Added "qwp" command

2 files changed, 586 insertions, 0 deletions

diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index e4b40c41..46beecd8 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -22,4 +22,5 @@ OBJS += passes/cmds/cover.o
 OBJS += passes/cmds/trace.o
 OBJS += passes/cmds/plugin.o
 OBJS += passes/cmds/check.o
+OBJS += passes/cmds/qwp.o
 
diff --git a/passes/cmds/qwp.cc b/passes/cmds/qwp.cc
new file mode 100644
index 00000000..86a7a555
--- /dev/null
+++ b/passes/cmds/qwp.cc
@@ -0,0 +1,585 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+#undef LOG_MATRICES
+#undef PYPLOT_EDGES
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+static uint32_t xorshift32_state;
+
+static double xorshift32()
+{
+	xorshift32_state ^= xorshift32_state << 13;
+	xorshift32_state ^= xorshift32_state >> 17;
+	xorshift32_state ^= xorshift32_state << 5;
+	return (xorshift32_state % 1000000) / 1e6;
+}
+
+struct QwpConfig
+{
+	bool ltr;
+	bool alpha;
+	double grid;
+
+	QwpConfig() {
+		ltr = false;
+		alpha = false;
+		grid = 1.0 / 16;
+	}
+};
+
+struct QwpWorker
+{
+	const QwpConfig &config;
+	Module *module;
+	char direction;
+
+	struct Node {
+		Cell *cell;
+		bool tied, alt_tied;
+
+		// pos = position in current direction
+		// alt_pos = position in the other direction
+		double pos, alt_pos;
+
+		Node() {
+			cell = nullptr;
+			tied = false;
+			pos = xorshift32();
+			alt_tied = false;
+			alt_pos = xorshift32();
+		}
+
+		void tie(double v) {
+			tied = true;
+			pos = v;
+		}
+
+		void alt_tie(double v) {
+			alt_tied = true;
+			alt_pos = v;
+		}
+
+		void swap_alt() {
+			std::swap(tied, alt_tied);
+			std::swap(pos, alt_pos);
+		}
+
+		void proj_left(double midpos) {
+			cell = nullptr;
+			tie(pos > midpos ? midpos : pos);
+		}
+
+		void proj_right(double midpos) {
+			cell = nullptr;
+			tie(pos < midpos ? midpos : pos);
+		}
+	};
+
+	vector<Node> nodes;
+	dict<pair<int, int>, double> edges;
+	dict<Cell*, int> cell_to_node;
+
+	QwpWorker(const QwpConfig &config, Module *module, char direction = 'x') : config(config), module(module), direction(direction)
+	{
+		log_assert(direction == 'x' || direction == 'y');
+	}
+
+	void load_module()
+	{
+		log_assert(direction == 'x');
+
+		SigMap sigmap(module);
+		dict<SigBit, pool<int>> bits_to_nodes;
+
+		if (config.ltr || config.alpha)
+		{
+			dict<Wire*, double> alpha_inputs, alpha_outputs;
+
+			if (config.alpha)
+			{
+				dict<string, Wire*> alpha_order;
+
+				for (auto wire : module->wires()) {
+					if (wire->port_input || wire->port_output)
+						alpha_order[wire->name.str()] = wire;
+				}
+
+				alpha_order.sort();
+
+				for (auto &it : alpha_order) {
+					if (it.second->port_input) {
+						int idx = GetSize(alpha_inputs);
+						alpha_inputs[it.second] = idx + 0.5;
+					}
+					if (it.second->port_output) {
+						int idx = GetSize(alpha_outputs);
+						alpha_outputs[it.second] = idx + 0.5;
+					}
+				}
+			}
+
+			for (auto wire : module->wires())
+			{
+				if (!wire->port_input && !wire->port_output)
+					continue;
+
+				int idx = GetSize(nodes);
+				nodes.push_back(Node());
+
+				if (config.ltr) {
+					if (wire->port_input)
+						nodes[idx].tie(0.0);
+					else
+						nodes[idx].tie(1.0);
+				}
+
+				if (config.alpha) {
+					if (wire->port_input)
+						nodes[idx].alt_tie(alpha_inputs.at(wire) / GetSize(alpha_inputs));
+					else
+						nodes[idx].alt_tie(alpha_outputs.at(wire) / GetSize(alpha_outputs));
+				}
+
+				for (auto bit : sigmap(wire))
+					bits_to_nodes[bit].insert(idx);
+			}
+		}
+
+		for (auto cell : module->selected_cells())
+		{
+			log_assert(cell_to_node.count(cell) == 0);
+			int idx = GetSize(nodes);
+			nodes.push_back(Node());
+
+			cell_to_node[cell] = GetSize(nodes);
+			nodes[idx].cell = cell;
+
+			for (auto &conn : cell->connections())
+			for (auto bit : sigmap(conn.second))
+				bits_to_nodes[bit].insert(idx);
+		}
+
+		for (auto &it : bits_to_nodes)
+		{
+			if (GetSize(it.second) > 100)
+				continue;
+
+			for (int idx1 : it.second)
+			for (int idx2 : it.second)
+				if (idx1 < idx2)
+					edges[pair<int, int>(idx1, idx2)] += 1.0 / GetSize(it.second);
+		}
+	}
+
+	void solve()
+	{
+		int observation_matrix_m = GetSize(edges) + GetSize(nodes);
+		int observation_matrix_n = GetSize(nodes);
+
+		// Column-major order
+		vector<double> observation_matrix(observation_matrix_m * observation_matrix_n);
+		vector<double> observation_rhs_vector(observation_matrix_m);
+
+		int i = 0;
+		for (auto &edge : edges) {
+			int idx1 = edge.first.first;
+			int idx2 = edge.first.second;
+			double weight = edge.second * (1.0 + xorshift32() * 1e-3);
+			observation_matrix[i + observation_matrix_m*idx1] = weight;
+			observation_matrix[i + observation_matrix_m*idx2] = -weight;
+			i++;
+		}
+
+		int j = 0;
+		for (auto &node : nodes) {
+			double weight = 1e-6;
+			if (node.tied) weight = 1e3;
+			weight *= (1.0 + xorshift32() * 1e-3);
+			observation_matrix[i + observation_matrix_m*j] = weight;
+			observation_rhs_vector[i] = node.pos * weight;
+			i++, j++;
+		}
+
+#ifdef LOG_MATRICES
+		log("----\n");
+		for (int i = 0; i < observation_matrix_m; i++) {
+			for (int j = 0; j < observation_matrix_n; j++)
+				log(" %10.2e", observation_matrix[i + observation_matrix_m*j]);
+			log(" |%9.2e\n", observation_rhs_vector[i]);
+		}
+#endif
+
+		// A := observation_matrix
+		// y := observation_rhs_vector
+		//
+		// AA = A' * A
+		// Ay = A' * y
+		//
+		// M := [AA Ay]
+
+		// Row major order
+		vector<double> M(observation_matrix_n * (observation_matrix_n+1));
+		int N = observation_matrix_n;
+
+		for (int i = 0; i < N; i++)
+		for (int j = 0; j < N; j++) {
+			double sum = 0;
+			for (int k = 0; k < observation_matrix_m; k++)
+				sum += observation_matrix[k + observation_matrix_m*i] * observation_matrix[k + observation_matrix_m*j];
+			M[(N+1)*i + j] = sum;
+		}
+
+		for (int i = 0; i < N; i++) {
+			double sum = 0;
+			for (int k = 0; k < observation_matrix_m; k++)
+				sum += observation_matrix[k + observation_matrix_m*i] * observation_rhs_vector[k];
+			M[(N+1)*i + N] = sum;
+		}
+
+#ifdef LOG_MATRICES
+		log("\n");
+		for (int i = 0; i < N; i++) {
+			for (int j = 0; j < N+1; j++)
+				log(" %10.2e", M[(N+1)*i + j]);
+			log("\n");
