https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92410
--- Comment #6 from Matthew Malcomson <matmal01 at gcc dot gnu.org> --- I believe the problem is that `remove_notes` followed by `reemit_notes` can generate these notes with a different UID. When `reemit_notes` adds the new note, the dataflow information is not updated automatically because `add_insn_before` only updates the information for INSN_P(insn). Hence the later lookup of this dataflow information is problematic. I'm not sure whether there's any pre-existing "should not use dataflow queries on notes" rule. If there is, then the regstat_bb_compute_calls_crossed function should be modified to check for NONDEBUG_INSN_P and continue earlier on its loop. If there isn't such a rule then I guess the best approach would be to ensure we call `df_insn_create_insn_record` whenever calling `emit_note_before` or `emit_note_after` once the dataflow information has been created. (assuming that notes don't need the information to be populated since `df_insn_rescan` seems to ignore notes). I've tried both moving the check for NONDEBUG_INSN_P in `regstat_bb_compute_calls_crossed` and adding a call to `df_insn_create_insn_record` into `reemit_notes` on a cross-compiler and both pass the testcase Martin found.
