This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: lib{atomic, itm}/configure.tgt uses -mcpu=v9 as default for sparc
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Carlos Sánchez de La Lama <csanchezdll at gmail dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 02 Jun 2014 22:30:48 +0200
- Subject: Re: lib{atomic, itm}/configure.tgt uses -mcpu=v9 as default for sparc
- Authentication-results: sourceware.org; auth=none
- References: <daz8upf8y2z dot fsf at sdf dot lonestar dot org> <4871468 dot TDuAmUELpQ at polaris> <dazwqcz7d9e dot fsf at sdf dot lonestar dot org>
> I have successfully built without the switch, but I am not sure of the
> effects at runtime.
For sure libitm cannot work, there is a 'flushw' in config/sparc/sjlj.S.
> If V9 is indeed required, is there a way to build without those libs? Or
> has pre V9 support been dropped at some point?
No, V8 is still supported, but nobody has ported the libraries to it.
> IMHO an efficiency enhancement should not prevent running less
> efficiently on a supported architecture. If target triple is
> sparcv9-*-*, the next case will match and will add the "-mcpu=v9" to
> XCFLAGS, but adding it for non-v9 sparc-*-* targets is at least weird.
Well, V9 is about 20 years old now so defaulting to it is not unreasonable,
especially for all the native OSes. But patches are of course welcome.
--
Eric Botcazou