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Re: changing the SPARC default
- From: Alexey Starovoytov <alexey dot starovoytov at sun dot com>
- To: Joel Sherrill <joel dot sherrill at oarcorp dot com>
- Cc: Jiri Gaisler <jiri at gaisler dot com>, Ralf Corsepius <ralf dot corsepius at rtems dot org>, <gcc at gcc dot gnu dot org>
- Date: Thu, 16 Mar 2006 18:51:59 -0800 (PST)
- Subject: Re: changing the SPARC default
> Debian has been running with V8PLUS as the default since the sarge release
> cycles started. I.e. years.
looking at linux64.h it seems that the default Linux config is -m64 -mcpu=v9.
Are you saying that Debian configured gcc package for -m32 -mcpu=v9?
How about other Linux distributions?
I saw one with gcc 4.0.3 configured with -mcpu=v7 whereas the Linux kernel
there was 64-bit. Seems very strange to me.
On Thu, 16 Mar 2006, Joel Sherrill wrote:
> Jiri Gaisler wrote:
> > I would therefore suggest that the gcc defaults for
> > sparc-elf and sparc-linux stays as is (V7) while the
> > solaris 10+ can safely be modified to V9.
> I can't speak for GNU/Linux or Solaris but I can speak for the
> embedded community. Don't break the embedded sparc support
> (e.g. sparc-elf and sparc-rtems*) for V7 and don't change the default
> for those. V7 is viable and alive in the embedded world even if
> it is no longer in use in workstations.
Agree. embedded sparcs should be kept at v7.
It seems everybody agreed that solaris 10+ can be changed to -mcpu=v9 default.
What are the thoughts about Solaris 7,8,9 ?
They don't run on embedded sparcs and the legacy of sun4c, sun4m, sun4d
systems can now be found mostly on ebay alongside 8bit ISA video card.
Really, solaris gcc users of sun4c rarity can always configure gcc with
--with_cpu=v7 or v8. Most of the solaris gcc users are on ultra2 and 3
and should see immediate benefit of better default.
I guess it's worth to sacrifice the convenience of the default install
for sun4c users, so the rest solaris gcc users can have better performance.