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