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

 /*

  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

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

  *

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

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

  * published by the Free Software Foundation.

  *

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

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

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

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

  * accompanied this code).

  *

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

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

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

  *

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

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

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/interpreterRuntime.hpp"

 #include "memory/allocation.inline.hpp"

 #include "prims/methodHandles.hpp"

 #define __ _masm->

 #ifdef PRODUCT

 #define BLOCK_COMMENT(str) /* nothing */

 #else

 #define BLOCK_COMMENT(str) __ block_comment(str)

 #endif

 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")

 // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.

 static RegisterOrConstant constant(int value) {

   return RegisterOrConstant(value);

 }

 address MethodHandleEntry::start_compiled_entry(MacroAssembler* _masm,

                                                 address interpreted_entry) {

   // Just before the actual machine code entry point, allocate space

   // for a MethodHandleEntry::Data record, so that we can manage everything

   // from one base pointer.

   __ align(wordSize);

   address target = __ pc() + sizeof(Data);

   while (__ pc() < target) {

     __ nop();

     __ align(wordSize);

   }

   MethodHandleEntry* me = (MethodHandleEntry*) __ pc();

   me->set_end_address(__ pc());         // set a temporary end_address

   me->set_from_interpreted_entry(interpreted_entry);

   me->set_type_checking_entry(NULL);

   return (address) me;

 }

 MethodHandleEntry* MethodHandleEntry::finish_compiled_entry(MacroAssembler* _masm,

                                                 address start_addr) {

   MethodHandleEntry* me = (MethodHandleEntry*) start_addr;

   assert(me->end_address() == start_addr, "valid ME");

   // Fill in the real end_address:

   __ align(wordSize);

   me->set_end_address(__ pc());

   return me;

 }

 // stack walking support

 frame MethodHandles::ricochet_frame_sender(const frame& fr, RegisterMap *map) {

   RicochetFrame* f = RicochetFrame::from_frame(fr);

   if (map->update_map())

     frame::update_map_with_saved_link(map, &f->_sender_link);

   return frame(f->extended_sender_sp(), f->exact_sender_sp(), f->sender_link(), f->sender_pc());

 }

 void MethodHandles::ricochet_frame_oops_do(const frame& fr, OopClosure* blk, const RegisterMap* reg_map) {

   RicochetFrame* f = RicochetFrame::from_frame(fr);

   // pick up the argument type descriptor:

   Thread* thread = Thread::current();

   Handle cookie(thread, f->compute_saved_args_layout(true, true));

   // process fixed part

   blk->do_oop((oop*)f->saved_target_addr());

   blk->do_oop((oop*)f->saved_args_layout_addr());

   // process variable arguments:

   if (cookie.is_null())  return;  // no arguments to describe

   // the cookie is actually the invokeExact method for my target

   // his argument signature is what I'm interested in

   assert(cookie->is_method(), "");

   methodHandle invoker(thread, methodOop(cookie()));

   assert(invoker->name() == vmSymbols::invokeExact_name(), "must be this kind of method");

   assert(!invoker->is_static(), "must have MH argument");

   int slot_count = invoker->size_of_parameters();

   assert(slot_count >= 1, "must include 'this'");

   intptr_t* base = f->saved_args_base();

   intptr_t* retval = NULL;

   if (f->has_return_value_slot())

     retval = f->return_value_slot_addr();

   int slot_num = slot_count;

   intptr_t* loc = &base[slot_num -= 1];

   //blk->do_oop((oop*) loc);   // original target, which is irrelevant

   int arg_num = 0;

   for (SignatureStream ss(invoker->signature()); !ss.is_done(); ss.next()) {

     if (ss.at_return_type())  continue;

     BasicType ptype = ss.type();

     if (ptype == T_ARRAY)  ptype = T_OBJECT; // fold all refs to T_OBJECT

     assert(ptype >= T_BOOLEAN && ptype <= T_OBJECT, "not array or void");

     loc = &base[slot_num -= type2size[ptype]];

     bool is_oop = (ptype == T_OBJECT && loc != retval);

     if (is_oop)  blk->do_oop((oop*)loc);

     arg_num += 1;

   }

   assert(slot_num == 0, "must have processed all the arguments");

 }

 oop MethodHandles::RicochetFrame::compute_saved_args_layout(bool read_cache, bool write_cache) {

   oop cookie = NULL;

   if (read_cache) {

     cookie = saved_args_layout();

     if (cookie != NULL)  return cookie;

   }

   oop target = saved_target();

   oop mtype  = java_lang_invoke_MethodHandle::type(target);

   oop mtform = java_lang_invoke_MethodType::form(mtype);

   cookie = java_lang_invoke_MethodTypeForm::vmlayout(mtform);

   if (write_cache)  {

     (*saved_args_layout_addr()) = cookie;

   }

   return cookie;

 }

 void MethodHandles::RicochetFrame::generate_ricochet_blob(MacroAssembler* _masm,

                                                           // output params:

                                                           int* bounce_offset,

                                                           int* exception_offset,

                                                           int* frame_size_in_words) {

   (*frame_size_in_words) = RicochetFrame::frame_size_in_bytes() / wordSize;

   address start = __ pc();

 #ifdef ASSERT

   __ hlt(); __ hlt(); __ hlt();

   // here's a hint of something special:

   __ push(MAGIC_NUMBER_1);

   __ push(MAGIC_NUMBER_2);

 #endif //ASSERT

   __ hlt();  // not reached

   // A return PC has just been popped from the stack.

   // Return values are in registers.

   // The ebp points into the RicochetFrame, which contains

   // a cleanup continuation we must return to.

   (*bounce_offset) = __ pc() - start;

   BLOCK_COMMENT("ricochet_blob.bounce");

   if (VerifyMethodHandles)  RicochetFrame::verify_clean(_masm);

   trace_method_handle(_masm, "return/ricochet_blob.bounce");

   __ jmp(frame_address(continuation_offset_in_bytes()));

   __ hlt();

   DEBUG_ONLY(__ push(MAGIC_NUMBER_2));

   (*exception_offset) = __ pc() - start;

   BLOCK_COMMENT("ricochet_blob.exception");

   // compare this to Interpreter::rethrow_exception_entry, which is parallel code

   // for example, see TemplateInterpreterGenerator::generate_throw_exception

   // Live registers in:

   //   rax: exception

   //   rdx: return address/pc that threw exception (ignored, always equal to bounce addr)

   __ verify_oop(rax);

   // no need to empty_FPU_stack or reinit_heapbase, since caller frame will do the same if needed

   // Take down the frame.

   // Cf. InterpreterMacroAssembler::remove_activation.

   leave_ricochet_frame(_masm, /*rcx_recv=*/ noreg,

                        saved_last_sp_register(),

                        /*sender_pc_reg=*/ rdx);

   // In between activations - previous activation type unknown yet

   // compute continuation point - the continuation point expects the

   // following registers set up:

   //

   // rax: exception

   // rdx: return address/pc that threw exception

   // rsp: expression stack of caller

   // rbp: ebp of caller

   __ push(rax);                                  // save exception

   __ push(rdx);                                  // save return address

   Register thread_reg = LP64_ONLY(r15_thread) NOT_LP64(rdi);

   NOT_LP64(__ get_thread(thread_reg));

   __ call_VM_leaf(CAST_FROM_FN_PTR(address,

                                    SharedRuntime::exception_handler_for_return_address),

                   thread_reg, rdx);

   __ mov(rbx, rax);                              // save exception handler

   __ pop(rdx);                                   // restore return address

   __ pop(rax);                                   // restore exception

   __ jmp(rbx);                                   // jump to exception

                                                  // handler of caller

 }

 void MethodHandles::RicochetFrame::enter_ricochet_frame(MacroAssembler* _masm,

                                                         Register rcx_recv,

                                                         Register rax_argv,

                                                         address return_handler,

                                                         Register rbx_temp) {

   const Register saved_last_sp = saved_last_sp_register();

   Address rcx_mh_vmtarget(    rcx_recv, java_lang_invoke_MethodHandle::vmtarget_offset_in_bytes() );

   Address rcx_amh_conversion( rcx_recv, java_lang_invoke_AdapterMethodHandle::conversion_offset_in_bytes() );

   // Push the RicochetFrame a word at a time.

   // This creates something similar to an interpreter frame.

   // Cf. TemplateInterpreterGenerator::generate_fixed_frame.

   BLOCK_COMMENT("push RicochetFrame {");

   DEBUG_ONLY(int rfo = (int) sizeof(RicochetFrame));

   assert((rfo -= wordSize) == RicochetFrame::sender_pc_offset_in_bytes(), "");

 #define RF_FIELD(push_value, name)                                      \

   { push_value;                                                         \

     assert((rfo -= wordSize) == RicochetFrame::name##_offset_in_bytes(), ""); }

   RF_FIELD(__ push(rbp),                   sender_link);

   RF_FIELD(__ push(saved_last_sp),         exact_sender_sp);  // rsi/r13

   RF_FIELD(__ pushptr(rcx_amh_conversion), conversion);

   RF_FIELD(__ push(rax_argv),              saved_args_base);   // can be updated if args are shifted

   RF_FIELD(__ push((int32_t) NULL_WORD),   saved_args_layout); // cache for GC layout cookie

   if (UseCompressedOops) {

     __ load_heap_oop(rbx_temp, rcx_mh_vmtarget);

     RF_FIELD(__ push(rbx_temp),            saved_target);

   } else {

     RF_FIELD(__ pushptr(rcx_mh_vmtarget),  saved_target);

   }

   __ lea(rbx_temp, ExternalAddress(return_handler));

   RF_FIELD(__ push(rbx_temp),              continuation);

 #undef RF_FIELD

   assert(rfo == 0, "fully initialized the RicochetFrame");

   // compute new frame pointer:

   __ lea(rbp, Address(rsp, RicochetFrame::sender_link_offset_in_bytes()));

   // Push guard word #1 in debug mode.

   DEBUG_ONLY(__ push((int32_t) RicochetFrame::MAGIC_NUMBER_1));

   // For debugging, leave behind an indication of which stub built this frame.

   DEBUG_ONLY({ Label L; __ call(L, relocInfo::none); __ bind(L); });

   BLOCK_COMMENT("} RicochetFrame");

 }

 void MethodHandles::RicochetFrame::leave_ricochet_frame(MacroAssembler* _masm,

                                                         Register rcx_recv,

                                                         Register new_sp_reg,

                                                         Register sender_pc_reg) {

   assert_different_registers(rcx_recv, new_sp_reg, sender_pc_reg);

   const Register saved_last_sp = saved_last_sp_register();

   // Take down the frame.

   // Cf. InterpreterMacroAssembler::remove_activation.

   BLOCK_COMMENT("end_ricochet_frame {");

   // TO DO: If (exact_sender_sp - extended_sender_sp) > THRESH, compact the frame down.

   // This will keep stack in bounds even with unlimited tailcalls, each with an adapter.

   if (rcx_recv->is_valid())

     __ movptr(rcx_recv,    RicochetFrame::frame_address(RicochetFrame::saved_target_offset_in_bytes()));

   __ movptr(sender_pc_reg, RicochetFrame::frame_address(RicochetFrame::sender_pc_offset_in_bytes()));

   __ movptr(saved_last_sp, RicochetFrame::frame_address(RicochetFrame::exact_sender_sp_offset_in_bytes()));

   __ movptr(rbp,           RicochetFrame::frame_address(RicochetFrame::sender_link_offset_in_bytes()));

   __ mov(rsp, new_sp_reg);

   BLOCK_COMMENT("} end_ricochet_frame");

 }

 // Emit code to verify that RBP is pointing at a valid ricochet frame.

 #ifdef ASSERT

 enum {

   ARG_LIMIT = 255, SLOP = 4,

   // use this parameter for checking for garbage stack movements:

   UNREASONABLE_STACK_MOVE = (ARG_LIMIT + SLOP)

   // the slop defends against false alarms due to fencepost errors

 };

 void MethodHandles::RicochetFrame::verify_clean(MacroAssembler* _masm) {

   // The stack should look like this:

   //    ... keep1 | dest=42 | keep2 | RF | magic | handler | magic | recursive args |

   // Check various invariants.

   verify_offsets();

   Register rdi_temp = rdi;

   Register rcx_temp = rcx;

   { __ push(rdi_temp); __ push(rcx_temp); }

 #define UNPUSH_TEMPS \

   { __ pop(rcx_temp);  __ pop(rdi_temp); }

   Address magic_number_1_addr  = RicochetFrame::frame_address(RicochetFrame::magic_number_1_offset_in_bytes());

   Address magic_number_2_addr  = RicochetFrame::frame_address(RicochetFrame::magic_number_2_offset_in_bytes());

   Address continuation_addr    = RicochetFrame::frame_address(RicochetFrame::continuation_offset_in_bytes());

   Address conversion_addr      = RicochetFrame::frame_address(RicochetFrame::conversion_offset_in_bytes());

   Address saved_args_base_addr = RicochetFrame::frame_address(RicochetFrame::saved_args_base_offset_in_bytes());

   Label L_bad, L_ok;

   BLOCK_COMMENT("verify_clean {");

   // Magic numbers must check out:

   __ cmpptr(magic_number_1_addr, (int32_t) MAGIC_NUMBER_1);

   __ jcc(Assembler::notEqual, L_bad);

   __ cmpptr(magic_number_2_addr, (int32_t) MAGIC_NUMBER_2);

   __ jcc(Assembler::notEqual, L_bad);

   // Arguments pointer must look reasonable:

   __ movptr(rcx_temp, saved_args_base_addr);

   __ cmpptr(rcx_temp, rbp);

   __ jcc(Assembler::below, L_bad);

   __ subptr(rcx_temp, UNREASONABLE_STACK_MOVE * Interpreter::stackElementSize);

   __ cmpptr(rcx_temp, rbp);

   __ jcc(Assembler::above, L_bad);

   load_conversion_dest_type(_masm, rdi_temp, conversion_addr);

   __ cmpl(rdi_temp, T_VOID);

   __ jcc(Assembler::equal, L_ok);

   __ movptr(rcx_temp, saved_args_base_addr);

   load_conversion_vminfo(_masm, rdi_temp, conversion_addr);

   __ cmpptr(Address(rcx_temp, rdi_temp, Interpreter::stackElementScale()),

             (int32_t) RETURN_VALUE_PLACEHOLDER);

   __ jcc(Assembler::equal, L_ok);

   __ BIND(L_bad);

   UNPUSH_TEMPS;

   __ stop("damaged ricochet frame");

   __ BIND(L_ok);

   UNPUSH_TEMPS;

   BLOCK_COMMENT("} verify_clean");

 #undef UNPUSH_TEMPS

 }

 #endif //ASSERT

 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {

   if (VerifyMethodHandles)

     verify_klass(_masm, klass_reg, SystemDictionaryHandles::Class_klass(),

                  "AMH argument is a Class");

   __ load_heap_oop(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));

 }

 void MethodHandles::load_conversion_vminfo(MacroAssembler* _masm, Register reg, Address conversion_field_addr) {

   int bits   = BitsPerByte;

   int offset = (CONV_VMINFO_SHIFT / bits);

   int shift  = (CONV_VMINFO_SHIFT % bits);

   __ load_unsigned_byte(reg, conversion_field_addr.plus_disp(offset));

   assert(CONV_VMINFO_MASK == right_n_bits(bits - shift), "else change type of previous load");

   assert(shift == 0, "no shift needed");

 }

 void MethodHandles::load_conversion_dest_type(MacroAssembler* _masm, Register reg, Address conversion_field_addr) {

   int bits   = BitsPerByte;

   int offset = (CONV_DEST_TYPE_SHIFT / bits);

   int shift  = (CONV_DEST_TYPE_SHIFT % bits);

   __ load_unsigned_byte(reg, conversion_field_addr.plus_disp(offset));

   assert(CONV_TYPE_MASK == right_n_bits(bits - shift), "else change type of previous load");

   __ shrl(reg, shift);

   DEBUG_ONLY(int conv_type_bits = (int) exact_log2(CONV_TYPE_MASK+1));

   assert((shift + conv_type_bits) == bits, "left justified in byte");

 }

 void MethodHandles::load_stack_move(MacroAssembler* _masm,

                                     Register rdi_stack_move,

                                     Register rcx_amh,

                                     bool might_be_negative) {

   BLOCK_COMMENT("load_stack_move {");

   Address rcx_amh_conversion(rcx_amh, java_lang_invoke_AdapterMethodHandle::conversion_offset_in_bytes());

   __ movl(rdi_stack_move, rcx_amh_conversion);

   __ sarl(rdi_stack_move, CONV_STACK_MOVE_SHIFT);

 #ifdef _LP64

   if (might_be_negative) {

     // clean high bits of stack motion register (was loaded as an int)

     __ movslq(rdi_stack_move, rdi_stack_move);

   }

 #endif //_LP64

   if (VerifyMethodHandles) {

     Label L_ok, L_bad;

     int32_t stack_move_limit = 0x4000;  // extra-large

     __ cmpptr(rdi_stack_move, stack_move_limit);

     __ jcc(Assembler::greaterEqual, L_bad);

     __ cmpptr(rdi_stack_move, -stack_move_limit);

     __ jcc(Assembler::greater, L_ok);

     __ bind(L_bad);

     __ stop("load_stack_move of garbage value");

     __ BIND(L_ok);

   }

   BLOCK_COMMENT("} load_stack_move");

 }

 #ifdef ASSERT

 void MethodHandles::RicochetFrame::verify_offsets() {

   // Check compatibility of this struct with the more generally used offsets of class frame:

   int ebp_off = sender_link_offset_in_bytes();  // offset from struct base to local rbp value

   assert(ebp_off + wordSize*frame::interpreter_frame_method_offset      == saved_args_base_offset_in_bytes(), "");

   assert(ebp_off + wordSize*frame::interpreter_frame_last_sp_offset     == conversion_offset_in_bytes(), "");

   assert(ebp_off + wordSize*frame::interpreter_frame_sender_sp_offset   == exact_sender_sp_offset_in_bytes(), "");

   // These last two have to be exact:

   assert(ebp_off + wordSize*frame::link_offset                          == sender_link_offset_in_bytes(), "");

   assert(ebp_off + wordSize*frame::return_addr_offset                   == sender_pc_offset_in_bytes(), "");

 }

 void MethodHandles::RicochetFrame::verify() const {

   verify_offsets();

   assert(magic_number_1() == MAGIC_NUMBER_1, "");

   assert(magic_number_2() == MAGIC_NUMBER_2, "");

   if (!Universe::heap()->is_gc_active()) {

     if (saved_args_layout() != NULL) {

       assert(saved_args_layout()->is_method(), "must be valid oop");

     }

     if (saved_target() != NULL) {

       assert(java_lang_invoke_MethodHandle::is_instance(saved_target()), "checking frame value");

     }

   }

   int conv_op = adapter_conversion_op(conversion());

   assert(conv_op == java_lang_invoke_AdapterMethodHandle::OP_COLLECT_ARGS ||

          conv_op == java_lang_invoke_AdapterMethodHandle::OP_FOLD_ARGS ||

          conv_op == java_lang_invoke_AdapterMethodHandle::OP_PRIM_TO_REF,

          "must be a sane conversion");

   if (has_return_value_slot()) {

     assert(*return_value_slot_addr() == RETURN_VALUE_PLACEHOLDER, "");

   }

 }

 #endif //PRODUCT

 #ifdef ASSERT

 void MethodHandles::verify_argslot(MacroAssembler* _masm,

                                    Register argslot_reg,

                                    const char* error_message) {

   // Verify that argslot lies within (rsp, rbp].

   Label L_ok, L_bad;

   BLOCK_COMMENT("verify_argslot {");

   __ cmpptr(argslot_reg, rbp);

   __ jccb(Assembler::above, L_bad);

   __ cmpptr(rsp, argslot_reg);

   __ jccb(Assembler::below, L_ok);

   __ bind(L_bad);

   __ stop(error_message);

   __ BIND(L_ok);

   BLOCK_COMMENT("} verify_argslot");

 }

 void MethodHandles::verify_argslots(MacroAssembler* _masm,

                                     RegisterOrConstant arg_slots,

                                     Register arg_slot_base_reg,

                                     bool negate_argslots,

                                     const char* error_message) {

   // Verify that [argslot..argslot+size) lies within (rsp, rbp).

   Label L_ok, L_bad;

   Register rdi_temp = rdi;

   BLOCK_COMMENT("verify_argslots {");

   __ push(rdi_temp);

   if (negate_argslots) {

     if (arg_slots.is_constant()) {

       arg_slots = -1 * arg_slots.as_constant();

     } else {

       __ movptr(rdi_temp, arg_slots);

       __ negptr(rdi_temp);

       arg_slots = rdi_temp;

     }

   }

   __ lea(rdi_temp, Address(arg_slot_base_reg, arg_slots, Interpreter::stackElementScale()));

   __ cmpptr(rdi_temp, rbp);

   __ pop(rdi_temp);

   __ jcc(Assembler::above, L_bad);

   __ cmpptr(rsp, arg_slot_base_reg);

   __ jcc(Assembler::below, L_ok);

   __ bind(L_bad);

   __ stop(error_message);

   __ BIND(L_ok);

   BLOCK_COMMENT("} verify_argslots");

 }

 // Make sure that arg_slots has the same sign as the given direction.

 // If (and only if) arg_slots is a assembly-time constant, also allow it to be zero.

 void MethodHandles::verify_stack_move(MacroAssembler* _masm,

                                       RegisterOrConstant arg_slots, int direction) {

   bool allow_zero = arg_slots.is_constant();

   if (direction == 0) { direction = +1; allow_zero = true; }

   assert(stack_move_unit() == -1, "else add extra checks here");

   if (arg_slots.is_register()) {

     Label L_ok, L_bad;

     BLOCK_COMMENT("verify_stack_move {");

     // testl(arg_slots.as_register(), -stack_move_unit() - 1);  // no need

     // jcc(Assembler::notZero, L_bad);

     __ cmpptr(arg_slots.as_register(), (int32_t) NULL_WORD);

     if (direction > 0) {

       __ jcc(allow_zero ? Assembler::less : Assembler::lessEqual, L_bad);

       __ cmpptr(arg_slots.as_register(), (int32_t) UNREASONABLE_STACK_MOVE);

       __ jcc(Assembler::less, L_ok);

     } else {

       __ jcc(allow_zero ? Assembler::greater : Assembler::greaterEqual, L_bad);

       __ cmpptr(arg_slots.as_register(), (int32_t) -UNREASONABLE_STACK_MOVE);

       __ jcc(Assembler::greater, L_ok);

     }

     __ bind(L_bad);

     if (direction > 0)

       __ stop("assert arg_slots > 0");

     else

       __ stop("assert arg_slots < 0");

     __ BIND(L_ok);

     BLOCK_COMMENT("} verify_stack_move");

   } else {

     intptr_t size = arg_slots.as_constant();

     if (direction < 0)  size = -size;

     assert(size >= 0, "correct direction of constant move");

     assert(size < UNREASONABLE_STACK_MOVE, "reasonable size of constant move");

   }

 }

 void MethodHandles::verify_klass(MacroAssembler* _masm,

                                  Register obj, KlassHandle klass,

                                  const char* error_message) {

   oop* klass_addr = klass.raw_value();

   assert(klass_addr >= SystemDictionaryHandles::Object_klass().raw_value() &&

          klass_addr <= SystemDictionaryHandles::Long_klass().raw_value(),

          "must be one of the SystemDictionaryHandles");

   Register temp = rdi;

   Label L_ok, L_bad;

   BLOCK_COMMENT("verify_klass {");

   __ verify_oop(obj);

   __ testptr(obj, obj);

   __ jcc(Assembler::zero, L_bad);

   __ push(temp);

   __ load_klass(temp, obj);

   __ cmpptr(temp, ExternalAddress((address) klass_addr));

   __ jcc(Assembler::equal, L_ok);

   intptr_t super_check_offset = klass->super_check_offset();

   __ movptr(temp, Address(temp, super_check_offset));

   __ cmpptr(temp, ExternalAddress((address) klass_addr));

   __ jcc(Assembler::equal, L_ok);

   __ pop(temp);

   __ bind(L_bad);

   __ stop(error_message);

   __ BIND(L_ok);

   __ pop(temp);

   BLOCK_COMMENT("} verify_klass");

 }

 #endif //ASSERT

 // Code generation

 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm) {

   // rbx: methodOop

   // rcx: receiver method handle (must load from sp[MethodTypeForm.vmslots])

   // rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)

   // rdx, rdi: garbage temp, blown away

   Register rbx_method = rbx;

   Register rcx_recv   = rcx;

   Register rax_mtype  = rax;

   Register rdx_temp   = rdx;

   Register rdi_temp   = rdi;

   // emit WrongMethodType path first, to enable jccb back-branch from main path

   Label wrong_method_type;

   __ bind(wrong_method_type);

   Label invoke_generic_slow_path, invoke_exact_error_path;

   assert(methodOopDesc::intrinsic_id_size_in_bytes() == sizeof(u1), "");;

   __ cmpb(Address(rbx_method, methodOopDesc::intrinsic_id_offset_in_bytes()), (int) vmIntrinsics::_invokeExact);

   __ jcc(Assembler::notEqual, invoke_generic_slow_path);

   __ jmp(invoke_exact_error_path);

   // here's where control starts out:

   __ align(CodeEntryAlignment);

   address entry_point = __ pc();

   // fetch the MethodType from the method handle into rax (the 'check' register)

   // FIXME: Interpreter should transmit pre-popped stack pointer, to locate base of arg list.

   // This would simplify several touchy bits of code.

