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 #include <errno.h>
  29
  30 static void fm_set_fsm_print(RTLIL::Cell *cell, RTLIL::Module *module, FsmData &fsm_data, const char *prefix, FILE *f)
  31 {
  32         std::string name = cell->parameters["\\NAME"].decode_string();
  33
  34         fprintf(f, "set_fsm_state_vector {");
  35         for (int i = fsm_data.state_bits-1; i >= 0; i--)
  36                 fprintf(f, " %s_reg[%d]", name[0] == '\\' ?  name.substr(1).c_str() : name.c_str(), i);
  37         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n", prefix, RTLIL::unescape_id(name).c_str(),
  38                         prefix, RTLIL::unescape_id(module->name).c_str());
  39
  40         fprintf(f, "set_fsm_encoding {");
  41         for (size_t i = 0; i < fsm_data.state_table.size(); i++) {
  42                 fprintf(f, " s%zd=2#", i);
  43                 for (int j = int(fsm_data.state_table[i].bits.size())-1; j >= 0; j--)
  44                         fprintf(f, "%c", fsm_data.state_table[i].bits[j] == RTLIL::State::S1 ? '1' : '0');
  45         }
  46         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n",
  47                         prefix, RTLIL::unescape_id(name).c_str(),
  48                         prefix, RTLIL::unescape_id(module->name).c_str());
  49 }
  50
  51 static void fsm_recode(RTLIL::Cell *cell, RTLIL::Module *module, FILE *fm_set_fsm_file, std::string default_encoding)
  52 {
  53         std::string encoding = cell->attributes.count("\\fsm_encoding") ? cell->attributes.at("\\fsm_encoding").decode_string() : "auto";
  54
  55         log("Recoding FSM `%s' from module `%s' using `%s' encoding:\n", cell->name.c_str(), module->name.c_str(), encoding.c_str());
  56         if (encoding != "none" && encoding != "one-hot" && encoding != "binary") {
  57                 if (encoding != "auto")
  58                         log("  unkown encoding `%s': using auto (%s) instead.\n", encoding.c_str(), default_encoding.c_str());
  59                 encoding = default_encoding;
  60         }
  61
  62         if (encoding == "none") {
  63                 log("  nothing to do for encoding `none'.\n");
  64                 return;
  65         }
  66
  67         FsmData fsm_data;
  68         fsm_data.copy_from_cell(cell);
  69
  70         if (fm_set_fsm_file != NULL)
  71                 fm_set_fsm_print(cell, module, fsm_data, "r", fm_set_fsm_file);
  72
  73         if (encoding == "one-hot") {
  74                 fsm_data.state_bits = fsm_data.state_table.size();
  75         } else
  76         if (encoding == "auto" || encoding == "binary") {
  77                 fsm_data.state_bits = ceil(log2(fsm_data.state_table.size()));
  78         } else
  79                 log_error("FSM encoding `%s' is not supported!\n", encoding.c_str());
  80
  81         int state_idx_counter = fsm_data.reset_state >= 0 ? 1 : 0;
  82         for (int i = 0; i < int(fsm_data.state_table.size()); i++)
  83         {
  84                 int state_idx = fsm_data.reset_state == i ? 0 : state_idx_counter++;
  85                 RTLIL::Const new_code;
  86
  87                 if (encoding == "one-hot") {
  88                         new_code = RTLIL::Const(RTLIL::State::Sa, fsm_data.state_bits);
  89                         new_code.bits[state_idx] = RTLIL::State::S1;
  90                 } else
  91                 if (encoding == "auto" || encoding == "binary") {
  92                         new_code = RTLIL::Const(state_idx, fsm_data.state_bits);
  93                 } else
  94                         log_abort();
  95
  96                 log("  %s -> %s\n", fsm_data.state_table[i].as_string().c_str(), new_code.as_string().c_str());
  97                 fsm_data.state_table[i] = new_code;
  98         }
  99
 100         if (fm_set_fsm_file != NULL)
 101                 fm_set_fsm_print(cell, module, fsm_data, "i", fm_set_fsm_file);
 102
 103         fsm_data.copy_to_cell(cell);
 104 }
 105
 106 struct FsmRecodePass : public Pass {
 107         FsmRecodePass() : Pass("fsm_recode", "recoding finite state machines") { }
 108         virtual void help()
 109         {
 110                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 111                 log("\n");
 112                 log("    fsm_recode [-encoding type] [-fm_set_fsm_file file] [selection]\n");
 113                 log("\n");
 114                 log("This pass reassign the state encodings for FSM cells. At the moment only\n");
 115                 log("one-hot encoding and binary encoding is supported. The option -encoding\n");
 116                 log("can be used to specify the encoding scheme used for FSMs without the\n");
 117                 log("`fsm_encoding' attribute (or with the attribute set to `auto'.\n");
 118                 log("\n");
 119                 log("The option -fm_set_fsm_file can be used to generate a file containing the\n");
 120                 log("mapping from old to new FSM encoding in form of Synopsys Formality set_fsm_*\n");
 121                 log("commands.\n");
 122                 log("\n");
 123         }
 124         virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
 125         {
 126                 FILE *fm_set_fsm_file = NULL;
 127                 std::string default_encoding = "one-hot";
 128
 129                 log_header("Executing FSM_RECODE pass (re-assigning FSM state encoding).\n");
 130                 size_t argidx;
 131                 for (argidx = 1; argidx < args.size(); argidx++) {
 132                         std::string arg = args[argidx];
 133                         if (arg == "-fm_set_fsm_file" && argidx+1 < args.size() && fm_set_fsm_file == NULL) {
 134                                 fm_set_fsm_file = fopen(args[++argidx].c_str(), "w");
 135                                 if (fm_set_fsm_file == NULL)
 136                                         log_error("Can't open fm_set_fsm_file `%s' for writing: %s\n", args[argidx].c_str(), strerror(errno));
 137                                 continue;
 138                         }
 139                         if (arg == "-encoding" && argidx+1 < args.size() && fm_set_fsm_file == NULL) {
 140                                 default_encoding = args[++argidx];
 141                                 continue;
 142                         }
 143                         break;
 144                 }
 145                 extra_args(args, argidx, design);
 146
 147                 for (auto &mod_it : design->modules)
 148                         if (design->selected(mod_it.second))
 149                                 for (auto &cell_it : mod_it.second->cells)
 150                                         if (cell_it.second->type == "$fsm" && design->selected(mod_it.second, cell_it.second))
 151                                                 fsm_recode(cell_it.second, mod_it.second, fm_set_fsm_file, default_encoding);
 152
 153                 if (fm_set_fsm_file != NULL)
 154                         fclose(fm_set_fsm_file);
 155         }
 156 } FsmRecodePass;
 157