Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "asm/assembler.hpp"

 #include "assembler_x86.inline.hpp"

 #include "interpreter/interpreter.hpp"

 #include "nativeInst_x86.hpp"

 #include "oops/instanceOop.hpp"

 #include "oops/methodOop.hpp"

 #include "oops/objArrayKlass.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/sharedRuntime.hpp"

 #include "runtime/stubCodeGenerator.hpp"

 #include "runtime/stubRoutines.hpp"

 #include "utilities/top.hpp"

 #ifdef TARGET_OS_FAMILY_linux

 # include "thread_linux.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_solaris

 # include "thread_solaris.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_windows

 # include "thread_windows.inline.hpp"

 #endif

 #ifdef COMPILER2

 #include "opto/runtime.hpp"

 #endif

 // 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->

 #define a__ ((Assembler*)_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

 const int FPU_CNTRL_WRD_MASK = 0xFFFF;

 // -------------------------------------------------------------------------------------------------------------------------

 // 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 //PRODUCT

   void inc_copy_counter_np(BasicType t) {

 #ifndef PRODUCT

     switch (t) {

     case T_BYTE:    inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr); return;

     case T_SHORT:   inc_counter_np(SharedRuntime::_jshort_array_copy_ctr); return;

     case T_INT:     inc_counter_np(SharedRuntime::_jint_array_copy_ctr); return;

     case T_LONG:    inc_counter_np(SharedRuntime::_jlong_array_copy_ctr); return;

     case T_OBJECT:  inc_counter_np(SharedRuntime::_oop_array_copy_ctr); return;

     }

     ShouldNotReachHere();

 #endif //PRODUCT

   }

   //------------------------------------------------------------------------------------------------------------------------

   // Call stubs are used to call Java from C

   //

   //    [ return_from_Java     ] <--- rsp

   //    [ argument word n      ]

   //      ...

   // -N [ argument word 1      ]

   // -7 [ Possible padding for stack alignment ]

   // -6 [ Possible padding for stack alignment ]

   // -5 [ Possible padding for stack alignment ]

   // -4 [ mxcsr save           ] <--- rsp_after_call

   // -3 [ saved rbx,            ]

   // -2 [ saved rsi            ]

   // -1 [ saved rdi            ]

   //  0 [ saved rbp,            ] <--- rbp,

   //  1 [ return address       ]

   //  2 [ ptr. to call wrapper ]

   //  3 [ result               ]

   //  4 [ result_type          ]

   //  5 [ method               ]

   //  6 [ entry_point          ]

   //  7 [ parameters           ]

   //  8 [ parameter_size       ]

   //  9 [ thread               ]

   address generate_call_stub(address& return_address) {

     StubCodeMark mark(this, "StubRoutines", "call_stub");

     address start = __ pc();

     // stub code parameters / addresses

     assert(frame::entry_frame_call_wrapper_offset == 2, "adjust this code");

     bool  sse_save = false;

     const Address rsp_after_call(rbp, -4 * wordSize); // same as in generate_catch_exception()!

     const int     locals_count_in_bytes  (4*wordSize);

     const Address mxcsr_save    (rbp, -4 * wordSize);

     const Address saved_rbx     (rbp, -3 * wordSize);

     const Address saved_rsi     (rbp, -2 * wordSize);

     const Address saved_rdi     (rbp, -1 * wordSize);

     const Address result        (rbp,  3 * wordSize);

     const Address result_type   (rbp,  4 * wordSize);

     const Address method        (rbp,  5 * wordSize);

     const Address entry_point   (rbp,  6 * wordSize);

     const Address parameters    (rbp,  7 * wordSize);

     const Address parameter_size(rbp,  8 * wordSize);

     const Address thread        (rbp,  9 * wordSize); // same as in generate_catch_exception()!

     sse_save =  UseSSE > 0;

     // stub code

     __ enter();

     __ movptr(rcx, parameter_size);              // parameter counter

     __ shlptr(rcx, Interpreter::logStackElementSize); // convert parameter count to bytes

     __ addptr(rcx, locals_count_in_bytes);       // reserve space for register saves

     __ subptr(rsp, rcx);

     __ andptr(rsp, -(StackAlignmentInBytes));    // Align stack

     // save rdi, rsi, & rbx, according to C calling conventions

     __ movptr(saved_rdi, rdi);

     __ movptr(saved_rsi, rsi);

     __ movptr(saved_rbx, rbx);

     // save and initialize %mxcsr

     if (sse_save) {

       Label skip_ldmx;

       __ stmxcsr(mxcsr_save);

       __ movl(rax, mxcsr_save);

       __ andl(rax, MXCSR_MASK);    // Only check control and mask bits

       ExternalAddress mxcsr_std(StubRoutines::addr_mxcsr_std());

       __ cmp32(rax, mxcsr_std);

       __ jcc(Assembler::equal, skip_ldmx);

       __ ldmxcsr(mxcsr_std);

       __ bind(skip_ldmx);

     }

     // make sure the control word is correct.

     __ fldcw(ExternalAddress(StubRoutines::addr_fpu_cntrl_wrd_std()));

 #ifdef ASSERT

     // make sure we have no pending exceptions

     { Label L;

       __ movptr(rcx, thread);

       __ cmpptr(Address(rcx, Thread::pending_exception_offset()), (int32_t)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(rcx, parameter_size);  // parameter counter

     __ testl(rcx, rcx);

     __ jcc(Assembler::zero, parameters_done);

     // parameter passing loop

     Label loop;

     // Copy Java parameters in reverse order (receiver last)

     // Note that the argument order is inverted in the process

     // source is rdx[rcx: N-1..0]

     // dest   is rsp[rbx: 0..N-1]

     __ movptr(rdx, parameters);          // parameter pointer

     __ xorptr(rbx, rbx);

     __ BIND(loop);

     // get parameter

     __ movptr(rax, Address(rdx, rcx, Interpreter::stackElementScale(), -wordSize));

     __ movptr(Address(rsp, rbx, Interpreter::stackElementScale(),

                     Interpreter::expr_offset_in_bytes(0)), rax);          // store parameter

     __ increment(rbx);

     __ decrement(rcx);

     __ jcc(Assembler::notZero, loop);

     // call Java function

     __ BIND(parameters_done);

     __ movptr(rbx, method);           // get methodOop

     __ movptr(rax, entry_point);      // get entry_point

     __ mov(rsi, rsp);                 // set sender sp

     BLOCK_COMMENT("call Java function");

     __ call(rax);

     BLOCK_COMMENT("call_stub_return_address:");

     return_address = __ pc();

     Label common_return;

     __ BIND(common_return);

     // store result depending on type

     // (everything that is not T_LONG, T_FLOAT or T_DOUBLE is treated as T_INT)

     __ movptr(rdi, result);

     Label is_long, is_float, is_double, exit;

     __ movl(rsi, result_type);

     __ cmpl(rsi, T_LONG);

     __ jcc(Assembler::equal, is_long);

     __ cmpl(rsi, T_FLOAT);

     __ jcc(Assembler::equal, is_float);

     __ cmpl(rsi, T_DOUBLE);

     __ jcc(Assembler::equal, is_double);

     // handle T_INT case

     __ movl(Address(rdi, 0), rax);

     __ BIND(exit);

     // check that FPU stack is empty

     __ verify_FPU(0, "generate_call_stub");

     // pop parameters

     __ lea(rsp, rsp_after_call);

     // restore %mxcsr

     if (sse_save) {

       __ ldmxcsr(mxcsr_save);

     }

     // restore rdi, rsi and rbx,

     __ movptr(rbx, saved_rbx);

     __ movptr(rsi, saved_rsi);

     __ movptr(rdi, saved_rdi);

     __ addptr(rsp, 4*wordSize);

     // return

     __ pop(rbp);

     __ ret(0);

     // handle return types different from T_INT

     __ BIND(is_long);

     __ movl(Address(rdi, 0 * wordSize), rax);

     __ movl(Address(rdi, 1 * wordSize), rdx);

     __ jmp(exit);

     __ BIND(is_float);

     // interpreter uses xmm0 for return values

     if (UseSSE >= 1) {

       __ movflt(Address(rdi, 0), xmm0);

     } else {

       __ fstp_s(Address(rdi, 0));

     }

     __ jmp(exit);

     __ BIND(is_double);

     // interpreter uses xmm0 for return values

     if (UseSSE >= 2) {

       __ movdbl(Address(rdi, 0), xmm0);

     } else {

       __ fstp_d(Address(rdi, 0));

     }

     __ jmp(exit);

     // If we call compiled code directly from the call stub we will

     // need to adjust the return back to the call stub to a specialized

     // piece of code that can handle compiled results and cleaning the fpu

     // stack. compiled code will be set to return here instead of the

     // return above that handles interpreter returns.

     BLOCK_COMMENT("call_stub_compiled_return:");

     StubRoutines::x86::set_call_stub_compiled_return( __ pc());

 #ifdef COMPILER2

     if (UseSSE >= 2) {

       __ verify_FPU(0, "call_stub_compiled_return");

     } else {

       for (int i = 1; i < 8; i++) {

         __ ffree(i);

       }

       // UseSSE <= 1 so double result should be left on TOS

       __ movl(rsi, result_type);

       __ cmpl(rsi, T_DOUBLE);

       __ jcc(Assembler::equal, common_return);

       if (UseSSE == 0) {

         // UseSSE == 0 so float result should be left on TOS

         __ cmpl(rsi, T_FLOAT);

         __ jcc(Assembler::equal, common_return);

       }

       __ ffree(0);

     }

 #endif /* COMPILER2 */

     __ jmp(common_return);

     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");

     const Address rsp_after_call(rbp, -4 * wordSize); // same as in generate_call_stub()!

     const Address thread        (rbp,  9 * wordSize); // same as in generate_call_stub()!

     address start = __ pc();

     // get thread directly

     __ movptr(rcx, thread);

 #ifdef ASSERT

     // verify that threads correspond

     { Label L;

       __ get_thread(rbx);

       __ cmpptr(rbx, rcx);

       __ jcc(Assembler::equal, L);

       __ stop("StubRoutines::catch_exception: threads must correspond");

       __ bind(L);

     }

 #endif

     // set pending exception

     __ verify_oop(rax);

     __ movptr(Address(rcx, Thread::pending_exception_offset()), rax          );

     __ lea(Address(rcx, Thread::exception_file_offset   ()),

            ExternalAddress((address)__FILE__));

     __ movl(Address(rcx, Thread::exception_line_offset   ()), __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();

     const Register thread = rcx;

     // other registers used in this stub

     const Register exception_oop = rax;

     const Register handler_addr  = rbx;

     const Register exception_pc  = rdx;

     // 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;

       __ get_thread(thread);

       __ cmpptr(Address(thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);

       __ jcc(Assembler::notEqual, L);

       __ stop("StubRoutines::forward exception: no pending exception (1)");

       __ bind(L);

     }

 #endif

     // compute exception handler into rbx,

     __ get_thread(thread);

     __ movptr(exception_pc, 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), thread, exception_pc);

     __ mov(handler_addr, rax);

     // setup rax & rdx, remove return address & clear pending exception

     __ get_thread(thread);

     __ pop(exception_pc);

     __ movptr(exception_oop, Address(thread, Thread::pending_exception_offset()));

     __ movptr(Address(thread, Thread::pending_exception_offset()), NULL_WORD);

 #ifdef ASSERT

     // make sure exception is set

     { Label L;

       __ testptr(exception_oop, exception_oop);

       __ jcc(Assembler::notEqual, L);

       __ stop("StubRoutines::forward exception: no pending exception (2)");

       __ bind(L);

     }

 #endif

     // Verify that there is really a valid exception in RAX.

     __ verify_oop(exception_oop);

     // Restore SP from BP if the exception PC is a MethodHandle call site.

     __ cmpl(Address(thread, JavaThread::is_method_handle_return_offset()), 0);

     __ cmovptr(Assembler::notEqual, rsp, rbp);

     // continue at exception handler (return address removed)

     // rax: exception

     // rbx: exception handler

     // rdx: throwing pc

     __ jmp(handler_addr);

     return start;

   }

   //----------------------------------------------------------------------------------------------------

   // Support for jint Atomic::xchg(jint exchange_value, volatile jint* dest)

   //

   // xchg exists as far back as 8086, lock needed for MP only

   // Stack layout immediately after call:

   //

   // 0 [ret addr ] <--- rsp

   // 1 [  ex     ]

   // 2 [  dest   ]

   //

   // Result:   *dest <- ex, return (old *dest)

   //

   // Note: win32 does not currently use this code

   address generate_atomic_xchg() {

     StubCodeMark mark(this, "StubRoutines", "atomic_xchg");

     address start = __ pc();

     __ push(rdx);

     Address exchange(rsp, 2 * wordSize);

     Address dest_addr(rsp, 3 * wordSize);

     __ movl(rax, exchange);

     __ movptr(rdx, dest_addr);

     __ xchgl(rax, Address(rdx, 0));

     __ pop(rdx);

     __ 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 && UseSSE > 0 ) {

       Label ok_ret;

       ExternalAddress mxcsr_std(StubRoutines::addr_mxcsr_std());

       __ push(rax);

       __ subptr(rsp, wordSize);      // allocate a temp location

       __ stmxcsr(mxcsr_save);

       __ movl(rax, mxcsr_save);

       __ andl(rax, MXCSR_MASK);

       __ cmp32(rax, mxcsr_std);

       __ jcc(Assembler::equal, ok_ret);

       __ warn("MXCSR changed by native JNI code.");

       __ ldmxcsr(mxcsr_std);

       __ bind(ok_ret);

       __ addptr(rsp, wordSize);

       __ pop(rax);

     }

     __ ret(0);

     return start;

   }

   //---------------------------------------------------------------------------

   // Support for void verify_fpu_cntrl_wrd()

   //

   // This routine is used with -Xcheck:jni to verify that native

   // JNI code does not return to Java code without restoring the

   // FP control word to our expected state.

   address generate_verify_fpu_cntrl_wrd() {

     StubCodeMark mark(this, "StubRoutines", "verify_spcw");

     address start = __ pc();

     const Address fpu_cntrl_wrd_save(rsp, 0);

     if (CheckJNICalls) {

       Label ok_ret;

       __ push(rax);

       __ subptr(rsp, wordSize);      // allocate a temp location

       __ fnstcw(fpu_cntrl_wrd_save);

       __ movl(rax, fpu_cntrl_wrd_save);

       __ andl(rax, FPU_CNTRL_WRD_MASK);

       ExternalAddress fpu_std(StubRoutines::addr_fpu_cntrl_wrd_std());

       __ cmp32(rax, fpu_std);

       __ jcc(Assembler::equal, ok_ret);

       __ warn("Floating point control word changed by native JNI code.");

       __ fldcw(fpu_std);

       __ bind(ok_ret);

       __ addptr(rsp, wordSize);

       __ pop(rax);

     }

     __ ret(0);

     return start;

   }

   //---------------------------------------------------------------------------

   // Wrapper for slow-case handling of double-to-integer conversion

   // d2i or f2i fast case failed either because it is nan or because

   // of under/overflow.

   // Input:  FPU TOS: float value

   // Output: rax, (rdx): integer (long) result

   address generate_d2i_wrapper(BasicType t, address fcn) {

     StubCodeMark mark(this, "StubRoutines", "d2i_wrapper");

     address start = __ pc();

   // Capture info about frame layout

   enum layout { FPUState_off         = 0,

                 rbp_off              = FPUStateSizeInWords,

                 rdi_off,

                 rsi_off,

                 rcx_off,

                 rbx_off,

                 saved_argument_off,

                 saved_argument_off2, // 2nd half of double

                 framesize

   };

   assert(FPUStateSizeInWords == 27, "update stack layout");

     // Save outgoing argument to stack across push_FPU_state()

     __ subptr(rsp, wordSize * 2);

     __ fstp_d(Address(rsp, 0));

     // Save CPU & FPU state

     __ push(rbx);

     __ push(rcx);

     __ push(rsi);

     __ push(rdi);

     __ push(rbp);

     __ push_FPU_state();

     // push_FPU_state() resets the FP top of stack

     // Load original double into FP top of stack

     __ fld_d(Address(rsp, saved_argument_off * wordSize));

     // Store double into stack as outgoing argument

     __ subptr(rsp, wordSize*2);

     __ fst_d(Address(rsp, 0));

     // Prepare FPU for doing math in C-land

     __ empty_FPU_stack();

     // Call the C code to massage the double.  Result in EAX

     if (t == T_INT)

       { BLOCK_COMMENT("SharedRuntime::d2i"); }

     else if (t == T_LONG)

       { BLOCK_COMMENT("SharedRuntime::d2l"); }

     __ call_VM_leaf( fcn, 2 );

     // Restore CPU & FPU state

     __ pop_FPU_state();

     __ pop(rbp);

     __ pop(rdi);

     __ pop(rsi);

     __ pop(rcx);

     __ pop(rbx);

     __ addptr(rsp, wordSize * 2);

     __ ret(0);

     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();

     __ push(0);                       // hole for return address-to-be

     __ pusha();                       // push registers

     Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);

     BLOCK_COMMENT("call handle_unsafe_access");

     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));

     __ movptr(next_pc, rax);          // stuff next address

     __ popa();

     __ ret(0);                        // jump to next address

     return start;

   }

   //----------------------------------------------------------------------------------------------------

   // Non-destructive plausibility checks for oops

   address generate_verify_oop() {

     StubCodeMark mark(this, "StubRoutines", "verify_oop");

     address start = __ pc();

     // Incoming arguments on stack after saving rax,:

     //

     // [tos    ]: saved rdx

     // [tos + 1]: saved EFLAGS

     // [tos + 2]: return address

     // [tos + 3]: char* error message

     // [tos + 4]: oop   object to verify

     // [tos + 5]: saved rax, - saved by caller and bashed

     Label exit, error;

     __ pushf();

     __ incrementl(ExternalAddress((address) StubRoutines::verify_oop_count_addr()));

     __ push(rdx);                                // save rdx

     // make sure object is 'reasonable'

     __ movptr(rax, Address(rsp, 4 * wordSize));    // get object

     __ testptr(rax, rax);

     __ jcc(Assembler::zero, exit);               // if obj is NULL it is ok

     // Check if the oop is in the right area of memory

     const int oop_mask = Universe::verify_oop_mask();

     const int oop_bits = Universe::verify_oop_bits();

     __ mov(rdx, rax);

     __ andptr(rdx, oop_mask);

     __ cmpptr(rdx, oop_bits);

     __ jcc(Assembler::notZero, error);

     // make sure klass is 'reasonable'

     __ movptr(rax, Address(rax, oopDesc::klass_offset_in_bytes())); // get klass

     __ testptr(rax, rax);

     __ jcc(Assembler::zero, error);              // if klass is NULL it is broken

     // Check if the klass is in the right area of memory

     const int klass_mask = Universe::verify_klass_mask();

     const int klass_bits = Universe::verify_klass_bits();

     __ mov(rdx, rax);

     __ andptr(rdx, klass_mask);

     __ cmpptr(rdx, klass_bits);

     __ jcc(Assembler::notZero, error);

     // make sure klass' klass is 'reasonable'

     __ movptr(rax, Address(rax, oopDesc::klass_offset_in_bytes())); // get klass' klass

     __ testptr(rax, rax);

     __ jcc(Assembler::zero, error);              // if klass' klass is NULL it is broken

     __ mov(rdx, rax);

     __ andptr(rdx, klass_mask);

     __ cmpptr(rdx, klass_bits);

     __ jcc(Assembler::notZero, error);           // if klass not in right area

                                                  // of memory it is broken too.

