/**CFile****************************************************************
FileName [ivyOper.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [And-Inverter Graph package.]
Synopsis [AIG operations.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - May 11, 2006.]
Revision [$Id: ivyOper.c,v 1.00 2006/05/11 00:00:00 alanmi Exp $]
***********************************************************************/
#include "ivy.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
// procedure to detect an EXOR gate
static inline int Ivy_ObjIsExorType( Ivy_Obj_t * p0, Ivy_Obj_t * p1, Ivy_Obj_t ** ppFan0, Ivy_Obj_t ** ppFan1 )
{
if ( !Ivy_IsComplement(p0) || !Ivy_IsComplement(p1) )
return 0;
p0 = Ivy_Regular(p0);
p1 = Ivy_Regular(p1);
if ( !Ivy_ObjIsAnd(p0) || !Ivy_ObjIsAnd(p1) )
return 0;
if ( Ivy_ObjFanin0(p0) != Ivy_ObjFanin0(p1) || Ivy_ObjFanin1(p0) != Ivy_ObjFanin1(p1) )
return 0;
if ( Ivy_ObjFaninC0(p0) == Ivy_ObjFaninC0(p1) || Ivy_ObjFaninC1(p0) == Ivy_ObjFaninC1(p1) )
return 0;
*ppFan0 = Ivy_ObjChild0(p0);
*ppFan1 = Ivy_ObjChild1(p0);
return 1;
}
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Perform one operation.]
Description [The argument nodes can be complemented.]
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Oper( Ivy_Man_t * p, Ivy_Obj_t * p0, Ivy_Obj_t * p1, Ivy_Type_t Type )
{
if ( Type == IVY_AND )
return Ivy_And( p, p0, p1 );
if ( Type == IVY_EXOR )
return Ivy_Exor( p, p0, p1 );
assert( 0 );
return NULL;
}
/**Function*************************************************************
Synopsis [Performs canonicization step.]
Description [The argument nodes can be complemented.]
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_And( Ivy_Man_t * p, Ivy_Obj_t * p0, Ivy_Obj_t * p1 )
{
// Ivy_Obj_t * pFan0, * pFan1;
// check trivial cases
if ( p0 == p1 )
return p0;
if ( p0 == Ivy_Not(p1) )
return Ivy_Not(p->pConst1);
if ( Ivy_Regular(p0) == p->pConst1 )
return p0 == p->pConst1 ? p1 : Ivy_Not(p->pConst1);
if ( Ivy_Regular(p1) == p->pConst1 )
return p1 == p->pConst1 ? p0 : Ivy_Not(p->pConst1);
// check if it can be an EXOR gate
// if ( Ivy_ObjIsExorType( p0, p1, &pFan0, &pFan1 ) )
// return Ivy_CanonExor( pFan0, pFan1 );
return Ivy_CanonAnd( p, p0, p1 );
}
/**Function*************************************************************
Synopsis [Performs canonicization step.]
Description [The argument nodes can be complemented.]
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Exor( Ivy_Man_t * p, Ivy_Obj_t * p0, Ivy_Obj_t * p1 )
{
/*
// check trivial cases
if ( p0 == p1 )
return Ivy_Not(p->pConst1);
if ( p0 == Ivy_Not(p1) )
return p->pConst1;
if ( Ivy_Regular(p0) == p->pConst1 )
return Ivy_NotCond( p1, p0 == p->pConst1 );
if ( Ivy_Regular(p1) == p->pConst1 )
return Ivy_NotCond( p0, p1 == p->pConst1 );
// check the table
return Ivy_CanonExor( p, p0, p1 );
*/
return Ivy_Or( p, Ivy_And(p, p0, Ivy_Not(p1)), Ivy_And(p, Ivy_Not(p0), p1) );
}
/**Function*************************************************************
Synopsis [Implements Boolean OR.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Or( Ivy_Man_t * p, Ivy_Obj_t * p0, Ivy_Obj_t * p1 )
{
return Ivy_Not( Ivy_And( p, Ivy_Not(p0), Ivy_Not(p1) ) );
}
/**Function*************************************************************
Synopsis [Implements ITE operation.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Mux( Ivy_Man_t * p, Ivy_Obj_t * pC, Ivy_Obj_t * p1, Ivy_Obj_t * p0 )
{
Ivy_Obj_t * pTempA1, * pTempA2, * pTempB1, * pTempB2, * pTemp;
int Count0, Count1;
// consider trivial cases
if ( p0 == Ivy_Not(p1) )
return Ivy_Exor( p, pC, p0 );
// other cases can be added
