--- /dev/null	2021-01-19 17:38:25.908523431 +0000
+++ new/src/cpu/aarch64/vm/javaFrameAnchor_aarch64.hpp	2021-01-25 19:31:47.442588998 +0000
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2013, Red Hat Inc.
+ * Copyright (c) 2002, 2010, 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.
+ *
+ */
+
+#ifndef CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
+#define CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
+
+private:
+
+  // FP value associated with _last_Java_sp:
+  intptr_t* volatile        _last_Java_fp;           // pointer is volatile not what it points to
+
+public:
+  // Each arch must define reset, save, restore
+  // These are used by objects that only care about:
+  //  1 - initializing a new state (thread creation, javaCalls)
+  //  2 - saving a current state (javaCalls)
+  //  3 - restoring an old state (javaCalls)
+
+  void clear(void) {
+    // clearing _last_Java_sp must be first
+    _last_Java_sp = NULL;
+    OrderAccess::release();
+    _last_Java_fp = NULL;
+    _last_Java_pc = NULL;
+  }
+
+  void copy(JavaFrameAnchor* src) {
+    // n.b. the writes to fp and pc do not require any preceding
+    // release(). when copying into the thread anchor, which only
+    // happens under ~JavaCallWrapper(), sp will have been NULLed by a
+    // call to zap() and the NULL write will have been published by a
+    // fence in the state transition to in_vm. contrariwise, when
+    // copying into the wrapper anchor, which only happens under
+    // JavaCallWrapper(), there is no ordering requirement at all
+    // since that object is thread local until the subsequent entry
+    // into java. JavaCallWrapper() call clear() after copy() thus
+    // ensuring that all 3 writes are visible() before the wrapper is
+    // accessible to other threads.
+    _last_Java_fp = src->_last_Java_fp;
+    _last_Java_pc = src->_last_Java_pc;
+    // Must be last so profiler will always see valid frame if
+    // has_last_frame() is true
+    OrderAccess::release();
+    _last_Java_sp = src->_last_Java_sp;
+  }
+
+  bool walkable(void)                            { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
+  void make_walkable(JavaThread* thread);
+  void capture_last_Java_pc(void);
+
+  intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }
+
+  address last_Java_pc(void)                     { return _last_Java_pc; }
+
+private:
+
+  static ByteSize last_Java_fp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }
+
+public:
+
+  // n.b. set_last_Java_sp and set_last_Java_fp are never called
+  // (which is good because they would need a preceding or following
+  // call to OrderAccess::release() to make sure the writes are
+  // visible in the correct order).
+void set_last_Java_sp(intptr_t* sp)            { assert(false, "should not be called"); _last_Java_sp = sp; }
+
+  intptr_t*   last_Java_fp(void)                     { return _last_Java_fp; }
+  // Assert (last_Java_sp == NULL || fp == NULL)
+  void set_last_Java_fp(intptr_t* fp)                { assert(false, "should not be called"); _last_Java_fp = fp; }
+
+#endif // CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP