http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59305
--- Comment #10 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Rainer Orth from comment #9) > I see the same issue on some Solaris 10/SPARC systems on UltraSPARC T2: do you use the default mutex-based implementation for lib atomic? (I suspect that this is where the darwin slowness originates) if I configure --with-cpu=core2 (which allows 16b exchanges) the time drops from ~50m => 5m with the complex double tests dominating as you have.