Extract $alu cells in alumacc
authorClifford Wolf <clifford@clifford.at>
Sun, 14 Sep 2014 11:23:44 +0000 (13:23 +0200)
committerClifford Wolf <clifford@clifford.at>
Sun, 14 Sep 2014 11:23:44 +0000 (13:23 +0200)
passes/techmap/alumacc.cc

index 5a15e82581a523162fc1b54bf88e0abe45d12dea..2a4f8178a1be2df32ccdd50995a0448c07181afa 100644 (file)
@@ -33,10 +33,78 @@ struct AlumaccWorker
                int users;
        };
 
+       struct alunode_t
+       {
+               std::vector<RTLIL::Cell*> cells;
+               RTLIL::SigSpec a, b, c, y;
+               std::vector<std::tuple<bool, bool, bool, bool, RTLIL::SigSpec>> cmp;
+               bool is_signed, invert_b;
+
+               RTLIL::Cell *alu_cell;
+               RTLIL::SigSpec cached_lt, cached_gt, cached_eq, cached_ne;
+               RTLIL::SigSpec cached_cf, cached_of, cached_sf;
+
+               RTLIL::SigSpec get_lt() {
+                       if (SIZE(cached_lt) == 0)
+                               cached_lt = is_signed ? alu_cell->module->Xor(NEW_ID, get_of(), get_sf()) : get_cf();
+                       return cached_lt;
+               }
+
+               RTLIL::SigSpec get_gt() {
+                       if (SIZE(cached_gt) == 0)
+                               cached_gt = alu_cell->module->Not(NEW_ID, alu_cell->module->Or(NEW_ID, get_lt(), get_eq()));
+                       return cached_gt;
+               }
+
+               RTLIL::SigSpec get_eq() {
+                       if (SIZE(cached_eq) == 0)
+                               cached_eq = alu_cell->module->ReduceAnd(NEW_ID, alu_cell->getPort("\\X"));
+                       return cached_eq;
+               }
+
+               RTLIL::SigSpec get_ne() {
+                       if (SIZE(cached_ne) == 0)
+                               cached_ne = alu_cell->module->Not(NEW_ID, get_eq());
+                       return cached_ne;
+               }
+
+               RTLIL::SigSpec get_cf() {
+                       if (SIZE(cached_cf) == 0) {
+                               cached_cf = alu_cell->getPort("\\CO");
+                               log_assert(SIZE(cached_cf) >= 1);
+                               cached_cf = alu_cell->module->Not(NEW_ID, cached_cf[SIZE(cached_cf)-1]);
+                       }
+                       return cached_cf;
+               }
+
+               RTLIL::SigSpec get_of() {
+                       if (SIZE(cached_of) == 0) {
+                               cached_of = {alu_cell->getPort("\\CO"), alu_cell->getPort("\\CI")};
+                               log_assert(SIZE(cached_of) >= 2);
+                               cached_of = alu_cell->module->Xor(NEW_ID, cached_of[SIZE(cached_of)-1], cached_of[SIZE(cached_of)-2]);
+                       }
+                       return cached_of;
+               }
+
+               RTLIL::SigSpec get_sf() {
+                       if (SIZE(cached_sf) == 0) {
+                               cached_sf = alu_cell->getPort("\\Y");
+                               cached_sf = cached_sf[SIZE(cached_sf)-1];
+                       }
+                       return cached_sf;
+               }
+       };
+
        std::map<RTLIL::SigBit, int> bit_users;
        std::map<RTLIL::SigSpec, maccnode_t*> sig_macc;
+       std::map<RTLIL::SigSig, std::set<alunode_t*>> sig_alu;
+       int macc_counter, alu_counter;
 
-       AlumaccWorker(RTLIL::Module *module) : module(module), sigmap(module) { }
+       AlumaccWorker(RTLIL::Module *module) : module(module), sigmap(module)
+       {
+               macc_counter = 0;
+               alu_counter = 0;
+       }
 
        void count_bit_users()
        {
@@ -158,12 +226,96 @@ struct AlumaccWorker
                }
        }
 
