--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/cpu/s390/relocInfo_s390.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016 SAP SE. 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_S390_VM_RELOCINFO_S390_HPP
+#define CPU_S390_VM_RELOCINFO_S390_HPP
+
+//----------------------------
+//  relocInfo layout
+//----------------------------
+
+// This description should be contained in code/relocInfo.hpp
+// but was put here to minimize shared code diffs.
+
+// Relocation information for a nmethod is stored in compressed
+// form in an array of element type short int (16 bits).
+// Each array element constitutes one relocInfo record.
+// The layout of one such record is described here.
+
+// +------------+---+---+------------------------------+
+// |    type    |  fmt  |      offset/offset_unit      |
+// +------------+---+---+------------------------------+
+//
+// |<-- value_width (16) ----------------------------->|
+// |<type_width>|<-- nontype_width (12) -------------->|
+//      (4)
+// |            |<--+-->|<-- offset_width (10) ------->|
+//              /       \
+//             /   (2)   \
+//            /<--format->\
+//            |    width  |
+
+
+// only for type == data_prefix_tag:
+// +------------+---+---+------------------------------+
+// |    type    |   |              data                |
+// +------------+---+---+------------------------------+
+// |     15     |<->|<-- datalen_width (11) ---------->|
+//                |
+//                +--datalen_tag (1)
+
+// relocType
+//   The type field holds a value of relocType (which is
+//   an enum of all possible relocation types). Currently,
+//   there are 16 distinct relocation types, requiring
+//   type_width to be (at least) 4.
+// relocFormat
+//   The format field holds a value of relocFormat (which is
+//   an enum of all possible relocation formats). Currently,
+//   there are 4 distinct relocation formats, requiring
+//   format_width to be (at least) 2.
+// offset
+//   Each relocInfo is related to one specific address in the CodeBlob.
+//   The address always points to the first byte of the target instruction.
+//   It does NOT refer directly to the relocation subfield or embedded constant.
+//   offset contains the distance of this relocInfo from the previous one.
+//   offset is scaled by offset_unit (the platform-specific instruction
+//   alignment requirement) to maximize the encodable distance.
+//   To obtain the absolute address in the CodeBlob the relocInfo is
+//   related to, you have to iterate over all relocInfos from the
+//   beginning, and then use RelocIterator::addr() to get the address.
+
+// relocType == data_prefix_tag
+//   These are relocInfo records containing inline data that belongs to
+//   the next non-data relocInfo record. Usage of that inline data is
+//   specific and private to that relocInfo record.
+//   For details refer to code/relocInfo.hpp
+
+
+  // machine-dependent parts of class relocInfo
+ private:
+  enum {
+    // Instructions are HW (2-byte) aligned on z/Architecture.
+    offset_unit        =  2,
+
+    // Encodes Assembler::disp32_operand vs. Assembler::imm64_operand.
+    // (Assembler::call32_operand is used on call instructions only.)
+    format_width       =  2
+  };
+
+ public:
+
+  enum relocFormat {
+    no_format           = 0,
+    uncompressed_format = 0,  // Relocation is for a regular oop.
+    compressed_format   = 1,  // Relocation is for a narrow (compressed) oop or klass.
+                              // Similar to relocInfo::narrow_oop_in_const.
+    pcrel_addr_format   = 2,  // Relocation is for the target LOCATION of a pc-relative instruction.
+    pcrel_data_format   = 3   // Relocation is for the target data of a pc-relative instruction.
+  };
+
+  // Store the new target address into an oop_Relocation cell, if any.
+  // Return indication if update happened.
+  static bool update_oop_pool(address begin, address end, address newTarget, CodeBlob* cb);
+
+#endif // CPU_S390_VM_RELOCINFO_S390_HPP