xref: /openbmc/linux/arch/m68k/lib/memcpy.c (revision 261a9af6)
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 
10 void *memcpy(void *to, const void *from, size_t n)
11 {
12 	void *xto = to;
13 	size_t temp, temp1;
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 (n > 2 && (long)to & 2) {
26 		short *sto = to;
27 		const short *sfrom = from;
28 		*sto++ = *sfrom++;
29 		to = sto;
30 		from = sfrom;
31 		n -= 2;
32 	}
33 	temp = n >> 2;
34 	if (temp) {
35 		long *lto = to;
36 		const long *lfrom = from;
37 #if defined(__mc68020__) || defined(__mc68030__) || \
38     defined(__mc68040__) || defined(__mc68060__) || defined(__mcpu32__)
39 		asm volatile (
40 			"	movel %2,%3\n"
41 			"	andw  #7,%3\n"
42 			"	lsrl  #3,%2\n"
43 			"	negw  %3\n"
44 			"	jmp   %%pc@(1f,%3:w:2)\n"
45 			"4:	movel %0@+,%1@+\n"
46 			"	movel %0@+,%1@+\n"
47 			"	movel %0@+,%1@+\n"
48 			"	movel %0@+,%1@+\n"
49 			"	movel %0@+,%1@+\n"
50 			"	movel %0@+,%1@+\n"
51 			"	movel %0@+,%1@+\n"
52 			"	movel %0@+,%1@+\n"
53 			"1:	dbra  %2,4b\n"
54 			"	clrw  %2\n"
55 			"	subql #1,%2\n"
56 			"	jpl   4b"
57 			: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
58 			: "0" (lfrom), "1" (lto), "2" (temp));
59 #else
60 		for (; temp; temp--)
61 			*lto++ = *lfrom++;
62 #endif
63 		to = lto;
64 		from = lfrom;
65 	}
66 	if (n & 2) {
67 		short *sto = to;
68 		const short *sfrom = from;
69 		*sto++ = *sfrom++;
70 		to = sto;
71 		from = sfrom;
72 	}
73 	if (n & 1) {
74 		char *cto = to;
75 		const char *cfrom = from;
76 		*cto = *cfrom;
77 	}
78 	return xto;
79 }
80 EXPORT_SYMBOL(memcpy);
81