http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47945
--- Comment #4 from Thomas Henlich <thenlich at users dot sourceforge.net> 2011-03-01 14:44:54 UTC --- (In reply to comment #3) > 0.14285714285714284921875000000000 is still within the accuracy of IEEE > double. > All numbers map to the same IEEE double. This is technically correct; however a program should also observe portability and usability rules and not just pick any number from a valid range, but the number which is the most useful to the program user: either the one most common across platforms and other compilers (0.14285714285714284921269268124888) or the "shortest" one (0.14285714285714285000000000000000). It is very hard to compare long numeric result listings obtained on different platforms/compilers if some digits (however insignificant) never match.
