Is a OpenSSL hint valid ?
/me wonders if this warning should be still emitted :
[notice] We were built to run on a 64-bit CPU, with OpenSSL 1.0.1 or later, but with a version of OpenSSL that apparently lacks accelerated support for the NIST P-224 and P-256 groups. Building openssl with such support (using the enable-ec_nistp_64_gcc_128 option when configuring it) would make ECDH much faster.
as long as there are serious concerns related to that OpenSSL feature in this bug report : https://bugs.gentoo.org/show_bug.cgi?id=469976