view src/cpu/sparc/vm/cppInterpreter_sparc.cpp @ 2352: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 8033953d67ff
children 92add02409c9
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 "shadow" interpreter frames are on stack. It is also
// used to distinguish interpreter frames.

extern "C" void RecursiveInterpreterActivation(interpreterState istate) {
  ShouldNotReachHere();
}

bool CppInterpreter::contains(address pc) {
  return ( _code->contains(pc) ||
         ( pc == (CAST_FROM_FN_PTR(address, RecursiveInterpreterActivation) + frame::pc_return_offset)));
}

#define STATE(field_name) Lstate, in_bytes(byte_offset_of(BytecodeInterpreter, field_name))
#define __ _masm->

Label frame_manager_entry;
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.

static address unctrap_frame_manager_entry  = NULL;

static address interpreter_return_address  = 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;

const Register prevState = G1_scratch;

void InterpreterGenerator::save_native_result(void) {
  // result potentially in O0/O1: save it across calls
  __ stf(FloatRegisterImpl::D, F0, STATE(_native_fresult));
#ifdef _LP64
  __ stx(O0, STATE(_native_lresult));
#else
  __ std(O0, STATE(_native_lresult));
#endif
}

void InterpreterGenerator::restore_native_result(void) {

  // Restore any method result value
  __ ldf(FloatRegisterImpl::D, STATE(_native_fresult), F0);
#ifdef _LP64
  __ ldx(STATE(_native_lresult), O0);
#else
  __ ldd(STATE(_native_lresult), O0);
#endif
}

// A result handler converts/unboxes a native call result into
// a java interpreter/compiler result. The current frame is an
// interpreter frame. The activation frame unwind code must be
// consistent with that of TemplateTable::_return(...). In the
// case of native methods, the caller's SP was not modified.
address CppInterpreterGenerator::generate_result_handler_for(BasicType type) {
  address entry = __ pc();
  Register Itos_i  = Otos_i ->after_save();
  Register Itos_l  = Otos_l ->after_save();
  Register Itos_l1 = Otos_l1->after_save();
  Register Itos_l2 = Otos_l2->after_save();
  switch (type) {
    case T_BOOLEAN: __ subcc(G0, O0, G0); __ addc(G0, 0, Itos_i); break; // !0 => true; 0 => false
    case T_CHAR   : __ sll(O0, 16, O0); __ srl(O0, 16, Itos_i);   break; // cannot use and3, 0xFFFF too big as immediate value!
    case T_BYTE   : __ sll(O0, 24, O0); __ sra(O0, 24, Itos_i);   break;
    case T_SHORT  : __ sll(O0, 16, O0); __ sra(O0, 16, Itos_i);   break;
    case T_LONG   :
#ifndef _LP64
                    __ mov(O1, Itos_l2);  // move other half of long
#endif              // ifdef or no ifdef, fall through to the T_INT case
    case T_INT    : __ mov(O0, Itos_i);                         break;
    case T_VOID   : /* nothing to do */                         break;
    case T_FLOAT  : assert(F0 == Ftos_f, "fix this code" );     break;
    case T_DOUBLE : assert(F0 == Ftos_d, "fix this code" );     break;
    case T_OBJECT :
      __ ld_ptr(STATE(_oop_temp), Itos_i);
      __ verify_oop(Itos_i);
      break;
    default       : ShouldNotReachHere();
  }
  __ ret();                           // return from interpreter activation
  __ delayed()->restore(I5_savedSP, G0, SP);  // remove interpreter frame
  NOT_PRODUCT(__ emit_long(0);)       // marker for disassembly
  return entry;
}

// tosca based result to c++ interpreter stack based result.
// Result goes to address in L1_scratch

address CppInterpreterGenerator::generate_tosca_to_stack_converter(BasicType type) {
  // A result is in the native abi result register from a native method call.
  // We need to return this result to the interpreter by pushing the result on the interpreter's
  // stack. This is relatively simple the destination is in L1_scratch
  // i.e. L1_scratch is the first free element on the stack. If we "push" a return value we must
  // adjust L1_scratch
  address entry = __ pc();
  switch (type) {
    case T_BOOLEAN:
      // !0 => true; 0 => false
      __ subcc(G0, O0, G0);
      __ addc(G0, 0, O0);
      __ st(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;

    // cannot use and3, 0xFFFF too big as immediate value!
    case T_CHAR   :
      __ sll(O0, 16, O0);
      __ srl(O0, 16, O0);
      __ st(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;

    case T_BYTE   :
      __ sll(O0, 24, O0);
      __ sra(O0, 24, O0);
      __ st(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;

    case T_SHORT  :
      __ sll(O0, 16, O0);
      __ sra(O0, 16, O0);
      __ st(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;
    case T_LONG   :
#ifndef _LP64
#if defined(COMPILER2)
  // All return values are where we want them, except for Longs.  C2 returns
  // longs in G1 in the 32-bit build whereas the interpreter wants them in O0/O1.
  // Since the interpreter will return longs in G1 and O0/O1 in the 32bit
  // build even if we are returning from interpreted we just do a little
  // stupid shuffing.
  // Note: I tried to make c2 return longs in O0/O1 and G1 so we wouldn't have to
  // do this here. Unfortunately if we did a rethrow we'd see an machepilog node
  // first which would move g1 -> O0/O1 and destroy the exception we were throwing.
      __ stx(G1, L1_scratch, -wordSize);
#else
      // native result is in O0, O1
      __ st(O1, L1_scratch, 0);                      // Low order
      __ st(O0, L1_scratch, -wordSize);              // High order
#endif /* COMPILER2 */
#else
      __ stx(O0, L1_scratch, -wordSize);
#endif
      __ sub(L1_scratch, 2*wordSize, L1_scratch);
      break;

    case T_INT    :
      __ st(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;

    case T_VOID   : /* nothing to do */
      break;

    case T_FLOAT  :
      __ stf(FloatRegisterImpl::S, F0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;

    case T_DOUBLE :
      // Every stack slot is aligned on 64 bit, However is this
      // the correct stack slot on 64bit?? QQQ
      __ stf(FloatRegisterImpl::D, F0, L1_scratch, -wordSize);
      __ sub(L1_scratch, 2*wordSize, L1_scratch);
      break;
    case T_OBJECT :
      __ verify_oop(O0);
      __ st_ptr(O0, L1_scratch, 0);
      __ sub(L1_scratch, wordSize, L1_scratch);
      break;
    default       : ShouldNotReachHere();
  }
  __ retl();                          // return from interpreter activation
  __ delayed()->nop();                // schedule this better
  NOT_PRODUCT(__ emit_long(0);)       // marker for disassembly
  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 Lstate 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 esp 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: O0 - points to source (callee stack top)
  //           O1 - points to destination (caller stack top [i.e. free location])
  // destroys O2, O3
  //

  address entry = __ pc();
  switch (type) {
    case T_VOID:  break;
      break;
    case T_FLOAT  :
    case T_BOOLEAN:
    case T_CHAR   :
    case T_BYTE   :
    case T_SHORT  :
    case T_INT    :
      // 1 word result
      __ ld(O0, 0, O2);
      __ st(O2, O1, 0);
      __ sub(O1, wordSize, O1);
      break;
    case T_DOUBLE  :
    case T_LONG    :
      // 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.
#ifdef _LP64
      __ ld_ptr(O0, 0, O2);
      __ st_ptr(O2, O1, -wordSize);
#else
      __ ld(O0, 0, O2);
      __ ld(O0, wordSize, O3);
      __ st(O3, O1, 0);
      __ st(O2, O1, -wordSize);
#endif
      __ sub(O1, 2*wordSize, O1);
      break;
    case T_OBJECT :
      __ ld_ptr(O0, 0, O2);
      __ verify_oop(O2);                                               // verify it
      __ st_ptr(O2, O1, 0);
      __ sub(O1, wordSize, O1);
      break;
    default       : ShouldNotReachHere();
  }
  __ retl();
  __ delayed()->nop(); // QQ schedule this better
  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.
  // We are in a new frame registers we set must be in caller (i.e. callstub) frame.
  //
  // 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: O0 - source (stack top)
  // On exit result in expected output register
  // QQQ schedule this better

  address entry = __ pc();
  switch (type) {
    case T_VOID:  break;
      break;
    case T_FLOAT  :
      __ ldf(FloatRegisterImpl::S, O0, 0, F0);
      break;
    case T_BOOLEAN:
    case T_CHAR   :
    case T_BYTE   :
    case T_SHORT  :
    case T_INT    :
      // 1 word result
      __ ld(O0, 0, O0->after_save());
      break;
    case T_DOUBLE  :
      __ ldf(FloatRegisterImpl::D, O0, 0, F0);
      break;
    case T_LONG    :
      // 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 interpretState
      // except we allocated one extra word for this intepretState so we won't overwrite it
      // when we return a two word result.
#ifdef _LP64
      __ ld_ptr(O0, 0, O0->after_save());
#else
      __ ld(O0, wordSize, O1->after_save());
      __ ld(O0, 0, O0->after_save());
#endif
#if defined(COMPILER2) && !defined(_LP64)
      // C2 expects long results in G1 we can't tell if we're returning to interpreted
      // or compiled so just be safe use G1 and O0/O1

