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Annotation of prex-old/usr/lib/libc/string/bcopy.c, Revision 1.1.1.1

1.1       nbrk        1: /*-
                      2:  * Copyright (c) 1990, 1993
                      3:  *     The Regents of the University of California.  All rights reserved.
                      4:  *
                      5:  * This code is derived from software contributed to Berkeley by
                      6:  * Chris Torek.
                      7:  *
                      8:  * Redistribution and use in source and binary forms, with or without
                      9:  * modification, are permitted provided that the following conditions
                     10:  * are met:
                     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. Redistributions in binary form must reproduce the above copyright
                     14:  *    notice, this list of conditions and the following disclaimer in the
                     15:  *    documentation and/or other materials provided with the distribution.
                     16:  * 3. Neither the name of the University nor the names of its contributors
                     17:  *    may be used to endorse or promote products derived from this software
                     18:  *    without specific prior written permission.
                     19:  *
                     20:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     21:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     22:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     23:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     24:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     25:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     26:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     27:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     28:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     29:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     30:  * SUCH DAMAGE.
                     31:  */
                     32:
                     33: #include <sys/cdefs.h>
                     34: #include <string.h>
                     35:
                     36: /*
                     37:  * Copy a block of memory, handling overlap.
                     38:  * This is the routine that actually implements
                     39:  * (the portable versions of) bcopy, memcpy, and memmove.
                     40:  */
                     41: #ifdef MEMCOPY
                     42: void *
                     43: memcpy(dst0, src0, length)
                     44: #else
                     45: #ifdef MEMMOVE
                     46: void *
                     47: memmove(dst0, src0, length)
                     48: #else
                     49: void
                     50: bcopy(src0, dst0, length)
                     51: #endif
                     52: #endif
                     53:        void *dst0;
                     54:        const void *src0;
                     55:        size_t length;
                     56: {
                     57:        char *dst = dst0;
                     58:        const char *src = src0;
                     59:
                     60:        if (length == 0 || dst == src)          /* nothing to do */
                     61:                goto done;
                     62:
                     63:        if (((unsigned long)dst < (unsigned long)src) &&
                     64:            ((unsigned long)dst < (unsigned long)src + length)) {
                     65:                /* Copy backwards. */
                     66:                src += length;
                     67:                dst += length;
                     68:                while (length--) {
                     69:                        *--dst = *--src;
                     70:                }
                     71:        } else {
                     72:                while (length--) {
                     73:                        *dst++ = *src++;
                     74:                }
                     75:        }
                     76: done:
                     77: #if defined(MEMCOPY) || defined(MEMMOVE)
                     78:        return (dst0);
                     79: #else
                     80:        return;
                     81: #endif
                     82: }