Version abc70906

5 files changed, 803 insertions, 0 deletions

diff --git a/src/aig/ioa/ioa.h b/src/aig/ioa/ioa.h
new file mode 100644
index 00000000..3458d12e
--- /dev/null
+++ b/src/aig/ioa/ioa.h
@@ -0,0 +1,80 @@
+/**CFile****************************************************************
+
+  FileName    [ioa.h]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [AIG package.]
+
+  Synopsis    [External declarations.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - April 28, 2007.]
+
+  Revision    [$Id: ioa.h,v 1.00 2007/04/28 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#ifndef __IOA_H__
+#define __IOA_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+////////////////////////////////////////////////////////////////////////
+///                          INCLUDES                                ///
+////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <time.h>
+
+#include "vec.h"
+#include "bar.h"
+#include "aig.h"
+
+////////////////////////////////////////////////////////////////////////
+///                         PARAMETERS                               ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                         BASIC TYPES                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                      MACRO DEFINITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                             ITERATORS                            ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                    FUNCTION DECLARATIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/*=== ioaReadAig.c ========================================================*/
+extern Aig_Man_t *    Ioa_ReadAiger( char * pFileName, int fCheck );
+/*=== ioaWriteAig.c =======================================================*/
+extern void           Ioa_WriteAiger( Aig_Man_t * pMan, char * pFileName, int fWriteSymbols );
+/*=== ioaUtil.c =======================================================*/
+extern int            Ioa_FileSize( char * pFileName );
+extern char *         Ioa_FileNameGeneric( char * FileName );
+extern char *         Ioa_TimeStamp();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
diff --git a/src/aig/ioa/ioaReadAig.c b/src/aig/ioa/ioaReadAig.c
new file mode 100644
index 00000000..937e446f
--- /dev/null
+++ b/src/aig/ioa/ioaReadAig.c
@@ -0,0 +1,312 @@
+/**CFile****************************************************************
+
+  FileName    [ioaReadAiger.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Command processing package.]
+
+  Synopsis    [Procedures to read binary AIGER format developed by
+  Armin Biere, Johannes Kepler University (http://fmv.jku.at/)]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - December 16, 2006.]
+
+  Revision    [$Id: ioaReadAiger.c,v 1.00 2006/12/16 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "ioa.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+unsigned Ioa_ReadAigerDecode( char ** ppPos );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Reads the AIG in the binary AIGER format.]
+
+  Description []
+  
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Aig_Man_t * Ioa_ReadAiger( char * pFileName, int fCheck )
+{
+    Bar_Progress_t * pProgress;
+    FILE * pFile;
+    Vec_Ptr_t * vNodes, * vDrivers;//, * vTerms;
+    Aig_Obj_t * pObj, * pNode0, * pNode1;
+    Aig_Man_t * pManNew;
+    int nTotal, nInputs, nOutputs, nLatches, nAnds, nFileSize, i;//, iTerm, nDigits;
+    char * pContents, * pDrivers, * pSymbols, * pCur, * pName;//, * pType;
+    unsigned uLit0, uLit1, uLit;
+
+    // read the file into the buffer
+    nFileSize = Ioa_FileSize( pFileName );
+    pFile = fopen( pFileName, "rb" );
+    pContents = ALLOC( char, nFileSize );
+    fread( pContents, nFileSize, 1, pFile );
+    fclose( pFile );
+
+    // check if the input file format is correct
