title: What does Intel mean by "retired"?
body: <p>In the <a href="http://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-3b-part-2-manual.html">Intel Manual</a>, there is mention of a lot of performance events which have descriptions like "Mispredicted taken branch instructions retired.". What exactly does <code>retired</code> mean in this context?</p>
  
  <p>Note that I have already looked at Intel's <a href="http://software.intel.com/sites/products/collateral/hpc/vtune/performance_analysis_guide.pdf">Performance Analysis Guide</a>, which states that "retired" has a very precise meaning (on page 8), referring to the diagram on page 7, but I think I lack the background knowledge to understand exactly what is mean by <code>Retirement / Writeback</code>. What exactly is that process and what does it involve?</p>