From: Andreas Larsson <andreas@gaisler.com>
To: davem@davemloft.net
Cc: sparclinux@vger.kernel.org, sam@ravnborg.org,
linux-kernel@vger.kernel.org, software@gaisler.com
Subject: [PATCH] sparc: Let memset return the address argument
Date: Fri, 29 Aug 2014 17:08:21 +0200 [thread overview]
Message-ID: <1409324901-19291-1-git-send-email-andreas@gaisler.com> (raw)
This makes memset follow the standard (instead of returning 0 on success). This
is needed when certain versions of gcc optimizes around memset calls and assume
that the address argument is preserved in %o0.
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
---
arch/sparc/lib/memset.S | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/arch/sparc/lib/memset.S b/arch/sparc/lib/memset.S
index 99c017b..f75e690 100644
--- a/arch/sparc/lib/memset.S
+++ b/arch/sparc/lib/memset.S
@@ -3,8 +3,9 @@
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
*
- * Returns 0, if ok, and number of bytes not yet set if exception
- * occurs and we were called as clear_user.
+ * Calls to memset returns initial %o0. Calls to bzero returns 0, if ok, and
+ * number of bytes not yet set if exception occurs and we were called as
+ * clear_user.
*/
#include <asm/ptrace.h>
@@ -65,6 +66,8 @@ __bzero_begin:
.globl __memset_start, __memset_end
__memset_start:
memset:
+ mov %o0, %g1
+ mov 1, %g4
and %o1, 0xff, %g3
sll %g3, 8, %g2
or %g3, %g2, %g3
@@ -89,6 +92,7 @@ memset:
sub %o0, %o2, %o0
__bzero:
+ clr %g4
mov %g0, %g3
1:
cmp %o1, 7
@@ -151,8 +155,8 @@ __bzero:
bne,a 8f
EX(stb %g3, [%o0], and %o1, 1)
8:
- retl
- clr %o0
+ b 0f
+ nop
7:
be 13b
orcc %o1, 0, %g0
@@ -164,6 +168,12 @@ __bzero:
bne 8b
EX(stb %g3, [%o0 - 1], add %o1, 1)
0:
+ andcc %g4, 1, %g0
+ be 5f
+ nop
+ retl
+ mov %g1, %o0
+5:
retl
clr %o0
__memset_end:
--
1.7.10.4
next reply other threads:[~2014-08-29 16:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-29 15:08 Andreas Larsson [this message]
2014-09-09 23:38 ` David Miller
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