// 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.
//
+// Pointer tagging is used to efficiently find the User corresponding
+// to a Use without having to store a User pointer in every Use. A
+// User is preceded in memory by all the Uses corresponding to its
+// operands, and the low bits of one of the fields (Prev) of the Use
+// class are used to encode offsets to be able to find that User given
+// a pointer to any Use. For details, see:
+//
+// http://www.llvm.org/docs/ProgrammersManual.html#UserLayout
+//
//===----------------------------------------------------------------------===//
#ifndef LLVM_USE_H
#define LLVM_USE_H
#include "llvm/Support/Casting.h"
-#include "llvm/ADT/iterator.h"
#include "llvm/ADT/PointerIntPair.h"
+#include <iterator>
namespace llvm {
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;
+class value_use_iterator : public std::iterator<std::forward_iterator_tag,
+ UserTy*, ptrdiff_t> {
+ typedef std::iterator<std::forward_iterator_tag, UserTy*, ptrdiff_t> super;
typedef value_use_iterator<UserTy> _Self;
Use *U;