ack/mach/i80/libem/dup.s
1985-03-18 12:46:51 +00:00

35 lines
419 B
ArmAsm

.define .dup
! Duplicate top bytes of stack
! Expects in de-registers: number of bytes to duplicate
.dup: mov a,e !trap if number is odd
rar
cc eoddz
pop h
shld .retadr
mov h,b
mov l,c
shld .bcreg
mov h,d
mov l,e
dad sp
1: dcx h
mov b,m
dcx h
mov c,m
push b
dcx d
dcx d !number of bytes must be a word-multiple i.e. even
mov a,d
ora e
jnz 1b
lhld .bcreg
mov b,h
mov c,l
lhld .retadr
pchl