[LLVMdev] [cfe-dev] Proposal to add Bitcode version field to bitcode file wrapper

[Renato Golin]

On 29 September 2014 16:58, Bob Wilson <bob.wilson at apple.com> wrote:
> It is a compiler IR but with LTO we need backward compatibility for IR in object files. This is not a new requirement. We have required auto-upgrade support for old bitcode files for as long as I have worked on LLVM for exactly this reason. The testing to enforce that has been pretty minimal, but we’re now making an effort to be more systematic about it.

By all means, I think we're on the same page as far as testing and the
burden of keeping the compatibility, I just didn't remember it being
such a big requirement.

Maybe I'm making a bigger issue than it needs to be... which is
actually quite likely. :)

cheers,
--renato