--- old/src/hotspot/share/gc/shared/stringdedup/stringDedupTable.cpp	2019-04-10 18:49:58.300904800 -0400
+++ new/src/hotspot/share/gc/shared/stringdedup/stringDedupTable.cpp	2019-04-10 18:49:57.386813400 -0400
@@ -351,14 +351,19 @@
   unsigned int hash = 0;
 
   if (use_java_hash()) {
-    if (!java_lang_String::hash_is_set(java_string)) {
-      stat->inc_hashed();
-    }
-    hash = java_lang_String::hash_code(java_string);
-  } else {
+    // Get hash code from cache
+    hash = java_lang_String::hash(java_string);
+  }
+
+  if (hash == 0) {
     // Compute hash
     hash = hash_code(value, latin1);
     stat->inc_hashed();
+
+    if (use_java_hash() && hash != 0) {
+      // Store hash code in cache
+      java_lang_String::set_hash(java_string, hash);
+    }
   }
 
   typeArrayOop existing_value = lookup_or_add(value, latin1, hash);