diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cce46237510..fc2f3871ef9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-12-23  David Edelsohn  <edelsohn@gnu.org>
+
+	* function.c (assign_parms): Update max_parm_reg and
+	parm_reg_stack_loc when adding new parm reg.
+
 2003-12-23  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/ns32k/ns32k.c: Convert to ISO-C.
diff --git a/gcc/function.c b/gcc/function.c
index 6eb44aeec34..30ede39ef02 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4740,9 +4740,28 @@ assign_parms (tree fndecl)
 
 	  if (REG_P (parmreg))
 	    {
+	      unsigned int regno = REGNO (parmreg);
+
 	      emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
 				int_size_in_bytes (TREE_TYPE (parm)));
 	      SET_DECL_RTL (parm, parmreg);
+
+	      if (regno >= max_parm_reg)
+		{
+		  rtx *new;
+		  int old_max_parm_reg = max_parm_reg;
+
+		  /* It's slow to expand this one register at a time,
+		     but it's also rare and we need max_parm_reg to be
+		     precisely correct.  */
+		  max_parm_reg = regno + 1;
+		  new = ggc_realloc (parm_reg_stack_loc,
+				     max_parm_reg * sizeof (rtx));
+		  memset (new + old_max_parm_reg, 0,
+			  (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
+		  parm_reg_stack_loc = new;
+		  parm_reg_stack_loc[regno] = stack_parm;
+		}
 	    }
 	}