/**CFile****************************************************************
FileName [saigConstr.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Sequential AIG package.]
Synopsis [Structural constraint detection.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: saigConstr.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "saig.h"
#include "sat/cnf/cnf.h"
#include "sat/bsat/satSolver.h"
#include "bool/kit/kit.h"
#include "aig/ioa/ioa.h"
ABC_NAMESPACE_IMPL_START
/*
Property holds iff it is const 0.
Constraint holds iff it is const 0.
The following structure is used for folding constraints:
- the output of OR gate is 0 as long as all constraints hold
- as soon as one constraint fail, the property output becomes 0 forever
because the flop becomes 1 and it stays 1 forever
property output
|
|-----|
| and |
|-----|
| |
| / \
| /inv\
| -----
____| |_________________________
| | |
/ \ ----------- |
/ \ | or | |
/ \ ----------- |
/ logic \ | | | |
/ cone \ | | | |
/___________\ | | | |
| | ------ |
| | |flop| (init=0) |
| | ------ |
| | | |
| | |______________|
| |
c1 c2
*/
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Collects the supergate.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Saig_DetectConstrCollectSuper_rec( Aig_Obj_t * pObj, Vec_Ptr_t * vSuper )
{
// if the new node is complemented or a PI, another gate begins
if ( Aig_IsComplement(pObj) || !Aig_ObjIsNode(pObj) )//|| (Aig_ObjRefs(pObj) > 1) )
{
Vec_PtrPushUnique( vSuper, Aig_Not(pObj) );
return;
}
// go through the branches
Saig_DetectConstrCollectSuper_rec( Aig_ObjChild0(pObj), vSuper );
Saig_DetectConstrCollectSuper_rec( Aig_ObjChild1(pObj), vSuper );
}
/**Function*************************************************************
Synopsis [Collects the supergate.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Ptr_t * Saig_DetectConstrCollectSuper( Aig_Obj_t * pObj )
{
Vec_Ptr_t * vSuper;
assert( !Aig_IsComplement(pObj) );
assert( Aig_ObjIsAnd(pObj) );
vSuper = Vec_PtrAlloc( 4 );
Saig_DetectConstrCollectSuper_rec( Aig_ObjChild0(pObj), vSuper );
Saig_DetectConstrCollectSuper_rec( Aig_ObjChild1(pObj), vSuper );
return vSuper;
}
/**Function*************************************************************
Synopsis [Returns NULL if not contained, or array with unique entries.]
Description [Returns NULL if vSuper2 is not contained in vSuper. Otherwise
returns the array of entries in vSuper that are not found in vSuper2.]
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Ptr_t * Saig_ManDetectConstrCheckCont( Vec_Ptr_t * vSuper, Vec_Ptr_t * vSuper2 )
{
Vec_Ptr_t * vUnique;
Aig_Obj_t * pObj, * pObj2;
int i;
Vec_PtrForEachEntry( Aig_Obj_t *, vSuper2, pObj2, i )
if ( Vec_PtrFind( vSuper, pObj2 ) == -1 )
return 0;
vUnique = Vec_PtrAlloc( 100 );
Vec_PtrForEachEntry( Aig_Obj_t *, vSuper, pObj, i )
if ( Vec_PtrFind( vSuper2, pObj ) == -1 )
Vec_PtrPush( vUnique, pObj );
return vUnique;
}
