llvm-6502/include/llvm/Pass.h
Chris Lattner 4c76fc048b Break part of Pass.h out into PassAnalysisSupport.h
Add PassSupport.h which contains code for Pass registration


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3010 91177308-0d34-0410-b5e6-96231b3b80d8
2002-07-23 17:59:55 +00:00

205 lines
7.8 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 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 <vector>
#include <map>
class Value;
class BasicBlock;
class Function;
class Module;
class AnalysisUsage;
class AnalysisID;
class PassInfo;
template<class UnitType> class PassManagerT;
struct AnalysisResolver;
//===----------------------------------------------------------------------===//
// 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:
Pass(AnalysisResolver *AR = 0) : Resolver(AR) {}
virtual ~Pass() {} // Destructor is virtual so we can be subclassed
// getPassName - Return a nice clean name for a pass. This should be
// overloaded by the pass, but if it is not, C++ RTTI will be consulted to get
// a SOMEWHAT intelligable name for the pass.
//
virtual const char *getPassName() const;
// getPassInfo - Return the PassInfo data structure that corresponds to this
// pass...
const PassInfo *getPassInfo() const;
// 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;
// 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);
protected:
// 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(AnalysisID AID = AnalysisType::ID) {
assert(Resolver && "Pass not resident in a PassManager object!");
return *(AnalysisType*)Resolver->getAnalysis(AID);
}
// 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.
//
template<typename AnalysisType>
AnalysisType *getAnalysisToUpdate(AnalysisID AID = AnalysisType::ID) {
assert(Resolver && "Pass not resident in a PassManager object!");
return (AnalysisType*)Resolver->getAnalysisToUpdate(AID);
}
private:
friend class PassManagerT<Module>;
friend class PassManagerT<Function>;
friend class PassManagerT<BasicBlock>;
virtual void addToPassManager(PassManagerT<Module> *PM, AnalysisUsage &AU);
};
//===----------------------------------------------------------------------===//
// 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, ie 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 neccesary per-module initialization.
//
virtual bool doInitialization(Module &M) { return false; }
// runOnFunction - Virtual method overriden by subclasses to do the
// per-function processing of the pass.
//
virtual bool runOnFunction(Function &F) = 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, 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);
};
//===----------------------------------------------------------------------===//
// 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 contstraints of FunctionPass's.
//
struct BasicBlockPass : public FunctionPass {
// runOnBasicBlock - Virtual method overriden by subclasses to do the
// per-basicblock processing of the pass.
//
virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
// To run this pass on a function, we simply call runOnBasicBlock once for
// each function.
//
virtual 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 seperate out to make it easier to read the header files.
//
#include "llvm/PassSupport.h"
#include "llvm/PassAnalysisSupport.h"
#endif