yosys/backends/btor/btor.cc

759 lines
20 KiB
C++

/*
* 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/rtlil.h"
#include "kernel/register.h"
#include "kernel/sigtools.h"
#include "kernel/celltypes.h"
#include "kernel/log.h"
#include <string>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct BtorWorker
{
std::ostream &f;
SigMap sigmap;
RTLIL::Module *module;
bool verbose;
int next_nid = 1;
int initstate_nid = -1;
// <width> => <sid>
dict<int, int> sorts_bv;
// (<address-width>, <data-width>) => <sid>
dict<pair<int, int>, int> sorts_mem;
// SigBit => (<nid>, <bitidx>)
dict<SigBit, pair<int, int>> bit_nid;
// <nid> => <bvwidth>
dict<int, int> nid_width;
// SigSpec => <nid>
dict<SigSpec, int> sig_nid;
// bit to driving cell
dict<SigBit, Cell*> bit_cell;
// nids for constants
dict<Const, int> consts;
// ff inputs that need to be evaluated (<nid>, <ff_cell>)
vector<pair<int, Cell*>> ff_todo;
pool<Cell*> cell_recursion_guard;
pool<string> output_symbols;
string indent;
void btorf(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
f << indent << vstringf(fmt, ap);
va_end(ap);
}
void btorf_push(const string &id)
{
if (verbose) {
f << indent << stringf(" ; begin %s\n", id.c_str());
indent += " ";
}
}
void btorf_pop(const string &id)
{
if (verbose) {
indent = indent.substr(4);
f << indent << stringf(" ; end %s\n", id.c_str());
}
}
int get_bv_sid(int width)
{
if (sorts_bv.count(width) == 0) {
int nid = next_nid++;
btorf("%d sort bitvec %d\n", nid, width);
sorts_bv[width] = nid;
}
return sorts_bv.at(width);
}
void add_nid_sig(int nid, const SigSpec &sig)
{
for (int i = 0; i < GetSize(sig); i++)
bit_nid[sig[i]] = make_pair(nid, i);
sig_nid[sig] = nid;
nid_width[nid] = GetSize(sig);
}
void export_cell(Cell *cell)
{
log_assert(cell_recursion_guard.count(cell) == 0);
cell_recursion_guard.insert(cell);
btorf_push(log_id(cell));
if (cell->type.in("$add", "$sub", "$and", "$or", "$xor", "$xnor", "$shl", "$sshl", "$shr", "$sshr",
"$_AND_", "$_NAND_", "$_OR_", "$_NOR_", "$_XOR_", "$_XNOR_"))
{
string btor_op;
if (cell->type == "$add") btor_op = "add";
if (cell->type == "$sub") btor_op = "sub";
if (cell->type.in("$shl", "$sshl")) btor_op = "sll";
if (cell->type == "$shr") btor_op = "srl";
if (cell->type == "$sshr") btor_op = "sra";
if (cell->type.in("$and", "$_AND_")) btor_op = "and";
if (cell->type.in("$or", "$_OR_")) btor_op = "or";
if (cell->type.in("$xor", "$_XOR_")) btor_op = "xor";
if (cell->type == "$_NAND_") btor_op = "nand";
if (cell->type == "$_NOR_") btor_op = "nor";
if (cell->type.in("$xnor", "$_XNOR_")) btor_op = "xnor";
log_assert(!btor_op.empty());
int width = GetSize(cell->getPort("\\Y"));
width = std::max(width, GetSize(cell->getPort("\\A")));
width = std::max(width, GetSize(cell->getPort("\\B")));
bool a_signed = cell->hasParam("\\A_SIGNED") ? cell->getParam("\\A_SIGNED").as_bool() : false;
