[Bug target/94393] Powerpc suboptimal 64-bit constant comparison

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94393

--- Comment #6 from Segher Boessenkool <segher at gcc dot gnu.org> ---
It certainly would be nice to improve this :-)  It won't help most code
very much -- how often do two-word values happen at all -- but we have
to revisit how all this is decided anyway (for prefixed instructions),
so now would be a good time :-)