jdk8-mips64-public/hotspot: src/cpu/x86/vm/stubGenerator_x86

src/cpu/x86/vm/stubGenerator_x86_64.cpp@bd441136a5ce (annotated)

src/cpu/x86/vm/stubGenerator_x86_64.cpp

Thu, 19 Mar 2009 09:13:24 -0700

author: kvn
date: Thu, 19 Mar 2009 09:13:24 -0700
changeset 1082: bd441136a5ce
parent 1014: 0fbdb4381b99
parent 1079: c517646eef23
child 1106: d0994e5bebce
permissions: -rw-r--r--

Merge

 /*
  * Copyright 2003-2009 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->
 #define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
 #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
 // 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();
     __ subptr(rsp, -rsp_after_call_off * wordSize);
     // save register parameters
 #ifndef _WIN64
     __ movptr(parameters,   c_rarg5); // parameters
     __ movptr(entry_point,  c_rarg4); // entry_point
 #endif
     __ movptr(method,       c_rarg3); // method
     __ movl(result_type,  c_rarg2);   // result type
     __ movptr(result,       c_rarg1); // result
     __ movptr(call_wrapper, c_rarg0); // call wrapper
     // save regs belonging to calling function
     __ movptr(rbx_save, rbx);
     __ movptr(r12_save, r12);
     __ movptr(r13_save, r13);
     __ movptr(r14_save, r14);
     __ movptr(r15_save, r15);
 #ifdef _WIN64
     const Address rdi_save(rbp, rdi_off * wordSize);
     const Address rsi_save(rbp, rsi_off * wordSize);
     __ movptr(rsi_save, rsi);
     __ movptr(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::x86::mxcsr_std());
       __ cmp32(rax, mxcsr_std);
       __ jcc(Assembler::equal, skip_ldmx);
       __ ldmxcsr(mxcsr_std);
       __ bind(skip_ldmx);
     }
 #endif
     // Load up thread register
     __ movptr(r15_thread, thread);
     __ reinit_heapbase();
 #ifdef ASSERT
     // make sure we have no pending exceptions
     {
       Label L;
       __ cmpptr(Address(r15_thread, 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(c_rarg3, parameter_size);
     __ testl(c_rarg3, c_rarg3);
     __ jcc(Assembler::zero, parameters_done);
     Label loop;
     __ movptr(c_rarg2, parameters);       // parameter pointer
     __ movl(c_rarg1, c_rarg3);            // parameter counter is in c_rarg1
     __ BIND(loop);
     if (TaggedStackInterpreter) {
       __ movl(rax, Address(c_rarg2, 0)); // get tag
       __ addptr(c_rarg2, wordSize);      // advance to next tag
       __ push(rax);                      // pass tag
     }
     __ movptr(rax, Address(c_rarg2, 0));// get parameter
     __ addptr(c_rarg2, wordSize);       // advance to next parameter
     __ decrementl(c_rarg1);             // decrement counter
     __ push(rax);                       // pass parameter
     __ jcc(Assembler::notZero, loop);
     // call Java function
     __ BIND(parameters_done);
     __ movptr(rbx, method);             // get methodOop
     __ movptr(c_rarg1, entry_point);    // get entry_point
     __ mov(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)
     __ movptr(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
     __ lea(rsp, rsp_after_call);
 #ifdef ASSERT
     // verify that threads correspond
     {
       Label L, S;
       __ cmpptr(r15_thread, thread);
       __ jcc(Assembler::notEqual, S);
       __ get_thread(rbx);
       __ cmpptr(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
     __ movptr(r15, r15_save);
     __ movptr(r14, r14_save);
     __ movptr(r13, r13_save);
     __ movptr(r12, r12_save);
     __ movptr(rbx, rbx_save);
 #ifdef _WIN64
     __ movptr(rdi, rdi_save);
     __ movptr(rsi, rsi_save);
 #else
     __ ldmxcsr(mxcsr_save);
 #endif
     // restore rsp
     __ addptr(rsp, -rsp_after_call_off * wordSize);
     // return
     __ pop(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;
       __ cmpptr(r15_thread, thread);
       __ jcc(Assembler::notEqual, S);
       __ get_thread(rbx);
       __ cmpptr(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);
     __ movptr(Address(r15_thread, Thread::pending_exception_offset()), rax);
     __ lea(rscratch1, ExternalAddress((address)__FILE__));
     __ movptr(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;
       __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t) NULL);
       __ jcc(Assembler::notEqual, L);
       __ stop("StubRoutines::forward exception: no pending exception (1)");
       __ bind(L);
     }
 #endif
     // compute exception handler into rbx
