fixes to sls

src/ast/sls/sat_ddfw.cpp

@@ -43,7 +43,7 @@ namespace sat {
             check_without_plugin();
         remove_assumptions();
         log();
-        return m_min_sz == 0 ? l_true : l_undef;
+        return m_min_sz == 0 && m_limit.inc()  ? m_last_result : l_undef;
     }
 
     void ddfw::check_without_plugin() {
@@ -401,7 +401,7 @@ namespace sat {
             m_model[i] = to_lbool(value(i));
         save_priorities();
         if (m_plugin)
-            m_plugin->on_save_model();        
+            m_last_result = m_plugin->on_save_model();   
     }
 
     void ddfw::save_best_values() {

src/ast/sls/sat_ddfw.h

@@ -39,7 +39,7 @@ namespace sat {
         //virtual void init_search() = 0;
         //virtual void finish_search() = 0;
         virtual void on_rescale() = 0;
-        virtual void on_save_model() = 0;
+        virtual lbool on_save_model() = 0;
         virtual void on_restart() = 0;
     };
 
@@ -90,6 +90,7 @@ namespace sat {
         unsigned_vector  m_flat_use_list;
         unsigned_vector  m_use_list_index;
         unsigned m_use_list_vars = 0, m_use_list_clauses = 0;
+        lbool                m_last_result = l_true;
 
         indexed_uint_set m_unsat;
         indexed_uint_set m_unsat_vars;  // set of variables that are in unsat clauses

src/ast/sls/sls_arith_base.cpp

@@ -256,9 +256,6 @@ namespace sls {
         num_t eps(1);
         if (!is_int(x) &&  abs(rh - lh) <= eps)
             eps = abs(rh - lh) / num_t(2);
-//        verbose_stream() << a << " " << b << " " << c << "\n";
-//        verbose_stream() << (-b - root) << " " << (2 * a) << " " << ll << " " << lh << "\n";
-//        verbose_stream() << (-b + root) << " " << (2 * a) << " " << rl << " " << rh << "\n";
         SASSERT(ll <= lh && ll + 1 >= lh);
         SASSERT(rl <= rh && rl + 1 >= rh);
         SASSERT(!is_square || ll != lh || a * ll * ll + b * ll + c == 0);
@@ -571,8 +568,6 @@ namespace sls {
     template<typename num_t>
     bool arith_base<num_t>::repair(sat::literal lit) {
 
-        //verbose_stream() << "repair " << lit << " " << (ctx.is_unit(lit)?"unit":"") << " " << mk_bounded_pp(ctx.atom(lit.var()), m) << "\n";
-        //verbose_stream() << *atom(lit.var()) << "\n";
         m_last_literal = lit;
         if (find_nl_moves(lit))
             return true;
@@ -673,8 +668,6 @@ namespace sls {
             return false;
         }
 
-        // IF_VERBOSE(0, display(verbose_stream(), v) << " := " << new_value << "\n");
-
 
 
 #if 0      
@@ -690,7 +683,6 @@ namespace sls {
             SASSERT(ctx.is_true(lit));
             ineq.m_args_value += coeff * (new_value - old_value);
             num_t dtt_new = dtt(old_sign, ineq);
-            // verbose_stream() << "dtt " << lit << " " << ineq << " " << dtt_new << "\n";
             if (dtt_new != 0)
                 ctx.flip(bv);
             SASSERT(dtt(sign(bv), ineq) == 0);
@@ -800,7 +792,6 @@ namespace sls {
                 SASSERT(ctx.is_true(lit));
                 ineq.m_args_value += coeff * (new_value - old_value);
                 num_t dtt_new = dtt(old_sign, ineq);
-                // verbose_stream() << "dtt " << lit << " " << ineq << " " << dtt_new << "\n";
                 if (dtt_new != 0)
                     ctx.flip(bv);
                 SASSERT(dtt(sign(bv), ineq) == 0);
@@ -1006,7 +997,6 @@ namespace sls {
     typename arith_base<num_t>::var_t arith_base<num_t>::mk_var(expr* e) {
         var_t v = m_expr2var.get(e->get_id(), UINT_MAX);
         if (v == UINT_MAX) {
-            // verbose_stream() << "mk-var " << mk_bounded_pp(e, m) << "\n";
             v = m_vars.size();
             m_expr2var.setx(e->get_id(), v, UINT_MAX);
             m_vars.push_back(var_info(e, a.is_int(e) ? var_sort::INT : var_sort::REAL));     
@@ -1245,7 +1235,6 @@ namespace sls {
             return false;
         flet<bool> _tabu(m_use_tabu, false);
         TRACE("sls", tout << "repair def " << mk_bounded_pp(vi.m_expr, m) << "\n");
-        // verbose_stream() << "repair down " << mk_bounded_pp(e, m) << "\n";
         switch (vi.m_op) {
         case arith_op_kind::LAST_ARITH_OP:
             break;
@@ -1522,11 +1511,8 @@ namespace sls {
         if (old_value == sum)
             return true;
 