      // Shift bits into high (msb) of G1
      __ sllx(Otos_l1->after_save(), 32, G1);
      // Zero extend low bits
      __ srl (Otos_l2->after_save(), 0, Otos_l2->after_save());
      __ or3 (Otos_l2->after_save(), G1, G1);
#endif /* COMPILER2 */
      break;
    case T_OBJECT :
      __ ld_ptr(O0, 0, O0->after_save());
      __ verify_oop(O0->after_save());                                               // verify it
      break;
    default       : ShouldNotReachHere();
  }
  __ retl();
  __ delayed()->nop();
  return entry;
}

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

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;
}

//
// 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
//
// Lmethod: method
// ??: invocation counter
//
void InterpreterGenerator::generate_counter_incr(Label* overflow, Label* profile_method, Label* profile_method_continue) {
  // Update standard invocation counters
  __ increment_invocation_counter(O0, G3_scratch);
  if (ProfileInterpreter) {  // %%% Merge this into methodDataOop
    __ ld_ptr(STATE(_method), G3_scratch);
    Address interpreter_invocation_counter(G3_scratch, 0, in_bytes(methodOopDesc::interpreter_invocation_counter_offset()));
    __ ld(interpreter_invocation_counter, G3_scratch);
    __ inc(G3_scratch);
    __ st(G3_scratch, interpreter_invocation_counter);
  }

  Address invocation_limit(G3_scratch, (address)&InvocationCounter::InterpreterInvocationLimit);
  __ sethi(invocation_limit);
  __ ld(invocation_limit, G3_scratch);
  __ cmp(O0, G3_scratch);
  __ br(Assembler::greaterEqualUnsigned, false, Assembler::pn, *overflow);
  __ delayed()->nop();

}

address InterpreterGenerator::generate_empty_entry(void) {

  // A method that does nothing but return...

  address entry = __ pc();
  Label slow_path;

  __ verify_oop(G5_method);

  // do nothing for empty methods (do not even increment invocation counter)
  if ( UseFastEmptyMethods) {
    // If we need a safepoint check, generate full interpreter entry.
    Address sync_state(G3_scratch, SafepointSynchronize::address_of_state());
    __ load_contents(sync_state, G3_scratch);
    __ cmp(G3_scratch, SafepointSynchronize::_not_synchronized);
    __ br(Assembler::notEqual, false, Assembler::pn, frame_manager_entry);
    __ delayed()->nop();

    // Code: _return
    __ retl();
    __ delayed()->mov(O5_savedSP, SP);
    return entry;
  }
  return NULL;
}

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

// Generates code to elide accessor methods
// Uses G3_scratch and G1_scratch as scratch
address InterpreterGenerator::generate_accessor_entry(void) {

  // 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.
  address entry = __ pc();
  Label slow_path;

  if ( UseFastAccessorMethods) {
    // Check if we need to reach a safepoint and generate full interpreter
    // frame if so.
    Address sync_state(G3_scratch, SafepointSynchronize::address_of_state());
    __ load_contents(sync_state, G3_scratch);
    __ cmp(G3_scratch, SafepointSynchronize::_not_synchronized);
    __ br(Assembler::notEqual, false, Assembler::pn, slow_path);
    __ delayed()->nop();

    // Check if local 0 != NULL
    __ ld_ptr(Gargs, G0, Otos_i ); // get local 0
    __ tst(Otos_i);  // check if local 0 == NULL and go the slow path
    __ brx(Assembler::zero, false, Assembler::pn, slow_path);
    __ delayed()->nop();


    // read first instruction word and extract bytecode @ 1 and index @ 2
    // get first 4 bytes of the bytecodes (big endian!)
    __ ld_ptr(Address(G5_method, 0, in_bytes(methodOopDesc::const_offset())), G1_scratch);
    __ ld(Address(G1_scratch, 0, in_bytes(constMethodOopDesc::codes_offset())), G1_scratch);

    // move index @ 2 far left then to the right most two bytes.
    __ sll(G1_scratch, 2*BitsPerByte, G1_scratch);
    __ srl(G1_scratch, 2*BitsPerByte - exact_log2(in_words(
                      ConstantPoolCacheEntry::size()) * BytesPerWord), G1_scratch);

    // get constant pool cache
    __ ld_ptr(G5_method, in_bytes(methodOopDesc::constants_offset()), G3_scratch);
    __ ld_ptr(G3_scratch, constantPoolOopDesc::cache_offset_in_bytes(), G3_scratch);

    // get specific constant pool cache entry
    __ add(G3_scratch, G1_scratch, G3_scratch);

    // Check the constant Pool cache entry to see if it has been resolved.
    // If not, need the slow path.
    ByteSize cp_base_offset = constantPoolCacheOopDesc::base_offset();
    __ ld_ptr(G3_scratch, in_bytes(cp_base_offset + ConstantPoolCacheEntry::indices_offset()), G1_scratch);
    __ srl(G1_scratch, 2*BitsPerByte, G1_scratch);
    __ and3(G1_scratch, 0xFF, G1_scratch);
    __ cmp(G1_scratch, Bytecodes::_getfield);
    __ br(Assembler::notEqual, false, Assembler::pn, slow_path);
    __ delayed()->nop();

    // Get the type and return field offset from the constant pool cache
    __ ld_ptr(G3_scratch, in_bytes(cp_base_offset + ConstantPoolCacheEntry::flags_offset()), G1_scratch);
    __ ld_ptr(G3_scratch, in_bytes(cp_base_offset + ConstantPoolCacheEntry::f2_offset()), G3_scratch);

    Label xreturn_path;
    // Need to differentiate between igetfield, agetfield, bgetfield etc.
    // because they are different sizes.
    // Get the type from the constant pool cache
    __ srl(G1_scratch, ConstantPoolCacheEntry::tosBits, G1_scratch);
    // Make sure we don't need to mask G1_scratch for tosBits after the above shift
    ConstantPoolCacheEntry::verify_tosBits();
    __ cmp(G1_scratch, atos );
    __ br(Assembler::equal, true, Assembler::pt, xreturn_path);
    __ delayed()->ld_ptr(Otos_i, G3_scratch, Otos_i);
    __ cmp(G1_scratch, itos);
    __ br(Assembler::equal, true, Assembler::pt, xreturn_path);
    __ delayed()->ld(Otos_i, G3_scratch, Otos_i);
    __ cmp(G1_scratch, stos);
    __ br(Assembler::equal, true, Assembler::pt, xreturn_path);
    __ delayed()->ldsh(Otos_i, G3_scratch, Otos_i);
    __ cmp(G1_scratch, ctos);
    __ br(Assembler::equal, true, Assembler::pt, xreturn_path);
    __ delayed()->lduh(Otos_i, G3_scratch, Otos_i);
#ifdef ASSERT
    __ cmp(G1_scratch, btos);
    __ br(Assembler::equal, true, Assembler::pt, xreturn_path);
    __ delayed()->ldsb(Otos_i, G3_scratch, Otos_i);
    __ should_not_reach_here();
#endif
    __ ldsb(Otos_i, G3_scratch, Otos_i);
    __ bind(xreturn_path);

    // _ireturn/_areturn
    __ retl();                      // return from leaf routine
    __ delayed()->mov(O5_savedSP, SP);

    // Generate regular method entry
    __ bind(slow_path);
    __ ba(false, fast_accessor_slow_entry_path);
    __ delayed()->nop();
    return entry;
  }
  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();
}

//
// Interpreter stub for calling a native method. (C++ interpreter)
// This sets up a somewhat different looking stack for calling the native method
// than the typical interpreter frame setup.
//

address InterpreterGenerator::generate_native_entry(bool synchronized) {
  address entry = __ pc();

  // the following temporary registers are used during frame creation
  const Register Gtmp1 = G3_scratch ;
  const Register Gtmp2 = G1_scratch;
  const Address size_of_parameters(G5_method, 0, in_bytes(methodOopDesc::size_of_parameters_offset()));

  bool inc_counter  = UseCompiler || CountCompiledCalls;

  // make sure registers are different!
  assert_different_registers(G2_thread, G5_method, Gargs, Gtmp1, Gtmp2);

  const Address access_flags      (G5_method, 0, in_bytes(methodOopDesc::access_flags_offset()));

  Label Lentry;
  __ bind(Lentry);

  __ verify_oop(G5_method);

  const Register Glocals_size = G3;
  assert_different_registers(Glocals_size, G4_scratch, Gframe_size);

  // make sure method is native & not abstract
  // rethink these assertions - they can be simplified and shared (gri 2/25/2000)
#ifdef ASSERT
  __ ld(access_flags, Gtmp1);
  {
    Label L;
    __ btst(JVM_ACC_NATIVE, Gtmp1);
    __ br(Assembler::notZero, false, Assembler::pt, L);
    __ delayed()->nop();
    __ stop("tried to execute non-native method as native");
    __ bind(L);
  }
  { Label L;
    __ btst(JVM_ACC_ABSTRACT, Gtmp1);
    __ br(Assembler::zero, false, Assembler::pt, L);
    __ delayed()->nop();
    __ stop("tried to execute abstract method as non-abstract");
    __ bind(L);
  }
#endif // ASSERT

  __ lduh(size_of_parameters, Gtmp1);
  __ sll(Gtmp1, LogBytesPerWord, Gtmp2);       // parameter size in bytes
  __ add(Gargs, Gtmp2, Gargs);                 // points to first local + BytesPerWord
  // NEW
  __ add(Gargs, -wordSize, Gargs);             // points to first local[0]
  // generate the code to allocate the interpreter stack frame
  // NEW FRAME ALLOCATED HERE
  // save callers original sp
  // __ mov(SP, I5_savedSP->after_restore());

  generate_compute_interpreter_state(Lstate, G0, true);

  // At this point Lstate points to new interpreter state
  //

  const Address do_not_unlock_if_synchronized(G2_thread, 0,
      in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()));
  // 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. If any exception was thrown by
  // runtime, exception handling i.e. unlock_if_synchronized_method will
  // check this thread local flag.
  // This flag has two effects, one is to force an unwind in the topmost
  // interpreter frame and not perform an unlock while doing so.

