passes/opt/opt_mem.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/yosys.h"
  21 #include "kernel/sigtools.h"
  22
  23 USING_YOSYS_NAMESPACE
  24 PRIVATE_NAMESPACE_BEGIN
  25
  26 struct OptMemWorker
  27 {
  28         RTLIL::Design *design;
  29         RTLIL::Module *module;
  30         SigMap sigmap;
  31         bool restart;
  32
  33         dict<IdString, vector<IdString>> memrd, memwr, meminit;
  34         pool<IdString> remove_mem, remove_cells;
  35
  36         OptMemWorker(RTLIL::Module *module) : design(module->design), module(module), sigmap(module), restart(false)
  37         {
  38                 for (auto &it : module->memories)
  39                 {
  40                         memrd[it.first];
  41                         memwr[it.first];
  42                         meminit[it.first];
  43                 }
  44
  45                 for (auto cell : module->cells())
  46                 {
  47                         if (cell->type == ID($memrd)) {
  48                                 IdString id = cell->getParam(ID::MEMID).decode_string();
  49                                 memrd.at(id).push_back(cell->name);
  50                         }
  51
  52                         if (cell->type == ID($memwr)) {
  53                                 IdString id = cell->getParam(ID::MEMID).decode_string();
  54                                 memwr.at(id).push_back(cell->name);
  55                         }
  56
  57                         if (cell->type == ID($meminit)) {
  58                                 IdString id = cell->getParam(ID::MEMID).decode_string();
  59                                 meminit.at(id).push_back(cell->name);
  60                         }
  61                 }
  62         }
  63
  64         ~OptMemWorker()
  65         {
  66                 for (auto it : remove_mem)
  67                 {
  68                         for (auto cell_name : memrd[it])
  69                                 module->remove(module->cell(cell_name));
  70                         for (auto cell_name : memwr[it])
  71                                 module->remove(module->cell(cell_name));
  72                         for (auto cell_name : meminit[it])
  73                                 module->remove(module->cell(cell_name));
  74
  75                         delete module->memories.at(it);
  76                         module->memories.erase(it);
  77                 }
  78
  79                 for (auto cell_name : remove_cells)
  80                         module->remove(module->cell(cell_name));
  81         }
  82
  83         int run(RTLIL::Memory *mem)
  84         {
  85                 if (restart || remove_mem.count(mem->name))
  86                         return 0;
  87
  88                 if (memwr.at(mem->name).empty() && meminit.at(mem->name).empty()) {
  89                         log("Removing memory %s.%s with no write ports or init data.\n", log_id(module), log_id(mem));
  90                         remove_mem.insert(mem->name);
  91                         return 1;
  92                 }
  93
  94                 return 0;
  95         }
  96 };
  97
  98 struct OptMemPass : public Pass {
  99         OptMemPass() : Pass("opt_mem", "optimize memories") { }
 100         void help() YS_OVERRIDE
 101         {
 102                 //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 103                 log("\n");
 104                 log("    opt_mem [options] [selection]\n");
 105                 log("\n");
 106                 log("This pass performs various optimizations on memories in the design.\n");
 107                 log("\n");
 108         }
 109         void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 110         {
 111                 log_header(design, "Executing OPT_MEM pass (optimize memories).\n");
 112
 113                 size_t argidx;
 114                 for (argidx = 1; argidx < args.size(); argidx++) {
 115                         // if (args[argidx] == "-nomux") {
 116                         //      mode_nomux = true;
 117                         //      continue;
 118                         // }
 119                         break;
 120                 }
 121                 extra_args(args, argidx, design);
 122
 123                 int total_count = 0;
 124                 for (auto module : design->selected_modules()) {
 125                         while (1) {
 126                                 int cnt = 0;
 127                                 OptMemWorker worker(module);
 128                                 for (auto &it : module->memories)
 129                                         if (module->selected(it.second))
 130                                                 cnt += worker.run(it.second);
 131                                 if (!cnt && !worker.restart)
 132                                         break;
 133                                 total_count += cnt;
 134                         }
 135                 }
 136
 137                 if (total_count)
 138                         design->scratchpad_set_bool("opt.did_something", true);
 139                 log("Performed a total of %d transformations.\n", total_count);
 140         }
 141 } OptMemPass;
 142
 143 PRIVATE_NAMESPACE_END