Re: A86: Faster way (_ldhlind)?

To: assembly-86@lists.ticalc.org
Subject: Re: A86: Faster way (_ldhlind)?
From: Kirk Meyer <kirk008@ibm.net>
Date: Fri, 07 Aug 1998 18:46:10 -0600
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
References: <3.0.5.32.19980807182932.0087e9f0@tfs.net>
Reply-To: assembly-86@lists.ticalc.org


er the _ldhlind does this:

	ld a,(hl)
	inc hl
	ld l,(hl)
	ld a,h

which appears to be as short as yours, only A rather than DE is killed

David Phillips wrote:
> 
> Does anyone know how the rom call _ldhlind work?  It effectively does this
> operation:
> 
> ld hl,(hl)
> 
> This is useful when hl points to a pointer, and you want it to point to the
> data pointed to by that pointer (I hope you understood that, because I
> didn't).  What I came up with is below and worked out well because I needed
> to de to have the old pointer anyway, but is there a better routine (that
> doesn't destroy other regs)?
> 
>  ld d,(hl)      ; 7T
>  inc hl ; 6T
>  ld e,(hl)      ; 7T
>  ex hl,de       ; 4T
>                 ;==== 24 t-states, HL = (HL), DE = HL + 1
> 
> Thanks,
> 
> --
> David Phillips
> mailto:electrum@tfs.net
> ICQ: 13811951
> AOL/AIM: electrum32

-- 

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Follow-Ups:

Re: A86: Faster way (_ldhlind)?

From: David Phillips <electrum@tfs.net>

References:

A86: Faster way (_ldhlind)?

From: David Phillips <electrum@tfs.net>