void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
                                        Register recv, Register method_temp,
                                        Register temp2,
                                        bool for_compiler_entry) {
  BLOCK_COMMENT("jump_to_lambda_form {");
  // This is the initial entry point of a lazy method handle.
  // After type checking, it picks up the invoker from the LambdaForm.
  assert_different_registers(recv, method_temp, temp2);
  assert(recv != noreg, "required register");
  assert(method_temp == rmethod, "required register for loading method");

  //NOT_PRODUCT({ FlagSetting fs(TraceMethodHandles, true); trace_method_handle(_masm, "LZMH"); });

  // Load the invoker, as MH -> MH.form -> LF.vmentry
  __ verify_oop(recv);
  __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())));
  __ verify_oop(method_temp);
  __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())));
  __ verify_oop(method_temp);
  // the following assumes that a Method* is normally compressed in the vmtarget field:
  __ ldr(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes())));

  if (VerifyMethodHandles && !for_compiler_entry) {
    // make sure recv is already on stack
    __ ldr(temp2, Address(method_temp, Method::const_offset()));
    __ load_sized_value(temp2,
                        Address(temp2, ConstMethod::size_of_parameters_offset()),
                        sizeof(u2), /*is_signed*/ false);
    // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
    Label L;
    __ ldr(rscratch1, __ argument_address(temp2, -1));
    __ cmp(recv, rscratch1);
    __ br(Assembler::EQ, L);
    __ ldr(r0, __ argument_address(temp2, -1));
    __ hlt(0);
    __ BIND(L);
  }

  jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
  BLOCK_COMMENT("} jump_to_lambda_form");
}
void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
  Label L;
  BLOCK_COMMENT("verify_ref_kind {");
  __ load_sized_value(temp, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes()), member_reg,
                      sizeof(u4), /*is_signed*/ false);
  // assert(sizeof(u4) == sizeof(java.lang.invoke.MemberName.flags), "");
  __ srwi( temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
  __ andi(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
  __ cmpwi(CCR1, temp, ref_kind);
  __ beq(CCR1, L);
  { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
    jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
    if (ref_kind == JVM_REF_invokeVirtual ||
        ref_kind == JVM_REF_invokeSpecial)
      // could do this for all ref_kinds, but would explode assembly code size
      trace_method_handle(_masm, buf);
    __ stop(buf);
  }
  BLOCK_COMMENT("} verify_ref_kind");
  __ BIND(L);
}
void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
                                        Register recv, Register method_temp,
                                        Register temp2, Register temp3,
                                        bool for_compiler_entry) {
  BLOCK_COMMENT("jump_to_lambda_form {");
  // This is the initial entry point of a lazy method handle.
  // After type checking, it picks up the invoker from the LambdaForm.
  assert_different_registers(recv, method_temp, temp2);  // temp3 is only passed on
  assert(method_temp == R19_method, "required register for loading method");

  // Load the invoker, as MH -> MH.form -> LF.vmentry
  __ verify_oop(recv);
  __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes()), recv, temp2);
  __ verify_oop(method_temp);
  __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes()), method_temp, temp2);
  __ verify_oop(method_temp);
  // The following assumes that a Method* is normally compressed in the vmtarget field:
  __ ld(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), method_temp);

  if (VerifyMethodHandles && !for_compiler_entry) {
    // Make sure recv is already on stack.
    __ ld(temp2, in_bytes(Method::const_offset()), method_temp);
    __ load_sized_value(temp2, in_bytes(ConstMethod::size_of_parameters_offset()), temp2,
                        sizeof(u2), /*is_signed*/ false);
    // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
    Label L;
    __ ld(temp2, __ argument_offset(temp2, temp2, 0), CC_INTERP_ONLY(R17_tos) NOT_CC_INTERP(R15_esp));
    __ cmpd(CCR1, temp2, recv);
    __ beq(CCR1, L);
    __ stop("receiver not on stack");
    __ BIND(L);
  }

  jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry);
  BLOCK_COMMENT("} jump_to_lambda_form");
}
// Code generation
address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
                                                                vmIntrinsics::ID iid) {
  const bool not_for_compiler_entry = false;  // this is the interpreter entry
  assert(is_signature_polymorphic(iid), "expected invoke iid");
  if (iid == vmIntrinsics::_invokeGeneric ||
      iid == vmIntrinsics::_compiledLambdaForm) {
    // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
    // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
    // They all allow an appendix argument.
    __ stop("Should not reach here");           // empty stubs make SG sick
    return NULL;
  }

