Add "viz" pass for visualizing big-picture data flow in larger designs

Signed-off-by: Claire Xenia Wolf <claire@clairexen.net>

2 files changed, 511 insertions, 0 deletions

diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index 8807950dc..29b3a1132 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -7,6 +7,7 @@ OBJS += passes/cmds/delete.o
 OBJS += passes/cmds/design.o
 OBJS += passes/cmds/select.o
 OBJS += passes/cmds/show.o
+OBJS += passes/cmds/viz.o
 OBJS += passes/cmds/rename.o
 OBJS += passes/cmds/autoname.o
 OBJS += passes/cmds/connect.o
diff --git a/passes/cmds/viz.cc b/passes/cmds/viz.cc
new file mode 100644
index 000000000..83919b50a
--- /dev/null
+++ b/passes/cmds/viz.cc
@@ -0,0 +1,510 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Claire Xenia Wolf <claire@yosyshq.com>
+ *
+ *  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"
+
+#ifndef _WIN32
+#  include <dirent.h>
+#endif
+
+#ifdef __APPLE__
+#  include <unistd.h>
+#endif
+
+#ifdef YOSYS_ENABLE_READLINE
+#  include <readline/readline.h>
+#endif
+
+#ifdef YOSYS_ENABLE_EDITLINE
+#  include <editline/readline.h>
+#endif
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct GraphNode {
+	int index = -1;
+	bool terminal = false;
+	GraphNode *replaced = nullptr;
+
+	GraphNode *get() {
+		if (replaced == nullptr)
+			return this;
+		return replaced = replaced->get();
+	}
+
+	pool<IdString> names_;
+	pool<GraphNode*, hash_ptr_ops> upstream_;
+	pool<GraphNode*, hash_ptr_ops> downstream_;
+
+	pool<IdString> &names() { return get()->names_; }
+	pool<GraphNode*, hash_ptr_ops> &upstream() { return get()->upstream_; }
+	pool<GraphNode*, hash_ptr_ops> &downstream() { return get()->downstream_; }
+
+	void replace(GraphNode *g) {
+		if (replaced) return get()->replace(g);
+
+		if (this == g->get()) return;
+		log_assert(terminal == g->terminal);
+
+		for (auto v : g->names())
+			names().insert(v);
+
+		for (auto v : g->upstream()) {
+			auto n = v->get();
+			if (n == this) continue;
+			upstream().insert(n);
+		}
+
+		for (auto v : g->downstream()) {
+			auto n = v->get();
+			if (n == this) continue;
+			downstream().insert(n);
+		}
+
+		g->names().clear();
+		g->upstream().clear();
+		g->downstream().clear();
+
+		g->get()->replaced = this;
+	}
+
+	void cleanup() {
+		if (replaced) return;
+
+		pool<GraphNode*, hash_ptr_ops> new_upstream;
+		pool<GraphNode*, hash_ptr_ops> new_downstream;
+
+		for (auto g : upstream_) {
+			auto n = g->get();
+			if (n == this) continue;
+			new_upstream.insert(n);
+		}
+		for (auto g : downstream_) {
+			auto n = g->get();
+			if (n == this) continue;
+			new_downstream.insert(n);
+		}
+
+		std::swap(upstream_, new_upstream);
+		std::swap(downstream_, new_downstream);
+	}
+};
+
+struct Graph {
+	int term_nodes_cnt;
+	int nonterm_nodes_cnt;
+
+	vector<GraphNode*> nodes;
+	vector<GraphNode*> replaced_nodes;
+
+	~Graph()
+	{
+		for (auto n : nodes) delete n;
+		for (auto n : replaced_nodes) delete n;
+	}
+
+	void cleanup()
+	{
+		vector<GraphNode*> new_nodes;
+
+		term_nodes_cnt = 0;
+		nonterm_nodes_cnt = 0;
+
+		for (auto n : nodes) {
+			if (n->replaced) {
+				replaced_nodes.push_back(n);
+			} else {
+				if (n->terminal)
+					term_nodes_cnt++;
+				else
+					nonterm_nodes_cnt++;
+				n->cleanup();
+				n->index = GetSize(new_nodes);
+				new_nodes.push_back(n);
+			}
+		}
+
+		std::swap(nodes, new_nodes);
+	}
+
+	bool merge_simple()
+	{
+		bool did_something = false;
+		while (true) {
+			vector<pair<GraphNode*,GraphNode*>> queued_merges;
+			typedef pair<pool<GraphNode*, hash_ptr_ops>, pool<GraphNode*, hash_ptr_ops>> node_conn_t;
+			dict<node_conn_t, pool<GraphNode*, hash_ptr_ops>> nodes_by_conn[2];
+			
+			for (auto g : nodes) {
+				if (g->replaced) continue;
