Re: build fix for x86_64...

From: H. Peter Anvin
Date: Fri Jul 20 2007 - 18:35:18 EST


Luck, Tony wrote:
> At the moment our problem is that there is some code that has
> been added to handle the compatability problem caused by u64
> objects having different alignment when running on 32-bit and
> 64-bit systems. This only affects ia64 and x86-64 because all
> the other 32/64 bit capable systems wisely avoided this issue
> by making 64-bit objects *always* 8-byte aligned.

> It is possible that in the future more such issues will arise
> (either because we find some more existing interfaces that
> have this problem, or because new interfaces are introduced
> that also have this problem). Such new code will also require
> some compatability functions. These functions will also only
> be needed on ia64 and x86-64, and even on these systems the
> code will only be needed if CONFIG_COMPAT=y

The issue here is I was looking at it from a new interfaces perspective,
and not from a legacy interfaces perspective. However, for new
interfaces we want the opposite -- properly aligned elements -- so
please disregard previous objection.

However, I'm still thinking it might be worthwhile to consider the
__i[us]64 typedefs previously discussed as a way to avoid alignment
bloopers in new interfaces.

-hpa
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