some micro tuning

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

src/sat/sat_aig_cuts.cpp

@@ -61,6 +61,9 @@ namespace sat {
         else if (n.is_var()) {
             SASSERT(!n.sign());
         }
+        else if (n.is_lut()) {
+            augment_lut(id, n, cs);
+        }
         else if (n.is_ite()) {
             augment_ite(id, n, cs);
         }
@@ -97,6 +100,47 @@ namespace sat {
         return true;
     }
 
+    void aig_cuts::augment_lut(unsigned v, node const& n, cut_set& cs) {
+        IF_VERBOSE(4, display(verbose_stream() << "augment_lut " << v << " ", n) << "\n");
+        literal l1 = child(n, 0);
+        for (auto const& a : m_cuts[l1.var()]) {
+            m_tables[0] = &a;
+            cut b(a);
+            augment_lut_rec(v, n, b, 1, cs);            
+        }
+    }
+
+    void aig_cuts::augment_lut_rec(unsigned v, node const& n, cut& a, unsigned idx, cut_set& cs) {
+        if (idx < n.size()) {
+            for (auto const& b : m_cuts[child(n, idx).var()]) {
+                cut ab;
+                if (ab.merge(a, b)) {
+                    m_tables[idx] = &b;
+                    augment_lut_rec(v, n, ab, idx + 1, cs);
+                }
+            }
+            return;
+        }
+        for (unsigned i = 0; i < n.size(); ++i) {
+            m_luts[i] = m_tables[i]->shift_table(a);            
+        }
+        uint64_t r = 0;
+        SASSERT(a.size() <= 6);
+        SASSERT(n.size() <= 6);
+        for (unsigned j = (1u << a.size()); j-- > 0; ) {
+            unsigned w = 0;
+            // when computing the output at position j, 
+            // the i'th bit to index into n.lut() is 
+            // based on the j'th output bit in lut[i]
+            for (unsigned i = n.size(); i-- > 0; ) {
+                w |= ((m_luts[i] >> j) & 0x1) << i;
+            }
+            r |= ((n.lut() >> w) & 0x1) << j;
+        } 
+        a.set_table(r);
+        insert_cut(v, a, cs);
+    }
+
     void aig_cuts::augment_ite(unsigned v, node const& n, cut_set& cs) {
         IF_VERBOSE(4, display(verbose_stream() << "augment_ite " << v << " ", n) << "\n");
         literal l1 = child(n, 0);

src/sat/sat_aig_cuts.h

@@ -39,6 +39,7 @@ namespace sat {
         and_op,
         ite_op,
         xor_op,
+        lut_op,
         no_op
     };
 
@@ -48,6 +49,7 @@ namespace sat {
         case and_op: return out << "&";
         case ite_op: return out << "?";
         case xor_op: return out << "^";
+        case lut_op: return out << "#";
         default: return out << "";
         }
     }
@@ -69,6 +71,7 @@ namespace sat {
         class node {
             bool     m_sign;
             bool_op  m_op;
+            uint64_t m_lut;
             unsigned m_size;
             unsigned m_offset;
         public:
@@ -78,17 +81,21 @@ namespace sat {
                 m_sign(false), m_op(var_op), m_size(0), m_offset(v) {}
             explicit node(bool sign, bool_op op, unsigned nc, unsigned o) : 
                 m_sign(sign), m_op(op), m_size(nc), m_offset(o) {}
+            explicit node(uint64_t lut, unsigned nc, unsigned o):
+                m_sign(false), m_op(lut_op), m_size(nc), m_offset(o) {}
             bool is_valid() const { return m_offset != UINT_MAX; }
             bool_op op() const { return m_op; }
             bool is_var() const { return m_op == var_op; }
             bool is_and() const { return m_op == and_op; }
             bool is_xor() const { return m_op == xor_op; }
             bool is_ite() const { return m_op == ite_op; }
+            bool is_lut() const { return m_op == lut_op; }
             bool is_const() const { return is_and() && size() == 0; }
             unsigned var() const { SASSERT(is_var()); return m_offset; }
             bool sign() const { return m_sign; }
             unsigned size() const { return m_size; }
             unsigned offset() const { return m_offset; }
+            uint64_t lut() const { return m_lut; }
         };
         random_gen            m_rand;
         config                m_config;
@@ -106,6 +113,8 @@ namespace sat {
         on_clause_t           m_on_clause_add, m_on_clause_del;
         cut_set::on_update_t  m_on_cut_add, m_on_cut_del;
         literal_vector        m_clause;
+        cut const*            m_tables[6];
+        uint64_t              m_luts[6];
 
         bool is_touched(bool_var v, node const& n);
         bool is_touched(literal lit) const { return is_touched(lit.var()); }
@@ -119,12 +128,15 @@ namespace sat {
         unsigned_vector filter_valid_nodes() const;
         void augment(unsigned_vector const& ids);
         void augment(unsigned id, node const& n);
-        void augment_ite(unsigned v, node const& n, cut_set& cs);
+        void augment_ite(unsigned v,  node const& n, cut_set& cs);
         void augment_aig0(unsigned v, node const& n, cut_set& cs);
         void augment_aig1(unsigned v, node const& n, cut_set& cs);
         void augment_aig2(unsigned v, node const& n, cut_set& cs);
         void augment_aigN(unsigned v, node const& n, cut_set& cs);
 
