, AnalysisUsage &AU) {
346 FunctionPass::addToPassManager(PM, AU);
348 virtual void addToPassManager(FunctionPassManagerT *PM, AnalysisUsage &AU);
349 virtual void addToPassManager(BasicBlockPassManager *PM,AnalysisUsage &AU);
353 /// If the user specifies the -time-passes argument on an LLVM tool command line
354 /// then the value of this boolean will be true, otherwise false.
355 /// @brief This is the storage for the -time-passes option.
356 extern bool TimePassesIsEnabled;
358 } // End llvm namespace
360 // Include support files that contain important APIs commonly used by Passes,
361 // but that we want to separate out to make it easier to read the header files.
363 #include "llvm/PassSupport.h"
364 #include "llvm/PassAnalysisSupport.h"