------- Comment #2 from jv244 at cam dot ac dot uk 2007-10-15 15:30 ------- (In reply to comment #1) > As Fortran allows open-coding of integral powers this is not a bug. But > I'll leave final closing as INVALID to more fortran-knowing people.
I agree that Fortran-wise this is not a bug. However, gcc tends to do some of the things that Fortran allows by default (x/y -> x*(1/y) ; x+Y+z -> (x=z)+y ; ..) only at -ffast-math. AFAIK, this seems to be the only optimisation in gcc that causes numerical results with CP2K to change going from -O0 to -O3. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33780
