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Mail Archives: djgpp-workers/2003/05/22/13:19:22

Message-ID: <0be401c32086$3feaba00$0600000a@broadpark.no>
From: "Gisle Vanem" <giva AT bgnett DOT no>
To: <djgpp-workers AT delorie DOT com>
References: <200305221512 DOT RAA06143 AT lws256 DOT lu DOT erisoft DOT se>
Subject: Re: Add with carry
Date: Thu, 22 May 2003 19:19:06 +0200
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Reply-To: djgpp-workers AT delorie DOT com

> > I was just hit by this elsewhere in some 16-bit nasm code. 
> > To increment a 32-bit variable I used
> >   inc word [di]
> >   adc word [di+2], 0
> > 
> > Seems resonable, but got wrong result cause the carry
> > was already set. Adding a 'clc' before the 'inc' fixed it.
> 
> inc and dec don't affect the carry flag. add, adc, sub etc. do.

Obs, must have been thinking of the AUX flag.
 
--gv

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