ack/mach/m68k4/libem/ara.s
1985-02-07 22:06:32 +00:00

104 lines
1.8 KiB
ArmAsm

.define .sar
.define .lar
.define .aar
!register usage:
! a0 : descriptor address
! d0 : index
! a1 : base address
.text
.aar:
movem.l d0/d1/a0/a1,.savreg
move.l (sp)+,.retara ! return address
move.l (sp)+,a0 ! descriptor address
move.l (sp)+,d0 ! index
move.l (sp)+,a1 ! base address
sub.l (a0),d0 ! index - lower bound : relative index
move.l 8(a0),-(sp) ! # bytes / element
move.l d0,-(sp)
jsr .mlu
add.l d1,a1 ! address of element
move.l a1,-(sp) ! returned on stack
move.l .retara,-(sp)
movem.l d0/d1/a0/a1,.savreg
rts
.lar:
! register usage: like .aar
! d2 : # bytes / element
movem.l d0/d1/d2/a0/a1,.savreg
move.l (sp)+,.retara ! return address
move.l (sp)+,a0
move.l (sp)+,d0
move.l (sp)+,a1
sub.l (a0),d0
move.l 8(a0),d2 ! # bytes / element
move.l d0,-(sp)
move.l d2,-(sp)
jsr .mlu
add.l d1,a1 ! address of element
add.l d2,a1 ! a1++ because of predecrement
clr.l d1 !?nodig?
asr #1,d2
bne 3f
move.b -(a1),d1 ! 1 byte element
move.l d1,-(sp)
bra 5f
3:
asr #1,d2
bne 4f
move.w -(a1),d1 ! 2 byte element
move.l d1,-(sp)
bra 5f
4:
sub.l #1,d2
1:
move.l -(a1),-(sp) ! 4n byte element (n = 1,2,...)
dbf d2,1b
5:
move.l .retara,-(sp)
movem.l .savreg,d0/d1/d2/a0/a1
rts
.sar:
!register usage: same as lar
movem.l d0/d1/a0/a1,.savreg
move.l (sp)+,.retara
move.l (sp)+,a0
move.l (sp)+,d0
move.l (sp)+,a1
sub.l (a0),d0
move.l 8(a0),d2 ! # bytes / element
move.l d0,-(sp)
move.l d2,-(sp)
jsr .mlu
add.l d1,a1
clr.l d1 !?nodig?
asr #1,d2
bne 3f
move.l (sp)+,d1
move.b d1,(a1) ! 1 byte element
bra 4f
3:
asr #1,d2
bne 5f
move.l (sp)+,d1
move.w d1,(a1) ! 2 byte element
bra 4f
5:
sub.l #1,d2
1:
move.l (sp)+,(a1)+ ! 4n byte element (n = 1,2,...)
dbf d2,1b
4:
move.l .retara,-(sp)
movem.l .savreg,d0/d1/a0/a1
rts
.data
.retara: .long 0
.align 2