4 files changed, 9 insertions, 6 deletions
diff --git a/lib/fuzzer/FuzzerDriver.cpp b/lib/fuzzer/FuzzerDriver.cpp
index f6b642dae..516b0038f 100644
--- a/lib/fuzzer/FuzzerDriver.cpp
+++ b/lib/fuzzer/FuzzerDriver.cpp
@@ -567,7 +567,7 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
   FuzzingOptions Options;
   Options.Verbosity = Flags.verbosity;
   Options.MaxLen = Flags.max_len;
-  Options.ExperimentalLenControl = Flags.experimental_len_control;
+  Options.LenControl = Flags.len_control;
   Options.UnitTimeoutSec = Flags.timeout;
   Options.ErrorExitCode = Flags.error_exitcode;
   Options.TimeoutExitCode = Flags.timeout_exitcode;
diff --git a/lib/fuzzer/FuzzerFlags.def b/lib/fuzzer/FuzzerFlags.def
index a32102a7d..7e722f415 100644
--- a/lib/fuzzer/FuzzerFlags.def
+++ b/lib/fuzzer/FuzzerFlags.def
@@ -17,7 +17,10 @@ FUZZER_FLAG_INT(runs, -1,
 FUZZER_FLAG_INT(max_len, 0, "Maximum length of the test input. "
     "If 0, libFuzzer tries to guess a good value based on the corpus "
     "and reports it. ")
-FUZZER_FLAG_INT(experimental_len_control, 0, "experimental flag")
+FUZZER_FLAG_INT(len_control, 1000, "Try generating small inputs first, "
+  "then try larger inputs over time.  Specifies the rate at which the length "
+  "limit is increased (smaller == faster).  If 0, immediately try inputs with "
+  "size up to max_len.")
 FUZZER_FLAG_INT(cross_over, 1, "If 1, cross over inputs.")
 FUZZER_FLAG_INT(mutate_depth, 5,
             "Apply this number of consecutive mutations to each input.")
diff --git a/lib/fuzzer/FuzzerLoop.cpp b/lib/fuzzer/FuzzerLoop.cpp
index 7366f69ff..7a3ce341f 100644
--- a/lib/fuzzer/FuzzerLoop.cpp
+++ b/lib/fuzzer/FuzzerLoop.cpp
@@ -755,15 +755,15 @@ void Fuzzer::Loop(const Vector<std::string> &CorpusDirs) {
       break;
 
     // Update TmpMaxMutationLen
-    if (Options.ExperimentalLenControl) {
+    if (Options.LenControl) {
       if (TmpMaxMutationLen < MaxMutationLen &&
           TotalNumberOfRuns - LastCorpusUpdateRun >
-              Options.ExperimentalLenControl * Log(TmpMaxMutationLen)) {
+              Options.LenControl * Log(TmpMaxMutationLen)) {
         TmpMaxMutationLen =
             Min(MaxMutationLen, TmpMaxMutationLen + Log(TmpMaxMutationLen));
         if (TmpMaxMutationLen <= MaxMutationLen)
           Printf("#%zd\tTEMP_MAX_LEN: %zd (%zd %zd)\n", TotalNumberOfRuns,
-                 TmpMaxMutationLen, Options.ExperimentalLenControl,
+                 TmpMaxMutationLen, Options.LenControl,
                  LastCorpusUpdateRun);
         LastCorpusUpdateRun = TotalNumberOfRuns;
       }
diff --git a/lib/fuzzer/FuzzerOptions.h b/lib/fuzzer/FuzzerOptions.h
index 15a378020..cedf7f37e 100644
--- a/lib/fuzzer/FuzzerOptions.h
+++ b/lib/fuzzer/FuzzerOptions.h
@@ -18,7 +18,7 @@ namespace fuzzer {
 struct FuzzingOptions {
   int Verbosity = 1;
   size_t MaxLen = 0;
-  size_t ExperimentalLenControl = 0;
+  size_t LenControl = 1000;
   int UnitTimeoutSec = 300;
   int TimeoutExitCode = 77;
   int ErrorExitCode = 77;