diff options
Diffstat (limited to 'arch/avr32/lib/memcpy.S')
| -rw-r--r-- | arch/avr32/lib/memcpy.S | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/avr32/lib/memcpy.S b/arch/avr32/lib/memcpy.S new file mode 100644 index 0000000..0abb261 --- /dev/null +++ b/arch/avr32/lib/memcpy.S @@ -0,0 +1,62 @@ +/* + * 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: sub r10, 4 + mov r9, r12 + 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 + 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 + rjmp 2b |