  Register argbase    = CC_INTERP_ONLY(R17_tos) NOT_CC_INTERP(R15_esp); // parameter (preserved)
  Register argslot    = R3;
  Register temp1      = R6;
  Register param_size = R7;

  // here's where control starts out:
  __ align(CodeEntryAlignment);
  address entry_point = __ pc();

  if (VerifyMethodHandles) {
    Label L;
    BLOCK_COMMENT("verify_intrinsic_id {");
    __ load_sized_value(temp1, Method::intrinsic_id_offset_in_bytes(), R19_method,
                        sizeof(u1), /*is_signed*/ false);
    // assert(sizeof(u1) == sizeof(Method::_intrinsic_id), "");
    __ cmpwi(CCR1, temp1, (int) iid);
    __ beq(CCR1, L);
    if (iid == vmIntrinsics::_linkToVirtual ||
        iid == vmIntrinsics::_linkToSpecial) {
      // could do this for all kinds, but would explode assembly code size
      trace_method_handle(_masm, "bad Method*:intrinsic_id");
    }
    __ stop("bad Method*::intrinsic_id");
    __ BIND(L);
    BLOCK_COMMENT("} verify_intrinsic_id");
  }

  // First task:  Find out how big the argument list is.
  int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
  assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
  if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
    __ ld(param_size, in_bytes(Method::const_offset()), R19_method);
    __ load_sized_value(param_size, in_bytes(ConstMethod::size_of_parameters_offset()), param_size,
                        sizeof(u2), /*is_signed*/ false);
    // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
  } else {
    DEBUG_ONLY(param_size = noreg);
  }

  Register tmp_mh = noreg;
  if (!is_signature_polymorphic_static(iid)) {
    __ ld(tmp_mh = temp1, __ argument_offset(param_size, param_size, 0), argbase);
    DEBUG_ONLY(param_size = noreg);
  }

  if (TraceMethodHandles) {
    if (tmp_mh != noreg) {
      __ mr(R23_method_handle, tmp_mh);  // make stub happy
    }
    trace_method_handle_interpreter_entry(_masm, iid);
  }

  if (iid == vmIntrinsics::_invokeBasic) {
    generate_method_handle_dispatch(_masm, iid, tmp_mh, noreg, not_for_compiler_entry);

  } else {
    // Adjust argument list by popping the trailing MemberName argument.
    Register tmp_recv = noreg;
    if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
      // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
      __ ld(tmp_recv = temp1, __ argument_offset(param_size, param_size, 0), argbase);
      DEBUG_ONLY(param_size = noreg);
    }
    Register R19_member = R19_method;  // MemberName ptr; incoming method ptr is dead now
    __ ld(R19_member, RegisterOrConstant((intptr_t)8), argbase);
    __ add(argbase, Interpreter::stackElementSize, argbase);
    generate_method_handle_dispatch(_masm, iid, tmp_recv, R19_member, not_for_compiler_entry);
  }

  return entry_point;
}
// Code generation
address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
                                                                vmIntrinsics::ID iid) {
  const bool not_for_compiler_entry = false;  // this is the interpreter entry
  assert(is_signature_polymorphic(iid), "expected invoke iid");
  if (iid == vmIntrinsics::_invokeGeneric ||
      iid == vmIntrinsics::_compiledLambdaForm) {
    // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
    // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
    // They all allow an appendix argument.
    __ hlt(0);           // empty stubs make SG sick
    return NULL;
  }

  // r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
  // rmethod: Method*
  // r3: argument locator (parameter slot count, added to rsp)
  // r1: used as temp to hold mh or receiver
  // r0, r11: garbage temps, blown away
  Register argp   = r3;   // argument list ptr, live on error paths
  Register temp   = r0;
  Register mh     = r1;   // MH receiver; dies quickly and is recycled

  // here's where control starts out:
  __ align(CodeEntryAlignment);
  address entry_point = __ pc();

  if (VerifyMethodHandles) {
    assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");

    Label L;
    BLOCK_COMMENT("verify_intrinsic_id {");
    __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset_in_bytes()));
    __ cmp(rscratch1, (int) iid);
    __ br(Assembler::EQ, L);
    if (iid == vmIntrinsics::_linkToVirtual ||
        iid == vmIntrinsics::_linkToSpecial) {
      // could do this for all kinds, but would explode assembly code size
      trace_method_handle(_masm, "bad Method*::intrinsic_id");
    }
    __ hlt(0);
    __ bind(L);
    BLOCK_COMMENT("} verify_intrinsic_id");
  }

