[PATCH] D84940: [JumpThreading] Conditionally freeze its condition when unfolding select

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune added a comment.

In D84940#2185603 <https://reviews.llvm.org/D84940#2185603>, @efriedma wrote:

> I'm not sure about your plan for enabling this.  You're going to get very little practical test coverage enabling this for "LTO".  (Big projects are much more likely to be using ThinLTO.)  And long-term, we don't to have a "please miscompile my code" argument for the JumpThreading pass.

As concerned, the argument should be removed & select should be unfolded with freeze by default in the long term.
By using this argument and gradually enabling this, we can control the speed of its increasing interaction with other optimizations.
Enabling this in LTO first might have a small impact, but I think having a benign start is good. Also, another patch that inserted freeze, D76483 <https://reviews.llvm.org/D76483> , was reported a performance change with LTO enabled.
The progress isn't fast yet, but I believe that once we have enough optimizations/analyses updated to deal with freeze, fixing remaining bugs with freeze should be much easier.


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