  __ movbool(true, G3_scratch);
  __ stbool(G3_scratch, do_not_unlock_if_synchronized);


  // increment invocation counter and check for overflow
  //
  // Note: checking for negative value instead of overflow
  //       so we have a 'sticky' overflow test (may be of
  //       importance as soon as we have true MT/MP)
  Label invocation_counter_overflow;
  if (inc_counter) {
    generate_counter_incr(&invocation_counter_overflow, NULL, NULL);
  }
  Label Lcontinue;
  __ bind(Lcontinue);

  bang_stack_shadow_pages(true);
  // reset the _do_not_unlock_if_synchronized flag
  __ stbool(G0, do_not_unlock_if_synchronized);

  // check for synchronized methods
  // Must happen AFTER invocation_counter check, so method is not locked
  // if counter overflows.

  if (synchronized) {
    lock_method();
    // Don't see how G2_thread is preserved here...
    // __ verify_thread(); QQQ destroys L0,L1 can't use
  } else {
#ifdef ASSERT
    { Label ok;
      __ ld_ptr(STATE(_method), G5_method);
      __ ld(access_flags, O0);
      __ btst(JVM_ACC_SYNCHRONIZED, O0);
      __ br( Assembler::zero, false, Assembler::pt, ok);
      __ delayed()->nop();
      __ stop("method needs synchronization");
      __ bind(ok);
    }
#endif // ASSERT
  }

  // start execution

//   __ verify_thread(); kills L1,L2 can't  use at the moment

  // jvmti/jvmpi support
  __ notify_method_entry();

  // native call

  // (note that O0 is never an oop--at most it is a handle)
  // It is important not to smash any handles created by this call,
  // until any oop handle in O0 is dereferenced.

  // (note that the space for outgoing params is preallocated)

  // get signature handler

  Label pending_exception_present;

  { Label L;
    __ ld_ptr(STATE(_method), G5_method);
    __ ld_ptr(Address(G5_method, 0, in_bytes(methodOopDesc::signature_handler_offset())), G3_scratch);
    __ tst(G3_scratch);
    __ brx(Assembler::notZero, false, Assembler::pt, L);
    __ delayed()->nop();
    __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::prepare_native_call), G5_method, false);
    __ ld_ptr(STATE(_method), G5_method);

    Address exception_addr(G2_thread, 0, in_bytes(Thread::pending_exception_offset()));
    __ ld_ptr(exception_addr, G3_scratch);
    __ br_notnull(G3_scratch, false, Assembler::pn, pending_exception_present);
    __ delayed()->nop();
    __ ld_ptr(Address(G5_method, 0, in_bytes(methodOopDesc::signature_handler_offset())), G3_scratch);
    __ bind(L);
  }

  // Push a new frame so that the args will really be stored in
  // Copy a few locals across so the new frame has the variables
  // we need but these values will be dead at the jni call and
  // therefore not gc volatile like the values in the current
  // frame (Lstate in particular)

  // Flush the state pointer to the register save area
  // Which is the only register we need for a stack walk.
  __ st_ptr(Lstate, SP, (Lstate->sp_offset_in_saved_window() * wordSize) + STACK_BIAS);

  __ mov(Lstate, O1);         // Need to pass the state pointer across the frame

  // Calculate current frame size
  __ sub(SP, FP, O3);         // Calculate negative of current frame size
  __ save(SP, O3, SP);        // Allocate an identical sized frame

  __ mov(I1, Lstate);          // In the "natural" register.

  // Note I7 has leftover trash. Slow signature handler will fill it in
  // should we get there. Normal jni call will set reasonable last_Java_pc
  // below (and fix I7 so the stack trace doesn't have a meaningless frame
  // in it).


  // call signature handler
  __ ld_ptr(STATE(_method), Lmethod);
  __ ld_ptr(STATE(_locals), Llocals);

  __ callr(G3_scratch, 0);
  __ delayed()->nop();
  __ ld_ptr(STATE(_thread), G2_thread);        // restore thread (shouldn't be needed)

  { Label not_static;

    __ ld_ptr(STATE(_method), G5_method);
    __ ld(access_flags, O0);
    __ btst(JVM_ACC_STATIC, O0);
    __ br( Assembler::zero, false, Assembler::pt, not_static);
    __ delayed()->
      // get native function entry point(O0 is a good temp until the very end)
       ld_ptr(Address(G5_method, 0, in_bytes(methodOopDesc::native_function_offset())), O0);
    // for static methods insert the mirror argument
    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();

    __ ld_ptr(Address(G5_method, 0, in_bytes(methodOopDesc:: constants_offset())), O1);
    __ ld_ptr(Address(O1, 0, constantPoolOopDesc::pool_holder_offset_in_bytes()), O1);
    __ ld_ptr(O1, mirror_offset, O1);
    // where the mirror handle body is allocated:
#ifdef ASSERT
    if (!PrintSignatureHandlers)  // do not dirty the output with this
    { Label L;
      __ tst(O1);
      __ brx(Assembler::notZero, false, Assembler::pt, L);
      __ delayed()->nop();
      __ stop("mirror is missing");
      __ bind(L);
    }
#endif // ASSERT
    __ st_ptr(O1, STATE(_oop_temp));
    __ add(STATE(_oop_temp), O1);            // this is really an LEA not an add
    __ bind(not_static);
  }

  // At this point, arguments have been copied off of stack into
  // their JNI positions, which are O1..O5 and SP[68..].
  // Oops are boxed in-place on the stack, with handles copied to arguments.
  // The result handler is in Lscratch.  O0 will shortly hold the JNIEnv*.

#ifdef ASSERT
  { Label L;
    __ tst(O0);
    __ brx(Assembler::notZero, false, Assembler::pt, L);
    __ delayed()->nop();
    __ stop("native entry point is missing");
    __ bind(L);
  }
#endif // ASSERT

  //
  // setup the java frame anchor
  //
  // The scavenge function only needs to know that the PC of this frame is
  // in the interpreter method entry code, it doesn't need to know the exact
  // PC and hence we can use O7 which points to the return address from the
  // previous call in the code stream (signature handler function)
  //
  // The other trick is we set last_Java_sp to FP instead of the usual SP because
  // we have pushed the extra frame in order to protect the volatile register(s)
  // in that frame when we return from the jni call
  //


  __ set_last_Java_frame(FP, O7);
  __ mov(O7, I7);  // make dummy interpreter frame look like one above,
                   // not meaningless information that'll confuse me.

  // flush the windows now. We don't care about the current (protection) frame
  // only the outer frames

  __ flush_windows();

  // mark windows as flushed
  Address flags(G2_thread,
                0,
                in_bytes(JavaThread::frame_anchor_offset()) + in_bytes(JavaFrameAnchor::flags_offset()));
  __ set(JavaFrameAnchor::flushed, G3_scratch);
  __ st(G3_scratch, flags);

  // Transition from _thread_in_Java to _thread_in_native. We are already safepoint ready.

  Address thread_state(G2_thread, 0, in_bytes(JavaThread::thread_state_offset()));
#ifdef ASSERT
  { Label L;
    __ ld(thread_state, G3_scratch);
    __ cmp(G3_scratch, _thread_in_Java);
    __ br(Assembler::equal, false, Assembler::pt, L);
    __ delayed()->nop();
    __ stop("Wrong thread state in native stub");
    __ bind(L);
  }
#endif // ASSERT
  __ set(_thread_in_native, G3_scratch);
  __ st(G3_scratch, thread_state);

  // Call the jni method, using the delay slot to set the JNIEnv* argument.
  __ callr(O0, 0);
  __ delayed()->
     add(G2_thread, in_bytes(JavaThread::jni_environment_offset()), O0);
  __ ld_ptr(STATE(_thread), G2_thread);  // restore thread

  // must we block?

