From:	nikki AT gameboutique DOT co (nikki)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Possible bug/misfeature in GCC
Date:	1 Feb 1997 11:03:25 GMT
Organization:	GameBoutique Ltd.
Lines:	24
Message-ID:	<5cv7tt$4b2@flex.uunet.pipex.com>
References:	<32F1A438 DOT 5509 AT rangenet DOT com>
NNTP-Posting-Host:	www.gameboutique.com
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> unsigned char inportb (int port)
> {
>   unsigned char c;
>   asm ("inb     %%dx, %%al"
>      : "=a" (c)
>      : "d" (port));
>   return c;
> }
> 

just a thought, would marking a and d as clobbered help at all?
ie. asm volatile ("inb %%dx,%%al"
		: "=a" (c)
		: "d" (port)
		: "al", "dx" ); ?
perhaps if gcc was forced to reload d each time it wouldn't be able to
optimise it by assuming the value in it was constant? mind you it might just
push it on a stack instead :)

regards,
nik
-- 
Graham Tootell           
nikki AT gameboutique DOT com  

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