swscale_altivec_template.c

video linux conference

/*
  AltiVec-enhanced yuv2yuvX

    Copyright (C) 2004 Romain Dolbeau <[e-mail]>
    based on the equivalent C code in "postproc/swscale.c"


    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifdef CONFIG_DARWIN
#define AVV(x...) (x)
#else
#define AVV(x...) {x}
#endif

static const vector signed int vzero =
  (const vector signed int)AVV(0, 0, 0, 0);
static const vector unsigned int altivec_vectorShiftInt19 =
  (const vector unsigned int)AVV(19, 19, 19, 19);

static inline void
altivec_packIntArrayToCharArray(int *val, uint8_t* dest, int dstW) {
  register int i;
  if ((unsigned long)dest % 16) {
    /* badly aligned store, we force store alignement */
    /* and will handle load misalignement on val w/ vec_perm */
    for (i = 0 ; (i < dstW) &&
	   (((unsigned long)dest + i) % 16) ; i++) {
      int t = val[i] >> 19;
      dest[i] = (t < 0) ? 0 : ((t > 255) ? 255 : t);
    }
    vector unsigned char perm1 = vec_lvsl(i << 2, val);
    vector signed int v1 = vec_ld(i << 2, val);
    for ( ; i < (dstW - 15); i+=16) {
      int offset = i << 2;
      vector signed int v2 = vec_ld(offset + 16, val);
      vector signed int v3 = vec_ld(offset + 32, val);
      vector signed int v4 = vec_ld(offset + 48, val);
      vector signed int v5 = vec_ld(offset + 64, val);
      vector signed int v12 = vec_perm(v1,v2,perm1);
      vector signed int v23 = vec_perm(v2,v3,perm1);
      vector signed int v34 = vec_perm(v3,v4,perm1);
      vector signed int v45 = vec_perm(v4,v5,perm1);
      
      vector signed int vA = vec_sra(v12, altivec_vectorShiftInt19);
      vector signed int vB = vec_sra(v23, altivec_vectorShiftInt19);
      vector signed int vC = vec_sra(v34, altivec_vectorShiftInt19);
      vector signed int vD = vec_sra(v45, altivec_vectorShiftInt19);
      vector unsigned short vs1 = vec_packsu(vA, vB);
      vector unsigned short vs2 = vec_packsu(vC, vD);
      vector unsigned char vf = vec_packsu(vs1, vs2);
      vec_st(vf, i, dest);
      v1 = v5;
    }
  } else { // dest is properly aligned, great
    for (i = 0; i < (dstW - 15); i+=16) {
      int offset = i << 2;
      vector signed int v1 = vec_ld(offset, val);
      vector signed int v2 = vec_ld(offset + 16, val);
      vector signed int v3 = vec_ld(offset + 32, val);
      vector signed int v4 = vec_ld(offset + 48, val);
      vector signed int v5 = vec_sra(v1, altivec_vectorShiftInt19);
      vector signed int v6 = vec_sra(v2, altivec_vectorShiftInt19);
      vector signed int v7 = vec_sra(v3, altivec_vectorShiftInt19);
      vector signed int v8 = vec_sra(v4, altivec_vectorShiftInt19);
      vector unsigned short vs1 = vec_packsu(v5, v6);
      vector unsigned short vs2 = vec_packsu(v7, v8);
      vector unsigned char vf = vec_packsu(vs1, vs2);
      vec_st(vf, i, dest);
    }
  }
  for ( ; i < dstW ; i++) {
    int t = val[i] >> 19;
    dest[i] = (t < 0) ? 0 : ((t > 255) ? 255 : t);
  }
}

static inline void
yuv2yuvX_altivec_real(int16_t *lumFilter, int16_t **lumSrc, int lumFilterSize,
		      int16_t *chrFilter, int16_t **chrSrc, int chrFilterSize,
		      uint8_t *dest, uint8_t *uDest, uint8_t *vDest, int dstW, int chrDstW)
{
  const vector signed int vini = {(1 << 18), (1 << 18), (1 << 18), (1 << 18)};
  register int i, j;
  {
    int __attribute__ ((aligned (16))) val[dstW];
    
    for (i = 0; i < (dstW -7); i+=4) {
      vec_st(vini, i << 2, val);
    }
    for (; i < dstW; i++) {
      val[i] = (1 << 18);
    }
    
    for (j = 0; j < lumFilterSize; j++) {
      vector signed short vLumFilter = vec_ld(j << 1, lumFilter);
      vector unsigned char perm0 = vec_lvsl(j << 1, lumFilter);
      vLumFilter = vec_perm(vLumFilter, vLumFilter, perm0);
      vLumFilter = vec_splat(vLumFilter, 0); // lumFilter[j] is loaded 8 times in vLumFilter
      
      vector unsigned char perm = vec_lvsl(0, lumSrc[j]);
      vector signed short l1 = vec_ld(0, lumSrc[j]);
      
      for (i = 0; i < (dstW - 7); i+=8) {
	int offset = i << 2;
	vector signed short l2 = vec_ld((i << 1) + 16, lumSrc[j]);
	
	vector signed int v1 = vec_ld(offset, val);
	vector signed int v2 = vec_ld(offset + 16, val);
	
	vector signed short ls = vec_perm(l1, l2, perm); // lumSrc[j][i] ... lumSrc[j][i+7]
	
	vector signed int i1 = vec_mule(vLumFilter, ls);
	vector signed int i2 = vec_mulo(vLumFilter, ls);
	
	vector signed int vf1 = vec_mergeh(i1, i2);
	vector signed int vf2 = vec_mergel(i1, i2); // lumSrc[j][i] * lumFilter[j] ... lumSrc[j][i+7] * lumFilter[j]
	
	vector signed int vo1 = vec_add(v1, vf1);
	vector signed int vo2 = vec_add(v2, vf2);
	
	vec_st(vo1, offset, val);
	vec_st(vo2, offset + 16, val);
	
	l1 = l2;
      }
      for ( ; i < dstW; i++) {
	val[i] += lumSrc[j][i] * lumFilter[j];
      }
    }
    altivec_packIntArrayToCharArray(val,dest,dstW);
  }
  if (uDest != 0) {
    int  __attribute__ ((aligned (16))) u[chrDstW];
    int  __attribute__ ((aligned (16))) v[chrDstW];

    for (i = 0; i < (chrDstW -7); i+=4) {
      vec_st(vini, i << 2, u);
      vec_st(vini, i << 2, v);
    }
    for (; i < chrDstW; i++) {
      u[i] = (1 << 18);
      v[i] = (1 << 18);
    }
    
    for (j = 0; j < chrFilterSize; j++) {
      vector signed short vChrFilter = vec_ld(j << 1, chrFilter);
      vector unsigned char perm0 = vec_lvsl(j << 1, chrFilter);
      vChrFilter = vec_perm(vChrFilter, vChrFilter, perm0);
      vChrFilter = vec_splat(vChrFilter, 0); // chrFilter[j] is loaded 8 times in vChrFilter
      
      vector unsigned char perm = vec_lvsl(0, chrSrc[j]);
      vector signed short l1 = vec_ld(0, chrSrc[j]);
      vector signed short l1_V = vec_ld(2048 << 1, chrSrc[j]);
      
      for (i = 0; i < (chrDstW - 7); i+=8) {
	int offset = i << 2;
	vector signed short l2 = vec_ld((i << 1) + 16, chrSrc[j]);
	vector signed short l2_V = vec_ld(((i + 2048) << 1) + 16, chrSrc[j]);
	
	vector signed int v1 = vec_ld(offset, u);
	vector signed int v2 = vec_ld(offset + 16, u);
	vector signed int v1_V = vec_ld(offset, v);
	vector signed int v2_V = vec_ld(offset + 16, v);
	
	vector signed short ls = vec_perm(l1, l2, perm); // chrSrc[j][i] ... chrSrc[j][i+7]
	vector signed short ls_V = vec_perm(l1_V, l2_V, perm); // chrSrc[j][i+2048] ... chrSrc[j][i+2055]
	
