Get rid of (* abc9_keep *) in write_xaiger too

diff --git a/backends/aiger/xaiger.cc b/backends/aiger/xaiger.cc
index 77659b4d8a5a84be0a7c062fc2b724a32c66f5de..9c6152dff9b22951b4a2ef6f5969345e41f117d8 100644 (file)
--- a/backends/aiger/xaiger.cc
+++ b/backends/aiger/xaiger.cc
@@ -250,7 +250,12 @@ struct XAigerWriter
 
                        RTLIL::Module* inst_module = module->design->module(cell->type);
                        if (inst_module) {
-                               bool abc9_box = inst_module->attributes.count("\\abc9_box_id") && !cell->get_bool_attribute("\\abc9_keep");
+                               bool abc9_box = inst_module->attributes.count("\\abc9_box_id");
+                               bool abc9_flop = inst_module->get_bool_attribute("\\abc9_flop");
+                               // The lack of an abc9_mergeability attribute indicates that
+                               //   we do want to keep this flop, so do not treat it as a box
+                               if (abc9_flop && !cell->attributes.count("\\abc9_mergeability"))
+                                       abc9_box = false;
 
                                for (const auto &conn : cell->connections()) {
                                        auto port_wire = inst_module->wire(conn.first);
@@ -279,15 +284,15 @@ struct XAigerWriter
                                        }
                                }
 
-                                if (abc9_box) {
-                                        abc9_box_seen = true;
+                               if (abc9_box) {
+                                       abc9_box_seen = true;
 
-                                        toposort.node(cell->name);
+                                       toposort.node(cell->name);
 
-                                        if (inst_module->get_bool_attribute("\\abc9_flop"))
-                                                flop_boxes.push_back(cell);
-                                        continue;
-                                }
+                                       if (abc9_flop)
+                                               flop_boxes.push_back(cell);
+                                       continue;
+                               }
                        }
 
                        bool cell_known = inst_module || cell->known();
@@ -322,11 +327,12 @@ struct XAigerWriter
                                SigBit d;
                                if (r.second) {
                                        for (const auto &conn : cell->connections()) {
-                                               const SigSpec &rhs = conn.second;
-                                               if (!rhs.is_bit())
+                                               if (!conn.second.is_bit())
                                                        continue;
-                                               if (!ff_bits.count(rhs))
+                                               d = conn.second;
+                                               if (!ff_bits.count(d))
                                                        continue;
+
                                                r.first->second.first = conn.first;
                                                Module *inst_module = module->design->module(cell->type);
                                                Wire *wire = inst_module->wire(conn.first);
@@ -337,7 +343,6 @@ struct XAigerWriter
                                                                log_error("Attribute 'abc9_arrival' on port '%s' of module '%s' is not an integer.\n", log_id(wire), log_id(cell->type));
                                                        r.first->second.second = jt->second.as_int();
                                                }
-                                               d = rhs;
                                                log_assert(d == sigmap(d));
                                                break;
                                        }
@@ -399,8 +404,7 @@ struct XAigerWriter
                                log_assert(cell);
 
                                RTLIL::Module* box_module = module->design->module(cell->type);
-                               if (!box_module || !box_module->attributes.count("\\abc9_box_id")
-                                               || cell->get_bool_attribute("\\abc9_keep"))
+                               if (!box_module || !box_module->attributes.count("\\abc9_box_id"))
                                        continue;
 
                                bool blackbox = box_module->get_blackbox_attribute(true /* ignore_wb */);
@@ -434,7 +438,6 @@ struct XAigerWriter
                                        if (carry_in == IdString() && carry_out != IdString())
                                                log_error("Module '%s' contains an 'abc9_carry' output port but no input port.\n", log_id(box_module));
                                        if (carry_in != IdString()) {
-                                               log_assert(carry_out != IdString());
                                                r.first->second.push_back(carry_in);
                                                r.first->second.push_back(carry_out);
                                        }