POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/log2f.html}
-Gnulib module: log2f
+Gnulib module: log2f or log2f-ieee
-Portability problems fixed by Gnulib:
+Portability problems fixed by either Gnulib module @code{log2f} or @code{log2f-ieee}:
@itemize
@item
This function is missing on some platforms:
Cygwin 1.7.9.
@end itemize
+Portability problems fixed by Gnulib module @code{log2f-ieee}:
+@itemize
+@item
+This function returns a wrong value for a negative argument on some platforms:
+NetBSD 5.1, Solaris 11 2011-11.
+@end itemize
+
Portability problems not fixed by Gnulib:
@itemize
@end itemize