[PATCH] D32877: Restrict call metadata based hotness detection to Sample PGO mode

[Teresa Johnson via Phabricator via llvm-commits]

tejohnson added a comment.

In https://reviews.llvm.org/D32877#747647, @eraman wrote:

> I feel the underlying problem here is the use of VP metadata to get counts in sample PGO mode.  Dehao, even when VP metadata is available, can we add branch_weights to the call? Then, only sample PGO will annotate branch weights to calls and that won't affect instrumented PGO.


That sounds like potentially a good longer term change. But I'd still like for this to go in as an immediate fix for the issue, which is causing a noticeable impact on instrumentation PGO performance, and because there is no reason AFAIK for anything other than Sample PGO to need to look at call metadata for determining hotness.


https://reviews.llvm.org/D32877