log2
====

POSIX specification: http://www.opengroup.org/susv3xsh/log2.html

Gnulib module: ---

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  * This function is missing on some platforms: MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, IRIX 6.5, Solaris 9, Cygwin.