tree 2939e0b5d6538491a540d4cab89de21cffd9402c
parent a4df1432e4872ef1fe3d76ed51ec0f71ab885651
author Max Moroz <mmoroz@chromium.org> 1535579595 +0000
committer Copybara-Service <copybara-worker@google.com> 1616739483 -0700

[libFuzzer] Remove mutation stats and weighted mutation selection.

Summary:
This was an experimental feature. After evaluating it with:

1) https://github.com/google/fuzzer-test-suite/tree/master/engine-comparison

2) enabling on real world fuzz targets running at ClusterFuzz and OSS-Fuzz

The following conclusions were made:

1) With fuzz targets that have reached a code coverage plateau, the feature does
   not improve libFuzzer's ability to discover new coverage and may actually
   negatively impact it.

2) With fuzz targets that have not yet reached a code coverage plateau, the
   feature might speed up new units discovery in some cases, but it is quite
   rare and hard to confirm with a high level on confidence.

Revert of https://reviews.llvm.org/D48054 and https://reviews.llvm.org/D49621.

Reviewers: metzman, morehouse

Reviewed By: metzman, morehouse

Subscribers: delcypher, #sanitizers, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D51455

llvm-svn: 340976
GitOrigin-RevId: 8c95b48ba273b28e22912191bfc25e8a2144377f