ack/mach/m68020/libem/aar.s
1988-10-03 10:53:47 +00:00

34 lines
734 B
ArmAsm

.define .aar
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
EILLINS = 18
.aar: ! (on entry d0 contains the integer size in the descriptor)
cmp.l #4, d0
beq 9f
move.l #EILLINS, -(sp)
jmp (.fatal)
9:
! register usage:
! a0: descriptor address
! a1: return address
! d0: index
! The address is calculated by taking the relative index
! (index - lower bound), multiplying that with the element
! size and adding the result to the array base address.
move.l (sp)+, a1 ! return address
move.l (sp)+, a0 ! descriptor address
move.l (sp)+, d0 ! index
sub.l (a0), d0 ! relative index
muls.l (8,a0), d0
move.l (sp)+, a0 ! array base address
add.l d0, a0 ! address of array element
jmp (a1) ! return
.align 2