bool b_signed = cell->hasParam("\\B_SIGNED") ? cell->getParam("\\B_SIGNED").as_bool() : false;
if (cell->type.in("$shl", "$shr")) {
a_signed = false;
b_signed = false;
}
int sid = get_bv_sid(width);
int nid_a = get_sig_nid(cell->getPort("\\A"), width, a_signed);
int nid_b = get_sig_nid(cell->getPort("\\B"), width, b_signed);
int nid = next_nid++;
btorf("%d %s %d %d %d\n", nid, btor_op.c_str(), sid, nid_a, nid_b);
SigSpec sig = sigmap(cell->getPort("\\Y"));
if (GetSize(sig) < width) {
int sid = get_bv_sid(GetSize(sig));
int nid2 = next_nid++;
btorf("%d slice %d %d %d 0\n", nid2, sid, nid, GetSize(sig)-1);
nid = nid2;
}
add_nid_sig(nid, sig);
goto okay;
}
if (cell->type.in("$_ANDNOT_", "$_ORNOT_"))
{
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_b = get_sig_nid(cell->getPort("\\B"));
int nid1 = next_nid++;
int nid2 = next_nid++;
if (cell->type == "$_ANDNOT_") {
btorf("%d not %d %d\n", nid1, sid, nid_b);
btorf("%d and %d %d %d\n", nid2, sid, nid_a, nid1);
}
if (cell->type == "$_ORNOT_") {
btorf("%d not %d %d\n", nid1, sid, nid_b);
btorf("%d or %d %d %d\n", nid2, sid, nid_a, nid1);
}
SigSpec sig = sigmap(cell->getPort("\\Y"));
add_nid_sig(nid2, sig);
goto okay;
}
if (cell->type.in("$_OAI3_", "$_AOI3_"))
{
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_b = get_sig_nid(cell->getPort("\\B"));
int nid_c = get_sig_nid(cell->getPort("\\C"));
int nid1 = next_nid++;
int nid2 = next_nid++;
int nid3 = next_nid++;
if (cell->type == "$_OAI3_") {
btorf("%d or %d %d %d\n", nid1, sid, nid_a, nid_b);
btorf("%d and %d %d %d\n", nid2, sid, nid1, nid_c);
btorf("%d not %d %d\n", nid3, sid, nid2);
}
if (cell->type == "$_AOI3_") {
btorf("%d and %d %d %d\n", nid1, sid, nid_a, nid_b);
btorf("%d or %d %d %d\n", nid2, sid, nid1, nid_c);
btorf("%d not %d %d\n", nid3, sid, nid2);
}
SigSpec sig = sigmap(cell->getPort("\\Y"));
add_nid_sig(nid3, sig);
goto okay;
}
if (cell->type.in("$_OAI4_", "$_AOI4_"))
{
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_b = get_sig_nid(cell->getPort("\\B"));
int nid_c = get_sig_nid(cell->getPort("\\C"));
int nid_d = get_sig_nid(cell->getPort("\\D"));
int nid1 = next_nid++;
int nid2 = next_nid++;
int nid3 = next_nid++;
int nid4 = next_nid++;
if (cell->type == "$_OAI4_") {
btorf("%d or %d %d %d\n", nid1, sid, nid_a, nid_b);
btorf("%d or %d %d %d\n", nid2, sid, nid_c, nid_d);
btorf("%d and %d %d %d\n", nid3, sid, nid1, nid2);
btorf("%d not %d %d\n", nid4, sid, nid3);
}
if (cell->type == "$_AOI4_") {
btorf("%d and %d %d %d\n", nid1, sid, nid_a, nid_b);
btorf("%d and %d %d %d\n", nid2, sid, nid_c, nid_d);
btorf("%d or %d %d %d\n", nid3, sid, nid1, nid2);
btorf("%d not %d %d\n", nid4, sid, nid3);
}
SigSpec sig = sigmap(cell->getPort("\\Y"));
add_nid_sig(nid4, sig);
goto okay;
}
if (cell->type.in("$lt", "$le", "$eq", "$eqx", "$ne", "$nex", "$ge", "$gt"))
{
string btor_op;
if (cell->type == "$lt") btor_op = "lt";
if (cell->type == "$le") btor_op = "lte";
if (cell->type.in("$eq", "$eqx")) btor_op = "eq";