  // Block, if necessary, before resuming in _thread_in_Java state.
  // In order for GC to work, don't clear the last_Java_sp until after blocking.
  { Label no_block;
    Address sync_state(G3_scratch, SafepointSynchronize::address_of_state());

    // Switch thread to "native transition" state before reading the synchronization state.
    // This additional state is necessary because reading and testing the synchronization
    // state is not atomic w.r.t. GC, as this scenario demonstrates:
    //     Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.
    //     VM thread changes sync state to synchronizing and suspends threads for GC.
    //     Thread A is resumed to finish this native method, but doesn't block here since it
    //     didn't see any synchronization is progress, and escapes.
    __ set(_thread_in_native_trans, G3_scratch);
    __ st(G3_scratch, thread_state);
    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(G2_thread, G1_scratch, G3_scratch);
    }
    __ load_contents(sync_state, G3_scratch);
    __ cmp(G3_scratch, SafepointSynchronize::_not_synchronized);


    Label L;
    Address suspend_state(G2_thread, 0, in_bytes(JavaThread::suspend_flags_offset()));
    __ br(Assembler::notEqual, false, Assembler::pn, L);
    __ delayed()->
      ld(suspend_state, G3_scratch);
    __ cmp(G3_scratch, 0);
    __ br(Assembler::equal, false, Assembler::pt, no_block);
    __ delayed()->nop();
    __ bind(L);

    // Block.  Save any potential method result value before the operation and
    // use a leaf call to leave the last_Java_frame setup undisturbed.
    save_native_result();
    __ call_VM_leaf(noreg,
                    CAST_FROM_FN_PTR(address, JavaThread::check_safepoint_and_suspend_for_native_trans),
                    G2_thread);
    __ ld_ptr(STATE(_thread), G2_thread);  // restore thread
    // Restore any method result value
    restore_native_result();
    __ bind(no_block);
  }

  // Clear the frame anchor now

  __ reset_last_Java_frame();

  // Move the result handler address
  __ mov(Lscratch, G3_scratch);
  // return possible result to the outer frame
#ifndef __LP64
  __ mov(O0, I0);
  __ restore(O1, G0, O1);
#else
  __ restore(O0, G0, O0);
#endif /* __LP64 */

  // Move result handler to expected register
  __ mov(G3_scratch, Lscratch);


  // thread state is thread_in_native_trans. Any safepoint blocking has
  // happened in the trampoline we are ready to switch to thread_in_Java.

  __ set(_thread_in_Java, G3_scratch);
  __ st(G3_scratch, thread_state);

  // If we have an oop result store it where it will be safe for any further gc
  // until we return now that we've released the handle it might be protected by

  {
    Label no_oop, store_result;

    __ set((intptr_t)AbstractInterpreter::result_handler(T_OBJECT), G3_scratch);
    __ cmp(G3_scratch, Lscratch);
    __ brx(Assembler::notEqual, false, Assembler::pt, no_oop);
    __ delayed()->nop();
    __ addcc(G0, O0, O0);
    __ brx(Assembler::notZero, true, Assembler::pt, store_result);     // if result is not NULL:
    __ delayed()->ld_ptr(O0, 0, O0);                                   // unbox it
    __ mov(G0, O0);

    __ bind(store_result);
    // Store it where gc will look for it and result handler expects it.
    __ st_ptr(O0, STATE(_oop_temp));

    __ bind(no_oop);

  }

  // reset handle block
  __ ld_ptr(G2_thread, in_bytes(JavaThread::active_handles_offset()), G3_scratch);
  __ st_ptr(G0, G3_scratch, JNIHandleBlock::top_offset_in_bytes());


  // handle exceptions (exception handling will handle unlocking!)
  { Label L;
    Address exception_addr (G2_thread, 0, in_bytes(Thread::pending_exception_offset()));

    __ ld_ptr(exception_addr, Gtemp);
    __ tst(Gtemp);
    __ brx(Assembler::equal, false, Assembler::pt, L);
    __ delayed()->nop();
    __ bind(pending_exception_present);
    // With c++ interpreter we just leave it pending caller will do the correct thing. However...
    // Like x86 we ignore the result of the native call and leave the method locked. This
    // seems wrong to leave things locked.

    __ br(Assembler::always, false, Assembler::pt, StubRoutines::forward_exception_entry(), relocInfo::runtime_call_type);
    __ delayed()->restore(I5_savedSP, G0, SP);  // remove interpreter frame

    __ bind(L);
  }

  // jvmdi/jvmpi support (preserves thread register)
  __ notify_method_exit(true, ilgl, InterpreterMacroAssembler::NotifyJVMTI);

  if (synchronized) {
    // save and restore any potential method result value around the unlocking operation
    save_native_result();

    const int entry_size            = frame::interpreter_frame_monitor_size() * wordSize;
    // Get the initial monitor we allocated
    __ sub(Lstate, entry_size, O1);                        // initial monitor
    __ unlock_object(O1);
    restore_native_result();
  }

#if defined(COMPILER2) && !defined(_LP64)

  // C2 expects long results in G1 we can't tell if we're returning to interpreted
  // or compiled so just be safe.

  __ sllx(O0, 32, G1);          // Shift bits into high G1
  __ srl (O1, 0, O1);           // Zero extend O1
  __ or3 (O1, G1, G1);          // OR 64 bits into G1

#endif /* COMPILER2 && !_LP64 */

#ifdef ASSERT
  {
    Label ok;
    __ cmp(I5_savedSP, FP);
    __ brx(Assembler::greaterEqualUnsigned, false, Assembler::pt, ok);
    __ delayed()->nop();
    __ stop("bad I5_savedSP value");
    __ should_not_reach_here();
    __ bind(ok);
  }
#endif
  // Calls result handler which POPS FRAME
  if (TraceJumps) {
    // Move target to register that is recordable
    __ mov(Lscratch, G3_scratch);
    __ JMP(G3_scratch, 0);
  } else {
    __ jmp(Lscratch, 0);
  }
  __ delayed()->nop();

  if (inc_counter) {
    // handle invocation counter overflow
    __ bind(invocation_counter_overflow);
    generate_counter_overflow(Lcontinue);
  }


  return entry;
}

void CppInterpreterGenerator::generate_compute_interpreter_state(const Register state,
                                                              const Register prev_state,
                                                              bool native) {

  // On entry
  // G5_method - caller's method
  // Gargs - points to initial parameters (i.e. locals[0])
  // G2_thread - valid? (C1 only??)
  // "prev_state" - contains any previous frame manager state which we must save a link
  //
  // 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.

  assert_different_registers(state, prev_state);
  assert_different_registers(prev_state, G3_scratch);
  const Register Gtmp = G3_scratch;
  const Address constants         (G5_method, 0, in_bytes(methodOopDesc::constants_offset()));
  const Address access_flags      (G5_method, 0, in_bytes(methodOopDesc::access_flags_offset()));
  const Address size_of_parameters(G5_method, 0, in_bytes(methodOopDesc::size_of_parameters_offset()));
  const Address max_stack         (G5_method, 0, in_bytes(methodOopDesc::max_stack_offset()));
  const Address size_of_locals    (G5_method, 0, in_bytes(methodOopDesc::size_of_locals_offset()));

  // slop factor is two extra slots on the expression stack so that
  // we always have room to store a result when returning from a call without parameters
  // that returns a result.

  const int slop_factor = 2*wordSize;

  const int fixed_size = ((sizeof(BytecodeInterpreter) + slop_factor) >> LogBytesPerWord) + // what is the slop factor?
                         //6815692//methodOopDesc::extra_stack_words() +  // extra push slots for MH adapters
                         frame::memory_parameter_word_sp_offset +  // register save area + param window
                         (native ?  frame::interpreter_frame_extra_outgoing_argument_words : 0); // JNI, class

  // XXX G5_method valid

  // Now compute new frame size

  if (native) {
    __ lduh( size_of_parameters, Gtmp );
    __ calc_mem_param_words(Gtmp, Gtmp);     // space for native call parameters passed on the stack in words
  } else {
    __ lduh(max_stack, Gtmp);                // Full size expression stack
  }
  __ add(Gtmp, fixed_size, Gtmp);           // plus the fixed portion

  __ neg(Gtmp);                               // negative space for stack/parameters in words
  __ and3(Gtmp, -WordsPerLong, Gtmp);        // make multiple of 2 (SP must be 2-word aligned)
  __ sll(Gtmp, LogBytesPerWord, Gtmp);       // negative space for frame in bytes

  // Need to do stack size check here before we fault on large frames

  Label stack_ok;

  const int max_pages = StackShadowPages > (StackRedPages+StackYellowPages) ? StackShadowPages :
                                                                              (StackRedPages+StackYellowPages);


  __ ld_ptr(G2_thread, in_bytes(Thread::stack_base_offset()), O0);
  __ ld_ptr(G2_thread, in_bytes(Thread::stack_size_offset()), O1);
  // compute stack bottom
  __ sub(O0, O1, O0);

  // Avoid touching the guard pages
  // Also a fudge for frame size of BytecodeInterpreter::run
  // It varies from 1k->4k depending on build type
  const int fudge = 6 * K;

  __ set(fudge + (max_pages * os::vm_page_size()), O1);

  __ add(O0, O1, O0);
  __ sub(O0, Gtmp, O0);
  __ cmp(SP, O0);
  __ brx(Assembler::greaterUnsigned, false, Assembler::pt, stack_ok);
  __ delayed()->nop();

     // throw exception return address becomes throwing pc

  __ call_VM(Oexception, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_StackOverflowError));
  __ stop("never reached");

  __ bind(stack_ok);

  __ save(SP, Gtmp, SP);                      // setup new frame and register window

  // New window I7 call_stub or previous activation
  // O6 - register save area, BytecodeInterpreter just below it, args/locals just above that
  //
  __ sub(FP, sizeof(BytecodeInterpreter), state);        // Point to new Interpreter state
  __ add(state, STACK_BIAS, state );         // Account for 64bit bias

#define XXX_STATE(field_name) state, in_bytes(byte_offset_of(BytecodeInterpreter, field_name))

