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yosys/backends/smt2/smt2.cc

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/*
* 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 Smt2Worker
{
CellTypes ct;
SigMap sigmap;
RTLIL::Module *module;
bool bvmode, memmode, regsmode, wiresmode, verbose;
int idcounter;
std::vector<std::string> decls, trans;
std::map<RTLIL::SigBit, RTLIL::Cell*> bit_driver;
std::set<RTLIL::Cell*> exported_cells;
pool<Cell*> recursive_cells, registers;
std::map<RTLIL::SigBit, std::pair<int, int>> fcache;
std::map<Cell*, int> memarrays;
std::map<int, int> bvsizes;
Smt2Worker(RTLIL::Module *module, bool bvmode, bool memmode, bool regsmode, bool wiresmode, bool verbose) :
ct(module->design), sigmap(module), module(module), bvmode(bvmode), memmode(memmode),
regsmode(regsmode), wiresmode(wiresmode), verbose(verbose), idcounter(0)
{
decls.push_back(stringf("(declare-sort |%s_s| 0)\n", log_id(module)));
for (auto cell : module->cells())
for (auto &conn : cell->connections()) {
bool is_input = ct.cell_input(cell->type, conn.first);
bool is_output = ct.cell_output(cell->type, conn.first);
if (is_output && !is_input)
for (auto bit : sigmap(conn.second)) {
if (bit_driver.count(bit))
log_error("Found multiple drivers for %s.\n", log_signal(bit));
bit_driver[bit] = cell;
}
else if (is_output || !is_input)
log_error("Unsupported or unknown directionality on port %s of cell %s.%s (%s).\n",
log_id(conn.first), log_id(module), log_id(cell), log_id(cell->type));
}
}
void register_bool(RTLIL::SigBit bit, int id)
{
if (verbose) log("%*s-> register_bool: %s %d\n", 2+2*GetSize(recursive_cells), "",
log_signal(bit), id);
sigmap.apply(bit);
log_assert(fcache.count(bit) == 0);
fcache[bit] = std::pair<int, int>(id, -1);
}
void register_bv(RTLIL::SigSpec sig, int id)
{
if (verbose) log("%*s-> register_bv: %s %d\n", 2+2*GetSize(recursive_cells), "",
log_signal(sig), id);
log_assert(bvmode);
sigmap.apply(sig);
log_assert(bvsizes.count(id) == 0);
bvsizes[id] = GetSize(sig);
for (int i = 0; i < GetSize(sig); i++) {
log_assert(fcache.count(sig[i]) == 0);
fcache[sig[i]] = std::pair<int, int>(id, i);
}
}
void register_boolvec(RTLIL::SigSpec sig, int id)
{
if (verbose) log("%*s-> register_boolvec: %s %d\n", 2+2*GetSize(recursive_cells), "",
log_signal(sig), id);
log_assert(bvmode);
sigmap.apply(sig);
register_bool(sig[0], id);
for (int i = 1; i < GetSize(sig); i++)
sigmap.add(sig[i], RTLIL::State::S0);
}
std::string get_bool(RTLIL::SigBit bit, const char *state_name = "state")
{
sigmap.apply(bit);
if (bit.wire == nullptr)
return bit == RTLIL::State::S1 ? "true" : "false";
if (bit_driver.count(bit))
export_cell(bit_driver.at(bit));
sigmap.apply(bit);
if (fcache.count(bit) == 0) {
if (verbose) log("%*s-> external bool: %s\n", 2+2*GetSize(recursive_cells), "",
log_signal(bit));
decls.push_back(stringf("(declare-fun |%s#%d| (|%s_s|) Bool) ; %s\n",
log_id(module), idcounter, log_id(module), log_signal(bit)));
register_bool(bit, idcounter++);
}
auto f = fcache.at(bit);
if (f.second >= 0)
return stringf("(= ((_ extract %d %d) (|%s#%d| %s)) #b1)", f.second, f.second, log_id(module), f.first, state_name);
return stringf("(|%s#%d| %s)", log_id(module), f.first, state_name);
}
std::string get_bool(RTLIL::SigSpec sig, const char *state_name = "state")
{
return get_bool(sig.as_bit(), state_name);
}
std::string get_bv(RTLIL::SigSpec sig, const char *state_name = "state")
{
log_assert(bvmode);
sigmap.apply(sig);
std::vector<std::string> subexpr;
SigSpec orig_sig;
