Bugfixes in equiv_struct

diff --git a/passes/equiv/equiv_struct.cc b/passes/equiv/equiv_struct.cc
index 283ccb0946bd1c200b64f297507acdf38efd65bf..714470ee5e6c4e58586874f3517d69bbae1e2b54 100644 (file)
--- a/passes/equiv/equiv_struct.cc
+++ b/passes/equiv/equiv_struct.cc
@@ -143,6 +143,7 @@ struct EquivStructWorker
                                SigBit sig_y = sigmap(cell->getPort("\\Y").as_bit());
                                if (sig_a == sig_b && equiv_inputs.count(sig_y)) {
                                        log("    Purging redundant $equiv cell %s.\n", log_id(cell));
+                                       module->connect(sig_y, sig_a);
                                        module->remove(cell);
                                        merge_count++;
                                }
@@ -205,11 +206,13 @@ struct EquivStructWorker
                                const char *strategy = nullptr;
                                vector<Cell*> gold_cells, gate_cells, other_cells;
                                vector<pair<Cell*, Cell*>> cell_pairs;
+                               IdString cells_type;
 
                                for (auto cell_name : merge_cache[key]) {
                                        Cell *c = module->cell(cell_name);
                                        if (c != nullptr) {
                                                string n = cell_name.str();
+                                               cells_type = c->type;
                                                if (GetSize(n) > 5 && n.substr(GetSize(n)-5) == "_gold")
                                                        gold_cells.push_back(c);
                                                else if (GetSize(n) > 5 && n.substr(GetSize(n)-5) == "_gate")
@@ -219,6 +222,9 @@ struct EquivStructWorker
                                        }
                                }
 
+                               if (phase && cells_type == "$equiv")
+                                       continue;
+
                                if (GetSize(gold_cells) > 1 || GetSize(gate_cells) > 1 || GetSize(other_cells) > 1)
                                {
                                        strategy = "deduplicate";
@@ -256,8 +262,9 @@ struct EquivStructWorker
                                continue;
 
                        run_strategy:
-                               log("    %s merging %d cells (from group of %d) using strategy %s:\n", phase ? "Bwd" : "Fwd",
-                                               2*GetSize(cell_pairs), GetSize(gold_cells) + GetSize(gate_cells) + GetSize(other_cells), strategy);
+                               int total_group_size = GetSize(gold_cells) + GetSize(gate_cells) + GetSize(other_cells);
+                               log("    %s merging %d %s cells (from group of %d) using strategy %s:\n", phase ? "Bwd" : "Fwd",
+                                               2*GetSize(cell_pairs), log_id(cells_type), total_group_size, strategy);
                                for (auto it : cell_pairs) {
                                        log("      Merging cells %s and %s.\n", log_id(it.first),  log_id(it.second));
                                        merge_cell_pair(it.first, it.second);