src/hotspot/cpu/s390/sharedRuntime_s390.cpp
changeset 47216 71c04702a3d5
parent 46726 7801367e3cc9
child 47795 5a69ba3a4fd1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/cpu/s390/sharedRuntime_s390.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,3553 @@
+/*
+ * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2017 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 "code/debugInfoRec.hpp"
+#include "code/icBuffer.hpp"
+#include "code/vtableStubs.hpp"
+#include "interpreter/interpreter.hpp"
+#include "interpreter/interp_masm.hpp"
+#include "memory/resourceArea.hpp"
+#include "oops/compiledICHolder.hpp"
+#include "registerSaver_s390.hpp"
+#include "runtime/sharedRuntime.hpp"
+#include "runtime/vframeArray.hpp"
+#include "utilities/align.hpp"
+#include "vmreg_s390.inline.hpp"
+#ifdef COMPILER1
+#include "c1/c1_Runtime1.hpp"
+#endif
+#ifdef COMPILER2
+#include "opto/ad.hpp"
+#include "opto/runtime.hpp"
+#endif
+
+#ifdef PRODUCT
+#define __ masm->
+#else
+#define __ (Verbose ? (masm->block_comment(FILE_AND_LINE),masm):masm)->
+#endif
+
+#define BLOCK_COMMENT(str) __ block_comment(str)
+#define BIND(label)        bind(label); BLOCK_COMMENT(#label ":")
+
+#define RegisterSaver_LiveIntReg(regname) \
+  { RegisterSaver::int_reg,   regname->encoding(), regname->as_VMReg() }
+
+#define RegisterSaver_LiveFloatReg(regname) \
+  { RegisterSaver::float_reg, regname->encoding(), regname->as_VMReg() }
+
+// Registers which are not saved/restored, but still they have got a frame slot.
+// Used to get same frame size for RegisterSaver_LiveRegs and RegisterSaver_LiveRegsWithoutR2
+#define RegisterSaver_ExcludedIntReg(regname) \
+  { RegisterSaver::excluded_reg, regname->encoding(), regname->as_VMReg() }
+
+// Registers which are not saved/restored, but still they have got a frame slot.
+// Used to get same frame size for RegisterSaver_LiveRegs and RegisterSaver_LiveRegsWithoutR2.
+#define RegisterSaver_ExcludedFloatReg(regname) \
+  { RegisterSaver::excluded_reg, regname->encoding(), regname->as_VMReg() }
+
+static const RegisterSaver::LiveRegType RegisterSaver_LiveRegs[] = {
+  // Live registers which get spilled to the stack. Register positions
+  // in this array correspond directly to the stack layout.
+  //
+  // live float registers:
+  //
+  RegisterSaver_LiveFloatReg(Z_F0 ),
+  // RegisterSaver_ExcludedFloatReg(Z_F1 ), // scratch (Z_fscratch_1)
+  RegisterSaver_LiveFloatReg(Z_F2 ),
+  RegisterSaver_LiveFloatReg(Z_F3 ),
+  RegisterSaver_LiveFloatReg(Z_F4 ),
+  RegisterSaver_LiveFloatReg(Z_F5 ),
+  RegisterSaver_LiveFloatReg(Z_F6 ),
+  RegisterSaver_LiveFloatReg(Z_F7 ),
+  RegisterSaver_LiveFloatReg(Z_F8 ),
+  RegisterSaver_LiveFloatReg(Z_F9 ),
+  RegisterSaver_LiveFloatReg(Z_F10),
+  RegisterSaver_LiveFloatReg(Z_F11),
+  RegisterSaver_LiveFloatReg(Z_F12),
+  RegisterSaver_LiveFloatReg(Z_F13),
+  RegisterSaver_LiveFloatReg(Z_F14),
+  RegisterSaver_LiveFloatReg(Z_F15),
+  //
+  // RegisterSaver_ExcludedIntReg(Z_R0), // scratch
+  // RegisterSaver_ExcludedIntReg(Z_R1), // scratch
+  RegisterSaver_LiveIntReg(Z_R2 ),
+  RegisterSaver_LiveIntReg(Z_R3 ),
+  RegisterSaver_LiveIntReg(Z_R4 ),
+  RegisterSaver_LiveIntReg(Z_R5 ),
+  RegisterSaver_LiveIntReg(Z_R6 ),
+  RegisterSaver_LiveIntReg(Z_R7 ),
+  RegisterSaver_LiveIntReg(Z_R8 ),
+  RegisterSaver_LiveIntReg(Z_R9 ),
+  RegisterSaver_LiveIntReg(Z_R10),
+  RegisterSaver_LiveIntReg(Z_R11),
+  RegisterSaver_LiveIntReg(Z_R12),
+  RegisterSaver_LiveIntReg(Z_R13),
+  // RegisterSaver_ExcludedIntReg(Z_R14), // return pc (Saved in caller frame.)
+  // RegisterSaver_ExcludedIntReg(Z_R15)  // stack pointer
+};
+
+static const RegisterSaver::LiveRegType RegisterSaver_LiveIntRegs[] = {
+  // Live registers which get spilled to the stack. Register positions
+  // in this array correspond directly to the stack layout.
+  //
+  // live float registers: All excluded, but still they get a stack slot to get same frame size.
+  //
+  RegisterSaver_ExcludedFloatReg(Z_F0 ),
+  // RegisterSaver_ExcludedFloatReg(Z_F1 ), // scratch (Z_fscratch_1)
+  RegisterSaver_ExcludedFloatReg(Z_F2 ),
+  RegisterSaver_ExcludedFloatReg(Z_F3 ),
+  RegisterSaver_ExcludedFloatReg(Z_F4 ),
+  RegisterSaver_ExcludedFloatReg(Z_F5 ),
+  RegisterSaver_ExcludedFloatReg(Z_F6 ),
+  RegisterSaver_ExcludedFloatReg(Z_F7 ),
+  RegisterSaver_ExcludedFloatReg(Z_F8 ),
+  RegisterSaver_ExcludedFloatReg(Z_F9 ),
+  RegisterSaver_ExcludedFloatReg(Z_F10),
+  RegisterSaver_ExcludedFloatReg(Z_F11),
+  RegisterSaver_ExcludedFloatReg(Z_F12),
+  RegisterSaver_ExcludedFloatReg(Z_F13),
+  RegisterSaver_ExcludedFloatReg(Z_F14),
+  RegisterSaver_ExcludedFloatReg(Z_F15),
+  //
+  // RegisterSaver_ExcludedIntReg(Z_R0), // scratch
+  // RegisterSaver_ExcludedIntReg(Z_R1), // scratch
+  RegisterSaver_LiveIntReg(Z_R2 ),
+  RegisterSaver_LiveIntReg(Z_R3 ),
+  RegisterSaver_LiveIntReg(Z_R4 ),
+  RegisterSaver_LiveIntReg(Z_R5 ),
+  RegisterSaver_LiveIntReg(Z_R6 ),
+  RegisterSaver_LiveIntReg(Z_R7 ),
+  RegisterSaver_LiveIntReg(Z_R8 ),
+  RegisterSaver_LiveIntReg(Z_R9 ),
+  RegisterSaver_LiveIntReg(Z_R10),
+  RegisterSaver_LiveIntReg(Z_R11),
+  RegisterSaver_LiveIntReg(Z_R12),
+  RegisterSaver_LiveIntReg(Z_R13),
+  // RegisterSaver_ExcludedIntReg(Z_R14), // return pc (Saved in caller frame.)
+  // RegisterSaver_ExcludedIntReg(Z_R15)  // stack pointer
+};
+
+static const RegisterSaver::LiveRegType RegisterSaver_LiveRegsWithoutR2[] = {
+  // Live registers which get spilled to the stack. Register positions
+  // in this array correspond directly to the stack layout.
+  //
+  // live float registers:
+  //
+  RegisterSaver_LiveFloatReg(Z_F0 ),
+  // RegisterSaver_ExcludedFloatReg(Z_F1 ), // scratch (Z_fscratch_1)
+  RegisterSaver_LiveFloatReg(Z_F2 ),
+  RegisterSaver_LiveFloatReg(Z_F3 ),
+  RegisterSaver_LiveFloatReg(Z_F4 ),
+  RegisterSaver_LiveFloatReg(Z_F5 ),
+  RegisterSaver_LiveFloatReg(Z_F6 ),
+  RegisterSaver_LiveFloatReg(Z_F7 ),
+  RegisterSaver_LiveFloatReg(Z_F8 ),
+  RegisterSaver_LiveFloatReg(Z_F9 ),
+  RegisterSaver_LiveFloatReg(Z_F10),
+  RegisterSaver_LiveFloatReg(Z_F11),
+  RegisterSaver_LiveFloatReg(Z_F12),
+  RegisterSaver_LiveFloatReg(Z_F13),
+  RegisterSaver_LiveFloatReg(Z_F14),
+  RegisterSaver_LiveFloatReg(Z_F15),
+  //
+  // RegisterSaver_ExcludedIntReg(Z_R0), // scratch
+  // RegisterSaver_ExcludedIntReg(Z_R1), // scratch
+  RegisterSaver_ExcludedIntReg(Z_R2), // Omit saving R2.
+  RegisterSaver_LiveIntReg(Z_R3 ),
+  RegisterSaver_LiveIntReg(Z_R4 ),
+  RegisterSaver_LiveIntReg(Z_R5 ),
+  RegisterSaver_LiveIntReg(Z_R6 ),
+  RegisterSaver_LiveIntReg(Z_R7 ),
+  RegisterSaver_LiveIntReg(Z_R8 ),
+  RegisterSaver_LiveIntReg(Z_R9 ),
+  RegisterSaver_LiveIntReg(Z_R10),
+  RegisterSaver_LiveIntReg(Z_R11),
+  RegisterSaver_LiveIntReg(Z_R12),
+  RegisterSaver_LiveIntReg(Z_R13),
+  // RegisterSaver_ExcludedIntReg(Z_R14), // return pc (Saved in caller frame.)
+  // RegisterSaver_ExcludedIntReg(Z_R15)  // stack pointer
+};
+
+// Live argument registers which get spilled to the stack.
+static const RegisterSaver::LiveRegType RegisterSaver_LiveArgRegs[] = {
+  RegisterSaver_LiveFloatReg(Z_FARG1),
+  RegisterSaver_LiveFloatReg(Z_FARG2),
+  RegisterSaver_LiveFloatReg(Z_FARG3),
+  RegisterSaver_LiveFloatReg(Z_FARG4),
+  RegisterSaver_LiveIntReg(Z_ARG1),
+  RegisterSaver_LiveIntReg(Z_ARG2),
+  RegisterSaver_LiveIntReg(Z_ARG3),
+  RegisterSaver_LiveIntReg(Z_ARG4),
+  RegisterSaver_LiveIntReg(Z_ARG5)
+};
+
+static const RegisterSaver::LiveRegType RegisterSaver_LiveVolatileRegs[] = {
+  // Live registers which get spilled to the stack. Register positions
+  // in this array correspond directly to the stack layout.
+  //
+  // live float registers:
+  //
+  RegisterSaver_LiveFloatReg(Z_F0 ),
+  // RegisterSaver_ExcludedFloatReg(Z_F1 ), // scratch (Z_fscratch_1)
+  RegisterSaver_LiveFloatReg(Z_F2 ),
+  RegisterSaver_LiveFloatReg(Z_F3 ),
+  RegisterSaver_LiveFloatReg(Z_F4 ),
+  RegisterSaver_LiveFloatReg(Z_F5 ),
+  RegisterSaver_LiveFloatReg(Z_F6 ),
+  RegisterSaver_LiveFloatReg(Z_F7 ),
+  // RegisterSaver_LiveFloatReg(Z_F8 ), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F9 ), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F10), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F11), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F12), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F13), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F14), // non-volatile
+  // RegisterSaver_LiveFloatReg(Z_F15), // non-volatile
+  //
+  // RegisterSaver_ExcludedIntReg(Z_R0), // scratch
+  // RegisterSaver_ExcludedIntReg(Z_R1), // scratch
+  RegisterSaver_LiveIntReg(Z_R2 ),
+  RegisterSaver_LiveIntReg(Z_R3 ),
+  RegisterSaver_LiveIntReg(Z_R4 ),
+  RegisterSaver_LiveIntReg(Z_R5 ),
+  // RegisterSaver_LiveIntReg(Z_R6 ), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R7 ), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R8 ), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R9 ), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R10), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R11), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R12), // non-volatile
+  // RegisterSaver_LiveIntReg(Z_R13), // non-volatile
+  // RegisterSaver_ExcludedIntReg(Z_R14), // return pc (Saved in caller frame.)
+  // RegisterSaver_ExcludedIntReg(Z_R15)  // stack pointer
+};
+
+int RegisterSaver::live_reg_save_size(RegisterSet reg_set) {
+  int reg_space = -1;
+  switch (reg_set) {
+    case all_registers:           reg_space = sizeof(RegisterSaver_LiveRegs); break;
+    case all_registers_except_r2: reg_space = sizeof(RegisterSaver_LiveRegsWithoutR2); break;
+    case all_integer_registers:   reg_space = sizeof(RegisterSaver_LiveIntRegs); break;
+    case all_volatile_registers:  reg_space = sizeof(RegisterSaver_LiveVolatileRegs); break;
+    case arg_registers:           reg_space = sizeof(RegisterSaver_LiveArgRegs); break;
+    default: ShouldNotReachHere();
+  }
+  return (reg_space / sizeof(RegisterSaver::LiveRegType)) * reg_size;
+}
+
+
+int RegisterSaver::live_reg_frame_size(RegisterSet reg_set) {
+  return live_reg_save_size(reg_set) + frame::z_abi_160_size;
+}
+
+
+// return_pc: Specify the register that should be stored as the return pc in the current frame.
+OopMap* RegisterSaver::save_live_registers(MacroAssembler* masm, RegisterSet reg_set, Register return_pc) {
+  // Record volatile registers as callee-save values in an OopMap so
+  // their save locations will be propagated to the caller frame's
+  // RegisterMap during StackFrameStream construction (needed for
+  // deoptimization; see compiledVFrame::create_stack_value).
+
+  // Calculate frame size.
+  const int frame_size_in_bytes  = live_reg_frame_size(reg_set);
+  const int frame_size_in_slots  = frame_size_in_bytes / sizeof(jint);
+  const int register_save_offset = frame_size_in_bytes - live_reg_save_size(reg_set);
+
+  // OopMap frame size is in c2 stack slots (sizeof(jint)) not bytes or words.
+  OopMap* map = new OopMap(frame_size_in_slots, 0);
+
+  int regstosave_num = 0;
+  const RegisterSaver::LiveRegType* live_regs = NULL;
+
+  switch (reg_set) {
+    case all_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveRegs;
+      break;
+    case all_registers_except_r2:
+      regstosave_num = sizeof(RegisterSaver_LiveRegsWithoutR2)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveRegsWithoutR2;
+      break;
+    case all_integer_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveIntRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveIntRegs;
+      break;
+    case all_volatile_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveVolatileRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveVolatileRegs;
+      break;
+    case arg_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveArgRegs)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveArgRegs;
+      break;
+    default: ShouldNotReachHere();
+  }
+
+  // Save return pc in old frame.
+  __ save_return_pc(return_pc);
+
+  // Push a new frame (includes stack linkage).
+  // use return_pc as scratch for push_frame. Z_R0_scratch (the default) and Z_R1_scratch are
+  // illegally used to pass parameters (SAPJVM extension) by RangeCheckStub::emit_code().
+  __ push_frame(frame_size_in_bytes, return_pc);
+  // We have to restore return_pc right away.
+  // Nobody else will. Furthermore, return_pc isn't necessarily the default (Z_R14).
+  // Nobody else knows which register we saved.
+  __ z_lg(return_pc, _z_abi16(return_pc) + frame_size_in_bytes, Z_SP);
+
+  // Register save area in new frame starts above z_abi_160 area.
+  int offset = register_save_offset;
+
+  Register first = noreg;
+  Register last  = noreg;
+  int      first_offset = -1;
+  bool     float_spilled = false;
+
+  for (int i = 0; i < regstosave_num; i++, offset += reg_size) {
+    int reg_num  = live_regs[i].reg_num;
+    int reg_type = live_regs[i].reg_type;
+
+    switch (reg_type) {
+      case RegisterSaver::int_reg: {
+        Register reg = as_Register(reg_num);
+        if (last != reg->predecessor()) {
+          if (first != noreg) {
+            __ z_stmg(first, last, first_offset, Z_SP);
+          }
+          first = reg;
+          first_offset = offset;
+          DEBUG_ONLY(float_spilled = false);
+        }
+        last = reg;
+        assert(last != Z_R0, "r0 would require special treatment");
+        assert(!float_spilled, "for simplicity, do not mix up ints and floats in RegisterSaver_LiveRegs[]");
+        break;
+      }
+
+      case RegisterSaver::excluded_reg: // Not saved/restored, but with dedicated slot.
+        continue; // Continue with next loop iteration.
+
+      case RegisterSaver::float_reg: {
+        FloatRegister freg = as_FloatRegister(reg_num);
+        __ z_std(freg, offset, Z_SP);
+        DEBUG_ONLY(float_spilled = true);
+        break;
+      }
+
+      default:
+        ShouldNotReachHere();
+        break;
+    }
+
+    // Second set_callee_saved is really a waste but we'll keep things as they were for now
+    map->set_callee_saved(VMRegImpl::stack2reg(offset >> 2), live_regs[i].vmreg);
+    map->set_callee_saved(VMRegImpl::stack2reg((offset + half_reg_size) >> 2), live_regs[i].vmreg->next());
+  }
+  assert(first != noreg, "Should spill at least one int reg.");
+  __ z_stmg(first, last, first_offset, Z_SP);
+
+  // And we're done.
+  return map;
+}
+
+
+// Generate the OopMap (again, regs where saved before).
+OopMap* RegisterSaver::generate_oop_map(MacroAssembler* masm, RegisterSet reg_set) {
+  // Calculate frame size.
+  const int frame_size_in_bytes  = live_reg_frame_size(reg_set);
+  const int frame_size_in_slots  = frame_size_in_bytes / sizeof(jint);
+  const int register_save_offset = frame_size_in_bytes - live_reg_save_size(reg_set);
+
+  // OopMap frame size is in c2 stack slots (sizeof(jint)) not bytes or words.