while (orig_sig != sig) {
for (auto bit : sig)
if (bit_driver.count(bit))
export_cell(bit_driver.at(bit));
orig_sig = sig;
sigmap.apply(sig);
}
for (int i = 0, j = 1; i < GetSize(sig); i += j, j = 1)
{
if (sig[i].wire == nullptr) {
while (i+j < GetSize(sig) && sig[i+j].wire == nullptr) j++;
subexpr.push_back("#b");
for (int k = i+j-1; k >= i; k--)
subexpr.back() += sig[k] == RTLIL::State::S1 ? "1" : "0";
continue;
}
if (fcache.count(sig[i]) && fcache.at(sig[i]).second == -1) {
subexpr.push_back(stringf("(ite %s #b1 #b0)", get_bool(sig[i], state_name).c_str()));
continue;
}
if (fcache.count(sig[i])) {
auto t1 = fcache.at(sig[i]);
while (i+j < GetSize(sig)) {
if (fcache.count(sig[i+j]) == 0)
break;
auto t2 = fcache.at(sig[i+j]);
if (t1.first != t2.first)
break;
if (t1.second+j != t2.second)
break;
j++;
}
if (t1.second == 0 && j == bvsizes.at(t1.first))
subexpr.push_back(stringf("(|%s#%d| %s)", log_id(module), t1.first, state_name));
else
subexpr.push_back(stringf("((_ extract %d %d) (|%s#%d| %s))",
t1.second + j - 1, t1.second, log_id(module), t1.first, state_name));
continue;
}
std::set<RTLIL::SigBit> seen_bits = { sig[i] };
while (i+j < GetSize(sig) && sig[i+j].wire && !fcache.count(sig[i+j]) && !seen_bits.count(sig[i+j]))
seen_bits.insert(sig[i+j]), j++;
if (verbose) log("%*s-> external bv: %s\n", 2+2*GetSize(recursive_cells), "",
log_signal(sig.extract(i, j)));
for (auto bit : sig.extract(i, j))
log_assert(bit_driver.count(bit) == 0);
decls.push_back(stringf("(declare-fun |%s#%d| (|%s_s|) (_ BitVec %d)) ; %s\n",
log_id(module), idcounter, log_id(module), j, log_signal(sig.extract(i, j))));
subexpr.push_back(stringf("(|%s#%d| %s)", log_id(module), idcounter, state_name));
register_bv(sig.extract(i, j), idcounter++);
}
if (GetSize(subexpr) > 1) {
std::string expr = "", end_str = "";
for (int i = GetSize(subexpr)-1; i >= 0; i--) {
if (i > 0) expr += " (concat", end_str += ")";
expr += " " + subexpr[i];
}
return expr.substr(1) + end_str;
} else {
log_assert(GetSize(subexpr) == 1);
return subexpr[0];
}
}
void export_gate(RTLIL::Cell *cell, std::string expr)
{
RTLIL::SigBit bit = sigmap(cell->getPort("\\Y").as_bit());
std::string processed_expr;
for (char ch : expr) {
if (ch == 'A') processed_expr += get_bool(cell->getPort("\\A"));
else if (ch == 'B') processed_expr += get_bool(cell->getPort("\\B"));
else if (ch == 'C') processed_expr += get_bool(cell->getPort("\\C"));
else if (ch == 'D') processed_expr += get_bool(cell->getPort("\\D"));
else if (ch == 'S') processed_expr += get_bool(cell->getPort("\\S"));
else processed_expr += ch;
}
if (verbose) log("%*s-> import cell: %s\n", 2+2*GetSize(recursive_cells), "",
log_id(cell));
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) Bool %s) ; %s\n",
log_id(module), idcounter, log_id(module), processed_expr.c_str(), log_signal(bit)));
register_bool(bit, idcounter++);
recursive_cells.erase(cell);
}
void export_bvop(RTLIL::Cell *cell, std::string expr, char type = 0)
{
RTLIL::SigSpec sig_a, sig_b;
RTLIL::SigSpec sig_y = sigmap(cell->getPort("\\Y"));
bool is_signed = cell->getParam("\\A_SIGNED").as_bool();
int width = GetSize(sig_y);
if (type == 's' || type == 'd' || type == 'b') {
width = max(width, GetSize(cell->getPort("\\A")));
width = max(width, GetSize(cell->getPort("\\B")));
}
if (cell->hasPort("\\A")) {
sig_a = cell->getPort("\\A");
sig_a.extend_u0(width, is_signed);
}
if (cell->hasPort("\\B")) {
sig_b = cell->getPort("\\B");
sig_b.extend_u0(width, is_signed && !(type == 's'));
}
std::string processed_expr;
for (char ch : expr) {
