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v2 of polysat

This commit is contained in:
Nikolaj Bjorner 2023-12-07 15:53:07 -08:00
parent d0a59f3740
commit 28820c8e0c
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/*++
Copyright (c) 2022 Microsoft Corporation
Module Name:
polysat_model.cpp
Abstract:
PolySAT model generation
Author:
Nikolaj Bjorner (nbjorner) 2022-01-26
--*/
#include "params/bv_rewriter_params.hpp"
#include "sat/smt/polysat_solver.h"
#include "sat/smt/euf_solver.h"
namespace polysat {
euf::theory_var solver::mk_var(euf::enode* n) {
return euf::th_euf_solver::mk_var(n);
}
sat::literal solver::internalize(expr* e, bool sign, bool root) {
force_push();
SASSERT(m.is_bool(e));
if (!visit_rec(m, e, sign, root))
return sat::null_literal;
sat::literal lit = expr2literal(e);
if (sign)
lit.neg();
return lit;
}
void solver::internalize(expr* e) {
force_push();
visit_rec(m, e, false, false);
}
bool solver::visit(expr* e) {
force_push();
if (!is_app(e) || to_app(e)->get_family_id() != get_id()) {
ctx.internalize(e);
return true;
}
m_stack.push_back(sat::eframe(e));
return false;
}
bool solver::visited(expr* e) {
euf::enode* n = expr2enode(e);
return n && n->is_attached_to(get_id());
}
bool solver::post_visit(expr* e, bool sign, bool root) {
euf::enode* n = expr2enode(e);
app* a = to_app(e);
if (visited(e))
return true;
SASSERT(!n || !n->is_attached_to(get_id()));
if (!n)
n = mk_enode(e, false);
SASSERT(!n->is_attached_to(get_id()));
mk_var(n);
SASSERT(n->is_attached_to(get_id()));
internalize_polysat(a);
return true;
}
void solver::internalize_polysat(app* a) {
#define if_unary(F) if (a->get_num_args() == 1) { internalize_unary(a, [&](pdd const& p) { return F(p); }); break; }
switch (a->get_decl_kind()) {
case OP_BMUL: internalize_binary(a, [&](pdd const& p, pdd const& q) { return p * q; }); break;
case OP_BADD: internalize_binary(a, [&](pdd const& p, pdd const& q) { return p + q; }); break;
case OP_BSUB: internalize_binary(a, [&](pdd const& p, pdd const& q) { return p - q; }); break;
case OP_BLSHR: internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.lshr(p, q); }); break;
case OP_BSHL: internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.shl(p, q); }); break;
case OP_BAND: internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.band(p, q); }); break;
case OP_BOR: internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.bor(p, q); }); break;
case OP_BXOR: internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.bxor(p, q); }); break;
case OP_BNAND: if_unary(m_core.bnot); internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.bnand(p, q); }); break;
case OP_BNOR: if_unary(m_core.bnot); internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.bnor(p, q); }); break;
case OP_BXNOR: if_unary(m_core.bnot); internalize_binary(a, [&](pdd const& p, pdd const& q) { return m_core.bxnor(p, q); }); break;
case OP_BNOT: internalize_unary(a, [&](pdd const& p) { return m_core.bnot(p); }); break;
case OP_BNEG: internalize_unary(a, [&](pdd const& p) { return -p; }); break;
case OP_MKBV: internalize_mkbv(a); break;
case OP_BV_NUM: internalize_num(a); break;
case OP_ULEQ: internalize_le<false, false, false>(a); break;
case OP_SLEQ: internalize_le<true, false, false>(a); break;
case OP_UGEQ: internalize_le<false, true, false>(a); break;
case OP_SGEQ: internalize_le<true, true, false>(a); break;
case OP_ULT: internalize_le<false, true, true>(a); break;