     __ movptr(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);
     __ mov(rbx, rax);
     // setup rax & rdx, remove return address & clear pending exception
     __ pop(rdx);
     __ movptr(rax, Address(r15_thread, Thread::pending_exception_offset()));
     __ movptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
 #ifdef ASSERT
     // make sure exception is set
     {
       Label L;
       __ testptr(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();
     __ movptr(rax, c_rarg0); // Copy to eax we need a return value anyhow
     __ xchgptr(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();
     __ movptr(rax, c_rarg0); // Copy to eax we need a return value anyhow
    if ( os::is_MP() ) __ lock();
     __ xaddptr(Address(c_rarg1, 0), c_rarg0);
     __ addptr(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();
     __ movptr(rax, old_fp); // callers fp
     __ movptr(rax, older_fp); // the frame for ps()
     __ pop(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;
       __ push(rax);
       __ subptr(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::x86::mxcsr_std()));
       __ jcc(Assembler::equal, ok_ret);
       __ warn("MXCSR changed by native JNI code, use -XX:+RestoreMXCSROnJNICall");
       __ ldmxcsr(ExternalAddress(StubRoutines::x86::mxcsr_std()));
       __ bind(ok_ret);
       __ addptr(rsp, wordSize);
       __ pop(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;
     __ push(rax);
     __ push(c_rarg3);
     __ push(c_rarg2);
     __ push(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);
     __ movptr(inout, c_rarg3);
     __ pop(c_rarg1);
     __ pop(c_rarg2);
     __ pop(c_rarg3);
     __ pop(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;
     __ push(rax);
     __ push(c_rarg3);
     __ push(c_rarg2);
     __ push(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);
     __ cmov(Assembler::positive, c_rarg3, rax);
     __ bind(L);
     __ movptr(inout, c_rarg3);
     __ pop(c_rarg1);
     __ pop(c_rarg2);
     __ pop(c_rarg3);
     __ pop(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;
     __ push(rax);
     __ push(c_rarg3);
     __ push(c_rarg2);
     __ push(c_rarg1);
     __ push(c_rarg0);
     __ movl(rax, 0x7ff00000);
     __ movq(c_rarg2, inout);
     __ movl(c_rarg3, c_rarg2);
     __ mov(c_rarg1, c_rarg2);
     __ mov(c_rarg0, c_rarg2);
     __ negl(c_rarg3);
     __ shrptr(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
     __ testptr(c_rarg0, c_rarg0); // signed ? min_jint : max_jint
     __ movl(c_rarg2, 0x80000000);
     __ movl(rax, 0x7fffffff);
     __ cmov(Assembler::positive, c_rarg2, rax);
     __ bind(L);
     __ movptr(inout, c_rarg2);
     __ pop(c_rarg0);
     __ pop(c_rarg1);
     __ pop(c_rarg2);
     __ pop(c_rarg3);
     __ pop(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;
     __ push(rax);
     __ push(c_rarg3);
     __ push(c_rarg2);
     __ push(c_rarg1);
     __ push(c_rarg0);
     __ movl(rax, 0x7ff00000);
     __ movq(c_rarg2, inout);
     __ movl(c_rarg3, c_rarg2);
     __ mov(c_rarg1, c_rarg2);
     __ mov(c_rarg0, c_rarg2);
     __ negl(c_rarg3);
     __ shrptr(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);
     __ pop(c_rarg0);
     __ pop(c_rarg1);
     __ pop(c_rarg2);
     __ pop(c_rarg3);
     __ pop(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();
     __ push(0);                       // hole for return address-to-be
     __ pusha();                       // push registers
     Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);
     __ subptr(rsp, frame::arg_reg_save_area_bytes);
     BLOCK_COMMENT("call handle_unsafe_access");
     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));
     __ addptr(rsp, frame::arg_reg_save_area_bytes);
     __ movptr(next_pc, rax);          // stuff next address
     __ popa();
     __ 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 r12 (several TemplateTable methods use it)
   //    [tos + 3]: saved flags
   //    [tos + 4]: return address
   //  * [tos + 5]: error message (char*)
   //  * [tos + 6]: object to verify (oop)
   //  * [tos + 7]: 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;
     __ pushf();
     __ incrementl(ExternalAddress((address) StubRoutines::verify_oop_count_addr()));
     __ push(r12);
     // save c_rarg2 and c_rarg3
     __ push(c_rarg2);
     __ push(c_rarg3);
     enum {
            // After previous pushes.