+		}
+#endif
+
+		// Solve "AA*x = Ay"
+		// (least squares fit for "A*x = y")
+		//
+		// Using gaussian elimination (no pivoting) to get M := [Id x]
+
+		// eliminate to upper triangular matrix
+		for (int i = 0; i < N; i++)
+		{
+			// normalize row
+			for (int j = i+1; j < N+1; j++)
+				M[(N+1)*i + j] /= M[(N+1)*i + i];
+			M[(N+1)*i + i] = 1.0;
+
+			// elimination
+			for (int j = i+1; j < N; j++) {
+				double d = M[(N+1)*j + i];
+				for (int k = 0; k < N+1; k++)
+					if (k > i)
+						M[(N+1)*j + k] -= d*M[(N+1)*i + k];
+					else
+						M[(N+1)*j + k] = 0.0;
+			}
+		}
+
+		// back substitution
+		for (int i = N-1; i >= 0; i--)
+		for (int j = i+1; j < N; j++)
+		{
+			M[(N+1)*i + N] -= M[(N+1)*i + j] * M[(N+1)*j + N];
+			M[(N+1)*i + j] = 0.0;
+		}
+
+#ifdef LOG_MATRICES
+		log("\n");
+		for (int i = 0; i < N; i++) {
+			for (int j = 0; j < N+1; j++)
+				log(" %10.2e", M[(N+1)*i + j]);
+			log("\n");
+		}
+#endif
+
+		// update node positions
+		for (int i = 0; i < N; i++)
+			if (!nodes[i].tied)
+				nodes[i].pos = M[(N+1)*i + N];
+	}
+
+	void log_cell_coordinates(int indent, bool log_all_nodes = false)
+	{
+		for (auto &node : nodes)
+		{
+			if (node.cell == nullptr && !log_all_nodes)
+				continue;
+
+			for (int i = 0; i < indent; i++)
+				log("  ");
+
+			if (direction == 'x')
+				log("X=%.2f, Y=%.2f", node.pos, node.alt_pos);
+			else
+				log("X=%.2f, Y=%.2f", node.alt_pos, node.pos);
+
+			if (node.tied)
+				log(" [%c-tied]", direction);
+
+			if (node.alt_tied)
+				log(" [%c-tied]", direction == 'x' ? 'y' : 'x');
+
+			if (node.cell != nullptr)
+				log(" %s (%s)", log_id(node.cell), log_id(node.cell->type));
+			else
+				log(" (none)");
+
+			log("\n");
+		}
+	}
+
+	void run_worker(int indent, double midpos, double radius, double alt_midpos, double alt_radius)
+	{
+		int count_cells = 0;
+
+		for (auto &node : nodes)
+			if (node.cell != nullptr)
+				count_cells++;
+
+		for (int i = 0; i < indent; i++)
+			log("  ");
+
+		if (direction == 'x')
+			log("x-qwp on X=%.2f:%.2f, Y=%.2f:%.2f with %d cells, %d nodes, and %d edges.\n",
+					midpos - radius, midpos + radius, alt_midpos - alt_radius, alt_midpos + alt_radius,
+					count_cells, GetSize(nodes), GetSize(edges));
+		else
+			log("y-qwp on X=%.2f:%.2f, Y=%.2f:%.2f with %d cells, %d nodes, and %d edges.\n",
+					alt_midpos - alt_radius, alt_midpos + alt_radius, midpos - radius, midpos + radius,
+					count_cells, GetSize(nodes), GetSize(edges));
+
+		solve();
+
+		for (auto &node : nodes) {
+			log_assert(node.pos + 0.1 >= midpos - radius);
+			log_assert(node.pos - 0.1 <= midpos + radius);
+			log_assert(node.alt_pos + 0.1 >= alt_midpos - alt_radius);
+			log_assert(node.alt_pos - 0.1 <= alt_midpos + alt_radius);
+		}
+
+		if (2*radius <= config.grid && 2*alt_radius <= config.grid) {
+			log_cell_coordinates(indent + 1);
+			return;
+		}
+
+		// detect median position
+
+		vector<pair<double, int>> sorted_pos;
+		for (int i = 0; i < GetSize(nodes); i++)
+			if (nodes[i].cell != nullptr)
+				sorted_pos.push_back(pair<double, int>(nodes[i].pos, i));
+
+		if (GetSize(sorted_pos) < 2) {
