projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 |