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 "kernel/register.h"
  21 #include "kernel/log.h"
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24
  25 USING_YOSYS_NAMESPACE
  26 PRIVATE_NAMESPACE_BEGIN
  27
  28 struct OptPass : public Pass {
  29         OptPass() : Pass("opt", "perform simple optimizations") { }
  30         void help() YS_OVERRIDE
  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_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
  41                 log("    opt_merge [-share_all] -nomux\n");
  42                 log("\n");
  43                 log("    do\n");
  44                 log("        opt_muxtree\n");
  45                 log("        opt_reduce [-fine] [-full]\n");
  46                 log("        opt_merge [-share_all]\n");
  47                 log("        opt_share (-full only)\n");
  48                 log("        opt_rmdff [-keepdc] [-sat]\n");
  49                 log("        opt_clean [-purge]\n");
  50                 log("        opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
  51                 log("    while <changed design>\n");
  52                 log("\n");
  53                 log("When called with -fast the following script is used instead:\n");
  54                 log("\n");
  55                 log("    do\n");
  56                 log("        opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
  57                 log("        opt_merge [-share_all]\n");
  58                 log("        opt_rmdff [-keepdc] [-sat]\n");
  59                 log("        opt_clean [-purge]\n");
  60                 log("    while <changed design in opt_rmdff>\n");
  61                 log("\n");
  62                 log("Note: Options in square brackets (such as [-keepdc]) are passed through to\n");
  63                 log("the opt_* commands when given to 'opt'.\n");
  64                 log("\n");
  65                 log("\n");
  66         }
  67         void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
  68         {
  69                 std::string opt_clean_args;
  70                 std::string opt_expr_args;
  71                 std::string opt_reduce_args;
  72                 std::string opt_merge_args;
  73                 std::string opt_rmdff_args;
  74                 bool opt_share = false;
  75                 bool fast_mode = false;
  76
  77                 log_header(design, "Executing OPT pass (performing simple optimizations).\n");
  78                 log_push();
  79
  80                 size_t argidx;
  81                 for (argidx = 1; argidx < args.size(); argidx++) {
  82                         if (args[argidx] == "-purge") {
  83                                 opt_clean_args += " -purge";
  84                                 continue;
  85                         }
  86                         if (args[argidx] == "-mux_undef") {
  87                                 opt_expr_args += " -mux_undef";
  88                                 continue;
  89                         }
  90                         if (args[argidx] == "-mux_bool") {
  91                                 opt_expr_args += " -mux_bool";
  92                                 continue;
  93                         }
  94                         if (args[argidx] == "-undriven") {
  95                                 opt_expr_args += " -undriven";
  96                                 continue;
  97                         }
  98                         if (args[argidx] == "-clkinv") {
  99                                 opt_expr_args += " -clkinv";
 100                                 continue;
 101                         }
 102                         if (args[argidx] == "-fine") {
 103                                 opt_expr_args += " -fine";
 104                                 opt_reduce_args += " -fine";
 105                                 continue;
 106                         }
 107                         if (args[argidx] == "-full") {
 108                                 opt_expr_args += " -full";
 109                                 opt_reduce_args += " -full";
 110                                 opt_share = true;
 111                                 continue;
 112                         }
 113                         if (args[argidx] == "-keepdc") {
 114                                 opt_expr_args += " -keepdc";
 115                                 opt_rmdff_args += " -keepdc";
 116                                 continue;
 117                         }
 118                         if (args[argidx] == "-sat") {
 119                                 opt_rmdff_args += " -sat";
 120                                 continue;
 121                         }
 122                         if (args[argidx] == "-share_all") {
 123                                 opt_merge_args += " -share_all";
 124                                 continue;
 125                         }
 126                         if (args[argidx] == "-fast") {
 127                                 fast_mode = true;
 128                                 continue;
 129                         }
 130                         break;
 131                 }
 132                 extra_args(args, argidx, design);
 133
 134                 if (fast_mode)
 135                 {
 136                         while (1) {
 137                                 Pass::call(design, "opt_expr" + opt_expr_args);
 138                                 Pass::call(design, "opt_merge" + opt_merge_args);
 139                                 design->scratchpad_unset("opt.did_something");
 140                                 Pass::call(design, "opt_rmdff" + opt_rmdff_args);
 141                                 if (design->scratchpad_get_bool("opt.did_something") == false)
 142                                         break;
 143                                 Pass::call(design, "opt_clean" + opt_clean_args);
 144                                 log_header(design, "Rerunning OPT passes. (Removed registers in this run.)\n");
 145                         }
 146                         Pass::call(design, "opt_clean" + opt_clean_args);
 147                 }
 148                 else
 149                 {
 150                         Pass::call(design, "opt_expr" + opt_expr_args);
 151                         Pass::call(design, "opt_merge -nomux" + opt_merge_args);
 152                         while (1) {
 153                                 design->scratchpad_unset("opt.did_something");
 154                                 Pass::call(design, "opt_muxtree");
 155                                 Pass::call(design, "opt_reduce" + opt_reduce_args);
 156                                 Pass::call(design, "opt_merge" + opt_merge_args);
 157                                 if (opt_share)
 158                                         Pass::call(design, "opt_share");
 159                                 Pass::call(design, "opt_rmdff" + opt_rmdff_args);
 160                                 Pass::call(design, "opt_clean" + opt_clean_args);
 161                                 Pass::call(design, "opt_expr" + opt_expr_args);
 162                                 if (design->scratchpad_get_bool("opt.did_something") == false)
 163                                         break;
 164                                 log_header(design, "Rerunning OPT passes. (Maybe there is more to do..)\n");
 165                         }
 166                 }
 167
 168                 design->optimize();
 169                 design->sort();
 170                 design->check();
 171
 172                 log_header(design, fast_mode ? "Finished fast OPT passes.\n" : "Finished OPT passes. (There is nothing left to do.)\n");
 173                 log_pop();
 174         }
 175 } OptPass;
 176
 177 PRIVATE_NAMESPACE_END