> fwprop may propagate a SET_SRC that contains the last use of a REG to a > later point, but it will leave the REG_DEAD note in place, even though > it is no longer correct. I noticed this while investigating PR50826: > the initialization of the internal_arg_pointer has a REG_DEAD note for > %r29, but even after it is fwpropped, the note remains there. This > patch fixes this bug.
This isn't necessarily a bug, i.e. passes aren't required to maintain REG_DEAD and REG_UNUSED notes up-to-date (another example is PR rtl-opt/48773). Instead passes consuming these notes have to invoke df_note_add_problem on entry. -- Eric Botcazou
