diff src/cpu/x86/vm/stubGenerator_x86_64.cpp @ 0:a61af66fc99e jdk7-b24

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children f8236e79048a
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,2907 @@
+/*
+ * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_stubGenerator_x86_64.cpp.incl"
+
+// Declaration and definition of StubGenerator (no .hpp file).
+// For a more detailed description of the stub routine structure
+// see the comment in stubRoutines.hpp
+
+#define __ _masm->
+
+#ifdef PRODUCT
+#define BLOCK_COMMENT(str) /* nothing */
+#else
+#define BLOCK_COMMENT(str) __ block_comment(str)
+#endif
+
+#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
+const int MXCSR_MASK = 0xFFC0;  // Mask out any pending exceptions
+
+// Stub Code definitions
+
+static address handle_unsafe_access() {
+  JavaThread* thread = JavaThread::current();
+  address pc = thread->saved_exception_pc();
+  // pc is the instruction which we must emulate
+  // doing a no-op is fine:  return garbage from the load
+  // therefore, compute npc
+  address npc = Assembler::locate_next_instruction(pc);
+
+  // request an async exception
+  thread->set_pending_unsafe_access_error();
+
+  // return address of next instruction to execute
+  return npc;
+}
+
+class StubGenerator: public StubCodeGenerator {
+ private:
+
+#ifdef PRODUCT
+#define inc_counter_np(counter) (0)
+#else
+  void inc_counter_np_(int& counter) {
+    __ incrementl(ExternalAddress((address)&counter));
+  }
+#define inc_counter_np(counter) \
+  BLOCK_COMMENT("inc_counter " #counter); \
+  inc_counter_np_(counter);
+#endif
+
+  // Call stubs are used to call Java from C
+  //
+  // Linux Arguments:
+  //    c_rarg0:   call wrapper address                   address
+  //    c_rarg1:   result                                 address
+  //    c_rarg2:   result type                            BasicType
+  //    c_rarg3:   method                                 methodOop
+  //    c_rarg4:   (interpreter) entry point              address
+  //    c_rarg5:   parameters                             intptr_t*
+  //    16(rbp): parameter size (in words)              int
+  //    24(rbp): thread                                 Thread*
+  //
+  //     [ return_from_Java     ] <--- rsp
+  //     [ argument word n      ]
+  //      ...
+  // -12 [ argument word 1      ]
+  // -11 [ saved r15            ] <--- rsp_after_call
+  // -10 [ saved r14            ]
+  //  -9 [ saved r13            ]
+  //  -8 [ saved r12            ]
+  //  -7 [ saved rbx            ]
+  //  -6 [ call wrapper         ]
+  //  -5 [ result               ]
+  //  -4 [ result type          ]
+  //  -3 [ method               ]
+  //  -2 [ entry point          ]
+  //  -1 [ parameters           ]
+  //   0 [ saved rbp            ] <--- rbp
+  //   1 [ return address       ]
+  //   2 [ parameter size       ]
+  //   3 [ thread               ]
+  //
+  // Windows Arguments:
+  //    c_rarg0:   call wrapper address                   address
+  //    c_rarg1:   result                                 address
+  //    c_rarg2:   result type                            BasicType
+  //    c_rarg3:   method                                 methodOop
+  //    48(rbp): (interpreter) entry point              address
+  //    56(rbp): parameters                             intptr_t*
+  //    64(rbp): parameter size (in words)              int
+  //    72(rbp): thread                                 Thread*
+  //
+  //     [ return_from_Java     ] <--- rsp
+  //     [ argument word n      ]
+  //      ...
+  //  -8 [ argument word 1      ]
+  //  -7 [ saved r15            ] <--- rsp_after_call
+  //  -6 [ saved r14            ]
+  //  -5 [ saved r13            ]
+  //  -4 [ saved r12            ]
+  //  -3 [ saved rdi            ]
+  //  -2 [ saved rsi            ]
+  //  -1 [ saved rbx            ]
+  //   0 [ saved rbp            ] <--- rbp
+  //   1 [ return address       ]
+  //   2 [ call wrapper         ]
+  //   3 [ result               ]
+  //   4 [ result type          ]
+  //   5 [ method               ]
+  //   6 [ entry point          ]
+  //   7 [ parameters           ]
+  //   8 [ parameter size       ]
+  //   9 [ thread               ]
+  //
+  //    Windows reserves the callers stack space for arguments 1-4.
+  //    We spill c_rarg0-c_rarg3 to this space.
+
+  // Call stub stack layout word offsets from rbp
+  enum call_stub_layout {
+#ifdef _WIN64
+    rsp_after_call_off = -7,
+    r15_off            = rsp_after_call_off,
+    r14_off            = -6,
+    r13_off            = -5,
+    r12_off            = -4,
+    rdi_off            = -3,
+    rsi_off            = -2,
+    rbx_off            = -1,
+    rbp_off            =  0,
+    retaddr_off        =  1,
+    call_wrapper_off   =  2,
+    result_off         =  3,
+    result_type_off    =  4,
+    method_off         =  5,
+    entry_point_off    =  6,
+    parameters_off     =  7,
+    parameter_size_off =  8,
+    thread_off         =  9
+#else
+    rsp_after_call_off = -12,
+    mxcsr_off          = rsp_after_call_off,
+    r15_off            = -11,
+    r14_off            = -10,
+    r13_off            = -9,
+    r12_off            = -8,
+    rbx_off            = -7,
+    call_wrapper_off   = -6,
+    result_off         = -5,
+    result_type_off    = -4,
+    method_off         = -3,
+    entry_point_off    = -2,
+    parameters_off     = -1,
+    rbp_off            =  0,
+    retaddr_off        =  1,
+    parameter_size_off =  2,
+    thread_off         =  3
+#endif
+  };
+
+  address generate_call_stub(address& return_address) {
+    assert((int)frame::entry_frame_after_call_words == -(int)rsp_after_call_off + 1 &&
+           (int)frame::entry_frame_call_wrapper_offset == (int)call_wrapper_off,
+           "adjust this code");
+    StubCodeMark mark(this, "StubRoutines", "call_stub");
+    address start = __ pc();
+
+    // same as in generate_catch_exception()!
+    const Address rsp_after_call(rbp, rsp_after_call_off * wordSize);
+
+    const Address call_wrapper  (rbp, call_wrapper_off   * wordSize);
+    const Address result        (rbp, result_off         * wordSize);
+    const Address result_type   (rbp, result_type_off    * wordSize);
+    const Address method        (rbp, method_off         * wordSize);
+    const Address entry_point   (rbp, entry_point_off    * wordSize);
+    const Address parameters    (rbp, parameters_off     * wordSize);
+    const Address parameter_size(rbp, parameter_size_off * wordSize);
+
+    // same as in generate_catch_exception()!
+    const Address thread        (rbp, thread_off         * wordSize);
+
+    const Address r15_save(rbp, r15_off * wordSize);
+    const Address r14_save(rbp, r14_off * wordSize);
+    const Address r13_save(rbp, r13_off * wordSize);
+    const Address r12_save(rbp, r12_off * wordSize);
+    const Address rbx_save(rbp, rbx_off * wordSize);
+
+    // stub code
+    __ enter();
+    __ subq(rsp, -rsp_after_call_off * wordSize);
+
+    // save register parameters
+#ifndef _WIN64
+    __ movq(parameters,   c_rarg5); // parameters
+    __ movq(entry_point,  c_rarg4); // entry_point
+#endif
+
+    __ movq(method,       c_rarg3); // method
+    __ movl(result_type,  c_rarg2); // result type
+    __ movq(result,       c_rarg1); // result
+    __ movq(call_wrapper, c_rarg0); // call wrapper
+
+    // save regs belonging to calling function
+    __ movq(rbx_save, rbx);
+    __ movq(r12_save, r12);
+    __ movq(r13_save, r13);
+    __ movq(r14_save, r14);
+    __ movq(r15_save, r15);
+
+#ifdef _WIN64
+    const Address rdi_save(rbp, rdi_off * wordSize);
+    const Address rsi_save(rbp, rsi_off * wordSize);
+
+    __ movq(rsi_save, rsi);
+    __ movq(rdi_save, rdi);
+#else
+    const Address mxcsr_save(rbp, mxcsr_off * wordSize);
+    {
+      Label skip_ldmx;
+      __ stmxcsr(mxcsr_save);
+      __ movl(rax, mxcsr_save);
+      __ andl(rax, MXCSR_MASK);    // Only check control and mask bits
+      ExternalAddress mxcsr_std(StubRoutines::amd64::mxcsr_std());
+      __ cmp32(rax, mxcsr_std);
+      __ jcc(Assembler::equal, skip_ldmx);
+      __ ldmxcsr(mxcsr_std);
+      __ bind(skip_ldmx);
+    }
+#endif
+
+    // Load up thread register
+    __ movq(r15_thread, thread);
+
+#ifdef ASSERT
+    // make sure we have no pending exceptions
+    {
+      Label L;
+      __ cmpq(Address(r15_thread, Thread::pending_exception_offset()), (int)NULL_WORD);
+      __ jcc(Assembler::equal, L);
+      __ stop("StubRoutines::call_stub: entered with pending exception");
+      __ bind(L);
+    }
+#endif
+
+    // pass parameters if any
+    BLOCK_COMMENT("pass parameters if any");
+    Label parameters_done;
+    __ movl(c_rarg3, parameter_size);
+    __ testl(c_rarg3, c_rarg3);
+    __ jcc(Assembler::zero, parameters_done);
+
+    Label loop;
+    __ movq(c_rarg2, parameters);     // parameter pointer
+    __ movl(c_rarg1, c_rarg3);        // parameter counter is in c_rarg1
+    __ BIND(loop);
+    if (TaggedStackInterpreter) {
+      __ movq(rax, Address(c_rarg2, 0)); // get tag
+      __ addq(c_rarg2, wordSize);     // advance to next tag
+      __ pushq(rax);                  // pass tag
+    }
+    __ movq(rax, Address(c_rarg2, 0));  // get parameter
+    __ addq(c_rarg2, wordSize);       // advance to next parameter
+    __ decrementl(c_rarg1);           // decrement counter
+    __ pushq(rax);                    // pass parameter
+    __ jcc(Assembler::notZero, loop);
+
+    // call Java function
+    __ BIND(parameters_done);
+    __ movq(rbx, method);             // get methodOop
+    __ movq(c_rarg1, entry_point);    // get entry_point
+    __ movq(r13, rsp);                // set sender sp
+    BLOCK_COMMENT("call Java function");
+    __ call(c_rarg1);
+
+    BLOCK_COMMENT("call_stub_return_address:");
+    return_address = __ pc();
+
+    // store result depending on type (everything that is not
+    // T_OBJECT, T_LONG, T_FLOAT or T_DOUBLE is treated as T_INT)
+    __ movq(c_rarg0, result);
+    Label is_long, is_float, is_double, exit;
+    __ movl(c_rarg1, result_type);
+    __ cmpl(c_rarg1, T_OBJECT);
+    __ jcc(Assembler::equal, is_long);
+    __ cmpl(c_rarg1, T_LONG);
+    __ jcc(Assembler::equal, is_long);
+    __ cmpl(c_rarg1, T_FLOAT);
+    __ jcc(Assembler::equal, is_float);
+    __ cmpl(c_rarg1, T_DOUBLE);
+    __ jcc(Assembler::equal, is_double);
+
+    // handle T_INT case
+    __ movl(Address(c_rarg0, 0), rax);
+
+    __ BIND(exit);
+
+    // pop parameters
+    __ leaq(rsp, rsp_after_call);
+
+#ifdef ASSERT
+    // verify that threads correspond
+    {
+      Label L, S;
+      __ cmpq(r15_thread, thread);
+      __ jcc(Assembler::notEqual, S);
+      __ get_thread(rbx);
+      __ cmpq(r15_thread, rbx);
+      __ jcc(Assembler::equal, L);
+      __ bind(S);
+      __ jcc(Assembler::equal, L);
+      __ stop("StubRoutines::call_stub: threads must correspond");
+      __ bind(L);
+    }
+#endif
+
+    // restore regs belonging to calling function
+    __ movq(r15, r15_save);
+    __ movq(r14, r14_save);
+    __ movq(r13, r13_save);
+    __ movq(r12, r12_save);
+    __ movq(rbx, rbx_save);
+
+#ifdef _WIN64
+    __ movq(rdi, rdi_save);
+    __ movq(rsi, rsi_save);
+#else
+    __ ldmxcsr(mxcsr_save);
+#endif
+
+    // restore rsp
+    __ addq(rsp, -rsp_after_call_off * wordSize);
+
+    // return
+    __ popq(rbp);
+    __ ret(0);
+
+    // handle return types different from T_INT
+    __ BIND(is_long);
+    __ movq(Address(c_rarg0, 0), rax);
+    __ jmp(exit);
+
+    __ BIND(is_float);
+    __ movflt(Address(c_rarg0, 0), xmm0);
+    __ jmp(exit);
+
+    __ BIND(is_double);
+    __ movdbl(Address(c_rarg0, 0), xmm0);
+    __ jmp(exit);
+
+    return start;
+  }
+
+  // Return point for a Java call if there's an exception thrown in
+  // Java code.  The exception is caught and transformed into a
+  // pending exception stored in JavaThread that can be tested from
+  // within the VM.
