view src/cpu/x86/vm/templateInterpreter_x86_64.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 638119ce7cfd
children 92add02409c9
line wrap: on
line source
/*
 * Copyright (c) 2003, 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/interpreter.hpp"
#include "interpreter/interpreterGenerator.hpp"
#include "interpreter/interpreterRuntime.hpp"
#include "interpreter/templateTable.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/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/synchronizer.hpp"
#include "runtime/timer.hpp"
#include "runtime/vframeArray.hpp"
#include "utilities/debug.hpp"

#define __ _masm->

#ifndef CC_INTERP

const int method_offset = frame::interpreter_frame_method_offset * wordSize;
const int bci_offset    = frame::interpreter_frame_bcx_offset    * wordSize;
const int locals_offset = frame::interpreter_frame_locals_offset * wordSize;

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

address TemplateInterpreterGenerator::generate_StackOverflowError_handler() {
  address entry = __ pc();

#ifdef ASSERT
  {
    Label L;
    __ lea(rax, Address(rbp,
                        frame::interpreter_frame_monitor_block_top_offset *
                        wordSize));
    __ cmpptr(rax, rsp); // rax = maximal rsp for current rbp (stack
                         // grows negative)
    __ jcc(Assembler::aboveEqual, L); // check if frame is complete
    __ stop ("interpreter frame not set up");
    __ bind(L);
  }
#endif // ASSERT
  // Restore bcp under the assumption that the current frame is still
  // interpreted
  __ restore_bcp();

  // expression stack must be empty before entering the VM if an
  // exception happened
  __ empty_expression_stack();
  // throw exception
  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address,
                              InterpreterRuntime::throw_StackOverflowError));
  return entry;
}

address TemplateInterpreterGenerator::generate_ArrayIndexOutOfBounds_handler(
        const char* name) {
  address entry = __ pc();
  // expression stack must be empty before entering the VM if an
  // exception happened
  __ empty_expression_stack();
  // setup parameters
  // ??? convention: expect aberrant index in register ebx
  __ lea(c_rarg1, ExternalAddress((address)name));
  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address,
                              InterpreterRuntime::
                              throw_ArrayIndexOutOfBoundsException),
             c_rarg1, rbx);
  return entry;
}

address TemplateInterpreterGenerator::generate_ClassCastException_handler() {
  address entry = __ pc();

  // object is at TOS
  __ pop(c_rarg1);

  // expression stack must be empty before entering the VM if an
  // exception happened
  __ empty_expression_stack();

  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address,
                              InterpreterRuntime::
                              throw_ClassCastException),
             c_rarg1);
  return entry;
}

// Arguments are: required type at TOS+8, failing object (or NULL) at TOS+4.
address TemplateInterpreterGenerator::generate_WrongMethodType_handler() {
  address entry = __ pc();

  __ pop(c_rarg2);              // failing object is at TOS
  __ pop(c_rarg1);              // required type is at TOS+8

  __ verify_oop(c_rarg1);
  __ verify_oop(c_rarg2);

  // Various method handle types use interpreter registers as temps.
  __ restore_bcp();
  __ restore_locals();

  // Expression stack must be empty before entering the VM for an exception.
  __ empty_expression_stack();

  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address,
                              InterpreterRuntime::throw_WrongMethodTypeException),
             // pass required type, failing object (or NULL)
             c_rarg1, c_rarg2);
  return entry;
}

address TemplateInterpreterGenerator::generate_exception_handler_common(
        const char* name, const char* message, bool pass_oop) {
  assert(!pass_oop || message == NULL, "either oop or message but not both");
  address entry = __ pc();
  if (pass_oop) {
    // object is at TOS
    __ pop(c_rarg2);
  }
  // expression stack must be empty before entering the VM if an
  // exception happened
  __ empty_expression_stack();
  // setup parameters
  __ lea(c_rarg1, ExternalAddress((address)name));
  if (pass_oop) {
    __ call_VM(rax, CAST_FROM_FN_PTR(address,
                                     InterpreterRuntime::
                                     create_klass_exception),
               c_rarg1, c_rarg2);
  } else {
    // kind of lame ExternalAddress can't take NULL because
    // external_word_Relocation will assert.
    if (message != NULL) {
      __ lea(c_rarg2, ExternalAddress((address)message));
    } else {
      __ movptr(c_rarg2, NULL_WORD);
    }
    __ call_VM(rax,
               CAST_FROM_FN_PTR(address, InterpreterRuntime::create_exception),
               c_rarg1, c_rarg2);
  }
  // throw exception
  __ jump(ExternalAddress(Interpreter::throw_exception_entry()));
  return entry;
}


address TemplateInterpreterGenerator::generate_continuation_for(TosState state) {
  address entry = __ pc();
  // NULL last_sp until next java call
  __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);
  __ dispatch_next(state);
  return entry;
}


address TemplateInterpreterGenerator::generate_return_entry_for(TosState state, int step) {
  address entry = __ pc();