     // return if everything seems ok

     __ bind(exit);

     __ movptr(rax, Address(rsp, 5 * wordSize));  // get saved rax, back

     __ pop(rdx);                                 // restore rdx

     __ popf();                                   // restore EFLAGS

     __ ret(3 * wordSize);                        // pop arguments

     // handle errors

     __ bind(error);

     __ movptr(rax, Address(rsp, 5 * wordSize));  // get saved rax, back

     __ pop(rdx);                                 // get saved rdx back

     __ popf();                                   // get saved EFLAGS off stack -- will be ignored

     __ pusha();                                  // push registers (eip = return address & msg are already pushed)

     BLOCK_COMMENT("call MacroAssembler::debug");

     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, MacroAssembler::debug32)));

     __ popa();

     __ ret(3 * wordSize);                        // pop arguments

     return start;

   }

   //

   //  Generate pre-barrier for array stores

   //

   //  Input:

   //     start   -  starting address

   //     count   -  element count

   void  gen_write_ref_array_pre_barrier(Register start, Register count) {

     assert_different_registers(start, count);

     BarrierSet* bs = Universe::heap()->barrier_set();

     switch (bs->kind()) {

       case BarrierSet::G1SATBCT:

       case BarrierSet::G1SATBCTLogging:

         {

           __ pusha();                      // push registers

           __ call_VM_leaf(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre),

                           start, count);

           __ popa();

         }

         break;

       case BarrierSet::CardTableModRef:

       case BarrierSet::CardTableExtension:

       case BarrierSet::ModRef:

         break;

       default      :

         ShouldNotReachHere();

     }

   }

   //

   // Generate a post-barrier for an array store

   //

   //     start    -  starting address

   //     count    -  element count

   //

   //  The two input registers are overwritten.

   //

   void  gen_write_ref_array_post_barrier(Register start, Register count) {

     BarrierSet* bs = Universe::heap()->barrier_set();

     assert_different_registers(start, count);

     switch (bs->kind()) {

       case BarrierSet::G1SATBCT:

       case BarrierSet::G1SATBCTLogging:

         {

           __ pusha();                      // push registers

           __ call_VM_leaf(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post),

                           start, count);

           __ popa();

         }

         break;

       case BarrierSet::CardTableModRef:

       case BarrierSet::CardTableExtension:

         {

           CardTableModRefBS* ct = (CardTableModRefBS*)bs;

           assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");

           Label L_loop;

           const Register end = count;  // elements count; end == start+count-1

           assert_different_registers(start, end);

           __ lea(end,  Address(start, count, Address::times_ptr, -wordSize));

           __ shrptr(start, CardTableModRefBS::card_shift);

           __ shrptr(end,   CardTableModRefBS::card_shift);

           __ subptr(end, start); // end --> count

         __ BIND(L_loop);

           intptr_t disp = (intptr_t) ct->byte_map_base;

           Address cardtable(start, count, Address::times_1, disp);

           __ movb(cardtable, 0);

           __ decrement(count);

           __ jcc(Assembler::greaterEqual, L_loop);

         }

         break;

       case BarrierSet::ModRef:

         break;

       default      :

         ShouldNotReachHere();

     }

   }

   // Copy 64 bytes chunks

   //

   // Inputs:

   //   from        - source array address

   //   to_from     - destination array address - from

   //   qword_count - 8-bytes element count, negative

   //

   void xmm_copy_forward(Register from, Register to_from, Register qword_count) {

     assert( UseSSE >= 2, "supported cpu only" );

     Label L_copy_64_bytes_loop, L_copy_64_bytes, L_copy_8_bytes, L_exit;

     // Copy 64-byte chunks

     __ jmpb(L_copy_64_bytes);

     __ align(OptoLoopAlignment);

   __ BIND(L_copy_64_bytes_loop);

     if(UseUnalignedLoadStores) {

       __ movdqu(xmm0, Address(from, 0));

       __ movdqu(Address(from, to_from, Address::times_1, 0), xmm0);

       __ movdqu(xmm1, Address(from, 16));

       __ movdqu(Address(from, to_from, Address::times_1, 16), xmm1);

       __ movdqu(xmm2, Address(from, 32));

       __ movdqu(Address(from, to_from, Address::times_1, 32), xmm2);

       __ movdqu(xmm3, Address(from, 48));

       __ movdqu(Address(from, to_from, Address::times_1, 48), xmm3);

     } else {

       __ movq(xmm0, Address(from, 0));

       __ movq(Address(from, to_from, Address::times_1, 0), xmm0);

       __ movq(xmm1, Address(from, 8));

       __ movq(Address(from, to_from, Address::times_1, 8), xmm1);

       __ movq(xmm2, Address(from, 16));

       __ movq(Address(from, to_from, Address::times_1, 16), xmm2);

       __ movq(xmm3, Address(from, 24));

       __ movq(Address(from, to_from, Address::times_1, 24), xmm3);

       __ movq(xmm4, Address(from, 32));

       __ movq(Address(from, to_from, Address::times_1, 32), xmm4);

       __ movq(xmm5, Address(from, 40));

       __ movq(Address(from, to_from, Address::times_1, 40), xmm5);

       __ movq(xmm6, Address(from, 48));

       __ movq(Address(from, to_from, Address::times_1, 48), xmm6);

       __ movq(xmm7, Address(from, 56));

       __ movq(Address(from, to_from, Address::times_1, 56), xmm7);

     }

     __ addl(from, 64);

   __ BIND(L_copy_64_bytes);

     __ subl(qword_count, 8);

     __ jcc(Assembler::greaterEqual, L_copy_64_bytes_loop);

     __ addl(qword_count, 8);

     __ jccb(Assembler::zero, L_exit);

     //

     // length is too short, just copy qwords

     //

   __ BIND(L_copy_8_bytes);

     __ movq(xmm0, Address(from, 0));

     __ movq(Address(from, to_from, Address::times_1), xmm0);

     __ addl(from, 8);

     __ decrement(qword_count);

     __ jcc(Assembler::greater, L_copy_8_bytes);

   __ BIND(L_exit);

   }

   // Copy 64 bytes chunks

   //

   // Inputs:

   //   from        - source array address

   //   to_from     - destination array address - from

   //   qword_count - 8-bytes element count, negative

   //

   void mmx_copy_forward(Register from, Register to_from, Register qword_count) {

     assert( VM_Version::supports_mmx(), "supported cpu only" );

     Label L_copy_64_bytes_loop, L_copy_64_bytes, L_copy_8_bytes, L_exit;

     // Copy 64-byte chunks

     __ jmpb(L_copy_64_bytes);

     __ align(OptoLoopAlignment);

   __ BIND(L_copy_64_bytes_loop);

     __ movq(mmx0, Address(from, 0));

     __ movq(mmx1, Address(from, 8));

     __ movq(mmx2, Address(from, 16));

     __ movq(Address(from, to_from, Address::times_1, 0), mmx0);

     __ movq(mmx3, Address(from, 24));

     __ movq(Address(from, to_from, Address::times_1, 8), mmx1);

     __ movq(mmx4, Address(from, 32));

     __ movq(Address(from, to_from, Address::times_1, 16), mmx2);

     __ movq(mmx5, Address(from, 40));

     __ movq(Address(from, to_from, Address::times_1, 24), mmx3);

     __ movq(mmx6, Address(from, 48));

     __ movq(Address(from, to_from, Address::times_1, 32), mmx4);

     __ movq(mmx7, Address(from, 56));

     __ movq(Address(from, to_from, Address::times_1, 40), mmx5);

     __ movq(Address(from, to_from, Address::times_1, 48), mmx6);

     __ movq(Address(from, to_from, Address::times_1, 56), mmx7);

     __ addptr(from, 64);

   __ BIND(L_copy_64_bytes);

     __ subl(qword_count, 8);

     __ jcc(Assembler::greaterEqual, L_copy_64_bytes_loop);

     __ addl(qword_count, 8);

     __ jccb(Assembler::zero, L_exit);

     //

     // length is too short, just copy qwords

     //

   __ BIND(L_copy_8_bytes);

     __ movq(mmx0, Address(from, 0));

     __ movq(Address(from, to_from, Address::times_1), mmx0);

     __ addptr(from, 8);

     __ decrement(qword_count);

     __ jcc(Assembler::greater, L_copy_8_bytes);

   __ BIND(L_exit);

     __ emms();

   }

   address generate_disjoint_copy(BasicType t, bool aligned,

                                  Address::ScaleFactor sf,

                                  address* entry, const char *name) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     Label L_0_count, L_exit, L_skip_align1, L_skip_align2, L_copy_byte;

     Label L_copy_2_bytes, L_copy_4_bytes, L_copy_64_bytes;

     int shift = Address::times_ptr - sf;

     const Register from     = rsi;  // source array address

     const Register to       = rdi;  // destination array address

     const Register count    = rcx;  // elements count

     const Register to_from  = to;   // (to - from)

     const Register saved_to = rdx;  // saved destination array address

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ push(rsi);

     __ push(rdi);

     __ movptr(from , Address(rsp, 12+ 4));

     __ movptr(to   , Address(rsp, 12+ 8));

     __ movl(count, Address(rsp, 12+ 12));

     if (t == T_OBJECT) {

       __ testl(count, count);

       __ jcc(Assembler::zero, L_0_count);

       gen_write_ref_array_pre_barrier(to, count);

       __ mov(saved_to, to);          // save 'to'

     }

     *entry = __ pc(); // Entry point from conjoint arraycopy stub.

