https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114567
--- Comment #1 from Kewen Lin <linkw at gcc dot gnu.org> --- This is power8 LE specific, for KFmode its mov expander calls rs6000_emit_le_vsx_move, so it's with V1TI subreg, then rs6000 specific pass swaps generate one MEM with AND -16, which make combine unable to optimize it with that *signbit<mode>2_dm_mem pattern due to mode_dependent_address_p returning false always for AND. Although it looks to me we can extend mode_dependent_address_p to consider the to-mode in that context, it's still sub-optimal due to the existence of AND -16, which result in an explicit "and" then.
