--- old/src/hotspot/share/opto/loopTransform.cpp	2019-08-21 16:33:55.327800773 +0800
+++ new/src/hotspot/share/opto/loopTransform.cpp	2019-08-21 16:33:55.215798859 +0800
@@ -831,6 +831,15 @@
     return false;
   }
 
+  // Protect against over-unrolling with SuperWordLoopUnrollAnalysis.
+  if (SuperWordLoopUnrollAnalysis &&
+      !cl->is_vectorized_loop() &&
+      future_unroll_cnt > LoopUnrollMin &&
+      cl->profile_trip_cnt() != COUNT_UNKNOWN &&
+      (uint)(2 * cl->unrolled_count()) > cl->trip_count()) {
+    return false;
+  }
+
   Node *init_n = cl->init_trip();
   Node *limit_n = cl->limit();
   int stride_con = cl->stride_con();