[PATCH] [AtomicExpand] Set branch weights when new basic blocks are created

[Philip Reames]

First, please update with full context.  I need to see the surrounding code to interpret a few of your changes.

I'm a bit concerned about the general approach.  Without profiling data, unconditionally predicting no contention seems questionable.  Can you quantify the performance impact here for both the contented and uncontended case?


================
Comment at: lib/CodeGen/AtomicExpandPass.cpp:388
@@ +387,3 @@
+  unsigned ExitWeight =
+      BranchProbabilityInfo::getBranchWeightAtomicExpand(true);
+  unsigned LoopWeight =
----------------
Please extract a helper function for this shared code

http://reviews.llvm.org/D7804

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/