https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123792
--- Comment #3 from Wilco <wilco at gcc dot gnu.org> --- Note the SUB/CMP issue is due to peepholes only considering adjacent instructions. -fschedule-insns generates SUBS for the example, but slight variations like stdc_bit_ceil (n - 1) won't. Making these fusion pairs might be better.
