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//===- llvm/Analysis/ValueNumbering.h - Value #'ing Interface ---*- 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 abstract ValueNumbering interface, which is used as the
// common interface used by all clients of value numbering information, and
// implemented by all value numbering implementations.
//
// Implementations of this interface must implement the various virtual methods,
// which automatically provides functionality for the entire suite of client
// APIs.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_VALUE_NUMBERING_H
#define LLVM_ANALYSIS_VALUE_NUMBERING_H
#include <vector>
#include "llvm/Pass.h"
namespace llvm {
class Value;
class Instruction;
struct ValueNumbering {
static char ID; // Class identification, replacement for typeinfo
virtual ~ValueNumbering(); // We want to be subclassed
/// getEqualNumberNodes - Return nodes with the same value number as the
/// specified Value. This fills in the argument vector with any equal values.
///
virtual void getEqualNumberNodes(Value *V1,
std::vector<Value*> &RetVals) const = 0;
///===-------------------------------------------------------------------===//
/// Interfaces to update value numbering analysis information as the client
/// changes the program.
///
/// deleteValue - This method should be called whenever an LLVM Value is
/// deleted from the program, for example when an instruction is found to be
/// redundant and is eliminated.
///
virtual void deleteValue(Value *V) {}
/// copyValue - This method should be used whenever a preexisting value in the
/// program is copied or cloned, introducing a new value. Note that analysis
/// implementations should tolerate clients that use this method to introduce
/// the same value multiple times: if the analysis already knows about a
/// value, it should ignore the request.
///
virtual void copyValue(Value *From, Value *To) {}
/// replaceWithNewValue - This method is the obvious combination of the two
/// above, and it provided as a helper to simplify client code.
///
void replaceWithNewValue(Value *Old, Value *New) {
copyValue(Old, New);
deleteValue(Old);
}
};
} // End llvm namespace
// Force any file including this header to get the implementation as well
FORCE_DEFINING_FILE_TO_BE_LINKED(BasicValueNumbering)
#endif