Re: 2*(void *) atomic swap?

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Sun, Aug 09, 2015 at 02:25:08PM +0200, Joerg Sonnenberger wrote:
> On Thu, Jul 30, 2015 at 06:23:33PM +0000, Taylor R Campbell wrote:
> >    I don't think you can have a portable function like that.
> > 
> > Not that hard:
> > 
> > - On i386, use cmpxchg8b.
> 
> Just for the archive, this effectively means Pentium+. There are
> actually 486-class SMP systems.

Heh.  There are 386-class SMP systems (including some massively parallel
ones, some of which even ran open-source operating systems) too.

We don't run on any of them.  I am pretty sure, though there may be some
vestigial code which in theory might have once made it possible, that we
never ran on and do not run on any 486 SMP systems either.

-- 
  Thor Lancelot Simon	                                     tls%panix.com@localhost

  "We cannot usually in social life pursue a single value or a single moral
   aim, untroubled by the need to compromise with others."      - H.L.A. Hart