flame
Make (even more) sure that user doesn't unknowingly build with generic subconfig
A spin-off from issue #358: "BLIS should warn loudly when CPU type can't be detected."
Are you suggesting outputting this message to stderr? It would take some rejiggering since I'd need to communicate to BLIS the difference between intentional vs. non-intentional use of generic.
Yessir. People should know when they're getting the reference implementation, because it is probably not what they want or expected.
Commit c40a331, which addresses #384, inserted a (relatively) loud warning at the end of the configure output whenever auto-detection returns the generic subconfig; however, it did not (in addition to the configure warning) insert any runtime message to stderr, as @devinamatthews suggested. The reason is simply that I prefer not outputting anything, even to stderr, unless (a) we're calling abort() anyway, or (b) the user asked for that output.
But I have an alternative solution that I think will satisfy @devinamatthews's original concern: only allow the auto-detect component of configure to select the generic subconfiguration if the user provides a special option at configure-time (e.g. --allow-auto-generic). Under this regime, if the auto-detection returns generic and the user failed to provide --allow-auto-generic, configure outputs an explanatory message and simply refuses to proceed unless the user re-runs with that option. (Attempting to run make at that point would result in a vanilla error message from the Makefile along the lines of "please run configure first".)
