undefined reference to `__sync_fetch_and_add_4' with OpenMP

[Richard Guenther]

On Feb 7, 2008 2:12 PM, FX <fxcoudert@gmail.com> wrote:
> > You need a CPU that supports __sync_fetch_and_add_4 - I suppose
> > you add -march=i486 (at least).  (You run on 32bit ia32, right?)
>
> Thanks Richard, I never realized that. As a matter of fact, the
> binaries I build and distribute for Linux, MacOS and Windows, are
> configure with --build=i386-*. I did it because I thought it might be
> best not to exclude any particular processor type, but if good OpenMP
> support requires more that i386, I will probably change it to i586 (so
> that people have a good first experience with gfortran, without having
> to add -march). Does anyone see a reason why i686 would be still
> better than i586? Is there anyone around here who still uses a bare
> i{3,4}86 are would like to complain about that change?

I think configuring for i586 is what most distributions do nowadays (apart
from debian, which uses i486 I think).  Already i486 adds most of the
stuff, i586 only adds cmov if I remember correctly.

Richard.