Subject: Re: More ELF stuff
To: Stephen Borrill <netbsd@brio.precedence.co.uk>
From: Richard Earnshaw <rearnsha@arm.com>
List: port-arm26
Date: 02/15/2001 11:00:11
> On Wed, 14 Feb 2001, Richard Earnshaw wrote:
> > Even with existing processors, only the ARM7500FE has been
> > shipped with an FPA in significant numbers, and on netbsd we still don't
> > make a use of it.
> >
> > So, to the question. If I knock up a hack to the compiler and assembler
> > so that for NetBSD/ARM/ELF they change to a pure little-endian floating
> > point format, would there be any objections?
>
> I guess that depends on whether there is ever likely to be support for the
> FPA in the ARM7500FE. If the answer is no, then do it. However, I would
> expect a speed up for X11 with an FPA and I'm quite interested in using
> things like NCs as X terminals. They are not overendowed with processing
> power and so any gain would be useful.
>
Well, is there? It would only happen if someone volunteered to do it.
IIRC most of the float code in X is single-precision. It might be
possible to knock up a version of the compiler that could just use the FPA
for single-precision operations and revert to libcalls for doubles. This
would then make X operations much more efficient while still allowing us
to switch to the new word endian format.
R.