Intriguing, but the original posts are from 2006 with a bump from 2008 and definitive answers are never given, just "this may require an NDA to discuss." If yo

Intriguing, but the original posts are from 2006 with a bump from 2008 and definitive answers are never given, just "this may require an NDA to discuss." If you care about optimising NOPs, you're probably wrting a compiler, so I am curious if these instructions have found their way into any mainstream compiler such as GCC or Clang. Does this post explain some odd compiler behaviour? Has newer information been published making this anything other than abuse of an undocumented quirk? I.e., liable to blow up on new processors, as it does on the Pentium MMX, according to the second post. I mean, it's interesting but I'm not sure why it's here.