diff options
Diffstat (limited to 'arch/sh/lib64/memcpy.c')
-rw-r--r-- | arch/sh/lib64/memcpy.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/sh/lib64/memcpy.c b/arch/sh/lib64/memcpy.c new file mode 100644 index 000000000000..fba436a92bfa --- /dev/null +++ b/arch/sh/lib64/memcpy.c | |||
@@ -0,0 +1,81 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2002 Mark Debbage (Mark.Debbage@superh.com) | ||
3 | * | ||
4 | * May be copied or modified under the terms of the GNU General Public | ||
5 | * License. See linux/COPYING for more information. | ||
6 | * | ||
7 | */ | ||
8 | |||
9 | #include <linux/types.h> | ||
10 | #include <asm/string.h> | ||
11 | |||
12 | // This is a simplistic optimization of memcpy to increase the | ||
13 | // granularity of access beyond one byte using aligned | ||
14 | // loads and stores. This is not an optimal implementation | ||
15 | // for SH-5 (especially with regard to prefetching and the cache), | ||
16 | // and a better version should be provided later ... | ||
17 | |||
18 | void *memcpy(void *dest, const void *src, size_t count) | ||
19 | { | ||
20 | char *d = (char *) dest, *s = (char *) src; | ||
21 | |||
22 | if (count >= 32) { | ||
23 | int i = 8 - (((unsigned long) d) & 0x7); | ||
24 | |||
25 | if (i != 8) | ||
26 | while (i-- && count--) { | ||
27 | *d++ = *s++; | ||
28 | } | ||
29 | |||
30 | if (((((unsigned long) d) & 0x7) == 0) && | ||
31 | ((((unsigned long) s) & 0x7) == 0)) { | ||
32 | while (count >= 32) { | ||
33 | unsigned long long t1, t2, t3, t4; | ||
34 | t1 = *(unsigned long long *) (s); | ||
35 | t2 = *(unsigned long long *) (s + 8); | ||
36 | t3 = *(unsigned long long *) (s + 16); | ||
37 | t4 = *(unsigned long long *) (s + 24); | ||
38 | *(unsigned long long *) (d) = t1; | ||
39 | *(unsigned long long *) (d + 8) = t2; | ||
40 | *(unsigned long long *) (d + 16) = t3; | ||
41 | *(unsigned long long *) (d + 24) = t4; | ||
42 | d += 32; | ||
43 | s += 32; | ||
44 | count -= 32; | ||
45 | } | ||
46 | while (count >= 8) { | ||
47 | *(unsigned long long *) d = | ||
48 | *(unsigned long long *) s; | ||
49 | d += 8; | ||
50 | s += 8; | ||
51 | count -= 8; | ||
52 | } | ||
53 | } | ||
54 | |||
55 | if (((((unsigned long) d) & 0x3) == 0) && | ||
56 | ((((unsigned long) s) & 0x3) == 0)) { | ||
57 | while (count >= 4) { | ||
58 | *(unsigned long *) d = *(unsigned long *) s; | ||
59 | d += 4; | ||
60 | s += 4; | ||
61 | count -= 4; | ||
62 | } | ||
63 | } | ||
64 | |||
65 | if (((((unsigned long) d) & 0x1) == 0) && | ||
66 | ((((unsigned long) s) & 0x1) == 0)) { | ||
67 | while (count >= 2) { | ||
68 | *(unsigned short *) d = *(unsigned short *) s; | ||
69 | d += 2; | ||
70 | s += 2; | ||
71 | count -= 2; | ||
72 | } | ||
73 | } | ||
74 | } | ||
75 | |||
76 | while (count--) { | ||
77 | *d++ = *s++; | ||
78 | } | ||
79 | |||
80 | return d; | ||
81 | } | ||