+			log_cell_coordinates(indent + 1);
+			return;
+		}
+
+		std::sort(sorted_pos.begin(), sorted_pos.end());
+
+		// create child workers
+
+		char child_direction = direction == 'x' ? 'y' : 'x';
+
+		QwpWorker left_worker(config, module, child_direction);
+		QwpWorker right_worker(config, module, child_direction);
+
+		// duplicate nodes into child workers
+
+		dict<int, int> left_nodes, right_nodes;
+
+		for (int k = 0; k < GetSize(sorted_pos); k++)
+		{
+			int i = sorted_pos[k].second;
+
+			if (k < GetSize(sorted_pos) / 2) {
+				left_nodes[i] = GetSize(left_worker.nodes);
+				left_worker.nodes.push_back(nodes[i]);
+				if (left_worker.nodes.back().pos > midpos)
+					left_worker.nodes.back().pos = midpos;
+				left_worker.nodes.back().swap_alt();
+			} else {
+				right_nodes[i] = GetSize(right_worker.nodes);
+				right_worker.nodes.push_back(nodes[i]);
+				if (right_worker.nodes.back().pos < midpos)
+					right_worker.nodes.back().pos = midpos;
+				right_worker.nodes.back().swap_alt();
+			}
+		}
+
+		// duplicate edges into child workers, project nodes as needed
+
+		for (auto &edge : edges)
+		{
+			int idx1 = edge.first.first;
+			int idx2 = edge.first.second;
+			double weight = edge.second;
+
+			if (nodes[idx1].cell == nullptr && nodes[idx2].cell == nullptr)
+				continue;
+
+			int left_idx1 = left_nodes.count(idx1) ? left_nodes.at(idx1) : -1;
+			int left_idx2 = left_nodes.count(idx2) ? left_nodes.at(idx2) : -1;
+
+			int right_idx1 = right_nodes.count(idx1) ? right_nodes.at(idx1) : -1;
+			int right_idx2 = right_nodes.count(idx2) ? right_nodes.at(idx2) : -1;
+
+			if (nodes[idx1].cell && left_idx1 >= 0 && left_idx2 < 0) {
+				left_idx2 = left_nodes[idx2] = GetSize(left_worker.nodes);
+				left_worker.nodes.push_back(nodes[idx2]);
+				left_worker.nodes.back().proj_left(midpos);
+				left_worker.nodes.back().swap_alt();
+			} else
+			if (nodes[idx2].cell && left_idx2 >= 0 && left_idx1 < 0) {
+				left_idx1 = left_nodes[idx1] = GetSize(left_worker.nodes);
+				left_worker.nodes.push_back(nodes[idx1]);
+				left_worker.nodes.back().proj_left(midpos);
+				left_worker.nodes.back().swap_alt();
+			}
+
+			if (nodes[idx1].cell && right_idx1 >= 0 && right_idx2 < 0) {
+				right_idx2 = right_nodes[idx2] = GetSize(right_worker.nodes);
+				right_worker.nodes.push_back(nodes[idx2]);
+				right_worker.nodes.back().proj_right(midpos);
+				right_worker.nodes.back().swap_alt();
+			} else
+			if (nodes[idx2].cell && right_idx2 >= 0 && right_idx1 < 0) {
+				right_idx1 = right_nodes[idx1] = GetSize(right_worker.nodes);
+				right_worker.nodes.push_back(nodes[idx1]);
+				right_worker.nodes.back().proj_right(midpos);
+				right_worker.nodes.back().swap_alt();
+			}
+
+			if (left_idx1 >= 0 && left_idx2 >= 0)
+				left_worker.edges[pair<int, int>(left_idx1, left_idx2)] += weight;
+
+			if (right_idx1 >= 0 && right_idx2 >= 0)
+				right_worker.edges[pair<int, int>(right_idx1, right_idx2)] += weight;
+		}
+
+		// run child workers
+
+		left_worker.run_worker(indent+1, alt_midpos, alt_radius, midpos - radius/2, radius/2);
