https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113609
--- Comment #1 from Hongtao Liu <liuhongt at gcc dot gnu.org> --- 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.
