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basic slicing conflict clause

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This commit is contained in:
Jakob Rath 2023-10-24 11:28:49 +02:00
parent 045b5ed683
commit f1b2a504d1
1 changed files with 63 additions and 31 deletions
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94
src/math/polysat/slicing.cpp
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@ -680,6 +680,8 @@ namespace polysat {
clause_ref slicing::build_conflict_clause() {
LOG_H1("slicing: build_conflict_clause");
// display_tree(verbose_stream());
SASSERT(invariant());
SASSERT(is_conflict());
SASSERT(m_marked_lits.empty());
@ -692,10 +694,16 @@ namespace polysat {
cb.insert(~lit);
};
auto add_conclusion = [this, &cb](signed_constraint c) {
LOG("Conclusion: " << lit_pp(m_solver, c));
cb.insert_eval(c);
};
pvar x = null_var; enode* sx = nullptr; sat::literal xlit = sat::null_literal;
pvar y = null_var; enode* sy = nullptr; sat::literal ylit = sat::null_literal;
for (void* dp : m_tmp_deps) {
dep_t const d = dep_t::decode(dp);
// LOG("dep: " << dep_pp(*this, d));
if (d.is_null())
continue;
if (d.is_lit()) {
@ -735,55 +743,79 @@ namespace polysat {
if (y != null_var) LOG("Variable v" << y << " with slice " << slice_pp(*this, sy) << " by literal " << lit_pp(m_solver, ylit));
// conflict has either 0 or 2 vars
SASSERT(x != null_var || y == null_var);
SASSERT(y != null_var || x == null_var);
VERIFY(x != null_var || y == null_var);
VERIFY(y != null_var || x == null_var);
signed_constraint c;
if (xlit != sat::null_literal && ylit != sat::null_literal) {
std::cout << "build_conflict_clause (2)" << std::endl;
verbose_stream() << "build_conflict_clause (2)" << std::endl;
add_premise(xlit);
add_premise(ylit);
}
else if (xlit != sat::null_literal && ylit == sat::null_literal) {
std::cout << "build_conflict_clause (1)" << std::endl;
verbose_stream() << "build_conflict_clause (1)" << std::endl;
add_premise(xlit);
unsigned hi, lo;
VERIFY(find_range_in_ancestor(sy, var2slice(y), hi, lo));
pvar const yy = mk_extract(y, hi, lo);
// rational const x_slice_value = get_value(get_value_node(var2slice(x)));
// LOG("v" << x << " slice_value: " << x_slice_value);
rational const y_slice_value = get_value(get_value_node(var2slice(y)));
LOG("v" << y << " slice_value: " << y_slice_value);
// SASSERT(x_slice_value != y_slice_value);
add_conclusion(~m_solver.eq(m_solver.var(y), y_slice_value));
/*
unsigned x_hi, x_lo;
VERIFY(find_range_in_ancestor(sx, var2slice(x), x_hi, x_lo));
pvar const xx = mk_extract(x, x_hi, x_lo);
LOG("find_range_in_ancestor: v" << x << "[" << x_hi << ":" << x_lo << "] = " << slice_pp(*this, sx) << " --> represented by variable v" << xx);
unsigned y_hi, y_lo;
VERIFY(find_range_in_ancestor(sy, var2slice(y), y_hi, y_lo));
pvar const yy = mk_extract(y, y_hi, y_lo);
LOG("find_range_in_ancestor: v" << y << "[" << y_hi << ":" << y_lo << "] = " << slice_pp(*this, sy) << " --> represented by variable v" << yy);
// LOG("v" << x << " has solver-value? " << m_solver.is_assigned(x));
if (m_solver.is_assigned(x)) LOG("v" << x << " has solver-value " << m_solver.get_value(x));
// LOG("v" << y << " has solver-value? " << m_solver.is_assigned(y));
if (m_solver.is_assigned(y)) LOG("v" << y << " has solver-value " << m_solver.get_value(y));
LOG("v" << x << " is slice " << slice_pp(*this, var2slice(x)));
LOG("v" << y << " is slice " << slice_pp(*this, var2slice(y)));