   // See 6984712: JSR 292 method handle calls need a clean argument base pointer

   {

     Register tem = rbx_method;

     for (jint* pchase = methodOopDesc::method_type_offsets_chain(); (*pchase) != -1; pchase++) {

       __ movptr(rax_mtype, Address(tem, *pchase));

       tem = rax_mtype;          // in case there is another indirection

     }

   }

   // given the MethodType, find out where the MH argument is buried

   __ load_heap_oop(rdx_temp, Address(rax_mtype, __ delayed_value(java_lang_invoke_MethodType::form_offset_in_bytes, rdi_temp)));

   Register rdx_vmslots = rdx_temp;

   __ movl(rdx_vmslots, Address(rdx_temp, __ delayed_value(java_lang_invoke_MethodTypeForm::vmslots_offset_in_bytes, rdi_temp)));

   Address mh_receiver_slot_addr = __ argument_address(rdx_vmslots);

   __ movptr(rcx_recv, mh_receiver_slot_addr);

   trace_method_handle(_masm, "invokeExact");

   __ check_method_handle_type(rax_mtype, rcx_recv, rdi_temp, wrong_method_type);

   // Nobody uses the MH receiver slot after this.  Make sure.

   DEBUG_ONLY(__ movptr(mh_receiver_slot_addr, (int32_t)0x999999));

   __ jump_to_method_handle_entry(rcx_recv, rdi_temp);

   // error path for invokeExact (only)

   __ bind(invoke_exact_error_path);

   // jump(ExternalAddress(Interpreter::throw_WrongMethodType_entry()));

   Register rdx_last_Java_sp = rdx_temp;

   __ lea(rdx_last_Java_sp, __ argument_address(constant(0)));

   __ super_call_VM(noreg,

                    rdx_last_Java_sp,

                    CAST_FROM_FN_PTR(address,

                                     InterpreterRuntime::throw_WrongMethodTypeException),

                    // pass required type, then failing mh object

                    rax_mtype, rcx_recv);

   // for invokeGeneric (only), apply argument and result conversions on the fly

   __ bind(invoke_generic_slow_path);

 #ifdef ASSERT

   if (VerifyMethodHandles) {

     Label L;

     __ cmpb(Address(rbx_method, methodOopDesc::intrinsic_id_offset_in_bytes()), (int) vmIntrinsics::_invokeGeneric);

     __ jcc(Assembler::equal, L);

     __ stop("bad methodOop::intrinsic_id");

     __ bind(L);

   }

 #endif //ASSERT

   Register rbx_temp = rbx_method;  // don't need it now

   // make room on the stack for another pointer:

   Register rcx_argslot = rcx_recv;

   __ lea(rcx_argslot, __ argument_address(rdx_vmslots, 1));

   insert_arg_slots(_masm, 2 * stack_move_unit(),

                    rcx_argslot, rbx_temp, rdx_temp);

   // load up an adapter from the calling type (Java weaves this)

   Register rdx_adapter = rdx_temp;

   __ load_heap_oop(rdx_temp,    Address(rax_mtype, __ delayed_value(java_lang_invoke_MethodType::form_offset_in_bytes,               rdi_temp)));

   __ load_heap_oop(rdx_adapter, Address(rdx_temp,  __ delayed_value(java_lang_invoke_MethodTypeForm::genericInvoker_offset_in_bytes, rdi_temp)));

   __ verify_oop(rdx_adapter);

   __ movptr(Address(rcx_argslot, 1 * Interpreter::stackElementSize), rdx_adapter);

   // As a trusted first argument, pass the type being called, so the adapter knows

   // the actual types of the arguments and return values.

   // (Generic invokers are shared among form-families of method-type.)

   __ movptr(Address(rcx_argslot, 0 * Interpreter::stackElementSize), rax_mtype);

   // FIXME: assert that rdx_adapter is of the right method-type.

   __ mov(rcx, rdx_adapter);

   trace_method_handle(_masm, "invokeGeneric");

   __ jump_to_method_handle_entry(rcx, rdi_temp);

   return entry_point;

 }

 // Helper to insert argument slots into the stack.

 // arg_slots must be a multiple of stack_move_unit() and < 0

 // rax_argslot is decremented to point to the new (shifted) location of the argslot

 // But, rdx_temp ends up holding the original value of rax_argslot.

 void MethodHandles::insert_arg_slots(MacroAssembler* _masm,

                                      RegisterOrConstant arg_slots,

                                      Register rax_argslot,

                                      Register rbx_temp, Register rdx_temp) {

   // allow constant zero

   if (arg_slots.is_constant() && arg_slots.as_constant() == 0)

     return;

   assert_different_registers(rax_argslot, rbx_temp, rdx_temp,

                              (!arg_slots.is_register() ? rsp : arg_slots.as_register()));

   if (VerifyMethodHandles)

     verify_argslot(_masm, rax_argslot, "insertion point must fall within current frame");

   if (VerifyMethodHandles)

     verify_stack_move(_masm, arg_slots, -1);

   // Make space on the stack for the inserted argument(s).

   // Then pull down everything shallower than rax_argslot.

   // The stacked return address gets pulled down with everything else.

   // That is, copy [rsp, argslot) downward by -size words.  In pseudo-code:

   //   rsp -= size;

   //   for (rdx = rsp + size; rdx < argslot; rdx++)

   //     rdx[-size] = rdx[0]

   //   argslot -= size;

   BLOCK_COMMENT("insert_arg_slots {");

   __ mov(rdx_temp, rsp);                        // source pointer for copy

   __ lea(rsp, Address(rsp, arg_slots, Interpreter::stackElementScale()));

   {

     Label loop;

     __ BIND(loop);

     // pull one word down each time through the loop

     __ movptr(rbx_temp, Address(rdx_temp, 0));

     __ movptr(Address(rdx_temp, arg_slots, Interpreter::stackElementScale()), rbx_temp);

     __ addptr(rdx_temp, wordSize);

     __ cmpptr(rdx_temp, rax_argslot);

     __ jcc(Assembler::below, loop);

   }

   // Now move the argslot down, to point to the opened-up space.

   __ lea(rax_argslot, Address(rax_argslot, arg_slots, Interpreter::stackElementScale()));

   BLOCK_COMMENT("} insert_arg_slots");

 }

 // Helper to remove argument slots from the stack.

 // arg_slots must be a multiple of stack_move_unit() and > 0

 void MethodHandles::remove_arg_slots(MacroAssembler* _masm,

                                      RegisterOrConstant arg_slots,

                                      Register rax_argslot,

                                      Register rbx_temp, Register rdx_temp) {

   // allow constant zero

   if (arg_slots.is_constant() && arg_slots.as_constant() == 0)

     return;

   assert_different_registers(rax_argslot, rbx_temp, rdx_temp,

                              (!arg_slots.is_register() ? rsp : arg_slots.as_register()));

   if (VerifyMethodHandles)

     verify_argslots(_masm, arg_slots, rax_argslot, false,

                     "deleted argument(s) must fall within current frame");

   if (VerifyMethodHandles)

     verify_stack_move(_masm, arg_slots, +1);

   BLOCK_COMMENT("remove_arg_slots {");

   // Pull up everything shallower than rax_argslot.

   // Then remove the excess space on the stack.

   // The stacked return address gets pulled up with everything else.

   // That is, copy [rsp, argslot) upward by size words.  In pseudo-code:

   //   for (rdx = argslot-1; rdx >= rsp; --rdx)

   //     rdx[size] = rdx[0]

   //   argslot += size;

   //   rsp += size;

   __ lea(rdx_temp, Address(rax_argslot, -wordSize)); // source pointer for copy

   {

     Label loop;

     __ BIND(loop);

     // pull one word up each time through the loop

     __ movptr(rbx_temp, Address(rdx_temp, 0));

     __ movptr(Address(rdx_temp, arg_slots, Interpreter::stackElementScale()), rbx_temp);

     __ addptr(rdx_temp, -wordSize);

     __ cmpptr(rdx_temp, rsp);

     __ jcc(Assembler::aboveEqual, loop);

   }

   // Now move the argslot up, to point to the just-copied block.

   __ lea(rsp, Address(rsp, arg_slots, Interpreter::stackElementScale()));

   // And adjust the argslot address to point at the deletion point.

   __ lea(rax_argslot, Address(rax_argslot, arg_slots, Interpreter::stackElementScale()));

   BLOCK_COMMENT("} remove_arg_slots");

 }

 // Helper to copy argument slots to the top of the stack.

 // The sequence starts with rax_argslot and is counted by slot_count

 // slot_count must be a multiple of stack_move_unit() and >= 0

 // This function blows the temps but does not change rax_argslot.

 void MethodHandles::push_arg_slots(MacroAssembler* _masm,

                                    Register rax_argslot,

                                    RegisterOrConstant slot_count,

                                    int skip_words_count,

                                    Register rbx_temp, Register rdx_temp) {

   assert_different_registers(rax_argslot, rbx_temp, rdx_temp,

                              (!slot_count.is_register() ? rbp : slot_count.as_register()),

                              rsp);

   assert(Interpreter::stackElementSize == wordSize, "else change this code");

   if (VerifyMethodHandles)

     verify_stack_move(_masm, slot_count, 0);

   // allow constant zero

   if (slot_count.is_constant() && slot_count.as_constant() == 0)

     return;

   BLOCK_COMMENT("push_arg_slots {");

   Register rbx_top = rbx_temp;

   // There is at most 1 word to carry down with the TOS.

   switch (skip_words_count) {

   case 1: __ pop(rdx_temp); break;

   case 0:                   break;

   default: ShouldNotReachHere();

   }

   if (slot_count.is_constant()) {

     for (int i = slot_count.as_constant() - 1; i >= 0; i--) {

       __ pushptr(Address(rax_argslot, i * wordSize));

     }

   } else {

     Label L_plural, L_loop, L_break;

     // Emit code to dynamically check for the common cases, zero and one slot.

     __ cmpl(slot_count.as_register(), (int32_t) 1);

     __ jccb(Assembler::greater, L_plural);

     __ jccb(Assembler::less, L_break);

     __ pushptr(Address(rax_argslot, 0));

     __ jmpb(L_break);

     __ BIND(L_plural);

     // Loop for 2 or more:

     //   rbx = &rax[slot_count]

     //   while (rbx > rax)  *(--rsp) = *(--rbx)

     __ lea(rbx_top, Address(rax_argslot, slot_count, Address::times_ptr));

     __ BIND(L_loop);

     __ subptr(rbx_top, wordSize);

     __ pushptr(Address(rbx_top, 0));

     __ cmpptr(rbx_top, rax_argslot);

     __ jcc(Assembler::above, L_loop);

     __ bind(L_break);

   }

   switch (skip_words_count) {

   case 1: __ push(rdx_temp); break;

   case 0:                    break;

   default: ShouldNotReachHere();

   }

   BLOCK_COMMENT("} push_arg_slots");

 }

 // in-place movement; no change to rsp

 // blows rax_temp, rdx_temp

 void MethodHandles::move_arg_slots_up(MacroAssembler* _masm,

                                       Register rbx_bottom,  // invariant

                                       Address  top_addr,     // can use rax_temp

                                       RegisterOrConstant positive_distance_in_slots,

                                       Register rax_temp, Register rdx_temp) {

   BLOCK_COMMENT("move_arg_slots_up {");

   assert_different_registers(rbx_bottom,

                              rax_temp, rdx_temp,

                              positive_distance_in_slots.register_or_noreg());

   Label L_loop, L_break;

   Register rax_top = rax_temp;

   if (!top_addr.is_same_address(Address(rax_top, 0)))

     __ lea(rax_top, top_addr);

   // Detect empty (or broken) loop:

 #ifdef ASSERT

   if (VerifyMethodHandles) {

     // Verify that &bottom < &top (non-empty interval)

     Label L_ok, L_bad;

     if (positive_distance_in_slots.is_register()) {

       __ cmpptr(positive_distance_in_slots.as_register(), (int32_t) 0);

       __ jcc(Assembler::lessEqual, L_bad);

     }

     __ cmpptr(rbx_bottom, rax_top);

     __ jcc(Assembler::below, L_ok);

     __ bind(L_bad);

     __ stop("valid bounds (copy up)");

     __ BIND(L_ok);

   }

 #endif

   __ cmpptr(rbx_bottom, rax_top);

   __ jccb(Assembler::aboveEqual, L_break);

   // work rax down to rbx, copying contiguous data upwards

   // In pseudo-code:

   //   [rbx, rax) = &[bottom, top)

   //   while (--rax >= rbx) *(rax + distance) = *(rax + 0), rax--;

   __ BIND(L_loop);

   __ subptr(rax_top, wordSize);

   __ movptr(rdx_temp, Address(rax_top, 0));

   __ movptr(          Address(rax_top, positive_distance_in_slots, Address::times_ptr), rdx_temp);

   __ cmpptr(rax_top, rbx_bottom);

   __ jcc(Assembler::above, L_loop);

   assert(Interpreter::stackElementSize == wordSize, "else change loop");

   __ bind(L_break);

   BLOCK_COMMENT("} move_arg_slots_up");

 }

 // in-place movement; no change to rsp

 // blows rax_temp, rdx_temp

 void MethodHandles::move_arg_slots_down(MacroAssembler* _masm,

                                         Address  bottom_addr,  // can use rax_temp

                                         Register rbx_top,      // invariant

                                         RegisterOrConstant negative_distance_in_slots,

                                         Register rax_temp, Register rdx_temp) {

   BLOCK_COMMENT("move_arg_slots_down {");

   assert_different_registers(rbx_top,

                              negative_distance_in_slots.register_or_noreg(),

                              rax_temp, rdx_temp);

   Label L_loop, L_break;

   Register rax_bottom = rax_temp;

   if (!bottom_addr.is_same_address(Address(rax_bottom, 0)))

     __ lea(rax_bottom, bottom_addr);

   // Detect empty (or broken) loop:

 #ifdef ASSERT

   assert(!negative_distance_in_slots.is_constant() || negative_distance_in_slots.as_constant() < 0, "");

   if (VerifyMethodHandles) {

     // Verify that &bottom < &top (non-empty interval)

     Label L_ok, L_bad;

     if (negative_distance_in_slots.is_register()) {

       __ cmpptr(negative_distance_in_slots.as_register(), (int32_t) 0);

       __ jcc(Assembler::greaterEqual, L_bad);

     }

     __ cmpptr(rax_bottom, rbx_top);

     __ jcc(Assembler::below, L_ok);

     __ bind(L_bad);

     __ stop("valid bounds (copy down)");

     __ BIND(L_ok);

   }

 #endif

   __ cmpptr(rax_bottom, rbx_top);

   __ jccb(Assembler::aboveEqual, L_break);

   // work rax up to rbx, copying contiguous data downwards

   // In pseudo-code:

   //   [rax, rbx) = &[bottom, top)

   //   while (rax < rbx) *(rax - distance) = *(rax + 0), rax++;

   __ BIND(L_loop);

   __ movptr(rdx_temp, Address(rax_bottom, 0));

   __ movptr(          Address(rax_bottom, negative_distance_in_slots, Address::times_ptr), rdx_temp);

   __ addptr(rax_bottom, wordSize);

   __ cmpptr(rax_bottom, rbx_top);

   __ jcc(Assembler::below, L_loop);

   assert(Interpreter::stackElementSize == wordSize, "else change loop");

   __ bind(L_break);

   BLOCK_COMMENT("} move_arg_slots_down");

 }

 // Copy from a field or array element to a stacked argument slot.