+  OopMap* map = new OopMap(frame_size_in_slots, 0);
+
+  int regstosave_num = 0;
+  const RegisterSaver::LiveRegType* live_regs = NULL;
+
+  switch (reg_set) {
+    case all_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveRegs;
+      break;
+    case all_registers_except_r2:
+      regstosave_num = sizeof(RegisterSaver_LiveRegsWithoutR2)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveRegsWithoutR2;
+      break;
+    case all_integer_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveIntRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveIntRegs;
+      break;
+    case all_volatile_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveVolatileRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveVolatileRegs;
+      break;
+    case arg_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveArgRegs)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveArgRegs;
+      break;
+    default: ShouldNotReachHere();
+  }
+
+  // Register save area in new frame starts above z_abi_160 area.
+  int offset = register_save_offset;
+  for (int i = 0; i < regstosave_num; i++) {
+    if (live_regs[i].reg_type < RegisterSaver::excluded_reg) {
+      map->set_callee_saved(VMRegImpl::stack2reg(offset>>2), live_regs[i].vmreg);
+      map->set_callee_saved(VMRegImpl::stack2reg((offset + half_reg_size)>>2), live_regs[i].vmreg->next());
+    }
+    offset += reg_size;
+  }
+  return map;
+}
+
+
+// Pop the current frame and restore all the registers that we saved.
+void RegisterSaver::restore_live_registers(MacroAssembler* masm, RegisterSet reg_set) {
+  int offset;
+  const int register_save_offset = live_reg_frame_size(reg_set) - live_reg_save_size(reg_set);
+
+  Register first = noreg;
+  Register last = noreg;
+  int      first_offset = -1;
+  bool     float_spilled = false;
+
+  int regstosave_num = 0;
+  const RegisterSaver::LiveRegType* live_regs = NULL;
+
+  switch (reg_set) {
+    case all_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveRegs)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveRegs;
+      break;
+    case all_registers_except_r2:
+      regstosave_num = sizeof(RegisterSaver_LiveRegsWithoutR2)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveRegsWithoutR2;
+      break;
+    case all_integer_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveIntRegs)/sizeof(RegisterSaver::LiveRegType);
+      live_regs      = RegisterSaver_LiveIntRegs;
+      break;
+    case all_volatile_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveVolatileRegs)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveVolatileRegs;
+      break;
+    case arg_registers:
+      regstosave_num = sizeof(RegisterSaver_LiveArgRegs)/sizeof(RegisterSaver::LiveRegType);;
+      live_regs      = RegisterSaver_LiveArgRegs;
+      break;
+    default: ShouldNotReachHere();
+  }
+
+  // Restore all registers (ints and floats).
+
+  // Register save area in new frame starts above z_abi_160 area.
+  offset = register_save_offset;
+
+  for (int i = 0; i < regstosave_num; i++, offset += reg_size) {
+    int reg_num  = live_regs[i].reg_num;
+    int reg_type = live_regs[i].reg_type;
+
+    switch (reg_type) {
+      case RegisterSaver::excluded_reg:
+        continue; // Continue with next loop iteration.
+
+      case RegisterSaver::int_reg: {
+        Register reg = as_Register(reg_num);
+        if (last != reg->predecessor()) {
+          if (first != noreg) {
+            __ z_lmg(first, last, first_offset, Z_SP);
+          }
+          first = reg;
+          first_offset = offset;
+          DEBUG_ONLY(float_spilled = false);
+        }
+        last = reg;
+        assert(last != Z_R0, "r0 would require special treatment");
+        assert(!float_spilled, "for simplicity, do not mix up ints and floats in RegisterSaver_LiveRegs[]");
+        break;
+      }
+
+      case RegisterSaver::float_reg: {
+        FloatRegister freg = as_FloatRegister(reg_num);
+        __ z_ld(freg, offset, Z_SP);
+        DEBUG_ONLY(float_spilled = true);
+        break;
+      }
+
+      default:
+        ShouldNotReachHere();
+    }
+  }
+  assert(first != noreg, "Should spill at least one int reg.");
+  __ z_lmg(first, last, first_offset, Z_SP);
+
+  // Pop the frame.
+  __ pop_frame();
+
+  // Restore the flags.
+  __ restore_return_pc();
+}
+
+
+// Pop the current frame and restore the registers that might be holding a result.
+void RegisterSaver::restore_result_registers(MacroAssembler* masm) {
+  int i;
+  int offset;
+  const int regstosave_num       = sizeof(RegisterSaver_LiveRegs) /
+                                   sizeof(RegisterSaver::LiveRegType);
+  const int register_save_offset = live_reg_frame_size(all_registers) - live_reg_save_size(all_registers);
+
+  // Restore all result registers (ints and floats).
+  offset = register_save_offset;
+  for (int i = 0; i < regstosave_num; i++, offset += reg_size) {
+    int reg_num = RegisterSaver_LiveRegs[i].reg_num;
+    int reg_type = RegisterSaver_LiveRegs[i].reg_type;
+    switch (reg_type) {
+      case RegisterSaver::excluded_reg:
+        continue; // Continue with next loop iteration.
+      case RegisterSaver::int_reg: {
+        if (as_Register(reg_num) == Z_RET) { // int result_reg
+          __ z_lg(as_Register(reg_num), offset, Z_SP);
+        }
+        break;
+      }
+      case RegisterSaver::float_reg: {
+        if (as_FloatRegister(reg_num) == Z_FRET) { // float result_reg
+          __ z_ld(as_FloatRegister(reg_num), offset, Z_SP);
+        }
+        break;
+      }
+      default:
+        ShouldNotReachHere();
+    }
+  }
+}
+
+size_t SharedRuntime::trampoline_size() {
+  return MacroAssembler::load_const_size() + 2;
+}
+
+void SharedRuntime::generate_trampoline(MacroAssembler *masm, address destination) {
+  // Think about using pc-relative branch.
+  __ load_const(Z_R1_scratch, destination);
+  __ z_br(Z_R1_scratch);
+}
+
+// ---------------------------------------------------------------------------
+void SharedRuntime::save_native_result(MacroAssembler * masm,
+                                       BasicType ret_type,
+                                       int frame_slots) {
+  Address memaddr(Z_SP, frame_slots * VMRegImpl::stack_slot_size);
+
+  switch (ret_type) {
+    case T_BOOLEAN:  // Save shorter types as int. Do we need sign extension at restore??
+    case T_BYTE:
+    case T_CHAR:
+    case T_SHORT:
+    case T_INT:
+      __ reg2mem_opt(Z_RET, memaddr, false);
+      break;
+    case T_OBJECT:   // Save pointer types as long.
+    case T_ARRAY:
+    case T_ADDRESS:
+    case T_VOID:
+    case T_LONG:
+      __ reg2mem_opt(Z_RET, memaddr);
+      break;
+    case T_FLOAT:
+      __ freg2mem_opt(Z_FRET, memaddr, false);
+      break;
+    case T_DOUBLE:
+      __ freg2mem_opt(Z_FRET, memaddr);
+      break;
+  }
+}
+
+void SharedRuntime::restore_native_result(MacroAssembler *masm,
+                                          BasicType       ret_type,
+                                          int             frame_slots) {
+  Address memaddr(Z_SP, frame_slots * VMRegImpl::stack_slot_size);
+
+  switch (ret_type) {
+    case T_BOOLEAN:  // Restore shorter types as int. Do we need sign extension at restore??
+    case T_BYTE:
+    case T_CHAR:
+    case T_SHORT:
+    case T_INT:
+      __ mem2reg_opt(Z_RET, memaddr, false);
+      break;
+    case T_OBJECT:   // Restore pointer types as long.
+    case T_ARRAY:
+    case T_ADDRESS:
+    case T_VOID:
+    case T_LONG:
+      __ mem2reg_opt(Z_RET, memaddr);
+      break;
+    case T_FLOAT:
+      __ mem2freg_opt(Z_FRET, memaddr, false);
+      break;
+    case T_DOUBLE:
+      __ mem2freg_opt(Z_FRET, memaddr);
+      break;
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Read the array of BasicTypes from a signature, and compute where the
+// arguments should go. Values in the VMRegPair regs array refer to 4-byte
+// quantities. Values less than VMRegImpl::stack0 are registers, those above
+// refer to 4-byte stack slots. All stack slots are based off of the stack pointer
+// as framesizes are fixed.
+// VMRegImpl::stack0 refers to the first slot 0(sp).
+// VMRegImpl::stack0+1 refers to the memory word 4-byes higher. Registers
+// up to RegisterImpl::number_of_registers are the 64-bit integer registers.
+
+// Note: the INPUTS in sig_bt are in units of Java argument words, which are
+// either 32-bit or 64-bit depending on the build. The OUTPUTS are in 32-bit
+// units regardless of build.
+
+// The Java calling convention is a "shifted" version of the C ABI.
+// By skipping the first C ABI register we can call non-static jni methods
+// with small numbers of arguments without having to shuffle the arguments
+// at all. Since we control the java ABI we ought to at least get some
+// advantage out of it.
+int SharedRuntime::java_calling_convention(const BasicType *sig_bt,
+                                           VMRegPair *regs,
+                                           int total_args_passed,
+                                           int is_outgoing) {
+  // c2c calling conventions for compiled-compiled calls.
+
+  // An int/float occupies 1 slot here.
+  const int inc_stk_for_intfloat   = 1; // 1 slots for ints and floats.
+  const int inc_stk_for_longdouble = 2; // 2 slots for longs and doubles.
+
+  const VMReg z_iarg_reg[5] = {
+    Z_R2->as_VMReg(),
+    Z_R3->as_VMReg(),
+    Z_R4->as_VMReg(),
+    Z_R5->as_VMReg(),
+    Z_R6->as_VMReg()
+  };
+  const VMReg z_farg_reg[4] = {
+    Z_F0->as_VMReg(),
+    Z_F2->as_VMReg(),
+    Z_F4->as_VMReg(),
+    Z_F6->as_VMReg()
+  };
+  const int z_num_iarg_registers = sizeof(z_iarg_reg) / sizeof(z_iarg_reg[0]);
+  const int z_num_farg_registers = sizeof(z_farg_reg) / sizeof(z_farg_reg[0]);
+
+  assert(RegisterImpl::number_of_arg_registers == z_num_iarg_registers, "iarg reg count mismatch");
+  assert(FloatRegisterImpl::number_of_arg_registers == z_num_farg_registers, "farg reg count mismatch");
+
+  int i;
+  int stk = 0;
+  int ireg = 0;
+  int freg = 0;
+
+  for (int i = 0; i < total_args_passed; ++i) {
+    switch (sig_bt[i]) {
+      case T_BOOLEAN:
+      case T_CHAR:
+      case T_BYTE:
+      case T_SHORT:
+      case T_INT:
+        if (ireg < z_num_iarg_registers) {
+          // Put int/ptr in register.
+          regs[i].set1(z_iarg_reg[ireg]);
+          ++ireg;
+        } else {
+          // Put int/ptr on stack.
+          regs[i].set1(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_intfloat;
+        }
+        break;
+      case T_LONG:
+        assert((i + 1) < total_args_passed && sig_bt[i+1] == T_VOID, "expecting half");
+        if (ireg < z_num_iarg_registers) {
+          // Put long in register.
+          regs[i].set2(z_iarg_reg[ireg]);
+          ++ireg;
+        } else {
+          // Put long on stack and align to 2 slots.
+          if (stk & 0x1) { ++stk; }
+          regs[i].set2(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_longdouble;
+        }
+        break;
+      case T_OBJECT:
+      case T_ARRAY:
+      case T_ADDRESS:
+        if (ireg < z_num_iarg_registers) {
+          // Put ptr in register.
+          regs[i].set2(z_iarg_reg[ireg]);
+          ++ireg;
+        } else {
+          // Put ptr on stack and align to 2 slots, because
+          // "64-bit pointers record oop-ishness on 2 aligned adjacent
+          // registers." (see OopFlow::build_oop_map).
+          if (stk & 0x1) { ++stk; }
+          regs[i].set2(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_longdouble;
+        }
+        break;
+      case T_FLOAT:
+        if (freg < z_num_farg_registers) {
+          // Put float in register.
+          regs[i].set1(z_farg_reg[freg]);
+          ++freg;
+        } else {
+          // Put float on stack.
+          regs[i].set1(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_intfloat;
+        }
+        break;
+      case T_DOUBLE:
+        assert((i + 1) < total_args_passed && sig_bt[i+1] == T_VOID, "expecting half");
+        if (freg < z_num_farg_registers) {
+          // Put double in register.
+          regs[i].set2(z_farg_reg[freg]);
+          ++freg;
+        } else {
+          // Put double on stack and align to 2 slots.
+          if (stk & 0x1) { ++stk; }
+          regs[i].set2(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_longdouble;
+        }
+        break;
+      case T_VOID:
+        assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
+        // Do not count halves.
+        regs[i].set_bad();
+        break;
+      default:
+        ShouldNotReachHere();
+    }
+  }
+  return align_up(stk, 2);
+}
+
+int SharedRuntime::c_calling_convention(const BasicType *sig_bt,
+                                        VMRegPair *regs,
+                                        VMRegPair *regs2,
+                                        int total_args_passed) {
+  assert(regs2 == NULL, "second VMRegPair array not used on this platform");
+
+  // Calling conventions for C runtime calls and calls to JNI native methods.
+  const VMReg z_iarg_reg[5] = {
+    Z_R2->as_VMReg(),
+    Z_R3->as_VMReg(),
+    Z_R4->as_VMReg(),
+    Z_R5->as_VMReg(),
+    Z_R6->as_VMReg()
+  };
+  const VMReg z_farg_reg[4] = {
+    Z_F0->as_VMReg(),
+    Z_F2->as_VMReg(),
+    Z_F4->as_VMReg(),
+    Z_F6->as_VMReg()
+  };
+  const int z_num_iarg_registers = sizeof(z_iarg_reg) / sizeof(z_iarg_reg[0]);
+  const int z_num_farg_registers = sizeof(z_farg_reg) / sizeof(z_farg_reg[0]);
+
+  // Check calling conventions consistency.
+  assert(RegisterImpl::number_of_arg_registers == z_num_iarg_registers, "iarg reg count mismatch");
+  assert(FloatRegisterImpl::number_of_arg_registers == z_num_farg_registers, "farg reg count mismatch");
+
+  // Avoid passing C arguments in the wrong stack slots.
+
+  // 'Stk' counts stack slots. Due to alignment, 32 bit values occupy
+  // 2 such slots, like 64 bit values do.
+  const int inc_stk_for_intfloat   = 2; // 2 slots for ints and floats.
+  const int inc_stk_for_longdouble = 2; // 2 slots for longs and doubles.
+
+  int i;
+  // Leave room for C-compatible ABI
+  int stk = (frame::z_abi_160_size - frame::z_jit_out_preserve_size) / VMRegImpl::stack_slot_size;
+  int freg = 0;
+  int ireg = 0;
+
+  // We put the first 5 arguments into registers and the rest on the
+  // stack. Float arguments are already in their argument registers
+  // due to c2c calling conventions (see calling_convention).
+  for (int i = 0; i < total_args_passed; ++i) {
+    switch (sig_bt[i]) {
+      case T_BOOLEAN:
+      case T_CHAR:
+      case T_BYTE:
+      case T_SHORT:
+      case T_INT:
+        // Fall through, handle as long.
+      case T_LONG:
+      case T_OBJECT:
+      case T_ARRAY:
+      case T_ADDRESS:
+      case T_METADATA:
+        // Oops are already boxed if required (JNI).
+        if (ireg < z_num_iarg_registers) {
+          regs[i].set2(z_iarg_reg[ireg]);
+          ++ireg;
+        } else {
+          regs[i].set2(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_longdouble;
+        }
+        break;
+      case T_FLOAT:
+        if (freg < z_num_farg_registers) {
+          regs[i].set1(z_farg_reg[freg]);
+          ++freg;
+        } else {
+          regs[i].set1(VMRegImpl::stack2reg(stk+1));
+          stk +=  inc_stk_for_intfloat;
+        }
+        break;
+      case T_DOUBLE:
+        assert((i + 1) < total_args_passed && sig_bt[i+1] == T_VOID, "expecting half");
+        if (freg < z_num_farg_registers) {
+          regs[i].set2(z_farg_reg[freg]);
+          ++freg;
+        } else {
+          // Put double on stack.
+          regs[i].set2(VMRegImpl::stack2reg(stk));
+          stk += inc_stk_for_longdouble;
+        }
+        break;
+      case T_VOID:
+        // Do not count halves.
+        regs[i].set_bad();
+        break;
+      default:
+        ShouldNotReachHere();
+    }
+  }
+  return align_up(stk, 2);
+}
+
+////////////////////////////////////////////////////////////////////////
+//
+//  Argument shufflers
+//
+////////////////////////////////////////////////////////////////////////
+
+//----------------------------------------------------------------------
+// The java_calling_convention describes stack locations as ideal slots on
+// a frame with no abi restrictions. Since we must observe abi restrictions
+// (like the placement of the register window) the slots must be biased by
+// the following value.
+//----------------------------------------------------------------------
+static int reg2slot(VMReg r) {
+  return r->reg2stack() + SharedRuntime::out_preserve_stack_slots();
+}
+
+static int reg2offset(VMReg r) {
+  return reg2slot(r) * VMRegImpl::stack_slot_size;
+}
+
+static void verify_oop_args(MacroAssembler *masm,
+                            int total_args_passed,
+                            const BasicType *sig_bt,
+                            const VMRegPair *regs) {
+  if (!VerifyOops) { return; }
+
+  for (int i = 0; i < total_args_passed; i++) {
+    if (sig_bt[i] == T_OBJECT || sig_bt[i] == T_ARRAY) {
+      VMReg r = regs[i].first();
+      assert(r->is_valid(), "bad oop arg");
+
+      if (r->is_stack()) {
+        __ z_lg(Z_R0_scratch,
+                Address(Z_SP, r->reg2stack() * VMRegImpl::stack_slot_size + wordSize));
+        __ verify_oop(Z_R0_scratch);
+      } else {
+        __ verify_oop(r->as_Register());
+      }
+    }
+  }
+}
+
+static void gen_special_dispatch(MacroAssembler *masm,
+                                 int total_args_passed,
+                                 vmIntrinsics::ID special_dispatch,
+                                 const BasicType *sig_bt,
+                                 const VMRegPair *regs) {
+  verify_oop_args(masm, total_args_passed, sig_bt, regs);
+
+  // Now write the args into the outgoing interpreter space.
