Difference between revisions of "Programming:Integer Division"

Revision as of 21:33, 4 August 2006

32bit division

Input: IY,BC=Value1, IX=Value2

Output: IY,BC=Value1/Value2, HL=Value1 MOD Value2

Destroyed: AF,DE,IY

clcd32c db 0
clcd32  ld hl,0
        db #dd:ld a,l
        db #dd:or h
        ret z           ;IY,BC=Value1(Counter)
        ld de,0         ;DE,HL=CalcVar
        ld a,32         ;Set Counter to 32
clcd321 ld (clcd32c),a
        rl c
        rl b
        db #fd:ld a,l:rla:db #fd:ld l,a
        db #fd:ld a,h:rla:db #fd:ld h,a
        rl l
        rl h
        rl e
        rl d
        ld a,l
        db #dd:sub l
        ld l,a
        ld a,h
        db #dd:sbc h
        ld h,a
        ld a,e
        sbc 0
        ld e,a
        ld a,d
        sbc 0
        ld d,a
        jr nc,clcd322
        ld a,l
        db #dd:add l
        ld l,a
        ld a,h
        db #dd:adc h
        ld h,a
        ld a,e
        adc 0
        ld e,a
        ld a,d
        adc 0
        ld d,a
        scf
clcd322 ccf
        ld a,(clcd32c)
        dec a
        jr nz,clcd321   ;HL=Value1 MOD Value2
        rl c
        rl b
        db #fd:ld a,l:rla:db #fd:ld l,a
        db #fd:ld a,h:rla:db #fd:ld h,a
        ret             ;IY,BC=Value1 DIV Value2