abc9_ops: -prep_xaiger exclude (* abc9_keep *) wires from toposort

diff --git a/passes/techmap/abc9_ops.cc b/passes/techmap/abc9_ops.cc
index 8d55b18a08f5373820f5cee26489eb5ae538f6c8..16b468b1900c6f236379e2ef5a0136cb7fe19d8f 100644 (file)
--- a/passes/techmap/abc9_ops.cc
+++ b/passes/techmap/abc9_ops.cc
@@ -719,8 +719,10 @@ void prep_xaiger(RTLIL::Module *module, bool dff)
                                        bit_users[bit].insert(cell->name);
 
                        if (cell->output(conn.first) && !abc9_flop)
-                               for (auto bit : sigmap(conn.second))
-                                       bit_drivers[bit].insert(cell->name);
+                               for (const auto &chunk : conn.second.chunks())
+                                   if (!chunk.wire->get_bool_attribute(ID::abc9_keep))
+                                           for (auto b : sigmap(SigSpec(chunk)))
+                                                   bit_drivers[b].insert(cell->name);
                }
                toposort.node(cell->name);
        }