+        void augment_lut(unsigned v,  node const& n, cut_set& cs);        
+        void augment_lut_rec(unsigned v, node const& n, cut& a, unsigned idx, cut_set& cs);
+
         bool insert_cut(unsigned v, cut const& c, cut_set& cs);
 
         void flush_roots();

src/smt/asserted_formulas.cpp

@@ -277,6 +277,9 @@ void asserted_formulas::reduce() {
     TRACE("macros", m_macro_manager.display(tout););
     flush_cache();
     CASSERT("well_sorted",check_well_sorted());
+
+//    display(std::cout);
+//    exit(0);
 }
 
 

src/smt/smt_context.cpp

@@ -2003,12 +2003,14 @@ namespace smt {
     */
 
     void context::add_lit_occs(clause const& cls) {
+        if (!track_occs()) return;
         for (literal l : cls) {
             inc_ref(l);
         }
     }
 
     void context::remove_lit_occs(clause const& cls, unsigned nbv) {
+        if (!track_occs()) return;
         for (literal l : cls) {
             if (l.var() < static_cast<int>(nbv)) 
                 dec_ref(l);
@@ -2016,9 +2018,9 @@ namespace smt {
     }
 
     // TBD: enable as assertion when ready to re-check
-    void context::dec_ref(literal l) { if (m_lit_occs[l.index()] > 0) m_lit_occs[l.index()]--; }
+    void context::dec_ref(literal l) { if (track_occs() && m_lit_occs[l.index()] > 0) m_lit_occs[l.index()]--; }
 
-    void context::inc_ref(literal l) { m_lit_occs[l.index()]++; }
+    void context::inc_ref(literal l) { if (track_occs()) m_lit_occs[l.index()]++; }
 
     /**
        \brief Delete the given clause.

src/smt/smt_context.h

@@ -839,6 +839,8 @@ namespace smt {
 
         void mk_ite_cnstr(app * n);
 
+        bool track_occs() const { return m_fparams.m_phase_selection == PS_THEORY; }
+        
         void dec_ref(literal l);
 
         void inc_ref(literal l);

src/smt/theory_lra.cpp

@@ -357,7 +357,8 @@ class theory_lra::imp {
     scoped_ptr<lp::lar_solver> m_solver;
     resource_limit         m_resource_limit;
     lp_bounds              m_new_bounds;
-    switcher m_switcher;
+    switcher               m_switcher;
+    symbol                 m_farkas;
 
     context& ctx() const { return th.get_context(); }
     theory_id get_id() const { return th.get_id(); }
@@ -1001,7 +1002,8 @@ public:
         m_model_eqs(DEFAULT_HASHTABLE_INITIAL_CAPACITY, var_value_hash(*this), var_value_eq(*this)),
         m_solver(nullptr),
         m_resource_limit(*this),
-        m_switcher(*this) {
+        m_switcher(*this),
+        m_farkas("farkas") {
     }
         
     ~imp() {
@@ -1911,17 +1913,19 @@ public:
         if (m_idiv_terms.empty()) {
             return true;
         }
-        init_variable_values();
+        // init_variable_values();
         bool all_divs_valid = true;        
         for (expr* n : m_idiv_terms) {
             expr* p = nullptr, *q = nullptr;
             VERIFY(a.is_idiv(n, p, q));
             theory_var v  = mk_var(n);
             theory_var v1 = mk_var(p);
-            rational r1 = get_value(v1);
+            lp::impq r1 = get_ivalue(v1);
+            SASSERT(r1.y.is_zero());
+            SASSERT(r1.x.is_int());
             rational r2;
 
-            if (!r1.is_int() || r1.is_neg()) {
+            if (!r1.x.is_int() || r1.x.is_neg()) {
                 // TBD
                 // r1 = 223/4, r2 = 2, r = 219/8 
                 // take ceil(r1), floor(r1), ceil(r2), floor(r2), for floor(r2) > 0
@@ -1932,15 +1936,17 @@ public:
             }
 
             if (a.is_numeral(q, r2) && r2.is_pos()) {
-                rational val_v = get_value(v);
-                if (val_v == div(r1, r2)) continue;
                 if (!is_bounded(n)) {
                     TRACE("arith", tout << "unbounded " << expr_ref(n, m) << "\n";);
                     continue;
                 }
+                lp::impq val_v = get_ivalue(v);
+                SASSERT(val_v.y.is_zero());
+                SASSERT(val_v.x.is_int());
+                if (val_v.x == div(r1.x, r2)) continue;
             
                 TRACE("arith", tout << get_value(v) << " != " << r1 << " div " << r2 << "\n";);
-                rational div_r = div(r1, r2);
+                rational div_r = div(r1.x, r2);
                 // p <= q * div(r1, q) + q - 1 => div(p, q) <= div(r1, r2)
                 // p >= q * div(r1, q) => div(r1, q) <= div(p, q)
                 rational mul(1);
@@ -2842,7 +2848,7 @@ public:
         m_core.reset();
         m_eqs.reset();
         m_core.push_back(lit1);
-        m_params.push_back(parameter(symbol("farkas")));
+        m_params.push_back(parameter(m_farkas));
         m_params.push_back(parameter(rational(1)));
         m_params.push_back(parameter(rational(1)));
         assign(lit2);