+		right_worker.run_worker(indent+1, alt_midpos, alt_radius, midpos + radius/2, radius/2);
+
+		// re-integrate results
+
+		for (auto &it : left_nodes)
+			if (left_worker.nodes[it.second].cell != nullptr) {
+				nodes[it.first].pos = left_worker.nodes[it.second].alt_pos;
+				nodes[it.first].alt_pos = left_worker.nodes[it.second].pos;
+			}
+
+		for (auto &it : right_nodes)
+			if (right_worker.nodes[it.second].cell != nullptr) {
+				nodes[it.first].pos = right_worker.nodes[it.second].alt_pos;
+				nodes[it.first].alt_pos = right_worker.nodes[it.second].pos;
+			}
+	}
+
+	void run()
+	{
+		log("Running qwp on module %s..\n", log_id(module));
+
+		load_module();
+		run_worker(1, 0.5, 0.5, 0.5, 0.5);
+
+		for (auto &node : nodes)
+			if (node.cell != nullptr)
+				node.cell->attributes["\\qwp_position"] = stringf("%f %f", node.pos, node.alt_pos);
+	}
+};
+
+struct QwpPass : public Pass {
+	QwpPass() : Pass("qwp", "quadratic wirelength placer") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    qwp [options] [selection]\n");
+		log("\n");
+		log("This command runs quadratic wirelength placement on the selected modules and\n");
+		log("annotates the cells in the design with 'qwp_position' attributes.\n");
+		log("\n");
+		log("    -ltr\n");
+		log("        Add left-to-right constraints: constrain all inputs on the left border\n");
+		log("        outputs to the right border.\n");
+		log("\n");
+		log("    -alpha\n");
+		log("        Add constraints for inputs/outputs to be placed in alphanumerical\n");
+		log("        order along the y-axis (top-to-bottom).\n");
+		log("\n");
+		log("    -grid N\n");
+		log("        Number of grid divisions in x- and y-direction. (default=16)\n");
+		log("\n");
+		log("Note: This implementation of a quadratic wirelength placer uses unoptimized\n");
+		log("dense matrix operations. It is only a toy-placer for small circuits.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	{
+		QwpConfig config;
+		xorshift32_state = 123456789;
+
+		log_header("Executing QWP pass (quadratic wirelength placer).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			if (args[argidx] == "-ltr") {
+				config.ltr = true;
+				continue;
+			}
+			if (args[argidx] == "-alpha") {
+				config.alpha = true;
+				continue;
+			}
+			if (args[argidx] == "-grid" && argidx+1 < args.size()) {
+				config.grid = 1.0 / atoi(args[++argidx].c_str());
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto module : design->selected_modules())
+		{
+			QwpWorker worker(config, module);
+			worker.run();
+
+#ifdef PYPLOT_EDGES
+			log("\n");
+			log("plt.figure(figsize=(10, 10));\n");
+
+			for (auto &edge : worker.edges) {
+				log("plt.plot([%.2f, %.2f], [%.2f, %.2f], \"r-\");\n",
+						worker.nodes[edge.first.first].pos,
+						worker.nodes[edge.first.second].pos,
+						worker.nodes[edge.first.first].alt_pos,
+						worker.nodes[edge.first.second].alt_pos);
+			}
+
+			for (auto &node : worker.nodes) {
+				const char *style = node.cell != nullptr ? "ko" : "ks";
+				log("plt.plot([%.2f], [%.2f], \"%s\");\n", node.pos, node.alt_pos, style);
+			}
+#endif
+		}
+	}
+} QwpPass;
+
+PRIVATE_NAMESPACE_END