ffmpeg/libavcodec/ppc/dsputil_altivec.c

/*
 * Copyright (c) 2002 Brian Foley
 * Copyright (c) 2002 Dieter Shirley
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
#include "../dsputil.h"
#include "dsputil_altivec.h"

#if CONFIG_DARWIN
#include <sys/sysctl.h>
#endif

#ifdef ALTIVEC_TBL_PERFORMANCE_REPORT
unsigned long long perfdata[altivec_perf_total][altivec_data_total];
/* list below must match enum in dsputil_altivec.h */
static unsigned char* perfname[] = {
  "fft_calc",
  "gmc1",
  "dct_unquantize_h263",
  "idct_add",
  "idct_put",
  "put_pixels_clamped",
  "put_pixels16",
  "avg_pixels16"
};
#include <stdio.h>
#endif

int pix_abs16x16_x2_altivec(uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned char zero = (const vector unsigned char)(0);
    vector unsigned char *tv;
    vector unsigned char pix1v, pix2v, pix2iv, avgv, t5;
    vector unsigned int sad;
    vector signed int sumdiffs;

    s = 0;
    sad = (vector unsigned int)(0);
    for(i=0;i<16;i++) {
        /*
           Read unaligned pixels into our vectors. The vectors are as follows:
           pix1v: pix1[0]-pix1[15]
           pix2v: pix2[0]-pix2[15]	pix2iv: pix2[1]-pix2[16]
        */
        tv = (vector unsigned char *) pix1;
        pix1v = vec_perm(tv[0], tv[1], vec_lvsl(0, pix1));
        
        tv = (vector unsigned char *) &pix2[0];
        pix2v = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix2[0]));

        tv = (vector unsigned char *) &pix2[1];
        pix2iv = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix2[1]));

        /* Calculate the average vector */
        avgv = vec_avg(pix2v, pix2iv);

        /* Calculate a sum of abs differences vector */
        t5 = vec_sub(vec_max(pix1v, avgv), vec_min(pix1v, avgv));

        /* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t5, sad);
        
        pix1 += line_size;
        pix2 += line_size;
    }
    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);

    return s;
}

int pix_abs16x16_y2_altivec(uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned char zero = (const vector unsigned char)(0);
    vector unsigned char *tv;
    vector unsigned char pix1v, pix2v, pix3v, avgv, t5;
    vector unsigned int sad;
    vector signed int sumdiffs;
    uint8_t *pix3 = pix2 + line_size;

    s = 0;
    sad = (vector unsigned int)(0);

    /*
       Due to the fact that pix3 = pix2 + line_size, the pix3 of one
       iteration becomes pix2 in the next iteration. We can use this
       fact to avoid a potentially expensive unaligned read, each
       time around the loop.
       Read unaligned pixels into our vectors. The vectors are as follows:
       pix2v: pix2[0]-pix2[15]
       Split the pixel vectors into shorts
    */
    tv = (vector unsigned char *) &pix2[0];
    pix2v = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix2[0]));
    
    for(i=0;i<16;i++) {
        /*
           Read unaligned pixels into our vectors. The vectors are as follows:
           pix1v: pix1[0]-pix1[15]
           pix3v: pix3[0]-pix3[15]
        */
        tv = (vector unsigned char *) pix1;
        pix1v = vec_perm(tv[0], tv[1], vec_lvsl(0, pix1));

        tv = (vector unsigned char *) &pix3[0];
        pix3v = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix3[0]));

        /* Calculate the average vector */
        avgv = vec_avg(pix2v, pix3v);

        /* Calculate a sum of abs differences vector */
        t5 = vec_sub(vec_max(pix1v, avgv), vec_min(pix1v, avgv));

        /* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t5, sad);
        
        pix1 += line_size;
        pix2v = pix3v;
        pix3 += line_size;
        
    }
    
    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);
    return s;    
}

int pix_abs16x16_xy2_altivec(uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    uint8_t *pix3 = pix2 + line_size;
    const vector unsigned char zero = (const vector unsigned char)(0);
    const vector unsigned short two = (const vector unsigned short)(2);
    vector unsigned char *tv, avgv, t5;
    vector unsigned char pix1v, pix2v, pix3v, pix2iv, pix3iv;
    vector unsigned short pix2lv, pix2hv, pix2ilv, pix2ihv;
    vector unsigned short pix3lv, pix3hv, pix3ilv, pix3ihv;
    vector unsigned short avghv, avglv;
    vector unsigned short t1, t2, t3, t4;
    vector unsigned int sad;
    vector signed int sumdiffs;

    sad = (vector unsigned int)(0);
    
    s = 0;