 // is_element (ignored) says whether caller is loading an array element instead of an instance field.

 void MethodHandles::move_typed_arg(MacroAssembler* _masm,

                                    BasicType type, bool is_element,

                                    Address slot_dest, Address value_src,

                                    Register rbx_temp, Register rdx_temp) {

   BLOCK_COMMENT(!is_element ? "move_typed_arg {" : "move_typed_arg { (array element)");

   if (type == T_OBJECT || type == T_ARRAY) {

     __ load_heap_oop(rbx_temp, value_src);

     __ movptr(slot_dest, rbx_temp);

   } else if (type != T_VOID) {

     int  arg_size      = type2aelembytes(type);

     bool arg_is_signed = is_signed_subword_type(type);

     int  slot_size     = (arg_size > wordSize) ? arg_size : wordSize;

     __ load_sized_value(  rdx_temp,  value_src, arg_size, arg_is_signed, rbx_temp);

     __ store_sized_value( slot_dest, rdx_temp,  slot_size,               rbx_temp);

   }

   BLOCK_COMMENT("} move_typed_arg");

 }

 void MethodHandles::move_return_value(MacroAssembler* _masm, BasicType type,

                                       Address return_slot) {

   BLOCK_COMMENT("move_return_value {");

   // Old versions of the JVM must clean the FPU stack after every return.

 #ifndef _LP64

 #ifdef COMPILER2

   // The FPU stack is clean if UseSSE >= 2 but must be cleaned in other cases

   if ((type == T_FLOAT && UseSSE < 1) || (type == T_DOUBLE && UseSSE < 2)) {

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

         __ ffree(i);

     }

   } else if (UseSSE < 2) {

     __ empty_FPU_stack();

   }

 #endif //COMPILER2

 #endif //!_LP64

   // Look at the type and pull the value out of the corresponding register.

   if (type == T_VOID) {

     // nothing to do

   } else if (type == T_OBJECT) {

     __ movptr(return_slot, rax);

   } else if (type == T_INT || is_subword_type(type)) {

     // write the whole word, even if only 32 bits is significant

     __ movptr(return_slot, rax);

   } else if (type == T_LONG) {

     // store the value by parts

     // Note: We assume longs are continguous (if misaligned) on the interpreter stack.

     __ store_sized_value(return_slot, rax, BytesPerLong, rdx);

   } else if (NOT_LP64((type == T_FLOAT  && UseSSE < 1) ||

                       (type == T_DOUBLE && UseSSE < 2) ||)

              false) {

     // Use old x86 FPU registers:

     if (type == T_FLOAT)

       __ fstp_s(return_slot);

     else

       __ fstp_d(return_slot);

   } else if (type == T_FLOAT) {

     __ movflt(return_slot, xmm0);

   } else if (type == T_DOUBLE) {

     __ movdbl(return_slot, xmm0);

   } else {

     ShouldNotReachHere();

   }

   BLOCK_COMMENT("} move_return_value");

 }

 #ifndef PRODUCT

 extern "C" void print_method_handle(oop mh);

 void trace_method_handle_stub(const char* adaptername,

                               oop mh,

                               intptr_t* saved_regs,

                               intptr_t* entry_sp,

                               intptr_t* saved_sp,

                               intptr_t* saved_bp) {

   // called as a leaf from native code: do not block the JVM!

   bool has_mh = (strstr(adaptername, "return/") == NULL);  // return adapters don't have rcx_mh

   intptr_t* last_sp = (intptr_t*) saved_bp[frame::interpreter_frame_last_sp_offset];

   intptr_t* base_sp = last_sp;

   typedef MethodHandles::RicochetFrame RicochetFrame;

   RicochetFrame* rfp = (RicochetFrame*)((address)saved_bp - RicochetFrame::sender_link_offset_in_bytes());

   if (!UseRicochetFrames || Universe::heap()->is_in((address) rfp->saved_args_base())) {

     // Probably an interpreter frame.

     base_sp = (intptr_t*) saved_bp[frame::interpreter_frame_monitor_block_top_offset];

   }

   intptr_t    mh_reg = (intptr_t)mh;

   const char* mh_reg_name = "rcx_mh";

   if (!has_mh)  mh_reg_name = "rcx";

   tty->print_cr("MH %s %s="PTR_FORMAT" sp=("PTR_FORMAT"+"INTX_FORMAT") stack_size="INTX_FORMAT" bp="PTR_FORMAT,

                 adaptername, mh_reg_name, mh_reg,

                 (intptr_t)entry_sp, (intptr_t)(saved_sp - entry_sp), (intptr_t)(base_sp - last_sp), (intptr_t)saved_bp);

   if (Verbose) {

     tty->print(" reg dump: ");

     int saved_regs_count = (entry_sp-1) - saved_regs;

     // 32 bit: rdi rsi rbp rsp; rbx rdx rcx (*) rax

     int i;

     for (i = 0; i <= saved_regs_count; i++) {

       if (i > 0 && i % 4 == 0 && i != saved_regs_count) {

         tty->cr();

         tty->print("   + dump: ");

       }

       tty->print(" %d: "PTR_FORMAT, i, saved_regs[i]);

     }

     tty->cr();

     if (last_sp != saved_sp && last_sp != NULL)

       tty->print_cr("*** last_sp="PTR_FORMAT, (intptr_t)last_sp);

     int stack_dump_count = 16;

     if (stack_dump_count < (int)(saved_bp + 2 - saved_sp))

       stack_dump_count = (int)(saved_bp + 2 - saved_sp);

     if (stack_dump_count > 64)  stack_dump_count = 48;

     for (i = 0; i < stack_dump_count; i += 4) {

       tty->print_cr(" dump at SP[%d] "PTR_FORMAT": "PTR_FORMAT" "PTR_FORMAT" "PTR_FORMAT" "PTR_FORMAT,

                     i, (intptr_t) &entry_sp[i+0], entry_sp[i+0], entry_sp[i+1], entry_sp[i+2], entry_sp[i+3]);

     }

     if (has_mh)

       print_method_handle(mh);

   }

 }

 // The stub wraps the arguments in a struct on the stack to avoid

 // dealing with the different calling conventions for passing 6

 // arguments.

 struct MethodHandleStubArguments {

   const char* adaptername;

   oopDesc* mh;

   intptr_t* saved_regs;

   intptr_t* entry_sp;

   intptr_t* saved_sp;

   intptr_t* saved_bp;

 };

 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) {

   trace_method_handle_stub(args->adaptername,

                            args->mh,

                            args->saved_regs,

                            args->entry_sp,

                            args->saved_sp,

                            args->saved_bp);

 }

 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {

   if (!TraceMethodHandles)  return;

   BLOCK_COMMENT("trace_method_handle {");

   __ push(rax);

   __ lea(rax, Address(rsp, wordSize * NOT_LP64(6) LP64_ONLY(14))); // entry_sp  __ pusha();

   __ pusha();

   __ mov(rbx, rsp);

   __ enter();

   // incoming state:

   // rcx: method handle

   // r13 or rsi: saved sp

   // To avoid calling convention issues, build a record on the stack and pass the pointer to that instead.

   __ push(rbp);               // saved_bp

   __ push(rsi);               // saved_sp

   __ push(rax);               // entry_sp

   __ push(rbx);               // pusha saved_regs

   __ push(rcx);               // mh

   __ push(rcx);               // adaptername

   __ movptr(Address(rsp, 0), (intptr_t) adaptername);

   __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub_wrapper), rsp);

   __ leave();

   __ popa();

   __ pop(rax);

   BLOCK_COMMENT("} trace_method_handle");

 }

 #endif //PRODUCT

 // which conversion op types are implemented here?

 int MethodHandles::adapter_conversion_ops_supported_mask() {

   return ((1<<java_lang_invoke_AdapterMethodHandle::OP_RETYPE_ONLY)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_RETYPE_RAW)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_CHECK_CAST)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_PRIM_TO_PRIM)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_REF_TO_PRIM)

           //OP_PRIM_TO_REF is below...

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_SWAP_ARGS)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_ROT_ARGS)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_DUP_ARGS)

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_DROP_ARGS)

           //OP_COLLECT_ARGS is below...

          |(1<<java_lang_invoke_AdapterMethodHandle::OP_SPREAD_ARGS)

          |(!UseRicochetFrames ? 0 :

            java_lang_invoke_MethodTypeForm::vmlayout_offset_in_bytes() <= 0 ? 0 :

            ((1<<java_lang_invoke_AdapterMethodHandle::OP_PRIM_TO_REF)

            |(1<<java_lang_invoke_AdapterMethodHandle::OP_COLLECT_ARGS)

            |(1<<java_lang_invoke_AdapterMethodHandle::OP_FOLD_ARGS)

             ))

          );

 }

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

 // MethodHandles::generate_method_handle_stub

 //

 // Generate an "entry" field for a method handle.

 // This determines how the method handle will respond to calls.

 void MethodHandles::generate_method_handle_stub(MacroAssembler* _masm, MethodHandles::EntryKind ek) {

   MethodHandles::EntryKind ek_orig = ek_original_kind(ek);

   // Here is the register state during an interpreted call,

   // as set up by generate_method_handle_interpreter_entry():

   // - rbx: garbage temp (was MethodHandle.invoke methodOop, unused)

   // - rcx: receiver method handle

   // - rax: method handle type (only used by the check_mtype entry point)

   // - rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)

   // - rdx: garbage temp, can blow away

   const Register rcx_recv    = rcx;

   const Register rax_argslot = rax;

   const Register rbx_temp    = rbx;

   const Register rdx_temp    = rdx;

   const Register rdi_temp    = rdi;

   // This guy is set up by prepare_to_jump_from_interpreted (from interpreted calls)

   // and gen_c2i_adapter (from compiled calls):

   const Register saved_last_sp = saved_last_sp_register();

   // Argument registers for _raise_exception.