+
+				nodes_by_conn[g->terminal][node_conn_t(g->upstream(), g->downstream())].insert(g);
+
+				if (GetSize(g->downstream()) == 1) {
+					auto n = (*g->downstream().begin())->get();
+					if (g->terminal != n->terminal) continue;
+					queued_merges.push_back(pair<GraphNode*,GraphNode*>(g, n));
+				}
+
+				if (GetSize(g->upstream()) == 1) {
+					auto n = (*g->upstream().begin())->get();
+					if (g->terminal != n->terminal) continue;
+					queued_merges.push_back(pair<GraphNode*,GraphNode*>(g, n));
+				}
+
+				for (auto n : g->downstream()) {
+					if (g->terminal != n->terminal) continue;
+					if (!n->downstream().count(g)) continue;
+					queued_merges.push_back(pair<GraphNode*,GraphNode*>(g, n));
+				}
+			}
+
+			for (int term = 0; term < 2; term++) {
+				for (auto &grp : nodes_by_conn[term]) {
+					auto it = grp.second.begin();
+					auto first = *it;
+					while (++it != grp.second.end())
+						queued_merges.push_back(pair<GraphNode*,GraphNode*>(first, *it));
+				}
+			}
+
+			int count_merges = 0;
+			for (auto m : queued_merges) {
+				auto g = m.first->get(), n = m.second->get();
+				if (g == n) continue;
+				g->replace(n);
+				count_merges++;
+			}
+			if (count_merges == 0) return did_something;
+
+			log("  Replaced %d nodes in merge_simple().\n", count_merges);
+			did_something = true;
+			cleanup();
+		}
+	}
+
+	Graph(Module *module)
+	{
+		SigMap sigmap(module);
+		dict<SigBit, GraphNode*> wire_nodes;
+
+		for (auto wire : module->selected_wires())
+		{
+			if (!wire->name.isPublic()) continue;
+			auto g = new GraphNode;
+			g->terminal = true;
+			g->names().insert(wire->name);
+			nodes.push_back(g);
+
+			for (auto bit : sigmap(wire)) {
+				if (!bit.wire) continue;
+				auto it = wire_nodes.find(bit);
+				if (it == wire_nodes.end())
+					wire_nodes[bit] = g;
+				else
+					g->replace(it->second);
+			}
+		}
+
+		dict<Cell*, GraphNode*> cell_nodes;
+		dict<SigBit, pool<GraphNode*, hash_ptr_ops>> sig_users;
+
+		for (auto cell : module->selected_cells()) {
+			auto g = new GraphNode;
+			cell_nodes[cell] = g;
+			g->names().insert(cell->name);
+			nodes.push_back(g);
+
+			for (auto &conn : cell->connections()) {
+				if (cell->input(conn.first))
+					for (auto bit : sigmap(conn.second)) {
+						if (!bit.wire) continue;
+						auto it = wire_nodes.find(bit);
+						if (it != wire_nodes.end()) {
+							g->upstream().insert(it->second);
+							it->second->downstream().insert(g);
+						}
+						sig_users[bit].insert(g);
+					}
+				if (cell->output(conn.first))
+					for (auto bit : sigmap(conn.second)) {
+						if (!bit.wire) continue;
+						auto it = wire_nodes.find(bit);
+						if (it != wire_nodes.end()) {
+							g->downstream().insert(it->second);
+							it->second->upstream().insert(g);
+						}
+					}
+			}
+		}
+
+		for (auto cell : module->selected_cells()) {
+			auto g = cell_nodes.at(cell);
+
+			for (auto &conn : cell->connections()) {
+				if (!cell->output(conn.first)) continue;
+				for (auto bit : sigmap(conn.second)) {
+					if (!bit.wire) continue;
+					for (auto u : sig_users[bit]) {
+						g->downstream().insert(u);
+						u->upstream().insert(g);
+					}
+				}
+			}
+		}
+
+		cleanup();
+	}
+};
+
+struct VizWorker
+{
+	FILE *f;
+	Graph graph;
+
+	VizWorker(FILE *f, Module *module) : graph(module)
+	{
+		log("Running Viz for module %s:\n", log_id(module));
+		log("  Initial number of terminal nodes is %d.\n", graph.term_nodes_cnt);
+		log("  Initial number of non-terminal nodes is %d.\n", graph.nonterm_nodes_cnt);
+
+		graph.merge_simple();
+
+		log("  Final number of terminal nodes is %d.\n", graph.term_nodes_cnt);
+		log("  Final number of non-terminal nodes is %d.\n", graph.nonterm_nodes_cnt);
