title: CRC Calculation for 256 bit chunks
body: <p>I'm using 256 bit variables (__m256i type) in new version of my program on AVX2 and I use Intel intrinsics. Before, 64 bit chunks are used for processing the data. So, <strong>_mm_crc32_u64</strong> function is used for CRC calculation. </p>
  
  <pre><code>crc = _mm_crc32_u64(seed,*chunk_64bit);
  </code></pre>
  
  <p>But now, in order to improve performance I want to calculate CRC for each 256 bit chunks (at least 128 bit chunks) seperately.
  One way can be like that apply <strong>_mm_crc32_u64</strong> in a loop with 64 bit values at each chunks. But I think it is not beneficial in terms of performance. </p>
  
  <p>What is the best method for calculating CRC over 256 bit chunk (or 128 bit) which is faster than <strong>_mm_crc32_u64</strong> operation in total ? </p>