/**Function*************************************************************
Synopsis [Detects constraints using structural methods.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Saig_ManDetectConstr( Aig_Man_t * p, int iOut, Vec_Ptr_t ** pvOuts, Vec_Ptr_t ** pvCons )
{
Vec_Ptr_t * vSuper, * vSuper2 = NULL, * vUnique;
Aig_Obj_t * pObj, * pObj2, * pFlop;
int i, nFlops, RetValue;
assert( iOut >= 0 && iOut < Saig_ManPoNum(p) );
*pvOuts = NULL;
*pvCons = NULL;
pObj = Aig_ObjChild0( Aig_ManCo(p, iOut) );
if ( pObj == Aig_ManConst0(p) )
{
vUnique = Vec_PtrStart( 1 );
Vec_PtrWriteEntry( vUnique, 0, Aig_ManConst1(p) );
*pvOuts = vUnique;
*pvCons = Vec_PtrAlloc( 0 );
return -1;
}
if ( Aig_IsComplement(pObj) || !Aig_ObjIsNode(pObj) )
{
printf( "The output is not an AND.\n" );
return 0;
}
vSuper = Saig_DetectConstrCollectSuper( pObj );
assert( Vec_PtrSize(vSuper) >= 2 );
nFlops = 0;
Vec_PtrForEachEntry( Aig_Obj_t *, vSuper, pObj, i )
nFlops += Saig_ObjIsLo( p, Aig_Regular(pObj) );
if ( nFlops == 0 )
{
printf( "There is no flop outputs.\n" );
Vec_PtrFree( vSuper );
return 0;
}
// try flops
vUnique = NULL;
Vec_PtrForEachEntry( Aig_Obj_t *, vSuper, pObj, i )
{
pFlop = Aig_Regular( pObj );
if ( !Saig_ObjIsLo(p, pFlop) )
continue;
pFlop = Saig_ObjLoToLi( p, pFlop );
pObj2 = Aig_ObjChild0( pFlop );
if ( !Aig_IsComplement(pObj2) || !Aig_ObjIsNode(Aig_Regular(pObj2)) )
continue;
vSuper2 = Saig_DetectConstrCollectSuper( Aig_Regular(pObj2) );
// every node in vSuper2 should appear in vSuper
vUnique = Saig_ManDetectConstrCheckCont( vSuper, vSuper2 );
if ( vUnique != NULL )
{
/// assert( !Aig_IsComplement(pObj) );
// assert( Vec_PtrFind( vSuper2, pObj ) >= 0 );
if ( Aig_IsComplement(pObj) )
{
printf( "Special flop input is complemented.\n" );
Vec_PtrFreeP( &vUnique );
Vec_PtrFree( vSuper2 );
break;
}
if ( Vec_PtrFind( vSuper2, pObj ) == -1 )
{
printf( "Cannot find special flop about the inputs of OR gate.\n" );
Vec_PtrFreeP( &vUnique );
Vec_PtrFree( vSuper2 );
break;
}
// remove the flop output
Vec_PtrRemove( vSuper2, pObj );
break;
}
Vec_PtrFree( vSuper2 );
}
Vec_PtrFree( vSuper );
if ( vUnique == NULL )
{
printf( "There is no structural constraints.\n" );
return 0;
}
// vUnique contains unique entries
// vSuper2 contains the supergate
printf( "Output %d : Structural analysis found %d original properties and %d constraints.\n",
iOut, Vec_PtrSize(vUnique), Vec_PtrSize(vSuper2) );
// remember the number of constraints
RetValue = Vec_PtrSize(vSuper2);
// make the AND of properties
// Vec_PtrFree( vUnique );
// Vec_PtrFree( vSuper2 );
*pvOuts = vUnique;
*pvCons = vSuper2;
return RetValue;
}
/**Function*************************************************************
Synopsis [Procedure used for sorting nodes by ID.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Saig_ManDupCompare( Aig_Obj_t ** pp1, Aig_Obj_t ** pp2 )
{
int Diff = Aig_ObjToLit(*pp1) - Aig_ObjToLit(*pp2);
if ( Diff < 0 )
