fix user push/pop with ba constraints

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

src/sat/ba_solver.cpp

@@ -64,6 +64,13 @@ namespace sat {
         return static_cast<xr const&>(*this);
     }
 
+    unsigned ba_solver::constraint::fold_max_var(unsigned w) const {
+        if (lit() != null_literal) w = std::max(w, lit().var());
+        for (unsigned i = 0; i < size(); ++i) w = std::max(w, get_lit(i).var());
+        return w;
+    }
+
+
     std::ostream& operator<<(std::ostream& out, ba_solver::constraint const& cnstr) {
         if (cnstr.lit() != null_literal) out << cnstr.lit() << " == ";
         switch (cnstr.tag()) {
@@ -2661,6 +2668,16 @@ namespace sat {
         c.set_psm(r);
     }
     
+    unsigned ba_solver::max_var(unsigned w) const {
+        for (constraint* cp : m_constraints) {
+            w = cp->fold_max_var(w);
+        }
+        for (constraint* cp : m_learned) {
+            w = cp->fold_max_var(w);
+        }
+        return w;
+    }
+
     void ba_solver::gc() {
         if (m_learned.size() >= 2 * m_constraints.size() && 
             (s().at_search_lvl() || s().at_base_lvl())) {

src/sat/ba_solver.h

@@ -101,6 +101,7 @@ namespace sat {
             bool is_clear() const { return m_watch == null_literal && m_lit != null_literal; }
             bool is_pure() const { return m_pure; }
             void set_pure() { m_pure = true; }
+            unsigned fold_max_var(unsigned w) const;
 
             size_t obj_size() const { return m_obj_size; }
             card& to_card();
@@ -552,6 +553,7 @@ namespace sat {
         void find_mutexes(literal_vector& lits, vector<literal_vector> & mutexes) override;
         void pop_reinit() override;
         void gc() override;
+        unsigned max_var(unsigned w) const override;
         double get_reward(literal l, ext_justification_idx idx, literal_occs_fun& occs) const override;
         bool is_extended_binary(ext_justification_idx idx, literal_vector & r) override;
         void init_use_list(ext_use_list& ul) override;

src/sat/sat_extension.h

@@ -80,6 +80,7 @@ namespace sat {
         virtual void init_use_list(ext_use_list& ul) = 0;
         virtual bool is_blocked(literal l, ext_constraint_idx) = 0;
         virtual bool check_model(model const& m) const = 0;
+        virtual unsigned max_var(unsigned w) const = 0;
     };
 
 };

src/sat/sat_solver.cpp

@@ -3274,17 +3274,19 @@ namespace sat {
     }
 
     void solver::gc_var(bool_var v) {
-        if (v > 0) {
+        bool_var w = max_var(m_learned, v);
-            bool_var w = max_var(m_learned, v-1);
         w = max_var(m_clauses, w);
         w = max_var(true, w);
         w = max_var(false, w);
         v = m_mc.max_var(w);
         for (literal lit : m_trail) {
-                if (lit.var() > w) w = lit.var();
+            w = std::max(w, lit.var());
         }
-            v = std::max(v, w + 1);
+        if (m_ext) {
+            w = m_ext->max_var(w);
         }
+        v = w + 1;
+        
         // v is an index of a variable that does not occur in solver state.
         if (v < m_level.size()) {
             for (bool_var i = v; i < m_level.size(); ++i) {

src/sat/sat_solver.h

@@ -543,6 +543,7 @@ namespace sat {
         void user_push();
         void user_pop(unsigned num_scopes);
         void pop_to_base_level();
+        unsigned num_user_scopes() const { return m_user_scope_literals.size(); }
         reslimit& rlimit() { return m_rlimit; }
         // -----------------------
         //

src/sat/tactic/goal2sat.cpp

@@ -444,13 +444,24 @@ struct goal2sat::imp {
         convert_to_wlits(t, lits, wlits);        
     }
 
+    void push_result(bool root, sat::literal lit, unsigned num_args) {
+        if (root) {
+            m_result_stack.reset();
+            mk_clause(lit);                
+        }
+        else {
+            m_result_stack.shrink(m_result_stack.size() - num_args);
+            m_result_stack.push_back(lit);
+        }
+    }
+
     void convert_pb_ge(app* t, bool root, bool sign) {
         rational k = pb.get_k(t);
         check_unsigned(k);                
         svector<wliteral> wlits;
         convert_pb_args(t, wlits);
         unsigned sz = m_result_stack.size();
-        if (root) {
+        if (root && m_solver.num_user_scopes() == 0) {
             m_result_stack.reset();
             unsigned k1 = k.get_unsigned();
             if (sign) {
@@ -467,8 +478,7 @@ struct goal2sat::imp {
             sat::literal lit(v, sign);
             m_ext->add_pb_ge(v, wlits, k.get_unsigned());
             TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
-            m_result_stack.shrink(sz - t->get_num_args());
+            push_result(root, lit, t->get_num_args());
-            m_result_stack.push_back(lit);
         }
     }
 
