Simple version of ECO.

src/sat/bmc/bmcEco.c

+/**CFile****************************************************************
+
+  FileName    [bmcEco.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT-based bounded model checking.]
+
+  Synopsis    []
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: bmcEco.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "bmc.h"
+#include "sat/cnf/cnf.h"
+#include "sat/bsat/satSolver.h"
+#include "aig/gia/giaAig.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Computes miter for ECO with given root node and fanins.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Bmc_EcoMiter( Gia_Man_t * pGold, Gia_Man_t * pOld, Vec_Int_t * vFans )
+{
+    Gia_Man_t * pNew, * pTemp;
+    Gia_Obj_t * pRoot = Gia_ObjFanin0( Gia_ManPo(pOld, Gia_ManPoNum(pOld)-1) ); // fanin of the last PO
+    Gia_Obj_t * pObj;
+    int i, NewPi, Miter;
+    assert( Gia_ManCiNum(pGold) == Gia_ManCiNum(pOld) );
+    assert( Gia_ManCoNum(pGold) == Gia_ManCoNum(pOld) - 1 );
+    assert( Gia_ObjIsAnd(pRoot) );
+    // create the miter
+    pNew = Gia_ManStart( 3 * Gia_ManObjNum(pGold) );
+    pNew->pName = Abc_UtilStrsav( pGold->pName );
+    Gia_ManHashAlloc( pNew );
+    // copy gold
+    Gia_ManConst0(pGold)->Value = 0;
+    Gia_ManForEachCi( pGold, pObj, i )
+        pObj->Value = Gia_ManAppendCi( pNew );
+    NewPi = Gia_ManAppendCi( pNew );
+    Gia_ManForEachAnd( pGold, pObj, i )
+        pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachCo( pGold, pObj, i )
+        pObj->Value = Gia_ObjFanin0Copy( pObj );
+    // create onset
+    Gia_ManConst0(pOld)->Value = 0;
+    Gia_ManForEachCi( pOld, pObj, i )
+        pObj->Value = Gia_ManCi(pGold, i)->Value;
+    Gia_ManForEachAnd( pOld, pObj, i )
+        if ( pObj == pRoot )
+            pObj->Value = NewPi;
+        else
+            pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachCo( pOld, pObj, i )
+        pObj->Value = Gia_ObjFanin0Copy( pObj );
+    Gia_ManForEachCo( pGold, pObj, i )
+        Gia_ManAppendCo( pNew, Gia_ManHashXor(pNew, pObj->Value, Gia_ManCo(pOld, i)->Value) );
+    // create offset
+    Gia_ManForEachAnd( pOld, pObj, i )
+        if ( pObj == pRoot )
+            pObj->Value = Abc_LitNot(NewPi);
+        else
+            pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachCo( pOld, pObj, i )
+        pObj->Value = Gia_ObjFanin0Copy( pObj );
+    Miter = 0;
+    Gia_ManForEachCo( pGold, pObj, i )
+        Miter = Gia_ManHashOr( pNew, Miter, Gia_ManHashXor(pNew, pObj->Value, Gia_ManCo(pOld, i)->Value) );
+    Gia_ManAppendCo( pNew, Miter );
+    // add outputs for the nodes
+    Gia_ManForEachObjVec( vFans, pOld, pObj, i )
+        Gia_ManAppendCo( pNew, pObj->Value );
+    // cleanup
+    pNew = Gia_ManCleanup( pTemp = pNew );
+    Gia_ManStop( pTemp );
+    assert( Gia_ManPiNum(pNew) == Gia_ManCiNum(pGold) + 1 );
+    assert( Gia_ManPoNum(pNew) == Gia_ManCoNum(pGold) + 1 + Vec_IntSize(vFans) );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Cnf_Dat_t * Cnf_DeriveGiaRemapped( Gia_Man_t * p )
+{
+    Cnf_Dat_t * pCnf;
+    Aig_Man_t * pAig = Gia_ManToAigSimple( p );
+    pAig->nRegs = 0;
+    pCnf = Cnf_Derive( pAig, Aig_ManCoNum(pAig) );
+    Aig_ManStop( pAig );
+    return pCnf;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Solve the enumeration problem.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Bmc_EcoSolve( sat_solver * pSat, int Root, Vec_Int_t * vVars )
+{
+    int nBTLimit = 1000000;
+    Vec_Int_t * vValues = Vec_IntAlloc( Vec_IntSize(vVars) );
+    Vec_Int_t * vLits   = Vec_IntAlloc( Vec_IntSize(vVars) );
+    int status, i, Div, iVar, nFinal, * pFinal, nIter = 0, RetValue = 0;
+    int pLits[2], nVars = sat_solver_nvars( pSat );
+    sat_solver_setnvars( pSat, nVars + 1 );
+    pLits[0] = Abc_Var2Lit( Root, 0 );  // F = 1
+    pLits[1] = Abc_Var2Lit( nVars, 0 ); // iNewLit
+    while ( 1 ) 
+    {
+        // find onset minterm
+        status = sat_solver_solve( pSat, pLits, pLits + 2, nBTLimit, 0, 0, 0 );
+        if ( status == l_Undef )
+            { RetValue = -1; break; }
+        if ( status == l_False )
+            { RetValue = 1; break; }
+        assert( status == l_True );
+        // remember variable values
+        Vec_IntClear( vValues );
+        Vec_IntForEachEntry( vVars, iVar, i )
