[A83] Re: Division

To: assembly-83@lists.ticalc.org
Subject: [A83] Re: Division
From: Patai Gergely <patai.ti@freemail.hu>
Date: Thu, 29 Nov 2001 23:24:13 +0100 (CET)
In-Reply-To: <000e01c1791c$5212bf10$0201a8c0@brinstar>
Reply-To: assembly-83@lists.ticalc.org


> Divide:
>  push bc  ; save bc
>  sub a    ; clear a
>  ld b,8   ; 8 shifts
> DivideL:
>  sla d    ; shift left d
>  rla    ; into a
>  cp c    ; is a >= c
>  jr c,DivideS ; skip if not
>  sub c
>  inc d   ; a = a-c, set bit in d
> DivideS:
>  djnz DivideL  ; loop
>  pop bc   ; restore bc
>  ret   ; done
> 
I have two problems with this routine:

1. It should be unrolled, if speed is important.
(if not, the rom routine is undoubtedly the best choice)

2. the dividend can only be 8 bits long,
which is basically useless for general
purposes.

PG

References:

[A83] Re: Division

From: "David Phillips" <david@acz.org>

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