  // Restore stack bottom in case i2c adjusted stack
  __ movptr(rsp, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
  // and NULL it as marker that esp is now tos until next java call
  __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);

  __ restore_bcp();
  __ restore_locals();

  Label L_got_cache, L_giant_index;
  if (EnableInvokeDynamic) {
    __ cmpb(Address(r13, 0), Bytecodes::_invokedynamic);
    __ jcc(Assembler::equal, L_giant_index);
  }
  __ get_cache_and_index_at_bcp(rbx, rcx, 1, sizeof(u2));
  __ bind(L_got_cache);
  __ movl(rbx, Address(rbx, rcx,
                       Address::times_ptr,
                       in_bytes(constantPoolCacheOopDesc::base_offset()) +
                       3 * wordSize));
  __ andl(rbx, 0xFF);
  __ lea(rsp, Address(rsp, rbx, Address::times_8));
  __ dispatch_next(state, step);

  // out of the main line of code...
  if (EnableInvokeDynamic) {
    __ bind(L_giant_index);
    __ get_cache_and_index_at_bcp(rbx, rcx, 1, sizeof(u4));
    __ jmp(L_got_cache);
  }

  return entry;
}


address TemplateInterpreterGenerator::generate_deopt_entry_for(TosState state,
                                                               int step) {
  address entry = __ pc();
  // NULL last_sp until next java call
  __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);
  __ restore_bcp();
  __ restore_locals();
  // handle exceptions
  {
    Label L;
    __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t) NULL_WORD);
    __ jcc(Assembler::zero, L);
    __ call_VM(noreg,
               CAST_FROM_FN_PTR(address,
                                InterpreterRuntime::throw_pending_exception));
    __ should_not_reach_here();
    __ bind(L);
  }
  __ dispatch_next(state, step);
  return entry;
}

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_LONG   : i = 5; break;
    case T_VOID   : i = 6; break;
    case T_FLOAT  : i = 7; break;
    case T_DOUBLE : i = 8; break;
    case T_OBJECT : i = 9; break;
    case T_ARRAY  : i = 9; break;
    default       : ShouldNotReachHere();
  }
  assert(0 <= i && i < AbstractInterpreter::number_of_result_handlers,
         "index out of bounds");
  return i;
}


address TemplateInterpreterGenerator::generate_result_handler_for(
        BasicType type) {
  address entry = __ pc();
  switch (type) {
  case T_BOOLEAN: __ c2bool(rax);            break;
  case T_CHAR   : __ movzwl(rax, rax);       break;
  case T_BYTE   : __ sign_extend_byte(rax);  break;
  case T_SHORT  : __ sign_extend_short(rax); break;
  case T_INT    : /* nothing to do */        break;
  case T_LONG   : /* nothing to do */        break;
  case T_VOID   : /* nothing to do */        break;
  case T_FLOAT  : /* nothing to do */        break;
  case T_DOUBLE : /* nothing to do */        break;
  case T_OBJECT :
    // retrieve result from frame
    __ movptr(rax, Address(rbp, frame::interpreter_frame_oop_temp_offset*wordSize));
    // and verify it
    __ verify_oop(rax);
    break;
  default       : ShouldNotReachHere();
  }
  __ ret(0);                                   // return from result handler
  return entry;
}

address TemplateInterpreterGenerator::generate_safept_entry_for(
        TosState state,
        address runtime_entry) {
  address entry = __ pc();
  __ push(state);
  __ call_VM(noreg, runtime_entry);
  __ dispatch_via(vtos, Interpreter::_normal_table.table_for(vtos));
  return entry;
}



// 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
// ecx: invocation counter
//
void InterpreterGenerator::generate_counter_incr(
        Label* overflow,
        Label* profile_method,
        Label* profile_method_continue) {
  const Address invocation_counter(rbx, in_bytes(methodOopDesc::invocation_counter_offset()) +
                                        in_bytes(InvocationCounter::counter_offset()));
  // Note: In tiered we increment either counters in methodOop or in MDO depending if we're profiling or not.
  if (TieredCompilation) {
    int increment = InvocationCounter::count_increment;
    int mask = ((1 << Tier0InvokeNotifyFreqLog)  - 1) << InvocationCounter::count_shift;
    Label no_mdo, done;
    if (ProfileInterpreter) {
      // Are we profiling?
      __ movptr(rax, Address(rbx, methodOopDesc::method_data_offset()));
      __ testptr(rax, rax);
      __ jccb(Assembler::zero, no_mdo);
      // Increment counter in the MDO
      const Address mdo_invocation_counter(rax, in_bytes(methodDataOopDesc::invocation_counter_offset()) +
                                                in_bytes(InvocationCounter::counter_offset()));
      __ increment_mask_and_jump(mdo_invocation_counter, increment, mask, rcx, false, Assembler::zero, overflow);
      __ jmpb(done);
    }
    __ bind(no_mdo);
    // Increment counter in methodOop (we don't need to load it, it's in ecx).
    __ increment_mask_and_jump(invocation_counter, increment, mask, rcx, true, Assembler::zero, overflow);
    __ bind(done);
  } else {
    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

    __ incrementl(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

    if (ProfileInterpreter && profile_method != NULL) {
      // Test to see if we should create a method data oop
      __ cmp32(rcx, ExternalAddress((address)&InvocationCounter::InterpreterProfileLimit));
      __ jcc(Assembler::less, *profile_method_continue);

      // if no method data exists, go to profile_method
      __ test_method_data_pointer(rax, *profile_method);
    }

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

void InterpreterGenerator::generate_counter_overflow(Label* do_continue) {

  // Asm interpreter on entry
  // r14 - locals
  // r13 - bcp
  // rbx - method
  // edx - cpool --- DOES NOT APPEAR TO BE TRUE
  // rbp - interpreter frame

  // On return (i.e. jump to entry_point) [ back to invocation of interpreter ]
  // Everything as it was on entry
  // rdx is not restored. Doesn't appear to really be set.

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

  // InterpreterRuntime::frequency_counter_overflow takes two
  // arguments, the first (thread) is passed by call_VM, the second
  // indicates if the counter overflow occurs at a backwards branch
  // (NULL bcp).  We pass zero for it.  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).
  __ movl(c_rarg1, 0);
  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address,
                              InterpreterRuntime::frequency_counter_overflow),
             c_rarg1);

  __ movptr(rbx, Address(rbp, method_offset));   // restore methodOop
  // Preserve invariant that r13/r14 contain bcp/locals of sender frame
  // and jump to the interpreted entry.
  __ jmp(*do_continue, relocInfo::none);
}

// 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.
//
// NOTE: Since the additional locals are also always pushed (wasn't
// obvious in generate_method_entry) so the guard should work for them
// too.
//
// Args:
//      rdx: number of additional locals this frame needs (what we must check)
//      rbx: methodOop
//
// Kills:
//      rax
void InterpreterGenerator::generate_stack_overflow_check(void) {

  // monitor entry size: see picture of stack set
  // (generate_method_entry) and frame_amd64.hpp
  const int entry_size = frame::interpreter_frame_monitor_size() * wordSize;

  // total overhead size: entry_size + (saved rbp through expr stack
  // bottom).  be sure to change this if you add/subtract anything
  // to/from the overhead area
  const int overhead_size =
    -(frame::interpreter_frame_initial_sp_offset * wordSize) + entry_size;

  const int page_size = os::vm_page_size();

  Label after_frame_check;

  // see if the frame is greater than one page in size. If so,
  // then we need to verify there is enough stack space remaining
  // for the additional locals.
  __ cmpl(rdx, (page_size - overhead_size) / Interpreter::stackElementSize);
  __ jcc(Assembler::belowEqual, after_frame_check);

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

  const Address stack_base(r15_thread, Thread::stack_base_offset());
  const Address stack_size(r15_thread, Thread::stack_size_offset());

  // locals + overhead, in bytes
  __ mov(rax, rdx);
  __ shlptr(rax, Interpreter::logStackElementSize);  // 2 slots per parameter.
  __ addptr(rax, overhead_size);

#ifdef ASSERT
  Label stack_base_okay, stack_size_okay;
  // verify that thread stack base is non-zero
  __ cmpptr(stack_base, (int32_t)NULL_WORD);
  __ 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, 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);

  // Use the maximum number of pages we might bang.
  const int max_pages = StackShadowPages > (StackRedPages+StackYellowPages) ? StackShadowPages :
                                                                              (StackRedPages+StackYellowPages);

  // add in the red and yellow zone sizes
  __ addptr(rax, max_pages * page_size);

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

  __ pop(rax); // get return address
  __ jump(ExternalAddress(Interpreter::throw_StackOverflowError_entry()));

  // all done with frame size check
  __ bind(after_frame_check);
}

// Allocate monitor and lock method (asm interpreter)
//
// Args:
//      rbx: methodOop
//      r14: locals
//
// Kills:
//      rax
//      c_rarg0, c_rarg1, c_rarg2, c_rarg3, ...(param regs)
//      rscratch1, rscratch2 (scratch regs)
void InterpreterGenerator::lock_method(void) {
  // synchronize method
  const Address access_flags(rbx, methodOopDesc::access_flags_offset());
  const Address monitor_block_top(
        rbp,
        frame::interpreter_frame_monitor_block_top_offset * wordSize);
  const int entry_size = frame::interpreter_frame_monitor_size() * wordSize;

#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
  {
    const int mirror_offset = klassOopDesc::klass_part_offset_in_bytes() +
                              Klass::java_mirror_offset_in_bytes();
    Label done;
    __ movl(rax, access_flags);
    __ testl(rax, JVM_ACC_STATIC);
    // get receiver (assume this is frequent case)
    __ movptr(rax, Address(r14, Interpreter::local_offset_in_bytes(0)));
    __ 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));

#ifdef ASSERT
    {
      Label L;
      __ testptr(rax, rax);
      __ jcc(Assembler::notZero, L);
      __ stop("synchronization object is NULL");
      __ bind(L);
    }
#endif // ASSERT

    __ bind(done);
  }

  // add space for monitor & lock
  __ subptr(rsp, entry_size); // add space for a monitor entry
  __ movptr(monitor_block_top, rsp);  // set new monitor block top
  // store object
  __ movptr(Address(rsp, BasicObjectLock::obj_offset_in_bytes()), rax);
  __ movptr(c_rarg1, rsp); // object address
  __ lock_object(c_rarg1);
}

// Generate a fixed interpreter frame. This is identical setup for
// interpreted methods and for native methods hence the shared code.
//
// Args:
//      rax: return address
//      rbx: methodOop
//      r14: pointer to locals
//      r13: sender sp
//      rdx: cp cache
void TemplateInterpreterGenerator::generate_fixed_frame(bool native_call) {
  // initialize fixed part of activation frame
  __ push(rax);        // save return address
  __ enter();          // save old & set new rbp
  __ push(r13);        // set sender sp
  __ push((int)NULL_WORD); // leave last_sp as null
  __ movptr(r13, Address(rbx, methodOopDesc::const_offset()));      // get constMethodOop
  __ lea(r13, Address(r13, constMethodOopDesc::codes_offset())); // get codebase
  __ push(rbx);        // save methodOop
  if (ProfileInterpreter) {
    Label method_data_continue;
    __ movptr(rdx, Address(rbx, in_bytes(methodOopDesc::method_data_offset())));
    __ testptr(rdx, rdx);
    __ jcc(Assembler::zero, method_data_continue);
    __ addptr(rdx, in_bytes(methodDataOopDesc::data_offset()));
    __ bind(method_data_continue);
    __ push(rdx);      // set the mdp (method data pointer)
  } else {
    __ push(0);
  }

  __ movptr(rdx, Address(rbx, methodOopDesc::constants_offset()));
  __ movptr(rdx, Address(rdx, constantPoolOopDesc::cache_offset_in_bytes()));
  __ push(rdx); // set constant pool cache
  __ push(r14); // set locals pointer
  if (native_call) {
    __ push(0); // no bcp
  } else {
    __ push(r13); // set bcp
  }
  __ push(0); // reserve word for pointer to expression stack bottom
  __ movptr(Address(rsp, 0), rsp); // set expression stack bottom
}

// End of helpers

// Various method entries
//------------------------------------------------------------------------------------------------------------------------
//
//

// Call an accessor method (assuming it is resolved, otherwise drop
// into vanilla (slow path) entry
address InterpreterGenerator::generate_accessor_entry(void) {
  // rbx: methodOop

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

  address entry_point = __ pc();
  Label xreturn_path;

  // do fastpath for resolved accessor methods
  if (UseFastAccessorMethods) {
    // 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.
    Label slow_path;
    // If we need a safepoint check, generate full interpreter entry.
    __ cmp32(ExternalAddress(SafepointSynchronize::address_of_state()),
             SafepointSynchronize::_not_synchronized);

    __ jcc(Assembler::notEqual, slow_path);
    // rbx: method
    __ 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
    // rdx: constant pool cache index
    // rdi: constant pool cache

    // 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_8,
                    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_8,
                      constantPoolCacheOopDesc::base_offset() +
                      ConstantPoolCacheEntry::f2_offset()));
    // edx: flags
    __ movl(rdx,
            Address(rdi,
                    rdx,
                    Address::times_8,
                    constantPoolCacheOopDesc::base_offset() +
                    ConstantPoolCacheEntry::flags_offset()));

    Label notObj, notInt, notByte, notShort;
    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 edx for tosBits after the above shift
    ConstantPoolCacheEntry::verify_tosBits();

    __ cmpl(rdx, atos);
    __ jcc(Assembler::notEqual, notObj);
    // atos
    __ load_heap_oop(rax, field_address);
    __ jmp(xreturn_path);

    __ bind(notObj);
    __ cmpl(rdx, itos);
    __ jcc(Assembler::notEqual, notInt);
    // itos
    __ movl(rax, field_address);
    __ jmp(xreturn_path);

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

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

    __ bind(notShort);
#ifdef ASSERT
    Label okay;
    __ cmpl(rdx, ctos);
    __ jcc(Assembler::equal, okay);
    __ stop("what type is this?");
    __ bind(okay);
#endif
    // ctos
    __ load_unsigned_short(rax, field_address);

    __ bind(xreturn_path);

    // _ireturn/_areturn
    __ pop(rdi);
    __ mov(rsp, r13);
    __ jmp(rdi);
    __ ret(0);

    // generate a vanilla interpreter entry as the slow path
    __ bind(slow_path);
    (void) generate_normal_entry(false);
  } else {
    (void) generate_normal_entry(false);
  }

  return entry_point;
}

// Method entry for java.lang.ref.Reference.get.
address InterpreterGenerator::generate_Reference_get_entry(void) {
#ifndef SERIALGC
  // Code: _aload_0, _getfield, _areturn
  // parameter size = 1
  //
  // The code that gets generated by this routine is split into 2 parts:
  //    1. The "intrinsified" code for G1 (or any SATB based GC),
  //    2. The slow path - which is an expansion of the regular method entry.
  //
  // Notes:-
  // * In the G1 code we do not check whether we need to block for
  //   a safepoint. If G1 is enabled then we must execute the specialized
  //   code for Reference.get (except when the Reference object is null)
  //   so that we can log the value in the referent field with an SATB
  //   update buffer.
  //   If the code for the getfield template is modified so that the
  //   G1 pre-barrier code is executed when the current method is
  //   Reference.get() then going through the normal method entry
  //   will be fine.
  // * The G1 code can, however, check the receiver object (the instance
  //   of java.lang.Reference) and jump to the slow path if null. If the
  //   Reference object is null then we obviously cannot fetch the referent
  //   and so we don't need to call the G1 pre-barrier. Thus we can use the
  //   regular method entry code to generate the NPE.
  //
  // This code is based on generate_accessor_enty.
  //
  // rbx: methodOop

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

  address entry = __ pc();

  const int referent_offset = java_lang_ref_Reference::referent_offset;
  guarantee(referent_offset > 0, "referent offset not initialized");

  if (UseG1GC) {
    Label slow_path;
    // rbx: method

    // Check if local 0 != NULL
    // If the receiver is null then it is OK to jump to the slow path.
    __ movptr(rax, Address(rsp, wordSize));

    __ testptr(rax, rax);
    __ jcc(Assembler::zero, slow_path);

    // rax: local 0
    // rbx: method (but can be used as scratch now)
    // rdx: scratch
    // rdi: scratch

    // Generate the G1 pre-barrier code to log the value of
    // the referent field in an SATB buffer.

    // Load the value of the referent field.
    const Address field_address(rax, referent_offset);
    __ load_heap_oop(rax, field_address);

    // Generate the G1 pre-barrier code to log the value of
    // the referent field in an SATB buffer.
    __ g1_write_barrier_pre(noreg /* obj */,
                            rax /* pre_val */,
                            r15_thread /* thread */,
                            rbx /* tmp */,
                            true /* tosca_live */,
                            true /* expand_call */);

    // _areturn
    __ pop(rdi);                // get return address
    __ mov(rsp, r13);           // set sp to sender sp
    __ jmp(rdi);
    __ ret(0);

    // generate a vanilla interpreter entry as the slow path
    __ bind(slow_path);
    (void) generate_normal_entry(false);

    return entry;
  }
#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. (asm 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) {
  // determine code generation flags
  bool inc_counter  = UseCompiler || CountCompiledCalls;

  // rbx: methodOop
  // r13: sender sp

  address entry_point = __ pc();

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

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

  // native calls don't need the stack size check since they have no
  // expression stack and the arguments are already on the stack and
  // we only add a handful of words to the stack

  // rbx: methodOop
  // rcx: size of parameters
  // r13: sender sp
  __ pop(rax);                                       // get return address

  // for natives the size of locals is zero

  // compute beginning of parameters (r14)
  __ lea(r14, Address(rsp, rcx, Address::times_8, -wordSize));

  // add 2 zero-initialized slots for native calls
  // initialize result_handler slot
  __ push((int) NULL_WORD);
  // slot for oop temp
  // (static native method holder mirror/jni oop result)
  __ push((int) NULL_WORD);

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

  // initialize fixed part of activation frame
  generate_fixed_frame(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

  // 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(r15_thread,
        in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()));
  __ movbool(do_not_unlock_if_synchronized, true);

  // 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
  __ movbool(do_not_unlock_if_synchronized, false);

  // check for synchronized methods
  // Must happen AFTER invocation_counter check and stack overflow check,
  // so method is not locked if overflows.
  if (synchronized) {
    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
#ifdef ASSERT
  {
    Label L;
    const Address monitor_block_top(rbp,
                 frame::interpreter_frame_monitor_block_top_offset * wordSize);
    __ movptr(rax, monitor_block_top);
    __ cmpptr(rax, rsp);
    __ jcc(Assembler::equal, L);
    __ stop("broken stack frame setup in interpreter");
    __ bind(L);
  }
#endif

  // jvmti support
  __ notify_method_entry();

  // work registers
  const Register method = rbx;
  const Register t      = r11;

  // allocate space for parameters
  __ get_method(method);
  __ verify_oop(method);
  __ load_unsigned_short(t,
                         Address(method,
                                 methodOopDesc::size_of_parameters_offset()));
  __ shll(t, Interpreter::logStackElementSize);

  __ subptr(rsp, t);
  __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
  __ andptr(rsp, -16); // must be 16 byte boundary (see amd64 ABI)

  // get signature handler
  {
    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);
    __ get_method(method);
    __ movptr(t, Address(method, methodOopDesc::signature_handler_offset()));
    __ bind(L);
  }