if (ch == 'A') processed_expr += get_bv(sig_a);
else if (ch == 'B') processed_expr += get_bv(sig_b);
else if (ch == 'L') processed_expr += is_signed ? "a" : "l";
else if (ch == 'U') processed_expr += is_signed ? "s" : "u";
else processed_expr += ch;
}
if (width != GetSize(sig_y) && type != 'b')
processed_expr = stringf("((_ extract %d 0) %s)", GetSize(sig_y)-1, processed_expr.c_str());
if (verbose) log("%*s-> import cell: %s\n", 2+2*GetSize(recursive_cells), "",
log_id(cell));
if (type == 'b') {
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) Bool %s) ; %s\n",
log_id(module), idcounter, log_id(module), processed_expr.c_str(), log_signal(sig_y)));
register_boolvec(sig_y, idcounter++);
} else {
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) (_ BitVec %d) %s) ; %s\n",
log_id(module), idcounter, log_id(module), GetSize(sig_y), processed_expr.c_str(), log_signal(sig_y)));
register_bv(sig_y, idcounter++);
}
recursive_cells.erase(cell);
}
void export_reduce(RTLIL::Cell *cell, std::string expr, bool identity_val)
{
RTLIL::SigSpec sig_y = sigmap(cell->getPort("\\Y"));
std::string processed_expr;
for (char ch : expr)
if (ch == 'A' || ch == 'B') {
RTLIL::SigSpec sig = sigmap(cell->getPort(stringf("\\%c", ch)));
for (auto bit : sig)
processed_expr += " " + get_bool(bit);
if (GetSize(sig) == 1)
processed_expr += identity_val ? " true" : " false";
} else
processed_expr += ch;
if (verbose) log("%*s-> import cell: %s\n", 2+2*GetSize(recursive_cells), "",
log_id(cell));
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) Bool %s) ; %s\n",
log_id(module), idcounter, log_id(module), processed_expr.c_str(), log_signal(sig_y)));
register_boolvec(sig_y, idcounter++);
recursive_cells.erase(cell);
}
void export_cell(RTLIL::Cell *cell)
{
if (verbose) log("%*s=> export_cell %s (%s) [%s]\n", 2+2*GetSize(recursive_cells), "",
log_id(cell), log_id(cell->type), exported_cells.count(cell) ? "old" : "new");
if (recursive_cells.count(cell))
log_error("Found logic loop in module %s! See cell %s.\n", log_id(module), log_id(cell));
if (exported_cells.count(cell))
return;
exported_cells.insert(cell);
recursive_cells.insert(cell);
if (cell->type == "$_DFF_P_" || cell->type == "$_DFF_N_")
{
registers.insert(cell);
decls.push_back(stringf("(declare-fun |%s#%d| (|%s_s|) Bool) ; %s\n",
log_id(module), idcounter, log_id(module), log_signal(cell->getPort("\\Q"))));
register_bool(cell->getPort("\\Q"), idcounter++);
recursive_cells.erase(cell);
return;
}
if (cell->type == "$_BUF_") return export_gate(cell, "A");
if (cell->type == "$_NOT_") return export_gate(cell, "(not A)");
if (cell->type == "$_AND_") return export_gate(cell, "(and A B)");
if (cell->type == "$_NAND_") return export_gate(cell, "(not (and A B))");
if (cell->type == "$_OR_") return export_gate(cell, "(or A B)");
if (cell->type == "$_NOR_") return export_gate(cell, "(not (or A B))");
if (cell->type == "$_XOR_") return export_gate(cell, "(xor A B)");
if (cell->type == "$_XNOR_") return export_gate(cell, "(not (xor A B))");
if (cell->type == "$_MUX_") return export_gate(cell, "(ite S B A)");
if (cell->type == "$_AOI3_") return export_gate(cell, "(not (or (and A B) C))");
if (cell->type == "$_OAI3_") return export_gate(cell, "(not (and (or A B) C))");
if (cell->type == "$_AOI4_") return export_gate(cell, "(not (or (and A B) (and C D)))");
if (cell->type == "$_OAI4_") return export_gate(cell, "(not (and (or A B) (or C D)))");
// FIXME: $lut
if (bvmode)
{
if (cell->type == "$dff")
{
registers.insert(cell);