+  //
+  // Note: Usually the parameters are removed by the callee. In case
+  // of an exception crossing an activation frame boundary, that is
+  // not the case if the callee is compiled code => need to setup the
+  // rsp.
+  //
+  // rax: exception oop
+
+  address generate_catch_exception() {
+    StubCodeMark mark(this, "StubRoutines", "catch_exception");
+    address start = __ pc();
+
+    // same as in generate_call_stub():
+    const Address rsp_after_call(rbp, rsp_after_call_off * wordSize);
+    const Address thread        (rbp, thread_off         * wordSize);
+
+#ifdef ASSERT
+    // verify that threads correspond
+    {
+      Label L, S;
+      __ cmpq(r15_thread, thread);
+      __ jcc(Assembler::notEqual, S);
+      __ get_thread(rbx);
+      __ cmpq(r15_thread, rbx);
+      __ jcc(Assembler::equal, L);
+      __ bind(S);
+      __ stop("StubRoutines::catch_exception: threads must correspond");
+      __ bind(L);
+    }
+#endif
+
+    // set pending exception
+    __ verify_oop(rax);
+
+    __ movq(Address(r15_thread, Thread::pending_exception_offset()), rax);
+    __ lea(rscratch1, ExternalAddress((address)__FILE__));
+    __ movq(Address(r15_thread, Thread::exception_file_offset()), rscratch1);
+    __ movl(Address(r15_thread, Thread::exception_line_offset()), (int)  __LINE__);
+
+    // complete return to VM
+    assert(StubRoutines::_call_stub_return_address != NULL,
+           "_call_stub_return_address must have been generated before");
+    __ jump(RuntimeAddress(StubRoutines::_call_stub_return_address));
+
+    return start;
+  }
+
+  // Continuation point for runtime calls returning with a pending
+  // exception.  The pending exception check happened in the runtime
+  // or native call stub.  The pending exception in Thread is
+  // converted into a Java-level exception.
+  //
+  // Contract with Java-level exception handlers:
+  // rax: exception
+  // rdx: throwing pc
+  //
+  // NOTE: At entry of this stub, exception-pc must be on stack !!
+
+  address generate_forward_exception() {
+    StubCodeMark mark(this, "StubRoutines", "forward exception");
+    address start = __ pc();
+
+    // Upon entry, the sp points to the return address returning into
+    // Java (interpreted or compiled) code; i.e., the return address
+    // becomes the throwing pc.
+    //
+    // Arguments pushed before the runtime call are still on the stack
+    // but the exception handler will reset the stack pointer ->
+    // ignore them.  A potential result in registers can be ignored as
+    // well.
+
+#ifdef ASSERT
+    // make sure this code is only executed if there is a pending exception
+    {
+      Label L;
+      __ cmpq(Address(r15_thread, Thread::pending_exception_offset()), (int) NULL);
+      __ jcc(Assembler::notEqual, L);
+      __ stop("StubRoutines::forward exception: no pending exception (1)");
+      __ bind(L);
+    }
+#endif
+
+    // compute exception handler into rbx
+    __ movq(c_rarg0, Address(rsp, 0));
+    BLOCK_COMMENT("call exception_handler_for_return_address");
+    __ call_VM_leaf(CAST_FROM_FN_PTR(address,
+                         SharedRuntime::exception_handler_for_return_address),
+                    c_rarg0);
+    __ movq(rbx, rax);
+
+    // setup rax & rdx, remove return address & clear pending exception
+    __ popq(rdx);
+    __ movq(rax, Address(r15_thread, Thread::pending_exception_offset()));
+    __ movptr(Address(r15_thread, Thread::pending_exception_offset()), (int)NULL_WORD);
+
+#ifdef ASSERT
+    // make sure exception is set
+    {
+      Label L;
+      __ testq(rax, rax);
+      __ jcc(Assembler::notEqual, L);
+      __ stop("StubRoutines::forward exception: no pending exception (2)");
+      __ bind(L);
+    }
+#endif
+
+    // continue at exception handler (return address removed)
+    // rax: exception
+    // rbx: exception handler
+    // rdx: throwing pc
+    __ verify_oop(rax);
+    __ jmp(rbx);
+
+    return start;
+  }
+
+  // Support for jint atomic::xchg(jint exchange_value, volatile jint* dest)
+  //
+  // Arguments :
+  //    c_rarg0: exchange_value
+  //    c_rarg0: dest
+  //
+  // Result:
+  //    *dest <- ex, return (orig *dest)
+  address generate_atomic_xchg() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_xchg");
+    address start = __ pc();
+
+    __ movl(rax, c_rarg0); // Copy to eax we need a return value anyhow
+    __ xchgl(rax, Address(c_rarg1, 0)); // automatic LOCK
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for intptr_t atomic::xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest)
+  //
+  // Arguments :
+  //    c_rarg0: exchange_value
+  //    c_rarg1: dest
+  //
+  // Result:
+  //    *dest <- ex, return (orig *dest)
+  address generate_atomic_xchg_ptr() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_xchg_ptr");
+    address start = __ pc();
+
+    __ movq(rax, c_rarg0); // Copy to eax we need a return value anyhow
+    __ xchgq(rax, Address(c_rarg1, 0)); // automatic LOCK
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for jint atomic::atomic_cmpxchg(jint exchange_value, volatile jint* dest,
+  //                                         jint compare_value)
+  //
+  // Arguments :
+  //    c_rarg0: exchange_value
+  //    c_rarg1: dest
+  //    c_rarg2: compare_value
+  //
+  // Result:
+  //    if ( compare_value == *dest ) {
+  //       *dest = exchange_value
+  //       return compare_value;
+  //    else
+  //       return *dest;
+  address generate_atomic_cmpxchg() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_cmpxchg");
+    address start = __ pc();
+
+    __ movl(rax, c_rarg2);
+   if ( os::is_MP() ) __ lock();
+    __ cmpxchgl(c_rarg0, Address(c_rarg1, 0));
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for jint atomic::atomic_cmpxchg_long(jlong exchange_value,
+  //                                             volatile jlong* dest,
+  //                                             jlong compare_value)
+  // Arguments :
+  //    c_rarg0: exchange_value
+  //    c_rarg1: dest
+  //    c_rarg2: compare_value
+  //
+  // Result:
+  //    if ( compare_value == *dest ) {
+  //       *dest = exchange_value
+  //       return compare_value;
+  //    else
+  //       return *dest;
+  address generate_atomic_cmpxchg_long() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_cmpxchg_long");
+    address start = __ pc();
+
+    __ movq(rax, c_rarg2);
+   if ( os::is_MP() ) __ lock();
+    __ cmpxchgq(c_rarg0, Address(c_rarg1, 0));
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for jint atomic::add(jint add_value, volatile jint* dest)
+  //
+  // Arguments :
+  //    c_rarg0: add_value
+  //    c_rarg1: dest
+  //
+  // Result:
+  //    *dest += add_value
+  //    return *dest;
+  address generate_atomic_add() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_add");
+    address start = __ pc();
+
+    __ movl(rax, c_rarg0);
+   if ( os::is_MP() ) __ lock();
+    __ xaddl(Address(c_rarg1, 0), c_rarg0);
+    __ addl(rax, c_rarg0);
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for intptr_t atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest)
+  //
+  // Arguments :
+  //    c_rarg0: add_value
+  //    c_rarg1: dest
+  //
+  // Result:
+  //    *dest += add_value
+  //    return *dest;
+  address generate_atomic_add_ptr() {
+    StubCodeMark mark(this, "StubRoutines", "atomic_add_ptr");
+    address start = __ pc();
+
+    __ movq(rax, c_rarg0); // Copy to eax we need a return value anyhow
+   if ( os::is_MP() ) __ lock();
+    __ xaddl(Address(c_rarg1, 0), c_rarg0);
+    __ addl(rax, c_rarg0);
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for intptr_t OrderAccess::fence()
+  //
+  // Arguments :
+  //
+  // Result:
+  address generate_orderaccess_fence() {
+    StubCodeMark mark(this, "StubRoutines", "orderaccess_fence");
+    address start = __ pc();
+    __ mfence();
+    __ ret(0);
+
+    return start;
+  }
+
+  // Support for intptr_t get_previous_fp()
+  //
+  // This routine is used to find the previous frame pointer for the
+  // caller (current_frame_guess). This is used as part of debugging
+  // ps() is seemingly lost trying to find frames.
+  // This code assumes that caller current_frame_guess) has a frame.
+  address generate_get_previous_fp() {
+    StubCodeMark mark(this, "StubRoutines", "get_previous_fp");
+    const Address old_fp(rbp, 0);
+    const Address older_fp(rax, 0);
+    address start = __ pc();
+
+    __ enter();
+    __ movq(rax, old_fp); // callers fp
+    __ movq(rax, older_fp); // the frame for ps()
+    __ popq(rbp);
+    __ ret(0);
+
+    return start;
+  }
+
+  //----------------------------------------------------------------------------------------------------
+  // Support for void verify_mxcsr()
+  //
+  // This routine is used with -Xcheck:jni to verify that native
+  // JNI code does not return to Java code without restoring the
+  // MXCSR register to our expected state.
+
+  address generate_verify_mxcsr() {
+    StubCodeMark mark(this, "StubRoutines", "verify_mxcsr");
+    address start = __ pc();
+
+    const Address mxcsr_save(rsp, 0);
+
+    if (CheckJNICalls) {
+      Label ok_ret;
+      __ pushq(rax);
+      __ subq(rsp, wordSize);      // allocate a temp location
+      __ stmxcsr(mxcsr_save);
+      __ movl(rax, mxcsr_save);
+      __ andl(rax, MXCSR_MASK);    // Only check control and mask bits
+      __ cmpl(rax, *(int *)(StubRoutines::amd64::mxcsr_std()));
+      __ jcc(Assembler::equal, ok_ret);
+
+      __ warn("MXCSR changed by native JNI code, use -XX:+RestoreMXCSROnJNICall");
+
+      __ ldmxcsr(ExternalAddress(StubRoutines::amd64::mxcsr_std()));
+
+      __ bind(ok_ret);
+      __ addq(rsp, wordSize);
+      __ popq(rax);
+    }
+
+    __ ret(0);
+
+    return start;
+  }
+
+  address generate_f2i_fixup() {
+    StubCodeMark mark(this, "StubRoutines", "f2i_fixup");
+    Address inout(rsp, 5 * wordSize); // return address + 4 saves
+
+    address start = __ pc();
+
+    Label L;
+
+    __ pushq(rax);
+    __ pushq(c_rarg3);
+    __ pushq(c_rarg2);
+    __ pushq(c_rarg1);
+
+    __ movl(rax, 0x7f800000);
+    __ xorl(c_rarg3, c_rarg3);
+    __ movl(c_rarg2, inout);
+    __ movl(c_rarg1, c_rarg2);
+    __ andl(c_rarg1, 0x7fffffff);
+    __ cmpl(rax, c_rarg1); // NaN? -> 0
+    __ jcc(Assembler::negative, L);
+    __ testl(c_rarg2, c_rarg2); // signed ? min_jint : max_jint
+    __ movl(c_rarg3, 0x80000000);
+    __ movl(rax, 0x7fffffff);
+    __ cmovl(Assembler::positive, c_rarg3, rax);
+
+    __ bind(L);
+    __ movq(inout, c_rarg3);
+
+    __ popq(c_rarg1);
+    __ popq(c_rarg2);
+    __ popq(c_rarg3);
+    __ popq(rax);
+
+    __ ret(0);
+
+    return start;
+  }
+
+  address generate_f2l_fixup() {
+    StubCodeMark mark(this, "StubRoutines", "f2l_fixup");
+    Address inout(rsp, 5 * wordSize); // return address + 4 saves
+    address start = __ pc();
+
+    Label L;
+
+    __ pushq(rax);
+    __ pushq(c_rarg3);
+    __ pushq(c_rarg2);
+    __ pushq(c_rarg1);
+
+    __ movl(rax, 0x7f800000);
+    __ xorl(c_rarg3, c_rarg3);
+    __ movl(c_rarg2, inout);
+    __ movl(c_rarg1, c_rarg2);
+    __ andl(c_rarg1, 0x7fffffff);
+    __ cmpl(rax, c_rarg1); // NaN? -> 0
+    __ jcc(Assembler::negative, L);
+    __ testl(c_rarg2, c_rarg2); // signed ? min_jlong : max_jlong
+    __ mov64(c_rarg3, 0x8000000000000000);
+    __ mov64(rax, 0x7fffffffffffffff);
+    __ cmovq(Assembler::positive, c_rarg3, rax);
+
+    __ bind(L);
+    __ movq(inout, c_rarg3);
+
+    __ popq(c_rarg1);
+    __ popq(c_rarg2);
+    __ popq(c_rarg3);
+    __ popq(rax);
+
+    __ ret(0);
+
+    return start;
+  }
+
+  address generate_d2i_fixup() {
+    StubCodeMark mark(this, "StubRoutines", "d2i_fixup");
+    Address inout(rsp, 6 * wordSize); // return address + 5 saves
+
+    address start = __ pc();
+
+    Label L;
+
+    __ pushq(rax);
+    __ pushq(c_rarg3);
+    __ pushq(c_rarg2);
+    __ pushq(c_rarg1);
+    __ pushq(c_rarg0);
+
+    __ movl(rax, 0x7ff00000);
+    __ movq(c_rarg2, inout);
+    __ movl(c_rarg3, c_rarg2);
+    __ movq(c_rarg1, c_rarg2);
+    __ movq(c_rarg0, c_rarg2);
+    __ negl(c_rarg3);
+    __ shrq(c_rarg1, 0x20);
+    __ orl(c_rarg3, c_rarg2);
+    __ andl(c_rarg1, 0x7fffffff);
+    __ xorl(c_rarg2, c_rarg2);
+    __ shrl(c_rarg3, 0x1f);
+    __ orl(c_rarg1, c_rarg3);
+    __ cmpl(rax, c_rarg1);
+    __ jcc(Assembler::negative, L); // NaN -> 0
+    __ testq(c_rarg0, c_rarg0); // signed ? min_jint : max_jint
+    __ movl(c_rarg2, 0x80000000);
+    __ movl(rax, 0x7fffffff);
+    __ cmovl(Assembler::positive, c_rarg2, rax);
+
+    __ bind(L);
+    __ movq(inout, c_rarg2);
+
+    __ popq(c_rarg0);
+    __ popq(c_rarg1);
+    __ popq(c_rarg2);
+    __ popq(c_rarg3);
+    __ popq(rax);
+
+    __ ret(0);
+
+    return start;
+  }
+
+  address generate_d2l_fixup() {
+    StubCodeMark mark(this, "StubRoutines", "d2l_fixup");
+    Address inout(rsp, 6 * wordSize); // return address + 5 saves
+
+    address start = __ pc();
+
+    Label L;
+
+    __ pushq(rax);
+    __ pushq(c_rarg3);
+    __ pushq(c_rarg2);
+    __ pushq(c_rarg1);
+    __ pushq(c_rarg0);
+
+    __ movl(rax, 0x7ff00000);
+    __ movq(c_rarg2, inout);
+    __ movl(c_rarg3, c_rarg2);
+    __ movq(c_rarg1, c_rarg2);
+    __ movq(c_rarg0, c_rarg2);
+    __ negl(c_rarg3);
+    __ shrq(c_rarg1, 0x20);
+    __ orl(c_rarg3, c_rarg2);
+    __ andl(c_rarg1, 0x7fffffff);
+    __ xorl(c_rarg2, c_rarg2);
+    __ shrl(c_rarg3, 0x1f);
+    __ orl(c_rarg1, c_rarg3);
+    __ cmpl(rax, c_rarg1);
+    __ jcc(Assembler::negative, L); // NaN -> 0
+    __ testq(c_rarg0, c_rarg0); // signed ? min_jlong : max_jlong
+    __ mov64(c_rarg2, 0x8000000000000000);
+    __ mov64(rax, 0x7fffffffffffffff);
+    __ cmovq(Assembler::positive, c_rarg2, rax);
+
+    __ bind(L);
+    __ movq(inout, c_rarg2);
+
+    __ popq(c_rarg0);
+    __ popq(c_rarg1);
+    __ popq(c_rarg2);
+    __ popq(c_rarg3);
+    __ popq(rax);
+
+    __ ret(0);
+
+    return start;
+  }
+
+  address generate_fp_mask(const char *stub_name, int64_t mask) {
+    StubCodeMark mark(this, "StubRoutines", stub_name);
+
+    __ align(16);
+    address start = __ pc();
+
+    __ emit_data64( mask, relocInfo::none );
+    __ emit_data64( mask, relocInfo::none );
+
+    return start;
+  }
+
+  // The following routine generates a subroutine to throw an
+  // asynchronous UnknownError when an unsafe access gets a fault that
+  // could not be reasonably prevented by the programmer.  (Example:
+  // SIGBUS/OBJERR.)
+  address generate_handler_for_unsafe_access() {
+    StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
+    address start = __ pc();
+
+    __ pushq(0);                      // hole for return address-to-be
+    __ pushaq();                      // push registers
+    Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);
+
+    __ subq(rsp, frame::arg_reg_save_area_bytes);
+    BLOCK_COMMENT("call handle_unsafe_access");
+    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));
+    __ addq(rsp, frame::arg_reg_save_area_bytes);
+
+    __ movq(next_pc, rax);            // stuff next address
+    __ popaq();
+    __ ret(0);                        // jump to next address
+
+    return start;
+  }
+
+  // Non-destructive plausibility checks for oops
+  //
+  // Arguments:
+  //    all args on stack!
+  //
+  // Stack after saving c_rarg3:
+  //    [tos + 0]: saved c_rarg3
+  //    [tos + 1]: saved c_rarg2
+  //    [tos + 2]: saved flags
+  //    [tos + 3]: return address
+  //  * [tos + 4]: error message (char*)
+  //  * [tos + 5]: object to verify (oop)
+  //  * [tos + 6]: saved rax - saved by caller and bashed
+  //  * = popped on exit
+  address generate_verify_oop() {
+    StubCodeMark mark(this, "StubRoutines", "verify_oop");
+    address start = __ pc();
+
+    Label exit, error;
+
+    __ pushfq();
+    __ incrementl(ExternalAddress((address) StubRoutines::verify_oop_count_addr()));
+
+    // save c_rarg2 and c_rarg3
+    __ pushq(c_rarg2);
+    __ pushq(c_rarg3);
+
+    // get object
+    __ movq(rax, Address(rsp, 5 * wordSize));
+
+    // make sure object is 'reasonable'
+    __ testq(rax, rax);
+    __ jcc(Assembler::zero, exit); // if obj is NULL it is OK
+    // Check if the oop is in the right area of memory
+    __ movq(c_rarg2, rax);
+    __ movptr(c_rarg3, (int64_t) Universe::verify_oop_mask());
+    __ andq(c_rarg2, c_rarg3);
+    __ movptr(c_rarg3, (int64_t) Universe::verify_oop_bits());
+    __ cmpq(c_rarg2, c_rarg3);
+    __ jcc(Assembler::notZero, error);
+
+    // make sure klass is 'reasonable'
+    __ movq(rax, Address(rax, oopDesc::klass_offset_in_bytes())); // get klass
+    __ testq(rax, rax);
+    __ jcc(Assembler::zero, error); // if klass is NULL it is broken
+    // Check if the klass is in the right area of memory
+    __ movq(c_rarg2, rax);
+    __ movptr(c_rarg3, (int64_t) Universe::verify_klass_mask());
+    __ andq(c_rarg2, c_rarg3);
+    __ movptr(c_rarg3, (int64_t) Universe::verify_klass_bits());
+    __ cmpq(c_rarg2, c_rarg3);
+    __ jcc(Assembler::notZero, error);
+
+    // make sure klass' klass is 'reasonable'
+    __ movq(rax, Address(rax, oopDesc::klass_offset_in_bytes()));
+    __ testq(rax, rax);
+    __ jcc(Assembler::zero, error); // if klass' klass is NULL it is broken
+    // Check if the klass' klass is in the right area of memory
+    __ movptr(c_rarg3, (int64_t) Universe::verify_klass_mask());
+    __ andq(rax, c_rarg3);
+    __ movptr(c_rarg3, (int64_t) Universe::verify_klass_bits());
+    __ cmpq(rax, c_rarg3);
+    __ jcc(Assembler::notZero, error);
+
+    // return if everything seems ok
+    __ bind(exit);
+    __ movq(rax, Address(rsp, 6 * wordSize));    // get saved rax back
+    __ popq(c_rarg3);                              // restore c_rarg3
+    __ popq(c_rarg2);                              // restore c_rarg2
+    __ popfq();                                  // restore flags
+    __ ret(3 * wordSize);                        // pop caller saved stuff
+
+    // handle errors
+    __ bind(error);
+    __ movq(rax, Address(rsp, 6 * wordSize));    // get saved rax back
+    __ popq(c_rarg3);                              // get saved c_rarg3 back
+    __ popq(c_rarg2);                              // get saved c_rarg2 back
+    __ popfq();                                  // get saved flags off stack --
+                                                 // will be ignored
+
+    __ pushaq();                                 // push registers
+                                                 // (rip is already
+                                                 // already pushed)
+    // debug(char* msg, int64_t regs[])
+    // We've popped the registers we'd saved (c_rarg3, c_rarg2 and flags), and
+    // pushed all the registers, so now the stack looks like:
+    //     [tos +  0] 16 saved registers
+    //     [tos + 16] return address
+    //     [tos + 17] error message (char*)
+
+    __ movq(c_rarg0, Address(rsp, 17 * wordSize)); // pass address of error message
+    __ movq(c_rarg1, rsp);                         // pass address of regs on stack
+    __ movq(r12, rsp);                           // remember rsp
+    __ subq(rsp, frame::arg_reg_save_area_bytes);// windows
+    __ andq(rsp, -16);                           // align stack as required by ABI
+    BLOCK_COMMENT("call MacroAssembler::debug");
+    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, MacroAssembler::debug)));
+    __ movq(rsp, r12);                           // restore rsp
+    __ popaq();                                  // pop registers
+    __ ret(3 * wordSize);                        // pop caller saved stuff
+
+    return start;
+  }
+
+  static address disjoint_byte_copy_entry;
+  static address disjoint_short_copy_entry;
+  static address disjoint_int_copy_entry;
+  static address disjoint_long_copy_entry;
+  static address disjoint_oop_copy_entry;
+
+  static address byte_copy_entry;
+  static address short_copy_entry;
+  static address int_copy_entry;
+  static address long_copy_entry;
+  static address oop_copy_entry;
+
+  static address checkcast_copy_entry;
+
+  //
+  // Verify that a register contains clean 32-bits positive value
+  // (high 32-bits are 0) so it could be used in 64-bits shifts.
+  //
+  //  Input:
+  //    Rint  -  32-bits value
+  //    Rtmp  -  scratch
+  //
+  void assert_clean_int(Register Rint, Register Rtmp) {
+#ifdef ASSERT
+    Label L;
+    assert_different_registers(Rtmp, Rint);
+    __ movslq(Rtmp, Rint);
+    __ cmpq(Rtmp, Rint);
+    __ jccb(Assembler::equal, L);
+    __ stop("high 32-bits of int value are not 0");
+    __ bind(L);
+#endif
+  }
+
+  //  Generate overlap test for array copy stubs
+  //
+  //  Input:
+  //     c_rarg0 - from
+  //     c_rarg1 - to
+  //     c_rarg2 - element count
+  //
+  //  Output:
+  //     rax   - &from[element count - 1]
+  //
+  void array_overlap_test(address no_overlap_target, Address::ScaleFactor sf) {
+    assert(no_overlap_target != NULL, "must be generated");
+    array_overlap_test(no_overlap_target, NULL, sf);
+  }
+  void array_overlap_test(Label& L_no_overlap, Address::ScaleFactor sf) {
+    array_overlap_test(NULL, &L_no_overlap, sf);
+  }
+  void array_overlap_test(address no_overlap_target, Label* NOLp, Address::ScaleFactor sf) {
+    const Register from     = c_rarg0;
+    const Register to       = c_rarg1;
+    const Register count    = c_rarg2;
+    const Register end_from = rax;
+
+    __ cmpq(to, from);
+    __ leaq(end_from, Address(from, count, sf, 0));
+    if (NOLp == NULL) {
+      ExternalAddress no_overlap(no_overlap_target);
+      __ jump_cc(Assembler::belowEqual, no_overlap);
+      __ cmpq(to, end_from);
+      __ jump_cc(Assembler::aboveEqual, no_overlap);
+    } else {
+      __ jcc(Assembler::belowEqual, (*NOLp));
+      __ cmpq(to, end_from);
+      __ jcc(Assembler::aboveEqual, (*NOLp));
+    }
+  }
+
+  // Shuffle first three arg regs on Windows into Linux/Solaris locations.
