signbit
=======

POSIX specification: http://www.opengroup.org/onlinepubs/9699919799/functions/signbit.html

Gnulib module: signbit

Portability problems fixed by Gnulib:

  * This function is missing on some platforms: MacOS X 10.3, OpenBSD 3.8, AIX 5.1, IRIX 6.5, OSF/1 5.1, Solaris 10, Interix 3.5.

Portability problems not fixed by Gnulib: