Re: [rfc] alpha-linux changing to 128-bit long double

[Jakub Jelinek <jakub at redhat dot com>]

On Sat, Mar 06, 2004 at 09:58:26PM -0800, Richard Henderson wrote:
> So I'm thinking that I'd like to finally get around to changing to
> 128-bit long double for alpha-linux.  I'm undecided how to go about
> doing this though.
> 
> The math routines would be easy to version, but things like printf
> definitely aren't.  Because of that, I was thinking that perhaps
> it might be best to just increment the soname to libc.so.6.2.  Which
> would be a good opportunity to get rid of some awful compatibility
> code in the alpha-linux glibc bits.
> 
> I would be comfortable getting all this done for glibc 2.3.4, and
> just say "use an older release if you don't want this abi change."
> Seems to me the ifdeffery (and worse, makefile ifdeffery) would be
> too awful to considering supporting both modes simultaneously.

On the other side, Alpha is not the only arch which want long double
and changing SONAME is really painful.  alpha, sparc32 and ppc*
are on the same boat.
Compatibility cruft can be easily solved with Ulrich's
attribute_compat_text_section.

http://sources.redhat.com/ml/libc-hacker/2002-08/msg00102.html
was my initial attempt to handle this (even including support for
compilation with 64bit or 128bit long double), it just did not handle
*printf/*scanf, but I wrote in there how could that be solved.

I can revive this patch, finish it and it could be then used on
alpha/sparc32/ppc*.

	Jakub