[PATCH] D30631: [BPI] Use metadata info before any other heuristics

[Chandler Carruth via Phabricator via llvm-commits]

chandlerc added a comment.

In addition to the issue David pointed out, I don't understand the motivation yet.

It would be much more helpful to describe in the patch exactly what motivates the change so that we don't have to guess. =]

Relatedly, I think there are several heuristics that are actually more accurate than any metadata. For example, even if there is metadata that says code which is post-dominated by unreachable is hot, it seems much more likely that the metadata is wrong as we are *guaranteed* unreachable is, er, not reached. =] If this is the heuristic you're trying to change, I suspect that there is instead a bug in how we are computing it, and it isn't just about metadata being more reliable.


https://reviews.llvm.org/D30631