[PATCH] D124490: [InstrProf] Minimal Block Coverage

[Ellis Hoag via Phabricator via llvm-commits]

ellis marked an inline comment as done.
ellis added a comment.

Can we get another review of this? CC @MaskRay



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Comment at: llvm/lib/Transforms/Instrumentation/BlockCoverageInference.cpp:137
+    BlockSet ReachableFromEntry, ReachableFromExit;
+    getReachableAvoiding(&EntryBlock, &BB, /*IsForward=*/true,
+                         ReachableFromEntry);
----------------
MaskRay wrote:
> The time complexity is O(|BB|^2) and can be problematic.
I've added a comment discussing the runtime. We do know of a linear time algorithm that would compute the Dependencies maps, but it is significantly more complicated. We thought it would be best to first add this simpler implementation and in the future we can use the linear algorithm if we find that it gives a significant speedup in practice.


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