Merge branch 'dev' of https://github.com/AFLplusplus/AFLplusplus into dev

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm_mode/afl-llvm-common.cc b/llvm_mode/afl-llvm-common.cc
index 04dd9475..c62b4c14 100644
--- a/llvm_mode/afl-llvm-common.cc
+++ b/llvm_mode/afl-llvm-common.cc
@@ -201,3 +201,20 @@ bool isInWhitelist(llvm::Function *F) {
 
 }
 
+// Calculate the number of average collisions that would occur if all
+// location IDs would be assigned randomly (like normal afl/afl++).
+// This uses the "balls in bins" algorithm.
+unsigned long long int calculateCollisions(uint32_t edges) {
+
+  double                 bins = MAP_SIZE;
+  double                 balls = edges;
+  double                 step1 = 1 - (1 / bins);
+  double                 step2 = pow(step1, balls);
+  double                 step3 = bins * step2;
+  double                 step4 = round(step3);
+  unsigned long long int empty = step4;
+  unsigned long long int collisions = edges - (MAP_SIZE - empty);
+  return collisions;
+
+}
+