+    if ( strncmp(pContents, "aig", 3) != 0 )
+    {
+        fprintf( stdout, "Wrong input file format.\n" );
+        return NULL;
+    }
+
+    // read the file type
+    pCur = pContents;         while ( *pCur++ != ' ' );
+    // read the number of objects
+    nTotal = atoi( pCur );    while ( *pCur++ != ' ' );
+    // read the number of inputs
+    nInputs = atoi( pCur );   while ( *pCur++ != ' ' );
+    // read the number of latches
+    nLatches = atoi( pCur );  while ( *pCur++ != ' ' );
+    // read the number of outputs
+    nOutputs = atoi( pCur );  while ( *pCur++ != ' ' );
+    // read the number of nodes
+    nAnds = atoi( pCur );     while ( *pCur++ != '\n' );  
+    // check the parameters
+    if ( nTotal != nInputs + nLatches + nAnds )
+    {
+        fprintf( stdout, "The paramters are wrong.\n" );
+        return NULL;
+    }
+
+    // allocate the empty AIG
+    pManNew = Aig_ManStart( nAnds );
+    pName = Ioa_FileNameGeneric( pFileName );
+    pManNew->pName = Aig_UtilStrsav( pName );
+//    pManNew->pSpec = Ioa_UtilStrsav( pFileName );
+    free( pName );
+
+    // prepare the array of nodes
+    vNodes = Vec_PtrAlloc( 1 + nInputs + nLatches + nAnds );
+    Vec_PtrPush( vNodes, Aig_ManConst0(pManNew) );
+
+    // create the PIs
+    for ( i = 0; i < nInputs + nLatches; i++ )
+    {
+        pObj = Aig_ObjCreatePi(pManNew);    
+        Vec_PtrPush( vNodes, pObj );
+    }
+/*
+    // create the POs
+    for ( i = 0; i < nOutputs + nLatches; i++ )
+    {
+        pObj = Aig_ObjCreatePo(pManNew);   
+    }
+*/
+    // create the latches
+    pManNew->nRegs = nLatches;
+/*
+    nDigits = Ioa_Base10Log( nLatches );
+    for ( i = 0; i < nLatches; i++ )
+    {
+        pObj = Aig_ObjCreateLatch(pManNew);
+        Aig_LatchSetInit0( pObj );
+        pNode0 = Aig_ObjCreateBi(pManNew);
+        pNode1 = Aig_ObjCreateBo(pManNew);
+        Aig_ObjAddFanin( pObj, pNode0 );
+        Aig_ObjAddFanin( pNode1, pObj );
+        Vec_PtrPush( vNodes, pNode1 );
+        // assign names to latch and its input
+//        Aig_ObjAssignName( pObj, Aig_ObjNameDummy("_L", i, nDigits), NULL );
+//        printf( "Creating latch %s with input %d and output %d.\n", Aig_ObjName(pObj), pNode0->Id, pNode1->Id );
+    } 
+*/
+    
+    // remember the beginning of latch/PO literals
+    pDrivers = pCur;
+
+    // scroll to the beginning of the binary data
+    for ( i = 0; i < nLatches + nOutputs; )
+        if ( *pCur++ == '\n' )
+            i++;
+
+    // create the AND gates
+    pProgress = Bar_ProgressStart( stdout, nAnds );
+    for ( i = 0; i < nAnds; i++ )
+    {
+        Bar_ProgressUpdate( pProgress, i, NULL );
+        uLit = ((i + 1 + nInputs + nLatches) << 1);
+        uLit1 = uLit  - Ioa_ReadAigerDecode( &pCur );
+        uLit0 = uLit1 - Ioa_ReadAigerDecode( &pCur );
+//        assert( uLit1 > uLit0 );
+        pNode0 = Aig_NotCond( Vec_PtrEntry(vNodes, uLit0 >> 1), uLit0 & 1 );
+        pNode1 = Aig_NotCond( Vec_PtrEntry(vNodes, uLit1 >> 1), uLit1 & 1 );
+        assert( Vec_PtrSize(vNodes) == i + 1 + nInputs + nLatches );
+        Vec_PtrPush( vNodes, Aig_And(pManNew, pNode0, pNode1) );
+    }
+    Bar_ProgressStop( pProgress );
+
+    // remember the place where symbols begin
+    pSymbols = pCur;
+
+    // read the latch driver literals
+    vDrivers = Vec_PtrAlloc( nLatches + nOutputs );
+    pCur = pDrivers;
+//    Aig_ManForEachLatchInput( pManNew, pObj, i )
+    for ( i = 0; i < nLatches; i++ )
+    {
+        uLit0 = atoi( pCur );  while ( *pCur++ != '\n' );
+        pNode0 = Aig_NotCond( Vec_PtrEntry(vNodes, uLit0 >> 1), (uLit0 & 1) );//^ (uLit0 < 2) );
+//        Aig_ObjAddFanin( pObj, pNode0 );
+        Vec_PtrPush( vDrivers, pNode0 );
+    }
+    // read the PO driver literals
+//    Aig_ManForEachPo( pManNew, pObj, i )
