Revert parts of 96d081c1 that touched source code or autotools files.

[platform/upstream/flac.git] / src / libFLAC / lpc.c

/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007,2008,2009  Josh Coalson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#include <math.h>
#include <inttypes.h>
#include "FLAC/assert.h"
#include "FLAC/format.h"
#include "private/bitmath.h"
#include "private/lpc.h"
#include "private/macros.h"
#if defined DEBUG || defined FLAC__OVERFLOW_DETECT || defined FLAC__OVERFLOW_DETECT_VERBOSE
#include <stdio.h>
#endif

/* OPT: #undef'ing this may improve the speed on some architectures */
#define FLAC__LPC_UNROLLED_FILTER_LOOPS

#ifndef FLAC__INTEGER_ONLY_LIBRARY

#ifndef M_LN2
/* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */
#define M_LN2 0.69314718055994530942
#endif

#if !defined(HAVE_LROUND)
#if defined(_MSC_VER)
#include <float.h>
#define copysign _copysign
#elif defined(__GNUC__)
#define copysign __builtin_copysign
#endif
static inline long int lround(double x) {
    return (long)(x + copysign (0.5, x));
}
//If this fails, we are in the precence of a mid 90's compiler..move along...
#endif

void FLAC__lpc_window_data(const FLAC__int32 in[], const FLAC__real window[], FLAC__real out[], unsigned data_len)
{
        unsigned i;
        for(i = 0; i < data_len; i++)
                out[i] = in[i] * window[i];
}

void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[])
{
        /* a readable, but slower, version */
#if 0
        FLAC__real d;
        unsigned i;

        FLAC__ASSERT(lag > 0);
        FLAC__ASSERT(lag <= data_len);

        /*
         * Technically we should subtract the mean first like so:
         *   for(i = 0; i < data_len; i++)
         *     data[i] -= mean;
         * but it appears not to make enough of a difference to matter, and
         * most signals are already closely centered around zero
         */
        while(lag--) {
                for(i = lag, d = 0.0; i < data_len; i++)
                        d += data[i] * data[i - lag];
                autoc[lag] = d;
        }
#endif

        /*
         * this version tends to run faster because of better data locality
         * ('data_len' is usually much larger than 'lag')
         */
        FLAC__real d;
        unsigned sample, coeff;
        const unsigned limit = data_len - lag;

        FLAC__ASSERT(lag > 0);
        FLAC__ASSERT(lag <= data_len);

        for(coeff = 0; coeff < lag; coeff++)
                autoc[coeff] = 0.0;
        for(sample = 0; sample <= limit; sample++) {
                d = data[sample];
                for(coeff = 0; coeff < lag; coeff++)
                        autoc[coeff] += d * data[sample+coeff];
        }
        for(; sample < data_len; sample++) {
                d = data[sample];
                for(coeff = 0; coeff < data_len - sample; coeff++)
                        autoc[coeff] += d * data[sample+coeff];
        }
}

void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned *max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[])
{
        unsigned i, j;
        FLAC__double r, err, lpc[FLAC__MAX_LPC_ORDER];

        FLAC__ASSERT(0 != max_order);
        FLAC__ASSERT(0 < *max_order);
        FLAC__ASSERT(*max_order <= FLAC__MAX_LPC_ORDER);
        FLAC__ASSERT(autoc[0] != 0.0);

        err = autoc[0];

        for(i = 0; i < *max_order; i++) {
                /* Sum up this iteration's reflection coefficient. */
                r = -autoc[i+1];
                for(j = 0; j < i; j++)
                        r -= lpc[j] * autoc[i-j];
                r /= err;

                /* Update LPC coefficients and total error. */
                lpc[i]=r;
                for(j = 0; j < (i>>1); j++) {
                        FLAC__double tmp = lpc[j];
                        lpc[j] += r * lpc[i-1-j];
                        lpc[i-1-j] += r * tmp;
                }
                if(i & 1)
                        lpc[j] += lpc[j] * r;

                err *= (1.0 - r * r);

