From 15fd615da5a119b4ee9cded9f44ae36fd66820f7 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Sun, 20 Jul 2014 03:03:04 +0200 Subject: [PATCH] Progress in "share" pass --- passes/sat/share.cc | 75 +++++++++++++++++++++++++++++++++------------ 1 file changed, 56 insertions(+), 19 deletions(-) diff --git a/passes/sat/share.cc b/passes/sat/share.cc index c04be7c8d..aad53e13c 100644 --- a/passes/sat/share.cc +++ b/passes/sat/share.cc @@ -27,7 +27,9 @@ struct ShareWorkerConfig { - bool opt_all; + bool opt_force; + bool opt_aggressive; + bool opt_fast; }; struct ShareWorker @@ -56,7 +58,7 @@ struct ShareWorker if (!design->selected(module, cell) || !modwalker.ct.cell_known(cell->type)) continue; - if (config.opt_all) { + if (config.opt_force) { candidates.push_back(cell); continue; } @@ -68,13 +70,19 @@ struct ShareWorker } if (cell->type == "$mul" || cell->type == "$div" || cell->type == "$mod") { - if (cell->parameters.at("\\Y_WIDTH").as_int() > 4) + if (config.opt_aggressive || cell->parameters.at("\\Y_WIDTH").as_int() > 4) candidates.push_back(cell); continue; } if (cell->type == "$shl" || cell->type == "$shr" || cell->type == "$sshl" || cell->type == "$sshr") { - if (cell->parameters.at("\\Y_WIDTH").as_int() > 8) + if (config.opt_aggressive || cell->parameters.at("\\Y_WIDTH").as_int() > 8) + candidates.push_back(cell); + continue; + } + + if (cell->type == "$add" || cell->type == "$sub") { + if (config.opt_aggressive || cell->parameters.at("\\Y_WIDTH").as_int() > 10) candidates.push_back(cell); continue; } @@ -109,7 +117,7 @@ struct ShareWorker return true; } - if (c1->type == "$mul" || c1->type == "$div" || c1->type == "$mod" || + if (c1->type == "$mul" || c1->type == "$div" || c1->type == "$mod" || c1->type == "$add" || c1->type == "$sub" || c1->type == "$shl" || c1->type == "$shr" || c1->type == "$sshl" || c1->type == "$sshr") { if (c1->parameters.at("\\A_SIGNED").as_bool() != c2->parameters.at("\\A_SIGNED").as_bool()) @@ -118,17 +126,20 @@ struct ShareWorker if (c1->parameters.at("\\B_SIGNED").as_bool() != c2->parameters.at("\\B_SIGNED").as_bool()) return false; - int a1_width = c1->parameters.at("\\A_WIDTH").as_int(); - int b1_width = c1->parameters.at("\\B_WIDTH").as_int(); - int y1_width = c1->parameters.at("\\Y_WIDTH").as_int(); + if (!config.opt_aggressive) + { + int a1_width = c1->parameters.at("\\A_WIDTH").as_int(); + int b1_width = c1->parameters.at("\\B_WIDTH").as_int(); + int y1_width = c1->parameters.at("\\Y_WIDTH").as_int(); - int a2_width = c2->parameters.at("\\A_WIDTH").as_int(); - int b2_width = c2->parameters.at("\\B_WIDTH").as_int(); - int y2_width = c2->parameters.at("\\Y_WIDTH").as_int(); + int a2_width = c2->parameters.at("\\A_WIDTH").as_int(); + int b2_width = c2->parameters.at("\\B_WIDTH").as_int(); + int y2_width = c2->parameters.at("\\Y_WIDTH").as_int(); - if (std::max(a1_width, a2_width) > 2 * std::min(a1_width, a2_width)) return false; - if (std::max(b1_width, b2_width) > 2 * std::min(b1_width, b2_width)) return false; - if (std::max(y1_width, y2_width) > 2 * std::min(y1_width, y2_width)) return false; + if (std::max(a1_width, a2_width) > 2 * std::min(a1_width, a2_width)) return false; + if (std::max(b1_width, b2_width) > 2 * std::min(b1_width, b2_width)) return false; + if (std::max(y1_width, y2_width) > 2 * std::min(y1_width, y2_width)) return false; + } return true; } @@ -365,10 +376,15 @@ struct ShareWorker for (auto &pbit : portbits) if (sat_cells.count(pbit.cell) == 0 && cone_ct.cell_known(pbit.cell->type)) { + if (config.opt_fast && modwalker.cell_outputs[pbit.cell].size() >= 4) + continue; // log(" Adding cell %s (%s) to SAT problem.\n", log_id(pbit.cell), log_id(pbit.cell->type)); satgen.importCell(pbit.cell); sat_cells.insert(pbit.cell); } + + if (config.opt_fast && sat_cells.size() > 100) + break; } all_ctrl_signals.sort_and_unify(); @@ -409,26 +425,47 @@ struct SharePass : public Pass { log("This pass merges shareable resources into a single resource. A SAT solver\n"); log("is used to determine if two resources are share-able.\n"); log("\n"); - log(" -all\n"); + log(" -force\n"); log(" Per default the selection of cells that is considered for sharing is\n"); - log(" narrowed using some built-in heuristics. With this option all selected\n"); + log(" narrowed using a list of cell types. With this option all selected\n"); log(" cells are considered for resource sharing.\n"); log("\n"); log(" IMPORTANT NOTE: If the -all option is used then no cells with internal\n"); log(" state must be selected!\n"); log("\n"); + log(" -aggressive\n"); + log(" Per default some heuristics are used to reduce the number of cells\n"); + log(" considered for resource sharing to only large resources. This options\n"); + log(" turns this heuristics off, resulting in much more cells being considered\n"); + log(" for resource sharing.\n"); + log("\n"); + log(" -fast\n"); + log(" Only consider comparable primitive control logic in SAT solving, resulting\n"); + log(" in much easier SAT problems at the cost of maybe missing some oportunities\n"); + log(" for resource sharing.\n"); + log("\n"); } virtual void execute(std::vector args, RTLIL::Design *design) { ShareWorkerConfig config; - config.opt_all = false; + config.opt_force = false; + config.opt_aggressive = false; + config.opt_fast = false; log_header("Executing SHARE pass (SAT-based resource sharing).\n"); size_t argidx; for (argidx = 1; argidx < args.size(); argidx++) { - if (args[argidx] == "-all") { - config.opt_all = true; + if (args[argidx] == "-force") { + config.opt_force = true; + continue; + } + if (args[argidx] == "-aggressive") { + config.opt_aggressive = true; + continue; + } + if (args[argidx] == "-fast") { + config.opt_fast = true; continue; } break; -- 2.30.2