Commit 7fde3b1c authored by multrus's avatar multrus
Browse files

add BASOP_Util_Divide3232_Scale_FhG

parent 2a4d5bb8

lib_com/basop_util.c

+87 −0
Original line number Diff line number Diff line
@@ -1037,8 +1037,94 @@ Word32 div_w( Word32 L_num, Word32 L_den ) 
    }

}



#ifdef BASOP_DIVIDE3232_FHG

// replace depreacted L_add_c() by L_add_co(); currently disabled, because of missing counting in L_add_co();

//#define REPLACE_DEPR_L_ADD_C

Word32 BASOP_Util_Divide3232_Scale_FhG( Word32 x, Word32 y, Word16 *s, Word16 bits )

{

    Word32 z;

    Word16 sx;

    Word16 sy;

    Word32 sign;

    Word16 iteration;

    Flag Carry;

#ifdef REPLACE_DEPR_L_ADD_C

    Flag Overflow;

#endif

    Word16 s_val;



    unset_carry( &Carry );

#ifdef REPLACE_DEPR_L_ADD_C

    unset_overflow( &Overflow );

#endif



    /* assert (x >= (Word32)0); */

    assert( y != (Word32) 0 );



    IF( x == (Word32) 0 )

    {

        *s = -31;

        move16();

        return ( (Word32) 0 );

    }



    sign = L_shr( L_xor( x, y ), 31 );



    sx = norm_l( x );

    x = L_shl( x, sx );

    x = L_shr( x, 1 );

    s_val = sub( 1, sx );

    if ( x < 0 )

    {

        x = L_negate( x );

    }



    sy = norm_l( y );

    y = L_shl( y, sy );

    y = L_shr( y, 1 );

    s_val = add( s_val, sy );

    if ( y >= 0 )

    {

        y = L_negate( y );

    }



    *s = s_val;

    move16();



    z = L_sub( x, x ); // z = 0



    FOR( iteration = (Word16) 0; iteration < (Word16) bits; iteration++ )

    {

        if ( L_add( x, y ) >= 0 )

        {

#ifdef REPLACE_DEPR_L_ADD_C

            x = L_add_co( x, y, &Carry, &Overflow ); // sets always carry=1

#else

            x = DEPR_L_add_c( x, y, &Carry ); // sets always carry=1

#endif

        }

#ifdef REPLACE_DEPR_L_ADD_C

        z = L_add_co( z, z, &Carry, &Overflow ); // sets always carry=0

#else

        z = DEPR_L_add_c( z, z, &Carry ); // sets always carry=0

#endif

        x = L_add( x, x );

    }



    if ( sign != 0 )

    {

        z = L_negate( z );

    }



    return L_shl( z, sub( 31, bits ) );

}

#endif



Word32 BASOP_Util_Divide3232_Scale_cadence( Word32 x, Word32 y, Word16 *s )

{

#ifdef BASOP_DIVIDE3232_FHG

    return BASOP_Util_Divide3232_Scale_FhG( x, y, s, 24 );

#else

    Word32 z;

    Word16 sx;

    Word16 sy;
@@ -1087,6 +1173,7 @@ Word32 BASOP_Util_Divide3232_Scale_cadence( Word32 x, Word32 y, Word16 *s ) 
    }



    return z;

#endif

}



Word16 BASOP_Util_Divide3232_Scale( Word32 x, Word32 y, Word16 *s )

lib_com/basop_util.h

+8 −0
Original line number Diff line number Diff line
@@ -328,6 +328,14 @@ Word16 BASOP_Util_Divide3232_Scale( Word32 x, /*!< i : Numerator*/ 
                                    Word32 y,    /*!< i  : Denominator*/

                                    Word16 *s ); /*!< o  : Additional scalefactor difference*/





#ifdef BASOP_DIVIDE3232_FHG

Word32 BASOP_Util_Divide3232_Scale_FhG( Word32 x,      /*!< i  : Numerator*/

                                        Word32 y,      /*!< i  : Denominator*/

                                        Word16 *s,     /*!< o  : Additional scalefactor difference*/

                                        Word16 bits ); /*!< i  : number of mantissa bits of result*/

#endif



Word32 BASOP_Util_Divide3232_Scale_cadence( Word32 x,    /*!< i  : Numerator*/

                                            Word32 y,    /*!< i  : Denominator*/

                                            Word16 *s ); /*!< o  : Additional scalefactor difference*/

lib_com/options.h

+1 −0
Original line number Diff line number Diff line
@@ -91,4 +91,5 @@ 
#define FIX_1054_IF_ELSE_CMPLX                          /* VA: Fix 1054 incorrect counting of complexity when ELSE-IF sequence is encoutered in two functions */

#define FIX_1052_COPY_CMPLX_DISCREPANCY       /* VA: modify IF-ELSE statements used in Copy*() functions to avoid dependency on x[] and y[] in RAM */

#define FIX_1049_SHR_RO_COMPLEXITY              /* VA: fix for issue 1049: incorrect counting of complexity in the shr_ro() function */

#define BASOP_DIVIDE3232_FHG                    /* FhG: scalable 32 by 32 division, use with 24 bit precision */

#endif