Adding command to dump UNSAT core of BMC instance.

3 files changed, 288 insertions, 2 deletions

diff --git a/src/sat/bmc/bmc.h b/src/sat/bmc/bmc.h
index 3eeeb7b5..558b2d62 100644
--- a/src/sat/bmc/bmc.h
+++ b/src/sat/bmc/bmc.h
@@ -94,7 +94,18 @@ struct Bmc_AndPar_t_
     int         nFailOuts;      // the number of failed outputs
     int         nDropOuts;      // the number of dropped outputs
 };
- 
+  
+typedef struct Bmc_BCorePar_t_ Bmc_BCorePar_t;
+struct Bmc_BCorePar_t_
+{
+    int         iFrame;         // timeframe
+    int         iOutput;        // property output
+    int         nTimeOut;       // timeout in seconds
+    char *      pFilePivots;    // file name with AIG IDs of pivot objects
+    char *      pFileProof;     // file name to write the resulting proof
+    int         fVerbose;       // verbose output
+};
+
 typedef struct Bmc_MulPar_t_ Bmc_MulPar_t;
 struct Bmc_MulPar_t_
 {
@@ -117,6 +128,8 @@ struct Bmc_MulPar_t_
 ///                    FUNCTION DECLARATIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
+/*=== bmcBCore.c ==========================================================*/
+extern void              Bmc_ManBCorePerform( Gia_Man_t * pGia, Bmc_BCorePar_t * pPars );
 /*=== bmcBmc.c ==========================================================*/
 extern int               Saig_ManBmcSimple( Aig_Man_t * pAig, int nFrames, int nSizeMax, int nBTLimit, int fRewrite, int fVerbose, int * piFrame, int nCofFanLit );
 /*=== bmcBmc2.c ==========================================================*/
diff --git a/src/sat/bmc/bmcBCore.c b/src/sat/bmc/bmcBCore.c
new file mode 100644
index 00000000..cde49f52
--- /dev/null
+++ b/src/sat/bmc/bmcBCore.c
@@ -0,0 +1,272 @@
+/**CFile****************************************************************
+
+  FileName    [bmcBCore.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT-based bounded model checking.]
+
+  Synopsis    [Performs recording of BMC core.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: bmcBCore.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "bmc.h"
+#include "sat/bsat/satSolver.h"
+#include "sat/bsat/satStore.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Collect pivot variables.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Bmc_ManBCoreReadPivots( char * pName )
+{
+    int Num;
+    Vec_Int_t * vPivots = Vec_IntAlloc( 100 );
+    FILE * pFile = fopen( pName, "r" );
+    while ( fscanf( pFile, "%d", &Num ) == 1 )
+        Vec_IntPush( vPivots, Num );
+    fclose( pFile );
+    return vPivots;
+}
+Vec_Int_t * Bmc_ManBCoreCollectPivots( Gia_Man_t * p, char * pName, Vec_Int_t * vVarMap )
+{
+    Gia_Obj_t * pObj;
+    int i, iVar, iFrame;
+    Vec_Int_t * vPivots = Vec_IntAlloc( 100 );
+    Vec_Int_t * vVars = Bmc_ManBCoreReadPivots( pName );
+    Gia_ManForEachObj( p, pObj, i )
+        pObj->fMark0 = 0;
+    Vec_IntForEachEntry( vVars, iVar, i )
+        if ( iVar > 0 && iVar < Gia_ManObjNum(p) )
+            Gia_ManObj( p, iVar )->fMark0 = 1;
+        else
+            printf( "Cannot find object with Id %d in the given AIG.\n", iVar );
+    Vec_IntForEachEntryDouble( vVarMap, iVar, iFrame, i )
+        if ( Gia_ManObj( p, iVar )->fMark0 )
+            Vec_IntPush( vPivots, Abc_Lit2Var(i) );
+    Gia_ManForEachObj( p, pObj, i )
+        pObj->fMark0 = 0;
+    Vec_IntFree( vVars );
+    return vPivots;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Collect (Id; Frame) pairs.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Bmc_ManBCoreAssignVar( Gia_Man_t * p, Gia_Obj_t * pObj, int f, Vec_Int_t * vNodes )
+{
+    pObj->Value = Abc_Lit2Var(Vec_IntSize(vNodes));
+    Vec_IntPush( vNodes, Gia_ObjId(p, pObj) );
+    Vec_IntPush( vNodes, f );
+//    printf( "Obj %3d  Frame %3d  --->  Var %3d    ", Gia_ObjId(p, pObj), f, pObj->Value );
+//    Gia_ObjPrint( p, pObj );
+}
+void Bmc_ManBCoreCollect_rec( Gia_Man_t * p, int Id, int f, Vec_Int_t * vNodes, Vec_Int_t * vRootsNew )
+{
+    Gia_Obj_t * pObj;
+    if ( Gia_ObjIsTravIdCurrentId(p, Id) )
+        return;
+    Gia_ObjSetTravIdCurrentId(p, Id);
+    pObj = Gia_ManObj( p, Id );
+    Bmc_ManBCoreAssignVar( p, pObj, f, vNodes );
+    if ( Gia_ObjIsPi(p, pObj) )
+        return;
+    if ( Gia_ObjIsRo(p, pObj) )
+    {
+        Vec_IntPush( vRootsNew, Gia_ObjId(p, Gia_ObjRoToRi(p, pObj)) );
+        return;
+    }
+    assert( Gia_ObjIsAnd(pObj) );
+    Bmc_ManBCoreCollect_rec( p, Gia_ObjFaninId0p(p, pObj), f, vNodes, vRootsNew );
+    Bmc_ManBCoreCollect_rec( p, Gia_ObjFaninId1p(p, pObj), f, vNodes, vRootsNew );
+}
+Vec_Int_t * Bmc_ManBCoreCollect( Gia_Man_t * p, int iFrame, int iOut, sat_solver * pSat )
+{
+    Gia_Obj_t * pObj; 
+    int f, i, iObj, nNodesOld;
+    Vec_Int_t * vNodes  = Vec_IntAlloc( 100 );
+    Vec_Int_t * vRoots  = Vec_IntAlloc( 100 );
+    Vec_Int_t * vRoots2 = Vec_IntAlloc( 100 );
+    assert( iFrame >= 0 && iOut >= 0 );
+    // add first variables
+    Vec_IntPush( vNodes, -1 );
+    Vec_IntPush( vNodes, -1 );
+    Bmc_ManBCoreAssignVar( p, Gia_ManPo(p, iOut), iFrame, vNodes );
+    // start with root node
+    Vec_IntPush( vRoots, Gia_ObjId(p, Gia_ManPo(p, iOut)) );
+    // iterate through time frames
+    for ( f = iFrame; f >= 0; f-- )
+    {
+        Gia_ManIncrementTravId( p );
+        // add constant node
+        Gia_ObjSetTravIdCurrent( p, Gia_ManConst0(p) );
+        Bmc_ManBCoreAssignVar( p, Gia_ManConst0(p), f, vNodes );
+        sat_solver_add_const( pSat, Gia_ManConst0(p)->Value, 1 );
+        // collect nodes in this timeframe
+        Vec_IntClear( vRoots2 );
+        nNodesOld = Vec_IntSize(vNodes);
+        Gia_ManForEachObjVec( vRoots, p, pObj, i )
+            Bmc_ManBCoreCollect_rec( p, Gia_ObjFaninId0p(p, pObj), f, vNodes, vRoots2 );
+        if ( f == iFrame )
+        {
+            // add the final clause
+            pObj = Gia_ManPo(p, iOut);
+            assert( pObj->Value == 1 );
+            assert( Gia_ObjFanin0(pObj)->Value == 3 );
+//            sat_solver_add_const( pSat, Gia_ObjFanin0(pObj)->Value, Gia_ObjFaninC0(pObj) );
+            sat_solver_add_constraint( pSat, Gia_ObjFanin0(pObj)->Value, pObj->Value, Gia_ObjFaninC0(pObj) );
+        }
+        else
+        {
+            // connect current RIs to previous ROs
+            Gia_ManForEachObjVec( vRoots, p, pObj, i )
+                sat_solver_add_buffer( pSat, pObj->Value, Gia_ObjFanin0(pObj)->Value, Gia_ObjFaninC0(pObj) );
+        }
+        Gia_ManForEachObjVec( vRoots2, p, pObj, i )
+            pObj->Value = Gia_ObjRiToRo(p, pObj)->Value;
+        // add nodes of this timeframe
+        Vec_IntForEachEntryStart( vNodes, iObj, i, nNodesOld )
+        {
+            pObj = Gia_ManObj(p, iObj); i++;
+            if ( Gia_ObjIsCi(pObj) )
+                continue;
+            assert( Gia_ObjIsAnd(pObj) );
+            sat_solver_add_and( pSat, pObj->Value, Gia_ObjFanin0(pObj)->Value, Gia_ObjFanin1(pObj)->Value, Gia_ObjFaninC0(pObj), Gia_ObjFaninC1(pObj), 0 );
+        }
+        // collect constant node