                /* save this order */
                for(j = 0; j <= i; j++)
                        lp_coeff[i][j] = (FLAC__real)(-lpc[j]); /* negate FIR filter coeff to get predictor coeff */
                error[i] = err;

                /* see SF bug #1601812 http://sourceforge.net/tracker/index.php?func=detail&aid=1601812&group_id=13478&atid=113478 */
                if(err == 0.0) {
                        *max_order = i+1;
                        return;
                }
        }
}

int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift)
{
        unsigned i;
        FLAC__double cmax;
        FLAC__int32 qmax, qmin;

        FLAC__ASSERT(precision > 0);
        FLAC__ASSERT(precision >= FLAC__MIN_QLP_COEFF_PRECISION);

        /* drop one bit for the sign; from here on out we consider only |lp_coeff[i]| */
        precision--;
        qmax = 1 << precision;
        qmin = -qmax;
        qmax--;

        /* calc cmax = max( |lp_coeff[i]| ) */
        cmax = 0.0;
        for(i = 0; i < order; i++) {
                const FLAC__double d = fabs(lp_coeff[i]);
                if(d > cmax)
                        cmax = d;
        }

        if(cmax <= 0.0) {
                /* => coefficients are all 0, which means our constant-detect didn't work */
                return 2;
        }
        else {
                const int max_shiftlimit = (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN-1)) - 1;
                const int min_shiftlimit = -max_shiftlimit - 1;
                int log2cmax;

                (void)frexp(cmax, &log2cmax);
                log2cmax--;
                *shift = (int)precision - log2cmax - 1;

                if(*shift > max_shiftlimit)
                        *shift = max_shiftlimit;
                else if(*shift < min_shiftlimit)
                        return 1;
        }

        if(*shift >= 0) {
                FLAC__double error = 0.0;
                FLAC__int32 q;
                for(i = 0; i < order; i++) {
                        error += lp_coeff[i] * (1 << *shift);
                        q = lround(error);

#ifdef FLAC__OVERFLOW_DETECT
                        if(q > qmax+1) /* we expect q==qmax+1 occasionally due to rounding */
                                fprintf(stderr,"FLAC__lpc_quantize_coefficients: quantizer overflow: q>qmax %d>%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n",q,qmax,*shift,cmax,precision+1,i,lp_coeff[i]);
                        else if(q < qmin)
                                fprintf(stderr,"FLAC__lpc_quantize_coefficients: quantizer overflow: q<qmin %d<%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n",q,qmin,*shift,cmax,precision+1,i,lp_coeff[i]);
#endif
                        if(q > qmax)
                                q = qmax;
                        else if(q < qmin)
                                q = qmin;
                        error -= q;
                        qlp_coeff[i] = q;
                }
        }
        /* negative shift is very rare but due to design flaw, negative shift is
         * a NOP in the decoder, so it must be handled specially by scaling down
         * coeffs
         */
        else {
                const int nshift = -(*shift);
                FLAC__double error = 0.0;
                FLAC__int32 q;
#ifdef DEBUG
                fprintf(stderr,"FLAC__lpc_quantize_coefficients: negative shift=%d order=%u cmax=%f\n", *shift, order, cmax);
#endif
                for(i = 0; i < order; i++) {
                        error += lp_coeff[i] / (1 << nshift);
                        q = lround(error);
#ifdef FLAC__OVERFLOW_DETECT
                        if(q > qmax+1) /* we expect q==qmax+1 occasionally due to rounding */
                                fprintf(stderr,"FLAC__lpc_quantize_coefficients: quantizer overflow: q>qmax %d>%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n",q,qmax,*shift,cmax,precision+1,i,lp_coeff[i]);
                        else if(q < qmin)
                                fprintf(stderr,"FLAC__lpc_quantize_coefficients: quantizer overflow: q<qmin %d<%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n",q,qmin,*shift,cmax,precision+1,i,lp_coeff[i]);
#endif
                        if(q > qmax)
                                q = qmax;
                        else if(q < qmin)
                                q = qmin;
                        error -= q;
                        qlp_coeff[i] = q;
                }
                *shift = 0;
        }

        return 0;
}

void FLAC__lpc_compute_residual_from_qlp_coefficients(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
#if defined(FLAC__OVERFLOW_DETECT) || !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
        FLAC__int64 sumo;
        unsigned i, j;
        FLAC__int32 sum;
        const FLAC__int32 *history;