+  bool     has_receiver   = false;
+  Register receiver_reg   = noreg;
+  int      member_arg_pos = -1;
+  Register member_reg     = noreg;
+  int      ref_kind       = MethodHandles::signature_polymorphic_intrinsic_ref_kind(special_dispatch);
+
+  if (ref_kind != 0) {
+    member_arg_pos = total_args_passed - 1;  // trailing MemberName argument
+    member_reg = Z_R9;                       // Known to be free at this point.
+    has_receiver = MethodHandles::ref_kind_has_receiver(ref_kind);
+  } else {
+    guarantee(special_dispatch == vmIntrinsics::_invokeBasic, "special_dispatch=%d", special_dispatch);
+    has_receiver = true;
+  }
+
+  if (member_reg != noreg) {
+    // Load the member_arg into register, if necessary.
+    assert(member_arg_pos >= 0 && member_arg_pos < total_args_passed, "oob");
+    assert(sig_bt[member_arg_pos] == T_OBJECT, "dispatch argument must be an object");
+
+    VMReg r = regs[member_arg_pos].first();
+    assert(r->is_valid(), "bad member arg");
+
+    if (r->is_stack()) {
+      __ z_lg(member_reg, Address(Z_SP, reg2offset(r)));
+    } else {
+      // No data motion is needed.
+      member_reg = r->as_Register();
+    }
+  }
+
+  if (has_receiver) {
+    // Make sure the receiver is loaded into a register.
+    assert(total_args_passed > 0, "oob");
+    assert(sig_bt[0] == T_OBJECT, "receiver argument must be an object");
+
+    VMReg r = regs[0].first();
+    assert(r->is_valid(), "bad receiver arg");
+
+    if (r->is_stack()) {
+      // Porting note: This assumes that compiled calling conventions always
+      // pass the receiver oop in a register. If this is not true on some
+      // platform, pick a temp and load the receiver from stack.
+      assert(false, "receiver always in a register");
+      receiver_reg = Z_R13;  // Known to be free at this point.
+      __ z_lg(receiver_reg, Address(Z_SP, reg2offset(r)));
+    } else {
+      // No data motion is needed.
+      receiver_reg = r->as_Register();
+    }
+  }
+
+  // Figure out which address we are really jumping to:
+  MethodHandles::generate_method_handle_dispatch(masm, special_dispatch,
+                                                 receiver_reg, member_reg,
+                                                 /*for_compiler_entry:*/ true);
+}
+
+////////////////////////////////////////////////////////////////////////
+//
+//  Argument shufflers
+//
+////////////////////////////////////////////////////////////////////////
+
+// Is the size of a vector size (in bytes) bigger than a size saved by default?
+// 8 bytes registers are saved by default on z/Architecture.
+bool SharedRuntime::is_wide_vector(int size) {
+  // Note, MaxVectorSize == 8 on this platform.
+  assert(size <= 8, "%d bytes vectors are not supported", size);
+  return size > 8;
+}
+
+//----------------------------------------------------------------------
+// An oop arg. Must pass a handle not the oop itself
+//----------------------------------------------------------------------
+static void object_move(MacroAssembler *masm,
+                        OopMap *map,
+                        int oop_handle_offset,
+                        int framesize_in_slots,
+                        VMRegPair src,
+                        VMRegPair dst,
+                        bool is_receiver,
+                        int *receiver_offset) {
+  int frame_offset = framesize_in_slots*VMRegImpl::stack_slot_size;
+
+  assert(!is_receiver || (is_receiver && (*receiver_offset == -1)), "only one receiving object per call, please.");
+
+  // Must pass a handle. First figure out the location we use as a handle.
+
+  if (src.first()->is_stack()) {
+    // Oop is already on the stack, put handle on stack or in register
+    // If handle will be on the stack, use temp reg to calculate it.
+    Register rHandle = dst.first()->is_stack() ? Z_R1 : dst.first()->as_Register();
+    Label    skip;
+    int      slot_in_older_frame = reg2slot(src.first());
+
+    guarantee(!is_receiver, "expecting receiver in register");
+    map->set_oop(VMRegImpl::stack2reg(slot_in_older_frame + framesize_in_slots));
+
+    __ add2reg(rHandle, reg2offset(src.first())+frame_offset, Z_SP);
+    __ load_and_test_long(Z_R0, Address(rHandle));
+    __ z_brne(skip);
+    // Use a NULL handle if oop is NULL.
+    __ clear_reg(rHandle, true, false);
+    __ bind(skip);
+
+    // Copy handle to the right place (register or stack).
+    if (dst.first()->is_stack()) {
+      __ z_stg(rHandle, reg2offset(dst.first()), Z_SP);
+    } // else
+      // nothing to do. rHandle uses the correct register
+  } else {
+    // Oop is passed in an input register. We must flush it to the stack.
+    const Register rOop = src.first()->as_Register();
+    const Register rHandle = dst.first()->is_stack() ? Z_R1 : dst.first()->as_Register();
+    int            oop_slot = (rOop->encoding()-Z_ARG1->encoding()) * VMRegImpl::slots_per_word + oop_handle_offset;
+    int            oop_slot_offset = oop_slot*VMRegImpl::stack_slot_size;
+    NearLabel skip;
+
+    if (is_receiver) {
+      *receiver_offset = oop_slot_offset;
+    }
+    map->set_oop(VMRegImpl::stack2reg(oop_slot));
+
+    // Flush Oop to stack, calculate handle.
+    __ z_stg(rOop, oop_slot_offset, Z_SP);
+    __ add2reg(rHandle, oop_slot_offset, Z_SP);
+
+    // If Oop == NULL, use a NULL handle.
+    __ compare64_and_branch(rOop, (RegisterOrConstant)0L, Assembler::bcondNotEqual, skip);
+    __ clear_reg(rHandle, true, false);
+    __ bind(skip);
+
+    // Copy handle to the right place (register or stack).
+    if (dst.first()->is_stack()) {
+      __ z_stg(rHandle, reg2offset(dst.first()), Z_SP);
+    } // else
+      // nothing to do here, since rHandle = dst.first()->as_Register in this case.
+  }
+}
+
+//----------------------------------------------------------------------
+// A float arg. May have to do float reg to int reg conversion
+//----------------------------------------------------------------------
+static void float_move(MacroAssembler *masm,
+                       VMRegPair src,
+                       VMRegPair dst,
+                       int framesize_in_slots,
+                       int workspace_slot_offset) {
+  int frame_offset = framesize_in_slots * VMRegImpl::stack_slot_size;
+  int workspace_offset = workspace_slot_offset * VMRegImpl::stack_slot_size;
+
+  // We do not accept an argument in a VMRegPair to be spread over two slots,
+  // no matter what physical location (reg or stack) the slots may have.
+  // We just check for the unaccepted slot to be invalid.
+  assert(!src.second()->is_valid(), "float in arg spread over two slots");
+  assert(!dst.second()->is_valid(), "float out arg spread over two slots");
+
+  if (src.first()->is_stack()) {
+    if (dst.first()->is_stack()) {
+      // stack -> stack. The easiest of the bunch.
+      __ z_mvc(Address(Z_SP, reg2offset(dst.first())),
+               Address(Z_SP, reg2offset(src.first()) + frame_offset), sizeof(float));
+    } else {
+      // stack to reg
+      Address memaddr(Z_SP, reg2offset(src.first()) + frame_offset);
+      if (dst.first()->is_Register()) {
+        __ mem2reg_opt(dst.first()->as_Register(), memaddr, false);
+      } else {
+        __ mem2freg_opt(dst.first()->as_FloatRegister(), memaddr, false);
+      }
+    }
+  } else if (src.first()->is_Register()) {
+    if (dst.first()->is_stack()) {
+      // gpr -> stack
+      __ reg2mem_opt(src.first()->as_Register(),
+                     Address(Z_SP, reg2offset(dst.first()), false ));
+    } else {
+      if (dst.first()->is_Register()) {
+        // gpr -> gpr
+        __ move_reg_if_needed(dst.first()->as_Register(), T_INT,
+                              src.first()->as_Register(), T_INT);
+      } else {
+        if (VM_Version::has_FPSupportEnhancements()) {
+          // gpr -> fpr. Exploit z10 capability of direct transfer.
+          __ z_ldgr(dst.first()->as_FloatRegister(), src.first()->as_Register());
+        } else {
+          // gpr -> fpr. Use work space on stack to transfer data.
+          Address   stackaddr(Z_SP, workspace_offset);
+
+          __ reg2mem_opt(src.first()->as_Register(), stackaddr, false);
+          __ mem2freg_opt(dst.first()->as_FloatRegister(), stackaddr, false);
+        }
+      }
+    }
+  } else {
+    if (dst.first()->is_stack()) {
+      // fpr -> stack
+      __ freg2mem_opt(src.first()->as_FloatRegister(),
+                      Address(Z_SP, reg2offset(dst.first())), false);
+    } else {
+      if (dst.first()->is_Register()) {
+        if (VM_Version::has_FPSupportEnhancements()) {
+          // fpr -> gpr.
+          __ z_lgdr(dst.first()->as_Register(), src.first()->as_FloatRegister());
+        } else {
+          // fpr -> gpr. Use work space on stack to transfer data.
+          Address   stackaddr(Z_SP, workspace_offset);
+
+          __ freg2mem_opt(src.first()->as_FloatRegister(), stackaddr, false);
+          __ mem2reg_opt(dst.first()->as_Register(), stackaddr, false);
+        }
+      } else {
+        // fpr -> fpr
+        __ move_freg_if_needed(dst.first()->as_FloatRegister(), T_FLOAT,
+                               src.first()->as_FloatRegister(), T_FLOAT);
+      }
+    }
+  }
+}
+
+//----------------------------------------------------------------------
+// A double arg. May have to do double reg to long reg conversion
+//----------------------------------------------------------------------
+static void double_move(MacroAssembler *masm,
+                        VMRegPair src,
+                        VMRegPair dst,
+                        int framesize_in_slots,
+                        int workspace_slot_offset) {
+  int frame_offset = framesize_in_slots*VMRegImpl::stack_slot_size;
+  int workspace_offset = workspace_slot_offset*VMRegImpl::stack_slot_size;
+
+  // Since src is always a java calling convention we know that the
+  // src pair is always either all registers or all stack (and aligned?)
+
+  if (src.first()->is_stack()) {
+    if (dst.first()->is_stack()) {
+      // stack -> stack. The easiest of the bunch.
+      __ z_mvc(Address(Z_SP, reg2offset(dst.first())),
+               Address(Z_SP, reg2offset(src.first()) + frame_offset), sizeof(double));
+    } else {
+      // stack to reg
+      Address stackaddr(Z_SP, reg2offset(src.first()) + frame_offset);
+
+      if (dst.first()->is_Register()) {
+        __ mem2reg_opt(dst.first()->as_Register(), stackaddr);
+      } else {
+        __ mem2freg_opt(dst.first()->as_FloatRegister(), stackaddr);
+      }
+    }
+  } else if (src.first()->is_Register()) {
+    if (dst.first()->is_stack()) {
+      // gpr -> stack
+      __ reg2mem_opt(src.first()->as_Register(),
+                     Address(Z_SP, reg2offset(dst.first())));
+    } else {
+      if (dst.first()->is_Register()) {
+        // gpr -> gpr
+        __ move_reg_if_needed(dst.first()->as_Register(), T_LONG,
+                              src.first()->as_Register(), T_LONG);
+      } else {
+        if (VM_Version::has_FPSupportEnhancements()) {
+          // gpr -> fpr. Exploit z10 capability of direct transfer.
+          __ z_ldgr(dst.first()->as_FloatRegister(), src.first()->as_Register());
+        } else {
+          // gpr -> fpr. Use work space on stack to transfer data.
+          Address stackaddr(Z_SP, workspace_offset);
+          __ reg2mem_opt(src.first()->as_Register(), stackaddr);
+          __ mem2freg_opt(dst.first()->as_FloatRegister(), stackaddr);
+        }
+      }
+    }
+  } else {
+    if (dst.first()->is_stack()) {
+      // fpr -> stack
+      __ freg2mem_opt(src.first()->as_FloatRegister(),
+                      Address(Z_SP, reg2offset(dst.first())));
+    } else {
+      if (dst.first()->is_Register()) {
+        if (VM_Version::has_FPSupportEnhancements()) {
+          // fpr -> gpr. Exploit z10 capability of direct transfer.
+          __ z_lgdr(dst.first()->as_Register(), src.first()->as_FloatRegister());
+        } else {
+          // fpr -> gpr. Use work space on stack to transfer data.
+          Address stackaddr(Z_SP, workspace_offset);
+
+          __ freg2mem_opt(src.first()->as_FloatRegister(), stackaddr);
+          __ mem2reg_opt(dst.first()->as_Register(), stackaddr);
+        }
+      } else {
+        // fpr -> fpr
+        // In theory these overlap but the ordering is such that this is likely a nop.
+        __ move_freg_if_needed(dst.first()->as_FloatRegister(), T_DOUBLE,
+                               src.first()->as_FloatRegister(), T_DOUBLE);
+      }
+    }
+  }
+}
+
+//----------------------------------------------------------------------
+// A long arg.
+//----------------------------------------------------------------------
+static void long_move(MacroAssembler *masm,
+                      VMRegPair src,
+                      VMRegPair dst,
+                      int framesize_in_slots) {
+  int frame_offset = framesize_in_slots*VMRegImpl::stack_slot_size;
+
+  if (src.first()->is_stack()) {
+    if (dst.first()->is_stack()) {
+      // stack -> stack. The easiest of the bunch.
+      __ z_mvc(Address(Z_SP, reg2offset(dst.first())),
+               Address(Z_SP, reg2offset(src.first()) + frame_offset), sizeof(long));
+    } else {
+      // stack to reg
+      assert(dst.first()->is_Register(), "long dst value must be in GPR");
+      __ mem2reg_opt(dst.first()->as_Register(),
+                      Address(Z_SP, reg2offset(src.first()) + frame_offset));
+    }
+  } else {
+    // reg to reg
+    assert(src.first()->is_Register(), "long src value must be in GPR");
+    if (dst.first()->is_stack()) {
+      // reg -> stack
+      __ reg2mem_opt(src.first()->as_Register(),
+                     Address(Z_SP, reg2offset(dst.first())));
+    } else {
+      // reg -> reg
+      assert(dst.first()->is_Register(), "long dst value must be in GPR");
+      __ move_reg_if_needed(dst.first()->as_Register(),
+                            T_LONG, src.first()->as_Register(), T_LONG);
+    }
+  }
+}
+
+
+//----------------------------------------------------------------------
+// A int-like arg.
+//----------------------------------------------------------------------
+// On z/Architecture we will store integer like items to the stack as 64 bit
+// items, according to the z/Architecture ABI, even though Java would only store
+// 32 bits for a parameter.
+// We do sign extension for all base types. That is ok since the only
+// unsigned base type is T_CHAR, and T_CHAR uses only 16 bits of an int.
+// Sign extension 32->64 bit will thus not affect the value.
+//----------------------------------------------------------------------
+static void move32_64(MacroAssembler *masm,
+                      VMRegPair src,
+                      VMRegPair dst,
+                      int framesize_in_slots) {
+  int frame_offset = framesize_in_slots * VMRegImpl::stack_slot_size;
+
+  if (src.first()->is_stack()) {
+    Address memaddr(Z_SP, reg2offset(src.first()) + frame_offset);
+    if (dst.first()->is_stack()) {
+      // stack -> stack. MVC not posible due to sign extension.
+      Address firstaddr(Z_SP, reg2offset(dst.first()));
+      __ mem2reg_signed_opt(Z_R0_scratch, memaddr);
+      __ reg2mem_opt(Z_R0_scratch, firstaddr);
+    } else {
+      // stack -> reg, sign extended
+      __ mem2reg_signed_opt(dst.first()->as_Register(), memaddr);
+    }
+  } else {
+    if (dst.first()->is_stack()) {
+      // reg -> stack, sign extended
+      Address firstaddr(Z_SP, reg2offset(dst.first()));
+      __ z_lgfr(src.first()->as_Register(), src.first()->as_Register());
+      __ reg2mem_opt(src.first()->as_Register(), firstaddr);
+    } else {
+      // reg -> reg, sign extended
+      __ z_lgfr(dst.first()->as_Register(), src.first()->as_Register());
+    }
+  }
+}
+
+static void save_or_restore_arguments(MacroAssembler *masm,
+                                      const int stack_slots,
+                                      const int total_in_args,
+                                      const int arg_save_area,
+                                      OopMap *map,
+                                      VMRegPair *in_regs,
+                                      BasicType *in_sig_bt) {
+
+  // If map is non-NULL then the code should store the values,
+  // otherwise it should load them.
+  int slot = arg_save_area;
+  // Handle double words first.
+  for (int i = 0; i < total_in_args; i++) {
+    if (in_regs[i].first()->is_FloatRegister() && in_sig_bt[i] == T_DOUBLE) {
+      int offset = slot * VMRegImpl::stack_slot_size;
+      slot += VMRegImpl::slots_per_word;
+      assert(slot <= stack_slots, "overflow (after DOUBLE stack slot)");
+      const FloatRegister   freg = in_regs[i].first()->as_FloatRegister();
+      Address   stackaddr(Z_SP, offset);
+      if (map != NULL) {
+        __ freg2mem_opt(freg, stackaddr);
+      } else {
+        __ mem2freg_opt(freg, stackaddr);
+      }
+    } else if (in_regs[i].first()->is_Register() &&
+               (in_sig_bt[i] == T_LONG || in_sig_bt[i] == T_ARRAY)) {
+      int offset = slot * VMRegImpl::stack_slot_size;
+      const Register   reg = in_regs[i].first()->as_Register();
+      if (map != NULL) {
+        __ z_stg(reg, offset, Z_SP);
+        if (in_sig_bt[i] == T_ARRAY) {
+          map->set_oop(VMRegImpl::stack2reg(slot));
+        }
+      } else {
+        __ z_lg(reg, offset, Z_SP);
+        slot += VMRegImpl::slots_per_word;
+        assert(slot <= stack_slots, "overflow (after LONG/ARRAY stack slot)");
+      }
+    }
+  }
+
+  // Save or restore single word registers.