+    for ( i = 0; i < nOutputs; i++ )
+    {
+        uLit0 = atoi( pCur );  while ( *pCur++ != '\n' );
+        pNode0 = Aig_NotCond( Vec_PtrEntry(vNodes, uLit0 >> 1), (uLit0 & 1) );//^ (uLit0 < 2) );
+//        Aig_ObjAddFanin( pObj, pNode0 );
+        Vec_PtrPush( vDrivers, pNode0 );
+    }
+
+
+    // create the POs
+    for ( i = 0; i < nOutputs; i++ )
+        Aig_ObjCreatePo( pManNew, Vec_PtrEntry(vDrivers, nLatches + i) );
+    for ( i = 0; i < nLatches; i++ )
+        Aig_ObjCreatePo( pManNew, Vec_PtrEntry(vDrivers, i) );
+    Vec_PtrFree( vDrivers );
+
+/*
+    // read the names if present
+    pCur = pSymbols;
+    if ( *pCur != 'c' )
+    {
+        int Counter = 0;
+        while ( pCur < pContents + nFileSize && *pCur != 'c' )
+        {
+            // get the terminal type
+            pType = pCur;
+            if ( *pCur == 'i' )
+                vTerms = pManNew->vPis;
+            else if ( *pCur == 'l' )
+                vTerms = pManNew->vBoxes;
+            else if ( *pCur == 'o' )
+                vTerms = pManNew->vPos;
+            else
+            {
+                fprintf( stdout, "Wrong terminal type.\n" );
+                return NULL;
+            }
+            // get the terminal number
+            iTerm = atoi( ++pCur );  while ( *pCur++ != ' ' );
+            // get the node
+            if ( iTerm >= Vec_PtrSize(vTerms) )
+            {
+                fprintf( stdout, "The number of terminal is out of bound.\n" );
+                return NULL;
+            }
+            pObj = Vec_PtrEntry( vTerms, iTerm );
+            if ( *pType == 'l' )
+                pObj = Aig_ObjFanout0(pObj);
+            // assign the name
+            pName = pCur;          while ( *pCur++ != '\n' );
+            // assign this name 
+            *(pCur-1) = 0;
+            Aig_ObjAssignName( pObj, pName, NULL );
+            if ( *pType == 'l' )
+            {
+                Aig_ObjAssignName( Aig_ObjFanin0(pObj), Aig_ObjName(pObj), "L" );
+                Aig_ObjAssignName( Aig_ObjFanin0(Aig_ObjFanin0(pObj)), Aig_ObjName(pObj), "_in" );
+            }
+            // mark the node as named
+            pObj->pCopy = (Aig_Obj_t *)Aig_ObjName(pObj);
+        } 
+
+        // assign the remaining names
+        Aig_ManForEachPi( pManNew, pObj, i )
+        {
+            if ( pObj->pCopy ) continue;
+            Aig_ObjAssignName( pObj, Aig_ObjName(pObj), NULL );
+            Counter++;
+        }
+        Aig_ManForEachLatchOutput( pManNew, pObj, i )
+        {
+            if ( pObj->pCopy ) continue;
+            Aig_ObjAssignName( pObj, Aig_ObjName(pObj), NULL );
+            Aig_ObjAssignName( Aig_ObjFanin0(pObj), Aig_ObjName(pObj), "L" );
+            Aig_ObjAssignName( Aig_ObjFanin0(Aig_ObjFanin0(pObj)), Aig_ObjName(pObj), "_in" );
+            Counter++;
+        }
+        Aig_ManForEachPo( pManNew, pObj, i )
+        {
+            if ( pObj->pCopy ) continue;
+            Aig_ObjAssignName( pObj, Aig_ObjName(pObj), NULL );
+            Counter++;
+        }
+        if ( Counter )
+            printf( "Ioa_ReadAiger(): Added %d default names for nameless I/O/register objects.\n", Counter );
+    }
+    else
+    {
+//        printf( "Ioa_ReadAiger(): I/O/register names are not given. Generating short names.\n" );
+        Aig_ManShortNames( pManNew );
+    }
+*/
+
+    // skipping the comments
+    free( pContents );
+    Vec_PtrFree( vNodes );
+
+    // remove the extra nodes
+    Aig_ManCleanup( pManNew );
+
+    // check the result
+    if ( fCheck && !Aig_ManCheck( pManNew ) )
+    {
+        printf( "Ioa_ReadAiger: The network check has failed.\n" );
+        Aig_ManStop( pManNew );
+        return NULL;
+    }
+    return pManNew;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Extracts one unsigned AIG edge from the input buffer.]
