| /* | |
| * Copyright (C) 2004-2006 Atmel Corporation | |
| * | |
| * This program is free software; you can redistribute it and/or modify | |
| * it under the terms of the GNU General Public License version 2 as | |
| * published by the Free Software Foundation. | |
| */ | |
| /* | |
| * void *memcpy(void *to, const void *from, unsigned long n) | |
| * | |
| * This implementation does word-aligned loads in the main loop, | |
| * possibly sacrificing alignment of stores. | |
| * | |
| * Hopefully, in most cases, both "to" and "from" will be | |
| * word-aligned to begin with. | |
| */ | |
| .text | |
| .global memcpy | |
| .type memcpy, @function | |
| memcpy: | |
| mov r9, r11 | |
| andl r9, 3, COH | |
| brne 1f | |
| /* At this point, "from" is word-aligned */ | |
| 2: mov r9, r12 | |
| 5: sub r10, 4 | |
| brlt 4f | |
| 3: ld.w r8, r11++ | |
| sub r10, 4 | |
| st.w r12++, r8 | |
| brge 3b | |
| 4: neg r10 | |
| reteq r9 | |
| /* Handle unaligned count */ | |
| lsl r10, 2 | |
| add pc, pc, r10 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| retal r9 | |
| /* Handle unaligned "from" pointer */ | |
| 1: sub r10, 4 | |
| movlt r9, r12 | |
| brlt 4b | |
| add r10, r9 | |
| lsl r9, 2 | |
| add pc, pc, r9 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| ld.ub r8, r11++ | |
| st.b r12++, r8 | |
| mov r8, r12 | |
| add pc, pc, r9 | |
| sub r8, 1 | |
| nop | |
| sub r8, 1 | |
| nop | |
| sub r8, 1 | |
| nop | |
| mov r9, r8 | |
| rjmp 5b |