     BLOCK_COMMENT("Entry:");

     __ subptr(to, from); // to --> to_from

     __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element

     __ jcc(Assembler::below, L_copy_4_bytes); // use unsigned cmp

     if (!UseUnalignedLoadStores && !aligned && (t == T_BYTE || t == T_SHORT)) {

       // align source address at 4 bytes address boundary

       if (t == T_BYTE) {

         // One byte misalignment happens only for byte arrays

         __ testl(from, 1);

         __ jccb(Assembler::zero, L_skip_align1);

         __ movb(rax, Address(from, 0));

         __ movb(Address(from, to_from, Address::times_1, 0), rax);

         __ increment(from);

         __ decrement(count);

       __ BIND(L_skip_align1);

       }

       // Two bytes misalignment happens only for byte and short (char) arrays

       __ testl(from, 2);

       __ jccb(Assembler::zero, L_skip_align2);

       __ movw(rax, Address(from, 0));

       __ movw(Address(from, to_from, Address::times_1, 0), rax);

       __ addptr(from, 2);

       __ subl(count, 1<<(shift-1));

     __ BIND(L_skip_align2);

     }

     if (!VM_Version::supports_mmx()) {

       __ mov(rax, count);      // save 'count'

       __ shrl(count, shift); // bytes count

       __ addptr(to_from, from);// restore 'to'

       __ rep_mov();

       __ subptr(to_from, from);// restore 'to_from'

       __ mov(count, rax);      // restore 'count'

       __ jmpb(L_copy_2_bytes); // all dwords were copied

     } else {

       if (!UseUnalignedLoadStores) {

         // align to 8 bytes, we know we are 4 byte aligned to start

         __ testptr(from, 4);

         __ jccb(Assembler::zero, L_copy_64_bytes);

         __ movl(rax, Address(from, 0));

         __ movl(Address(from, to_from, Address::times_1, 0), rax);

         __ addptr(from, 4);

         __ subl(count, 1<<shift);

       }

     __ BIND(L_copy_64_bytes);

       __ mov(rax, count);

       __ shrl(rax, shift+1);  // 8 bytes chunk count

       //

       // Copy 8-byte chunks through MMX registers, 8 per iteration of the loop

       //

       if (UseXMMForArrayCopy) {

         xmm_copy_forward(from, to_from, rax);

       } else {

         mmx_copy_forward(from, to_from, rax);

       }

     }

     // copy tailing dword

   __ BIND(L_copy_4_bytes);

     __ testl(count, 1<<shift);

     __ jccb(Assembler::zero, L_copy_2_bytes);

     __ movl(rax, Address(from, 0));

     __ movl(Address(from, to_from, Address::times_1, 0), rax);

     if (t == T_BYTE || t == T_SHORT) {

       __ addptr(from, 4);

     __ BIND(L_copy_2_bytes);

       // copy tailing word

       __ testl(count, 1<<(shift-1));

       __ jccb(Assembler::zero, L_copy_byte);

       __ movw(rax, Address(from, 0));

       __ movw(Address(from, to_from, Address::times_1, 0), rax);

       if (t == T_BYTE) {

         __ addptr(from, 2);

       __ BIND(L_copy_byte);

         // copy tailing byte

         __ testl(count, 1);

         __ jccb(Assembler::zero, L_exit);

         __ movb(rax, Address(from, 0));

         __ movb(Address(from, to_from, Address::times_1, 0), rax);

       __ BIND(L_exit);

       } else {

       __ BIND(L_copy_byte);

       }

     } else {

     __ BIND(L_copy_2_bytes);

     }

     if (t == T_OBJECT) {

       __ movl(count, Address(rsp, 12+12)); // reread 'count'

       __ mov(to, saved_to); // restore 'to'

       gen_write_ref_array_post_barrier(to, count);

     __ BIND(L_0_count);

     }

     inc_copy_counter_np(t);

     __ pop(rdi);

     __ pop(rsi);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ xorptr(rax, rax); // return 0

     __ ret(0);

     return start;

   }

   address generate_fill(BasicType t, bool aligned, const char *name) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     BLOCK_COMMENT("Entry:");

     const Register to       = rdi;  // source array address

     const Register value    = rdx;  // value

     const Register count    = rsi;  // elements count

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ push(rsi);

     __ push(rdi);

     __ movptr(to   , Address(rsp, 12+ 4));

     __ movl(value, Address(rsp, 12+ 8));

     __ movl(count, Address(rsp, 12+ 12));

     __ generate_fill(t, aligned, to, value, count, rax, xmm0);

     __ pop(rdi);

     __ pop(rsi);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ ret(0);

     return start;

   }

   address generate_conjoint_copy(BasicType t, bool aligned,

                                  Address::ScaleFactor sf,

                                  address nooverlap_target,

                                  address* entry, const char *name) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     Label L_0_count, L_exit, L_skip_align1, L_skip_align2, L_copy_byte;

     Label L_copy_2_bytes, L_copy_4_bytes, L_copy_8_bytes, L_copy_8_bytes_loop;

     int shift = Address::times_ptr - sf;

     const Register src   = rax;  // source array address

     const Register dst   = rdx;  // destination array address

     const Register from  = rsi;  // source array address

     const Register to    = rdi;  // destination array address

     const Register count = rcx;  // elements count

     const Register end   = rax;  // array end address

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ push(rsi);

     __ push(rdi);

     __ movptr(src  , Address(rsp, 12+ 4));   // from

     __ movptr(dst  , Address(rsp, 12+ 8));   // to

     __ movl2ptr(count, Address(rsp, 12+12)); // count

     if (t == T_OBJECT) {

        gen_write_ref_array_pre_barrier(dst, count);

     }

     if (entry != NULL) {

       *entry = __ pc(); // Entry point from generic arraycopy stub.

       BLOCK_COMMENT("Entry:");

     }

     if (t == T_OBJECT) {

       __ testl(count, count);

       __ jcc(Assembler::zero, L_0_count);

     }

     __ mov(from, src);

     __ mov(to  , dst);

     // arrays overlap test

     RuntimeAddress nooverlap(nooverlap_target);

     __ cmpptr(dst, src);

     __ lea(end, Address(src, count, sf, 0)); // src + count * elem_size

     __ jump_cc(Assembler::belowEqual, nooverlap);

     __ cmpptr(dst, end);

     __ jump_cc(Assembler::aboveEqual, nooverlap);

     // copy from high to low

     __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element

     __ jcc(Assembler::below, L_copy_4_bytes); // use unsigned cmp

     if (t == T_BYTE || t == T_SHORT) {

       // Align the end of destination array at 4 bytes address boundary

       __ lea(end, Address(dst, count, sf, 0));

       if (t == T_BYTE) {

         // One byte misalignment happens only for byte arrays

         __ testl(end, 1);

         __ jccb(Assembler::zero, L_skip_align1);

         __ decrement(count);

         __ movb(rdx, Address(from, count, sf, 0));

         __ movb(Address(to, count, sf, 0), rdx);

       __ BIND(L_skip_align1);

       }

       // Two bytes misalignment happens only for byte and short (char) arrays

       __ testl(end, 2);

       __ jccb(Assembler::zero, L_skip_align2);

       __ subptr(count, 1<<(shift-1));

       __ movw(rdx, Address(from, count, sf, 0));

       __ movw(Address(to, count, sf, 0), rdx);

     __ BIND(L_skip_align2);

       __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element

       __ jcc(Assembler::below, L_copy_4_bytes);

     }

     if (!VM_Version::supports_mmx()) {

       __ std();

       __ mov(rax, count); // Save 'count'

       __ mov(rdx, to);    // Save 'to'

       __ lea(rsi, Address(from, count, sf, -4));

       __ lea(rdi, Address(to  , count, sf, -4));

       __ shrptr(count, shift); // bytes count

       __ rep_mov();

       __ cld();

       __ mov(count, rax); // restore 'count'

       __ andl(count, (1<<shift)-1);      // mask the number of rest elements

       __ movptr(from, Address(rsp, 12+4)); // reread 'from'

       __ mov(to, rdx);   // restore 'to'

       __ jmpb(L_copy_2_bytes); // all dword were copied

    } else {

       // Align to 8 bytes the end of array. It is aligned to 4 bytes already.

       __ testptr(end, 4);

       __ jccb(Assembler::zero, L_copy_8_bytes);

       __ subl(count, 1<<shift);

       __ movl(rdx, Address(from, count, sf, 0));

       __ movl(Address(to, count, sf, 0), rdx);

       __ jmpb(L_copy_8_bytes);

       __ align(OptoLoopAlignment);

       // Move 8 bytes

     __ BIND(L_copy_8_bytes_loop);

       if (UseXMMForArrayCopy) {

         __ movq(xmm0, Address(from, count, sf, 0));

         __ movq(Address(to, count, sf, 0), xmm0);

       } else {

         __ movq(mmx0, Address(from, count, sf, 0));

         __ movq(Address(to, count, sf, 0), mmx0);

       }

     __ BIND(L_copy_8_bytes);

       __ subl(count, 2<<shift);

       __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);

       __ addl(count, 2<<shift);

       if (!UseXMMForArrayCopy) {

         __ emms();

       }

     }

   __ BIND(L_copy_4_bytes);

     // copy prefix qword

     __ testl(count, 1<<shift);

     __ jccb(Assembler::zero, L_copy_2_bytes);

     __ movl(rdx, Address(from, count, sf, -4));

     __ movl(Address(to, count, sf, -4), rdx);

     if (t == T_BYTE || t == T_SHORT) {

         __ subl(count, (1<<shift));

       __ BIND(L_copy_2_bytes);

         // copy prefix dword

         __ testl(count, 1<<(shift-1));

         __ jccb(Assembler::zero, L_copy_byte);

         __ movw(rdx, Address(from, count, sf, -2));

         __ movw(Address(to, count, sf, -2), rdx);

         if (t == T_BYTE) {

           __ subl(count, 1<<(shift-1));

         __ BIND(L_copy_byte);

           // copy prefix byte

           __ testl(count, 1);

           __ jccb(Assembler::zero, L_exit);

           __ movb(rdx, Address(from, 0));

           __ movb(Address(to, 0), rdx);

         __ BIND(L_exit);

         } else {

         __ BIND(L_copy_byte);

         }

     } else {

     __ BIND(L_copy_2_bytes);

     }

     if (t == T_OBJECT) {

       __ movl2ptr(count, Address(rsp, 12+12)); // reread count

       gen_write_ref_array_post_barrier(to, count);

     __ BIND(L_0_count);

     }

     inc_copy_counter_np(t);

     __ pop(rdi);

     __ pop(rsi);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ xorptr(rax, rax); // return 0

     __ ret(0);

     return start;

   }

   address generate_disjoint_long_copy(address* entry, const char *name) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     Label L_copy_8_bytes, L_copy_8_bytes_loop;

     const Register from       = rax;  // source array address

     const Register to         = rdx;  // destination array address

     const Register count      = rcx;  // elements count

     const Register to_from    = rdx;  // (to - from)

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ movptr(from , Address(rsp, 8+0));       // from

     __ movptr(to   , Address(rsp, 8+4));       // to

     __ movl2ptr(count, Address(rsp, 8+8));     // count

     *entry = __ pc(); // Entry point from conjoint arraycopy stub.

