85 строки
1.1 KiB
ArmAsm
85 строки
1.1 KiB
ArmAsm
;;; memcpy.S
|
|
|
|
#include <asm/linkage.h>
|
|
|
|
#if defined(__H8300H__)
|
|
.h8300h
|
|
#endif
|
|
#if defined(__H8300S__)
|
|
.h8300s
|
|
#endif
|
|
|
|
.text
|
|
.global _memcpy
|
|
|
|
;;; void *memcpy(void *to, void *from, size_t n)
|
|
_memcpy:
|
|
mov.l er2,er2
|
|
bne 1f
|
|
rts
|
|
1:
|
|
;; address check
|
|
bld #0,r0l
|
|
bxor #0,r1l
|
|
bcs 4f
|
|
mov.l er4,@-sp
|
|
mov.l er0,@-sp
|
|
btst #0,r0l
|
|
beq 1f
|
|
;; (aligned even) odd address
|
|
mov.b @er1,r3l
|
|
mov.b r3l,@er0
|
|
adds #1,er1
|
|
adds #1,er0
|
|
dec.l #1,er2
|
|
beq 3f
|
|
1:
|
|
;; n < sizeof(unsigned long) check
|
|
sub.l er4,er4
|
|
adds #4,er4 ; loop count check value
|
|
cmp.l er4,er2
|
|
blo 2f
|
|
;; unsigned long copy
|
|
1:
|
|
mov.l @er1,er3
|
|
mov.l er3,@er0
|
|
adds #4,er0
|
|
adds #4,er1
|
|
subs #4,er2
|
|
cmp.l er4,er2
|
|
bcc 1b
|
|
;; rest
|
|
2:
|
|
mov.l er2,er2
|
|
beq 3f
|
|
1:
|
|
mov.b @er1,r3l
|
|
mov.b r3l,@er0
|
|
adds #1,er1
|
|
adds #1,er0
|
|
dec.l #1,er2
|
|
bne 1b
|
|
3:
|
|
mov.l @sp+,er0
|
|
mov.l @sp+,er4
|
|
rts
|
|
|
|
;; odd <- even / even <- odd
|
|
4:
|
|
mov.l er4,er3
|
|
mov.l er2,er4
|
|
mov.l er5,er2
|
|
mov.l er1,er5
|
|
mov.l er6,er1
|
|
mov.l er0,er6
|
|
1:
|
|
eepmov.w
|
|
mov.w r4,r4
|
|
bne 1b
|
|
dec.w #1,e4
|
|
bpl 1b
|
|
mov.l er1,er6
|
|
mov.l er2,er5
|
|
mov.l er3,er4
|
|
rts
|