[LLVMdev] [RFC] Module Flags Metadata

[Rafael Ávila de Espíndola]

 > My understanding of metadata was that it can be discarded by
> optimizations, or any other transformations, without affecting
> correctness; however, discarded != ignored. That is, the optimization
> is expected to either update the metadata appropriated for whatever
> transformations it performed or delete the metadata entirely. Is that
> incorrect?

I think that is correct. A clarification in the language doc would be
nice. In the case of TBAA, I think the problem that Dan points out is
that the a change in one instruction (the alloca) can require
modifications (at least by discarding) to metadata in other instructions
(loads).

> -Jim

Cheers,
Rafael