     BLOCK_COMMENT("Entry:");

     __ subptr(to, from); // to --> to_from

     if (VM_Version::supports_mmx()) {

       if (UseXMMForArrayCopy) {

         xmm_copy_forward(from, to_from, count);

       } else {

         mmx_copy_forward(from, to_from, count);

       }

     } else {

       __ jmpb(L_copy_8_bytes);

       __ align(OptoLoopAlignment);

     __ BIND(L_copy_8_bytes_loop);

       __ fild_d(Address(from, 0));

       __ fistp_d(Address(from, to_from, Address::times_1));

       __ addptr(from, 8);

     __ BIND(L_copy_8_bytes);

       __ decrement(count);

       __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);

     }

     inc_copy_counter_np(T_LONG);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ xorptr(rax, rax); // return 0

     __ ret(0);

     return start;

   }

   address generate_conjoint_long_copy(address nooverlap_target,

                                       address* entry, const char *name) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     Label L_copy_8_bytes, L_copy_8_bytes_loop;

     const Register from       = rax;  // source array address

     const Register to         = rdx;  // destination array address

     const Register count      = rcx;  // elements count

     const Register end_from   = rax;  // source array end address

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ movptr(from , Address(rsp, 8+0));       // from

     __ movptr(to   , Address(rsp, 8+4));       // to

     __ movl2ptr(count, Address(rsp, 8+8));     // count

     *entry = __ pc(); // Entry point from generic arraycopy stub.

     BLOCK_COMMENT("Entry:");

     // arrays overlap test

     __ cmpptr(to, from);

     RuntimeAddress nooverlap(nooverlap_target);

     __ jump_cc(Assembler::belowEqual, nooverlap);

     __ lea(end_from, Address(from, count, Address::times_8, 0));

     __ cmpptr(to, end_from);

     __ movptr(from, Address(rsp, 8));  // from

     __ jump_cc(Assembler::aboveEqual, nooverlap);

     __ jmpb(L_copy_8_bytes);

     __ align(OptoLoopAlignment);

   __ BIND(L_copy_8_bytes_loop);

     if (VM_Version::supports_mmx()) {

       if (UseXMMForArrayCopy) {

         __ movq(xmm0, Address(from, count, Address::times_8));

         __ movq(Address(to, count, Address::times_8), xmm0);

       } else {

         __ movq(mmx0, Address(from, count, Address::times_8));

         __ movq(Address(to, count, Address::times_8), mmx0);

       }

     } else {

       __ fild_d(Address(from, count, Address::times_8));

       __ fistp_d(Address(to, count, Address::times_8));

     }

   __ BIND(L_copy_8_bytes);

     __ decrement(count);

     __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);

     if (VM_Version::supports_mmx() && !UseXMMForArrayCopy) {

       __ emms();

     }

     inc_copy_counter_np(T_LONG);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ xorptr(rax, rax); // return 0

     __ ret(0);

     return start;

   }

   // Helper for generating a dynamic type check.

   // The sub_klass must be one of {rbx, rdx, rsi}.

   // The temp is killed.

   void generate_type_check(Register sub_klass,

                            Address& super_check_offset_addr,

                            Address& super_klass_addr,

                            Register temp,

                            Label* L_success, Label* L_failure) {

     BLOCK_COMMENT("type_check:");

     Label L_fallthrough;

 #define LOCAL_JCC(assembler_con, label_ptr)                             \

     if (label_ptr != NULL)  __ jcc(assembler_con, *(label_ptr));        \

     else                    __ jcc(assembler_con, L_fallthrough) /*omit semi*/

     // The following is a strange variation of the fast path which requires

     // one less register, because needed values are on the argument stack.

     // __ check_klass_subtype_fast_path(sub_klass, *super_klass*, temp,

     //                                  L_success, L_failure, NULL);

     assert_different_registers(sub_klass, temp);

     int sc_offset = (klassOopDesc::header_size() * HeapWordSize +

                      Klass::secondary_super_cache_offset_in_bytes());

     // if the pointers are equal, we are done (e.g., String[] elements)

     __ cmpptr(sub_klass, super_klass_addr);

     LOCAL_JCC(Assembler::equal, L_success);

     // check the supertype display:

     __ movl2ptr(temp, super_check_offset_addr);

     Address super_check_addr(sub_klass, temp, Address::times_1, 0);

     __ movptr(temp, super_check_addr); // load displayed supertype

     __ cmpptr(temp, super_klass_addr); // test the super type

     LOCAL_JCC(Assembler::equal, L_success);

     // if it was a primary super, we can just fail immediately

     __ cmpl(super_check_offset_addr, sc_offset);

     LOCAL_JCC(Assembler::notEqual, L_failure);

     // The repne_scan instruction uses fixed registers, which will get spilled.

     // We happen to know this works best when super_klass is in rax.

     Register super_klass = temp;

     __ movptr(super_klass, super_klass_addr);

     __ check_klass_subtype_slow_path(sub_klass, super_klass, noreg, noreg,

                                      L_success, L_failure);

     __ bind(L_fallthrough);

     if (L_success == NULL) { BLOCK_COMMENT("L_success:"); }

     if (L_failure == NULL) { BLOCK_COMMENT("L_failure:"); }

 #undef LOCAL_JCC

   }

   //

   //  Generate checkcasting array copy stub

   //

   //  Input:

   //    4(rsp)   - source array address

   //    8(rsp)   - destination array address

   //   12(rsp)   - element count, can be zero

   //   16(rsp)   - size_t ckoff (super_check_offset)

   //   20(rsp)   - 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, address* entry) {

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     Label L_load_element, L_store_element, L_do_card_marks, L_done;

     // register use:

     //  rax, rdx, rcx -- loop control (end_from, end_to, count)

     //  rdi, rsi      -- element access (oop, klass)

     //  rbx,           -- temp

     const Register from       = rax;    // source array address

     const Register to         = rdx;    // destination array address

     const Register length     = rcx;    // elements count

     const Register elem       = rdi;    // each oop copied

     const Register elem_klass = rsi;    // each elem._klass (sub_klass)

     const Register temp       = rbx;    // lone remaining temp

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ push(rsi);

     __ push(rdi);

     __ push(rbx);

     Address   from_arg(rsp, 16+ 4);     // from

     Address     to_arg(rsp, 16+ 8);     // to

     Address length_arg(rsp, 16+12);     // elements count

     Address  ckoff_arg(rsp, 16+16);     // super_check_offset

     Address  ckval_arg(rsp, 16+20);     // super_klass

     // Load up:

     __ movptr(from,     from_arg);

     __ movptr(to,         to_arg);

     __ movl2ptr(length, length_arg);

     *entry = __ pc(); // Entry point from generic arraycopy stub.

     BLOCK_COMMENT("Entry:");

     //---------------------------------------------------------------

     // 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.

     // Loop-invariant addresses.  They are exclusive end pointers.

     Address end_from_addr(from, length, Address::times_ptr, 0);

     Address   end_to_addr(to,   length, Address::times_ptr, 0);

     Register end_from = from;           // re-use

     Register end_to   = to;             // re-use

     Register count    = length;         // re-use

     // Loop-variant addresses.  They assume post-incremented count < 0.

     Address from_element_addr(end_from, count, Address::times_ptr, 0);

     Address   to_element_addr(end_to,   count, Address::times_ptr, 0);

     Address elem_klass_addr(elem, oopDesc::klass_offset_in_bytes());

     // Copy from low to high addresses, indexed from the end of each array.

     gen_write_ref_array_pre_barrier(to, count);

     __ lea(end_from, end_from_addr);

     __ lea(end_to,   end_to_addr);

     assert(length == count, "");        // else fix next line:

     __ negptr(count);                   // negate and test the length

     __ jccb(Assembler::notZero, L_load_element);

     // Empty array:  Nothing to do.

     __ xorptr(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,to last element.

     __ align(OptoLoopAlignment);

     __ BIND(L_store_element);

     __ movptr(to_element_addr, elem);     // store the oop

     __ increment(count);                // increment the count toward zero

     __ jccb(Assembler::zero, L_do_card_marks);

     // ======== loop entry is here ========

     __ BIND(L_load_element);

     __ movptr(elem, from_element_addr);   // load the oop

     __ testptr(elem, elem);

     __ jccb(Assembler::zero, L_store_element);

     // (Could do a trick here:  Remember last successful non-null

     // element stored and make a quick oop equality check on it.)

     __ movptr(elem_klass, elem_klass_addr); // query the object klass

     generate_type_check(elem_klass, ckoff_arg, ckval_arg, temp,

                         &L_store_element, NULL);

       // (On fall-through, we have failed the element type check.)