+
+		fprintf(f, "digraph \"%s\" {", log_id(module));
+		fprintf(f, "  rankdir = LR;");
+
+		for (int i = 0; i < GetSize(graph.nodes); i++) {
+			auto g = graph.nodes[i];
+			if (g->terminal) {
+				std::string label;
+				for (auto n : g->names()) {
+					if (!label.empty())
+						label += "\\n";
+					label += log_id(n);
+				}
+				fprintf(f, "\tn%d [shape=octagon,label=\"%s\"];\n", g->index, label.c_str());
+			} else {
+				fprintf(f, "\tn%d [label=\"%d cells\"];\n", g->index, GetSize(g->names()));
+			}
+		}
+
+		for (int i = 0; i < GetSize(graph.nodes); i++) {
+			auto g = graph.nodes[i];
+			for (auto n : g->downstream()) {
+				if (g->terminal && !n->terminal && n->downstream().count(g)) continue;
+				fprintf(f, "\tn%d -> n%d;\n", g->index, n->index);
+			}
+		}
+
+		fprintf(f, "}");
+	}
+};
+
+struct VizPass : public Pass {
+	VizPass() : Pass("viz", "visualize data flow graph") { }
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    viz [options] [selection]\n");
+		log("\n");
+		log("Create a graphviz DOT file for the selected part of the design, showing the\n");
+		log("relationships between the selected wires, and compile it to a graphics\n");
+		log("file (usually SVG or PostScript).\n");
+		log("\n");
+		log("    -viewer <viewer>\n");
+		log("        Run the specified command with the graphics file as parameter.\n");
+		log("        On Windows, this pauses yosys until the viewer exits.\n");
+		log("\n");
+		log("    -format <format>\n");
+		log("        Generate a graphics file in the specified format. Use 'dot' to just\n");
+		log("        generate a .dot file, or other <format> strings such as 'svg' or 'ps'\n");
+		log("        to generate files in other formats (this calls the 'dot' command).\n");
+		log("\n");
+		log("    -prefix <prefix>\n");
+		log("        generate <prefix>.* instead of ~/.yosys_show.*\n");
+		log("\n");
+		log("    -pause\n");
+		log("        wait for the user to press enter to before returning\n");
+		log("\n");
+		log("    -nobg\n");
+		log("        don't run viewer in the background, IE wait for the viewer tool to\n");
+		log("        exit before returning\n");
+		log("\n");
+		log("When no <format> is specified, 'dot' is used. When no <format> and <viewer> is\n");
+		log("specified, 'xdot' is used to display the schematic (POSIX systems only).\n");
+		log("\n");
+		log("The generated output files are '~/.yosys_show.dot' and '~/.yosys_show.<format>',\n");
+		log("unless another prefix is specified using -prefix <prefix>.\n");
+		log("\n");
+		log("Yosys on Windows and YosysJS use different defaults: The output is written\n");
+		log("to 'show.dot' in the current directory and new viewer is launched each time\n");
+		log("the 'show' command is executed.\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) override
+	{
+		log_header(design, "Generating Graphviz representation of design.\n");
+		log_push();
+
+#if defined(_WIN32) || defined(YOSYS_DISABLE_SPAWN)
+		std::string format = "dot";
+		std::string prefix = "show";
+#else
+		std::string format;
+		std::string prefix = stringf("%s/.yosys_show", getenv("HOME") ? getenv("HOME") : ".");
+#endif
+		std::string viewer_exe;
+		bool flag_pause = false;
+		bool custom_prefix = false;
+		std::string background = "&";
+		RTLIL::IdString colorattr;
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			std::string arg = args[argidx];
+			if (arg == "-viewer" && argidx+1 < args.size()) {
+				viewer_exe = args[++argidx];
+				continue;
+			}
+			if (arg == "-prefix" && argidx+1 < args.size()) {
+				prefix = args[++argidx];
+				custom_prefix = true;
+				continue;
+			}
+			if (arg == "-format" && argidx+1 < args.size()) {
+				format = args[++argidx];
+				continue;
+			}