    /*
       Due to the fact that pix3 = pix2 + line_size, the pix3 of one
       iteration becomes pix2 in the next iteration. We can use this
       fact to avoid a potentially expensive unaligned read, as well
       as some splitting, and vector addition each time around the loop.
       Read unaligned pixels into our vectors. The vectors are as follows:
       pix2v: pix2[0]-pix2[15]	pix2iv: pix2[1]-pix2[16]
       Split the pixel vectors into shorts
    */
    tv = (vector unsigned char *) &pix2[0];
    pix2v = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix2[0]));

    tv = (vector unsigned char *) &pix2[1];
    pix2iv = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix2[1]));

    pix2hv = (vector unsigned short) vec_mergeh(zero, pix2v);
    pix2lv = (vector unsigned short) vec_mergel(zero, pix2v);
    pix2ihv = (vector unsigned short) vec_mergeh(zero, pix2iv);
    pix2ilv = (vector unsigned short) vec_mergel(zero, pix2iv);
    t1 = vec_add(pix2hv, pix2ihv);
    t2 = vec_add(pix2lv, pix2ilv);
    
    for(i=0;i<16;i++) {
        /*
           Read unaligned pixels into our vectors. The vectors are as follows:
           pix1v: pix1[0]-pix1[15]
           pix3v: pix3[0]-pix3[15]	pix3iv: pix3[1]-pix3[16]
        */
        tv = (vector unsigned char *) pix1;
        pix1v = vec_perm(tv[0], tv[1], vec_lvsl(0, pix1));

        tv = (vector unsigned char *) &pix3[0];
        pix3v = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix3[0]));

        tv = (vector unsigned char *) &pix3[1];
        pix3iv = vec_perm(tv[0], tv[1], vec_lvsl(0, &pix3[1]));

        /*
          Note that Altivec does have vec_avg, but this works on vector pairs
          and rounds up. We could do avg(avg(a,b),avg(c,d)), but the rounding
          would mean that, for example, avg(3,0,0,1) = 2, when it should be 1.
          Instead, we have to split the pixel vectors into vectors of shorts,
          and do the averaging by hand.
        */

        /* Split the pixel vectors into shorts */
        pix3hv = (vector unsigned short) vec_mergeh(zero, pix3v);
        pix3lv = (vector unsigned short) vec_mergel(zero, pix3v);
        pix3ihv = (vector unsigned short) vec_mergeh(zero, pix3iv);
        pix3ilv = (vector unsigned short) vec_mergel(zero, pix3iv);

        /* Do the averaging on them */
        t3 = vec_add(pix3hv, pix3ihv);
        t4 = vec_add(pix3lv, pix3ilv);

        avghv = vec_sr(vec_add(vec_add(t1, t3), two), two);
        avglv = vec_sr(vec_add(vec_add(t2, t4), two), two);

        /* Pack the shorts back into a result */
        avgv = vec_pack(avghv, avglv);

        /* Calculate a sum of abs differences vector */
        t5 = vec_sub(vec_max(pix1v, avgv), vec_min(pix1v, avgv));

        /* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t5, sad);

        pix1 += line_size;
        pix3 += line_size;
        /* Transfer the calculated values for pix3 into pix2 */
        t1 = t3;
        t2 = t4;
    }
    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);

    return s;
}

int pix_abs16x16_altivec(uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char perm1, perm2, *pix1v, *pix2v;
    vector unsigned char t1, t2, t3,t4, t5;
    vector unsigned int sad;
    vector signed int sumdiffs;
    
    sad = (vector unsigned int) (0);


    for(i=0;i<16;i++) {
	/* Read potentially unaligned pixels into t1 and t2 */
        perm1 = vec_lvsl(0, pix1);
        pix1v = (vector unsigned char *) pix1;
        perm2 = vec_lvsl(0, pix2);
        pix2v = (vector unsigned char *) pix2;
        t1 = vec_perm(pix1v[0], pix1v[1], perm1);
        t2 = vec_perm(pix2v[0], pix2v[1], perm2);
       
	/* Calculate a sum of abs differences vector */ 
        t3 = vec_max(t1, t2);
        t4 = vec_min(t1, t2);
        t5 = vec_sub(t3, t4);
	
	/* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t5, sad);

        pix1 += line_size;
        pix2 += line_size;
    }

    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);
    
    return s;
}

int pix_abs8x8_altivec(uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char perm1, perm2, permclear, *pix1v, *pix2v;
    vector unsigned char t1, t2, t3,t4, t5;
    vector unsigned int sad;
    vector signed int sumdiffs;

    sad = (vector unsigned int)(0);
    permclear = (vector unsigned char) (255,255,255,255,255,255,255,255,0,0,0,0,0,0,0,0);

    for(i=0;i<8;i++) {
	/* Read potentially unaligned pixels into t1 and t2
	   Since we're reading 16 pixels, and actually only want 8,
	   mask out the last 8 pixels. The 0s don't change the sum. */
        perm1 = vec_lvsl(0, pix1);
        pix1v = (vector unsigned char *) pix1;
        perm2 = vec_lvsl(0, pix2);
        pix2v = (vector unsigned char *) pix2;
        t1 = vec_and(vec_perm(pix1v[0], pix1v[1], perm1), permclear);
        t2 = vec_and(vec_perm(pix2v[0], pix2v[1], perm2), permclear);

	/* Calculate a sum of abs differences vector */ 
        t3 = vec_max(t1, t2);
        t4 = vec_min(t1, t2);
        t5 = vec_sub(t3, t4);

	/* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t5, sad);

        pix1 += line_size;
        pix2 += line_size;
    }

    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);

    return s;
}

int pix_norm1_altivec(uint8_t *pix, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char *tv;
    vector unsigned char pixv;
    vector unsigned int sv;
    vector signed int sum;
    
    sv = (vector unsigned int)(0);
    
    s = 0;
    for (i = 0; i < 16; i++) {
        /* Read in the potentially unaligned pixels */
        tv = (vector unsigned char *) pix;
        pixv = vec_perm(tv[0], tv[1], vec_lvsl(0, pix));

        /* Square the values, and add them to our sum */
        sv = vec_msum(pixv, pixv, sv);

        pix += line_size;
    }
    /* Sum up the four partial sums, and put the result into s */
    sum = vec_sums((vector signed int) sv, (vector signed int) zero);
    sum = vec_splat(sum, 3);
    vec_ste(sum, 0, &s);

    return s;
}

/**
 * Sum of Squared Errors for a 8x8 block.
 * AltiVec-enhanced.
 * It's the pix_abs8x8_altivec code above w/ squaring added.
 */
int sse8_altivec(void *v, uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char perm1, perm2, permclear, *pix1v, *pix2v;
    vector unsigned char t1, t2, t3,t4, t5;
    vector unsigned int sum;
    vector signed int sumsqr;
    
    sum = (vector unsigned int)(0);
    permclear = (vector unsigned char)(0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00);
    
    for(i=0;i<8;i++) {
	/* Read potentially unaligned pixels into t1 and t2
	   Since we're reading 16 pixels, and actually only want 8,
	   mask out the last 8 pixels. The 0s don't change the sum. */
        perm1 = vec_lvsl(0, pix1);
        pix1v = (vector unsigned char *) pix1;
        perm2 = vec_lvsl(0, pix2);
        pix2v = (vector unsigned char *) pix2;
        t1 = vec_and(vec_perm(pix1v[0], pix1v[1], perm1), permclear);
        t2 = vec_and(vec_perm(pix2v[0], pix2v[1], perm2), permclear);

        /*
          Since we want to use unsigned chars, we can take advantage
          of the fact that abs(a-b)^2 = (a-b)^2.
        */
        
	/* Calculate abs differences vector */ 
        t3 = vec_max(t1, t2);
        t4 = vec_min(t1, t2);
        t5 = vec_sub(t3, t4);
        
