glibc/string/strrchr.c
Adhemerval Zanella 167f6230af string: Improve generic strrchr with memrchr and strlen
Now that both strlen and memrchr have word vectorized implementation,
it should be faster to implement strrchr based on memrchr over the
string length instead of calling strchr on a loop.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu,
and powerpc64-linux-gnu by removing the arch-specific assembly
implementation and disabling multi-arch (it covers both LE and BE
for 64 and 32 bits).
2023-02-06 16:19:35 -03:00

38 lines
1.1 KiB
C

/* Copyright (C) 1991-2023 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 <string.h>
#undef strrchr
#ifndef STRRCHR
# define STRRCHR strrchr
#endif
/* Find the last occurrence of C in S. */
char *
STRRCHR (const char *s, int c)
{
return __memrchr (s, c, strlen (s) + 1);
}
#ifdef weak_alias
#undef rindex
weak_alias (strrchr, rindex)
#endif
libc_hidden_builtin_def (strrchr)