http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50724
--- Comment #11 from Ethan Tira-Thompson <ejtttje at gmail dot com> 2011-10-14 22:07:44 UTC --- Marc: is this code perusable? I'm curious because I expect either the calculations may generate NaN or not at all. If they might and you even have test cases to handle it, then I'm surprised you would ever want to support running with -ff-m-o. Conversely if you knew the code doesn't generate the nonfinite values, then you don't need the classifications in the first place...? I'm guessing (and apologies if this is inaccurate) that this might boil down to saying that you want to interpret an end user setting -ff-m-o as an opportunity to skip validating their input or skip doing assertions during its processing, which could be a reasonable thing to do, but that's a choice I'd rather leave to individual developers, e.g. can also wrap code with #if __FINITE_MATH_ONLY__==0 or such... Or in other words, it's only a missed optimization if you wind up with classification calls, whereas it's a full-fledged execution error when NaN gets past validation.
