yosys/techlibs/xilinx/synth_xilinx.cc

423 lines
13 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
* (C) 2019 Eddie Hung <eddie@fpgeh.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/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(" -family {xcup|xcu|xc7|xc6s}\n");
log(" run synthesis for the specified Xilinx architecture\n");
log(" generate the synthesis netlist for the specified family.\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(" -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(" -widemux <int>\n");
log(" enable inference of hard multiplexer resources (MUXF[78]) for muxes at or\n");
log(" above this number of inputs (minimum value 2, recommended value >= 5).\n");
log(" default: 0 (no inference)\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, family;
bool flatten, retime, vpr, nobram, nodram, nosrl, nocarry, nowidelut, abc9;
int widemux;
void clear_flags() YS_OVERRIDE
{
top_opt = "-auto-top";
edif_file.clear();
blif_file.clear();
family = "xc7";
flatten = false;
retime = false;
vpr = false;
nocarry = false;
nobram = false;
nodram = false;
nosrl = false;
nocarry = false;
nowidelut = false;
abc9 = false;
widemux = 0;
}
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] == "-family" || args[argidx] == "-arch") && argidx+1 < args.size()) {
family = 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] == "-widemux" && argidx+1 < args.size()) {
widemux = std::stoi(args[++argidx]);
continue;
}
if (args[argidx] == "-abc9") {
abc9 = true;
continue;
}
break;
}
extra_args(args, argidx, design);
if (family != "xcup" && family != "xcu" && family != "xc7" && family != "xc6s")
log_cmd_error("Invalid Xilinx -family setting: '%s'.\n", family.c_str());
if (widemux != 0 && widemux < 2)
log_cmd_error("-widemux value must be 0 or >= 2.\n");
if (!design->full_selection())
log_cmd_error("This command only operates on fully selected designs!\n");
if (abc9 && retime)
log_cmd_error("-retime option not currently compatible with -abc9!\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 -icells -D _ABC -D_EXPLICIT_CARRY +/xilinx/cells_sim.v");
else
run("read_verilog -lib -icells -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("coarse")) {
run("proc");
if (help_mode || flatten)
run("flatten", "(if -flatten)");
run("opt_expr");
run("opt_clean");
run("check");
run("opt");
if (help_mode)
run("wreduce [-keepdc]", "(option for '-widemux')");
else
run("wreduce" + std::string(widemux > 0 ? " -keepdc" : ""));
run("peepopt");
run("opt_clean");
if (widemux > 0 || help_mode)
run("muxpack", " ('-widemux' only)");
// shregmap -tech xilinx can cope with $shiftx and $mux
// cells for identifying variable-length shift registers,
// so attempt to convert $pmux-es to the former
// Also: wide multiplexer inference benefits from this too
if (!(nosrl && widemux == 0) || help_mode) {
run("pmux2shiftx", "(skip if '-nosrl' and '-widemux=0')");
run("clean", " (skip if '-nosrl' and '-widemux=0')");
}
run("techmap -map +/cmp2lut.v -D LUT_WIDTH=6");
run("alumacc");
run("share");
run("opt");
run("fsm");
run("opt -fast");
run("memory -nomap");
run("opt_clean");
}
if (check_label("bram", "(skip if '-nobram')")) {
if (!nobram || help_mode) {
run("memory_bram -rules +/xilinx/brams.txt");
run("techmap -map +/xilinx/brams_map.v");
}
}
if (check_label("dram", "(skip if '-nodram')")) {
if (!nodram || help_mode) {
run("memory_bram -rules +/xilinx/drams.txt");
run("techmap -map +/xilinx/drams_map.v");
}
}
if (check_label("fine")) {
if (widemux > 0)
run("opt -fast -mux_bool -undriven -fine"); // Necessary to omit -mux_undef otherwise muxcover
// performs less efficiently
else
run("opt -fast -full");
run("memory_map");
run("dffsr2dff");
run("dff2dffe");
if (help_mode) {
run("simplemap t:$mux", " ('-widemux' only)");
run("muxcover <internal options>, ('-widemux' only)");
}
else if (widemux > 0) {
run("simplemap t:$mux");
constexpr int cost_mux2 = 100;
std::string muxcover_args = stringf(" -nodecode -mux2=%d", cost_mux2);
switch (widemux) {
case 2: muxcover_args += stringf(" -mux4=%d -mux8=%d -mux16=%d", cost_mux2+1, cost_mux2+2, cost_mux2+3); break;
case 3:
case 4: muxcover_args += stringf(" -mux4=%d -mux8=%d -mux16=%d", cost_mux2*(widemux-1)-2, cost_mux2*(widemux-1)-1, cost_mux2*(widemux-1)); break;
case 5:
case 6:
case 7:
case 8: muxcover_args += stringf(" -mux8=%d -mux16=%d", cost_mux2*(widemux-1)-1, cost_mux2*(widemux-1)); break;
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
default: muxcover_args += stringf(" -mux16=%d", cost_mux2*(widemux-1)-1); break;
}
run("muxcover " + muxcover_args);
}
run("opt -full");
if (!nosrl || help_mode) {
// shregmap operates on bit-level flops, not word-level,
// so break those down here
run("simplemap t:$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_args = " -map +/techmap.v";
if (help_mode)
techmap_args += " [-map +/xilinx/mux_map.v]";
else if (widemux > 0)
techmap_args += stringf(" -D MIN_MUX_INPUTS=%d -map +/xilinx/mux_map.v", widemux);
if (help_mode)
techmap_args += " [-map +/xilinx/arith_map.v]";
else if (!nocarry) {
techmap_args += " -map +/xilinx/arith_map.v";
if (vpr)
techmap_args += " -D _EXPLICIT_CARRY";
else if (abc9)
techmap_args += " -D _CLB_CARRY";
}
run("techmap " + techmap_args);
run("opt -fast");
}
if (check_label("map_cells")) {
std::string techmap_args = "-map +/techmap.v -D _ABC -map +/xilinx/cells_map.v";
if (widemux > 0)
techmap_args += stringf(" -D MIN_MUX_INPUTS=%d", widemux);
if (abc9)
techmap_args += " -map +/xilinx/ff_map.v -D _ABC -map +/xilinx/abc_ff.v";
run("techmap " + techmap_args);
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]", "(option for 'nowidelut', option for '-retime')");
else if (abc9) {
if (family != "xc7")
log_warning("'synth_xilinx -abc9' currently supports '-family xc7' only.\n");
run("read_verilog -icells -lib +/xilinx/abc_ff.v");
if (nowidelut)
run("abc9 -lut +/xilinx/abc_xc7_nowide.lut -box +/xilinx/abc_xc7.box -W " + std::to_string(XC7_WIRE_DELAY));
else
run("abc9 -lut +/xilinx/abc_xc7.lut -box +/xilinx/abc_xc7.box -W " + std::to_string(XC7_WIRE_DELAY));
}
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')");
if (abc9)
run("techmap -map +/xilinx/lut_map.v -map +/xilinx/cells_map.v");
else
run("techmap -map +/xilinx/lut_map.v -map +/xilinx/cells_map.v -map +/xilinx/ff_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