title: What does UnsignedSaturate in SSE instruction mean?
body: <p>I am converting SIMD code into equivalent c code. I am stuck at one of SSE instructions</p>
  
  <pre><code>__m128i _mm_packus_epi16 (__m128i a, __m128i b)
  </code></pre>
  
  <p>it returns </p>
  
  <pre><code>r0 := UnsignedSaturate(a0)
  r1 := UnsignedSaturate(a1)
  
  ...
  r7 := UnsignedSaturate(a7)
  r8 := UnsignedSaturate(b0)
  r9 := UnsignedSaturate(b1)
  ...
  r15 := UnsignedSaturate(b7)
  </code></pre>
  
  <p>What does <code>UnsignedSaturate</code> mean?</p>