   // 32-bit: Pass first two oop/int args in registers ECX and EDX.

   const Register rarg0_code     = LP64_ONLY(j_rarg0) NOT_LP64(rcx);

   const Register rarg1_actual   = LP64_ONLY(j_rarg1) NOT_LP64(rdx);

   const Register rarg2_required = LP64_ONLY(j_rarg2) NOT_LP64(rdi);

   assert_different_registers(rarg0_code, rarg1_actual, rarg2_required, saved_last_sp);

   guarantee(java_lang_invoke_MethodHandle::vmentry_offset_in_bytes() != 0, "must have offsets");

   // some handy addresses

   Address rbx_method_fie(     rbx,      methodOopDesc::from_interpreted_offset() );

   Address rbx_method_fce(     rbx,      methodOopDesc::from_compiled_offset() );

   Address rcx_mh_vmtarget(    rcx_recv, java_lang_invoke_MethodHandle::vmtarget_offset_in_bytes() );

   Address rcx_dmh_vmindex(    rcx_recv, java_lang_invoke_DirectMethodHandle::vmindex_offset_in_bytes() );

   Address rcx_bmh_vmargslot(  rcx_recv, java_lang_invoke_BoundMethodHandle::vmargslot_offset_in_bytes() );

   Address rcx_bmh_argument(   rcx_recv, java_lang_invoke_BoundMethodHandle::argument_offset_in_bytes() );

   Address rcx_amh_vmargslot(  rcx_recv, java_lang_invoke_AdapterMethodHandle::vmargslot_offset_in_bytes() );

   Address rcx_amh_argument(   rcx_recv, java_lang_invoke_AdapterMethodHandle::argument_offset_in_bytes() );

   Address rcx_amh_conversion( rcx_recv, java_lang_invoke_AdapterMethodHandle::conversion_offset_in_bytes() );

   Address vmarg;                // __ argument_address(vmargslot)

   const int java_mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();

   if (have_entry(ek)) {

     __ nop();                   // empty stubs make SG sick

     return;

   }

 #ifdef ASSERT

   __ push((int32_t) 0xEEEEEEEE);

   __ push((int32_t) (intptr_t) entry_name(ek));

   LP64_ONLY(__ push((int32_t) high((intptr_t) entry_name(ek))));

   __ push((int32_t) 0x33333333);

 #endif //ASSERT

   address interp_entry = __ pc();

   trace_method_handle(_masm, entry_name(ek));

   BLOCK_COMMENT(err_msg("Entry %s {", entry_name(ek)));

   switch ((int) ek) {

   case _raise_exception:

     {

       // Not a real MH entry, but rather shared code for raising an

       // exception.  Since we use the compiled entry, arguments are

       // expected in compiler argument registers.

       assert(raise_exception_method(), "must be set");

       assert(raise_exception_method()->from_compiled_entry(), "method must be linked");

       const Register rdi_pc = rax;

       __ pop(rdi_pc);  // caller PC

       __ mov(rsp, saved_last_sp);  // cut the stack back to where the caller started

       Register rbx_method = rbx_temp;

       Label L_no_method;

       // FIXME: fill in _raise_exception_method with a suitable java.lang.invoke method

       __ movptr(rbx_method, ExternalAddress((address) &_raise_exception_method));

       __ testptr(rbx_method, rbx_method);

       __ jccb(Assembler::zero, L_no_method);

       const int jobject_oop_offset = 0;

       __ movptr(rbx_method, Address(rbx_method, jobject_oop_offset));  // dereference the jobject

       __ testptr(rbx_method, rbx_method);

       __ jccb(Assembler::zero, L_no_method);

       __ verify_oop(rbx_method);

       NOT_LP64(__ push(rarg2_required));

       __ push(rdi_pc);         // restore caller PC

       __ jmp(rbx_method_fce);  // jump to compiled entry

       // Do something that is at least causes a valid throw from the interpreter.

       __ bind(L_no_method);

       __ push(rarg2_required);

       __ push(rarg1_actual);

       __ jump(ExternalAddress(Interpreter::throw_WrongMethodType_entry()));

     }

     break;

   case _invokestatic_mh:

   case _invokespecial_mh:

     {

       Register rbx_method = rbx_temp;

       __ load_heap_oop(rbx_method, rcx_mh_vmtarget); // target is a methodOop

       __ verify_oop(rbx_method);

       // same as TemplateTable::invokestatic or invokespecial,

       // minus the CP setup and profiling:

       if (ek == _invokespecial_mh) {

         // Must load & check the first argument before entering the target method.

         __ load_method_handle_vmslots(rax_argslot, rcx_recv, rdx_temp);

         __ movptr(rcx_recv, __ argument_address(rax_argslot, -1));

         __ null_check(rcx_recv);

         __ verify_oop(rcx_recv);

       }

       __ jmp(rbx_method_fie);

     }

     break;

   case _invokevirtual_mh:

     {

       // same as TemplateTable::invokevirtual,

       // minus the CP setup and profiling:

       // pick out the vtable index and receiver offset from the MH,

       // and then we can discard it:

       __ load_method_handle_vmslots(rax_argslot, rcx_recv, rdx_temp);

       Register rbx_index = rbx_temp;

       __ movl(rbx_index, rcx_dmh_vmindex);

       // Note:  The verifier allows us to ignore rcx_mh_vmtarget.

       __ movptr(rcx_recv, __ argument_address(rax_argslot, -1));

       __ null_check(rcx_recv, oopDesc::klass_offset_in_bytes());

       // get receiver klass

       Register rax_klass = rax_argslot;

       __ load_klass(rax_klass, rcx_recv);

       __ verify_oop(rax_klass);

       // get target methodOop & entry point

       const int base = instanceKlass::vtable_start_offset() * wordSize;

       assert(vtableEntry::size() * wordSize == wordSize, "adjust the scaling in the code below");

       Address vtable_entry_addr(rax_klass,

                                 rbx_index, Address::times_ptr,

                                 base + vtableEntry::method_offset_in_bytes());

       Register rbx_method = rbx_temp;

       __ movptr(rbx_method, vtable_entry_addr);

       __ verify_oop(rbx_method);

       __ jmp(rbx_method_fie);

     }

     break;

   case _invokeinterface_mh:

     {

       // same as TemplateTable::invokeinterface,

       // minus the CP setup and profiling:

       // pick out the interface and itable index from the MH.

       __ load_method_handle_vmslots(rax_argslot, rcx_recv, rdx_temp);

       Register rdx_intf  = rdx_temp;

       Register rbx_index = rbx_temp;

       __ load_heap_oop(rdx_intf, rcx_mh_vmtarget);

       __ movl(rbx_index, rcx_dmh_vmindex);

       __ movptr(rcx_recv, __ argument_address(rax_argslot, -1));

       __ null_check(rcx_recv, oopDesc::klass_offset_in_bytes());

       // get receiver klass

       Register rax_klass = rax_argslot;

       __ load_klass(rax_klass, rcx_recv);

       __ verify_oop(rax_klass);

       Register rbx_method = rbx_index;

       // get interface klass

       Label no_such_interface;

       __ verify_oop(rdx_intf);

       __ lookup_interface_method(rax_klass, rdx_intf,

                                  // note: next two args must be the same:

                                  rbx_index, rbx_method,

                                  rdi_temp,

                                  no_such_interface);

       __ verify_oop(rbx_method);

       __ jmp(rbx_method_fie);

       __ hlt();

       __ bind(no_such_interface);

       // Throw an exception.

       // For historical reasons, it will be IncompatibleClassChangeError.

       __ mov(rbx_temp, rcx_recv);  // rarg2_required might be RCX

       assert_different_registers(rarg2_required, rbx_temp);

       __ movptr(rarg2_required, Address(rdx_intf, java_mirror_offset));  // required interface

       __ mov(   rarg1_actual,   rbx_temp);                               // bad receiver

       __ movl(  rarg0_code,     (int) Bytecodes::_invokeinterface);      // who is complaining?

       __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));

     }

     break;

   case _bound_ref_mh:

   case _bound_int_mh:

   case _bound_long_mh:

   case _bound_ref_direct_mh:

   case _bound_int_direct_mh:

   case _bound_long_direct_mh:

     {

       const bool direct_to_method = (ek >= _bound_ref_direct_mh);

       BasicType arg_type  = ek_bound_mh_arg_type(ek);

       int       arg_slots = type2size[arg_type];

       // make room for the new argument:

       __ movl(rax_argslot, rcx_bmh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot));

       insert_arg_slots(_masm, arg_slots * stack_move_unit(), rax_argslot, rbx_temp, rdx_temp);

       // store bound argument into the new stack slot:

       __ load_heap_oop(rbx_temp, rcx_bmh_argument);

       if (arg_type == T_OBJECT) {

         __ movptr(Address(rax_argslot, 0), rbx_temp);

       } else {

         Address prim_value_addr(rbx_temp, java_lang_boxing_object::value_offset_in_bytes(arg_type));

         move_typed_arg(_masm, arg_type, false,

                        Address(rax_argslot, 0),

                        prim_value_addr,

                        rbx_temp, rdx_temp);

       }

       if (direct_to_method) {

         Register rbx_method = rbx_temp;

         __ load_heap_oop(rbx_method, rcx_mh_vmtarget);

         __ verify_oop(rbx_method);

         __ jmp(rbx_method_fie);

       } else {

         __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

         __ verify_oop(rcx_recv);

         __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

       }

     }

     break;

   case _adapter_retype_only:

   case _adapter_retype_raw:

     // immediately jump to the next MH layer:

     __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

     __ verify_oop(rcx_recv);

     __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     // This is OK when all parameter types widen.

     // It is also OK when a return type narrows.

     break;

   case _adapter_check_cast:

     {

       // temps:

       Register rbx_klass = rbx_temp; // interesting AMH data

       // check a reference argument before jumping to the next layer of MH:

       __ movl(rax_argslot, rcx_amh_vmargslot);

       vmarg = __ argument_address(rax_argslot);

       // What class are we casting to?

       __ load_heap_oop(rbx_klass, rcx_amh_argument); // this is a Class object!

       load_klass_from_Class(_masm, rbx_klass);

       Label done;

       __ movptr(rdx_temp, vmarg);

       __ testptr(rdx_temp, rdx_temp);

       __ jcc(Assembler::zero, done);         // no cast if null

       __ load_klass(rdx_temp, rdx_temp);

       // live at this point:

       // - rbx_klass:  klass required by the target method

       // - rdx_temp:   argument klass to test

       // - rcx_recv:   adapter method handle

       __ check_klass_subtype(rdx_temp, rbx_klass, rax_argslot, done);

       // If we get here, the type check failed!

       // Call the wrong_method_type stub, passing the failing argument type in rax.

       Register rax_mtype = rax_argslot;

       __ movl(rax_argslot, rcx_amh_vmargslot);  // reload argslot field

       __ movptr(rdx_temp, vmarg);

       assert_different_registers(rarg2_required, rdx_temp);

       __ load_heap_oop(rarg2_required, rcx_amh_argument);             // required class

       __ mov(          rarg1_actual,   rdx_temp);                     // bad object

       __ movl(         rarg0_code,     (int) Bytecodes::_checkcast);  // who is complaining?

       __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));

       __ bind(done);

       // get the new MH:

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_prim_to_prim:

   case _adapter_ref_to_prim:

   case _adapter_prim_to_ref:

     // handled completely by optimized cases

     __ stop("init_AdapterMethodHandle should not issue this");

     break;

   case _adapter_opt_i2i:        // optimized subcase of adapt_prim_to_prim

 //case _adapter_opt_f2i:        // optimized subcase of adapt_prim_to_prim

   case _adapter_opt_l2i:        // optimized subcase of adapt_prim_to_prim

   case _adapter_opt_unboxi:     // optimized subcase of adapt_ref_to_prim

     {

       // perform an in-place conversion to int or an int subword

       __ movl(rax_argslot, rcx_amh_vmargslot);

       vmarg = __ argument_address(rax_argslot);

       switch (ek) {

       case _adapter_opt_i2i:

         __ movl(rdx_temp, vmarg);

         break;

       case _adapter_opt_l2i:

         {

           // just delete the extra slot; on a little-endian machine we keep the first

           __ lea(rax_argslot, __ argument_address(rax_argslot, 1));

           remove_arg_slots(_masm, -stack_move_unit(),

                            rax_argslot, rbx_temp, rdx_temp);

           vmarg = Address(rax_argslot, -Interpreter::stackElementSize);

           __ movl(rdx_temp, vmarg);

         }

         break;

       case _adapter_opt_unboxi:

         {

           // Load the value up from the heap.

           __ movptr(rdx_temp, vmarg);

           int value_offset = java_lang_boxing_object::value_offset_in_bytes(T_INT);

 #ifdef ASSERT

           for (int bt = T_BOOLEAN; bt < T_INT; bt++) {

             if (is_subword_type(BasicType(bt)))

               assert(value_offset == java_lang_boxing_object::value_offset_in_bytes(BasicType(bt)), "");

           }

 #endif

           __ null_check(rdx_temp, value_offset);

           __ movl(rdx_temp, Address(rdx_temp, value_offset));

           // We load this as a word.  Because we are little-endian,

           // the low bits will be correct, but the high bits may need cleaning.

           // The vminfo will guide us to clean those bits.

         }

         break;

       default:

         ShouldNotReachHere();

       }

       // Do the requested conversion and store the value.

       Register rbx_vminfo = rbx_temp;

       load_conversion_vminfo(_masm, rbx_vminfo, rcx_amh_conversion);

       // get the new MH:

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       // (now we are done with the old MH)

       // original 32-bit vmdata word must be of this form:

       //    | MBZ:6 | signBitCount:8 | srcDstTypes:8 | conversionOp:8 |

       __ xchgptr(rcx, rbx_vminfo);                // free rcx for shifts

       __ shll(rdx_temp /*, rcx*/);

       Label zero_extend, done;

       __ testl(rcx, CONV_VMINFO_SIGN_FLAG);

       __ jccb(Assembler::zero, zero_extend);

       // this path is taken for int->byte, int->short

       __ sarl(rdx_temp /*, rcx*/);

       __ jmpb(done);

       __ bind(zero_extend);

       // this is taken for int->char

       __ shrl(rdx_temp /*, rcx*/);

       __ bind(done);

       __ movl(vmarg, rdx_temp);  // Store the value.

       __ xchgptr(rcx, rbx_vminfo);                // restore rcx_recv

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_opt_i2l:        // optimized subcase of adapt_prim_to_prim

   case _adapter_opt_unboxl:     // optimized subcase of adapt_ref_to_prim

     {

       // perform an in-place int-to-long or ref-to-long conversion

       __ movl(rax_argslot, rcx_amh_vmargslot);

       // on a little-endian machine we keep the first slot and add another after

       __ lea(rax_argslot, __ argument_address(rax_argslot, 1));

       insert_arg_slots(_masm, stack_move_unit(),

                        rax_argslot, rbx_temp, rdx_temp);

       Address vmarg1(rax_argslot, -Interpreter::stackElementSize);

       Address vmarg2 = vmarg1.plus_disp(Interpreter::stackElementSize);

       switch (ek) {

       case _adapter_opt_i2l:

         {

 #ifdef _LP64

           __ movslq(rdx_temp, vmarg1);  // Load sign-extended

           __ movq(vmarg1, rdx_temp);    // Store into first slot

 #else

           __ movl(rdx_temp, vmarg1);

           __ sarl(rdx_temp, BitsPerInt - 1);  // __ extend_sign()

           __ movl(vmarg2, rdx_temp); // store second word

 #endif

         }

         break;

       case _adapter_opt_unboxl:

         {

           // Load the value up from the heap.

