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|
/**CFile****************************************************************
FileName [aigTsim.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [AIG package.]
Synopsis [Ternary simulation.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - April 28, 2007.]
Revision [$Id: aigTsim.c,v 1.00 2007/04/28 00:00:00 alanmi Exp $]
***********************************************************************/
#include "aig.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
#define TSI_MAX_ROUNDS 1000
#define TSI_ONE_SERIES 300
#define AIG_XVS0 1
#define AIG_XVS1 2
#define AIG_XVSX 3
static inline void Aig_ObjSetXsim( Aig_Obj_t * pObj, int Value ) { pObj->nCuts = Value; }
static inline int Aig_ObjGetXsim( Aig_Obj_t * pObj ) { return pObj->nCuts; }
static inline int Aig_XsimInv( int Value )
{
if ( Value == AIG_XVS0 )
return AIG_XVS1;
if ( Value == AIG_XVS1 )
return AIG_XVS0;
assert( Value == AIG_XVSX );
return AIG_XVSX;
}
static inline int Aig_XsimAnd( int Value0, int Value1 )
{
if ( Value0 == AIG_XVSX || Value1 == AIG_XVSX )
return AIG_XVSX;
if ( Value0 == AIG_XVS0 || Value1 == AIG_XVS0 )
return AIG_XVS0;
assert( Value0 == AIG_XVS1 && Value1 == AIG_XVS1 );
return AIG_XVS1;
}
static inline int Aig_XsimRand2()
{
return (Aig_ManRandom(0) & 1) ? AIG_XVS1 : AIG_XVS0;
}
static inline int Aig_XsimRand3()
{
int RetValue;
do {
RetValue = Aig_ManRandom(0) & 3;
} while ( RetValue == 0 );
return RetValue;
}
static inline int Aig_ObjGetXsimFanin0( Aig_Obj_t * pObj )
{
int RetValue;
RetValue = Aig_ObjGetXsim(Aig_ObjFanin0(pObj));
return Aig_ObjFaninC0(pObj)? Aig_XsimInv(RetValue) : RetValue;
}
static inline int Aig_ObjGetXsimFanin1( Aig_Obj_t * pObj )
{
int RetValue;
RetValue = Aig_ObjGetXsim(Aig_ObjFanin1(pObj));
return Aig_ObjFaninC1(pObj)? Aig_XsimInv(RetValue) : RetValue;
}
static inline void Aig_XsimPrint( FILE * pFile, int Value )
{
if ( Value == AIG_XVS0 )
{
fprintf( pFile, "0" );
return;
}
if ( Value == AIG_XVS1 )
{
fprintf( pFile, "1" );
return;
}
assert( Value == AIG_XVSX );
fprintf( pFile, "x" );
}
// simulation manager
typedef struct Aig_Tsi_t_ Aig_Tsi_t;
struct Aig_Tsi_t_
{
Aig_Man_t * pAig; // the original AIG manager
// ternary state representation
int nWords; // the number of words in the states
Vec_Ptr_t * vStates; // the collection of ternary states
Aig_MmFixed_t * pMem; // memory for ternary states
// hash table for terminary states
unsigned ** pBins;
int nBins;
};
static inline unsigned * Aig_TsiNext( unsigned * pState, int nWords ) { return *((unsigned **)(pState + nWords)); }
static inline void Aig_TsiSetNext( unsigned * pState, int nWords, unsigned * pNext ) { *((unsigned **)(pState + nWords)) = pNext; }
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Allocates simulation manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Aig_Tsi_t * Aig_TsiStart( Aig_Man_t * pAig )
{
Aig_Tsi_t * p;
p = ABC_ALLOC( Aig_Tsi_t, 1 );
memset( p, 0, sizeof(Aig_Tsi_t) );
p->pAig = pAig;
p->nWords = Aig_BitWordNum( 2*Aig_ManRegNum(pAig) );
p->vStates = Vec_PtrAlloc( 1000 );
p->pMem = Aig_MmFixedStart( sizeof(unsigned) * p->nWords + sizeof(unsigned *), 10000 );
p->nBins = Aig_PrimeCudd(TSI_MAX_ROUNDS/2);
p->pBins = ABC_ALLOC( unsigned *, p->nBins );
memset( p->pBins, 0, sizeof(unsigned *) * p->nBins );
return p;
}
/**Function*************************************************************
Synopsis [Deallocates simulation manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Aig_TsiStop( Aig_Tsi_t * p )
{
Aig_MmFixedStop( p->pMem, 0 );
Vec_PtrFree( p->vStates );
ABC_FREE( p->pBins );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis [Computes hash value of the node using its simulation info.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Aig_TsiStateHash( unsigned * pState, int nWords, int nTableSize )
{
static int s_FPrimes[128] = {
