title: How to convert a binary integer number to a hex string?
body: <p>Given a number in a register (a binary integer), how to convert it to a string of hexadecimal ASCII digits?  (i.e. serialize it into a text format.)</p>
  
  <p>Digits can be stored in memory or printed on the fly, but storing in memory and printing all at once is usually more efficient.  (You can modify a loop that stores to instead print one at a time.)</p>
  
  <p>Can we efficiently handle all the nibbles in parallel with SIMD?  (SSE2 or later?)</p>