DE_mod_HL by Xeda

DE_mod_HL:
;Inputs:
;     HL is an odd 16-bit number
     bit 7,h
     jr nz,$+6
       add hl,hl
       jp p,$-1   ;21
     ex de,hl
;DE is a modulus thingy
;HL is the number
     or a
ModLoop:
     sbc hl,de    ;15
     jr nc,$+3    ;12+6b
     add hl,de    ;--
     sra d        ;8
     rr e         ;8
     jr nc,ModLoop;12|7
     ret
;1313 max
;76a+6b+83, a is at most 15, b is at most 15