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btor2_encoder.cpp
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/********************* */
/*! \file
** \verbatim
** Top contributors (to current version):
** Makai Mann
** This file is part of the pono project.
** Copyright (c) 2019 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file LICENSE in the top-level source
** directory for licensing information.\endverbatim
**
** \brief
**
**
**/
#include "smt-switch/utils.h"
#include "btor2_encoder.h"
#include "utils/logger.h"
#include <iostream>
#include "assert.h"
using namespace smt;
using namespace std;
namespace wamcer {
// Maps for use in conversion
const unordered_map<Btor2Tag, int> basemap({{BTOR2_TAG_const, 2},
{BTOR2_TAG_constd, 10},
{BTOR2_TAG_consth, 16}});
const unordered_map <Btor2Tag, smt::PrimOp> bvopmap({
{BTOR2_TAG_add, BVAdd},
{BTOR2_TAG_and, BVAnd},
// { BTOR2_TAG_bad, },
{BTOR2_TAG_concat, Concat},
//{ BTOR2_TAG_const, },
//{ BTOR2_TAG_constraint, },
//{ BTOR2_TAG_constd, },
//{ BTOR2_TAG_consth, },
//{ BTOR2_TAG_dec, },
// { BTOR2_TAG_eq, BVComp }, // handled this specially, because could also
// have array arguments
//{ BTOR2_TAG_fair, },
{BTOR2_TAG_iff, BVComp},
// { BTOR2_TAG_implies, Implies }, // handle specially (needs to work with
// boolector AND other solvers), gets complicated with bools and BV(1) are
// aliased
//{ BTOR2_TAG_inc, },
//{ BTOR2_TAG_init, },
//{ BTOR2_TAG_input, },
//{ BTOR2_TAG_ite, Ite },
//{ BTOR2_TAG_justice, },
{BTOR2_TAG_mul, BVMul},
{BTOR2_TAG_nand, BVNand},
// handled this specially, because could also have array arguments
// { BTOR2_TAG_neq, Distinct },
{BTOR2_TAG_neg, BVNeg},
//{ BTOR2_TAG_next, },
{BTOR2_TAG_nor, BVNor},
{BTOR2_TAG_not, BVNot},
//{ BTOR2_TAG_one, },
//{ BTOR2_TAG_ones, },
{BTOR2_TAG_or, BVOr},
//{ BTOR2_TAG_output, },
// { BTOR2_TAG_read, Select }, // handle specially -- make sure it's casted
// to bv
//{ BTOR2_TAG_redand, },
//{ BTOR2_TAG_redor, },
//{ BTOR2_TAG_redxor, },
// { BTOR2_TAG_rol, },
// { BTOR2_TAG_ror, },
//{ BTOR2_TAG_saddo, },
{BTOR2_TAG_sdiv, BVSdiv},
//{ BTOR2_TAG_sdivo, },
//{ BTOR2_TAG_sext, },
{BTOR2_TAG_sgt, BVSgt},
{BTOR2_TAG_sgte, BVSge},
//{ BTOR2_TAG_slice, },
{BTOR2_TAG_sll, BVShl},
{BTOR2_TAG_slt, BVSlt},
{BTOR2_TAG_slte, BVSle},
//{ BTOR2_TAG_sort, },
{BTOR2_TAG_smod, BVSmod},
//{ BTOR2_TAG_smulo, },
{BTOR2_TAG_sra, BVAshr},
{BTOR2_TAG_srem, BVSrem},
{BTOR2_TAG_srl, BVLshr},
//{ BTOR2_TAG_ssubo, },
//{ BTOR2_TAG_state, },
{BTOR2_TAG_sub, BVSub},
//{ BTOR2_TAG_uaddo, },
{BTOR2_TAG_udiv, BVUdiv},
//{ BTOR2_TAG_uext, },
{BTOR2_TAG_ugt, BVUgt},
{BTOR2_TAG_ugte, BVUge},
{BTOR2_TAG_ult, BVUlt},
{BTOR2_TAG_ulte, BVUle},
//{ BTOR2_TAG_umulo, },
{BTOR2_TAG_urem, BVUrem},
//{ BTOR2_TAG_usubo, },
//{ BTOR2_TAG_write, Store }, // handle specially -- make sure it's casted
// to bv
{BTOR2_TAG_xnor, BVXnor},
{BTOR2_TAG_xor, BVXor},
//{ BTOR2_TAG_zero, }
});
const unordered_map <Btor2Tag, smt::PrimOp> boolopmap({
{BTOR2_TAG_and, And},
{BTOR2_TAG_or, Or},
{BTOR2_TAG_xor, Xor},
{BTOR2_TAG_not, Not},
// { BTOR2_TAG_implies, Implies },
{BTOR2_TAG_iff, Equal},
// handling specially -- could have array arguments
// { BTOR2_TAG_eq, Equal },
//{ BTOR2_TAG_neq, Distinct }
});
Term BTOR2Encoder::bool_to_bv(const Term &t) const {
if (t->get_sort()->get_sort_kind() == BOOL) {
Sort bv1sort = solver_->make_sort(BV, 1);
return solver_->make_term(
Ite, t, solver_->make_term(1, bv1sort), solver_->make_term(0, bv1sort));
} else {
return t;
}
}
Term BTOR2Encoder::bv_to_bool(const Term &t) const {
Sort sort = t->get_sort();
