On Thu, 17 Feb 2022, Jan Hubicka wrote:
> > +/* Returns whether the control parents of BB are preserved. */
> > +
> > +static bool
> > +control_parents_preserved_p (basic_block bb)
> > +{
> > + /* If we marked the control parents from BB they are preserved. */
> > + if (bitmap_bit_p (visited_control_parents, bb->index))
> > + return true;
> > +
> > + /* But they can also end up being marked from elsewhere. */
> > + bitmap_iterator bi;
> > + unsigned edge_number;
> > + EXECUTE_IF_SET_IN_BITMAP (cd->get_edges_dependent_on (bb->index),
> > + 0, edge_number, bi)
> > + {
> > + basic_block cd_bb = cd->get_edge_src (edge_number);
> > + if (cd_bb != bb
> > + && !bitmap_bit_p (last_stmt_necessary, cd_bb->index))
> > + return false;
> > + }
> > + return true;
> I suppose you can also set visited_control_parents bit here so the loop
> is not re-done for every clobber in a BB.
Good idea, will do that.
Richard.
