From b09926e8e26de8df20a3973a3c9a1c63b06952cb Mon Sep 17 00:00:00 2001
From: Alan Mishchenko <alanmi@berkeley.edu>
Date: Sun, 28 Apr 2013 01:25:29 -0700
Subject: SAT sweeping under constraints.

---
 src/proof/ssc/ssc.h     |   1 +
 src/proof/ssc/sscCore.c |   5 +++
 src/proof/ssc/sscSat.c  |   2 +-
 src/proof/ssc/sscUtil.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 120 insertions(+), 1 deletion(-)

(limited to 'src/proof')

diff --git a/src/proof/ssc/ssc.h b/src/proof/ssc/ssc.h
index de32ffc1..1112719c 100644
--- a/src/proof/ssc/ssc.h
+++ b/src/proof/ssc/ssc.h
@@ -47,6 +47,7 @@ struct Ssc_Pars_t_
     int              nBTLimit;      // conflict limit at a node
     int              nSatVarMax;    // the max number of SAT variables
     int              nCallsRecycle; // calls to perform before recycling SAT solver
+    int              fAppend;       // append constraints to the resulting AIG
     int              fVerbose;      // verbose stats
 };
 
diff --git a/src/proof/ssc/sscCore.c b/src/proof/ssc/sscCore.c
index 00491e31..b29a0193 100644
--- a/src/proof/ssc/sscCore.c
+++ b/src/proof/ssc/sscCore.c
@@ -313,6 +313,11 @@ Gia_Man_t * Ssc_PerformSweepingConstr( Gia_Man_t * p, Ssc_Pars_t * pPars )
     pAig = Gia_ManDupLevelized( pResult = pAig );
     Gia_ManStop( pResult );
     pResult = Ssc_PerformSweeping( pAig, pCare, pPars );
+    if ( pPars->fAppend )
+    {
+        Gia_ManDupAppendShare( pResult, pCare );
+        pResult->nConstrs = Gia_ManPoNum(pCare);
+    }
     Gia_ManStop( pAig );
     Gia_ManStop( pCare );
     return pResult;
diff --git a/src/proof/ssc/sscSat.c b/src/proof/ssc/sscSat.c
index f6d5e9af..1de99c2e 100644
--- a/src/proof/ssc/sscSat.c
+++ b/src/proof/ssc/sscSat.c
@@ -260,7 +260,7 @@ p->timeCnfGen += clock() - clk;
 ***********************************************************************/
 void Ssc_ManStartSolver( Ssc_Man_t * p )
 {
-    Aig_Man_t * pMan = Gia_ManToAig( p->pFraig, 0 );
+    Aig_Man_t * pMan = Gia_ManToAigSimple( p->pFraig );
     Cnf_Dat_t * pDat = Cnf_Derive( pMan, 0 );
     Gia_Obj_t * pObj;
     sat_solver * pSat;
diff --git a/src/proof/ssc/sscUtil.c b/src/proof/ssc/sscUtil.c
index 21d78f85..c4edaba6 100644
--- a/src/proof/ssc/sscUtil.c
+++ b/src/proof/ssc/sscUtil.c
@@ -19,6 +19,8 @@
 ***********************************************************************/
 
 #include "sscInt.h"
+#include "sat/cnf/cnf.h"
+#include "aig/gia/giaAig.h"
 
 ABC_NAMESPACE_IMPL_START
 
@@ -42,6 +44,117 @@ ABC_NAMESPACE_IMPL_START
   SeeAlso     []
 
 ***********************************************************************/
+Gia_Man_t * Gia_ManDropContained( Gia_Man_t * p )
+{
+    Gia_Man_t * pNew;
+    Aig_Man_t * pMan = Gia_ManToAigSimple( p );
+    Cnf_Dat_t * pDat = Cnf_Derive( pMan, Gia_ManPoNum(p) );
+    Gia_Obj_t * pObj;
+    Vec_Int_t * vLits, * vKeep;
+    sat_solver * pSat;
+    int i, status, Count = 0;
+    Aig_ManStop( pMan );
+
+    vLits = Vec_IntAlloc( Gia_ManPoNum(p) );
+    Gia_ManForEachPo( p, pObj, i )
+    {
+        int iObj = Gia_ObjId( p, pObj );
+        Vec_IntPush( vLits, Abc_Var2Lit(pDat->pVarNums[iObj], 1) );
+    }
+
+    // start the SAT solver
+    pSat = sat_solver_new();
+    sat_solver_setnvars( pSat, pDat->nVars );
+    for ( i = 0; i < pDat->nClauses; i++ )
+    {
+        if ( !sat_solver_addclause( pSat, pDat->pClauses[i], pDat->pClauses[i+1] ) )
+        {
+            Cnf_DataFree( pDat );
+            sat_solver_delete( pSat );
+            Vec_IntFree( vLits );
+            return NULL;
+        }
+    }
+    status = sat_solver_simplify( pSat );
+    if ( status == 0 )
+    {
+        Cnf_DataFree( pDat );
+        sat_solver_delete( pSat );
+        Vec_IntFree( vLits );
+        return NULL;
+    }
+
+    // iterate over POs
+    vKeep = Vec_IntAlloc( Gia_ManPoNum(p) );
+    Gia_ManForEachPo( p, pObj, i )
+    {
+        Vec_IntWriteEntry( vLits, i, Abc_LitNot(Vec_IntEntry(vLits,i)) );
+        status = sat_solver_solve( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits), 0, 0, 0, 0 );
+        Vec_IntWriteEntry( vLits, i, Abc_LitNot(Vec_IntEntry(vLits,i)) );
+        if ( status == l_False )
+            Vec_IntWriteEntry( vLits, i, Abc_Var2Lit(pDat->pVarNums[0], 0) ); // const1 SAT var is always true
+        else 
+        {
+            assert( status = l_True );
+            Vec_IntPush( vKeep, i );
+        }
+    }
+    Cnf_DataFree( pDat );
+    sat_solver_delete( pSat );
+    Vec_IntFree( vLits );
+
+    if ( Vec_IntSize(vKeep) == Gia_ManPoNum(p) )
+    {
+        Vec_IntFree( vKeep );
+        return Gia_ManDup(p);
+    }
+    pNew = Gia_ManDupCones( p, Vec_IntArray(vKeep), Vec_IntSize(vKeep), 0 );
+    Vec_IntFree( vKeep );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_ManOptimizeRing( Gia_Man_t * p )
+{
+    Ssc_Pars_t Pars, * pPars = &Pars;
+    Gia_Man_t * pTemp, * pAux;
+    int i;
+    assert( p->nConstrs == 0 );
+    printf( "User AIG: " );
+    Gia_ManPrintStats( p, 0, 0, 0 );
+    pTemp = Gia_ManDropContained( p );
+    printf( "Drop AIG: " );
+    Gia_ManPrintStats( pTemp, 0, 0, 0 );
+//    return pTemp;
+    if ( Gia_ManPoNum(pTemp) == 1 )
+        return pTemp;
+    Ssc_ManSetDefaultParams( pPars );
+    pPars->fAppend  = 1;
+    pPars->fVerbose = 1;
+    pTemp->nConstrs = Gia_ManPoNum(pTemp) - 1;    
+    for ( i = 0; i < Gia_ManPoNum(pTemp); i++ )
+    {
+        Gia_ManSwapPos( pTemp, i );
+        pTemp = Ssc_PerformSweepingConstr( pAux = pTemp, pPars );
+        Gia_ManStop( pAux );
+        pTemp = Gia_ManDupNormalize( pAux = pTemp );
+        Gia_ManStop( pAux );
+        Gia_ManSwapPos( pTemp, i );
+        printf( "AIG%3d  : " );
+        Gia_ManPrintStats( pTemp, 0, 0, 0 );
+    }
+    return pTemp;
+}
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
-- 
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