| /* Copyright (C) 2011-2014 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> |
| |
| void * |
| __rawmemchr (const void *s, int c) |
| { |
| /* Get an aligned pointer. */ |
| const uintptr_t s_int = (uintptr_t) s; |
| const uint32_t *p = (const uint32_t *) (s_int & -4); |
| |
| /* Create four copies of the byte for which we are looking. */ |
| const uint32_t goal = 0x01010101 * (uint8_t) c; |
| |
| /* Read the first word, but munge it so that bytes before the array |
| will not match goal. Note that this shift count expression works |
| because we know shift counts are taken mod 32. */ |
| const uint32_t before_mask = (1 << (s_int << 3)) - 1; |
| uint32_t v = (*p | before_mask) ^ (goal & before_mask); |
| |
| uint32_t bits; |
| while ((bits = __insn_seqb (v, goal)) == 0) |
| v = *++p; |
| |
| return ((char *) p) + (__insn_ctz (bits) >> 3); |
| } |
| libc_hidden_def (__rawmemchr) |
| weak_alias (__rawmemchr, rawmemchr) |