           __ movptr(rdx_temp, vmarg1);

           int value_offset = java_lang_boxing_object::value_offset_in_bytes(T_LONG);

           assert(value_offset == java_lang_boxing_object::value_offset_in_bytes(T_DOUBLE), "");

           __ null_check(rdx_temp, value_offset);

 #ifdef _LP64

           __ movq(rbx_temp, Address(rdx_temp, value_offset));

           __ movq(vmarg1, rbx_temp);

 #else

           __ movl(rbx_temp, Address(rdx_temp, value_offset + 0*BytesPerInt));

           __ movl(rdx_temp, Address(rdx_temp, value_offset + 1*BytesPerInt));

           __ movl(vmarg1, rbx_temp);

           __ movl(vmarg2, rdx_temp);

 #endif

         }

         break;

       default:

         ShouldNotReachHere();

       }

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_opt_f2d:        // optimized subcase of adapt_prim_to_prim

   case _adapter_opt_d2f:        // optimized subcase of adapt_prim_to_prim

     {

       // perform an in-place floating primitive conversion

       __ movl(rax_argslot, rcx_amh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot, 1));

       if (ek == _adapter_opt_f2d) {

         insert_arg_slots(_masm, stack_move_unit(),

                          rax_argslot, rbx_temp, rdx_temp);

       }

       Address vmarg(rax_argslot, -Interpreter::stackElementSize);

 #ifdef _LP64

       if (ek == _adapter_opt_f2d) {

         __ movflt(xmm0, vmarg);

         __ cvtss2sd(xmm0, xmm0);

         __ movdbl(vmarg, xmm0);

       } else {

         __ movdbl(xmm0, vmarg);

         __ cvtsd2ss(xmm0, xmm0);

         __ movflt(vmarg, xmm0);

       }

 #else //_LP64

       if (ek == _adapter_opt_f2d) {

         __ fld_s(vmarg);        // load float to ST0

         __ fstp_d(vmarg);       // store double

       } else {

         __ fld_d(vmarg);        // load double to ST0

         __ fstp_s(vmarg);       // store single

       }

 #endif //_LP64

       if (ek == _adapter_opt_d2f) {

         remove_arg_slots(_masm, -stack_move_unit(),

                          rax_argslot, rbx_temp, rdx_temp);

       }

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_swap_args:

   case _adapter_rot_args:

     // handled completely by optimized cases

     __ stop("init_AdapterMethodHandle should not issue this");

     break;

   case _adapter_opt_swap_1:

   case _adapter_opt_swap_2:

   case _adapter_opt_rot_1_up:

   case _adapter_opt_rot_1_down:

   case _adapter_opt_rot_2_up:

   case _adapter_opt_rot_2_down:

     {

       int swap_slots = ek_adapter_opt_swap_slots(ek);

       int rotate     = ek_adapter_opt_swap_mode(ek);

       // 'argslot' is the position of the first argument to swap

       __ movl(rax_argslot, rcx_amh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot));

       // 'vminfo' is the second

       Register rbx_destslot = rbx_temp;

       load_conversion_vminfo(_masm, rbx_destslot, rcx_amh_conversion);

       __ lea(rbx_destslot, __ argument_address(rbx_destslot));

       if (VerifyMethodHandles)

         verify_argslot(_masm, rbx_destslot, "swap point must fall within current frame");

       assert(Interpreter::stackElementSize == wordSize, "else rethink use of wordSize here");

       if (!rotate) {

         // simple swap

         for (int i = 0; i < swap_slots; i++) {

           __ movptr(rdi_temp, Address(rax_argslot,  i * wordSize));

           __ movptr(rdx_temp, Address(rbx_destslot, i * wordSize));

           __ movptr(Address(rax_argslot,  i * wordSize), rdx_temp);

           __ movptr(Address(rbx_destslot, i * wordSize), rdi_temp);

         }

       } else {

         // A rotate is actually pair of moves, with an "odd slot" (or pair)

         // changing place with a series of other slots.

         // First, push the "odd slot", which is going to get overwritten

         for (int i = swap_slots - 1; i >= 0; i--) {

           // handle one with rdi_temp instead of a push:

           if (i == 0)  __ movptr(rdi_temp, Address(rax_argslot, i * wordSize));

           else         __ pushptr(         Address(rax_argslot, i * wordSize));

         }

         if (rotate > 0) {

           // Here is rotate > 0:

           // (low mem)                                          (high mem)

           //     | dest:     more_slots...     | arg: odd_slot :arg+1 |

           // =>

           //     | dest: odd_slot | dest+1: more_slots...      :arg+1 |

           // work argslot down to destslot, copying contiguous data upwards

           // pseudo-code:

           //   rax = src_addr - swap_bytes

           //   rbx = dest_addr

           //   while (rax >= rbx) *(rax + swap_bytes) = *(rax + 0), rax--;

           move_arg_slots_up(_masm,

                             rbx_destslot,

                             Address(rax_argslot, 0),

                             swap_slots,

                             rax_argslot, rdx_temp);

         } else {

           // Here is the other direction, rotate < 0:

           // (low mem)                                          (high mem)

           //     | arg: odd_slot | arg+1: more_slots...       :dest+1 |

           // =>

           //     | arg:    more_slots...     | dest: odd_slot :dest+1 |

           // work argslot up to destslot, copying contiguous data downwards

           // pseudo-code:

           //   rax = src_addr + swap_bytes

           //   rbx = dest_addr

           //   while (rax <= rbx) *(rax - swap_bytes) = *(rax + 0), rax++;

           __ addptr(rbx_destslot, wordSize);

           move_arg_slots_down(_masm,

                               Address(rax_argslot, swap_slots * wordSize),

                               rbx_destslot,

                               -swap_slots,

                               rax_argslot, rdx_temp);

           __ subptr(rbx_destslot, wordSize);

         }

         // pop the original first chunk into the destination slot, now free

         for (int i = 0; i < swap_slots; i++) {

           if (i == 0)  __ movptr(Address(rbx_destslot, i * wordSize), rdi_temp);

           else         __ popptr(Address(rbx_destslot, i * wordSize));

         }

       }

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_dup_args:

     {

       // 'argslot' is the position of the first argument to duplicate

       __ movl(rax_argslot, rcx_amh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot));

       // 'stack_move' is negative number of words to duplicate

       Register rdi_stack_move = rdi_temp;

       load_stack_move(_masm, rdi_stack_move, rcx_recv, true);

       if (VerifyMethodHandles) {

         verify_argslots(_masm, rdi_stack_move, rax_argslot, true,

                         "copied argument(s) must fall within current frame");

       }

       // insert location is always the bottom of the argument list:

       Address insert_location = __ argument_address(constant(0));

       int pre_arg_words = insert_location.disp() / wordSize;   // return PC is pushed

       assert(insert_location.base() == rsp, "");

       __ negl(rdi_stack_move);

       push_arg_slots(_masm, rax_argslot, rdi_stack_move,

                      pre_arg_words, rbx_temp, rdx_temp);

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_drop_args:

     {

       // 'argslot' is the position of the first argument to nuke

       __ movl(rax_argslot, rcx_amh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot));

       // (must do previous push after argslot address is taken)

       // 'stack_move' is number of words to drop

       Register rdi_stack_move = rdi_temp;

       load_stack_move(_masm, rdi_stack_move, rcx_recv, false);

       remove_arg_slots(_masm, rdi_stack_move,

                        rax_argslot, rbx_temp, rdx_temp);

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

     }

     break;

   case _adapter_collect_args:

   case _adapter_fold_args:

   case _adapter_spread_args:

     // handled completely by optimized cases

     __ stop("init_AdapterMethodHandle should not issue this");

     break;

   case _adapter_opt_collect_ref:

   case _adapter_opt_collect_int:

   case _adapter_opt_collect_long:

   case _adapter_opt_collect_float:

   case _adapter_opt_collect_double:

   case _adapter_opt_collect_void:

   case _adapter_opt_collect_0_ref:

   case _adapter_opt_collect_1_ref:

   case _adapter_opt_collect_2_ref:

   case _adapter_opt_collect_3_ref:

   case _adapter_opt_collect_4_ref:

   case _adapter_opt_collect_5_ref:

   case _adapter_opt_filter_S0_ref:

   case _adapter_opt_filter_S1_ref:

   case _adapter_opt_filter_S2_ref:

   case _adapter_opt_filter_S3_ref:

   case _adapter_opt_filter_S4_ref:

   case _adapter_opt_filter_S5_ref:

   case _adapter_opt_collect_2_S0_ref:

   case _adapter_opt_collect_2_S1_ref:

   case _adapter_opt_collect_2_S2_ref:

   case _adapter_opt_collect_2_S3_ref:

   case _adapter_opt_collect_2_S4_ref:

   case _adapter_opt_collect_2_S5_ref:

   case _adapter_opt_fold_ref:

   case _adapter_opt_fold_int:

   case _adapter_opt_fold_long:

   case _adapter_opt_fold_float:

   case _adapter_opt_fold_double:

   case _adapter_opt_fold_void:

   case _adapter_opt_fold_1_ref:

   case _adapter_opt_fold_2_ref:

   case _adapter_opt_fold_3_ref:

   case _adapter_opt_fold_4_ref:

   case _adapter_opt_fold_5_ref:

     {

       // Given a fresh incoming stack frame, build a new ricochet frame.

       // On entry, TOS points at a return PC, and RBP is the callers frame ptr.

       // RSI/R13 has the caller's exact stack pointer, which we must also preserve.

       // RCX contains an AdapterMethodHandle of the indicated kind.

       // Relevant AMH fields:

       // amh.vmargslot:

       //   points to the trailing edge of the arguments

       //   to filter, collect, or fold.  For a boxing operation,

       //   it points just after the single primitive value.

       // amh.argument:

       //   recursively called MH, on |collect| arguments

       // amh.vmtarget:

       //   final destination MH, on return value, etc.

       // amh.conversion.dest:

       //   tells what is the type of the return value

       //   (not needed here, since dest is also derived from ek)

       // amh.conversion.vminfo:

       //   points to the trailing edge of the return value

       //   when the vmtarget is to be called; this is

       //   equal to vmargslot + (retained ? |collect| : 0)

       // Pass 0 or more argument slots to the recursive target.

       int collect_count_constant = ek_adapter_opt_collect_count(ek);

       // The collected arguments are copied from the saved argument list:

       int collect_slot_constant = ek_adapter_opt_collect_slot(ek);

       assert(ek_orig == _adapter_collect_args ||

              ek_orig == _adapter_fold_args, "");

       bool retain_original_args = (ek_orig == _adapter_fold_args);

       // The return value is replaced (or inserted) at the 'vminfo' argslot.

       // Sometimes we can compute this statically.

       int dest_slot_constant = -1;

       if (!retain_original_args)

         dest_slot_constant = collect_slot_constant;

       else if (collect_slot_constant >= 0 && collect_count_constant >= 0)

         // We are preserving all the arguments, and the return value is prepended,

         // so the return slot is to the left (above) the |collect| sequence.

         dest_slot_constant = collect_slot_constant + collect_count_constant;

       // Replace all those slots by the result of the recursive call.

       // The result type can be one of ref, int, long, float, double, void.

       // In the case of void, nothing is pushed on the stack after return.

       BasicType dest = ek_adapter_opt_collect_type(ek);

       assert(dest == type2wfield[dest], "dest is a stack slot type");

       int dest_count = type2size[dest];

       assert(dest_count == 1 || dest_count == 2 || (dest_count == 0 && dest == T_VOID), "dest has a size");

       // Choose a return continuation.

       EntryKind ek_ret = _adapter_opt_return_any;

       if (dest != T_CONFLICT && OptimizeMethodHandles) {

         switch (dest) {

         case T_INT    : ek_ret = _adapter_opt_return_int;     break;

         case T_LONG   : ek_ret = _adapter_opt_return_long;    break;

         case T_FLOAT  : ek_ret = _adapter_opt_return_float;   break;

         case T_DOUBLE : ek_ret = _adapter_opt_return_double;  break;

         case T_OBJECT : ek_ret = _adapter_opt_return_ref;     break;

         case T_VOID   : ek_ret = _adapter_opt_return_void;    break;

         default       : ShouldNotReachHere();

         }

         if (dest == T_OBJECT && dest_slot_constant >= 0) {

           EntryKind ek_try = EntryKind(_adapter_opt_return_S0_ref + dest_slot_constant);

           if (ek_try <= _adapter_opt_return_LAST &&

               ek_adapter_opt_return_slot(ek_try) == dest_slot_constant) {

             ek_ret = ek_try;

           }

         }

         assert(ek_adapter_opt_return_type(ek_ret) == dest, "");

       }

       // Already pushed:  ... keep1 | collect | keep2 | sender_pc |

       // push(sender_pc);

       // Compute argument base:

       Register rax_argv = rax_argslot;

       __ lea(rax_argv, __ argument_address(constant(0)));

       // Push a few extra argument words, if we need them to store the return value.

