title: gcc; Aarch64; Armv8; enable crypto; -mcpu=cortex-a53+crypto
body: <p>I am trying to optimize an Arm processor (Corte-A53) with an Armv8 architecture for crypto purposes. </p>
  
  <p>The problem is that however the compiler accepts <code>-mcpu=cortex-a53+crypto</code> etc it doesn't change the output (I checked the assembly output).</p>
  
  <p>Changing mfpu, mcpu add futures like crypto or simd, it doesn't matter, it is completely ignored. </p>
  
  <p>To enable Neon code -ftree-vectorize is needed, how to make use of crypto?</p>
  
  <p>(I checked the -O(1,2,3) flags, it won't help).</p>
  
  <p>Edit: I realized I made  a mistake by thinking the crypto flag works like an optimization flag solved by the compiler. My bad.</p>