additional robustness check for incremental sat solver core when it recieves interpreted constants, added PB equality to interface and special handling of equalities to adddress performance gap documented in #755

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/sat/sat_solver/inc_sat_solver.cpp

@@ -371,8 +371,18 @@ private:
             return l_undef;
         }
         g = m_subgoals[0];
+        expr_ref_vector atoms(m);
         TRACE("sat", g->display_with_dependencies(tout););
         m_goal2sat(*g, m_params, m_solver, m_map, dep2asm, true);
+        m_goal2sat.get_interpreted_atoms(atoms);
+        if (!atoms.empty()) {
+            std::stringstream strm;
+            strm << "interpreted atoms sent to SAT solver " << atoms;
+            TRACE("sat", std::cout << strm.str() << "\n";);
+            IF_VERBOSE(1, verbose_stream() << strm.str() << "\n";);
+            set_reason_unknown(strm.str().c_str());
+            return l_undef;
+        }
         return l_true;
     }
 

src/sat/tactic/goal2sat.cpp

@@ -59,6 +59,7 @@ struct goal2sat::imp {
     bool                        m_ite_extra;
     unsigned long long          m_max_memory;
     expr_ref_vector             m_trail;
+    expr_ref_vector             m_interpreted_atoms;
     bool                        m_default_external;
     
     imp(ast_manager & _m, params_ref const & p, sat::solver & s, atom2bool_var & map, dep2asm_map& dep2asm, bool default_external):
@@ -67,6 +68,7 @@ struct goal2sat::imp {
         m_map(map),
         m_dep2asm(dep2asm),
         m_trail(m),
+        m_interpreted_atoms(m),
         m_default_external(default_external) {
         updt_params(p);
         m_true = sat::null_bool_var;
@@ -128,6 +130,9 @@ struct goal2sat::imp {
                 m_map.insert(t, v);
                 l = sat::literal(v, sign);
                 TRACE("goal2sat", tout << "new_var: " << v << "\n" << mk_ismt2_pp(t, m) << "\n";);
+                if (ext && !is_uninterp_const(t)) {
+                    m_interpreted_atoms.push_back(t);
+                }
             }
         }
         else {
@@ -474,7 +479,7 @@ bool goal2sat::has_unsupported_bool(goal const & g) {
     return test<unsupported_bool_proc>(g);
 }
 
-goal2sat::goal2sat():m_imp(0) {
+goal2sat::goal2sat():m_imp(0), m_interpreted_atoms(0) {
 }
 
 void goal2sat::collect_param_descrs(param_descrs & r) {
@@ -492,10 +497,20 @@ struct goal2sat::scoped_set_imp {
     }
 };
 
+
 void goal2sat::operator()(goal const & g, params_ref const & p, sat::solver & t, atom2bool_var & m, dep2asm_map& dep2asm, bool default_external) {
     imp proc(g.m(), p, t, m, dep2asm, default_external);
     scoped_set_imp set(this, &proc);
     proc(g);
+    dealloc(m_interpreted_atoms);
+    m_interpreted_atoms = alloc(expr_ref_vector, g.m());
+    m_interpreted_atoms->append(proc.m_interpreted_atoms);
+}
+
+void goal2sat::get_interpreted_atoms(expr_ref_vector& atoms) {
+    if (m_interpreted_atoms) {
+        atoms.append(*m_interpreted_atoms);
+    }
 }
 
 

src/sat/tactic/goal2sat.h

@@ -38,8 +38,11 @@ class goal2sat {
     struct imp;
     imp *  m_imp;
     struct scoped_set_imp;
+    expr_ref_vector* m_interpreted_atoms;
+
 public:
     goal2sat();
+    ~goal2sat() { dealloc(m_interpreted_atoms); }
 
     typedef obj_map<expr, sat::literal> dep2asm_map;
 
@@ -53,12 +56,13 @@ public:
        
        \remark m doesn't need to be empty. the definitions there are 
        reused.
-    
+       
        \warning conversion throws a tactic_exception, if it is interrupted (by set_cancel),
        an unsupported operator is found, or memory consumption limit is reached (set with param :max-memory).
     */
     void operator()(goal const & g, params_ref const & p, sat::solver & t, atom2bool_var & m, dep2asm_map& dep2asm, bool default_external = false);
 
+    void get_interpreted_atoms(expr_ref_vector& atoms);
 
 };