if (cell->type.in("$ne", "$nex")) btor_op = "ne";
if (cell->type == "$ge") btor_op = "gte";
if (cell->type == "$gt") btor_op = "gt";
log_assert(!btor_op.empty());
int width = 1;
width = std::max(width, GetSize(cell->getPort("\\A")));
width = std::max(width, GetSize(cell->getPort("\\B")));
bool a_signed = cell->hasParam("\\A_SIGNED") ? cell->getParam("\\A_SIGNED").as_bool() : false;
bool b_signed = cell->hasParam("\\B_SIGNED") ? cell->getParam("\\B_SIGNED").as_bool() : false;
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"), width, a_signed);
int nid_b = get_sig_nid(cell->getPort("\\B"), width, b_signed);
int nid = next_nid++;
if (cell->type.in("$lt", "$le", "$ge", "$gt")) {
btorf("%d %c%s %d %d %d\n", nid, a_signed || b_signed ? 's' : 'u', btor_op.c_str(), sid, nid_a, nid_b);
} else {
btorf("%d %s %d %d %d\n", nid, btor_op.c_str(), sid, nid_a, nid_b);
}
SigSpec sig = sigmap(cell->getPort("\\Y"));
if (GetSize(sig) > 1) {
int sid = get_bv_sid(GetSize(sig));
int nid2 = next_nid++;
btorf("%d uext %d %d %d\n", nid2, sid, nid, GetSize(sig) - 1);
nid = nid2;
}
add_nid_sig(nid, sig);
goto okay;
}
if (cell->type.in("$not", "$neg", "$_NOT_"))
{
string btor_op;
if (cell->type.in("$not", "$_NOT_")) btor_op = "not";
if (cell->type == "$neg") btor_op = "neg";
log_assert(!btor_op.empty());
int width = GetSize(cell->getPort("\\Y"));
width = std::max(width, GetSize(cell->getPort("\\A")));
bool a_signed = cell->hasParam("\\A_SIGNED") ? cell->getParam("\\A_SIGNED").as_bool() : false;
int sid = get_bv_sid(width);
int nid_a = get_sig_nid(cell->getPort("\\A"), width, a_signed);
int nid = next_nid++;
btorf("%d %s %d %d\n", nid, btor_op.c_str(), sid, nid_a);
SigSpec sig = sigmap(cell->getPort("\\Y"));
if (GetSize(sig) < width) {
int sid = get_bv_sid(GetSize(sig));
int nid2 = next_nid++;
btorf("%d slice %d %d %d 0\n", nid2, sid, nid, GetSize(sig)-1);
nid = nid2;
}
add_nid_sig(nid, sig);
goto okay;
}
if (cell->type.in("$logic_and", "$logic_or", "$logic_not"))
{
string btor_op;
if (cell->type == "$logic_and") btor_op = "and";
if (cell->type == "$logic_or") btor_op = "or";
if (cell->type == "$logic_not") btor_op = "not";
log_assert(!btor_op.empty());
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_b = btor_op != "not" ? get_sig_nid(cell->getPort("\\B")) : 0;
if (GetSize(cell->getPort("\\A")) > 1) {
int nid_red_a = next_nid++;
btorf("%d redor %d %d\n", nid_red_a, sid, nid_a);
nid_a = nid_red_a;
}
if (btor_op != "not" && GetSize(cell->getPort("\\B")) > 1) {
int nid_red_b = next_nid++;
btorf("%d redor %d %d\n", nid_red_b, sid, nid_b);
nid_b = nid_red_b;
}
int nid = next_nid++;
if (btor_op != "not")
btorf("%d %s %d %d %d\n", nid, btor_op.c_str(), sid, nid_a, nid_b);
else
btorf("%d %s %d %d\n", nid, btor_op.c_str(), sid, nid_a);
SigSpec sig = sigmap(cell->getPort("\\Y"));
if (GetSize(sig) > 1) {
int sid = get_bv_sid(GetSize(sig));
