-//===- llvm/Pass.h - Base class for XForm Passes -----------------*- C++ -*--=//
+//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file defines a base class that indicates that a specified class is a
// transformation pass implementation.
//
// Passes should extend one of the classes below, depending on the guarantees
// that it can make about what will be modified as it is run. For example, most
-// global optimizations should derive from MethodPass, because they do not add
-// or delete methods, they operate on the internals of the method.
+// global optimizations should derive from FunctionPass, because they do not add
+// or delete functions, they operate on the internals of the function.
+//
+// Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the
+// bottom), so the APIs exposed by these files are also automatically available
+// to all users of this file.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PASS_H
#define LLVM_PASS_H
-#include "llvm/Module.h"
-#include "llvm/Method.h"
+#include <vector>
+#include <map>
+#include <iosfwd>
+#include <typeinfo>
+#include <cassert>
+class Value;
+class BasicBlock;
+class Function;
+class Module;
+class AnalysisUsage;
+class PassInfo;
+class ImmutablePass;
+template<class UnitType> class PassManagerT;
+struct AnalysisResolver;
-class MethodPassBatcher;
+// AnalysisID - Use the PassInfo to identify a pass...
+typedef const PassInfo* AnalysisID;
//===----------------------------------------------------------------------===//
-// Pass interface - Implemented by all 'passes'. Subclass this if you are an
-// interprocedural optimization or you do not fit into any of the more
-// constrained passes described below.
-//
-struct Pass {
- // Destructor - Virtual so we can be subclassed
- inline virtual ~Pass() {}
+/// Pass interface - Implemented by all 'passes'. Subclass this if you are an
+/// interprocedural optimization or you do not fit into any of the more
+/// constrained passes described below.
+///
+class Pass {
+ friend class AnalysisResolver;
+ AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by...
+ const PassInfo *PassInfoCache;
- virtual bool run(Module *M) = 0;
-};
+ // AnalysisImpls - This keeps track of which passes implement the interfaces
+ // that are required by the current pass (to implement getAnalysis()).
+ //
+ std::vector<std::pair<const PassInfo*, Pass*> > AnalysisImpls;
+ void operator=(const Pass&); // DO NOT IMPLEMENT
+ Pass(const Pass &); // DO NOT IMPLEMENT
+public:
+ Pass() : Resolver(0), PassInfoCache(0) {}
+ virtual ~Pass() {} // Destructor is virtual so we can be subclassed
-//===----------------------------------------------------------------------===//
-// MethodPass class - This class is used to implement most global optimizations.
-// Optimizations should subclass this class if they meet the following
-// constraints:
-// 1. Optimizations are organized globally, ie a method at a time
-// 2. Optimizing a method does not cause the addition or removal of any methods
-// in the module
-//
-struct MethodPass : public Pass {
- // doInitialization - Virtual method overridden by subclasses to do
- // any neccesary per-module initialization.
- //
- virtual bool doInitialization(Module *M) { return false; }
+ /// getPassName - Return a nice clean name for a pass. This usually
+ /// implemented in terms of the name that is registered by one of the
+ /// Registration templates, but can be overloaded directly, and if nothing
+ /// else is available, C++ RTTI will be consulted to get a SOMEWHAT
+ /// intelligible name for the pass.
+ ///
+ virtual const char *getPassName() const;
- // runOnMethod - Virtual method overriden by subclasses to do the per-method
- // processing of the pass.
- //
- virtual bool runOnMethod(Method *M) = 0;
+ /// getPassInfo - Return the PassInfo data structure that corresponds to this
+ /// pass... If the pass has not been registered, this will return null.
+ ///
+ const PassInfo *getPassInfo() const;
- // doFinalization - Virtual method overriden by subclasses to do any post
- // processing needed after all passes have run.
- //
- virtual bool doFinalization(Module *M) { return false; }
+ /// run - Run this pass, returning true if a modification was made to the
+ /// module argument. This should be implemented by all concrete subclasses.
