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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/m68k/lib/memcpy.c
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/*

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 * This file is subject to the terms and conditions of the GNU General Public

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 * License.  See the file COPYING in the main directory of this archive

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 * for more details.

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 */

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#include <linux/module.h>

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#include <linux/string.h>

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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 defined(CONFIG_M68000)

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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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#endif

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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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	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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#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)

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		for (; temp; temp--)

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			*lto++ = *lfrom++;

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#else

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		size_t temp1;

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		asm volatile (

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			"	movel %2,%3\n"

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			"	andw  #7,%3\n"

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			"	lsrl  #3,%2\n"

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			"	negw  %3\n"

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			"	jmp   %%pc@(1f,%3:w:2)\n"

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			"4:	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"	movel %0@+,%1@+\n"

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			"1:	dbra  %2,4b\n"

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			"	clrw  %2\n"

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			"	subql #1,%2\n"

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			"	jpl   4b"

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			: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)

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			: "0" (lfrom), "1" (lto), "2" (temp));

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#endif

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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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}

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EXPORT_SYMBOL(memcpy);

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