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	flowmap: cleanup for clarity. NFCI.
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					 3 changed files with 185 additions and 113 deletions
				
			
		|  | @ -402,29 +402,34 @@ struct FlowGraph | |||
| struct FlowmapWorker | ||||
| { | ||||
| 	int order; | ||||
| 	pool<IdString> cell_types; | ||||
| 	bool debug; | ||||
| 
 | ||||
| 	RTLIL::Module *module; | ||||
| 	SigMap sigmap; | ||||
| 	ModIndex index; | ||||
| 	pool<RTLIL::Cell*> cells; | ||||
| 
 | ||||
| 	dict<RTLIL::SigBit, ModIndex::PortInfo> node_origins; | ||||
| 
 | ||||
| 	pool<RTLIL::SigBit> nodes, inputs, outputs; | ||||
| 	dict<RTLIL::SigBit, pool<RTLIL::SigBit>> edges_fw, edges_bw; | ||||
| 	dict<RTLIL::SigBit, int> labels; | ||||
| 
 | ||||
| 	dict<RTLIL::SigBit, pool<RTLIL::SigBit>> lut_gates, lut_inputs; | ||||
| 	pool<RTLIL::SigBit> lut_nodes; | ||||
| 	dict<RTLIL::SigBit, pool<RTLIL::SigBit>> lut_gates; | ||||
| 	dict<RTLIL::SigBit, pool<RTLIL::SigBit>> lut_edges_fw, lut_edges_bw; | ||||
| 
 | ||||
| 	dict<RTLIL::SigBit, ModIndex::PortInfo> node_origins; | ||||
| 	dict<RTLIL::Cell*, pool<RTLIL::SigBit>> cell_fanout; | ||||
| 	int gate_count = 0, lut_count = 0, packed_count = 0; | ||||
| 	int gate_area = 0, lut_area = 0; | ||||
| 
 | ||||
| 	int mapped_count = 0, packed_count = 0, unique_packed_count = 0; | ||||
| 	enum class GraphMode { | ||||
| 		Label, | ||||
| 		Cut, | ||||
| 	}; | ||||
| 
 | ||||
| 	void dump_dot_graph(string filename, | ||||
| 	void dump_dot_graph(string filename, GraphMode mode, | ||||
| 	                    pool<RTLIL::SigBit> subgraph_nodes = {}, dict<RTLIL::SigBit, pool<RTLIL::SigBit>> subgraph_edges = {}, | ||||
| 	                    pair<pool<RTLIL::SigBit>, pool<RTLIL::SigBit>> cut = {}, | ||||
| 	                    dict<RTLIL::SigBit, pool<RTLIL::SigBit>> collapsed = {}) | ||||
| 	                    dict<RTLIL::SigBit, pool<RTLIL::SigBit>> collapsed = {}, | ||||
| 	                    pair<pool<RTLIL::SigBit>, pool<RTLIL::SigBit>> cut = {}) | ||||
| 	{ | ||||
| 		if (subgraph_nodes.empty()) | ||||
| 			subgraph_nodes = nodes; | ||||
|  | @ -436,26 +441,29 @@ struct FlowmapWorker | |||
| 			for (auto collapsed_node : collapsed[node]) | ||||
| 				if (collapsed_node != node) | ||||
| 					label += stringf(" %s", log_signal(collapsed_node)); | ||||
| 			if (labels[node] == -1) | ||||
| 				label += "\nl=?"; | ||||
| 			else | ||||
| 				label += stringf("\nl=%d", labels[node]); | ||||
| 			if (cut.first.empty() && cut.second.empty()) | ||||
| 			switch (mode) | ||||
| 			{ | ||||
| 				if (labels[node] == -1) | ||||
| 				case GraphMode::Label: | ||||
| 					if (labels[node] == -1) | ||||
| 					{ | ||||
| 						label += "\nl=?"; | ||||
| 						return GraphStyle{label}; | ||||
| 					} | ||||
| 					else | ||||
| 					{ | ||||
| 						label += stringf("\nl=%d", labels[node]); | ||||
| 						string fillcolor = stringf("/set311/%d", 1 + labels[node] % 11); | ||||
| 						return GraphStyle{label, "", fillcolor}; | ||||
| 					} | ||||
| 
 | ||||
| 				case GraphMode::Cut: | ||||
| 					if (cut.first[node]) | ||||
| 						return GraphStyle{label, "blue"}; | ||||
| 					if (cut.second[node]) | ||||
| 						return GraphStyle{label, "red"}; | ||||
| 					return GraphStyle{label}; | ||||
| 				string fillcolor = stringf("/set311/%d", 1 + labels[node] % 11); | ||||
| 				return GraphStyle{label, "", fillcolor}; | ||||
| 			} | ||||
| 			else | ||||
| 			{ | ||||
| 				string color = "black"; | ||||
| 				if (cut.first[node]) | ||||
| 					color = "blue"; | ||||
| 				if (cut.second[node]) | ||||
| 					color = "red"; | ||||
| 				return GraphStyle{label, color}; | ||||
| 			} | ||||
| 			return GraphStyle{label}; | ||||
| 		}; | ||||
| 		auto edge_style = [&](RTLIL::SigBit, RTLIL::SigBit) { | ||||
| 			return GraphStyle{}; | ||||
|  | @ -519,57 +527,56 @@ struct FlowmapWorker | |||
| 		return flow_graph; | ||||
| 	} | ||||
| 
 | ||||
| 	FlowmapWorker(int order, pool<IdString> cell_types, bool debug, RTLIL::Module *module) : | ||||
| 		order(order), cell_types(cell_types), debug(debug), module(module), sigmap(module), index(module) | ||||
| 	void discover_nodes(pool<IdString> cell_types) | ||||
| 	{ | ||||
| 		log("Labeling cells.\n"); | ||||
| 		for (auto cell : module->selected_cells()) | ||||
| 		{ | ||||
| 			if (cell_types[cell->type]) | ||||
| 			if (!cell_types[cell->type]) | ||||
| 				continue; | ||||
| 
 | ||||
| 			if (!cell->known()) | ||||
| 				log_error("Cell %s (%s.%s) is unknown.\n", cell->type.c_str(), log_id(module), log_id(cell)); | ||||
| 
 | ||||
| 			pool<RTLIL::SigBit> fanout; | ||||
| 			for (auto conn : cell->connections()) | ||||
| 			{ | ||||
| 				if (!cell->known()) | ||||
| 				if (!cell->output(conn.first)) continue; | ||||
| 				int offset = -1; | ||||
| 				for (auto bit : conn.second) | ||||
| 				{ | ||||
| 					log_error("Cell %s (%s.%s) is unknown.\n", cell->type.c_str(), log_id(module), log_id(cell)); | ||||
| 					offset++; | ||||
| 					if (!bit.wire) continue; | ||||
| 					auto mapped_bit = sigmap(bit); | ||||
| 					if (nodes[mapped_bit]) | ||||
| 						log_error("Multiple drivers found for wire %s.\n", log_signal(mapped_bit)); | ||||
| 					nodes.insert(mapped_bit); | ||||
| 					node_origins[mapped_bit] = ModIndex::PortInfo(cell, conn.first, offset); | ||||
| 					fanout.insert(mapped_bit); | ||||
| 				} | ||||
| 				cells.insert(cell); | ||||
| 
 | ||||
| 				for (auto conn : cell->connections()) | ||||
| 				{ | ||||
| 					if (!cell->output(conn.first)) continue; | ||||
| 					int offset = -1; | ||||
| 					for (auto bit : conn.second) | ||||
| 					{ | ||||
| 						offset++; | ||||
| 						if (!bit.wire) continue; | ||||
| 						auto mapped_bit = sigmap(bit); | ||||
| 						if (nodes[mapped_bit]) | ||||
| 							log_error("Multiple drivers found for wire %s.\n", log_signal(mapped_bit)); | ||||
| 						nodes.insert(mapped_bit); | ||||
| 						node_origins[mapped_bit] = ModIndex::PortInfo(cell, conn.first, offset); | ||||
| 						cell_fanout[cell].insert(mapped_bit); | ||||
| 					} | ||||
| 				} | ||||
| 
 | ||||
| 				int fanin = 0; | ||||
| 				for (auto conn : cell->connections()) | ||||
| 				{ | ||||
| 					if (!cell->input(conn.first)) continue; | ||||
| 					for (auto bit : sigmap(conn.second)) | ||||
| 					{ | ||||
| 						if (!bit.wire) continue; | ||||
| 						for (auto fanout_bit : cell_fanout[cell]) | ||||
| 						{ | ||||
| 							edges_fw[bit].insert(fanout_bit); | ||||
| 							edges_bw[fanout_bit].insert(bit); | ||||
| 						} | ||||
| 						fanin++; | ||||
| 					} | ||||
| 				} | ||||
| 
 | ||||
| 				if (fanin > order) | ||||
| 					log_error("Cell %s (%s.%s) with fan-in %d cannot be mapped to a %d-LUT.\n", | ||||
| 					          cell->type.c_str(), log_id(module), log_id(cell), fanin, order); | ||||
| 			} | ||||
| 
 | ||||
| 			int fanin = 0; | ||||
| 			for (auto conn : cell->connections()) | ||||
| 			{ | ||||
| 				if (!cell->input(conn.first)) continue; | ||||
| 				for (auto bit : sigmap(conn.second)) | ||||
| 				{ | ||||
| 					if (!bit.wire) continue; | ||||
| 					for (auto fanout_bit : fanout) | ||||
| 					{ | ||||
| 						edges_fw[bit].insert(fanout_bit); | ||||
| 						edges_bw[fanout_bit].insert(bit); | ||||
| 					} | ||||
| 					fanin++; | ||||
| 				} | ||||
| 			} | ||||
| 
 | ||||
| 			if (fanin > order) | ||||
| 				log_error("Cell %s (%s.%s) with fan-in %d cannot be mapped to a %d-LUT.\n", | ||||
| 				          cell->type.c_str(), log_id(module), log_id(cell), fanin, order); | ||||
| 
 | ||||
| 			gate_count++; | ||||
| 			gate_area += 1 << fanin; | ||||
| 		} | ||||
| 
 | ||||
| 		for (auto edge : edges_fw) | ||||
|  | @ -591,15 +598,23 @@ struct FlowmapWorker | |||
| 					outputs.insert(node); | ||||
| 		} | ||||
| 
 | ||||
| 		if (debug) | ||||
| 		{ | ||||
| 			dump_dot_graph("flowmap-initial.dot", GraphMode::Label); | ||||
| 			log("Dumped initial graph to `flowmap-initial.dot`.\n"); | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	void label_nodes() | ||||
| 	{ | ||||
| 		for (auto node : nodes) | ||||
| 			labels[node] = -1; | ||||
| 		for (auto input : inputs) | ||||
| 			labels[input] = 0; | ||||
| 
 | ||||
| 		if (debug) | ||||
| 		{ | ||||
| 			dump_dot_graph("flowmap-initial.dot"); | ||||
| 			log("Dumped complete initial graph to `flowmap-initial.dot`.\n"); | ||||
| 			if (input.wire->attributes.count("\\$flowmap_level")) | ||||
| 				labels[input] = input.wire->attributes["\\$flowmap_level"].as_int(); | ||||
| 			else | ||||
| 				labels[input] = 0; | ||||
| 		} | ||||
| 
 | ||||
| 		pool<RTLIL::SigBit> worklist = nodes; | ||||
|  | @ -661,70 +676,73 @@ struct FlowmapWorker | |||
| 						k.insert(xi_node_pred); | ||||
| 			} | ||||
| 			log_assert((int)k.size() <= order); | ||||
| 			lut_inputs[sink] = k; | ||||
| 			lut_edges_bw[sink] = k; | ||||
| 			for (auto k_node : k) | ||||
| 				lut_edges_fw[k_node].insert(sink); | ||||
| 
 | ||||
| 			if (debug) | ||||
| 			{ | ||||
| 				log("  Maximum flow: %d. Assigned label %d.\n", flow, labels[sink]); | ||||
| 				dump_dot_graph(stringf("flowmap-%d-sub.dot", debug_num), subgraph, {}, {x, xi}); | ||||
| 				dump_dot_graph(stringf("flowmap-%d-sub.dot", debug_num), GraphMode::Cut, subgraph, {}, {}, {x, xi}); | ||||
| 				log("  Dumped subgraph to `flowmap-%d-sub.dot`.\n", debug_num); | ||||
| 				flow_graph.dump_dot_graph(stringf("flowmap-%d-flow.dot", debug_num)); | ||||
| 				log("  Dumped flow graph to `flowmap-%d-flow.dot`.\n", debug_num); | ||||
| 				log("    LUT packed:"); | ||||
| 				for (auto xi_node : xi) | ||||
| 					log(" %s", log_signal(xi_node)); | ||||
| 				log(".\n"); | ||||
| 				log("    LUT inputs:"); | ||||
| 				for (auto k_node : k) | ||||
| 					log(" %s", log_signal(k_node)); | ||||
| 				log(".\n"); | ||||
| 				log("    LUT packed gates:"); | ||||
| 				for (auto xi_node : xi) | ||||
| 					log(" %s", log_signal(xi_node)); | ||||
| 				log(".\n"); | ||||
| 			} | ||||
| 
 | ||||
| 			for (auto sink_succ : edges_fw[sink]) | ||||
| 				worklist.insert(sink_succ); | ||||
| 		} | ||||
| 
 | ||||
| 		int depth = 0; | ||||
| 		for (auto label : labels) | ||||
| 			depth = max(depth, label.second); | ||||
| 		log("Maximum depth: %d levels.\n", depth); | ||||
| 
 | ||||
| 		if (debug) | ||||
| 		{ | ||||
| 			dump_dot_graph("flowmap-labeled.dot"); | ||||
| 			log("Dumped complete labeled graph to `flowmap-labeled.dot`.\n"); | ||||
| 			dump_dot_graph("flowmap-labeled.dot", GraphMode::Label); | ||||
| 			log("Dumped labeled graph to `flowmap-labeled.dot`.\n"); | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 		pool<RTLIL::SigBit> lut_nodes; | ||||
| 		dict<RTLIL::SigBit, pool<RTLIL::SigBit>> lut_edges; | ||||
| 		worklist = outputs; | ||||
| 	int pack_luts() | ||||
| 	{ | ||||
| 		pool<RTLIL::SigBit> worklist = outputs; | ||||
| 		while (!worklist.empty()) | ||||
| 		{ | ||||
| 			auto lut_node = worklist.pop(); | ||||
| 			lut_nodes.insert(lut_node); | ||||
| 			for (auto input_node : lut_inputs[lut_node]) | ||||
| 			{ | ||||
| 				lut_edges[input_node].insert(lut_node); | ||||
| 			for (auto input_node : lut_edges_bw[lut_node]) | ||||
| 				if (!lut_nodes[input_node] && !inputs[input_node]) | ||||
| 					worklist.insert(input_node); | ||||
| 			} | ||||
| 		} | ||||
| 
 | ||||
| 		int depth = 0; | ||||
| 		for (auto label : labels) | ||||
| 			depth = max(depth, label.second); | ||||
| 		log("Solved to %d LUTs in %d levels.\n", (int)lut_nodes.size(), depth); | ||||
| 
 | ||||
| 		if (debug) | ||||
| 		{ | ||||
| 			pool<RTLIL::SigBit> lut_and_input_nodes = lut_nodes; | ||||
| 			pool<RTLIL::SigBit> lut_and_input_nodes; | ||||
| 			lut_and_input_nodes.insert(lut_nodes.begin(), lut_nodes.end()); | ||||
| 			lut_and_input_nodes.insert(inputs.begin(), inputs.end()); | ||||
| 			dump_dot_graph("flowmap-packed.dot", lut_and_input_nodes, lut_edges, {}, lut_gates); | ||||
| 			log("Dumped complete packed graph to `flowmap-packed.dot`.\n"); | ||||
| 			dump_dot_graph("flowmap-packed.dot", GraphMode::Label, lut_and_input_nodes, lut_edges_fw, lut_gates); | ||||
| 			log("Dumped packed graph to `flowmap-packed.dot`.\n"); | ||||
| 		} | ||||
| 
 | ||||
| 		return depth; | ||||
| 	} | ||||
| 
 | ||||
| 	void map_cells() | ||||
| 	{ | ||||
| 		ConstEval ce(module); | ||||
| 		for (auto input_node : inputs) | ||||
| 			ce.stop(input_node); | ||||
| 
 | ||||
| 		log("\n"); | ||||
| 		log("Mapping cells.\n"); | ||||
| 
 | ||||
| 		pool<RTLIL::SigBit> mapped_nodes; | ||||
| 		for (auto node : lut_nodes) | ||||
| 		{ | ||||
|  | @ -759,7 +777,7 @@ struct FlowmapWorker | |||
| 					    log_id(module), log_id(gate_origin.cell), gate_origin.port.c_str(), gate_origin.offset, log_signal(gate_node)); | ||||
| 			} | ||||
| 
 | ||||
| 			vector<RTLIL::SigBit> input_nodes(lut_inputs[node].begin(), lut_inputs[node].end()); | ||||
| 			vector<RTLIL::SigBit> input_nodes(lut_edges_bw[node].begin(), lut_edges_bw[node].end()); | ||||
| 			RTLIL::Const lut_table(State::Sx, 1 << input_nodes.size()); | ||||
| 			for (unsigned i = 0; i < (1 << input_nodes.size()); i++) | ||||
| 			{ | ||||
|  | @ -786,7 +804,6 @@ struct FlowmapWorker | |||
| 				lut_a.append_bit(input_node); | ||||
| 
 | ||||
| 			RTLIL::Cell *lut = module->addLut(NEW_ID, lut_a, lut_y, lut_table); | ||||
| 			mapped_count++; | ||||
| 			mapped_nodes.insert(node); | ||||
| 			for (auto gate_node : lut_gates[node]) | ||||
| 			{ | ||||
|  | @ -794,11 +811,11 @@ struct FlowmapWorker | |||
