[PATCH] D77417: [BFI][CGP] Add limited support for detecting missed BFI updates and fix one in CodeGenPrepare.

[David Li via Phabricator via llvm-commits]

davidxl added inline comments.


================
Comment at: llvm/include/llvm/Analysis/BlockFrequencyInfoImpl.h:1467
+    }
+    for (auto &Entry : OtherValidNodes) {
+      const BlockT* OtherBB = Entry.first;
----------------
yamauchi wrote:
> davidxl wrote:
> > If there is no mismatch detected at this point, the following check is redundant.
> If there's a valid block in the Other BFI that's not in this BFI, this code is useful, as the comparison goes both ways?
There are two cases:
1) when the NumberOfValidNodes is different 
2) when the NumberOfValidNodes is the same.

For the first case, the mismatch will be caught earlier. For the second case, in order to be 'mismatched',  there must be a validNode in *this not in Other. Otherwise, Other will be a superset of *this, and it will become case #1.   THis means the case 2 will also be caught in the previous loop.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D77417/new/

https://reviews.llvm.org/D77417