2 @section @code{signbit}
5 POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/signbit.html}
9 Portability problems fixed by Gnulib:
12 This function is missing on some platforms:
13 Mac OS X 10.13, OpenBSD 6.7, AIX 5.1, IRIX 6.5, Solaris 11.0, MSVC 9, Android 9.0.
16 Portability problems not fixed by Gnulib: