From a7fe87f8886900b3e9056caf392978e06c5a74ae Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Sat, 3 Jan 2015 17:34:05 +0100 Subject: Added memory_bram 'or_next_if_better' feature --- passes/memory/memory_bram.cc | 198 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 156 insertions(+), 42 deletions(-) (limited to 'passes') diff --git a/passes/memory/memory_bram.cc b/passes/memory/memory_bram.cc index 83a1d5b1..86828989 100644 --- a/passes/memory/memory_bram.cc +++ b/passes/memory/memory_bram.cc @@ -63,6 +63,7 @@ struct rules_t struct match_t { IdString name; dict min_limits, max_limits; + bool or_next_if_better; }; dict brams; @@ -174,6 +175,7 @@ struct rules_t match_t data; data.name = RTLIL::escape_id(tokens[1]); + data.or_next_if_better = false; while (next_line()) { @@ -192,6 +194,11 @@ struct rules_t continue; } + if (GetSize(tokens) == 1 && tokens[0] == "or_next_if_better") { + data.or_next_if_better = true; + continue; + } + break; } @@ -217,7 +224,7 @@ struct rules_t } }; -bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_t&) +bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_t &match, dict &match_properties, int mode) { Module *module = cell->module; @@ -247,7 +254,7 @@ bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_ transp_max = std::max(transp_max, pi.transp); } - log(" Mapping to bram type %s:\n", log_id(bram.name)); + log(" Mapping to bram type %s:\n", log_id(bram.name)); int mem_size = cell->getParam("\\SIZE").as_int(); int mem_abits = cell->getParam("\\ABITS").as_int(); @@ -287,7 +294,7 @@ bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_ if (!clken) clkdom = pair(State::S1, false); - log(" Write port #%d is in clock domain %s%s.\n", + log(" Write port #%d is in clock domain %s%s.\n", cell_port_i, clkdom.second ? "" : "!", clken ? log_signal(clkdom.first) : "~async~"); @@ -301,20 +308,20 @@ bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_ if (clken) { if (pi.clocks == 0) { - log(" Bram port %c%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1); + log(" Bram port %c%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1); goto skip_bram_wport; } if (clock_domains.count(pi.clocks) && clock_domains.at(pi.clocks) != clkdom) { - log(" Bram port %c%d is in a different clock domain.\n", pi.group + 'A', pi.index + 1); + log(" Bram port %c%d is in a different clock domain.\n", pi.group + 'A', pi.index + 1); goto skip_bram_wport; } if (clock_polarities.count(pi.clkpol) && clock_polarities.at(pi.clkpol) != clkpol) { - log(" Bram port %c%d has incompatible clock polarity.\n", pi.group + 'A', pi.index + 1); + log(" Bram port %c%d has incompatible clock polarity.\n", pi.group + 'A', pi.index + 1); goto skip_bram_wport; } } else { if (pi.clocks != 0) { - log(" Bram port %c%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1); + log(" Bram port %c%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1); goto skip_bram_wport; } } @@ -327,12 +334,12 @@ bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_ sig_en.append(last_en_bit); } if (last_en_bit != wr_en[i + cell_port_i*mem_width]) { - log(" Bram port %c%d has incompatible enable structure.\n", pi.group + 'A', pi.index + 1); + log(" Bram port %c%d has incompatible enable structure.\n", pi.group + 'A', pi.index + 1); goto skip_bram_wport; } } - log(" Mapped to bram port %c%d.\n", pi.group + 'A', pi.index + 1); + log(" Mapped to bram port %c%d.\n", pi.group + 'A', pi.index + 1); pi.mapped_port = cell_port_i; if (clken) { @@ -350,7 +357,7 @@ bool replace_cell(Cell *cell, const rules_t::bram_t &bram, const rules_t::match_ goto mapped_wr_port; } - log(" Failed to map write port #%d.\n", cell_port_i); + log(" Failed to map write port #%d.\n", cell_port_i); return false; mapped_wr_port:; } @@ -405,7 +412,7 @@ grow_read_ports:; if (!clken) clkdom = pair(State::S1, false); - log(" Read port #%d is in clock domain %s%s.\n", + log(" Read port #%d is in clock domain %s%s.\n", cell_port_i, clkdom.second ? "" : "!", clken ? log_signal(clkdom.first) : "~async~"); @@ -419,29 +426,29 @@ grow_read_ports:; if (clken) { if (pi.clocks == 0) { - log(" Bram port %c%d.%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Bram port %c%d.%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); goto skip_bram_rport; } if (clock_domains.count(pi.clocks) && clock_domains.at(pi.clocks) != clkdom) { - log(" Bram port %c%d.%d is in a different clock domain.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Bram port %c%d.%d is in a different clock domain.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); goto skip_bram_rport; } if (clock_polarities.count(pi.clkpol) && clock_polarities.at(pi.clkpol) != clkpol) { - log(" Bram port %c%d.%d has incompatible clock polarity.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Bram port %c%d.%d has incompatible clock polarity.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); goto skip_bram_rport; } if (read_transp.count(pi.transp) && read_transp.at(pi.transp) != transp) { - log(" Bram port %c%d.%d has incompatible read transparancy.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Bram port %c%d.%d has incompatible read transparancy.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); goto skip_bram_rport; } } else { if (pi.clocks != 0) { - log(" Bram port %c%d.%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Bram port %c%d.%d has incompatible clock type.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); goto skip_bram_rport; } } - log(" Mapped to bram port %c%d.%d.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); + log(" Mapped to bram port %c%d.%d.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1); pi.mapped_port = cell_port_i; if (clken) { @@ -463,15 +470,51 @@ grow_read_ports:; goto mapped_rd_port; } - log(" Failed to map read port #%d.\n", cell_port_i); + log(" Failed to map read port #%d.\n", cell_port_i); if (try_growing_more_read_ports) { - log(" Growing more read ports by duplicating bram cells.\n"); + log(" Growing more read ports by duplicating bram cells.\n"); goto grow_read_ports; } return false; mapped_rd_port:; } + if (mode <= 1) + { + match_properties["dups"] = dup_count; + match_properties["waste"] = match_properties["dups"] * match_properties["bwaste"]; + + int cells = ((match_properties["dbits"] + bram.dbits - 1) / bram.dbits) * ((match_properties["words"] + (1 << bram.abits) - 1) / (1 << bram.abits)); + match_properties["efficiency"] = (100 * match_properties["bits"]) / (dup_count * cells * bram.dbits * (1 << bram.abits)); + + log(" Updated properties: dups=%d waste=%d efficiency=%d\n", + match_properties["dups"], match_properties["waste"], match_properties["efficiency"]); + + for (auto it : match.min_limits) { + if (!match_properties.count(it.first)) + log_error("Unknown property '%s' in match rule for bram type %s.\n", + it.first.c_str(), log_id(match.name)); + if (match_properties[it.first] >= it.second) + continue; + log(" Rule for bram type %s rejected: requirement 'min %s %d' not met.\n", + log_id(match.name), it.first.c_str(), it.second); + return false; + } + for (auto it : match.max_limits) { + if (!match_properties.count(it.first)) + log_error("Unknown property '%s' in match rule for bram type %s.\n", + it.first.c_str(), log_id(match.name)); + if (match_properties[it.first] <= it.second) + continue; + log(" Rule for bram type %s rejected: requirement 'max %s %d' not met.\n", + log_id(match.name), it.first.c_str(), it.second); + return false; + } + + if (mode == 1) + return true; + } + dict> dout_cache; for (int grid_d = 0; grid_d*bram.dbits < mem_width; grid_d++) @@ -479,7 +522,7 @@ grow_read_ports:; for (int dupidx = 0; dupidx < dup_count; dupidx++) { Cell *c = module->addCell(module->uniquify(stringf("%s.%d.%d.