        /* Square the values and add them to our sum */
        sum = vec_msum(t5, t5, sum);
        
        pix1 += line_size;
        pix2 += line_size;
    }
    
    /* Sum up the four partial sums, and put the result into s */
    sumsqr = vec_sums((vector signed int) sum, (vector signed int) zero);
    sumsqr = vec_splat(sumsqr, 3);
    vec_ste(sumsqr, 0, &s);
    
    return s;
}

/**
 * Sum of Squared Errors for a 16x16 block.
 * AltiVec-enhanced.
 * It's the pix_abs16x16_altivec code above w/ squaring added.
 */
int sse16_altivec(void *v, uint8_t *pix1, uint8_t *pix2, int line_size)
{
    int i;
    int s __attribute__((aligned(16)));
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char perm1, perm2, *pix1v, *pix2v;
    vector unsigned char t1, t2, t3,t4, t5;
    vector unsigned int sum;
    vector signed int sumsqr;
    
    sum = (vector unsigned int)(0);
    
    for(i=0;i<16;i++) {
	/* Read potentially unaligned pixels into t1 and t2 */
        perm1 = vec_lvsl(0, pix1);
        pix1v = (vector unsigned char *) pix1;
        perm2 = vec_lvsl(0, pix2);
        pix2v = (vector unsigned char *) pix2;
        t1 = vec_perm(pix1v[0], pix1v[1], perm1);
        t2 = vec_perm(pix2v[0], pix2v[1], perm2);

        /*
          Since we want to use unsigned chars, we can take advantage
          of the fact that abs(a-b)^2 = (a-b)^2.
        */
        
	/* Calculate abs differences vector */ 
        t3 = vec_max(t1, t2);
        t4 = vec_min(t1, t2);
        t5 = vec_sub(t3, t4);
        
        /* Square the values and add them to our sum */
        sum = vec_msum(t5, t5, sum);
        
        pix1 += line_size;
        pix2 += line_size;
    }
    
    /* Sum up the four partial sums, and put the result into s */
    sumsqr = vec_sums((vector signed int) sum, (vector signed int) zero);
    sumsqr = vec_splat(sumsqr, 3);
    vec_ste(sumsqr, 0, &s);
    
    return s;
}

int pix_sum_altivec(UINT8 * pix, int line_size)
{
    const vector unsigned int zero = (const vector unsigned int)(0);
    vector unsigned char perm, *pixv;
    vector unsigned char t1;
    vector unsigned int sad;
    vector signed int sumdiffs;

    int i;
    int s __attribute__((aligned(16)));
    
    sad = (vector unsigned int) (0);
    
    for (i = 0; i < 16; i++) {
	/* Read the potentially unaligned 16 pixels into t1 */
        perm = vec_lvsl(0, pix);
        pixv = (vector unsigned char *) pix;
        t1 = vec_perm(pixv[0], pixv[1], perm);

	/* Add each 4 pixel group together and put 4 results into sad */
        sad = vec_sum4s(t1, sad);
        
        pix += line_size;
    }
    
    /* Sum up the four partial sums, and put the result into s */
    sumdiffs = vec_sums((vector signed int) sad, (vector signed int) zero);
    sumdiffs = vec_splat(sumdiffs, 3);
    vec_ste(sumdiffs, 0, &s);
    
    return s;
}

void get_pixels_altivec(DCTELEM *restrict block, const UINT8 *pixels, int line_size)
{
    int i;
    vector unsigned char perm, bytes, *pixv;
    const vector unsigned char zero = (const vector unsigned char) (0);
    vector signed short shorts;

    for(i=0;i<8;i++)
    {
        // Read potentially unaligned pixels.
        // We're reading 16 pixels, and actually only want 8,
        // but we simply ignore the extras.
        perm = vec_lvsl(0, pixels);
        pixv = (vector unsigned char *) pixels;
        bytes = vec_perm(pixv[0], pixv[1], perm);

        // convert the bytes into shorts
        shorts = (vector signed short)vec_mergeh(zero, bytes);