-        //display(verbose_stream() << "repair add v" << v << " ", ad) << " " << old_value << " sum " << sum << "\n";
 
         m_updates.reset();
-//        display(verbose_stream(), v) << " ";
-//        verbose_stream() << mk_bounded_pp(m_vars[v].m_expr, m) << " := " << old_value << " " << sum << "\n";
 
         for (auto const& [coeff, w] : coeffs) {
             auto delta = divide(w, sum - old_value, coeff);
@@ -1590,8 +1576,6 @@ namespace sls {
             }
         }
 
-        // verbose_stream() << "repair product v" << v << "\n";
-
         if (apply_update())
             return eval_is_correct(v);
 
@@ -1957,7 +1941,6 @@ namespace sls {
                 }
                 else
                     new_value = val;
-                //verbose_stream() << v << " " << vi.m_value << " -> " << new_value << "\n";
                 vi.m_value = new_value;
             }
             else {
@@ -2308,7 +2291,6 @@ namespace sls {
         num_t val = i.m_coeff;
         for (auto const& [c, v] : i.m_args)
             val += c * value(v);
-        //verbose_stream() << "invariant " << i << "\n";
         if (val != i.m_args_value)
             verbose_stream() << i << "\n";
         SASSERT(val == i.m_args_value);

src/ast/sls/sls_smt_plugin.cpp

@@ -156,10 +156,8 @@ namespace sls {
         if (!e)
             return false;
         bv_util bv(m);
-        if (bv.is_bit2bool(e, t) && m_shared_terms.contains(t->get_id())) {
-            verbose_stream() << "shared bit2bool " << mk_bounded_pp(e, ctx.get_manager()) << "\n";
-            return true;
-        }
+        if (bv.is_bit2bool(e, t) && m_shared_terms.contains(t->get_id())) 
+            return true;        
 
         // if arith.is_le(e, s, t) && t is a numeral, s is shared-term....
         return false;
@@ -175,7 +173,6 @@ namespace sls {
     }
 
     void smt_plugin::add_unit(sat::literal lit) {
-        verbose_stream() << "add unit " << lit << " " << is_shared(lit) << "\n";
         if (!is_shared(lit))
             return;
         std::lock_guard<std::mutex> lock(m_mutex);
@@ -222,6 +219,7 @@ namespace sls {
     }
 
     void smt_plugin::smt_phase_to_sls() {
+        IF_VERBOSE(2, verbose_stream() << "SMT -> SLS phase\n");
         for (auto v : m_shared_bool_vars) {
             auto w = m_smt_bool_var2sls_bool_var[v];
             auto phase = ctx.get_best_phase(v);
@@ -232,6 +230,7 @@ namespace sls {
     }
 
     void smt_plugin::smt_values_to_sls() {
+        IF_VERBOSE(2, verbose_stream() << "SMT -> SLS values\n");
         for (auto const& [t, t_sync] : m_smt2sync_uninterp) {
             expr_ref val_t(m);
             if (!ctx.get_smt_value(t, val_t))
@@ -261,7 +260,9 @@ namespace sls {
             if (m_shared_bool_vars.contains(v)) {
                 auto w = m_smt_bool_var2sls_bool_var[v];
                 sat::literal sls_lit(w, lit.sign());
-                IF_VERBOSE(2, verbose_stream() << "unit " << sls_lit << "\n");
+                if (m_context.is_unit(sls_lit))
+                    continue;
+                IF_VERBOSE(3, verbose_stream() << "unit " << sls_lit << "\n");
                 m_ddfw->add(1, &sls_lit);
             }
             else {
@@ -350,15 +351,17 @@ namespace sls {
         m_sls2sync_uninterp.insert(sls_t, sync_t);
     }
 