int zeros_nid = get_sig_nid(Const(0, GetSize(sig)-1));
int nid2 = next_nid++;
btorf("%d concat %d %d %d\n", nid2, sid, zeros_nid, nid);
nid = nid2;
}
add_nid_sig(nid, sig);
goto okay;
}
if (cell->type.in("$reduce_and", "$reduce_or", "$reduce_bool", "$reduce_xor", "$reduce_xnor"))
{
string btor_op;
if (cell->type == "$reduce_and") btor_op = "redand";
if (cell->type.in("$reduce_or", "$reduce_bool")) btor_op = "redor";
if (cell->type.in("$reduce_xor", "$reduce_xnor")) btor_op = "redxor";
log_assert(!btor_op.empty());
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid = next_nid++;
btorf("%d %s %d %d\n", nid, btor_op.c_str(), sid, nid_a);
if (cell->type == "$reduce_xnor") {
int nid2 = next_nid++;
btorf("%d not %d %d %d\n", nid2, sid, nid);
nid = nid2;
}
SigSpec sig = sigmap(cell->getPort("\\Y"));
if (GetSize(sig) > 1) {
int sid = get_bv_sid(GetSize(sig));
int zeros_nid = get_sig_nid(Const(0, GetSize(sig)-1));
int nid2 = next_nid++;
btorf("%d concat %d %d %d\n", nid2, sid, zeros_nid, nid);
nid = nid2;
}
add_nid_sig(nid, sig);
goto okay;
}
if (cell->type.in("$mux", "$_MUX_"))
{
SigSpec sig_a = sigmap(cell->getPort("\\A"));
SigSpec sig_b = sigmap(cell->getPort("\\B"));
SigSpec sig_s = sigmap(cell->getPort("\\S"));
SigSpec sig_y = sigmap(cell->getPort("\\Y"));
int nid_a = get_sig_nid(sig_a);
int nid_b = get_sig_nid(sig_b);
int nid_s = get_sig_nid(sig_s);
int sid = get_bv_sid(GetSize(sig_y));
int nid = next_nid++;
btorf("%d ite %d %d %d %d\n", nid, sid, nid_s, nid_b, nid_a);
add_nid_sig(nid, sig_y);
goto okay;
}
if (cell->type == "$pmux")
{
SigSpec sig_a = sigmap(cell->getPort("\\A"));
SigSpec sig_b = sigmap(cell->getPort("\\B"));
SigSpec sig_s = sigmap(cell->getPort("\\S"));
SigSpec sig_y = sigmap(cell->getPort("\\Y"));
int width = GetSize(sig_a);
int sid = get_bv_sid(width);
int nid = get_sig_nid(sig_a);
for (int i = 0; i < GetSize(sig_s); i++) {
int nid_b = get_sig_nid(sig_b.extract(i*width, width));
int nid_s = get_sig_nid(sig_s.extract(i));
int nid2 = next_nid++;
btorf("%d ite %d %d %d %d\n", nid2, sid, nid_s, nid_b, nid);
nid = nid2;
}
add_nid_sig(nid, sig_y);
goto okay;
}
if (cell->type.in("$dff", "$ff", "$_DFF_P_", "$_DFF_N", "$_FF_"))
{
SigSpec sig_d = sigmap(cell->getPort("\\D"));
SigSpec sig_q = sigmap(cell->getPort("\\Q"));
string symbol = log_signal(sig_q);
if (symbol.find(' ') != string::npos)
symbol = log_id(cell);
if (symbol[0] == '\\')
symbol = symbol.substr(1);
int sid = get_bv_sid(GetSize(sig_q));
int nid = next_nid++;
if (output_symbols.count(symbol))
btorf("%d state %d\n", nid, sid);
else
btorf("%d state %d %s\n", nid, sid, symbol.c_str());
ff_todo.push_back(make_pair(nid, cell));
add_nid_sig(nid, sig_q);
goto okay;
}
if (cell->type == "$initstate")
{
SigSpec sig_y = sigmap(cell->getPort("\\Y"));
if (initstate_nid < 0)
{
int sid = get_bv_sid(1);
int one_nid = get_sig_nid(Const(1, 1));
int zero_nid = get_sig_nid(Const(0, 1));
initstate_nid = next_nid++;