+ ///
+ virtual bool run(Module &M) = 0;
+ /// print - Print out the internal state of the pass. This is called by
+ /// Analyze to print out the contents of an analysis. Otherwise it is not
+ /// necessary to implement this method. Beware that the module pointer MAY be
+ /// null. This automatically forwards to a virtual function that does not
+ /// provide the Module* in case the analysis doesn't need it it can just be
+ /// ignored.
+ ///
+ virtual void print(std::ostream &O, const Module *M) const { print(O); }
+ virtual void print(std::ostream &O) const;
+ void dump() const; // dump - call print(std::cerr, 0);
- virtual bool run(Module *M) {
- bool Changed = doInitialization(M);
- for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
- Changed |= runOnMethod(*I);
+ /// getAnalysisUsage - This function should be overriden by passes that need
+ /// analysis information to do their job. If a pass specifies that it uses a
+ /// particular analysis result to this function, it can then use the
+ /// getAnalysis<AnalysisType>() function, below.
+ ///
+ virtual void getAnalysisUsage(AnalysisUsage &Info) const {
+ // By default, no analysis results are used, all are invalidated.
+ }
+
+ /// releaseMemory() - This member can be implemented by a pass if it wants to
+ /// be able to release its memory when it is no longer needed. The default
+ /// behavior of passes is to hold onto memory for the entire duration of their
+ /// lifetime (which is the entire compile time). For pipelined passes, this
+ /// is not a big deal because that memory gets recycled every time the pass is
+ /// invoked on another program unit. For IP passes, it is more important to
+ /// free memory when it is unused.
+ ///
+ /// Optionally implement this function to release pass memory when it is no
+ /// longer used.
+ ///
+ virtual void releaseMemory() {}
+
+ // dumpPassStructure - Implement the -debug-passes=PassStructure option
+ virtual void dumpPassStructure(unsigned Offset = 0);
- return Changed | doFinalization(M);
+
+ // getPassInfo - Static method to get the pass information from a class name.
+ template<typename AnalysisClass>
+ static const PassInfo *getClassPassInfo() {
+ return lookupPassInfo(typeid(AnalysisClass));
}
- bool run(Method *M) {
- return doInitialization(M->getParent()) | runOnMethod(M)
- | doFinalization(M->getParent());
+ // lookupPassInfo - Return the pass info object for the specified pass class,
+ // or null if it is not known.
+ static const PassInfo *lookupPassInfo(const std::type_info &TI);
+
+ /// getAnalysisToUpdate<AnalysisType>() - This function is used by subclasses
+ /// to get to the analysis information that might be around that needs to be
+ /// updated. This is different than getAnalysis in that it can fail (ie the
+ /// analysis results haven't been computed), so should only be used if you
+ /// provide the capability to update an analysis that exists. This method is
+ /// often used by transformation APIs to update analysis results for a pass
+ /// automatically as the transform is performed.
+ ///
+ template<typename AnalysisType>
+ AnalysisType *getAnalysisToUpdate() const; // Defined in PassAnalysisSupport.h
+
+ /// mustPreserveAnalysisID - This method serves the same function as
+ /// getAnalysisToUpdate, but works if you just have an AnalysisID. This
+ /// obviously cannot give you a properly typed instance of the class if you
+ /// don't have the class name available (use getAnalysisToUpdate if you do),
+ /// but it can tell you if you need to preserve the pass at least.
+ ///
+ bool mustPreserveAnalysisID(const PassInfo *AnalysisID) const;
+
+ /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
+ /// to the analysis information that they claim to use by overriding the
+ /// getAnalysisUsage function.
+ ///
+ template<typename AnalysisType>
+ AnalysisType &getAnalysis() const {
+ assert(Resolver && "Pass has not been inserted into a PassManager object!");
+ const PassInfo *PI = getClassPassInfo<AnalysisType>();
+ return getAnalysisID<AnalysisType>(PI);
+ }
+
+ template<typename AnalysisType>
+ AnalysisType &getAnalysisID(const PassInfo *PI) const {
+ assert(Resolver && "Pass has not been inserted into a PassManager object!");
+ assert(PI && "getAnalysis for unregistered pass!");
+
+ // PI *must* appear in AnalysisImpls. Because the number of passes used
+ // should be a small number, we just do a linear search over a (dense)
+ // vector.
+ Pass *ResultPass = 0;
+ for (unsigned i = 0; ; ++i) {
+ assert(i != AnalysisImpls.size() &&
+ "getAnalysis*() called on an analysis that we not "
+ "'required' by pass!");
+ if (AnalysisImpls[i].first == PI) {
+ ResultPass = AnalysisImpls[i].second;
+ break;
+ }
+ }
+
+ // Because the AnalysisType may not be a subclass of pass (for
+ // AnalysisGroups), we must use dynamic_cast here to potentially adjust the
+ // return pointer (because the class may multiply inherit, once from pass,
+ // once from AnalysisType).
+ //
+ AnalysisType *Result = dynamic_cast<AnalysisType*>(ResultPass);
+ assert(Result && "Pass does not implement interface required!");
+ return *Result;
}
+
+private:
+ friend class PassManagerT<Module>;
+ friend class PassManagerT<Function>;
+ friend class PassManagerT<BasicBlock>;
+ virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisUsage &AU);
};
+inline std::ostream &operator<<(std::ostream &OS, const Pass &P) {
+ P.print(OS, 0); return OS;
+}
+
//===----------------------------------------------------------------------===//
-// CFGSafeMethodPass class - This class is used to implement global
-// optimizations that do not modify the CFG of a method. Optimizations should
-// subclass this class if they meet the following constraints:
-// 1. Optimizations are global, operating on a method at a time.
-// 2. Optimizations do not modify the CFG of the contained method, by adding,
-// removing, or changing the order of basic blocks in a method.
-// 3. Optimizations conform to all of the contstraints of MethodPass's.
-//
-struct CFGSafeMethodPass : public MethodPass {
+/// ImmutablePass class - This class is used to provide information that does
+/// not need to be run. This is useful for things like target information and
+/// "basic" versions of AnalysisGroups.
+///
+struct ImmutablePass : public Pass {
+ /// initializePass - This method may be overriden by immutable passes to allow
+ /// them to perform various initialization actions they require. This is
+ /// primarily because an ImmutablePass can "require" another ImmutablePass,
+ /// and if it does, the overloaded version of initializePass may get access to
+ /// these passes with getAnalysis<>.
+ ///
+ virtual void initializePass() {}
- // TODO: Differentiation from MethodPass will come later
+ /// ImmutablePasses are never run.
+ ///
+ virtual bool run(Module &M) { return false; }
+private:
+ friend class PassManagerT<Module>;
+ virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisUsage &AU);
};
//===----------------------------------------------------------------------===//
-// BasicBlockPass class - This class is used to implement most local
-// optimizations. Optimizations should subclass this class if they
-// meet the following constraints:
-// 1. Optimizations are local, operating on either a basic block or
-// instruction at a time.
-// 2. Optimizations do not modify the CFG of the contained method, or any
-// other basic block in the method.
-// 3. Optimizations conform to all of the contstraints of CFGSafeMethodPass's.
-//
-struct BasicBlockPass : public CFGSafeMethodPass {
- // runOnBasicBlock - Virtual method overriden by subclasses to do the
- // per-basicblock processing of the pass.
- //
- virtual bool runOnBasicBlock(BasicBlock *M) = 0;
+/// FunctionPass class - This class is used to implement most global
+/// optimizations. Optimizations should subclass this class if they meet the
+/// following constraints:
+///
+/// 1. Optimizations are organized globally, i.e., a function at a time
+/// 2. Optimizing a function does not cause the addition or removal of any
+/// functions in the module
+///
+struct FunctionPass : public Pass {
+ /// doInitialization - Virtual method overridden by subclasses to do
+ /// any necessary per-module initialization.
+ ///
+ virtual bool doInitialization(Module &M) { return false; }
- virtual bool runOnMethod(Method *M) {
- bool Changed = false;
- for (Method::iterator I = M->begin(), E = M->end(); I != E; ++I)
- Changed |= runOnBasicBlock(*I);
- return Changed;
- }
+ /// runOnFunction - Virtual method overriden by subclasses to do the
+ /// per-function processing of the pass.
+ ///
+ virtual bool runOnFunction(Function &F) = 0;
- bool run(BasicBlock *BB) {
- Module *M = BB->getParent()->getParent();
- return doInitialization(M) | runOnBasicBlock(BB) | doFinalization(M);
- }
+ /// doFinalization - Virtual method overriden by subclasses to do any post
+ /// processing needed after all passes have run.
+ ///
+ virtual bool doFinalization(Module &M) { return false; }
+
+ /// run - On a module, we run this pass by initializing, ronOnFunction'ing
+ /// once for every function in the module, then by finalizing.
+ ///
+ virtual bool run(Module &M);
+
+ /// run - On a function, we simply initialize, run the function, then
+ /// finalize.
+ ///
+ bool run(Function &F);
+
+private:
+ friend class PassManagerT<Module>;
+ friend class PassManagerT<Function>;
+ friend class PassManagerT<BasicBlock>;
+ virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisUsage &AU);
+ virtual void addToPassManager(PassManagerT<Function> *PM, AnalysisUsage &AU);
};
+
//===----------------------------------------------------------------------===//
-// PassManager - Container object for passes. The PassManager destructor
-// deletes all passes contained inside of the PassManager, so you shouldn't
-// delete passes manually, and all passes should be dynamically allocated.
-//
-class PassManager {
- std::vector<Pass*> Passes;
- MethodPassBatcher *Batcher;
-public:
- PassManager() : Batcher(0) {}
- ~PassManager();
-
- bool run(Module *M) {
- bool MadeChanges = false;
- // Run all of the pass initializers
- for (unsigned i = 0, e = Passes.size(); i < e; ++i)
- MadeChanges |= Passes[i]->run(M);
- return MadeChanges;
- }
+/// BasicBlockPass class - This class is used to implement most local
+/// optimizations. Optimizations should subclass this class if they
+/// meet the following constraints:
+/// 1. Optimizations are local, operating on either a basic block or
+/// instruction at a time.
+/// 2. Optimizations do not modify the CFG of the contained function, or any
+/// other basic block in the function.
+/// 3. Optimizations conform to all of the constraints of FunctionPass's.
+///
+struct BasicBlockPass : public FunctionPass {
+ /// doInitialization - Virtual method overridden by subclasses to do
+ /// any necessary per-module initialization.
+ ///
+ virtual bool doInitialization(Module &M) { return false; }
+
+ /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
+ /// to do any necessary per-function initialization.
+ ///
+ virtual bool doInitialization(Function &F) { return false; }
+
+ /// runOnBasicBlock - Virtual method overriden by subclasses to do the
+ /// per-basicblock processing of the pass.
+ ///
+ virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
+
+ /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
+ /// do any post processing needed after all passes have run.
+ ///
+ virtual bool doFinalization(Function &F) { return false; }
+
+ /// doFinalization - Virtual method overriden by subclasses to do any post
+ /// processing needed after all passes have run.
+ ///
+ virtual bool doFinalization(Module &M) { return false; }
- // add - Add a pass to the queue of passes to run. This passes ownership of
- // the Pass to the PassManager. When the PassManager is destroyed, the pass
- // will be destroyed as well, so there is no need to delete the pass. Also,
- // all passes MUST be new'd.
+
+ // To run this pass on a function, we simply call runOnBasicBlock once for
+ // each function.
//
- void add(Pass *P);
- void add(MethodPass *P);
- void add(BasicBlockPass *P);
+ bool runOnFunction(Function &F);
+
+ /// To run directly on the basic block, we initialize, runOnBasicBlock, then
+ /// finalize.
+ ///
+ bool run(BasicBlock &BB);
+
+private:
+ friend class PassManagerT<Function>;
+ friend class PassManagerT<BasicBlock>;
+ virtual void addToPassManager(PassManagerT<Function> *PM, AnalysisUsage &AU);
+ virtual void addToPassManager(PassManagerT<BasicBlock> *PM,AnalysisUsage &AU);
};
+// Include support files that contain important APIs commonly used by Passes,
+// but that we want to separate out to make it easier to read the header files.
+//
+#include "llvm/PassSupport.h"
+#include "llvm/PassAnalysisSupport.h"
+
#endif