view src/cpu/x86/vm/cppInterpreter_x86.cpp @ 2346:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents 638119ce7cfd
children 3d2ab563047a
line wrap: on
line source
/*
 * Copyright (c) 2007, 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 "asm/assembler.hpp"
#include "interpreter/bytecodeHistogram.hpp"
#include "interpreter/cppInterpreter.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/interpreterGenerator.hpp"
#include "interpreter/interpreterRuntime.hpp"
#include "oops/arrayOop.hpp"
#include "oops/methodDataOop.hpp"
#include "oops/methodOop.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/jvmtiThreadState.hpp"
#include "runtime/arguments.hpp"
#include "runtime/deoptimization.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/interfaceSupport.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/synchronizer.hpp"
#include "runtime/timer.hpp"
#include "runtime/vframeArray.hpp"
#include "utilities/debug.hpp"
#ifdef SHARK
#include "shark/shark_globals.hpp"
#endif

#ifdef CC_INTERP

// Routine exists to make tracebacks look decent in debugger
// while we are recursed in the frame manager/c++ interpreter.
// We could use an address in the frame manager but having
// frames look natural in the debugger is a plus.
extern "C" void RecursiveInterpreterActivation(interpreterState istate )
{
  //
  ShouldNotReachHere();
}


#define __ _masm->
#define STATE(field_name) (Address(state, byte_offset_of(BytecodeInterpreter, field_name)))

Label fast_accessor_slow_entry_path;  // fast accessor methods need to be able to jmp to unsynchronized
                                      // c++ interpreter entry point this holds that entry point label.

// default registers for state and sender_sp
// state and sender_sp are the same on 32bit because we have no choice.
// state could be rsi on 64bit but it is an arg reg and not callee save
// so r13 is better choice.

const Register state = NOT_LP64(rsi) LP64_ONLY(r13);
const Register sender_sp_on_entry = NOT_LP64(rsi) LP64_ONLY(r13);

// NEEDED for JVMTI?
// address AbstractInterpreter::_remove_activation_preserving_args_entry;

static address unctrap_frame_manager_entry  = NULL;

static address deopt_frame_manager_return_atos  = NULL;
static address deopt_frame_manager_return_btos  = NULL;
static address deopt_frame_manager_return_itos  = NULL;
static address deopt_frame_manager_return_ltos  = NULL;
static address deopt_frame_manager_return_ftos  = NULL;
static address deopt_frame_manager_return_dtos  = NULL;
static address deopt_frame_manager_return_vtos  = NULL;

int AbstractInterpreter::BasicType_as_index(BasicType type) {
  int i = 0;
  switch (type) {
    case T_BOOLEAN: i = 0; break;
    case T_CHAR   : i = 1; break;
    case T_BYTE   : i = 2; break;
    case T_SHORT  : i = 3; break;
    case T_INT    : i = 4; break;
    case T_VOID   : i = 5; break;
    case T_FLOAT  : i = 8; break;
    case T_LONG   : i = 9; break;
    case T_DOUBLE : i = 6; break;
    case T_OBJECT : // fall through
    case T_ARRAY  : i = 7; break;
    default       : ShouldNotReachHere();
  }
  assert(0 <= i && i < AbstractInterpreter::number_of_result_handlers, "index out of bounds");
  return i;
}

// Is this pc anywhere within code owned by the interpreter?
// This only works for pc that might possibly be exposed to frame
// walkers. It clearly misses all of the actual c++ interpreter
// implementation
bool CppInterpreter::contains(address pc)            {
    return (_code->contains(pc) ||
            pc == CAST_FROM_FN_PTR(address, RecursiveInterpreterActivation));
}


address CppInterpreterGenerator::generate_result_handler_for(BasicType type) {
  address entry = __ pc();
  switch (type) {
    case T_BOOLEAN: __ c2bool(rax);            break;
    case T_CHAR   : __ andl(rax, 0xFFFF);      break;
    case T_BYTE   : __ sign_extend_byte (rax); break;
    case T_SHORT  : __ sign_extend_short(rax); break;
    case T_VOID   : // fall thru
    case T_LONG   : // fall thru
    case T_INT    : /* nothing to do */        break;

    case T_DOUBLE :
    case T_FLOAT  :
      {
        const Register t = InterpreterRuntime::SignatureHandlerGenerator::temp();
        __ pop(t);                            // remove return address first
        // Must return a result for interpreter or compiler. In SSE
        // mode, results are returned in xmm0 and the FPU stack must
        // be empty.
        if (type == T_FLOAT && UseSSE >= 1) {
#ifndef _LP64
          // Load ST0
          __ fld_d(Address(rsp, 0));
          // Store as float and empty fpu stack
          __ fstp_s(Address(rsp, 0));
#endif // !_LP64
          // and reload
          __ movflt(xmm0, Address(rsp, 0));
        } else if (type == T_DOUBLE && UseSSE >= 2 ) {
          __ movdbl(xmm0, Address(rsp, 0));
        } else {
          // restore ST0
          __ fld_d(Address(rsp, 0));
        }
        // and pop the temp
        __ addptr(rsp, 2 * wordSize);
        __ push(t);                            // restore return address
      }
      break;
    case T_OBJECT :
      // retrieve result from frame
      __ movptr(rax, STATE(_oop_temp));
      // and verify it
      __ verify_oop(rax);
      break;
    default       : ShouldNotReachHere();
  }
  __ ret(0);                                   // return from result handler
  return entry;
}

// tosca based result to c++ interpreter stack based result.
// Result goes to top of native stack.

#undef EXTEND  // SHOULD NOT BE NEEDED
address CppInterpreterGenerator::generate_tosca_to_stack_converter(BasicType type) {
  // A result is in the tosca (abi result) from either a native method call or compiled
  // code. Place this result on the java expression stack so C++ interpreter can use it.
  address entry = __ pc();

  const Register t = InterpreterRuntime::SignatureHandlerGenerator::temp();
  __ pop(t);                            // remove return address first
  switch (type) {
    case T_VOID:
       break;
    case T_BOOLEAN:
#ifdef EXTEND
      __ c2bool(rax);
#endif
      __ push(rax);
      break;
    case T_CHAR   :
#ifdef EXTEND
      __ andl(rax, 0xFFFF);
#endif
      __ push(rax);
      break;
    case T_BYTE   :
#ifdef EXTEND
      __ sign_extend_byte (rax);
#endif
      __ push(rax);
      break;
    case T_SHORT  :
#ifdef EXTEND
      __ sign_extend_short(rax);
#endif
      __ push(rax);
      break;
    case T_LONG    :
      __ push(rdx);                             // pushes useless junk on 64bit
      __ push(rax);
      break;
    case T_INT    :
      __ push(rax);
      break;
    case T_FLOAT  :
      // Result is in ST(0)/xmm0
      __ subptr(rsp, wordSize);
      if ( UseSSE < 1) {
        __ fstp_s(Address(rsp, 0));
      } else {
        __ movflt(Address(rsp, 0), xmm0);
      }
      break;
    case T_DOUBLE  :
      __ subptr(rsp, 2*wordSize);
      if ( UseSSE < 2 ) {
        __ fstp_d(Address(rsp, 0));
      } else {
        __ movdbl(Address(rsp, 0), xmm0);
      }
      break;
    case T_OBJECT :
      __ verify_oop(rax);                      // verify it
      __ push(rax);
      break;
    default       : ShouldNotReachHere();
  }
  __ jmp(t);                                   // return from result handler
  return entry;
}

address CppInterpreterGenerator::generate_stack_to_stack_converter(BasicType type) {
  // A result is in the java expression stack of the interpreted method that has just
  // returned. Place this result on the java expression stack of the caller.
  //
  // The current interpreter activation in rsi/r13 is for the method just returning its
  // result. So we know that the result of this method is on the top of the current
  // execution stack (which is pre-pushed) and will be return to the top of the caller
  // stack. The top of the callers stack is the bottom of the locals of the current
  // activation.
  // Because of the way activation are managed by the frame manager the value of rsp is
  // below both the stack top of the current activation and naturally the stack top
  // of the calling activation. This enable this routine to leave the return address
  // to the frame manager on the stack and do a vanilla return.
  //
  // On entry: rsi/r13 - interpreter state of activation returning a (potential) result
  // On Return: rsi/r13 - unchanged
  //            rax - new stack top for caller activation (i.e. activation in _prev_link)
  //
  // Can destroy rdx, rcx.
  //

  address entry = __ pc();
  const Register t = InterpreterRuntime::SignatureHandlerGenerator::temp();
  switch (type) {
    case T_VOID:
      __ movptr(rax, STATE(_locals));                                   // pop parameters get new stack value
      __ addptr(rax, wordSize);                                         // account for prepush before we return
      break;
    case T_FLOAT  :
    case T_BOOLEAN:
    case T_CHAR   :
    case T_BYTE   :
    case T_SHORT  :
    case T_INT    :
      // 1 word result
      __ movptr(rdx, STATE(_stack));
      __ movptr(rax, STATE(_locals));                                   // address for result
      __ movl(rdx, Address(rdx, wordSize));                             // get result
      __ movptr(Address(rax, 0), rdx);                                  // and store it
      break;
    case T_LONG    :
    case T_DOUBLE  :
      // return top two words on current expression stack to caller's expression stack
      // The caller's expression stack is adjacent to the current frame manager's intepretState
      // except we allocated one extra word for this intepretState so we won't overwrite it
      // when we return a two word result.

      __ movptr(rax, STATE(_locals));                                   // address for result
      __ movptr(rcx, STATE(_stack));
      __ subptr(rax, wordSize);                                         // need addition word besides locals[0]
      __ movptr(rdx, Address(rcx, 2*wordSize));                         // get result word (junk in 64bit)
      __ movptr(Address(rax, wordSize), rdx);                           // and store it
      __ movptr(rdx, Address(rcx, wordSize));                           // get result word
      __ movptr(Address(rax, 0), rdx);                                  // and store it
      break;
    case T_OBJECT :
      __ movptr(rdx, STATE(_stack));
      __ movptr(rax, STATE(_locals));                                   // address for result
      __ movptr(rdx, Address(rdx, wordSize));                           // get result
      __ verify_oop(rdx);                                               // verify it
      __ movptr(Address(rax, 0), rdx);                                  // and store it
      break;
    default       : ShouldNotReachHere();
  }
  __ ret(0);
  return entry;
}

address CppInterpreterGenerator::generate_stack_to_native_abi_converter(BasicType type) {
  // A result is in the java expression stack of the interpreted method that has just
  // returned. Place this result in the native abi that the caller expects.
  //
  // Similar to generate_stack_to_stack_converter above. Called at a similar time from the
  // frame manager execept in this situation the caller is native code (c1/c2/call_stub)
  // and so rather than return result onto caller's java expression stack we return the
  // result in the expected location based on the native abi.
  // On entry: rsi/r13 - interpreter state of activation returning a (potential) result
  // On Return: rsi/r13 - unchanged
  // Other registers changed [rax/rdx/ST(0) as needed for the result returned]

