/*- * SPDX-License-Identifier: MIT * * Copyright (c) 2005-2014 Rich Felker, et al. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); #include <string.h> #include <stdint.h> #include <limits.h> #define SS (sizeof(size_t)) #define ALIGN (sizeof(size_t)-1) #define ONES ((size_t)-1/UCHAR_MAX) #define HIGHS (ONES * (UCHAR_MAX/2+1)) #define HASZERO(x) (((x)-ONES) & ~(x) & HIGHS) void *memchr(const void *src, int c, size_t n) { const unsigned char *s = src; c = (unsigned char)c; #ifdef __GNUC__ for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--); if (n && *s != c) { typedef size_t __attribute__((__may_alias__)) word; const word *w; size_t k = ONES * c; for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS); s = (const void *)w; } #endif for (; n && *s != c; s++, n--); return n ? (void *)s : 0; } |