/*
 *  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

#include "passes/pmgen/xilinx_dsp_pm.h"

void pack_xilinx_dsp(dict<SigBit, Cell*> &bit_to_driver, xilinx_dsp_pm &pm)
{
	auto &st = pm.st_xilinx_dsp;

#if 1
	log("\n");
	log("ffA:        %s\n", log_id(st.ffA, "--"));
	log("ffAmux:     %s\n", log_id(st.ffAmux, "--"));
	log("ffB:        %s\n", log_id(st.ffB, "--"));
	log("ffBmux:     %s\n", log_id(st.ffBmux, "--"));
	log("dsp:        %s\n", log_id(st.dsp, "--"));
	log("ffM:        %s\n", log_id(st.ffM, "--"));
	log("ffMmux:     %s\n", log_id(st.ffMmux, "--"));
	log("postAdd:    %s\n", log_id(st.postAdd, "--"));
	log("postAddMux: %s\n", log_id(st.postAddMux, "--"));
	log("ffP:        %s\n", log_id(st.ffP, "--"));
	log("ffPmux:     %s\n", log_id(st.ffPmux, "--"));
#endif

	log("Analysing %s.%s for Xilinx DSP packing.\n", log_id(pm.module), log_id(st.dsp));

	Cell *cell = st.dsp;
	bit_to_driver.insert(std::make_pair(cell->getPort("\\P")[17], cell));
	SigSpec C = st.sigC;
	SigSpec P = st.sigP;

	if (st.postAdd) {
		log("  adder %s (%s)\n", log_id(st.postAdd), log_id(st.postAdd->type));

		SigSpec &opmode = cell->connections_.at("\\OPMODE");
		if (st.postAddMux) {
			log_assert(st.ffP);
			opmode[4] = st.postAddMux->getPort("\\S");
			pm.autoremove(st.postAddMux);
		}
		else if (st.ffP && C == P) {
			C = SigSpec();
			opmode[4] = State::S0;
		}
		else
			opmode[4] = State::S1;
		opmode[6] = State::S0;
		opmode[5] = State::S1;

		pm.autoremove(st.postAdd);
	}

	if (st.clock != SigBit())
	{
		cell->setPort("\\CLK", st.clock);

		if (st.ffA) {
			SigSpec A = cell->getPort("\\A");
			SigSpec D = st.ffA->getPort("\\D");
			SigSpec Q = pm.sigmap(st.ffA->getPort("\\Q"));
			A.replace(Q, D);
			if (st.ffAmux) {
				SigSpec Y = st.ffAmux->getPort("\\Y");
				SigSpec AB = st.ffAmux->getPort(st.ffAenpol ? "\\A" : "\\B");
				A.replace(Y, AB);
				SigSpec S = st.ffAmux->getPort("\\S");
				cell->setPort("\\CEA2", st.ffAenpol ? S : pm.module->Not(NEW_ID, S));
			}
			else
				cell->setPort("\\CEA2", State::S1);
			cell->setPort("\\A", A);

			cell->setParam("\\AREG", 1);
		}
		if (st.ffB) {
			SigSpec B = cell->getPort("\\B");
			SigSpec D = st.ffB->getPort("\\D");
			SigSpec Q = st.ffB->getPort("\\Q");
			B.replace(Q, D);
			if (st.ffBmux) {
				SigSpec Y = st.ffBmux->getPort("\\Y");
				SigSpec AB = st.ffBmux->getPort(st.ffBmuxAB == "\\A" ? "\\B" : "\\A");
				B.replace(Y, AB);
				cell->setPort("\\CEB2", st.ffBmux->getPort("\\S"));
			}
			else
				cell->setPort("\\CEB2", State::S1);
			cell->setPort("\\B", B);

			cell->setParam("\\BREG", 1);
		}
		if (st.ffM) {
			if (st.ffMmux) {
				cell->setPort("\\CEM", st.ffMmux->getPort("\\S"));
				pm.autoremove(st.ffMmux);
			}
			else
				cell->setPort("\\CEM", State::S1);
			SigSpec D = st.ffM->getPort("\\D");
			SigSpec Q = st.ffM->getPort("\\Q");
			P.replace(pm.sigmap(D), Q);

