1 files changed, 27 insertions, 40 deletions

diff --git a/include/llvm/IR/User.h b/include/llvm/IR/User.h
index 505bdeb178e9..848adae9ceca 100644
--- a/include/llvm/IR/User.h
+++ b/include/llvm/IR/User.h
@@ -19,6 +19,8 @@
 #ifndef LLVM_IR_USER_H
 #define LLVM_IR_USER_H
 
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/IR/Value.h"
 #include "llvm/Support/ErrorHandling.h"
 
@@ -37,6 +39,10 @@ class User : public Value {
   friend struct HungoffOperandTraits;
   virtual void anchor();
 protected:
+  /// NumOperands - The number of values used by this User.
+  ///
+  unsigned NumOperands;
+
   /// OperandList - This is a pointer to the array of Uses for this User.
   /// For nodes of fixed arity (e.g. a binary operator) this array will live
   /// prefixed to some derived class instance.  For nodes of resizable variable
@@ -44,17 +50,13 @@ protected:
   /// allocated and should be destroyed by the classes' virtual dtor.
   Use *OperandList;
 
-  /// NumOperands - The number of values used by this User.
-  ///
-  unsigned NumOperands;
-
   void *operator new(size_t s, unsigned Us);
   User(Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
-    : Value(ty, vty), OperandList(OpList), NumOperands(NumOps) {}
+    : Value(ty, vty), NumOperands(NumOps), OperandList(OpList) {}
   Use *allocHungoffUses(unsigned) const;
   void dropHungoffUses() {
     Use::zap(OperandList, OperandList + NumOperands, true);
-    OperandList = 0;
+    OperandList = nullptr;
     // Reset NumOperands so User::operator delete() does the right thing.
     NumOperands = 0;
   }
@@ -112,41 +114,29 @@ public:
   //
   typedef Use*       op_iterator;
   typedef const Use* const_op_iterator;
+  typedef iterator_range<op_iterator> op_range;
+  typedef iterator_range<const_op_iterator> const_op_range;
 
   inline op_iterator       op_begin()       { return OperandList; }
   inline const_op_iterator op_begin() const { return OperandList; }
   inline op_iterator       op_end()         { return OperandList+NumOperands; }
   inline const_op_iterator op_end()   const { return OperandList+NumOperands; }
+  inline op_range operands() {
+    return op_range(op_begin(), op_end());
+  }
+  inline const_op_range operands() const {
+    return const_op_range(op_begin(), op_end());
+  }
 
   /// Convenience iterator for directly iterating over the Values in the
   /// OperandList
-  class value_op_iterator : public std::iterator<std::forward_iterator_tag,
-                                                 Value*> {
-    op_iterator OI;
-  public:
-    explicit value_op_iterator(Use *U) : OI(U) {}
-
-    bool operator==(const value_op_iterator &x) const {
-      return OI == x.OI;
-    }
-    bool operator!=(const value_op_iterator &x) const {
-      return !operator==(x);
-    }
-
-    /// Iterator traversal: forward iteration only
-    value_op_iterator &operator++() {          // Preincrement
-      ++OI;
-      return *this;
-    }
-    value_op_iterator operator++(int) {        // Postincrement
-      value_op_iterator tmp = *this; ++*this; return tmp;
-    }
-
-    /// Retrieve a pointer to the current Value.
-    Value *operator*() const {
-      return *OI;
-    }
+  struct value_op_iterator
+      : iterator_adaptor_base<value_op_iterator, op_iterator,
+                              std::random_access_iterator_tag, Value *,
+                              ptrdiff_t, Value *, Value *> {
+    explicit value_op_iterator(Use *U = nullptr) : iterator_adaptor_base(U) {}
 
+    Value *operator*() const { return *I; }
     Value *operator->() const { return operator*(); }
   };
 
@@ -156,6 +146,9 @@ public:
   inline value_op_iterator value_op_end() {
     return value_op_iterator(op_end());
   }
+  inline iterator_range<value_op_iterator> operand_values() {
+    return iterator_range<value_op_iterator>(value_op_begin(), value_op_end());
+  }
 
   // dropAllReferences() - This function is in charge of "letting go" of all
   // objects that this User refers to.  This allows one to
@@ -166,8 +159,8 @@ public:
   // delete.
   //
   void dropAllReferences() {
-    for (op_iterator i = op_begin(), e = op_end(); i != e; ++i)
-      i->set(0);
+    for (Use &U : operands())
+      U.set(nullptr);
   }
 
   /// replaceUsesOfWith - Replaces all references to the "From" definition with
@@ -194,12 +187,6 @@ template<> struct simplify_type<User::const_op_iterator> {
   }
 };
 
-// value_use_iterator::getOperandNo - Requires the definition of the User class.
-template<typename UserTy>
-unsigned value_use_iterator<UserTy>::getOperandNo() const {
-  return U - U->getUser()->op_begin();
-}
-
 } // End llvm namespace
 
 #endif