Commit 617c0edf authored by thomas dettbarn's avatar thomas dettbarn
Browse files

added comments to track the Q and exponents.

parent 7d9a7a48

lib_dec/ivas_svd_dec_fx.c

+36 −38
Original line number Diff line number Diff line
@@ -995,7 +995,7 @@ static void HouseholderReduction_fx( 
 *-------------------------------------------------------------------------*/



static void biDiagonalReductionLeft_64(

    Word64 singularVectors_Left_64[MAX_OUTPUT_CHANNELS][MAX_OUTPUT_CHANNELS],

    Word64 singularVectors_Left_64[MAX_OUTPUT_CHANNELS][MAX_OUTPUT_CHANNELS],		// q(sing)	exp(sing)

    const Word16 nChannelsL,  /* Q0 */

    const Word16 nChannelsC,  /* Q0 */

    const Word16 currChannel, /* Q0 */
@@ -1027,12 +1027,12 @@ static void biDiagonalReductionLeft_64( 
        move64();

        FOR( jCh = currChannel; jCh < nChannelsL; jCh++ ) /* nChannelsL */

        {

            tmp = W_extract_l( W_shr( singularVectors_Left_64[jCh][currChannel], HEADROOM_LEFT_1 ) );

            norm_64 = W_add( norm_64, W_mult0_32_32( tmp, tmp ) );

            tmp = W_extract_l( W_shr( singularVectors_Left_64[jCh][currChannel], HEADROOM_LEFT_1 ) );	// q(sing)-H1			// exp(sing)+H1

            norm_64 = W_add( norm_64, W_mult0_32_32( tmp, tmp ) );					// q(norm)=2*q(sing)-2*H1	// exp(norm)=2*exp(sing)+2*H1

        }

        norm_x_e = W_norm( norm_64 );			

        norm_x_e0 = W_norm( norm_64 );

        norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );

        norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );	// q(norm_x)=32-exp(norm_x)	exp(norm_x)=exp(norm)-32

    }

    IF( norm_x )

    {
@@ -1040,51 +1040,50 @@ static void biDiagonalReductionLeft_64( 
        Word16 tmp_e;

        Word64 tmpmul;



        Word64 r_64; //  = sqrt(norm)*singularVectors_Left_64[currChannel][currChannel]-norm OR -sqrt(norm)*singularVectors_Left_64[currChannel][currChannel]-norm

        Word64 r_64; 

        Word32 r, invVal;

        Word16 r_e, invVal_e;



        ( *g_e ) = add( sub( ( HEADROOM_LEFT_1 + HEADROOM_LEFT_1 ), norm_x_e ), 1 );

        ( *g_e ) = add( sub( add( HEADROOM_LEFT_1, HEADROOM_LEFT_1 ), norm_x_e ), 1 );		// exp(g)=(2*H1-exp(norm_x)+1)

        move16();

        ( *g ) = Sqrt32( norm_x, g_e );

        ( *g ) = Sqrt32( norm_x, g_e );								// --> exp(g)=((2*H1-exp(norm_x)+1)/2)

        IF( GE_64( singularVectors_Left_64[currChannel][currChannel], 0 ) )

        {

            ( *g ) = L_negate( *g );

        }

        factor2 = W_extract_l( W_shr( singularVectors_Left_64[currChannel][currChannel], HEADROOM_LEFT_2 ) );

        factor2 = W_extract_l( W_shr( singularVectors_Left_64[currChannel][currChannel], HEADROOM_LEFT_2 ) );	// q(factor2)=q(sing)-H2	exp(factor2)=exp(qsing)+H2

        tmp_e = sub( 2 * HEADROOM_LEFT_1 - HEADROOM_LEFT_2, ( *g_e ) );						

        tmpmul = W_mult0_32_32( ( *g ), factor2 );

        tmpmul = W_shr( tmpmul, tmp_e );

        r_64 = W_sub( tmpmul, norm_64 );

        tmpmul = W_mult0_32_32( ( *g ), factor2 );	// q(tmpmul)=q(g)+q(factor2)

        tmpmul = W_shr( tmpmul, tmp_e );		// --> q(tmpmul)=q(g)+q(factor2)-(2*H1-H2-q(g))

        r_64 = W_sub( tmpmul, norm_64 );		// q(r_64)=max(q(tmpmul),q(norm))

        r_e = W_norm( r_64 );

        r = W_extract_h( W_shl( r_64, r_e ) );



        invVal_e = 0;

        move16();

        invVal = BASOP_Util_Divide3232_Scale_newton( MAXVAL_WORD32, maxWithSign_fx( r ), &invVal_e );

        invVal = BASOP_Util_Divide3232_Scale_newton( MAXVAL_WORD32, maxWithSign_fx( r ), &invVal_e );	// invVal=1/r --> q(invVal)=-q(r)





        tmp_e = sub( 32, *g_e );

        singularVectors_Left_64[currChannel][currChannel] = W_sub( singularVectors_Left_64[currChannel][currChannel], W_shr( W_deposit32_h( *g ), tmp_e ) ); // here, the exponent goes up.

