https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113609
--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Hongtao Liu from comment #1) > Since they're different modes, CCZ for cmp, but CCS for kortest, it could be > diffcult to optimize it in RA stage by adding alternatives(like we did for > compared to 0). So the easy way could be adding peephole to hanlde that. You can use pre-reload split for this. Please see for example how *jcc_bt<mode> and *bt<mode>_setcqi provide compound operation (constructed from CCZmode compare) that is later split to CCCmode operation. You will have to provide jcc and setcc patterns to fully handle mode change.
