Updating multilib support after a compiler is built

[Jon Beniston]

Hi,

Is it possible to update the multilib combinations supported by GCC after it
has been built? (I would like to build some libraries optimised for
different CPUs variants, that aren't built by default).

I tried doing this via a specs file, but something like the following fails:

%rename multilib_matches old_multilib_matches
*multilib_matches:
mcpu=xyz mcpu=xyz;%(old_multilib_matches);

with:

multilib spec 'mcpu=xyz mcpu=xyz;%(old_multilib_matches);' is invalid

So it looks like GCC isn't performing substitutions for the %s in
multilib_matches specs. (The same seems to be true for  the other multilib
specs).

Perhaps there's a simpler way?

Cheers,
Jon