~linaro-toolchain-dev/cortex-strings/trunk : contents of reference/bionic-c/bcopy.c at revision 123

~linaro-toolchain-dev/cortex-strings/trunk : (revision 123)

/*	$OpenBSD: bcopy.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <string.h>

/*
 * sizeof(word) MUST BE A POWER OF TWO
 * SO THAT wmask BELOW IS ALL ONES
 */
typedef	long word;		/* "word" used for optimal copy speed */

#define	wsize	sizeof(word)
#define	wmask	(wsize - 1)

/*
 * Copy a block of memory, handling overlap.
 * This is the routine that actually implements
 * (the portable versions of) bcopy, memcpy, and memmove.
 */
#ifdef MEMCOPY
void *
memcpy(void *dst0, const void *src0, size_t length)
#else
#ifdef MEMMOVE
void *
memmove(void *dst0, const void *src0, size_t length)
#else
void
bcopy(const void *src0, void *dst0, size_t length)
#endif
#endif
{
	char *dst = dst0;
	const char *src = src0;
	size_t t;

	if (length == 0 || dst == src)		/* nothing to do */
		goto done;

	/*
	 * Macros: loop-t-times; and loop-t-times, t>0
	 */
#define	TLOOP(s) if (t) TLOOP1(s)
#define	TLOOP1(s) do { s; } while (--t)

	if ((unsigned long)dst < (unsigned long)src) {
		/*
		 * Copy forward.
		 */
		t = (long)src;	/* only need low bits */
		if ((t | (long)dst) & wmask) {
			/*
			 * Try to align operands.  This cannot be done
			 * unless the low bits match.
			 */
			if ((t ^ (long)dst) & wmask || length < wsize)
				t = length;
			else
				t = wsize - (t & wmask);
			length -= t;
			TLOOP1(*dst++ = *src++);
		}
		/*
		 * Copy whole words, then mop up any trailing bytes.
		 */
		t = length / wsize;
		TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
		t = length & wmask;
		TLOOP(*dst++ = *src++);
	} else {
		/*
		 * Copy backwards.  Otherwise essentially the same.
		 * Alignment works as before, except that it takes
		 * (t&wmask) bytes to align, not wsize-(t&wmask).
		 */
		src += length;
		dst += length;
		t = (long)src;
		if ((t | (long)dst) & wmask) {
			if ((t ^ (long)dst) & wmask || length <= wsize)
				t = length;
			else
				t &= wmask;
			length -= t;
			TLOOP1(*--dst = *--src);
		}
		t = length / wsize;
		TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src);
		t = length & wmask;
		TLOOP(*--dst = *--src);
	}
done:
#if defined(MEMCOPY) || defined(MEMMOVE)
	return (dst0);
#else
	return;
#endif
}

69 by Michael Hope Added the C only routines from Bionic 4.04r2+20120606~gita985076b	1	/* $OpenBSD: bcopy.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
	2	/*-
	3	* Copyright (c) 1990 The Regents of the University of California.
	4	* All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* Chris Torek.
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in the
	16	* documentation and/or other materials provided with the distribution.
	17	* 3. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#include <string.h>
	35
	36	/*
	37	* sizeof(word) MUST BE A POWER OF TWO
	38	* SO THAT wmask BELOW IS ALL ONES
	39	*/
	40	typedef long word; /* "word" used for optimal copy speed */
	41
	42	#define wsize sizeof(word)
	43	#define wmask (wsize - 1)
	44
	45	/*
	46	* Copy a block of memory, handling overlap.
	47	* This is the routine that actually implements
	48	* (the portable versions of) bcopy, memcpy, and memmove.
	49	*/
	50	#ifdef MEMCOPY
	51	void *
	52	memcpy(void dst0, const void src0, size_t length)
	53	#else
	54	#ifdef MEMMOVE
	55	void *
	56	memmove(void dst0, const void src0, size_t length)
	57	#else
	58	void
	59	bcopy(const void src0, void dst0, size_t length)
	60	#endif
	61	#endif
	62	{
	63	char *dst = dst0;
	64	const char *src = src0;
65	size_t t;
66
67	if (length == 0 \|\| dst == src) /* nothing to do */
68	goto done;
69
70	/*
71	* Macros: loop-t-times; and loop-t-times, t>0
72	*/
73	#define TLOOP(s) if (t) TLOOP1(s)
74	#define TLOOP1(s) do { s; } while (--t)
75
76	if ((unsigned long)dst < (unsigned long)src) {
77	/*
78	* Copy forward.
79	*/
80	t = (long)src; /* only need low bits */
81	if ((t \| (long)dst) & wmask) {
82	/*
83	* Try to align operands. This cannot be done
84	* unless the low bits match.
85	*/
86	if ((t ^ (long)dst) & wmask \|\| length < wsize)
87	t = length;
88	else
89	t = wsize - (t & wmask);
90	length -= t;
91	TLOOP1(dst++ = src++);
92	}
93	/*
94	* Copy whole words, then mop up any trailing bytes.
95	*/
96	t = length / wsize;
97	TLOOP((word )dst = (word )src; src += wsize; dst += wsize);
98	t = length & wmask;
99	TLOOP(dst++ = src++);
100	} else {
101	/*
102	* Copy backwards. Otherwise essentially the same.
103	* Alignment works as before, except that it takes
104	* (t&wmask) bytes to align, not wsize-(t&wmask).
105	*/
106	src += length;
107	dst += length;
108	t = (long)src;
109	if ((t \| (long)dst) & wmask) {
110	if ((t ^ (long)dst) & wmask \|\| length <= wsize)
111	t = length;
112	else
113	t &= wmask;
114	length -= t;
115	TLOOP1(--dst = --src);
116	}
117	t = length / wsize;
118	TLOOP(src -= wsize; dst -= wsize; (word )dst = (word )src);
119	t = length & wmask;
120	TLOOP(--dst = --src);
121	}
122	done:
123	#if defined(MEMCOPY) \|\| defined(MEMMOVE)
124	return (dst0);
125	#else
126	return;
127	#endif
128	}