  address entry = __ pc();
  switch (type) {
    case T_VOID:
       break;
    case T_BOOLEAN:
    case T_CHAR   :
    case T_BYTE   :
    case T_SHORT  :
    case T_INT    :
      __ movptr(rdx, STATE(_stack));                                    // get top of stack
      __ movl(rax, Address(rdx, wordSize));                             // get result word 1
      break;
    case T_LONG    :
      __ movptr(rdx, STATE(_stack));                                    // get top of stack
      __ movptr(rax, Address(rdx, wordSize));                           // get result low word
      NOT_LP64(__ movl(rdx, Address(rdx, 2*wordSize));)                 // get result high word
      break;
    case T_FLOAT  :
      __ movptr(rdx, STATE(_stack));                                    // get top of stack
      if ( UseSSE >= 1) {
        __ movflt(xmm0, Address(rdx, wordSize));
      } else {
        __ fld_s(Address(rdx, wordSize));                               // pushd float result
      }
      break;
    case T_DOUBLE  :
      __ movptr(rdx, STATE(_stack));                                    // get top of stack
      if ( UseSSE > 1) {
        __ movdbl(xmm0, Address(rdx, wordSize));
      } else {
        __ fld_d(Address(rdx, wordSize));                               // push double result
      }
      break;
    case T_OBJECT :
      __ movptr(rdx, STATE(_stack));                                    // get top of stack
      __ movptr(rax, Address(rdx, wordSize));                           // get result word 1
      __ verify_oop(rax);                                               // verify it
      break;
    default       : ShouldNotReachHere();
  }
  __ ret(0);
  return entry;
}

address CppInterpreter::return_entry(TosState state, int length) {
  // make it look good in the debugger
  return CAST_FROM_FN_PTR(address, RecursiveInterpreterActivation);
}

address CppInterpreter::deopt_entry(TosState state, int length) {
  address ret = NULL;
  if (length != 0) {
    switch (state) {
      case atos: ret = deopt_frame_manager_return_atos; break;
      case btos: ret = deopt_frame_manager_return_btos; break;
      case ctos:
      case stos:
      case itos: ret = deopt_frame_manager_return_itos; break;
      case ltos: ret = deopt_frame_manager_return_ltos; break;
      case ftos: ret = deopt_frame_manager_return_ftos; break;
      case dtos: ret = deopt_frame_manager_return_dtos; break;
      case vtos: ret = deopt_frame_manager_return_vtos; break;
    }
  } else {
    ret = unctrap_frame_manager_entry;  // re-execute the bytecode ( e.g. uncommon trap)
  }
  assert(ret != NULL, "Not initialized");
  return ret;
}

// C++ Interpreter
void CppInterpreterGenerator::generate_compute_interpreter_state(const Register state,
                                                                 const Register locals,
                                                                 const Register sender_sp,
                                                                 bool native) {

  // On entry the "locals" argument points to locals[0] (or where it would be in case no locals in
  // a static method). "state" contains any previous frame manager state which we must save a link
  // to in the newly generated state object. On return "state" is a pointer to the newly allocated
  // state object. We must allocate and initialize a new interpretState object and the method
  // expression stack. Because the returned result (if any) of the method will be placed on the caller's
  // expression stack and this will overlap with locals[0] (and locals[1] if double/long) we must
  // be sure to leave space on the caller's stack so that this result will not overwrite values when
  // locals[0] and locals[1] do not exist (and in fact are return address and saved rbp). So when
  // we are non-native we in essence ensure that locals[0-1] exist. We play an extra trick in
  // non-product builds and initialize this last local with the previous interpreterState as
  // this makes things look real nice in the debugger.

  // State on entry
  // Assumes locals == &locals[0]
  // Assumes state == any previous frame manager state (assuming call path from c++ interpreter)
  // Assumes rax = return address
  // rcx == senders_sp
  // rbx == method
  // Modifies rcx, rdx, rax
  // Returns:
  // state == address of new interpreterState
  // rsp == bottom of method's expression stack.

  const Address const_offset      (rbx, methodOopDesc::const_offset());


  // On entry sp is the sender's sp. This includes the space for the arguments
  // that the sender pushed. If the sender pushed no args (a static) and the
  // caller returns a long then we need two words on the sender's stack which
  // are not present (although when we return a restore full size stack the
  // space will be present). If we didn't allocate two words here then when
  // we "push" the result of the caller's stack we would overwrite the return
  // address and the saved rbp. Not good. So simply allocate 2 words now
  // just to be safe. This is the "static long no_params() method" issue.
  // See Lo.java for a testcase.
  // We don't need this for native calls because they return result in
  // register and the stack is expanded in the caller before we store
  // the results on the stack.

  if (!native) {
#ifdef PRODUCT
    __ subptr(rsp, 2*wordSize);
#else /* PRODUCT */
    __ push((int32_t)NULL_WORD);
    __ push(state);                         // make it look like a real argument
#endif /* PRODUCT */
  }

  // Now that we are assure of space for stack result, setup typical linkage

  __ push(rax);
  __ enter();

  __ mov(rax, state);                                  // save current state

  __ lea(rsp, Address(rsp, -(int)sizeof(BytecodeInterpreter)));
  __ mov(state, rsp);

  // rsi/r13 == state/locals rax == prevstate

  // initialize the "shadow" frame so that use since C++ interpreter not directly
  // recursive. Simpler to recurse but we can't trim expression stack as we call
  // new methods.
  __ movptr(STATE(_locals), locals);                    // state->_locals = locals()
  __ movptr(STATE(_self_link), state);                  // point to self
  __ movptr(STATE(_prev_link), rax);                    // state->_link = state on entry (NULL or previous state)
  __ movptr(STATE(_sender_sp), sender_sp);              // state->_sender_sp = sender_sp
#ifdef _LP64
  __ movptr(STATE(_thread), r15_thread);                // state->_bcp = codes()
#else
  __ get_thread(rax);                                   // get vm's javathread*
  __ movptr(STATE(_thread), rax);                       // state->_bcp = codes()
#endif // _LP64
  __ movptr(rdx, Address(rbx, methodOopDesc::const_offset())); // get constantMethodOop
  __ lea(rdx, Address(rdx, constMethodOopDesc::codes_offset())); // get code base
  if (native) {
    __ movptr(STATE(_bcp), (int32_t)NULL_WORD);         // state->_bcp = NULL
  } else {
    __ movptr(STATE(_bcp), rdx);                        // state->_bcp = codes()
  }
  __ xorptr(rdx, rdx);
  __ movptr(STATE(_oop_temp), rdx);                     // state->_oop_temp = NULL (only really needed for native)
  __ movptr(STATE(_mdx), rdx);                          // state->_mdx = NULL
  __ movptr(rdx, Address(rbx, methodOopDesc::constants_offset()));
  __ movptr(rdx, Address(rdx, constantPoolOopDesc::cache_offset_in_bytes()));
  __ movptr(STATE(_constants), rdx);                    // state->_constants = constants()

  __ movptr(STATE(_method), rbx);                       // state->_method = method()
  __ movl(STATE(_msg), (int32_t) BytecodeInterpreter::method_entry);   // state->_msg = initial method entry
  __ movptr(STATE(_result._to_call._callee), (int32_t) NULL_WORD); // state->_result._to_call._callee_callee = NULL


  __ movptr(STATE(_monitor_base), rsp);                 // set monitor block bottom (grows down) this would point to entry [0]
                                                        // entries run from -1..x where &monitor[x] ==

  {
    // Must not attempt to lock method until we enter interpreter as gc won't be able to find the
    // initial frame. However we allocate a free monitor so we don't have to shuffle the expression stack
    // immediately.

    // synchronize method
    const Address access_flags      (rbx, methodOopDesc::access_flags_offset());
    const int entry_size            = frame::interpreter_frame_monitor_size() * wordSize;
    Label not_synced;

    __ movl(rax, access_flags);
    __ testl(rax, JVM_ACC_SYNCHRONIZED);
    __ jcc(Assembler::zero, not_synced);

    // Allocate initial monitor and pre initialize it
    // get synchronization object

    Label done;
    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();
    __ movl(rax, access_flags);
    __ testl(rax, JVM_ACC_STATIC);
    __ movptr(rax, Address(locals, 0));                   // get receiver (assume this is frequent case)
    __ jcc(Assembler::zero, done);
    __ movptr(rax, Address(rbx, methodOopDesc::constants_offset()));
    __ movptr(rax, Address(rax, constantPoolOopDesc::pool_holder_offset_in_bytes()));
    __ movptr(rax, Address(rax, mirror_offset));
    __ bind(done);
    // add space for monitor & lock
    __ subptr(rsp, entry_size);                                           // add space for a monitor entry
    __ movptr(Address(rsp, BasicObjectLock::obj_offset_in_bytes()), rax); // store object
    __ bind(not_synced);
  }

  __ movptr(STATE(_stack_base), rsp);                                     // set expression stack base ( == &monitors[-count])
  if (native) {
    __ movptr(STATE(_stack), rsp);                                        // set current expression stack tos
    __ movptr(STATE(_stack_limit), rsp);
  } else {
    __ subptr(rsp, wordSize);                                             // pre-push stack
    __ movptr(STATE(_stack), rsp);                                        // set current expression stack tos

    // compute full expression stack limit

    const Address size_of_stack    (rbx, methodOopDesc::max_stack_offset());
    const int extra_stack = 0; //6815692//methodOopDesc::extra_stack_words();
    __ load_unsigned_short(rdx, size_of_stack);                           // get size of expression stack in words
    __ negptr(rdx);                                                       // so we can subtract in next step
    // Allocate expression stack
    __ lea(rsp, Address(rsp, rdx, Address::times_ptr, -extra_stack));
    __ movptr(STATE(_stack_limit), rsp);
  }

#ifdef _LP64
  // Make sure stack is properly aligned and sized for the abi
  __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
  __ andptr(rsp, -16); // must be 16 byte boundary (see amd64 ABI)
#endif // _LP64



}

// Helpers for commoning out cases in the various type of method entries.
//

// increment invocation count & check for overflow
//
// Note: checking for negative value instead of overflow
//       so we have a 'sticky' overflow test
//
// rbx,: method
// rcx: invocation counter
//
void InterpreterGenerator::generate_counter_incr(Label* overflow, Label* profile_method, Label* profile_method_continue) {

  const Address invocation_counter(rbx, methodOopDesc::invocation_counter_offset() + InvocationCounter::counter_offset());
  const Address backedge_counter  (rbx, methodOopDesc::backedge_counter_offset() + InvocationCounter::counter_offset());

  if (ProfileInterpreter) { // %%% Merge this into methodDataOop
    __ incrementl(Address(rbx,methodOopDesc::interpreter_invocation_counter_offset()));
  }
  // Update standard invocation counters
  __ movl(rax, backedge_counter);               // load backedge counter

  __ increment(rcx, InvocationCounter::count_increment);
  __ andl(rax, InvocationCounter::count_mask_value);  // mask out the status bits

  __ movl(invocation_counter, rcx);             // save invocation count
  __ addl(rcx, rax);                            // add both counters

  // profile_method is non-null only for interpreted method so
  // profile_method != NULL == !native_call
  // BytecodeInterpreter only calls for native so code is elided.

  __ cmp32(rcx,
           ExternalAddress((address)&InvocationCounter::InterpreterInvocationLimit));
  __ jcc(Assembler::aboveEqual, *overflow);

}

void InterpreterGenerator::generate_counter_overflow(Label* do_continue) {

  // C++ interpreter on entry
  // rsi/r13 - new interpreter state pointer
  // rbp - interpreter frame pointer
  // rbx - method

  // On return (i.e. jump to entry_point) [ back to invocation of interpreter ]
  // rbx, - method
  // rcx - rcvr (assuming there is one)
  // top of stack return address of interpreter caller
  // rsp - sender_sp

  // C++ interpreter only
  // rsi/r13 - previous interpreter state pointer

  const Address size_of_parameters(rbx, methodOopDesc::size_of_parameters_offset());

  // InterpreterRuntime::frequency_counter_overflow takes one argument
  // indicating if the counter overflow occurs at a backwards branch (non-NULL bcp).
  // The call returns the address of the verified entry point for the method or NULL
  // if the compilation did not complete (either went background or bailed out).
  __ movptr(rax, (int32_t)false);
  __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::frequency_counter_overflow), rax);

  // for c++ interpreter can rsi really be munged?
  __ lea(state, Address(rbp, -(int)sizeof(BytecodeInterpreter)));                               // restore state
  __ movptr(rbx, Address(state, byte_offset_of(BytecodeInterpreter, _method)));            // restore method
  __ movptr(rdi, Address(state, byte_offset_of(BytecodeInterpreter, _locals)));            // get locals pointer

  __ jmp(*do_continue, relocInfo::none);

}

void InterpreterGenerator::generate_stack_overflow_check(void) {
  // see if we've got enough room on the stack for locals plus overhead.
  // the expression stack grows down incrementally, so the normal guard
  // page mechanism will work for that.
  //
  // Registers live on entry:
  //
  // Asm interpreter
  // rdx: number of additional locals this frame needs (what we must check)
  // rbx,: methodOop

  // C++ Interpreter
  // rsi/r13: previous interpreter frame state object
  // rdi: &locals[0]
  // rcx: # of locals
  // rdx: number of additional locals this frame needs (what we must check)
  // rbx: methodOop

  // destroyed on exit
  // rax,

  // NOTE:  since the additional locals are also always pushed (wasn't obvious in
  // generate_method_entry) so the guard should work for them too.
  //

  // monitor entry size: see picture of stack set (generate_method_entry) and frame_i486.hpp
  const int entry_size    = frame::interpreter_frame_monitor_size() * wordSize;

  // total overhead size: entry_size + (saved rbp, thru expr stack bottom).
  // be sure to change this if you add/subtract anything to/from the overhead area
  const int overhead_size = (int)sizeof(BytecodeInterpreter);

  const int page_size = os::vm_page_size();

  Label after_frame_check;

  // compute rsp as if this were going to be the last frame on
  // the stack before the red zone

  Label after_frame_check_pop;

  // save rsi == caller's bytecode ptr (c++ previous interp. state)
  // QQQ problem here?? rsi overload????
  __ push(state);

  const Register thread = LP64_ONLY(r15_thread) NOT_LP64(rsi);

  NOT_LP64(__ get_thread(thread));

  const Address stack_base(thread, Thread::stack_base_offset());
  const Address stack_size(thread, Thread::stack_size_offset());

  // locals + overhead, in bytes
    const Address size_of_stack    (rbx, methodOopDesc::max_stack_offset());
    // Always give one monitor to allow us to start interp if sync method.
    // Any additional monitors need a check when moving the expression stack
    const int one_monitor = frame::interpreter_frame_monitor_size() * wordSize;
    const int extra_stack = 0; //6815692//methodOopDesc::extra_stack_entries();
  __ load_unsigned_short(rax, size_of_stack);                           // get size of expression stack in words
  __ lea(rax, Address(noreg, rax, Interpreter::stackElementScale(), extra_stack + one_monitor));
  __ lea(rax, Address(rax, rdx, Interpreter::stackElementScale(), overhead_size));

#ifdef ASSERT
  Label stack_base_okay, stack_size_okay;
  // verify that thread stack base is non-zero
  __ cmpptr(stack_base, (int32_t)0);
  __ jcc(Assembler::notEqual, stack_base_okay);
  __ stop("stack base is zero");
  __ bind(stack_base_okay);
  // verify that thread stack size is non-zero
  __ cmpptr(stack_size, (int32_t)0);
  __ jcc(Assembler::notEqual, stack_size_okay);
  __ stop("stack size is zero");
  __ bind(stack_size_okay);
#endif

  // Add stack base to locals and subtract stack size
  __ addptr(rax, stack_base);
  __ subptr(rax, stack_size);

  // We should have a magic number here for the size of the c++ interpreter frame.
  // We can't actually tell this ahead of time. The debug version size is around 3k
  // product is 1k and fastdebug is 4k
  const int slop = 6 * K;

  // Use the maximum number of pages we might bang.
  const int max_pages = StackShadowPages > (StackRedPages+StackYellowPages) ? StackShadowPages :
                                                                              (StackRedPages+StackYellowPages);
  // Only need this if we are stack banging which is temporary while
  // we're debugging.
  __ addptr(rax, slop + 2*max_pages * page_size);

  // check against the current stack bottom
  __ cmpptr(rsp, rax);
  __ jcc(Assembler::above, after_frame_check_pop);

  __ pop(state);  //  get c++ prev state.

     // throw exception return address becomes throwing pc
  __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_StackOverflowError));

  // all done with frame size check
  __ bind(after_frame_check_pop);
  __ pop(state);

  __ bind(after_frame_check);
}

// Find preallocated  monitor and lock method (C++ interpreter)
// rbx - methodOop
//
void InterpreterGenerator::lock_method(void) {
  // assumes state == rsi/r13 == pointer to current interpreterState
  // minimally destroys rax, rdx|c_rarg1, rdi
  //
  // synchronize method
  const int entry_size            = frame::interpreter_frame_monitor_size() * wordSize;
  const Address access_flags      (rbx, methodOopDesc::access_flags_offset());

  const Register monitor  = NOT_LP64(rdx) LP64_ONLY(c_rarg1);

  // find initial monitor i.e. monitors[-1]
  __ movptr(monitor, STATE(_monitor_base));                                   // get monitor bottom limit
  __ subptr(monitor, entry_size);                                             // point to initial monitor

#ifdef ASSERT
  { Label L;
    __ movl(rax, access_flags);
    __ testl(rax, JVM_ACC_SYNCHRONIZED);
    __ jcc(Assembler::notZero, L);
    __ stop("method doesn't need synchronization");
    __ bind(L);
  }
#endif // ASSERT
  // get synchronization object
  { Label done;
    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();
    __ movl(rax, access_flags);
    __ movptr(rdi, STATE(_locals));                                     // prepare to get receiver (assume common case)
    __ testl(rax, JVM_ACC_STATIC);
    __ movptr(rax, Address(rdi, 0));                                    // get receiver (assume this is frequent case)
    __ jcc(Assembler::zero, done);
    __ movptr(rax, Address(rbx, methodOopDesc::constants_offset()));
    __ movptr(rax, Address(rax, constantPoolOopDesc::pool_holder_offset_in_bytes()));
    __ movptr(rax, Address(rax, mirror_offset));
    __ bind(done);
  }
#ifdef ASSERT
  { Label L;
    __ cmpptr(rax, Address(monitor, BasicObjectLock::obj_offset_in_bytes()));   // correct object?
    __ jcc(Assembler::equal, L);
    __ stop("wrong synchronization lobject");
    __ bind(L);
  }
#endif // ASSERT
  // can destroy rax, rdx|c_rarg1, rcx, and (via call_VM) rdi!
  __ lock_object(monitor);
}

// Call an accessor method (assuming it is resolved, otherwise drop into vanilla (slow path) entry

address InterpreterGenerator::generate_accessor_entry(void) {

  // rbx: methodOop

  // rsi/r13: senderSP must preserved for slow path, set SP to it on fast path

  Label xreturn_path;

  // do fastpath for resolved accessor methods
  if (UseFastAccessorMethods) {

    address entry_point = __ pc();

    Label slow_path;
    // If we need a safepoint check, generate full interpreter entry.
    ExternalAddress state(SafepointSynchronize::address_of_state());
    __ cmp32(ExternalAddress(SafepointSynchronize::address_of_state()),
             SafepointSynchronize::_not_synchronized);

    __ jcc(Assembler::notEqual, slow_path);
    // ASM/C++ Interpreter
    // Code: _aload_0, _(i|a)getfield, _(i|a)return or any rewrites thereof; parameter size = 1
    // Note: We can only use this code if the getfield has been resolved
    //       and if we don't have a null-pointer exception => check for
    //       these conditions first and use slow path if necessary.
    // rbx,: method
    // rcx: receiver
    __ movptr(rax, Address(rsp, wordSize));

    // check if local 0 != NULL and read field
    __ testptr(rax, rax);
    __ jcc(Assembler::zero, slow_path);

    __ movptr(rdi, Address(rbx, methodOopDesc::constants_offset()));
    // read first instruction word and extract bytecode @ 1 and index @ 2
    __ movptr(rdx, Address(rbx, methodOopDesc::const_offset()));
    __ movl(rdx, Address(rdx, constMethodOopDesc::codes_offset()));
    // Shift codes right to get the index on the right.
    // The bytecode fetched looks like <index><0xb4><0x2a>
    __ shrl(rdx, 2*BitsPerByte);
    __ shll(rdx, exact_log2(in_words(ConstantPoolCacheEntry::size())));
    __ movptr(rdi, Address(rdi, constantPoolOopDesc::cache_offset_in_bytes()));

    // rax,: local 0
    // rbx,: method
    // rcx: receiver - do not destroy since it is needed for slow path!
    // rcx: scratch
    // rdx: constant pool cache index
    // rdi: constant pool cache
    // rsi/r13: sender sp

    // check if getfield has been resolved and read constant pool cache entry
    // check the validity of the cache entry by testing whether _indices field
    // contains Bytecode::_getfield in b1 byte.
    assert(in_words(ConstantPoolCacheEntry::size()) == 4, "adjust shift below");
    __ movl(rcx,
            Address(rdi,
                    rdx,
                    Address::times_ptr, constantPoolCacheOopDesc::base_offset() + ConstantPoolCacheEntry::indices_offset()));
    __ shrl(rcx, 2*BitsPerByte);
    __ andl(rcx, 0xFF);
    __ cmpl(rcx, Bytecodes::_getfield);
    __ jcc(Assembler::notEqual, slow_path);

    // Note: constant pool entry is not valid before bytecode is resolved
    __ movptr(rcx,
            Address(rdi,
                    rdx,
                    Address::times_ptr, constantPoolCacheOopDesc::base_offset() + ConstantPoolCacheEntry::f2_offset()));
    __ movl(rdx,
            Address(rdi,
                    rdx,
                    Address::times_ptr, constantPoolCacheOopDesc::base_offset() + ConstantPoolCacheEntry::flags_offset()));

    Label notByte, notShort, notChar;
    const Address field_address (rax, rcx, Address::times_1);

    // Need to differentiate between igetfield, agetfield, bgetfield etc.
    // because they are different sizes.
    // Use the type from the constant pool cache
    __ shrl(rdx, ConstantPoolCacheEntry::tosBits);
    // Make sure we don't need to mask rdx for tosBits after the above shift
    ConstantPoolCacheEntry::verify_tosBits();
#ifdef _LP64
    Label notObj;
    __ cmpl(rdx, atos);
    __ jcc(Assembler::notEqual, notObj);
    // atos
    __ movptr(rax, field_address);
    __ jmp(xreturn_path);

    __ bind(notObj);
#endif // _LP64
    __ cmpl(rdx, btos);
    __ jcc(Assembler::notEqual, notByte);
    __ load_signed_byte(rax, field_address);
    __ jmp(xreturn_path);

    __ bind(notByte);
    __ cmpl(rdx, stos);
    __ jcc(Assembler::notEqual, notShort);
    __ load_signed_short(rax, field_address);
    __ jmp(xreturn_path);

    __ bind(notShort);
    __ cmpl(rdx, ctos);
    __ jcc(Assembler::notEqual, notChar);
    __ load_unsigned_short(rax, field_address);
    __ jmp(xreturn_path);

    __ bind(notChar);
#ifdef ASSERT
    Label okay;
#ifndef _LP64
    __ cmpl(rdx, atos);
    __ jcc(Assembler::equal, okay);
#endif // _LP64
    __ cmpl(rdx, itos);
    __ jcc(Assembler::equal, okay);
    __ stop("what type is this?");
    __ bind(okay);
#endif // ASSERT
    // All the rest are a 32 bit wordsize
    __ movl(rax, field_address);

    __ bind(xreturn_path);

    // _ireturn/_areturn
    __ pop(rdi);                               // get return address
    __ mov(rsp, sender_sp_on_entry);           // set sp to sender sp
    __ jmp(rdi);

    // generate a vanilla interpreter entry as the slow path
    __ bind(slow_path);
    // We will enter c++ interpreter looking like it was
    // called by the call_stub this will cause it to return
    // a tosca result to the invoker which might have been
    // the c++ interpreter itself.