if (sort->get_sort_kind() == BV) {
if (sort->get_width() != 1) {
throw PonoException("Can't convert non-width 1 bitvector to bool.");
}
return solver_->make_term(
Equal, t, solver_->make_term(1, solver_->make_sort(BV, 1)));
} else {
return t;
}
}
TermVec BTOR2Encoder::lazy_convert(const TermVec &tvec) const {
TermVec res;
res.reserve(tvec.size());
unsigned int num_bools = 0;
bool wide_bvs;
Sort sort;
UnorderedSortSet sortset;
for (auto t: tvec) {
res.push_back(t);
sort = t->get_sort();
sortset.insert(sort);
if (sort->get_sort_kind() == BOOL) {
num_bools++;
} else if (!(sort->get_sort_kind() == BV && sort->get_width() == 1)) {
wide_bvs = true;
}
}
if (sortset.size() > 1) {
if (num_bools > tvec.size() / 2 && !wide_bvs) {
for (size_t i = 0; i < res.size(); i++) {
res[i] = bv_to_bool(res[i]);
}
} else {
for (size_t i = 0; i < res.size(); i++) {
res[i] = bool_to_bv(res[i]);
}
}
}
return res;
}
// to handle the case where yosys generate sth. like this
// state (with no name)
// output (with name)
// for Verilog : output reg xxx;
// this function go over the file and record this case
// when we encounter it again we shall replace the state's name
void BTOR2Encoder::preprocess(const std::string &filename) {
FILE *input_file = fopen(filename.c_str(), "r");
if (!input_file) {
throw PonoException("Could not open " + filename);
}
reader_ = btor2parser_new();
if (!btor2parser_read_lines(reader_, input_file)) {
throw PonoException(std::string(btor2parser_error(reader_)));
}
it_ = btor2parser_iter_init(reader_);
std::unordered_set < uint64_t > unamed_state_ids;
while ((l_ = btor2parser_iter_next(&it_))) {
if (l_->tag == BTOR2_TAG_state) {
if (!l_->symbol) { // if we see state has no name, record it
unamed_state_ids.insert(l_->id);
}
} else if (l_->tag == BTOR2_TAG_output && l_->symbol) {
// if we see an output with name
if (l_->nargs == 0)
throw PonoException("Missing term for id " + std::to_string(l_->id));
// we'd like to know if it refers to a state without name
auto pos = unamed_state_ids.find(l_->args[0]); // so, *pos is its btor id
if (pos != unamed_state_ids.end()) {
// in such case, we record that we can name if with this new name
auto state_name_pos = state_renaming_table.find(*pos);
if (state_name_pos == state_renaming_table.end()) {
state_renaming_table.insert(std::make_pair(*pos, l_->symbol));
} // otherwise we already have a name for it, then just ignore this one
}
} // end of if input
} // end of while
fclose(input_file);
btor2parser_delete(reader_);
} // end of preprocess
void BTOR2Encoder::parse(const std::string &filename) {
FILE *input_file = fopen(filename.c_str(), "r");
if (!input_file) {
throw PonoException("Could not open " + filename);
}
reader_ = btor2parser_new();
if (!btor2parser_read_lines(reader_, input_file)) {
throw PonoException(std::string(btor2parser_error(reader_)));
}
uint64_t num_states = 0;
std::unordered_map < int64_t, uint64_t > id2statenum;
it_ = btor2parser_iter_init(reader_);
while ((l_ = btor2parser_iter_next(&it_))) {
/******************************** Identify sort
* ********************************/
if (l_->tag != BTOR2_TAG_sort && l_->sort.id) {
linesort_ = sorts_.at(l_->sort.id);
}
/******************************** Gather term arguments
* ********************************/
termargs_.clear();
termargs_.reserve(l_->nargs);
for (i_ = 0; i_ < l_->nargs; i_++) {
negated_ = false;
idx_ = l_->args[i_];
if (idx_ < 0) {
negated_ = true;
idx_ = -idx_;
}
if (terms_.find(idx_) == terms_.end()) {
throw PonoException("Missing term for id " + std::to_string(idx_));
