Added support for sr flip-flops to dfflibmap
authorClifford Wolf <clifford@clifford.at>
Thu, 24 Oct 2013 16:20:06 +0000 (18:20 +0200)
committerClifford Wolf <clifford@clifford.at>
Thu, 24 Oct 2013 16:20:06 +0000 (18:20 +0200)
passes/techmap/dfflibmap.cc

index 5e3219d55bf7f7502c0805a743e083b1182ae80e..111f2f91926361bd66e844c0343427b1105e6012 100644 (file)
@@ -35,12 +35,14 @@ static void logmap(std::string dff)
        if (cell_mappings.count(dff) == 0) {
                log("    unmapped dff cell: %s\n", dff.c_str());
        } else {
-               log("    %s %s(", cell_mappings[dff].cell_name.c_str(), dff.substr(1).c_str());
+               log("    %s %s (", cell_mappings[dff].cell_name.c_str(), dff.substr(1).c_str());
                bool first = true;
                for (auto &port : cell_mappings[dff].ports) {
                        char arg[3] = { port.second, 0, 0 };
                        if ('a' <= arg[0] && arg[0] <= 'z')
                                arg[1] = arg[0] - ('a' - 'A'), arg[0] = '~';
+                       else
+                               arg[1] = arg[0], arg[0] = ' ';
                        log("%s.%s(%s)", first ? "" : ", ", port.first.c_str(), arg);
                        first = false;
                }
@@ -52,6 +54,7 @@ static void logmap_all()
 {
        logmap("$_DFF_N_");
        logmap("$_DFF_P_");
+
        logmap("$_DFF_NN0_");
        logmap("$_DFF_NN1_");
        logmap("$_DFF_NP0_");
@@ -60,6 +63,15 @@ static void logmap_all()
        logmap("$_DFF_PN1_");
        logmap("$_DFF_PP0_");
        logmap("$_DFF_PP1_");
+
+       logmap("$_DFFSR_NNN_");
+       logmap("$_DFFSR_NNP_");
+       logmap("$_DFFSR_NPN_");
+       logmap("$_DFFSR_NPP_");
+       logmap("$_DFFSR_PNN_");
+       logmap("$_DFFSR_PNP_");
+       logmap("$_DFFSR_PPN_");
+       logmap("$_DFFSR_PPP_");
 }
 
 static bool parse_pin(LibertyAst *cell, LibertyAst *attr, std::string &pin_name, bool &pin_pol)
@@ -175,6 +187,88 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool
        }
 }
 
+static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bool setpol, bool clrpol)
+{
+       LibertyAst *best_cell = NULL;
+       std::map<std::string, char> best_cell_ports;
+       int best_cell_pins = 0;
+
+       if (ast->id != "library")
+               log_error("Format error in liberty file.\n");
+
+       for (auto cell : ast->children)
+       {
+               if (cell->id != "cell" || cell->args.size() != 1)
+                       continue;
+
+               LibertyAst *ff = cell->find("ff");
+               if (ff == NULL)
+                       continue;
+
+               std::string cell_clk_pin, cell_set_pin, cell_clr_pin, cell_next_pin;
+               bool cell_clk_pol, cell_set_pol, cell_clr_pol, cell_next_pol;
+
+               if (!parse_pin(cell, ff->find("clocked_on"), cell_clk_pin, cell_clk_pol) || cell_clk_pol != clkpol)
+                       continue;
+               if (!parse_pin(cell, ff->find("next_state"), cell_next_pin, cell_next_pol))
+                       continue;
+               if (!parse_pin(cell, ff->find("preset"), cell_set_pin, cell_set_pol) || cell_set_pol != setpol)
+                       continue;
+               if (!parse_pin(cell, ff->find("clear"), cell_clr_pin, cell_clr_pol) || cell_clr_pol != clrpol)
+                       continue;
+
+               std::map<std::string, char> this_cell_ports;
+               this_cell_ports[cell_clk_pin] = 'C';
+               this_cell_ports[cell_set_pin] = 'S';
+               this_cell_ports[cell_clr_pin] = 'R';
+               this_cell_ports[cell_next_pin] = 'D';
+
+               int num_pins = 0;
+               bool found_output = false;
+               for (auto pin : cell->children)
+               {
+                       if (pin->id != "pin" || pin->args.size() != 1)
+                               continue;
+
+                       LibertyAst *dir = pin->find("direction");
+                       if (dir == NULL || dir->value == "internal")
+                               continue;
+                       num_pins++;
+
+                       if (dir->value == "input" && this_cell_ports.count(pin->args[0]) == 0)
+                               goto continue_cell_loop;
+
+                       LibertyAst *func = pin->find("function");
+                       if (dir->value == "output" && func != NULL) {
+                               std::string value = func->value;
+                               for (size_t pos = value.find_first_of("\" \t"); pos != std::string::npos; pos = value.find_first_of("\" \t"))
+                                       value.erase(pos, 1);
+                               if ((cell_next_pol == true && value == ff->args[0]) || (cell_next_pol == false && value == ff->args[1])) {
+                                       this_cell_ports[pin->args[0]] = 'Q';
+                                       found_output = true;
+                               }
+                       }
+
+                       if (this_cell_ports.count(pin->args[0]) == 0)
+                               this_cell_ports[pin->args[0]] = 0;
+               }
+
+               if (!found_output || (best_cell != NULL && num_pins > best_cell_pins))
+                       continue;
+
+               best_cell = cell;
+               best_cell_pins = num_pins;
+               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());
+               cell_mappings[cell_type].cell_name = best_cell->args[0];
+               cell_mappings[cell_type].ports = best_cell_ports;
+       }
+}
+
 static bool expand_cellmap_worker(std::string from, std::string to, std::string inv)
 {
        if (cell_mappings.count(to) > 0)
@@ -185,7 +279,10 @@ static bool expand_cellmap_worker(std::string from, std::string to, std::string
        cell_mappings[to].ports = cell_mappings[from].ports;
 
        for (auto &it : cell_mappings[to].ports) {
-               if (inv.find(it.second) == std::string::npos)
+               char cmp_ch = it.second;
+               if ('a' <= cmp_ch && cmp_ch <= 'z')
+                       cmp_ch -= 'a' - 'A';
+               if (inv.find(cmp_ch) == std::string::npos)
                        continue;
                if ('a' <= it.second && it.second <= 'z')
                        it.second -= 'a' - 'A';
@@ -223,6 +320,48 @@ static bool expand_cellmap(std::string pattern, std::string inv)
        return return_status;
 }
 
