llvm-6502/include/llvm/Pass.h
Misha Brukman c4b611af63 Fix grammar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12590 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-01 17:15:42 +00:00

344 lines
13 KiB
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.
//
// 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>
#include <iosfwd>
#include <typeinfo>
#include <cassert>
namespace llvm {
class Value;
class BasicBlock;
class Function;
class Module;
class AnalysisUsage;
class PassInfo;
class ImmutablePass;
template<class UnitType> class PassManagerT;
struct AnalysisResolver;
// 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.
///
class Pass {
friend class AnalysisResolver;
AnalysisResolver *Resolver; // AnalysisResolver this pass is owned by...
const PassInfo *PassInfoCache;
// 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
/// 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;
/// 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;
/// 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);
/// 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);
// getPassInfo - Static method to get the pass information from a class name.
template<typename AnalysisClass>
static const PassInfo *getClassPassInfo() {
return lookupPassInfo(typeid(AnalysisClass));
}
// 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 was 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;
}
//===----------------------------------------------------------------------===//
/// 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() {}
/// ImmutablePasses are never run.
///
virtual bool run(Module &M) { return false; }
private:
friend class PassManagerT<Module>;
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, 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; }
/// 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 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; }
// To run this pass on a function, we simply call runOnBasicBlock once for
// each function.
//
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);
};
} // End llvm namespace
// 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