So they wanted to speed up numpy and machine learning algs and I have no idea how I was going to do it.<p>To cut a long story short, I compiled python 3 for servers with a customized makefile:<p>```
./configure --enable-optimizations --with-lto
```<p>and then, I replaced `-O3` in make file with `-Ofast`.<p>That was it. And of course, I wonder why these are not defaults.<p>--