PATCH middle-end: handle decimal float moves

[Ben Elliston]

This patch, originally suggested by Geoff Keating, emits moves for
decimal float modes using the existing integer mode moves, eliminating
the need for mov?d patterns in the machine descriptions.

Bootstrapping and regression testing on powerpc-unknown-linux-gnu is
currently underway.  Okay for the trunk, provided testing succeeds?

:ADDPATCH middle-end:

2006-01-10  Ben Elliston  <bje@au.ibm.com>

	* expr.c (emit_move_change_mode): Always adjust addresses, not
	just during reload.  Copy replacements only during reload.
	(emit_move_insn_1): Move MODE_DECIMAL_FLOAT modes by invoking
	emit_move_via_integer.

Index: expr.c
===================================================================
--- expr.c	(revision 109509)
+++ expr.c	(working copy)
@@ -1,6 +1,7 @@
 /* Convert tree expression to rtl instructions, for GNU compiler.
    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation,
+   Inc.
 
 This file is part of GCC.
 
@@ -2783,7 +2784,7 @@ emit_move_change_mode (enum machine_mode
 {
   rtx ret;
 
-  if (reload_in_progress && MEM_P (x))
+  if (MEM_P (x))
     {
       /* We can't use gen_lowpart here because it may call change_address
 	 which is not appropriate if we were called when a reload was in
@@ -2791,9 +2792,9 @@ emit_move_change_mode (enum machine_mode
 	 the size in bytes is supposed to be the same.  Copy the MEM to
 	 change the mode and move any substitutions from the old MEM to
 	 the new one.  */
-
       ret = adjust_address_nv (x, new_mode, 0);
-      copy_replacements (x, ret);
+      if (reload_in_progress)
+	copy_replacements (x, ret);
     }
   else
     {
@@ -3128,6 +3129,9 @@ emit_move_insn_1 (rtx x, rtx y)
   if (COMPLEX_MODE_P (mode))
     return emit_move_complex (mode, x, y);
 
+  if (GET_MODE_CLASS (mode) == MODE_DECIMAL_FLOAT)
+    return emit_move_via_integer (mode, x, y, false);
+
   if (GET_MODE_CLASS (mode) == MODE_CC)
     return emit_move_ccmode (mode, x, y);