From 72cebef279357435cde115851bc095375763108c Mon Sep 17 00:00:00 2001 From: Alberto Gonzalez Date: Thu, 23 Apr 2020 06:41:58 +0000 Subject: [PATCH] glift: Add replacement scoring and area minimization option. --- passes/cmds/glift.cc | 59 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 56 insertions(+), 3 deletions(-) diff --git a/passes/cmds/glift.cc b/passes/cmds/glift.cc index b8c33a3f1..b35179fd1 100644 --- a/passes/cmds/glift.cc +++ b/passes/cmds/glift.cc @@ -27,10 +27,11 @@ PRIVATE_NAMESPACE_BEGIN struct GliftPass : public Pass { private: - bool opt_create, opt_sketchify, opt_taintconstants, opt_keepoutputs; + bool opt_create, opt_sketchify, opt_taintconstants, opt_keepoutputs, opt_nomodeloptimize; std::vector args; std::vector::size_type argidx; std::vector new_taint_outputs; + std::vector meta_mux_selects; RTLIL::Module *module; void parse_args() { @@ -51,6 +52,10 @@ struct GliftPass : public Pass { opt_keepoutputs = true; continue; } + if (args[argidx] == "-no-model-optimize") { + opt_nomodeloptimize = true; + continue; + } break; } if(!opt_create && !opt_sketchify) log_cmd_error("One of `-create` or `-sketchify` must be specified.\n"); @@ -116,6 +121,22 @@ struct GliftPass : public Pass { module->addOr(cell->name.str() + "_t_4_1", port_a_taint, port_b_taint, port_y_taint, false, cell->get_src_attribute()); } + RTLIL::SigSpec score_metamux_select(const RTLIL::SigSpec &metamux_select) { + log_assert(metamux_select.is_wire()); + log_assert(metamux_select.as_wire()->width == 2); + + RTLIL::Const precise_y_cost(5); //5 AND/OR gates + RTLIL::Const imprecise_1_y_cost(2); + RTLIL::Const imprecise_2_y_cost(2); + RTLIL::Const imprecise_3_y_cost(1); + + RTLIL::SigSpec meta_mux1 = module->Pmux(metamux_select.as_wire()->name.str() + "_mux1", precise_y_cost, imprecise_1_y_cost, metamux_select[1], metamux_select.as_wire()->get_src_attribute()); + RTLIL::SigSpec meta_mux2 = module->Pmux(metamux_select.as_wire()->name.str() + "_mux2", imprecise_2_y_cost, imprecise_3_y_cost, metamux_select[1], metamux_select.as_wire()->get_src_attribute()); + RTLIL::SigSpec ret = module->Pmux(metamux_select.as_wire()->name.str() + "_mux3", meta_mux1, meta_mux2, metamux_select[0], metamux_select.as_wire()->get_src_attribute()); + + return ret; + } + void create_glift_logic() { std::vector connections(module->connections()); std::vector new_connections; @@ -149,8 +170,9 @@ struct GliftPass : public Pass { add_imprecise_GLIFT_logic_3(cell, port_taints[A], port_taints[B], imprecise_3_y); RTLIL::SigSpec meta_mux_select(module->addWire(cell->name.str() + "_sel", 2)); - //meta_mux_select.as_wire()->set_bool_attribute("\\maximize"); + meta_mux_selects.push_back(meta_mux_select); new_connections.emplace_back(meta_mux_select, module->Anyconst(cell->name.str() + "_hole", 2, cell->get_src_attribute())); + RTLIL::SigSpec meta_mux1(module->Mux(cell->name.str() + "_mux1", precise_y, imprecise_1_y, meta_mux_select[1])); RTLIL::SigSpec meta_mux2(module->Mux(cell->name.str() + "_mux2", imprecise_2_y, imprecise_3_y, meta_mux_select[1])); module->addMux(cell->name.str() + "_mux3", meta_mux1, meta_mux2, meta_mux_select[0], port_taints[Y]); @@ -187,6 +209,30 @@ struct GliftPass : public Pass { new_taint_outputs.push_back(first.as_wire()); } //end foreach conn in connections + //Create a rough model of area by summing the "weight" score of each meta-mux select: + if (!opt_nomodeloptimize) { + std::vector meta_mux_select_sums; + std::vector meta_mux_select_sums_buf; + for (auto &wire : meta_mux_selects) { + meta_mux_select_sums.emplace_back(score_metamux_select(wire)); + } + for (unsigned int i = 0; meta_mux_select_sums.size() > 1; ) { + meta_mux_select_sums_buf.clear(); + for (i = 0; i + 1 < meta_mux_select_sums.size(); i += 2) { + meta_mux_select_sums_buf.push_back(module->Add(meta_mux_select_sums[i].as_wire()->name.str() + "_add", meta_mux_select_sums[i], meta_mux_select_sums[i+1], false)); + } + if (meta_mux_select_sums.size() % 2 == 1) + meta_mux_select_sums_buf.push_back(meta_mux_select_sums[meta_mux_select_sums.size()-1]); + meta_mux_select_sums.swap(meta_mux_select_sums_buf); + } + if (meta_mux_select_sums.size() > 0) { + meta_mux_select_sums[0].as_wire()->set_bool_attribute("\\minimize"); + meta_mux_select_sums[0].as_wire()->set_bool_attribute("\\keep"); + module->rename(meta_mux_select_sums[0].as_wire(), ID(__glift_weight)); + } + } + + //Add new connections and mark new module outputs: for (auto &conn : new_connections) module->connect(conn); @@ -206,15 +252,17 @@ struct GliftPass : public Pass { opt_sketchify = false; opt_taintconstants = false; opt_keepoutputs = false; + opt_nomodeloptimize = false; module = nullptr; args.clear(); argidx = 0; new_taint_outputs.clear(); + meta_mux_selects.clear(); } public: - GliftPass() : Pass("glift", "create and transform GLIFT models"), opt_create(false), opt_sketchify(false), opt_taintconstants(false), opt_keepoutputs(false), module(nullptr) { } + GliftPass() : Pass("glift", "create and transform GLIFT models"), opt_create(false), opt_sketchify(false), opt_taintconstants(false), opt_keepoutputs(false), opt_nomodeloptimize(false), module(nullptr) { } void help() YS_OVERRIDE { @@ -248,7 +296,12 @@ struct GliftPass : public Pass { log(" alongside the orignal outputs.\n"); log(" (default: original module outputs are removed)\n"); log("\n"); + log(" -no-model-optimize\n"); + log(" Do not model imprecise taint tracking logic area and attempt to minimize it.\n"); + log(" (default: model area and give that signal the \"minimize\" attribute)\n"); + log("\n"); } + void execute(std::vector _args, RTLIL::Design *design) YS_OVERRIDE { log_header(design, "Executing GLIFT pass (creating and manipulating GLIFT models).\n"); -- 2.30.2