       {

         int extra_slots = 0;

         if (retain_original_args) {

           extra_slots = dest_count;

         } else if (collect_count_constant == -1) {

           extra_slots = dest_count;  // collect_count might be zero; be generous

         } else if (dest_count > collect_count_constant) {

           extra_slots = (dest_count - collect_count_constant);

         } else {

           // else we know we have enough dead space in |collect| to repurpose for return values

         }

         DEBUG_ONLY(extra_slots += 1);

         if (extra_slots > 0) {

           __ pop(rbx_temp);   // return value

           __ subptr(rsp, (extra_slots * Interpreter::stackElementSize));

           // Push guard word #2 in debug mode.

           DEBUG_ONLY(__ movptr(Address(rsp, 0), (int32_t) RicochetFrame::MAGIC_NUMBER_2));

           __ push(rbx_temp);

         }

       }

       RicochetFrame::enter_ricochet_frame(_masm, rcx_recv, rax_argv,

                                           entry(ek_ret)->from_interpreted_entry(), rbx_temp);

       // Now pushed:  ... keep1 | collect | keep2 | RF |

       // some handy frame slots:

       Address exact_sender_sp_addr = RicochetFrame::frame_address(RicochetFrame::exact_sender_sp_offset_in_bytes());

       Address conversion_addr      = RicochetFrame::frame_address(RicochetFrame::conversion_offset_in_bytes());

       Address saved_args_base_addr = RicochetFrame::frame_address(RicochetFrame::saved_args_base_offset_in_bytes());

 #ifdef ASSERT

       if (VerifyMethodHandles && dest != T_CONFLICT) {

         BLOCK_COMMENT("verify AMH.conv.dest");

         load_conversion_dest_type(_masm, rbx_temp, conversion_addr);

         Label L_dest_ok;

         __ cmpl(rbx_temp, (int) dest);

         __ jcc(Assembler::equal, L_dest_ok);

         if (dest == T_INT) {

           for (int bt = T_BOOLEAN; bt < T_INT; bt++) {

             if (is_subword_type(BasicType(bt))) {

               __ cmpl(rbx_temp, (int) bt);

               __ jcc(Assembler::equal, L_dest_ok);

             }

           }

         }

         __ stop("bad dest in AMH.conv");

         __ BIND(L_dest_ok);

       }

 #endif //ASSERT

       // Find out where the original copy of the recursive argument sequence begins.

       Register rax_coll = rax_argv;

       {

         RegisterOrConstant collect_slot = collect_slot_constant;

         if (collect_slot_constant == -1) {

           __ movl(rdi_temp, rcx_amh_vmargslot);

           collect_slot = rdi_temp;

         }

         if (collect_slot_constant != 0)

           __ lea(rax_coll, Address(rax_argv, collect_slot, Interpreter::stackElementScale()));

         // rax_coll now points at the trailing edge of |collect| and leading edge of |keep2|

       }

       // Replace the old AMH with the recursive MH.  (No going back now.)

       // In the case of a boxing call, the recursive call is to a 'boxer' method,

       // such as Integer.valueOf or Long.valueOf.  In the case of a filter

       // or collect call, it will take one or more arguments, transform them,

       // and return some result, to store back into argument_base[vminfo].

       __ load_heap_oop(rcx_recv, rcx_amh_argument);

       if (VerifyMethodHandles)  verify_method_handle(_masm, rcx_recv);

       // Push a space for the recursively called MH first:

       __ push((int32_t)NULL_WORD);

       // Calculate |collect|, the number of arguments we are collecting.

       Register rdi_collect_count = rdi_temp;

       RegisterOrConstant collect_count;

       if (collect_count_constant >= 0) {

         collect_count = collect_count_constant;

       } else {

         __ load_method_handle_vmslots(rdi_collect_count, rcx_recv, rdx_temp);

         collect_count = rdi_collect_count;

       }

 #ifdef ASSERT

       if (VerifyMethodHandles && collect_count_constant >= 0) {

         __ load_method_handle_vmslots(rbx_temp, rcx_recv, rdx_temp);

         Label L_count_ok;

         __ cmpl(rbx_temp, collect_count_constant);

         __ jcc(Assembler::equal, L_count_ok);

         __ stop("bad vminfo in AMH.conv");

         __ BIND(L_count_ok);

       }

 #endif //ASSERT

       // copy |collect| slots directly to TOS:

       push_arg_slots(_masm, rax_coll, collect_count, 0, rbx_temp, rdx_temp);

       // Now pushed:  ... keep1 | collect | keep2 | RF... | collect |

       // rax_coll still points at the trailing edge of |collect| and leading edge of |keep2|

       // If necessary, adjust the saved arguments to make room for the eventual return value.

       // Normal adjustment:  ... keep1 | +dest+ | -collect- | keep2 | RF... | collect |

       // If retaining args:  ... keep1 | +dest+ |  collect  | keep2 | RF... | collect |

       // In the non-retaining case, this might move keep2 either up or down.

       // We don't have to copy the whole | RF... collect | complex,

       // but we must adjust RF.saved_args_base.

       // Also, from now on, we will forget about the original copy of |collect|.

       // If we are retaining it, we will treat it as part of |keep2|.

       // For clarity we will define |keep3| = |collect|keep2| or |keep2|.

       BLOCK_COMMENT("adjust trailing arguments {");

       // Compare the sizes of |+dest+| and |-collect-|, which are opposed opening and closing movements.

       int                open_count  = dest_count;

       RegisterOrConstant close_count = collect_count_constant;

       Register rdi_close_count = rdi_collect_count;

       if (retain_original_args) {

         close_count = constant(0);

       } else if (collect_count_constant == -1) {

         close_count = rdi_collect_count;

       }

       // How many slots need moving?  This is simply dest_slot (0 => no |keep3|).

       RegisterOrConstant keep3_count;

       Register rsi_keep3_count = rsi;  // can repair from RF.exact_sender_sp

       if (dest_slot_constant >= 0) {

         keep3_count = dest_slot_constant;

       } else  {

         load_conversion_vminfo(_masm, rsi_keep3_count, conversion_addr);

         keep3_count = rsi_keep3_count;

       }

 #ifdef ASSERT

       if (VerifyMethodHandles && dest_slot_constant >= 0) {

         load_conversion_vminfo(_masm, rbx_temp, conversion_addr);

         Label L_vminfo_ok;

         __ cmpl(rbx_temp, dest_slot_constant);

         __ jcc(Assembler::equal, L_vminfo_ok);

         __ stop("bad vminfo in AMH.conv");

         __ BIND(L_vminfo_ok);

       }

 #endif //ASSERT

       // tasks remaining:

       bool move_keep3 = (!keep3_count.is_constant() || keep3_count.as_constant() != 0);

       bool stomp_dest = (NOT_DEBUG(dest == T_OBJECT) DEBUG_ONLY(dest_count != 0));

       bool fix_arg_base = (!close_count.is_constant() || open_count != close_count.as_constant());

       if (stomp_dest | fix_arg_base) {

         // we will probably need an updated rax_argv value

         if (collect_slot_constant >= 0) {

           // rax_coll already holds the leading edge of |keep2|, so tweak it

           assert(rax_coll == rax_argv, "elided a move");

           if (collect_slot_constant != 0)

             __ subptr(rax_argv, collect_slot_constant * Interpreter::stackElementSize);

         } else {

           // Just reload from RF.saved_args_base.

           __ movptr(rax_argv, saved_args_base_addr);

         }

       }

       // Old and new argument locations (based at slot 0).

       // Net shift (&new_argv - &old_argv) is (close_count - open_count).

       bool zero_open_count = (open_count == 0);  // remember this bit of info

       if (move_keep3 && fix_arg_base) {

         // It will be easier to have everything in one register:

         if (close_count.is_register()) {

           // Deduct open_count from close_count register to get a clean +/- value.

           __ subptr(close_count.as_register(), open_count);

         } else {

           close_count = close_count.as_constant() - open_count;

         }

         open_count = 0;

       }

       Address old_argv(rax_argv, 0);

       Address new_argv(rax_argv, close_count,  Interpreter::stackElementScale(),

                                 - open_count * Interpreter::stackElementSize);

       // First decide if any actual data are to be moved.

       // We can skip if (a) |keep3| is empty, or (b) the argument list size didn't change.

       // (As it happens, all movements involve an argument list size change.)

       // If there are variable parameters, use dynamic checks to skip around the whole mess.

       Label L_done;

       if (!keep3_count.is_constant()) {

         __ testl(keep3_count.as_register(), keep3_count.as_register());

         __ jcc(Assembler::zero, L_done);

       }

       if (!close_count.is_constant()) {

         __ cmpl(close_count.as_register(), open_count);

         __ jcc(Assembler::equal, L_done);

       }

       if (move_keep3 && fix_arg_base) {

         bool emit_move_down = false, emit_move_up = false, emit_guard = false;

         if (!close_count.is_constant()) {

           emit_move_down = emit_guard = !zero_open_count;

           emit_move_up   = true;

         } else if (open_count != close_count.as_constant()) {

           emit_move_down = (open_count > close_count.as_constant());

           emit_move_up   = !emit_move_down;

         }

         Label L_move_up;

         if (emit_guard) {

           __ cmpl(close_count.as_register(), open_count);

           __ jcc(Assembler::greater, L_move_up);

         }

         if (emit_move_down) {

           // Move arguments down if |+dest+| > |-collect-|

           // (This is rare, except when arguments are retained.)

           // This opens space for the return value.

           if (keep3_count.is_constant()) {

             for (int i = 0; i < keep3_count.as_constant(); i++) {

               __ movptr(rdx_temp, old_argv.plus_disp(i * Interpreter::stackElementSize));

               __ movptr(          new_argv.plus_disp(i * Interpreter::stackElementSize), rdx_temp);

             }

           } else {

             Register rbx_argv_top = rbx_temp;

             __ lea(rbx_argv_top, old_argv.plus_disp(keep3_count, Interpreter::stackElementScale()));

             move_arg_slots_down(_masm,

                                 old_argv,     // beginning of old argv

                                 rbx_argv_top, // end of old argv

                                 close_count,  // distance to move down (must be negative)

                                 rax_argv, rdx_temp);

             // Used argv as an iteration variable; reload from RF.saved_args_base.

             __ movptr(rax_argv, saved_args_base_addr);

           }

         }

         if (emit_guard) {

           __ jmp(L_done);  // assumes emit_move_up is true also

           __ BIND(L_move_up);

         }

         if (emit_move_up) {

           // Move arguments up if |+dest+| < |-collect-|

           // (This is usual, except when |keep3| is empty.)

           // This closes up the space occupied by the now-deleted collect values.

           if (keep3_count.is_constant()) {

             for (int i = keep3_count.as_constant() - 1; i >= 0; i--) {

               __ movptr(rdx_temp, old_argv.plus_disp(i * Interpreter::stackElementSize));

               __ movptr(          new_argv.plus_disp(i * Interpreter::stackElementSize), rdx_temp);

             }

           } else {

             Address argv_top = old_argv.plus_disp(keep3_count, Interpreter::stackElementScale());

             move_arg_slots_up(_masm,

                               rax_argv,     // beginning of old argv

                               argv_top,     // end of old argv

                               close_count,  // distance to move up (must be positive)

                               rbx_temp, rdx_temp);

           }

         }

       }

       __ BIND(L_done);

       if (fix_arg_base) {

         // adjust RF.saved_args_base by adding (close_count - open_count)

         if (!new_argv.is_same_address(Address(rax_argv, 0)))

           __ lea(rax_argv, new_argv);

         __ movptr(saved_args_base_addr, rax_argv);

       }

       if (stomp_dest) {

         // Stomp the return slot, so it doesn't hold garbage.

         // This isn't strictly necessary, but it may help detect bugs.

         int forty_two = RicochetFrame::RETURN_VALUE_PLACEHOLDER;

         __ movptr(Address(rax_argv, keep3_count, Address::times_ptr),

                   (int32_t) forty_two);

         // uses rsi_keep3_count

       }

       BLOCK_COMMENT("} adjust trailing arguments");

       BLOCK_COMMENT("do_recursive_call");

       __ mov(saved_last_sp, rsp);    // set rsi/r13 for callee

       __ pushptr(ExternalAddress(SharedRuntime::ricochet_blob()->bounce_addr()).addr());

       // The globally unique bounce address has two purposes:

       // 1. It helps the JVM recognize this frame (frame::is_ricochet_frame).

       // 2. When returned to, it cuts back the stack and redirects control flow

       //    to the return handler.

       // The return handler will further cut back the stack when it takes

       // down the RF.  Perhaps there is a way to streamline this further.

       // State during recursive call:

       // ... keep1 | dest | dest=42 | keep3 | RF... | collect | bounce_pc |

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

       break;

     }

   case _adapter_opt_return_ref:

   case _adapter_opt_return_int:

   case _adapter_opt_return_long:

   case _adapter_opt_return_float:

   case _adapter_opt_return_double:

   case _adapter_opt_return_void:

   case _adapter_opt_return_S0_ref:

   case _adapter_opt_return_S1_ref:

   case _adapter_opt_return_S2_ref:

   case _adapter_opt_return_S3_ref:

   case _adapter_opt_return_S4_ref:

   case _adapter_opt_return_S5_ref:

     {

       BasicType dest_type_constant = ek_adapter_opt_return_type(ek);

       int       dest_slot_constant = ek_adapter_opt_return_slot(ek);

       if (VerifyMethodHandles)  RicochetFrame::verify_clean(_masm);

       if (dest_slot_constant == -1) {

         // The current stub is a general handler for this dest_type.

         // It can be called from _adapter_opt_return_any below.

         // Stash the address in a little table.

         assert((dest_type_constant & CONV_TYPE_MASK) == dest_type_constant, "oob");

         address return_handler = __ pc();

         _adapter_return_handlers[dest_type_constant] = return_handler;

         if (dest_type_constant == T_INT) {

           // do the subword types too

           for (int bt = T_BOOLEAN; bt < T_INT; bt++) {

             if (is_subword_type(BasicType(bt)) &&

                 _adapter_return_handlers[bt] == NULL) {

               _adapter_return_handlers[bt] = return_handler;

             }

           }

         }

       }

       Register rbx_arg_base = rbx_temp;

       assert_different_registers(rax, rdx,  // possibly live return value registers

                                  rdi_temp, rbx_arg_base);

       Address conversion_addr      = RicochetFrame::frame_address(RicochetFrame::conversion_offset_in_bytes());

       Address saved_args_base_addr = RicochetFrame::frame_address(RicochetFrame::saved_args_base_offset_in_bytes());

       __ movptr(rbx_arg_base, saved_args_base_addr);

       RegisterOrConstant dest_slot = dest_slot_constant;

       if (dest_slot_constant == -1) {

         load_conversion_vminfo(_masm, rdi_temp, conversion_addr);

         dest_slot = rdi_temp;

       }

       // Store the result back into the argslot.

       // This code uses the interpreter calling sequence, in which the return value

       // is usually left in the TOS register, as defined by InterpreterMacroAssembler::pop.

       // There are certain irregularities with floating point values, which can be seen

       // in TemplateInterpreterGenerator::generate_return_entry_for.

       move_return_value(_masm, dest_type_constant, Address(rbx_arg_base, dest_slot, Interpreter::stackElementScale()));

       RicochetFrame::leave_ricochet_frame(_masm, rcx_recv, rbx_arg_base, rdx_temp);

       __ push(rdx_temp);  // repush the return PC

       // Load the final target and go.

       if (VerifyMethodHandles)  verify_method_handle(_masm, rcx_recv);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

       __ hlt(); // --------------------

       break;

     }

   case _adapter_opt_return_any:

     {

       if (VerifyMethodHandles)  RicochetFrame::verify_clean(_masm);

       Register rdi_conv = rdi_temp;

       assert_different_registers(rax, rdx,  // possibly live return value registers

                                  rdi_conv, rbx_temp);

       Address conversion_addr = RicochetFrame::frame_address(RicochetFrame::conversion_offset_in_bytes());

       load_conversion_dest_type(_masm, rdi_conv, conversion_addr);

       __ lea(rbx_temp, ExternalAddress((address) &_adapter_return_handlers[0]));

       __ movptr(rbx_temp, Address(rbx_temp, rdi_conv, Address::times_ptr));

 #ifdef ASSERT

       { Label L_badconv;

         __ testptr(rbx_temp, rbx_temp);

         __ jccb(Assembler::zero, L_badconv);

         __ jmp(rbx_temp);

         __ bind(L_badconv);

         __ stop("bad method handle return");

       }

 #else //ASSERT

       __ jmp(rbx_temp);

 #endif //ASSERT

       break;

     }

   case _adapter_opt_spread_0:

   case _adapter_opt_spread_1_ref:

   case _adapter_opt_spread_2_ref:

   case _adapter_opt_spread_3_ref:

   case _adapter_opt_spread_4_ref:

   case _adapter_opt_spread_5_ref:

   case _adapter_opt_spread_ref:

   case _adapter_opt_spread_byte:

   case _adapter_opt_spread_char:

   case _adapter_opt_spread_short:

   case _adapter_opt_spread_int:

   case _adapter_opt_spread_long:

   case _adapter_opt_spread_float:

   case _adapter_opt_spread_double:

     {

       // spread an array out into a group of arguments

       int length_constant = ek_adapter_opt_spread_count(ek);

       bool length_can_be_zero = (length_constant == 0);

       if (length_constant < 0) {

         // some adapters with variable length must handle the zero case

         if (!OptimizeMethodHandles ||

             ek_adapter_opt_spread_type(ek) != T_OBJECT)

           length_can_be_zero = true;

       }

       // find the address of the array argument

       __ movl(rax_argslot, rcx_amh_vmargslot);

       __ lea(rax_argslot, __ argument_address(rax_argslot));

       // grab another temp

       Register rsi_temp = rsi;

       { if (rsi_temp == saved_last_sp)  __ push(saved_last_sp); }

       // (preceding push must be done after argslot address is taken!)

 #define UNPUSH_RSI \

       { if (rsi_temp == saved_last_sp)  __ pop(saved_last_sp); }

       // arx_argslot points both to the array and to the first output arg

       vmarg = Address(rax_argslot, 0);

       // Get the array value.

       Register  rsi_array       = rsi_temp;

       Register  rdx_array_klass = rdx_temp;

       BasicType elem_type = ek_adapter_opt_spread_type(ek);

       int       elem_slots = type2size[elem_type];  // 1 or 2

       int       array_slots = 1;  // array is always a T_OBJECT

       int       length_offset   = arrayOopDesc::length_offset_in_bytes();

       int       elem0_offset    = arrayOopDesc::base_offset_in_bytes(elem_type);

       __ movptr(rsi_array, vmarg);

       Label L_array_is_empty, L_insert_arg_space, L_copy_args, L_args_done;

       if (length_can_be_zero) {

         // handle the null pointer case, if zero is allowed

         Label L_skip;

         if (length_constant < 0) {

           load_conversion_vminfo(_masm, rbx_temp, rcx_amh_conversion);

           __ testl(rbx_temp, rbx_temp);

           __ jcc(Assembler::notZero, L_skip);

         }

         __ testptr(rsi_array, rsi_array);

         __ jcc(Assembler::zero, L_array_is_empty);

         __ bind(L_skip);

       }

       __ null_check(rsi_array, oopDesc::klass_offset_in_bytes());

       __ load_klass(rdx_array_klass, rsi_array);

       // Check the array type.

       Register rbx_klass = rbx_temp;

       __ load_heap_oop(rbx_klass, rcx_amh_argument); // this is a Class object!

       load_klass_from_Class(_masm, rbx_klass);

       Label ok_array_klass, bad_array_klass, bad_array_length;

       __ check_klass_subtype(rdx_array_klass, rbx_klass, rdi_temp, ok_array_klass);

       // If we get here, the type check failed!

       __ jmp(bad_array_klass);

       __ BIND(ok_array_klass);

       // Check length.

       if (length_constant >= 0) {

         __ cmpl(Address(rsi_array, length_offset), length_constant);

       } else {

         Register rbx_vminfo = rbx_temp;

         load_conversion_vminfo(_masm, rbx_vminfo, rcx_amh_conversion);

         __ cmpl(rbx_vminfo, Address(rsi_array, length_offset));

       }

       __ jcc(Assembler::notEqual, bad_array_length);

       Register rdx_argslot_limit = rdx_temp;

       // Array length checks out.  Now insert any required stack slots.

       if (length_constant == -1) {

         // Form a pointer to the end of the affected region.

         __ lea(rdx_argslot_limit, Address(rax_argslot, Interpreter::stackElementSize));

         // 'stack_move' is negative number of words to insert

         // This number already accounts for elem_slots.

         Register rdi_stack_move = rdi_temp;

         load_stack_move(_masm, rdi_stack_move, rcx_recv, true);

         __ cmpptr(rdi_stack_move, 0);

         assert(stack_move_unit() < 0, "else change this comparison");

         __ jcc(Assembler::less, L_insert_arg_space);

         __ jcc(Assembler::equal, L_copy_args);

         // single argument case, with no array movement

         __ BIND(L_array_is_empty);

         remove_arg_slots(_masm, -stack_move_unit() * array_slots,

                          rax_argslot, rbx_temp, rdx_temp);

         __ jmp(L_args_done);  // no spreading to do

         __ BIND(L_insert_arg_space);

         // come here in the usual case, stack_move < 0 (2 or more spread arguments)

         Register rsi_temp = rsi_array;  // spill this

         insert_arg_slots(_masm, rdi_stack_move,

                          rax_argslot, rbx_temp, rsi_temp);

         // reload the array since rsi was killed

         // reload from rdx_argslot_limit since rax_argslot is now decremented

         __ movptr(rsi_array, Address(rdx_argslot_limit, -Interpreter::stackElementSize));

       } else if (length_constant >= 1) {

         int new_slots = (length_constant * elem_slots) - array_slots;

         insert_arg_slots(_masm, new_slots * stack_move_unit(),

                          rax_argslot, rbx_temp, rdx_temp);

       } else if (length_constant == 0) {

         __ BIND(L_array_is_empty);

         remove_arg_slots(_masm, -stack_move_unit() * array_slots,

                          rax_argslot, rbx_temp, rdx_temp);

       } else {

         ShouldNotReachHere();

       }

       // Copy from the array to the new slots.

       // Note: Stack change code preserves integrity of rax_argslot pointer.

       // So even after slot insertions, rax_argslot still points to first argument.

       // Beware:  Arguments that are shallow on the stack are deep in the array,

       // and vice versa.  So a downward-growing stack (the usual) has to be copied

       // elementwise in reverse order from the source array.

       __ BIND(L_copy_args);

       if (length_constant == -1) {

         // [rax_argslot, rdx_argslot_limit) is the area we are inserting into.

         // Array element [0] goes at rdx_argslot_limit[-wordSize].

         Register rsi_source = rsi_array;

         __ lea(rsi_source, Address(rsi_array, elem0_offset));

         Register rdx_fill_ptr = rdx_argslot_limit;

         Label loop;

         __ BIND(loop);

         __ addptr(rdx_fill_ptr, -Interpreter::stackElementSize * elem_slots);

         move_typed_arg(_masm, elem_type, true,

                        Address(rdx_fill_ptr, 0), Address(rsi_source, 0),

                        rbx_temp, rdi_temp);

         __ addptr(rsi_source, type2aelembytes(elem_type));

         __ cmpptr(rdx_fill_ptr, rax_argslot);

         __ jcc(Assembler::above, loop);

       } else if (length_constant == 0) {

         // nothing to copy

       } else {

         int elem_offset = elem0_offset;

         int slot_offset = length_constant * Interpreter::stackElementSize;

         for (int index = 0; index < length_constant; index++) {

           slot_offset -= Interpreter::stackElementSize * elem_slots;  // fill backward

           move_typed_arg(_masm, elem_type, true,

                          Address(rax_argslot, slot_offset), Address(rsi_array, elem_offset),

                          rbx_temp, rdi_temp);

           elem_offset += type2aelembytes(elem_type);

         }

       }

       __ BIND(L_args_done);

       // Arguments are spread.  Move to next method handle.

       UNPUSH_RSI;

       __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);

       __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

       __ bind(bad_array_klass);

       UNPUSH_RSI;

       assert(!vmarg.uses(rarg2_required), "must be different registers");

       __ load_heap_oop( rarg2_required, Address(rdx_array_klass, java_mirror_offset));  // required type

       __ movptr(        rarg1_actual,   vmarg);                                         // bad array

       __ movl(          rarg0_code,     (int) Bytecodes::_aaload);                      // who is complaining?

       __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));

       __ bind(bad_array_length);

       UNPUSH_RSI;

       assert(!vmarg.uses(rarg2_required), "must be different registers");

       __ mov(    rarg2_required, rcx_recv);                       // AMH requiring a certain length

       __ movptr( rarg1_actual,   vmarg);                          // bad array

       __ movl(   rarg0_code,     (int) Bytecodes::_arraylength);  // who is complaining?

       __ jump(ExternalAddress(from_interpreted_entry(_raise_exception)));

 #undef UNPUSH_RSI

       break;

     }

   default:

     // do not require all platforms to recognize all adapter types

     __ nop();

     return;

   }

   BLOCK_COMMENT(err_msg("} Entry %s", entry_name(ek)));

   __ hlt();

   address me_cookie = MethodHandleEntry::start_compiled_entry(_masm, interp_entry);

   __ unimplemented(entry_name(ek)); // %%% FIXME: NYI

   init_entry(ek, MethodHandleEntry::finish_compiled_entry(_masm, me_cookie));

 }