ack/mach/6500/libem/ret.s

44 lines
902 B
ArmAsm
Raw Normal View History

1984-12-17 11:03:13 +00:00
.define Ret
! This subroutine stores the returnvalue in the return area.
! This area is in zeropage.
! The size of the object to be returned is in zeropage location
! RETSIZE.
! It also restores the localbases and the stackpointer of the
! invoking procedure.
Ret:
sty RETSIZE ! save returnsize
beq 1f ! the return size is zero
lda #0 ! address of returnvalue area (highbyte)
ldx #RETURN ! address of returnvalue area (lowbyte)
cpy #2
bne 2f
jsr Sti ! store word
jmp 1f
2: cpy #4
jsr Sdi ! store fourbyte word
1: ldx LB ! get old stackpointer (lowbyte)
stx SP+2
lda LB+1 ! get old stackpointer (highbyte)
sta SP+1
inc LB
inc LB
bne 1f
inc LB+1
1: jsr Pop ! get old localbase
stx LB ! localbase (lowbyte)
sta LB+1 ! localbase (highbyte)
pha
sec
txa
sbc #BASE
sta LBl ! second localbase (lowbyte)
pla
sbc #0
sta LBl+1 ! second localbase (highbyte)
rts