}
Term term_ = terms_.at(idx_);
if (negated_) {
if (term_->get_sort()->get_sort_kind() == BV) {
term_ = solver_->make_term(BVNot, term_);
} else {
term_ = solver_->make_term(Not, term_);
}
}
termargs_.push_back(term_);
}
/******************************** Handle special cases
* ********************************/
if (l_->tag == BTOR2_TAG_state) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
auto renaming_lookup_pos = state_renaming_table.find(l_->id);
if (renaming_lookup_pos != state_renaming_table.end())
symbol_ = renaming_lookup_pos->second;
else
symbol_ = "state" + to_string(l_->id);
}
Term state = ts_.make_statevar(symbol_, linesort_);
terms_[l_->id] = state;
statesvec_.push_back(state);
// will be removed from this map if there's a next function for this state
no_next_states_[num_states] = state;
id2statenum[l_->id] = num_states;
num_states++;
} else if (l_->tag == BTOR2_TAG_input) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
symbol_ = "input" + to_string(l_->id);
}
Term input = ts_.make_inputvar(symbol_, linesort_);
terms_[l_->id] = input;
inputsvec_.push_back(input);
} else if (l_->tag == BTOR2_TAG_output) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
symbol_ = "output" + to_string(l_->id);
}
try {
ts_.name_term(symbol_, termargs_[0]);
}
catch (PonoException &e) {
ts_.name_term("_out_" + symbol_, termargs_[0]);
}
terms_[l_->id] = termargs_[0];
} else if (l_->tag == BTOR2_TAG_sort) {
switch (l_->sort.tag) {
case BTOR2_TAG_SORT_bitvec: {
linesort_ = solver_->make_sort(BV, l_->sort.bitvec.width);
sorts_[l_->id] = linesort_;
break;
}
case BTOR2_TAG_SORT_array: {
linesort_ = solver_->make_sort(ARRAY,
sorts_.at(l_->sort.array.index),
sorts_.at(l_->sort.array.element));
sorts_[l_->id] = linesort_;
break;
}
default:
// TODO: maybe only check this in debug? or could always check cause
// it's really bad
throw PonoException("Unknown sort tag");
}
} else if (l_->tag == BTOR2_TAG_constraint) {
Term constraint = bv_to_bool(termargs_[0]);
// BTOR2 allows constraints over inputs
// in Pono these need to be promoted to state variables
UnorderedTermSet free_vars;
get_free_symbolic_consts(constraint, free_vars);
for (const auto &v: free_vars) {
if (ts_.is_input_var(v)) {
ts_.promote_inputvar(v);
}
}
ts_.add_constraint(constraint);
constraints_.push_back(constraint);
terms_[l_->id] = constraint;
} else if (l_->tag == BTOR2_TAG_init) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two term arguments to init");
} else if (linesort_ != termargs_[0]->get_sort()) {
throw PonoException(
"Expecting to init sort to match first argument's sort");
}
Term init_eq;
if (linesort_->get_sort_kind() == BV) {
init_eq = solver_->make_term(Equal, termargs_);
} else if (linesort_->get_sort_kind() == ARRAY) {
if (termargs_[1]->get_sort()->get_sort_kind() == BV) {
init_eq = solver_->make_term(
Equal, termargs_[0], solver_->make_term(termargs_[1], linesort_));
} else {
init_eq = solver_->make_term(Equal, termargs_[0], termargs_[1]);
}
} else {
throw PonoException("Unhandled sort: "
+ termargs_[0]->get_sort()->to_string());
}
ts_.constrain_init(init_eq);
terms_[l_->id] = init_eq;
} else if (l_->tag == BTOR2_TAG_next) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to next");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 == s1) {
ts_.assign_next(t0, t1);
terms_[l_->id] = t1;
} else if (((sk0 == BV) && (sk1 == BOOL))
|| ((sk0 == BOOL) && (sk1 == BV))) {
// need to cast
ts_.assign_next(bool_to_bv(t0), bool_to_bv(t1));
terms_[l_->id] = bool_to_bv(t1);
} else {
