diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6a0bbc41780..18539e6cc27 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 Mon Jul  9 06:41:07 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
+	* emit-rtl.c (adjust_address, adjust_address_nv): Handle an
+	address that is a LO_SUM specially.
+	* explow.c (plus_constant_wide, case LO_SUM): Deleted.
+
 	* c-lang.c (start_cdtor): Remove extra parameter from start_function.
 
 	* emit-rtl.c (adjust_address_nv, replace_equiv_address_nv): New fcns.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 3a96906424e..4187468538d 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -1612,8 +1612,18 @@ adjust_address (memref, mode, offset)
 {
   /* For now, this is just a wrapper for change_address, but eventually
      will do memref tracking.  */
-  return
-    change_address (memref, mode, plus_constant (XEXP (memref, 0), offset));
+  rtx addr = XEXP (memref, 0);
+
+  /* If MEMREF is a LO_SUM and the offset is within the size of the
+     object, we can merge it into the LO_SUM.  */
+  if (GET_MODE (memref) != BLKmode && GET_CODE (addr) == LO_SUM
+      && offset >= 0 && offset < GET_MODE_SIZE (GET_MODE (memref)))
+    addr = gen_rtx_LO_SUM (mode, XEXP (addr, 0),
+			   plus_constant (XEXP (addr, 1), offset));
+  else
+    addr = plus_constant (addr, offset);
+
+  return change_address (memref, mode, addr);
 }
 
 /* Likewise, but the reference is not required to be valid.  */
@@ -1626,8 +1636,18 @@ adjust_address_nv (memref, mode, offset)
 {
   /* For now, this is just a wrapper for change_address, but eventually
      will do memref tracking.  */
-  return change_address_1 (memref, mode,
-			   plus_constant (XEXP (memref, 0), offset), 0);
+  rtx addr = XEXP (memref, 0);
+
+  /* If MEMREF is a LO_SUM and the offset is within the size of the
+     object, we can merge it into the LO_SUM.  */
+  if (GET_MODE (memref) != BLKmode && GET_CODE (addr) == LO_SUM
+      && offset >= 0 && offset < GET_MODE_SIZE (GET_MODE (memref)))
+    addr = gen_rtx_LO_SUM (mode, XEXP (addr, 0),
+			   plus_constant (XEXP (addr, 1), offset));
+  else
+    addr = plus_constant (addr, offset);
+
+  return change_address_1 (memref, mode, addr, 0);
 }
 
 /* Return a memory reference like MEMREF, but with its address changed to
diff --git a/gcc/explow.c b/gcc/explow.c
index f7e00be1ce9..cafbf2e2afa 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -180,11 +180,6 @@ plus_constant_wide (x, c)
 	}
       break;
 
-    case LO_SUM:
-      return gen_rtx_LO_SUM (mode, XEXP (x, 0),
-			     plus_constant (XEXP (x, 1), c));
-
-      
     default:
       break;
     }