//===- llvm/Analysis/ValueNumbering.h - Value #'ing Interface ---*- 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 the abstract ValueNumbering interface, which is used as the
namespace llvm {
class Value;
+class Instruction;
struct ValueNumbering {
virtual ~ValueNumbering(); // We want to be subclassed
///===-------------------------------------------------------------------===//
/// Interfaces to update value numbering analysis information as the client
- /// changes the program
+ /// changes the program.
///
- /// deleteInstruction - Clients should invoke this method when they delete an
- /// instruction from the program. This allows the analysis implementations to
- /// avoid having dangling pointers in their representation.
- virtual void deleteInstruction(Instruction *I) {}
-};
+ /// 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) {}
-extern void BasicValueNumberingStub();
-static IncludeFile
-HDR_INCLUDE_VALUENUMBERING_CPP((void*)&BasicValueNumberingStub);
+ /// 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