From 1edad85b16fdda43c8ab809e2779e8bf64ab8bb2 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Thu, 26 Mar 2009 15:24:37 +0100
Subject: [S390] use compiler builtin versions of strlen/strcpy/strcat
Use builtin variants if gcc 4 or newer is used to compile the kernel.
Generates better code than the asm variants.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/lib/string.c | 8 ++++++++
1 file changed, 8 insertions(+)
(limited to 'arch/s390/lib/string.c')
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
index ae5cf5d03d41..4143b7c19096 100644
--- a/arch/s390/lib/string.c
+++ b/arch/s390/lib/string.c
@@ -44,7 +44,11 @@ static inline char *__strnend(const char *s, size_t n)
*/
size_t strlen(const char *s)
{
+#if __GNUC__ < 4
return __strend(s) - s;
+#else
+ return __builtin_strlen(s);
+#endif
}
EXPORT_SYMBOL(strlen);
@@ -70,6 +74,7 @@ EXPORT_SYMBOL(strnlen);
*/
char *strcpy(char *dest, const char *src)
{
+#if __GNUC__ < 4
register int r0 asm("0") = 0;
char *ret = dest;
@@ -78,6 +83,9 @@ char *strcpy(char *dest, const char *src)
: "+&a" (dest), "+&a" (src) : "d" (r0)
: "cc", "memory" );
return ret;
+#else
+ return __builtin_strcpy(dest, src);
+#endif
}
EXPORT_SYMBOL(strcpy);
--
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