+static void map_sr_to_arst(const char *from, const char *to)
+{
+       if (cell_mappings.count(to) > 0)
+               return;
+
+       char from_clk_pol = from[8], from_set_pol = from[9], from_clr_pol = from[10];
+       char to_clk_pol = to[6], to_rst_pol = to[7], to_rst_val = to[8];
+
+       log_assert(from_clk_pol == to_clk_pol);
+       log_assert(to_rst_pol == from_set_pol && to_rst_pol == from_clr_pol);
+
+       log("  create mapping for %s from mapping for %s.\n", to, from);
+       cell_mappings[to].cell_name = cell_mappings[from].cell_name;
+       cell_mappings[to].ports = cell_mappings[from].ports;
+
+       for (auto &it : cell_mappings[to].ports)
+       {
+               bool is_set_pin = it.second == 'S' || it.second == 's';
+               bool is_clr_pin = it.second == 'R' || it.second == 'r';
+
+               if (!is_set_pin && !is_clr_pin)
+                       continue;
+
+               if ((to_rst_val == '0' && is_set_pin) || (to_rst_val == '1' && is_clr_pin))
+               {
+                       // this is the unused set/clr pin -- deactivate it
+                       if (is_set_pin)
+                               it.second = (from_set_pol == 'P') == (it.second == 'S') ? '0' : '1';
+                       else
+                               it.second = (from_clr_pol == 'P') == (it.second == 'R') ? '0' : '1';
+               }
+               else
+               {
+                       // this is the used set/clr pin -- rename it to 'reset'
+                       if (it.second == 'S')
+                               it.second = 'R';
+                       if (it.second == 's')
+                               it.second = 'r';
+               }
+       }
+}
+
 static void dfflibmap(RTLIL::Design *design, RTLIL::Module *module)
 {
        log("Mapping DFF cells in module `%s':\n", module->name.c_str());
@@ -256,7 +395,11 @@ static void dfflibmap(RTLIL::Design *design, RTLIL::Module *module)
                                inv_cell->connections[port.second == 'q' ? "\\A" : "\\Y"] = sig;
                                module->cells[inv_cell->name] = inv_cell;
                                module->wires[inv_wire->name] = inv_wire;
-                       }
+                       } else
+                       if (port.second == '0' || port.second == '1') {
+                               sig = RTLIL::SigSpec(port.second == '0' ? 0 : 1, 1);
+                       } else
+                               log_abort();
                        new_cell->connections["\\" + port.first] = sig;
                }
                stats[stringf("  mapped %%d %s cells to %s cells.\n", cell->type.c_str(), new_cell->type.c_str())]++;
@@ -311,6 +454,7 @@ struct DfflibmapPass : public Pass {
 
                find_cell(libparser.ast, "$_DFF_N_", false, false, false, false);
                find_cell(libparser.ast, "$_DFF_P_", true, false, false, false);
+
                find_cell(libparser.ast, "$_DFF_NN0_", false, true, false, false);
                find_cell(libparser.ast, "$_DFF_NN1_", false, true, false, true);
                find_cell(libparser.ast, "$_DFF_NP0_", false, true, true, false);
@@ -320,6 +464,15 @@ struct DfflibmapPass : public Pass {
                find_cell(libparser.ast, "$_DFF_PP0_", true, true, true, false);
                find_cell(libparser.ast, "$_DFF_PP1_", true, true, true, true);
 
+               find_cell_sr(libparser.ast, "$_DFFSR_NNN_", false, false, false);
+               find_cell_sr(libparser.ast, "$_DFFSR_NNP_", false, false, true);
+               find_cell_sr(libparser.ast, "$_DFFSR_NPN_", false, true, false);
+               find_cell_sr(libparser.ast, "$_DFFSR_NPP_", false, true, true);
+               find_cell_sr(libparser.ast, "$_DFFSR_PNN_", true, false, false);
+               find_cell_sr(libparser.ast, "$_DFFSR_PNP_", true, false, true);
+               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;
@@ -327,7 +480,19 @@ struct DfflibmapPass : public Pass {
                        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");
                }
+
+               map_sr_to_arst("$_DFFSR_NNN_", "$_DFF_NN0_");
+               map_sr_to_arst("$_DFFSR_NNN_", "$_DFF_NN1_");
+               map_sr_to_arst("$_DFFSR_NPP_", "$_DFF_NP0_");
+               map_sr_to_arst("$_DFFSR_NPP_", "$_DFF_NP1_");
+               map_sr_to_arst("$_DFFSR_PNN_", "$_DFF_PN0_");
+               map_sr_to_arst("$_DFFSR_PNN_", "$_DFF_PN1_");
+               map_sr_to_arst("$_DFFSR_PPP_", "$_DFF_PP0_");
+               map_sr_to_arst("$_DFFSR_PPP_", "$_DFF_PP1_");
  
                log("  final dff cell mappings:\n");
                logmap_all();