opt.cc

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/*
 *  yosys -- Yosys Open SYnthesis Suite
 *
 *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
 *  
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *  
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include "kernel/register.h"
#include "kernel/log.h"
#include <stdlib.h>
#include <stdio.h>

USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN

struct OptPass : public Pass {
    OptPass() : Pass("opt", "perform simple optimizations") { }
    virtual void help()
    {
        //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
        log("\n");
        log("    opt [options] [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");
        log("passes in the following order:\n");
        log("\n");
        log("    opt_const [-mux_undef] [-mux_bool] [-undriven] [-fine] [-full] [-keepdc]\n");
        log("    opt_share -nomux\n");
        log("\n");
        log("    do\n");
        log("        opt_muxtree\n");
        log("        opt_reduce [-fine] [-full]\n");
        log("        opt_share\n");
        log("        opt_rmdff\n");
        log("        opt_clean [-purge]\n");
        log("        opt_const [-mux_undef] [-mux_bool] [-undriven] [-fine] [-full] [-keepdc]\n");
        log("    while <changed design>\n");
        log("\n");
        log("When called with -fast the following script is used instead:\n");
        log("\n");
        log("    do\n");
        log("        opt_const [-mux_undef] [-mux_bool] [-undriven] [-fine] [-full] [-keepdc]\n");
        log("        opt_share\n");
        log("        opt_rmdff\n");
        log("        opt_clean [-purge]\n");
        log("    while <changed design in opt_rmdff>\n");
        log("\n");
        log("Note: Options in square brackets (such as [-keepdc]) are passed through to\n");
        log("the opt_* commands when given to 'opt'.\n");
        log("\n");
        log("\n");
    }
    virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
    {
        std::string opt_clean_args;
        std::string opt_const_args;
        std::string opt_reduce_args;
        bool fast_mode = false;

        log_header("Executing OPT pass (performing simple optimizations).\n");
        log_push();

        size_t argidx;
        for (argidx = 1; argidx < args.size(); argidx++) {
            if (args[argidx] == "-purge") {
                opt_clean_args += " -purge";
                continue;
            }
            if (args[argidx] == "-mux_undef") {
                opt_const_args += " -mux_undef";
                continue;
            }
            if (args[argidx] == "-mux_bool") {
                opt_const_args += " -mux_bool";
                continue;
            }
            if (args[argidx] == "-undriven") {
                opt_const_args += " -undriven";
                continue;
            }
            if (args[argidx] == "-fine") {
                opt_const_args += " -fine";
                opt_reduce_args += " -fine";
                continue;
            }
            if (args[argidx] == "-full") {
                opt_const_args += " -full";
                opt_reduce_args += " -full";
                continue;
            }
            if (args[argidx] == "-keepdc") {
                opt_const_args += " -keepdc";
                continue;
            }
            if (args[argidx] == "-fast") {
                fast_mode = true;
                continue;
            }
            break;
        }
        extra_args(args, argidx, design);

        if (fast_mode)
        {
            while (1) {
                Pass::call(design, "opt_const" + opt_const_args);
                Pass::call(design, "opt_share");
                design->scratchpad_unset("opt.did_something");
                Pass::call(design, "opt_rmdff");
                if (design->scratchpad_get_bool("opt.did_something") == false)
                    break;
                Pass::call(design, "opt_clean" + opt_clean_args);
                log_header("Rerunning OPT passes. (Removed registers in this run.)\n");
            }
            Pass::call(design, "opt_clean" + opt_clean_args);
        }
        else
        {
            Pass::call(design, "opt_const" + opt_const_args);
            Pass::call(design, "opt_share -nomux");
            while (1) {
                design->scratchpad_unset("opt.did_something");
                Pass::call(design, "opt_muxtree");
                Pass::call(design, "opt_reduce" + opt_reduce_args);
                Pass::call(design, "opt_share");
                Pass::call(design, "opt_rmdff");
                Pass::call(design, "opt_clean" + opt_clean_args);
                Pass::call(design, "opt_const" + opt_const_args);
                if (design->scratchpad_get_bool("opt.did_something") == false)
                    break;
                log_header("Rerunning OPT passes. (Maybe there is more to do..)\n");
            }
        }

        log_header(fast_mode ? "Finished fast OPT passes." : "Finished OPT passes. (There is nothing left to do.)\n");
        log_pop();
    }
} OptPass;
 
PRIVATE_NAMESPACE_END