+  //
+  // Outputs:
+  //    rdi - rcx
+  //    rsi - rdx
+  //    rdx - r8
+  //    rcx - r9
+  //
+  // Registers r9 and r10 are used to save rdi and rsi on Windows, which latter
+  // are non-volatile.  r9 and r10 should not be used by the caller.
+  //
+  void setup_arg_regs(int nargs = 3) {
+    const Register saved_rdi = r9;
+    const Register saved_rsi = r10;
+    assert(nargs == 3 || nargs == 4, "else fix");
+#ifdef _WIN64
+    assert(c_rarg0 == rcx && c_rarg1 == rdx && c_rarg2 == r8 && c_rarg3 == r9,
+           "unexpected argument registers");
+    if (nargs >= 4)
+      __ movq(rax, r9);  // r9 is also saved_rdi
+    __ movq(saved_rdi, rdi);
+    __ movq(saved_rsi, rsi);
+    __ movq(rdi, rcx); // c_rarg0
+    __ movq(rsi, rdx); // c_rarg1
+    __ movq(rdx, r8);  // c_rarg2
+    if (nargs >= 4)
+      __ movq(rcx, rax); // c_rarg3 (via rax)
+#else
+    assert(c_rarg0 == rdi && c_rarg1 == rsi && c_rarg2 == rdx && c_rarg3 == rcx,
+           "unexpected argument registers");
+#endif
+  }
+
+  void restore_arg_regs() {
+    const Register saved_rdi = r9;
+    const Register saved_rsi = r10;
+#ifdef _WIN64
+    __ movq(rdi, saved_rdi);
+    __ movq(rsi, saved_rsi);
+#endif
+  }
+
+  // Generate code for an array write pre barrier
+  //
+  //     addr    -  starting address
+  //     count    -  element count
+  //
+  //     Destroy no registers!
+  //
+  void  gen_write_ref_array_pre_barrier(Register addr, Register count) {
+#if 0 // G1 - only
+    assert_different_registers(addr, c_rarg1);
+    assert_different_registers(count, c_rarg0);
+    BarrierSet* bs = Universe::heap()->barrier_set();
+    switch (bs->kind()) {
+      case BarrierSet::G1SATBCT:
+      case BarrierSet::G1SATBCTLogging:
+        {
+          __ pushaq();                      // push registers
+          __ movq(c_rarg0, addr);
+          __ movq(c_rarg1, count);
+          __ call(RuntimeAddress(BarrierSet::static_write_ref_array_pre));
+          __ popaq();
+        }
+        break;
+      case BarrierSet::CardTableModRef:
+      case BarrierSet::CardTableExtension:
+      case BarrierSet::ModRef:
+        break;
+      default      :
+        ShouldNotReachHere();
+
+    }
+#endif // 0 G1 - only
+  }
+
+  //
+  // Generate code for an array write post barrier
+  //
+  //  Input:
+  //     start    - register containing starting address of destination array
+  //     end      - register containing ending address of destination array
+  //     scratch  - scratch register
+  //
+  //  The input registers are overwritten.
+  //  The ending address is inclusive.
+  void  gen_write_ref_array_post_barrier(Register start, Register end, Register scratch) {
+    assert_different_registers(start, end, scratch);
+    BarrierSet* bs = Universe::heap()->barrier_set();
+    switch (bs->kind()) {
+#if 0 // G1 - only
+      case BarrierSet::G1SATBCT:
+      case BarrierSet::G1SATBCTLogging:
+
+        {
+          __ pushaq();                      // push registers (overkill)
+          // must compute element count unless barrier set interface is changed (other platforms supply count)
+          assert_different_registers(start, end, scratch);
+          __ leaq(scratch, Address(end, wordSize));
+          __ subq(scratch, start);
+          __ shrq(scratch, LogBytesPerWord);
+          __ movq(c_rarg0, start);
+          __ movq(c_rarg1, scratch);
+          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post));
+          __ popaq();
+        }
+        break;
+#endif // 0 G1 - only
+      case BarrierSet::CardTableModRef:
+      case BarrierSet::CardTableExtension:
+        {
+          CardTableModRefBS* ct = (CardTableModRefBS*)bs;
+          assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
+
+          Label L_loop;
+
+           __ shrq(start, CardTableModRefBS::card_shift);
+           __ shrq(end, CardTableModRefBS::card_shift);
+           __ subq(end, start); // number of bytes to copy
+
+          const Register count = end; // 'end' register contains bytes count now
+          __ lea(scratch, ExternalAddress((address)ct->byte_map_base));
+          __ addq(start, scratch);
+        __ BIND(L_loop);
+          __ movb(Address(start, count, Address::times_1), 0);
+          __ decrementq(count);
+          __ jcc(Assembler::greaterEqual, L_loop);
+        }
+      }
+   }
+
+  // Copy big chunks forward
+  //
+  // Inputs:
+  //   end_from     - source arrays end address
+  //   end_to       - destination array end address
+  //   qword_count  - 64-bits element count, negative
+  //   to           - scratch
+  //   L_copy_32_bytes - entry label
+  //   L_copy_8_bytes  - exit  label
+  //
+  void copy_32_bytes_forward(Register end_from, Register end_to,
+                             Register qword_count, Register to,
+                             Label& L_copy_32_bytes, Label& L_copy_8_bytes) {
+    DEBUG_ONLY(__ stop("enter at entry label, not here"));
+    Label L_loop;
+    __ align(16);
+  __ BIND(L_loop);
+    __ movq(to, Address(end_from, qword_count, Address::times_8, -24));
+    __ movq(Address(end_to, qword_count, Address::times_8, -24), to);
+    __ movq(to, Address(end_from, qword_count, Address::times_8, -16));
+    __ movq(Address(end_to, qword_count, Address::times_8, -16), to);
+    __ movq(to, Address(end_from, qword_count, Address::times_8, - 8));
+    __ movq(Address(end_to, qword_count, Address::times_8, - 8), to);
+    __ movq(to, Address(end_from, qword_count, Address::times_8, - 0));
+    __ movq(Address(end_to, qword_count, Address::times_8, - 0), to);
+  __ BIND(L_copy_32_bytes);
+    __ addq(qword_count, 4);
+    __ jcc(Assembler::lessEqual, L_loop);
+    __ subq(qword_count, 4);
+    __ jcc(Assembler::less, L_copy_8_bytes); // Copy trailing qwords
+  }
+
+
+  // Copy big chunks backward
+  //
+  // Inputs:
+  //   from         - source arrays address
+  //   dest         - destination array address
+  //   qword_count  - 64-bits element count
+  //   to           - scratch
+  //   L_copy_32_bytes - entry label
+  //   L_copy_8_bytes  - exit  label
+  //
+  void copy_32_bytes_backward(Register from, Register dest,
+                              Register qword_count, Register to,
+                              Label& L_copy_32_bytes, Label& L_copy_8_bytes) {
+    DEBUG_ONLY(__ stop("enter at entry label, not here"));
+    Label L_loop;
+    __ align(16);
+  __ BIND(L_loop);
+    __ movq(to, Address(from, qword_count, Address::times_8, 24));
+    __ movq(Address(dest, qword_count, Address::times_8, 24), to);
+    __ movq(to, Address(from, qword_count, Address::times_8, 16));
+    __ movq(Address(dest, qword_count, Address::times_8, 16), to);
+    __ movq(to, Address(from, qword_count, Address::times_8,  8));
+    __ movq(Address(dest, qword_count, Address::times_8,  8), to);
+    __ movq(to, Address(from, qword_count, Address::times_8,  0));
+    __ movq(Address(dest, qword_count, Address::times_8,  0), to);
+  __ BIND(L_copy_32_bytes);
+    __ subq(qword_count, 4);
+    __ jcc(Assembler::greaterEqual, L_loop);
+    __ addq(qword_count, 4);
+    __ jcc(Assembler::greater, L_copy_8_bytes); // Copy trailing qwords
+  }
+
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4-, 2-, or 1-byte boundaries,
+  // we let the hardware handle it.  The one to eight bytes within words,
+  // dwords or qwords that span cache line boundaries will still be loaded
+  // and stored atomically.
+  //
+  // Side Effects:
+  //   disjoint_byte_copy_entry is set to the no-overlap entry point
+  //   used by generate_conjoint_byte_copy().
+  //
+  address generate_disjoint_byte_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_4_bytes, L_copy_2_bytes;
+    Label L_copy_byte, L_exit;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register byte_count  = rcx;
+    const Register qword_count = count;
+    const Register end_from    = from; // source array end address
+    const Register end_to      = to;   // destination array end address
+    // End pointers are inclusive, and if count is not zero they point
+    // to the last unit copied:  end_to[0] := end_from[0]
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    disjoint_byte_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(byte_count, count);
+    __ shrq(count, 3); // count => qword_count
+
+    // Copy from low to high addresses.  Use 'to' as scratch.
+    __ leaq(end_from, Address(from, qword_count, Address::times_8, -8));
+    __ leaq(end_to,   Address(to,   qword_count, Address::times_8, -8));
+    __ negq(qword_count); // make the count negative
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(end_from, qword_count, Address::times_8, 8));
+    __ movq(Address(end_to, qword_count, Address::times_8, 8), rax);
+    __ incrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    // Check for and copy trailing dword
+  __ BIND(L_copy_4_bytes);
+    __ testq(byte_count, 4);
+    __ jccb(Assembler::zero, L_copy_2_bytes);
+    __ movl(rax, Address(end_from, 8));
+    __ movl(Address(end_to, 8), rax);
+
+    __ addq(end_from, 4);
+    __ addq(end_to, 4);
+
+    // Check for and copy trailing word
+  __ BIND(L_copy_2_bytes);
+    __ testq(byte_count, 2);
+    __ jccb(Assembler::zero, L_copy_byte);
+    __ movw(rax, Address(end_from, 8));
+    __ movw(Address(end_to, 8), rax);
+
+    __ addq(end_from, 2);
+    __ addq(end_to, 2);
+
+    // Check for and copy trailing byte
+  __ BIND(L_copy_byte);
+    __ testq(byte_count, 1);
+    __ jccb(Assembler::zero, L_exit);
+    __ movb(rax, Address(end_from, 8));
+    __ movb(Address(end_to, 8), rax);
+
+  __ BIND(L_exit);
+    inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_forward(end_from, end_to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+    __ jmp(L_copy_4_bytes);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4-, 2-, or 1-byte boundaries,
+  // we let the hardware handle it.  The one to eight bytes within words,
+  // dwords or qwords that span cache line boundaries will still be loaded
+  // and stored atomically.
+  //
+  address generate_conjoint_byte_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_4_bytes, L_copy_2_bytes;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register byte_count  = rcx;
+    const Register qword_count = count;
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    byte_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    array_overlap_test(disjoint_byte_copy_entry, Address::times_1);
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(byte_count, count);
+    __ shrq(count, 3);   // count => qword_count
+
+    // Copy from high to low addresses.
+
+    // Check for and copy trailing byte
+    __ testq(byte_count, 1);
+    __ jcc(Assembler::zero, L_copy_2_bytes);
+    __ movb(rax, Address(from, byte_count, Address::times_1, -1));
+    __ movb(Address(to, byte_count, Address::times_1, -1), rax);
+    __ decrementq(byte_count); // Adjust for possible trailing word
+
+    // Check for and copy trailing word
+  __ BIND(L_copy_2_bytes);
+    __ testq(byte_count, 2);
+    __ jcc(Assembler::zero, L_copy_4_bytes);
+    __ movw(rax, Address(from, byte_count, Address::times_1, -2));
+    __ movw(Address(to, byte_count, Address::times_1, -2), rax);
+
+    // Check for and copy trailing dword
+  __ BIND(L_copy_4_bytes);
+    __ testq(byte_count, 4);
+    __ jcc(Assembler::zero, L_copy_32_bytes);
+    __ movl(rax, Address(from, qword_count, Address::times_8));
+    __ movl(Address(to, qword_count, Address::times_8), rax);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(from, qword_count, Address::times_8, -8));
+    __ movq(Address(to, qword_count, Address::times_8, -8), rax);
+    __ decrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_backward(from, to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4- or 2-byte boundaries, we
+  // let the hardware handle it.  The two or four words within dwords
+  // or qwords that span cache line boundaries will still be loaded
+  // and stored atomically.
+  //
+  // Side Effects:
+  //   disjoint_short_copy_entry is set to the no-overlap entry point
+  //   used by generate_conjoint_short_copy().
+  //
+  address generate_disjoint_short_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_4_bytes,L_copy_2_bytes,L_exit;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register word_count  = rcx;
+    const Register qword_count = count;
+    const Register end_from    = from; // source array end address
+    const Register end_to      = to;   // destination array end address
+    // End pointers are inclusive, and if count is not zero they point
+    // to the last unit copied:  end_to[0] := end_from[0]
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    disjoint_short_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(word_count, count);
+    __ shrq(count, 2); // count => qword_count
+
+    // Copy from low to high addresses.  Use 'to' as scratch.