decls.push_back(stringf("(declare-fun |%s#%d| (|%s_s|) (_ BitVec %d)) ; %s\n",
log_id(module), idcounter, log_id(module), GetSize(cell->getPort("\\Q")), log_signal(cell->getPort("\\Q"))));
register_bv(cell->getPort("\\Q"), idcounter++);
recursive_cells.erase(cell);
return;
}
if (cell->type == "$and") return export_bvop(cell, "(bvand A B)");
if (cell->type == "$or") return export_bvop(cell, "(bvor A B)");
if (cell->type == "$xor") return export_bvop(cell, "(bvxor A B)");
if (cell->type == "$xnor") return export_bvop(cell, "(bvxnor A B)");
if (cell->type == "$shl") return export_bvop(cell, "(bvshl A B)", 's');
if (cell->type == "$shr") return export_bvop(cell, "(bvlshr A B)", 's');
if (cell->type == "$sshl") return export_bvop(cell, "(bvshl A B)", 's');
if (cell->type == "$sshr") return export_bvop(cell, "(bvLshr A B)", 's');
// FIXME: $shift $shiftx
if (cell->type == "$lt") return export_bvop(cell, "(bvUlt A B)", 'b');
if (cell->type == "$le") return export_bvop(cell, "(bvUle A B)", 'b');
if (cell->type == "$ge") return export_bvop(cell, "(bvUge A B)", 'b');
if (cell->type == "$gt") return export_bvop(cell, "(bvUgt A B)", 'b');
if (cell->type == "$ne") return export_bvop(cell, "(distinct A B)", 'b');
if (cell->type == "$nex") return export_bvop(cell, "(distinct A B)", 'b');
if (cell->type == "$eq") return export_bvop(cell, "(= A B)", 'b');
if (cell->type == "$eqx") return export_bvop(cell, "(= A B)", 'b');
if (cell->type == "$not") return export_bvop(cell, "(bvnot A)");
if (cell->type == "$pos") return export_bvop(cell, "A");
if (cell->type == "$neg") return export_bvop(cell, "(bvneg A)");
if (cell->type == "$add") return export_bvop(cell, "(bvadd A B)");
if (cell->type == "$sub") return export_bvop(cell, "(bvsub A B)");
if (cell->type == "$mul") return export_bvop(cell, "(bvmul A B)");
if (cell->type == "$div") return export_bvop(cell, "(bvUdiv A B)", 'd');
if (cell->type == "$mod") return export_bvop(cell, "(bvUrem A B)", 'd');
if (cell->type == "$reduce_and") return export_reduce(cell, "(and A)", true);
if (cell->type == "$reduce_or") return export_reduce(cell, "(or A)", false);
if (cell->type == "$reduce_xor") return export_reduce(cell, "(xor A)", false);
if (cell->type == "$reduce_xnor") return export_reduce(cell, "(not (xor A))", false);
if (cell->type == "$reduce_bool") return export_reduce(cell, "(or A)", false);
if (cell->type == "$logic_not") return export_reduce(cell, "(not (or A))", false);
if (cell->type == "$logic_and") return export_reduce(cell, "(and (or A) (or B))", false);
if (cell->type == "$logic_or") return export_reduce(cell, "(or A B)", false);
if (cell->type == "$mux" || cell->type == "$pmux")
{
int width = GetSize(cell->getPort("\\Y"));
std::string processed_expr = get_bv(cell->getPort("\\A"));
RTLIL::SigSpec sig_b = cell->getPort("\\B");
RTLIL::SigSpec sig_s = cell->getPort("\\S");
get_bv(sig_b);
get_bv(sig_s);
for (int i = 0; i < GetSize(sig_s); i++)
processed_expr = stringf("(ite %s %s %s)", get_bool(sig_s[i]).c_str(),
get_bv(sig_b.extract(i*width, width)).c_str(), processed_expr.c_str());
if (verbose) log("%*s-> import cell: %s\n", 2+2*GetSize(recursive_cells), "",
log_id(cell));
RTLIL::SigSpec sig = sigmap(cell->getPort("\\Y"));
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) (_ BitVec %d) %s) ; %s\n",
log_id(module), idcounter, log_id(module), width, processed_expr.c_str(), log_signal(sig)));
register_bv(sig, idcounter++);
recursive_cells.erase(cell);
return;
}
// FIXME: $slice $concat
}
if (memmode && cell->type == "$mem")
{
int arrayid = idcounter++;
