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Diffstat (limited to 'llvm_mode/README.neverzero')
| -rw-r--r-- | llvm_mode/README.neverzero | 22 |
1 files changed, 0 insertions, 22 deletions
diff --git a/llvm_mode/README.neverzero b/llvm_mode/README.neverzero deleted file mode 100644 index ef873acb..00000000 --- a/llvm_mode/README.neverzero +++ /dev/null @@ -1,22 +0,0 @@ -Usage -===== - -In larger, complex or reiterative programs the map that collects the edge pairs -can easily fill up and wrap. -This is not that much of an issue - unless by chance it wraps just to a 0 -when the program execution ends. -In this case afl-fuzz is not able to see that the pair has been accessed and -will ignore it. - -NeverZero prevents this behaviour. If a counter wraps, it jumps over the 0 -directly to a 1. This improves path discovery (by a very little amount) -at a very little cost (one instruction per edge). - -This is implemented in afl-gcc, however for llvm_mode this is optional if -the llvm version is below 9 - as there is a perfomance bug that is only fixed -in version 9 and onwards. - -If you want to enable this for llvm < 9 then set - -export AFL_LLVM_NOT_ZERO=1 - |