Index: gcc/cp/name-lookup.c
===================================================================
--- gcc/cp/name-lookup.c	(revision 191152)
+++ gcc/cp/name-lookup.c	(working copy)
@@ -2504,7 +2504,7 @@
 		  if (new_fn == old_fn)
 		    /* The function already exists in the current namespace.  */
 		    break;
-		  else if (OVL_USED (tmp1))
+		  else if (TREE_CODE (tmp1) == OVERLOAD && OVL_USED (tmp1))
 		    continue; /* this is a using decl */
 		  else if (compparms (TYPE_ARG_TYPES (TREE_TYPE (new_fn)),
 				      TYPE_ARG_TYPES (TREE_TYPE (old_fn))))
@@ -2519,7 +2519,7 @@
 			break;
 		      else
 			{
-			  error ("%qD is already declared in this scope", name);
+			  diagnose_name_conflict (new_fn, old_fn);
 			  break;
 			}
 		    }
Index: gcc/cp/cp-tree.h
===================================================================
--- gcc/cp/cp-tree.h	(revision 191152)
+++ gcc/cp/cp-tree.h	(working copy)
@@ -324,7 +324,7 @@
 /* If set, this was imported in a using declaration.
    This is not to confuse with being used somewhere, which
    is not important for this node.  */
-#define OVL_USED(NODE)		TREE_USED (NODE)
+#define OVL_USED(NODE)		TREE_USED (OVERLOAD_CHECK (NODE))
 /* If set, this OVERLOAD was created for argument-dependent lookup
    and can be freed afterward.  */
 #define OVL_ARG_DEPENDENT(NODE) TREE_LANG_FLAG_0 (OVERLOAD_CHECK (NODE))
Index: gcc/testsuite/g++.dg/overload/using2.C
===================================================================
--- gcc/testsuite/g++.dg/overload/using2.C	(revision 191152)
+++ gcc/testsuite/g++.dg/overload/using2.C	(working copy)
@@ -45,7 +45,7 @@
   extern "C" void exit (int) throw ();
   extern "C" void *malloc (__SIZE_TYPE__) throw () __attribute__((malloc));
 
-  void abort (void) throw ();
+  void abort (void) throw (); // { dg-message "previous" }
   void _exit (int) throw (); // { dg-error "conflicts" "conflicts" }
                              // { dg-message "void _exit" "_exit" { target *-*-* } 49 }
 
@@ -54,14 +54,14 @@
                            // { dg-message "void C1" "C1" { target *-*-* } 53 }
 
   extern "C" void c2 (void) throw ();
-  void C2 (void) throw ();
+  void C2 (void) throw (); // { dg-message "previous" }
 
   int C3 (int) throw ();
 
 using std::malloc;
-using std::abort; // { dg-error "already declared" }
+using std::abort; // { dg-error "conflicts" }
 using std::c2;
-using std::C2; // { dg-error "already declared" }
+using std::C2; // { dg-error "conflicts" }
 
 using std::c3; using other::c3;
 using std::C3; using other::C3;
Index: gcc/testsuite/g++.dg/overload/using3.C
===================================================================
--- gcc/testsuite/g++.dg/overload/using3.C	(revision 0)
+++ gcc/testsuite/g++.dg/overload/using3.C	(revision 0)
@@ -0,0 +1,16 @@
+// { dg-do compile }
+
+namespace a
+{
+  void f(int);
+}
+
+namespace b
+{
+  void f(int); // { dg-message "previous" }
+  void g()
+  {
+    f (3);
+  }
+  using a::f; // { dg-error "conflicts" }
+}
Index: gcc/testsuite/g++.dg/lookup/using9.C
===================================================================
--- gcc/testsuite/g++.dg/lookup/using9.C	(revision 191152)
+++ gcc/testsuite/g++.dg/lookup/using9.C	(working copy)
@@ -27,5 +27,5 @@
 void m()
 {
   void f(int);
-  using B::f;   // { dg-error "already declared" }
+  using B::f;   // { dg-error "previous declaration" }
 }
Index: libstdc++-v3/include/tr1/cmath
===================================================================
--- libstdc++-v3/include/tr1/cmath	(revision 191152)
+++ libstdc++-v3/include/tr1/cmath	(working copy)
@@ -986,9 +986,6 @@
 
   // DR 550. What should the return type of pow(float,int) be?
   // NB: C++0x and TR1 != C++03.
-  inline double
-  pow(double __x, double __y)
-  { return std::pow(__x, __y); }
 
   inline float
   pow(float __x, float __y)