        singularVectors_Left_64[currChannel][currChannel] = W_sub( singularVectors_Left_64[currChannel][currChannel], W_shr( W_deposit32_h( *g ), tmp_e ) ); // q(sing)=max(q(sing),q(r)-(2*H1-H2-exp(r))



        FOR( iCh = add( currChannel, 1 ); iCh < nChannelsC; iCh++ )

        {

            Word32 factor1;

            Word32 factor2;

            Word32 f; // = norm / r

                      //            Word16 f_e;      // not really needed

            Word16 magic_shift;



            norm_64 = 0;

            for ( jCh = currChannel; jCh < nChannelsL; jCh++ )

            {

                factor1 = W_extract_h( W_shl( singularVectors_Left_64[jCh][currChannel], 32 - HEADROOM_LEFT_3 ) );

                factor2 = W_extract_h( W_shl( singularVectors_Left_64[jCh][iCh], 32 - HEADROOM_LEFT_3 ) );

                norm_64 = W_add( norm_64, W_mult0_32_32( factor1, factor2 ) );

                factor1 = W_extract_h( W_shl( singularVectors_Left_64[jCh][currChannel], 32 - HEADROOM_LEFT_3 ) );	// q(factor1) = q(sing)-H3

                factor2 = W_extract_h( W_shl( singularVectors_Left_64[jCh][iCh], 32 - HEADROOM_LEFT_3 ) );		// q(factor2) = q(sing)-H3

                norm_64 = W_add( norm_64, W_mult0_32_32( factor1, factor2 ) );						// q(norm)=2*q(sing)-2*H3

            }

            norm_x_e = W_norm( norm_64 );

            norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );

            f = Mpy_32_32( norm_x, invVal );

            norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );	// Note: different norm

            f = Mpy_32_32( norm_x, invVal );		// q(f)=q(norm_x)-q(invVal)

            magic_shift = ( norm_x_e - 2 * HEADROOM_LEFT_3 ) - ( r_e - 2 * HEADROOM_LEFT_1 ) + ( 32 - HEADROOM_LEFT_4 ) - 2 * invVal_e;

            FOR( jCh = currChannel; jCh < nChannelsL; jCh++ )

            {
@@ -1134,12 +1133,12 @@ static void biDiagonalReductionRight_64( 
        FOR( jCh = idx; jCh < nChannelsC; jCh++ )

        {

            Word32 tmp;

            tmp = W_extract_l( W_shr( singularVectors_Left_64[currChannel][jCh], HEADROOM_RIGHT_1 ) );

            norm_64 = W_add( norm_64, W_mult0_32_32( tmp, tmp ) );

            tmp = W_extract_l( W_shr( singularVectors_Left_64[currChannel][jCh], HEADROOM_RIGHT_1 ) );	// q(sing)-H1			// exp(sing)+H1	

            norm_64 = W_add( norm_64, W_mult0_32_32( tmp, tmp ) );					// q(norm)=2*q(sing)-2*H1	// exp(norm)=2*exp(sing)+2*H1

        }

        norm_x_e = W_norm( norm_64 );

        norm_x_e0 = W_norm( norm_64 );

        norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );

        norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );	// q(norm_x)=32-exp(norm_x)	exp(norm_x)=exp(norm)-32

        move16();



        IF( norm_x )
@@ -1156,29 +1155,28 @@ static void biDiagonalReductionRight_64( 
            Word32 invVal;

            Word16 invVal_e;



            ( *g_e ) = add( sub( ( HEADROOM_RIGHT_1 + HEADROOM_RIGHT_1 ), norm_x_e ), 1 );

            ( *g_e ) = add( sub( ( HEADROOM_RIGHT_1 + HEADROOM_RIGHT_1 ), norm_x_e ), 1 );	// exp(g)=(2*H1-exp(norm_x)+1)

            move16();

