llvm-6502/include/llvm/Use.h
Dan Gohman 7e4d5b6002 Fix a copy+paste error in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49820 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-16 21:57:29 +00:00

182 lines
4.7 KiB
C++

//===-- llvm/Use.h - Definition of the Use class ----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines the Use class. The Use class represents the operand of an
// instruction or some other User instance which refers to a Value. The Use
// class keeps the "use list" of the referenced value up to date.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_USE_H
#define LLVM_USE_H
#include "llvm/Support/Casting.h"
#include "llvm/ADT/iterator"
namespace llvm {
class Value;
class User;
//===----------------------------------------------------------------------===//
// Use Class
//===----------------------------------------------------------------------===//
// Use is here to make keeping the "use" list of a Value up-to-date really easy.
//
class Use {
public:
inline void init(Value *V, User *U);
Use(Value *V, User *U) { init(V, U); }
Use(const Use &U) { init(U.Val, U.U); }
inline ~Use() {
if (Val) removeFromList();
}
/// Default ctor - This leaves the Use completely unitialized. The only thing
/// that is valid to do with this use is to call the "init" method.
inline Use() : Val(0) {}
operator Value*() const { return Val; }
Value *get() const { return Val; }
User *getUser() const { return U; }
inline void set(Value *Val);
Value *operator=(Value *RHS) {
set(RHS);
return RHS;
}
const Use &operator=(const Use &RHS) {
set(RHS.Val);
return *this;
}
Value *operator->() { return Val; }
const Value *operator->() const { return Val; }
Use *getNext() const { return Next; }
private:
Use *Next, **Prev;
Value *Val;
User *U;
void addToList(Use **List) {
Next = *List;
if (Next) Next->Prev = &Next;
Prev = List;
*List = this;
}
void removeFromList() {
*Prev = Next;
if (Next) Next->Prev = Prev;
}
friend class Value;
};
// simplify_type - Allow clients to treat uses just like values when using
// casting operators.
template<> struct simplify_type<Use> {
typedef Value* SimpleType;
static SimpleType getSimplifiedValue(const Use &Val) {
return static_cast<SimpleType>(Val.get());
}
};
template<> struct simplify_type<const Use> {
typedef Value* SimpleType;
static SimpleType getSimplifiedValue(const Use &Val) {
return static_cast<SimpleType>(Val.get());
}
};
template<typename UserTy> // UserTy == 'User' or 'const User'
class value_use_iterator : public forward_iterator<UserTy*, ptrdiff_t> {
typedef forward_iterator<UserTy*, ptrdiff_t> super;
typedef value_use_iterator<UserTy> _Self;
Use *U;
explicit value_use_iterator(Use *u) : U(u) {}
friend class Value;
public:
typedef typename super::reference reference;
typedef typename super::pointer pointer;
value_use_iterator(const _Self &I) : U(I.U) {}
value_use_iterator() {}
bool operator==(const _Self &x) const {
return U == x.U;
}
bool operator!=(const _Self &x) const {
return !operator==(x);
}
/// atEnd - return true if this iterator is equal to use_end() on the value.
bool atEnd() const { return U == 0; }
// Iterator traversal: forward iteration only
_Self &operator++() { // Preincrement
assert(U && "Cannot increment end iterator!");
U = U->getNext();
return *this;
}
_Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
// Retrieve a reference to the current User
UserTy *operator*() const {
assert(U && "Cannot increment end iterator!");
return U->getUser();
}
UserTy *operator->() const { return operator*(); }
Use &getUse() const { return *U; }
/// getOperandNo - Return the operand # of this use in its User. Defined in
/// User.h
///
unsigned getOperandNo() const;
};
template<> struct simplify_type<value_use_iterator<User> > {
typedef User* SimpleType;
static SimpleType getSimplifiedValue(const value_use_iterator<User> &Val) {
return *Val;
}
};
template<> struct simplify_type<const value_use_iterator<User> >
: public simplify_type<value_use_iterator<User> > {};
template<> struct simplify_type<value_use_iterator<const User> > {
typedef const User* SimpleType;
static SimpleType getSimplifiedValue(const
value_use_iterator<const User> &Val) {
return *Val;
}
};
template<> struct simplify_type<const value_use_iterator<const User> >
: public simplify_type<value_use_iterator<const User> > {};
} // End llvm namespace
#endif