diff -r b87dc103bf45 -r 2be326848943 src/share/vm/opto/memnode.cpp
--- a/src/share/vm/opto/memnode.cpp	Sat Nov 09 20:15:27 2019 +0800
+++ b/src/share/vm/opto/memnode.cpp	Sat Nov 09 20:29:45 2019 +0800
@@ -1359,6 +1359,14 @@
         Node* in = mem->in(i);
         Node*  m = optimize_memory_chain(in, t_oop, this, phase);
         if (m == mem) {
+          if (i == 1) {
+            // if the first edge was a loop, check second edge too.
+            // If both are replaceable - we are in an infinite loop
+            Node *n = optimize_memory_chain(mem->in(2), t_oop, this, phase);
+            if (n == mem) {
+              break;
+            }
+          }
           set_req(Memory, mem->in(cnt - i));
           return this; // made change
         }