http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52053
--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-01-30 14:28:13 UTC --- This is not a bug: 16777216. == 2.0**24, then you can add 1.0 as much as you like without changing the result. If one want a bug here, it is a missed optimization as SUM does not seem to be vectorized (one day I should compile libgfortran with -O3 and the option allowing operations to be reordered).
