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/**CFile****************************************************************
FileName [abcQuant.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Network and node package.]
Synopsis [AIG-based variable quantification.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: abcQuant.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "abc.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Performs fast synthesis.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkSynthesize( Abc_Ntk_t ** ppNtk, int fMoreEffort )
{
Abc_Ntk_t * pNtk, * pNtkTemp;
pNtk = *ppNtk;
Abc_NtkRewrite( pNtk, 0, 0, 0, 0, 0 );
Abc_NtkRefactor( pNtk, 10, 16, 0, 0, 0, 0 );
pNtk = Abc_NtkBalance( pNtkTemp = pNtk, 0, 0, 0 );
Abc_NtkDelete( pNtkTemp );
if ( fMoreEffort )
{
Abc_NtkRewrite( pNtk, 0, 0, 0, 0, 0 );
Abc_NtkRefactor( pNtk, 10, 16, 0, 0, 0, 0 );
pNtk = Abc_NtkBalance( pNtkTemp = pNtk, 0, 0, 0 );
Abc_NtkDelete( pNtkTemp );
}
*ppNtk = pNtk;
}
/**Function*************************************************************
Synopsis [Existentially quantifies one variable.]
Description []
SideEffects [This procedure creates dangling nodes in the AIG.]
SeeAlso []
***********************************************************************/
int Abc_NtkQuantify( Abc_Ntk_t * pNtk, int iVar, int fVerbose )
{
Vec_Ptr_t * vNodes;
Abc_Obj_t * pObj, * pNext, * pFanin;
int i;
assert( Abc_NtkIsStrash(pNtk) );
assert( iVar < Abc_NtkCiNum(pNtk) );
// collect the internal nodes
pObj = Abc_NtkCi( pNtk, iVar );
vNodes = Abc_NtkDfsReverseNodes( pNtk, &pObj, 1 );
// assign the cofactors of the CI node to be constants
pObj->pCopy = Abc_ObjNot( Abc_AigConst1(pNtk) );
pObj->pData = Abc_AigConst1(pNtk);
// quantify the nodes
Vec_PtrForEachEntry( vNodes, pObj, i )
{
for ( pNext = pObj? pObj->pCopy : pObj; pObj; pObj = pNext, pNext = pObj? pObj->pCopy : pObj )
{
pFanin = Abc_ObjFanin0(pObj);
if ( !Abc_NodeIsTravIdCurrent(pFanin) )
pFanin->pCopy = pFanin->pData = pFanin;
pFanin = Abc_ObjFanin1(pObj);
if ( !Abc_NodeIsTravIdCurrent(pFanin) )
pFanin->pCopy = pFanin->pData = pFanin;
pObj->pCopy = Abc_AigAnd( pNtk->pManFunc, Abc_ObjChild0Copy(pObj), Abc_ObjChild1Copy(pObj) );
pObj->pData = Abc_AigAnd( pNtk->pManFunc, Abc_ObjChild0Data(pObj), Abc_ObjChild1Data(pObj) );
}
}
Vec_PtrFree( vNodes );
// update the affected COs
Abc_NtkForEachCo( pNtk, pObj, i )
{
if ( !Abc_NodeIsTravIdCurrent(pObj) )
continue;
pFanin = Abc_ObjFanin0(pObj);
// get the result of quantification
pNext = Abc_AigOr( pNtk->pManFunc, Abc_ObjChild0Copy(pObj), Abc_ObjChild0Data(pObj) );