%d", cell->name.c_str(), grid_d, grid_a, dupidx)), bram.name); - log(" Creating %s cell at grid position <%d %d %d>: %s\n", log_id(bram.name), grid_d, grid_a, dupidx, log_id(c)); + log(" Creating %s cell at grid position <%d %d %d>: %s\n", log_id(bram.name), grid_d, grid_a, dupidx, log_id(c)); for (auto &pi : portinfos) { @@ -585,6 +628,7 @@ void handle_cell(Cell *cell, const rules_t &rules) log("\n"); pool failed_brams; + dict best_rule_cache; for (int i = 0; i < GetSize(rules.matches); i++) { @@ -597,6 +641,23 @@ void handle_cell(Cell *cell, const rules_t &rules) if (match.name.in(failed_brams)) continue; + int avail_rd_ports = 0; + int avail_wr_ports = 0; + for (int j = 0; j < bram.groups; j++) { + if (GetSize(bram.wrmode) < j || bram.wrmode.at(j) == 0) + avail_rd_ports += GetSize(bram.ports) < j ? bram.ports.at(j) : 0; + if (GetSize(bram.wrmode) < j || bram.wrmode.at(j) != 0) + avail_wr_ports += GetSize(bram.ports) < j ? bram.ports.at(j) : 0; + } + + log(" Checking rule #%d for bram type %s:\n", i, log_id(match.name)); + log(" Bram geometry: abits=%d dbits=%d wports=%d rports=%d\n", bram.abits, bram.dbits, avail_wr_ports, avail_rd_ports); + + int dups = avail_rd_ports ? (match_properties["rports"] + avail_rd_ports - 1) / avail_rd_ports : 1; + match_properties["dups"] = dups; + + log(" Estimated number of duplicates for more read ports: dups=%d\n", match_properties["dups"]); + int aover = match_properties["words"] % (1 << bram.abits); int awaste = aover ? (1 << bram.abits) - aover : 0; match_properties["awaste"] = awaste; @@ -605,19 +666,28 @@ void handle_cell(Cell *cell, const rules_t &rules) int dwaste = dover ? bram.dbits - dover : 0; match_properties["dwaste"] = dwaste; - int waste = awaste * bram.dbits + dwaste * (1 << bram.abits) - awaste * dwaste; + int bwaste = awaste * bram.dbits + dwaste * (1 << bram.abits) - awaste * dwaste; + match_properties["bwaste"] = bwaste; + + int waste = match_properties["dups"] * bwaste; match_properties["waste"] = waste; - log(" Wasted bits for bram type %s: awaste=%d dwaste=%d waste=%d\n", - log_id(match.name), awaste, dwaste, waste); + int cells = ((match_properties["dbits"] + bram.dbits - 1) / bram.dbits) * ((match_properties["words"] + (1 << bram.abits) - 1) / (1 << bram.abits)); + int efficiency = (100 * match_properties["bits"]) / (dups * cells * bram.dbits * (1 << bram.abits)); + match_properties["efficiency"] = efficiency; + + log(" Metrics for %s: awaste=%d dwaste=%d bwaste=%d waste=%d efficiency=%d %d\n", + log_id(match.name), awaste, dwaste, bwaste, waste, efficiency, cells); for (auto it : match.min_limits) { + if (it.first == "waste" || it.first == "dups") + continue; if (!match_properties.count(it.first)) log_error("Unknown property '%s' in match rule for bram type %s.\n", it.first.c_str(), log_id(match.name)); if (match_properties[it.first] >= it.second) continue; - log(" Rule #%d for bram type %s rejected: requirement 'min %s %d' not met.\n", + log(" Rule #%d for bram type %s rejected: requirement 'min %s %d' not met.\n", i, log_id(match.name), it.first.c_str(), it.second); goto next_match_rule; } @@ -627,21 +697,57 @@ void handle_cell(Cell *cell, const rules_t &rules) it.first.c_str(), log_id(match.name)); if (match_properties[it.first] <= it.second) continue; - log(" Rule #%d for bram type %s rejected: requirement 'max %s %d' not met.\n", + log(" Rule #%d for bram type %s rejected: requirement 'max %s %d' not met.\n", i, log_id(match.name), it.first.c_str(), it.second); goto next_match_rule; } - log(" Rule #%d for bram type %s accepted.\n", i, log_id(match.name)); + log(" Rule #%d for bram type %s accepted.\n", i, log_id(match.name)); + + if (match.or_next_if_better || !best_rule_cache.empty()) + { + if (match.or_next_if_better && i+1 == GetSize(rules.matches)) + log_error("Found 'or_next_if_better' in last match rule.\n"); + + if (!replace_cell(cell, bram, match, match_properties, 1)) { + log(" Mapping to bram type %s failed.\n", log_id(match.name)); + failed_brams.insert(match.name); + goto next_match_rule; + } + + log(" Storing for later selection.\n"); + best_rule_cache[i] = match_properties["efficiency"]; + + if (match.or_next_if_better) + goto next_match_rule; + + next_match_rule: + if (match.or_next_if_better || best_rule_cache.empty()) + continue; + + log(" Selecting best of %d rules:\n", GetSize(best_rule_cache)); + int best_rule = best_rule_cache.begin()->first; + + for (auto &it : best_rule_cache) { + if (it.second > best_rule_cache[best_rule]) + best_rule = it.first; + log(" Efficiency for rule %d: %d\n", it.first, it.second); + } + + log(" Selected rule %d with efficiency %d.