Commit | Line | Data |
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5f97f7f9 HS |
1 | /* |
2 | * Copyright (C) 2004-2006 Atmel Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | /* | |
10 | * void *memcpy(void *to, const void *from, unsigned long n) | |
11 | * | |
12 | * This implementation does word-aligned loads in the main loop, | |
13 | * possibly sacrificing alignment of stores. | |
14 | * | |
15 | * Hopefully, in most cases, both "to" and "from" will be | |
16 | * word-aligned to begin with. | |
17 | */ | |
18 | .text | |
19 | .global memcpy | |
20 | .type memcpy, @function | |
21 | memcpy: | |
22 | mov r9, r11 | |
23 | andl r9, 3, COH | |
24 | brne 1f | |
25 | ||
26 | /* At this point, "from" is word-aligned */ | |
505d62d0 SAS |
27 | 2: mov r9, r12 |
28 | 5: sub r10, 4 | |
5f97f7f9 HS |
29 | brlt 4f |
30 | ||
31 | 3: ld.w r8, r11++ | |
32 | sub r10, 4 | |
33 | st.w r12++, r8 | |
34 | brge 3b | |
35 | ||
36 | 4: neg r10 | |
37 | reteq r9 | |
38 | ||
39 | /* Handle unaligned count */ | |
40 | lsl r10, 2 | |
41 | add pc, pc, r10 | |
42 | ld.ub r8, r11++ | |
43 | st.b r12++, r8 | |
44 | ld.ub r8, r11++ | |
45 | st.b r12++, r8 | |
46 | ld.ub r8, r11++ | |
47 | st.b r12++, r8 | |
48 | retal r9 | |
49 | ||
50 | /* Handle unaligned "from" pointer */ | |
51 | 1: sub r10, 4 | |
251ab1a3 | 52 | movlt r9, r12 |
5f97f7f9 HS |
53 | brlt 4b |
54 | add r10, r9 | |
55 | lsl r9, 2 | |
56 | add pc, pc, r9 | |
57 | ld.ub r8, r11++ | |
58 | st.b r12++, r8 | |
59 | ld.ub r8, r11++ | |
60 | st.b r12++, r8 | |
61 | ld.ub r8, r11++ | |
62 | st.b r12++, r8 | |
505d62d0 SAS |
63 | mov r8, r12 |
64 | add pc, pc, r9 | |
65 | sub r8, 1 | |
66 | nop | |
67 | sub r8, 1 | |
68 | nop | |
69 | sub r8, 1 | |
70 | nop | |
71 | mov r9, r8 | |
72 | rjmp 5b |