[PATCH] D47553: Add TargetLowering::shouldExpandAtomicToLibCall and query it from AtomicExpandPass

[JF Bastien via Phabricator via llvm-commits]

jfb added a comment.

Could you detail what type of code will generate this? In C++ the standard library is responsible for guaranteeing properly sized and aligned atomics. Size will always be accurate, but I'm worried that your change wants perfect alignment information and you might not have that information. Say two pieces of code communicate through the same atomic location, but they have different alignment information, and one gets a libcall and the other doesn't... You're in trouble.


Repository:
  rL LLVM

https://reviews.llvm.org/D47553