        // save the data to the block, we assume the block is 16-byte aligned
        vec_st(shorts, i*16, (vector signed short*)block);

        pixels += line_size;
    }
}

void diff_pixels_altivec(DCTELEM *restrict block, const UINT8 *s1,
        const UINT8 *s2, int stride)
{
    int i;
    vector unsigned char perm, bytes, *pixv;
    const vector unsigned char zero = (const vector unsigned char) (0);
    vector signed short shorts1, shorts2;

    for(i=0;i<4;i++)
    {
        // Read potentially unaligned pixels
        // We're reading 16 pixels, and actually only want 8,
        // but we simply ignore the extras.
        perm = vec_lvsl(0, s1);
        pixv = (vector unsigned char *) s1;
        bytes = vec_perm(pixv[0], pixv[1], perm);

        // convert the bytes into shorts
        shorts1 = (vector signed short)vec_mergeh(zero, bytes);

        // Do the same for the second block of pixels
        perm = vec_lvsl(0, s2);
        pixv = (vector unsigned char *) s2;
        bytes = vec_perm(pixv[0], pixv[1], perm);

        // convert the bytes into shorts
        shorts2 = (vector signed short)vec_mergeh(zero, bytes);

        // Do the subtraction
        shorts1 = vec_sub(shorts1, shorts2);

        // save the data to the block, we assume the block is 16-byte aligned
        vec_st(shorts1, 0, (vector signed short*)block);

        s1 += stride;
        s2 += stride;
        block += 8;


        // The code below is a copy of the code above... This is a manual
        // unroll.

        // Read potentially unaligned pixels
        // We're reading 16 pixels, and actually only want 8,
        // but we simply ignore the extras.
        perm = vec_lvsl(0, s1);
        pixv = (vector unsigned char *) s1;
        bytes = vec_perm(pixv[0], pixv[1], perm);

        // convert the bytes into shorts
        shorts1 = (vector signed short)vec_mergeh(zero, bytes);

        // Do the same for the second block of pixels
        perm = vec_lvsl(0, s2);
        pixv = (vector unsigned char *) s2;
        bytes = vec_perm(pixv[0], pixv[1], perm);

        // convert the bytes into shorts
        shorts2 = (vector signed short)vec_mergeh(zero, bytes);

        // Do the subtraction
        shorts1 = vec_sub(shorts1, shorts2);

        // save the data to the block, we assume the block is 16-byte aligned
        vec_st(shorts1, 0, (vector signed short*)block);

        s1 += stride;
        s2 += stride;
        block += 8;
    }
}

int sad16x16_altivec(void *s, uint8_t *a, uint8_t *b, int stride) {
  return pix_abs16x16_altivec(a,b,stride);
}

int sad8x8_altivec(void *s, uint8_t *a, uint8_t *b, int stride) {
  return pix_abs8x8_altivec(a,b,stride);
}

void add_bytes_altivec(uint8_t *dst, uint8_t *src, int w) {
#ifdef ALTIVEC_USE_REFERENCE_C_CODE
    int i;
    for(i=0; i+7<w; i++){
        dst[i+0] += src[i+0];
        dst[i+1] += src[i+1];
        dst[i+2] += src[i+2];
        dst[i+3] += src[i+3];
        dst[i+4] += src[i+4];
        dst[i+5] += src[i+5];
        dst[i+6] += src[i+6];
        dst[i+7] += src[i+7];
    }
    for(; i<w; i++)
        dst[i+0] += src[i+0];
#else /* ALTIVEC_USE_REFERENCE_C_CODE */
    register int i;
    register vector unsigned char vdst, vsrc;
    
    /* dst and src are 16 bytes-aligned (guaranteed) */
    for(i = 0 ; (i + 15) < w ; i++)
    {
      vdst = vec_ld(i << 4, (unsigned char*)dst);
      vsrc = vec_ld(i << 4, (unsigned char*)src);
      vdst = vec_add(vsrc, vdst);
      vec_st(vdst, i << 4, (unsigned char*)dst);
    }
    /* if w is not a multiple of 16 */
    for (; (i < w) ; i++)
    {
      dst[i] = src[i];
    }
#endif /* ALTIVEC_USE_REFERENCE_C_CODE */
}

extern UINT8 cropTbl[];
void put_pixels_clamped_altivec(const DCTELEM *block, UINT8 *restrict pixels,
                                int line_size)
{
ALTIVEC_TBL_DECLARE(altivec_put_pixels_clamped_num, 1);
#ifdef ALTIVEC_USE_REFERENCE_C_CODE
    int i;
    UINT8 *cm = cropTbl + MAX_NEG_CROP;