throw PonoException("Got two different sorts in next update.");
}
no_next_states_.erase(id2statenum.at(l_->args[0]));
} else if (l_->tag == BTOR2_TAG_bad) {
Term bad = bv_to_bool(termargs_[0]);
Term prop = solver_->make_term(Not, bad);
propvec_.push_back(prop);
terms_[l_->id] = prop;
} else if (l_->tag == BTOR2_TAG_justice) {
std::cout << "Warning: ignoring justice term" << std::endl;
justicevec_.push_back(termargs_[0]);
terms_[l_->id] = termargs_[0];
} else if (l_->tag == BTOR2_TAG_fair) {
std::cout << "Warning: ignoring fair term" << std::endl;
fairvec_.push_back(termargs_[0]);
terms_[l_->id] = termargs_[0];
} else if (l_->constant) {
terms_[l_->id] =
solver_->make_term(l_->constant, linesort_, basemap.at(l_->tag));
} else if (l_->tag == BTOR2_TAG_one) {
terms_[l_->id] = solver_->make_term(1, linesort_);
} else if (l_->tag == BTOR2_TAG_ones) {
terms_[l_->id] =
solver_->make_term(string(linesort_->get_width(), '1'), linesort_, 2);
} else if (l_->tag == BTOR2_TAG_zero) {
terms_[l_->id] = solver_->make_term(0, linesort_);
} else if (l_->tag == BTOR2_TAG_eq) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to eq");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 != s1) {
if (((sk0 == BV) && (sk1 == BOOL)) || ((sk0 == BOOL) && (sk1 == BV))) {
// cast to bit-vectors
t0 = bool_to_bv(t0);
t1 = bool_to_bv(t1);
sk0 = BV;
sk1 = BV;
} else {
throw PonoException(
"Expecting arguments to eq to have the same sort");
}
}
if (sk0 == BV) {
terms_[l_->id] = solver_->make_term(BVComp, t0, t1);
} else {
terms_[l_->id] = solver_->make_term(Equal, t0, t1);
}
} else if (l_->tag == BTOR2_TAG_neq) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to neq");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 != s1) {
if (((sk0 == BV) && (sk1 == BOOL)) || ((sk0 == BOOL) && (sk1 == BV))) {
// cast to bit-vectors
t0 = bool_to_bv(t0);
t1 = bool_to_bv(t1);
sk0 = BV;
sk1 = BV;
} else {
throw PonoException(
"Expecting arguments to neq to have the same sort");
}
}
if (sk0 == BV) {
terms_[l_->id] =
solver_->make_term(BVNot, solver_->make_term(BVComp, t0, t1));
} else {
terms_[l_->id] = solver_->make_term(Distinct, t0, t1);
}
} else if (l_->tag == BTOR2_TAG_slice) {
terms_[l_->id] = solver_->make_term(Op(Extract, l_->args[1], l_->args[2]),
bool_to_bv(termargs_[0]));
} else if (l_->tag == BTOR2_TAG_sext) {
terms_[l_->id] = solver_->make_term(Op(Sign_Extend, l_->args[1]),
bool_to_bv(termargs_[0]));
} else if (l_->tag == BTOR2_TAG_uext) {
terms_[l_->id] = solver_->make_term(Op(Zero_Extend, l_->args[1]),
bool_to_bv(termargs_[0]));
} else if (l_->tag == BTOR2_TAG_rol) {
terms_[l_->id] = solver_->make_term(Op(Rotate_Left, l_->args[1]),
bool_to_bv(termargs_[0]));
} else if (l_->tag == BTOR2_TAG_ror) {
terms_[l_->id] = solver_->make_term(Op(Rotate_Right, l_->args[1]),
bool_to_bv(termargs_[0]));
} else if (l_->tag == BTOR2_TAG_inc) {
Term t = bool_to_bv(termargs_[0]);
terms_[l_->id] =
solver_->make_term(BVAdd, t, solver_->make_term(1, t->get_sort()));
} else if (l_->tag == BTOR2_TAG_dec) {
Term t = bool_to_bv(termargs_[0]);
terms_[l_->id] =
solver_->make_term(BVSub, t, solver_->make_term(1, t->get_sort()));
} else if (l_->tag == BTOR2_TAG_implies) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to implies");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 != s1) {
if (((sk0 == BV) && (sk1 == BOOL)) || ((sk0 == BOOL) && (sk1 == BV))) {
// cast to bools
t0 = bv_to_bool(t0);
t1 = bv_to_bool(t1);
sk0 = BOOL;
sk1 = BOOL;
} else {
throw PonoException(
"Expecting arguments to implies to have the same sort");
}
}
if (sk0 == BV) {
terms_[l_->id] =
