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

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

__atomic_* should be lock-free for i8/i16/i32 on rv32ia; that's not really a special requirement, it's necessary to allow linking rv32i and rv32ia code.

But even if they are lock-free, it still requires linking to the shared library libatomic; we don't want to impose that requirement on users if it isn't necessary.


https://reviews.llvm.org/D47553