Subject: Re: 64bit divide
To: Izumi Tsutsui <>
From: Garrett D'Amore <>
List: port-mips
Date: 07/10/2006 08:31:38
Izumi Tsutsui wrote:
> wrote:
>> I'm porting a VR4120A based micro to netbsd.
>> I've got the initial setup done, console, cache etc
>  :
>> The div_d routine is in arch/mips/mips though so I would
>> not have thought endian had anything to do with it.
> I'm afraid there are few people who tried mips SOFTFLOAT code
> on big endian environment. (anyone tried it on alchemy?)

I run alchemy little endian, because there are some ugly PCI quirks when
it runs big endian.

I'll try to take a look at this on AR5312, which also runs big endian.

> I guess you would have to add some #if _BYTE_ORDER
> like locore_mips3.S to swap high/low words in some
> 64bit functions.
> BTW, do NEC VR41xx processors work properly on big endian?
> I heard a rumour that some embedded peripherals didn't work
> on big endian since they were designed for WindowsCE.

Alchemy PCI works far better in little endian mode.  I don't recall the
precise details offhand, but I know it was something for which there
wasn't a simple workaround.

    -- Garrett
> ---
> Izumi Tsutsui

Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
Phone: 951 325-2134  Fax: 951 325-2191