| 				lut->add_strpool_attribute("\\src", gate_origin.cell->get_strpool_attribute("\\src")); | ||||
| 				packed_count++; | ||||
| 			} | ||||
| 			lut_count++; | ||||
| 			lut_area += 1 << input_nodes.size(); | ||||
| 			log("  Packed into a %d-LUT %s.%s.\n", (int)input_nodes.size(), log_id(module), log_id(lut)); | ||||
| 		} | ||||
| 
 | ||||
| 		unique_packed_count += nodes.size(); | ||||
| 
 | ||||
| 		for (auto node : mapped_nodes) | ||||
| 		{ | ||||
| 			auto origin = node_origins[node]; | ||||
|  | @ -807,6 +824,19 @@ struct FlowmapWorker | |||
| 			origin.cell->setPort(origin.port, driver); | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	FlowmapWorker(int order, pool<IdString> cell_types, bool debug, RTLIL::Module *module) : | ||||
| 		order(order), debug(debug), module(module), sigmap(module), index(module) | ||||
| 	{ | ||||
| 		log("Labeling cells.\n"); | ||||
| 		discover_nodes(cell_types); | ||||
| 		label_nodes(); | ||||
| 		pack_luts(); | ||||
| 
 | ||||
| 		log("\n"); | ||||
| 		log("Mapping cells.\n"); | ||||
| 		map_cells(); | ||||
| 	} | ||||
| }; | ||||
| 
 | ||||
| static void split(std::vector<std::string> &tokens, const std::string &text, char sep) | ||||
|  | @ -832,7 +862,7 @@ struct FlowmapPass : public Pass { | |||
| 		log("be evaluated with the `eval` pass, including cells with multiple output ports\n"); | ||||
| 		log("and multi-bit input and output ports.\n"); | ||||
| 		log("\n"); | ||||
| 		log("    -maxlut <k>\n"); | ||||
| 		log("    -maxlut k\n"); | ||||
| 		log("        perform technology mapping for a k-LUT architecture. if not specified,\n"); | ||||
| 		log("        defaults to 3.\n"); | ||||
| 		log("\n"); | ||||
|  | @ -846,8 +876,6 @@ struct FlowmapPass : public Pass { | |||
| 	} | ||||
| 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE | ||||
| 	{ | ||||
| 		log_header(design, "Executing FLOWMAP pass (pack LUTs with FlowMap).\n"); | ||||
| 
 | ||||
| 		int order = 3; | ||||
| 		vector<string> cells; | ||||
| 		bool debug = false; | ||||
|  | @ -885,18 +913,24 @@ struct FlowmapPass : public Pass { | |||
| 			cell_types = {"$_NOT_", "$_AND_", "$_OR_", "$_XOR_", "$_MUX_"}; | ||||
| 		} | ||||
| 
 | ||||
| 		int mapped_count = 0, packed_count = 0, unique_packed_count = 0; | ||||
| 		log_header(design, "Executing FLOWMAP pass (pack LUTs with FlowMap).\n"); | ||||
| 
 | ||||
| 		int gate_count = 0, lut_count = 0, packed_count = 0; | ||||
| 		int gate_area = 0, lut_area = 0; | ||||
| 		for (auto module : design->selected_modules()) | ||||
| 		{ | ||||
| 			FlowmapWorker worker(order, cell_types, debug, module); | ||||
| 			mapped_count += worker.mapped_count; | ||||
| 			gate_count += worker.gate_count; | ||||
| 			lut_count += worker.lut_count; | ||||
| 			packed_count += worker.packed_count; | ||||
| 			unique_packed_count += worker.unique_packed_count; | ||||
| 			gate_area += worker.gate_area; | ||||
| 			lut_area += worker.lut_area; | ||||
| 		} | ||||
| 
 | ||||
| 		log("\n"); | ||||
| 		log("Mapped %d LUTs.\n", mapped_count); | ||||
| 		log("Packed %d cells %d times.\n", unique_packed_count, packed_count); | ||||
| 		log("Mapped %d LUTs.\n", lut_count); | ||||
| 		log("Packed %d cells; duplicated %d cells.\n", packed_count, packed_count - gate_count); | ||||
| 		log("Solution has %.1f%% area overhead.\n", (lut_area - gate_area) * 100.0 / gate_area); | ||||
| 	} | ||||
| } FlowmapPass; | ||||
| 
 | ||||
|  |  | |||
							
