From 48aa72ae8ff481d5e35d8a04eda4b0f2e43f1da7 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Tue, 18 Jun 2013 17:11:36 +0200
Subject: [PATCH] Added splitnets command

---
 passes/cmds/Makefile.inc |   2 +
 passes/cmds/splitnets.cc | 108 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 passes/cmds/splitnets.cc

diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index 166e91590..75bfa5b8b 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -3,3 +3,5 @@ OBJS += passes/cmds/select.o
 OBJS += passes/cmds/show.o
 OBJS += passes/cmds/rename.o
 OBJS += passes/cmds/scatter.o
+OBJS += passes/cmds/splitnets.o
+
diff --git a/passes/cmds/splitnets.cc b/passes/cmds/splitnets.cc
new file mode 100644
index 000000000..73393da8b
--- /dev/null
+++ b/passes/cmds/splitnets.cc
@@ -0,0 +1,108 @@
+/*
+ *  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/register.h"
+#include "kernel/celltypes.h"
+#include "kernel/rtlil.h"
+#include "kernel/log.h"
+
+struct SplitnetsWorker
+{
+	std::map<RTLIL::Wire*, std::vector<RTLIL::Wire*>> splitmap;
+
+	void operator()(RTLIL::SigSpec &sig)
+	{
+		sig.expand();
+		for (auto &c : sig.chunks)
+			if (splitmap.count(c.wire) > 0) {
+				c.wire = splitmap.at(c.wire).at(c.offset);
+				c.offset = 0;
+			}
+		sig.optimize();
+	}
+};
+
+struct SplitnetsPass : public Pass {
+	SplitnetsPass() : Pass("splitnets", "split up multi-bit nets") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    splitnets [options] [selection]\n");
+		log("\n");
+		log("This command splits multi-bit nets into single-bit nets.\n");
+		log("\n");
+		log("    -ports\n");
+		log("        also split module ports. per default only internal signals are split.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	{
+		bool flag_ports = false;
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			if (args[argidx] == "-ports") {
+				flag_ports = true;
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto &mod_it : design->modules)
+		{
+			RTLIL::Module *module = mod_it.second;
+			if (!design->selected(module))
+				continue;
+
+			SplitnetsWorker worker;
+
+			for (auto &w : module->wires) {
+				RTLIL::Wire *wire = w.second;
+				if (wire->width > 1 && (wire->port_id == 0 || flag_ports))
+					worker.splitmap[wire] = std::vector<RTLIL::Wire*>();
+			}
+
+			for (auto &it : worker.splitmap)
+				for (int i = 0; i < it.first->width; i++) {
+					RTLIL::Wire *wire = new RTLIL::Wire;
+					wire->port_id = it.first->port_id;
+					wire->port_input = it.first->port_input;
+					wire->port_output = it.first->port_output;
+					wire->name = it.first->name + stringf("[%d]", i);
+					while (module->count_id(wire->name) > 0)
+						wire->name = wire->name + "_";
+					module->add(wire);
+					it.second.push_back(wire);
+				}
+
+			module->rewrite_sigspecs(worker);
+
+			for (auto &it : worker.splitmap) {
+				module->wires.erase(it.first->name);
+				delete it.first;
+			}
+
+			module->fixup_ports();
+		}
+	}
+} SplitnetsPass;
+ 
-- 
2.30.2