1  /* Copyright (C) 1996-2023 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  
      24  wchar_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  }
      62  libc_hidden_def (__wmemchr)
      63  weak_alias (__wmemchr, wmemchr)
      64  libc_hidden_weak (wmemchr)