https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113485
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Note the issue is really: 9730 rtx op = lowpart_subreg (<VNARROWQ2>mode, operands[1], <VNARROWQ>mode); We have: (subreg:V8QI (reg/v:V4x8QI 110 [ input_pixels ]) 8) And then lowpart_subreg returns null. Note I still have my doubts about aarch64_get_shareable_reg, especially when spread across different splits.