[Bug target/114004] GCC emits a superfluous instruction for simple test case on ppc

[segher at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114004

--- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> ---
So, the rlwinm keeps all the top 32 bits intact, but those are all zero to
begin
with.  Somehow we don't see that, or don't take that into account anyway.