Merge $macc cells in alumacc pass

diff --git a/passes/techmap/alumacc.cc b/passes/techmap/alumacc.cc
index 757dc7cf2907cd6877be004404d3131be83e57bd..5a15e82581a523162fc1b54bf88e0abe45d12dea 100644 (file)
--- a/passes/techmap/alumacc.cc
+++ b/passes/techmap/alumacc.cc
@@ -57,6 +57,8 @@ struct AlumaccWorker
                        if (!cell->type.in("$pos", "$neg", "$add", "$sub", "$mul"))
                                continue;
 
+                       log("  creating $macc model for %s (%s).\n", log_id(cell), log_id(cell->type));
+
                        maccnode_t *n = new maccnode_t;
                        Macc::port_t new_port;
 
@@ -67,7 +69,6 @@ struct AlumaccWorker
                        for (auto bit : n->y)
                                n->users = std::max(n->users, bit_users.at(bit) - 1);
 
-
                        if (cell->type.in("$pos", "$neg"))
                        {
                                new_port.in_a = sigmap(cell->getPort("\\A"));
@@ -103,6 +104,60 @@ struct AlumaccWorker
                }
        }
 
+       void merge_macc()
+       {
+               while (1)
+               {
+                       std::set<maccnode_t*> delete_nodes;
+
+                       for (auto &it : sig_macc)
+                       {
+                               auto n = it.second;
+
+                               if (delete_nodes.count(n))
+                                       continue;
+
+                               for (int i = 0; i < SIZE(n->macc.ports); i++)
+                               {
+                                       auto &port = n->macc.ports[i];
+
+                                       if (SIZE(port.in_b) > 0 || sig_macc.count(port.in_a) == 0)
+                                               continue;
+
+                                       auto other_n = sig_macc.at(port.in_a);
+
+                                       if (other_n->users > 1)
+                                               continue;
+
+                                       if (SIZE(other_n->y) != SIZE(n->y))
+                                               continue;
+
+                                       log("  merging $macc model for %s into %s.\n", log_id(other_n->cell), log_id(n->cell));
+
+                                       bool do_subtract = port.do_subtract;
+                                       for (int j = 0; j < SIZE(other_n->macc.ports); j++) {
+                                               if (do_subtract)
+                                                       other_n->macc.ports[j].do_subtract = !other_n->macc.ports[j].do_subtract;
+                                               if (j == 0)
+                                                       n->macc.ports[i--] = other_n->macc.ports[j];
+                                               else
+                                                       n->macc.ports.push_back(other_n->macc.ports[j]);
+                                       }
+
+                                       delete_nodes.insert(other_n);
+                               }
+                       }
+
+                       if (delete_nodes.empty())
+                               break;
+
+                       for (auto n : delete_nodes) {
+                               sig_macc.erase(n->y);
+                               delete n;
+                       }
+               }
+       }
+
        void replace_macc()
        {
                for (auto &it : sig_macc)
@@ -121,8 +176,11 @@ struct AlumaccWorker
 
        void run()
        {
+               log("Extracting $alu and $macc cells in module %s:\n", log_id(module));
+
                count_bit_users();
                extract_macc();
+               merge_macc();
                replace_macc();
        }
 };