    __ jmp(fast_accessor_slow_entry_path);
    return entry_point;

  } else {
    return NULL;
  }

}

address InterpreterGenerator::generate_Reference_get_entry(void) {
#ifndef SERIALGC
  if (UseG1GC) {
    // We need to generate have a routine that generates code to:
    //   * load the value in the referent field
    //   * passes that value to the pre-barrier.
    //
    // In the case of G1 this will record the value of the
    // referent in an SATB buffer if marking is active.
    // This will cause concurrent marking to mark the referent
    // field as live.
    Unimplemented();
  }
#endif // SERIALGC

  // If G1 is not enabled then attempt to go through the accessor entry point
  // Reference.get is an accessor
  return generate_accessor_entry();
}

//
// C++ Interpreter stub for calling a native method.
// This sets up a somewhat different looking stack for calling the native method
// than the typical interpreter frame setup but still has the pointer to
// an interpreter state.
//

address InterpreterGenerator::generate_native_entry(bool synchronized) {
  // determine code generation flags
  bool inc_counter  = UseCompiler || CountCompiledCalls;

  // rbx: methodOop
  // rcx: receiver (unused)
  // rsi/r13: previous interpreter state (if called from C++ interpreter) must preserve
  //      in any case. If called via c1/c2/call_stub rsi/r13 is junk (to use) but harmless
  //      to save/restore.
  address entry_point = __ pc();

  const Address size_of_parameters(rbx, methodOopDesc::size_of_parameters_offset());
  const Address size_of_locals    (rbx, methodOopDesc::size_of_locals_offset());
  const Address invocation_counter(rbx, methodOopDesc::invocation_counter_offset() + InvocationCounter::counter_offset());
  const Address access_flags      (rbx, methodOopDesc::access_flags_offset());

  // rsi/r13 == state/locals rdi == prevstate
  const Register locals = rdi;

  // get parameter size (always needed)
  __ load_unsigned_short(rcx, size_of_parameters);

  // rbx: methodOop
  // rcx: size of parameters
  __ pop(rax);                                       // get return address
  // for natives the size of locals is zero

  // compute beginning of parameters /locals
  __ lea(locals, Address(rsp, rcx, Address::times_ptr, -wordSize));

  // initialize fixed part of activation frame

  // Assumes rax = return address

  // allocate and initialize new interpreterState and method expression stack
  // IN(locals) ->  locals
  // IN(state) -> previous frame manager state (NULL from stub/c1/c2)
  // destroys rax, rcx, rdx
  // OUT (state) -> new interpreterState
  // OUT(rsp) -> bottom of methods expression stack

  // save sender_sp
  __ mov(rcx, sender_sp_on_entry);
  // start with NULL previous state
  __ movptr(state, (int32_t)NULL_WORD);
  generate_compute_interpreter_state(state, locals, rcx, true);

#ifdef ASSERT
  { Label L;
    __ movptr(rax, STATE(_stack_base));
#ifdef _LP64
    // duplicate the alignment rsp got after setting stack_base
    __ subptr(rax, frame::arg_reg_save_area_bytes); // windows
    __ andptr(rax, -16); // must be 16 byte boundary (see amd64 ABI)
#endif // _LP64
    __ cmpptr(rax, rsp);
    __ jcc(Assembler::equal, L);
    __ stop("broken stack frame setup in interpreter");
    __ bind(L);
  }
#endif

  if (inc_counter) __ movl(rcx, invocation_counter);  // (pre-)fetch invocation count

  const Register unlock_thread = LP64_ONLY(r15_thread) NOT_LP64(rax);
  NOT_LP64(__ movptr(unlock_thread, STATE(_thread));) // get thread
  // Since at this point in the method invocation the exception handler
  // would try to exit the monitor of synchronized methods which hasn't
  // been entered yet, we set the thread local variable
  // _do_not_unlock_if_synchronized to true. The remove_activation will
  // check this flag.

  const Address do_not_unlock_if_synchronized(unlock_thread,
        in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()));
  __ movbool(do_not_unlock_if_synchronized, true);

  // make sure method is native & not abstract
#ifdef ASSERT
  __ movl(rax, access_flags);
  {
    Label L;
    __ testl(rax, JVM_ACC_NATIVE);
    __ jcc(Assembler::notZero, L);
    __ stop("tried to execute non-native method as native");
    __ bind(L);
  }
  { Label L;
    __ testl(rax, JVM_ACC_ABSTRACT);
    __ jcc(Assembler::zero, L);
    __ stop("tried to execute abstract method in interpreter");
    __ bind(L);
  }
#endif


  // increment invocation count & check for overflow
  Label invocation_counter_overflow;
  if (inc_counter) {
    generate_counter_incr(&invocation_counter_overflow, NULL, NULL);
  }

  Label continue_after_compile;

  __ bind(continue_after_compile);

  bang_stack_shadow_pages(true);

  // reset the _do_not_unlock_if_synchronized flag
  NOT_LP64(__ movl(rax, STATE(_thread));)                       // get thread
  __ movbool(do_not_unlock_if_synchronized, false);


  // check for synchronized native methods
  //
  // Note: This must happen *after* invocation counter check, since
  //       when overflow happens, the method should not be locked.
  if (synchronized) {
    // potentially kills rax, rcx, rdx, rdi
    lock_method();
  } else {
    // no synchronization necessary
#ifdef ASSERT
      { Label L;
        __ movl(rax, access_flags);
        __ testl(rax, JVM_ACC_SYNCHRONIZED);
        __ jcc(Assembler::zero, L);
        __ stop("method needs synchronization");
        __ bind(L);
      }
#endif
  }

  // start execution

  // jvmti support
  __ notify_method_entry();

  // work registers
  const Register method = rbx;
  const Register thread = LP64_ONLY(r15_thread) NOT_LP64(rdi);
  const Register t      = InterpreterRuntime::SignatureHandlerGenerator::temp();    // rcx|rscratch1

  // allocate space for parameters
  __ movptr(method, STATE(_method));
  __ verify_oop(method);
  __ load_unsigned_short(t, Address(method, methodOopDesc::size_of_parameters_offset()));
  __ shll(t, 2);
#ifdef _LP64
  __ subptr(rsp, t);
  __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
  __ andptr(rsp, -16); // must be 16 byte boundary (see amd64 ABI)
#else
  __ addptr(t, 2*wordSize);     // allocate two more slots for JNIEnv and possible mirror
  __ subptr(rsp, t);
  __ andptr(rsp, -(StackAlignmentInBytes)); // gcc needs 16 byte aligned stacks to do XMM intrinsics
#endif // _LP64

  // get signature handler
    Label pending_exception_present;

  { Label L;
    __ movptr(t, Address(method, methodOopDesc::signature_handler_offset()));
    __ testptr(t, t);
    __ jcc(Assembler::notZero, L);
    __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::prepare_native_call), method, false);
    __ movptr(method, STATE(_method));
    __ cmpptr(Address(thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
    __ jcc(Assembler::notEqual, pending_exception_present);
    __ verify_oop(method);
    __ movptr(t, Address(method, methodOopDesc::signature_handler_offset()));
    __ bind(L);
  }
#ifdef ASSERT
  {
    Label L;
    __ push(t);
    __ get_thread(t);                                   // get vm's javathread*
    __ cmpptr(t, STATE(_thread));
    __ jcc(Assembler::equal, L);
    __ int3();
    __ bind(L);
    __ pop(t);
  }
#endif //

  const Register from_ptr = InterpreterRuntime::SignatureHandlerGenerator::from();
  // call signature handler
  assert(InterpreterRuntime::SignatureHandlerGenerator::to  () == rsp, "adjust this code");

  // The generated handlers do not touch RBX (the method oop).
  // However, large signatures cannot be cached and are generated
  // each time here.  The slow-path generator will blow RBX
  // sometime, so we must reload it after the call.
  __ movptr(from_ptr, STATE(_locals));  // get the from pointer
  __ call(t);
  __ movptr(method, STATE(_method));
  __ verify_oop(method);

  // result handler is in rax
  // set result handler
  __ movptr(STATE(_result_handler), rax);


  // get native function entry point
  { Label L;
    __ movptr(rax, Address(method, methodOopDesc::native_function_offset()));
    __ testptr(rax, rax);
    __ jcc(Assembler::notZero, L);
    __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::prepare_native_call), method);
    __ movptr(method, STATE(_method));
    __ verify_oop(method);
    __ movptr(rax, Address(method, methodOopDesc::native_function_offset()));
    __ bind(L);
  }

  // pass mirror handle if static call
  { Label L;
    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();
    __ movl(t, Address(method, methodOopDesc::access_flags_offset()));
    __ testl(t, JVM_ACC_STATIC);
    __ jcc(Assembler::zero, L);
    // get mirror
    __ movptr(t, Address(method, methodOopDesc:: constants_offset()));
    __ movptr(t, Address(t, constantPoolOopDesc::pool_holder_offset_in_bytes()));
    __ movptr(t, Address(t, mirror_offset));
    // copy mirror into activation object
    __ movptr(STATE(_oop_temp), t);
    // pass handle to mirror
#ifdef _LP64
    __ lea(c_rarg1, STATE(_oop_temp));
#else
    __ lea(t, STATE(_oop_temp));
    __ movptr(Address(rsp, wordSize), t);
#endif // _LP64
    __ bind(L);
  }
#ifdef ASSERT
  {
    Label L;
    __ push(t);
    __ get_thread(t);                                   // get vm's javathread*
    __ cmpptr(t, STATE(_thread));
    __ jcc(Assembler::equal, L);
    __ int3();
    __ bind(L);
    __ pop(t);
  }
#endif //

  // pass JNIEnv
#ifdef _LP64
  __ lea(c_rarg0, Address(thread, JavaThread::jni_environment_offset()));
#else
  __ movptr(thread, STATE(_thread));          // get thread
  __ lea(t, Address(thread, JavaThread::jni_environment_offset()));

  __ movptr(Address(rsp, 0), t);
#endif // _LP64

#ifdef ASSERT
  {
    Label L;
    __ push(t);
    __ get_thread(t);                                   // get vm's javathread*
    __ cmpptr(t, STATE(_thread));
    __ jcc(Assembler::equal, L);
    __ int3();
    __ bind(L);
    __ pop(t);
  }
#endif //

#ifdef ASSERT
  { Label L;
    __ movl(t, Address(thread, JavaThread::thread_state_offset()));
    __ cmpl(t, _thread_in_Java);
    __ jcc(Assembler::equal, L);
    __ stop("Wrong thread state in native stub");
    __ bind(L);
  }
#endif

  // Change state to native (we save the return address in the thread, since it might not
  // be pushed on the stack when we do a a stack traversal). It is enough that the pc()
  // points into the right code segment. It does not have to be the correct return pc.

