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limit iterations on equality solver based on experimenting with #4178

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This commit is contained in:
Nikolaj Bjorner 2020-05-02 17:10:18 -07:00
parent 37f6364547
commit dc9221e4bd
1 changed files with 28 additions and 39 deletions
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67
src/tactic/core/solve_eqs_tactic.cpp
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@ -173,16 +173,6 @@ class solve_eqs_tactic : public tactic {
return false;
}
#if 0
bool not_bool_eq(expr * f, app_ref & var, expr_ref & def, proof_ref & pr) {
if (!m().is_not(f))
return false;
expr * eq = to_app(f)->get_arg(0);
if (!m().is_eq(f))
return false;
}
#endif
/**
\brief Given t of the form (f s_0 ... s_n),
@ -376,12 +366,7 @@ class solve_eqs_tactic : public tactic {
if (m().is_eq(f, arg1, arg2)) {
return solve_eq(arg1, arg2, f, var, def, pr);
}
#if 0
if (not_bool_eq(f, var, def, pr))
return true;
#endif
if (m_ite_solver && m().is_ite(f))
return solve_ite(to_app(f), var, def, pr);
@ -966,31 +951,25 @@ class solve_eqs_tactic : public tactic {
}
void collect_num_occs(expr * t, expr_fast_mark1 & visited) {
ptr_buffer<expr, 128> stack;
ptr_buffer<app, 128> stack;
#define VISIT(ARG) { \
if (is_uninterp_const(ARG)) { \
m_num_occs.insert_if_not_there(ARG, 0)++; \
} \
if (!visited.is_marked(ARG)) { \
visited.mark(ARG, true); \
stack.push_back(ARG); \
} \
}
auto visit = [&](expr* arg) {
if (is_uninterp_const(arg)) {
m_num_occs.insert_if_not_there(arg, 0)++;
}
if (!visited.is_marked(arg) && is_app(arg)) {
visited.mark(arg, true);
stack.push_back(to_app(arg));
}
};
VISIT(t);
visit(t);
while (!stack.empty()) {
expr * t = stack.back();
app * t = stack.back();
stack.pop_back();
if (!is_app(t))
continue;
unsigned j = to_app(t)->get_num_args();
while (j > 0) {
--j;
expr * arg = to_app(t)->get_arg(j);
VISIT(arg);
}
for (expr* arg : *t)
visit(arg);
}
}
@ -1012,6 +991,12 @@ class solve_eqs_tactic : public tactic {
return m_num_eliminated_vars;
}
//
// TBD: rewrite the tactic to first apply a topological sorting that
// approximates the dependencies between variables. Then apply
// simplification on top of this sorting, so that it can apply sub-quadratic
// equality and unit propagation.
//
void operator()(goal_ref const & g, goal_ref_buffer & result) {
model_converter_ref mc;
tactic_report report("solve_eqs", *g);
@ -1023,13 +1008,15 @@ class solve_eqs_tactic : public tactic {
if (!g->inconsistent()) {
m_subst = alloc(expr_substitution, m(), m_produce_unsat_cores, m_produce_proofs);
m_norm_subst = alloc(expr_substitution, m(), m_produce_unsat_cores, m_produce_proofs);
while (true) {
if (!m_produce_proofs && m_context_solve) {
unsigned rounds = 0;
while (rounds < 20) {
++rounds;
if (!m_produce_proofs && m_context_solve && rounds < 3) {
distribute_and_or(*(g.get()));
}
collect_num_occs(*g);
collect(*g);
if (!m_produce_proofs && m_context_solve) {
if (!m_produce_proofs && m_context_solve && rounds < 3) {
collect_hoist(*g);
}
if (m_subst->empty()) {
@ -1046,6 +1033,8 @@ class solve_eqs_tactic : public tactic {
}
save_elim_vars(mc);
TRACE("solve_eqs_round", g->display(tout); if (mc) mc->display(tout););
if (rounds > 10 && m_ordered_vars.size() == 1)
break;
}
}
g->inc_depth();