[PATCH] D50591: [PGO] Control Height Reduction

[Richard Trieu via Phabricator via llvm-commits]

rtrieu added inline comments.


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Comment at: llvm/trunk/lib/Transforms/Instrumentation/ControlHeightReduction.cpp:610-616
+  APInt TrueWt = TrueWeight->getValue();
+  APInt FalseWt = FalseWeight->getValue();
+  APInt SumWt = TrueWt + FalseWt;
+  TrueProb = BranchProbability::getBranchProbability(TrueWt.getZExtValue(),
+                                                     SumWt.getZExtValue());
+  FalseProb = BranchProbability::getBranchProbability(FalseWt.getZExtValue(),
+                                                      SumWt.getZExtValue());
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This calculation is in danger of overflowing when the weights are large.  I made a fix in r341444 to calculate the sum weight in 64 bits to prevent the overflow.


Repository:
  rL LLVM

https://reviews.llvm.org/D50591