solver_->make_term(BVOr, solver_->make_term(BVNot, t0), t1);
} else {
terms_[l_->id] = solver_->make_term(Implies, t0, t1);
}
} else if (l_->tag == BTOR2_TAG_redand) {
Term t = bool_to_bv(termargs_[0]);
Term ones = solver_->make_term(
std::string(t->get_sort()->get_width(), '1'), t->get_sort(), 2);
terms_[l_->id] = solver_->make_term(BVComp, t, ones);
} else if (l_->tag == BTOR2_TAG_redor) {
Term t = bool_to_bv(termargs_[0]);
Term zero = solver_->make_term(0, t->get_sort());
terms_[l_->id] = solver_->make_term(Distinct, t, zero);
} else if (l_->tag == BTOR2_TAG_redxor) {
Term t = bool_to_bv(termargs_[0]);
unsigned int width = t->get_sort()->get_width();
Term res = solver_->make_term(Op(Extract, width - 1, width - 1), t);
for (int i = width - 2; i >= 0; i--) {
res = solver_->make_term(
BVXor, res, solver_->make_term(Op(Extract, i, i), t));
}
terms_[l_->id] = res;
} else if (l_->tag == BTOR2_TAG_ite) {
Term cond = bv_to_bool(termargs_[0]);
// Always cast to bit-vectors because mathsat doesn't support ite over
// bools
Term t1 = bool_to_bv(termargs_[1]);
Term t2 = bool_to_bv(termargs_[2]);
terms_[l_->id] = solver_->make_term(Ite, cond, t1, t2);
} else if (l_->tag == BTOR2_TAG_uaddo) {
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int orig_width = t0->get_sort()->get_width();
t0 = solver_->make_term(Op(Zero_Extend, 1), t0);
t1 = solver_->make_term(Op(Zero_Extend, 1), t1);
Term sum = solver_->make_term(BVAdd, t0, t1);
// overflow occurs if there's a carry out bit
terms_[l_->id] =
solver_->make_term(Op(Extract, orig_width, orig_width), sum);
} else if (l_->tag == BTOR2_TAG_saddo) {
// From https://www.doc.ic.ac.uk/~eedwards/compsys/arithmetic/index.html
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int width = t0->get_sort()->get_width();
Term sum = solver_->make_term(BVAdd, t0, t1);
// overflow occurs if
// both operands are positive and the result is negative or
// both operands are negative and the result is positive
Term t0_top = solver_->make_term(Op(Extract, width - 1, width - 1), t0);
Term t1_top = solver_->make_term(Op(Extract, width - 1, width - 1), t1);
Term sum_top = solver_->make_term(Op(Extract, width - 1, width - 1), sum);
terms_[l_->id] =
solver_->make_term(Equal,
solver_->make_term(Equal, t0_top, t1_top),
solver_->make_term(Distinct, t0_top, sum_top));
} else if (l_->tag == BTOR2_TAG_sdivo) {
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int width = t0->get_sort()->get_width();
Sort sort = solver_->make_sort(BV, width);
Term sum = solver_->make_term(BVAdd, t0, t1);
// overflow occurs if
// t0 is int_min (e.g. 1 followed by zeros) and
// t1 is -1
std::string sint_min("1");
sint_min += std::string(width - 1, '0');
std::string snegone = std::string(width, '1');
Term int_min = solver_->make_term(sint_min, sort, 2);
Term negone = solver_->make_term(snegone, sort, 2);
terms_[l_->id] =
solver_->make_term(And,
solver_->make_term(Equal, t0, int_min),
solver_->make_term(Equal, t1, negone));
} else if (l_->tag == BTOR2_TAG_umulo) {
// from Hacker's Delight
// overflow if hi(x*y) != 0
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int orig_width = t0->get_sort()->get_width();
t0 = solver_->make_term(Op(Zero_Extend, orig_width), t0);
t1 = solver_->make_term(Op(Zero_Extend, orig_width), t1);
Term prod = solver_->make_term(BVMul, t0, t1);
// overflow occurs if the upper bits are non-zero
terms_[l_->id] = solver_->make_term(
Distinct,
solver_->make_term(Op(Extract, 2 * orig_width - 1, orig_width), prod),
solver_->make_term(0, solver_->make_sort(BV, orig_width)));