     // ======== end loop ========

     // It was a real error; we must depend on the caller to finish the job.

     // Register "count" = -1 * number of *remaining* oops, length_arg = *total* oops.

     // Emit GC store barriers for the oops we have copied (length_arg + count),

     // and report their number to the caller.

     __ addl(count, length_arg);         // transfers = (length - remaining)

     __ movl2ptr(rax, count);            // save the value

     __ notptr(rax);                     // report (-1^K) to caller

     __ movptr(to, to_arg);              // reload

     assert_different_registers(to, count, rax);

     gen_write_ref_array_post_barrier(to, count);

     __ jmpb(L_done);

     // Come here on success only.

     __ BIND(L_do_card_marks);

     __ movl2ptr(count, length_arg);

     __ movptr(to, to_arg);                // reload

     gen_write_ref_array_post_barrier(to, count);

     __ xorptr(rax, rax);                  // return 0 on success

     // Common exit point (success or failure).

     __ BIND(L_done);

     __ pop(rbx);

     __ pop(rdi);

     __ pop(rsi);

     inc_counter_np(SharedRuntime::_checkcast_array_copy_ctr);

     __ 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:

   //    4(rsp)   - source array address

   //    8(rsp)   - destination array address

   //   12(rsp)   - byte count, can be zero

   //

   //  Output:

   //    rax, ==  0  -  success

   //    rax, == -1  -  need to call System.arraycopy

   //

   // Examines the alignment of the operands and dispatches

   // to a long, int, short, or byte copy loop.

   //

   address generate_unsafe_copy(const char *name,

                                address byte_copy_entry,

                                address short_copy_entry,

                                address int_copy_entry,

                                address long_copy_entry) {

     Label L_long_aligned, L_int_aligned, L_short_aligned;

     __ align(CodeEntryAlignment);

     StubCodeMark mark(this, "StubRoutines", name);

     address start = __ pc();

     const Register from       = rax;  // source array address

     const Register to         = rdx;  // destination array address

     const Register count      = rcx;  // elements count

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     __ push(rsi);

     __ push(rdi);

     Address  from_arg(rsp, 12+ 4);      // from

     Address    to_arg(rsp, 12+ 8);      // to

     Address count_arg(rsp, 12+12);      // byte count

     // Load up:

     __ movptr(from ,  from_arg);

     __ movptr(to   ,    to_arg);

     __ movl2ptr(count, count_arg);

     // bump this on entry, not on exit:

     inc_counter_np(SharedRuntime::_unsafe_array_copy_ctr);

     const Register bits = rsi;

     __ mov(bits, from);

     __ orptr(bits, to);

     __ orptr(bits, count);

     __ testl(bits, BytesPerLong-1);

     __ jccb(Assembler::zero, L_long_aligned);

     __ testl(bits, BytesPerInt-1);

     __ jccb(Assembler::zero, L_int_aligned);

     __ testl(bits, BytesPerShort-1);

     __ jump_cc(Assembler::notZero, RuntimeAddress(byte_copy_entry));

     __ BIND(L_short_aligned);

     __ shrptr(count, LogBytesPerShort); // size => short_count

     __ movl(count_arg, count);          // update 'count'

     __ jump(RuntimeAddress(short_copy_entry));

     __ BIND(L_int_aligned);

     __ shrptr(count, LogBytesPerInt); // size => int_count

     __ movl(count_arg, count);          // update 'count'

     __ jump(RuntimeAddress(int_copy_entry));

     __ BIND(L_long_aligned);

     __ shrptr(count, LogBytesPerLong); // size => qword_count

     __ movl(count_arg, count);          // update 'count'

     __ pop(rdi); // Do pops here since jlong_arraycopy stub does not do it.

     __ pop(rsi);

     __ jump(RuntimeAddress(long_copy_entry));

     return start;

   }

   // Perform range checks on the proposed arraycopy.

   // Smashes src_pos and dst_pos.  (Uses them up for temps.)

   void arraycopy_range_checks(Register src,

                               Register src_pos,

                               Register dst,

                               Register dst_pos,

                               Address& length,

                               Label& L_failed) {

     BLOCK_COMMENT("arraycopy_range_checks:");

     const Register src_end = src_pos;   // source array end position

     const Register dst_end = dst_pos;   // destination array end position

     __ addl(src_end, length); // src_pos + length

     __ addl(dst_end, length); // dst_pos + length

     //  if (src_pos + length > arrayOop(src)->length() ) FAIL;

     __ cmpl(src_end, Address(src, arrayOopDesc::length_offset_in_bytes()));

     __ jcc(Assembler::above, L_failed);

     //  if (dst_pos + length > arrayOop(dst)->length() ) FAIL;

     __ cmpl(dst_end, Address(dst, arrayOopDesc::length_offset_in_bytes()));

     __ jcc(Assembler::above, L_failed);

     BLOCK_COMMENT("arraycopy_range_checks done");

   }

   //

   //  Generate generic array copy stubs

   //

   //  Input:

   //     4(rsp)    -  src oop

   //     8(rsp)    -  src_pos

   //    12(rsp)    -  dst oop

   //    16(rsp)    -  dst_pos

   //    20(rsp)    -  element count

   //

   //  Output:

   //    rax, ==  0  -  success

   //    rax, == -1^K - failure, where K is partial transfer count

   //

   address generate_generic_copy(const char *name,

                                 address entry_jbyte_arraycopy,

                                 address entry_jshort_arraycopy,

                                 address entry_jint_arraycopy,

                                 address entry_oop_arraycopy,

                                 address entry_jlong_arraycopy,

                                 address entry_checkcast_arraycopy) {

     Label L_failed, L_failed_0, L_objArray;

     { 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

     __ push(rsi);

     __ push(rdi);

     // bump this on entry, not on exit:

     inc_counter_np(SharedRuntime::_generic_array_copy_ctr);

     // Input values

     Address SRC     (rsp, 12+ 4);

     Address SRC_POS (rsp, 12+ 8);

     Address DST     (rsp, 12+12);

     Address DST_POS (rsp, 12+16);

     Address LENGTH  (rsp, 12+20);

     //-----------------------------------------------------------------------

     // 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.

     //

     const Register src     = rax;       // source array oop

     const Register src_pos = rsi;

     const Register dst     = rdx;       // destination array oop

     const Register dst_pos = rdi;

     const Register length  = rcx;       // transfer count

     //  if (src == NULL) return -1;

     __ movptr(src, SRC);      // src oop

     __ testptr(src, src);

     __ jccb(Assembler::zero, L_failed_0);

     //  if (src_pos < 0) return -1;

     __ movl2ptr(src_pos, SRC_POS);  // src_pos

     __ testl(src_pos, src_pos);

     __ jccb(Assembler::negative, L_failed_0);

     //  if (dst == NULL) return -1;

     __ movptr(dst, DST);      // dst oop

     __ testptr(dst, dst);

     __ jccb(Assembler::zero, L_failed_0);

     //  if (dst_pos < 0) return -1;

     __ movl2ptr(dst_pos, DST_POS);  // dst_pos

     __ testl(dst_pos, dst_pos);

     __ jccb(Assembler::negative, L_failed_0);

     //  if (length < 0) return -1;

     __ movl2ptr(length, LENGTH);   // length

     __ testl(length, length);

     __ jccb(Assembler::negative, L_failed_0);

     //  if (src->klass() == NULL) return -1;

     Address src_klass_addr(src, oopDesc::klass_offset_in_bytes());

     Address dst_klass_addr(dst, oopDesc::klass_offset_in_bytes());

     const Register rcx_src_klass = rcx;    // array klass

     __ movptr(rcx_src_klass, Address(src, oopDesc::klass_offset_in_bytes()));

 #ifdef ASSERT

     //  assert(src->klass() != NULL);

     BLOCK_COMMENT("assert klasses not null");

     { Label L1, L2;

       __ testptr(rcx_src_klass, rcx_src_klass);

       __ jccb(Assembler::notZero, L2);   // it is broken if klass is NULL

       __ bind(L1);

       __ stop("broken null klass");

       __ bind(L2);

       __ cmpptr(dst_klass_addr, (int32_t)NULL_WORD);

       __ jccb(Assembler::equal, L1);      // this would be broken also

       BLOCK_COMMENT("assert done");

     }

 #endif //ASSERT

     // 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();

     Address src_klass_lh_addr(rcx_src_klass, lh_offset);

     // Handle objArrays completely differently...

     jint objArray_lh = Klass::array_layout_helper(T_OBJECT);

     __ cmpl(src_klass_lh_addr, objArray_lh);

     __ jcc(Assembler::equal, L_objArray);

     //  if (src->klass() != dst->klass()) return -1;

     __ cmpptr(rcx_src_klass, dst_klass_addr);

     __ jccb(Assembler::notEqual, L_failed_0);

     const Register rcx_lh = rcx;  // layout helper

     assert(rcx_lh == rcx_src_klass, "known alias");

     __ movl(rcx_lh, src_klass_lh_addr);

     //  if (!src->is_Array()) return -1;

     __ cmpl(rcx_lh, Klass::_lh_neutral_value);

     __ jcc(Assembler::greaterEqual, L_failed_0); // signed cmp

     // At this point, it is known to be a typeArray (array_tag 0x3).

 #ifdef ASSERT

     { Label L;

       __ cmpl(rcx_lh, (Klass::_lh_array_tag_type_value << Klass::_lh_array_tag_shift));

       __ jcc(Assembler::greaterEqual, L); // signed cmp

       __ stop("must be a primitive array");

       __ bind(L);

     }

 #endif

     assert_different_registers(src, src_pos, dst, dst_pos, rcx_lh);

     arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, 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 rsi_offset = rsi; // array offset

     const Register src_array  = src; // src array offset

     const Register dst_array  = dst; // dst array offset

     const Register rdi_elsize = rdi; // log2 element size

     __ mov(rsi_offset, rcx_lh);

     __ shrptr(rsi_offset, Klass::_lh_header_size_shift);

     __ andptr(rsi_offset, Klass::_lh_header_size_mask);   // array_offset

     __ addptr(src_array, rsi_offset);  // src array offset

     __ addptr(dst_array, rsi_offset);  // dst array offset

     __ andptr(rcx_lh, Klass::_lh_log2_element_size_mask); // log2 elsize

     // next registers should be set before the jump to corresponding stub

     const Register from       = src; // source array address

     const Register to         = dst; // destination array address

     const Register count      = rcx; // elements count

     // some of them should be duplicated on stack

 #define FROM   Address(rsp, 12+ 4)

 #define TO     Address(rsp, 12+ 8)   // Not used now

 #define COUNT  Address(rsp, 12+12)   // Only for oop arraycopy

     BLOCK_COMMENT("scale indexes to element size");

     __ movl2ptr(rsi, SRC_POS);  // src_pos

     __ shlptr(rsi);             // src_pos << rcx (log2 elsize)

     assert(src_array == from, "");

     __ addptr(from, rsi);       // from = src_array + SRC_POS << log2 elsize

     __ movl2ptr(rdi, DST_POS);  // dst_pos

     __ shlptr(rdi);             // dst_pos << rcx (log2 elsize)

     assert(dst_array == to, "");

     __ addptr(to,  rdi);        // to   = dst_array + DST_POS << log2 elsize

     __ movptr(FROM, from);      // src_addr

     __ mov(rdi_elsize, rcx_lh); // log2 elsize

     __ movl2ptr(count, LENGTH); // elements count

     BLOCK_COMMENT("choose copy loop based on element size");

     __ cmpl(rdi_elsize, 0);

     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jbyte_arraycopy));

     __ cmpl(rdi_elsize, LogBytesPerShort);

     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jshort_arraycopy));

     __ cmpl(rdi_elsize, LogBytesPerInt);

     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jint_arraycopy));

 #ifdef ASSERT

     __ cmpl(rdi_elsize, LogBytesPerLong);

     __ jccb(Assembler::notEqual, L_failed);

 #endif

     __ pop(rdi); // Do pops here since jlong_arraycopy stub does not do it.

     __ pop(rsi);

     __ jump(RuntimeAddress(entry_jlong_arraycopy));

   __ BIND(L_failed);

     __ xorptr(rax, rax);

     __ notptr(rax); // return -1

     __ pop(rdi);

     __ pop(rsi);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     __ ret(0);

     // objArrayKlass

   __ BIND(L_objArray);

     // live at this point:  rcx_src_klass, src[_pos], dst[_pos]

     Label L_plain_copy, L_checkcast_copy;

     //  test array classes for subtyping

     __ cmpptr(rcx_src_klass, dst_klass_addr); // usual case is exact equality

     __ jccb(Assembler::notEqual, L_checkcast_copy);

     // Identically typed arrays can be copied without element-wise checks.

     assert_different_registers(src, src_pos, dst, dst_pos, rcx_src_klass);

     arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, L_failed);

   __ BIND(L_plain_copy);

     __ movl2ptr(count, LENGTH); // elements count

     __ movl2ptr(src_pos, SRC_POS);  // reload src_pos

     __ lea(from, Address(src, src_pos, Address::times_ptr,

                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // src_addr

     __ movl2ptr(dst_pos, DST_POS);  // reload dst_pos

     __ lea(to,   Address(dst, dst_pos, Address::times_ptr,

                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // dst_addr

     __ movptr(FROM,  from);   // src_addr

     __ movptr(TO,    to);     // dst_addr

     __ movl(COUNT, count);  // count

     __ jump(RuntimeAddress(entry_oop_arraycopy));

   __ BIND(L_checkcast_copy);

     // live at this point:  rcx_src_klass, dst[_pos], src[_pos]

     {

       // Handy offsets:

       int  ek_offset = (klassOopDesc::header_size() * HeapWordSize +

                         objArrayKlass::element_klass_offset_in_bytes());

       int sco_offset = (klassOopDesc::header_size() * HeapWordSize +

                         Klass::super_check_offset_offset_in_bytes());

       Register rsi_dst_klass = rsi;

       Register rdi_temp      = rdi;

       assert(rsi_dst_klass == src_pos, "expected alias w/ src_pos");

       assert(rdi_temp      == dst_pos, "expected alias w/ dst_pos");

       Address dst_klass_lh_addr(rsi_dst_klass, lh_offset);

       // Before looking at dst.length, make sure dst is also an objArray.

       __ movptr(rsi_dst_klass, dst_klass_addr);

       __ cmpl(dst_klass_lh_addr, objArray_lh);

       __ jccb(Assembler::notEqual, L_failed);

       // It is safe to examine both src.length and dst.length.

       __ movl2ptr(src_pos, SRC_POS);        // reload rsi

       arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, L_failed);

       // (Now src_pos and dst_pos are killed, but not src and dst.)

       // We'll need this temp (don't forget to pop it after the type check).

       __ push(rbx);

       Register rbx_src_klass = rbx;

       __ mov(rbx_src_klass, rcx_src_klass); // spill away from rcx

       __ movptr(rsi_dst_klass, dst_klass_addr);

       Address super_check_offset_addr(rsi_dst_klass, sco_offset);

       Label L_fail_array_check;

       generate_type_check(rbx_src_klass,

                           super_check_offset_addr, dst_klass_addr,

                           rdi_temp, NULL, &L_fail_array_check);

       // (On fall-through, we have passed the array type check.)

       __ pop(rbx);

       __ jmp(L_plain_copy);

       __ BIND(L_fail_array_check);

       // Reshuffle arguments so we can call checkcast_arraycopy:

       // match initial saves for checkcast_arraycopy

       // push(rsi);    // already done; see above

       // push(rdi);    // already done; see above

       // push(rbx);    // already done; see above

       // Marshal outgoing arguments now, freeing registers.

       Address   from_arg(rsp, 16+ 4);   // from

       Address     to_arg(rsp, 16+ 8);   // to

       Address length_arg(rsp, 16+12);   // elements count

       Address  ckoff_arg(rsp, 16+16);   // super_check_offset

       Address  ckval_arg(rsp, 16+20);   // super_klass

       Address SRC_POS_arg(rsp, 16+ 8);

       Address DST_POS_arg(rsp, 16+16);

       Address  LENGTH_arg(rsp, 16+20);

       // push rbx, changed the incoming offsets (why not just use rbp,??)

       // assert(SRC_POS_arg.disp() == SRC_POS.disp() + 4, "");

       __ movptr(rbx, Address(rsi_dst_klass, ek_offset));

       __ movl2ptr(length, LENGTH_arg);    // reload elements count

       __ movl2ptr(src_pos, SRC_POS_arg);  // reload src_pos

       __ movl2ptr(dst_pos, DST_POS_arg);  // reload dst_pos

       __ movptr(ckval_arg, rbx);          // destination element type

       __ movl(rbx, Address(rbx, sco_offset));

       __ movl(ckoff_arg, rbx);          // corresponding class check offset

       __ movl(length_arg, length);      // outgoing length argument

       __ lea(from, Address(src, src_pos, Address::times_ptr,

                             arrayOopDesc::base_offset_in_bytes(T_OBJECT)));

       __ movptr(from_arg, from);

       __ lea(to, Address(dst, dst_pos, Address::times_ptr,

                           arrayOopDesc::base_offset_in_bytes(T_OBJECT)));

       __ movptr(to_arg, to);

       __ jump(RuntimeAddress(entry_checkcast_arraycopy));

     }

     return start;

   }

   void generate_arraycopy_stubs() {

     address entry;

     address entry_jbyte_arraycopy;

     address entry_jshort_arraycopy;

     address entry_jint_arraycopy;

     address entry_oop_arraycopy;

     address entry_jlong_arraycopy;

     address entry_checkcast_arraycopy;

     StubRoutines::_arrayof_jbyte_disjoint_arraycopy =

         generate_disjoint_copy(T_BYTE,  true, Address::times_1, &entry,

                                "arrayof_jbyte_disjoint_arraycopy");

     StubRoutines::_arrayof_jbyte_arraycopy =

         generate_conjoint_copy(T_BYTE,  true, Address::times_1,  entry,

                                NULL, "arrayof_jbyte_arraycopy");

     StubRoutines::_jbyte_disjoint_arraycopy =

         generate_disjoint_copy(T_BYTE, false, Address::times_1, &entry,

                                "jbyte_disjoint_arraycopy");

     StubRoutines::_jbyte_arraycopy =

         generate_conjoint_copy(T_BYTE, false, Address::times_1,  entry,

                                &entry_jbyte_arraycopy, "jbyte_arraycopy");

     StubRoutines::_arrayof_jshort_disjoint_arraycopy =

         generate_disjoint_copy(T_SHORT,  true, Address::times_2, &entry,

                                "arrayof_jshort_disjoint_arraycopy");

     StubRoutines::_arrayof_jshort_arraycopy =

         generate_conjoint_copy(T_SHORT,  true, Address::times_2,  entry,

                                NULL, "arrayof_jshort_arraycopy");

     StubRoutines::_jshort_disjoint_arraycopy =

         generate_disjoint_copy(T_SHORT, false, Address::times_2, &entry,

                                "jshort_disjoint_arraycopy");

     StubRoutines::_jshort_arraycopy =

         generate_conjoint_copy(T_SHORT, false, Address::times_2,  entry,

                                &entry_jshort_arraycopy, "jshort_arraycopy");

     // Next arrays are always aligned on 4 bytes at least.