+    __ leaq(end_from, Address(from, qword_count, Address::times_8, -8));
+    __ leaq(end_to,   Address(to,   qword_count, Address::times_8, -8));
+    __ negq(qword_count);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(end_from, qword_count, Address::times_8, 8));
+    __ movq(Address(end_to, qword_count, Address::times_8, 8), rax);
+    __ incrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    // Original 'dest' is trashed, so we can't use it as a
+    // base register for a possible trailing word copy
+
+    // Check for and copy trailing dword
+  __ BIND(L_copy_4_bytes);
+    __ testq(word_count, 2);
+    __ jccb(Assembler::zero, L_copy_2_bytes);
+    __ movl(rax, Address(end_from, 8));
+    __ movl(Address(end_to, 8), rax);
+
+    __ addq(end_from, 4);
+    __ addq(end_to, 4);
+
+    // Check for and copy trailing word
+  __ BIND(L_copy_2_bytes);
+    __ testq(word_count, 1);
+    __ jccb(Assembler::zero, L_exit);
+    __ movw(rax, Address(end_from, 8));
+    __ movw(Address(end_to, 8), rax);
+
+  __ BIND(L_exit);
+    inc_counter_np(SharedRuntime::_jshort_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_forward(end_from, end_to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+    __ jmp(L_copy_4_bytes);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4- or 2-byte boundaries, we
+  // let the hardware handle it.  The two or four words within dwords
+  // or qwords that span cache line boundaries will still be loaded
+  // and stored atomically.
+  //
+  address generate_conjoint_short_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_4_bytes;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register word_count  = rcx;
+    const Register qword_count = count;
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    short_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    array_overlap_test(disjoint_short_copy_entry, Address::times_2);
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(word_count, count);
+    __ shrq(count, 2); // count => qword_count
+
+    // Copy from high to low addresses.  Use 'to' as scratch.
+
+    // Check for and copy trailing word
+    __ testq(word_count, 1);
+    __ jccb(Assembler::zero, L_copy_4_bytes);
+    __ movw(rax, Address(from, word_count, Address::times_2, -2));
+    __ movw(Address(to, word_count, Address::times_2, -2), rax);
+
+    // Check for and copy trailing dword
+  __ BIND(L_copy_4_bytes);
+    __ testq(word_count, 2);
+    __ jcc(Assembler::zero, L_copy_32_bytes);
+    __ movl(rax, Address(from, qword_count, Address::times_8));
+    __ movl(Address(to, qword_count, Address::times_8), rax);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(from, qword_count, Address::times_8, -8));
+    __ movq(Address(to, qword_count, Address::times_8, -8), rax);
+    __ decrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jshort_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_backward(from, to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jshort_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4-byte boundaries, we let
+  // the hardware handle it.  The two dwords within qwords that span
+  // cache line boundaries will still be loaded and stored atomicly.
+  //
+  // Side Effects:
+  //   disjoint_int_copy_entry is set to the no-overlap entry point
+  //   used by generate_conjoint_int_copy().
+  //
+  address generate_disjoint_int_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_4_bytes, L_exit;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register dword_count = rcx;
+    const Register qword_count = count;
+    const Register end_from    = from; // source array end address
+    const Register end_to      = to;   // destination array end address
+    // End pointers are inclusive, and if count is not zero they point
+    // to the last unit copied:  end_to[0] := end_from[0]
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    disjoint_int_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(dword_count, count);
+    __ shrq(count, 1); // count => qword_count
+
+    // Copy from low to high addresses.  Use 'to' as scratch.
+    __ leaq(end_from, Address(from, qword_count, Address::times_8, -8));
+    __ leaq(end_to,   Address(to,   qword_count, Address::times_8, -8));
+    __ negq(qword_count);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(end_from, qword_count, Address::times_8, 8));
+    __ movq(Address(end_to, qword_count, Address::times_8, 8), rax);
+    __ incrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    // Check for and copy trailing dword
+  __ BIND(L_copy_4_bytes);
+    __ testq(dword_count, 1); // Only byte test since the value is 0 or 1
+    __ jccb(Assembler::zero, L_exit);
+    __ movl(rax, Address(end_from, 8));
+    __ movl(Address(end_to, 8), rax);
+
+  __ BIND(L_exit);
+    inc_counter_np(SharedRuntime::_jint_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy 32-bytes chunks
+    copy_32_bytes_forward(end_from, end_to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+    __ jmp(L_copy_4_bytes);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord == 8-byte boundary
+  //             ignored
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // If 'from' and/or 'to' are aligned on 4-byte boundaries, we let
+  // the hardware handle it.  The two dwords within qwords that span
+  // cache line boundaries will still be loaded and stored atomicly.
+  //
+  address generate_conjoint_int_copy(bool aligned, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_copy_2_bytes;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register count       = rdx;  // elements count
+    const Register dword_count = rcx;
+    const Register qword_count = count;
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    int_copy_entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    array_overlap_test(disjoint_int_copy_entry, Address::times_4);
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'count' are now valid
+    __ movq(dword_count, count);
+    __ shrq(count, 1); // count => qword_count
+
+    // Copy from high to low addresses.  Use 'to' as scratch.
+
+    // Check for and copy trailing dword
+    __ testq(dword_count, 1);
+    __ jcc(Assembler::zero, L_copy_32_bytes);
+    __ movl(rax, Address(from, dword_count, Address::times_4, -4));
+    __ movl(Address(to, dword_count, Address::times_4, -4), rax);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(from, qword_count, Address::times_8, -8));
+    __ movq(Address(to, qword_count, Address::times_8, -8), rax);
+    __ decrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jint_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_backward(from, to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+
+    inc_counter_np(SharedRuntime::_jint_array_copy_ctr);
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord boundary == 8 bytes
+  //             ignored
+  //   is_oop  - true => oop array, so generate store check code
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  // Side Effects:
+  //   disjoint_oop_copy_entry or disjoint_long_copy_entry is set to the
+  //   no-overlap entry point used by generate_conjoint_long_oop_copy().
+  //
+  address generate_disjoint_long_oop_copy(bool aligned, bool is_oop, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_exit;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register qword_count = rdx;  // elements count
+    const Register end_from    = from; // source array end address
+    const Register end_to      = rcx;  // destination array end address
+    const Register saved_to    = to;
+    // End pointers are inclusive, and if count is not zero they point
+    // to the last unit copied:  end_to[0] := end_from[0]
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    // Save no-overlap entry point for generate_conjoint_long_oop_copy()
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    if (is_oop) {
+      disjoint_oop_copy_entry  = __ pc();
+      // no registers are destroyed by this call
+      gen_write_ref_array_pre_barrier(/* dest */ c_rarg1, /* count */ c_rarg2);
+    } else {
+      disjoint_long_copy_entry = __ pc();
+    }
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'qword_count' are now valid
+
+    // Copy from low to high addresses.  Use 'to' as scratch.
+    __ leaq(end_from, Address(from, qword_count, Address::times_8, -8));
+    __ leaq(end_to,   Address(to, qword_count, Address::times_8, -8));
+    __ negq(qword_count);
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(end_from, qword_count, Address::times_8, 8));
+    __ movq(Address(end_to, qword_count, Address::times_8, 8), rax);
+    __ incrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    if (is_oop) {
+      __ jmp(L_exit);
+    } else {
+      inc_counter_np(SharedRuntime::_jlong_array_copy_ctr);
+      restore_arg_regs();
+      __ xorq(rax, rax); // return 0
+      __ leave(); // required for proper stackwalking of RuntimeStub frame
+      __ ret(0);
+    }
+
+    // Copy 64-byte chunks
+    copy_32_bytes_forward(end_from, end_to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+
+    if (is_oop) {
+    __ BIND(L_exit);
+      gen_write_ref_array_post_barrier(saved_to, end_to, rax);
+      inc_counter_np(SharedRuntime::_oop_array_copy_ctr);
+    } else {
+      inc_counter_np(SharedRuntime::_jlong_array_copy_ctr);
+    }
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+  // Arguments:
+  //   aligned - true => Input and output aligned on a HeapWord boundary == 8 bytes
+  //             ignored
+  //   is_oop  - true => oop array, so generate store check code
+  //   name    - stub name string
+  //
+  // Inputs:
+  //   c_rarg0   - source array address
+  //   c_rarg1   - destination array address
+  //   c_rarg2   - element count, treated as ssize_t, can be zero
+  //
+  address generate_conjoint_long_oop_copy(bool aligned, bool is_oop, const char *name) {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    Label L_copy_32_bytes, L_copy_8_bytes, L_exit;
+    const Register from        = rdi;  // source array address
+    const Register to          = rsi;  // destination array address
+    const Register qword_count = rdx;  // elements count
+    const Register saved_count = rcx;
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+    assert_clean_int(c_rarg2, rax);    // Make sure 'count' is clean int.
+
+    address disjoint_copy_entry = NULL;
+    if (is_oop) {
+      disjoint_copy_entry = disjoint_oop_copy_entry;
+      oop_copy_entry  = __ pc();
+    } else {
+      disjoint_copy_entry = disjoint_long_copy_entry;
+      long_copy_entry = __ pc();
+    }
+    BLOCK_COMMENT("Entry:");
+    // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
+
+    array_overlap_test(disjoint_copy_entry, Address::times_8);
+    setup_arg_regs(); // from => rdi, to => rsi, count => rdx
+                      // r9 and r10 may be used to save non-volatile registers
+
+    // 'from', 'to' and 'qword_count' are now valid
+
+    if (is_oop) {
+      // Save to and count for store barrier
+      __ movq(saved_count, qword_count);
+      // No registers are destroyed by this call
+      gen_write_ref_array_pre_barrier(to, saved_count);
+    }
+
+    // Copy from high to low addresses.  Use rcx as scratch.
+
+    __ jmp(L_copy_32_bytes);
+
+    // Copy trailing qwords
+  __ BIND(L_copy_8_bytes);
+    __ movq(rax, Address(from, qword_count, Address::times_8, -8));
+    __ movq(Address(to, qword_count, Address::times_8, -8), rax);
+    __ decrementq(qword_count);
+    __ jcc(Assembler::notZero, L_copy_8_bytes);
+
+    if (is_oop) {
+      __ jmp(L_exit);
+    } else {
+      inc_counter_np(SharedRuntime::_jlong_array_copy_ctr);
+      restore_arg_regs();
+      __ xorq(rax, rax); // return 0
+      __ leave(); // required for proper stackwalking of RuntimeStub frame
+      __ ret(0);
+    }
+
+    // Copy in 32-bytes chunks
+    copy_32_bytes_backward(from, to, qword_count, rax, L_copy_32_bytes, L_copy_8_bytes);
+
+    if (is_oop) {
+    __ BIND(L_exit);
+      __ leaq(rcx, Address(to, saved_count, Address::times_8, -8));
+      gen_write_ref_array_post_barrier(to, rcx, rax);
+      inc_counter_np(SharedRuntime::_oop_array_copy_ctr);
+    } else {
+      inc_counter_np(SharedRuntime::_jlong_array_copy_ctr);
+    }
+    restore_arg_regs();
+    __ xorq(rax, rax); // return 0
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+
+  // Helper for generating a dynamic type check.
+  // Smashes no registers.
+  void generate_type_check(Register sub_klass,
+                           Register super_check_offset,
+                           Register super_klass,
+                           Label& L_success) {
+    assert_different_registers(sub_klass, super_check_offset, super_klass);
+
+    BLOCK_COMMENT("type_check:");
+
+    Label L_miss;
+
+    // a couple of useful fields in sub_klass:
+    int ss_offset = (klassOopDesc::header_size() * HeapWordSize +
+                     Klass::secondary_supers_offset_in_bytes());
+    int sc_offset = (klassOopDesc::header_size() * HeapWordSize +
+                     Klass::secondary_super_cache_offset_in_bytes());
+    Address secondary_supers_addr(sub_klass, ss_offset);
+    Address super_cache_addr(     sub_klass, sc_offset);
+
+    // if the pointers are equal, we are done (e.g., String[] elements)
+    __ cmpq(super_klass, sub_klass);
+    __ jcc(Assembler::equal, L_success);
+
+    // check the supertype display:
+    Address super_check_addr(sub_klass, super_check_offset, Address::times_1, 0);
+    __ cmpq(super_klass, super_check_addr); // test the super type
+    __ jcc(Assembler::equal, L_success);
+
+    // if it was a primary super, we can just fail immediately
+    __ cmpl(super_check_offset, sc_offset);
+    __ jcc(Assembler::notEqual, L_miss);
+
+    // Now do a linear scan of the secondary super-klass chain.