+
+  Description [This procedure is a slightly modified version of Armin Biere's
+  procedure "unsigned decode (FILE * file)". ]
+  
+  SideEffects [Updates the current reading position.]
+
+  SeeAlso     []
+
+***********************************************************************/
+unsigned Ioa_ReadAigerDecode( char ** ppPos )
+{
+    unsigned x = 0, i = 0;
+    unsigned char ch;
+
+//    while ((ch = getnoneofch (file)) & 0x80)
+    while ((ch = *(*ppPos)++) & 0x80)
+        x |= (ch & 0x7f) << (7 * i++);
+
+    return x | (ch << (7 * i));
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/aig/ioa/ioaUtil.c b/src/aig/ioa/ioaUtil.c
new file mode 100644
index 00000000..79dcca1e
--- /dev/null
+++ b/src/aig/ioa/ioaUtil.c
@@ -0,0 +1,117 @@
+/**CFile****************************************************************
+
+  FileName    [ioaUtil.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Command processing package.]
+
+  Synopsis    [Procedures to read binary AIGER format developed by
+  Armin Biere, Johannes Kepler University (http://fmv.jku.at/)]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - December 16, 2006.]
+
+  Revision    [$Id: ioaUtil.c,v 1.00 2006/12/16 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "ioa.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Returns the file size.]
+
+  Description [The file should be closed.]
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ioa_FileSize( char * pFileName )
+{
+    FILE * pFile;
+    int nFileSize;
+    pFile = fopen( pFileName, "r" );
+    if ( pFile == NULL )
+    {
+        printf( "Ioa_FileSize(): The file is unavailable (absent or open).\n" );
+        return 0;
+    }
+    fseek( pFile, 0, SEEK_END );  
+    nFileSize = ftell( pFile ); 
+    fclose( pFile );
+    return nFileSize;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+char * Ioa_FileNameGeneric( char * FileName )
+{
+    char * pDot;
+    char * pUnd;
+    char * pRes;
+    
+    // find the generic name of the file
+    pRes = Aig_UtilStrsav( FileName );
+    // find the pointer to the "." symbol in the file name
+//  pUnd = strstr( FileName, "_" );
+    pUnd = NULL;
+    pDot = strstr( FileName, "." );
+    if ( pUnd )
+        pRes[pUnd - FileName] = 0;
+    else if ( pDot )
+        pRes[pDot - FileName] = 0;
+    return pRes;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns the time stamp.]
+
+  Description [The file should be closed.]
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+char * Ioa_TimeStamp()
+{
+    static char Buffer[100];
+    char * TimeStamp;
+    time_t ltime;
+    // get the current time
+    time( &ltime );
+    TimeStamp = asctime( localtime( &ltime ) );
+    TimeStamp[ strlen(TimeStamp) - 1 ] = 0;
+    strcpy( Buffer, TimeStamp );
+    return Buffer;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/aig/ioa/ioaWriteAig.c b/src/aig/ioa/ioaWriteAig.c
new file mode 100644
index 00000000..74462bbd
--- /dev/null
+++ b/src/aig/ioa/ioaWriteAig.c
@@ -0,0 +1,291 @@
+/**CFile****************************************************************
+
+  FileName    [ioaWriteAiger.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Command processing package.]