     StubRoutines::_jint_disjoint_arraycopy =

         generate_disjoint_copy(T_INT, true, Address::times_4, &entry,

                                "jint_disjoint_arraycopy");

     StubRoutines::_jint_arraycopy =

         generate_conjoint_copy(T_INT, true, Address::times_4,  entry,

                                &entry_jint_arraycopy, "jint_arraycopy");

     StubRoutines::_oop_disjoint_arraycopy =

         generate_disjoint_copy(T_OBJECT, true, Address::times_ptr, &entry,

                                "oop_disjoint_arraycopy");

     StubRoutines::_oop_arraycopy =

         generate_conjoint_copy(T_OBJECT, true, Address::times_ptr,  entry,

                                &entry_oop_arraycopy, "oop_arraycopy");

     StubRoutines::_jlong_disjoint_arraycopy =

         generate_disjoint_long_copy(&entry, "jlong_disjoint_arraycopy");

     StubRoutines::_jlong_arraycopy =

         generate_conjoint_long_copy(entry, &entry_jlong_arraycopy,

                                     "jlong_arraycopy");

     StubRoutines::_jbyte_fill = generate_fill(T_BYTE, false, "jbyte_fill");

     StubRoutines::_jshort_fill = generate_fill(T_SHORT, false, "jshort_fill");

     StubRoutines::_jint_fill = generate_fill(T_INT, false, "jint_fill");

     StubRoutines::_arrayof_jbyte_fill = generate_fill(T_BYTE, true, "arrayof_jbyte_fill");

     StubRoutines::_arrayof_jshort_fill = generate_fill(T_SHORT, true, "arrayof_jshort_fill");

     StubRoutines::_arrayof_jint_fill = generate_fill(T_INT, true, "arrayof_jint_fill");

     StubRoutines::_arrayof_jint_disjoint_arraycopy  =

         StubRoutines::_jint_disjoint_arraycopy;

     StubRoutines::_arrayof_oop_disjoint_arraycopy   =

         StubRoutines::_oop_disjoint_arraycopy;

     StubRoutines::_arrayof_jlong_disjoint_arraycopy =

         StubRoutines::_jlong_disjoint_arraycopy;

     StubRoutines::_arrayof_jint_arraycopy  = StubRoutines::_jint_arraycopy;

     StubRoutines::_arrayof_oop_arraycopy   = StubRoutines::_oop_arraycopy;

     StubRoutines::_arrayof_jlong_arraycopy = StubRoutines::_jlong_arraycopy;

     StubRoutines::_checkcast_arraycopy =

         generate_checkcast_copy("checkcast_arraycopy",

                                   &entry_checkcast_arraycopy);

     StubRoutines::_unsafe_arraycopy =

         generate_unsafe_copy("unsafe_arraycopy",

                                entry_jbyte_arraycopy,

                                entry_jshort_arraycopy,

                                entry_jint_arraycopy,

                                entry_jlong_arraycopy);

     StubRoutines::_generic_arraycopy =

         generate_generic_copy("generic_arraycopy",

                                entry_jbyte_arraycopy,

                                entry_jshort_arraycopy,

                                entry_jint_arraycopy,

                                entry_oop_arraycopy,

                                entry_jlong_arraycopy,

                                entry_checkcast_arraycopy);

   }

   void generate_math_stubs() {

     {

       StubCodeMark mark(this, "StubRoutines", "log");

       StubRoutines::_intrinsic_log = (double (*)(double)) __ pc();

       __ fld_d(Address(rsp, 4));

       __ flog();

       __ ret(0);

     }

     {

       StubCodeMark mark(this, "StubRoutines", "log10");

       StubRoutines::_intrinsic_log10 = (double (*)(double)) __ pc();

       __ fld_d(Address(rsp, 4));

       __ flog10();

       __ ret(0);

     }

     {

       StubCodeMark mark(this, "StubRoutines", "sin");

       StubRoutines::_intrinsic_sin = (double (*)(double))  __ pc();

       __ fld_d(Address(rsp, 4));

       __ trigfunc('s');

       __ ret(0);

     }

     {

       StubCodeMark mark(this, "StubRoutines", "cos");

       StubRoutines::_intrinsic_cos = (double (*)(double)) __ pc();

       __ fld_d(Address(rsp, 4));

       __ trigfunc('c');

       __ ret(0);

     }

     {

       StubCodeMark mark(this, "StubRoutines", "tan");

       StubRoutines::_intrinsic_tan = (double (*)(double)) __ pc();

       __ fld_d(Address(rsp, 4));

       __ trigfunc('t');

       __ ret(0);

     }

     // The intrinsic version of these seem to return the same value as

     // the strict version.

     StubRoutines::_intrinsic_exp = SharedRuntime::dexp;

     StubRoutines::_intrinsic_pow = SharedRuntime::dpow;

   }

  public:

   // 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 {

     thread_off,    // last_java_sp

     rbp_off,       // callee saved register

     ret_pc,

     framesize

   };

  private:

 #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.

   //

   // Previously the compiler (c2) allowed for callee save registers on Java calls.

   // This is no longer true after adapter frames were removed but could possibly

   // be brought back in the future if the interpreter code was reworked and it

   // was deemed worthwhile. The comment below was left to describe what must

   // happen here if callee saves were resurrected. As it stands now this stub

   // could actually be a vanilla BufferBlob and have now oopMap at all.

   // Since it doesn't make much difference we've chosen to leave it the

   // way it was in the callee save days and keep the comment.

   // If we need to preserve callee-saved values 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) {

     int insts_size = 256;

     int locs_size  = 32;

     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

     Register java_thread = rbx;

     __ get_thread(java_thread);

     if (restore_saved_exception_pc) {

       __ movptr(rax, Address(java_thread, in_bytes(JavaThread::saved_exception_pc_offset())));

       __ push(rax);

     }

     __ enter(); // required for proper stackwalking of RuntimeStub frame

     // pc and rbp, already pushed

     __ subptr(rsp, (framesize-2) * wordSize); // prolog

     // Frame is now completed as far as size and linkage.

     int frame_complete = __ pc() - start;

     // push java thread (becomes first argument of C function)

     __ movptr(Address(rsp, thread_off * wordSize), java_thread);

     // Set up last_Java_sp and last_Java_fp

     __ set_last_Java_frame(java_thread, rsp, rbp, NULL);

     // Call runtime

     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);

     // restore the thread (cannot use the pushed argument since arguments

     // may be overwritten by C code generated by an optimizing compiler);

     // however can use the register value directly if it is callee saved.

     __ get_thread(java_thread);

     __ reset_last_Java_frame(java_thread, true, false);

     __ leave(); // required for proper stackwalking of RuntimeStub frame

     // check for pending exceptions

 #ifdef ASSERT

     Label L;

     __ cmpptr(Address(java_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);

     __ jcc(Assembler::notEqual, L);

     __ should_not_reach_here();

     __ bind(L);

 #endif /* ASSERT */

     __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));

     RuntimeStub* stub = RuntimeStub::new_runtime_stub(name, &code, frame_complete, framesize, oop_maps, false);

     return stub->entry_point();

   }

   void create_control_words() {

     // Round to nearest, 53-bit mode, exceptions masked

     StubRoutines::_fpu_cntrl_wrd_std   = 0x027F;

     // Round to zero, 53-bit mode, exception mased

     StubRoutines::_fpu_cntrl_wrd_trunc = 0x0D7F;

     // Round to nearest, 24-bit mode, exceptions masked

     StubRoutines::_fpu_cntrl_wrd_24    = 0x007F;

     // Round to nearest, 64-bit mode, exceptions masked

     StubRoutines::_fpu_cntrl_wrd_64    = 0x037F;

     // Round to nearest, 64-bit mode, exceptions masked

     StubRoutines::_mxcsr_std           = 0x1F80;

     // Note: the following two constants are 80-bit values

     //       layout is critical for correct loading by FPU.

     // Bias for strict fp multiply/divide

     StubRoutines::_fpu_subnormal_bias1[0]= 0x00000000; // 2^(-15360) == 0x03ff 8000 0000 0000 0000

     StubRoutines::_fpu_subnormal_bias1[1]= 0x80000000;

     StubRoutines::_fpu_subnormal_bias1[2]= 0x03ff;

     // Un-Bias for strict fp multiply/divide

     StubRoutines::_fpu_subnormal_bias2[0]= 0x00000000; // 2^(+15360) == 0x7bff 8000 0000 0000 0000

     StubRoutines::_fpu_subnormal_bias2[1]= 0x80000000;

     StubRoutines::_fpu_subnormal_bias2[2]= 0x7bff;

   }

   //---------------------------------------------------------------------------

   // Initialization

   void generate_initial() {

     // Generates all stubs and initializes the entry points

     //------------------------------------------------------------------------------------------------------------------------

     // 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();

     // These are currently used by Solaris/Intel

     StubRoutines::_atomic_xchg_entry            = generate_atomic_xchg();

     StubRoutines::_handler_for_unsafe_access_entry =

       generate_handler_for_unsafe_access();

     // platform dependent

     create_control_words();

     StubRoutines::x86::_verify_mxcsr_entry                 = generate_verify_mxcsr();

     StubRoutines::x86::_verify_fpu_cntrl_wrd_entry         = generate_verify_fpu_cntrl_wrd();

     StubRoutines::_d2i_wrapper                              = generate_d2i_wrapper(T_INT,

                                                                                    CAST_FROM_FN_PTR(address, SharedRuntime::d2i));

     StubRoutines::_d2l_wrapper                              = generate_d2i_wrapper(T_LONG,

                                                                                    CAST_FROM_FN_PTR(address, SharedRuntime::d2l));

   }

   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_IncompatibleClassChangeError_entry= generate_throw_exception("IncompatibleClassChangeError throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_IncompatibleClassChangeError),  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

     // 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();

     generate_math_stubs();

   }

  public:

   StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {

     if (all) {

       generate_all();

     } else {

       generate_initial();

     }

   }

 }; // end class declaration

 void StubGenerator_generate(CodeBuffer* code, bool all) {

   StubGenerator g(code, all);

 }