yosys/techlibs/xilinx/synth_xilinx.cc

/*
 *  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"

USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN

#define XC7_WIRE_DELAY "300" // Number with which ABC will map a 6-input gate
                             // to one LUT6 (instead of a LUT5 + LUT2)

struct SynthXilinxPass : public ScriptPass
{
	SynthXilinxPass() : ScriptPass("synth_xilinx", "synthesis for Xilinx FPGAs") { }

	void help() YS_OVERRIDE
	{
		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
		log("\n");
		log("    synth_xilinx [options]\n");
		log("\n");
		log("This command runs synthesis for Xilinx FPGAs. This command does not operate on\n");
		log("partly selected designs. At the moment this command creates netlists that are\n");
		log("compatible with 7-Series Xilinx devices.\n");
		log("\n");
		log("    -top <module>\n");
		log("        use the specified module as top module\n");
		log("\n");
		log("    -arch {xcup|xcu|xc7|xc6s}\n");
		log("        run synthesis for the specified Xilinx architecture\n");
		log("        default: xc7\n");
		log("\n");
		log("    -edif <file>\n");
		log("        write the design to the specified edif file. writing of an output file\n");
		log("        is omitted if this parameter is not specified.\n");
		log("\n");
		log("    -blif <file>\n");
		log("        write the design to the specified BLIF file. writing of an output file\n");
		log("        is omitted if this parameter is not specified.\n");
		log("\n");
		log("    -vpr\n");
		log("        generate an output netlist (and BLIF file) suitable for VPR\n");
		log("        (this feature is experimental and incomplete)\n");
		log("\n");
		log("    -nocarry\n");
		log("        disable inference of carry chains\n");
		log("\n");
		log("    -nobram\n");
		log("        disable inference of block rams\n");
		log("\n");
		log("    -nodram\n");
		log("        disable inference of distributed rams\n");
		log("\n");
		log("    -nosrl\n");
		log("        disable inference of shift registers\n");
		log("\n");
		log("    -nocarry\n");
		log("        do not use XORCY/MUXCY/CARRY4 cells in output netlist\n");
		log("\n");
		log("    -nowidelut\n");
		log("        do not use MUXF[78] resources to implement LUTs larger than LUT6s\n");
		log("\n");
		log("    -run <from_label>:<to_label>\n");
		log("        only run the commands between the labels (see below). an empty\n");
		log("        from label is synonymous to 'begin', and empty to label is\n");
		log("        synonymous to the end of the command list.\n");
		log("\n");
		log("    -flatten\n");
		log("        flatten design before synthesis\n");
		log("\n");
		log("    -retime\n");
		log("        run 'abc' with -dff option\n");
		log("\n");
		log("    -abc9\n");
		log("        use new ABC9 flow (EXPERIMENTAL)\n");
		log("\n");
		log("\n");
		log("The following commands are executed by this synthesis command:\n");
		help_script();
		log("\n");
	}

	std::string top_opt, edif_file, blif_file, arch;
	bool flatten, retime, vpr, nobram, nodram, nosrl, nocarry, nowidelut, abc9;

	void clear_flags() YS_OVERRIDE
	{
		top_opt = "-auto-top";
		edif_file.clear();
		blif_file.clear();
		arch = "xc7";
		flatten = false;
		retime = false;
		vpr = false;
		nocarry = false;
		nobram = false;
		nodram = false;
		nosrl = false;
		nocarry = false;
		nowidelut = false;
		abc9 = false;
	}

	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
	{
		std::string run_from, run_to;
		clear_flags();

		size_t argidx;
		for (argidx = 1; argidx < args.size(); argidx++)
		{
			if (args[argidx] == "-top" && argidx+1 < args.size()) {
				top_opt = "-top " + args[++argidx];
				continue;
			}
			if (args[argidx] == "-arch" && argidx+1 < args.size()) {
				arch = args[++argidx];
				continue;
			}
			if (args[argidx] == "-edif" && argidx+1 < args.size()) {
				edif_file = args[++argidx];
				continue;
			}
			if (args[argidx] == "-blif" && argidx+1 < args.size()) {
				blif_file = args[++argidx];
				continue;
			}
			if (args[argidx] == "-run" && argidx+1 < args.size()) {
				size_t pos = args[argidx+1].find(':');
				if (pos == std::string::npos)
					break;
				run_from = args[++argidx].substr(0, pos);
				run_to = args[argidx].substr(pos+1);
				continue;
			}
			if (args[argidx] == "-flatten") {
				flatten = true;
				continue;
			}
			if (args[argidx] == "-retime") {
				retime = true;
				continue;
			}
			if (args[argidx] == "-nocarry") {
				nocarry = true;
				continue;
			}
			if (args[argidx] == "-nowidelut") {
				nowidelut = true;
				continue;
			}
			if (args[argidx] == "-vpr") {
				vpr = true;
				continue;
			}
			if (args[argidx] == "-nocarry") {
				nocarry = true;
				continue;
			}
			if (args[argidx] == "-nobram") {
				nobram = true;
				continue;
			}
			if (args[argidx] == "-nodram") {
				nodram = true;
				continue;
			}
			if (args[argidx] == "-nosrl") {
				nosrl = true;
				continue;
			}
			if (args[argidx] == "-abc9") {
				abc9 = true;
				continue;
			}
			break;
		}
		extra_args(args, argidx, design);

		if (arch != "xcup" && arch != "xcu" && arch != "xc7" && arch != "xc6s")
			log_cmd_error("Invalid Xilinx -arch setting: %s\n", arch.c_str());

		if (!design->full_selection())
			log_cmd_error("This command only operates on fully selected designs!\n");

