[PATCH] D40334: [X86] Break false dependencies for POPCNT, LZCNT, TZCNT

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

Yes we need a feature flag. As far as I know it doesn't happen on AMD.  On Intel LZCNT/TZCNT have a problem on Sandybridge, ivybridge, haswell, broadwell. It's fixed on skylake. For popcnt, it has a problem on sandybridge, ivybridge, haswell, broadwell, skylake. I believe it is fixed in cannonlake.


Repository:
  rL LLVM

https://reviews.llvm.org/D40334