From f83c5cf53e6635fe88ebc5a0597ad7b5f5069fbe Mon Sep 17 00:00:00 2001
From: neliasso <none@none>
Date: Mon, 19 Aug 2019 17:36:36 +0200
Subject: [PATCH] 8219517: assert(false) failed: infinite loop in
 PhaseIterGVN::optimize Reviewed-by: kvn, thartmann

--HG--
extra : rebase_source : e1af5b86db38ac1b7ed27b4f39be267bb8b27d0e
---
 src/share/vm/opto/memnode.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/share/vm/opto/memnode.cpp b/src/share/vm/opto/memnode.cpp
index 14b0ff9a9..590111a39 100644
--- a/src/share/vm/opto/memnode.cpp
+++ b/src/share/vm/opto/memnode.cpp
@@ -1359,6 +1359,14 @@ Node *LoadNode::split_through_phi(PhaseGVN *phase) {
         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
         }
-- 
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