-    void smt_plugin::on_save_model()  {
+    lbool smt_plugin::on_save_model()  {
         TRACE("sls", display(tout));
+        lbool r = l_true;
         while (unsat().empty()) {
-            m_context.check();
+            r = m_context.check();
             if (!m_new_clause_added)
                 break;
             m_ddfw->reinit();
             m_new_clause_added = false;
         }
         export_from_sls();
+        return r;
     }
 }

src/ast/sls/sls_smt_plugin.h

@@ -124,10 +124,10 @@ namespace sls {
                 m_ddfw->reinit();
         }
 
-        void on_save_model() override;
+        lbool on_save_model() override;
 
         void on_model(model_ref& mdl) override {
-            IF_VERBOSE(3, verbose_stream() << "on-model " << "\n");
+            IF_VERBOSE(2, verbose_stream() << "on-model " << "\n");
             m_sls_model = mdl;
         }
 

src/ast/sls/sls_smt_solver.cpp

@@ -49,24 +49,25 @@ namespace sls {
         }
 
         bool m_on_save_model = false;
-        void on_save_model() override {
+        lbool on_save_model() override {
+            lbool r = l_true;
             if (m_on_save_model)
-                return;
+                return r;
             flet<bool> _on_save_model(m_on_save_model, true);
             CTRACE("sls", unsat().empty(), display(tout));
             while (unsat().empty()) {
-                m_context.check();
+                r = m_context.check();
                 if (!m_new_constraint)
                     break;
                 TRACE("sls", display(tout));
                 //m_ddfw.simplify();
                 m_ddfw.reinit();
                 m_new_constraint = false;
             }
+            return r;
         }
 
-        void on_model(model_ref& mdl) override {
-            IF_VERBOSE(1, verbose_stream() << "on-model " << "\n");
+        void on_model(model_ref& mdl) override {           
             m_model = mdl;
         }
 

src/smt/theory_sls.cpp

@@ -105,10 +105,9 @@ namespace smt {
         if (!m_smt_plugin)
             return;
 
-        unsigned scope_lvl = ctx.get_scope_level();
-        if (ctx.get_search_level() == scope_lvl - n) {
+        if (ctx.get_search_level() == ctx.get_scope_level() - n) {
             auto& lits = ctx.assigned_literals();
-            for (; m_trail_lim < lits.size() && ctx.get_assign_level(lits[m_trail_lim]) == scope_lvl; ++m_trail_lim) 
+            for (; m_trail_lim < lits.size() && ctx.get_assign_level(lits[m_trail_lim]) == ctx.get_search_level(); ++m_trail_lim) 
                 m_smt_plugin->add_unit(lits[m_trail_lim]);            
         }
 
@@ -141,7 +140,8 @@ namespace smt {
             m_threshold *= 2;
             m_smt_plugin->smt_units_to_sls();
             bounded_run(m_restart_ls_steps);
-            m_smt_plugin->sls_activity_to_smt();
+            if (m_smt_plugin)
+                m_smt_plugin->sls_activity_to_smt();
         }
         m_difference_score = 0;
         m_difference_score_threshold = 1;
@@ -170,11 +170,12 @@ namespace smt {
         m_smt_plugin->smt_values_to_sls();
         bounded_run(m_final_check_ls_steps);
         dec_final_check_ls_steps();
-        m_smt_plugin->sls_phase_to_smt();
-        m_smt_plugin->sls_values_to_smt();
-        if (m_num_guided_sls % 20 == 0) 
-            m_smt_plugin->sls_activity_to_smt();
-
+        if (m_smt_plugin) {
+            m_smt_plugin->sls_phase_to_smt();
+            m_smt_plugin->sls_values_to_smt();
+            if (m_num_guided_sls % 20 == 0)
+                m_smt_plugin->sls_activity_to_smt();
+        }
         return FC_DONE;
     }
 

src/smt/theory_sls.h

@@ -56,7 +56,6 @@ namespace smt {
         bool m_checking = false;
         bool m_parallel_mode = true;
         unsigned m_threshold = 1;
-        unsigned m_restart_sls_count = 0;
         unsigned m_difference_score = 0;
         unsigned m_difference_score_threshold = 0;
         unsigned m_num_guided_sls = 0;