passes/fsm/fsm_recode.cc

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2012  Claire Xenia Wolf <claire@yosyshq.com>
   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 USING_YOSYS_NAMESPACE
  31 PRIVATE_NAMESPACE_BEGIN
  32
  33 static void fm_set_fsm_print(RTLIL::Cell *cell, RTLIL::Module *module, FsmData &fsm_data, const char *prefix, FILE *f)
  34 {
  35         std::string name = cell->parameters[ID::NAME].decode_string();
  36
  37         fprintf(f, "set_fsm_state_vector {");
  38         for (int i = fsm_data.state_bits-1; i >= 0; i--)
  39                 fprintf(f, " %s_reg[%d]", name[0] == '\\' ?  name.substr(1).c_str() : name.c_str(), i);
  40         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n", prefix, RTLIL::unescape_id(name).c_str(),
  41                         prefix, RTLIL::unescape_id(module->name).c_str());
  42
  43         fprintf(f, "set_fsm_encoding {");
  44         for (int i = 0; i < GetSize(fsm_data.state_table); i++) {
  45                 fprintf(f, " s%d=2#", i);
  46                 for (int j = GetSize(fsm_data.state_table[i].bits)-1; j >= 0; j--)
  47                         fprintf(f, "%c", fsm_data.state_table[i].bits[j] == RTLIL::State::S1 ? '1' : '0');
  48         }
  49         fprintf(f, " } -name {%s_%s} {%s:/WORK/%s}\n",
  50                         prefix, RTLIL::unescape_id(name).c_str(),
  51                         prefix, RTLIL::unescape_id(module->name).c_str());
  52 }
  53
  54 static void fsm_recode(RTLIL::Cell *cell, RTLIL::Module *module, FILE *fm_set_fsm_file, FILE *encfile, std::string default_encoding)
  55 {
  56         std::string encoding = cell->attributes.count(ID::fsm_encoding) ? cell->attributes.at(ID::fsm_encoding).decode_string() : "auto";
  57
  58         log("Recoding FSM `%s' from module `%s' using `%s' encoding:\n", cell->name.c_str(), module->name.c_str(), encoding.c_str());
  59
  60         if (encoding != "none" && encoding != "user" && encoding != "one-hot" && encoding != "binary" && encoding != "auto") {
  61                 log("  unknown encoding `%s': using auto instead.\n", encoding.c_str());
  62                 encoding = "auto";
  63         }
  64
  65         if (encoding == "none" || encoding == "user") {
  66                 log("  nothing to do for encoding `%s'.\n", encoding.c_str());
  67                 return;
  68         }
  69
  70         FsmData fsm_data;
  71         fsm_data.copy_from_cell(cell);
  72
  73         if (fm_set_fsm_file != NULL)
  74                 fm_set_fsm_print(cell, module, fsm_data, "r", fm_set_fsm_file);
  75
  76         if (encoding == "auto") {
  77                 if (!default_encoding.empty())
  78                         encoding = default_encoding;
  79                 else
  80                         encoding = GetSize(fsm_data.state_table) < 32 ? "one-hot" : "binary";
  81                 log("  mapping auto encoding to `%s` for this FSM.\n", encoding.c_str());
  82         }
  83
  84         if (encoding == "one-hot") {
  85                 fsm_data.state_bits = fsm_data.state_table.size();
  86         } else
  87         if (encoding == "binary") {
  88                 int new_num_state_bits = ceil_log2(fsm_data.state_table.size());
  89                 if (fsm_data.state_bits == new_num_state_bits) {
  90                         log("  existing encoding is already a packed binary encoding.\n");
  91                         return;
  92                 }
  93                 fsm_data.state_bits = new_num_state_bits;
  94         } else
  95                 log_error("FSM encoding `%s' is not supported!\n", encoding.c_str());
  96
  97         if (encfile)
  98                 fprintf(encfile, ".fsm %s %s\n", log_id(module), RTLIL::unescape_id(cell->parameters[ID::NAME].decode_string()).c_str());
  99
 100         int state_idx_counter = fsm_data.reset_state >= 0 ? 1 : 0;
 101         for (int i = 0; i < int(fsm_data.state_table.size()); i++)
 102         {
 103                 int state_idx = fsm_data.reset_state == i ? 0 : state_idx_counter++;
 104                 RTLIL::Const new_code;
 105
 106                 if (encoding == "one-hot") {
 107                         new_code = RTLIL::Const(RTLIL::State::Sa, fsm_data.state_bits);
 108                         new_code.bits[state_idx] = RTLIL::State::S1;
 109                 } else
 110                 if (encoding == "binary") {
 111                         new_code = RTLIL::Const(state_idx, fsm_data.state_bits);
 112                 } else
 113                         log_abort();
 114
