commit 51ddb8830078f36e7a8109716d03f5ea72e582cc
author Kostya Serebryany <kcc@google.com> Tue Jul 03 22:33:09 2018 +0000
committer Kostya Serebryany <kcc@google.com> Tue Jul 03 22:33:09 2018 +0000
tree 94a1a3069231435e84cbe43f274720e8e1760096
parent f5d83f376813c8adbd94bdc498225f75d3adaffd

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

llvm-svn: 336234

compiler-rt/lib/fuzzer/FuzzerTracePC.cpp

diff --git a/compiler-rt/lib/fuzzer/FuzzerTracePC.cpp b/compiler-rt/lib/fuzzer/FuzzerTracePC.cpp
index 540d888..19c1eaf 100644
--- a/compiler-rt/lib/fuzzer/FuzzerTracePC.cpp
+++ b/compiler-rt/lib/fuzzer/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) {