Programming:Integer Division
From CPCWiki - THE Amstrad CPC encyclopedia!
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