+       void macc_to_alu()
+       {
+               std::set<maccnode_t*> delete_nodes;
+
+               for (auto &it : sig_macc)
+               {
+                       auto n = it.second;
+                       RTLIL::SigSpec A, B, C = n->macc.bit_ports;
+                       bool a_signed = false, b_signed = false;
+                       bool subtract_b = false;
+                       alunode_t *alunode;
+
+                       for (auto &port : n->macc.ports)
+                               if (SIZE(port.in_b) > 0) {
+                                       goto next_macc;
+                               } else if (SIZE(port.in_a) == 1 && !port.is_signed && !port.do_subtract) {
+                                       C.append(port.in_a);
+                               } else if (SIZE(A) || port.do_subtract) {
+                                       if (SIZE(B))
+                                               goto next_macc;
+                                       B = port.in_a;
+                                       b_signed = port.is_signed;
+                                       subtract_b = port.do_subtract;
+                               } else {
+                                       if (SIZE(A))
+                                               goto next_macc;
+                                       A = port.in_a;
+                                       a_signed = port.is_signed;
+                               }
+
+                       if (!a_signed || !b_signed) {
+                               if (SIZE(A) == SIZE(n->y))
+                                       a_signed = false;
+                               if (SIZE(B) == SIZE(n->y))
+                                       b_signed = false;
+                               if (a_signed != b_signed)
+                                       goto next_macc;
+                       }
+
+                       if (SIZE(A) == 0 && SIZE(C) > 0) {
+                               A = C[0];
+                               C.remove(0);
+                       }
+
+                       if (SIZE(B) == 0 && SIZE(C) > 0) {
+                               B = C[0];
+                               C.remove(0);
+                       }
+
+                       if (subtract_b)
+                               C.append(RTLIL::S1);
+
+                       if (SIZE(C) > 1)
+                               goto next_macc;
+
+                       if (!subtract_b && B < A)
+                               std::swap(A, B);
+
+                       log("  creating $alu model for $macc %s.\n", log_id(n->cell));
+
+                       alunode = new alunode_t;
+                       alunode->cells.push_back(n->cell);
+                       alunode->is_signed = a_signed;
+                       alunode->invert_b = subtract_b;
+
+                       alunode->a = A;
+                       alunode->b = B;
+                       alunode->c = C;
+                       alunode->y = n->y;
+
+                       sig_alu[RTLIL::SigSig(A, B)].insert(alunode);
+                       delete_nodes.insert(n);
+               next_macc:;
+               }
+
+               for (auto n : delete_nodes) {
+                       sig_macc.erase(n->y);
+                       delete n;
+               }
+       }
+
        void replace_macc()
        {
+               macc_counter += SIZE(sig_macc);
+
                for (auto &it : sig_macc)
                {
                        auto n = it.second;
                        auto cell = module->addCell(NEW_ID, "$macc");
+                       log("  creating $macc cell for %s: %s\n", log_id(n->cell), log_id(cell));
                        n->macc.to_cell(cell);
                        cell->setPort("\\Y", n->y);
                        cell->fixup_parameters();
@@ -174,6 +326,144 @@ struct AlumaccWorker
                sig_macc.clear();
        }
 
