diff options
Diffstat (limited to 'passes/techmap/dfflibmap.cc')
| -rw-r--r-- | passes/techmap/dfflibmap.cc | 55 |
1 files changed, 43 insertions, 12 deletions
diff --git a/passes/techmap/dfflibmap.cc b/passes/techmap/dfflibmap.cc index 0324afa84..40caf7801 100644 --- a/passes/techmap/dfflibmap.cc +++ b/passes/techmap/dfflibmap.cc @@ -106,6 +106,7 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool LibertyAst *best_cell = NULL; std::map<std::string, char> best_cell_ports; int best_cell_pins = 0; + float best_cell_area = 0; if (ast->id != "library") log_error("Format error in liberty file.\n"); @@ -141,6 +142,11 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool this_cell_ports[cell_rst_pin] = 'R'; this_cell_ports[cell_next_pin] = 'D'; + float area = 0; + LibertyAst *ar = cell->find("area"); + if (ar != NULL && !ar->value.empty()) + area = atof(ar->value.c_str()); + int num_pins = 0; bool found_output = false; for (auto pin : cell->children) @@ -174,14 +180,18 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool if (!found_output || (best_cell != NULL && num_pins > best_cell_pins)) continue; + if (best_cell != NULL && num_pins == best_cell_pins && area > best_cell_area) + continue; + best_cell = cell; best_cell_pins = num_pins; + best_cell_area = area; best_cell_ports.swap(this_cell_ports); continue_cell_loop:; } if (best_cell != NULL) { - log(" cell %s is a direct match for cell type %s.\n", best_cell->args[0].c_str(), cell_type.substr(1).c_str()); + log(" cell %s (pins=%d, area=%.2f) is a direct match for cell type %s.\n", best_cell->args[0].c_str(), best_cell_pins, best_cell_area, cell_type.substr(1).c_str()); cell_mappings[cell_type].cell_name = best_cell->args[0]; cell_mappings[cell_type].ports = best_cell_ports; } @@ -192,6 +202,7 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo LibertyAst *best_cell = NULL; std::map<std::string, char> best_cell_ports; int best_cell_pins = 0; + float best_cell_area = 0; if (ast->id != "library") log_error("Format error in liberty file.\n"); @@ -223,6 +234,11 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo this_cell_ports[cell_clr_pin] = 'R'; this_cell_ports[cell_next_pin] = 'D'; + float area = 0; + LibertyAst *ar = cell->find("area"); + if (ar != NULL && !ar->value.empty()) + area = atof(ar->value.c_str()); + int num_pins = 0; bool found_output = false; for (auto pin : cell->children) @@ -256,14 +272,18 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo if (!found_output || (best_cell != NULL && num_pins > best_cell_pins)) continue; + if (best_cell != NULL && num_pins == best_cell_pins && area > best_cell_area) + continue; + best_cell = cell; best_cell_pins = num_pins; + best_cell_area = area; best_cell_ports.swap(this_cell_ports); continue_cell_loop:; } if (best_cell != NULL) { - log(" cell %s is a direct match for cell type %s.\n", best_cell->args[0].c_str(), cell_type.substr(1).c_str()); + log(" cell %s (pins=%d, area=%.2f) is a direct match for cell type %s.\n", best_cell->args[0].c_str(), best_cell_pins, best_cell_area, cell_type.substr(1).c_str()); cell_mappings[cell_type].cell_name = best_cell->args[0]; cell_mappings[cell_type].ports = best_cell_ports; } @@ -399,6 +419,7 @@ static void dfflibmap(RTLIL::Design *design, RTLIL::Module *module) if (port.second == '0' || port.second == '1') { sig = RTLIL::SigSpec(port.second == '0' ? 0 : 1, 1); } else + if (port.second != 0) log_abort(); new_cell->connections["\\" + port.first] = sig; } @@ -473,16 +494,26 @@ struct DfflibmapPass : public Pass { find_cell_sr(libparser.ast, "$_DFFSR_PPN_", true, true, false); find_cell_sr(libparser.ast, "$_DFFSR_PPP_", true, true, true); - bool keep_running = true; - while (keep_running) { - keep_running = false; - keep_running |= expand_cellmap("$_DFF_*_", "C"); - keep_running |= expand_cellmap("$_DFF_*??_", "C"); - keep_running |= expand_cellmap("$_DFF_?*?_", "R"); - keep_running |= expand_cellmap("$_DFF_??*_", "DQ"); - keep_running |= expand_cellmap("$_DFFSR_*??_", "C"); - keep_running |= expand_cellmap("$_DFFSR_?*?_", "S"); - keep_running |= expand_cellmap("$_DFFSR_??*_", "R"); + // try to implement as many cells as possible just by inverting + // the SET and RESET pins. If necessary, implement cell types + // by inverting both D and Q. Only invert clock pins if there + // is no other way of implementing the cell. + while (1) + { + if (expand_cellmap("$_DFF_?*?_", "R") || + expand_cellmap("$_DFFSR_?*?_", "S") || + expand_cellmap("$_DFFSR_??*_", "R")) + continue; + + if (expand_cellmap("$_DFF_??*_", "DQ")) + continue; + + if (expand_cellmap("$_DFF_*_", "C") || + expand_cellmap("$_DFF_*??_", "C") || + expand_cellmap("$_DFFSR_*??_", "C")) + continue; + + break; } map_sr_to_arst("$_DFFSR_NNN_", "$_DFF_NN0_"); |