[PATCH] D24164: Remove debug info when hoisting instruction from then/else branch.

Andrea Di Biagio via llvm-commits llvm-commits at lists.llvm.org
Fri Sep 2 02:32:14 PDT 2016


andreadb added a comment.

In https://reviews.llvm.org/D24164#532594, @dblaikie wrote:

> I would worry that this might produce a worse experience for a sanitizer user, for example - but I'm not sure. (the sanitizer user won't have any trail back to why the store in this example is happening - granted, the way the code currently works, they may be told the store is happening in the wrong branch, which isn't great either)


I don't know about the sanitizer user experience. However, based on my experience with sample pgo, this kind of changes tend to improve the quality of the sample profile from autofdo.

@Dehao,
we have identified a couple of similar issues where the debug location of a tail-merged instruction is incorrectly set. We already have plans to send a couple of small patches to fix these issues (those would need https://reviews.llvm.org/D24180); in our sample-pgo experiments, this kind of small fixes for hoisted/tail merged instructions tend to have a very positive impact on the quality of the sample profile.


https://reviews.llvm.org/D24164





More information about the llvm-commits mailing list