+            Vec_IntPush( vValues, sat_solver_var_value(pSat, iVar) );
+        // collect divisor literals
+        Vec_IntClear( vLits );
+        Vec_IntPush( vLits, Abc_LitNot(pLits[0]) ); // F = 0
+        Vec_IntForEachEntry( vVars, Div, i )
+            Vec_IntPush( vLits, sat_solver_var_literal(pSat, Div) );
+        // check against offset
+        status = sat_solver_solve( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits), nBTLimit, 0, 0, 0 );
+        if ( status == l_Undef )
+            { RetValue = -1; break; }
+        if ( status == l_True )
+            break;
+        assert( status == l_False );
+        // compute cube and add clause
+        nFinal = sat_solver_final( pSat, &pFinal );
+        Vec_IntClear( vLits );
+        Vec_IntPush( vLits, Abc_LitNot(pLits[1]) ); // NOT(iNewLit)
+        printf( "Cube %d : ", nIter );
+        for ( i = 0; i < nFinal; i++ )
+        {
+            if ( pFinal[i] == pLits[0] )
+                continue;
+            Vec_IntPush( vLits, pFinal[i] );
+            iVar = Vec_IntFind( vVars, Abc_Lit2Var(pFinal[i]) );   assert( iVar >= 0 );
+            printf( "%s%d ", Abc_LitIsCompl(pFinal[i]) ? "+":"-", iVar );
+        }
+        printf( "\n" );
+        status = sat_solver_addclause( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits) );
+        assert( status );
+        nIter++;
+    }
+//    assert( status == l_True );
+    Vec_IntFree( vValues );
+    Vec_IntFree( vLits );
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Compute the patch function.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Bmc_EcoPatch( Gia_Man_t * p, int nIns, int nOuts )
+{
+    int i, Lit, RetValue, Root;
+    Gia_Obj_t * pObj;
+    Vec_Int_t * vVars;
+    // generate CNF and solver
+    Cnf_Dat_t * pCnf = Cnf_DeriveGiaRemapped( p );
+    sat_solver * pSat = sat_solver_new();
+    sat_solver_setnvars( pSat, pCnf->nVars );
+    // add timeframe clauses
+    for ( i = 0; i < pCnf->nClauses; i++ )
+        if ( !sat_solver_addclause( pSat, pCnf->pClauses[i], pCnf->pClauses[i+1] ) )
+            assert( 0 );
+    // add equality constraints
+    assert( Gia_ManPoNum(p) == nOuts + 1 + nIns );
+    Gia_ManForEachPo( p, pObj, i )
+    {
+        if ( i == nOuts )
+            break;
+        Lit = Abc_Var2Lit( pCnf->pVarNums[Gia_ObjId(p, pObj)], 1 ); // neg lit
+        RetValue = sat_solver_addclause( pSat, &Lit, &Lit + 1 );
+        assert( RetValue );
+    }
+    // add inequality constraint
+    pObj = Gia_ManPo( p, nOuts );
+    Lit = Abc_Var2Lit( pCnf->pVarNums[Gia_ObjId(p, pObj)], 0 ); // pos lit
+    RetValue = sat_solver_addclause( pSat, &Lit, &Lit + 1 );
+    assert( RetValue );
+    // simplify the SAT solver
+    RetValue = sat_solver_simplify( pSat );
+    assert( RetValue );
+    // collect input variables
+    vVars = Vec_IntAlloc( nIns );
+    Gia_ManForEachPo( p, pObj, i )
+        if ( i >= nOuts + 1 )
+            Vec_IntPush( vVars, pCnf->pVarNums[Gia_ObjId(p, pObj)] );
+    assert( Vec_IntSize(vVars) == nIns );
+    // derive the root variable
+    pObj = Gia_ManPi( p, Gia_ManPiNum(p) - 1 );
+    Root = pCnf->pVarNums[Gia_ObjId(p, pObj)];
+    // solve the problem
+    RetValue = Bmc_EcoSolve( pSat, Root, vVars );
+    Vec_IntFree( vVars );
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Tests the ECO miter.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Bmc_EcoMiterTest()
+{
+    Vec_Int_t * vFans;
+    Gia_Man_t * pMiter;
+    Gia_Obj_t * pObj;
+    Gia_Man_t * pGold = Gia_AigerRead( "eco_gold.aig", 0, 0 );
+    Gia_Man_t * pOld  = Gia_AigerRead( "eco_old.aig", 0, 0 );
+    int i, RetValue;
+    // create ECO miter
+    vFans = Vec_IntAlloc( Gia_ManCiNum(pOld) );
+    Gia_ManForEachCi( pOld, pObj, i )
+        Vec_IntPush( vFans, Gia_ObjId(pOld, pObj) );
+    pMiter = Bmc_EcoMiter( pGold, pOld, vFans );
+    Vec_IntFree( vFans );
+    Gia_AigerWrite( pMiter, "eco_miter.aig", 0, 0 );
+    // find the patch
+    RetValue = Bmc_EcoPatch( pMiter, Gia_ManCiNum(pGold), Gia_ManCoNum(pGold) );
+    if ( RetValue == 1 )
+        printf( "Patch is computed.\n" );
+    if ( RetValue == 0 )
+        printf( "Cannot be patched.\n" );
+    if ( RetValue == -1 )
+        printf( "Resource limit exceeded.\n" );
+    Gia_ManStop( pMiter );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+