	vector signed int i1 = vec_mule(vChrFilter, ls);
	vector signed int i2 = vec_mulo(vChrFilter, ls);
	vector signed int i1_V = vec_mule(vChrFilter, ls_V);
	vector signed int i2_V = vec_mulo(vChrFilter, ls_V);
	
	vector signed int vf1 = vec_mergeh(i1, i2);
	vector signed int vf2 = vec_mergel(i1, i2); // chrSrc[j][i] * chrFilter[j] ... chrSrc[j][i+7] * chrFilter[j]
	vector signed int vf1_V = vec_mergeh(i1_V, i2_V);
	vector signed int vf2_V = vec_mergel(i1_V, i2_V); // chrSrc[j][i] * chrFilter[j] ... chrSrc[j][i+7] * chrFilter[j]
	
	vector signed int vo1 = vec_add(v1, vf1);
	vector signed int vo2 = vec_add(v2, vf2);
	vector signed int vo1_V = vec_add(v1_V, vf1_V);
	vector signed int vo2_V = vec_add(v2_V, vf2_V);
	
	vec_st(vo1, offset, u);
	vec_st(vo2, offset + 16, u);
	vec_st(vo1_V, offset, v);
	vec_st(vo2_V, offset + 16, v);
	
	l1 = l2;
	l1_V = l2_V;
      }
      for ( ; i < chrDstW; i++) {
	u[i] += chrSrc[j][i] * chrFilter[j];
	v[i] += chrSrc[j][i + 2048] * chrFilter[j];
      } 
    }
    altivec_packIntArrayToCharArray(u,uDest,chrDstW);
    altivec_packIntArrayToCharArray(v,vDest,chrDstW);
  }
}

static inline void hScale_altivec_real(int16_t *dst, int dstW, uint8_t *src, int srcW, int xInc, int16_t *filter, int16_t *filterPos, int filterSize) {
  register int i;
  int __attribute__ ((aligned (16))) tempo[4];

  if (filterSize % 4) {
    for(i=0; i<dstW; i++) {
      register int j;
      register int srcPos = filterPos[i];
      register int val = 0;
      for(j=0; j<filterSize; j++) {
	val += ((int)src[srcPos + j])*filter[filterSize*i + j];
      }
      dst[i] = MIN(MAX(0, val>>7), (1<<15)-1);
    }
  }
  else
  switch (filterSize) {
  case 4:
    {
      for(i=0; i<dstW; i++) {
	register int j;
	register int srcPos = filterPos[i];

	vector unsigned char src_v0 = vec_ld(srcPos, src);
	vector unsigned char src_v1;
	if ((((int)src + srcPos)% 16) > 12) {
	  src_v1 = vec_ld(srcPos + 16, src);
	}
	vector unsigned char src_vF = vec_perm(src_v0, src_v1, vec_lvsl(srcPos, src));

	vector signed short src_v = // vec_unpackh sign-extends...
	  (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
	// now put our elements in the even slots
	src_v = vec_mergeh(src_v, (vector signed short)vzero);

	vector signed short filter_v = vec_ld(i << 3, filter);
        // the 3 above is 2 (filterSize == 4) + 1 (sizeof(short) == 2)

        // the neat trick : we only care for half the elements,
        // high or low depending on (i<<3)%16 (it's 0 or 8 here),
        // and we're going to use vec_mule, so we chose
        // carefully how to "unpack" the elements into the even slots
	if ((i << 3) % 16)
	  filter_v = vec_mergel(filter_v,(vector signed short)vzero);
	else
	  filter_v = vec_mergeh(filter_v,(vector signed short)vzero);

	vector signed int val_vEven = vec_mule(src_v, filter_v);
	vector signed int val_s = vec_sums(val_vEven, vzero);
	vec_st(val_s, 0, tempo);
	dst[i] = MIN(MAX(0, tempo[3]>>7), (1<<15)-1);
      }
    }