title: maxreg = 51 --> uses 48 registers. If maxreg = 0 --> uses 47 registers. Also "limited" version is faster
body: <p>I'm curious why if I put an upper limit in register usage (51 in my exemple) it can produce a higher register kernel than if i let the limit unbounded.</p>
  
  <p>Also the higher register seems faster (10us over 700).</p>
  
  <p>What phases in optimization stages changes?</p>