// implement the first MUX (F = C * x1 + C' * x0)
pTempA1 = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, pC, p1, IVY_AND, IVY_INIT_NONE) );
pTempA2 = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, Ivy_Not(pC), p0, IVY_AND, IVY_INIT_NONE) );
if ( pTempA1 && pTempA2 )
{
pTemp = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, Ivy_Not(pTempA1), Ivy_Not(pTempA2), IVY_AND, IVY_INIT_NONE) );
if ( pTemp ) return Ivy_Not(pTemp);
}
Count0 = (pTempA1 != NULL) + (pTempA2 != NULL);
// implement the second MUX (F' = C * x1' + C' * x0')
pTempB1 = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, pC, Ivy_Not(p1), IVY_AND, IVY_INIT_NONE) );
pTempB2 = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, Ivy_Not(pC), Ivy_Not(p0), IVY_AND, IVY_INIT_NONE) );
if ( pTempB1 && pTempB2 )
{
pTemp = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, Ivy_Not(pTempB1), Ivy_Not(pTempB2), IVY_AND, IVY_INIT_NONE) );
if ( pTemp ) return pTemp;
}
Count1 = (pTempB1 != NULL) + (pTempB2 != NULL);
// compare and decide which one to implement
if ( Count0 >= Count1 )
{
pTempA1 = pTempA1? pTempA1 : Ivy_And(p, pC, p1);
pTempA2 = pTempA2? pTempA2 : Ivy_And(p, Ivy_Not(pC), p0);
return Ivy_Or( p, pTempA1, pTempA2 );
}
pTempB1 = pTempB1? pTempB1 : Ivy_And(p, pC, Ivy_Not(p1));
pTempB2 = pTempB2? pTempB2 : Ivy_And(p, Ivy_Not(pC), Ivy_Not(p0));
return Ivy_Not( Ivy_Or( p, pTempB1, pTempB2 ) );
// return Ivy_Or( Ivy_And(pC, p1), Ivy_And(Ivy_Not(pC), p0) );
}
/**Function*************************************************************
Synopsis [Implements ITE operation.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Maj( Ivy_Man_t * p, Ivy_Obj_t * pA, Ivy_Obj_t * pB, Ivy_Obj_t * pC )
{
return Ivy_Or( p, Ivy_Or(p, Ivy_And(p, pA, pB), Ivy_And(p, pA, pC)), Ivy_And(p, pB, pC) );
}
/**Function*************************************************************
Synopsis [Constructs the well-balanced tree of gates.]
Description [Disregards levels and possible logic sharing.]
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Multi_rec( Ivy_Man_t * p, Ivy_Obj_t ** ppObjs, int nObjs, Ivy_Type_t Type )
{
Ivy_Obj_t * pObj1, * pObj2;
if ( nObjs == 1 )
return ppObjs[0];
pObj1 = Ivy_Multi_rec( p, ppObjs, nObjs/2, Type );
pObj2 = Ivy_Multi_rec( p, ppObjs + nObjs/2, nObjs - nObjs/2, Type );
return Ivy_Oper( p, pObj1, pObj2, Type );
}
/**Function*************************************************************
Synopsis [Old code.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Multi( Ivy_Man_t * p, Ivy_Obj_t ** pArgs, int nArgs, Ivy_Type_t Type )
{
assert( Type == IVY_AND || Type == IVY_EXOR );
assert( nArgs > 0 );
return Ivy_Multi_rec( p, pArgs, nArgs, Type );
}
/**Function*************************************************************
Synopsis [Implements the miter.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Miter( Ivy_Man_t * p, Vec_Ptr_t * vPairs )
{
int i;
assert( vPairs->nSize > 0 );
assert( vPairs->nSize % 2 == 0 );
// go through the cubes of the node's SOP
for ( i = 0; i < vPairs->nSize; i += 2 )
vPairs->pArray[i/2] = Ivy_Not( Ivy_Exor( p, vPairs->pArray[i], vPairs->pArray[i+1] ) );
vPairs->nSize = vPairs->nSize/2;
return Ivy_Not( Ivy_Multi_rec( p, (Ivy_Obj_t **)vPairs->pArray, vPairs->nSize, IVY_AND ) );
}
/**Function*************************************************************
Synopsis [Performs canonicization step.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Ivy_Obj_t * Ivy_Latch( Ivy_Man_t * p, Ivy_Obj_t * pObj, Ivy_Init_t Init )
{
return Ivy_CanonLatch( p, pObj, Init );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////