const vector float zero = {FOUR_INSTANCES(0.0f)};
const vector float zero = (vector float)(FOUR_INSTANCES(0.0f));
int dct_quantize_altivec(MpegEncContext* s,                         DCTELEM* data, int n,                        int qscale, int* overflow){    int lastNonZero;    vector float row0, row1, row2, row3, row4, row5, row6, row7;    vector float alt0, alt1, alt2, alt3, alt4, alt5, alt6, alt7;    const vector float zero = {FOUR_INSTANCES(0.0f)};    // Load the data into the row/alt vectors    {        vector signed short data0, data1, data2, data3, data4, data5, data6, data7;        data0 = vec_ld(0, data);        data1 = vec_ld(16, data);        data2 = vec_ld(32, data);        data3 = vec_ld(48, data);        data4 = vec_ld(64, data);        data5 = vec_ld(80, data);        data6 = vec_ld(96, data);        data7 = vec_ld(112, data);        // Transpose the data before we start        TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);        // load the data into floating point vectors.  We load        // the high half of each row into the main row vectors        // and the low half into the alt vectors.        row0 = vec_ctf(vec_unpackh(data0), 0);        alt0 = vec_ctf(vec_unpackl(data0), 0);        row1 = vec_ctf(vec_unpackh(data1), 0);        alt1 = vec_ctf(vec_unpackl(data1), 0);        row2 = vec_ctf(vec_unpackh(data2), 0);        alt2 = vec_ctf(vec_unpackl(data2), 0);        row3 = vec_ctf(vec_unpackh(data3), 0);        alt3 = vec_ctf(vec_unpackl(data3), 0);        row4 = vec_ctf(vec_unpackh(data4), 0);        alt4 = vec_ctf(vec_unpackl(data4), 0);        row5 = vec_ctf(vec_unpackh(data5), 0);        alt5 = vec_ctf(vec_unpackl(data5), 0);        row6 = vec_ctf(vec_unpackh(data6), 0);        alt6 = vec_ctf(vec_unpackl(data6), 0);        row7 = vec_ctf(vec_unpackh(data7), 0);        alt7 = vec_ctf(vec_unpackl(data7), 0);    }    // The following block could exist as a separate an altivec dct		// function.  However, if we put it inline, the DCT data can remain		// in the vector local variables, as floats, which we'll use during the		// quantize step...    {        const vector float vec_0_298631336 = {FOUR_INSTANCES(0.298631336f)};        const vector float vec_0_390180644 = {FOUR_INSTANCES(-0.390180644f)};        const vector float vec_0_541196100 = {FOUR_INSTANCES(0.541196100f)};        const vector float vec_0_765366865 = {FOUR_INSTANCES(0.765366865f)};        const vector float vec_0_899976223 = {FOUR_INSTANCES(-0.899976223f)};        const vector float vec_1_175875602 = {FOUR_INSTANCES(1.175875602f)};        const vector float vec_1_501321110 = {FOUR_INSTANCES(1.501321110f)};        const vector float vec_1_847759065 = {FOUR_INSTANCES(-1.847759065f)};        const vector float vec_1_961570560 = {FOUR_INSTANCES(-1.961570560f)};        const vector float vec_2_053119869 = {FOUR_INSTANCES(2.053119869f)};        const vector float vec_2_562915447 = {FOUR_INSTANCES(-2.562915447f)};        const vector float vec_3_072711026 = {FOUR_INSTANCES(3.072711026f)};        int whichPass, whichHalf;        for(whichPass = 1; whichPass<=2; whichPass++)        {            for(whichHalf = 1; whichHalf<=2; whichHalf++)            {                vector float tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;                vector float tmp10, tmp11, tmp12, tmp13;                vector float z1, z2, z3, z4, z5;                tmp0 = vec_add(row0, row7); // tmp0 = dataptr[0] + dataptr[7];                tmp7 = vec_sub(row0, row7); // tmp7 = dataptr[0] - dataptr[7];                tmp3 = vec_add(row3, row4); // tmp3 = dataptr[3] + dataptr[4];                tmp4 = vec_sub(row3, row4); // tmp4 = dataptr[3] - dataptr[4];                tmp1 = vec_add(row1, row6); // tmp1 = dataptr[1] + dataptr[6];                tmp6 = vec_sub(row1, row6); // tmp6 = dataptr[1] - dataptr[6];                tmp2 = vec_add(row2, row5); // tmp2 = dataptr[2] + dataptr[5];                tmp5 = vec_sub(row2, row5); // tmp5 = dataptr[2] - dataptr[5];                tmp10 = vec_add(tmp0, tmp3); // tmp10 = tmp0 + tmp3;                tmp13 = vec_sub(tmp0, tmp3); // tmp13 = tmp0 - tmp3;                tmp11 = vec_add(tmp1, tmp2); // tmp11 = tmp1 + tmp2;                tmp12 = vec_sub(tmp1, tmp2); // tmp12 = tmp1 - tmp2;                // dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);                