pNext = Abc_ObjNotCond( pNext, Abc_ObjFaninC0(pObj) );
if ( Abc_ObjRegular(pNext) == pFanin )
continue;
// update the fanins of the CO
Abc_ObjPatchFanin( pObj, pFanin, pNext );
// if ( Abc_ObjFanoutNum(pFanin) == 0 )
// Abc_AigDeleteNode( pNtk->pManFunc, pFanin );
}
// make sure the node has no fanouts
// pObj = Abc_NtkCi( pNtk, iVar );
// assert( Abc_ObjFanoutNum(pObj) == 0 );
return 1;
}
/**Function*************************************************************
Synopsis [Constructs the transition relation.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkTransRel( Abc_Ntk_t * pNtk, int fInputs, int fVerbose )
{
char Buffer[1000];
Vec_Ptr_t * vPairs;
Abc_Ntk_t * pNtkNew;
Abc_Obj_t * pObj, * pMiter;
int i, nLatches;
int fSynthesis = 1;
assert( Abc_NtkIsStrash(pNtk) );
assert( Abc_NtkLatchNum(pNtk) );
nLatches = Abc_NtkLatchNum(pNtk);
// start the network
pNtkNew = Abc_NtkAlloc( ABC_NTK_STRASH, ABC_FUNC_AIG, 1 );
// duplicate the name and the spec
sprintf( Buffer, "%s_TR", pNtk->pName );
pNtkNew->pName = Extra_UtilStrsav(pNtk->pName);
// pNtkNew->pSpec = Extra_UtilStrsav(pNtk->pSpec);
Abc_NtkCleanCopy( pNtk );
// create current state variables
Abc_NtkForEachLatchOutput( pNtk, pObj, i )
{
pObj->pCopy = Abc_NtkCreatePi(pNtkNew);
Abc_ObjAssignName( pObj->pCopy, Abc_ObjName(pObj), NULL );
}
// create next state variables
Abc_NtkForEachLatchInput( pNtk, pObj, i )
Abc_ObjAssignName( Abc_NtkCreatePi(pNtkNew), Abc_ObjName(pObj), NULL );
// create PI variables
Abc_NtkForEachPi( pNtk, pObj, i )
Abc_NtkDupObj( pNtkNew, pObj, 1 );
// create the PO
Abc_NtkCreatePo( pNtkNew );
// restrash the nodes (assuming a topological order of the old network)
Abc_AigConst1(pNtk)->pCopy = Abc_AigConst1(pNtkNew);
Abc_NtkForEachNode( pNtk, pObj, i )
pObj->pCopy = Abc_AigAnd( pNtkNew->pManFunc, Abc_ObjChild0Copy(pObj), Abc_ObjChild1Copy(pObj) );
// create the function of the primary output
assert( Abc_NtkBoxNum(pNtk) == Abc_NtkLatchNum(pNtk) );
vPairs = Vec_PtrAlloc( 2*nLatches );
Abc_NtkForEachLatchInput( pNtk, pObj, i )
{
Vec_PtrPush( vPairs, Abc_ObjChild0Copy(pObj) );
Vec_PtrPush( vPairs, Abc_NtkPi(pNtkNew, i+nLatches) );
}
pMiter = Abc_AigMiter( pNtkNew->pManFunc, vPairs );
Vec_PtrFree( vPairs );
// add the primary output
Abc_ObjAddFanin( Abc_NtkPo(pNtkNew,0), Abc_ObjNot(pMiter) );
Abc_ObjAssignName( Abc_NtkPo(pNtkNew,0), "rel", NULL );
// quantify inputs
if ( fInputs )
{
assert( Abc_NtkPiNum(pNtkNew) == Abc_NtkPiNum(pNtk) + 2*nLatches );
for ( i = Abc_NtkPiNum(pNtkNew) - 1; i >= 2*nLatches; i-- )
// for ( i = 2*nLatches; i < Abc_NtkPiNum(pNtkNew); i++ )
{
Abc_NtkQuantify( pNtkNew, i, fVerbose );
