newlib-cygwin/newlib/libc/machine/h8300/reg_memcpy.S

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2000-02-18 03:39:52 +08:00
#include "defines.h"
#ifdef __H8300H__
.h8300h
#endif
#ifdef __H8300S__
.h8300s
#endif
; dst A0
; src A1
; len A2
.global ___reg_memcpy
___reg_memcpy:
MOVP A0P,A3P ; keep copy of result
ADDP A2P,A0P ; point to end of dst
ADDP A2P,A1P ; point to end of src
CMPP A0P,A3P ; see if anything to do
beq quit
loop: subs #1,A1P ; point to byte
mov.b @A1P,A2L ; get byte
mov.b A2L,@-A0P ; save byte
CMPP A0P,A3P ; at the front again ?
bne loop
; return with A0 pointing to dst
quit: rts