row0 = vec_add(tmp10, tmp11);                // dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);                row4 = vec_sub(tmp10, tmp11);                // z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);                z1 = vec_madd(vec_add(tmp12, tmp13), vec_0_541196100, (vector float)zero);                // dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),                //		   CONST_BITS-PASS1_BITS);                row2 = vec_madd(tmp13, vec_0_765366865, z1);                // dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),                //		   CONST_BITS-PASS1_BITS);                row6 = vec_madd(tmp12, vec_1_847759065, z1);                z1 = vec_add(tmp4, tmp7); // z1 = tmp4 + tmp7;                z2 = vec_add(tmp5, tmp6); // z2 = tmp5 + tmp6;                z3 = vec_add(tmp4, tmp6); // z3 = tmp4 + tmp6;                z4 = vec_add(tmp5, tmp7); // z4 = tmp5 + tmp7;                // z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */                z5 = vec_madd(vec_add(z3, z4), vec_1_175875602, (vector float)zero);                // z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */                z3 = vec_madd(z3, vec_1_961570560, z5);                // z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */                z4 = vec_madd(z4, vec_0_390180644, z5);                // The following adds are rolled into the multiplies above                // z3 = vec_add(z3, z5);  // z3 += z5;                // z4 = vec_add(z4, z5);  // z4 += z5;                // z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */                // Wow!  It's actually more effecient to roll this multiply                // into the adds below, even thought the multiply gets done twice!                // z2 = vec_madd(z2, vec_2_562915447, (vector float)zero);                // z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */                // Same with this one...                // z1 = vec_madd(z1, vec_0_899976223, (vector float)zero);                // tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */                // dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);                row7 = vec_madd(tmp4, vec_0_298631336, vec_madd(z1, vec_0_899976223, z3));                // tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */                // dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);                row5 = vec_madd(tmp5, vec_2_053119869, vec_madd(z2, vec_2_562915447, z4));                // tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */                // dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);                row3 = vec_madd(tmp6, vec_3_072711026, vec_madd(z2, vec_2_562915447, z3));                // tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */                // dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);                row1 = vec_madd(z1, vec_0_899976223, vec_madd(tmp7, vec_1_501321110, z4));                // Swap the row values with the alts.  If this is the first half,                // this sets up the low values to be acted on in the second half.                // If this is the second half, it puts the high values back in                // the row values where they are expected to be when we're done.                SWAP(row0, alt0);                SWAP(row1, alt1);                SWAP(row2, alt2);                SWAP(row3, alt3);                SWAP(row4, alt4);                SWAP(row5, alt5);                SWAP(row6, alt6);                SWAP(row7, alt7);            }            if (whichPass == 1)            {                // transpose the data for the second pass                                 // First, block transpose the upper right with lower left.                SWAP(row4, alt0);                SWAP(row5, alt1);                SWAP(row6, alt2);                SWAP(row7, alt3);                // Now, transpose each block of four                TRANSPOSE4(row0, row1, row2, row3);                TRANSPOSE4(row4, row5, row6, row7);                TRANSPOSE4(alt0, alt1, alt2, alt3);                TRANSPOSE4(alt4, alt5, alt6, alt7);            }        }    }    // used after quantise step    int oldBaseValue = 0;    // perform the quantise step, using the floating point data    // still in the row/alt registers    {        const int* biasAddr;        const vector signed int* qmat;        vector float bias, negBias;        if (s->mb_intra)        {            vector signed int baseVector;            // We must cache element 0 in the intra case            // (it needs special handling).            