+
+  Synopsis    [Procedures to write binary AIGER format developed by
+  Armin Biere, Johannes Kepler University (http://fmv.jku.at/)]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - December 16, 2006.]
+
+  Revision    [$Id: ioaWriteAiger.c,v 1.00 2006/12/16 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "ioa.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+/*
+    The following is taken from the AIGER format description, 
+    which can be found at http://fmv.jku.at/aiger
+*/
+
+
+/*
+         The AIGER And-Inverter Graph (AIG) Format Version 20061129
+         ----------------------------------------------------------
+              Armin Biere, Johannes Kepler University, 2006
+
+  This report describes the AIG file format as used by the AIGER library.
+  The purpose of this report is not only to motivate and document the
+  format, but also to allow independent implementations of writers and
+  readers by giving precise and unambiguous definitions.
+
+  ...
+
+Introduction
+
+  The name AIGER contains as one part the acronym AIG of And-Inverter
+  Graphs and also if pronounced in German sounds like the name of the
+  'Eiger', a mountain in the Swiss alps.  This choice should emphasize the
+  origin of this format. It was first openly discussed at the Alpine
+  Verification Meeting 2006 in Ascona as a way to provide a simple, compact
+  file format for a model checking competition affiliated to CAV 2007.
+
+  ...
+
+Binary Format Definition
+
+  The binary format is semantically a subset of the ASCII format with a
+  slightly different syntax.  The binary format may need to reencode
+  literals, but translating a file in binary format into ASCII format and
+  then back in to binary format will result in the same file.
+
+  The main differences of the binary format to the ASCII format are as
+  follows.  After the header the list of input literals and all the
+  current state literals of a latch can be omitted.  Furthermore the
+  definitions of the AND gates are binary encoded.  However, the symbol
+  table and the comment section are as in the ASCII format.
+
+  The header of an AIGER file in binary format has 'aig' as format
+  identifier, but otherwise is identical to the ASCII header.  The standard
+  file extension for the binary format is therefore '.aig'. 
+  
+  A header for the binary format is still in ASCII encoding:
+
+    aig M I L O A
+
+  Constants, variables and literals are handled in the same way as in the
+  ASCII format.  The first simplifying restriction is on the variable
+  indices of inputs and latches.  The variable indices of inputs come first,
+  followed by the pseudo-primary inputs of the latches and then the variable
+  indices of all LHS of AND gates:
+
+    input variable indices        1,          2,  ... ,  I
+    latch variable indices      I+1,        I+2,  ... ,  (I+L)
+    AND variable indices      I+L+1,      I+L+2,  ... ,  (I+L+A) == M
+
+  The corresponding unsigned literals are
+
+    input literals                2,          4,  ... ,  2*I
+    latch literals            2*I+2,      2*I+4,  ... ,  2*(I+L)
+    AND literals          2*(I+L)+2,  2*(I+L)+4,  ... ,  2*(I+L+A) == 2*M
+                    
+  All literals have to be defined, and therefore 'M = I + L + A'.  With this
+  restriction it becomes possible that the inputs and the current state
+  literals of the latches do not have to be listed explicitly.  Therefore,
+  after the header only the list of 'L' next state literals follows, one per
+  latch on a single line, and then the 'O' outputs, again one per line.
+
+  In the binary format we assume that the AND gates are ordered and respect
+  the child parent relation.  AND gates with smaller literals on the LHS
+  come first.  Therefore we can assume that the literals on the right-hand
+  side of a definition of an AND gate are smaller than the LHS literal.
