rand (eZ80 optimized)

rand:
;;Input: A is the range.
;;Output: Returns in A a random number from 0 to (input)A-1.
;;  B=0
;;  DE is a pseudo-random 16-bit integer.
;;Destroys:
;;  HL
;;Speed:
    push af
    call prng24
    ex de,hl
    pop af
    or a \ sbc hl,hl
    ld b,h
    add a,a \ jr nc,$+5 \ push de \ pop hl
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ jr nc,$+4 \ add hl,de \ adc a,b
    add hl,hl \ rla \ ret nc \ add hl,de \ adc a,b
    ret