Backport 624d714

Author: duke

src/hotspot/share/opto/escape.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1058,6 +1058,39 @@ void ConnectionGraph::updates_after_load_split(Node* data_phi, Node* previous_lo
     // "new_load" might actually be a constant, parameter, etc.
     if (new_load->is_Load()) {
       Node* new_addp = new_load->in(MemNode::Address);
+
+      // If new_load is a Load but not from an AddP, it means that the load is folded into another
+      // load. And since this load is not from a field, we cannot create a unique type for it.
+      // For example:
+      //
+      //   if (b) {
+      //       Holder h1 = new Holder();
+      //       Object o = ...;
+      //       h.o = o.getClass();
+      //   } else {
+      //       Holder h2 = ...;
+      //   }
+      //   Holder h = Phi(h1, h2);
+      //   Object r = h.o;
+      //
+      // Then, splitting r through the merge point results in:
+      //
+      //   if (b) {
+      //       Holder h1 = new Holder();
+      //       Object o = ...;
+      //       h.o = o.getClass();
+      //       Object o1 = h.o;
+      //   } else {
+      //       Holder h2 = ...;
+      //       Object o2 = h2.o;
+      //   }
+      //   Object r = Phi(o1, o2);
+      //
+      // In this case, o1 is folded to o.getClass() which is a Load but not from an AddP, but from
+      // an OopHandle that is loaded from the Klass of o.
+      if (!new_addp->is_AddP()) {
+        continue;
+      }
       Node* base = get_addp_base(new_addp);
 
       // The base might not be something that we can create an unique

test/hotspot/jtreg/compiler/escapeAnalysis/TestSplitLoadThroughPhiDuringEA.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package compiler.escapeAnalysis;
+
+import java.util.Objects;
+
+/*
+ * @test
+ * @bug 8374435
+ * @summary assert during escape analysis when splitting a Load through a Phi because the input of
+ *          the result Phi is a Load not from an AddP
+ * @run main/othervm -XX:-UseOnStackReplacement -XX:-UseCompressedOops ${test.main.class}
+ */
+public class TestSplitLoadThroughPhiDuringEA {
+    static class Holder {
+        Object o;
+    }
+
+    public static void main(String[] args) {
+        Object o = new Object();
+        Holder h = new Holder();
+        for (int i = 0; i < 20000; i++) {
+            test(true, h, o);
+            test(false, h, o);
+        }
+    }
+
+    private static Object test(boolean b, Holder h, Object o) {
+        h = Objects.requireNonNull(h);
+        if (b) {
+            h = new Holder();
+            // This access has the pattern LoadP -> LoadP, which upsets the compiler because the
+            // pointer input of a LoadP is not an AddP
+            h.o = o.getClass();
+        }
+        return h.o;
+    }
+}