[PATCH] D49621: [libFuzzer] Initial implementation of weighted mutation leveraging during runtime.

[Jonathan Metzman via Phabricator via llvm-commits]

metzman added inline comments.


================
Comment at: lib/fuzzer/FuzzerMutate.cpp:606
+    if (Stats[i] == 0) MutationWeights[i] = 1;
+    // 1000 due to 3 decimal places
+    else
----------------
metzman wrote:
> I think the placement of this comment is awkward. Maybe put on the same line as `else`.
I'm also unsure what three decimal places this comment is referring to. We don't round anywhere here do we?


================
Comment at: lib/fuzzer/FuzzerMutate.cpp:622
+    else
+      RandomMark -= MutationWeights[i];
+  }
----------------
metzman wrote:
> Is the purpose of this to ensure that we return an index on the last iteration?
> I need to think about this technique more but I am not sure it is fair (ie: things with equal weight have equal chance of being picked).
Actually I think it is fair. But let's have a comment explaining how this technique works. 


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D49621