From 96e821dc6cf170168218fa4cddc7c9ddafd6f439 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Sun, 21 Sep 2014 19:36:56 +0200 Subject: [PATCH] Various improvements regarding logic loops in "share" results --- passes/opt/share.cc | 145 +++++++++++++++++++++++++++++++++----------- 1 file changed, 108 insertions(+), 37 deletions(-) diff --git a/passes/opt/share.cc b/passes/opt/share.cc index b91a67ee0..e3b0159c0 100644 --- a/passes/opt/share.cc +++ b/passes/opt/share.cc @@ -44,6 +44,7 @@ struct ShareWorker CellTypes fwd_ct, cone_ct; ModWalker modwalker; + ModIndex mi; std::set cells_to_remove; std::set recursion_state; @@ -102,7 +103,7 @@ struct ShareWorker // Find shareable cells and compatible groups of cells // --------------------------------------------------- - std::set shareable_cells; + std::set> shareable_cells; void find_shareable_cells() { @@ -252,7 +253,7 @@ struct ShareWorker // Create replacement cell // ----------------------- - RTLIL::Cell *make_supercell(RTLIL::Cell *c1, RTLIL::Cell *c2, RTLIL::SigSpec act) + RTLIL::Cell *make_supercell(RTLIL::Cell *c1, RTLIL::Cell *c2, RTLIL::SigSpec act, std::set &supercell_aux) { log_assert(c1->type == c2->type); @@ -283,10 +284,12 @@ struct ShareWorker int a_width = std::max(a1.size(), a2.size()); int y_width = std::max(y1.size(), y2.size()); - if (a1.size() != a_width) a1 = module->addPos(NEW_ID, a1, module->addWire(NEW_ID, a_width), a_signed)->getPort("\\Y"); - if (a2.size() != a_width) a2 = module->addPos(NEW_ID, a2, module->addWire(NEW_ID, a_width), a_signed)->getPort("\\Y"); + a1.extend_u0(a_width, a_signed); + a2.extend_u0(a_width, a_signed); + + RTLIL::SigSpec a = module->addWire(NEW_ID, a_width); + supercell_aux.insert(module->addMux(NEW_ID, a2, a1, act, a)); - RTLIL::SigSpec a = module->Mux(NEW_ID, a2, a1, act); RTLIL::Wire *y = module->addWire(NEW_ID, y_width); RTLIL::Cell *supercell = module->addCell(NEW_ID, c1->type); @@ -296,12 +299,10 @@ struct ShareWorker supercell->setPort("\\A", a); supercell->setPort("\\Y", y); - RTLIL::SigSpec new_y1(y, 0, y1.size()); - RTLIL::SigSpec new_y2(y, 0, y2.size()); - - module->connect(RTLIL::SigSig(y1, new_y1)); - module->connect(RTLIL::SigSig(y2, new_y2)); + supercell_aux.insert(module->addPos(NEW_ID, y, y1)); + supercell_aux.insert(module->addPos(NEW_ID, y, y2)); + supercell_aux.insert(supercell); return supercell; } @@ -386,23 +387,27 @@ struct ShareWorker { a_width = std::max(y_width, a_width); - if (a1.size() < y1.size()) a1 = module->addPos(NEW_ID, a1, module->addWire(NEW_ID, y1.size()), true)->getPort("\\Y"); - if (a2.size() < y2.size()) a2 = module->addPos(NEW_ID, a2, module->addWire(NEW_ID, y2.size()), true)->getPort("\\Y"); + if (a1.size() < y1.size()) a1.extend_u0(y1.size(), true); + if (a2.size() < y2.size()) a2.extend_u0(y2.size(), true); - if (a1.size() != a_width) a1 = module->addPos(NEW_ID, a1, module->addWire(NEW_ID, a_width), false)->getPort("\\Y"); - if (a2.size() != a_width) a2 = module->addPos(NEW_ID, a2, module->addWire(NEW_ID, a_width), false)->getPort("\\Y"); + a1.extend_u0(a_width, false); + a2.extend_u0(a_width, false); } else { - if (a1.size() != a_width) a1 = module->addPos(NEW_ID, a1, module->addWire(NEW_ID, a_width), a_signed)->getPort("\\Y"); - if (a2.size() != a_width) a2 = module->addPos(NEW_ID, a2, module->addWire(NEW_ID, a_width), a_signed)->getPort("\\Y"); + a1.extend_u0(a_width, a_signed); + a2.extend_u0(a_width, a_signed); } - if (b1.size() != b_width) b1 = module->addPos(NEW_ID, b1, module->addWire(NEW_ID, b_width), b_signed)->getPort("\\Y"); - if (b2.size() != b_width) b2 = module->addPos(NEW_ID, b2, module->addWire(NEW_ID, b_width), b_signed)->getPort("\\Y"); + b1.extend_u0(b_width, b_signed); + b2.extend_u0(b_width, b_signed); + + RTLIL::SigSpec a = module->addWire(NEW_ID, a_width); + RTLIL::SigSpec b = module->addWire(NEW_ID, b_width); + + supercell_aux.insert(module->addMux(NEW_ID, a2, a1, act, a)); + supercell_aux.insert(module->addMux(NEW_ID, b2, b1, act, b)); - RTLIL::SigSpec a = module->Mux(NEW_ID, a2, a1, act); - RTLIL::SigSpec b = module->Mux(NEW_ID, b2, b1, act); RTLIL::Wire *y = module->addWire(NEW_ID, y_width); RTLIL::Cell *supercell = module->addCell(NEW_ID, c1->type); @@ -416,19 +421,18 @@ struct ShareWorker supercell->setPort("\\Y", y); supercell->check(); - RTLIL::SigSpec new_y1(y, 0, y1.size()); - RTLIL::SigSpec new_y2(y, 0, y2.size()); - - module->connect(RTLIL::SigSig(y1, new_y1)); - module->connect(RTLIL::SigSig(y2, new_y2)); + supercell_aux.insert(module->addPos(NEW_ID, y, y1)); + supercell_aux.insert(module->addPos(NEW_ID, y, y2)); + supercell_aux.insert(supercell); return supercell; } if (c1->type == "$memrd") { RTLIL::Cell *supercell = module->addCell(NEW_ID, c1); - module->connect(c2->getPort("\\DATA"), supercell->getPort("\\DATA")); + supercell_aux.insert(module->addPos(NEW_ID, supercell->getPort("\\DATA"), c2->getPort("\\DATA"))); + supercell_aux.insert(supercell); return supercell; } @@ -633,16 +637,21 @@ struct ShareWorker } } - RTLIL::SigSpec make_cell_activation_logic(const std::set> &activation_patterns) + RTLIL::SigSpec make_cell_activation_logic(const std::set> &activation_patterns, std::set &supercell_aux) { RTLIL::Wire *all_cases_wire = module->addWire(NEW_ID, 0); + for (auto &p : activation_patterns) { all_cases_wire->width++; - module->addEq(NEW_ID, p.first, p.second, RTLIL::SigSpec(all_cases_wire, all_cases_wire->width - 1)); + supercell_aux.insert(module->addEq(NEW_ID, p.first, p.second, RTLIL::SigSpec(all_cases_wire, all_cases_wire->width - 1))); } + if (all_cases_wire->width == 1) return all_cases_wire; - return module->ReduceOr(NEW_ID, all_cases_wire); + + RTLIL::Wire *result_wire = module->addWire(NEW_ID); + supercell_aux.insert(module->addReduceOr(NEW_ID, all_cases_wire, result_wire)); + return result_wire; } @@ -690,6 +699,13 @@ struct ShareWorker bool found_scc = !toposort.sort(); topo_cell_drivers = std::move(toposort.database); + if (found_scc && toposort.analyze_loops) + for (auto &loop : toposort.loops) { + log("### loop ###\n"); + for (auto &c : loop) + log("%s (%s)\n", log_id(c), log_id(c->type)); + } + return found_scc; } @@ -715,13 +731,52 @@ struct ShareWorker return find_in_input_cone_worker(root, needle, stop); } + bool