ack/mach/m68k4/libem/sar.s
1987-03-27 09:47:16 +00:00

59 lines
1 KiB
ArmAsm

.define .sar
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
! (on entry d0 contains the integer size in the descriptor)
.sar:
cmp.l #4, d0
beq 9f
move.l #EILLINS, -(sp)
jmp .fatal
9:
! register usage:
! a0: descriptor address, later base address
! a1: return address
! d0: index
! d2: # bytes / element
! For address calculation; see comment in 'aar.s'.
! If the element size is a fraction of EM_WSIZE (4)
! the calculation is done by adding.
move.l (sp)+,a1 ! return address
move.l (sp)+, a0
move.l (sp)+, d0
sub.l (a0), d0
move.l 8(a0), d2 ! # bytes / element
move.l (sp)+, a0
clr.l d1
cmp.l #1, d2
bne 2f
move.l (sp)+, d1
move.b d1, 0(a0, d0.l) ! store one byte element
bra 5f
2:
cmp.l #2, d2
bne 4f
asl.l #1, d0
move.l (sp)+, d1
move.w d1, 0(a0, d0.l) ! store two byte element
bra 5f
4: ! here: 4n byte element
move.l a0,-(sp)
move.l d0, -(sp)
move.l d2, -(sp)
jsr .mlu
move.l (sp)+,a0
add.l d1, a0 ! address of 4n byte element
asr.l #2, d2
sub.l #1, d2
1:
move.l (sp)+, (a0)+
dbf d2, 1b
5:
jmp (a1)
.align 2