[Bug rtl-optimization/101523] Huge number of combine attempts

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101523

--- Comment #29 from Segher Boessenkool <segher at gcc dot gnu.org> ---
I did manage to build one, but it does not know _Float64x and stuff.

Do you have a basic C-only testcase, maybe?