[GR-68172] Fix MonitorEnter virtualization issues

PullRequest: graal/21678

Author: gergo-

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/java/MonitorEnterNode.java

@@ -41,6 +41,7 @@
 import jdk.graal.compiler.nodes.spi.PlatformConfigurationProvider;
 import jdk.graal.compiler.nodes.spi.Virtualizable;
 import jdk.graal.compiler.nodes.spi.VirtualizerTool;
+import jdk.graal.compiler.nodes.virtual.AllocatedObjectNode;
 import jdk.graal.compiler.nodes.virtual.VirtualObjectNode;
 import jdk.graal.compiler.serviceprovider.SpeculationReasonGroup;
 import jdk.vm.ci.meta.SpeculationLog;
@@ -107,6 +108,14 @@ public void virtualize(VirtualizerTool tool) {
             if (virtual.hasIdentity() && tool.canVirtualizeLock(virtual, getMonitorId())) {
                 tool.addLock(virtual, getMonitorId());
                 if (!tool.getPlatformConfigurationProvider().areLocksSideEffectFree()) {
+                    if (object() instanceof AllocatedObjectNode) {
+                        /*
+                         * Don't let the allocation sink past the state split proxy, otherwise we
+                         * end up with a virtual object in the state instead of the actual allocated
+                         * one.
+                         */
+                        tool.ensureMaterialized(virtual);
+                    }
                     // Ensure that the locks appear to have been acquired in the nearest FrameState.
                     tool.ensureAdded(new StateSplitProxyNode(stateAfter));
                 }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/virtual/phases/ea/GraphEffectList.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2025, 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
@@ -117,9 +117,9 @@ public void apply(StructuredGraph graph) {
                 assert position == null || position.isAlive();
                 if (!node.isAlive()) {
                     graph.addWithoutUniqueWithInputs(node);
-                    if (node instanceof FixedWithNextNode) {
-                        graph.addBeforeFixed(position, (FixedWithNextNode) node);
-                    }
+                }
+                if (node instanceof FixedWithNextNode fixedWithNextNode && fixedWithNextNode.next() == null) {
+                    graph.addBeforeFixed(position, fixedWithNextNode);
                 }
             }