ALTIVEC_TBL_START_COUNT(altivec_put_pixels_clamped_num, 1);
    
    /* read the pixels */
    for(i=0;i<8;i++) {
        pixels[0] = cm[block[0]];
        pixels[1] = cm[block[1]];
        pixels[2] = cm[block[2]];
        pixels[3] = cm[block[3]];
        pixels[4] = cm[block[4]];
        pixels[5] = cm[block[5]];
        pixels[6] = cm[block[6]];
        pixels[7] = cm[block[7]];

        pixels += line_size;
        block += 8;
    }

ALTIVEC_TBL_STOP_COUNT(altivec_put_pixels_clamped_num, 1);

#else /* ALTIVEC_USE_REFERENCE_C_CODE */
    register const vector short vczero = (const vector short)(0);
    register vector short
      blockv0, blockv1, blockv2, blockv3,
      blockv4, blockv5, blockv6, blockv7;
    register vector unsigned char
      pixelsv0, pixelsv1, pixelsv2, pixelsv3, pixelsv4,
      pixelsv0old, pixelsv4old;

ALTIVEC_TBL_START_COUNT(altivec_put_pixels_clamped_num, 1);

    blockv0 = vec_ld(0, block);
    blockv1 = vec_ld(16, block);
    blockv2 = vec_ld(32, block);
    blockv3 = vec_ld(48, block);
    blockv4 = vec_ld(64, block);
    blockv5 = vec_ld(80, block);
    blockv6 = vec_ld(96, block);
    blockv7 = vec_ld(112, block);
    if (((unsigned long)pixels) & 0x0000000F)
    {
      pixelsv0old = vec_ld(-8, pixels);
      pixelsv4old = vec_ld(56, pixels);
      pixelsv0 = vec_packsu(vczero, blockv0);
      pixelsv1 = vec_packsu(blockv1, blockv2);
      pixelsv2 = vec_packsu(blockv3, blockv4);
      pixelsv3 = vec_packsu(blockv5, blockv6);
      pixelsv4 = vec_packsu(blockv5, vczero);
      pixelsv0 = vec_perm(pixelsv0old, pixelsv0, vcprm(0, 1, s2, s3));
      pixelsv4 = vec_perm(pixelsv4, pixelsv4old, vcprm(0, 1, s2, s3));
      vec_st(pixelsv0, -8, pixels);
      vec_st(pixelsv1, 8, pixels);
      vec_st(pixelsv2, 24, pixels);
      vec_st(pixelsv3, 40, pixels);
      vec_st(pixelsv4, 56, pixels);
    }
    else
    {
      pixelsv0 = vec_packsu(blockv0, blockv1);
      pixelsv1 = vec_packsu(blockv2, blockv3);
      pixelsv2 = vec_packsu(blockv4, blockv5);
      pixelsv3 = vec_packsu(blockv6, blockv7);
      vec_st(pixelsv0, 0, pixels);
      vec_st(pixelsv1, 16, pixels);
      vec_st(pixelsv2, 32, pixels);
      vec_st(pixelsv3, 48, pixels);
    }

ALTIVEC_TBL_STOP_COUNT(altivec_put_pixels_clamped_num, 1);
#endif /* ALTIVEC_USE_REFERENCE_C_CODE */
}

void put_pixels16_altivec(uint8_t *block, const uint8_t *pixels, int line_size, int h)
{
ALTIVEC_TBL_DECLARE(altivec_put_pixels16_num, 1);
#ifdef ALTIVEC_USE_REFERENCE_C_CODE
    int i;

ALTIVEC_TBL_START_COUNT(altivec_put_pixels16_num, 1);

    for(i=0; i<h; i++) {
      *((uint32_t*)(block )) = (((const struct unaligned_32 *) (pixels))->l);
      *((uint32_t*)(block+4)) = (((const struct unaligned_32 *) (pixels+4))->l);
      *((uint32_t*)(block+8)) = (((const struct unaligned_32 *) (pixels+8))->l);
      *((uint32_t*)(block+12)) = (((const struct unaligned_32 *) (pixels+12))->l);
      pixels+=line_size;
      block +=line_size;
    }

ALTIVEC_TBL_STOP_COUNT(altivec_put_pixels16_num, 1);

