sum = ADD32(sum,SHR(part,6));
sum = ADD32(sum,SHR32(part,6));
static spx_word32_t inner_prod(const spx_word16_t *x, const spx_word16_t *y, int len){   int i;   spx_word32_t sum=0;   for (i=0;i<len;i+=4)   {      spx_word32_t part=0;      part = MAC16_16(part,x[i],y[i]);      part = MAC16_16(part,x[i+1],y[i+1]);      part = MAC16_16(part,x[i+2],y[i+2]);      part = MAC16_16(part,x[i+3],y[i+3]);      sum = ADD32(sum,SHR(part,6));   }   return sum;}