add stubs for npn3

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

src/sat/sat_config.cpp

@@ -109,6 +109,7 @@ namespace sat {
         m_cut_aig           = p.cut_aig();
         m_cut_lut           = p.cut_lut();
         m_cut_xor           = p.cut_xor();
+        m_cut_npn3          = p.cut_npn3();
         m_cut_dont_cares    = p.cut_dont_cares();
         m_cut_force         = p.cut_force();
         m_lookahead_simplify = p.lookahead_simplify();

src/sat/sat_config.h

@@ -126,6 +126,7 @@ namespace sat {
         bool               m_cut_aig;
         bool               m_cut_lut;
         bool               m_cut_xor;
+        bool               m_cut_npn3;
         bool               m_cut_dont_cares;
         bool               m_cut_force;
         bool               m_anf_simplify;

src/sat/sat_cut_simplifier.cpp

@@ -19,6 +19,7 @@
 #include "sat/sat_cut_simplifier.h"
 #include "sat/sat_xor_finder.h"
 #include "sat/sat_lut_finder.h"
+#include "sat/sat_npn3_finder.h"
 #include "sat/sat_elim_eqs.h"
 
 namespace sat {
@@ -183,6 +184,7 @@ namespace sat {
         }
 
         clause_vector clauses(s.clauses());
+        if (m_config.m_learned2aig) clauses.append(s.learned());
                
         std::function<void (literal head, literal_vector const& ands)> on_and = 
             [&,this](literal head, literal_vector const& ands) {
@@ -199,10 +201,10 @@ namespace sat {
             aig_finder af(s);
             af.set(on_and);
             af.set(on_ite);
-            if (m_config.m_learned2aig) clauses.append(s.learned());
             af(clauses);        
         }
 
+
         std::function<void (literal_vector const&)> on_xor = 
             [&,this](literal_vector const& xors) {
             SASSERT(xors.size() > 1);
@@ -243,6 +245,23 @@ namespace sat {
             m_aig_cuts.add_node(v, lut, vars.size(), vars.c_ptr());
         };
 
+        if (s.m_config.m_cut_npn3) {
+            npn3_finder nf(s);
+            // TBD: stubs for npn3
+            // question: perhaps just use a LUT interface?
+            // nf.set_on_mux
+            // nf.set_on_maj
+            // nf.set_on_orand
+            // nf.set_on_and
+            // nf.set_on_xor
+            // nf.set_on_andxor
+            // nf.set_on_xorand
+            // nf.set_on_gamble
+            // nf.set_on_onehot
+            // nf.set_on_dot
+            // nf(clauses);
+        }
+
         if (s.m_config.m_cut_lut) {
             lut_finder lf(s);
             lf.set(on_lut);

src/sat/sat_npn3_finder.cpp

@@ -226,7 +226,6 @@ namespace sat {
                 if (c1) c1->mark_used();
                 if (c2) c2->mark_used();
                 if (c3) c3->mark_used();
-                // DEBUG_CODE(validate_if(~x, ~y, z, u, c, c1, c2, c3););
                 m_on_mux(~x, ~y, z, u);
                 return true;
             }
@@ -271,7 +270,6 @@ namespace sat {
                 if (c4) c4->mark_used();
                 if (c5) c5->mark_used();
                 if (c6) c6->mark_used();
-                // DEBUG_CODE(validate_if(~x, ~y, z, u, c, c1, c2, c3););
                 m_on_maj(~x, y, z, u);
                 return true;
             }
@@ -614,51 +612,4 @@ namespace sat {
         filter(clauses);
     }
 
-    void npn3_finder::validate_clause(literal_vector const& clause, vector<literal_vector> const& clauses) {
-        solver vs(s.params(), s.rlimit());
-        for (unsigned i = 0; i < s.num_vars(); ++i) {
-            vs.mk_var();
-        }
-        svector<solver::bin_clause> bins;
-        s.collect_bin_clauses(bins, true, false);
-        for (auto b : bins) {
-            vs.mk_clause(b.first, b.second);
-        }
-        for (auto const& cl : clauses) {
-            vs.mk_clause(cl);
-        }
-        for (literal l : clause) {
-            literal nl = ~l;
-            vs.mk_clause(1, &nl);
-        }
-        lbool r = vs.check();
-        if (r != l_false) {
-            vs.display(verbose_stream());
-            UNREACHABLE();
-        }
-    }
-
-    void npn3_finder::validate_clause(literal x, literal y, literal z, vector<literal_vector> const& clauses) {
-        literal_vector clause;
-        clause.push_back(x);
-        clause.push_back(y);
-        clause.push_back(z);
-        validate_clause(clause, clauses);
-    }
-
-    void npn3_finder::validate_if(literal x, literal c, literal t, literal e, clause const& c0, clause const* c1, clause const* c2, clause const* c3) {
-        IF_VERBOSE(2, verbose_stream() << "validate if: " << x << " == " << c << " ? " << t << " : " << e << "\n");
-        vector<literal_vector> clauses;
-        clauses.push_back(literal_vector(c0.size(), c0.begin()));
-        if (c1) clauses.push_back(literal_vector(c1->size(), c1->begin()));
-        if (c2) clauses.push_back(literal_vector(c2->size(), c2->begin()));
-        if (c3) clauses.push_back(literal_vector(c3->size(), c3->begin()));
-        literal_vector clause;
-        validate_clause(~x, ~c, t, clauses);
-        validate_clause(~x, c, e, clauses);
-        validate_clause(~t, ~c, x, clauses);
-        validate_clause(~e, c, x, clauses);
-    }
-
-
 }

src/sat/sat_npn3_finder.h

@@ -102,7 +102,6 @@ namespace sat {
         void filter(clause_vector& clauses) const;
         void find_npn3(clause_vector& clauses, on_function_t const& on_function, std::function<bool(binary_hash_table_t const&, ternary_hash_table_t const&, literal, literal, literal, clause&)> const& checker);
         void find_mux(clause_vector& clauses);
-        void validate_if(literal x, literal c, literal t, literal e, clause const& c0, clause const* c1, clause const* c2, clause const* c3);
         void find_maj(clause_vector& clauses);
         void find_orand(clause_vector& clauses);
         void find_and(clause_vector& clauses);
@@ -112,8 +111,6 @@ namespace sat {
         void find_gamble(clause_vector& clauses);
         void find_onehot(clause_vector& clauses);
         void find_dot(clause_vector& clauses);
-        void validate_clause(literal x, literal y, literal z, vector<literal_vector> const& clauses);
-        void validate_clause(literal_vector const& clause, vector<literal_vector> const& clauses);
 
 
     public:

src/sat/sat_params.pyg

@@ -79,6 +79,7 @@ def_module_params('sat',
                           ('cut.aig',   BOOL, False, 'extract aigs (and ites) from cluases for cut simplification'),
                           ('cut.lut',   BOOL, False, 'extract luts from clauses for cut simplification'),
                           ('cut.xor',   BOOL, False, 'extract xors from clauses for cut simplification'),
+                          ('cut.npn3',  BOOL, False, 'extract 3 input functions from clauses for cut simplification'),
                           ('cut.dont_cares', BOOL, True, 'integrate dont cares with cuts'),
                           ('cut.force', BOOL, False, 'force redoing cut-enumeration until a fixed-point'),
                           ('lookahead.cube.cutoff', SYMBOL, 'depth', 'cutoff type used to create lookahead cubes: depth, freevars, psat, adaptive_freevars, adaptive_psat'),