#else /* ALTIVEC_USE_REFERENCE_C_CODE */

    register vector unsigned char perm = vec_lvsl(0, pixels); 
    register vector unsigned char pixelsv1, pixelsv2;
    int i;

ALTIVEC_TBL_START_COUNT(altivec_put_pixels16_num, 1);

    for(i=0; i<h; i++) {
      pixelsv1 = vec_ld(0, (unsigned char*)pixels);
      pixelsv2 = vec_ld(16, (unsigned char*)pixels);
      vec_st(vec_perm(pixelsv1, pixelsv2, perm), 0, (unsigned char*)block);
      pixels+=line_size;
      block +=line_size;
    }

ALTIVEC_TBL_STOP_COUNT(altivec_put_pixels16_num, 1);

#endif /* ALTIVEC_USE_REFERENCE_C_CODE */
}

#define op_avg(a,b)  a = ( ((a)|(b)) - ((((a)^(b))&0xFEFEFEFEUL)>>1) )
void avg_pixels16_altivec(uint8_t *block, const uint8_t *pixels, int line_size, int h)
{
ALTIVEC_TBL_DECLARE(altivec_avg_pixels16_num, 1);
#ifdef ALTIVEC_USE_REFERENCE_C_CODE
    int i;

ALTIVEC_TBL_START_COUNT(altivec_avg_pixels16_num, 1);

    for(i=0; i<h; i++) {
      op_avg(*((uint32_t*)(block)),(((const struct unaligned_32 *)(pixels))->l));
      op_avg(*((uint32_t*)(block+4)),(((const struct unaligned_32 *)(pixels+4))->l));
      op_avg(*((uint32_t*)(block+8)),(((const struct unaligned_32 *)(pixels+8))->l));
      op_avg(*((uint32_t*)(block+12)),(((const struct unaligned_32 *)(pixels+12))->l));
      pixels+=line_size;
      block +=line_size;
    }

ALTIVEC_TBL_STOP_COUNT(altivec_avg_pixels16_num, 1);

#else /* ALTIVEC_USE_REFERENCE_C_CODE */

    register vector unsigned char perm = vec_lvsl(0, pixels); 
    register vector unsigned char pixelsv1, pixelsv2, pixelsv, blockv;
    int i;

ALTIVEC_TBL_START_COUNT(altivec_avg_pixels16_num, 1);

    for(i=0; i<h; i++) {
      pixelsv1 = vec_ld(0, (unsigned char*)pixels);
      pixelsv2 = vec_ld(16, (unsigned char*)pixels);
      blockv = vec_ld(0, block);
      pixelsv = vec_perm(pixelsv1, pixelsv2, perm);
      blockv = vec_avg(blockv,pixelsv);
      vec_st(blockv, 0, (unsigned char*)block);
      pixels+=line_size;
      block +=line_size;
    }

ALTIVEC_TBL_STOP_COUNT(altivec_avg_pixels16_num, 1);

#endif /* ALTIVEC_USE_REFERENCE_C_CODE */
}

int has_altivec(void)
{
#if CONFIG_DARWIN
    int sels[2] = {CTL_HW, HW_VECTORUNIT};
    int has_vu = 0;
    size_t len = sizeof(has_vu);
    int err;

    err = sysctl(sels, 2, &has_vu, &len, NULL, 0);

    if (err == 0) return (has_vu != 0);
#endif
    return 0;
}

#ifdef ALTIVEC_TBL_PERFORMANCE_REPORT
void altivec_display_perf_report(void)
{
  int i;
  fprintf(stderr, "AltiVec performance report\n Values are from the Time Base register, and represent 4 bus cycles.\n");
  for(i = 0 ; i < altivec_perf_total ; i++)
  {
    if (perfdata[i][altivec_data_num] != (unsigned long long)0)
      fprintf(stderr, " Function \"%s\":\n\tmin: %llu\n\tmax: %llu\n\tavg: %1.2lf (%llu)\n",
              perfname[i],
              perfdata[i][altivec_data_min],
              perfdata[i][altivec_data_max],
              (double)perfdata[i][altivec_data_sum] /
              (double)perfdata[i][altivec_data_num],
              perfdata[i][altivec_data_num]);
  }
}
#endif /* ALTIVEC_TBL_PERFORMANCE_REPORT */