+       void extract_cmp_alu()
+       {
+               std::vector<RTLIL::Cell*> lge_cells, eq_cells;
+
+               for (auto cell : module->selected_cells())
+               {
+                       if (cell->type.in("$lt", "$le", "$ge", "$gt"))
+                               lge_cells.push_back(cell);
+                       if (cell->type.in("$eq", "$eqx", "$ne", "$nex"))
+                               eq_cells.push_back(cell);
+               }
+
+               for (auto cell : lge_cells)
+               {
+                       log("  creating $alu model for %s (%s):", log_id(cell), log_id(cell->type));
+
+                       bool cmp_less = cell->type.in("$lt", "$le");
+                       bool cmp_equal = cell->type.in("$le", "$ge");
+                       bool is_signed = cell->getParam("\\A_SIGNED").as_bool();
+
+                       RTLIL::SigSpec A = sigmap(cell->getPort("\\A"));
+                       RTLIL::SigSpec B = sigmap(cell->getPort("\\B"));
+                       RTLIL::SigSpec Y = sigmap(cell->getPort("\\Y"));
+
+                       if (B < A) {
+                               cmp_less = !cmp_less;
+                               std::swap(A, B);
+                       }
+
+                       alunode_t *n = nullptr;
+
+                       for (auto node : sig_alu[RTLIL::SigSig(A, B)])
+                               if (node->is_signed == is_signed && node->invert_b && node->c == RTLIL::S1) {
+                                       n = node;
+                                       break;
+                               }
+
+                       if (n == nullptr) {
+                               n = new alunode_t;
+                               n->a = A;
+                               n->b = B;
+                               n->c = RTLIL::S1;
+                               n->y = module->addWire(NEW_ID, std::max(SIZE(A), SIZE(B)));
+                               n->is_signed = is_signed;
+                               n->invert_b = true;
+                               sig_alu[RTLIL::SigSig(A, B)].insert(n);
+                               log(" new $alu\n");
+                       } else {
+                               log(" merged with %s.\n", log_id(n->cells.front()));
+                       }
+
+                       n->cells.push_back(cell);
+                       n->cmp.push_back(std::make_tuple(cmp_less, !cmp_less, cmp_equal, false, Y));
+               }
+
+               for (auto cell : eq_cells)
+               {
+                       bool cmp_equal = cell->type.in("$eq", "$eqx");
+                       bool is_signed = cell->getParam("\\A_SIGNED").as_bool();
+
+                       RTLIL::SigSpec A = sigmap(cell->getPort("\\A"));
+                       RTLIL::SigSpec B = sigmap(cell->getPort("\\B"));
+                       RTLIL::SigSpec Y = sigmap(cell->getPort("\\Y"));
+
+                       if (B < A)
+                               std::swap(A, B);
+
+                       alunode_t *n = nullptr;
+
+                       for (auto node : sig_alu[RTLIL::SigSig(A, B)])
+                               if (node->is_signed == is_signed && node->invert_b && node->c == RTLIL::S1) {
+                                       n = node;
+                                       break;
+                               }
+
+                       if (n != nullptr) {
+                               log("  creating $alu model for %s (%s): merged with %s.\n", log_id(cell), log_id(cell->type), log_id(n->cells.front()));
+                               n->cells.push_back(cell);
+                               n->cmp.push_back(std::make_tuple(false, false, cmp_equal, !cmp_equal, Y));
+                       }
+               }
+       }
+
+       void replace_alu()
+       {
+               alu_counter += SIZE(sig_alu);
+
+               for (auto &it1 : sig_alu)
+               for (auto n : it1.second)
+               {
+                       n->alu_cell = module->addCell(NEW_ID, "$alu");
+
+                       log("  creating $alu cell for ");
+                       for (int i = 0; i < SIZE(n->cells); i++)
+                               log("%s%s", i ? ", ": "", log_id(n->cells[i]));
+                       log(": %s\n", log_id(n->alu_cell));
+
+                       RTLIL::Wire *x = module->addWire(NEW_ID, SIZE(n->y));
+                       RTLIL::Wire *co = module->addWire(NEW_ID, SIZE(n->y));
+
+                       n->alu_cell->setPort("\\A", n->a);
+                       n->alu_cell->setPort("\\B", n->b);
+                       n->alu_cell->setPort("\\CI", SIZE(n->c) ? n->c : RTLIL::S0);
+                       n->alu_cell->setPort("\\BI", n->invert_b ? RTLIL::S1 : RTLIL::S0);
+                       n->alu_cell->setPort("\\Y", n->y);
+                       n->alu_cell->setPort("\\X", x);
+                       n->alu_cell->setPort("\\CO", co);
+                       n->alu_cell->fixup_parameters();
+
+                       for (auto &it : n->cmp)
+                       {
+                               bool cmp_lt = std::get<0>(it);
+                               bool cmp_gt = std::get<1>(it);
+                               bool cmp_eq = std::get<2>(it);
+                               bool cmp_ne = std::get<3>(it);
+                               RTLIL::SigSpec cmp_y = std::get<4>(it);
+
+                               RTLIL::SigSpec sig;
+                               if (cmp_lt) sig.append(n->get_lt());
+                               if (cmp_gt) sig.append(n->get_gt());
+                               if (cmp_eq) sig.append(n->get_eq());
+                               if (cmp_ne) sig.append(n->get_ne());
+
+                               if (SIZE(sig) > 1)
+                                       sig = module->ReduceOr(NEW_ID, sig);
+
+                               sig.extend(SIZE(cmp_y));
+                               module->connect(cmp_y, sig);
+                       }
+
+                       for (auto c : n->cells)
+                               module->remove(c);
+                       delete n;
+               }
+
+               sig_alu.clear();
+       }
+
        void run()
        {
                log("Extracting $alu and $macc cells in module %s:\n", log_id(module));
@@ -181,7 +471,12 @@ struct AlumaccWorker
                count_bit_users();
                extract_macc();
                merge_macc();
+               macc_to_alu();
                replace_macc();
+               extract_cmp_alu();
+               replace_alu();
+
+               log("  created %d $alu and %d $macc cells.\n", alu_counter, macc_counter);
        }
 };