SASSERT_EQ(sy->get_root(), var2slice(yy)->get_root());
rational const sy_slice_value = get_value(get_value_node(sy));
// rational const sy_solver_value = mod2k(machine_div2k(m_solver.get_value(y), lo), hi - lo + 1);
c = m_solver.eq(m_solver.var(yy), sy_slice_value);
NOT_IMPLEMENTED_YET(); // alert when this branch is taken (TODO: check results)
// c = m_solver.eq(m_solver.var(yy), sy_slice_value);
*/
}
else {
std::cout << "build_conflict_clause (0)" << std::endl;
verbose_stream() << "build_conflict_clause (0)" << std::endl;
SASSERT(xlit == sat::null_literal);
SASSERT(ylit == sat::null_literal);
unsigned x_hi, x_lo, y_hi, y_lo;
VERIFY(find_range_in_ancestor(sx, var2slice(x), x_hi, x_lo));
VERIFY(find_range_in_ancestor(sy, var2slice(y), y_hi, y_lo));
pvar const xx = mk_extract(x, x_hi, x_lo);
pvar const yy = mk_extract(y, y_hi, y_lo);
SASSERT_EQ(sx->get_root(), var2slice(xx)->get_root());
SASSERT_EQ(sy->get_root(), var2slice(yy)->get_root());
rational sval = mod2k(machine_div2k(m_solver.get_value(x), x_lo), x_hi - x_lo + 1);
LOG("find_range_in_ancestor: v" << x << "[" << x_hi << ":" << x_lo << "] = " << slice_pp(*this, sx) << " --> represented by variable v" << xx);
LOG("find_range_in_ancestor: v" << y << "[" << y_hi << ":" << y_lo << "] = " << slice_pp(*this, sy) << " --> represented by variable v" << yy);
SASSERT(xx != yy);
c = m_solver.eq(m_solver.var(xx), m_solver.var(yy)); // similar to what Algorithm 1 in BitvectorsMCSAT is doing
// unsigned x_hi, x_lo, y_hi, y_lo;
// VERIFY(find_range_in_ancestor(sx, var2slice(x), x_hi, x_lo));
// VERIFY(find_range_in_ancestor(sy, var2slice(y), y_hi, y_lo));
// pvar const xx = mk_extract(x, x_hi, x_lo);
// pvar const yy = mk_extract(y, y_hi, y_lo);
// SASSERT_EQ(sx->get_root(), var2slice(xx)->get_root());
// SASSERT_EQ(sy->get_root(), var2slice(yy)->get_root());
// rational sval = mod2k(machine_div2k(m_solver.get_value(x), x_lo), x_hi - x_lo + 1);
// LOG("find_range_in_ancestor: v" << x << "[" << x_hi << ":" << x_lo << "] = " << slice_pp(*this, sx) << " --> represented by variable v" << xx);
// LOG("find_range_in_ancestor: v" << y << "[" << y_hi << ":" << y_lo << "] = " << slice_pp(*this, sy) << " --> represented by variable v" << yy);
LOG("v" << x << " is slice " << slice_pp(*this, var2slice(x)));
LOG("v" << y << " is slice " << slice_pp(*this, var2slice(y)));
if (m_solver.is_assigned(x)) LOG("v" << x << " has solver-value " << m_solver.get_value(x));
if (m_solver.is_assigned(y)) LOG("v" << y << " has solver-value " << m_solver.get_value(y));
// SASSERT(xx != yy);
// c = m_solver.eq(m_solver.var(xx), m_solver.var(yy)); // similar to what Algorithm 1 in BitvectorsMCSAT is doing
// LOG("c: " << lit_pp(m_solver, c));
NOT_IMPLEMENTED_YET(); // alert when this branch is taken (TODO: check results)
rational const x_slice_value = get_value(get_value_node(var2slice(x)));
LOG("v" << x << " slice-value: " << x_slice_value);
add_conclusion(~m_solver.eq(m_solver.var(x), x_slice_value));
rational const y_slice_value = get_value(get_value_node(var2slice(y)));
LOG("v" << y << " slice-value: " << y_slice_value);
add_conclusion(~m_solver.eq(m_solver.var(y), y_slice_value));
}
if (c) {
LOG("Conclusion: " << lit_pp(m_solver, c));
cb.insert_eval(c);
} else {
LOG("Conclusion: <conflict>");
}
// TODO: we don't need clauses like this ... rather set up the conflict core from it
return cb.build();
}