\n", best_rule, best_rule_cache[best_rule]); + best_rule_cache.clear(); + + if (!replace_cell(cell, rules.brams.at(rules.matches.at(best_rule).name), rules.matches.at(best_rule), match_properties, 2)) + log_error("Mapping to bram type %s after pre-selection failed.\n", log_id(rules.matches.at(best_rule).name)); + return; + } - if (!replace_cell(cell, bram, match)) { - log(" Mapping to bram type %s failed.\n", log_id(match.name)); + if (!replace_cell(cell, bram, match, match_properties, 0)) { + log(" Mapping to bram type %s failed.\n", log_id(match.name)); failed_brams.insert(match.name); goto next_match_rule; } return; - - next_match_rule:; } log(" No acceptable bram resources found.\n"); @@ -663,7 +769,7 @@ struct MemoryBramPass : public Pass { log("rules. A block ram description looks like this:\n"); log("\n"); log(" bram RAMB1024X32 # name of BRAM cell\n"); - log(" init 1 # set to '1' if BRAM can be initialized\n"); + // log(" init 1 # set to '1' if BRAM can be initialized\n"); log(" abits 10 # number of address bits\n"); log(" dbits 32 # number of data bits\n"); log(" groups 2 # number of port groups\n"); @@ -690,27 +796,35 @@ struct MemoryBramPass : public Pass { log("A match rule looks like this:\n"); log("\n"); log(" match RAMB1024X32\n"); - log(" max waste 16384 # only use this if <= 16384 bram bits are unused\n"); + log(" max waste 16384 # only use this bram if <= 16k ram bits are unused\n"); + log(" min efficiency 80 # only use this bram if efficiency is at least 80%%\n"); log(" endmatch\n"); log("\n"); log("It is possible to match against the following values with min/max rules:\n"); log("\n"); - log(" words .... number of words in memory in design\n"); - log(" abits .... number of adress bits on memory in design\n"); - log(" dbits .... number of data bits on memory in design\n"); - log(" wports ... number of write ports on memory in design\n"); - log(" rports ... number of read ports on memory in design\n"); - log(" ports .... number of ports on memory in design\n"); - log(" bits ..... number of bits in memory in design\n"); + log(" words ........ number of words in memory in design\n"); + log(" abits ........ number of adress bits on memory in design\n"); + log(" dbits ........ number of data bits on memory in design\n"); + log(" wports ....... number of write ports on memory in design\n"); + log(" rports ....... number of read ports on memory in design\n"); + log(" ports ........ number of ports on memory in design\n"); + log(" bits ......... number of bits in memory in design\n"); + log(" dups .......... number of duplications for more read ports\n"); log("\n"); - log(" awaste ... number of unused address slots for this match\n"); - log(" dwaste ... number of unused data bits for this match\n"); - log(" waste .... total number of unused bram bits for this match\n"); + log(" awaste ....... number of unused address slots for this match\n"); + log(" dwaste ....... number of unused data bits for this match\n"); + log(" bwaste ....... number of unused bram bits for this match\n"); + log(" waste ........ total number of unused bram bits (bwaste*dups)\n"); + log(" efficiency ... total percentage of used and non-duplicated bits\n"); log("\n"); log("The interface for the created bram instances is dervived from the bram\n"); log("description. Use 'techmap' to convert the created bram instances into\n"); log("instances of the actual bram cells of your target architecture.\n"); log("\n"); + log("A match containing the command 'or_next_if_better' is only used if it\n"); + log("has a higher efficiency than the next match (and the one after that if\n"); + log("the next also has 'or_next_if_better' set, and so forth).\n"); + log("\n"); } virtual void execute(vector args, Design *design) { -- cgit v1.2.3