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

		run_script(design, run_from, run_to);

		log_pop();
	}

	void script() YS_OVERRIDE
	{
		if (check_label("begin")) {
			if (vpr)
				run("read_verilog -lib -D _ABC -D_EXPLICIT_CARRY +/xilinx/cells_sim.v");
			else
				run("read_verilog -lib -D _ABC +/xilinx/cells_sim.v");

			run("read_verilog -lib +/xilinx/cells_xtra.v");

			if (!nobram || help_mode)
				run("read_verilog -lib +/xilinx/brams_bb.v", "(skip if '-nobram')");

			run(stringf("hierarchy -check %s", top_opt.c_str()));
		}

		if (check_label("flatten", "(with '-flatten' only)")) {
			if (flatten || help_mode) {
				run("proc");
				run("flatten");
			}
		}

		if (check_label("coarse")) {
			run("synth -run coarse");

			// shregmap -tech xilinx can cope with $shiftx and $mux
			//   cells for identifying variable-length shift registers,
			//   so attempt to convert $pmux-es to the former
			if (!nosrl || help_mode)
				run("pmux2shiftx", "(skip if '-nosrl')");

			// Run a number of peephole optimisations, including one
			//   that optimises $mul cells driving $shiftx's B input
			//   and that aids wide mux analysis
			run("peepopt");
		}

		if (check_label("bram", "(skip if '-nobram')")) {
			if (!nobram || help_mode) {
				run("memory_bram -rules +/xilinx/brams.txt");
				run("techmap -map +/xilinx/brams_map.v");
			}
		}

		if (check_label("dram", "(skip if '-nodram')")) {
			if (!nodram || help_mode) {
				run("memory_bram -rules +/xilinx/drams.txt");
				run("techmap -map +/xilinx/drams_map.v");
			}
		}

		if (check_label("fine")) {
			run("opt -fast -full");
			run("memory_map");
			run("dffsr2dff");
			run("dff2dffe");
			run("opt -full");

			if (!nosrl || help_mode) {
				// shregmap operates on bit-level flops, not word-level,
				//   so break those down here
				run("simplemap t:$dff t:$dffe", "(skip if '-nosrl')");
				// shregmap with '-tech xilinx' infers variable length shift regs
				run("shregmap -tech xilinx -minlen 3", "(skip if '-nosrl')");
			}

			std::string techmap_files = " -map +/techmap.v";
			if (help_mode)
				techmap_files += " [-map +/xilinx/arith_map.v]";
			else if (!nocarry) {
				techmap_files += " -map +/xilinx/arith_map.v";
				if (vpr)
					techmap_files += " -D _EXPLICIT_CARRY";
				else if (abc9)
					techmap_files += " -D _CLB_CARRY";
			}
			run("techmap " + techmap_files);
			run("opt -fast");
		}

		if (check_label("map_cells")) {
			run("techmap -map +/techmap.v -map +/xilinx/cells_map.v");
			run("clean");
		}

		if (check_label("map_luts")) {
			run("opt_expr -mux_undef");
			if (help_mode)
				run("abc -luts 2:2,3,6:5[,10,20] [-dff]", "(skip if 'nowidelut', only for '-retime')");
			else if (abc9) {
				if (nowidelut)
					run("abc9 -lut +/xilinx/abc_xc7_nowide.lut -box +/xilinx/abc_xc7.box -W " + std::string(XC7_WIRE_DELAY) + string(retime ? " -dff" : ""));
				else
					run("abc9 -lut +/xilinx/abc_xc7.lut -box +/xilinx/abc_xc7.box -W " + std::string(XC7_WIRE_DELAY) + string(retime ? " -dff" : ""));
			}
			else {
				if (nowidelut)
					run("abc -luts 2:2,3,6:5" + string(retime ? " -dff" : ""));
				else
					run("abc -luts 2:2,3,6:5,10,20" + string(retime ? " -dff" : ""));
			}
			run("clean");

			// This shregmap call infers fixed length shift registers after abc
			//   has performed any necessary retiming
			if (!nosrl || help_mode)
				run("shregmap -minlen 3 -init -params -enpol any_or_none", "(skip if '-nosrl')");
			run("techmap -map +/xilinx/lut_map.v -map +/xilinx/ff_map.v -map +/xilinx/cells_map.v");
			run("dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT -ff FDSE Q INIT "
					"-ff FDRE_1 Q INIT -ff FDCE_1 Q INIT -ff FDPE_1 Q INIT -ff FDSE_1 Q INIT");
			run("clean");
		}

		if (check_label("check")) {
			run("hierarchy -check");
			run("stat -tech xilinx");
			run("check -noinit");
		}

		if (check_label("edif")) {
			if (!edif_file.empty() || help_mode)
				run(stringf("write_edif -pvector bra %s", edif_file.c_str()));
		}

		if (check_label("blif")) {
			if (!blif_file.empty() || help_mode)
				run(stringf("write_blif %s", edif_file.c_str()));
		}
	}
} SynthXilinxPass;

PRIVATE_NAMESPACE_END