--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/cpu/s390/gc/shared/cardTableBarrierSetAssembler_s390.cpp	Wed Mar 21 14:38:32 2018 +0100
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "asm/macroAssembler.inline.hpp"
+#include "gc/shared/barrierSet.hpp"
+#include "gc/shared/cardTable.hpp"
+#include "gc/shared/cardTableBarrierSet.hpp"
+#include "gc/shared/cardTableBarrierSetAssembler.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "interpreter/interp_masm.hpp"
+
+#define __ masm->
+
+#ifdef PRODUCT
+#define BLOCK_COMMENT(str) /* nothing */
+#else
+#define BLOCK_COMMENT(str) __ block_comment(str)
+#endif
+
+#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
+
+#define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
+
+void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count,
+                                                                    bool do_return) {
+  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(Universe::heap()->barrier_set());
+  CardTable* ct = ctbs->card_table();
+  assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
+
+  NearLabel doXC, done;
+  assert_different_registers(Z_R0, Z_R1, addr, count);
+
+  // Nothing to do if count <= 0.
+  if (!do_return) {
+    __ compare64_and_branch(count, (intptr_t) 0, Assembler::bcondNotHigh, done);
+  } else {
+    __ z_ltgr(count, count);
+    __ z_bcr(Assembler::bcondNotPositive, Z_R14);
+  }
+
+  // Note: We can't combine the shifts. We could lose a carry
+  // from calculating the array end address.
+  // count = (count-1)*BytesPerHeapOop + addr
+  // Count holds addr of last oop in array then.
+  __ z_sllg(count, count, LogBytesPerHeapOop);
+  __ add2reg_with_index(count, -BytesPerHeapOop, count, addr);
+
+  // Get base address of card table.
+  __ load_const_optimized(Z_R1, (address)ct->byte_map_base());
+
+  // count = (count>>shift) - (addr>>shift)
+  __ z_srlg(addr,  addr,  CardTable::card_shift);
+  __ z_srlg(count, count, CardTable::card_shift);
+
+  // Prefetch first elements of card table for update.
+  if (VM_Version::has_Prefetch()) {
+    __ z_pfd(0x02, 0, addr, Z_R1);
+  }
+
+  // Special case: clear just one byte.
+  __ clear_reg(Z_R0, true, false);  // Used for doOneByte.
+  __ z_sgr(count, addr);            // Count = n-1 now, CC used for brc below.
+  __ z_stc(Z_R0, 0, addr, Z_R1);    // Must preserve CC from z_sgr.
+  if (!do_return) {
+    __ z_brz(done);
+  } else {
+    __ z_bcr(Assembler::bcondZero, Z_R14);
+  }
+
+  __ z_cghi(count, 255);
+  __ z_brnh(doXC);
+
+  // MVCLE: clear a long area.
+  // Start addr of card table range = base + addr.
+  // # bytes in    card table range = (count + 1)
+  __ add2reg_with_index(Z_R0, 0, Z_R1, addr);
+  __ add2reg(Z_R1, 1, count);
+
+  // dirty hack:
+  // There are just two callers. Both pass
+  // count in Z_ARG3 = Z_R4
+  // addr  in Z_ARG2 = Z_R3
+  // ==> use Z_ARG2 as src len reg = 0
+  //         Z_ARG1 as src addr (ignored)
+  assert(count == Z_ARG3, "count: unexpected register number");
+  assert(addr  == Z_ARG2, "addr:  unexpected register number");
+  __ clear_reg(Z_ARG2, true, false);
+
+  __ MacroAssembler::move_long_ext(Z_R0, Z_ARG1, 0);
+
+  if (!do_return) {
+    __ z_bru(done);
+  } else {
+    __ z_bcr(Assembler::bcondAlways, Z_R14);
+  }
+
+  // XC: clear a short area.
+  Label XC_template; // Instr template, never exec directly!
+  __ bind(XC_template);
+  __ z_xc(0, 0, addr, 0, addr);
+
+  __ bind(doXC);
+  // start addr of card table range = base + addr
+  // end   addr of card table range = base + addr + count
+  __ add2reg_with_index(addr, 0, Z_R1, addr);
+
+  if (VM_Version::has_ExecuteExtensions()) {
+    __ z_exrl(count, XC_template);   // Execute XC with var. len.
+  } else {
+    __ z_larl(Z_R1, XC_template);
+    __ z_ex(count, 0, Z_R0, Z_R1);   // Execute XC with var. len.
+  }
+  if (do_return) {
+    __ z_br(Z_R14);
+  }
+
+  __ bind(done);
+}