#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
        fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
        for(i=0;i<order;i++)
                fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
        fprintf(stderr,"\n");
#endif
        FLAC__ASSERT(order > 0);

        for(i = 0; i < data_len; i++) {
                sumo = 0;
                sum = 0;
                history = data;
                for(j = 0; j < order; j++) {
                        sum += qlp_coeff[j] * (*(--history));
                        sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
                                fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%" PRId64 "\n",i,j,qlp_coeff[j],*history,sumo);
                }
                *(residual++) = *(data++) - (sum >> lp_quantization);
        }

        /* Here's a slower but clearer version:
        for(i = 0; i < data_len; i++) {
                sum = 0;
                for(j = 0; j < order; j++)
                        sum += qlp_coeff[j] * data[i-j-1];
                residual[i] = data[i] - (sum >> lp_quantization);
        }
        */
}
#else /* fully unrolled version for normal use */
{
        int i;
        FLAC__int32 sum;

        FLAC__ASSERT(order > 0);
        FLAC__ASSERT(order <= 32);

        /*
         * We do unique versions up to 12th order since that's the subset limit.
         * Also they are roughly ordered to match frequency of occurrence to
         * minimize branching.
         */
        if(order <= 12) {
                if(order > 8) {
                        if(order > 10) {
                                if(order == 12) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[11] * data[i-12];
                                                sum += qlp_coeff[10] * data[i-11];
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 11 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[10] * data[i-11];
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 10) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 9 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else if(order > 4) {
                        if(order > 6) {
                                if(order == 8) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 7 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 6) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 5 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else {
                        if(order > 2) {
                                if(order == 4) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 3 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 2) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                residual[i] = data[i] - (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 1 */
                                        for(i = 0; i < (int)data_len; i++)
                                                residual[i] = data[i] - ((qlp_coeff[0] * data[i-1]) >> lp_quantization);
                                }
                        }
                }
        }
        else { /* order > 12 */
                for(i = 0; i < (int)data_len; i++) {
                        sum = 0;
                        switch(order) {
                                case 32: sum += qlp_coeff[31] * data[i-32];
                                case 31: sum += qlp_coeff[30] * data[i-31];
                                case 30: sum += qlp_coeff[29] * data[i-30];
                                case 29: sum += qlp_coeff[28] * data[i-29];
                                case 28: sum += qlp_coeff[27] * data[i-28];
                                case 27: sum += qlp_coeff[26] * data[i-27];
                                case 26: sum += qlp_coeff[25] * data[i-26];
                                case 25: sum += qlp_coeff[24] * data[i-25];
                                case 24: sum += qlp_coeff[23] * data[i-24];
                                case 23: sum += qlp_coeff[22] * data[i-23];
                                case 22: sum += qlp_coeff[21] * data[i-22];
                                case 21: sum += qlp_coeff[20] * data[i-21];
                                case 20: sum += qlp_coeff[19] * data[i-20];
                                case 19: sum += qlp_coeff[18] * data[i-19];
                                case 18: sum += qlp_coeff[17] * data[i-18];
                                case 17: sum += qlp_coeff[16] * data[i-17];
                                case 16: sum += qlp_coeff[15] * data[i-16];
                                case 15: sum += qlp_coeff[14] * data[i-15];
                                case 14: sum += qlp_coeff[13] * data[i-14];
                                case 13: sum += qlp_coeff[12] * data[i-13];
                                         sum += qlp_coeff[11] * data[i-12];
                                         sum += qlp_coeff[10] * data[i-11];
                                         sum += qlp_coeff[ 9] * data[i-10];
                                         sum += qlp_coeff[ 8] * data[i- 9];
                                         sum += qlp_coeff[ 7] * data[i- 8];
                                         sum += qlp_coeff[ 6] * data[i- 7];
                                         sum += qlp_coeff[ 5] * data[i- 6];
                                         sum += qlp_coeff[ 4] * data[i- 5];
                                         sum += qlp_coeff[ 3] * data[i- 4];
                                         sum += qlp_coeff[ 2] * data[i- 3];
                                         sum += qlp_coeff[ 1] * data[i- 2];
                                         sum += qlp_coeff[ 0] * data[i- 1];
                        }
                        residual[i] = data[i] - (sum >> lp_quantization);
                }
        }
}
#endif