  __ set_last_Java_frame(thread, noreg, rbp, __ pc());

  __ movl(Address(thread, JavaThread::thread_state_offset()), _thread_in_native);

  __ call(rax);

  // result potentially in rdx:rax or ST0
  __ movptr(method, STATE(_method));
  NOT_LP64(__ movptr(thread, STATE(_thread));)                  // get thread

  // The potential result is in ST(0) & rdx:rax
  // With C++ interpreter we leave any possible result in ST(0) until we are in result handler and then
  // we do the appropriate stuff for returning the result. rdx:rax must always be saved because just about
  // anything we do here will destroy it, st(0) is only saved if we re-enter the vm where it would
  // be destroyed.
  // It is safe to do these pushes because state is _thread_in_native and return address will be found
  // via _last_native_pc and not via _last_jave_sp

    // Must save the value of ST(0)/xmm0 since it could be destroyed before we get to result handler
    { Label Lpush, Lskip;
      ExternalAddress float_handler(AbstractInterpreter::result_handler(T_FLOAT));
      ExternalAddress double_handler(AbstractInterpreter::result_handler(T_DOUBLE));
      __ cmpptr(STATE(_result_handler), float_handler.addr());
      __ jcc(Assembler::equal, Lpush);
      __ cmpptr(STATE(_result_handler), double_handler.addr());
      __ jcc(Assembler::notEqual, Lskip);
      __ bind(Lpush);
      __ subptr(rsp, 2*wordSize);
      if ( UseSSE < 2 ) {
        __ fstp_d(Address(rsp, 0));
      } else {
        __ movdbl(Address(rsp, 0), xmm0);
      }
      __ bind(Lskip);
    }

  // save rax:rdx for potential use by result handler.
  __ push(rax);
#ifndef _LP64
  __ push(rdx);
#endif // _LP64

  // Either restore the MXCSR register after returning from the JNI Call
  // or verify that it wasn't changed.
  if (VM_Version::supports_sse()) {
    if (RestoreMXCSROnJNICalls) {
      __ ldmxcsr(ExternalAddress(StubRoutines::addr_mxcsr_std()));
    }
    else if (CheckJNICalls ) {
      __ call(RuntimeAddress(StubRoutines::x86::verify_mxcsr_entry()));
    }
  }

#ifndef _LP64
  // Either restore the x87 floating pointer control word after returning
  // from the JNI call or verify that it wasn't changed.
  if (CheckJNICalls) {
    __ call(RuntimeAddress(StubRoutines::x86::verify_fpu_cntrl_wrd_entry()));
  }
#endif // _LP64


  // change thread state
  __ movl(Address(thread, JavaThread::thread_state_offset()), _thread_in_native_trans);
  if(os::is_MP()) {
    // Write serialization page so VM thread can do a pseudo remote membar.
    // We use the current thread pointer to calculate a thread specific
    // offset to write to within the page. This minimizes bus traffic
    // due to cache line collision.
    __ serialize_memory(thread, rcx);
  }

  // check for safepoint operation in progress and/or pending suspend requests
  { Label Continue;

    __ cmp32(ExternalAddress(SafepointSynchronize::address_of_state()),
             SafepointSynchronize::_not_synchronized);

    // threads running native code and they are expected to self-suspend
    // when leaving the _thread_in_native state. We need to check for
    // pending suspend requests here.
    Label L;
    __ jcc(Assembler::notEqual, L);
    __ cmpl(Address(thread, JavaThread::suspend_flags_offset()), 0);
    __ jcc(Assembler::equal, Continue);
    __ bind(L);

    // Don't use call_VM as it will see a possible pending exception and forward it
    // and never return here preventing us from clearing _last_native_pc down below.
    // Also can't use call_VM_leaf either as it will check to see if rsi & rdi are
    // preserved and correspond to the bcp/locals pointers.
    //

    ((MacroAssembler*)_masm)->call_VM_leaf(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans),
                          thread);
    __ increment(rsp, wordSize);

    __ movptr(method, STATE(_method));
    __ verify_oop(method);
    __ movptr(thread, STATE(_thread));                       // get thread

    __ bind(Continue);
  }

  // change thread state
  __ movl(Address(thread, JavaThread::thread_state_offset()), _thread_in_Java);

  __ reset_last_Java_frame(thread, true, true);

  // reset handle block
  __ movptr(t, Address(thread, JavaThread::active_handles_offset()));
  __ movptr(Address(t, JNIHandleBlock::top_offset_in_bytes()), (int32_t)NULL_WORD);

  // If result was an oop then unbox and save it in the frame
  { Label L;
    Label no_oop, store_result;
      ExternalAddress oop_handler(AbstractInterpreter::result_handler(T_OBJECT));
    __ cmpptr(STATE(_result_handler), oop_handler.addr());
    __ jcc(Assembler::notEqual, no_oop);
#ifndef _LP64
    __ pop(rdx);
#endif // _LP64
    __ pop(rax);
    __ testptr(rax, rax);
    __ jcc(Assembler::zero, store_result);
    // unbox
    __ movptr(rax, Address(rax, 0));
    __ bind(store_result);
    __ movptr(STATE(_oop_temp), rax);
    // keep stack depth as expected by pushing oop which will eventually be discarded
    __ push(rax);
#ifndef _LP64
    __ push(rdx);
#endif // _LP64
    __ bind(no_oop);
  }

  {
     Label no_reguard;
     __ cmpl(Address(thread, JavaThread::stack_guard_state_offset()), JavaThread::stack_guard_yellow_disabled);
     __ jcc(Assembler::notEqual, no_reguard);

     __ pusha();
     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages)));
     __ popa();

     __ bind(no_reguard);
   }


  // QQQ Seems like for native methods we simply return and the caller will see the pending
  // exception and do the right thing. Certainly the interpreter will, don't know about
  // compiled methods.
  // Seems that the answer to above is no this is wrong. The old code would see the exception
  // and forward it before doing the unlocking and notifying jvmdi that method has exited.
  // This seems wrong need to investigate the spec.

  // handle exceptions (exception handling will handle unlocking!)
  { Label L;
    __ cmpptr(Address(thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
    __ jcc(Assembler::zero, L);
    __ bind(pending_exception_present);

    // There are potential results on the stack (rax/rdx, ST(0)) we ignore these and simply
    // return and let caller deal with exception. This skips the unlocking here which
    // seems wrong but seems to be what asm interpreter did. Can't find this in the spec.
    // Note: must preverve method in rbx
    //

    // remove activation

    __ movptr(t, STATE(_sender_sp));
    __ leave();                                  // remove frame anchor
    __ pop(rdi);                                 // get return address
    __ movptr(state, STATE(_prev_link));         // get previous state for return
    __ mov(rsp, t);                              // set sp to sender sp
    __ push(rdi);                                // push throwing pc
    // The skips unlocking!! This seems to be what asm interpreter does but seems
    // very wrong. Not clear if this violates the spec.
    __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
    __ bind(L);
  }

  // do unlocking if necessary
  { Label L;
    __ movl(t, Address(method, methodOopDesc::access_flags_offset()));
    __ testl(t, JVM_ACC_SYNCHRONIZED);
    __ jcc(Assembler::zero, L);
    // the code below should be shared with interpreter macro assembler implementation
    { Label unlock;
    const Register monitor = NOT_LP64(rdx) LP64_ONLY(c_rarg1);
      // BasicObjectLock will be first in list, since this is a synchronized method. However, need
      // to check that the object has not been unlocked by an explicit monitorexit bytecode.
      __ movptr(monitor, STATE(_monitor_base));
      __ subptr(monitor, frame::interpreter_frame_monitor_size() * wordSize);  // address of initial monitor

      __ movptr(t, Address(monitor, BasicObjectLock::obj_offset_in_bytes()));
      __ testptr(t, t);
      __ jcc(Assembler::notZero, unlock);

      // Entry already unlocked, need to throw exception
      __ MacroAssembler::call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_illegal_monitor_state_exception));
      __ should_not_reach_here();

      __ bind(unlock);
      __ unlock_object(monitor);
      // unlock can blow rbx so restore it for path that needs it below
      __ movptr(method, STATE(_method));
    }
    __ bind(L);
  }

  // jvmti support
  // Note: This must happen _after_ handling/throwing any exceptions since
  //       the exception handler code notifies the runtime of method exits
  //       too. If this happens before, method entry/exit notifications are
  //       not properly paired (was bug - gri 11/22/99).
  __ notify_method_exit(vtos, InterpreterMacroAssembler::NotifyJVMTI);

  // restore potential result in rdx:rax, call result handler to restore potential result in ST0 & handle result
#ifndef _LP64
  __ pop(rdx);
#endif // _LP64
  __ pop(rax);
  __ movptr(t, STATE(_result_handler));       // get result handler
  __ call(t);                                 // call result handler to convert to tosca form

  // remove activation

  __ movptr(t, STATE(_sender_sp));

  __ leave();                                  // remove frame anchor
  __ pop(rdi);                                 // get return address
  __ movptr(state, STATE(_prev_link));         // get previous state for return (if c++ interpreter was caller)
  __ mov(rsp, t);                              // set sp to sender sp
  __ jmp(rdi);

  // invocation counter overflow
  if (inc_counter) {
    // Handle overflow of counter and compile method
    __ bind(invocation_counter_overflow);
    generate_counter_overflow(&continue_after_compile);
  }

  return entry_point;
}

// Generate entries that will put a result type index into rcx
void CppInterpreterGenerator::generate_deopt_handling() {

  Label return_from_deopt_common;

  // Generate entries that will put a result type index into rcx
  // deopt needs to jump to here to enter the interpreter (return a result)
  deopt_frame_manager_return_atos  = __ pc();

  // rax is live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_OBJECT));    // Result stub address array index
  __ jmp(return_from_deopt_common);


  // deopt needs to jump to here to enter the interpreter (return a result)
  deopt_frame_manager_return_btos  = __ pc();

  // rax is live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_BOOLEAN));    // Result stub address array index
  __ jmp(return_from_deopt_common);

  // deopt needs to jump to here to enter the interpreter (return a result)
  deopt_frame_manager_return_itos  = __ pc();

  // rax is live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_INT));    // Result stub address array index
  __ jmp(return_from_deopt_common);

  // deopt needs to jump to here to enter the interpreter (return a result)

  deopt_frame_manager_return_ltos  = __ pc();
  // rax,rdx are live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_LONG));    // Result stub address array index
  __ jmp(return_from_deopt_common);

  // deopt needs to jump to here to enter the interpreter (return a result)

  deopt_frame_manager_return_ftos  = __ pc();
  // st(0) is live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_FLOAT));    // Result stub address array index
  __ jmp(return_from_deopt_common);

  // deopt needs to jump to here to enter the interpreter (return a result)
  deopt_frame_manager_return_dtos  = __ pc();

  // st(0) is live here
  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_DOUBLE));    // Result stub address array index
  __ jmp(return_from_deopt_common);

  // deopt needs to jump to here to enter the interpreter (return a result)
  deopt_frame_manager_return_vtos  = __ pc();

  __ movl(rcx, AbstractInterpreter::BasicType_as_index(T_VOID));

  // Deopt return common
  // an index is present in rcx that lets us move any possible result being
  // return to the interpreter's stack
  //
  // Because we have a full sized interpreter frame on the youngest
  // activation the stack is pushed too deep to share the tosca to
  // stack converters directly. We shrink the stack to the desired
  // amount and then push result and then re-extend the stack.
  // We could have the code in size_activation layout a short
  // frame for the top activation but that would look different
  // than say sparc (which needs a full size activation because
  // the windows are in the way. Really it could be short? QQQ
  //
  __ bind(return_from_deopt_common);

  __ lea(state, Address(rbp, -(int)sizeof(BytecodeInterpreter)));

  // setup rsp so we can push the "result" as needed.
  __ movptr(rsp, STATE(_stack));                                   // trim stack (is prepushed)
  __ addptr(rsp, wordSize);                                        // undo prepush

  ExternalAddress tosca_to_stack((address)CppInterpreter::_tosca_to_stack);
  // Address index(noreg, rcx, Address::times_ptr);
  __ movptr(rcx, ArrayAddress(tosca_to_stack, Address(noreg, rcx, Address::times_ptr)));
  // __ movl(rcx, Address(noreg, rcx, Address::times_ptr, int(AbstractInterpreter::_tosca_to_stack)));
  __ call(rcx);                                                   // call result converter

  __ movl(STATE(_msg), (int)BytecodeInterpreter::deopt_resume);
  __ lea(rsp, Address(rsp, -wordSize));                            // prepush stack (result if any already present)
  __ movptr(STATE(_stack), rsp);                                   // inform interpreter of new stack depth (parameters removed,
                                                                   // result if any on stack already )
  __ movptr(rsp, STATE(_stack_limit));                             // restore expression stack to full depth
}

// Generate the code to handle a more_monitors message from the c++ interpreter
void CppInterpreterGenerator::generate_more_monitors() {


  Label entry, loop;
  const int entry_size = frame::interpreter_frame_monitor_size() * wordSize;
  // 1. compute new pointers                     // rsp: old expression stack top
  __ movptr(rdx, STATE(_stack_base));            // rdx: old expression stack bottom
  __ subptr(rsp, entry_size);                    // move expression stack top limit
  __ subptr(STATE(_stack), entry_size);          // update interpreter stack top
  __ subptr(STATE(_stack_limit), entry_size);    // inform interpreter
  __ subptr(rdx, entry_size);                    // move expression stack bottom
  __ movptr(STATE(_stack_base), rdx);            // inform interpreter
  __ movptr(rcx, STATE(_stack));                 // set start value for copy loop
  __ jmp(entry);
  // 2. move expression stack contents
  __ bind(loop);
  __ movptr(rbx, Address(rcx, entry_size));      // load expression stack word from old location
  __ movptr(Address(rcx, 0), rbx);               // and store it at new location
  __ addptr(rcx, wordSize);                      // advance to next word
  __ bind(entry);
  __ cmpptr(rcx, rdx);                           // check if bottom reached
  __ jcc(Assembler::notEqual, loop);             // if not at bottom then copy next word
  // now zero the slot so we can find it.
  __ movptr(Address(rdx, BasicObjectLock::obj_offset_in_bytes()), (int32_t) NULL_WORD);
  __ movl(STATE(_msg), (int)BytecodeInterpreter::got_monitors);
}


// Initial entry to C++ interpreter from the call_stub.
// This entry point is called the frame manager since it handles the generation
// of interpreter activation frames via requests directly from the vm (via call_stub)
// and via requests from the interpreter. The requests from the call_stub happen
// directly thru the entry point. Requests from the interpreter happen via returning
// from the interpreter and examining the message the interpreter has returned to
// the frame manager. The frame manager can take the following requests:

// NO_REQUEST - error, should never happen.
// MORE_MONITORS - need a new monitor. Shuffle the expression stack on down and
//                 allocate a new monitor.
// CALL_METHOD - setup a new activation to call a new method. Very similar to what
//               happens during entry during the entry via the call stub.
// RETURN_FROM_METHOD - remove an activation. Return to interpreter or call stub.
//
// Arguments:
//
// rbx: methodOop
// rcx: receiver - unused (retrieved from stack as needed)
// rsi/r13: previous frame manager state (NULL from the call_stub/c1/c2)
//
//
// Stack layout at entry
//
// [ return address     ] <--- rsp
// [ parameter n        ]
//   ...
// [ parameter 1        ]
// [ expression stack   ]
//
//
// We are free to blow any registers we like because the call_stub which brought us here
// initially has preserved the callee save registers already.
//
//

static address interpreter_frame_manager = NULL;

address InterpreterGenerator::generate_normal_entry(bool synchronized) {

  // rbx: methodOop
  // rsi/r13: sender sp

  // Because we redispatch "recursive" interpreter entries thru this same entry point
  // the "input" register usage is a little strange and not what you expect coming
  // from the call_stub. From the call stub rsi/rdi (current/previous) interpreter
  // state are NULL but on "recursive" dispatches they are what you'd expect.
  // rsi: current interpreter state (C++ interpreter) must preserve (null from call_stub/c1/c2)


  // A single frame manager is plenty as we don't specialize for synchronized. We could and
  // the code is pretty much ready. Would need to change the test below and for good measure
  // modify generate_interpreter_state to only do the (pre) sync stuff stuff for synchronized
  // routines. Not clear this is worth it yet.

  if (interpreter_frame_manager) return interpreter_frame_manager;

  address entry_point = __ pc();

  // Fast accessor methods share this entry point.
  // This works because frame manager is in the same codelet
  if (UseFastAccessorMethods && !synchronized) __ bind(fast_accessor_slow_entry_path);

  Label dispatch_entry_2;
  __ movptr(rcx, sender_sp_on_entry);
  __ movptr(state, (int32_t)NULL_WORD);                              // no current activation

  __ jmp(dispatch_entry_2);

  const Register locals  = rdi;

  Label re_dispatch;

  __ bind(re_dispatch);

  // save sender sp (doesn't include return address
  __ lea(rcx, Address(rsp, wordSize));

  __ bind(dispatch_entry_2);

  // save sender sp
  __ push(rcx);

  const Address size_of_parameters(rbx, methodOopDesc::size_of_parameters_offset());
  const Address size_of_locals    (rbx, methodOopDesc::size_of_locals_offset());
  const Address access_flags      (rbx, methodOopDesc::access_flags_offset());

  // const Address monitor_block_top (rbp, frame::interpreter_frame_monitor_block_top_offset * wordSize);
  // const Address monitor_block_bot (rbp, frame::interpreter_frame_initial_sp_offset        * wordSize);
  // const Address monitor(rbp, frame::interpreter_frame_initial_sp_offset * wordSize - (int)sizeof(BasicObjectLock));

  // get parameter size (always needed)
  __ load_unsigned_short(rcx, size_of_parameters);

  // rbx: methodOop
  // rcx: size of parameters
  __ load_unsigned_short(rdx, size_of_locals);                     // get size of locals in words

  __ subptr(rdx, rcx);                                             // rdx = no. of additional locals

  // see if we've got enough room on the stack for locals plus overhead.
  generate_stack_overflow_check();                                 // C++

  // c++ interpreter does not use stack banging or any implicit exceptions
  // leave for now to verify that check is proper.
  bang_stack_shadow_pages(false);



  // compute beginning of parameters (rdi)
  __ lea(locals, Address(rsp, rcx, Address::times_ptr, wordSize));

  // save sender's sp
  // __ movl(rcx, rsp);

  // get sender's sp
  __ pop(rcx);

  // get return address
  __ pop(rax);

  // rdx - # of additional locals
  // allocate space for locals
  // explicitly initialize locals
  {
    Label exit, loop;
    __ testl(rdx, rdx);                               // (32bit ok)
    __ jcc(Assembler::lessEqual, exit);               // do nothing if rdx <= 0
    __ bind(loop);
    __ push((int32_t)NULL_WORD);                      // initialize local variables
    __ decrement(rdx);                                // until everything initialized
    __ jcc(Assembler::greater, loop);
    __ bind(exit);
  }


  // Assumes rax = return address

  // allocate and initialize new interpreterState and method expression stack
  // IN(locals) ->  locals
  // IN(state) -> any current interpreter activation
  // destroys rax, rcx, rdx, rdi
  // OUT (state) -> new interpreterState
  // OUT(rsp) -> bottom of methods expression stack

  generate_compute_interpreter_state(state, locals, rcx, false);

  // Call interpreter

  Label call_interpreter;
  __ bind(call_interpreter);

  // c++ interpreter does not use stack banging or any implicit exceptions
  // leave for now to verify that check is proper.
  bang_stack_shadow_pages(false);


  // Call interpreter enter here if message is
  // set and we know stack size is valid

  Label call_interpreter_2;

  __ bind(call_interpreter_2);

  {
    const Register thread  = NOT_LP64(rcx) LP64_ONLY(r15_thread);

#ifdef _LP64
    __ mov(c_rarg0, state);
#else
    __ push(state);                                                 // push arg to interpreter
    __ movptr(thread, STATE(_thread));
#endif // _LP64

    // We can setup the frame anchor with everything we want at this point
    // as we are thread_in_Java and no safepoints can occur until we go to
    // vm mode. We do have to clear flags on return from vm but that is it
    //
    __ movptr(Address(thread, JavaThread::last_Java_fp_offset()), rbp);
    __ movptr(Address(thread, JavaThread::last_Java_sp_offset()), rsp);

    // Call the interpreter

    RuntimeAddress normal(CAST_FROM_FN_PTR(address, BytecodeInterpreter::run));
    RuntimeAddress checking(CAST_FROM_FN_PTR(address, BytecodeInterpreter::runWithChecks));

    __ call(JvmtiExport::can_post_interpreter_events() ? checking : normal);
    NOT_LP64(__ pop(rax);)                                          // discard parameter to run
    //
    // state is preserved since it is callee saved
    //

    // reset_last_Java_frame

    NOT_LP64(__ movl(thread, STATE(_thread));)
    __ reset_last_Java_frame(thread, true, true);
  }

  // examine msg from interpreter to determine next action

  __ movl(rdx, STATE(_msg));                                       // Get new message

  Label call_method;
  Label return_from_interpreted_method;
  Label throw_exception;
  Label bad_msg;
  Label do_OSR;

  __ cmpl(rdx, (int32_t)BytecodeInterpreter::call_method);
  __ jcc(Assembler::equal, call_method);
  __ cmpl(rdx, (int32_t)BytecodeInterpreter::return_from_method);
  __ jcc(Assembler::equal, return_from_interpreted_method);
  __ cmpl(rdx, (int32_t)BytecodeInterpreter::do_osr);
  __ jcc(Assembler::equal, do_OSR);
  __ cmpl(rdx, (int32_t)BytecodeInterpreter::throwing_exception);
  __ jcc(Assembler::equal, throw_exception);
  __ cmpl(rdx, (int32_t)BytecodeInterpreter::more_monitors);
  __ jcc(Assembler::notEqual, bad_msg);

  // Allocate more monitor space, shuffle expression stack....

  generate_more_monitors();

  __ jmp(call_interpreter);

  // uncommon trap needs to jump to here to enter the interpreter (re-execute current bytecode)
  unctrap_frame_manager_entry  = __ pc();
  //
  // Load the registers we need.
  __ lea(state, Address(rbp, -(int)sizeof(BytecodeInterpreter)));
  __ movptr(rsp, STATE(_stack_limit));                             // restore expression stack to full depth
  __ jmp(call_interpreter_2);



  //=============================================================================
  // Returning from a compiled method into a deopted method. The bytecode at the
  // bcp has completed. The result of the bytecode is in the native abi (the tosca
  // for the template based interpreter). Any stack space that was used by the
  // bytecode that has completed has been removed (e.g. parameters for an invoke)
  // so all that we have to do is place any pending result on the expression stack
  // and resume execution on the next bytecode.


  generate_deopt_handling();
  __ jmp(call_interpreter);


  // Current frame has caught an exception we need to dispatch to the
  // handler. We can get here because a native interpreter frame caught
  // an exception in which case there is no handler and we must rethrow
  // If it is a vanilla interpreted frame the we simply drop into the
  // interpreter and let it do the lookup.