} else if (l_->tag == BTOR2_TAG_smulo) {
// from Hacker's Delight
// overflow if hi(x*y) != (lo(x*y) >>s (width-1))
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int orig_width = t0->get_sort()->get_width();
t0 = solver_->make_term(Op(Zero_Extend, orig_width), t0);
t1 = solver_->make_term(Op(Zero_Extend, orig_width), t1);
Term prod = solver_->make_term(BVMul, t0, t1);
Term hi =
solver_->make_term(Op(Extract, 2 * orig_width - 1, orig_width), prod);
Term lo = solver_->make_term(Op(Extract, orig_width - 1, 0), prod);
terms_[l_->id] = solver_->make_term(
Distinct,
hi,
solver_->make_term(
BVAshr,
lo,
solver_->make_term(orig_width - 1,
solver_->make_sort(BV, orig_width))));
} else if (l_->tag == BTOR2_TAG_usubo) {
// From
// https://github.com/Boolector/boolector/blob/cd757d099433d95ffdb2a839504b220eff18ee51/src/btorexp.c#L1236
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
unsigned int width = t0->get_sort()->get_width();
Sort sort = solver_->make_sort(BV, width + 1);
t0 = solver_->make_term(Op(Zero_Extend, 1), t0);
t1 = solver_->make_term(Op(Zero_Extend, 1), t1);
Term one = solver_->make_term(1, sort);
Term add1 = solver_->make_term(BVAdd, t1, one);
Term add2 = solver_->make_term(BVAdd, t0, add1);
terms_[l_->id] = solver_->make_term(
BVNot, solver_->make_term(Op(Extract, width, width), add2));
} else if (l_->tag == BTOR2_TAG_ssubo) {
// From https://www.doc.ic.ac.uk/~eedwards/compsys/arithmetic/index.html
// overflow occurs if signs are different and subtrahend sign matches
// result sign
// TODO: check this, not sure if it can overflow when signs aren't
// different
// seems like maybe not but should double check
Term t0 = bool_to_bv(termargs_[0]);
Term t1 = bool_to_bv(termargs_[1]);
int width = t0->get_sort()->get_width();
Term diff = solver_->make_term(BVSub, t0, t1);
Term t0_top = solver_->make_term(Op(Extract, width - 1, width - 1), t0);
Term t1_top = solver_->make_term(Op(Extract, width - 1, width - 1), t1);
Term diff_top =
solver_->make_term(Op(Extract, width - 1, width - 1), diff);
terms_[l_->id] =
solver_->make_term(And,
solver_->make_term(Distinct, t0_top, t1_top),
solver_->make_term(Equal, t1_top, diff_top));
} else if (l_->tag == BTOR2_TAG_read) {
Term arr = termargs_[0];
Term idx = bool_to_bv(termargs_[1]);
terms_[l_->id] = solver_->make_term(Select, arr, idx);
} else if (l_->tag == BTOR2_TAG_write) {
Term arr = termargs_[0];
Term idx = bool_to_bv(termargs_[1]);
Term elem = bool_to_bv(termargs_[2]);
terms_[l_->id] = solver_->make_term(Store, arr, idx, elem);
}
/******************************** Handle general case
********************************/
else {
if (!termargs_.size()) {
throw PonoException("Expecting non-zero number of terms");
}
if (boolopmap.find(l_->tag) != boolopmap.end()) {
// TODO: potentially remove this, have to treat specially for boolector
// vs other solvers anyway
if (bvopmap.find(l_->tag) == bvopmap.end()) {
// only a boolean op
// convert all to bools
for (size_t i = 0; i < termargs_.size(); i++) {
termargs_[i] = bv_to_bool(termargs_[i]);
}
} else {
termargs_ = lazy_convert(termargs_);
}
SortKind sk = termargs_[0]->get_sort()->get_sort_kind();
if (sk == BV) {
terms_[l_->id] = solver_->make_term(bvopmap.at(l_->tag), termargs_);
} else if (sk == BOOL) {
terms_[l_->id] = solver_->make_term(boolopmap.at(l_->tag), termargs_);
} else {
throw PonoException("Unexpected sort");
}
} else {
for (int i = 0; i < termargs_.size(); i++) {
termargs_[i] = bool_to_bv(termargs_[i]);
}
terms_[l_->id] = solver_->make_term(bvopmap.at(l_->tag), termargs_);
}
}