void FLAC__lpc_compute_residual_from_qlp_coefficients_wide(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
#if defined(FLAC__OVERFLOW_DETECT) || !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
        unsigned i, j;
        FLAC__int64 sum;
        const FLAC__int32 *history;

#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
        fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
        for(i=0;i<order;i++)
                fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
        fprintf(stderr,"\n");
#endif
        FLAC__ASSERT(order > 0);

        for(i = 0; i < data_len; i++) {
                sum = 0;
                history = data;
                for(j = 0; j < order; j++)
                        sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
                if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
                        fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%" PRId64 "\n", i, (sum >> lp_quantization));
                        break;
                }
                if(FLAC__bitmath_silog2_wide((FLAC__int64)(*data) - (sum >> lp_quantization)) > 32) {
                        fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%" PRId64 ", residual=%" PRId64 "\n", i, *data, (long long)(sum >> lp_quantization), ((FLAC__int64)(*data) - (sum >> lp_quantization)));
                        break;
                }
                *(residual++) = *(data++) - (FLAC__int32)(sum >> lp_quantization);
        }
}
#else /* fully unrolled version for normal use */
{
        int i;
        FLAC__int64 sum;

        FLAC__ASSERT(order > 0);
        FLAC__ASSERT(order <= 32);

        /*
         * We do unique versions up to 12th order since that's the subset limit.
         * Also they are roughly ordered to match frequency of occurrence to
         * minimize branching.
         */
        if(order <= 12) {
                if(order > 8) {
                        if(order > 10) {
                                if(order == 12) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[11] * (FLAC__int64)data[i-12];
                                                sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 11 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 10) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 9 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else if(order > 4) {
                        if(order > 6) {
                                if(order == 8) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 7 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 6) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 5 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else {
                        if(order > 2) {
                                if(order == 4) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 3 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 2) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 1 */
                                        for(i = 0; i < (int)data_len; i++)
                                                residual[i] = data[i] - (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i-1]) >> lp_quantization);
                                }
                        }
                }
        }
        else { /* order > 12 */
                for(i = 0; i < (int)data_len; i++) {
                        sum = 0;
                        switch(order) {
                                case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i-32];
                                case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i-31];
                                case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i-30];
                                case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i-29];
                                case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i-28];
                                case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i-27];
                                case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i-26];
                                case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i-25];
                                case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i-24];
                                case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i-23];
                                case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i-22];
                                case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i-21];
                                case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i-20];
                                case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i-19];
                                case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i-18];
                                case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i-17];
                                case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i-16];
                                case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i-15];
                                case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i-14];
                                case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i-13];
                                         sum += qlp_coeff[11] * (FLAC__int64)data[i-12];
                                         sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                         sum += qlp_coeff[ 9] * (FLAC__int64)data[i-10];
                                         sum += qlp_coeff[ 8] * (FLAC__int64)data[i- 9];
                                         sum += qlp_coeff[ 7] * (FLAC__int64)data[i- 8];
                                         sum += qlp_coeff[ 6] * (FLAC__int64)data[i- 7];
                                         sum += qlp_coeff[ 5] * (FLAC__int64)data[i- 6];
                                         sum += qlp_coeff[ 4] * (FLAC__int64)data[i- 5];
                                         sum += qlp_coeff[ 3] * (FLAC__int64)data[i- 4];
                                         sum += qlp_coeff[ 2] * (FLAC__int64)data[i- 3];
                                         sum += qlp_coeff[ 1] * (FLAC__int64)data[i- 2];
                                         sum += qlp_coeff[ 0] * (FLAC__int64)data[i- 1];
                        }
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                }
        }
}
#endif