+  for (int i = 0; i < total_in_args; i++) {
+    if (in_regs[i].first()->is_FloatRegister()) {
+      if (in_sig_bt[i] == T_FLOAT) {
+        int offset = slot * VMRegImpl::stack_slot_size;
+        slot++;
+        assert(slot <= stack_slots, "overflow (after FLOAT stack slot)");
+        const FloatRegister   freg = in_regs[i].first()->as_FloatRegister();
+        Address   stackaddr(Z_SP, offset);
+        if (map != NULL) {
+          __ freg2mem_opt(freg, stackaddr, false);
+        } else {
+          __ mem2freg_opt(freg, stackaddr, false);
+        }
+      }
+    } else if (in_regs[i].first()->is_stack() &&
+               in_sig_bt[i] == T_ARRAY && map != NULL) {
+      int offset_in_older_frame = in_regs[i].first()->reg2stack() + SharedRuntime::out_preserve_stack_slots();
+      map->set_oop(VMRegImpl::stack2reg(offset_in_older_frame + stack_slots));
+    }
+  }
+}
+
+// Check GCLocker::needs_gc and enter the runtime if it's true. This
+// keeps a new JNI critical region from starting until a GC has been
+// forced. Save down any oops in registers and describe them in an OopMap.
+static void check_needs_gc_for_critical_native(MacroAssembler   *masm,
+                                                const int stack_slots,
+                                                const int total_in_args,
+                                                const int arg_save_area,
+                                                OopMapSet *oop_maps,
+                                                VMRegPair *in_regs,
+                                                BasicType *in_sig_bt) {
+  __ block_comment("check GCLocker::needs_gc");
+  Label cont;
+
+  // Check GCLocker::_needs_gc flag.
+  __ load_const_optimized(Z_R1_scratch, (long) GCLocker::needs_gc_address());
+  __ z_cli(0, Z_R1_scratch, 0);
+  __ z_bre(cont);
+
+  // Save down any values that are live in registers and call into the
+  // runtime to halt for a GC.
+  OopMap *map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
+
+  save_or_restore_arguments(masm, stack_slots, total_in_args,
+                            arg_save_area, map, in_regs, in_sig_bt);
+  address the_pc = __ pc();
+  __ set_last_Java_frame(Z_SP, noreg);
+
+  __ block_comment("block_for_jni_critical");
+  __ z_lgr(Z_ARG1, Z_thread);
+
+  address entry_point = CAST_FROM_FN_PTR(address, SharedRuntime::block_for_jni_critical);
+  __ call_c(entry_point);
+  oop_maps->add_gc_map(__ offset(), map);
+
+  __ reset_last_Java_frame();
+
+  // Reload all the register arguments.
+  save_or_restore_arguments(masm, stack_slots, total_in_args,
+                            arg_save_area, NULL, in_regs, in_sig_bt);
+
+  __ bind(cont);
+
+  if (StressCriticalJNINatives) {
+    // Stress register saving
+    OopMap *map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
+    save_or_restore_arguments(masm, stack_slots, total_in_args,
+                              arg_save_area, map, in_regs, in_sig_bt);
+
+    // Destroy argument registers.
+    for (int i = 0; i < total_in_args; i++) {
+      if (in_regs[i].first()->is_Register()) {
+        // Don't set CC.
+        __ clear_reg(in_regs[i].first()->as_Register(), true, false);
+      } else {
+        if (in_regs[i].first()->is_FloatRegister()) {
+          FloatRegister fr = in_regs[i].first()->as_FloatRegister();
+          __ z_lcdbr(fr, fr);
+        }
+      }
+    }
+
+    save_or_restore_arguments(masm, stack_slots, total_in_args,
+                              arg_save_area, NULL, in_regs, in_sig_bt);
+  }
+}
+
+static void move_ptr(MacroAssembler *masm,
+                     VMRegPair src,
+                     VMRegPair dst,
+                     int framesize_in_slots) {
+  int frame_offset = framesize_in_slots * VMRegImpl::stack_slot_size;
+
+  if (src.first()->is_stack()) {
+    if (dst.first()->is_stack()) {
+      // stack to stack
+      __ mem2reg_opt(Z_R0_scratch, Address(Z_SP, reg2offset(src.first()) + frame_offset));
+      __ reg2mem_opt(Z_R0_scratch, Address(Z_SP, reg2offset(dst.first())));
+    } else {
+      // stack to reg
+      __ mem2reg_opt(dst.first()->as_Register(),
+                     Address(Z_SP, reg2offset(src.first()) + frame_offset));
+    }
+  } else {
+    if (dst.first()->is_stack()) {
+      // reg to stack
+    __ reg2mem_opt(src.first()->as_Register(), Address(Z_SP, reg2offset(dst.first())));
+    } else {
+    __ lgr_if_needed(dst.first()->as_Register(), src.first()->as_Register());
+    }
+  }
+}
+
+// Unpack an array argument into a pointer to the body and the length
+// if the array is non-null, otherwise pass 0 for both.
+static void unpack_array_argument(MacroAssembler *masm,
+                                   VMRegPair reg,
+                                   BasicType in_elem_type,
+                                   VMRegPair body_arg,
+                                   VMRegPair length_arg,
+                                   int framesize_in_slots) {
+  Register tmp_reg = Z_tmp_2;
+  Register tmp2_reg = Z_tmp_1;
+
+  assert(!body_arg.first()->is_Register() || body_arg.first()->as_Register() != tmp_reg,
+         "possible collision");
+  assert(!length_arg.first()->is_Register() || length_arg.first()->as_Register() != tmp_reg,
+         "possible collision");
+
+  // Pass the length, ptr pair.
+  NearLabel set_out_args;
+  VMRegPair tmp, tmp2;
+
+  tmp.set_ptr(tmp_reg->as_VMReg());
+  tmp2.set_ptr(tmp2_reg->as_VMReg());
+  if (reg.first()->is_stack()) {
+    // Load the arg up from the stack.
+    move_ptr(masm, reg, tmp, framesize_in_slots);
+    reg = tmp;
+  }
+
+  const Register first = reg.first()->as_Register();
+
+  // Don't set CC, indicate unused result.
+  (void) __ clear_reg(tmp2_reg, true, false);
+  if (tmp_reg != first) {
+    __ clear_reg(tmp_reg, true, false);  // Don't set CC.
+  }
+  __ compare64_and_branch(first, (RegisterOrConstant)0L, Assembler::bcondEqual, set_out_args);
+  __ z_lgf(tmp2_reg, Address(first, arrayOopDesc::length_offset_in_bytes()));
+  __ add2reg(tmp_reg, arrayOopDesc::base_offset_in_bytes(in_elem_type), first);
+
+  __ bind(set_out_args);
+  move_ptr(masm, tmp, body_arg, framesize_in_slots);
+  move32_64(masm, tmp2, length_arg, framesize_in_slots);
+}
+
+//----------------------------------------------------------------------
+// Wrap a JNI call.
+//----------------------------------------------------------------------
+#undef USE_RESIZE_FRAME
+nmethod *SharedRuntime::generate_native_wrapper(MacroAssembler *masm,
+                                                const methodHandle& method,
+                                                int compile_id,
+                                                BasicType *in_sig_bt,
+                                                VMRegPair *in_regs,
+                                                BasicType ret_type) {
+#ifdef COMPILER2
+  int total_in_args = method->size_of_parameters();
+  if (method->is_method_handle_intrinsic()) {
+    vmIntrinsics::ID iid = method->intrinsic_id();
+    intptr_t start = (intptr_t) __ pc();
+    int vep_offset = ((intptr_t) __ pc()) - start;
+
+    gen_special_dispatch(masm, total_in_args,
+                         method->intrinsic_id(), in_sig_bt, in_regs);
+
+    int frame_complete = ((intptr_t)__ pc()) - start; // Not complete, period.
+
+    __ flush();
+
+    int stack_slots = SharedRuntime::out_preserve_stack_slots();  // No out slots at all, actually.
+
+    return nmethod::new_native_nmethod(method,
+                                       compile_id,
+                                       masm->code(),
+                                       vep_offset,
+                                       frame_complete,
+                                       stack_slots / VMRegImpl::slots_per_word,
+                                       in_ByteSize(-1),
+                                       in_ByteSize(-1),
+                                       (OopMapSet *) NULL);
+  }
+
+
+  ///////////////////////////////////////////////////////////////////////
+  //
+  //  Precalculations before generating any code
+  //
+  ///////////////////////////////////////////////////////////////////////
+
+  bool is_critical_native = true;
+  address native_func = method->critical_native_function();
+  if (native_func == NULL) {
+    native_func = method->native_function();
+    is_critical_native = false;
+  }
+  assert(native_func != NULL, "must have function");
+
+  //---------------------------------------------------------------------
+  // We have received a description of where all the java args are located
+  // on entry to the wrapper. We need to convert these args to where
+  // the jni function will expect them. To figure out where they go
+  // we convert the java signature to a C signature by inserting
+  // the hidden arguments as arg[0] and possibly arg[1] (static method).
+  //
+  // The first hidden argument arg[0] is a pointer to the JNI environment.
+  // It is generated for every call.
+  // The second argument arg[1] to the JNI call, which is hidden for static
+  // methods, is the boxed lock object. For static calls, the lock object
+  // is the static method itself. The oop is constructed here. for instance
+  // calls, the lock is performed on the object itself, the pointer of
+  // which is passed as the first visible argument.
+  //---------------------------------------------------------------------
+
+  // Additionally, on z/Architecture we must convert integers
+  // to longs in the C signature. We do this in advance in order to have
+  // no trouble with indexes into the bt-arrays.
+  // So convert the signature and registers now, and adjust the total number
+  // of in-arguments accordingly.
+  bool method_is_static = method->is_static();
+  int  total_c_args     = total_in_args;
+
+  if (!is_critical_native) {
+    int n_hidden_args = method_is_static ? 2 : 1;
+    total_c_args += n_hidden_args;
+  } else {
+    // No JNIEnv*, no this*, but unpacked arrays (base+length).
+    for (int i = 0; i < total_in_args; i++) {
+      if (in_sig_bt[i] == T_ARRAY) {
+        total_c_args ++;
+      }
+    }
+  }
+
+  BasicType *out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_c_args);
+  VMRegPair *out_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_c_args);
+  BasicType* in_elem_bt = NULL;
+
+  // Create the signature for the C call:
+  //   1) add the JNIEnv*
+  //   2) add the class if the method is static
+  //   3) copy the rest of the incoming signature (shifted by the number of
+  //      hidden arguments)
+
+  int argc = 0;
+  if (!is_critical_native) {
+    out_sig_bt[argc++] = T_ADDRESS;
+    if (method->is_static()) {
+      out_sig_bt[argc++] = T_OBJECT;
+    }
+
+    for (int i = 0; i < total_in_args; i++) {
+      out_sig_bt[argc++] = in_sig_bt[i];
+    }
+  } else {
+    Thread* THREAD = Thread::current();
+    in_elem_bt = NEW_RESOURCE_ARRAY(BasicType, total_in_args);
+    SignatureStream ss(method->signature());
+    int o = 0;
+    for (int i = 0; i < total_in_args; i++, o++) {
+      if (in_sig_bt[i] == T_ARRAY) {
+        // Arrays are passed as tuples (int, elem*).
+        Symbol* atype = ss.as_symbol(CHECK_NULL);
+        const char* at = atype->as_C_string();
+        if (strlen(at) == 2) {
+          assert(at[0] == '[', "must be");
+          switch (at[1]) {
+            case 'B': in_elem_bt[o]  = T_BYTE; break;
+            case 'C': in_elem_bt[o]  = T_CHAR; break;
+            case 'D': in_elem_bt[o]  = T_DOUBLE; break;
+            case 'F': in_elem_bt[o]  = T_FLOAT; break;
+            case 'I': in_elem_bt[o]  = T_INT; break;
+            case 'J': in_elem_bt[o]  = T_LONG; break;
+            case 'S': in_elem_bt[o]  = T_SHORT; break;
+            case 'Z': in_elem_bt[o]  = T_BOOLEAN; break;
+            default: ShouldNotReachHere();
+          }
+        }
+      } else {
+        in_elem_bt[o] = T_VOID;
+      }
+      if (in_sig_bt[i] != T_VOID) {
+        assert(in_sig_bt[i] == ss.type(), "must match");
+        ss.next();
+      }
+    }
+    assert(total_in_args == o, "must match");
+
+    for (int i = 0; i < total_in_args; i++) {
+      if (in_sig_bt[i] == T_ARRAY) {
+        // Arrays are passed as tuples (int, elem*).
+        out_sig_bt[argc++] = T_INT;
+        out_sig_bt[argc++] = T_ADDRESS;
+      } else {
+        out_sig_bt[argc++] = in_sig_bt[i];
+      }
+    }
+  }
+
+  ///////////////////////////////////////////////////////////////////////
+  // Now figure out where the args must be stored and how much stack space
+  // they require (neglecting out_preserve_stack_slots but providing space
+  // for storing the first five register arguments).
+  // It's weird, see int_stk_helper.
+  ///////////////////////////////////////////////////////////////////////
+
+  //---------------------------------------------------------------------
+  // Compute framesize for the wrapper.
+  //
+  // - We need to handlize all oops passed in registers.
+  // - We must create space for them here that is disjoint from the save area.
+  // - We always just allocate 5 words for storing down these object.
+  //   This allows us to simply record the base and use the Ireg number to
+  //   decide which slot to use.
+  // - Note that the reg number used to index the stack slot is the inbound
+  //   number, not the outbound number.
+  // - We must shuffle args to match the native convention,
+  //   and to include var-args space.
+  //---------------------------------------------------------------------
+
+  //---------------------------------------------------------------------
+  // Calculate the total number of stack slots we will need:
+  // - 1) abi requirements
+  // - 2) outgoing args
+  // - 3) space for inbound oop handle area
+  // - 4) space for handlizing a klass if static method
+  // - 5) space for a lock if synchronized method
+  // - 6) workspace (save rtn value, int<->float reg moves, ...)
+  // - 7) filler slots for alignment
+  //---------------------------------------------------------------------
+  // Here is how the space we have allocated will look like.
+  // Since we use resize_frame, we do not create a new stack frame,
+  // but just extend the one we got with our own data area.
+  //
+  // If an offset or pointer name points to a separator line, it is
+  // assumed that addressing with offset 0 selects storage starting
+  // at the first byte above the separator line.
+  //
+  //
+  //     ...                   ...
+  //      | caller's frame      |
+  // FP-> |---------------------|
+  //      | filler slots, if any|
+  //     7| #slots == mult of 2 |
+  //      |---------------------|
+  //      | work space          |
+  //     6| 2 slots = 8 bytes   |
+  //      |---------------------|
+  //     5| lock box (if sync)  |
+  //      |---------------------| <- lock_slot_offset
+  //     4| klass (if static)   |
+  //      |---------------------| <- klass_slot_offset
+  //     3| oopHandle area      |
+  //      | (save area for      |
+  //      |  critical natives)  |
+  //      |                     |
+  //      |                     |
+  //      |---------------------| <- oop_handle_offset
+  //     2| outbound memory     |
+  //     ...                   ...
+  //      | based arguments     |
+  //      |---------------------|
+  //      | vararg              |
+  //     ...                   ...
+  //      | area                |
+  //      |---------------------| <- out_arg_slot_offset
+  //     1| out_preserved_slots |
+  //     ...                   ...
+  //      | (z_abi spec)        |
+  // SP-> |---------------------| <- FP_slot_offset (back chain)
+  //     ...                   ...
+  //
+  //---------------------------------------------------------------------
+
+  // *_slot_offset indicates offset from SP in #stack slots
+  // *_offset      indicates offset from SP in #bytes
+
+  int stack_slots = c_calling_convention(out_sig_bt, out_regs, /*regs2=*/NULL, total_c_args) + // 1+2
+                    SharedRuntime::out_preserve_stack_slots(); // see c_calling_convention
+
+  // Now the space for the inbound oop handle area.
+  int total_save_slots = RegisterImpl::number_of_arg_registers * VMRegImpl::slots_per_word;
+  if (is_critical_native) {
+    // Critical natives may have to call out so they need a save area
+    // for register arguments.
+    int double_slots = 0;
+    int single_slots = 0;
+    for (int i = 0; i < total_in_args; i++) {
+      if (in_regs[i].first()->is_Register()) {
+        const Register reg = in_regs[i].first()->as_Register();
+        switch (in_sig_bt[i]) {
+          case T_BOOLEAN:
+          case T_BYTE:
+          case T_SHORT:
+          case T_CHAR:
+          case T_INT:
+          // Fall through.
+          case T_ARRAY:
+          case T_LONG: double_slots++; break;
+          default:  ShouldNotReachHere();
+        }
+      } else {
+        if (in_regs[i].first()->is_FloatRegister()) {
+          switch (in_sig_bt[i]) {
+            case T_FLOAT:  single_slots++; break;
+            case T_DOUBLE: double_slots++; break;
+            default:  ShouldNotReachHere();
+          }
+        }
+      }
+    }  // for
+    total_save_slots = double_slots * 2 + align_up(single_slots, 2); // Round to even.
+  }
+
+  int oop_handle_slot_offset = stack_slots;
+  stack_slots += total_save_slots;                                        // 3)
+
+  int klass_slot_offset = 0;
+  int klass_offset      = -1;
+  if (method_is_static && !is_critical_native) {                          // 4)
+    klass_slot_offset  = stack_slots;
+    klass_offset       = klass_slot_offset * VMRegImpl::stack_slot_size;
+    stack_slots       += VMRegImpl::slots_per_word;
+  }
+
+  int lock_slot_offset = 0;
+  int lock_offset      = -1;
+  if (method->is_synchronized()) {                                        // 5)
+    lock_slot_offset   = stack_slots;
+    lock_offset        = lock_slot_offset * VMRegImpl::stack_slot_size;
+    stack_slots       += VMRegImpl::slots_per_word;
+  }
+
+  int workspace_slot_offset= stack_slots;                                 // 6)
+  stack_slots         += 2;
+
+  // Now compute actual number of stack words we need.
+  // Round to align stack properly.
+  stack_slots = align_up(stack_slots,                                     // 7)
+                         frame::alignment_in_bytes / VMRegImpl::stack_slot_size);
+  int frame_size_in_bytes = stack_slots * VMRegImpl::stack_slot_size;
+
+
+  ///////////////////////////////////////////////////////////////////////
+  // Now we can start generating code
+  ///////////////////////////////////////////////////////////////////////
+
+  unsigned int wrapper_CodeStart  = __ offset();
+  unsigned int wrapper_UEPStart;
+  unsigned int wrapper_VEPStart;
+  unsigned int wrapper_FrameDone;
+  unsigned int wrapper_CRegsSet;
+  Label     handle_pending_exception;
+  Label     ic_miss;
+
+  //---------------------------------------------------------------------
+  // Unverified entry point (UEP)
+  //---------------------------------------------------------------------
+  wrapper_UEPStart = __ offset();
+
+  // check ic: object class <-> cached class
+  if (!method_is_static) __ nmethod_UEP(ic_miss);
+  // Fill with nops (alignment of verified entry point).