// use the symbol to name the term (if applicable)
// input, output, and state already named
if (l_->symbol && l_->tag != BTOR2_TAG_input && l_->tag != BTOR2_TAG_output
&& l_->tag != BTOR2_TAG_state && terms_.find(l_->id) != terms_.end()) {
try {
ts_.name_term(l_->symbol, terms_.at(l_->id));
}
catch (PonoException &e) {
logger.log(1, "BTOR2Encoder Warning: {}", e.what());
}
}
// sort tag should be the only one that doesn't populate terms_
assert(l_->tag == BTOR2_TAG_sort || terms_.find(l_->id) != terms_.end());
}
fclose(input_file);
btor2parser_delete(reader_);
}
void BTOR2Encoder::parse_without_constraint(const std::string &filename) {
FILE *input_file = fopen(filename.c_str(), "r");
if (!input_file) {
throw PonoException("Could not open " + filename);
}
reader_ = btor2parser_new();
if (!btor2parser_read_lines(reader_, input_file)) {
throw PonoException(std::string(btor2parser_error(reader_)));
}
uint64_t num_states = 0;
std::unordered_map < int64_t, uint64_t > id2statenum;
it_ = btor2parser_iter_init(reader_);
while ((l_ = btor2parser_iter_next(&it_))) {
/******************************** Identify sort
* ********************************/
if (l_->tag != BTOR2_TAG_sort && l_->sort.id) {
linesort_ = sorts_.at(l_->sort.id);
}
/******************************** Gather term arguments
* ********************************/
termargs_.clear();
termargs_.reserve(l_->nargs);
for (i_ = 0; i_ < l_->nargs; i_++) {
negated_ = false;
idx_ = l_->args[i_];
if (idx_ < 0) {
negated_ = true;
idx_ = -idx_;
}
if (terms_.find(idx_) == terms_.end()) {
throw PonoException("Missing term for id " + std::to_string(idx_));
}
Term term_ = terms_.at(idx_);
if (negated_) {
if (term_->get_sort()->get_sort_kind() == BV) {
term_ = solver_->make_term(BVNot, term_);
} else {
term_ = solver_->make_term(Not, term_);
}
}
termargs_.push_back(term_);
}
/******************************** Handle special cases
* ********************************/
if (l_->tag == BTOR2_TAG_state) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
auto renaming_lookup_pos = state_renaming_table.find(l_->id);
if (renaming_lookup_pos != state_renaming_table.end())
symbol_ = renaming_lookup_pos->second;
else
symbol_ = "state" + to_string(l_->id);
}
Term state = ts_.make_statevar(symbol_, linesort_);
terms_[l_->id] = state;
statesvec_.push_back(state);
// will be removed from this map if there's a next function for this state
no_next_states_[num_states] = state;
id2statenum[l_->id] = num_states;
num_states++;
} else if (l_->tag == BTOR2_TAG_input) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
symbol_ = "input" + to_string(l_->id);
}
Term input = ts_.make_inputvar(symbol_, linesort_);
terms_[l_->id] = input;
inputsvec_.push_back(input);
} else if (l_->tag == BTOR2_TAG_output) {
if (l_->symbol) {
symbol_ = l_->symbol;
} else {
symbol_ = "output" + to_string(l_->id);
}
try {
ts_.name_term(symbol_, termargs_[0]);
}
catch (PonoException &e) {
ts_.name_term("_out_" + symbol_, termargs_[0]);
}
terms_[l_->id] = termargs_[0];
} else if (l_->tag == BTOR2_TAG_sort) {
switch (l_->sort.tag) {
case BTOR2_TAG_SORT_bitvec: {
linesort_ = solver_->make_sort(BV, l_->sort.bitvec.width);
sorts_[l_->id] = linesort_;
break;
}
case BTOR2_TAG_SORT_array: {
linesort_ = solver_->make_sort(ARRAY,
sorts_.at(l_->sort.array.index),
sorts_.at(l_->sort.array.element));
sorts_[l_->id] = linesort_;
break;
}
default:
// TODO: maybe only check this in debug? or could always check cause
// it's really bad
throw PonoException("Unknown sort tag");
}
} else if (l_->tag == BTOR2_TAG_constraint) {
