https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105231
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #8)
> > Yes, but still the float_extend:XF would have made may_trap_p say
> > the insn possibly traps but there's no EH on it despite
> > -fnon-call-exceptions.
>
> The REG_EH note is added by make_reg_eh_region_note but then removed by
> purge_dead_edges because of the REG_EQUAL note:
>
> /* If this instruction cannot trap, remove REG_EH_REGION notes. */
> if (NONJUMP_INSN_P (insn)
> && (note = find_reg_note (insn, REG_EH_REGION, NULL)))
> {
> rtx eqnote;
>
> if (! may_trap_p (PATTERN (insn))
> || ((eqnote = find_reg_equal_equiv_note (insn))
> && ! may_trap_p (XEXP (eqnote, 0))))
> remove_note (insn, note);
> }
Interesting - so should combine maybe have this exception as well when it
tests for may_trap_p? Not sure if the above makes sense.
