From 3a553e15ac2f6c035bab1bec32c76ca8830ac4d7 Mon Sep 17 00:00:00 2001
From: Alan Mishchenko <alanmi@berkeley.edu>
Date: Tue, 12 Apr 2016 11:58:55 -0700
Subject: Removing unused feature of the SAT solver (native support for
 cardinality constraint).

---
 src/sat/bsat/satSolver.c | 23 ++---------------------
 src/sat/bsat/satSolver.h | 10 ----------
 src/sat/bsat/satUtil.c   |  2 --
 3 files changed, 2 insertions(+), 33 deletions(-)

(limited to 'src/sat')

diff --git a/src/sat/bsat/satSolver.c b/src/sat/bsat/satSolver.c
index 58f2ed21..433f7c5f 100644
--- a/src/sat/bsat/satSolver.c
+++ b/src/sat/bsat/satSolver.c
@@ -508,12 +508,6 @@ static inline int sat_solver_enqueue(sat_solver* s, lit l, int from)
         s->reasons[v] = from;
         s->trail[s->qtail++] = l;
         order_assigned(s, v);
-        // if cardinality clause is present, add positive literals
-        if ( s->cardinality && !lit_sign(l) && s->nCard >= (int)s->cardinality->size )
-        {
-//printf( "setting trail[%d] = %d\n", s->qtail-1, l );
-            s->cardinality->lits[s->nCard - s->cardinality->size++] = lit_neg(l);
-        }
         return true;
     }
 }
@@ -555,13 +549,6 @@ static void sat_solver_canceluntil(sat_solver* s, int level) {
         s->reasons[x] = 0;
         if ( c < lastLev )
             var_set_polar( s, x, !lit_sign(s->trail[c]) );
-        // if cardinality clause is present, remove positive
-        if ( s->cardinality && s->cardinality->lits[s->nCard+1 - s->cardinality->size] == lit_neg(s->trail[c]) )
-        {
-//printf( "undoing trail[%d] = %d\n", c, s->trail[c] );
-            assert( s->cardinality->size > 0 );
-            s->cardinality->size--;
-        }
     }
     //printf( "\n" );
 
@@ -795,7 +782,7 @@ static void sat_solver_analyze(sat_solver* s, int h, veci* learnt)
     lit      p       = lit_Undef;
     int      ind     = s->qtail-1;
     lit*     lits;
-    int      i, j, minl;// int hTemp = h;
+    int      i, j, minl;
     veci_push(learnt,lit_Undef);
     do{
         assert(h != 0);
@@ -810,7 +797,7 @@ static void sat_solver_analyze(sat_solver* s, int h, veci* learnt)
                     veci_push(learnt,clause_read_lit(h));
             }
         }else{
-            clause* c = h == -2 ? s->cardinality : clause_read(s, h);
+            clause* c = clause_read(s, h);
             
             if (clause_learnt(c))
                 act_clause_bump(s,c);
@@ -893,8 +880,6 @@ static void sat_solver_analyze(sat_solver* s, int h, veci* learnt)
         printf(" } at level %d\n", lev);
     }
 #endif
-//    if ( hTemp == -2 )
-//        printf( "%d ", veci_size(learnt) );
 }
 
 //#define TEST_CNF_LOAD
@@ -1200,7 +1185,6 @@ void sat_solver_delete(sat_solver* s)
     }
 
     sat_solver_store_free(s);
-    ABC_FREE(s->cardinality);
     ABC_FREE(s);
 }
 
@@ -1641,8 +1625,6 @@ static lbool sat_solver_search(sat_solver* s, ABC_INT64_T nof_conflicts)
 
     for (;;){
         int hConfl = sat_solver_propagate(s);
-        if ( hConfl == 0 && s->cardinality && (int)s->cardinality->size == s->nCard+1 )
-            hConfl = -2, s->nCardClauses++;
         if (hConfl != 0){
             // CONFLICT
             int blevel;
@@ -1925,7 +1907,6 @@ int sat_solver_solve(sat_solver* s, lit* begin, lit* end, ABC_INT64_T nConfLimit
             fflush(stdout);
         }
         nof_conflicts = (ABC_INT64_T)( 100 * luby(2, restart_iter++) );
-//        assert( s->cardinality->size == 0 );
         status = sat_solver_search(s, nof_conflicts);
 //        nof_learnts    = nof_learnts * 11 / 10; //*= 1.1;
         // quit the loop if reached an external limit
diff --git a/src/sat/bsat/satSolver.h b/src/sat/bsat/satSolver.h
index c7e324cd..e19b0b15 100644
--- a/src/sat/bsat/satSolver.h
+++ b/src/sat/bsat/satSolver.h
@@ -100,9 +100,6 @@ struct sat_solver_t
     int         hLearnts;      // the first learnt clause
     int         hBinary;       // the special binary clause
     clause *    binary;
-    clause *    cardinality;   // cardinality clause
-    int         nCard;         // cardinality size
-    int         nCardClauses;  // cardinality conflicts
     veci*       wlists;        // watcher lists
     veci        act_clas;      // contain clause activities
 
@@ -294,13 +291,6 @@ static inline int sat_solver_count_usedvars(sat_solver* s)
         }
     return nVars;
 }
-static inline void sat_solver_start_cardinality(sat_solver* s, int nSize)
-{
-    assert( s->cardinality == NULL );
-    s->cardinality = (clause*)ABC_CALLOC(int, nSize+2);
-    s->nCard = nSize;
-    s->nCardClauses = 0;
-}
 static void sat_solver_set_polarity(sat_solver* s, int * pVars, int nVars )
 {
     int i;
diff --git a/src/sat/bsat/satUtil.c b/src/sat/bsat/satUtil.c
index 188c308b..f1f03ce2 100644
--- a/src/sat/bsat/satUtil.c
+++ b/src/sat/bsat/satUtil.c
@@ -195,8 +195,6 @@ void Sat_SolverPrintStats( FILE * pFile, sat_solver * p )
 //    printf( "calls         : %10d (%d)\n", (int)p->nCalls, (int)p->nCalls2 );
     printf( "starts        : %16.0f\n", Sat_Wrd2Dbl(p->stats.starts) );
     printf( "conflicts     : %16.0f\n", Sat_Wrd2Dbl(p->stats.conflicts) );
-    if ( p->nCardClauses )
-    printf( "conflictsCard : %16.0f\n", Sat_Wrd2Dbl((word)p->nCardClauses) );
     printf( "decisions     : %16.0f\n", Sat_Wrd2Dbl(p->stats.decisions) );
     printf( "propagations  : %16.0f\n", Sat_Wrd2Dbl(p->stats.propagations) );
 //    printf( "inspects      : %10d\n", (int)p->stats.inspects );
-- 
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