Annotation of prex/usr/lib/libc/string/bcopy.c, Revision 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: }
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