Re: port-hp700/35531: iee0 does not work on 735/99

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

The following reply was made to PR port-hp700/35531; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
To: nick.hudson%gmx.co.uk@localhost
Cc: gnats-bugs%NetBSD.org@localhost, port-hp700-maintainer%NetBSD.org@localhost,
        gnats-admin%NetBSD.org@localhost, netbsd-bugs%NetBSD.org@localhost, 
root%garbled.net@localhost,
        tsutsui%ceres.dti.ne.jp@localhost
Subject: Re: port-hp700/35531: iee0 does not work on 735/99
Date: Tue, 5 May 2009 02:37:09 +0900

 nick.hudson%gmx.co.uk@localhost wrote:
 
 > I've tested this on my 715/50 against netbsd-5 as I've got too many changes 
 > in 
 > my -current source trees :)
 
 The same patch can be applied to -current too ;-)
 
 > >  As noted in comments, it might be better to detect chip revision
 > >  and switch flags at runtime, but I can't find how we ca do it
 > >  in the Intel manual.
 > 
 > Is it worth running IEE_SYSBUS_BE at all? Is there a big performance impact 
 > on 
 > the machines with rev C chips? If there isn't a big hit I'd say we just use 
 > iee(4) without IEE_SYSBUS_BE on hppa.
 
 The manual says "no software byteswap code is required on
 the enhanched BE mode" so the only difference is
 "(((x) << 16) | ((x) >> 16))" ops around 32 bit pointers,
 but I don't think they are so expensive.
 
 I'll commit the patch after some more tests.
 
 ---
 Izumi Tsutsui