[Bug libstdc++/50724] isnan broken by -ffinite-math-only in g++

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50724

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-10-14 09:15:35 UTC ---
With -ffinite-math-only you are telling that there are no NaNs and thus
GCC optimizes isnan (x) to 0.  That math.h "works" probably means it has
isnan implemented as macro expanding to inline assmbler.