Years ago I discovered Chrome was optimizing with -march=x86-64, and knowing was an undocumented arch that would optimize for K8 I laughed at it and just removed that piece of idiocy from our fork of Chromium, so it would be faster than upstream. Recently though I noticed phoronix is also using now sometimes optimize with -march=x86-64 instead of using, well.. nothing. as they should. And checking recent GCC documentation I noticed that in gcc 8 and gcc 9 documentation you are now documenting -march=x86-64 and calling it a generic 64-bit processor. So now it is no longer a laughing matter that people mistake it for that.
I would suggest instead of fixing the documentation to say what -march=x86-64 actually does, that we should perhaps change it to do what people expect and make it an alias for generic? Best regards 'Allan