[patch] m68k: Fix binary compatibility problem with -mno-strict-align. (Take 2)

Nathan Sidwell nathan@codesourcery.com
Wed Aug 29 17:14:00 GMT 2007


Roman Zippel wrote:

> I see.
> What concerns me here is that this produces incompatibilities for ColdFire 
> code between Linux and other targets. It also makes the support for this 
> in libffi interesting (e.g. if you ever want Java support for ColdFire).

Agreed.  But unfortunately it is what it is.  There's more to ABIs than just 
whether structures are returned in memory.  For instance, %d0 and %a0 are used 
differently too wrt structure returning.  And of course there are other ABI 
considerations too.

> Since this is a special case I would seriously consider to ignore the 
> alignment mode for this in m68k_return_in_memory. Since this is an ABI 
> issue there probably should be an option to get the old behaviour.

I'm strongly in favour of not breaking existing ABIs.

nathan

-- 
Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery



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