baseVector = vec_cts(vec_splat(row0, 0), 0);            vec_ste(baseVector, 0, &oldBaseValue);            qmat = (vector signed int*)s->q_intra_matrix[qscale];            biasAddr = &(s->intra_quant_bias);        }        else        {            qmat = (vector signed int*)s->q_inter_matrix[qscale];            biasAddr = &(s->inter_quant_bias);        }        // Load the bias vector (We add 0.5 to the bias so that we're				// rounding when we convert to int, instead of flooring.)        {            vector signed int biasInt;            const vector float negOneFloat = (vector float)(FOUR_INSTANCES(-1.0f));            LOAD4(biasInt, biasAddr);            bias = vec_ctf(biasInt, QUANT_BIAS_SHIFT);            negBias = vec_madd(bias, negOneFloat, zero);        }        {            vector float q0, q1, q2, q3, q4, q5, q6, q7;            q0 = vec_ctf(qmat[0], QMAT_SHIFT);            q1 = vec_ctf(qmat[2], QMAT_SHIFT);            q2 = vec_ctf(qmat[4], QMAT_SHIFT);            q3 = vec_ctf(qmat[6], QMAT_SHIFT);            q4 = vec_ctf(qmat[8], QMAT_SHIFT);            q5 = vec_ctf(qmat[10], QMAT_SHIFT);            q6 = vec_ctf(qmat[12], QMAT_SHIFT);            q7 = vec_ctf(qmat[14], QMAT_SHIFT);            row0 = vec_sel(vec_madd(row0, q0, negBias), vec_madd(row0, q0, bias),                    vec_cmpgt(row0, zero));            row1 = vec_sel(vec_madd(row1, q1, negBias), vec_madd(row1, q1, bias),                    vec_cmpgt(row1, zero));            row2 = vec_sel(vec_madd(row2, q2, negBias), vec_madd(row2, q2, bias),                    vec_cmpgt(row2, zero));            row3 = vec_sel(vec_madd(row3, q3, negBias), vec_madd(row3, q3, bias),                    vec_cmpgt(row3, zero));            row4 = vec_sel(vec_madd(row4, q4, negBias), vec_madd(row4, q4, bias),                    vec_cmpgt(row4, zero));            row5 = vec_sel(vec_madd(row5, q5, negBias), vec_madd(row5, q5, bias),                    vec_cmpgt(row5, zero));            row6 = vec_sel(vec_madd(row6, q6, negBias), vec_madd(row6, q6, bias),                    vec_cmpgt(row6, zero));            row7 = vec_sel(vec_madd(row7, q7, negBias), vec_madd(row7, q7, bias),                    vec_cmpgt(row7, zero));            q0 = vec_ctf(qmat[1], QMAT_SHIFT);            q1 = vec_ctf(qmat[3], QMAT_SHIFT);            q2 = vec_ctf(qmat[5], QMAT_SHIFT);            q3 = vec_ctf(qmat[7], QMAT_SHIFT);            q4 = vec_ctf(qmat[9], QMAT_SHIFT);            q5 = vec_ctf(qmat[11], QMAT_SHIFT);            q6 = vec_ctf(qmat[13], QMAT_SHIFT);            q7 = vec_ctf(qmat[15], QMAT_SHIFT);            alt0 = vec_sel(vec_madd(alt0, q0, negBias), vec_madd(alt0, q0, bias),                    vec_cmpgt(alt0, zero));            alt1 = vec_sel(vec_madd(alt1, q1, negBias), vec_madd(alt1, q1, bias),                    vec_cmpgt(alt1, zero));            alt2 = vec_sel(vec_madd(alt2, q2, negBias), vec_madd(alt2, q2, bias),                    vec_cmpgt(alt2, zero));            alt3 = vec_sel(vec_madd(alt3, q3, negBias), vec_madd(alt3, q3, bias),                    vec_cmpgt(alt3, zero));            alt4 = vec_sel(vec_madd(alt4, q4, negBias), vec_madd(alt4, q4, bias),                    vec_cmpgt(alt4, zero));            alt5 = vec_sel(vec_madd(alt5, q5, negBias), vec_madd(alt5, q5, bias),                    vec_cmpgt(alt5, zero));            alt6 = vec_sel(vec_madd(alt6, q6, negBias), vec_madd(alt6, q6, bias),                    vec_cmpgt(alt6, zero));            alt7 = vec_sel(vec_madd(alt7, q7, negBias), vec_madd(alt7, q7, bias),                    vec_cmpgt(alt7, zero));        }     }    // Store the data back into the original block    {        vector signed short data0, data1, data2, data3, data4, data5, data6, data7;        data0 = vec_pack(vec_cts(row0, 0), vec_cts(alt0, 0));        data1 = vec_pack(vec_cts(row1, 0), vec_cts(alt1, 0));        data2 = vec_pack(vec_cts(row2, 0), vec_cts(alt2, 0));        data3 = vec_pack(vec_cts(row3, 0), vec_cts(alt3, 0));        data4 = vec_pack(vec_cts(row4, 0), vec_cts(alt4, 0));        data5 = vec_pack(vec_cts(row5, 0), vec_cts(alt5, 0));        data6 = vec_pack(vec_cts(row6, 0), vec_cts(alt6, 0));        data7 = vec_pack(vec_cts(row7, 0), vec_cts(alt7, 0));        {            // Clamp for overflow            vector signed int max_q_int, min_q_int;            vector signed short max_q, min_q;            LOAD4(max_q_int, &(s->max_qcoeff));            LOAD4(min_q_int, &(s->min_qcoeff));            max_q = vec_pack(max_q_int, max_q_int);            min_q = vec_pack(min_q_int, min_q_int);            data0 = vec_max(vec_min(data0, max_q), min_q);            data1 = vec_max(vec_min(data1, max_q), min_q);            data2 = vec_max(vec_min(data2, max_q), min_q);            data4 = vec_max(vec_min(data4, max_q), min_q);            data5 = vec_max(vec_min(data5, max_q), min_q);            data6 = vec_max(vec_min(data6, max_q), min_q);            data7 = vec_max(vec_min(data7, max_q), min_q);        }        vector bool char zero_01, zero_23, zero_45, zero_67;        vector signed char scanIndices_01, scanIndices_23, scanIndices_45, scanIndices_67;        vector signed char negOne = vec_splat_s8(-1);        vector signed char* scanPtr =                (vector signed char*)(s->intra_scantable.inverse);        // Determine the largest non-zero index.        zero_01 = vec_pack(vec_cmpeq(data0, (vector short)zero),                vec_cmpeq(data1, (vector short)zero));        zero_23 = vec_pack(vec_cmpeq(data2, (vector short)zero),                vec_cmpeq(data3, (vector short)zero));        zero_45 = vec_pack(vec_cmpeq(data4, (vector short)zero),                vec_cmpeq(data5, (vector short)zero));        zero_67 = vec_pack(vec_cmpeq(data6, (vector short)zero),                vec_cmpeq(data7, (vector short)zero));        // 64 biggest values        scanIndices_01 = vec_sel(scanPtr[0], negOne, zero_01);        scanIndices_23 = vec_sel(scanPtr[1], negOne, zero_23);        scanIndices_45 = vec_sel(scanPtr[2], negOne, zero_45);        scanIndices_67 = vec_sel(scanPtr[3], negOne, zero_67);        // 32 largest values        scanIndices_01 = vec_max(scanIndices_01, scanIndices_23);        scanIndices_45 = vec_max(scanIndices_45, scanIndices_67);        // 16 largest values        scanIndices_01 = vec_max(scanIndices_01, scanIndices_45);        // 8 largest values        scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),                vec_mergel(scanIndices_01, negOne));        // 4 largest values        scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),                vec_mergel(scanIndices_01, negOne));        // 2 largest values        scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),                vec_mergel(scanIndices_01, negOne));        // largest value        scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),                vec_mergel(scanIndices_01, negOne));        scanIndices_01 = vec_splat(scanIndices_01, 0);        signed char lastNonZeroChar;        vec_ste(scanIndices_01, 0, &lastNonZeroChar);        lastNonZero = lastNonZeroChar;                // While the data is still in vectors we check for the transpose IDCT permute        // and handle it using the vector unit if we can.  This is the permute used        // by the altivec idct, so it is common when using the altivec dct.        if ((lastNonZero > 0) && (s->idct_permutation_type == FF_TRANSPOSE_IDCT_PERM))        {            TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);        }        vec_st(data0, 0, data);        vec_st(data1, 16, data);        vec_st(data2, 32, data);        vec_st(data3, 48, data);        vec_st(data4, 64, data);        vec_st(data5, 80, data);        vec_st(data6, 96, data);        vec_st(data7, 112, data);    }    // special handling of block[0]    if (s->mb_intra)    {        if (!s->h263_aic)        {            if (n < 4)                oldBaseValue /= s->y_dc_scale;            else                oldBaseValue /= s->c_dc_scale;        }        // Divide by 8, rounding the result        data[0] = (oldBaseValue + 4) >> 3;    }    // We handled the tranpose permutation above and we don't    // need to permute the "no" permutation case.    if ((lastNonZero > 0) &&        (s->idct_permutation_type != FF_TRANSPOSE_IDCT_PERM) &&        (s->idct_permutation_type != FF_NO_IDCT_PERM))    {        ff_block_permute(data, s->idct_permutation,                s->intra_scantable.scantable, lastNonZero);    }    return lastNonZero;}