memarrays[cell] = arrayid;
int abits = cell->getParam("\\ABITS").as_int();
int width = cell->getParam("\\WIDTH").as_int();
int rd_ports = cell->getParam("\\RD_PORTS").as_int();
decls.push_back(stringf("(declare-fun |%s#%d#0| (|%s_s|) (Array (_ BitVec %d) (_ BitVec %d))) ; %s\n",
log_id(module), arrayid, log_id(module), abits, width, log_id(cell)));
decls.push_back(stringf("(define-fun |%s_m %s| ((state |%s_s|)) (Array (_ BitVec %d) (_ BitVec %d)) (|%s#%d#0| state))\n",
log_id(module), log_id(cell), log_id(module), abits, width, log_id(module), arrayid));
for (int i = 0; i < rd_ports; i++)
{
std::string addr = get_bv(cell->getPort("\\RD_ADDR").extract(abits*i, abits));
SigSpec data_sig = cell->getPort("\\RD_DATA").extract(width*i, width);
if (cell->getParam("\\RD_CLK_ENABLE").extract(i).as_bool())
log_error("Read port %d (%s) of memory %s.%s is clocked. This is not supported by \"write_smt2\"! "
"Call \"memory\" with -nordff to avoid this error.\n", i, log_signal(data_sig), log_id(cell), log_id(module));
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) (_ BitVec %d) (select (|%s#%d#0| state) %s)) ; %s\n",
log_id(module), idcounter, log_id(module), width, log_id(module), arrayid, addr.c_str(), log_signal(data_sig)));
register_bv(data_sig, idcounter++);
}
registers.insert(cell);
recursive_cells.erase(cell);
return;
}
log_error("Unsupported cell type %s for cell %s.%s. (Maybe this cell type would be supported in -bv or -mem mode?)\n",
log_id(cell->type), log_id(module), log_id(cell));
}
void run()
{
if (verbose) log("=> export logic driving outputs\n");
pool<SigBit> reg_bits;
if (regsmode) {
for (auto cell : module->cells())
if (cell->type.in("$_DFF_P_", "$_DFF_N_", "$dff")) {
// not using sigmap -- we want the net directly at the dff output
for (auto bit : cell->getPort("\\Q"))
reg_bits.insert(bit);
}
}
for (auto wire : module->wires()) {
bool is_register = false;
if (regsmode)
for (auto bit : SigSpec(wire))
if (reg_bits.count(bit))
is_register = true;
if (wire->port_id || is_register || wire->get_bool_attribute("\\keep") || (wiresmode && wire->name[0] == '\\')) {
RTLIL::SigSpec sig = sigmap(wire);
if (wire->port_input)
decls.push_back(stringf("; yosys-smt2-input %s %d\n", log_id(wire), wire->width));
if (wire->port_output)
decls.push_back(stringf("; yosys-smt2-output %s %d\n", log_id(wire), wire->width));
if (is_register)
decls.push_back(stringf("; yosys-smt2-register %s %d\n", log_id(wire), wire->width));
if (wire->get_bool_attribute("\\keep") || (wiresmode && wire->name[0] == '\\'))
decls.push_back(stringf("; yosys-smt2-wire %s %d\n", log_id(wire), wire->width));
if (bvmode && GetSize(sig) > 1) {
decls.push_back(stringf("(define-fun |%s_n %s| ((state |%s_s|)) (_ BitVec %d) %s)\n",
log_id(module), log_id(wire), log_id(module), GetSize(sig), get_bv(sig).c_str()));
} else {
for (int i = 0; i < GetSize(sig); i++)
if (GetSize(sig) > 1)
decls.push_back(stringf("(define-fun |%s_n %s %d| ((state |%s_s|)) Bool %s)\n",
log_id(module), log_id(wire), i, log_id(module), get_bool(sig[i]).c_str()));
else
decls.push_back(stringf("(define-fun |%s_n %s| ((state |%s_s|)) Bool %s)\n",
log_id(module), log_id(wire), log_id(module), get_bool(sig[i]).c_str()));
}
}
}
if (verbose) log("=> export logic associated with the initial state\n");
vector<string> init_list;
for (auto wire : module->wires())
if (wire->attributes.count("\\init")) {
RTLIL::SigSpec sig = sigmap(wire);
Const val = wire->attributes.at("\\init");
val.bits.resize(GetSize(sig));
if (bvmode && GetSize(sig) > 1) {
