-.mul16::
-.mulu16::
- LD HL,#0x00 ; Product = 0
- LD A,#15 ; Count = bit length - 1
- ;; Shift-and-add algorithm
- ;; If MSB of multiplier is 1, add multiplicand to partial product
- ;; Shift partial product, multiplier left 1 bit
-.mlp:
- SLA E ; Shift multiplier left 1 bit
- RL D
- JR NC,.mlp1 ; Jump if MSB of multiplier = 0
- ADD HL,BC ; Add multiplicand to partial product
-.mlp1:
- ADD HL,HL ; Shift partial product left
- DEC A
- JR NZ,.mlp ; Continue until count = 0
- ;; Add multiplicand one last time if MSB of multiplier is 1
- BIT 7,D ; Get MSB of multiplier
- JR Z,.mend ; Exit if MSB of multiplier is 0
- ADD HL,BC ; Add multiplicand to product
-.mend:
- RET ; HL = result