ack/mach/z80/libem/csa.s

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ArmAsm
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1985-03-29 21:44:50 +00:00
.define .csa
! this is not a subroutine, but just a
! piece of code that computes the jump-
! address and jumps to it.
! traps if resulting address is zero
.csa:
pop ix
pop hl
push bc
ld c,(ix)
ld b,(ix+1)
ld e,(ix+2)
ld d,(ix+3)
xor a
sbc hl,de
jp m,1f
ex de,hl
ld l,(ix+4)
ld h,(ix+5)
xor a
sbc hl,de
jp m,1f
ex de,hl
add hl,hl
ld de,6
add hl,de
ex de,hl
add ix,de
ld l,(ix)
ld h,(ix+1)
ld a,h
or l
jr nz,2f
1: ld a,b
or c
jr z,.trp.z
ld l,c
ld h,b
2: pop bc
jp (hl)