mips.c (mips_expand_prologue): Don't calculate the last argument register unless we need it.

	* mips.c (mips_expand_prologue): Don't calculate the last
	argument register unless we need it.  When we are calculating
	this, make sure FUNCTION_ARG is giving us a REG.

From-SVN: r35094

gcc/ChangeLog

+Mon Jul 17 08:26:35 2000  Clinton Popetz  <cpopetz@cygnus.com>
+
+	* mips.c (mips_expand_prologue): Don't calculate the last               
+	argument register unless we need it.  When we are calculating 
+	this, make sure FUNCTION_ARG is giving us a REG.                        
+
 2000-07-17  Stephane Carrez  <Stephane.Carrez@worldnet.fr>
 
 	* flow.c (libcall_dead_p): Use single_set to verify the insn
@@ -6,6 +12,7 @@
 
 2000-07-17  Mark Klein <mklein@dis.com>
 
+
          * pa.c (emit_hpdiv_const): Update to match new pattern for udivsi3.
 
 2000-07-17  J. David Anglin  <dave@hiauly1.hia.nrc.ca>

gcc/config/mips/mips.c

@@ -6942,6 +6942,8 @@ mips_expand_prologue ()
   tree cur_arg;
   CUMULATIVE_ARGS args_so_far;
   rtx reg_18_save = NULL_RTX;
+  int store_args_on_stack = (mips_abi == ABI_32 || mips_abi == ABI_O64)
+                            && (! mips_entry || mips_can_use_return_insn ());
 
   /* If struct value address is treated as the first argument, make it so.  */
   if (aggregate_value_p (DECL_RESULT (fndecl))
@@ -6960,7 +6962,9 @@ mips_expand_prologue ()
      of the first argument in the variable part of the argument list,
      otherwise GP_ARG_LAST+1.  Note also if the last argument is 
      the varargs special argument, and treat it as part of the
-     variable arguments. */
+     variable arguments. 
+     
+     This is only needed if store_args_on_stack is true. */
 
   INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
   regno = GP_ARG_FIRST;
@@ -6982,7 +6986,7 @@ mips_expand_prologue ()
       FUNCTION_ARG_ADVANCE (args_so_far, passed_mode, passed_type, 1);
       next_arg = TREE_CHAIN (cur_arg);
 
-      if (entry_parm)
+      if (entry_parm && store_args_on_stack)
 	{
 	  if (next_arg == 0
 	      && DECL_NAME (cur_arg)
@@ -6997,7 +7001,10 @@ mips_expand_prologue ()
 	  else
 	    {
 	      int words;
-	  
+
+	      if (GET_CODE (entry_parm) != REG)
+	        abort ();
+
 	      /* passed in a register, so will get homed automatically */
 	      if (GET_MODE (entry_parm) == BLKmode)
 		words = (int_size_in_bytes (passed_type) + 3) / 4;
@@ -7042,8 +7049,7 @@ mips_expand_prologue ()
 
   /* If this function is a varargs function, store any registers that
      would normally hold arguments ($4 - $7) on the stack.  */
-  if ((mips_abi == ABI_32 || mips_abi == ABI_O64)
-      && (! mips_entry || mips_can_use_return_insn ())
+  if (store_args_on_stack
       && ((TYPE_ARG_TYPES (fntype) != 0
 	   && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
 	       != void_type_node))