[PATCH] D17555: [Feedback requested] Implement cold spliting

Amaury SECHET via llvm-commits llvm-commits at lists.llvm.org
Wed Feb 24 15:07:00 PST 2016

deadalnix added a comment.

@Gerolf The patch was originally made for LLVM's HHVM backend. The kind of code generated is very branchy, with a lot of cold branches, large and with a flat profile (ie most function are being used, but various path within these function are almost never taken). This optimization has proven to be very valuable for this kind of code. HHVM already uses large pages for JITed code, and even with this this is a valuable optimization. The effectiveness of the technique is heavily dependent on the type of code at hand, and, while it proves to be useful for HHVM, isn't in the general case.

I'd say if you have a large application, with a relatively flat profile, you may want to try this. If not then this is useless to you and may even hurt.


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