Computing polynomials for AIGs representing arithmetic functions.

src/aig/gia/giaPolyn.c

+/**CFile****************************************************************
+
+  FileName    [giaPolyn.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Scalable AIG package.]
+
+  Synopsis    [Polynomial manipulation.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: giaPolyn.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+#include "misc/vec/vecWec.h"
+#include "misc/vec/vecHsh.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+/*
+!a            ->   1 - a
+a & b         ->   ab
+a | b         ->   a + b - ab
+a ^ b         ->   a + b - 2ab
+MUX(a, b, c)  ->   ab | (1 - a)c = ab + (1-a)c - ab(1-a)c = ab + c - ac
+
+!a & b        ->   (1 - a)b = b - ab
+ a & !b       ->   a(1 - b) = a - ab
+!a & !b       ->   1 - a - b + ab
+!(a & b)      ->   1 - ab
+*/
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_PolynAddNew( Hsh_VecMan_t * pHash, Vec_Int_t * vCoef, int Coef, Vec_Int_t * vProd, Vec_Wec_t * vMap )
+{
+    int i, Lit, Value;
+    //Vec_IntPrint( vProd );
+
+    Value = Hsh_VecManAdd( pHash, vProd );
+    if ( Value == Vec_IntSize(vCoef) )
+    {
+        Vec_IntPush( vCoef, 0 );
+        Vec_IntForEachEntry( vProd, Lit, i )
+            Vec_WecPush( vMap, Abc_Lit2Var(Lit), Value );
+    }
+    assert( Value < Vec_IntSize(vCoef) );
+    Vec_IntAddToEntry( vCoef, Value, Coef );
+}
+int Gia_PolynTransform1( Hsh_VecMan_t * pHash, Vec_Int_t * vCoef, int Coef, Vec_Int_t * vProd, Vec_Wec_t * vMap, int Id )
+{
+    int i, Lit;
+    Vec_IntForEachEntry( vProd, Lit, i )
+        if ( Abc_Lit2Var(Lit) == Id )
+            break;
+    assert( i < Vec_IntSize(vProd) );
+    if ( !Abc_LitIsCompl(Lit) )
+        return 0;
+    // update array
+    Vec_IntWriteEntry( vProd, i, Abc_LitNot(Lit) );
+    Gia_PolynAddNew( pHash, vCoef, Coef, vProd, vMap );
+    Vec_IntWriteEntry( vProd, i, Lit );
+    return 1;
+}
+void Gia_PolynTransform( Hsh_VecMan_t * pHash, Vec_Int_t * vCoef, int Coef, Vec_Int_t * vProd, Vec_Wec_t * vMap, int Id, int Lit0, int Lit1, Vec_Int_t * vTemp )
+{
+    int pArray[2] = { Lit0, Lit1 };
+    Vec_Int_t vTwo = { 2, 2, pArray };
+
+    int Var0 = Abc_Lit2Var( Lit0 );
+    int Var1 = Abc_Lit2Var( Lit1 );
+    int i, Lit = Vec_IntPop(vProd);
+
+    assert( Abc_Lit2Var(Lit) == Id );
+    if ( Abc_LitIsCompl(Lit) )
+    {
+        Gia_PolynAddNew( pHash, vCoef, Coef, vProd, vMap );
+        Coef = -Coef;
+    }
+
+    assert( Var0 < Var1 );
+    Vec_IntForEachEntry( vProd, Lit, i )
+        if ( Abc_LitNot(Lit) == Lit0 || Abc_LitNot(Lit) == Lit1 )
+            return;
+    assert( Vec_IntCap(vTemp) >= Vec_IntSize(vTemp) + 2 );
+
+    // merge inputs
+    Vec_IntTwoMerge2Int( vProd, &vTwo, vTemp );
+/*
+    printf( "\n" );
+    Vec_IntPrint( vProd );
+    Vec_IntPrint( &vTwo );
+    Vec_IntPrint( vTemp );
+    printf( "\n" );
+*/
+    // create new
+    Gia_PolynAddNew( pHash, vCoef, Coef, vTemp, vMap );
+}
+int Gia_PolynPrint( Hsh_VecMan_t * pHash, Vec_Int_t * vCoef )
+{
+    Vec_Int_t * vProd;
