1/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <wchar.h>
19
20#ifdef WMEMCHR
21# define __wmemchr WMEMCHR
22#endif
23
24wchar_t *
25__wmemchr (const wchar_t *s, wchar_t c, size_t n)
26{
27 /* For performance reasons unfold the loop four times. */
28 while (n >= 4)
29 {
30 if (s[0] == c)
31 return (wchar_t *) s;
32 if (s[1] == c)
33 return (wchar_t *) &s[1];
34 if (s[2] == c)
35 return (wchar_t *) &s[2];
36 if (s[3] == c)
37 return (wchar_t *) &s[3];
38 s += 4;
39 n -= 4;
40 }
41
42 if (n > 0)
43 {
44 if (*s == c)
45 return (wchar_t *) s;
46 ++s;
47 --n;
48 }
49 if (n > 0)
50 {
51 if (*s == c)
52 return (wchar_t *) s;
53 ++s;
54 --n;
55 }
56 if (n > 0)
57 if (*s == c)
58 return (wchar_t *) s;
59
60 return NULL;
61}
62libc_hidden_def (__wmemchr)
63weak_alias (__wmemchr, wmemchr)
64libc_hidden_weak (wmemchr)
65

source code of glibc/wcsmbs/wmemchr.c