            oop_to_verify = 6 * wordSize,
            saved_rax     = 7 * wordSize,
            // Before the call to MacroAssembler::debug(), see below.
            return_addr   = 16 * wordSize,
            error_msg     = 17 * wordSize
     };
     // get object
     __ movptr(rax, Address(rsp, oop_to_verify));
     // make sure object is 'reasonable'
     __ 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
     __ movptr(c_rarg2, rax);
     __ movptr(c_rarg3, (intptr_t) Universe::verify_oop_mask());
     __ andptr(c_rarg2, c_rarg3);
     __ movptr(c_rarg3, (intptr_t) Universe::verify_oop_bits());
     __ cmpptr(c_rarg2, c_rarg3);
     __ jcc(Assembler::notZero, error);
     // set r12 to heapbase for load_klass()
     __ reinit_heapbase();
     // make sure klass is 'reasonable'
     __ load_klass(rax, rax);  // 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
     __ mov(c_rarg2, rax);
     __ movptr(c_rarg3, (intptr_t) Universe::verify_klass_mask());
     __ andptr(c_rarg2, c_rarg3);
     __ movptr(c_rarg3, (intptr_t) Universe::verify_klass_bits());
     __ cmpptr(c_rarg2, c_rarg3);
     __ jcc(Assembler::notZero, error);
     // make sure klass' klass is 'reasonable'
     __ load_klass(rax, rax);
     __ testptr(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, (intptr_t) Universe::verify_klass_mask());
     __ andptr(rax, c_rarg3);
     __ movptr(c_rarg3, (intptr_t) Universe::verify_klass_bits());
     __ cmpptr(rax, c_rarg3);
     __ jcc(Assembler::notZero, error);
     // return if everything seems ok
     __ bind(exit);
     __ movptr(rax, Address(rsp, saved_rax));     // get saved rax back
     __ pop(c_rarg3);                             // restore c_rarg3
     __ pop(c_rarg2);                             // restore c_rarg2
     __ pop(r12);                                 // restore r12
     __ popf();                                   // restore flags
     __ ret(3 * wordSize);                        // pop caller saved stuff
     // handle errors
     __ bind(error);
     __ movptr(rax, Address(rsp, saved_rax));     // get saved rax back
     __ pop(c_rarg3);                             // get saved c_rarg3 back
     __ pop(c_rarg2);                             // get saved c_rarg2 back
     __ pop(r12);                                 // get saved r12 back
     __ popf();                                   // get saved flags off stack --
                                                  // will be ignored
     __ pusha();                                  // push registers
                                                  // (rip is already
                                                  // already pushed)
     // debug(char* msg, int64_t pc, 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*)
     //   * [tos + 18] object to verify (oop)
     //   * [tos + 19] saved rax - saved by caller and bashed
     //   * = popped on exit
     __ movptr(c_rarg0, Address(rsp, error_msg));    // pass address of error message
     __ movptr(c_rarg1, Address(rsp, return_addr));  // pass return address
     __ movq(c_rarg2, rsp);                          // pass address of regs on stack
     __ mov(r12, rsp);                               // remember rsp
     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
     __ andptr(rsp, -16);                            // align stack as required by ABI
     BLOCK_COMMENT("call MacroAssembler::debug");
     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, MacroAssembler::debug64)));
     __ mov(rsp, r12);                               // restore rsp
     __ popa();                                      // pop registers (includes r12)
     __ 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);
     __ jcc(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;
     __ cmpptr(to, from);
     __ lea(end_from, Address(from, count, sf, 0));
     if (NOLp == NULL) {
       ExternalAddress no_overlap(no_overlap_target);
       __ jump_cc(Assembler::belowEqual, no_overlap);
       __ cmpptr(to, end_from);
       __ jump_cc(Assembler::aboveEqual, no_overlap);
     } else {
       __ jcc(Assembler::belowEqual, (*NOLp));
       __ cmpptr(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)
       __ mov(rax, r9);  // r9 is also saved_rdi
     __ movptr(saved_rdi, rdi);
     __ movptr(saved_rsi, rsi);
     __ mov(rdi, rcx); // c_rarg0
     __ mov(rsi, rdx); // c_rarg1
     __ mov(rdx, r8);  // c_rarg2
     if (nargs >= 4)
       __ mov(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
     __ movptr(rdi, saved_rdi);
     __ movptr(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) {
     BarrierSet* bs = Universe::heap()->barrier_set();
     switch (bs->kind()) {
       case BarrierSet::G1SATBCT:
       case BarrierSet::G1SATBCTLogging:
         {
           __ pusha();                      // push registers
           if (count == c_rarg0) {
             if (addr == c_rarg1) {
               // exactly backwards!!
               __ xchgptr(c_rarg1, c_rarg0);
             } else {
               __ movptr(c_rarg1, count);
               __ movptr(c_rarg0, addr);
             }
           } else {
             __ movptr(c_rarg0, addr);
             __ movptr(c_rarg1, count);
           }
           __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre)));
           __ popa();
         }
         break;
       case BarrierSet::CardTableModRef:
       case BarrierSet::CardTableExtension:
       case BarrierSet::ModRef:
         break;
       default:
         ShouldNotReachHere();
     }
   }
   //
   // 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()) {
       case BarrierSet::G1SATBCT:
       case BarrierSet::G1SATBCTLogging:
         {
           __ pusha();                      // push registers (overkill)
           // must compute element count unless barrier set interface is changed (other platforms supply count)
           assert_different_registers(start, end, scratch);
           __ lea(scratch, Address(end, wordSize));
           __ subptr(scratch, start);
           __ shrptr(scratch, LogBytesPerWord);
           __ mov(c_rarg0, start);
           __ mov(c_rarg1, scratch);
           __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post)));
           __ 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;
            __ shrptr(start, CardTableModRefBS::card_shift);
            __ shrptr(end, CardTableModRefBS::card_shift);
            __ subptr(end, start); // number of bytes to copy
           intptr_t disp = (intptr_t) ct->byte_map_base;
           if (__ is_simm32(disp)) {
             Address cardtable(noreg, noreg, Address::no_scale, disp);
             __ lea(scratch, cardtable);
           } else {
             ExternalAddress cardtable((address)disp);
             __ lea(scratch, cardtable);
           }
           const Register count = end; // 'end' register contains bytes count now
           __ addptr(start, scratch);
         __ BIND(L_loop);
           __ movb(Address(start, count, Address::times_1), 0);
           __ decrement(count);
           __ jcc(Assembler::greaterEqual, L_loop);
         }
         break;
       default:
         ShouldNotReachHere();
     }
   }
   // 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);
     if(UseUnalignedLoadStores) {
       __ movdqu(xmm0, Address(end_from, qword_count, Address::times_8, -24));
       __ movdqu(Address(end_to, qword_count, Address::times_8, -24), xmm0);
       __ movdqu(xmm1, Address(end_from, qword_count, Address::times_8, - 8));
       __ movdqu(Address(end_to, qword_count, Address::times_8, - 8), xmm1);
     } else {
       __ 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);
     __ addptr(qword_count, 4);
     __ jcc(Assembler::lessEqual, L_loop);
     __ subptr(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);
     if(UseUnalignedLoadStores) {
       __ movdqu(xmm0, Address(from, qword_count, Address::times_8, 16));
       __ movdqu(Address(dest, qword_count, Address::times_8, 16), xmm0);
       __ movdqu(xmm1, Address(from, qword_count, Address::times_8,  0));
       __ movdqu(Address(dest, qword_count, Address::times_8,  0), xmm1);
     } else {
       __ 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);
     __ subptr(qword_count, 4);
     __ jcc(Assembler::greaterEqual, L_loop);
     __ addptr(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
     __ movptr(byte_count, count);
     __ shrptr(count, 3); // count => qword_count
     // Copy from low to high addresses.  Use 'to' as scratch.