  // Initialize a new Interpreter state
  // orig_sp - caller's original sp
  // G2_thread - thread
  // Gargs - &locals[0] (unbiased?)
  // G5_method - method
  // SP (biased) - accounts for full size java stack, BytecodeInterpreter object, register save area, and register parameter save window


  __ set(0xdead0004, O1);


  __ st_ptr(Gargs, XXX_STATE(_locals));
  __ st_ptr(G0, XXX_STATE(_oop_temp));

  __ st_ptr(state, XXX_STATE(_self_link));                // point to self
  __ st_ptr(prev_state->after_save(), XXX_STATE(_prev_link)); // Chain interpreter states
  __ st_ptr(G2_thread, XXX_STATE(_thread));               // Store javathread

  if (native) {
    __ st_ptr(G0, XXX_STATE(_bcp));
  } else {
    __ ld_ptr(G5_method, in_bytes(methodOopDesc::const_offset()), O2); // get constMethodOop
    __ add(O2, in_bytes(constMethodOopDesc::codes_offset()), O2);        // get bcp
    __ st_ptr(O2, XXX_STATE(_bcp));
  }

  __ st_ptr(G0, XXX_STATE(_mdx));
  __ st_ptr(G5_method, XXX_STATE(_method));

  __ set((int) BytecodeInterpreter::method_entry, O1);
  __ st(O1, XXX_STATE(_msg));

  __ ld_ptr(constants, O3);
  __ ld_ptr(O3, constantPoolOopDesc::cache_offset_in_bytes(), O2);
  __ st_ptr(O2, XXX_STATE(_constants));

  __ st_ptr(G0, XXX_STATE(_result._to_call._callee));

  // Monitor base is just start of BytecodeInterpreter object;
  __ mov(state, O2);
  __ st_ptr(O2, XXX_STATE(_monitor_base));

  // Do we need a monitor for synchonized method?
  {
    __ ld(access_flags, O1);
    Label done;
    Label got_obj;
    __ btst(JVM_ACC_SYNCHRONIZED, O1);
    __ br( Assembler::zero, false, Assembler::pt, done);

    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() + Klass::java_mirror_offset_in_bytes();
    __ delayed()->btst(JVM_ACC_STATIC, O1);
    __ ld_ptr(XXX_STATE(_locals), O1);
    __ br( Assembler::zero, true, Assembler::pt, got_obj);
    __ delayed()->ld_ptr(O1, 0, O1);                  // get receiver for not-static case
    __ ld_ptr(constants, O1);
    __ ld_ptr( O1, constantPoolOopDesc::pool_holder_offset_in_bytes(), O1);
    // lock the mirror, not the klassOop
    __ ld_ptr( O1, mirror_offset, O1);

    __ bind(got_obj);

  #ifdef ASSERT
    __ tst(O1);
    __ breakpoint_trap(Assembler::zero);
  #endif // ASSERT

    const int entry_size            = frame::interpreter_frame_monitor_size() * wordSize;
    __ sub(SP, entry_size, SP);                         // account for initial monitor
    __ sub(O2, entry_size, O2);                        // initial monitor
    __ st_ptr(O1, O2, BasicObjectLock::obj_offset_in_bytes()); // and allocate it for interpreter use
    __ bind(done);
  }

  // Remember initial frame bottom

  __ st_ptr(SP, XXX_STATE(_frame_bottom));

  __ st_ptr(O2, XXX_STATE(_stack_base));

  __ sub(O2, wordSize, O2);                    // prepush
  __ st_ptr(O2, XXX_STATE(_stack));                // PREPUSH

  __ lduh(max_stack, O3);                      // Full size expression stack
  guarantee(!EnableMethodHandles, "no support yet for java.lang.invoke.MethodHandle"); //6815692
  //6815692//if (EnableMethodHandles)
  //6815692//  __ inc(O3, methodOopDesc::extra_stack_entries());
  __ sll(O3, LogBytesPerWord, O3);
  __ sub(O2, O3, O3);
//  __ sub(O3, wordSize, O3);                    // so prepush doesn't look out of bounds
  __ st_ptr(O3, XXX_STATE(_stack_limit));

  if (!native) {
    //
    // Code to initialize locals
    //
    Register init_value = noreg;    // will be G0 if we must clear locals
    // Now zero locals
    if (true /* zerolocals */ || ClearInterpreterLocals) {
      // explicitly initialize locals
      init_value = G0;
    } else {
    #ifdef ASSERT
      // initialize locals to a garbage pattern for better debugging
      init_value = O3;
      __ set( 0x0F0F0F0F, init_value );
    #endif // ASSERT
    }
    if (init_value != noreg) {
      Label clear_loop;

      // NOTE: If you change the frame layout, this code will need to
      // be updated!
      __ lduh( size_of_locals, O2 );
      __ lduh( size_of_parameters, O1 );
      __ sll( O2, LogBytesPerWord, O2);
      __ sll( O1, LogBytesPerWord, O1 );
      __ ld_ptr(XXX_STATE(_locals), L2_scratch);
      __ sub( L2_scratch, O2, O2 );
      __ sub( L2_scratch, O1, O1 );

      __ bind( clear_loop );
      __ inc( O2, wordSize );

      __ cmp( O2, O1 );
      __ br( Assembler::lessEqualUnsigned, true, Assembler::pt, clear_loop );
      __ delayed()->st_ptr( init_value, O2, 0 );
    }
  }
}
// Find preallocated  monitor and lock method (C++ interpreter)
//
void InterpreterGenerator::lock_method(void) {
// Lock the current method.
// Destroys registers L2_scratch, L3_scratch, O0
//
// Find everything relative to Lstate

#ifdef ASSERT
  __ ld_ptr(STATE(_method), L2_scratch);
  __ ld(L2_scratch, in_bytes(methodOopDesc::access_flags_offset()), O0);

 { Label ok;
   __ btst(JVM_ACC_SYNCHRONIZED, O0);
   __ br( Assembler::notZero, false, Assembler::pt, ok);
   __ delayed()->nop();
   __ stop("method doesn't need synchronization");
   __ bind(ok);
  }
#endif // ASSERT

  // monitor is already allocated at stack base
  // and the lockee is already present
  __ ld_ptr(STATE(_stack_base), L2_scratch);
  __ ld_ptr(L2_scratch, BasicObjectLock::obj_offset_in_bytes(), O0);   // get object
  __ lock_object(L2_scratch, O0);

}

//  Generate code for handling resuming a deopted method
void CppInterpreterGenerator::generate_deopt_handling() {

  Label return_from_deopt_common;

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

  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_OBJECT), L3_scratch);    // Result stub address array index


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

  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_BOOLEAN), L3_scratch);    // Result stub address array index

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

  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_INT), L3_scratch);    // Result stub address array index

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

  deopt_frame_manager_return_ltos  = __ pc();
#if !defined(_LP64) && defined(COMPILER2)
  // All return values are where we want them, except for Longs.  C2 returns
  // longs in G1 in the 32-bit build whereas the interpreter wants them in O0/O1.
  // Since the interpreter will return longs in G1 and O0/O1 in the 32bit
  // build even if we are returning from interpreted we just do a little
  // stupid shuffing.
  // Note: I tried to make c2 return longs in O0/O1 and G1 so we wouldn't have to
  // do this here. Unfortunately if we did a rethrow we'd see an machepilog node
  // first which would move g1 -> O0/O1 and destroy the exception we were throwing.

  __ srl (G1, 0,O1);
  __ srlx(G1,32,O0);
#endif /* !_LP64 && COMPILER2 */
  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_LONG), L3_scratch);    // Result stub address array index

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

  deopt_frame_manager_return_ftos  = __ pc();
  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_FLOAT), L3_scratch);    // Result stub address array index

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

  // O0/O1 live
  __ ba(false, return_from_deopt_common);
  __ delayed()->set(AbstractInterpreter::BasicType_as_index(T_DOUBLE), L3_scratch);    // Result stub address array index

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

  // O0/O1 live
  __ set(AbstractInterpreter::BasicType_as_index(T_VOID), L3_scratch);

  // Deopt return common
  // an index is present that lets us move any possible result being
  // return to the interpreter's stack
  //
  __ bind(return_from_deopt_common);

  // Result if any is in native abi result (O0..O1/F0..F1). The java expression
  // stack is in the state that the  calling convention left it.
  // Copy the result from native abi result and place it on java expression stack.

