There are performance options[0] that enable PGO, LTO and bolt, and are known to speed things up, maybe more significantly than -march and -mtune.

But I found one report[1] that says these compiler flags do (or did, some time ago) make a difference.

[0] https://docs.python.org/3/using/configure.html#performance-o...

[1] https://atleastfornow.net/posts/py3-enable-optimisations/