return -1;
if ( Diff > 0 )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Duplicates the AIG while unfolding constraints.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Aig_Man_t * Saig_ManDupUnfoldConstrs( Aig_Man_t * pAig )
{
Vec_Ptr_t * vOutsAll, * vConsAll;
Vec_Ptr_t * vOuts, * vCons, * vCons0;
Aig_Man_t * pAigNew;
Aig_Obj_t * pMiter, * pObj;
int i, k, RetValue;
// detect constraints for each output
vOutsAll = Vec_PtrAlloc( Saig_ManPoNum(pAig) );
vConsAll = Vec_PtrAlloc( Saig_ManPoNum(pAig) );
Saig_ManForEachPo( pAig, pObj, i )
{
RetValue = Saig_ManDetectConstr( pAig, i, &vOuts, &vCons );
if ( RetValue == 0 )
{
Vec_PtrFreeP( &vOuts );
Vec_PtrFreeP( &vCons );
Vec_VecFree( (Vec_Vec_t *)vOutsAll );
Vec_VecFree( (Vec_Vec_t *)vConsAll );
return Aig_ManDupDfs( pAig );
}
Vec_PtrSort( vOuts, (int (*)(const void *, const void *))Saig_ManDupCompare );
Vec_PtrSort( vCons, (int (*)(const void *, const void *))Saig_ManDupCompare );
Vec_PtrPush( vOutsAll, vOuts );
Vec_PtrPush( vConsAll, vCons );
}
// check if constraints are compatible
vCons0 = (Vec_Ptr_t *)Vec_PtrEntry( vConsAll, 0 );
Vec_PtrForEachEntry( Vec_Ptr_t *, vConsAll, vCons, i )
if ( Vec_PtrSize(vCons) )
vCons0 = vCons;
Vec_PtrForEachEntry( Vec_Ptr_t *, vConsAll, vCons, i )
{
// Constant 0 outputs are always compatible (vOuts stores the negation)
vOuts = (Vec_Ptr_t *)Vec_PtrEntry( vOutsAll, i );
if ( Vec_PtrSize(vOuts) == 1 && (Aig_Obj_t *)Vec_PtrEntry( vOuts, 0 ) == Aig_ManConst1(pAig) )
continue;
if ( !Vec_PtrEqual(vCons0, vCons) )
break;
}
if ( i < Vec_PtrSize(vConsAll) )
{
printf( "Collected constraints are not compatible.\n" );
Vec_VecFree( (Vec_Vec_t *)vOutsAll );
Vec_VecFree( (Vec_Vec_t *)vConsAll );
return Aig_ManDupDfs( pAig );
}
// start the new manager
pAigNew = Aig_ManStart( Aig_ManNodeNum(pAig) );
pAigNew->pName = Abc_UtilStrsav( pAig->pName );
// map the constant node
Aig_ManConst1(pAig)->pData = Aig_ManConst1( pAigNew );
// create variables for PIs
Aig_ManForEachCi( pAig, pObj, i )
pObj->pData = Aig_ObjCreateCi( pAigNew );
// add internal nodes of this frame
Aig_ManForEachNode( pAig, pObj, i )
pObj->pData = Aig_And( pAigNew, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
// transform each output
Vec_PtrForEachEntry( Vec_Ptr_t *, vOutsAll, vOuts, i )
{
// AND the outputs
pMiter = Aig_ManConst1( pAigNew );
Vec_PtrForEachEntry( Aig_Obj_t *, vOuts, pObj, k )
pMiter = Aig_And( pAigNew, pMiter, Aig_Not(Aig_ObjRealCopy(pObj)) );
Aig_ObjCreateCo( pAigNew, pMiter );
}
// add constraints
pAigNew->nConstrs = Vec_PtrSize(vCons0);
Vec_PtrForEachEntry( Aig_Obj_t *, vCons0, pObj, i )
Aig_ObjCreateCo( pAigNew, Aig_ObjRealCopy(pObj) );
// transfer to register outputs
Saig_ManForEachLi( pAig, pObj, i )
Aig_ObjCreateCo( pAigNew, Aig_ObjChild0Copy(pObj) );
// Vec_PtrFreeP( &vOuts );
// Vec_PtrFreeP( &vCons );
Vec_VecFree( (Vec_Vec_t *)vOutsAll );
Vec_VecFree( (Vec_Vec_t *)vConsAll );