is_part_of_scc(RTLIL::Cell *cell) + { + CellTypes ct; + ct.setup_internals(); + ct.setup_stdcells(); + + std::set queue, covered; + queue.insert(cell); + + while (!queue.empty()) + { + std::set new_queue; + + for (auto c : queue) { + if (!ct.cell_known(c->type)) + continue; + for (auto &conn : c->connections()) + if (ct.cell_input(c->type, conn.first)) + for (auto bit : conn.second) + for (auto &pi : mi.query_ports(bit)) + if (ct.cell_known(pi.cell->type) && ct.cell_output(pi.cell->type, pi.port)) + new_queue.insert(pi.cell); + covered.insert(c); + } + + queue.clear(); + for (auto c : new_queue) { + if (cells_to_remove.count(c)) + continue; + if (c == cell) + return true; + if (!covered.count(c)) + queue.insert(c); + } + } + + return false; + } + // ------------- // Setup and run // ------------- ShareWorker(ShareWorkerConfig config, RTLIL::Design *design, RTLIL::Module *module) : - config(config), design(design), module(module) + config(config), design(design), module(module), mi(module) { bool before_scc = module_has_scc(); @@ -934,18 +989,37 @@ struct ShareWorker other_cell_select_score += p.first.size(); RTLIL::Cell *supercell; + std::set supercell_aux; if (cell_select_score <= other_cell_select_score) { - RTLIL::SigSpec act = make_cell_activation_logic(filtered_cell_activation_patterns); - supercell = make_supercell(cell, other_cell, act); + RTLIL::SigSpec act = make_cell_activation_logic(filtered_cell_activation_patterns, supercell_aux); + supercell = make_supercell(cell, other_cell, act, supercell_aux); log(" Activation signal for %s: %s\n", log_id(cell), log_signal(act)); } else { - RTLIL::SigSpec act = make_cell_activation_logic(filtered_other_cell_activation_patterns); - supercell = make_supercell(other_cell, cell, act); + RTLIL::SigSpec act = make_cell_activation_logic(filtered_other_cell_activation_patterns, supercell_aux); + supercell = make_supercell(other_cell, cell, act, supercell_aux); log(" Activation signal for %s: %s\n", log_id(other_cell), log_signal(act)); } log(" New cell: %s (%s)\n", log_id(supercell), log_id(supercell->type)); + cells_to_remove.insert(cell); + cells_to_remove.insert(other_cell); + + for (auto c : supercell_aux) + if (is_part_of_scc(c)) + goto do_rollback; + + if (0) { + do_rollback: + log(" New topology contains loops! Rolling back..\n"); + cells_to_remove.erase(cell); + cells_to_remove.erase(other_cell); + shareable_cells.insert(other_cell); + for (auto cc : supercell_aux) + module->remove(cc); + continue; + } + std::set> supercell_activation_patterns; supercell_activation_patterns.insert(filtered_cell_activation_patterns.begin(), filtered_cell_activation_patterns.end()); supercell_activation_patterns.insert(filtered_other_cell_activation_patterns.begin(), filtered_other_cell_activation_patterns.end()); @@ -953,9 +1027,6 @@ struct ShareWorker activation_patterns_cache[supercell] = supercell_activation_patterns; shareable_cells.insert(supercell); - cells_to_remove.insert(cell); - cells_to_remove.insert(other_cell); - for (auto bit : topo_sigmap(all_ctrl_signals)) for (auto c : topo_bit_drivers[bit]) topo_cell_drivers[supercell].insert(c);