#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */

void FLAC__lpc_restore_signal(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
#if defined(FLAC__OVERFLOW_DETECT) || !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
        FLAC__int64 sumo;
        unsigned i, j;
        FLAC__int32 sum;
        const FLAC__int32 *r = residual, *history;

#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
        fprintf(stderr,"FLAC__lpc_restore_signal: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
        for(i=0;i<order;i++)
                fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
        fprintf(stderr,"\n");
#endif
        FLAC__ASSERT(order > 0);

        for(i = 0; i < data_len; i++) {
                sumo = 0;
                sum = 0;
                history = data;
                for(j = 0; j < order; j++) {
                        sum += qlp_coeff[j] * (*(--history));
                        sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
                        if(sumo > 2147483647ll || sumo < -2147483648ll)
                                fprintf(stderr,"FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%" PRId64 "\n",i,j,qlp_coeff[j],*history,sumo);
                }
                *(data++) = *(r++) + (sum >> lp_quantization);
        }

        /* Here's a slower but clearer version:
        for(i = 0; i < data_len; i++) {
                sum = 0;
                for(j = 0; j < order; j++)
                        sum += qlp_coeff[j] * data[i-j-1];
                data[i] = residual[i] + (sum >> lp_quantization);
        }
        */
}
#else /* fully unrolled version for normal use */
{
        int i;
        FLAC__int32 sum;

        FLAC__ASSERT(order > 0);
        FLAC__ASSERT(order <= 32);