 115                 log("  %s -> %s\n", fsm_data.state_table[i].as_string().c_str(), new_code.as_string().c_str());
 116                 if (encfile)
 117                         fprintf(encfile, ".map %s %s\n", fsm_data.state_table[i].as_string().c_str(), new_code.as_string().c_str());
 118                 fsm_data.state_table[i] = new_code;
 119         }
 120
 121         if (fm_set_fsm_file != NULL)
 122                 fm_set_fsm_print(cell, module, fsm_data, "i", fm_set_fsm_file);
 123
 124         fsm_data.copy_to_cell(cell);
 125 }
 126
 127 struct FsmRecodePass : public Pass {
 128         FsmRecodePass() : Pass("fsm_recode", "recoding finite state machines") { }
 129         void help() override
 130         {
 131                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 132                 log("\n");
 133                 log("    fsm_recode [options] [selection]\n");
 134                 log("\n");
 135                 log("This pass reassign the state encodings for FSM cells. At the moment only\n");
 136                 log("one-hot encoding and binary encoding is supported.\n");
 137
 138                 log("    -encoding <type>\n");
 139                 log("        specify the encoding scheme used for FSMs without the\n");
 140                 log("        'fsm_encoding' attribute or with the attribute set to `auto'.\n");
 141                 log("\n");
 142                 log("    -fm_set_fsm_file <file>\n");
 143                 log("        generate a file containing the mapping from old to new FSM encoding\n");
 144                 log("        in form of Synopsys Formality set_fsm_* commands.\n");
 145                 log("\n");
 146                 log("    -encfile <file>\n");
 147                 log("        write the mappings from old to new FSM encoding to a file in the\n");
 148                 log("        following format:\n");
 149                 log("\n");
 150                 log("            .fsm <module_name> <state_signal>\n");
 151                 log("            .map <old_bitpattern> <new_bitpattern>\n");
 152                 log("\n");
 153         }
 154         void execute(std::vector<std::string> args, RTLIL::Design *design) override
 155         {
 156                 FILE *fm_set_fsm_file = NULL;
 157                 FILE *encfile = NULL;
 158                 std::string default_encoding;
 159
 160                 log_header(design, "Executing FSM_RECODE pass (re-assigning FSM state encoding).\n");
 161                 size_t argidx;
 162                 for (argidx = 1; argidx < args.size(); argidx++) {
 163                         std::string arg = args[argidx];
 164                         if (arg == "-fm_set_fsm_file" && argidx+1 < args.size() && fm_set_fsm_file == NULL) {
 165                                 fm_set_fsm_file = fopen(args[++argidx].c_str(), "w");
 166                                 if (fm_set_fsm_file == NULL)
 167                                         log_error("Can't open fm_set_fsm_file `%s' for writing: %s\n", args[argidx].c_str(), strerror(errno));
 168                                 continue;
 169                         }
 170                         if (arg == "-encfile" && argidx+1 < args.size() && encfile == NULL) {
 171                                 encfile = fopen(args[++argidx].c_str(), "w");
 172                                 if (encfile == NULL)
 173                                         log_error("Can't open encfile `%s' for writing: %s\n", args[argidx].c_str(), strerror(errno));
 174                                 continue;
 175                         }
 176                         if (arg == "-encoding" && argidx+1 < args.size() && default_encoding.empty()) {
 177                                 default_encoding = args[++argidx];
 178                                 continue;
 179                         }
 180                         break;
 181                 }
 182                 extra_args(args, argidx, design);
 183
 184                 for (auto mod : design->selected_modules())
 185                         for (auto cell : mod->selected_cells())
 186                                 if (cell->type == ID($fsm))
 187                                         fsm_recode(cell, mod, fm_set_fsm_file, encfile, default_encoding);
 188
 189                 if (fm_set_fsm_file != NULL)
 190                         fclose(fm_set_fsm_file);
 191                 if (encfile != NULL)
 192                         fclose(encfile);
 193         }
 194 } FsmRecodePass;
 195
 196 PRIVATE_NAMESPACE_END