+  Furthermore we can sort the literals on the RHS, such that the larger
+  literal comes first.  A definition thus consists of three literals
+    
+      lhs rhs0 rhs1
+
+  with 'lhs' even and 'lhs > rhs0 >= rhs1'.  Also the variable indices are
+  pairwise different to avoid combinational self loops.  Since the LHS
+  indices of the definitions are all consecutive (as even integers),
+  the binary format does not have to keep 'lhs'.  In addition, we can use
+  the order restriction and only write the differences 'delta0' and 'delta1'
+  instead of 'rhs0' and 'rhs1', with
+
+      delta0 = lhs - rhs0,  delta1 = rhs0 - rhs1
+  
+  The differences will all be strictly positive, and in practice often very
+  small.  We can take advantage of this fact by the simple little-endian
+  encoding of unsigned integers of the next section.  After the binary delta
+  encoding of the RHSs of all AND gates, the optional symbol table and
+  optional comment section start in the same format as in the ASCII case.
+
+  ...
+
+*/
+
+static unsigned Ioa_ObjMakeLit( int Var, int fCompl )                 { return (Var << 1) | fCompl;    }
+static unsigned Ioa_ObjAigerNum( Aig_Obj_t * pObj )                   { return (unsigned)pObj->pData;  }
+static void     Ioa_ObjSetAigerNum( Aig_Obj_t * pObj, unsigned Num )  { pObj->pData = (void *)Num;     }
+
+int      Ioa_WriteAigerEncode( char * pBuffer, int Pos, unsigned x );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Writes the AIG in the binary AIGER format.]
+
+  Description []
+  
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Ioa_WriteAiger( Aig_Man_t * pMan, char * pFileName, int fWriteSymbols )
+{
+    Bar_Progress_t * pProgress;
+    FILE * pFile;
+    Aig_Obj_t * pObj, * pDriver;
+    int i, nNodes, Pos, nBufferSize;
+    unsigned char * pBuffer;
+    unsigned uLit0, uLit1, uLit;
+
+//    assert( Aig_ManIsStrash(pMan) );
+    // start the output stream
+    pFile = fopen( pFileName, "wb" );
+    if ( pFile == NULL )
+    {
+        fprintf( stdout, "Ioa_WriteAiger(): Cannot open the output file \"%s\".\n", pFileName );
+        return;
+    }
+/*
+    Aig_ManForEachLatch( pMan, pObj, i )
+        if ( !Aig_LatchIsInit0(pObj) )
+        {
+            fprintf( stdout, "Ioa_WriteAiger(): Cannot write AIGER format with non-0 latch init values. Run \"zero\".\n" );
+            return;
+        }
+*/
+    // set the node numbers to be used in the output file
+    nNodes = 0;
+    Ioa_ObjSetAigerNum( Aig_ManConst1(pMan), nNodes++ );
+    Aig_ManForEachPi( pMan, pObj, i )
+        Ioa_ObjSetAigerNum( pObj, nNodes++ );
+    Aig_ManForEachNode( pMan, pObj, i )
+        Ioa_ObjSetAigerNum( pObj, nNodes++ );
+
+    // write the header "M I L O A" where M = I + L + A
+    fprintf( pFile, "aig %u %u %u %u %u\n", 
+        Aig_ManPiNum(pMan) + Aig_ManNodeNum(pMan), 
+        Aig_ManPiNum(pMan) - Aig_ManRegNum(pMan),
+        Aig_ManRegNum(pMan),
+        Aig_ManPoNum(pMan) - Aig_ManRegNum(pMan),
+        Aig_ManNodeNum(pMan) );
+
+    // if the driver node is a constant, we need to complement the literal below
+    // because, in the AIGER format, literal 0/1 is represented as number 0/1
+    // while, in ABC, constant 1 node has number 0 and so literal 0/1 will be 1/0
+
+    // write latch drivers
+    Aig_ManForEachLiSeq( pMan, pObj, i )
+    {
+        pDriver = Aig_ObjFanin0(pObj);