btorf("%d state %d\n", initstate_nid, sid);
btorf("%d init %d %d %d\n", next_nid++, sid, initstate_nid, one_nid);
btorf("%d next %d %d %d\n", next_nid++, sid, initstate_nid, zero_nid);
}
add_nid_sig(initstate_nid, sig_y);
goto okay;
}
log_error("Unsupported cell type: %s (%s)\n", log_id(cell->type), log_id(cell));
okay:
btorf_pop(log_id(cell));
cell_recursion_guard.erase(cell);
}
int get_sig_nid(SigSpec sig, int to_width = -1, bool is_signed = false)
{
sigmap.apply(sig);
if (sig_nid.count(sig) == 0)
{
// <nid>, <bitidx>
vector<pair<int, int>> nidbits;
// collect all bits
for (int i = 0; i < GetSize(sig); i++)
{
SigBit bit = sig[i];
if (bit_nid.count(bit) == 0)
{
if (bit.wire == nullptr)
{
Const c(bit.data);
while (i+GetSize(c) < GetSize(sig) && sig[i+GetSize(c)].wire == nullptr)
c.bits.push_back(sig[i+GetSize(c)].data);
if (consts.count(c) == 0) {
int sid = get_bv_sid(GetSize(c));
int nid = next_nid++;
btorf("%d const %d %s\n", nid, sid, c.as_string().c_str());
consts[c] = nid;
nid_width[nid] = GetSize(c);
}
int nid = consts.at(c);
for (int j = 0; j < GetSize(c); j++)
nidbits.push_back(make_pair(nid, j));
i += GetSize(c)-1;
continue;
}
else
{
export_cell(bit_cell.at(bit));
log_assert(bit_nid.count(bit));
}
}
nidbits.push_back(bit_nid.at(bit));
}
int width = 0;
int nid = -1;
// group bits and emit slice-concat chain
for (int i = 0; i < GetSize(nidbits); i++)
{
int nid2 = nidbits[i].first;
int lower = nidbits[i].second;
int upper = lower;
while (i+1 < GetSize(nidbits) && nidbits[i+1].first == nidbits[i].first &&
nidbits[i+1].second == nidbits[i].second+1)
upper++, i++;
int nid3 = nid2;
if (lower != 0 || upper+1 != nid_width.at(nid2)) {
int sid = get_bv_sid(upper-lower+1);
nid3 = next_nid++;
btorf("%d slice %d %d %d %d\n", nid3, sid, nid2, upper, lower);
}
int nid4 = nid3;
if (nid >= 0) {
int sid = get_bv_sid(width+upper-lower+1);
nid4 = next_nid++;
btorf("%d concat %d %d %d\n", nid4, sid, nid3, nid);
}
width += upper-lower+1;
nid = nid4;
}
sig_nid[sig] = nid;
nid_width[nid] = width;
}
int nid = sig_nid.at(sig);
if (to_width >= 0 && to_width != GetSize(sig))
{
if (to_width < GetSize(sig))
{
int sid = get_bv_sid(to_width);
int nid2 = next_nid++;
btorf("%d slice %d %d %d 0\n", nid2, sid, nid, to_width-1);
nid = nid2;
}
else
{
int sid = get_bv_sid(to_width);
int nid2 = next_nid++;
btorf("%d %s %d %d %d\n", nid2, is_signed ? "sext" : "uext",
sid, nid, to_width - GetSize(sig));
nid = nid2;
}
}
return nid;
}
BtorWorker(std::ostream &f, RTLIL::Module *module, bool verbose) :
f(f), sigmap(module), module(module), verbose(verbose)
{
btorf_push("inputs");
for (auto wire : module->wires())
{
if (!wire->port_id || !wire->port_input)
continue;
SigSpec sig = sigmap(wire);
int sid = get_bv_sid(GetSize(sig));
int nid = next_nid++;
btorf("%d input %d %s\n", nid, sid, log_id(wire));
add_nid_sig(nid, sig);
}
btorf_pop("inputs");
for (auto cell : module->cells())
