glibc/wcsmbs/wcsnlen.c
Adhemerval Zanella 457208b1e9 wcsmbs: optimize wcsnlen
This patch rewrites wcsnlen using wmemchr.  The generic wmemchr
already uses the strategy (loop unrolling and tail handling) and
by using it it allows architectures that have optimized wmemchr
(s390 and x86_64) to optimize wcsnlen as well.

Checked on x86_64-linux-gnu.

	* wcsmbs/wcsnlen.c (__wcsnlen): Rewrite using wmemchr.
2019-02-27 10:00:37 -03:00

37 lines
1.2 KiB
C

/* Copyright (C) 1998-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <wchar.h>
#ifdef WCSNLEN
# define __wcsnlen WCSNLEN
#endif
/* Return length of string S at most maxlen. */
size_t
__wcsnlen (const wchar_t *s, size_t maxlen)
{
const wchar_t *ret = __wmemchr (s, L'\0', maxlen);
if (ret)
maxlen = ret - s;
return maxlen;
}
#ifndef WCSNLEN
weak_alias (__wcsnlen, wcsnlen)
#endif