Term constraint = bv_to_bool(termargs_[0]);
// BTOR2 allows constraints over inputs
// in Pono these need to be promoted to state variables
UnorderedTermSet free_vars;
get_free_symbolic_consts(constraint, free_vars);
for (const auto &v: free_vars) {
if (ts_.is_input_var(v)) {
ts_.promote_inputvar(v);
}
}
if (ts_.only_curr(constraint)) {
constraints_.push_back(constraint);
} else {
throw PonoException("Constraints over next state variables or input are not supported");
}
terms_[l_->id] = constraint;
} else if (l_->tag == BTOR2_TAG_init) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two term arguments to init");
} else if (linesort_ != termargs_[0]->get_sort()) {
throw PonoException(
"Expecting to init sort to match first argument's sort");
}
Term init_eq;
if (linesort_->get_sort_kind() == BV) {
init_eq = solver_->make_term(Equal, termargs_);
} else if (linesort_->get_sort_kind() == ARRAY) {
if (termargs_[1]->get_sort()->get_sort_kind() == BV) {
init_eq = solver_->make_term(
Equal, termargs_[0], solver_->make_term(termargs_[1], linesort_));
} else {
init_eq = solver_->make_term(Equal, termargs_[0], termargs_[1]);
}
} else {
throw PonoException("Unhandled sort: "
+ termargs_[0]->get_sort()->to_string());
}
ts_.constrain_init(init_eq);
terms_[l_->id] = init_eq;
} else if (l_->tag == BTOR2_TAG_next) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to next");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 == s1) {
ts_.assign_next(t0, t1);
terms_[l_->id] = t1;
} else if (((sk0 == BV) && (sk1 == BOOL))
|| ((sk0 == BOOL) && (sk1 == BV))) {
// need to cast
ts_.assign_next(bool_to_bv(t0), bool_to_bv(t1));
terms_[l_->id] = bool_to_bv(t1);
} else {
throw PonoException("Got two different sorts in next update.");
}
no_next_states_.erase(id2statenum.at(l_->args[0]));
} else if (l_->tag == BTOR2_TAG_bad) {
Term bad = bv_to_bool(termargs_[0]);
Term prop = solver_->make_term(Not, bad);
propvec_.push_back(prop);
terms_[l_->id] = prop;
} else if (l_->tag == BTOR2_TAG_justice) {
std::cout << "Warning: ignoring justice term" << std::endl;
justicevec_.push_back(termargs_[0]);
terms_[l_->id] = termargs_[0];
} else if (l_->tag == BTOR2_TAG_fair) {
std::cout << "Warning: ignoring fair term" << std::endl;
fairvec_.push_back(termargs_[0]);
terms_[l_->id] = termargs_[0];
} else if (l_->constant) {
terms_[l_->id] =
solver_->make_term(l_->constant, linesort_, basemap.at(l_->tag));
} else if (l_->tag == BTOR2_TAG_one) {
terms_[l_->id] = solver_->make_term(1, linesort_);
} else if (l_->tag == BTOR2_TAG_ones) {
terms_[l_->id] =
solver_->make_term(string(linesort_->get_width(), '1'), linesort_, 2);
} else if (l_->tag == BTOR2_TAG_zero) {
terms_[l_->id] = solver_->make_term(0, linesort_);
} else if (l_->tag == BTOR2_TAG_eq) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to eq");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();
SortKind sk1 = s1->get_sort_kind();
if (s0 != s1) {
if (((sk0 == BV) && (sk1 == BOOL)) || ((sk0 == BOOL) && (sk1 == BV))) {
// cast to bit-vectors
t0 = bool_to_bv(t0);
t1 = bool_to_bv(t1);
sk0 = BV;
sk1 = BV;
} else {
throw PonoException(
"Expecting arguments to eq to have the same sort");
}
}
if (sk0 == BV) {
terms_[l_->id] = solver_->make_term(BVComp, t0, t1);
} else {
terms_[l_->id] = solver_->make_term(Equal, t0, t1);
}
} else if (l_->tag == BTOR2_TAG_neq) {
if (termargs_.size() != 2) {
throw PonoException("Expecting two arguments to neq");
}
Term t0 = termargs_[0];
Term t1 = termargs_[1];
Sort s0 = t0->get_sort();
Sort s1 = t1->get_sort();
SortKind sk0 = s0->get_sort_kind();