@@ -483,7 +493,7 @@ struct goal2sat::imp {
         }
         check_unsigned(k);
         unsigned sz = m_result_stack.size();
-        if (root) {
+        if (root && m_solver.num_user_scopes() == 0) {
             m_result_stack.reset();
             unsigned k1 = k.get_unsigned();
             if (sign) {
@@ -500,19 +510,19 @@ struct goal2sat::imp {
             sat::literal lit(v, sign);
             m_ext->add_pb_ge(v, wlits, k.get_unsigned());
             TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
-            m_result_stack.shrink(sz - t->get_num_args());
+            push_result(root, lit, t->get_num_args());
-            m_result_stack.push_back(lit);
         }
     }
 
     void convert_pb_eq(app* t, bool root, bool sign) {
-        IF_VERBOSE(0, verbose_stream() << "pbeq: " << mk_pp(t, m) << "\n";);
+        //IF_VERBOSE(0, verbose_stream() << "pbeq: " << mk_pp(t, m) << "\n";);
         rational k = pb.get_k(t);
         SASSERT(k.is_unsigned());
         svector<wliteral> wlits;
         convert_pb_args(t, wlits);
-        sat::bool_var v1 = (root && !sign) ? sat::null_bool_var : m_solver.mk_var(true);
+        bool base_assert = (root && !sign && m_solver.num_user_scopes() == 0);
-        sat::bool_var v2 = (root && !sign) ? sat::null_bool_var : m_solver.mk_var(true);
+        sat::bool_var v1 = base_assert ? sat::null_bool_var : m_solver.mk_var(true);
+        sat::bool_var v2 = base_assert ? sat::null_bool_var : m_solver.mk_var(true);
         m_ext->add_pb_ge(v1, wlits, k.get_unsigned());        
         k.neg();
         for (wliteral& wl : wlits) {
@@ -521,7 +531,7 @@ struct goal2sat::imp {
         }
         check_unsigned(k);
         m_ext->add_pb_ge(v2, wlits, k.get_unsigned());
-        if (root && !sign) {
+        if (base_assert) {
             m_result_stack.reset();
         }
         else {
@@ -532,13 +542,8 @@ struct goal2sat::imp {
             mk_clause(~l, l2);
             mk_clause(~l1, ~l2, l);
             m_cache.insert(t, l);
-            m_result_stack.shrink(m_result_stack.size() - t->get_num_args());
             if (sign) l.neg();
-            m_result_stack.push_back(l);
+            push_result(root, l, t->get_num_args());
-            if (root) {
-                m_result_stack.reset();
-                mk_clause(l);
-            }
         }
     }
 
@@ -547,7 +552,7 @@ struct goal2sat::imp {
         sat::literal_vector lits;
         unsigned sz = m_result_stack.size();
         convert_pb_args(t->get_num_args(), lits);
-        if (root) {
+        if (root && m_solver.num_user_scopes() == 0) {
             m_result_stack.reset();
             m_ext->add_at_least(sat::null_bool_var, lits, k.get_unsigned());
         }
@@ -558,8 +563,7 @@ struct goal2sat::imp {
             m_cache.insert(t, lit);
             if (sign) lit.neg();
             TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
-            m_result_stack.shrink(sz - t->get_num_args());
+            push_result(root, lit, t->get_num_args());
-            m_result_stack.push_back(lit);
         }
     }
 
@@ -571,7 +575,7 @@ struct goal2sat::imp {
         for (sat::literal& l : lits) {
             l.neg();
         }
-        if (root) {
+        if (root && m_solver.num_user_scopes() == 0) {
             m_result_stack.reset();
             m_ext->add_at_least(sat::null_bool_var, lits, lits.size() - k.get_unsigned());
         }
@@ -580,9 +584,8 @@ struct goal2sat::imp {
             sat::literal lit(v, false);
             m_ext->add_at_least(v, lits, lits.size() - k.get_unsigned());
             m_cache.insert(t, lit);
-            m_result_stack.shrink(sz - t->get_num_args());
             if (sign) lit.neg();
-            m_result_stack.push_back(lit);
+            push_result(root, lit, t->get_num_args());
         }        
     }
 
@@ -610,13 +613,8 @@ struct goal2sat::imp {
             mk_clause(~l, l2);
             mk_clause(~l1, ~l2, l);
             m_cache.insert(t, l);
-            m_result_stack.shrink(m_result_stack.size() - t->get_num_args());
             if (sign) l.neg();
-            m_result_stack.push_back(l);
+            push_result(root, l, t->get_num_args());
-            if (root) {
-                mk_clause(l);
-                m_result_stack.reset();
-            }
         }
     }