  // First task:  Find out how big the argument list is.
  Address r3_first_arg_addr;
  int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
  assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
  if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
    __ ldr(argp, Address(rmethod, Method::const_offset()));
    __ load_sized_value(argp,
                        Address(argp, ConstMethod::size_of_parameters_offset()),
                        sizeof(u2), /*is_signed*/ false);
    // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
    r3_first_arg_addr = __ argument_address(argp, -1);
  } else {
    DEBUG_ONLY(argp = noreg);
  }

  if (!is_signature_polymorphic_static(iid)) {
    __ ldr(mh, r3_first_arg_addr);
    DEBUG_ONLY(argp = noreg);
  }

  // r3_first_arg_addr is live!

  trace_method_handle_interpreter_entry(_masm, iid);
  if (iid == vmIntrinsics::_invokeBasic) {
    generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);

  } else {
    // Adjust argument list by popping the trailing MemberName argument.
    Register recv = noreg;
    if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
      // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
      __ ldr(recv = r2, r3_first_arg_addr);
    }
    DEBUG_ONLY(argp = noreg);
    Register rmember = rmethod;  // MemberName ptr; incoming method ptr is dead now
    __ pop(rmember);             // extract last argument
    generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
  }

  return entry_point;
}
Exemple #6
0
//------------------------------------------------------------------------------
// 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) {
  // 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;

  // 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 = LP64_ONLY(r13) NOT_LP64(rsi);

  // 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;
  }

  address interp_entry = __ pc();

  trace_method_handle(_masm, entry_name(ek));

  BLOCK_COMMENT(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 rdi_temp   = rdi;
      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:
    {
      bool direct_to_method = (ek >= _bound_ref_direct_mh);
      BasicType arg_type  = T_ILLEGAL;
      int       arg_mask  = _INSERT_NO_MASK;
      int       arg_slots = -1;
      get_ek_bound_mh_info(ek, arg_type, arg_mask, arg_slots);

      // 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(), arg_mask, 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));
        const int arg_size = type2aelembytes(arg_type);
        __ load_sized_value(rdx_temp, prim_value_addr, arg_size, is_signed_subword_type(arg_type), rbx_temp);
        __ store_sized_value(Address(rax_argslot, 0), rdx_temp, arg_size, rbx_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_heap_oop(rbx_klass, Address(rbx_klass, java_lang_Class::klass_offset_in_bytes()));

      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:
    // 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;
      __ movl(rbx_vminfo, rcx_amh_conversion);
      assert(CONV_VMINFO_SHIFT == 0, "preshifted");

      // 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(), _INSERT_INT_MASK,
                       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(), _INSERT_INT_MASK,
                         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_s(vmarg);       // store single
      } 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_prim_to_ref:
    __ unimplemented(entry_name(ek)); // %%% FIXME: NYI
    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_bytes = 0, rotate = 0;
      get_ek_adapter_opt_swap_rot_info(ek, swap_bytes, rotate);

      // '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;
      __ movl(rbx_destslot, rcx_amh_conversion);
      assert(CONV_VMINFO_SHIFT == 0, "preshifted");
      __ andl(rbx_destslot, CONV_VMINFO_MASK);
      __ lea(rbx_destslot, __ argument_address(rbx_destslot));
      DEBUG_ONLY(verify_argslot(_masm, rbx_destslot, "swap point must fall within current frame"));

      if (!rotate) {
        for (int i = 0; i < swap_bytes; i += wordSize) {
          __ movptr(rdx_temp, Address(rax_argslot , i));
          __ push(rdx_temp);
          __ movptr(rdx_temp, Address(rbx_destslot, i));
          __ movptr(Address(rax_argslot, i), rdx_temp);
          __ pop(rdx_temp);
          __ movptr(Address(rbx_destslot, i), rdx_temp);
        }
      } else {
        // push the first chunk, which is going to get overwritten
        for (int i = swap_bytes; (i -= wordSize) >= 0; ) {
          __ movptr(rdx_temp, Address(rax_argslot, i));
          __ push(rdx_temp);
        }

