One final update for 2018: new gcc

[SMcNeill]

@SMcNeill
I don't know why I struck a wrong note with you, I have nothing against you and I am familiar with the gcc compiler options, the link I provided was not for you but for the rest who are not familiar with gcc's intrinsics.

No wrong note at all.  ;)

I just thought you might like the list of the complete options, as well as a better description of what those -O, -O2, and -O3 flags are actually doing.  :D

[FellippeHeitor]

All's working well on my Windows XP VM.