+        ABC_SWAP( Vec_Int_t *, vRoots, vRoots2 );
+    }
+    // add constraint variables for the init state
+    Gia_ManForEachObjVec( vRoots, p, pObj, i )
+    {
+        sat_solver_add_constraint( pSat, pObj->Value, Abc_Lit2Var(Vec_IntSize(vNodes)), 1 );
+        pObj = Gia_ObjRiToRo(p, pObj);
+        Bmc_ManBCoreAssignVar( p, pObj, -1, vNodes );
+    }
+    Vec_IntFree( vRoots );
+    Vec_IntFree( vRoots2 );
+    return vNodes;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Bmc_ManBCorePerform( Gia_Man_t * p, Bmc_BCorePar_t * pPars )
+{
+    clock_t clk = clock();
+    Intp_Man_t * pManProof;
+    Vec_Int_t * vVarMap, * vCore;
+    sat_solver * pSat;
+    FILE * pFile;
+    void * pSatCnf; 
+    int RetValue;
+    // create SAT solver
+    pSat = sat_solver_new();
+    sat_solver_store_alloc( pSat ); 
+    sat_solver_setnvars( pSat, 1000 );
+    sat_solver_set_runtime_limit( pSat, pPars->nTimeOut ? pPars->nTimeOut * CLOCKS_PER_SEC + Abc_Clock(): 0 );
+    vVarMap = Bmc_ManBCoreCollect( p, pPars->iFrame, pPars->iOutput, pSat );
+    sat_solver_store_mark_roots( pSat ); 
+    // create pivot variables
+    if ( pPars->pFilePivots )
+    {
+        Vec_Int_t * vPivots = Bmc_ManBCoreCollectPivots(p, pPars->pFilePivots, vVarMap);
+        sat_solver_set_pivot_variables( pSat, Vec_IntArray(vPivots), Vec_IntSize(vPivots) );
+        Vec_IntReleaseArray( vPivots );
+        Vec_IntFree( vPivots );
+    }
+    // solve the problem
+    RetValue = sat_solver_solve( pSat, NULL, NULL, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
+    if ( RetValue == l_Undef )
+    {
+        Vec_IntFree( vVarMap );
+        sat_solver_delete( pSat );
+        printf( "Timeout of conflict limit is reached.\n" );
+        return;
+    }
+    if ( RetValue == l_True )
+    {
+        Vec_IntFree( vVarMap );
+        sat_solver_delete( pSat );
+        printf( "The BMC problem is SAT.\n" );
+        return;
+    }
+    if ( pPars->fVerbose )
+    {
+        printf( "SAT solver returned UNSAT after %7d conflicts.      ", (int)pSat->stats.conflicts );
+        Abc_PrintTime( 1, "Time", clock() - clk );
+    }
+    assert( RetValue == l_False );
+    pSatCnf = sat_solver_store_release( pSat ); 
+    Sto_ManDumpClauses( (Sto_Man_t *)pSatCnf, "cnf_store.txt" );
+    // derive the UNSAT core
+    clk = clock();
+    pManProof = Intp_ManAlloc();
+    vCore = (Vec_Int_t *)Intp_ManUnsatCore( pManProof, (Sto_Man_t *)pSatCnf, 1, pPars->fVerbose );
+    Intp_ManFree( pManProof );
+    if ( pPars->fVerbose )
+    {
+        printf( "UNSAT core contains %8d (out of %8d) learned clauses.   ", Vec_IntSize(vCore), sat_solver_nconflicts(pSat) );
+        Abc_PrintTime( 1, "Time", clock() - clk );
+    }
+    // write the problem
+    pFile = pPars->pFileProof ? fopen( pPars->pFileProof, "wb" ) : stdout;
+    Intp_ManUnsatCorePrintForBmc( pFile, (Sto_Man_t *)pSatCnf, vCore, vVarMap );
+    if ( pFile != stdout )
+        fclose( pFile );
+    // cleanup
+    Sto_ManFree( (Sto_Man_t *)pSatCnf );
+    Vec_IntFree( vVarMap );
+    Vec_IntFree( vCore );
+    sat_solver_delete( pSat );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/sat/bmc/module.make b/src/sat/bmc/module.make
index 6deb9eb1..2ce321c6 100644
--- a/src/sat/bmc/module.make
+++ b/src/sat/bmc/module.make
@@ -1,4 +1,5 @@
-SRC +=    src/sat/bmc/bmcBmc.c \
+SRC +=    src/sat/bmc/bmcBCore.c \
+    src/sat/bmc/bmcBmc.c \
     src/sat/bmc/bmcBmc2.c \
     src/sat/bmc/bmcBmc3.c \
     src/sat/bmc/bmcBmcAnd.c \