+  __ align(CodeEntryAlignment);
+
+  //---------------------------------------------------------------------
+  // Verified entry point (VEP)
+  //---------------------------------------------------------------------
+  wrapper_VEPStart = __ offset();
+
+  __ save_return_pc();
+  __ generate_stack_overflow_check(frame_size_in_bytes);  // Check before creating frame.
+#ifndef USE_RESIZE_FRAME
+  __ push_frame(frame_size_in_bytes);                     // Create a new frame for the wrapper.
+#else
+  __ resize_frame(-frame_size_in_bytes, Z_R0_scratch);    // No new frame for the wrapper.
+                                                          // Just resize the existing one.
+#endif
+
+  wrapper_FrameDone = __ offset();
+
+  __ verify_thread();
+
+  // Native nmethod wrappers never take possession of the oop arguments.
+  // So the caller will gc the arguments.
+  // The only thing we need an oopMap for is if the call is static.
+  //
+  // An OopMap for lock (and class if static), and one for the VM call itself
+  OopMapSet  *oop_maps        = new OopMapSet();
+  OopMap     *map             = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
+
+  if (is_critical_native) {
+    check_needs_gc_for_critical_native(masm, stack_slots, total_in_args,
+                                       oop_handle_slot_offset, oop_maps, in_regs, in_sig_bt);
+  }
+
+
+  //////////////////////////////////////////////////////////////////////
+  //
+  // The Grand Shuffle
+  //
+  //////////////////////////////////////////////////////////////////////
+  //
+  // We immediately shuffle the arguments so that for any vm call we have
+  // to make from here on out (sync slow path, jvmti, etc.) we will have
+  // captured the oops from our caller and have a valid oopMap for them.
+  //
+  //--------------------------------------------------------------------
+  // Natives require 1 or 2 extra arguments over the normal ones: the JNIEnv*
+  // (derived from JavaThread* which is in Z_thread) and, if static,
+  // the class mirror instead of a receiver. This pretty much guarantees that
+  // register layout will not match. We ignore these extra arguments during
+  // the shuffle. The shuffle is described by the two calling convention
+  // vectors we have in our possession. We simply walk the java vector to
+  // get the source locations and the c vector to get the destinations.
+  //
+  // This is a trick. We double the stack slots so we can claim
+  // the oops in the caller's frame. Since we are sure to have
+  // more args than the caller doubling is enough to make
+  // sure we can capture all the incoming oop args from the caller.
+  //--------------------------------------------------------------------
+
+  // Record sp-based slot for receiver on stack for non-static methods.
+  int receiver_offset = -1;
+
+  //--------------------------------------------------------------------
+  // We move the arguments backwards because the floating point registers
+  // destination will always be to a register with a greater or equal
+  // register number or the stack.
+  //   jix is the index of the incoming Java arguments.
+  //   cix is the index of the outgoing C arguments.
+  //--------------------------------------------------------------------
+
+#ifdef ASSERT
+  bool reg_destroyed[RegisterImpl::number_of_registers];
+  bool freg_destroyed[FloatRegisterImpl::number_of_registers];
+  for (int r = 0; r < RegisterImpl::number_of_registers; r++) {
+    reg_destroyed[r] = false;
+  }
+  for (int f = 0; f < FloatRegisterImpl::number_of_registers; f++) {
+    freg_destroyed[f] = false;
+  }
+#endif // ASSERT
+
+  for (int jix = total_in_args - 1, cix = total_c_args - 1; jix >= 0; jix--, cix--) {
+#ifdef ASSERT
+    if (in_regs[jix].first()->is_Register()) {
+      assert(!reg_destroyed[in_regs[jix].first()->as_Register()->encoding()], "ack!");
+    } else {
+      if (in_regs[jix].first()->is_FloatRegister()) {
+        assert(!freg_destroyed[in_regs[jix].first()->as_FloatRegister()->encoding()], "ack!");
+      }
+    }
+    if (out_regs[cix].first()->is_Register()) {
+      reg_destroyed[out_regs[cix].first()->as_Register()->encoding()] = true;
+    } else {
+      if (out_regs[cix].first()->is_FloatRegister()) {
+        freg_destroyed[out_regs[cix].first()->as_FloatRegister()->encoding()] = true;
+      }
+    }
+#endif // ASSERT
+
+    switch (in_sig_bt[jix]) {
+      // Due to casting, small integers should only occur in pairs with type T_LONG.
+      case T_BOOLEAN:
+      case T_CHAR:
+      case T_BYTE:
+      case T_SHORT:
+      case T_INT:
+        // Move int and do sign extension.
+        move32_64(masm, in_regs[jix], out_regs[cix], stack_slots);
+        break;
+
+      case T_LONG :
+        long_move(masm, in_regs[jix], out_regs[cix], stack_slots);
+        break;
+
+      case T_ARRAY:
+        if (is_critical_native) {
+          int body_arg = cix;
+          cix -= 2; // Point to length arg.
+          unpack_array_argument(masm, in_regs[jix], in_elem_bt[jix], out_regs[body_arg], out_regs[cix], stack_slots);
+          break;
+        }
+        // else fallthrough
+      case T_OBJECT:
+        assert(!is_critical_native, "no oop arguments");
+        object_move(masm, map, oop_handle_slot_offset, stack_slots, in_regs[jix], out_regs[cix],
+                    ((jix == 0) && (!method_is_static)),
+                    &receiver_offset);
+        break;
+      case T_VOID:
+        break;
+
+      case T_FLOAT:
+        float_move(masm, in_regs[jix], out_regs[cix], stack_slots, workspace_slot_offset);
+        break;
+
+      case T_DOUBLE:
+        assert(jix+1 <  total_in_args && in_sig_bt[jix+1]  == T_VOID && out_sig_bt[cix+1] == T_VOID, "bad arg list");
+        double_move(masm, in_regs[jix], out_regs[cix], stack_slots, workspace_slot_offset);
+        break;
+
+      case T_ADDRESS:
+        assert(false, "found T_ADDRESS in java args");
+        break;
+
+      default:
+        ShouldNotReachHere();
+    }
+  }
+
+  //--------------------------------------------------------------------
+  // Pre-load a static method's oop into ARG2.
+  // Used both by locking code and the normal JNI call code.
+  //--------------------------------------------------------------------
+  if (method_is_static && !is_critical_native) {
+    __ set_oop_constant(JNIHandles::make_local(method->method_holder()->java_mirror()), Z_ARG2);
+
+    // Now handlize the static class mirror in ARG2. It's known not-null.
+    __ z_stg(Z_ARG2, klass_offset, Z_SP);
+    map->set_oop(VMRegImpl::stack2reg(klass_slot_offset));
+    __ add2reg(Z_ARG2, klass_offset, Z_SP);
+  }
+
+  // Get JNIEnv* which is first argument to native.
+  if (!is_critical_native) {
+    __ add2reg(Z_ARG1, in_bytes(JavaThread::jni_environment_offset()), Z_thread);
+  }
+
+  //////////////////////////////////////////////////////////////////////
+  // We have all of the arguments setup at this point.
+  // We MUST NOT touch any outgoing regs from this point on.
+  // So if we must call out we must push a new frame.
+  //////////////////////////////////////////////////////////////////////
+
+
+  // Calc the current pc into Z_R10 and into wrapper_CRegsSet.
+  // Both values represent the same position.
+  __ get_PC(Z_R10);                // PC into register
+  wrapper_CRegsSet = __ offset();  // and into into variable.
+
+  // Z_R10 now has the pc loaded that we will use when we finally call to native.
+
+  // We use the same pc/oopMap repeatedly when we call out.
+  oop_maps->add_gc_map((int)(wrapper_CRegsSet-wrapper_CodeStart), map);
+
+  // Lock a synchronized method.
+
+  if (method->is_synchronized()) {
+    assert(!is_critical_native, "unhandled");
+
+    // ATTENTION: args and Z_R10 must be preserved.
+    Register r_oop  = Z_R11;
+    Register r_box  = Z_R12;
+    Register r_tmp1 = Z_R13;
+    Register r_tmp2 = Z_R7;
+    Label done;
+
+    // Load the oop for the object or class. R_carg2_classorobject contains
+    // either the handlized oop from the incoming arguments or the handlized
+    // class mirror (if the method is static).
+    __ z_lg(r_oop, 0, Z_ARG2);
+
+    lock_offset = (lock_slot_offset * VMRegImpl::stack_slot_size);
+    // Get the lock box slot's address.
+    __ add2reg(r_box, lock_offset, Z_SP);
+
+#ifdef ASSERT
+    if (UseBiasedLocking)
+      // Making the box point to itself will make it clear it went unused
+      // but also be obviously invalid.
+      __ z_stg(r_box, 0, r_box);
+#endif // ASSERT
+
+    // Try fastpath for locking.
+    // Fast_lock kills r_temp_1, r_temp_2. (Don't use R1 as temp, won't work!)
+    __ compiler_fast_lock_object(r_oop, r_box, r_tmp1, r_tmp2);
+    __ z_bre(done);
+
+    //-------------------------------------------------------------------------
+    // None of the above fast optimizations worked so we have to get into the
+    // slow case of monitor enter. Inline a special case of call_VM that
+    // disallows any pending_exception.
+    //-------------------------------------------------------------------------
+
+    Register oldSP = Z_R11;
+
+    __ z_lgr(oldSP, Z_SP);
+
+    RegisterSaver::save_live_registers(masm, RegisterSaver::arg_registers);
+
+    // Prepare arguments for call.
+    __ z_lg(Z_ARG1, 0, Z_ARG2); // Ynboxed class mirror or unboxed object.
+    __ add2reg(Z_ARG2, lock_offset, oldSP);
+    __ z_lgr(Z_ARG3, Z_thread);
+
+    __ set_last_Java_frame(oldSP, Z_R10 /* gc map pc */);
+
+    // Do the call.
+    __ load_const_optimized(Z_R1_scratch, CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_locking_C));
+    __ call(Z_R1_scratch);
+
+    __ reset_last_Java_frame();
+
+    RegisterSaver::restore_live_registers(masm, RegisterSaver::arg_registers);
+#ifdef ASSERT
+    { Label L;
+      __ load_and_test_long(Z_R0, Address(Z_thread, Thread::pending_exception_offset()));
+      __ z_bre(L);
+      __ stop("no pending exception allowed on exit from IR::monitorenter");
+      __ bind(L);
+    }
+#endif
+    __ bind(done);
+  } // lock for synchronized methods
+
+
+  //////////////////////////////////////////////////////////////////////
+  // Finally just about ready to make the JNI call.
+  //////////////////////////////////////////////////////////////////////
+
+  // Use that pc we placed in Z_R10 a while back as the current frame anchor.
+  __ set_last_Java_frame(Z_SP, Z_R10);
+
+  // Transition from _thread_in_Java to _thread_in_native.
+  __ set_thread_state(_thread_in_native);
+
+
+  //////////////////////////////////////////////////////////////////////
+  // This is the JNI call.
+  //////////////////////////////////////////////////////////////////////
+
+  __ call_c(native_func);
+
+
+  //////////////////////////////////////////////////////////////////////
+  // We have survived the call once we reach here.
+  //////////////////////////////////////////////////////////////////////
+
+
+  //--------------------------------------------------------------------
+  // Unpack native results.
+  //--------------------------------------------------------------------
+  // For int-types, we do any needed sign-extension required.
+  // Care must be taken that the return value (in Z_ARG1 = Z_RET = Z_R2
+  // or in Z_FARG0 = Z_FRET = Z_F0) will survive any VM calls for
+  // blocking or unlocking.
+  // An OOP result (handle) is done specially in the slow-path code.
+  //--------------------------------------------------------------------
+  switch (ret_type) {  //GLGLGL
+    case T_VOID:    break;         // Nothing to do!
+    case T_FLOAT:   break;         // Got it where we want it (unless slow-path)
+    case T_DOUBLE:  break;         // Got it where we want it (unless slow-path)
+    case T_LONG:    break;         // Got it where we want it (unless slow-path)
+    case T_OBJECT:  break;         // Really a handle.
+                                   // Cannot de-handlize until after reclaiming jvm_lock.
+    case T_ARRAY:   break;
+
+    case T_BOOLEAN:                // 0 -> false(0); !0 -> true(1)
+      __ z_lngfr(Z_RET, Z_RET);    // Force sign bit on except for zero.
+      __ z_srlg(Z_RET, Z_RET, 63); // Shift sign bit into least significant pos.
+      break;
+    case T_BYTE:    __ z_lgbr(Z_RET, Z_RET);  break; // sign extension
+    case T_CHAR:    __ z_llghr(Z_RET, Z_RET); break; // unsigned result
+    case T_SHORT:   __ z_lghr(Z_RET, Z_RET);  break; // sign extension
+    case T_INT:     __ z_lgfr(Z_RET, Z_RET);  break; // sign-extend for beauty.
+
+    default:
+      ShouldNotReachHere();
+      break;
+  }
+
+
+  // Switch thread to "native transition" state before reading the synchronization state.
+  // This additional state is necessary because reading and testing the synchronization
+  // state is not atomic w.r.t. GC, as this scenario demonstrates:
+  //   - Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.
+  //   - VM thread changes sync state to synchronizing and suspends threads for GC.
+  //   - Thread A is resumed to finish this native method, but doesn't block here since it
+  //     didn't see any synchronization in progress, and escapes.
+
+  // Transition from _thread_in_native to _thread_in_native_trans.
+  __ set_thread_state(_thread_in_native_trans);
+
+  // Safepoint synchronization
+  //--------------------------------------------------------------------
+  // Must we block?
+  //--------------------------------------------------------------------
+  // Block, if necessary, before resuming in _thread_in_Java state.
+  // In order for GC to work, don't clear the last_Java_sp until after blocking.
+  //--------------------------------------------------------------------
+  Label after_transition;
+  {
+    Label no_block, sync;
+
+    save_native_result(masm, ret_type, workspace_slot_offset); // Make Z_R2 available as work reg.
+
+    if (os::is_MP()) {
+      if (UseMembar) {
+        // Force this write out before the read below.
+        __ z_fence();
+      } else {
+        // Write serialization page so VM thread can do a pseudo remote membar.
+        // We use the current thread pointer to calculate a thread specific
+        // offset to write to within the page. This minimizes bus traffic
+        // due to cache line collision.
+        __ serialize_memory(Z_thread, Z_R1, Z_R2);
+      }
+    }
+    __ generate_safepoint_check(sync, Z_R1, true);
+
+    __ load_and_test_int(Z_R0, Address(Z_thread, JavaThread::suspend_flags_offset()));
+    __ z_bre(no_block);
+
+    // Block. Save any potential method result value before the operation and
+    // use a leaf call to leave the last_Java_frame setup undisturbed. Doing this
+    // lets us share the oopMap we used when we went native rather than create
+    // a distinct one for this pc.
+    //
+    __ bind(sync);
+    __ z_acquire();
+
+    address entry_point = is_critical_native ? CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans_and_transition)
+                                             : CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans);
+
+    __ call_VM_leaf(entry_point, Z_thread);
+
+    if (is_critical_native) {
+      restore_native_result(masm, ret_type, workspace_slot_offset);
+      __ z_bru(after_transition); // No thread state transition here.
+    }
+    __ bind(no_block);
+    restore_native_result(masm, ret_type, workspace_slot_offset);
+  }
+
+  //--------------------------------------------------------------------
+  // Thread state is thread_in_native_trans. Any safepoint blocking has
+  // already happened so we can now change state to _thread_in_Java.
+  //--------------------------------------------------------------------
+  // Transition from _thread_in_native_trans to _thread_in_Java.
+  __ set_thread_state(_thread_in_Java);
+  __ bind(after_transition);
+
+
+  //--------------------------------------------------------------------
+  // Reguard any pages if necessary.
+  // Protect native result from being destroyed.
+  //--------------------------------------------------------------------
+
+  Label no_reguard;
+
+  __ z_cli(Address(Z_thread, JavaThread::stack_guard_state_offset() + in_ByteSize(sizeof(JavaThread::StackGuardState) - 1)),
+           JavaThread::stack_guard_yellow_reserved_disabled);
+
+  __ z_bre(no_reguard);
+
+  save_native_result(masm, ret_type, workspace_slot_offset);
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages), Z_method);
+  restore_native_result(masm, ret_type, workspace_slot_offset);
+
+  __ bind(no_reguard);
+
+
+  // Synchronized methods (slow path only)
+  // No pending exceptions for now.
+  //--------------------------------------------------------------------
+  // Handle possibly pending exception (will unlock if necessary).
+  // Native result is, if any is live, in Z_FRES or Z_RES.
+  //--------------------------------------------------------------------
+  // Unlock
+  //--------------------------------------------------------------------
+  if (method->is_synchronized()) {
+    const Register r_oop        = Z_R11;
+    const Register r_box        = Z_R12;
+    const Register r_tmp1       = Z_R13;
+    const Register r_tmp2       = Z_R7;
+    Label done;
+
+    // Get unboxed oop of class mirror or object ...
+    int   offset = method_is_static ? klass_offset : receiver_offset;
+
+    assert(offset != -1, "");
+    __ z_lg(r_oop, offset, Z_SP);
+
+    // ... and address of lock object box.
+    __ add2reg(r_box, lock_offset, Z_SP);
+
+    // Try fastpath for unlocking.
+    __ compiler_fast_unlock_object(r_oop, r_box, r_tmp1, r_tmp2); // Don't use R1 as temp.
+    __ z_bre(done);
+
+    // Slow path for unlocking.
+    // Save and restore any potential method result value around the unlocking operation.
+    const Register R_exc = Z_R11;
+
+    save_native_result(masm, ret_type, workspace_slot_offset);
+
+    // Must save pending exception around the slow-path VM call. Since it's a
+    // leaf call, the pending exception (if any) can be kept in a register.