			cell->setParam("\\MREG", State::S1);
			pm.autoremove(st.ffM);
		}
		if (st.ffP) {
			if (st.ffPmux) {
				cell->setPort("\\CEP", st.ffPmux->getPort("\\S"));
				st.ffPmux->connections_.at("\\Y").replace(P, pm.module->addWire(NEW_ID, GetSize(P)));
			}
			else
				cell->setPort("\\CEP", State::S1);
			SigSpec D = st.ffP->getPort("\\D");
			SigSpec Q = st.ffP->getPort("\\Q");
			P.replace(pm.sigmap(D), Q);
			st.ffP->connections_.at("\\Q").replace(P, pm.module->addWire(NEW_ID, GetSize(P)));

			cell->setParam("\\PREG", State::S1);
		}

		log("  clock: %s (%s)", log_signal(st.clock), "posedge");

		if (st.ffA)
			log(" ffA:%s", log_id(st.ffA));

		if (st.ffB)
			log(" ffB:%s", log_id(st.ffB));

		if (st.ffM)
			log(" ffM:%s", log_id(st.ffM));

		if (st.ffP)
			log(" ffP:%s", log_id(st.ffP));

		log("\n");
	}

	if (!C.empty()) {
		if (GetSize(C) < 48)
			C.extend_u0(48, true);
		cell->setPort("\\C", C);
	}

	if (GetSize(P) < 48)
		P.append(pm.module->addWire(NEW_ID, 48-GetSize(P)));
	cell->setPort("\\P", P);

	pm.blacklist(cell);
}

struct XilinxDspPass : public Pass {
	XilinxDspPass() : Pass("xilinx_dsp", "Xilinx: pack DSP registers") { }
	void help() YS_OVERRIDE
	{
		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
		log("\n");
		log("    xilinx_dsp [options] [selection]\n");
		log("\n");
		log("Pack registers into Xilinx DSPs\n");
		log("\n");
	}
	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
	{
		log_header(design, "Executing XILINX_DSP pass (pack DSPs).\n");

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

		for (auto module : design->selected_modules()) {
			xilinx_dsp_pm pm(module, module->selected_cells());
			dict<SigBit, Cell*> bit_to_driver;
			auto f = [&bit_to_driver](xilinx_dsp_pm &pm){ pack_xilinx_dsp(bit_to_driver, pm); };
			pm.run_xilinx_dsp(f);

			// Look for ability to convert C input from another DSP into PCIN
			//   NB: Needs to be done after pattern matcher has folded all
			//       $add cells into the DSP
			for (auto cell : module->cells()) {
				if (cell->type != "\\DSP48E1")
					continue;
				SigSpec &opmode = cell->connections_.at("\\OPMODE");
				if (opmode.extract(4,3) != Const::from_string("011"))
					continue;
				SigSpec C = pm.sigmap(cell->getPort("\\C"));
				if (C.has_const())
					continue;
				auto it = bit_to_driver.find(C[0]);
				if (it == bit_to_driver.end())
					continue;
				auto driver = it->second;

				// Unextend C
				int i;
				for (i = GetSize(C)-1; i > 0; i--)
					if (C[i] != C[i-1])
						break;
				if (i > 48-17)
					continue;
				if (driver->getPort("\\P").extract(17, i) == C.extract(0, i)) {
					cell->setPort("\\C", Const(0, 48));
					Wire *cascade = module->addWire(NEW_ID, 48);
					driver->setPort("\\PCOUT", cascade);
					cell->setPort("\\PCIN", cascade);
					opmode[6] = State::S1;
					opmode[5] = State::S0;
					opmode[4] = State::S1;
					bit_to_driver.erase(it);
				}
			}
		}
	}
} XilinxDspPass;

PRIVATE_NAMESPACE_END