     __ lea(end_from, Address(from, qword_count, Address::times_8, -8));
     __ lea(end_to,   Address(to,   qword_count, Address::times_8, -8));
     __ negptr(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);
     __ increment(qword_count);
     __ jcc(Assembler::notZero, L_copy_8_bytes);
     // Check for and copy trailing dword
   __ BIND(L_copy_4_bytes);
     __ testl(byte_count, 4);
     __ jccb(Assembler::zero, L_copy_2_bytes);
     __ movl(rax, Address(end_from, 8));
     __ movl(Address(end_to, 8), rax);
     __ addptr(end_from, 4);
     __ addptr(end_to, 4);
     // Check for and copy trailing word
   __ BIND(L_copy_2_bytes);
     __ testl(byte_count, 2);
     __ jccb(Assembler::zero, L_copy_byte);
     __ movw(rax, Address(end_from, 8));
     __ movw(Address(end_to, 8), rax);
     __ addptr(end_from, 2);
     __ addptr(end_to, 2);
     // Check for and copy trailing byte
   __ BIND(L_copy_byte);
     __ testl(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();
     __ xorptr(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
     __ movptr(byte_count, count);
     __ shrptr(count, 3);   // count => qword_count
     // Copy from high to low addresses.
     // Check for and copy trailing byte
     __ testl(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);
     __ decrement(byte_count); // Adjust for possible trailing word
     // Check for and copy trailing word
   __ BIND(L_copy_2_bytes);
     __ testl(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);
     __ testl(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);
     __ decrement(qword_count);
     __ jcc(Assembler::notZero, L_copy_8_bytes);
     inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr);
     restore_arg_regs();
     __ xorptr(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();
     __ xorptr(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
     __ movptr(word_count, count);
     __ shrptr(count, 2); // count => qword_count
     // Copy from low to high addresses.  Use 'to' as scratch.
     __ lea(end_from, Address(from, qword_count, Address::times_8, -8));
     __ lea(end_to,   Address(to,   qword_count, Address::times_8, -8));
     __ negptr(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);
     __ increment(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);
     __ testl(word_count, 2);
     __ jccb(Assembler::zero, L_copy_2_bytes);
     __ movl(rax, Address(end_from, 8));
     __ movl(Address(end_to, 8), rax);
     __ addptr(end_from, 4);
     __ addptr(end_to, 4);
     // Check for and copy trailing word
   __ BIND(L_copy_2_bytes);
     __ testl(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();
     __ xorptr(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
     __ movptr(word_count, count);
     __ shrptr(count, 2); // count => qword_count
     // Copy from high to low addresses.  Use 'to' as scratch.
     // Check for and copy trailing word
     __ testl(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);
     __ testl(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);
     __ decrement(qword_count);
     __ jcc(Assembler::notZero, L_copy_8_bytes);
     inc_counter_np(SharedRuntime::_jshort_array_copy_ctr);
     restore_arg_regs();
     __ xorptr(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();
     __ xorptr(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
   //   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
   //
   // 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_oop_copy().
   //
   address generate_disjoint_int_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_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
     const Register saved_to    = r11;  // saved destination array 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.
     (is_oop ? disjoint_oop_copy_entry : disjoint_int_copy_entry) = __ pc();
     if (is_oop) {
       // no registers are destroyed by this call
       gen_write_ref_array_pre_barrier(/* dest */ c_rarg1, /* count */ c_rarg2);
     }
     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
     if (is_oop) {
       __ movq(saved_to, to);
     }
     // 'from', 'to' and 'count' are now valid
     __ movptr(dword_count, count);
     __ shrptr(count, 1); // count => qword_count
     // Copy from low to high addresses.  Use 'to' as scratch.
     __ lea(end_from, Address(from, qword_count, Address::times_8, -8));
     __ lea(end_to,   Address(to,   qword_count, Address::times_8, -8));
     __ negptr(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);
     __ increment(qword_count);
     __ jcc(Assembler::notZero, L_copy_8_bytes);
     // Check for and copy trailing dword
   __ BIND(L_copy_4_bytes);
     __ testl(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);
     if (is_oop) {
       __ leaq(end_to, Address(saved_to, dword_count, Address::times_4, -4));
       gen_write_ref_array_post_barrier(saved_to, end_to, rax);
     }
     inc_counter_np(SharedRuntime::_jint_array_copy_ctr);
     restore_arg_regs();
     __ xorptr(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
   //   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
   //
   // 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_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_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 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.
     if (is_oop) {
       // no registers are destroyed by this call
       gen_write_ref_array_pre_barrier(/* dest */ c_rarg1, /* count */ c_rarg2);
     }
     (is_oop ? oop_copy_entry : int_copy_entry) = __ pc();
     BLOCK_COMMENT("Entry:");
     // caller can pass a 64-bit byte count here (from Unsafe.copyMemory)
     array_overlap_test(is_oop ? disjoint_oop_copy_entry : 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
     assert_clean_int(count, rax); // Make sure 'count' is clean int.
     // 'from', 'to' and 'count' are now valid
     __ movptr(dword_count, count);
     __ shrptr(count, 1); // count => qword_count
     // Copy from high to low addresses.  Use 'to' as scratch.
     // Check for and copy trailing dword
     __ testl(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);
     __ decrement(qword_count);
     __ jcc(Assembler::notZero, L_copy_8_bytes);
     inc_counter_np(SharedRuntime::_jint_array_copy_ctr);
     if (is_oop) {
       __ jmp(L_exit);
     }
     restore_arg_regs();
     __ xorptr(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);
    __ bind(L_exit);
      if (is_oop) {
        Register end_to = rdx;
        __ leaq(end_to, Address(to, dword_count, Address::times_4, -4));
        gen_write_ref_array_post_barrier(to, end_to, rax);
      }
     restore_arg_regs();
     __ xorptr(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.
     __ lea(end_from, Address(from, qword_count, Address::times_8, -8));
     __ lea(end_to,   Address(to,   qword_count, Address::times_8, -8));
     __ negptr(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);
     __ increment(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();
       __ xorptr(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();
     __ xorptr(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) {
       assert(!UseCompressedOops, "shouldn't be called for compressed oops");
       disjoint_copy_entry = disjoint_oop_copy_entry;
       oop_copy_entry  = __ pc();
       array_overlap_test(disjoint_oop_copy_entry, Address::times_8);
     } else {
       disjoint_copy_entry = disjoint_long_copy_entry;
       long_copy_entry = __ pc();
       array_overlap_test(disjoint_long_copy_entry, Address::times_8);
     }
     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
       __ movptr(saved_count, qword_count);
       // No registers are destroyed by this call
       gen_write_ref_array_pre_barrier(to, saved_count);
     }
     __ 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);
     __ decrement(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();
       __ xorptr(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);
       __ lea(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();
     __ xorptr(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;
     __ check_klass_subtype_fast_path(sub_klass, super_klass, noreg,        &L_success, &L_miss, NULL,
                                      super_check_offset);
     __ check_klass_subtype_slow_path(sub_klass, super_klass, noreg, noreg, &L_success, NULL);
     // 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, TIMES_OOP);
       __ 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
     };
     __ subptr(rsp, saved_rbp_offset * wordSize);
     __ movptr(Address(rsp, saved_r13_offset * wordSize), r13);
     __ movptr(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;
     __ movptr(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, TIMES_OOP, 0);
     Address   end_to_addr(to,   length, TIMES_OOP, 0);
     // Loop-variant addresses.  They assume post-incremented count < 0.
