Re: ABI choice for MIPS on debian lenny?

[Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>]

Laurent GUERBY <laurent@guerby.net> writes:

> Hi,

Hi,
>
> On debian lenny I'm playing with GCC trunk (4.4) to build a tri-ABI
> compiler on a lemote netbook (running gnewsense kernel and lenny
> userspace).
>
> My understanding is that lenny userspace is -mabi=32 (o32) and
> GCC and libc support abi=32,n32,64, the kernel being 64.
>
> n32 seems to be more performant than 32, 

fwiw, it would be also interesting to compare o32 with -march=mips3 with
n32. I'm not sure that in such kind of case the differences will be
big. 

> do you know why it is not used by default? 

I think only irix is using it by default :)
As regards linux, imho, nobody's using it due to the amount of bugs
hidden waiting for a fix (this is a guess, maybe there are better
reason).

> Is it unsupported on some hardware?

iirc you need mips3 or newer ISA. I'm not sure that there are 64bit
mips not fitting in this category.

Arnaud