title: Does GCC have builtins for AVX512 operations?
body: <p>I was expecting to find functions like</p>
  
  <p><code>__builtin_ia32_fmaddps512</code></p>
  
  <p>in a recent GCC to enable use of 512 bit AVX512 registers in the same way that one can use the 256 bit AVX2 registers, but they do not exist in GCC 9.2, according to the manual. Is it just a matter of waiting, or is there some policy reason why they don't exist?</p>