+			if (arg == "-pause") {
+				flag_pause= true;
+				continue;
+			}
+			if (arg == "-nobg") {
+				background= "";
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		int modcount = 0;
+		for (auto module : design->selected_modules()) {
+			if (module->get_blackbox_attribute())
+				continue;
+			if (module->cells().size() == 0 && module->connections().empty())
+				continue;
+			modcount++;
+		}
+		if (format != "ps" && format != "dot" && modcount > 1)
+			log_cmd_error("For formats different than 'ps' or 'dot' only one module must be selected.\n");
+		if (modcount == 0)
+			log_cmd_error("Nothing there to show.\n");
+
+		std::string dot_file = stringf("%s.dot", prefix.c_str());
+		std::string out_file = stringf("%s.%s", prefix.c_str(), format.empty() ? "svg" : format.c_str());
+
+		log("Writing dot description to `%s'.\n", dot_file.c_str());
+		FILE *f = fopen(dot_file.c_str(), "w");
+		if (custom_prefix)
+			yosys_output_files.insert(dot_file);
+		if (f == nullptr) {
+			log_cmd_error("Can't open dot file `%s' for writing.\n", dot_file.c_str());
+		}
+		for (auto module : design->selected_modules()) {
+			if (module->get_blackbox_attribute())
+				continue;
+			if (module->cells().size() == 0 && module->connections().empty())
+				continue;
+			VizWorker worker(f, module);
+		}
+		fclose(f);
+
+		if (format != "dot" && !format.empty()) {
+			#ifdef _WIN32
+				// system()/cmd.exe does not understand single quotes on Windows.
+				#define DOT_CMD "dot -T%s \"%s\" > \"%s.new\" && move \"%s.new\" \"%s\""
+			#else
+				#define DOT_CMD "dot -T%s '%s' > '%s.new' && mv '%s.new' '%s'"
+			#endif
+			std::string cmd = stringf(DOT_CMD, format.c_str(), dot_file.c_str(), out_file.c_str(), out_file.c_str(), out_file.c_str());
+			#undef DOT_CMD
+			log("Exec: %s\n", cmd.c_str());
+			#if !defined(YOSYS_DISABLE_SPAWN)
+				if (run_command(cmd) != 0)
+					log_cmd_error("Shell command failed!\n");
+			#endif
+		}
+
+		#if defined(YOSYS_DISABLE_SPAWN)
+			log_assert(viewer_exe.empty() && !format.empty());
+		#else
+		if (!viewer_exe.empty()) {
+			#ifdef _WIN32
+				// system()/cmd.exe does not understand single quotes nor
+				// background tasks on Windows. So we have to pause yosys
+				// until the viewer exits.
+				std::string cmd = stringf("%s \"%s\"", viewer_exe.c_str(), out_file.c_str());
+			#else
+				std::string cmd = stringf("%s '%s' %s", viewer_exe.c_str(), out_file.c_str(), background.c_str());
+			#endif
+			log("Exec: %s\n", cmd.c_str());
+			if (run_command(cmd) != 0)
+				log_cmd_error("Shell command failed!\n");
+		} else
+		if (format.empty()) {
+			#ifdef __APPLE__
+			std::string cmd = stringf("ps -fu %d | grep -q '[ ]%s' || xdot '%s' %s", getuid(), dot_file.c_str(), dot_file.c_str(), background.c_str());
+			#else
+			std::string cmd = stringf("{ test -f '%s.pid' && fuser -s '%s.pid' 2> /dev/null; } || ( echo $$ >&3; exec xdot '%s'; ) 3> '%s.pid' %s", dot_file.c_str(), dot_file.c_str(), dot_file.c_str(), dot_file.c_str(), background.c_str());
+			#endif
+			log("Exec: %s\n", cmd.c_str());
+			if (run_command(cmd) != 0)
+				log_cmd_error("Shell command failed!\n");
+		}
+		#endif
+
+		if (flag_pause) {
+		#ifdef YOSYS_ENABLE_READLINE
+			char *input = nullptr;
+			while ((input = readline("Press ENTER to continue (or type 'shell' to open a shell)> ")) != nullptr) {
+				if (input[strspn(input, " \t\r\n")] == 0)
+					break;
+				char *p = input + strspn(input, " \t\r\n");
+				if (!strcmp(p, "shell")) {
+					Pass::call(design, "shell");
+					break;
+				}
+			}
+		#else
+			log_cmd_error("This version of yosys is built without readline support => 'show -pause' is not available.\n");
+		#endif
+		}
+
+		log_pop();
+	}
+} VizPass;
+
+PRIVATE_NAMESPACE_END