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/Ethereal-msm8939-beta9/arch/m68k/lib/memcpy.c

https://bitbucket.org/MilosStamenkovic95/etherealos
C | 89 lines | 81 code | 3 blank | 5 comment | 11 complexity | 703bfcba21483061aa7ad213b2676a30 MD5 | raw file
 1/*
 2 * This file is subject to the terms and conditions of the GNU General Public
 3 * License.  See the file COPYING in the main directory of this archive
 4 * for more details.
 5 */
 6
 7#include <linux/module.h>
 8#include <linux/string.h>
 9
10void *memcpy(void *to, const void *from, size_t n)
11{
12	void *xto = to;
13	size_t temp;
14
15	if (!n)
16		return xto;
17	if ((long)to & 1) {
18		char *cto = to;
19		const char *cfrom = from;
20		*cto++ = *cfrom++;
21		to = cto;
22		from = cfrom;
23		n--;
24	}
25#if defined(CONFIG_M68000)
26	if ((long)from & 1) {
27		char *cto = to;
28		const char *cfrom = from;
29		for (; n; n--)
30			*cto++ = *cfrom++;
31		return xto;
32	}
33#endif
34	if (n > 2 && (long)to & 2) {
35		short *sto = to;
36		const short *sfrom = from;
37		*sto++ = *sfrom++;
38		to = sto;
39		from = sfrom;
40		n -= 2;
41	}
42	temp = n >> 2;
43	if (temp) {
44		long *lto = to;
45		const long *lfrom = from;
46#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
47		for (; temp; temp--)
48			*lto++ = *lfrom++;
49#else
50		size_t temp1;
51		asm volatile (
52			"	movel %2,%3\n"
53			"	andw  #7,%3\n"
54			"	lsrl  #3,%2\n"
55			"	negw  %3\n"
56			"	jmp   %%pc@(1f,%3:w:2)\n"
57			"4:	movel %0@+,%1@+\n"
58			"	movel %0@+,%1@+\n"
59			"	movel %0@+,%1@+\n"
60			"	movel %0@+,%1@+\n"
61			"	movel %0@+,%1@+\n"
62			"	movel %0@+,%1@+\n"
63			"	movel %0@+,%1@+\n"
64			"	movel %0@+,%1@+\n"
65			"1:	dbra  %2,4b\n"
66			"	clrw  %2\n"
67			"	subql #1,%2\n"
68			"	jpl   4b"
69			: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
70			: "0" (lfrom), "1" (lto), "2" (temp));
71#endif
72		to = lto;
73		from = lfrom;
74	}
75	if (n & 2) {
76		short *sto = to;
77		const short *sfrom = from;
78		*sto++ = *sfrom++;
79		to = sto;
80		from = sfrom;
81	}
82	if (n & 1) {
83		char *cto = to;
84		const char *cfrom = from;
85		*cto = *cfrom;
86	}
87	return xto;
88}
89EXPORT_SYMBOL(memcpy);