9.398 hypot

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

Gnulib module: hypot or hypot-ieee

Portability problems fixed by either Gnulib module hypot or hypot-ieee:

Portability problems fixed by Gnulib module hypot-ieee:

• When the arguments are mixed NaN and Infinity, this function returns a wrong value on some platforms: OSF/1 5.1, mingw, MSVC 9.

Portability problems not fixed by Gnulib: