On 2005-05-24 09:04:11 +0200, Uros Bizjak wrote: > I would like to point out that for applications that crunch data > from real world (no infinites or nans, where precision is not > critical) such as various simulations, -ffast-math is something that > can speed up application a lot.
But note that even when precision is not critical, you may get consistency problems or annoying unintuitive side effects. For instance, see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15134 where float x = 30.0; int main() { if ( 90.0/x != 3.0) abort(); return 0; } fails with -ffast-math (on x86). I would not recommend it, unless the user knows all the consequences. -- Vincent Lefèvre <[EMAIL PROTECTED]> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / SPACES project at LORIA
