Re: Softfloat on i386

[Greg Troxel <gdt%lexort.com@localhost>]

David Holland <dholland-pkgtech%netbsd.org@localhost> writes:

>  >   Semi-restricted CPUs for embedded/SBC.  I have an apu2 which has
>  >     cpu0: AMD GX-412TC SOC                               , id 0x730f01
>  >   which runs amd64 but my previous one was a 586-ish geode.
>
> That's the exception to where I wrote "mostly" above. Rad-hardened
> devices for aerospace use in particular lag a long way behind. I don't
> know what the current state of things is but I wouldn't be surprised
> to see 586-ish and even 486-ish processors still floating around.
>
> OTOH, most people noodling with such devices also have build machines,
> and building your own i386 packages in a chroot on an amd64 build
> machine is not complicated. (Unlike many other combinations.)

Agreed.  I build packages for my pcengines apu2 on an i386 domU under
xen on a i7-12700 dom0.

>  >   Machines that were modern in 2003 but don't quite run amd64.
>  > 
>  >   Then there's true 486 from the 90s, which if desktoppy I sort into
>  >   retrocomputing.
>
> I'd describe both of these as retrocomputing. There's no reason to
> junk a running 20-year-old x86 if you have a mission for it that fits
> in its RAM. But there aren't many such missions, or so many
> still-working machines, and likely the power bill justifies replacing
> them anyway. :-|

More or less, but I sort "retrocomputing" if people are playing with
things because it is cool that they are old, and not retrocomputing if
they are using something because it can do what they want to do, even if
it is old.   I am running 2x RPI3 right now, and they are old and slow
and really not sensible, but it's easier to keep them running than replace.

> So I guess the question is: which parts of this audience are we really
> intending to cater to, and how much of it is pre-sse2 hardware? Or
> should we be running multiple sets of (maybe smaller) builds?
>
> (Obviously support or not support of something just in golang is not
> itself a reason to rearrange the set of builds we have or the
> subcategories of x86 they're intended for. But looking at that
> categorization periodically to see if it's still sensible is probably
> worthwhile.)

Maybe a poll is in order.  Your email more or less convinces me that
defaulting to building for CPUs w/o sse2 should be default.

I think my leaning to "assume sse2 as normal and people can rebuild"
comes from so many things that just don't work at all w/o sse2,
e.g. those that need 64-bit atomic operations, it seems.

Overall, I suspect almost everyone using i386 can rebuild a few
packages.  So I say let's not worry that much until actual people raise
actual complaints.