On Sun, Feb 21, 2010 at 11:45:49AM -0800, Martin Guy wrote: > > You want to cater for a minority with old hardware. I > > actually expect you'll find that those users are less naive than the > > average gcc user. > I want to cater for everyone, especially youngsters, learners and the > poor struggling with whatever they can get their hands on. > It's not even a rich country/poor country thing: I live in a run down > industrial area of England where the local kids are gagging for > anything that works.
Let's step back a bit and look at the tradeoffs. I see two main inflection points where the choice of default has a real impact. First, you have to assume i486 if you want a libstdc++ that supports locking correctly. If you default to i386, you screw every user of an i486-or-later processor by giving them locking that doesn't work, for the benefit of a processor that hasn't been manufactured in several years, and was only used in embedded markets for a number of years before that. To me, that's a no-brainer; we should assume 486 and ask the tiny minority trying to make an ancient system work to use the appropriate switches. Right now, GNU/Linux distros are already doing that. The second inflection point is being able to assume enough SSE to generate improved floating point. Here, it seems less clear that it's better to change the default, as it's more possible that the users of older systems that you champion could be impacted.