init_list.push_back(stringf("(= %s #b%s) ; %s", get_bv(sig).c_str(), val.as_string().c_str(), log_id(wire)));
} else {
for (int i = 0; i < GetSize(sig); i++)
init_list.push_back(stringf("(= %s %s) ; %s", get_bool(sig[i]).c_str(), val.bits[i] == State::S1 ? "true" : "false", log_id(wire)));
}
}
if (verbose) log("=> export logic driving asserts\n");
vector<int> assert_list, assume_list;
for (auto cell : module->cells())
if (cell->type.in("$assert", "$assume")) {
string name_a = get_bool(cell->getPort("\\A"));
string name_en = get_bool(cell->getPort("\\EN"));
decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) Bool (or %s (not %s))) ; %s\n",
log_id(module), idcounter, log_id(module), name_a.c_str(), name_en.c_str(), log_id(cell)));
if (cell->type == "$assert")
assert_list.push_back(idcounter++);
else
assume_list.push_back(idcounter++);
}
for (int iter = 1; !registers.empty(); iter++)
{
pool<Cell*> this_regs;
this_regs.swap(registers);
if (verbose) log("=> export logic driving registers [iteration %d]\n", iter);
for (auto cell : this_regs)
{
if (cell->type == "$_DFF_P_" || cell->type == "$_DFF_N_")
{
std::string expr_d = get_bool(cell->getPort("\\D"));
std::string expr_q = get_bool(cell->getPort("\\Q"), "next_state");
trans.push_back(stringf(" (= %s %s) ; %s %s\n", expr_d.c_str(), expr_q.c_str(), log_id(cell), log_signal(cell->getPort("\\Q"))));
}
if (cell->type == "$dff")
{
std::string expr_d = get_bv(cell->getPort("\\D"));
std::string expr_q = get_bv(cell->getPort("\\Q"), "next_state");
trans.push_back(stringf(" (= %s %s) ; %s %s\n", expr_d.c_str(), expr_q.c_str(), log_id(cell), log_signal(cell->getPort("\\Q"))));
}
if (cell->type == "$mem")
{
int arrayid = memarrays.at(cell);
int abits = cell->getParam("\\ABITS").as_int();
int width = cell->getParam("\\WIDTH").as_int();
int wr_ports = cell->getParam("\\WR_PORTS").as_int();
for (int i = 0; i < wr_ports; i++)
{
std::string addr = get_bv(cell->getPort("\\WR_ADDR").extract(abits*i, abits));
std::string data = get_bv(cell->getPort("\\WR_DATA").extract(width*i, width));
std::string mask = get_bv(cell->getPort("\\WR_EN").extract(width*i, width));
data = stringf("(bvor (bvand %s %s) (bvand (select (|%s#%d#%d| state) %s) (bvnot %s)))",
data.c_str(), mask.c_str(), log_id(module), arrayid, i, addr.c_str(), mask.c_str());
decls.push_back(stringf("(define-fun |%s#%d#%d| ((state |%s_s|)) (Array (_ BitVec %d) (_ BitVec %d)) "
"(store (|%s#%d#%d| state) %s %s)) ; %s\n",
log_id(module), arrayid, i+1, log_id(module), abits, width,
log_id(module), arrayid, i, addr.c_str(), data.c_str(), log_id(cell)));
}
std::string expr_d = stringf("(|%s#%d#%d| state)", log_id(module), arrayid, wr_ports);
std::string expr_q = stringf("(|%s#%d#0| next_state)", log_id(module), arrayid);
trans.push_back(stringf(" (= %s %s) ; %s\n", expr_d.c_str(), expr_q.c_str(), log_id(cell)));
}
}
}
string assert_expr = assert_list.empty() ? "true" : "(and";
if (!assert_list.empty()) {
for (int i : assert_list)
assert_expr += stringf(" (|%s#%d| state)", log_id(module), i);
assert_expr += ")";
}
decls.push_back(stringf("(define-fun |%s_a| ((state |%s_s|)) Bool %s)\n",
log_id(module), log_id(module), assert_expr.c_str()));
string assume_expr = assume_list.empty() ? "true" : "(and";
if (!assume_list.empty()) {
for (int i : assume_list)
assume_expr += stringf(" (|%s#%d| state)", log_id(module), i);
assume_expr += ")";
}
decls.push_back(stringf("(define-fun |%s_u| ((state |%s_s|)) Bool %s)\n",
log_id(module), log_id(module), assume_expr.c_str()));
