https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90671
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Created attachment 46431 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46431&action=edit gcc10-pr90671.patch Untested fix. If during the first call the template block is empty, neither gsi_split_seq_after nor gsi_insert_seq_after can actually work. My understanding is in that case we want to hide the whole bb_seq from the create_block_for_threading because it contains only debug stmts we do not want to copy there.