+    __ z_lg(R_exc, Address(Z_thread, Thread::pending_exception_offset()));
+    assert(R_exc->is_nonvolatile(), "exception register must be non-volatile");
+
+    // Must clear pending-exception before re-entering the VM. Since this is
+    // a leaf call, pending-exception-oop can be safely kept in a register.
+    __ clear_mem(Address(Z_thread, Thread::pending_exception_offset()), sizeof(intptr_t));
+
+    // Inline a special case of call_VM that disallows any pending_exception.
+
+    // Get locked oop from the handle we passed to jni.
+    __ z_lg(Z_ARG1, offset, Z_SP);
+    __ add2reg(Z_ARG2, lock_offset, Z_SP);
+    __ z_lgr(Z_ARG3, Z_thread);
+
+    __ load_const_optimized(Z_R1_scratch, CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C));
+
+    __ call(Z_R1_scratch);
+
+#ifdef ASSERT
+    {
+      Label L;
+      __ load_and_test_long(Z_R0, Address(Z_thread, Thread::pending_exception_offset()));
+      __ z_bre(L);
+      __ stop("no pending exception allowed on exit from IR::monitorexit");
+      __ bind(L);
+    }
+#endif
+
+    // Check_forward_pending_exception jump to forward_exception if any pending
+    // exception is set. The forward_exception routine expects to see the
+    // exception in pending_exception and not in a register. Kind of clumsy,
+    // since all folks who branch to forward_exception must have tested
+    // pending_exception first and hence have it in a register already.
+    __ z_stg(R_exc, Address(Z_thread, Thread::pending_exception_offset()));
+    restore_native_result(masm, ret_type, workspace_slot_offset);
+    __ z_bru(done);
+    __ z_illtrap(0x66);
+
+    __ bind(done);
+  }
+
+
+  //--------------------------------------------------------------------
+  // Clear "last Java frame" SP and PC.
+  //--------------------------------------------------------------------
+  __ verify_thread(); // Z_thread must be correct.
+
+  __ reset_last_Java_frame();
+
+  // Unpack oop result, e.g. JNIHandles::resolve result.
+  if (ret_type == T_OBJECT || ret_type == T_ARRAY) {
+    __ resolve_jobject(Z_RET, /* tmp1 */ Z_R13, /* tmp2 */ Z_R7);
+  }
+
+  if (CheckJNICalls) {
+    // clear_pending_jni_exception_check
+    __ clear_mem(Address(Z_thread, JavaThread::pending_jni_exception_check_fn_offset()), sizeof(oop));
+  }
+
+  // Reset handle block.
+  if (!is_critical_native) {
+    __ z_lg(Z_R1_scratch, Address(Z_thread, JavaThread::active_handles_offset()));
+    __ clear_mem(Address(Z_R1_scratch, JNIHandleBlock::top_offset_in_bytes()), 4);
+
+    // Check for pending exceptions.
+    __ load_and_test_long(Z_R0, Address(Z_thread, Thread::pending_exception_offset()));
+    __ z_brne(handle_pending_exception);
+  }
+
+
+  //////////////////////////////////////////////////////////////////////
+  // Return
+  //////////////////////////////////////////////////////////////////////
+
+
+#ifndef USE_RESIZE_FRAME
+  __ pop_frame();                     // Pop wrapper frame.
+#else
+  __ resize_frame(frame_size_in_bytes, Z_R0_scratch);  // Revert stack extension.
+#endif
+  __ restore_return_pc();             // This is the way back to the caller.
+  __ z_br(Z_R14);
+
+
+  //////////////////////////////////////////////////////////////////////
+  // Out-of-line calls to the runtime.
+  //////////////////////////////////////////////////////////////////////
+
+
+  if (!is_critical_native) {
+
+    //---------------------------------------------------------------------
+    // Handler for pending exceptions (out-of-line).
+    //---------------------------------------------------------------------
+    // Since this is a native call, we know the proper exception handler
+    // is the empty function. We just pop this frame and then jump to
+    // forward_exception_entry. Z_R14 will contain the native caller's
+    // return PC.
+    __ bind(handle_pending_exception);
+    __ pop_frame();
+    __ load_const_optimized(Z_R1_scratch, StubRoutines::forward_exception_entry());
+    __ restore_return_pc();
+    __ z_br(Z_R1_scratch);
+
+    //---------------------------------------------------------------------
+    // Handler for a cache miss (out-of-line)
+    //---------------------------------------------------------------------
+    __ call_ic_miss_handler(ic_miss, 0x77, 0, Z_R1_scratch);
+  }
+  __ flush();
+
+
+  //////////////////////////////////////////////////////////////////////
+  // end of code generation
+  //////////////////////////////////////////////////////////////////////
+
+
+  nmethod *nm = nmethod::new_native_nmethod(method,
+                                            compile_id,
+                                            masm->code(),
+                                            (int)(wrapper_VEPStart-wrapper_CodeStart),
+                                            (int)(wrapper_FrameDone-wrapper_CodeStart),
+                                            stack_slots / VMRegImpl::slots_per_word,
+                                            (method_is_static ? in_ByteSize(klass_offset) : in_ByteSize(receiver_offset)),
+                                            in_ByteSize(lock_offset),
+                                            oop_maps);
+
+  if (is_critical_native) {
+    nm->set_lazy_critical_native(true);
+  }
+
+  return nm;
+#else
+  ShouldNotReachHere();
+  return NULL;
+#endif // COMPILER2
+}
+
+static address gen_c2i_adapter(MacroAssembler  *masm,
+                               int total_args_passed,
+                               int comp_args_on_stack,
+                               const BasicType *sig_bt,
+                               const VMRegPair *regs,
+                               Label &skip_fixup) {
+  // Before we get into the guts of the C2I adapter, see if we should be here
+  // at all. We've come from compiled code and are attempting to jump to the
+  // interpreter, which means the caller made a static call to get here
+  // (vcalls always get a compiled target if there is one). Check for a
+  // compiled target. If there is one, we need to patch the caller's call.
+
+  // These two defs MUST MATCH code in gen_i2c2i_adapter!
+  const Register ientry = Z_R11;
+  const Register code   = Z_R11;
+
+  address c2i_entrypoint;
+  Label   patch_callsite;
+
+  // Regular (verified) c2i entry point.
+  c2i_entrypoint = __ pc();
+
+  // Call patching needed?
+  __ load_and_test_long(Z_R0_scratch, method_(code));
+  __ z_lg(ientry, method_(interpreter_entry));  // Preload interpreter entry (also if patching).
+  __ z_brne(patch_callsite);                    // Patch required if code != NULL (compiled target exists).
+
+  __ bind(skip_fixup);  // Return point from patch_callsite.
+
+  // Since all args are passed on the stack, total_args_passed*wordSize is the
+  // space we need. We need ABI scratch area but we use the caller's since
+  // it has already been allocated.
+
+  const int abi_scratch = frame::z_top_ijava_frame_abi_size;
+  int       extraspace  = align_up(total_args_passed, 2)*wordSize + abi_scratch;
+  Register  sender_SP   = Z_R10;
+  Register  value       = Z_R12;
+
+  // Remember the senderSP so we can pop the interpreter arguments off of the stack.
+  // In addition, frame manager expects initial_caller_sp in Z_R10.
+  __ z_lgr(sender_SP, Z_SP);
+
+  // This should always fit in 14 bit immediate.
+  __ resize_frame(-extraspace, Z_R0_scratch);
+
+  // We use the caller's ABI scratch area (out_preserved_stack_slots) for the initial
+  // args. This essentially moves the callers ABI scratch area from the top to the
+  // bottom of the arg area.
+
+  int st_off =  extraspace - wordSize;
+
+  // Now write the args into the outgoing interpreter space.
+  for (int i = 0; i < total_args_passed; i++) {
+    VMReg r_1 = regs[i].first();
+    VMReg r_2 = regs[i].second();
+    if (!r_1->is_valid()) {
+      assert(!r_2->is_valid(), "");
+      continue;
+    }
+    if (r_1->is_stack()) {
+      // The calling convention produces OptoRegs that ignore the preserve area (abi scratch).
+      // We must account for it here.
+      int ld_off = (r_1->reg2stack() + SharedRuntime::out_preserve_stack_slots()) * VMRegImpl::stack_slot_size;
+
+      if (!r_2->is_valid()) {
+        __ z_mvc(Address(Z_SP, st_off), Address(sender_SP, ld_off), sizeof(void*));
+      } else {
+        // longs are given 2 64-bit slots in the interpreter,
+        // but the data is passed in only 1 slot.
+        if (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
+#ifdef ASSERT
+          __ clear_mem(Address(Z_SP, st_off), sizeof(void *));
+#endif
+          st_off -= wordSize;
+        }
+        __ z_mvc(Address(Z_SP, st_off), Address(sender_SP, ld_off), sizeof(void*));
+      }
+    } else {
+      if (r_1->is_Register()) {
+        if (!r_2->is_valid()) {
+          __ z_st(r_1->as_Register(), st_off, Z_SP);
+        } else {
+          // longs are given 2 64-bit slots in the interpreter, but the
+          // data is passed in only 1 slot.
+          if (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
+#ifdef ASSERT
+            __ clear_mem(Address(Z_SP, st_off), sizeof(void *));
+#endif
+            st_off -= wordSize;
+          }
+          __ z_stg(r_1->as_Register(), st_off, Z_SP);
+        }
+      } else {
+        assert(r_1->is_FloatRegister(), "");
+        if (!r_2->is_valid()) {
+          __ z_ste(r_1->as_FloatRegister(), st_off, Z_SP);
+        } else {
+          // In 64bit, doubles are given 2 64-bit slots in the interpreter, but the
+          // data is passed in only 1 slot.
+          // One of these should get known junk...
+#ifdef ASSERT
+          __ z_lzdr(Z_F1);
+          __ z_std(Z_F1, st_off, Z_SP);
+#endif
+          st_off-=wordSize;
+          __ z_std(r_1->as_FloatRegister(), st_off, Z_SP);
+        }
+      }
+    }
+    st_off -= wordSize;
+  }
+
+
+  // Jump to the interpreter just as if interpreter was doing it.
+  __ add2reg(Z_esp, st_off, Z_SP);
+
+  // Frame_manager expects initial_caller_sp (= SP without resize by c2i) in Z_R10.
+  __ z_br(ientry);
+
+
+  // Prevent illegal entry to out-of-line code.
+  __ z_illtrap(0x22);
+
+  // Generate out-of-line runtime call to patch caller,
+  // then continue as interpreted.
+
+  // IF you lose the race you go interpreted.
+  // We don't see any possible endless c2i -> i2c -> c2i ...
+  // transitions no matter how rare.
+  __ bind(patch_callsite);
+
+  RegisterSaver::save_live_registers(masm, RegisterSaver::arg_registers);
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::fixup_callers_callsite), Z_method, Z_R14);
+  RegisterSaver::restore_live_registers(masm, RegisterSaver::arg_registers);
+  __ z_bru(skip_fixup);
+
+  // end of out-of-line code
+
+  return c2i_entrypoint;
+}
+
+// On entry, the following registers are set
+//
+//    Z_thread  r8  - JavaThread*
+//    Z_method  r9  - callee's method (method to be invoked)
+//    Z_esp     r7  - operand (or expression) stack pointer of caller. one slot above last arg.
+//    Z_SP      r15 - SP prepared by call stub such that caller's outgoing args are near top
+//
+void SharedRuntime::gen_i2c_adapter(MacroAssembler *masm,
+                                    int total_args_passed,
+                                    int comp_args_on_stack,
+                                    const BasicType *sig_bt,
+                                    const VMRegPair *regs) {
+  const Register value = Z_R12;
+  const Register ld_ptr= Z_esp;
+
+  int ld_offset = total_args_passed * wordSize;
+
+  // Cut-out for having no stack args.
+  if (comp_args_on_stack) {
+    // Sig words on the stack are greater than VMRegImpl::stack0. Those in
+    // registers are below. By subtracting stack0, we either get a negative
+    // number (all values in registers) or the maximum stack slot accessed.
+    // Convert VMRegImpl (4 byte) stack slots to words.
+    int comp_words_on_stack = align_up(comp_args_on_stack*VMRegImpl::stack_slot_size, wordSize)>>LogBytesPerWord;
+    // Round up to miminum stack alignment, in wordSize
+    comp_words_on_stack = align_up(comp_words_on_stack, 2);
+
+    __ resize_frame(-comp_words_on_stack*wordSize, Z_R0_scratch);
+  }
+
+  // Now generate the shuffle code. Pick up all register args and move the
+  // rest through register value=Z_R12.
+  for (int i = 0; i < total_args_passed; i++) {
+    if (sig_bt[i] == T_VOID) {
+      assert(i > 0 && (sig_bt[i-1] == T_LONG || sig_bt[i-1] == T_DOUBLE), "missing half");
+      continue;
+    }
+
+    // Pick up 0, 1 or 2 words from ld_ptr.
+    assert(!regs[i].second()->is_valid() || regs[i].first()->next() == regs[i].second(),
+           "scrambled load targets?");
+    VMReg r_1 = regs[i].first();
+    VMReg r_2 = regs[i].second();
+    if (!r_1->is_valid()) {
+      assert(!r_2->is_valid(), "");
+      continue;
+    }
+    if (r_1->is_FloatRegister()) {
+      if (!r_2->is_valid()) {
+        __ z_le(r_1->as_FloatRegister(), ld_offset, ld_ptr);
+        ld_offset-=wordSize;
+      } else {
+        // Skip the unused interpreter slot.
+        __ z_ld(r_1->as_FloatRegister(), ld_offset - wordSize, ld_ptr);
+        ld_offset -= 2 * wordSize;
+      }
+    } else {
+      if (r_1->is_stack()) {
+        // Must do a memory to memory move.
+        int st_off = (r_1->reg2stack() + SharedRuntime::out_preserve_stack_slots()) * VMRegImpl::stack_slot_size;
+
+        if (!r_2->is_valid()) {
+          __ z_mvc(Address(Z_SP, st_off), Address(ld_ptr, ld_offset), sizeof(void*));
+        } else {
+          // In 64bit, longs are given 2 64-bit slots in the interpreter, but the
+          // data is passed in only 1 slot.
+          if (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
+            ld_offset -= wordSize;
+          }
+          __ z_mvc(Address(Z_SP, st_off), Address(ld_ptr, ld_offset), sizeof(void*));
+        }
+      } else {
+        if (!r_2->is_valid()) {
+          // Not sure we need to do this but it shouldn't hurt.
+          if (sig_bt[i] == T_OBJECT || sig_bt[i] == T_ADDRESS || sig_bt[i] == T_ARRAY) {
+            __ z_lg(r_1->as_Register(), ld_offset, ld_ptr);
+          } else {
+            __ z_l(r_1->as_Register(), ld_offset, ld_ptr);
+          }
+        } else {
+          // In 64bit, longs are given 2 64-bit slots in the interpreter, but the
+          // data is passed in only 1 slot.
+          if (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
+            ld_offset -= wordSize;
+          }
+          __ z_lg(r_1->as_Register(), ld_offset, ld_ptr);
+        }
+      }
+      ld_offset -= wordSize;
+    }
+  }
+
+  // Jump to the compiled code just as if compiled code was doing it.
+  // load target address from method oop:
+  __ z_lg(Z_R1_scratch, Address(Z_method, Method::from_compiled_offset()));
+
+  // Store method oop into thread->callee_target.
+  // 6243940: We might end up in handle_wrong_method if
+  // the callee is deoptimized as we race thru here. If that
+  // happens we don't want to take a safepoint because the
+  // caller frame will look interpreted and arguments are now
+  // "compiled" so it is much better to make this transition
+  // invisible to the stack walking code. Unfortunately, if
+  // we try and find the callee by normal means a safepoint
+  // is possible. So we stash the desired callee in the thread
+  // and the vm will find it there should this case occur.
+  __ z_stg(Z_method, thread_(callee_target));
+
+  __ z_br(Z_R1_scratch);
+}
+
+AdapterHandlerEntry* SharedRuntime::generate_i2c2i_adapters(MacroAssembler *masm,
+                                                            int total_args_passed,
+                                                            int comp_args_on_stack,
+                                                            const BasicType *sig_bt,
+                                                            const VMRegPair *regs,
+                                                            AdapterFingerPrint* fingerprint) {
+  __ align(CodeEntryAlignment);
+  address i2c_entry = __ pc();
+  gen_i2c_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs);
+
+  address c2i_unverified_entry;
+
+  Label skip_fixup;
+  {
+    Label ic_miss;
+    const int klass_offset         = oopDesc::klass_offset_in_bytes();
+    const int holder_klass_offset  = CompiledICHolder::holder_klass_offset();
+    const int holder_method_offset = CompiledICHolder::holder_method_offset();
+
+    // Out-of-line call to ic_miss handler.
+    __ call_ic_miss_handler(ic_miss, 0x11, 0, Z_R1_scratch);
+
+    // Unverified Entry Point UEP
+    __ align(CodeEntryAlignment);
+    c2i_unverified_entry = __ pc();
+
+    // Check the pointers.
+    if (!ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(klass_offset)) {
+      __ z_ltgr(Z_ARG1, Z_ARG1);
+      __ z_bre(ic_miss);
+    }
+    __ verify_oop(Z_ARG1);
+
+    // Check ic: object class <-> cached class
+    // Compress cached class for comparison. That's more efficient.
+    if (UseCompressedClassPointers) {
+      __ z_lg(Z_R11, holder_klass_offset, Z_method);             // Z_R11 is overwritten a few instructions down anyway.
+      __ compare_klass_ptr(Z_R11, klass_offset, Z_ARG1, false); // Cached class can't be zero.
+    } else {
+      __ z_clc(klass_offset, sizeof(void *)-1, Z_ARG1, holder_klass_offset, Z_method);
+    }
+    __ z_brne(ic_miss);  // Cache miss: call runtime to handle this.
+
+    // This def MUST MATCH code in gen_c2i_adapter!
+    const Register code = Z_R11;
+
+    __ z_lg(Z_method, holder_method_offset, Z_method);
+    __ load_and_test_long(Z_R0, method_(code));
+    __ z_brne(ic_miss);  // Cache miss: call runtime to handle this.
+
+    // Fallthru to VEP. Duplicate LTG, but saved taken branch.
+  }
+
+  address c2i_entry;
+  c2i_entry = gen_c2i_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs, skip_fixup);
+
+  return AdapterHandlerLibrary::new_entry(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry);
+}
+
+// This function returns the adjust size (in number of words) to a c2i adapter
+// activation for use during deoptimization.
