> (set (reg:SI 93) > (neg:SI (ltu:SI (reg:CCC 17 flags) (const_int 0 [0])))) > > as > > (set (reg:SI 93) > (neg:SI (ltu:SI (const_int 1) (const_int 0 [0])))) > > which leads to incorrect results since LTU on MODE_CC register isn't the > same as "unsigned less than" in x86 backend.
That's not specific to the x86 back-end, i.e. it's a generic caveat. > PR target/107172 > * config/i386/i386.md (UNSPEC_CC_NE): New. > Replace ne:CCC/ne:CCO with UNSPEC_CC_NE in neg patterns. FWIW the SPARC back-end uses a COMPARE instead of an UNSPEC here. -- Eric Botcazou
