Re: X32 psABI status

From: Joseph S. Myers
Date: Sun Feb 13 2011 - 12:38:05 EST


On Sun, 13 Feb 2011, Petr Baudis wrote:

> I think it would be great if you could add some text like this plus some
> rationale (AIUI, this is geared mainly at new Atoms and other x86_64
> embedded platforms) to the document.
>
> (BTW, it is not really convincing to me that such a niche is worth all
> the trouble this is going to bring.)

It seems to me there's a much more general utility for this. After all,
the normal practice on 64-bit Power Architecture GNU/Linux systems, say,
is for most programs to be 32-bit and only a few that have a use for a
large address space to be 64-bit. For most programs, large pointers and
size_t are just a waste of memory (and so of cache) - but the extra
registers are significantly beneficial (as are such things as being able
to assume SSE to be supported). (Large files, 64-bit time_t, etc.,
however, are of wider use than large address space, but as I noted in
<http://gcc.gnu.org/ml/gcc/2010-12/msg00509.html> it would be a fairly
substantial project to address all such issues of inappropriate arbitrary
limits in C APIs.)

--
Joseph S. Myers
joseph@xxxxxxxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/