117 lines
3.1 KiB
C
117 lines
3.1 KiB
C
/* $OpenBSD: strlen.c,v 1.8 2014/06/10 04:17:37 deraadt Exp $ */
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/*-
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <string.h>
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size_t
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strlen(const char *str)
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{
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const char *s;
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for (s = str; *s; ++s)
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;
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return (s - str);
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}
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/**
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* memcpy - Copies one area of memory to another
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* @dest: Destination
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* @src: Source
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* @n: The size to copy.
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*/
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void *memcpy(void *to, const void *from, size_t n)
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{
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void *xto = to;
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size_t temp;
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if(!n)
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return xto;
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if((long)to & 1) {
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char *cto = to;
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const char *cfrom = from;
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*cto++ = *cfrom++;
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to = cto;
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from = cfrom;
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n--;
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}
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if((long)from & 1) {
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char *cto = to;
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const char *cfrom = from;
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for (; n; n--)
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*cto++ = *cfrom++;
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return xto;
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}
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if(n > 2 && (long)to & 2) {
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short *sto = to;
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const short *sfrom = from;
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*sto++ = *sfrom++;
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to = sto;
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from = sfrom;
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n -= 2;
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}
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if((long)from & 2) {
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short *sto = to;
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const short *sfrom = from;
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temp = n >> 1;
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for (; temp; temp--)
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*sto++ = *sfrom++;
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to = sto;
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from = sfrom;
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if(n & 1) {
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char *cto = to;
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const char *cfrom = from;
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*cto = *cfrom;
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}
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return xto;
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}
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temp = n >> 2;
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if(temp) {
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long *lto = to;
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const long *lfrom = from;
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for(; temp; temp--)
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*lto++ = *lfrom++;
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to = lto;
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from = lfrom;
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}
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if(n & 2) {
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short *sto = to;
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const short *sfrom = from;
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*sto++ = *sfrom++;
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to = sto;
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from = sfrom;
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}
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if(n & 1) {
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char *cto = to;
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const char *cfrom = from;
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*cto = *cfrom;
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}
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return xto;
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} |