  Interpreter::_rethrow_exception_entry = __ pc();
  // rax: exception
  // rdx: return address/pc that threw exception

  Label return_with_exception;
  Label unwind_and_forward;

  // restore state pointer.
  __ lea(state, Address(rbp,  -(int)sizeof(BytecodeInterpreter)));

  __ movptr(rbx, STATE(_method));                       // get method
#ifdef _LP64
  __ movptr(Address(r15_thread, Thread::pending_exception_offset()), rax);
#else
  __ movl(rcx, STATE(_thread));                       // get thread

  // Store exception with interpreter will expect it
  __ movptr(Address(rcx, Thread::pending_exception_offset()), rax);
#endif // _LP64

  // is current frame vanilla or native?

  __ movl(rdx, access_flags);
  __ testl(rdx, JVM_ACC_NATIVE);
  __ jcc(Assembler::zero, return_with_exception);     // vanilla interpreted frame, handle directly

  // We drop thru to unwind a native interpreted frame with a pending exception
  // We jump here for the initial interpreter frame with exception pending
  // We unwind the current acivation and forward it to our caller.

  __ bind(unwind_and_forward);

  // unwind rbp, return stack to unextended value and re-push return address

  __ movptr(rcx, STATE(_sender_sp));
  __ leave();
  __ pop(rdx);
  __ mov(rsp, rcx);
  __ push(rdx);
  __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));

  // Return point from a call which returns a result in the native abi
  // (c1/c2/jni-native). This result must be processed onto the java
  // expression stack.
  //
  // A pending exception may be present in which case there is no result present

  Label resume_interpreter;
  Label do_float;
  Label do_double;
  Label done_conv;

  // The FPU stack is clean if UseSSE >= 2 but must be cleaned in other cases
  if (UseSSE < 2) {
    __ lea(state, Address(rbp,  -(int)sizeof(BytecodeInterpreter)));
    __ movptr(rbx, STATE(_result._to_call._callee));                   // get method just executed
    __ movl(rcx, Address(rbx, methodOopDesc::result_index_offset()));
    __ cmpl(rcx, AbstractInterpreter::BasicType_as_index(T_FLOAT));    // Result stub address array index
    __ jcc(Assembler::equal, do_float);
    __ cmpl(rcx, AbstractInterpreter::BasicType_as_index(T_DOUBLE));    // Result stub address array index
    __ jcc(Assembler::equal, do_double);
#if !defined(_LP64) || defined(COMPILER1) || !defined(COMPILER2)
    __ empty_FPU_stack();
#endif // COMPILER2
    __ jmp(done_conv);

    __ bind(do_float);
#ifdef COMPILER2
    for (int i = 1; i < 8; i++) {
      __ ffree(i);
    }
#endif // COMPILER2
    __ jmp(done_conv);
    __ bind(do_double);
#ifdef COMPILER2
    for (int i = 1; i < 8; i++) {
      __ ffree(i);
    }
#endif // COMPILER2
    __ jmp(done_conv);
  } else {
    __ MacroAssembler::verify_FPU(0, "generate_return_entry_for compiled");
    __ jmp(done_conv);
  }

  // Return point to interpreter from compiled/native method
  InternalAddress return_from_native_method(__ pc());

  __ bind(done_conv);


  // Result if any is in tosca. The java expression stack is in the state that the
  // calling convention left it (i.e. params may or may not be present)
  // Copy the result from tosca and place it on java expression stack.

  // Restore rsi/r13 as compiled code may not preserve it

  __ lea(state, Address(rbp,  -(int)sizeof(BytecodeInterpreter)));

  // restore stack to what we had when we left (in case i2c extended it)

  __ movptr(rsp, STATE(_stack));
  __ lea(rsp, Address(rsp, wordSize));

  // If there is a pending exception then we don't really have a result to process

#ifdef _LP64
  __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
#else
  __ movptr(rcx, STATE(_thread));                       // get thread
  __ cmpptr(Address(rcx, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
#endif // _LP64
  __ jcc(Assembler::notZero, return_with_exception);

  // get method just executed
  __ movptr(rbx, STATE(_result._to_call._callee));

  // callee left args on top of expression stack, remove them
  __ load_unsigned_short(rcx, Address(rbx, methodOopDesc::size_of_parameters_offset()));
  __ lea(rsp, Address(rsp, rcx, Address::times_ptr));

  __ movl(rcx, Address(rbx, methodOopDesc::result_index_offset()));
  ExternalAddress tosca_to_stack((address)CppInterpreter::_tosca_to_stack);
  // Address index(noreg, rax, Address::times_ptr);
  __ movptr(rcx, ArrayAddress(tosca_to_stack, Address(noreg, rcx, Address::times_ptr)));
  // __ movl(rcx, Address(noreg, rcx, Address::times_ptr, int(AbstractInterpreter::_tosca_to_stack)));
  __ call(rcx);                                               // call result converter
  __ jmp(resume_interpreter);

  // An exception is being caught on return to a vanilla interpreter frame.
  // Empty the stack and resume interpreter

  __ bind(return_with_exception);

  // Exception present, empty stack
  __ movptr(rsp, STATE(_stack_base));
  __ jmp(resume_interpreter);

  // Return from interpreted method we return result appropriate to the caller (i.e. "recursive"
  // interpreter call, or native) and unwind this interpreter activation.
  // All monitors should be unlocked.

  __ bind(return_from_interpreted_method);

  Label return_to_initial_caller;

  __ movptr(rbx, STATE(_method));                                   // get method just executed
  __ cmpptr(STATE(_prev_link), (int32_t)NULL_WORD);                 // returning from "recursive" interpreter call?
  __ movl(rax, Address(rbx, methodOopDesc::result_index_offset())); // get result type index
  __ jcc(Assembler::equal, return_to_initial_caller);               // back to native code (call_stub/c1/c2)

  // Copy result to callers java stack
  ExternalAddress stack_to_stack((address)CppInterpreter::_stack_to_stack);
  // Address index(noreg, rax, Address::times_ptr);

  __ movptr(rax, ArrayAddress(stack_to_stack, Address(noreg, rax, Address::times_ptr)));
  // __ movl(rax, Address(noreg, rax, Address::times_ptr, int(AbstractInterpreter::_stack_to_stack)));
  __ call(rax);                                                     // call result converter

  Label unwind_recursive_activation;
  __ bind(unwind_recursive_activation);

  // returning to interpreter method from "recursive" interpreter call
  // result converter left rax pointing to top of the java stack for method we are returning
  // to. Now all we must do is unwind the state from the completed call

  __ movptr(state, STATE(_prev_link));                              // unwind state
  __ leave();                                                       // pop the frame
  __ mov(rsp, rax);                                                 // unwind stack to remove args

  // Resume the interpreter. The current frame contains the current interpreter
  // state object.
  //

  __ bind(resume_interpreter);

  // state == interpreterState object for method we are resuming

  __ movl(STATE(_msg), (int)BytecodeInterpreter::method_resume);
  __ lea(rsp, Address(rsp, -wordSize));                            // prepush stack (result if any already present)
  __ movptr(STATE(_stack), rsp);                                   // inform interpreter of new stack depth (parameters removed,
                                                                   // result if any on stack already )
  __ movptr(rsp, STATE(_stack_limit));                             // restore expression stack to full depth
  __ jmp(call_interpreter_2);                                      // No need to bang

  // interpreter returning to native code (call_stub/c1/c2)
  // convert result and unwind initial activation
  // rax - result index

  __ bind(return_to_initial_caller);
  ExternalAddress stack_to_native((address)CppInterpreter::_stack_to_native_abi);
  // Address index(noreg, rax, Address::times_ptr);

  __ movptr(rax, ArrayAddress(stack_to_native, Address(noreg, rax, Address::times_ptr)));
  __ call(rax);                                                    // call result converter

  Label unwind_initial_activation;
  __ bind(unwind_initial_activation);

  // RETURN TO CALL_STUB/C1/C2 code (result if any in rax/rdx ST(0))

  /* Current stack picture

        [ incoming parameters ]
        [ extra locals ]
        [ return address to CALL_STUB/C1/C2]
  fp -> [ CALL_STUB/C1/C2 fp ]
        BytecodeInterpreter object
        expression stack
  sp ->

  */

  // return restoring the stack to the original sender_sp value

  __ movptr(rcx, STATE(_sender_sp));
  __ leave();
  __ pop(rdi);                                                        // get return address
  // set stack to sender's sp
  __ mov(rsp, rcx);
  __ jmp(rdi);                                                        // return to call_stub

  // OSR request, adjust return address to make current frame into adapter frame
  // and enter OSR nmethod

  __ bind(do_OSR);

  Label remove_initial_frame;

  // We are going to pop this frame. Is there another interpreter frame underneath
  // it or is it callstub/compiled?

  // Move buffer to the expected parameter location
  __ movptr(rcx, STATE(_result._osr._osr_buf));

  __ movptr(rax, STATE(_result._osr._osr_entry));

  __ cmpptr(STATE(_prev_link), (int32_t)NULL_WORD);            // returning from "recursive" interpreter call?
  __ jcc(Assembler::equal, remove_initial_frame);              // back to native code (call_stub/c1/c2)

  __ movptr(sender_sp_on_entry, STATE(_sender_sp));            // get sender's sp in expected register
  __ leave();                                                  // pop the frame
  __ mov(rsp, sender_sp_on_entry);                             // trim any stack expansion


  // We know we are calling compiled so push specialized return
  // method uses specialized entry, push a return so we look like call stub setup
  // this path will handle fact that result is returned in registers and not
  // on the java stack.

  __ pushptr(return_from_native_method.addr());

  __ jmp(rax);

  __ bind(remove_initial_frame);

  __ movptr(rdx, STATE(_sender_sp));
  __ leave();
  // get real return
  __ pop(rsi);
  // set stack to sender's sp
  __ mov(rsp, rdx);
  // repush real return
  __ push(rsi);
  // Enter OSR nmethod
  __ jmp(rax);




  // Call a new method. All we do is (temporarily) trim the expression stack
  // push a return address to bring us back to here and leap to the new entry.

  __ bind(call_method);

  // stack points to next free location and not top element on expression stack
  // method expects sp to be pointing to topmost element

  __ movptr(rsp, STATE(_stack));                                     // pop args to c++ interpreter, set sp to java stack top
  __ lea(rsp, Address(rsp, wordSize));

  __ movptr(rbx, STATE(_result._to_call._callee));                   // get method to execute

  // don't need a return address if reinvoking interpreter

  // Make it look like call_stub calling conventions

  // Get (potential) receiver
  __ load_unsigned_short(rcx, size_of_parameters);                   // get size of parameters in words

  ExternalAddress recursive(CAST_FROM_FN_PTR(address, RecursiveInterpreterActivation));
  __ pushptr(recursive.addr());                                      // make it look good in the debugger

  InternalAddress entry(entry_point);
  __ cmpptr(STATE(_result._to_call._callee_entry_point), entry.addr()); // returning to interpreter?
  __ jcc(Assembler::equal, re_dispatch);                             // yes

  __ pop(rax);                                                       // pop dummy address


  // get specialized entry
  __ movptr(rax, STATE(_result._to_call._callee_entry_point));
  // set sender SP
  __ mov(sender_sp_on_entry, rsp);

  // method uses specialized entry, push a return so we look like call stub setup
  // this path will handle fact that result is returned in registers and not
  // on the java stack.

