/*
 *  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"

USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN

struct CutpointPass : public Pass {
	CutpointPass() : Pass("cutpoint", "adds formal cut points to the design") { }
	void help() YS_OVERRIDE
	{
		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
		log("\n");
		log("    cutpoint [options] [selection]\n");
		log("\n");
		log("This command adds formal cut points to the design.\n");
		log("\n");
		log("    -undef\n");
		log("        set cupoint nets to undef (x). the default behavior is to create a\n");
		log("        $anyseq cell and drive the cutpoint net from that\n");
		log("\n");
	}
	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
	{
		 bool flag_undef = false;

		log_header(design, "Executing CUTPOINT pass.\n");

		size_t argidx;
		for (argidx = 1; argidx < args.size(); argidx++)
		{
			if (args[argidx] == "-undef") {
				flag_undef = true;
				continue;
			}
			break;
		}
		extra_args(args, argidx, design);

		for (auto module : design->selected_modules())
		{
			if (design->selected_whole_module(module->name)) {
				log("Making all outputs of module %s cut points, removing module contents.\n", log_id(module));
				module->new_connections(std::vector<RTLIL::SigSig>());
				for (auto cell : vector<Cell*>(module->cells()))
					module->remove(cell);
				vector<Wire*> output_wires;
				for (auto wire : module->wires())
					if (wire->port_output)
						output_wires.push_back(wire);
				for (auto wire : output_wires)
					module->connect(wire, flag_undef ? Const(State::Sx, GetSize(wire)) : module->Anyseq(NEW_ID, GetSize(wire)));
				continue;
			}

			SigMap sigmap(module);
			pool<SigBit> cutpoint_bits;

			for (auto cell : module->selected_cells()) {
				if (cell->type == "$anyseq")
					continue;
				log("Removing cell %s.%s, making all cell outputs cutpoints.\n", log_id(module), log_id(cell));
				for (auto &conn : cell->connections()) {
					if (cell->output(conn.first))
						module->connect(conn.second, flag_undef ? Const(State::Sx, GetSize(conn.second)) : module->Anyseq(NEW_ID, GetSize(conn.second)));
				}
				module->remove(cell);
			}

			for (auto wire : module->selected_wires()) {
				if (wire->port_output) {
					log("Making output wire %s.%s a cutpoint.\n", log_id(module), log_id(wire));
					Wire *new_wire = module->addWire(NEW_ID, wire);
					module->swap_names(wire, new_wire);
					module->connect(new_wire, flag_undef ? Const(State::Sx, GetSize(new_wire)) : module->Anyseq(NEW_ID, GetSize(new_wire)));
					wire->port_id = 0;
					wire->port_input = false;
					wire->port_output = false;
					continue;
				}
				log("Making wire %s.%s a cutpoint.\n", log_id(module), log_id(wire));
				for (auto bit : sigmap(wire))
					cutpoint_bits.insert(bit);
			}

			if (!cutpoint_bits.empty())
			{
				for (auto cell : module->cells()) {
					for (auto &conn : cell->connections()) {
						if (!cell->output(conn.first))
							continue;
						SigSpec sig = sigmap(conn.second);
						int bit_count = 0;
						for (auto &bit : sig) {
							if (cutpoint_bits.count(bit))
								bit_count++;
						}
						if (bit_count == 0)
							continue;
						SigSpec dummy = module->addWire(NEW_ID, bit_count);
						bit_count = 0;
						for (auto &bit : sig) {
							if (cutpoint_bits.count(bit))
								bit = dummy[bit_count++];
						}
						cell->setPort(conn.first, sig);
					}
				}

				vector<Wire*> rewrite_wires;
				for (auto wire : module->wires()) {
					if (!wire->port_input)
						continue;
					int bit_count = 0;
					for (auto &bit : sigmap(wire))
						if (cutpoint_bits.count(bit))
							bit_count++;
					if (bit_count)
						rewrite_wires.push_back(wire);
				}

				for (auto wire : rewrite_wires) {
					Wire *new_wire = module->addWire(NEW_ID, wire);
					SigSpec lhs, rhs, sig = sigmap(wire);
					for (int i = 0; i < GetSize(sig); i++)
						if (!cutpoint_bits.count(sig[i])) {
							lhs.append(SigBit(wire, i));
							rhs.append(SigBit(new_wire, i));
						}
					if (GetSize(lhs))
						module->connect(lhs, rhs);
					module->swap_names(wire, new_wire);
					wire->port_id = 0;
					wire->port_input = false;
					wire->port_output = false;
				}

				SigSpec sig(cutpoint_bits);
				sig.sort_and_unify();

				for (auto chunk : sig.chunks()) {
					SigSpec s(chunk);
					module->connect(s, flag_undef ? Const(State::Sx, GetSize(s)) : module->Anyseq(NEW_ID, GetSize(s)));
				}
			}
		}
	}
} CutpointPass;

PRIVATE_NAMESPACE_END