5 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/floorf.html}
9 Portability problems fixed by Gnulib:
12 This function is missing on some platforms:
13 AIX 5.1, HP-UX 11, Solaris 9.
16 Portability problems not fixed by Gnulib: