llvm-6502/include/llvm/Pass.h
Chris Lattner ce885e9f9d * Make debugging output nicer
* Implement pass memory freeing after the pass is unused
* Expose PassManager typedef in Pass.h instead of PassManager.h


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1617 91177308-0d34-0410-b5e6-96231b3b80d8
2002-01-31 18:32:27 +00:00

264 lines
9.9 KiB
C++

//===- llvm/Pass.h - Base class for XForm Passes -----------------*- C++ -*--=//
//
// This file defines a base class that indicates that a specified class is a
// transformation pass implementation.
//
// Pass's are designed this way so that it is possible to run passes in a cache
// and organizationally optimal order without having to specify it at the front
// end. This allows arbitrary passes to be strung together and have them
// executed as effeciently as possible.
//
// 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.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PASS_H
#define LLVM_PASS_H
#include <vector>
#include <map>
class Value;
class BasicBlock;
class Method;
class Module;
class AnalysisID;
class Pass;
template<class UnitType> class PassManagerT;
struct AnalysisResolver;
// PassManager - Top level PassManagerT instantiation intended to be used.
// Implemented in PassManager.h
typedef PassManagerT<Module> PassManager;
//===----------------------------------------------------------------------===//
// 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...
public:
typedef std::vector<AnalysisID> AnalysisSet;
inline Pass(AnalysisResolver *AR = 0) : Resolver(AR) {}
inline virtual ~Pass() {} // Destructor is virtual so we can be subclassed
// 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;
// getAnalysisUsageInfo - 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.
//
// The Destroyed vector is used to communicate what analyses are invalidated
// by this pass. This is critical to specify so that the PassManager knows
// which analysis must be rerun after this pass has proceeded. Analysis are
// only invalidated if run() returns true.
//
// The Provided vector is used for passes that provide analysis information,
// these are the analysis passes themselves. All analysis passes should
// override this method to return themselves in the provided set.
//
virtual void getAnalysisUsageInfo(AnalysisSet &Required,
AnalysisSet &Destroyed,
AnalysisSet &Provided) {
// By default, no analysis results are used or destroyed.
}
// 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() {}
#ifndef NDEBUG
// dumpPassStructure - Implement the -debug-passes=PassStructure option
virtual void dumpPassStructure(unsigned Offset = 0);
#endif
protected:
// getAnalysis<AnalysisType>() - This function is used by subclasses to get to
// the analysis information that they claim to use by overriding the
// getAnalysisUsageInfo function.
//
template<typename AnalysisType>
AnalysisType &getAnalysis(AnalysisID AID = AnalysisType::ID) {
assert(Resolver && "Pass not resident in a PassManager object!");
return *(AnalysisType*)Resolver->getAnalysis(AID);
}
private:
friend class PassManagerT<Module>;
friend class PassManagerT<Method>;
friend class PassManagerT<BasicBlock>;
virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisSet &Req,
AnalysisSet &Destroyed, AnalysisSet &Provided);
};
//===----------------------------------------------------------------------===//
// 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; }
// runOnMethod - Virtual method overriden by subclasses to do the per-method
// processing of the pass.
//
virtual bool runOnMethod(Method *M) = 0;
// 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, ronOnMethod'ing once
// for every method in the module, then by finalizing.
//
virtual bool run(Module *M);
// run - On a method, we simply initialize, run the method, then finalize.
//
bool run(Method *M);
private:
friend class PassManagerT<Module>;
friend class PassManagerT<Method>;
friend class PassManagerT<BasicBlock>;
virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisSet &Req,
AnalysisSet &Dest, AnalysisSet &Prov);
virtual void addToPassManager(PassManagerT<Method> *PM,AnalysisSet &Req,
AnalysisSet &Dest, AnalysisSet &Prov);
};
//===----------------------------------------------------------------------===//
// 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 MethodPass's.
//
struct BasicBlockPass : public MethodPass {
// runOnBasicBlock - Virtual method overriden by subclasses to do the
// per-basicblock processing of the pass.
//
virtual bool runOnBasicBlock(BasicBlock *M) = 0;
// To run this pass on a method, we simply call runOnBasicBlock once for each
// method.
//
virtual bool runOnMethod(Method *BB);
// To run directly on the basic block, we initialize, runOnBasicBlock, then
// finalize.
//
bool run(BasicBlock *BB);
private:
friend class PassManagerT<Method>;
friend class PassManagerT<BasicBlock>;
virtual void addToPassManager(PassManagerT<Method> *PM, AnalysisSet &,
AnalysisSet &, AnalysisSet &);
virtual void addToPassManager(PassManagerT<BasicBlock> *PM, AnalysisSet &,
AnalysisSet &, AnalysisSet &);
};
// CreatePass - Helper template to invoke the constructor for the AnalysisID
// class. Note that this should be a template internal to AnalysisID, but
// GCC 2.95.3 crashes if we do that, doh.
//
template<class AnalysisType>
static Pass *CreatePass(AnalysisID ID) { return new AnalysisType(ID); }
//===----------------------------------------------------------------------===//
// AnalysisID - This class is used to uniquely identify an analysis pass that
// is referenced by a transformation.
//
class AnalysisID {
static unsigned NextID; // Next ID # to deal out...
unsigned ID; // Unique ID for this analysis
Pass *(*Constructor)(AnalysisID); // Constructor to return the Analysis
AnalysisID(); // Disable default ctor
AnalysisID(unsigned id, Pass *(*Ct)(AnalysisID)) : ID(id), Constructor(Ct) {}
public:
// create - the only way to define a new AnalysisID. This static method is
// supposed to be used to define the class static AnalysisID's that are
// provided by analysis passes. In the implementation (.cpp) file for the
// class, there should be a line that looks like this (using CallGraph as an
// example):
//
// AnalysisID CallGraph::ID(AnalysisID::create<CallGraph>());
//
template<class AnalysisType>
static AnalysisID create() {
return AnalysisID(NextID++, CreatePass<AnalysisType>);
}
inline Pass *createPass() const { return Constructor(*this); }
inline bool operator==(const AnalysisID &A) const {
return A.ID == ID;
}
inline bool operator!=(const AnalysisID &A) const {
return A.ID != ID;
}
inline bool operator<(const AnalysisID &A) const {
return ID < A.ID;
}
};
//===----------------------------------------------------------------------===//
// AnalysisResolver - Simple interface implemented by PassManagers objects that
// is used to pull analysis information out of them.
//
struct AnalysisResolver {
virtual Pass *getAnalysisOrNullUp(AnalysisID ID) const = 0;
virtual Pass *getAnalysisOrNullDown(AnalysisID ID) const = 0;
Pass *getAnalysis(AnalysisID ID) {
Pass *Result = getAnalysisOrNullUp(ID);
assert(Result && "Pass has an incorrect analysis uses set!");
return Result;
}
virtual unsigned getDepth() const = 0;
virtual void markPassUsed(AnalysisID P, Pass *User) = 0;
protected:
void setAnalysisResolver(Pass *P, AnalysisResolver *AR);
};
#endif