llvm-6502/include/llvm/Analysis/LazyValueInfo.h

80 lines
2.6 KiB
C++

//===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interface for lazy computation of value constraint
// information.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_LIVEVALUES_H
#define LLVM_ANALYSIS_LIVEVALUES_H
#include "llvm/Pass.h"
namespace llvm {
class Constant;
class TargetData;
class Value;
/// LazyValueInfo - This pass computes, caches, and vends lazy value constraint
/// information.
class LazyValueInfo : public FunctionPass {
class TargetData *TD;
void *PImpl;
LazyValueInfo(const LazyValueInfo&); // DO NOT IMPLEMENT.
void operator=(const LazyValueInfo&); // DO NOT IMPLEMENT.
public:
static char ID;
LazyValueInfo() : FunctionPass(ID), PImpl(0) {}
~LazyValueInfo() { assert(PImpl == 0 && "releaseMemory not called"); }
/// Tristate - This is used to return true/false/dunno results.
enum Tristate {
Unknown = -1, False = 0, True = 1
};
// Public query interface.
/// getPredicateOnEdge - Determine whether the specified value comparison
/// with a constant is known to be true or false on the specified CFG edge.
/// Pred is a CmpInst predicate.
Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C,
BasicBlock *FromBB, BasicBlock *ToBB);
/// getConstant - Determine whether the specified value is known to be a
/// constant at the end of the specified block. Return null if not.
Constant *getConstant(Value *V, BasicBlock *BB);
/// getConstantOnEdge - Determine whether the specified value is known to be a
/// constant on the specified edge. Return null if not.
Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB);
/// threadEdge - Inform the analysis cache that we have threaded an edge from
/// PredBB to OldSucc to be from PredBB to NewSucc instead.
void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc);
/// eraseBlock - Inform the analysis cache that we have erased a block.
void eraseBlock(BasicBlock *BB);
// Implementation boilerplate.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
virtual void releaseMemory();
virtual bool runOnFunction(Function &F);
};
} // end namespace llvm
#endif