+    // The repne_scan instruction uses fixed registers, which we must spill.
+    // (We need a couple more temps in any case.)
+    // This code is rarely used, so simplicity is a virtue here.
+    inc_counter_np(SharedRuntime::_partial_subtype_ctr);
+    {
+      __ pushq(rax);
+      __ pushq(rcx);
+      __ pushq(rdi);
+      assert_different_registers(sub_klass, super_klass, rax, rcx, rdi);
+
+      __ movq(rdi, secondary_supers_addr);
+      // Load the array length.
+      __ movl(rcx, Address(rdi, arrayOopDesc::length_offset_in_bytes()));
+      // Skip to start of data.
+      __ addq(rdi, arrayOopDesc::base_offset_in_bytes(T_OBJECT));
+      // Scan rcx words at [rdi] for occurance of rax
+      // Set NZ/Z based on last compare
+      __ movq(rax, super_klass);
+      __ repne_scan();
+
+      // Unspill the temp. registers:
+      __ popq(rdi);
+      __ popq(rcx);
+      __ popq(rax);
+
+      __ jcc(Assembler::notEqual, L_miss);
+    }
+
+    // Success.  Cache the super we found and proceed in triumph.
+    __ movq(super_cache_addr, super_klass); // note: rax is dead
+    __ jmp(L_success);
+
+    // Fall through on failure!
+    __ BIND(L_miss);
+  }
+
+  //
+  //  Generate checkcasting array copy stub
+  //
+  //  Input:
+  //    c_rarg0   - source array address
+  //    c_rarg1   - destination array address
+  //    c_rarg2   - element count, treated as ssize_t, can be zero
+  //    c_rarg3   - size_t ckoff (super_check_offset)
+  // not Win64
+  //    c_rarg4   - oop ckval (super_klass)
+  // Win64
+  //    rsp+40    - oop ckval (super_klass)
+  //
+  //  Output:
+  //    rax ==  0  -  success
+  //    rax == -1^K - failure, where K is partial transfer count
+  //
+  address generate_checkcast_copy(const char *name) {
+
+    Label L_load_element, L_store_element, L_do_card_marks, L_done;
+
+    // Input registers (after setup_arg_regs)
+    const Register from        = rdi;   // source array address
+    const Register to          = rsi;   // destination array address
+    const Register length      = rdx;   // elements count
+    const Register ckoff       = rcx;   // super_check_offset
+    const Register ckval       = r8;    // super_klass
+
+    // Registers used as temps (r13, r14 are save-on-entry)
+    const Register end_from    = from;  // source array end address
+    const Register end_to      = r13;   // destination array end address
+    const Register count       = rdx;   // -(count_remaining)
+    const Register r14_length  = r14;   // saved copy of length
+    // End pointers are inclusive, and if length is not zero they point
+    // to the last unit copied:  end_to[0] := end_from[0]
+
+    const Register rax_oop    = rax;    // actual oop copied
+    const Register r11_klass  = r11;    // oop._klass
+
+    //---------------------------------------------------------------
+    // Assembler stub will be used for this call to arraycopy
+    // if the two arrays are subtypes of Object[] but the
+    // destination array type is not equal to or a supertype
+    // of the source type.  Each element must be separately
+    // checked.
+
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+
+    checkcast_copy_entry  = __ pc();
+    BLOCK_COMMENT("Entry:");
+
+#ifdef ASSERT
+    // caller guarantees that the arrays really are different
+    // otherwise, we would have to make conjoint checks
+    { Label L;
+      array_overlap_test(L, Address::times_8);
+      __ stop("checkcast_copy within a single array");
+      __ bind(L);
+    }
+#endif //ASSERT
+
+    // allocate spill slots for r13, r14
+    enum {
+      saved_r13_offset,
+      saved_r14_offset,
+      saved_rbp_offset,
+      saved_rip_offset,
+      saved_rarg0_offset
+    };
+    __ subq(rsp, saved_rbp_offset * wordSize);
+    __ movq(Address(rsp, saved_r13_offset * wordSize), r13);
+    __ movq(Address(rsp, saved_r14_offset * wordSize), r14);
+    setup_arg_regs(4); // from => rdi, to => rsi, length => rdx
+                       // ckoff => rcx, ckval => r8
+                       // r9 and r10 may be used to save non-volatile registers
+#ifdef _WIN64
+    // last argument (#4) is on stack on Win64
+    const int ckval_offset = saved_rarg0_offset + 4;
+    __ movq(ckval, Address(rsp, ckval_offset * wordSize));
+#endif
+
+    // check that int operands are properly extended to size_t
+    assert_clean_int(length, rax);
+    assert_clean_int(ckoff, rax);
+
+#ifdef ASSERT
+    BLOCK_COMMENT("assert consistent ckoff/ckval");
+    // The ckoff and ckval must be mutually consistent,
+    // even though caller generates both.
+    { Label L;
+      int sco_offset = (klassOopDesc::header_size() * HeapWordSize +
+                        Klass::super_check_offset_offset_in_bytes());
+      __ cmpl(ckoff, Address(ckval, sco_offset));
+      __ jcc(Assembler::equal, L);
+      __ stop("super_check_offset inconsistent");
+      __ bind(L);
+    }
+#endif //ASSERT
+
+    // Loop-invariant addresses.  They are exclusive end pointers.
+    Address end_from_addr(from, length, Address::times_8, 0);
+    Address   end_to_addr(to,   length, Address::times_8, 0);
+    // Loop-variant addresses.  They assume post-incremented count < 0.
+    Address from_element_addr(end_from, count, Address::times_8, 0);
+    Address   to_element_addr(end_to,   count, Address::times_8, 0);
+    Address oop_klass_addr(rax_oop, oopDesc::klass_offset_in_bytes());
+
+    gen_write_ref_array_pre_barrier(to, count);
+
+    // Copy from low to high addresses, indexed from the end of each array.
+    __ leaq(end_from, end_from_addr);
+    __ leaq(end_to,   end_to_addr);
+    __ movq(r14_length, length);        // save a copy of the length
+    assert(length == count, "");        // else fix next line:
+    __ negq(count);                     // negate and test the length
+    __ jcc(Assembler::notZero, L_load_element);
+
+    // Empty array:  Nothing to do.
+    __ xorq(rax, rax);                  // return 0 on (trivial) success
+    __ jmp(L_done);
+
+    // ======== begin loop ========
+    // (Loop is rotated; its entry is L_load_element.)
+    // Loop control:
+    //   for (count = -count; count != 0; count++)
+    // Base pointers src, dst are biased by 8*(count-1),to last element.
+    __ align(16);
+
+    __ BIND(L_store_element);
+    __ movq(to_element_addr, rax_oop);  // store the oop
+    __ incrementq(count);               // increment the count toward zero
+    __ jcc(Assembler::zero, L_do_card_marks);
+
+    // ======== loop entry is here ========
+    __ BIND(L_load_element);
+    __ movq(rax_oop, from_element_addr); // load the oop
+    __ testq(rax_oop, rax_oop);
+    __ jcc(Assembler::zero, L_store_element);
+
+    __ movq(r11_klass, oop_klass_addr); // query the object klass
+    generate_type_check(r11_klass, ckoff, ckval, L_store_element);
+    // ======== end loop ========
+
+    // It was a real error; we must depend on the caller to finish the job.
+    // Register rdx = -1 * number of *remaining* oops, r14 = *total* oops.
+    // Emit GC store barriers for the oops we have copied (r14 + rdx),
+    // and report their number to the caller.
+    assert_different_registers(rax, r14_length, count, to, end_to, rcx);
+    __ leaq(end_to, to_element_addr);
+    gen_write_ref_array_post_barrier(to, end_to, rcx);
+    __ movq(rax, r14_length);           // original oops
+    __ addq(rax, count);                // K = (original - remaining) oops
+    __ notq(rax);                       // report (-1^K) to caller
+    __ jmp(L_done);
+
+    // Come here on success only.
+    __ BIND(L_do_card_marks);
+    __ addq(end_to, -wordSize);         // make an inclusive end pointer
+    gen_write_ref_array_post_barrier(to, end_to, rcx);
+    __ xorq(rax, rax);                  // return 0 on success
+
+    // Common exit point (success or failure).
+    __ BIND(L_done);
+    __ movq(r13, Address(rsp, saved_r13_offset * wordSize));
+    __ movq(r14, Address(rsp, saved_r14_offset * wordSize));
+    inc_counter_np(SharedRuntime::_checkcast_array_copy_ctr);
+    restore_arg_regs();
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+  //
+  //  Generate 'unsafe' array copy stub
+  //  Though just as safe as the other stubs, it takes an unscaled
+  //  size_t argument instead of an element count.
+  //
+  //  Input:
+  //    c_rarg0   - source array address
+  //    c_rarg1   - destination array address
+  //    c_rarg2   - byte count, treated as ssize_t, can be zero
+  //
+  // Examines the alignment of the operands and dispatches
+  // to a long, int, short, or byte copy loop.
+  //
+  address generate_unsafe_copy(const char *name) {
+
+    Label L_long_aligned, L_int_aligned, L_short_aligned;
+
+    // Input registers (before setup_arg_regs)
+    const Register from        = c_rarg0;  // source array address
+    const Register to          = c_rarg1;  // destination array address
+    const Register size        = c_rarg2;  // byte count (size_t)
+
+    // Register used as a temp
+    const Register bits        = rax;      // test copy of low bits
+
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", name);
+    address start = __ pc();
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+
+    // bump this on entry, not on exit:
+    inc_counter_np(SharedRuntime::_unsafe_array_copy_ctr);
+
+    __ movq(bits, from);
+    __ orq(bits, to);
+    __ orq(bits, size);
+
+    __ testb(bits, BytesPerLong-1);
+    __ jccb(Assembler::zero, L_long_aligned);
+
+    __ testb(bits, BytesPerInt-1);
+    __ jccb(Assembler::zero, L_int_aligned);
+
+    __ testb(bits, BytesPerShort-1);
+    __ jump_cc(Assembler::notZero, RuntimeAddress(byte_copy_entry));
+
+    __ BIND(L_short_aligned);
+    __ shrq(size, LogBytesPerShort); // size => short_count
+    __ jump(RuntimeAddress(short_copy_entry));
+
+    __ BIND(L_int_aligned);
+    __ shrq(size, LogBytesPerInt); // size => int_count
+    __ jump(RuntimeAddress(int_copy_entry));
+
+    __ BIND(L_long_aligned);
+    __ shrq(size, LogBytesPerLong); // size => qword_count
+    __ jump(RuntimeAddress(long_copy_entry));
+
+    return start;
+  }
+
+  // Perform range checks on the proposed arraycopy.
+  // Kills temp, but nothing else.
+  // Also, clean the sign bits of src_pos and dst_pos.
+  void arraycopy_range_checks(Register src,     // source array oop (c_rarg0)
+                              Register src_pos, // source position (c_rarg1)
+                              Register dst,     // destination array oo (c_rarg2)
+                              Register dst_pos, // destination position (c_rarg3)
+                              Register length,
+                              Register temp,
+                              Label& L_failed) {
+    BLOCK_COMMENT("arraycopy_range_checks:");
+
+    //  if (src_pos + length > arrayOop(src)->length())  FAIL;
+    __ movl(temp, length);
+    __ addl(temp, src_pos);             // src_pos + length
+    __ cmpl(temp, Address(src, arrayOopDesc::length_offset_in_bytes()));
+    __ jcc(Assembler::above, L_failed);
+
+    //  if (dst_pos + length > arrayOop(dst)->length())  FAIL;
+    __ movl(temp, length);
+    __ addl(temp, dst_pos);             // dst_pos + length
+    __ cmpl(temp, Address(dst, arrayOopDesc::length_offset_in_bytes()));
+    __ jcc(Assembler::above, L_failed);
+
+    // Have to clean up high 32-bits of 'src_pos' and 'dst_pos'.
+    // Move with sign extension can be used since they are positive.
