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| author | Matt Morehouse <mascasa@google.com> | 2018-03-22 17:07:51 +0000 |
|---|---|---|
| committer | Matt Morehouse <mascasa@google.com> | 2018-03-22 17:07:51 +0000 |
| commit | 236cdaf84c684a985fa501721bf99b93ce2614da (patch) | |
| tree | fe5f6bf678a35bd33afc33628d5ad860195240a9 /llvm/lib/Bitcode/Reader/BitcodeReader.cpp | |
| parent | 4c86af7579156d3d07fb4cb6148786e56b03b9ca (diff) | |
| download | bcm5719-llvm-236cdaf84c684a985fa501721bf99b93ce2614da.tar.gz bcm5719-llvm-236cdaf84c684a985fa501721bf99b93ce2614da.zip | |
[SimplifyCFG] Create attribute for fuzzing-specific optimizations.
Summary:
When building with libFuzzer, converting control flow to selects or
obscuring the original operands of CMPs reduces the effectiveness of
libFuzzer's heuristics.
This patch provides an attribute to disable or modify certain optimizations
for optimal fuzzing signal.
Provides a less aggressive alternative to https://reviews.llvm.org/D44057.
Reviewers: vitalybuka, davide, arsenm, hfinkel
Reviewed By: vitalybuka
Subscribers: junbuml, mehdi_amini, wdng, javed.absar, hiraditya, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D44232
llvm-svn: 328214
Diffstat (limited to 'llvm/lib/Bitcode/Reader/BitcodeReader.cpp')
| -rw-r--r-- | llvm/lib/Bitcode/Reader/BitcodeReader.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp index 74b57a86b8b..5867db46272 100644 --- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp +++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp @@ -1161,6 +1161,7 @@ static uint64_t getRawAttributeMask(Attribute::AttrKind Val) { case Attribute::StrictFP: return 1ULL << 55; case Attribute::SanitizeHWAddress: return 1ULL << 56; case Attribute::NoCfCheck: return 1ULL << 57; + case Attribute::OptForFuzzing: return 1ULL << 58; case Attribute::Dereferenceable: llvm_unreachable("dereferenceable attribute not supported in raw format"); break; @@ -1343,6 +1344,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) { return Attribute::NoCfCheck; case bitc::ATTR_KIND_NO_UNWIND: return Attribute::NoUnwind; + case bitc::ATTR_KIND_OPT_FOR_FUZZING: + return Attribute::OptForFuzzing; case bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE: return Attribute::OptimizeForSize; case bitc::ATTR_KIND_OPTIMIZE_NONE: |
