func: static void FUNCC(pred4x4_horizontal_add)(uint8_t *_pix, const int16_t *_block,
  
                                            ptrdiff_t stride)
  
  {
  
      int i;
  
      pixel *pix = (pixel*)_pix;
  
      const dctcoef *block = (const dctcoef*)_block;
  
      stride >>= sizeof(pixel)-1;
  
      for(i=0; i<4; i++){
  
          pixel v = pix[-1];
  
          pix[0]= v += block[0];
  
          pix[1]= v += block[1];
  
          pix[2]= v += block[2];
  
          pix[3]= v +  block[3];
  
          pix+= stride;
  
          block+= 4;
  
      }
  
  }
  