title: trouble with result from _mm_cmpestri in c
body: <p>I'm trying to get the following code to run but the result is always zero. What am I missing?</p>
  
  <pre><code>const int simd_compare_string_mode = _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_NEGATIVE_POLARITY | _SIDD_BIT_MASK;
  
  static const unsigned char wtf1[16] = "thisisatesttestt";
  static const unsigned char wtf2[16] = "dacb";
  
  const __m128i simd_a = _mm_loadu_si128((__m128i *)&amp;wtf1[0]);
  const __m128i simd_b = _mm_loadu_si128((__m128i *)&amp;wtf2[0]);
  int result = _mm_cmpestri(simd_b, 4, simd_a , 16, simd_compare_string_mode);
  </code></pre>
  
  <p>I don't really understand if the result is supposed to be from the 1st input (variable simd_b in this case) or from the second (simd_a). I was thinking in the above example that I might get something (result = 7 or 2?) indicating that the 'a' was in both strings.</p>