for (auto &conn : cell->connections())
{
if (!cell->output(conn.first))
continue;
for (auto bit : sigmap(conn.second))
bit_cell[bit] = cell;
}
for (auto wire : module->wires())
if (wire->port_output)
output_symbols.insert(log_id(wire));
for (auto wire : module->wires())
{
if (!wire->port_id || !wire->port_output)
continue;
btorf_push(stringf("output %s", log_id(wire)));
int sid = get_bv_sid(GetSize(wire));
int nid = get_sig_nid(wire);
btorf("%d output %d %d %s\n", next_nid++, sid, nid, log_id(wire));
btorf_pop(stringf("output %s", log_id(wire)));
}
for (auto cell : module->cells())
{
if (cell->type == "$assume")
{
btorf_push(log_id(cell));
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_en = get_sig_nid(cell->getPort("\\EN"));
int nid_not_en = next_nid++;
int nid_a_or_not_en = next_nid++;
int nid = next_nid++;
btorf("%d not %d %d\n", nid_not_en, sid, nid_en);
btorf("%d or %d %d %d\n", nid_a_or_not_en, sid, nid_a, nid_not_en);
btorf("%d constraint %d\n", nid, nid_a_or_not_en);
btorf_pop(log_id(cell));
}
if (cell->type == "$assert")
{
btorf_push(log_id(cell));
int sid = get_bv_sid(1);
int nid_a = get_sig_nid(cell->getPort("\\A"));
int nid_en = get_sig_nid(cell->getPort("\\EN"));
int nid_not_a = next_nid++;
int nid_en_and_not_a = next_nid++;
int nid = next_nid++;
btorf("%d not %d %d\n", nid_not_a, sid, nid_a);
btorf("%d and %d %d %d\n", nid_en_and_not_a, sid, nid_en, nid_not_a);
btorf("%d bad %d\n", nid, nid_en_and_not_a);
btorf_pop(log_id(cell));
}
}
while (!ff_todo.empty())
{
vector<pair<int, Cell*>> todo;
todo.swap(ff_todo);
for (auto &it : todo)
{
btorf_push(stringf("next %s", log_id(it.second)));
SigSpec sig = sigmap(it.second->getPort("\\D"));
int nid = get_sig_nid(sig);
int sid = get_bv_sid(GetSize(sig));
btorf("%d next %d %d %d\n", next_nid++, sid, it.first, nid);
btorf_pop(stringf("next %s", log_id(it.second)));
}
}
}
};
struct BtorBackend : public Backend {
BtorBackend() : Backend("btor", "write design to BTOR file") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" write_btor [options] [filename]\n");
log("\n");
log("Write a BTOR description of the current design.\n");
log("\n");
log(" -v\n");
log(" Add comments and indentation to BTOR output file\n");
log("\n");
}
virtual void execute(std::ostream *&f, std::string filename, std::vector<std::string> args, RTLIL::Design *design)
{
bool verbose = false;
log_header(design, "Executing BTOR backend.\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
if (args[argidx] == "-v") {
verbose = true;
continue;
}
break;
}
extra_args(f, filename, args, argidx);
RTLIL::Module *topmod = design->top_module();
if (topmod == nullptr)
log_cmd_error("No top module found.\n");
*f << stringf("; BTOR description generated by %s for module %s.\n",
yosys_version_str, log_id(topmod));
BtorWorker(*f, topmod, verbose);
*f << stringf("; end of yosys output\n");
}
} BtorBackend;
PRIVATE_NAMESPACE_END