+    __ movslq(src_pos, src_pos);
+    __ movslq(dst_pos, dst_pos);
+
+    BLOCK_COMMENT("arraycopy_range_checks done");
+  }
+
+  //
+  //  Generate generic array copy stubs
+  //
+  //  Input:
+  //    c_rarg0    -  src oop
+  //    c_rarg1    -  src_pos (32-bits)
+  //    c_rarg2    -  dst oop
+  //    c_rarg3    -  dst_pos (32-bits)
+  // not Win64
+  //    c_rarg4    -  element count (32-bits)
+  // Win64
+  //    rsp+40     -  element count (32-bits)
+  //
+  //  Output:
+  //    rax ==  0  -  success
+  //    rax == -1^K - failure, where K is partial transfer count
+  //
+  address generate_generic_copy(const char *name) {
+
+    Label L_failed, L_failed_0, L_objArray;
+    Label L_copy_bytes, L_copy_shorts, L_copy_ints, L_copy_longs;
+
+    // Input registers
+    const Register src        = c_rarg0;  // source array oop
+    const Register src_pos    = c_rarg1;  // source position
+    const Register dst        = c_rarg2;  // destination array oop
+    const Register dst_pos    = c_rarg3;  // destination position
+    // elements count is on stack on Win64
+#ifdef _WIN64
+#define C_RARG4 Address(rsp, 6 * wordSize)
+#else
+#define C_RARG4 c_rarg4
+#endif
+
+    { int modulus = CodeEntryAlignment;
+      int target  = modulus - 5; // 5 = sizeof jmp(L_failed)
+      int advance = target - (__ offset() % modulus);
+      if (advance < 0)  advance += modulus;
+      if (advance > 0)  __ nop(advance);
+    }
+    StubCodeMark mark(this, "StubRoutines", name);
+
+    // Short-hop target to L_failed.  Makes for denser prologue code.
+    __ BIND(L_failed_0);
+    __ jmp(L_failed);
+    assert(__ offset() % CodeEntryAlignment == 0, "no further alignment needed");
+
+    __ align(CodeEntryAlignment);
+    address start = __ pc();
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+
+    // bump this on entry, not on exit:
+    inc_counter_np(SharedRuntime::_generic_array_copy_ctr);
+
+    //-----------------------------------------------------------------------
+    // Assembler stub will be used for this call to arraycopy
+    // if the following conditions are met:
+    //
+    // (1) src and dst must not be null.
+    // (2) src_pos must not be negative.
+    // (3) dst_pos must not be negative.
+    // (4) length  must not be negative.
+    // (5) src klass and dst klass should be the same and not NULL.
+    // (6) src and dst should be arrays.
+    // (7) src_pos + length must not exceed length of src.
+    // (8) dst_pos + length must not exceed length of dst.
+    //
+
+    //  if (src == NULL) return -1;
+    __ testq(src, src);         // src oop
+    size_t j1off = __ offset();
+    __ jccb(Assembler::zero, L_failed_0);
+
+    //  if (src_pos < 0) return -1;
+    __ testl(src_pos, src_pos); // src_pos (32-bits)
+    __ jccb(Assembler::negative, L_failed_0);
+
+    //  if (dst == NULL) return -1;
+    __ testq(dst, dst);         // dst oop
+    __ jccb(Assembler::zero, L_failed_0);
+
+    //  if (dst_pos < 0) return -1;
+    __ testl(dst_pos, dst_pos); // dst_pos (32-bits)
+    size_t j4off = __ offset();
+    __ jccb(Assembler::negative, L_failed_0);
+
+    // The first four tests are very dense code,
+    // but not quite dense enough to put four
+    // jumps in a 16-byte instruction fetch buffer.
+    // That's good, because some branch predicters
+    // do not like jumps so close together.
+    // Make sure of this.
+    guarantee(((j1off ^ j4off) & ~15) != 0, "I$ line of 1st & 4th jumps");
+
+    // registers used as temp
+    const Register r11_length    = r11; // elements count to copy
+    const Register r10_src_klass = r10; // array klass
+
+    //  if (length < 0) return -1;
+    __ movl(r11_length, C_RARG4);       // length (elements count, 32-bits value)
+    __ testl(r11_length, r11_length);
+    __ jccb(Assembler::negative, L_failed_0);
+
+    Address src_klass_addr(src, oopDesc::klass_offset_in_bytes());
+    Address dst_klass_addr(dst, oopDesc::klass_offset_in_bytes());
+    __ movq(r10_src_klass, src_klass_addr);
+#ifdef ASSERT
+    //  assert(src->klass() != NULL);
+    BLOCK_COMMENT("assert klasses not null");
+    { Label L1, L2;
+      __ testq(r10_src_klass, r10_src_klass);
+      __ jcc(Assembler::notZero, L2);   // it is broken if klass is NULL
+      __ bind(L1);
+      __ stop("broken null klass");
+      __ bind(L2);
+      __ cmpq(dst_klass_addr, 0);
+      __ jcc(Assembler::equal, L1);     // this would be broken also
+      BLOCK_COMMENT("assert done");
+    }
+#endif
+
+    // Load layout helper (32-bits)
+    //
+    //  |array_tag|     | header_size | element_type |     |log2_element_size|
+    // 32        30    24            16              8     2                 0
+    //
+    //   array_tag: typeArray = 0x3, objArray = 0x2, non-array = 0x0
+    //
+
+    int lh_offset = klassOopDesc::header_size() * HeapWordSize +
+                    Klass::layout_helper_offset_in_bytes();
+
+    const Register rax_lh = rax;  // layout helper
+
+    __ movl(rax_lh, Address(r10_src_klass, lh_offset));
+
+    // Handle objArrays completely differently...
+    jint objArray_lh = Klass::array_layout_helper(T_OBJECT);
+    __ cmpl(rax_lh, objArray_lh);
+    __ jcc(Assembler::equal, L_objArray);
+
+    //  if (src->klass() != dst->klass()) return -1;
+    __ cmpq(r10_src_klass, dst_klass_addr);
+    __ jcc(Assembler::notEqual, L_failed);
+
+    //  if (!src->is_Array()) return -1;
+    __ cmpl(rax_lh, Klass::_lh_neutral_value);
+    __ jcc(Assembler::greaterEqual, L_failed);
+
+    // At this point, it is known to be a typeArray (array_tag 0x3).
+#ifdef ASSERT
+    { Label L;
+      __ cmpl(rax_lh, (Klass::_lh_array_tag_type_value << Klass::_lh_array_tag_shift));
+      __ jcc(Assembler::greaterEqual, L);
+      __ stop("must be a primitive array");
+      __ bind(L);
+    }
+#endif
+
+    arraycopy_range_checks(src, src_pos, dst, dst_pos, r11_length,
+                           r10, L_failed);
+
+    // typeArrayKlass
+    //
+    // src_addr = (src + array_header_in_bytes()) + (src_pos << log2elemsize);
+    // dst_addr = (dst + array_header_in_bytes()) + (dst_pos << log2elemsize);
+    //
+
+    const Register r10_offset = r10;    // array offset
+    const Register rax_elsize = rax_lh; // element size
+
+    __ movl(r10_offset, rax_lh);
+    __ shrl(r10_offset, Klass::_lh_header_size_shift);
+    __ andq(r10_offset, Klass::_lh_header_size_mask);   // array_offset
+    __ addq(src, r10_offset);           // src array offset
+    __ addq(dst, r10_offset);           // dst array offset
+    BLOCK_COMMENT("choose copy loop based on element size");
+    __ andl(rax_lh, Klass::_lh_log2_element_size_mask); // rax_lh -> rax_elsize
+
+    // next registers should be set before the jump to corresponding stub
+    const Register from     = c_rarg0;  // source array address
+    const Register to       = c_rarg1;  // destination array address
+    const Register count    = c_rarg2;  // elements count
+
+    // 'from', 'to', 'count' registers should be set in such order
+    // since they are the same as 'src', 'src_pos', 'dst'.
+
+  __ BIND(L_copy_bytes);
+    __ cmpl(rax_elsize, 0);
+    __ jccb(Assembler::notEqual, L_copy_shorts);
+    __ leaq(from, Address(src, src_pos, Address::times_1, 0));// src_addr
+    __ leaq(to,   Address(dst, dst_pos, Address::times_1, 0));// dst_addr
+    __ movslq(count, r11_length); // length
+    __ jump(RuntimeAddress(byte_copy_entry));
+
+  __ BIND(L_copy_shorts);
+    __ cmpl(rax_elsize, LogBytesPerShort);
+    __ jccb(Assembler::notEqual, L_copy_ints);
+    __ leaq(from, Address(src, src_pos, Address::times_2, 0));// src_addr
+    __ leaq(to,   Address(dst, dst_pos, Address::times_2, 0));// dst_addr
+    __ movslq(count, r11_length); // length
+    __ jump(RuntimeAddress(short_copy_entry));
+
+  __ BIND(L_copy_ints);
+    __ cmpl(rax_elsize, LogBytesPerInt);
+    __ jccb(Assembler::notEqual, L_copy_longs);
+    __ leaq(from, Address(src, src_pos, Address::times_4, 0));// src_addr
+    __ leaq(to,   Address(dst, dst_pos, Address::times_4, 0));// dst_addr
+    __ movslq(count, r11_length); // length
+    __ jump(RuntimeAddress(int_copy_entry));
+
+  __ BIND(L_copy_longs);
+#ifdef ASSERT
+    { Label L;
+      __ cmpl(rax_elsize, LogBytesPerLong);
+      __ jcc(Assembler::equal, L);
+      __ stop("must be long copy, but elsize is wrong");
+      __ bind(L);
+    }
+#endif
+    __ leaq(from, Address(src, src_pos, Address::times_8, 0));// src_addr
+    __ leaq(to,   Address(dst, dst_pos, Address::times_8, 0));// dst_addr
+    __ movslq(count, r11_length); // length
+    __ jump(RuntimeAddress(long_copy_entry));
+
+    // objArrayKlass
+  __ BIND(L_objArray);
+    // live at this point:  r10_src_klass, src[_pos], dst[_pos]
+
+    Label L_plain_copy, L_checkcast_copy;
+    //  test array classes for subtyping
+    __ cmpq(r10_src_klass, dst_klass_addr); // usual case is exact equality
+    __ jcc(Assembler::notEqual, L_checkcast_copy);
+
+    // Identically typed arrays can be copied without element-wise checks.
+    arraycopy_range_checks(src, src_pos, dst, dst_pos, r11_length,
+                           r10, L_failed);
+
+    __ leaq(from, Address(src, src_pos, Address::times_8,
+                 arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // src_addr
+    __ leaq(to,   Address(dst, dst_pos, Address::times_8,
+                 arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // dst_addr
+    __ movslq(count, r11_length); // length
+  __ BIND(L_plain_copy);
+    __ jump(RuntimeAddress(oop_copy_entry));
+
+  __ BIND(L_checkcast_copy);
+    // live at this point:  r10_src_klass, !r11_length
+    {
+      // assert(r11_length == C_RARG4); // will reload from here
+      Register r11_dst_klass = r11;
+      __ movq(r11_dst_klass, dst_klass_addr);
+
+      // Before looking at dst.length, make sure dst is also an objArray.
+      __ cmpl(Address(r11_dst_klass, lh_offset), objArray_lh);
+      __ jcc(Assembler::notEqual, L_failed);
+
+      // It is safe to examine both src.length and dst.length.
+#ifndef _WIN64
+      arraycopy_range_checks(src, src_pos, dst, dst_pos, C_RARG4,
+                             rax, L_failed);
+#else
+      __ movl(r11_length, C_RARG4);     // reload
+      arraycopy_range_checks(src, src_pos, dst, dst_pos, r11_length,
+                             rax, L_failed);
+      __ movl(r11_dst_klass, dst_klass_addr); // reload
+#endif
+
+      // Marshal the base address arguments now, freeing registers.
+      __ leaq(from, Address(src, src_pos, Address::times_8,
+                   arrayOopDesc::base_offset_in_bytes(T_OBJECT)));
+      __ leaq(to,   Address(dst, dst_pos, Address::times_8,
+                   arrayOopDesc::base_offset_in_bytes(T_OBJECT)));
+      __ movl(count, C_RARG4);          // length (reloaded)
+      Register sco_temp = c_rarg3;      // this register is free now
+      assert_different_registers(from, to, count, sco_temp,
+                                 r11_dst_klass, r10_src_klass);
+      assert_clean_int(count, sco_temp);
+
+      // Generate the type check.
+      int sco_offset = (klassOopDesc::header_size() * HeapWordSize +
+                        Klass::super_check_offset_offset_in_bytes());
+      __ movl(sco_temp, Address(r11_dst_klass, sco_offset));
+      assert_clean_int(sco_temp, rax);
+      generate_type_check(r10_src_klass, sco_temp, r11_dst_klass, L_plain_copy);
+
+      // Fetch destination element klass from the objArrayKlass header.
+      int ek_offset = (klassOopDesc::header_size() * HeapWordSize +
+                       objArrayKlass::element_klass_offset_in_bytes());
+      __ movq(r11_dst_klass, Address(r11_dst_klass, ek_offset));
+      __ movl(sco_temp,      Address(r11_dst_klass, sco_offset));
+      assert_clean_int(sco_temp, rax);
+
+      // the checkcast_copy loop needs two extra arguments:
+      assert(c_rarg3 == sco_temp, "#3 already in place");
+      __ movq(C_RARG4, r11_dst_klass);  // dst.klass.element_klass
+      __ jump(RuntimeAddress(checkcast_copy_entry));
+    }
+
+  __ BIND(L_failed);
+    __ xorq(rax, rax);
+    __ notq(rax); // return -1
+    __ leave();   // required for proper stackwalking of RuntimeStub frame
+    __ ret(0);
+
+    return start;
+  }
+
+#undef length_arg
+
+  void generate_arraycopy_stubs() {
+    // Call the conjoint generation methods immediately after
+    // the disjoint ones so that short branches from the former
+    // to the latter can be generated.
