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working on #5614

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there are some different sources for the performance regression illustrated by the example. The mitigations will be enabled separately:
- m_bv_to_propagate is too expensive
- lp_bound_propagator misses equalities in two different ways:
   - it resets row checks after backtracking even though they could still propagate
   - it misses equalities for fixed rows when the fixed constant value does not correspond to a fixed variable.

FYI @levnach
This commit is contained in:
Nikolaj Bjorner 2021-11-02 14:55:28 -07:00
parent a94e2e62af
commit 87d4ce2659
13 changed files with 422 additions and 385 deletions
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13
src/sat/smt/arith_solver.cpp
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@ -301,26 +301,27 @@ namespace arith {
m_explanation.add_pair(j, v);
}
void solver::add_eq(lpvar u, lpvar v, lp::explanation const& e) {
bool solver::add_eq(lpvar u, lpvar v, lp::explanation const& e, bool is_fixed) {
if (s().inconsistent())
return;
return false;
theory_var uv = lp().local_to_external(u); // variables that are returned should have external representations
theory_var vv = lp().local_to_external(v); // so maybe better to have them already transformed to external form
if (is_equal(uv, vv))
return;
return false;
enode* n1 = var2enode(uv);
enode* n2 = var2enode(vv);
expr* e1 = n1->get_expr();
expr* e2 = n2->get_expr();
if (m.is_ite(e1) || m.is_ite(e2))
return;
if (!is_fixed && !a.is_numeral(e1) && !a.is_numeral(e2) && (m.is_ite(e1) || m.is_ite(e2)))
return false;
if (e1->get_sort() != e2->get_sort())
return;
return false;
reset_evidence();
for (auto ev : e)
set_evidence(ev.ci(), m_core, m_eqs);
auto* jst = euf::th_explain::propagate(*this, m_core, m_eqs, n1, n2);
ctx.propagate(n1, n2, jst->to_index());
return true;
}
bool solver::bound_is_interesting(unsigned vi, lp::lconstraint_kind kind, const rational& bval) const {

2
src/sat/smt/arith_solver.h
View file

@ -450,7 +450,7 @@ namespace arith {
lp::lar_solver& lp() { return *m_solver; }
lp::lar_solver const& lp() const { return *m_solver; }
bool is_equal(theory_var x, theory_var y) const;
void add_eq(lpvar u, lpvar v, lp::explanation const& e);
bool add_eq(lpvar u, lpvar v, lp::explanation const& e, bool is_fixed);
void consume(rational const& v, lp::constraint_index j);
bool bound_is_interesting(unsigned vi, lp::lconstraint_kind kind, const rational& bval) const;
};