glibc/wcsmbs/wmemchr.c

65 lines
1.5 KiB
C

/* Copyright (C) 1996-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <wchar.h>
#ifdef WMEMCHR
# define __wmemchr WMEMCHR
#endif
wchar_t *
__wmemchr (const wchar_t *s, wchar_t c, size_t n)
{
/* For performance reasons unfold the loop four times. */
while (n >= 4)
{
if (s[0] == c)
return (wchar_t *) s;
if (s[1] == c)
return (wchar_t *) &s[1];
if (s[2] == c)
return (wchar_t *) &s[2];
if (s[3] == c)
return (wchar_t *) &s[3];
s += 4;
n -= 4;
}
if (n > 0)
{
if (*s == c)
return (wchar_t *) s;
++s;
--n;
}
if (n > 0)
{
if (*s == c)
return (wchar_t *) s;
++s;
--n;
}
if (n > 0)
if (*s == c)
return (wchar_t *) s;
return NULL;
}
libc_hidden_def (__wmemchr)
weak_alias (__wmemchr, wmemchr)
libc_hidden_weak (wmemchr)