On 2013-10-13 11:34:42 +0200, Tom Lane wrote:
> Andres Freund <andres@2ndquadrant.com> writes:
> > I think we should remove support for the following architectures:
> > - superH
>
> This one was contributed just a year or two ago, if memory serves,
> which suggests that somebody out there cares about it. OTOH, if
> they still care, we could insist they provide whatever atomic ops
> we want to depend on.
It was 2009 - aac3c301b5e8178841e5749b3657c1a639ba06c1 . I haven't yet
verified if gcc's atomics support is acceptable for the platform
(checkout is running for the last 3h...).
If it's supported, falling back to that seems easy enough.
> > - PA-RISC. I think Tom was the remaining user there? Maybe just !gcc.
>
> Until pretty recently, there was a PA-RISC machine (not mine) in the
> buildfarm. I don't see it in the list today though. In any case,
> HP's compiler has always been a PITA, so no objection to requiring gcc
> for this platform.
The reason I'd like to generally get rid of PA-RISC is that it's the
only platform that doesn't seem to have any form of compare and
swap. GCC should provide fallbacks - with some warnings - using
spinlocks instead but I am afraid people will start doing things like
atomic operations in signal handlers that won't be noticed and will be a
PITA to debug.
Having read a fair amount of assembler looking at this I have to say,
anybody thinking LL/SC architectures are neat...
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services