string init_expr = init_list.empty() ? "true" : "(and";
if (!init_list.empty()) {
for (auto &str : init_list)
init_expr += stringf("\n\t%s", str.c_str());
init_expr += "\n)";
}
decls.push_back(stringf("(define-fun |%s_i| ((state |%s_s|)) Bool %s)\n",
log_id(module), log_id(module), init_expr.c_str()));
}
void write(std::ostream &f)
{
for (auto it : decls)
f << it;
f << stringf("; yosys-smt2-module %s\n", log_id(module));
f << stringf("(define-fun |%s_t| ((state |%s_s|) (next_state |%s_s|)) Bool ", log_id(module), log_id(module), log_id(module));
if (GetSize(trans) > 1) {
f << "(and\n";
for (auto it : trans)
f << it;
f << "))";
} else
if (GetSize(trans) == 1)
f << "\n" + trans.front() + ")";
else
f << "true)";
f << stringf(" ; end of module %s\n", log_id(module));
}
};
struct Smt2Backend : public Backend {
Smt2Backend() : Backend("smt2", "write design to SMT-LIBv2 file") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" write_smt2 [options] [filename]\n");
log("\n");
log("Write a SMT-LIBv2 [1] description of the current design. For a module with name\n");
log("'<mod>' this will declare the sort '<mod>_s' (state of the module) and the\n");
log("functions operating on that state.\n");
log("\n");
log("The '<mod>_s' sort represents a module state. Additional '<mod>_n' functions\n");
log("are provided that can be used to access the values of the signals in the module.\n");
log("Only ports, and signals with the 'keep' attribute set are made available via\n");
log("such functions. Without the -bv option, multi-bit wires are exported as\n");
log("separate functions of type Bool for the individual bits. With the -bv option\n");
log("multi-bit wires are exported as single functions of type BitVec.\n");
log("\n");
log("The '<mod>_t' function evaluates to 'true' when the given pair of states\n");
log("describes a valid state transition.\n");
log("\n");
log("The '<mod>_a' function evaluates to 'true' when the given state satisfies\n");
log("the asserts in the module.\n");
log("\n");
log("The '<mod>_u' function evaluates to 'true' when the given state satisfies\n");
log("the assumptions in the module.\n");
log("\n");
log("The '<mod>_i' function evaluates to 'true' when the given state conforms\n");
log("to the initial state.\n");
log("\n");
log(" -verbose\n");
log(" this will print the recursive walk used to export the modules.\n");
log("\n");
log(" -bv\n");
log(" enable support for BitVec (FixedSizeBitVectors theory). with this\n");
log(" option set multi-bit wires are represented using the BitVec sort and\n");
log(" support for coarse grain cells (incl. arithmetic) is enabled.\n");
log("\n");
log(" -mem\n");
log(" enable support for memories (via ArraysEx theory). this option\n");
log(" also implies -bv. only $mem cells without merged registers in\n");
log(" read ports are supported. call \"memory\" with -nordff to make sure\n");
log(" that no registers are merged into $mem read ports. '<mod>_m' functions\n");
log(" will be generated for accessing the arrays that are used to represent\n");
log(" memories.\n");
log("\n");
log(" -regs\n");
log(" also create '<mod>_n' functions for all registers.\n");
log("\n");
log(" -wires\n");
log(" also create '<mod>_n' functions for all public wires.\n");
log("\n");
log(" -tpl <template_file>\n");
log(" use the given template file. the line containing only the token '%%%%'\n");
log(" is replaced with the regular output of this command.\n");
log("\n");
log("[1] For more information on SMT-LIBv2 visit http://smt-lib.org/ or read David\n");