+        fprintf( pFile, "%u\n", Ioa_ObjMakeLit( Ioa_ObjAigerNum(pDriver), Aig_ObjFaninC0(pObj) ^ (Ioa_ObjAigerNum(pDriver) == 0) ) );
+    }
+
+    // write PO drivers
+    Aig_ManForEachPoSeq( pMan, pObj, i )
+    {
+        pDriver = Aig_ObjFanin0(pObj);
+        fprintf( pFile, "%u\n", Ioa_ObjMakeLit( Ioa_ObjAigerNum(pDriver), Aig_ObjFaninC0(pObj) ^ (Ioa_ObjAigerNum(pDriver) == 0) ) );
+    }
+
+    // write the nodes into the buffer
+    Pos = 0;
+    nBufferSize = 6 * Aig_ManNodeNum(pMan) + 100; // skeptically assuming 3 chars per one AIG edge
+    pBuffer = ALLOC( char, nBufferSize );
+    pProgress = Bar_ProgressStart( stdout, Aig_ManObjNumMax(pMan) );
+    Aig_ManForEachNode( pMan, pObj, i )
+    {
+        Bar_ProgressUpdate( pProgress, i, NULL );
+        uLit  = Ioa_ObjMakeLit( Ioa_ObjAigerNum(pObj), 0 );
+        uLit0 = Ioa_ObjMakeLit( Ioa_ObjAigerNum(Aig_ObjFanin0(pObj)), Aig_ObjFaninC0(pObj) );
+        uLit1 = Ioa_ObjMakeLit( Ioa_ObjAigerNum(Aig_ObjFanin1(pObj)), Aig_ObjFaninC1(pObj) );
+        assert( uLit0 < uLit1 );
+        Pos = Ioa_WriteAigerEncode( pBuffer, Pos, uLit  - uLit1 );
+        Pos = Ioa_WriteAigerEncode( pBuffer, Pos, uLit1 - uLit0 );
+        if ( Pos > nBufferSize - 10 )
+        {
+            printf( "Ioa_WriteAiger(): AIGER generation has failed because the allocated buffer is too small.\n" );
+            fclose( pFile );
+            return;
+        }
+    }
+    assert( Pos < nBufferSize );
+    Bar_ProgressStop( pProgress );
+
+    // write the buffer
+    fwrite( pBuffer, 1, Pos, pFile );
+    free( pBuffer );
+/*
+    // write the symbol table
+    if ( fWriteSymbols )
+    {
+        // write PIs
+        Aig_ManForEachPi( pMan, pObj, i )
+            fprintf( pFile, "i%d %s\n", i, Aig_ObjName(pObj) );
+        // write latches
+        Aig_ManForEachLatch( pMan, pObj, i )
+            fprintf( pFile, "l%d %s\n", i, Aig_ObjName(Aig_ObjFanout0(pObj)) );
+        // write POs
+        Aig_ManForEachPo( pMan, pObj, i )
+            fprintf( pFile, "o%d %s\n", i, Aig_ObjName(pObj) );
+    }
+*/
+    // write the comment
+    fprintf( pFile, "c\n" );
+    fprintf( pFile, "%s\n", pMan->pName );
+    fprintf( pFile, "This file was produced by the AIG package in ABC on %s\n", Ioa_TimeStamp() );
+    fprintf( pFile, "For information about AIGER format, refer to %s\n", "http://fmv.jku.at/aiger" );
+    fclose( pFile );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds one unsigned AIG edge to the output buffer.]
+
+  Description [This procedure is a slightly modified version of Armin Biere's
+  procedure "void encode (FILE * file, unsigned x)" ]
+  
+  SideEffects [Returns the current writing position.]
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ioa_WriteAigerEncode( char * pBuffer, int Pos, unsigned x )
+{
+    unsigned char ch;
+    while (x & ~0x7f)
+    {
+        ch = (x & 0x7f) | 0x80;
+//        putc (ch, file);
+        pBuffer[Pos++] = ch;
+        x >>= 7;
+    }
+    ch = x;
+//    putc (ch, file);
+    pBuffer[Pos++] = ch;
+    return Pos;
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/aig/ioa/module.make b/src/aig/ioa/module.make
new file mode 100644
index 00000000..66b4a0d5
--- /dev/null
+++ b/src/aig/ioa/module.make
@@ -0,0 +1,3 @@
+SRC +=    src/aig/ioa/ioaReadAig.c \
+    src/aig/ioa/ioaWriteAig.c \
+    src/aig/ioa/ioaUtil.c