Added opt_const -mux_bool

diff --git a/passes/opt/opt.cc b/passes/opt/opt.cc
index 467baf235409c5aea00d5c5e9278131079b98c81..53c27e0f50de7ff5497b1b9a3e0b28449da98529 100644 (file)
--- a/passes/opt/opt.cc
+++ b/passes/opt/opt.cc
@@ -31,7 +31,7 @@ struct OptPass : public Pass {
        {
                //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
                log("\n");
-               log("    opt [selection]\n");
+               log("    opt [-mux_undef] [-mux_bool] [selection]\n");
                log("\n");
                log("This pass calls all the other opt_* passes in a useful order. This performs\n");
                log("a series of trivial optimizations and cleanups. This pass executes the other\n");
@@ -46,16 +46,30 @@ struct OptPass : public Pass {
                log("        opt_share\n");
                log("        opt_rmdff\n");
                log("        opt_clean\n");
-               log("        opt_const\n");
+               log("        opt_const [-mux_undef] [-mux_bool]\n");
                log("    while [changed design]\n");
                log("\n");
        }
        virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
        {
+               std::string opt_const_args;
+
                log_header("Executing OPT pass (performing simple optimizations).\n");
                log_push();
 
-               extra_args(args, 1, design);
+               size_t argidx;
+               for (argidx = 1; argidx < args.size(); argidx++) {
+                       if (args[argidx] == "-mux_undef") {
+                               opt_const_args += " -mux_undef";
+                               continue;
+                       }
+                       if (args[argidx] == "-mux_bool") {
+                               opt_const_args += " -mux_bool";
+                               continue;
+                       }
+                       break;
+               }
+               extra_args(args, argidx, design);
 
                log_header("Optimizing in-memory representation of design.\n");
                design->optimize();
@@ -69,7 +83,7 @@ struct OptPass : public Pass {
                        Pass::call(design, "opt_share");
                        Pass::call(design, "opt_rmdff");
                        Pass::call(design, "opt_clean");
-                       Pass::call(design, "opt_const");
+                       Pass::call(design, "opt_const" + opt_const_args);
                        if (OPT_DID_SOMETHING == false)
                                break;
                        log_header("Rerunning OPT passes. (Maybe there is more to do..)\n");

diff --git a/passes/opt/opt_const.cc b/passes/opt/opt_const.cc
index 2b2c83a514adcc3d0cb198c8e1b6d180f96244eb..535dd02fc2165be5caa8ffe9114daabb8c117eaf 100644 (file)
--- a/passes/opt/opt_const.cc
+++ b/passes/opt/opt_const.cc
@@ -42,7 +42,7 @@ void replace_cell(RTLIL::Module *module, RTLIL::Cell *cell, std::string info, st
        did_something = true;
 }
 
-void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef)
+void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef, bool mux_bool)
 {
        if (!design->selected(module))
                return;
@@ -244,6 +244,24 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
                        }
                }
 
+               if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(0, 1) && cell->connections["\\B"] == RTLIL::SigSpec(1, 1)) {
+                       replace_cell(module, cell, "mux_bool", "\\Y", cell->connections["\\S"]);
+                       goto next_cell;
+               }
+
+               if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(1, 1) && cell->connections["\\B"] == RTLIL::SigSpec(0, 1)) {
+                       cell->connections["\\A"] = cell->connections["\\S"];
+                       cell->connections.erase("\\B");
+                       cell->connections.erase("\\S");
+                       cell->parameters["\\A_WIDTH"] = cell->parameters["\\WIDTH"];
+                       cell->parameters["\\Y_WIDTH"] = cell->parameters["\\WIDTH"];
+                       cell->parameters["\\A_SIGNED"] = 0;
+                       cell->parameters.erase("\\WIDTH");
+                       cell->type = "$not";
+                       did_something = true;
+                       goto next_cell;
+               }
+
                if (mux_undef && (cell->type == "$mux" || cell->type == "$pmux")) {
                        RTLIL::SigSpec new_a, new_b, new_s;
                        int width = cell->connections.at("\\A").width;
@@ -392,10 +410,14 @@ struct OptConstPass : public Pass {
                log("    -mux_undef\n");
                log("        remove 'undef' inputs from $mux, $pmux and $_MUX_ cells\n");
                log("\n");
+               log("    -mux_bool\n");
+               log("        replace $mux cells with inverters or buffers when possible\n");
+               log("\n");
        }
        virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
        {
                bool mux_undef = false;
+               bool mux_bool = false;
 
                log_header("Executing OPT_CONST pass (perform const folding).\n");
                log_push();
@@ -406,6 +428,10 @@ struct OptConstPass : public Pass {
                                mux_undef = true;
                                continue;
                        }
+                       if (args[argidx] == "-mux_bool") {
+                               mux_bool = true;
+                               continue;
+                       }
                        break;
                }
                extra_args(args, argidx, design);
@@ -414,9 +440,9 @@ struct OptConstPass : public Pass {
                        do {
                                do {
                                        did_something = false;
-                                       replace_const_cells(design, mod_it.second, false, mux_undef);
+                                       replace_const_cells(design, mod_it.second, false, mux_undef, mux_bool);
                                } while (did_something);
-                               replace_const_cells(design, mod_it.second, true, mux_undef);
+                               replace_const_cells(design, mod_it.second, true, mux_undef, mux_bool);
                        } while (did_something);
 
                log_pop();