        /*
         * We do unique versions up to 12th order since that's the subset limit.
         * Also they are roughly ordered to match frequency of occurrence to
         * minimize branching.
         */
        if(order <= 12) {
                if(order > 8) {
                        if(order > 10) {
                                if(order == 12) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[11] * data[i-12];
                                                sum += qlp_coeff[10] * data[i-11];
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 11 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[10] * data[i-11];
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 10) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[9] * data[i-10];
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 9 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[8] * data[i-9];
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else if(order > 4) {
                        if(order > 6) {
                                if(order == 8) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[7] * data[i-8];
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 7 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[6] * data[i-7];
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 6) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[5] * data[i-6];
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 5 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[4] * data[i-5];
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else {
                        if(order > 2) {
                                if(order == 4) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[3] * data[i-4];
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 3 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[2] * data[i-3];
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 2) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[1] * data[i-2];
                                                sum += qlp_coeff[0] * data[i-1];
                                                data[i] = residual[i] + (sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 1 */
                                        for(i = 0; i < (int)data_len; i++)
                                                data[i] = residual[i] + ((qlp_coeff[0] * data[i-1]) >> lp_quantization);
                                }
                        }
                }
        }
        else { /* order > 12 */
                for(i = 0; i < (int)data_len; i++) {
                        sum = 0;
                        switch(order) {
                                case 32: sum += qlp_coeff[31] * data[i-32];
                                case 31: sum += qlp_coeff[30] * data[i-31];
                                case 30: sum += qlp_coeff[29] * data[i-30];
                                case 29: sum += qlp_coeff[28] * data[i-29];
                                case 28: sum += qlp_coeff[27] * data[i-28];
                                case 27: sum += qlp_coeff[26] * data[i-27];
                                case 26: sum += qlp_coeff[25] * data[i-26];
                                case 25: sum += qlp_coeff[24] * data[i-25];
                                case 24: sum += qlp_coeff[23] * data[i-24];
                                case 23: sum += qlp_coeff[22] * data[i-23];
                                case 22: sum += qlp_coeff[21] * data[i-22];
                                case 21: sum += qlp_coeff[20] * data[i-21];
                                case 20: sum += qlp_coeff[19] * data[i-20];
                                case 19: sum += qlp_coeff[18] * data[i-19];
                                case 18: sum += qlp_coeff[17] * data[i-18];
                                case 17: sum += qlp_coeff[16] * data[i-17];
                                case 16: sum += qlp_coeff[15] * data[i-16];
                                case 15: sum += qlp_coeff[14] * data[i-15];
                                case 14: sum += qlp_coeff[13] * data[i-14];
                                case 13: sum += qlp_coeff[12] * data[i-13];
                                         sum += qlp_coeff[11] * data[i-12];
                                         sum += qlp_coeff[10] * data[i-11];
                                         sum += qlp_coeff[ 9] * data[i-10];
                                         sum += qlp_coeff[ 8] * data[i- 9];
                                         sum += qlp_coeff[ 7] * data[i- 8];
                                         sum += qlp_coeff[ 6] * data[i- 7];
                                         sum += qlp_coeff[ 5] * data[i- 6];
                                         sum += qlp_coeff[ 4] * data[i- 5];
                                         sum += qlp_coeff[ 3] * data[i- 4];
                                         sum += qlp_coeff[ 2] * data[i- 3];
                                         sum += qlp_coeff[ 1] * data[i- 2];
                                         sum += qlp_coeff[ 0] * data[i- 1];
                        }
                        data[i] = residual[i] + (sum >> lp_quantization);
                }
        }
}
#endif

void FLAC__lpc_restore_signal_wide(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
#if defined(FLAC__OVERFLOW_DETECT) || !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
        unsigned i, j;
        FLAC__int64 sum;
        const FLAC__int32 *r = residual, *history;

#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
        fprintf(stderr,"FLAC__lpc_restore_signal_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
        for(i=0;i<order;i++)
                fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
        fprintf(stderr,"\n");
#endif
        FLAC__ASSERT(order > 0);

        for(i = 0; i < data_len; i++) {
                sum = 0;
                history = data;
                for(j = 0; j < order; j++)
                        sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
                if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
                        fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%" PRId64 "\n", i, (sum >> lp_quantization));
                        break;
                }
                if(FLAC__bitmath_silog2_wide((FLAC__int64)(*r) + (sum >> lp_quantization)) > 32) {
                        fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%" PRId64 ", data=%" PRId64 "\n", i, *r, (sum >> lp_quantization), ((FLAC__int64)(*r) + (sum >> lp_quantization)));
                        break;
                }
                *(data++) = *(r++) + (FLAC__int32)(sum >> lp_quantization);
        }
}
#else /* fully unrolled version for normal use */
{
        int i;
        FLAC__int64 sum;

        FLAC__ASSERT(order > 0);
        FLAC__ASSERT(order <= 32);