  // Current interpreter state is present in Lstate

  // Get current pre-pushed top of interpreter stack
  // Any result (if any) is in native abi
  // result type index is in L3_scratch

  __ ld_ptr(STATE(_stack), L1_scratch);                                          // get top of java expr stack

  __ set((intptr_t)CppInterpreter::_tosca_to_stack, L4_scratch);
  __ sll(L3_scratch, LogBytesPerWord, L3_scratch);
  __ ld_ptr(L4_scratch, L3_scratch, Lscratch);                                       // get typed result converter address
  __ jmpl(Lscratch, G0, O7);                                         // and convert it
  __ delayed()->nop();

  // L1_scratch points to top of stack (prepushed)
  __ st_ptr(L1_scratch, STATE(_stack));
}

// 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                                // esp: old expression stack top
  __ delayed()->ld_ptr(STATE(_stack_base), L4_scratch);            // current expression stack bottom
  __ sub(L4_scratch, entry_size, L4_scratch);
  __ st_ptr(L4_scratch, STATE(_stack_base));

  __ sub(SP, entry_size, SP);                  // Grow stack
  __ st_ptr(SP, STATE(_frame_bottom));

  __ ld_ptr(STATE(_stack_limit), L2_scratch);
  __ sub(L2_scratch, entry_size, L2_scratch);
  __ st_ptr(L2_scratch, STATE(_stack_limit));

  __ ld_ptr(STATE(_stack), L1_scratch);                // Get current stack top
  __ sub(L1_scratch, entry_size, L1_scratch);
  __ st_ptr(L1_scratch, STATE(_stack));
  __ ba(false, entry);
  __ delayed()->add(L1_scratch, wordSize, L1_scratch);        // first real entry (undo prepush)

  // 2. move expression stack

  __ bind(loop);
  __ st_ptr(L3_scratch, Address(L1_scratch, 0));
  __ add(L1_scratch, wordSize, L1_scratch);
  __ bind(entry);
  __ cmp(L1_scratch, L4_scratch);
  __ br(Assembler::notEqual, false, Assembler::pt, loop);
  __ delayed()->ld_ptr(L1_scratch, entry_size, L3_scratch);

  // now zero the slot so we can find it.
  __ st_ptr(G0, L4_scratch, BasicObjectLock::obj_offset_in_bytes());

}

// 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:
//
// ebx: methodOop
// ecx: receiver - unused (retrieved from stack as needed)
// esi: previous frame manager state (NULL from the call_stub/c1/c2)
//
//
// Stack layout at entry
//
// [ return address     ] <--- esp
// [ 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;

#ifdef ASSERT
  #define VALIDATE_STATE(scratch, marker)                         \
  {                                                               \
    Label skip;                                                   \
    __ ld_ptr(STATE(_self_link), scratch);                        \
    __ cmp(Lstate, scratch);                                      \
    __ brx(Assembler::equal, false, Assembler::pt, skip);         \
    __ delayed()->nop();                                          \
    __ breakpoint_trap();                                         \
    __ emit_long(marker);                                         \
    __ bind(skip);                                                \
  }
#else
  #define VALIDATE_STATE(scratch, marker)
#endif /* ASSERT */

void CppInterpreterGenerator::adjust_callers_stack(Register args) {
//
// Adjust caller's stack so that all the locals can be contiguous with
// the parameters.
// Worries about stack overflow make this a pain.
//
// Destroys args, G3_scratch, G3_scratch
// In/Out O5_savedSP (sender's original SP)
//
//  assert_different_registers(state, prev_state);
  const Register Gtmp = G3_scratch;
  const Register tmp = O2;
  const Address size_of_parameters(G5_method, 0, in_bytes(methodOopDesc::size_of_parameters_offset()));
  const Address size_of_locals    (G5_method, 0, in_bytes(methodOopDesc::size_of_locals_offset()));

  __ lduh(size_of_parameters, tmp);
  __ sll(tmp, LogBytesPerWord, Gtmp);       // parameter size in bytes
  __ add(args, Gtmp, Gargs);                // points to first local + BytesPerWord
  // NEW
  __ add(Gargs, -wordSize, Gargs);             // points to first local[0]
  // determine extra space for non-argument locals & adjust caller's SP
  // Gtmp1: parameter size in words
  __ lduh(size_of_locals, Gtmp);
  __ compute_extra_locals_size_in_bytes(tmp, Gtmp, Gtmp);

#if 1
  // c2i adapters place the final interpreter argument in the register save area for O0/I0
  // the call_stub will place the final interpreter argument at
  // frame::memory_parameter_word_sp_offset. This is mostly not noticable for either asm
  // or c++ interpreter. However with the c++ interpreter when we do a recursive call
  // and try to make it look good in the debugger we will store the argument to
  // RecursiveInterpreterActivation in the register argument save area. Without allocating
  // extra space for the compiler this will overwrite locals in the local array of the
  // interpreter.
  // QQQ still needed with frameless adapters???

  const int c2i_adjust_words = frame::memory_parameter_word_sp_offset - frame::callee_register_argument_save_area_sp_offset;

  __ add(Gtmp, c2i_adjust_words*wordSize, Gtmp);
#endif // 1


  __ sub(SP, Gtmp, SP);                      // just caller's frame for the additional space we need.
}

address InterpreterGenerator::generate_normal_entry(bool synchronized) {

  // G5_method: methodOop
  // G2_thread: thread (unused)
  // Gargs:   bottom of args (sender_sp)
  // O5: sender's sp

  // 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;
  }

  __ bind(frame_manager_entry);

  // the following temporary registers are used during frame creation
  const Register Gtmp1 = G3_scratch;
  // const Register Lmirror = L1;     // native mirror (native calls only)

  const Address constants         (G5_method, 0, in_bytes(methodOopDesc::constants_offset()));
  const Address access_flags      (G5_method, 0, in_bytes(methodOopDesc::access_flags_offset()));
  const Address size_of_parameters(G5_method, 0, in_bytes(methodOopDesc::size_of_parameters_offset()));
  const Address max_stack         (G5_method, 0, in_bytes(methodOopDesc::max_stack_offset()));
  const Address size_of_locals    (G5_method, 0, in_bytes(methodOopDesc::size_of_locals_offset()));

  address entry_point = __ pc();
  __ mov(G0, prevState);                                                 // no current activation


  Label re_dispatch;

  __ bind(re_dispatch);

  // Interpreter needs to have locals completely contiguous. In order to do that
  // We must adjust the caller's stack pointer for any locals beyond just the
  // parameters
  adjust_callers_stack(Gargs);

  // O5_savedSP still contains sender's sp

  // NEW FRAME

  generate_compute_interpreter_state(Lstate, prevState, false);

  // At this point a new interpreter frame and state object are created and initialized
  // Lstate has the pointer to the new activation
  // Any stack banging or limit check should already be done.

  Label call_interpreter;

  __ bind(call_interpreter);


#if 1
  __ set(0xdead002, Lmirror);
  __ set(0xdead002, L2_scratch);
  __ set(0xdead003, L3_scratch);
  __ set(0xdead004, L4_scratch);
  __ set(0xdead005, Lscratch);
  __ set(0xdead006, Lscratch2);
  __ set(0xdead007, L7_scratch);

  __ set(0xdeaf002, O2);
  __ set(0xdeaf003, O3);
  __ set(0xdeaf004, O4);
  __ set(0xdeaf005, O5);
#endif

  // Call interpreter (stack bang complete) enter here if message is
  // set and we know stack size is valid

  Label call_interpreter_2;

  __ bind(call_interpreter_2);

#ifdef ASSERT
  {
    Label skip;
    __ ld_ptr(STATE(_frame_bottom), G3_scratch);
    __ cmp(G3_scratch, SP);
    __ brx(Assembler::equal, false, Assembler::pt, skip);
    __ delayed()->nop();
    __ stop("SP not restored to frame bottom");
    __ bind(skip);
  }
#endif

  VALIDATE_STATE(G3_scratch, 4);
  __ set_last_Java_frame(SP, noreg);
  __ mov(Lstate, O0);                 // (arg) pointer to current state

  __ call(CAST_FROM_FN_PTR(address,
                           JvmtiExport::can_post_interpreter_events() ?
                                                                  BytecodeInterpreter::runWithChecks
                                                                : BytecodeInterpreter::run),
         relocInfo::runtime_call_type);

  __ delayed()->nop();

  __ ld_ptr(STATE(_thread), G2_thread);
  __ reset_last_Java_frame();

  // examine msg from interpreter to determine next action
  __ ld_ptr(STATE(_thread), G2_thread);                                  // restore G2_thread

  __ ld(STATE(_msg), L1_scratch);                                       // Get new message

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

  __ cmp(L1_scratch, (int)BytecodeInterpreter::call_method);
  __ br(Assembler::equal, false, Assembler::pt, call_method);
  __ delayed()->cmp(L1_scratch, (int)BytecodeInterpreter::return_from_method);
  __ br(Assembler::equal, false, Assembler::pt, return_from_interpreted_method);
  __ delayed()->cmp(L1_scratch, (int)BytecodeInterpreter::throwing_exception);
  __ br(Assembler::equal, false, Assembler::pt, throw_exception);
  __ delayed()->cmp(L1_scratch, (int)BytecodeInterpreter::do_osr);
  __ br(Assembler::equal, false, Assembler::pt, do_OSR);
  __ delayed()->cmp(L1_scratch, (int)BytecodeInterpreter::more_monitors);
  __ br(Assembler::notEqual, false, Assembler::pt, bad_msg);

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

  generate_more_monitors();

  // new monitor slot allocated, resume the interpreter.

  __ set((int)BytecodeInterpreter::got_monitors, L1_scratch);
  VALIDATE_STATE(G3_scratch, 5);
  __ ba(false, call_interpreter);
  __ delayed()->st(L1_scratch, STATE(_msg));

  // uncommon trap needs to jump to here to enter the interpreter (re-execute current bytecode)
  unctrap_frame_manager_entry  = __ pc();

  // QQQ what message do we send

  __ ba(false, call_interpreter);
  __ delayed()->ld_ptr(STATE(_frame_bottom), SP);                  // restore to full stack frame

  //=============================================================================
  // 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();

  // ready to resume the interpreter

  __ set((int)BytecodeInterpreter::deopt_resume, L1_scratch);
  __ ba(false, call_interpreter);
  __ delayed()->st(L1_scratch, STATE(_msg));

  // 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();

  Label return_with_exception;
  Label unwind_and_forward;

  // O0: exception
  // O7: throwing pc

  // We want exception in the thread no matter what we ultimately decide about frame type.

  Address exception_addr (G2_thread, 0, in_bytes(Thread::pending_exception_offset()));
  __ verify_thread();
  __ st_ptr(O0, exception_addr);

  // get the methodOop
  __ ld_ptr(STATE(_method), G5_method);

  // if this current frame vanilla or native?

  __ ld(access_flags, Gtmp1);
  __ btst(JVM_ACC_NATIVE, Gtmp1);
  __ br(Assembler::zero, false, Assembler::pt, return_with_exception);  // vanilla interpreted frame handle directly
  __ delayed()->nop();

  // 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 frame and jump to forward exception. unwinding will place throwing pc in O7
  // as expected by forward_exception.

  __ restore(FP, G0, SP);                  // unwind interpreter state frame
  __ br(Assembler::always, false, Assembler::pt, StubRoutines::forward_exception_entry(), relocInfo::runtime_call_type);
  __ delayed()->mov(I5_savedSP->after_restore(), SP);

  // 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

  address return_from_native_method = __ pc();

  VALIDATE_STATE(G3_scratch, 6);

  // Result if any is in native abi result (O0..O1/F0..F1). The java expression
  // stack is in the state that the  calling convention left it.
  // Copy the result from native abi result and place it on java expression stack.

  // Current interpreter state is present in Lstate

  // Exception pending?

  __ ld_ptr(STATE(_frame_bottom), SP);                             // restore to full stack frame
  __ ld_ptr(exception_addr, Lscratch);                                         // get any pending exception
  __ tst(Lscratch);                                                            // exception pending?
  __ brx(Assembler::notZero, false, Assembler::pt, return_with_exception);
  __ delayed()->nop();

  // Process the native abi result to java expression stack

  __ ld_ptr(STATE(_result._to_call._callee), L4_scratch);                        // called method
  __ ld_ptr(STATE(_stack), L1_scratch);                                          // get top of java expr stack
  __ lduh(L4_scratch, in_bytes(methodOopDesc::size_of_parameters_offset()), L2_scratch); // get parameter size
  __ sll(L2_scratch, LogBytesPerWord, L2_scratch     );                           // parameter size in bytes
  __ add(L1_scratch, L2_scratch, L1_scratch);                                      // stack destination for result
  __ ld(L4_scratch, in_bytes(methodOopDesc::result_index_offset()), L3_scratch); // called method result type index

  // tosca is really just native abi
  __ set((intptr_t)CppInterpreter::_tosca_to_stack, L4_scratch);
  __ sll(L3_scratch, LogBytesPerWord, L3_scratch);
  __ ld_ptr(L4_scratch, L3_scratch, Lscratch);                                       // get typed result converter address
  __ jmpl(Lscratch, G0, O7);                                                   // and convert it
  __ delayed()->nop();

  // L1_scratch points to top of stack (prepushed)

  __ ba(false, resume_interpreter);
  __ delayed()->mov(L1_scratch, O1);

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

  __ bind(return_with_exception);

  __ ld_ptr(STATE(_frame_bottom), SP);                             // restore to full stack frame
  __ ld_ptr(STATE(_stack_base), O1);                               // empty java expression stack
  __ ba(false, resume_interpreter);
  __ delayed()->sub(O1, wordSize, O1);                             // account for prepush

  // 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);

  VALIDATE_STATE(G3_scratch, 7);

  Label return_to_initial_caller;

  // Interpreted result is on the top of the completed activation expression stack.
  // We must return it to the top of the callers stack if caller was interpreted
  // otherwise we convert to native abi result and return to call_stub/c1/c2
  // The caller's expression stack was truncated by the call however the current activation
  // has enough stuff on the stack that we have usable space there no matter what. The
  // other thing that makes it easy is that the top of the caller's stack is stored in STATE(_locals)
  // for the current activation

  __ ld_ptr(STATE(_prev_link), L1_scratch);
  __ ld_ptr(STATE(_method), L2_scratch);                               // get method just executed
  __ ld(L2_scratch, in_bytes(methodOopDesc::result_index_offset()), L2_scratch);
  __ tst(L1_scratch);
  __ brx(Assembler::zero, false, Assembler::pt, return_to_initial_caller);
  __ delayed()->sll(L2_scratch, LogBytesPerWord, L2_scratch);

  // Copy result to callers java stack

  __ set((intptr_t)CppInterpreter::_stack_to_stack, L4_scratch);
  __ ld_ptr(L4_scratch, L2_scratch, Lscratch);                          // get typed result converter address
  __ ld_ptr(STATE(_stack), O0);                                       // current top (prepushed)
  __ ld_ptr(STATE(_locals), O1);                                      // stack destination

  // O0 - will be source, O1 - will be destination (preserved)
  __ jmpl(Lscratch, G0, O7);                                          // and convert it
  __ delayed()->add(O0, wordSize, O0);                                // get source (top of current expr stack)

  // O1 == &locals[0]

  // Result is now on caller's stack. Just unwind current activation and resume

  Label unwind_recursive_activation;


  __ bind(unwind_recursive_activation);

  // O1 == &locals[0] (really callers stacktop) for activation now returning
  // returning to interpreter method from "recursive" interpreter call
  // result converter left O1 pointing to top of the( prepushed) java stack for method we are returning
  // to. Now all we must do is unwind the state from the completed call

  // Must restore stack
  VALIDATE_STATE(G3_scratch, 8);

  // Return to interpreter method after a method call (interpreted/native/c1/c2) has completed.
  // Result if any is already on the caller's stack. All we must do now is remove the now dead
  // frame and tell interpreter to resume.


  __ mov(O1, I1);                                                     // pass back new stack top across activation
  // POP FRAME HERE ==================================
  __ restore(FP, G0, SP);                                             // unwind interpreter state frame
  __ ld_ptr(STATE(_frame_bottom), SP);                                // restore to full stack frame


  // Resume the interpreter. The current frame contains the current interpreter
  // state object.
  //
  // O1 == new java stack pointer

  __ bind(resume_interpreter);
  VALIDATE_STATE(G3_scratch, 10);

  // A frame we have already used before so no need to bang stack so use call_interpreter_2 entry

  __ set((int)BytecodeInterpreter::method_resume, L1_scratch);
  __ st(L1_scratch, STATE(_msg));
  __ ba(false, call_interpreter_2);
  __ delayed()->st_ptr(O1, STATE(_stack));


  // Fast accessor methods share this entry point.
  // This works because frame manager is in the same codelet
  // This can either be an entry via call_stub/c1/c2 or a recursive interpreter call
  // we need to do a little register fixup here once we distinguish the two of them
  if (UseFastAccessorMethods && !synchronized) {
  // Call stub_return address still in O7
    __ bind(fast_accessor_slow_entry_path);
    __ set((intptr_t)return_from_native_method - 8, Gtmp1);
    __ cmp(Gtmp1, O7);                                                // returning to interpreter?
    __ brx(Assembler::equal, true, Assembler::pt, re_dispatch);       // yep
    __ delayed()->nop();
    __ ba(false, re_dispatch);
    __ delayed()->mov(G0, prevState);                                   // initial entry

  }

  // interpreter returning to native code (call_stub/c1/c2)
  // convert result and unwind initial activation
  // L2_scratch - scaled result type index

  __ bind(return_to_initial_caller);

  __ set((intptr_t)CppInterpreter::_stack_to_native_abi, L4_scratch);
  __ ld_ptr(L4_scratch, L2_scratch, Lscratch);                           // get typed result converter address
  __ ld_ptr(STATE(_stack), O0);                                        // current top (prepushed)
  __ jmpl(Lscratch, G0, O7);                                           // and convert it
  __ delayed()->add(O0, wordSize, O0);                                 // get source (top of current expr stack)

  Label unwind_initial_activation;
  __ bind(unwind_initial_activation);

  // RETURN TO CALL_STUB/C1/C2 code (result if any in I0..I1/(F0/..F1)
  // we can return here with an exception that wasn't handled by interpreted code
  // how does c1/c2 see it on return?

  // compute resulting sp before/after args popped depending upon calling convention
  // __ ld_ptr(STATE(_saved_sp), Gtmp1);
  //
  // POP FRAME HERE ==================================
  __ restore(FP, G0, SP);
  __ retl();
  __ delayed()->mov(I5_savedSP->after_restore(), SP);

  // OSR request, unwind the current frame and transfer to the OSR entry
  // and enter OSR nmethod

  __ bind(do_OSR);
  Label remove_initial_frame;
  __ ld_ptr(STATE(_prev_link), L1_scratch);
  __ ld_ptr(STATE(_result._osr._osr_buf), G1_scratch);

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

  __ tst(L1_scratch);
  __ brx(Assembler::zero, false, Assembler::pt, remove_initial_frame);
  __ delayed()->ld_ptr(STATE(_result._osr._osr_entry), G3_scratch);

  // Frame underneath is an interpreter frame simply unwind
  // POP FRAME HERE ==================================
  __ restore(FP, G0, SP);                                             // unwind interpreter state frame
  __ mov(I5_savedSP->after_restore(), SP);

  // Since we are now calling native need to change our "return address" from the
  // dummy RecursiveInterpreterActivation to a return from native

  __ set((intptr_t)return_from_native_method - 8, O7);

  __ jmpl(G3_scratch, G0, G0);
  __ delayed()->mov(G1_scratch, O0);

  __ bind(remove_initial_frame);

  // POP FRAME HERE ==================================
  __ restore(FP, G0, SP);
  __ mov(I5_savedSP->after_restore(), SP);
  __ jmpl(G3_scratch, G0, G0);
  __ delayed()->mov(G1_scratch, O0);

  // 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.
  // At this point we have a topmost frame that was allocated by the frame manager
  // which contains the current method interpreted state. We trim this frame
  // of excess java expression stack entries and then recurse.

  __ 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

  __ ld_ptr(STATE(_thread), G2_thread);
  __ ld_ptr(STATE(_result._to_call._callee), G5_method);


  // SP already takes in to account the 2 extra words we use for slop
  // when we call a "static long no_params()" method. So if
  // we trim back sp by the amount of unused java expression stack
  // there will be automagically the 2 extra words we need.
  // We also have to worry about keeping SP aligned.

  __ ld_ptr(STATE(_stack), Gargs);
  __ ld_ptr(STATE(_stack_limit), L1_scratch);

  // compute the unused java stack size
  __ sub(Gargs, L1_scratch, L2_scratch);                       // compute unused space

  // Round down the unused space to that stack is always 16-byte aligned
  // by making the unused space a multiple of the size of two longs.

  __ and3(L2_scratch, -2*BytesPerLong, L2_scratch);

  // Now trim the stack
  __ add(SP, L2_scratch, SP);


  // Now point to the final argument (account for prepush)
  __ add(Gargs, wordSize, Gargs);
#ifdef ASSERT
  // Make sure we have space for the window
  __ sub(Gargs, SP, L1_scratch);
  __ cmp(L1_scratch, 16*wordSize);
  {
    Label skip;
    __ brx(Assembler::greaterEqual, false, Assembler::pt, skip);
    __ delayed()->nop();
    __ stop("killed stack");
    __ bind(skip);
  }
#endif // ASSERT

  // Create a new frame where we can store values that make it look like the interpreter
  // really recursed.

  // prepare to recurse or call specialized entry

  // First link the registers we need

  // make the pc look good in debugger
  __ set(CAST_FROM_FN_PTR(intptr_t, RecursiveInterpreterActivation), O7);
  // argument too
  __ mov(Lstate, I0);

  // Record our sending SP
  __ mov(SP, O5_savedSP);

  __ ld_ptr(STATE(_result._to_call._callee_entry_point), L2_scratch);
  __ set((intptr_t) entry_point, L1_scratch);
  __ cmp(L1_scratch, L2_scratch);
  __ brx(Assembler::equal, false, Assembler::pt, re_dispatch);
  __ delayed()->mov(Lstate, prevState);                                // link activations

  // 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.

  __ set((intptr_t)return_from_native_method - 8, O7);
  __ jmpl(L2_scratch, G0, G0);                               // Do specialized entry
  __ delayed()->nop();

  //
  // Bad Message from interpreter
  //
  __ 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

  __ bind(throw_exception);
  __ ld_ptr(STATE(_prev_link), L1_scratch);
  __ tst(L1_scratch);
  __ brx(Assembler::zero, false, Assembler::pt, unwind_and_forward);
  __ delayed()->nop();

  __ ld_ptr(STATE(_locals), O1);                                   // get result of popping callee's args
  __ ba(false, unwind_recursive_activation);
  __ delayed()->nop();

  interpreter_frame_manager = entry_point;
  return entry_point;
}

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


static int size_activation_helper(int callee_extra_locals, int max_stack, int monitor_size) {

  // Figure out the size of an interpreter frame (in words) given that we have a fully allocated
  // expression stack, the callee will have callee_extra_locals (so we can account for
  // frame extension) and monitor_size for monitors. Basically we need to calculate
  // this exactly like generate_fixed_frame/generate_compute_interpreter_state.
  //
  //
  // The big complicating thing here is that we must ensure that the stack stays properly
  // aligned. This would be even uglier if monitor size wasn't modulo what the stack
  // needs to be aligned for). We are given that the sp (fp) is already aligned by
  // the caller so we must ensure that it is properly aligned for our callee.
  //
  // Ths c++ interpreter always makes sure that we have a enough extra space on the
  // stack at all times to deal with the "stack long no_params()" method issue. This
  // is "slop_factor" here.
  const int slop_factor = 2;

  const int fixed_size = sizeof(BytecodeInterpreter)/wordSize +           // interpreter state object
                         frame::memory_parameter_word_sp_offset;   // register save area + param window
  const int extra_stack = 0; //6815692//methodOopDesc::extra_stack_entries();
  return (round_to(max_stack +
                   extra_stack +
                   slop_factor +
                   fixed_size +
                   monitor_size +
                   (callee_extra_locals * Interpreter::stackElementWords()), WordsPerLong));

}

int AbstractInterpreter::size_top_interpreter_activation(methodOop method) {

  // See call_stub code
  int call_stub_size  = round_to(7 + frame::memory_parameter_word_sp_offset,
                                 WordsPerLong);    // 7 + register save area

  // 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;
  return size_activation_helper(method->max_locals(), method->max_stack(),
                                 monitor_size) + call_stub_size;
}

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;

  // Fill in the registers for the frame

  // Need to install _sender_sp. Actually not too hard in C++!
  // When the skeletal frames are layed out we fill in a value
  // for _sender_sp. That value is only correct for the oldest
  // skeletal frame constructed (because there is only a single
  // entry for "caller_adjustment". While the skeletal frames
  // exist that is good enough. We correct that calculation
  // here and get all the frames correct.

  // to_fill->_sender_sp = locals - (method->size_of_parameters() - 1);

  *current->register_addr(Lstate) = (intptr_t) to_fill;
  // skeletal already places a useful value here and this doesn't account
  // for alignment so don't bother.
  // *current->register_addr(I5_savedSP) =     (intptr_t) locals - (method->size_of_parameters() - 1);

  if (caller->is_interpreted_frame()) {
    interpreterState prev  = caller->get_interpreterState();
    to_fill->_prev_link = 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() + 1 + extra_stack);
  to_fill->_monitor_base = (BasicObjectLock*) monitor_base;

  // sparc specific
  to_fill->_frame_bottom = frame_bottom;
  to_fill->_self_link = to_fill;
#ifdef ASSERT
  to_fill->_native_fresult = 123456.789;
  to_fill->_native_lresult = CONST64(0xdeadcafedeafcafe);
#endif
}

void BytecodeInterpreter::pd_layout_interpreterState(interpreterState istate, address last_Java_pc, intptr_t* last_Java_fp) {
  istate->_last_Java_pc = (intptr_t*) last_Java_pc;
}


int AbstractInterpreter::layout_activation(methodOop method,
                                           int tempcount, // Number of slots on java expression stack in use
                                           int popframe_extra_args,
                                           int moncount,  // Number of active monitors
                                           int callee_param_size,
                                           int callee_locals_size,
                                           frame* caller,
                                           frame* interpreter_frame,
                                           bool is_top_frame) {

  assert(popframe_extra_args == 0, "NEED TO FIX");
  // 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_size - callee_param_size;
  int monitor_size = (sizeof(BasicObjectLock) * moncount) / wordSize;
  int full_frame_words = size_activation_helper(extra_locals_size, method->max_stack(), monitor_size);
  int short_frame_words = size_activation_helper(extra_locals_size, method->max_stack(), monitor_size);
  int frame_words = is_top_frame ? full_frame_words : short_frame_words;


  /*
    if we actually have a frame to layout we must now fill in all the pieces. This means both
    the interpreterState and the registers.
  */
  if (interpreter_frame != NULL) {

    // MUCHO HACK

    intptr_t* frame_bottom = interpreter_frame->sp() - (full_frame_words - frame_words);
    // 'interpreter_frame->sp()' is unbiased while 'frame_bottom' must be a biased value in 64bit mode.
    assert(((intptr_t)frame_bottom & 0xf) == 0, "SP biased in layout_activation");
    frame_bottom = (intptr_t*)((intptr_t)frame_bottom - STACK_BIAS);

    /* Now fillin the interpreterState object */

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


    intptr_t* locals;

    // Calculate the postion of locals[0]. This is painful because of
    // stack alignment (same as ia64). The problem is that we can
    // not compute the location of locals from fp(). fp() will account
    // for the extra locals but it also accounts for aligning the stack
    // and we can't determine if the locals[0] was misaligned but max_locals
    // was enough to have the
    // calculate postion of locals. fp already accounts for extra locals.
    // +2 for the static long no_params() issue.

    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();
    } else {
      // Lay out locals block in the caller adjacent to the register window save area.
      //
      // Compiled frames do not allocate a varargs area which is why this if
      // statement is needed.
      //
      intptr_t* fp = interpreter_frame->fp();
      int local_words = method->max_locals() * Interpreter::stackElementWords();

      if (caller->is_compiled_frame()) {
        locals = fp + frame::register_save_words + local_words - 1;
      } else {
        locals = fp + frame::memory_parameter_word_sp_offset + local_words - 1;
      }

    }
    // END MUCHO HACK

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


    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_words;
}

#endif // CC_INTERP