Aig_ManSetRegNum( pAigNew, Aig_ManRegNum(pAig) );
Aig_ManCleanup( pAigNew );
Aig_ManSeqCleanup( pAigNew );
return pAigNew;
}
/**Function*************************************************************
Synopsis [Duplicates the AIG while folding in the constraints.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Aig_Man_t * Saig_ManDupFoldConstrs( Aig_Man_t * pAig, Vec_Int_t * vConstrs )
{
Aig_Man_t * pAigNew;
Aig_Obj_t * pMiter, * pFlopOut, * pFlopIn, * pObj;
int Entry, i;
assert( Saig_ManRegNum(pAig) > 0 );
// start the new manager
pAigNew = Aig_ManStart( Aig_ManNodeNum(pAig) );
pAigNew->pName = Abc_UtilStrsav( pAig->pName );
// map the constant node
Aig_ManConst1(pAig)->pData = Aig_ManConst1( pAigNew );
// create variables for PIs
Aig_ManForEachCi( pAig, pObj, i )
pObj->pData = Aig_ObjCreateCi( pAigNew );
// add internal nodes of this frame
Aig_ManForEachNode( pAig, pObj, i )
pObj->pData = Aig_And( pAigNew, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
// OR the constraint outputs
pMiter = Aig_ManConst0( pAigNew );
Vec_IntForEachEntry( vConstrs, Entry, i )
{
assert( Entry > 0 && Entry < Saig_ManPoNum(pAig) );
pObj = Aig_ManCo( pAig, Entry );
pMiter = Aig_Or( pAigNew, pMiter, Aig_ObjChild0Copy(pObj) );
}
// create additional flop
pFlopOut = Aig_ObjCreateCi( pAigNew );
pFlopIn = Aig_Or( pAigNew, pMiter, pFlopOut );
// create primary output
Saig_ManForEachPo( pAig, pObj, i )
{
pMiter = Aig_And( pAigNew, Aig_ObjChild0Copy(pObj), Aig_Not(pFlopIn) );
Aig_ObjCreateCo( pAigNew, pMiter );
}
// transfer to register outputs
Saig_ManForEachLi( pAig, pObj, i )
Aig_ObjCreateCo( pAigNew, Aig_ObjChild0Copy(pObj) );
// create additional flop
Aig_ObjCreateCo( pAigNew, pFlopIn );
Aig_ManSetRegNum( pAigNew, Aig_ManRegNum(pAig)+1 );
Aig_ManCleanup( pAigNew );
Aig_ManSeqCleanup( pAigNew );
return pAigNew;
}
/**Function*************************************************************
Synopsis [Tests the above two procedures.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Saig_ManFoldConstrTest( Aig_Man_t * pAig )
{
Aig_Man_t * pAig1, * pAig2;
Vec_Int_t * vConstrs;
// unfold constraints
pAig1 = Saig_ManDupUnfoldConstrs( pAig );
// create the constraint list
vConstrs = Vec_IntStartNatural( Saig_ManPoNum(pAig1) );
Vec_IntRemove( vConstrs, 0 );
// fold constraints back
pAig2 = Saig_ManDupFoldConstrs( pAig1, vConstrs );
Vec_IntFree( vConstrs );
// compare the two AIGs
Ioa_WriteAiger( pAig2, "test.aig", 0, 0 );
Aig_ManStop( pAig1 );
Aig_ManStop( pAig2 );
}
/**Function*************************************************************
Synopsis [Experiment with the above procedure.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Saig_ManDetectConstrTest( Aig_Man_t * p )
{
Vec_Ptr_t * vOuts, * vCons;
int RetValue = Saig_ManDetectConstr( p, 0, &vOuts, &vCons );
Vec_PtrFreeP( &vOuts );
Vec_PtrFreeP( &vCons );
return RetValue;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END