        if (rotate > 0) {
          // rotate upward
          __ subptr(rax_argslot, swap_bytes);
#ifdef ASSERT
          {
            // Verify that argslot > destslot, by at least swap_bytes.
            Label L_ok;
            __ cmpptr(rax_argslot, rbx_destslot);
            __ jccb(Assembler::aboveEqual, L_ok);
            __ stop("source must be above destination (upward rotation)");
            __ bind(L_ok);
          }
#endif
          // 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--;
          Label loop;
          __ bind(loop);
          __ movptr(rdx_temp, Address(rax_argslot, 0));
          __ movptr(Address(rax_argslot, swap_bytes), rdx_temp);
          __ addptr(rax_argslot, -wordSize);
          __ cmpptr(rax_argslot, rbx_destslot);
          __ jccb(Assembler::aboveEqual, loop);
        } else {
          __ addptr(rax_argslot, swap_bytes);
#ifdef ASSERT
          {
            // Verify that argslot < destslot, by at least swap_bytes.
            Label L_ok;
            __ cmpptr(rax_argslot, rbx_destslot);
            __ jccb(Assembler::belowEqual, L_ok);
            __ stop("source must be below destination (downward rotation)");
            __ bind(L_ok);
          }
#endif
          // 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++;
          Label loop;
          __ bind(loop);
          __ movptr(rdx_temp, Address(rax_argslot, 0));
          __ movptr(Address(rax_argslot, -swap_bytes), rdx_temp);
          __ addptr(rax_argslot, wordSize);
          __ cmpptr(rax_argslot, rbx_destslot);
          __ jccb(Assembler::belowEqual, loop);
        }

        // pop the original first chunk into the destination slot, now free
        for (int i = 0; i < swap_bytes; i += wordSize) {
          __ pop(rdx_temp);
          __ movptr(Address(rbx_destslot, i), rdx_temp);
        }
      }

      __ 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 rdx_stack_move = rdx_temp;
      __ movl2ptr(rdx_stack_move, rcx_amh_conversion);
      __ sarptr(rdx_stack_move, CONV_STACK_MOVE_SHIFT);

      int argslot0_num = 0;
      Address argslot0 = __ argument_address(RegisterOrConstant(argslot0_num));
      assert(argslot0.base() == rsp, "");
      int pre_arg_size = argslot0.disp();
      assert(pre_arg_size % wordSize == 0, "");
      assert(pre_arg_size > 0, "must include PC");

      // remember the old rsp+1 (argslot[0])
      Register rbx_oldarg = rbx_temp;
      __ lea(rbx_oldarg, argslot0);

      // move rsp down to make room for dups
      __ lea(rsp, Address(rsp, rdx_stack_move, Address::times_ptr));

      // compute the new rsp+1 (argslot[0])
      Register rdx_newarg = rdx_temp;
      __ lea(rdx_newarg, argslot0);

      __ push(rdi);             // need a temp
      // (preceding push must be done after arg addresses are taken!)

      // pull down the pre_arg_size data (PC)
      for (int i = -pre_arg_size; i < 0; i += wordSize) {
        __ movptr(rdi, Address(rbx_oldarg, i));
        __ movptr(Address(rdx_newarg, i), rdi);
      }

      // copy from rax_argslot[0...] down to new_rsp[1...]
      // pseudo-code:
      //   rbx = old_rsp+1
      //   rdx = new_rsp+1
      //   rax = argslot
      //   while (rdx < rbx) *rdx++ = *rax++
      Label loop;
      __ bind(loop);
      __ movptr(rdi, Address(rax_argslot, 0));
      __ movptr(Address(rdx_newarg, 0), rdi);
      __ addptr(rax_argslot, wordSize);
      __ addptr(rdx_newarg, wordSize);
      __ cmpptr(rdx_newarg, rbx_oldarg);
      __ jccb(Assembler::less, loop);

      __ pop(rdi);              // restore 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));

      __ push(rdi);             // need a temp
      // (must do previous push after argslot address is taken)

      // 'stack_move' is number of words to drop
      Register rdi_stack_move = rdi;
      __ movl2ptr(rdi_stack_move, rcx_amh_conversion);
      __ sarptr(rdi_stack_move, CONV_STACK_MOVE_SHIFT);
      remove_arg_slots(_masm, rdi_stack_move,
                       rax_argslot, rbx_temp, rdx_temp);

      __ pop(rdi);              // restore temp

      __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);
      __ jump_to_method_handle_entry(rcx_recv, rdx_temp);
    }
    break;

