passes/fsm/fsm_recode.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/log.h"
  21 #include "kernel/register.h"
  22 #include "kernel/sigtools.h"
  23 #include "kernel/consteval.h"
  24 #include "kernel/celltypes.h"
  25 #include "fsmdata.h"
  26 #include "math.h"
  27 #include <string.h>
  28
  29 static void fm_set_fsm_print(RTLIL::Cell *cell, RTLIL::Module *module, FsmData &fsm_data, const char *prefix, FILE *f)
  30 {
  31         fprintf(f, "set_fsm_state_vector {");
  32         for (int i = fsm_data.state_bits-1; i >= 0; i--)
  33                 fprintf(f, " %s_reg[%d]", cell->parameters["\\NAME"].str[0] == '\\' ?
  34                                 cell->parameters["\\NAME"].str.substr(1).c_str() : cell->parameters["\\NAME"].str.c_str(), i);
  35         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n",
  36                         prefix, RTLIL::unescape_id(cell->parameters["\\NAME"].str).c_str(),
  37                         prefix, RTLIL::unescape_id(module->name).c_str());
  38
  39         fprintf(f, "set_fsm_encoding {");
  40         for (size_t i = 0; i < fsm_data.state_table.size(); i++) {
  41                 fprintf(f, " s%zd=2#", i);
  42                 for (int j = int(fsm_data.state_table[i].bits.size())-1; j >= 0; j--)
  43                         fprintf(f, "%c", fsm_data.state_table[i].bits[j] == RTLIL::State::S1 ? '1' : '0');
  44         }
  45         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n",
  46                         prefix, RTLIL::unescape_id(cell->parameters["\\NAME"].str).c_str(),
  47                         prefix, RTLIL::unescape_id(module->name).c_str());
  48 }
  49
  50 static void fsm_recode(RTLIL::Cell *cell, RTLIL::Module *module, FILE *fm_set_fsm_file, std::string default_encoding)
  51 {
  52         std::string encoding = cell->attributes.count("\\fsm_encoding") ? cell->attributes.at("\\fsm_encoding").str : "auto";
  53
  54         log("Recoding FSM `%s' from module `%s' using `%s' encoding:\n", cell->name.c_str(), module->name.c_str(), encoding.c_str());
  55         if (encoding != "none" && encoding != "one-hot" && encoding != "binary") {
  56                 if (encoding != "auto")
  57                         log("  unkown encoding `%s': using auto (%s) instead.\n", encoding.c_str(), default_encoding.c_str());
  58                 encoding = default_encoding;
  59         }
  60
  61         if (encoding == "none") {
  62                 log("  nothing to do for encoding `none'.\n");
  63                 return;
  64         }
  65
  66         FsmData fsm_data;
  67         fsm_data.copy_from_cell(cell);
  68
  69         if (fm_set_fsm_file != NULL)
  70                 fm_set_fsm_print(cell, module, fsm_data, "r", fm_set_fsm_file);
  71
  72         if (encoding == "one-hot") {
  73                 fsm_data.state_bits = fsm_data.state_table.size();
  74         } else
  75         if (encoding == "auto" || encoding == "binary") {
  76                 fsm_data.state_bits = ceil(log2(fsm_data.state_table.size()));
  77         } else
  78                 log_error("FSM encoding `%s' is not supported!\n", encoding.c_str());
  79
  80         int state_idx_counter = fsm_data.reset_state >= 0 ? 1 : 0;
  81         for (int i = 0; i < int(fsm_data.state_table.size()); i++)
  82         {
  83                 int state_idx = fsm_data.reset_state == i ? 0 : state_idx_counter++;
  84                 RTLIL::Const new_code;
  85
  86                 if (encoding == "one-hot") {
  87                         new_code = RTLIL::Const(RTLIL::State::Sa, fsm_data.state_bits);
  88                         new_code.bits[state_idx] = RTLIL::State::S1;
  89                 } else
  90                 if (encoding == "auto" || encoding == "binary") {
  91                         new_code = RTLIL::Const(state_idx, fsm_data.state_bits);
  92                 } else
  93                         log_abort();
  94
  95                 log("  %s -> %s\n", fsm_data.state_table[i].as_string().c_str(), new_code.as_string().c_str());
  96                 fsm_data.state_table[i] = new_code;
  97         }
  98
  99         if (fm_set_fsm_file != NULL)
 100                 fm_set_fsm_print(cell, module, fsm_data, "i", fm_set_fsm_file);
 101
 102         fsm_data.copy_to_cell(cell);
 103 }
 104
 105 struct FsmRecodePass : public Pass {
 106         FsmRecodePass() : Pass("fsm_recode", "recoding finite state machines") { }
 107         virtual void help()
 108         {
 109                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 110                 log("\n");
 111                 log("    fsm_recode [-encoding type] [-fm_set_fsm_file file] [selection]\n");
 112                 log("\n");
 113                 log("This pass reassign the state encodings for FSM cells. At the moment only\n");
 114                 log("one-hot encoding and binary encoding is supported. The option -encoding\n");
 115                 log("can be used to specify the encoding scheme used for FSMs without the\n");
 116                 log("`fsm_encoding' attribute (or with the attribute set to `auto'.\n");
 117                 log("\n");
 118                 log("The option -fm_set_fsm_file can be used to generate a file containing the\n");
 119                 log("mapping from old to new FSM encoding in form of Synopsys Formality set_fsm_*\n");
 120                 log("commands.\n");
 121                 log("\n");
 122         }
 123         virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
 124         {
 125                 FILE *fm_set_fsm_file = NULL;
 126                 std::string default_encoding = "one-hot";
 127
 128                 log_header("Executing FSM_RECODE pass (re-assigning FSM state encoding).\n");
 129                 size_t argidx;
 130                 for (argidx = 1; argidx < args.size(); argidx++) {
 131                         std::string arg = args[argidx];
 132                         if (arg == "-fm_set_fsm_file" && argidx+1 < args.size() && fm_set_fsm_file == NULL) {
 133                                 fm_set_fsm_file = fopen(args[++argidx].c_str(), "w");
 134                                 if (fm_set_fsm_file == NULL)
 135                                         log_error("Can't open fm_set_fsm_file `%s' for writing: %s\n", args[argidx].c_str(), strerror(errno));
 136                                 continue;
 137                         }
 138                         if (arg == "-encoding" && argidx+1 < args.size() && fm_set_fsm_file == NULL) {
 139                                 default_encoding = args[++argidx];
 140                                 continue;
 141                         }
 142                         break;
 143                 }
 144                 extra_args(args, argidx, design);
 145
 146                 for (auto &mod_it : design->modules)
 147                         if (design->selected(mod_it.second))
 148                                 for (auto &cell_it : mod_it.second->cells)
 149                                         if (cell_it.second->type == "$fsm" && design->selected(mod_it.second, cell_it.second))
 150                                                 fsm_recode(cell_it.second, mod_it.second, fm_set_fsm_file, default_encoding);
 151
 152                 if (fm_set_fsm_file != NULL)
 153                         fclose(fm_set_fsm_file);
 154         }
 155 } FsmRecodePass;
 156