title: average operation ARM NEON
body: <p>I need to compute the same operation as the SSE one:</p>
  
  <pre><code>__m128i result1=_mm_avg_epu8 (upper, lower);
  </code></pre>
  
  <p>With NEON I do the following:</p>
  
  <pre><code>uint8x16_t result1=vhaddq_u8(upper, lower);
  </code></pre>
  
  <p>The results should be the same but with the SSE instruction I obtain:</p>
  
  <pre><code>91cb c895 aaa3 b0d4 cfc0 c1b0 aac7 b9b9
  </code></pre>
  
  <p>whereas with the NEON instruction I obtain:</p>
  
  <pre><code>91ca c894 a9a2 b0d3 cec0 c1af aac7 b8b8 
  </code></pre>
  
  <p>I don't understand why the two results are different. Can you help me?</p>