As I'm currently working on a compiler from a madeup language for compiler lectures, I had to find a rather decently fast division algorithm for ARM9, which is my target platform, since DIV command was introduced not sooner than ARM11 architecture.

So I found a simple divison algorithm, that speeds up basic “school child” subtractive division with shifting:

```
CMP R2, #0
BEQ divide_end
;check for divide by zero!
MOV R0,#0 ;clear R0 to accumulate result
MOV R3,#1 ;set bit 0 in R3, which will be
;shifted left then right
.start
CMP R2,R1
MOVLS R2,R2,LSL#1
MOVLS R3,R3,LSL#1
BLS start
;shift R2 left until it is about to
;be bigger than R1
;shift R3 left in parallel in order
;to flag how far we have to go
.next
CMP R1,R2 ;carry set if R1>R2 (don't ask why)
SUBCS R1,R1,R2 ;subtract R2 from R1 if this would
;give a positive answer
ADDCS R0,R0,R3 ;and add the current bit in R3 to
;the accumulating answer in R0
MOVS R3,R3,LSR#1 ;Shift R3 right into carry flag
MOVCC R2,R2,LSR#1 ;and if bit 0 of R3 was zero, also
;shift R2 right
BCC next ;If carry not clear, R3 has shifted
;back to where it started, and we
;can end
.divide_end
MOV R25, R24 ;exit routine
```

More in-depth description of the algorithm workings is available on the source site.