case OP_SLT: internalize_le<true, true, true>(a); break;
case OP_UGT: internalize_le<false, false, true>(a); break;
case OP_SGT: internalize_le<true, false, true>(a); break;
case OP_BUMUL_NO_OVFL: internalize_binaryc(a, [&](pdd const& p, pdd const& q) { return m_core.umul_ovfl(p, q); }); break;
case OP_BSMUL_NO_OVFL: internalize_binaryc(a, [&](pdd const& p, pdd const& q) { return m_core.smul_ovfl(p, q); }); break;
case OP_BSMUL_NO_UDFL: internalize_binaryc(a, [&](pdd const& p, pdd const& q) { return m_core.smul_udfl(p, q); }); break;
case OP_BUMUL_OVFL:
case OP_BSMUL_OVFL:
case OP_BSDIV_OVFL:
case OP_BNEG_OVFL:
case OP_BUADD_OVFL:
case OP_BSADD_OVFL:
case OP_BUSUB_OVFL:
case OP_BSSUB_OVFL:
// handled by bv_rewriter for now
UNREACHABLE();
break;
case OP_BUDIV_I: internalize_div_rem_i(a, true); break;
case OP_BUREM_I: internalize_div_rem_i(a, false); break;
case OP_BUDIV: internalize_div_rem(a, true); break;
case OP_BUREM: internalize_div_rem(a, false); break;
case OP_BSDIV0: UNREACHABLE(); break;
case OP_BUDIV0: UNREACHABLE(); break;
case OP_BSREM0: UNREACHABLE(); break;
case OP_BUREM0: UNREACHABLE(); break;
case OP_BSMOD0: UNREACHABLE(); break;
case OP_EXTRACT: internalize_extract(a); break;
case OP_CONCAT: internalize_concat(a); break;
case OP_ZERO_EXT: internalize_par_unary(a, [&](pdd const& p, unsigned sz) { return m_core.zero_ext(p, sz); }); break;
case OP_SIGN_EXT: internalize_par_unary(a, [&](pdd const& p, unsigned sz) { return m_core.sign_ext(p, sz); }); break;
// polysat::solver should also support at least:
case OP_BREDAND: // x == 2^K - 1 unary, return single bit, 1 if all input bits are set.
case OP_BREDOR: // x > 0 unary, return single bit, 1 if at least one input bit is set.
case OP_BCOMP: // x == y binary, return single bit, 1 if the arguments are equal.
case OP_BSDIV:
case OP_BSREM:
case OP_BSMOD:
case OP_BSDIV_I:
case OP_BSREM_I:
case OP_BSMOD_I:
case OP_BASHR:
IF_VERBOSE(0, verbose_stream() << mk_pp(a, m) << "\n");
NOT_IMPLEMENTED_YET();
return;
default:
IF_VERBOSE(0, verbose_stream() << mk_pp(a, m) << "\n");
NOT_IMPLEMENTED_YET();
return;
}
#undef if_unary
}
class solver::mk_atom_trail : public trail {
solver& th;
sat::bool_var m_var;
public:
mk_atom_trail(sat::bool_var v, solver& th) : th(th), m_var(v) {}
void undo() override {
solver::atom* a = th.get_bv2a(m_var);
a->~atom();
th.erase_bv2a(m_var);
}
};
solver::atom* solver::mk_atom(sat::bool_var bv) {
atom* a = get_bv2a(bv);
if (a)
return a;
a = new (get_region()) atom(bv);
insert_bv2a(bv, a);
ctx.push(mk_atom_trail(bv, *this));
return a;
}
void solver::internalize_binaryc(app* e, std::function<polysat::signed_constraint(pdd, pdd)> const& fn) {
auto p = expr2pdd(e->get_arg(0));
auto q = expr2pdd(e->get_arg(1));
auto sc = ~fn(p, q);
sat::literal lit = expr2literal(e);
mk_atom(lit.var())->m_sc = sc;
}
void solver::internalize_div_rem_i(app* e, bool is_div) {
auto p = expr2pdd(e->get_arg(0));
auto q = expr2pdd(e->get_arg(1));
auto [quot, rem] = m_core.quot_rem(p, q);
internalize_set(e, is_div ? quot : rem);
}
void solver::internalize_div_rem(app* e, bool is_div) {
bv_rewriter_params p(s().params());
if (p.hi_div0()) {
internalize_div_rem_i(e, is_div);
return;
}
expr* arg1 = e->get_arg(0);
expr* arg2 = e->get_arg(1);
unsigned sz = bv.get_bv_size(e);
expr_ref zero(bv.mk_numeral(0, sz), m);
sat::literal eqZ = eq_internalize(arg2, zero);
