diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0b582475060..d96fbe42a5a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-03-16  Richard Henderson  <rth@redhat.com>
+
+        * simplify-rtx (simplify_binary_operation): Don't abort for
+        SS_PLUS, US_PLUS, SS_MINUS, US_MINUS.
+
 2003-03-16  Richard Henderson  <rth@redhat.com>
 
         * config/i386/i386.md (movstrictqi, movstrictqi_1): Check
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 0bd9b6055b6..50c436f6339 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -1863,6 +1863,13 @@ simplify_binary_operation (code, mode, op0, op1)
 	     > (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1);
       break;
 
+    case SS_PLUS:
+    case US_PLUS:
+    case SS_MINUS:
+    case US_MINUS:
+      /* ??? There are simplifications that can be done.  */
+      return 0;
+
     default:
       abort ();
     }