--- /dev/null	2021-01-19 17:38:25.908523431 +0000
+++ new/src/cpu/aarch64/vm/immediate_aarch64.hpp	2021-01-25 19:31:43.892551686 +0000
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2013, Red Hat Inc.
+ * 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.
+ *
+ */
+
+#ifndef _IMMEDIATE_H
+#define _IMMEDIATE_H
+
+#include <sys/types.h>
+
+/*
+ * functions to map backwards and forwards between logical or floating
+ * point immediates and their corresponding encodings. the mapping
+ * from encoding to immediate is required by the simulator. the reverse
+ * mapping is required by the OpenJDK assembler.
+ *
+ * a logical immediate value supplied to or returned from a map lookup
+ * is always 64 bits. this is sufficient for looking up 32 bit
+ * immediates or their encodings since a 32 bit immediate has the same
+ * encoding as the 64 bit immediate produced by concatenating the
+ * immediate with itself.
+ *
+ * a logical immediate encoding is 13 bits N:immr:imms (3 fields of
+ * widths 1:6:6 -- see the arm spec). they appear as bits [22:10] of a
+ * logical immediate instruction. encodings are supplied and returned
+ * as 32 bit values. if a given 13 bit immediate has no corresponding
+ * encoding then a map lookup will return 0xffffffff.
+ */
+
+u_int64_t logical_immediate_for_encoding(u_int32_t encoding);
+u_int32_t encoding_for_logical_immediate(u_int64_t immediate);
+u_int64_t fp_immediate_for_encoding(u_int32_t imm8, int is_dp);
+u_int32_t encoding_for_fp_immediate(float immediate);
+
+#endif // _IMMEDIATE_H