     Address from_element_addr(end_from, count, TIMES_OOP, 0);
     Address   to_element_addr(end_to,   count, TIMES_OOP, 0);
     gen_write_ref_array_pre_barrier(to, count);
     // Copy from low to high addresses, indexed from the end of each array.
     __ lea(end_from, end_from_addr);
     __ lea(end_to,   end_to_addr);
     __ movptr(r14_length, length);        // save a copy of the length
     assert(length == count, "");          // else fix next line:
     __ negptr(count);                     // negate and test the length
     __ jcc(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-1),to last element.
     __ align(16);
     __ BIND(L_store_element);
     __ store_heap_oop(to_element_addr, rax_oop);  // store the oop
     __ increment(count);               // increment the count toward zero
     __ jcc(Assembler::zero, L_do_card_marks);
     // ======== loop entry is here ========
     __ BIND(L_load_element);
     __ load_heap_oop(rax_oop, from_element_addr); // load the oop
     __ testptr(rax_oop, rax_oop);
     __ jcc(Assembler::zero, L_store_element);
     __ load_klass(r11_klass, rax_oop);// 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);
     __ lea(end_to, to_element_addr);
     gen_write_ref_array_post_barrier(to, end_to, rscratch1);
     __ movptr(rax, r14_length);           // original oops
     __ addptr(rax, count);                // K = (original - remaining) oops
     __ notptr(rax);                       // report (-1^K) to caller
     __ jmp(L_done);
     // Come here on success only.
     __ BIND(L_do_card_marks);
     __ addptr(end_to, -wordSize);         // make an inclusive end pointer
     gen_write_ref_array_post_barrier(to, end_to, rscratch1);
     __ xorptr(rax, rax);                  // return 0 on success
     // Common exit point (success or failure).
     __ BIND(L_done);
     __ movptr(r13, Address(rsp, saved_r13_offset * wordSize));
     __ movptr(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);
     __ mov(bits, from);
     __ orptr(bits, to);
     __ orptr(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);
     __ shrptr(size, LogBytesPerShort); // size => short_count
     __ jump(RuntimeAddress(short_copy_entry));
     __ BIND(L_int_aligned);
     __ shrptr(size, LogBytesPerInt); // size => int_count
     __ jump(RuntimeAddress(int_copy_entry));
     __ BIND(L_long_aligned);
     __ shrptr(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;
     __ testptr(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;
     __ testptr(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
     const Register r9_dst_klass  = r9;  // dest 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);
     __ load_klass(r10_src_klass, src);
 #ifdef ASSERT
     //  assert(src->klass() != NULL);
     BLOCK_COMMENT("assert klasses not null");
     { Label L1, L2;
       __ testptr(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);
       __ load_klass(r9_dst_klass, dst);
       __ cmpq(r9_dst_klass, 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;
     __ load_klass(r9_dst_klass, dst);
     __ cmpq(r10_src_klass, r9_dst_klass);
     __ 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);
     __ andptr(r10_offset, Klass::_lh_header_size_mask);   // array_offset
     __ addptr(src, r10_offset);           // src array offset
     __ addptr(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);
     __ lea(from, Address(src, src_pos, Address::times_1, 0));// src_addr
     __ lea(to,   Address(dst, dst_pos, Address::times_1, 0));// dst_addr
     __ movl2ptr(count, r11_length); // length
     __ jump(RuntimeAddress(byte_copy_entry));
   __ BIND(L_copy_shorts);
     __ cmpl(rax_elsize, LogBytesPerShort);
     __ jccb(Assembler::notEqual, L_copy_ints);
     __ lea(from, Address(src, src_pos, Address::times_2, 0));// src_addr
     __ lea(to,   Address(dst, dst_pos, Address::times_2, 0));// dst_addr
     __ movl2ptr(count, r11_length); // length
