undefined reference to `__sync_fetch_and_add_4' with OpenMP

[FX]

> 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?


-- 
FX Coudert
http://www.homepages.ucl.ac.uk/~uccafco/