glibc/sysdeps/tile/tilegx/rawmemchr.c

46 lines
1.6 KiB
C

/* Copyright (C) 2011-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
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 <string.h>
#include <stdint.h>
#include "string-endian.h"
void *
__rawmemchr (const void *s, int c)
{
/* Get an aligned pointer. */
const uintptr_t s_int = (uintptr_t) s;
const uint64_t *p = (const uint64_t *) (s_int & -8);
/* Create eight copies of the byte for which we are looking. */
const uint64_t goal = copy_byte(c);
/* Read the first word, but munge it so that bytes before the array
will not match goal. */
const uint64_t before_mask = MASK (s_int);
uint64_t v = (*p | before_mask) ^ (goal & before_mask);
uint64_t bits;
while ((bits = __insn_v1cmpeq (v, goal)) == 0)
v = *++p;
return ((char *) p) + (CFZ (bits) >> 3);
}
libc_hidden_def (__rawmemchr)
weak_alias (__rawmemchr, rawmemchr)