log("R. Cok's tutorial: http://www.grammatech.com/resources/smt/SMTLIBTutorial.pdf\n");
log("\n");
log("---------------------------------------------------------------------------\n");
log("\n");
log("Example:\n");
log("\n");
log("Consider the following module (test.v). We want to prove that the output can\n");
log("never transition from a non-zero value to a zero value.\n");
log("\n");
log(" module test(input clk, output reg [3:0] y);\n");
log(" always @(posedge clk)\n");
log(" y <= (y << 1) | ^y;\n");
log(" endmodule\n");
log("\n");
log("For this proof we create the following template (test.tpl).\n");
log("\n");
log(" ; we need QF_UFBV for this poof\n");
log(" (set-logic QF_UFBV)\n");
log("\n");
log(" ; insert the auto-generated code here\n");
log(" %%%%\n");
log("\n");
log(" ; declare two state variables s1 and s2\n");
log(" (declare-fun s1 () test_s)\n");
log(" (declare-fun s2 () test_s)\n");
log("\n");
log(" ; state s2 is the successor of state s1\n");
log(" (assert (test_t s1 s2))\n");
log("\n");
log(" ; we are looking for a model with y non-zero in s1\n");
log(" (assert (distinct (|test_n y| s1) #b0000))\n");
log("\n");
log(" ; we are looking for a model with y zero in s2\n");
log(" (assert (= (|test_n y| s2) #b0000))\n");
log("\n");
log(" ; is there such a model?\n");
log(" (check-sat)\n");
log("\n");
log("The following yosys script will create a 'test.smt2' file for our proof:\n");
log("\n");
log(" read_verilog test.v\n");
log(" hierarchy -check; proc; opt; check -assert\n");
log(" write_smt2 -bv -tpl test.tpl test.smt2\n");
log("\n");
log("Running 'cvc4 test.smt2' will print 'unsat' because y can never transition\n");
log("from non-zero to zero in the test design.\n");
log("\n");
}
virtual void execute(std::ostream *&f, std::string filename, std::vector<std::string> args, RTLIL::Design *design)
{
std::ifstream template_f;
bool bvmode = false, memmode = false, regsmode = false, wiresmode = false, verbose = false;
log_header(design, "Executing SMT2 backend.\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
if (args[argidx] == "-tpl" && argidx+1 < args.size()) {
template_f.open(args[++argidx]);
if (template_f.fail())
log_error("Can't open template file `%s'.\n", args[argidx].c_str());
continue;
}
if (args[argidx] == "-bv") {
bvmode = true;
continue;
}
if (args[argidx] == "-mem") {
bvmode = true;
memmode = true;
continue;
}
if (args[argidx] == "-regs") {
regsmode = true;
continue;
}
if (args[argidx] == "-wires") {
wiresmode = true;
continue;
}
if (args[argidx] == "-verbose") {
verbose = true;
continue;
}
break;
}
extra_args(f, filename, args, argidx);
if (template_f.is_open()) {
std::string line;
while (std::getline(template_f, line)) {
int indent = 0;
while (indent < GetSize(line) && (line[indent] == ' ' || line[indent] == '\t'))
indent++;
if (line.substr(indent, 2) == "%%")
break;
*f << line << std::endl;
}
}
*f << stringf("; SMT-LIBv2 description generated by %s\n", yosys_version_str);
for (auto module : design->modules())
{
if (module->get_bool_attribute("\\blackbox") || module->has_memories_warn() || module->has_processes_warn())
continue;
log("Creating SMT-LIBv2 representation of module %s.\n", log_id(module));
Smt2Worker worker(module, bvmode, memmode, regsmode, wiresmode, verbose);
worker.run();
worker.write(*f);
}
*f << stringf("; end of yosys output\n");
if (template_f.is_open()) {
std::string line;
while (std::getline(template_f, line))
*f << line << std::endl;
}
}
} Smt2Backend;
PRIVATE_NAMESPACE_END
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