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

  case _adapter_spread_args:
    // handled completely by optimized cases
    __ stop("init_AdapterMethodHandle should not issue this");
    break;

  case _adapter_opt_spread_0:
  case _adapter_opt_spread_1:
  case _adapter_opt_spread_more:
    {
      // spread an array out into a group of arguments
      int length_constant = get_ek_adapter_opt_spread_info(ek);

      // find the address of the array argument
      __ movl(rax_argslot, rcx_amh_vmargslot);
      __ lea(rax_argslot, __ argument_address(rax_argslot));

      // grab some temps
      { __ push(rsi); __ push(rdi); }
      // (preceding pushes must be done after argslot address is taken!)
#define UNPUSH_RSI_RDI \
      { __ pop(rdi); __ pop(rsi); }

      // 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;
      Register  rdx_array_klass = rdx_temp;
      BasicType elem_type       = 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 skip_array_check;
      if (length_constant == 0) {
        __ testptr(rsi_array, rsi_array);
        __ jcc(Assembler::zero, skip_array_check);
      }
      __ 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_heap_oop(rbx_klass, Address(rbx_klass, java_lang_Class::klass_offset_in_bytes()));

      Label ok_array_klass, bad_array_klass, bad_array_length;
      __ check_klass_subtype(rdx_array_klass, rbx_klass, rdi, 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;
        __ movl(rbx_vminfo, rcx_amh_conversion);
        assert(CONV_VMINFO_SHIFT == 0, "preshifted");
        __ andl(rbx_vminfo, CONV_VMINFO_MASK);
        __ 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
        Register rdi_stack_move = rdi;
        __ movl2ptr(rdi_stack_move, rcx_amh_conversion);
        __ sarptr(rdi_stack_move, CONV_STACK_MOVE_SHIFT);
        Register rsi_temp = rsi_array;  // spill this
        insert_arg_slots(_masm, rdi_stack_move, -1,
                         rax_argslot, rbx_temp, rsi_temp);
        // reload the array (since rsi was killed)
        __ movptr(rsi_array, vmarg);
      } else if (length_constant > 1) {
        int arg_mask = 0;
        int new_slots = (length_constant - 1);
        for (int i = 0; i < new_slots; i++) {
          arg_mask <<= 1;
          arg_mask |= _INSERT_REF_MASK;
        }
        insert_arg_slots(_masm, new_slots * stack_move_unit(), arg_mask,
                         rax_argslot, rbx_temp, rdx_temp);
      } else if (length_constant == 1) {
        // no stack resizing required
      } else if (length_constant == 0) {
        remove_arg_slots(_masm, -stack_move_unit(),
                         rax_argslot, rbx_temp, rdx_temp);
      }

      // 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.
      if (length_constant == -1) {
        // [rax_argslot, rdx_argslot_limit) is the area we are inserting into.
        Register rsi_source = rsi_array;
        __ lea(rsi_source, Address(rsi_array, elem0_offset));
        Label loop;
        __ bind(loop);
        __ movptr(rbx_temp, Address(rsi_source, 0));
        __ movptr(Address(rax_argslot, 0), rbx_temp);
        __ addptr(rsi_source, type2aelembytes(elem_type));
        __ addptr(rax_argslot, Interpreter::stackElementSize);
        __ cmpptr(rax_argslot, rdx_argslot_limit);
        __ jccb(Assembler::less, loop);
      } else if (length_constant == 0) {
        __ bind(skip_array_check);
        // nothing to copy
      } else {
        int elem_offset = elem0_offset;
        int slot_offset = 0;
        for (int index = 0; index < length_constant; index++) {
          __ movptr(rbx_temp, Address(rsi_array, elem_offset));
          __ movptr(Address(rax_argslot, slot_offset), rbx_temp);
          elem_offset += type2aelembytes(elem_type);
           slot_offset += Interpreter::stackElementSize;
        }
      }

      // Arguments are spread.  Move to next method handle.
      UNPUSH_RSI_RDI;
      __ load_heap_oop(rcx_recv, rcx_mh_vmtarget);
      __ jump_to_method_handle_entry(rcx_recv, rdx_temp);

      __ bind(bad_array_klass);
      UNPUSH_RSI_RDI;
      assert(!vmarg.uses(rarg2_required), "must be different registers");
      __ movptr(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_RDI;
      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_RDI
    }
    break;

  case _adapter_flyby:
  case _adapter_ricochet:
    __ unimplemented(entry_name(ek)); // %%% FIXME: NYI
    break;

  default:  ShouldNotReachHere();
  }
  __ 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));
}