+    StubRoutines::_jbyte_disjoint_arraycopy  = generate_disjoint_byte_copy(false, "jbyte_disjoint_arraycopy");
+    StubRoutines::_jbyte_arraycopy           = generate_conjoint_byte_copy(false, "jbyte_arraycopy");
+
+    StubRoutines::_jshort_disjoint_arraycopy = generate_disjoint_short_copy(false, "jshort_disjoint_arraycopy");
+    StubRoutines::_jshort_arraycopy          = generate_conjoint_short_copy(false, "jshort_arraycopy");
+
+    StubRoutines::_jint_disjoint_arraycopy   = generate_disjoint_int_copy(false, "jint_disjoint_arraycopy");
+    StubRoutines::_jint_arraycopy            = generate_conjoint_int_copy(false, "jint_arraycopy");
+
+    StubRoutines::_jlong_disjoint_arraycopy  = generate_disjoint_long_oop_copy(false, false, "jlong_disjoint_arraycopy");
+    StubRoutines::_jlong_arraycopy           = generate_conjoint_long_oop_copy(false, false, "jlong_arraycopy");
+
+    StubRoutines::_oop_disjoint_arraycopy    = generate_disjoint_long_oop_copy(false, true, "oop_disjoint_arraycopy");
+    StubRoutines::_oop_arraycopy             = generate_conjoint_long_oop_copy(false, true, "oop_arraycopy");
+
+    StubRoutines::_checkcast_arraycopy = generate_checkcast_copy("checkcast_arraycopy");
+    StubRoutines::_unsafe_arraycopy    = generate_unsafe_copy("unsafe_arraycopy");
+    StubRoutines::_generic_arraycopy   = generate_generic_copy("generic_arraycopy");
+
+    // We don't generate specialized code for HeapWord-aligned source
+    // arrays, so just use the code we've already generated
+    StubRoutines::_arrayof_jbyte_disjoint_arraycopy  = StubRoutines::_jbyte_disjoint_arraycopy;
+    StubRoutines::_arrayof_jbyte_arraycopy           = StubRoutines::_jbyte_arraycopy;
+
+    StubRoutines::_arrayof_jshort_disjoint_arraycopy = StubRoutines::_jshort_disjoint_arraycopy;
+    StubRoutines::_arrayof_jshort_arraycopy          = StubRoutines::_jshort_arraycopy;
+
+    StubRoutines::_arrayof_jint_disjoint_arraycopy   = StubRoutines::_jint_disjoint_arraycopy;
+    StubRoutines::_arrayof_jint_arraycopy            = StubRoutines::_jint_arraycopy;
+
+    StubRoutines::_arrayof_jlong_disjoint_arraycopy  = StubRoutines::_jlong_disjoint_arraycopy;
+    StubRoutines::_arrayof_jlong_arraycopy           = StubRoutines::_jlong_arraycopy;
+
+    StubRoutines::_arrayof_oop_disjoint_arraycopy    = StubRoutines::_oop_disjoint_arraycopy;
+    StubRoutines::_arrayof_oop_arraycopy             = StubRoutines::_oop_arraycopy;
+  }
+
+#undef __
+#define __ masm->
+
+  // Continuation point for throwing of implicit exceptions that are
+  // not handled in the current activation. Fabricates an exception
+  // oop and initiates normal exception dispatching in this
+  // frame. Since we need to preserve callee-saved values (currently
+  // only for C2, but done for C1 as well) we need a callee-saved oop
+  // map and therefore have to make these stubs into RuntimeStubs
+  // rather than BufferBlobs.  If the compiler needs all registers to
+  // be preserved between the fault point and the exception handler
+  // then it must assume responsibility for that in
+  // AbstractCompiler::continuation_for_implicit_null_exception or
+  // continuation_for_implicit_division_by_zero_exception. All other
+  // implicit exceptions (e.g., NullPointerException or
+  // AbstractMethodError on entry) are either at call sites or
+  // otherwise assume that stack unwinding will be initiated, so
+  // caller saved registers were assumed volatile in the compiler.
+  address generate_throw_exception(const char* name,
+                                   address runtime_entry,
+                                   bool restore_saved_exception_pc) {
+    // Information about frame layout at time of blocking runtime call.
+    // Note that we only have to preserve callee-saved registers since
+    // the compilers are responsible for supplying a continuation point
+    // if they expect all registers to be preserved.
+    enum layout {
+      rbp_off = frame::arg_reg_save_area_bytes/BytesPerInt,
+      rbp_off2,
+      return_off,
+      return_off2,
+      framesize // inclusive of return address
+    };
+
+    int insts_size = 512;
+    int locs_size  = 64;
+
+    CodeBuffer code(name, insts_size, locs_size);
+    OopMapSet* oop_maps  = new OopMapSet();
+    MacroAssembler* masm = new MacroAssembler(&code);
+
+    address start = __ pc();
+
+    // This is an inlined and slightly modified version of call_VM
+    // which has the ability to fetch the return PC out of
+    // thread-local storage and also sets up last_Java_sp slightly
+    // differently than the real call_VM
+    if (restore_saved_exception_pc) {
+      __ movq(rax,
+              Address(r15_thread,
+                      in_bytes(JavaThread::saved_exception_pc_offset())));
+      __ pushq(rax);
+    }
+
+    __ enter(); // required for proper stackwalking of RuntimeStub frame
+
+    assert(is_even(framesize/2), "sp not 16-byte aligned");
+
+    // return address and rbp are already in place
+    __ subq(rsp, (framesize-4) << LogBytesPerInt); // prolog
+
+    int frame_complete = __ pc() - start;
+
+    // Set up last_Java_sp and last_Java_fp
+    __ set_last_Java_frame(rsp, rbp, NULL);
+
+    // Call runtime
+    __ movq(c_rarg0, r15_thread);
+    BLOCK_COMMENT("call runtime_entry");
+    __ call(RuntimeAddress(runtime_entry));
+
+    // Generate oop map
+    OopMap* map = new OopMap(framesize, 0);
+
+    oop_maps->add_gc_map(__ pc() - start, map);
+
+    __ reset_last_Java_frame(true, false);
+
+    __ leave(); // required for proper stackwalking of RuntimeStub frame
+
+    // check for pending exceptions
+#ifdef ASSERT
+    Label L;
+    __ cmpq(Address(r15_thread, Thread::pending_exception_offset()),
+            (int) NULL);
+    __ jcc(Assembler::notEqual, L);
+    __ should_not_reach_here();
+    __ bind(L);
+#endif // ASSERT
+    __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
+
+
+    // codeBlob framesize is in words (not VMRegImpl::slot_size)
+    RuntimeStub* stub =
+      RuntimeStub::new_runtime_stub(name,
+                                    &code,
+                                    frame_complete,
+                                    (framesize >> (LogBytesPerWord - LogBytesPerInt)),
+                                    oop_maps, false);
+    return stub->entry_point();
+  }
+
+  // Initialization
+  void generate_initial() {
+    // Generates all stubs and initializes the entry points
+
+    // This platform-specific stub is needed by generate_call_stub()
+    StubRoutines::amd64::_mxcsr_std        = generate_fp_mask("mxcsr_std",        0x0000000000001F80);
+
+    // entry points that exist in all platforms Note: This is code
+    // that could be shared among different platforms - however the
+    // benefit seems to be smaller than the disadvantage of having a
+    // much more complicated generator structure. See also comment in
+    // stubRoutines.hpp.
+
+    StubRoutines::_forward_exception_entry = generate_forward_exception();
+
+    StubRoutines::_call_stub_entry =
+      generate_call_stub(StubRoutines::_call_stub_return_address);
+
+    // is referenced by megamorphic call
+    StubRoutines::_catch_exception_entry = generate_catch_exception();
+
+    // atomic calls
+    StubRoutines::_atomic_xchg_entry         = generate_atomic_xchg();
+    StubRoutines::_atomic_xchg_ptr_entry     = generate_atomic_xchg_ptr();
+    StubRoutines::_atomic_cmpxchg_entry      = generate_atomic_cmpxchg();
+    StubRoutines::_atomic_cmpxchg_long_entry = generate_atomic_cmpxchg_long();
+    StubRoutines::_atomic_add_entry          = generate_atomic_add();
+    StubRoutines::_atomic_add_ptr_entry      = generate_atomic_add_ptr();
+    StubRoutines::_fence_entry               = generate_orderaccess_fence();
+
+    StubRoutines::_handler_for_unsafe_access_entry =
+      generate_handler_for_unsafe_access();
+
+    // platform dependent
+    StubRoutines::amd64::_get_previous_fp_entry = generate_get_previous_fp();
+
+    StubRoutines::amd64::_verify_mxcsr_entry    = generate_verify_mxcsr();
+  }
+
+  void generate_all() {
+    // Generates all stubs and initializes the entry points
+
+    // These entry points require SharedInfo::stack0 to be set up in
+    // non-core builds and need to be relocatable, so they each
+    // fabricate a RuntimeStub internally.
+    StubRoutines::_throw_AbstractMethodError_entry =
+      generate_throw_exception("AbstractMethodError throw_exception",
+                               CAST_FROM_FN_PTR(address,
+                                                SharedRuntime::
+                                                throw_AbstractMethodError),
+                               false);
+
+    StubRoutines::_throw_ArithmeticException_entry =
+      generate_throw_exception("ArithmeticException throw_exception",
+                               CAST_FROM_FN_PTR(address,
+                                                SharedRuntime::
+                                                throw_ArithmeticException),
+                               true);
+
+    StubRoutines::_throw_NullPointerException_entry =
+      generate_throw_exception("NullPointerException throw_exception",
+                               CAST_FROM_FN_PTR(address,
+                                                SharedRuntime::
+                                                throw_NullPointerException),
+                               true);
+
+    StubRoutines::_throw_NullPointerException_at_call_entry =
+      generate_throw_exception("NullPointerException at call throw_exception",
+                               CAST_FROM_FN_PTR(address,
+                                                SharedRuntime::
+                                                throw_NullPointerException_at_call),
+                               false);
+
+    StubRoutines::_throw_StackOverflowError_entry =
+      generate_throw_exception("StackOverflowError throw_exception",
+                               CAST_FROM_FN_PTR(address,
+                                                SharedRuntime::
+                                                throw_StackOverflowError),
+                               false);
+
+    // entry points that are platform specific
+    StubRoutines::amd64::_f2i_fixup = generate_f2i_fixup();
+    StubRoutines::amd64::_f2l_fixup = generate_f2l_fixup();
+    StubRoutines::amd64::_d2i_fixup = generate_d2i_fixup();
+    StubRoutines::amd64::_d2l_fixup = generate_d2l_fixup();
+
+    StubRoutines::amd64::_float_sign_mask  = generate_fp_mask("float_sign_mask",  0x7FFFFFFF7FFFFFFF);
+    StubRoutines::amd64::_float_sign_flip  = generate_fp_mask("float_sign_flip",  0x8000000080000000);
+    StubRoutines::amd64::_double_sign_mask = generate_fp_mask("double_sign_mask", 0x7FFFFFFFFFFFFFFF);
+    StubRoutines::amd64::_double_sign_flip = generate_fp_mask("double_sign_flip", 0x8000000000000000);
+
+    // support for verify_oop (must happen after universe_init)
+    StubRoutines::_verify_oop_subroutine_entry = generate_verify_oop();
+
+    // arraycopy stubs used by compilers
+    generate_arraycopy_stubs();
+  }
+
+ public:
+  StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {
+    if (all) {
+      generate_all();
+    } else {
+      generate_initial();
+    }
+  }
+}; // end class declaration
+
+address StubGenerator::disjoint_byte_copy_entry  = NULL;
+address StubGenerator::disjoint_short_copy_entry = NULL;
+address StubGenerator::disjoint_int_copy_entry   = NULL;
+address StubGenerator::disjoint_long_copy_entry  = NULL;
+address StubGenerator::disjoint_oop_copy_entry   = NULL;
+
+address StubGenerator::byte_copy_entry  = NULL;
+address StubGenerator::short_copy_entry = NULL;
+address StubGenerator::int_copy_entry   = NULL;
+address StubGenerator::long_copy_entry  = NULL;
+address StubGenerator::oop_copy_entry   = NULL;
+
+address StubGenerator::checkcast_copy_entry = NULL;
+
+void StubGenerator_generate(CodeBuffer* code, bool all) {
+  StubGenerator g(code, all);
+}