From dac06a329a834678c45b7cd60002704edb6f0d82 Mon Sep 17 00:00:00 2001
From: Andrew Haley <aph@openjdk.org>
Date: Tue, 21 Apr 2026 15:22:16 +0000
Subject: [PATCH] 8359166: C2 asserts in Assembler::addr_nop_5 with
 -XX:-UseAddressNop

Reviewed-by: aseoane, qamai
---
 src/hotspot/cpu/x86/x86.ad                   |  2 +-
 test/hotspot/jtreg/runtime/8359166/Test.java | 39 ++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 test/hotspot/jtreg/runtime/8359166/Test.java

diff --git a/src/hotspot/cpu/x86/x86.ad b/src/hotspot/cpu/x86/x86.ad
index eaa88d900c7..9b80697601c 100644
--- a/src/hotspot/cpu/x86/x86.ad
+++ b/src/hotspot/cpu/x86/x86.ad
@@ -4568,7 +4568,7 @@ encode %{
     } else if (_method->intrinsic_id() == vmIntrinsicID::_ensureMaterializedForStackWalk) {
       // The NOP here is purely to ensure that eliding a call to
       // JVM_EnsureMaterializedForStackWalk doesn't change the code size.
-      __ addr_nop_5();
+      __ nop(5);
       __ block_comment("call JVM_EnsureMaterializedForStackWalk (elided)");
     } else {
       int method_index = resolved_method_index(masm);
diff --git a/test/hotspot/jtreg/runtime/8359166/Test.java b/test/hotspot/jtreg/runtime/8359166/Test.java
new file mode 100644
index 00000000000..509a06a3de1
--- /dev/null
+++ b/test/hotspot/jtreg/runtime/8359166/Test.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2026, IBM Corp.
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8359166
+ * @requires os.arch=="amd64" | os.arch=="x86_64"
+ * @requires vm.debug
+ *
+ * @run main/othervm
+ *        -XX:-UseAddressNop -Xcomp -Xbatch -XX:-TieredCompilation Test
+ */
+
+public class Test {
+    public static void main(String[] args) {
+
+    }
+}