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 | * unsigned int csum_partial(const unsigned char *buff, | |
11 | * int len, unsigned int sum) | |
12 | */ | |
13 | .text | |
14 | .global csum_partial | |
15 | .type csum_partial,"function" | |
16 | .align 1 | |
17 | csum_partial: | |
18 | /* checksum complete words, aligned or not */ | |
19 | 3: sub r11, 4 | |
20 | brlt 5f | |
21 | 4: ld.w r9, r12++ | |
22 | add r10, r9 | |
23 | acr r10 | |
24 | sub r11, 4 | |
25 | brge 4b | |
26 | ||
27 | /* return if we had a whole number of words */ | |
28 | 5: sub r11, -4 | |
29 | reteq r10 | |
30 | ||
31 | /* checksum any remaining bytes at the end */ | |
32 | mov r9, 0 | |
33 | mov r8, 0 | |
34 | cp r11, 2 | |
35 | brlt 6f | |
36 | ld.uh r9, r12++ | |
37 | sub r11, 2 | |
38 | breq 7f | |
39 | lsl r9, 16 | |
40 | 6: ld.ub r8, r12++ | |
41 | lsl r8, 8 | |
42 | 7: or r9, r8 | |
43 | add r10, r9 | |
44 | acr r10 | |
45 | ||
46 | retal r10 | |
47 | .size csum_partial, . - csum_partial |