            ( *g ) = Sqrt32( norm_x, g_e );

            ( *g ) = Sqrt32( norm_x, g_e );							// --> exp(g)=((2*H1-exp(norm_x)+1)/2)

            IF( GE_64( singularVectors_Left_64[currChannel][idx], 0 ) )

            {

                ( *g ) = L_negate( *g );

            }

            move32();

            move16();

            factor2 = W_extract_l( W_shr( singularVectors_Left_64[currChannel][idx], HEADROOM_RIGHT_2 ) );

            factor2 = W_extract_l( W_shr( singularVectors_Left_64[currChannel][idx], HEADROOM_RIGHT_2 ) );	// q(factor2)=q(sing)-H2	exp(factor2)=exp(qsing)+H2

            tmp_e = sub( 2 * HEADROOM_RIGHT_1 - HEADROOM_RIGHT_2, *g_e );

            tmpmul = W_mult0_32_32( *g, factor2 );

            tmpmul = W_shr( tmpmul, tmp_e );

            r_64 = W_sub( tmpmul, norm_64 );

            tmpmul = W_mult0_32_32( *g, factor2 );	// q(tmpmul)=q(g)+q(factor2)

            tmpmul = W_shr( tmpmul, tmp_e );		// --> q(tmpmul)=q(g)+q(factor2)-(2*H1-H2-q(g))

            r_64 = W_sub( tmpmul, norm_64 );		// q(r_64)=max(q(tmpmul),q(norm))

            r_e = W_norm( r_64 );

            r = W_extract_h( W_shl( r_64, r_e ) );



            invVal_e = 0;

            move16();

            invVal = BASOP_Util_Divide3232_Scale_newton( MAXVAL_WORD32, maxWithSign_fx( r ), &invVal_e );



            invVal = BASOP_Util_Divide3232_Scale_newton( MAXVAL_WORD32, maxWithSign_fx( r ), &invVal_e );	// invVal=1/r --> q(invVal)=-q(r)

            tmp_e = sub( 32, *g_e );

            singularVectors_Left_64[currChannel][idx] = W_sub( singularVectors_Left_64[currChannel][idx], W_shr( W_deposit32_h( *g ), tmp_e ) ); // here, the exponent goes up

            singularVectors_Left_64[currChannel][idx] = W_sub( singularVectors_Left_64[currChannel][idx], W_shr( W_deposit32_h( *g ), tmp_e ) );	// q(sing)=max(q(sing),q(r)-(2*H1-H2-exp(r)))



            FOR( iCh = idx; iCh < nChannelsL; iCh++ )

            {
@@ -1187,14 +1185,14 @@ static void biDiagonalReductionRight_64( 
                move64();

                FOR( jCh = idx; jCh < nChannelsC; jCh++ )

                {

                    factor1 = W_extract_h( W_shl( singularVectors_Left_64[iCh][jCh], 32 - HEADROOM_RIGHT_3 ) );

                    factor2 = W_extract_h( W_shl( singularVectors_Left_64[currChannel][jCh], 32 - HEADROOM_RIGHT_3 ) );

                    norm_64 = W_add( norm_64, W_mult0_32_32( factor1, factor2 ) );

                    factor1 = W_extract_h( W_shl( singularVectors_Left_64[iCh][jCh], 32 - HEADROOM_RIGHT_3 ) );		// q(factor1) = q(sing)-H3

                    factor2 = W_extract_h( W_shl( singularVectors_Left_64[currChannel][jCh], 32 - HEADROOM_RIGHT_3 ) );	// q(factor2) = q(sing)-H3

                    norm_64 = W_add( norm_64, W_mult0_32_32( factor1, factor2 ) );					// q(norm)=2*q(sing)-2*H3

                }



                norm_x_e = W_norm( norm_64 );

                norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );

                f = Mpy_32_32( norm_x, invVal );

                norm_x = W_extract_h( W_shl( norm_64, norm_x_e ) );	// Note: different norm

                f = Mpy_32_32( norm_x, invVal );	// q(f)=q(norm_x)-q(invVal)

                magic_shift = ( norm_x_e - 2 * HEADROOM_RIGHT_3 ) - ( r_e - 2 * HEADROOM_RIGHT_1 ) + ( 32 - HEADROOM_RIGHT_4 ) - 2 * invVal_e;



                FOR( jCh = idx; jCh < nChannelsC; jCh++ )