[Bug rtl-optimization/89310] Poor code generation returning float field from a struct

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89310

--- Comment #6 from Segher Boessenkool <segher at gcc dot gnu.org> ---
rldicr is one of the insns generated by "*rotl<mode>3_mask", which
recognises all canonical formulations of all our rotate-and-mask
instructions.