        /*
         * We do unique versions up to 12th order since that's the subset limit.
         * Also they are roughly ordered to match frequency of occurrence to
         * minimize branching.
         */
        if(order <= 12) {
                if(order > 8) {
                        if(order > 10) {
                                if(order == 12) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[11] * (FLAC__int64)data[i-12];
                                                sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 11 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 10) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[9] * (FLAC__int64)data[i-10];
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 9 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[8] * (FLAC__int64)data[i-9];
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else if(order > 4) {
                        if(order > 6) {
                                if(order == 8) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[7] * (FLAC__int64)data[i-8];
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 7 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[6] * (FLAC__int64)data[i-7];
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 6) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[5] * (FLAC__int64)data[i-6];
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 5 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[4] * (FLAC__int64)data[i-5];
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                }
                else {
                        if(order > 2) {
                                if(order == 4) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[3] * (FLAC__int64)data[i-4];
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 3 */
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[2] * (FLAC__int64)data[i-3];
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                        }
                        else {
                                if(order == 2) {
                                        for(i = 0; i < (int)data_len; i++) {
                                                sum = 0;
                                                sum += qlp_coeff[1] * (FLAC__int64)data[i-2];
                                                sum += qlp_coeff[0] * (FLAC__int64)data[i-1];
                                                data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                                        }
                                }
                                else { /* order == 1 */
                                        for(i = 0; i < (int)data_len; i++)
                                                data[i] = residual[i] + (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i-1]) >> lp_quantization);
                                }
                        }
                }
        }
        else { /* order > 12 */
                for(i = 0; i < (int)data_len; i++) {
                        sum = 0;
                        switch(order) {
                                case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i-32];
                                case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i-31];
                                case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i-30];
                                case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i-29];
                                case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i-28];
                                case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i-27];
                                case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i-26];
                                case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i-25];
                                case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i-24];
                                case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i-23];
                                case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i-22];
                                case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i-21];
                                case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i-20];
                                case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i-19];
                                case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i-18];
                                case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i-17];
                                case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i-16];
                                case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i-15];
                                case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i-14];
                                case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i-13];
                                         sum += qlp_coeff[11] * (FLAC__int64)data[i-12];
                                         sum += qlp_coeff[10] * (FLAC__int64)data[i-11];
                                         sum += qlp_coeff[ 9] * (FLAC__int64)data[i-10];
                                         sum += qlp_coeff[ 8] * (FLAC__int64)data[i- 9];
                                         sum += qlp_coeff[ 7] * (FLAC__int64)data[i- 8];
                                         sum += qlp_coeff[ 6] * (FLAC__int64)data[i- 7];
                                         sum += qlp_coeff[ 5] * (FLAC__int64)data[i- 6];
                                         sum += qlp_coeff[ 4] * (FLAC__int64)data[i- 5];
                                         sum += qlp_coeff[ 3] * (FLAC__int64)data[i- 4];
                                         sum += qlp_coeff[ 2] * (FLAC__int64)data[i- 3];
                                         sum += qlp_coeff[ 1] * (FLAC__int64)data[i- 2];
                                         sum += qlp_coeff[ 0] * (FLAC__int64)data[i- 1];
                        }
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                }
        }
}
#endif

#ifndef FLAC__INTEGER_ONLY_LIBRARY

FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples)
{
        FLAC__double error_scale;

        FLAC__ASSERT(total_samples > 0);

        error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;

        return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale);
}

FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale)
{
        if(lpc_error > 0.0) {
                FLAC__double bps = (FLAC__double)0.5 * log(error_scale * lpc_error) / M_LN2;
                if(bps >= 0.0)
                        return bps;
                else
                        return 0.0;
        }
        else if(lpc_error < 0.0) { /* error should not be negative but can happen due to inadequate floating-point resolution */
                return 1e32;
        }
        else {
                return 0.0;
        }
}

unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned overhead_bits_per_order)
{
        unsigned order, index, best_index; /* 'index' the index into lpc_error; index==order-1 since lpc_error[0] is for order==1, lpc_error[1] is for order==2, etc */
        FLAC__double bits, best_bits, error_scale;

        FLAC__ASSERT(max_order > 0);
        FLAC__ASSERT(total_samples > 0);

        error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;

        best_index = 0;
        best_bits = (unsigned)(-1);

        for(index = 0, order = 1; index < max_order; index++, order++) {
                bits = FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error[index], error_scale) * (FLAC__double)(total_samples - order) + (FLAC__double)(order * overhead_bits_per_order);
                if(bits < best_bits) {
                        best_index = index;
                        best_bits = bits;
                }
        }

        return best_index+1; /* +1 since index of lpc_error[] is order-1 */
}

#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */