ack/mach/m68020/libem/exg.s
1987-01-29 22:10:18 +00:00

21 lines
305 B
ArmAsm

.define .exg
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
! d0 : exchange size in bytes
.exg:
lea (4,sp,d0), a0 ! address of bottom block
lea (4,sp), a1 ! address of top block
asr.l #2, d0
sub.l #1, d0
1:
move.l (a1), d1
move.l (a0), (a1)+
move.l d1, (a0)+
dbf d0, 1b
rts
.align 2