[Bug target/87949] PowerPC saves CR registers across calls

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87949

--- Comment #8 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Bill Schmidt from comment #4)
> Seems like a potential opportunity for shrink-wrap separate on the CRs.  I'm
> not sure whether that's implemented yet.

It isn't; there are some technical problems to implement it.  Nothing that
cannot be overcome though.

The benefit wouldn't be huge; a much bigger benefit can be had by not using
non-volatile CR fields in the first place.