[Bug rtl-optimization/98178] Combine splitter does not split to single instruction

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98178

--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Yup, this is true in general, we almost never say why we don't combine so
far.  Patches welcome!  (Make sure you use TDF_DETAILS for such prints).