title: Does gcc use Intel's SSE 4.2 instructions for text processing if available?
body: <p>I read <a href="https://ieeexplore.ieee.org/document/5762731" rel="nofollow noreferrer">here</a> that Intel introduced <code>SSE 4.2 instructions</code> for accelerating string processing.</p>
  <p><strong>Quote from the article:</strong></p>
  <blockquote>
  <p>The SSE 4.2 instruction set, first implemented in Intel's Core i7,
  provides string and text processing instructions (STTNI) that utilize
  SIMD operations for processing character data. Though originally
  conceived for accelerating string, text, and XML processing, the
  powerful new capabilities of these instructions are useful outside of
  these domains, and it is worth revisiting the search and recognition
  stages of numerous applications to utilize STTNI to improve
  performance</p>
  </blockquote>
  <ul>
  <li>Does gcc make use of these instructions if they are available?</li>
  <li>If so, which version?</li>
  <li>If it doesn't, are there any open source libraries
  which offer this?</li>
  </ul>