+    int Value, Coef, Lit, i, Count = 0;
+    Vec_IntForEachEntry( vCoef, Coef, Value )
+    {
+        if ( Coef == 0 )
+            continue;
+        vProd = Hsh_VecReadEntry( pHash, Value );
+        printf( "(%d)", Coef );
+        Vec_IntForEachEntry( vProd, Lit, i )
+            printf( "*%d", Lit );
+        printf( " " );
+        Count++;
+    }
+    printf( "\n" );
+    return Count;
+}
+void Gia_PolynTest( Gia_Man_t * pGia )
+{
+    Hsh_VecMan_t * pHash = Hsh_VecManStart( 1000000 );
+    Vec_Int_t * vCoef = Vec_IntAlloc( 1000000 );
+    Vec_Wec_t * vMap = Vec_WecStart( Gia_ManObjNum(pGia) );
+    Vec_Int_t * vTemp = Vec_IntAlloc( 100000 );
+    Vec_Int_t * vThisOne, * vProd;
+    Gia_Obj_t * pObj;
+    int i, k, Value, Coef, Count;
+    abctime clk = Abc_Clock();
+
+    assert( Gia_ManPoNum(pGia) < 32 );
+
+    // add constant
+    Value = Hsh_VecManAdd( pHash, vTemp );
+    assert( Value == 0 );
+    Vec_IntPush( vCoef, 0 );
+
+    // start the outputs
+    Gia_ManForEachPo( pGia, pObj, i )
+    {
+        assert( Gia_ObjFaninId0p(pGia, pObj) > 0 );
+        Vec_IntFill( vTemp, 1, Gia_ObjFaninLit0p(pGia, pObj) );
+        Value = Hsh_VecManAdd( pHash, vTemp );
+        //assert( Value == i + 1 );
+        Vec_IntPush( vCoef, 1 << i );
+        Vec_WecPush( vMap, Gia_ObjFaninId0p(pGia, pObj), Value );
+    }
+    assert( Vec_IntSize(vCoef) == Hsh_VecSize(pHash) );
+
+    Gia_PolynPrint( pHash, vCoef );
+
+    // substitute
+    Gia_ManForEachAndReverse( pGia, pObj, i )
+    {
+        vThisOne = Vec_WecEntry( vMap, i );
+        assert( Vec_IntSize(vThisOne) > 0 );
+        Vec_IntForEachEntry( vThisOne, Value, k )
+        {
+            vProd = Hsh_VecReadEntry( pHash, Value );
+            Coef = Vec_IntEntry( vCoef, Value );
+            if ( Coef == 0 )
+                continue;
+            Gia_PolynTransform( pHash, vCoef, Coef, vProd, vMap, i, Gia_ObjFaninLit0p(pGia, pObj), Gia_ObjFaninLit1p(pGia, pObj), vTemp );
+            Vec_IntWriteEntry( vCoef, Value, 0 );
+        }
+        Vec_IntErase( vThisOne );
+    }
+
+    // inputs
+    Gia_ManForEachCiReverse( pGia, pObj, i )
+    {
+        vThisOne = Vec_WecEntry( vMap, Gia_ObjId(pGia, pObj) );
+        if ( Vec_IntSize(vThisOne) == 0 )
+            continue;
+        assert( Vec_IntSize(vThisOne) > 0 );
+        Vec_IntForEachEntry( vThisOne, Value, k )
+        {
+            vProd = Hsh_VecReadEntry( pHash, Value );
+            Coef = Vec_IntEntry( vCoef, Value );
+            if ( Coef == 0 )
+                continue;
+            if ( Gia_PolynTransform1( pHash, vCoef, Coef, vProd, vMap, Gia_ObjId(pGia, pObj) ) )
+                Vec_IntWriteEntry( vCoef, Value, 0 );
+        }
+        Vec_IntErase( vThisOne );
+    }
+
+    Count = Gia_PolynPrint( pHash, vCoef );
+    printf( "Entries = %d. Useful = %d.  ", Vec_IntSize(vCoef), Count );
+    Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+
+    Hsh_VecManStop( pHash );
+    Vec_IntFree( vCoef );
+    Vec_WecFree( vMap );
+    Vec_IntFree( vTemp );
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+