passes/opt/opt.cc

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
   5  *
   6  *  Permission to use, copy, modify, and/or distribute this software for any
   7  *  purpose with or without fee is hereby granted, provided that the above
   8  *  copyright notice and this permission notice appear in all copies.
   9  *
  10  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  */
  19
  20 #include "opt_status.h"
  21 #include "kernel/register.h"
  22 #include "kernel/log.h"
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25
  26 bool OPT_DID_SOMETHING;
  27
  28 struct OptPass : public Pass {
  29         OptPass() : Pass("opt", "perform simple optimizations") { }
  30         virtual void help()
  31         {
  32                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
  33                 log("\n");
  34                 log("    opt [options] [selection]\n");
  35                 log("\n");
  36                 log("This pass calls all the other opt_* passes in a useful order. This performs\n");
  37                 log("a series of trivial optimizations and cleanups. This pass executes the other\n");
  38                 log("passes in the following order:\n");
  39                 log("\n");
  40                 log("    opt_const\n");
  41                 log("    opt_share -nomux\n");
  42                 log("\n");
  43                 log("    do\n");
  44                 log("        opt_muxtree\n");
  45                 log("        opt_reduce [-fine]\n");
  46                 log("        opt_share\n");
  47                 log("        opt_rmdff\n");
  48                 log("        opt_clean [-purge]\n");
  49                 log("        opt_const [-mux_undef] [-mux_bool] [-undriven] [-fine] [-keepdc]\n");
  50                 log("    while <changed design>\n");
  51                 log("\n");
  52                 log("Note: Options in square brackets (such as [-keepdc]) are passed through to\n");
  53                 log("the opt_* commands when given to 'opt'.\n");
  54                 log("\n");
  55         }
  56         virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
  57         {
  58                 std::string opt_clean_args;
  59                 std::string opt_const_args;
  60                 std::string opt_reduce_args;
  61
  62                 log_header("Executing OPT pass (performing simple optimizations).\n");
  63                 log_push();
  64
  65                 size_t argidx;
  66                 for (argidx = 1; argidx < args.size(); argidx++) {
  67                         if (args[argidx] == "-purge") {
  68                                 opt_clean_args += " -purge";
  69                                 continue;
  70                         }
  71                         if (args[argidx] == "-mux_undef") {
  72                                 opt_const_args += " -mux_undef";
  73                                 continue;
  74                         }
  75                         if (args[argidx] == "-mux_bool") {
  76                                 opt_const_args += " -mux_bool";
  77                                 continue;
  78                         }
  79                         if (args[argidx] == "-undriven") {
  80                                 opt_const_args += " -undriven";
  81                                 continue;
  82                         }
  83                         if (args[argidx] == "-fine") {
  84                                 opt_const_args += " -fine";
  85                                 opt_reduce_args += " -fine";
  86                                 continue;
  87                         }
  88                         if (args[argidx] == "-keepdc") {
  89                                 opt_const_args += " -keepdc";
  90                                 continue;
  91                         }
  92                         break;
  93                 }
  94                 extra_args(args, argidx, design);
  95
  96                 log_header("Optimizing in-memory representation of design.\n");
  97                 design->optimize();
  98
  99                 Pass::call(design, "opt_const");
 100                 Pass::call(design, "opt_share -nomux");
 101                 while (1) {
 102                         OPT_DID_SOMETHING = false;
 103                         Pass::call(design, "opt_muxtree");
 104                         Pass::call(design, "opt_reduce" + opt_reduce_args);
 105                         Pass::call(design, "opt_share");
 106                         Pass::call(design, "opt_rmdff");
 107                         Pass::call(design, "opt_clean" + opt_clean_args);
 108                         Pass::call(design, "opt_const" + opt_const_args);
 109                         if (OPT_DID_SOMETHING == false)
 110                                 break;
 111                         log_header("Rerunning OPT passes. (Maybe there is more to do..)\n");
 112                 }
 113
 114                 log_header("Optimizing in-memory representation of design.\n");
 115                 design->optimize();
 116
 117                 log_header("Finished OPT passes. (There is nothing left to do.)\n");
 118                 log_pop();
 119         }
 120 } OptPass;
 121