diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 0f5673e9cdc1d8848a7e3269982a3b3866326af2..3adedeb13f3169d01ac23e7c4f334d1256137567 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2002-05-15  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>
+
+	PR c++/6620
+	* pt.c (verify_class_unification): Don't check if PARM is template
+	parameter dependent.  Simplify.
+	(unify) [TEMPLATE_PARM_INDEX]: Handle when ARG is a template
+	parameter dependent expression.
+
 2002-05-14  Jason Merrill  <jason@redhat.com>
 
 	* rtti.c (get_tinfo_decl): Don't call comdat_linkage.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index c4e119e10cb18c216c36b5aeeda11c3e14367b4b..58fe3c57369fa453f85b7fcb8e3ed1f7f82bd9fd 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -8307,29 +8307,12 @@ static int
 verify_class_unification (targs, parms, args)
      tree targs, parms, args;
 {
-  int i;
-  int nparms = TREE_VEC_LENGTH (parms);
-  tree new_parms = tsubst (parms, add_outermost_template_args (args, targs),
-  			   tf_none, NULL_TREE);
-  if (new_parms == error_mark_node)
+  parms = tsubst (parms, add_outermost_template_args (args, targs),
+  		  tf_none, NULL_TREE);
+  if (parms == error_mark_node)
     return 1;
 
-  args = INNERMOST_TEMPLATE_ARGS (args);
-
-  for (i = 0; i < nparms; i++)
-    {
-      tree parm = TREE_VEC_ELT (new_parms, i);
-      tree arg = TREE_VEC_ELT (args, i);
-
-      /* In case we are deducing from a function argument of a function
-	 templates, some parameters may not be deduced yet.  So we
-	 make sure that only fully substituted elements of PARM are
-	 compared below.  */
-
-      if (!uses_template_parms (parm) && !template_args_equal (parm, arg))
-	return 1;
-    }
-  return 0;
+  return !comp_template_args (parms, INNERMOST_TEMPLATE_ARGS (args));
 }
 
 /* PARM is a template class (perhaps with unbound template
@@ -8812,8 +8795,12 @@ unify (tparms, targs, parm, arg, strict)
 	 deduced from an array bound may be of any integral type. 
 	 The non-type parameter might use already deduced type parameters.  */
       tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
-      if (same_type_p (TREE_TYPE (arg), tparm))
-	  /* OK */;
+      if (!TREE_TYPE (arg))
+	/* Template-parameter dependent expression.  Just accept it for now.
+	   It will later be processed in convert_template_argument.  */
+	;
+      else if (same_type_p (TREE_TYPE (arg), tparm))
+	/* OK */;
       else if ((strict & UNIFY_ALLOW_INTEGER)
 	       && (TREE_CODE (tparm) == INTEGER_TYPE
 		   || TREE_CODE (tparm) == BOOLEAN_TYPE))
diff --git a/gcc/testsuite/g++.dg/template/partial1.C b/gcc/testsuite/g++.dg/template/partial1.C
new file mode 100644
index 0000000000000000000000000000000000000000..41ea530396962987bbaa5c735a85f94cdb98100a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/partial1.C
@@ -0,0 +1,36 @@
+// { dg-do run }
+// Origin: Jo Totland <jototland@hotmail.com>
+
+// PR c++/6620
+// Partial specialization involving expression of non-type template
+// parameter causes ICE.
+
+extern "C" void abort();
+
+template <int N> struct HoldInt
+{
+};
+
+template <class A, class B> struct Add
+{
+};
+
+template <int N> struct Add<HoldInt<N>, HoldInt<-N> >
+{
+  typedef int type;
+  int f() { return 0; }
+};
+
+template <int N, int M> 
+struct Add<HoldInt<N>, HoldInt<M> >
+{
+  typedef HoldInt<N+M> type;
+  int f() { return 1; }
+};
+
+int main() {
+  Add<HoldInt<1>, HoldInt<-1> > a;
+  Add<HoldInt<1>, HoldInt<-2> > b;
+  if (a.f() != 0 || b.f() != 1)
+    abort();
+}