[PATCH] D29376: LTO: align the Monolithic LTO optimization pipeline on the ThinLTO and O2/O3 one

[Peter Collingbourne via Phabricator via llvm-commits]

pcc added a comment.

For a start, this pipeline doesn't look right as it needs to include at least the CFI passes with the correct summary action.

But a higher level point is that it seems premature to do this until there is a proven migration path from regular to thin LTO for users of the CFI and whole-program devirtualization features, such as Chromium. This at least means that the features must be supported. For the migration path to be proven, at least one major user of the feature (i.e. Chromium) must have moved its official builds from regular to thin LTO.

We hope to have completed the migration by the end of the quarter, but that is, as always, optimistic.


https://reviews.llvm.org/D29376