  __ pushptr(return_from_native_method.addr());

  __ jmp(rax);

  __ bind(bad_msg);
  __ stop("Bad message from interpreter");

  // Interpreted method "returned" with an exception pass it on...
  // Pass result, unwind activation and continue/return to interpreter/call_stub
  // We handle result (if any) differently based on return to interpreter or call_stub

  Label unwind_initial_with_pending_exception;

  __ bind(throw_exception);
  __ cmpptr(STATE(_prev_link), (int32_t)NULL_WORD);                 // returning from recursive interpreter call?
  __ jcc(Assembler::equal, unwind_initial_with_pending_exception);  // no, back to native code (call_stub/c1/c2)
  __ movptr(rax, STATE(_locals));                                   // pop parameters get new stack value
  __ addptr(rax, wordSize);                                         // account for prepush before we return
  __ jmp(unwind_recursive_activation);

  __ bind(unwind_initial_with_pending_exception);

  // We will unwind the current (initial) interpreter frame and forward
  // the exception to the caller. We must put the exception in the
  // expected register and clear pending exception and then forward.

  __ jmp(unwind_and_forward);

  interpreter_frame_manager = entry_point;
  return entry_point;
}

address AbstractInterpreterGenerator::generate_method_entry(AbstractInterpreter::MethodKind kind) {
  // determine code generation flags
  bool synchronized = false;
  address entry_point = NULL;

  switch (kind) {
    case Interpreter::zerolocals             :                                                                             break;
    case Interpreter::zerolocals_synchronized: synchronized = true;                                                        break;
    case Interpreter::native                 : entry_point = ((InterpreterGenerator*)this)->generate_native_entry(false);  break;
    case Interpreter::native_synchronized    : entry_point = ((InterpreterGenerator*)this)->generate_native_entry(true);   break;
    case Interpreter::empty                  : entry_point = ((InterpreterGenerator*)this)->generate_empty_entry();        break;
    case Interpreter::accessor               : entry_point = ((InterpreterGenerator*)this)->generate_accessor_entry();     break;
    case Interpreter::abstract               : entry_point = ((InterpreterGenerator*)this)->generate_abstract_entry();     break;
    case Interpreter::method_handle          : entry_point = ((InterpreterGenerator*)this)->generate_method_handle_entry(); break;

    case Interpreter::java_lang_math_sin     : // fall thru
    case Interpreter::java_lang_math_cos     : // fall thru
    case Interpreter::java_lang_math_tan     : // fall thru
    case Interpreter::java_lang_math_abs     : // fall thru
    case Interpreter::java_lang_math_log     : // fall thru
    case Interpreter::java_lang_math_log10   : // fall thru
    case Interpreter::java_lang_math_sqrt    : entry_point = ((InterpreterGenerator*)this)->generate_math_entry(kind);     break;
    case Interpreter::java_lang_ref_reference_get
                                             : entry_point = ((InterpreterGenerator*)this)->generate_Reference_get_entry(); break;
    default                                  : ShouldNotReachHere();                                                       break;
  }

  if (entry_point) return entry_point;

  return ((InterpreterGenerator*)this)->generate_normal_entry(synchronized);

}

InterpreterGenerator::InterpreterGenerator(StubQueue* code)
 : CppInterpreterGenerator(code) {
   generate_all(); // down here so it can be "virtual"
}

// Deoptimization helpers for C++ interpreter

// How much stack a method activation needs in words.
int AbstractInterpreter::size_top_interpreter_activation(methodOop method) {

  const int stub_code = 4;  // see generate_call_stub
  // Save space for one monitor to get into the interpreted method in case
  // the method is synchronized
  int monitor_size    = method->is_synchronized() ?
                                1*frame::interpreter_frame_monitor_size() : 0;

  // total static overhead size. Account for interpreter state object, return
  // address, saved rbp and 2 words for a "static long no_params() method" issue.

  const int overhead_size = sizeof(BytecodeInterpreter)/wordSize +
    ( frame::sender_sp_offset - frame::link_offset) + 2;

  const int extra_stack = 0; //6815692//methodOopDesc::extra_stack_entries();
  const int method_stack = (method->max_locals() + method->max_stack() + extra_stack) *
                           Interpreter::stackElementWords();
  return overhead_size + method_stack + stub_code;
}

// returns the activation size.
static int size_activation_helper(int extra_locals_size, int monitor_size) {
  return (extra_locals_size +                  // the addition space for locals
          2*BytesPerWord +                     // return address and saved rbp
          2*BytesPerWord +                     // "static long no_params() method" issue
          sizeof(BytecodeInterpreter) +               // interpreterState
          monitor_size);                       // monitors
}

void BytecodeInterpreter::layout_interpreterState(interpreterState to_fill,
                                           frame* caller,
                                           frame* current,
                                           methodOop method,
                                           intptr_t* locals,
                                           intptr_t* stack,
                                           intptr_t* stack_base,
                                           intptr_t* monitor_base,
                                           intptr_t* frame_bottom,
                                           bool is_top_frame
                                           )
{
  // What about any vtable?
  //
  to_fill->_thread = JavaThread::current();
  // This gets filled in later but make it something recognizable for now
  to_fill->_bcp = method->code_base();
  to_fill->_locals = locals;
  to_fill->_constants = method->constants()->cache();
  to_fill->_method = method;
  to_fill->_mdx = NULL;
  to_fill->_stack = stack;
  if (is_top_frame && JavaThread::current()->popframe_forcing_deopt_reexecution() ) {
    to_fill->_msg = deopt_resume2;
  } else {
    to_fill->_msg = method_resume;
  }
  to_fill->_result._to_call._bcp_advance = 0;
  to_fill->_result._to_call._callee_entry_point = NULL; // doesn't matter to anyone
  to_fill->_result._to_call._callee = NULL; // doesn't matter to anyone
  to_fill->_prev_link = NULL;

  to_fill->_sender_sp = caller->unextended_sp();

  if (caller->is_interpreted_frame()) {
    interpreterState prev  = caller->get_interpreterState();
    to_fill->_prev_link = prev;
    // *current->register_addr(GR_Iprev_state) = (intptr_t) prev;
    // Make the prev callee look proper
    prev->_result._to_call._callee = method;
    if (*prev->_bcp == Bytecodes::_invokeinterface) {
      prev->_result._to_call._bcp_advance = 5;
    } else {
      prev->_result._to_call._bcp_advance = 3;
    }
  }
  to_fill->_oop_temp = NULL;
  to_fill->_stack_base = stack_base;
  // Need +1 here because stack_base points to the word just above the first expr stack entry
  // and stack_limit is supposed to point to the word just below the last expr stack entry.
  // See generate_compute_interpreter_state.
  int extra_stack = 0; //6815692//methodOopDesc::extra_stack_entries();
  to_fill->_stack_limit = stack_base - (method->max_stack() + extra_stack + 1);
  to_fill->_monitor_base = (BasicObjectLock*) monitor_base;

  to_fill->_self_link = to_fill;
  assert(stack >= to_fill->_stack_limit && stack < to_fill->_stack_base,
         "Stack top out of range");
}

int AbstractInterpreter::layout_activation(methodOop method,
                                                int tempcount,  //
                                                int popframe_extra_args,
                                                int moncount,
                                                int callee_param_count,
                                                int callee_locals,
                                                frame* caller,
                                                frame* interpreter_frame,
                                                bool is_top_frame) {

  assert(popframe_extra_args == 0, "FIX ME");
  // NOTE this code must exactly mimic what InterpreterGenerator::generate_compute_interpreter_state()
  // does as far as allocating an interpreter frame.
  // If interpreter_frame!=NULL, set up the method, locals, and monitors.
  // The frame interpreter_frame, if not NULL, is guaranteed to be the right size,
  // as determined by a previous call to this method.
  // It is also guaranteed to be walkable even though it is in a skeletal state
  // NOTE: return size is in words not bytes
  // NOTE: tempcount is the current size of the java expression stack. For top most
  //       frames we will allocate a full sized expression stack and not the curback
  //       version that non-top frames have.

  // Calculate the amount our frame will be adjust by the callee. For top frame
  // this is zero.

  // NOTE: ia64 seems to do this wrong (or at least backwards) in that it
  // calculates the extra locals based on itself. Not what the callee does
  // to it. So it ignores last_frame_adjust value. Seems suspicious as far
  // as getting sender_sp correct.

  int extra_locals_size = (callee_locals - callee_param_count) * BytesPerWord;
  int monitor_size = sizeof(BasicObjectLock) * moncount;

  // First calculate the frame size without any java expression stack
  int short_frame_size = size_activation_helper(extra_locals_size,
                                                monitor_size);

  // Now with full size expression stack
  int extra_stack = 0; //6815692//methodOopDesc::extra_stack_entries();
  int full_frame_size = short_frame_size + (method->max_stack() + extra_stack) * BytesPerWord;

  // and now with only live portion of the expression stack
  short_frame_size = short_frame_size + tempcount * BytesPerWord;

  // the size the activation is right now. Only top frame is full size
  int frame_size = (is_top_frame ? full_frame_size : short_frame_size);

  if (interpreter_frame != NULL) {
#ifdef ASSERT
    assert(caller->unextended_sp() == interpreter_frame->interpreter_frame_sender_sp(), "Frame not properly walkable");
#endif

    // MUCHO HACK

    intptr_t* frame_bottom = (intptr_t*) ((intptr_t)interpreter_frame->sp() - (full_frame_size - frame_size));

    /* Now fillin the interpreterState object */

    // The state object is the first thing on the frame and easily located

    interpreterState cur_state = (interpreterState) ((intptr_t)interpreter_frame->fp() - sizeof(BytecodeInterpreter));


    // Find the locals pointer. This is rather simple on x86 because there is no
    // confusing rounding at the callee to account for. We can trivially locate
    // our locals based on the current fp().
    // Note: the + 2 is for handling the "static long no_params() method" issue.
    // (too bad I don't really remember that issue well...)

    intptr_t* locals;
    // If the caller is interpreted we need to make sure that locals points to the first
    // argument that the caller passed and not in an area where the stack might have been extended.
    // because the stack to stack to converter needs a proper locals value in order to remove the
    // arguments from the caller and place the result in the proper location. Hmm maybe it'd be
    // simpler if we simply stored the result in the BytecodeInterpreter object and let the c++ code
    // adjust the stack?? HMMM QQQ
    //
    if (caller->is_interpreted_frame()) {
      // locals must agree with the caller because it will be used to set the
      // caller's tos when we return.
      interpreterState prev  = caller->get_interpreterState();
      // stack() is prepushed.
      locals = prev->stack() + method->size_of_parameters();
      // locals = caller->unextended_sp() + (method->size_of_parameters() - 1);
      if (locals != interpreter_frame->fp() + frame::sender_sp_offset + (method->max_locals() - 1) + 2) {
        // os::breakpoint();
      }
    } else {
      // this is where a c2i would have placed locals (except for the +2)
      locals = interpreter_frame->fp() + frame::sender_sp_offset + (method->max_locals() - 1) + 2;
    }

    intptr_t* monitor_base = (intptr_t*) cur_state;
    intptr_t* stack_base = (intptr_t*) ((intptr_t) monitor_base - monitor_size);
    /* +1 because stack is always prepushed */
    intptr_t* stack = (intptr_t*) ((intptr_t) stack_base - (tempcount + 1) * BytesPerWord);


    BytecodeInterpreter::layout_interpreterState(cur_state,
                                          caller,
                                          interpreter_frame,
                                          method,
                                          locals,
                                          stack,
                                          stack_base,
                                          monitor_base,
                                          frame_bottom,
                                          is_top_frame);

    // BytecodeInterpreter::pd_layout_interpreterState(cur_state, interpreter_return_address, interpreter_frame->fp());
  }
  return frame_size/BytesPerWord;
}

#endif // CC_INTERP (all)