1 //===- llvm/Analysis/ValueNumbering.h - Value #'ing Interface ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the abstract ValueNumbering interface, which is used as the
11 // common interface used by all clients of value numbering information, and
12 // implemented by all value numbering implementations.
14 // Implementations of this interface must implement the various virtual methods,
15 // which automatically provides functionality for the entire suite of client
18 //===----------------------------------------------------------------------===//
20 #ifndef LLVM_ANALYSIS_VALUE_NUMBERING_H
21 #define LLVM_ANALYSIS_VALUE_NUMBERING_H
24 #include "llvm/Pass.h"
25 #include "llvm/System/IncludeFile.h"
32 struct ValueNumbering {
33 static char ID; // Class identification, replacement for typeinfo
34 virtual ~ValueNumbering(); // We want to be subclassed
36 /// getEqualNumberNodes - Return nodes with the same value number as the
37 /// specified Value. This fills in the argument vector with any equal values.
39 virtual void getEqualNumberNodes(Value *V1,
40 std::vector<Value*> &RetVals) const = 0;
42 ///===-------------------------------------------------------------------===//
43 /// Interfaces to update value numbering analysis information as the client
44 /// changes the program.
47 /// deleteValue - This method should be called whenever an LLVM Value is
48 /// deleted from the program, for example when an instruction is found to be
49 /// redundant and is eliminated.
51 virtual void deleteValue(Value *V) {}
53 /// copyValue - This method should be used whenever a preexisting value in the
54 /// program is copied or cloned, introducing a new value. Note that analysis
55 /// implementations should tolerate clients that use this method to introduce
56 /// the same value multiple times: if the analysis already knows about a
57 /// value, it should ignore the request.
59 virtual void copyValue(Value *From, Value *To) {}
61 /// replaceWithNewValue - This method is the obvious combination of the two
62 /// above, and it provided as a helper to simplify client code.
64 void replaceWithNewValue(Value *Old, Value *New) {
70 } // End llvm namespace
72 // Force any file including this header to get the implementation as well
73 FORCE_DEFINING_FILE_TO_BE_LINKED(BasicValueNumbering)