[PATCH] D27324: IPO: Introduce ThinLTOBitcodeWriter pass.

[Teresa Johnson via Phabricator via llvm-commits]

tejohnson added a comment.

In https://reviews.llvm.org/D27324#612037, @pcc wrote:

> In https://reviews.llvm.org/D27324#612009, @mehdi_amini wrote:
>
> > Another high-level comment: technically I don't think we need to split anything for type-based LTO devirtualization.
>
>
> It may be possible to implement vcall opt without splitting, but it certainly seems a lot more complicated. For example virtual const prop works by "evaluating" each virtual function; we'd somehow need to figure out which virtual functions can be evaluated and store the values in the summary.


I haven't thought through this, but is it possible to evaluate the virtual functions at compile time (without WPA)? I.e. is the issue deciding which virtual functions can be evaluated, doing the evaluation, or how to store that in the summary?


https://reviews.llvm.org/D27324