https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68955
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- It uses the wrong PHI arg value for the exit PHI of the unswitched loop It's unswitched on two conditions thus gets 4 loop copies but appearantly the m_lsm.28 exit PHI gets its arg from the PHI of the condition we unswitched on rather than the correct one (in two cases).