8.518 log1p

POSIX specification:
http://www.opengroup.org/onlinepubs/9699919799/functions/log1p.html

Gnulib module: log1p

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This function is missing on some platforms: Minix 3.1.8, MSVC 9.