// if ( fSynthesis && (i % 3 == 2) )
if ( fSynthesis )
{
Abc_NtkCleanData( pNtkNew );
Abc_AigCleanup( pNtkNew->pManFunc );
Abc_NtkSynthesize( &pNtkNew, 1 );
}
// printf( "Var = %3d. Nodes = %6d. ", Abc_NtkPiNum(pNtkNew) - 1 - i, Abc_NtkNodeNum(pNtkNew) );
// printf( "Var = %3d. Nodes = %6d. ", i - 2*nLatches, Abc_NtkNodeNum(pNtkNew) );
}
// printf( "\n" );
Abc_NtkCleanData( pNtkNew );
Abc_AigCleanup( pNtkNew->pManFunc );
for ( i = Abc_NtkPiNum(pNtkNew) - 1; i >= 2*nLatches; i-- )
{
pObj = Abc_NtkPi( pNtkNew, i );
assert( Abc_ObjFanoutNum(pObj) == 0 );
Abc_NtkDeleteObj( pObj );
}
}
// check consistency of the network
if ( !Abc_NtkCheck( pNtkNew ) )
{
printf( "Abc_NtkTransRel: The network check has failed.\n" );
Abc_NtkDelete( pNtkNew );
return NULL;
}
return pNtkNew;
}
/**Function*************************************************************
Synopsis [Performs one image computation.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkInitialState( Abc_Ntk_t * pNtk )
{
Abc_Ntk_t * pNtkNew;
Abc_Obj_t * pMiter;
int i, nVars = Abc_NtkPiNum(pNtk)/2;
assert( Abc_NtkIsStrash(pNtk) );
// start the new network
pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_STRASH, ABC_FUNC_AIG );
// compute the all-zero state in terms of the CS variables
pMiter = Abc_AigConst1(pNtkNew);
for ( i = 0; i < nVars; i++ )
pMiter = Abc_AigAnd( pNtkNew->pManFunc, pMiter, Abc_ObjNot( Abc_NtkPi(pNtkNew, i) ) );
// add the PO
Abc_ObjAddFanin( Abc_NtkPo(pNtkNew,0), pMiter );
return pNtkNew;
}
/**Function*************************************************************
Synopsis [Swaps current state and next state variables.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkSwapVariables( Abc_Ntk_t * pNtk )
{
Abc_Ntk_t * pNtkNew;
Abc_Obj_t * pMiter, * pObj, * pObj0, * pObj1;
int i, nVars = Abc_NtkPiNum(pNtk)/2;
assert( Abc_NtkIsStrash(pNtk) );
// start the new network
pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_STRASH, ABC_FUNC_AIG );
// update the PIs
for ( i = 0; i < nVars; i++ )
{
pObj0 = Abc_NtkPi( pNtk, i );
pObj1 = Abc_NtkPi( pNtk, i+nVars );
pMiter = pObj0->pCopy;
pObj0->pCopy = pObj1->pCopy;
pObj1->pCopy = pMiter;
}
// restrash
Abc_NtkForEachNode( pNtk, pObj, i )
pObj->pCopy = Abc_AigAnd( pNtkNew->pManFunc, Abc_ObjChild0Copy(pObj), Abc_ObjChild1Copy(pObj) );
// add the PO
pMiter = Abc_ObjChild0Copy( Abc_NtkPo(pNtk,0) );
Abc_ObjAddFanin( Abc_NtkPo(pNtkNew,0), pMiter );
return pNtkNew;
}
/**Function*************************************************************
Synopsis [Performs reachability analisys.]
Description [Assumes that the input is the transition relation.]
