commit 3850d066dbea4e9f9529941169644ea6e0fa99a7
author kcc <kcc> Tue Jul 03 22:33:09 2018 +0000
committer kcc <kcc> Tue Jul 03 22:33:09 2018 +0000
tree 47e606de80a2d8abbec3dda748f6022436dc7886
parent 09b480d6af71486a3e266b41e7f5d5fec75a0cb8

[libFuzzer] add one more value profile metric, under a flag (experimental)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@336234 91177308-0d34-0410-b5e6-96231b3b80d8

FuzzerTracePC.cpp

diff --git a/FuzzerTracePC.cpp b/FuzzerTracePC.cpp
index 540d888..19c1eaf 100644
--- a/FuzzerTracePC.cpp
+++ b/FuzzerTracePC.cpp
@@ -356,7 +356,14 @@
       TORC4.Insert(ArgXor, Arg1, Arg2);
   else if (sizeof(T) == 8)
       TORC8.Insert(ArgXor, Arg1, Arg2);
-  ValueProfileMap.AddValue(Idx);
+  // TODO: remove these flags and instead use all metrics at once.
+  if (UseValueProfileMask & 1)
+    ValueProfileMap.AddValue(Idx);
+  if (UseValueProfileMask & 2)
+    ValueProfileMap.AddValue(
+        PC * 64 + (Arg1 == Arg2 ? 0 : __builtin_clzll(Arg1 - Arg2) + 1));
+  if (UseValueProfileMask & 4)  // alternative way to use the hamming distance
+    ValueProfileMap.AddValue(PC * 64 + ArgDistance);
 }
 
 static size_t InternalStrnlen(const char *S, size_t MaxLen) {