[PATCH] D26321: [X86] Add LLVM version number for each intrinsic handled by auto upgrade for age tracking

[Craig Topper via llvm-commits]

craig.topper added a comment.

The original statement from Chris Lattner in the 3.1 timeframe was that we needed to keep them until we reached a merge version of 4.0 where we were allowed to break bitcode compatibility.

With the more recent discussions on what major version 4.0 means, this original policy is no longer implementable since we are still required to maintain bitcode compatibility for a certain time period.

I had a brief discussion with Chandler about this at the conference. He said we can try to propose a time based policy for this after 4.0 branches. He suggested we may either have a sliding window of X years back. Or alternatively some fixed point back greater than Y years and we would have to explicitly decide each time we wanted to move this point.


https://reviews.llvm.org/D26321