[src/trunk]: src/sys/arch/powerpc/booke Fool gcc into thinking we aren't usin...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6e7f8babd140
branches:  trunk
changeset: 781466:6e7f8babd140
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Sep 07 18:05:11 2012 +0000

description:
Fool gcc into thinking we aren't using r31.  We do use it but we don't
clobber it since it save and restore it from a temporary register.

diffstat:

 sys/arch/powerpc/booke/booke_pmap.c |  18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diffs (40 lines):

diff -r 440e538c2a69 -r 6e7f8babd140 sys/arch/powerpc/booke/booke_pmap.c
--- a/sys/arch/powerpc/booke/booke_pmap.c       Fri Sep 07 17:11:43 2012 +0000
+++ b/sys/arch/powerpc/booke/booke_pmap.c       Fri Sep 07 18:05:11 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: booke_pmap.c,v 1.15 2012/07/09 17:45:22 matt Exp $     */
+/*     $NetBSD: booke_pmap.c,v 1.16 2012/09/07 18:05:11 matt Exp $     */
 /*-
  * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc.
  * All rights reserved.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: booke_pmap.c,v 1.15 2012/07/09 17:45:22 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: booke_pmap.c,v 1.16 2012/09/07 18:05:11 matt Exp $");
 
 #include <sys/param.h>
 #include <sys/kcore.h>
@@ -364,12 +364,16 @@
                for (u_int i = 0;
                     i < line_size;
                     src_va += 32, dst_va += 32, i += 32) {
-                       __asm(
-                               "lmw    24,0(%0)" "\n\t"
-                               "stmw   24,0(%1)"
-                           :: "b"(src_va), "b"(dst_va)
+                       register_t tmp;
+                       __asm __volatile(
+                               "mr     %[tmp],31"      "\n\t"
+                               "lmw    24,0(%[src])"   "\n\t"
+                               "stmw   24,0(%[dst])"   "\n\t"
+                               "mr     31,%[tmp]"      "\n\t"
+                           : [tmp] "=&r"(tmp)
+                           : [src] "b"(src_va), [dst] "b"(dst_va)
                            : "r24", "r25", "r26", "r27",
-                             "r28", "r29", "r30", "r31");
+                             "r28", "r29", "r30", "memory");
                }
        }
        pmap_md_unmap_poolpage(src_va, NBPG);