63 lines
844 B
ArmAsm
63 lines
844 B
ArmAsm
.sect .text; .sect .rom; .sect .data; .sect .bss
|
|
.sect .text
|
|
.define .rmu4
|
|
|
|
yl=6
|
|
yh=8
|
|
xl=10
|
|
xh=12
|
|
|
|
.rmu4:
|
|
push si
|
|
push di
|
|
mov si,sp ! copy of sp
|
|
mov bx,yl(si)
|
|
mov ax,yh(si)
|
|
or ax,ax
|
|
jne 7f
|
|
1:
|
|
xor dx,dx
|
|
mov cx,xl(si)
|
|
mov ax,xh(si)
|
|
2:
|
|
div bx
|
|
xchg ax,cx
|
|
div bx
|
|
xor bx,bx
|
|
9:
|
|
! bx is high order result
|
|
! dx is low order result
|
|
mov ax,dx
|
|
mov dx,bx
|
|
pop di
|
|
pop si
|
|
ret 8 ! result in ax/dx
|
|
|
|
7:
|
|
mov di,ax
|
|
xor bx,bx
|
|
mov ax,xl(si)
|
|
mov dx,xh(si)
|
|
mov cx,16
|
|
1:
|
|
shl ax,1
|
|
rcl dx,1
|
|
rcl bx,1
|
|
cmp di,bx
|
|
ja 3f
|
|
jb 2f
|
|
cmp yl(si),dx
|
|
jbe 2f
|
|
3:
|
|
loop 1b
|
|
! dx=result(low), bx=result(high)
|
|
jmp 9b
|
|
2:
|
|
sub dx,yl(si)
|
|
sbb bx,di
|
|
inc ax
|
|
loop 1b
|
|
1:
|
|
! dx=result(low), bx=result(high)
|
|
jmp 9b
|