1009, 1049, 1093, 1151, 1201, 1249, 1297, 1361, 1427, 1459,
1499, 1559, 1607, 1657, 1709, 1759, 1823, 1877, 1933, 1997,
2039, 2089, 2141, 2213, 2269, 2311, 2371, 2411, 2467, 2543,
2609, 2663, 2699, 2741, 2797, 2851, 2909, 2969, 3037, 3089,
3169, 3221, 3299, 3331, 3389, 3461, 3517, 3557, 3613, 3671,
3719, 3779, 3847, 3907, 3943, 4013, 4073, 4129, 4201, 4243,
4289, 4363, 4441, 4493, 4549, 4621, 4663, 4729, 4793, 4871,
4933, 4973, 5021, 5087, 5153, 5227, 5281, 5351, 5417, 5471,
5519, 5573, 5651, 5693, 5749, 5821, 5861, 5923, 6011, 6073,
6131, 6199, 6257, 6301, 6353, 6397, 6481, 6563, 6619, 6689,
6737, 6803, 6863, 6917, 6977, 7027, 7109, 7187, 7237, 7309,
7393, 7477, 7523, 7561, 7607, 7681, 7727, 7817, 7877, 7933,
8011, 8039, 8059, 8081, 8093, 8111, 8123, 8147
};
unsigned uHash;
int i;
uHash = 0;
for ( i = 0; i < nWords; i++ )
uHash ^= pState[i] * s_FPrimes[i & 0x7F];
return uHash % nTableSize;
}
/**Function*************************************************************
Synopsis [Inserts value into the table.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Aig_TsiStateLookup( Aig_Tsi_t * p, unsigned * pState, int nWords )
{
unsigned * pEntry;
int Hash;
Hash = Aig_TsiStateHash( pState, nWords, p->nBins );
for ( pEntry = p->pBins[Hash]; pEntry; pEntry = Aig_TsiNext(pEntry, nWords) )
if ( !memcmp( pEntry, pState, sizeof(unsigned) * nWords ) )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Inserts value into the table.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Aig_TsiStateInsert( Aig_Tsi_t * p, unsigned * pState, int nWords )
{
int Hash = Aig_TsiStateHash( pState, nWords, p->nBins );
assert( !Aig_TsiStateLookup( p, pState, nWords ) );
Aig_TsiSetNext( pState, nWords, p->pBins[Hash] );
p->pBins[Hash] = pState;
}
/**Function*************************************************************
Synopsis [Inserts value into the table.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
unsigned * Aig_TsiStateNew( Aig_Tsi_t * p )
{
unsigned * pState;
pState = (unsigned *)Aig_MmFixedEntryFetch( p->pMem );
memset( pState, 0, sizeof(unsigned) * p->nWords );
Vec_PtrPush( p->vStates, pState );
return pState;
}
/**Function*************************************************************
Synopsis [Inserts value into the table.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Aig_TsiStatePrint( Aig_Tsi_t * p, unsigned * pState )
{
int i, Value, nZeros = 0, nOnes = 0, nDcs = 0;
for ( i = 0; i < Aig_ManRegNum(p->pAig); i++ )
{
Value = (Aig_InfoHasBit( pState, 2 * i + 1 ) << 1) | Aig_InfoHasBit( pState, 2 * i );
if ( Value == 1 )
printf( "0" ), nZeros++;
else if ( Value == 2 )
printf( "1" ), nOnes++;
else if ( Value == 3 )
printf( "x" ), nDcs++;
else
assert( 0 );
}
printf( " (0=%5d, 1=%5d, x=%5d)\n", nZeros, nOnes, nDcs );
}
/**Function*************************************************************
Synopsis [Count constant values in the state.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Aig_TsiStateCount( Aig_Tsi_t * p, unsigned * pState )
{
Aig_Obj_t * pObjLi, * pObjLo;
int i, Value, nCounter = 0;
Aig_ManForEachLiLoSeq( p->pAig, pObjLi, pObjLo, i )
{
Value = (Aig_InfoHasBit( pState, 2 * i + 1 ) << 1) | Aig_InfoHasBit( pState, 2 * i );
nCounter += (Value == 1 || Value == 2);
}
return nCounter;
}
/**Function*************************************************************
Synopsis [Count constant values in the state.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Aig_TsiStateOrAll( Aig_Tsi_t * pTsi, unsigned * pState )
{
unsigned * pPrev;
int i, k;
Vec_PtrForEachEntry( pTsi->vStates, pPrev, i )
{
for ( k = 0; k < pTsi->nWords; k++ )
pState[k] |= pPrev[k];
}
}
/**Function*************************************************************
Synopsis [Cycles the circuit to create a new initial state.]
Description [Simulates the circuit with random input for the given
number of timeframes to get a better initial state.]