+//
+// Actually only compiled frames need to be adjusted, but it
+// doesn't harm to adjust entry and interpreter frames, too.
+//
+int Deoptimization::last_frame_adjust(int callee_parameters, int callee_locals) {
+  assert(callee_locals >= callee_parameters,
+          "test and remove; got more parms than locals");
+  // Handle the abi adjustment here instead of doing it in push_skeleton_frames.
+  return (callee_locals - callee_parameters) * Interpreter::stackElementWords +
+         frame::z_parent_ijava_frame_abi_size / BytesPerWord;
+}
+
+uint SharedRuntime::out_preserve_stack_slots() {
+  return frame::z_jit_out_preserve_size/VMRegImpl::stack_slot_size;
+}
+
+//
+// Frame generation for deopt and uncommon trap blobs.
+//
+static void push_skeleton_frame(MacroAssembler* masm,
+                          /* Unchanged */
+                          Register frame_sizes_reg,
+                          Register pcs_reg,
+                          /* Invalidate */
+                          Register frame_size_reg,
+                          Register pc_reg) {
+  BLOCK_COMMENT("  push_skeleton_frame {");
+   __ z_lg(pc_reg, 0, pcs_reg);
+   __ z_lg(frame_size_reg, 0, frame_sizes_reg);
+   __ z_stg(pc_reg, _z_abi(return_pc), Z_SP);
+   Register fp = pc_reg;
+   __ push_frame(frame_size_reg, fp);
+#ifdef ASSERT
+   // The magic is required for successful walking skeletal frames.
+   __ load_const_optimized(frame_size_reg/*tmp*/, frame::z_istate_magic_number);
+   __ z_stg(frame_size_reg, _z_ijava_state_neg(magic), fp);
+   // Fill other slots that are supposedly not necessary with eye catchers.
+   __ load_const_optimized(frame_size_reg/*use as tmp*/, 0xdeadbad1);
+   __ z_stg(frame_size_reg, _z_ijava_state_neg(top_frame_sp), fp);
+   // The sender_sp of the bottom frame is set before pushing it.
+   // The sender_sp of non bottom frames is their caller's top_frame_sp, which
+   // is unknown here. Luckily it is not needed before filling the frame in
+   // layout_activation(), we assert this by setting an eye catcher (see
+   // comments on sender_sp in frame_s390.hpp).
+   __ z_stg(frame_size_reg, _z_ijava_state_neg(sender_sp), Z_SP);
+#endif // ASSERT
+  BLOCK_COMMENT("  } push_skeleton_frame");
+}
+
+// Loop through the UnrollBlock info and create new frames.
+static void push_skeleton_frames(MacroAssembler* masm, bool deopt,
+                            /* read */
+                            Register unroll_block_reg,
+                            /* invalidate */
+                            Register frame_sizes_reg,
+                            Register number_of_frames_reg,
+                            Register pcs_reg,
+                            Register tmp1,
+                            Register tmp2) {
+  BLOCK_COMMENT("push_skeleton_frames {");
+  // _number_of_frames is of type int (deoptimization.hpp).
+  __ z_lgf(number_of_frames_reg,
+           Address(unroll_block_reg, Deoptimization::UnrollBlock::number_of_frames_offset_in_bytes()));
+  __ z_lg(pcs_reg,
+          Address(unroll_block_reg, Deoptimization::UnrollBlock::frame_pcs_offset_in_bytes()));
+  __ z_lg(frame_sizes_reg,
+          Address(unroll_block_reg, Deoptimization::UnrollBlock::frame_sizes_offset_in_bytes()));
+
+  // stack: (caller_of_deoptee, ...).
+
+  // If caller_of_deoptee is a compiled frame, then we extend it to make
+  // room for the callee's locals and the frame::z_parent_ijava_frame_abi.
+  // See also Deoptimization::last_frame_adjust() above.
+  // Note: entry and interpreted frames are adjusted, too. But this doesn't harm.
+
+  __ z_lgf(Z_R1_scratch,
+           Address(unroll_block_reg, Deoptimization::UnrollBlock::caller_adjustment_offset_in_bytes()));
+  __ z_lgr(tmp1, Z_SP);  // Save the sender sp before extending the frame.
+  __ resize_frame_sub(Z_R1_scratch, tmp2/*tmp*/);
+  // The oldest skeletal frame requires a valid sender_sp to make it walkable
+  // (it is required to find the original pc of caller_of_deoptee if it is marked
+  // for deoptimization - see nmethod::orig_pc_addr()).
+  __ z_stg(tmp1, _z_ijava_state_neg(sender_sp), Z_SP);
+
+  // Now push the new interpreter frames.
+  Label loop, loop_entry;
+
+  // Make sure that there is at least one entry in the array.
+  DEBUG_ONLY(__ z_ltgr(number_of_frames_reg, number_of_frames_reg));
+  __ asm_assert_ne("array_size must be > 0", 0x205);
+
+  __ z_bru(loop_entry);
+
+  __ bind(loop);
+
+  __ add2reg(frame_sizes_reg, wordSize);
+  __ add2reg(pcs_reg, wordSize);
+
+  __ bind(loop_entry);
+
+  // Allocate a new frame, fill in the pc.
+  push_skeleton_frame(masm, frame_sizes_reg, pcs_reg, tmp1, tmp2);
+
+  __ z_aghi(number_of_frames_reg, -1);  // Emit AGHI, because it sets the condition code
+  __ z_brne(loop);
+
+  // Set the top frame's return pc.
+  __ add2reg(pcs_reg, wordSize);
+  __ z_lg(Z_R0_scratch, 0, pcs_reg);
+  __ z_stg(Z_R0_scratch, _z_abi(return_pc), Z_SP);
+  BLOCK_COMMENT("} push_skeleton_frames");
+}
+
+//------------------------------generate_deopt_blob----------------------------
+void SharedRuntime::generate_deopt_blob() {
+  // Allocate space for the code.
+  ResourceMark rm;
+  // Setup code generation tools.
+  CodeBuffer buffer("deopt_blob", 2048, 1024);
+  InterpreterMacroAssembler* masm = new InterpreterMacroAssembler(&buffer);
+  Label exec_mode_initialized;
+  OopMap* map = NULL;
+  OopMapSet *oop_maps = new OopMapSet();
+
+  unsigned int start_off = __ offset();
+  Label cont;
+
+  // --------------------------------------------------------------------------
+  // Normal entry (non-exception case)
+  //
+  // We have been called from the deopt handler of the deoptee.
+  // Z_R14 points behind the call in the deopt handler. We adjust
+  // it such that it points to the start of the deopt handler.
+  // The return_pc has been stored in the frame of the deoptee and
+  // will replace the address of the deopt_handler in the call
+  // to Deoptimization::fetch_unroll_info below.
+  // The (int) cast is necessary, because -((unsigned int)14)
+  // is an unsigned int.
+  __ add2reg(Z_R14, -(int)HandlerImpl::size_deopt_handler());
+
+  const Register   exec_mode_reg = Z_tmp_1;
+
+  // stack: (deoptee, caller of deoptee, ...)
+
+  // pushes an "unpack" frame
+  // R14 contains the return address pointing into the deoptimized
+  // nmethod that was valid just before the nmethod was deoptimized.
+  // save R14 into the deoptee frame.  the `fetch_unroll_info'
+  // procedure called below will read it from there.
+  map = RegisterSaver::save_live_registers(masm, RegisterSaver::all_registers);
+
+  // note the entry point.
+  __ load_const_optimized(exec_mode_reg, Deoptimization::Unpack_deopt);
+  __ z_bru(exec_mode_initialized);
+
+#ifndef COMPILER1
+  int reexecute_offset = 1; // odd offset will produce odd pc, which triggers an hardware trap
+#else
+  // --------------------------------------------------------------------------
+  // Reexecute entry
+  // - Z_R14 = Deopt Handler in nmethod
+
+  int reexecute_offset = __ offset() - start_off;
+
+  // No need to update map as each call to save_live_registers will produce identical oopmap
+  (void) RegisterSaver::save_live_registers(masm, RegisterSaver::all_registers);
+
+  __ load_const_optimized(exec_mode_reg, Deoptimization::Unpack_reexecute);
+  __ z_bru(exec_mode_initialized);
+#endif
+
+
+  // --------------------------------------------------------------------------
+  // Exception entry. We reached here via a branch. Registers on entry:
+  // - Z_EXC_OOP (Z_ARG1) = exception oop
+  // - Z_EXC_PC  (Z_ARG2) = the exception pc.
+
+  int exception_offset = __ offset() - start_off;
+
+  // all registers are dead at this entry point, except for Z_EXC_OOP, and
+  // Z_EXC_PC which contain the exception oop and exception pc
+  // respectively.  Set them in TLS and fall thru to the
+  // unpack_with_exception_in_tls entry point.
+
+  // Store exception oop and pc in thread (location known to GC).
+  // Need this since the call to "fetch_unroll_info()" may safepoint.
+  __ z_stg(Z_EXC_OOP, Address(Z_thread, JavaThread::exception_oop_offset()));
+  __ z_stg(Z_EXC_PC,  Address(Z_thread, JavaThread::exception_pc_offset()));
+
+  // fall through
+
+  int exception_in_tls_offset = __ offset() - start_off;
+
+  // new implementation because exception oop is now passed in JavaThread
+
+  // Prolog for exception case
+  // All registers must be preserved because they might be used by LinearScan
+  // Exceptiop oop and throwing PC are passed in JavaThread
+
+  // load throwing pc from JavaThread and us it as the return address of the current frame.
+  __ z_lg(Z_R1_scratch, Address(Z_thread, JavaThread::exception_pc_offset()));
+
+  // Save everything in sight.
+  (void) RegisterSaver::save_live_registers(masm, RegisterSaver::all_registers, Z_R1_scratch);
+
+  // Now it is safe to overwrite any register
+
+  // Clear the exception pc field in JavaThread
+  __ clear_mem(Address(Z_thread, JavaThread::exception_pc_offset()), 8);
+
+  // Deopt during an exception.  Save exec mode for unpack_frames.
+  __ load_const_optimized(exec_mode_reg, Deoptimization::Unpack_exception);
+
+
+#ifdef ASSERT
+  // verify that there is really an exception oop in JavaThread
+  __ z_lg(Z_ARG1, Address(Z_thread, JavaThread::exception_oop_offset()));
+  __ verify_oop(Z_ARG1);
+
+  // verify that there is no pending exception
+  __ asm_assert_mem8_is_zero(in_bytes(Thread::pending_exception_offset()), Z_thread,
+                             "must not have pending exception here", __LINE__);
+#endif
+
+  // --------------------------------------------------------------------------
+  // At this point, the live registers are saved and
+  // the exec_mode_reg has been set up correctly.
+  __ bind(exec_mode_initialized);
+
+  // stack: ("unpack" frame, deoptee, caller_of_deoptee, ...).
+
+  {
+  const Register unroll_block_reg  = Z_tmp_2;
+
+  // we need to set `last_Java_frame' because `fetch_unroll_info' will
+  // call `last_Java_frame()'.  however we can't block and no gc will
+  // occur so we don't need an oopmap. the value of the pc in the
+  // frame is not particularly important.  it just needs to identify the blob.
+
+  // Don't set last_Java_pc anymore here (is implicitly NULL then).
+  // the correct PC is retrieved in pd_last_frame() in that case.
+  __ set_last_Java_frame(/*sp*/Z_SP, noreg);
+  // With EscapeAnalysis turned on, this call may safepoint
+  // despite it's marked as "leaf call"!
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, Deoptimization::fetch_unroll_info), Z_thread, exec_mode_reg);
+  // Set an oopmap for the call site this describes all our saved volatile registers
+  int offs = __ offset();
+  oop_maps->add_gc_map(offs, map);
+
+  __ reset_last_Java_frame();
+  // save the return value.
+  __ z_lgr(unroll_block_reg, Z_RET);
+  // restore the return registers that have been saved
+  // (among other registers) by save_live_registers(...).
+  RegisterSaver::restore_result_registers(masm);
+
+  // reload the exec mode from the UnrollBlock (it might have changed)
+  __ z_llgf(exec_mode_reg, Address(unroll_block_reg, Deoptimization::UnrollBlock::unpack_kind_offset_in_bytes()));
+
+  // In excp_deopt_mode, restore and clear exception oop which we
+  // stored in the thread during exception entry above. The exception
+  // oop will be the return value of this stub.
+  NearLabel skip_restore_excp;
+  __ compare64_and_branch(exec_mode_reg, Deoptimization::Unpack_exception, Assembler::bcondNotEqual, skip_restore_excp);
+  __ z_lg(Z_RET, thread_(exception_oop));
+  __ clear_mem(thread_(exception_oop), 8);
+  __ bind(skip_restore_excp);
+
+  // remove the "unpack" frame
+  __ pop_frame();
+
+  // stack: (deoptee, caller of deoptee, ...).
+
+  // pop the deoptee's frame
+  __ pop_frame();
+
+  // stack: (caller_of_deoptee, ...).
+
+  // loop through the `UnrollBlock' info and create interpreter frames.
+  push_skeleton_frames(masm, true/*deopt*/,
+                  unroll_block_reg,
+                  Z_tmp_3,
+                  Z_tmp_4,
+                  Z_ARG5,
+                  Z_ARG4,
+                  Z_ARG3);
+
+  // stack: (skeletal interpreter frame, ..., optional skeletal
+  // interpreter frame, caller of deoptee, ...).
+  }
+
+  // push an "unpack" frame taking care of float / int return values.
+  __ push_frame(RegisterSaver::live_reg_frame_size(RegisterSaver::all_registers));
+
+  // stack: (unpack frame, skeletal interpreter frame, ..., optional
+  // skeletal interpreter frame, caller of deoptee, ...).
+
+  // spill live volatile registers since we'll do a call.
+  __ z_stg(Z_RET, offset_of(frame::z_abi_160_spill, spill[0]), Z_SP);
+  __ z_std(Z_FRET, offset_of(frame::z_abi_160_spill, spill[1]), Z_SP);
+
+  // let the unpacker layout information in the skeletal frames just allocated.
+  __ get_PC(Z_RET);
+  __ set_last_Java_frame(/*sp*/Z_SP, /*pc*/Z_RET);
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames),
+                  Z_thread/*thread*/, exec_mode_reg/*exec_mode*/);
+
+  __ reset_last_Java_frame();
+
+  // restore the volatiles saved above.
+  __ z_lg(Z_RET, offset_of(frame::z_abi_160_spill, spill[0]), Z_SP);
+  __ z_ld(Z_FRET, offset_of(frame::z_abi_160_spill, spill[1]), Z_SP);
+
+  // pop the "unpack" frame.
+  __ pop_frame();
+  __ restore_return_pc();
+
+  // stack: (top interpreter frame, ..., optional interpreter frame,
+  // caller of deoptee, ...).
+
+  __ z_lg(Z_fp, _z_abi(callers_sp), Z_SP); // restore frame pointer
+  __ restore_bcp();
+  __ restore_locals();
+  __ restore_esp();
+
+  // return to the interpreter entry point.
+  __ z_br(Z_R14);
+
+  // Make sure all code is generated
+  masm->flush();
+
+  _deopt_blob = DeoptimizationBlob::create(&buffer, oop_maps, 0, exception_offset, reexecute_offset, RegisterSaver::live_reg_frame_size(RegisterSaver::all_registers)/wordSize);
+  _deopt_blob->set_unpack_with_exception_in_tls_offset(exception_in_tls_offset);
+}
+
+
+#ifdef COMPILER2
+//------------------------------generate_uncommon_trap_blob--------------------
+void SharedRuntime::generate_uncommon_trap_blob() {
+  // Allocate space for the code
+  ResourceMark rm;
+  // Setup code generation tools
+  CodeBuffer buffer("uncommon_trap_blob", 2048, 1024);
+  InterpreterMacroAssembler* masm = new InterpreterMacroAssembler(&buffer);
+
+  Register unroll_block_reg = Z_tmp_1;
+  Register klass_index_reg  = Z_ARG2;
+  Register unc_trap_reg     = Z_ARG2;
+
+  // stack: (deoptee, caller_of_deoptee, ...).
+
+  // push a dummy "unpack" frame and call
+  // `Deoptimization::uncommon_trap' to pack the compiled frame into a
+  // vframe array and return the `UnrollBlock' information.
+
+  // save R14 to compiled frame.
+  __ save_return_pc();
+  // push the "unpack_frame".
+  __ push_frame_abi160(0);
+
+  // stack: (unpack frame, deoptee, caller_of_deoptee, ...).
+
+  // set the "unpack" frame as last_Java_frame.
+  // `Deoptimization::uncommon_trap' expects it and considers its
+  // sender frame as the deoptee frame.
+  __ get_PC(Z_R1_scratch);
+  __ set_last_Java_frame(/*sp*/Z_SP, /*pc*/Z_R1_scratch);
+
+  __ z_lgr(klass_index_reg, Z_ARG1);  // passed implicitly as ARG2
+  __ z_lghi(Z_ARG3, Deoptimization::Unpack_uncommon_trap);  // passed implicitly as ARG3
+  BLOCK_COMMENT("call Deoptimization::uncommon_trap()");
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, Deoptimization::uncommon_trap), Z_thread);
+
+  __ reset_last_Java_frame();
+
+  // pop the "unpack" frame
+  __ pop_frame();
+
+  // stack: (deoptee, caller_of_deoptee, ...).
+
+  // save the return value.
+  __ z_lgr(unroll_block_reg, Z_RET);
+
+  // pop the deoptee frame.
+  __ pop_frame();
+
+  // stack: (caller_of_deoptee, ...).
+
+#ifdef ASSERT
+  assert(Immediate::is_uimm8(Deoptimization::Unpack_LIMIT), "Code not fit for larger immediates");
+  assert(Immediate::is_uimm8(Deoptimization::Unpack_uncommon_trap), "Code not fit for larger immediates");
+  const int unpack_kind_byte_offset = Deoptimization::UnrollBlock::unpack_kind_offset_in_bytes()
+#ifndef VM_LITTLE_ENDIAN
+  + 3
+#endif
+  ;
+  if (Displacement::is_shortDisp(unpack_kind_byte_offset)) {
+    __ z_cli(unpack_kind_byte_offset, unroll_block_reg, Deoptimization::Unpack_uncommon_trap);
+  } else {
+    __ z_cliy(unpack_kind_byte_offset, unroll_block_reg, Deoptimization::Unpack_uncommon_trap);
+  }
+  __ asm_assert_eq("SharedRuntime::generate_deopt_blob: expected Unpack_uncommon_trap", 0);
+#endif
+
+  __ zap_from_to(Z_SP, Z_SP, Z_R0_scratch, Z_R1, 500, -1);
+
+  // allocate new interpreter frame(s) and possibly resize the caller's frame
+  // (no more adapters !)
