cvs commit: src/lib/libc/i386/net htonl.S ntohl.S

[David Schultz]

On Wed, Oct 20, 2004, Peter Jeremy wrote:
> On Tue, 2004-Oct-19 18:52:31 -0400, David Schultz wrote:
> >First of all, your 80386 (if it worked) would probably be much
> >snappier running FreeBSD 3.X or 4.X or NetBSD 1.[2-5].
> 
> It is a lot easier to administer a collection of machines that are
> all running close-to-the-same software.  And FreeBSD 2.x is probably
> a better match for 386-class hardware (the memory and disk footprint
> is much smaller).

Yes, so please don't try to justify continued support for i386 if
you don't have a running i386.  Every time this bikeshed comes up,
there is no shortage of people who rally behind hardware they
don't have.

> >> > Nice.  \me can't wait for the day when developers are no longer
> >> > required to spend time and effort to support anything older than a PPro.
> >> 
> >> That day will hopefully be far in the future. Personally I don't have
> >> anything as modern as a PPro.
> >
> >Don't worry, it will be.  I can dream, can't I?
> 
> The 486 and Pentium provide useful new instructions and system controls.
> What benefits does a PPro provide as far as the kernel and core userland
> is concerned?

Now we're really getting sidetracked.  The main new feature of
interest for me (and admittedly not for most other people) is MMX,
for a couple of bad reasons.  First, gcc generates slightly more
correct floating-point code with MMX.  Second, as long as we
support !MMX, we would have to multilib the math library in order
to make it work correctly with programs compiled for newer
processors, in particular with respect to the floating-point
exception flags.  Granted, a few Pentium I chips have MMX support,
too.  But when you consider that the PPro also has CMOV and FCMOV,
that the scheduling is fundamentally different for all processors
after the Pentium, and that we currently have several hacks for
Pentium I errata, drawing the line at PPro makes sense.

But all this talk is all moot because if history is any lesson,
this isn't going to happen for another decade.  (Moreover, there
*are* still plenty of FreeBSD users out there with Pentiums.)