     __ jump(RuntimeAddress(short_copy_entry));
   __ BIND(L_copy_ints);
     __ cmpl(rax_elsize, LogBytesPerInt);
     __ jccb(Assembler::notEqual, L_copy_longs);
     __ lea(from, Address(src, src_pos, Address::times_4, 0));// src_addr
     __ lea(to,   Address(dst, dst_pos, Address::times_4, 0));// dst_addr
     __ movl2ptr(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
     __ lea(from, Address(src, src_pos, Address::times_8, 0));// src_addr
     __ lea(to,   Address(dst, dst_pos, Address::times_8, 0));// dst_addr
     __ movl2ptr(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
     __ load_klass(r9_dst_klass, dst);
     __ cmpq(r10_src_klass, r9_dst_klass); // 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);
     __ lea(from, Address(src, src_pos, TIMES_OOP,
                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // src_addr
     __ lea(to,   Address(dst, dst_pos, TIMES_OOP,
                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // dst_addr
     __ movl2ptr(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;
       __ load_klass(r11_dst_klass, dst);
       // 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);
       __ load_klass(r11_dst_klass, dst); // reload
 #endif
       // Marshal the base address arguments now, freeing registers.
       __ lea(from, Address(src, src_pos, TIMES_OOP,
                    arrayOopDesc::base_offset_in_bytes(T_OBJECT)));
       __ lea(to,   Address(dst, dst_pos, TIMES_OOP,
                    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());
       __ movptr(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");
       __ movptr(C_RARG4, r11_dst_klass);  // dst.klass.element_klass
       __ jump(RuntimeAddress(checkcast_copy_entry));
     }
   __ BIND(L_failed);
     __ xorptr(rax, rax);
     __ notptr(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_oop_copy(false, false, "jint_disjoint_arraycopy");
     StubRoutines::_jint_arraycopy            = generate_conjoint_int_oop_copy(false, 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");
     if (UseCompressedOops) {
       StubRoutines::_oop_disjoint_arraycopy  = generate_disjoint_int_oop_copy(false, true, "oop_disjoint_arraycopy");
       StubRoutines::_oop_arraycopy           = generate_conjoint_int_oop_copy(false, true, "oop_arraycopy");
     } else {
       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) {
       __ movptr(rax,
                 Address(r15_thread,
                         in_bytes(JavaThread::saved_exception_pc_offset())));
       __ push(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
     __ subptr(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
     __ movptr(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;
     __ cmpptr(Address(r15_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()));
     // 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::x86::_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::x86::_get_previous_fp_entry = generate_get_previous_fp();
     StubRoutines::x86::_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_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
     StubRoutines::x86::_f2i_fixup = generate_f2i_fixup();
     StubRoutines::x86::_f2l_fixup = generate_f2l_fixup();
     StubRoutines::x86::_d2i_fixup = generate_d2i_fixup();
     StubRoutines::x86::_d2l_fixup = generate_d2l_fixup();
     StubRoutines::x86::_float_sign_mask  = generate_fp_mask("float_sign_mask",  0x7FFFFFFF7FFFFFFF);
     StubRoutines::x86::_float_sign_flip  = generate_fp_mask("float_sign_flip",  0x8000000080000000);
     StubRoutines::x86::_double_sign_mask = generate_fp_mask("double_sign_mask", 0x7FFFFFFFFFFFFFFF);
     StubRoutines::x86::_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);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/cpu/x86/vm/stubGenerator_x86_64.cpp@bd441136a5ce (annotated)

src/cpu/x86/vm/stubGenerator_x86_64.cpp