								
								
									
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								passes/tests/flowmap/flow.v
									
										
									
									
									
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								passes/tests/flowmap/flow.v
									
										
									
									
									
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							|  | @ -0,0 +1,22 @@ | |||
| // Exact reproduction of Figure 2(a) from 10.1109/43.273754. | ||||
| module top(...); | ||||
| 	input a,b,c,d,e,f; | ||||
| 	wire nA = b&c; | ||||
| 	wire A = !nA; | ||||
| 	wire nB = c|d; | ||||
| 	wire B = !nB; | ||||
| 	wire nC = e&f; | ||||
| 	wire C = !nC; | ||||
| 	wire D = A|B; | ||||
| 	wire E = a&D; | ||||
| 	wire nF = D&C; | ||||
| 	wire F = !nF; | ||||
| 	wire nG = F|B; | ||||
| 	wire G = !nG; | ||||
| 	wire H = a&F; | ||||
| 	wire I = E|G; | ||||
| 	wire J = G&C; | ||||
| 	wire np = H&I; | ||||
| 	output p = !np; | ||||
| 	output q = A|J; | ||||
| endmodule | ||||
							
								
								
									
										16
									
								
								passes/tests/flowmap/flowp.v
									
										
									
									
									
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										16
									
								
								passes/tests/flowmap/flowp.v
									
										
									
									
									
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							|  | @ -0,0 +1,16 @@ | |||
| // Like flow.v, but results in a network identical to Figure 2(b). | ||||
| module top(...); | ||||
| 	input a,b,c,d,e,f; | ||||
| 	wire A = b&c; | ||||
| 	wire B = c|d; | ||||
| 	wire C = e&f; | ||||
| 	wire D = A|B; | ||||
| 	wire E = a&D; | ||||
| 	wire F = D&C; | ||||
| 	wire G = F|B; | ||||
| 	wire H = a&F; | ||||
| 	wire I = E|G; | ||||
| 	wire J = G&C; | ||||
| 	output p = H&I; | ||||
| 	output q = A|J; | ||||
| endmodule | ||||
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