Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 17 Jul 2001 14:48:58 -0700 (PDT)
From:      John Baldwin <jhb@FreeBSD.org>
To:        Matthew Jacob <mjacob@feral.com>
Cc:        hackers@FreeBSD.org, Terry Lambert <tlambert2@mindspring.com>
Subject:   RE: x86 unaligned access followup.
Message-ID:  <XFMail.010717144858.jhb@FreeBSD.org>
In-Reply-To: <20010717095413.G83710-100000@wonky.feral.com>

next in thread | previous in thread | raw e-mail | index | archive | help

On 17-Jul-01 Matthew Jacob wrote:
> 
> 
>> Actually, since the 486, it's been possible for us to turn on unaligned
>> access exceptions on the x86.  We should probably consider doing this, to
>> ensure better performance, and to avoid the unnecessary bus overhead we
>> eat for unaligned access today... not to mention how it could shake out
>> the drivers.
> 
> 
> Now *that* is a very cool idea. As Johnny Carson would say "I did not know
> that". How would this be done? I assume it's some bit-flip for the chip?
> D'ya have a sample bit 'o code for this?

It's the AC bit in eflags.

> -matt

-- 

John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?XFMail.010717144858.jhb>