p class="Body">To get rid of unused MMX optimizations entirely the symbol 
  OMIT_MMX needs to be defined. With this define the EMMS procedure is still 
  present, but due to its inline definition it does not have the slightest 
  impact on performance.</p> 
<p class="Body">NOTE: As all x86 64-bit systems feature SSE2, OMIT_MMX is 
  defined by default here. This does not only result in a better performance,
  but also in smaller executables</p> 
<p class="Body">NOTE: Due to issues with the disassembler in 