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Re: X32 psABI status
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@codesourcery.com