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Ptr_t * Aig_ManTernarySimulate( Aig_Man_t * p, int fVerbose )
{
Aig_Tsi_t * pTsi;
Vec_Ptr_t * vMap;
Aig_Obj_t * pObj, * pObjLi, * pObjLo;
unsigned * pState;//, * pPrev;
int i, f, fConstants, Value, nCounter;
// allocate the simulation manager
pTsi = Aig_TsiStart( p );
// initialize the values
Aig_ObjSetXsim( Aig_ManConst1(p), AIG_XVS1 );
Aig_ManForEachPiSeq( p, pObj, i )
Aig_ObjSetXsim( pObj, AIG_XVSX );
Aig_ManForEachLoSeq( p, pObj, i )
Aig_ObjSetXsim( pObj, AIG_XVS0 );
// simulate for the given number of timeframes
for ( f = 0; f < TSI_MAX_ROUNDS; f++ )
{
// collect this state
pState = Aig_TsiStateNew( pTsi );
Aig_ManForEachLiLoSeq( p, pObjLi, pObjLo, i )
{
Value = Aig_ObjGetXsim(pObjLo);
if ( Value & 1 )
Aig_InfoSetBit( pState, 2 * i );
if ( Value & 2 )
Aig_InfoSetBit( pState, 2 * i + 1 );
}
// printf( "%d ", Aig_TsiStateCount(pTsi, pState) );
//Aig_TsiStatePrint( pTsi, pState );
// check if this state exists
if ( Aig_TsiStateLookup( pTsi, pState, pTsi->nWords ) )
break;
// nCounter = 0;
// Aig_ManForEachLiLoSeq( p, pObjLi, pObjLo, i )
// nCounter += (Aig_ObjGetXsim(pObjLo) == AIG_XVS0);
//printf( "%d -> ", nCounter );
// insert this state
Aig_TsiStateInsert( pTsi, pState, pTsi->nWords );
// simulate internal nodes
Aig_ManForEachNode( p, pObj, i )
Aig_ObjSetXsim( pObj, Aig_XsimAnd(Aig_ObjGetXsimFanin0(pObj), Aig_ObjGetXsimFanin1(pObj)) );
// transfer the latch values
Aig_ManForEachLiSeq( p, pObj, i )
Aig_ObjSetXsim( pObj, Aig_ObjGetXsimFanin0(pObj) );
nCounter = 0;
Aig_ManForEachLiLoSeq( p, pObjLi, pObjLo, i )
{
if ( f < TSI_ONE_SERIES )
Aig_ObjSetXsim( pObjLo, Aig_ObjGetXsim(pObjLi) );
else
{
if ( Aig_ObjGetXsim(pObjLi) != Aig_ObjGetXsim(pObjLo) )
Aig_ObjSetXsim( pObjLo, AIG_XVSX );
}
nCounter += (Aig_ObjGetXsim(pObjLo) == AIG_XVS0);
}
// if ( f && (f % 1000 == 0) )
// printf( "%d \n", f );
//printf( "%d ", nCounter );
}
//printf( "\n" );
if ( f == TSI_MAX_ROUNDS )
{
printf( "Aig_ManTernarySimulate(): Did not reach a fixed point after %d iterations (not a bug).\n", TSI_MAX_ROUNDS );
Aig_TsiStop( pTsi );
return NULL;
}
// OR all the states
pState = Vec_PtrEntry( pTsi->vStates, 0 );
Aig_TsiStateOrAll( pTsi, pState );
// check if there are constants
fConstants = 0;
if ( 2*Aig_ManRegNum(p) == 32*pTsi->nWords )
{
for ( i = 0; i < pTsi->nWords; i++ )
if ( pState[i] != ~0 )
fConstants = 1;
}
else
{
for ( i = 0; i < pTsi->nWords - 1; i++ )
if ( pState[i] != ~0 )
fConstants = 1;
if ( pState[i] != Aig_InfoMask( 2*Aig_ManRegNum(p) - 32*(pTsi->nWords-1) ) )
fConstants = 1;
}
if ( fConstants == 0 )
{
Aig_TsiStop( pTsi );
return NULL;
}
// start mapping by adding the true PIs
vMap = Vec_PtrAlloc( Aig_ManPiNum(p) );
Aig_ManForEachPiSeq( p, pObj, i )
Vec_PtrPush( vMap, pObj );
// find constant registers
nCounter = 0;
Aig_ManForEachLiLoSeq( p, pObjLi, pObjLo, i )
{
Value = (Aig_InfoHasBit( pState, 2 * i + 1 ) << 1) | Aig_InfoHasBit( pState, 2 * i );
nCounter += (Value == 1 || Value == 2);
if ( Value == 1 )
Vec_PtrPush( vMap, Aig_ManConst0(p) );
else if ( Value == 2 )
Vec_PtrPush( vMap, Aig_ManConst1(p) );
else if ( Value == 3 )
Vec_PtrPush( vMap, pObjLo );
else
assert( 0 );
// Aig_XsimPrint( stdout, Value );
}
// printf( "\n" );
Aig_TsiStop( pTsi );
if ( fVerbose )
printf( "Detected %d constants after %d iterations of ternary simulation.\n", nCounter, f );
return vMap;
}
/**Function*************************************************************
Synopsis [Reduces the circuit using ternary simulation.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Aig_Man_t * Aig_ManConstReduce( Aig_Man_t * p, int fVerbose )
{
Aig_Man_t * pTemp;
Vec_Ptr_t * vMap;
while ( (vMap = Aig_ManTernarySimulate( p, fVerbose )) )
{
p = Aig_ManRemap( pTemp = p, vMap );
Vec_PtrFree( vMap );
Aig_ManSeqCleanup( p );
if ( fVerbose )
Aig_ManReportImprovement( pTemp, p );
Aig_ManStop( pTemp );
}
return p;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