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkReachability( Abc_Ntk_t * pNtkRel, int nIters, int fVerbose )
{
Abc_Obj_t * pObj;
Abc_Ntk_t * pNtkFront, * pNtkReached, * pNtkNext, * pNtkTemp;
int clk, i, v, nVars, nNodesOld, nNodesNew, nNodesPrev;
int fFixedPoint = 0;
int fSynthesis = 1;
int fMoreEffort = 1;
assert( Abc_NtkIsStrash(pNtkRel) );
assert( Abc_NtkLatchNum(pNtkRel) == 0 );
assert( Abc_NtkPiNum(pNtkRel) % 2 == 0 );
// compute the network composed of the initial states
pNtkFront = Abc_NtkInitialState( pNtkRel );
pNtkReached = Abc_NtkDup( pNtkFront );
//Abc_NtkShow( pNtkReached, 0, 0, 0 );
// if ( fVerbose )
// printf( "Transition relation = %6d.\n", Abc_NtkNodeNum(pNtkRel) );
// perform iterations of reachability analysis
nNodesPrev = Abc_NtkNodeNum(pNtkFront);
nVars = Abc_NtkPiNum(pNtkRel)/2;
for ( i = 0; i < nIters; i++ )
{
clk = clock();
// get the set of next states
pNtkNext = Abc_NtkMiterAnd( pNtkRel, pNtkFront, 0, 0 );
Abc_NtkDelete( pNtkFront );
// quantify the current state variables
for ( v = 0; v < nVars; v++ )
{
Abc_NtkQuantify( pNtkNext, v, fVerbose );
if ( fSynthesis && (v % 3 == 2) )
{
Abc_NtkCleanData( pNtkNext );
Abc_AigCleanup( pNtkNext->pManFunc );
Abc_NtkSynthesize( &pNtkNext, fMoreEffort );
}
}
Abc_NtkCleanData( pNtkNext );
Abc_AigCleanup( pNtkNext->pManFunc );
if ( fSynthesis )
Abc_NtkSynthesize( &pNtkNext, 1 );
// map the next states into the current states
pNtkNext = Abc_NtkSwapVariables( pNtkTemp = pNtkNext );
Abc_NtkDelete( pNtkTemp );
// check the termination condition
if ( Abc_ObjFanin0(Abc_NtkPo(pNtkNext,0)) == Abc_AigConst1(pNtkNext) )
{
fFixedPoint = 1;
printf( "Fixed point is reached!\n" );
Abc_NtkDelete( pNtkNext );
break;
}
// compute new front
pNtkFront = Abc_NtkMiterAnd( pNtkNext, pNtkReached, 0, 1 );
Abc_NtkDelete( pNtkNext );
// add the reached states
pNtkReached = Abc_NtkMiterAnd( pNtkTemp = pNtkReached, pNtkFront, 1, 0 );
Abc_NtkDelete( pNtkTemp );
// compress the size of Front
nNodesOld = Abc_NtkNodeNum(pNtkFront);
if ( fSynthesis )
{
Abc_NtkSynthesize( &pNtkFront, fMoreEffort );
Abc_NtkSynthesize( &pNtkReached, fMoreEffort );
}
nNodesNew = Abc_NtkNodeNum(pNtkFront);
// print statistics
if ( fVerbose )
{
printf( "I = %3d : Reach = %6d Fr = %6d FrM = %6d %7.2f %% ",
i + 1, Abc_NtkNodeNum(pNtkReached), nNodesOld, nNodesNew, 100.0*(nNodesNew-nNodesPrev)/nNodesPrev );
PRT( "T", clock() - clk );
}
nNodesPrev = Abc_NtkNodeNum(pNtkFront);
}
if ( !fFixedPoint )
fprintf( stdout, "Reachability analysis stopped after %d iterations.\n", nIters );
// complement the output to represent the set of unreachable states
Abc_ObjXorFaninC( Abc_NtkPo(pNtkReached,0), 0 );
// remove next state variables
for ( i = 2*nVars - 1; i >= nVars; i-- )
{
pObj = Abc_NtkPi( pNtkReached, i );
assert( Abc_ObjFanoutNum(pObj) == 0 );
Abc_NtkDeleteObj( pObj );
}
// check consistency of the network
if ( !Abc_NtkCheck( pNtkReached ) )
{
printf( "Abc_NtkReachability: The network check has failed.\n" );
Abc_NtkDelete( pNtkReached );
return NULL;
}
return pNtkReached;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