sat::literal eqU = eq_internalize(e, is_div ? bv.mk_bv_udiv0(arg1) : bv.mk_bv_urem0(arg1));
sat::literal eqI = eq_internalize(e, is_div ? bv.mk_bv_udiv_i(arg1, arg2) : bv.mk_bv_urem_i(arg1, arg2));
add_clause(~eqZ, eqU);
add_clause(eqZ, eqI);
ctx.add_aux(~eqZ, eqU);
ctx.add_aux(eqZ, eqI);
}
void solver::internalize_num(app* a) {
rational val;
unsigned sz = 0;
VERIFY(bv.is_numeral(a, val, sz));
auto p = m_core.value(val, sz);
internalize_set(a, p);
}
// TODO - test that internalize works with recursive call on bit2bool
void solver::internalize_mkbv(app* a) {
unsigned i = 0;
for (expr* arg : *a) {
expr_ref b2b(m);
b2b = bv.mk_bit2bool(a, i);
sat::literal bit_i = ctx.internalize(b2b, false, false);
sat::literal lit = expr2literal(arg);
add_equiv(lit, bit_i);
#if 0
ctx.add_aux_equiv(lit, bit_i);
#endif
++i;
}
}
void solver::internalize_extract(app* e) {
unsigned const hi = bv.get_extract_high(e);
unsigned const lo = bv.get_extract_low(e);
auto const src = expr2pdd(e->get_arg(0));
auto const p = m_core.extract(src, hi, lo);
SASSERT_EQ(p.power_of_2(), hi - lo + 1);
internalize_set(e, p);
}
void solver::internalize_concat(app* e) {
SASSERT(bv.is_concat(e));
vector<pdd> args;
for (expr* arg : *e)
args.push_back(expr2pdd(arg));
auto const p = m_core.concat(args.size(), args.data());
internalize_set(e, p);
}
void solver::internalize_par_unary(app* e, std::function<pdd(pdd,unsigned)> const& fn) {
pdd const p = expr2pdd(e->get_arg(0));
unsigned const par = e->get_parameter(0).get_int();
internalize_set(e, fn(p, par));
}
void solver::internalize_binary(app* e, std::function<pdd(pdd, pdd)> const& fn) {
SASSERT(e->get_num_args() >= 1);
auto p = expr2pdd(e->get_arg(0));
for (unsigned i = 1; i < e->get_num_args(); ++i)
p = fn(p, expr2pdd(e->get_arg(i)));
internalize_set(e, p);
}
void solver::internalize_unary(app* e, std::function<pdd(pdd)> const& fn) {
SASSERT(e->get_num_args() == 1);
auto p = expr2pdd(e->get_arg(0));
internalize_set(e, fn(p));
}
template<bool Signed, bool Rev, bool Negated>
void solver::internalize_le(app* e) {
auto p = expr2pdd(e->get_arg(0));
auto q = expr2pdd(e->get_arg(1));
if (Rev)
std::swap(p, q);
auto sc = Signed ? m_core.sle(p, q) : m_core.ule(p, q);
if (Negated)
sc = ~sc;
sat::literal lit = expr2literal(e);
atom* a = mk_atom(lit.var());
a->m_sc = sc;
}
void solver::internalize_bit2bool(atom* a, expr* e, unsigned idx) {
pdd p = expr2pdd(e);
a->m_sc = m_core.bit(p, idx);
}
dd::pdd solver::expr2pdd(expr* e) {
return var2pdd(get_th_var(e));
}
dd::pdd solver::var2pdd(euf::theory_var v) {
if (!m_var2pdd_valid.get(v, false)) {
unsigned bv_size = get_bv_size(v);
pvar pv = m_core.add_var(bv_size);
m_pddvar2var.setx(pv, v, UINT_MAX);
pdd p = m_core.var(pv);
internalize_set(v, p);
return p;
}
return m_var2pdd[v];
}
void solver::apply_sort_cnstr(euf::enode* n, sort* s) {
if (!bv.is_bv(n->get_expr()))
return;
theory_var v = n->get_th_var(get_id());
if (v == euf::null_theory_var)
v = mk_var(n);
var2pdd(v);
}
void solver::internalize_set(expr* e, pdd const& p) {
internalize_set(get_th_var(e), p);
}
void solver::internalize_set(euf::theory_var v, pdd const& p) {
SASSERT_EQ(get_bv_size(v), p.power_of_2());
m_var2pdd.reserve(get_num_vars(), p);
m_var2pdd_valid.reserve(get_num_vars(), false);
ctx.push(set_bitvector_trail(m_var2pdd_valid, v));
#if 0
m_var2pdd[v].reset(p.manager());
#endif
m_var2pdd[v] = p;
}
void solver::eq_internalized(euf::enode* n) {
SASSERT(m.is_eq(n->get_expr()));
}
}