+  push_skeleton_frames(masm, false/*deopt*/,
+                  unroll_block_reg,
+                  Z_tmp_2,
+                  Z_tmp_3,
+                  Z_tmp_4,
+                  Z_ARG5,
+                  Z_ARG4);
+
+  // stack: (skeletal interpreter frame, ..., optional skeletal
+  // interpreter frame, (resized) caller of deoptee, ...).
+
+  // push a dummy "unpack" frame taking care of float return values.
+  // call `Deoptimization::unpack_frames' to layout information in the
+  // interpreter frames just created
+
+  // push the "unpack" frame
+   const unsigned int framesize_in_bytes = __ push_frame_abi160(0);
+
+  // stack: (unpack frame, skeletal interpreter frame, ..., optional
+  // skeletal interpreter frame, (resized) caller of deoptee, ...).
+
+  // set the "unpack" frame as last_Java_frame
+  __ get_PC(Z_R1_scratch);
+  __ set_last_Java_frame(/*sp*/Z_SP, /*pc*/Z_R1_scratch);
+
+  // indicate it is the uncommon trap case
+  BLOCK_COMMENT("call Deoptimization::Unpack_uncommon_trap()");
+  __ load_const_optimized(unc_trap_reg, Deoptimization::Unpack_uncommon_trap);
+  // let the unpacker layout information in the skeletal frames just allocated.
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames), Z_thread);
+
+  __ reset_last_Java_frame();
+  // pop the "unpack" frame
+  __ pop_frame();
+  // restore LR from top interpreter frame
+  __ restore_return_pc();
+
+  // stack: (top interpreter frame, ..., optional interpreter frame,
+  // (resized) caller of deoptee, ...).
+
+  __ z_lg(Z_fp, _z_abi(callers_sp), Z_SP); // restore frame pointer
+  __ restore_bcp();
+  __ restore_locals();
+  __ restore_esp();
+
+  // return to the interpreter entry point
+  __ z_br(Z_R14);
+
+  masm->flush();
+  _uncommon_trap_blob = UncommonTrapBlob::create(&buffer, NULL, framesize_in_bytes/wordSize);
+}
+#endif // COMPILER2
+
+
+//------------------------------generate_handler_blob------
+//
+// Generate a special Compile2Runtime blob that saves all registers,
+// and setup oopmap.
+SafepointBlob* SharedRuntime::generate_handler_blob(address call_ptr, int poll_type) {
+  assert(StubRoutines::forward_exception_entry() != NULL,
+         "must be generated before");
+
+  ResourceMark rm;
+  OopMapSet *oop_maps = new OopMapSet();
+  OopMap* map;
+
+  // Allocate space for the code. Setup code generation tools.
+  CodeBuffer buffer("handler_blob", 2048, 1024);
+  MacroAssembler* masm = new MacroAssembler(&buffer);
+
+  unsigned int start_off = __ offset();
+  address call_pc = NULL;
+  int frame_size_in_bytes;
+
+  bool cause_return = (poll_type == POLL_AT_RETURN);
+  // Make room for return address (or push it again)
+  if (!cause_return)
+    __ z_lg(Z_R14, Address(Z_thread, JavaThread::saved_exception_pc_offset()));
+
+  // Save registers, fpu state, and flags
+  map = RegisterSaver::save_live_registers(masm, RegisterSaver::all_registers);
+
+  // The following is basically a call_VM. However, we need the precise
+  // address of the call in order to generate an oopmap. Hence, we do all the
+  // work outselves.
+  __ set_last_Java_frame(Z_SP, noreg);
+
+  // call into the runtime to handle the safepoint poll
+  __ call_VM_leaf(call_ptr, Z_thread);
+
+
+  // Set an oopmap for the call site. This oopmap will map all
+  // oop-registers and debug-info registers as callee-saved. This
+  // will allow deoptimization at this safepoint to find all possible
+  // debug-info recordings, as well as let GC find all oops.
+
+  oop_maps->add_gc_map((int)(__ offset()-start_off), map);
+
+  Label noException;
+
+  __ reset_last_Java_frame();
+
+  __ load_and_test_long(Z_R1, thread_(pending_exception));
+  __ z_bre(noException);
+
+  // Pending exception case, used (sporadically) by
+  // api/java_lang/Thread.State/index#ThreadState et al.
+  RegisterSaver::restore_live_registers(masm, RegisterSaver::all_registers);
+
+  // Jump to forward_exception_entry, with the issuing PC in Z_R14
+  // so it looks like the original nmethod called forward_exception_entry.
+  __ load_const_optimized(Z_R1_scratch, StubRoutines::forward_exception_entry());
+  __ z_br(Z_R1_scratch);
+
+  // No exception case
+  __ bind(noException);
+
+  // Normal exit, restore registers and exit.
+  RegisterSaver::restore_live_registers(masm, RegisterSaver::all_registers);
+
+  __ z_br(Z_R14);
+
+  // Make sure all code is generated
+  masm->flush();
+
+  // Fill-out other meta info
+  return SafepointBlob::create(&buffer, oop_maps, RegisterSaver::live_reg_frame_size(RegisterSaver::all_registers)/wordSize);
+}
+
+
+//
+// generate_resolve_blob - call resolution (static/virtual/opt-virtual/ic-miss
+//
+// Generate a stub that calls into vm to find out the proper destination
+// of a Java call. All the argument registers are live at this point
+// but since this is generic code we don't know what they are and the caller
+// must do any gc of the args.
+//
+RuntimeStub* SharedRuntime::generate_resolve_blob(address destination, const char* name) {
+  assert (StubRoutines::forward_exception_entry() != NULL, "must be generated before");
+
+  // allocate space for the code
+  ResourceMark rm;
+
+  CodeBuffer buffer(name, 1000, 512);
+  MacroAssembler* masm                = new MacroAssembler(&buffer);
+
+  OopMapSet *oop_maps = new OopMapSet();
+  OopMap* map = NULL;
+
+  unsigned int start_off = __ offset();
+
+  map = RegisterSaver::save_live_registers(masm, RegisterSaver::all_registers);
+
+  // We must save a PC from within the stub as return PC
+  // C code doesn't store the LR where we expect the PC,
+  // so we would run into trouble upon stack walking.
+  __ get_PC(Z_R1_scratch);
+
+  unsigned int frame_complete = __ offset();
+
+  __ set_last_Java_frame(/*sp*/Z_SP, Z_R1_scratch);
+
+  __ call_VM_leaf(destination, Z_thread, Z_method);
+
+
+  // Set an oopmap for the call site.
+  // We need this not only for callee-saved registers, but also for volatile
+  // registers that the compiler might be keeping live across a safepoint.
+
+  oop_maps->add_gc_map((int)(frame_complete-start_off), map);
+
+  // clear last_Java_sp
+  __ reset_last_Java_frame();
+
+  // check for pending exceptions
+  Label pending;
+  __ load_and_test_long(Z_R0, Address(Z_thread, Thread::pending_exception_offset()));
+  __ z_brne(pending);
+
+  __ z_lgr(Z_R1_scratch, Z_R2); // r1 is neither saved nor restored, r2 contains the continuation.
+  RegisterSaver::restore_live_registers(masm, RegisterSaver::all_registers);
+
+  // get the returned method
+  __ get_vm_result_2(Z_method);
+
+  // We are back the the original state on entry and ready to go.
+  __ z_br(Z_R1_scratch);
+
+  // Pending exception after the safepoint
+
+  __ bind(pending);
+
+  RegisterSaver::restore_live_registers(masm, RegisterSaver::all_registers);
+
+  // exception pending => remove activation and forward to exception handler
+
+  __ z_lgr(Z_R2, Z_R0); // pending_exception
+  __ clear_mem(Address(Z_thread, JavaThread::vm_result_offset()), sizeof(jlong));
+  __ load_const_optimized(Z_R1_scratch, StubRoutines::forward_exception_entry());
+  __ z_br(Z_R1_scratch);
+
+  // -------------
+  // make sure all code is generated
+  masm->flush();
+
+  // return the blob
+  // frame_size_words or bytes??
+  return RuntimeStub::new_runtime_stub(name, &buffer, frame_complete, RegisterSaver::live_reg_frame_size(RegisterSaver::all_registers)/wordSize,
+                                       oop_maps, true);
+
+}
+
+//------------------------------Montgomery multiplication------------------------
+//
+
+// Subtract 0:b from carry:a. Return carry.
+static unsigned long
+sub(unsigned long a[], unsigned long b[], unsigned long carry, long len) {
+  unsigned long i, c = 8 * (unsigned long)(len - 1);
+  __asm__ __volatile__ (
+    "SLGR   %[i], %[i]         \n" // initialize to 0 and pre-set carry
+    "LGHI   0, 8               \n" // index increment (for BRXLG)
+    "LGR    1, %[c]            \n" // index limit (for BRXLG)
+    "0:                        \n"
+    "LG     %[c], 0(%[i],%[a]) \n"
+    "SLBG   %[c], 0(%[i],%[b]) \n" // subtract with borrow
+    "STG    %[c], 0(%[i],%[a]) \n"
+    "BRXLG  %[i], 0, 0b        \n" // while ((i+=8)<limit);
+    "SLBGR  %[c], %[c]         \n" // save carry - 1
+    : [i]"=&a"(i), [c]"+r"(c)
+    : [a]"a"(a), [b]"a"(b)
+    : "cc", "memory", "r0", "r1"
+ );
+  return carry + c;
+}
+
+// Multiply (unsigned) Long A by Long B, accumulating the double-
+// length result into the accumulator formed of T0, T1, and T2.
+inline void MACC(unsigned long A[], long A_ind,
+                 unsigned long B[], long B_ind,
+                 unsigned long &T0, unsigned long &T1, unsigned long &T2) {
+  long A_si = 8 * A_ind,
+       B_si = 8 * B_ind;
+  __asm__ __volatile__ (
+    "LG     1, 0(%[A_si],%[A]) \n"
+    "MLG    0, 0(%[B_si],%[B]) \n" // r0r1 = A * B
+    "ALGR   %[T0], 1           \n"
+    "LGHI   1, 0               \n" // r1 = 0
+    "ALCGR  %[T1], 0           \n"
+    "ALCGR  %[T2], 1           \n"
+    : [T0]"+r"(T0), [T1]"+r"(T1), [T2]"+r"(T2)
+    : [A]"r"(A), [A_si]"r"(A_si), [B]"r"(B), [B_si]"r"(B_si)
+    : "cc", "r0", "r1"
+ );
+}
+
+// As above, but add twice the double-length result into the
+// accumulator.
+inline void MACC2(unsigned long A[], long A_ind,
+                  unsigned long B[], long B_ind,
+                  unsigned long &T0, unsigned long &T1, unsigned long &T2) {
+  const unsigned long zero = 0;
+  long A_si = 8 * A_ind,
+       B_si = 8 * B_ind;
+  __asm__ __volatile__ (
+    "LG     1, 0(%[A_si],%[A]) \n"
+    "MLG    0, 0(%[B_si],%[B]) \n" // r0r1 = A * B
+    "ALGR   %[T0], 1           \n"
+    "ALCGR  %[T1], 0           \n"
+    "ALCGR  %[T2], %[zero]     \n"
+    "ALGR   %[T0], 1           \n"
+    "ALCGR  %[T1], 0           \n"
+    "ALCGR  %[T2], %[zero]     \n"
+    : [T0]"+r"(T0), [T1]"+r"(T1), [T2]"+r"(T2)
+    : [A]"r"(A), [A_si]"r"(A_si), [B]"r"(B), [B_si]"r"(B_si), [zero]"r"(zero)
+    : "cc", "r0", "r1"
+ );
+}
+
+// Fast Montgomery multiplication. The derivation of the algorithm is
+// in "A Cryptographic Library for the Motorola DSP56000,
+// Dusse and Kaliski, Proc. EUROCRYPT 90, pp. 230-237".
+static void
+montgomery_multiply(unsigned long a[], unsigned long b[], unsigned long n[],
+                    unsigned long m[], unsigned long inv, int len) {
+  unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator
+  int i;
+
+  assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");
+
+  for (i = 0; i < len; i++) {
+    int j;
+    for (j = 0; j < i; j++) {
+      MACC(a, j, b, i-j, t0, t1, t2);
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    MACC(a, i, b, 0, t0, t1, t2);
+    m[i] = t0 * inv;
+    MACC(m, i, n, 0, t0, t1, t2);
+
+    assert(t0 == 0, "broken Montgomery multiply");
+
+    t0 = t1; t1 = t2; t2 = 0;
+  }
+
+  for (i = len; i < 2 * len; i++) {
+    int j;
+    for (j = i - len + 1; j < len; j++) {
+      MACC(a, j, b, i-j, t0, t1, t2);
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    m[i-len] = t0;
+    t0 = t1; t1 = t2; t2 = 0;
+  }
+
+  while (t0) {
+    t0 = sub(m, n, t0, len);
+  }
+}
+
+// Fast Montgomery squaring. This uses asymptotically 25% fewer
+// multiplies so it should be up to 25% faster than Montgomery
+// multiplication. However, its loop control is more complex and it
+// may actually run slower on some machines.
+static void
+montgomery_square(unsigned long a[], unsigned long n[],
+                  unsigned long m[], unsigned long inv, int len) {
+  unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator
+  int i;
+
+  assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");
+
+  for (i = 0; i < len; i++) {
+    int j;
+    int end = (i+1)/2;
+    for (j = 0; j < end; j++) {
+      MACC2(a, j, a, i-j, t0, t1, t2);
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    if ((i & 1) == 0) {
+      MACC(a, j, a, j, t0, t1, t2);
+    }
+    for (; j < i; j++) {
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    m[i] = t0 * inv;
+    MACC(m, i, n, 0, t0, t1, t2);
+
+    assert(t0 == 0, "broken Montgomery square");
+
+    t0 = t1; t1 = t2; t2 = 0;
+  }
+
+  for (i = len; i < 2*len; i++) {
+    int start = i-len+1;
+    int end = start + (len - start)/2;
+    int j;
+    for (j = start; j < end; j++) {
+      MACC2(a, j, a, i-j, t0, t1, t2);
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    if ((i & 1) == 0) {
+      MACC(a, j, a, j, t0, t1, t2);
+    }
+    for (; j < len; j++) {
+      MACC(m, j, n, i-j, t0, t1, t2);
+    }
+    m[i-len] = t0;
+    t0 = t1; t1 = t2; t2 = 0;
+  }
+
+  while (t0) {
+    t0 = sub(m, n, t0, len);
+  }
+}
+
+// The threshold at which squaring is advantageous was determined
+// experimentally on an i7-3930K (Ivy Bridge) CPU @ 3.5GHz.
+// Value seems to be ok for other platforms, too.
+#define MONTGOMERY_SQUARING_THRESHOLD 64
+
+// Copy len longwords from s to d, word-swapping as we go. The
+// destination array is reversed.
+static void reverse_words(unsigned long *s, unsigned long *d, int len) {
+  d += len;
+  while(len-- > 0) {
+    d--;
+    unsigned long s_val = *s;
+    // Swap words in a longword on little endian machines.
+#ifdef VM_LITTLE_ENDIAN
+     Unimplemented();
+#endif
+    *d = s_val;
+    s++;
+  }
+}
+
+void SharedRuntime::montgomery_multiply(jint *a_ints, jint *b_ints, jint *n_ints,
+                                        jint len, jlong inv,
+                                        jint *m_ints) {
+  len = len & 0x7fffFFFF; // C2 does not respect int to long conversion for stub calls.
+  assert(len % 2 == 0, "array length in montgomery_multiply must be even");
+  int longwords = len/2;
+
+  // Make very sure we don't use so much space that the stack might
+  // overflow. 512 jints corresponds to an 16384-bit integer and
+  // will use here a total of 8k bytes of stack space.
+  int total_allocation = longwords * sizeof (unsigned long) * 4;
+  guarantee(total_allocation <= 8192, "must be");
+  unsigned long *scratch = (unsigned long *)alloca(total_allocation);
+
+  // Local scratch arrays
+  unsigned long
+    *a = scratch + 0 * longwords,
+    *b = scratch + 1 * longwords,
+    *n = scratch + 2 * longwords,
+    *m = scratch + 3 * longwords;
+
+  reverse_words((unsigned long *)a_ints, a, longwords);
+  reverse_words((unsigned long *)b_ints, b, longwords);
+  reverse_words((unsigned long *)n_ints, n, longwords);
+
+  ::montgomery_multiply(a, b, n, m, (unsigned long)inv, longwords);
+
+  reverse_words(m, (unsigned long *)m_ints, longwords);
+}
+
+void SharedRuntime::montgomery_square(jint *a_ints, jint *n_ints,
+                                      jint len, jlong inv,
+                                      jint *m_ints) {
+  len = len & 0x7fffFFFF; // C2 does not respect int to long conversion for stub calls.
+  assert(len % 2 == 0, "array length in montgomery_square must be even");
+  int longwords = len/2;
+
+  // Make very sure we don't use so much space that the stack might
+  // overflow. 512 jints corresponds to an 16384-bit integer and
+  // will use here a total of 6k bytes of stack space.
+  int total_allocation = longwords * sizeof (unsigned long) * 3;
+  guarantee(total_allocation <= 8192, "must be");
+  unsigned long *scratch = (unsigned long *)alloca(total_allocation);
+
+  // Local scratch arrays
+  unsigned long
+    *a = scratch + 0 * longwords,
+    *n = scratch + 1 * longwords,
+    *m = scratch + 2 * longwords;
+
+  reverse_words((unsigned long *)a_ints, a, longwords);
+  reverse_words((unsigned long *)n_ints, n, longwords);
+
+  if (len >= MONTGOMERY_SQUARING_THRESHOLD) {
+    ::montgomery_square(a, n, m, (unsigned long)inv, longwords);
+  } else {
+    ::montgomery_multiply(a, a, n, m, (unsigned long)inv, longwords);
+  }
+
+  reverse_words(m, (unsigned long *)m_ints, longwords);
+}
+
+extern "C"
+int SpinPause() {
+  return 0;
+}