  // call signature handler
  assert(InterpreterRuntime::SignatureHandlerGenerator::from() == r14,
         "adjust this code");
  assert(InterpreterRuntime::SignatureHandlerGenerator::to() == rsp,
         "adjust this code");
  assert(InterpreterRuntime::SignatureHandlerGenerator::temp() == rscratch1,
          "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 can do a GC on return,
  // so we must reload it after the call.
  __ call(t);
  __ get_method(method);        // slow path can do a GC, reload RBX


  // result handler is in rax
  // set result handler
  __ movptr(Address(rbp,
                    (frame::interpreter_frame_result_handler_offset) * wordSize),
            rax);

  // 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 frame
    __ movptr(Address(rbp, frame::interpreter_frame_oop_temp_offset * wordSize),
            t);
    // pass handle to mirror
    __ lea(c_rarg1,
           Address(rbp, frame::interpreter_frame_oop_temp_offset * wordSize));
    __ bind(L);
  }

  // get native function entry point
  {
    Label L;
    __ movptr(rax, Address(method, methodOopDesc::native_function_offset()));
    ExternalAddress unsatisfied(SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
    __ movptr(rscratch2, unsatisfied.addr());
    __ cmpptr(rax, rscratch2);
    __ jcc(Assembler::notEqual, L);
    __ call_VM(noreg,
               CAST_FROM_FN_PTR(address,
                                InterpreterRuntime::prepare_native_call),
               method);
    __ get_method(method);
    __ verify_oop(method);
    __ movptr(rax, Address(method, methodOopDesc::native_function_offset()));
    __ bind(L);
  }

  // pass JNIEnv
  __ lea(c_rarg0, Address(r15_thread, JavaThread::jni_environment_offset()));

  // 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(rsp, rbp, (address) __ pc());

  // change thread state
#ifdef ASSERT
  {
    Label L;
    __ movl(t, Address(r15_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

  __ movl(Address(r15_thread, JavaThread::thread_state_offset()),
          _thread_in_native);

  // Call the native method.
  __ call(rax);
  // result potentially in rax or xmm0

  // Depending on runtime options, either restore the MXCSR
  // register after returning from the JNI Call or verify that
  // it wasn't changed during -Xcheck:jni.
  if (RestoreMXCSROnJNICalls) {
    __ ldmxcsr(ExternalAddress(StubRoutines::x86::mxcsr_std()));
  }
  else if (CheckJNICalls) {
    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::x86::verify_mxcsr_entry())));
  }

  // NOTE: The order of these pushes is known to frame::interpreter_frame_result
  // in order to extract the result of a method call. If the order of these
  // pushes change or anything else is added to the stack then the code in
  // interpreter_frame_result must also change.

  __ push(dtos);
  __ push(ltos);

  // change thread state
  __ movl(Address(r15_thread, JavaThread::thread_state_offset()),
          _thread_in_native_trans);

  if (os::is_MP()) {
    if (UseMembar) {
      // Force this write out before the read below
      __ membar(Assembler::Membar_mask_bits(
           Assembler::LoadLoad | Assembler::LoadStore |
           Assembler::StoreLoad | Assembler::StoreStore));
    } else {
      // 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(r15_thread, rscratch2);
    }
  }

  // check for safepoint operation in progress and/or pending suspend requests
  {
    Label Continue;
    __ cmp32(ExternalAddress(SafepointSynchronize::address_of_state()),
             SafepointSynchronize::_not_synchronized);

    Label L;
    __ jcc(Assembler::notEqual, L);
    __ cmpl(Address(r15_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 r13 & r14 are
    // preserved and correspond to the bcp/locals pointers. So we do a
    // runtime call by hand.
    //
    __ mov(c_rarg0, r15_thread);
    __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
    __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
    __ andptr(rsp, -16); // align stack as required by ABI
    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans)));
    __ mov(rsp, r12); // restore sp
    __ reinit_heapbase();
    __ bind(Continue);
  }

  // change thread state
  __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_Java);

  // reset_last_Java_frame
  __ reset_last_Java_frame(true, true);

  // reset handle block
  __ movptr(t, Address(r15_thread, JavaThread::active_handles_offset()));
  __ movptr(Address(t, JNIHandleBlock::top_offset_in_bytes()), (int32_t)NULL_WORD);

  // If result is an oop unbox and store it in frame where gc will see it
  // and result handler will pick it up

  {
    Label no_oop, store_result;
    __ lea(t, ExternalAddress(AbstractInterpreter::result_handler(T_OBJECT)));
    __ cmpptr(t, Address(rbp, frame::interpreter_frame_result_handler_offset*wordSize));
    __ jcc(Assembler::notEqual, no_oop);
    // retrieve result
    __ pop(ltos);
    __ testptr(rax, rax);
    __ jcc(Assembler::zero, store_result);
    __ movptr(rax, Address(rax, 0));
    __ bind(store_result);
    __ movptr(Address(rbp, frame::interpreter_frame_oop_temp_offset*wordSize), rax);
    // keep stack depth as expected by pushing oop which will eventually be discarde
    __ push(ltos);
    __ bind(no_oop);
  }


  {
    Label no_reguard;
    __ cmpl(Address(r15_thread, JavaThread::stack_guard_state_offset()),
            JavaThread::stack_guard_yellow_disabled);
    __ jcc(Assembler::notEqual, no_reguard);

    __ pusha(); // XXX only save smashed registers
    __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
    __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
    __ andptr(rsp, -16); // align stack as required by ABI
    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages)));
    __ mov(rsp, r12); // restore sp
    __ popa(); // XXX only restore smashed registers
    __ reinit_heapbase();

    __ bind(no_reguard);
  }


  // The method register is junk from after the thread_in_native transition
  // until here.  Also can't call_VM until the bcp has been
  // restored.  Need bcp for throwing exception below so get it now.
  __ get_method(method);
  __ verify_oop(method);

  // restore r13 to have legal interpreter frame, i.e., bci == 0 <=>
  // r13 == code_base()
  __ movptr(r13, Address(method, methodOopDesc::const_offset()));   // get constMethodOop
  __ lea(r13, Address(r13, constMethodOopDesc::codes_offset()));    // get codebase
  // handle exceptions (exception handling will handle unlocking!)
  {
    Label L;
    __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t) NULL_WORD);
    __ jcc(Assembler::zero, L);
    // Note: At some point we may want to unify this with the code
    // used in call_VM_base(); i.e., we should use the
    // StubRoutines::forward_exception code. For now this doesn't work
    // here because the rsp is not correctly set at this point.
    __ MacroAssembler::call_VM(noreg,
                               CAST_FROM_FN_PTR(address,
                               InterpreterRuntime::throw_pending_exception));
    __ should_not_reach_here();
    __ 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;
      // 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.
      const Address monitor(rbp,
                            (intptr_t)(frame::interpreter_frame_initial_sp_offset *
                                       wordSize - sizeof(BasicObjectLock)));

      // monitor expect in c_rarg1 for slow unlock path
      __ lea(c_rarg1, monitor); // address of first monitor

      __ movptr(t, Address(c_rarg1, 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(c_rarg1);
    }
    __ 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 edx:eax, call result handler to
  // restore potential result in ST0 & handle result

  __ pop(ltos);
  __ pop(dtos);

  __ movptr(t, Address(rbp,
                       (frame::interpreter_frame_result_handler_offset) * wordSize));
  __ call(t);

  // remove activation
  __ movptr(t, Address(rbp,
                       frame::interpreter_frame_sender_sp_offset *
                       wordSize)); // get sender sp
  __ leave();                                // remove frame anchor
  __ pop(rdi);                               // get return address
  __ mov(rsp, t);                            // set sp to sender sp
  __ jmp(rdi);

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

  return entry_point;
}

//
// Generic interpreted method entry to (asm) interpreter
//
address InterpreterGenerator::generate_normal_entry(bool synchronized) {
  // determine code generation flags
  bool inc_counter  = UseCompiler || CountCompiledCalls;

  // ebx: methodOop
  // r13: sender sp
  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());

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

  // rbx: methodOop
  // rcx: size of parameters
  // r13: sender_sp (could differ from sp+wordSize if we were called via c2i )

  __ load_unsigned_short(rdx, size_of_locals); // get size of locals in words
  __ subl(rdx, rcx); // rdx = no. of additional locals

  // YYY
//   __ incrementl(rdx);
//   __ andl(rdx, -2);

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

  // get return address
  __ pop(rax);

  // compute beginning of parameters (r14)
  __ lea(r14, Address(rsp, rcx, Address::times_8, -wordSize));

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

  // (pre-)fetch invocation count
  if (inc_counter) {
    __ movl(rcx, invocation_counter);
  }
  // initialize fixed part of activation frame
  generate_fixed_frame(false);

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

  // 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(r15_thread,
        in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()));
  __ movbool(do_not_unlock_if_synchronized, true);

  // increment invocation count & check for overflow
  Label invocation_counter_overflow;
  Label profile_method;
  Label profile_method_continue;
  if (inc_counter) {
    generate_counter_incr(&invocation_counter_overflow,
                          &profile_method,
                          &profile_method_continue);
    if (ProfileInterpreter) {
      __ bind(profile_method_continue);
    }
  }

  Label continue_after_compile;
  __ bind(continue_after_compile);

  // check for synchronized interpreted methods
  bang_stack_shadow_pages(false);

  // reset the _do_not_unlock_if_synchronized flag
  __ movbool(do_not_unlock_if_synchronized, false);

  // check for synchronized methods
  // Must happen AFTER invocation_counter check and stack overflow check,
  // so method is not locked if overflows.
  if (synchronized) {
    // Allocate monitor and lock method
    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
#ifdef ASSERT
  {
    Label L;
     const Address monitor_block_top (rbp,
                 frame::interpreter_frame_monitor_block_top_offset * wordSize);
    __ movptr(rax, monitor_block_top);
    __ cmpptr(rax, rsp);
    __ jcc(Assembler::equal, L);
    __ stop("broken stack frame setup in interpreter");
    __ bind(L);
  }
#endif

  // jvmti support
  __ notify_method_entry();

  __ dispatch_next(vtos);

  // invocation counter overflow
  if (inc_counter) {
    if (ProfileInterpreter) {
      // We have decided to profile this method in the interpreter
      __ bind(profile_method);
      __ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::profile_method));
      __ set_method_data_pointer_for_bcp();
      __ get_method(rbx);
      __ jmp(profile_method_continue);
    }
    // Handle overflow of counter and compile method
    __ bind(invocation_counter_overflow);
    generate_counter_overflow(&continue_after_compile);
  }

  return entry_point;
}

// Entry points
//
// Here we generate the various kind of entries into the interpreter.
// The two main entry type are generic bytecode methods and native
// call method.  These both come in synchronized and non-synchronized
// versions but the frame layout they create is very similar. The
// other method entry types are really just special purpose entries
// that are really entry and interpretation all in one. These are for
// trivial methods like accessor, empty, or special math methods.
//
// When control flow reaches any of the entry types for the interpreter
// the following holds ->
//
// Arguments:
//
// rbx: methodOop
//
// Stack layout immediately at entry
//
// [ return address     ] <--- rsp
// [ parameter n        ]
//   ...
// [ parameter 1        ]
// [ expression stack   ] (caller's java expression stack)

// Assuming that we don't go to one of the trivial specialized entries
// the stack will look like below when we are ready to execute the
// first bytecode (or call the native routine). The register usage
// will be as the template based interpreter expects (see
// interpreter_amd64.hpp).
//
// local variables follow incoming parameters immediately; i.e.
// the return address is moved to the end of the locals).
//
// [ monitor entry      ] <--- rsp
//   ...
// [ monitor entry      ]
// [ expr. stack bottom ]
// [ saved r13          ]
// [ current r14        ]
// [ methodOop          ]
// [ saved ebp          ] <--- rbp
// [ return address     ]
// [ local variable m   ]
//   ...
// [ local variable 1   ]
// [ parameter n        ]
//   ...
// [ parameter 1        ] <--- r14

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);
}

// These should never be compiled since the interpreter will prefer
// the compiled version to the intrinsic version.
bool AbstractInterpreter::can_be_compiled(methodHandle m) {
  switch (method_kind(m)) {
    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    :
      return false;
    default:
      return true;
  }
}

// How much stack a method activation needs in words.
int AbstractInterpreter::size_top_interpreter_activation(methodOop method) {
  const int entry_size = frame::interpreter_frame_monitor_size();

  // 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 =
    -(frame::interpreter_frame_initial_sp_offset) + entry_size;

  const int stub_code = frame::entry_frame_after_call_words;
  const int extra_stack = 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);
}

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) {
  // Note: This calculation must exactly parallel the frame setup
  // in AbstractInterpreterGenerator::generate_method_entry.
  // 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

  // fixed size of an interpreter frame:
  int max_locals = method->max_locals() * Interpreter::stackElementWords;
  int extra_locals = (method->max_locals() - method->size_of_parameters()) *
                     Interpreter::stackElementWords;

  int overhead = frame::sender_sp_offset -
                 frame::interpreter_frame_initial_sp_offset;
  // Our locals were accounted for by the caller (or last_frame_adjust
  // on the transistion) Since the callee parameters already account
  // for the callee's params we only need to account for the extra
  // locals.
  int size = overhead +
         (callee_locals - callee_param_count)*Interpreter::stackElementWords +
         moncount * frame::interpreter_frame_monitor_size() +
         tempcount* Interpreter::stackElementWords + popframe_extra_args;
  if (interpreter_frame != NULL) {
#ifdef ASSERT
    if (!EnableMethodHandles)
      // @@@ FIXME: Should we correct interpreter_frame_sender_sp in the calling sequences?
      // Probably, since deoptimization doesn't work yet.
      assert(caller->unextended_sp() == interpreter_frame->interpreter_frame_sender_sp(), "Frame not properly walkable");
    assert(caller->sp() == interpreter_frame->sender_sp(), "Frame not properly walkable(2)");
#endif

    interpreter_frame->interpreter_frame_set_method(method);
    // NOTE the difference in using sender_sp and
    // interpreter_frame_sender_sp interpreter_frame_sender_sp is
    // the original sp of the caller (the unextended_sp) and
    // sender_sp is fp+16 XXX
    intptr_t* locals = interpreter_frame->sender_sp() + max_locals - 1;

    interpreter_frame->interpreter_frame_set_locals(locals);
    BasicObjectLock* montop = interpreter_frame->interpreter_frame_monitor_begin();
    BasicObjectLock* monbot = montop - moncount;
    interpreter_frame->interpreter_frame_set_monitor_end(monbot);

    // Set last_sp
    intptr_t*  esp = (intptr_t*) monbot -
                     tempcount*Interpreter::stackElementWords -
                     popframe_extra_args;
    interpreter_frame->interpreter_frame_set_last_sp(esp);

    // All frames but the initial (oldest) interpreter frame we fill in have
    // a value for sender_sp that allows walking the stack but isn't
    // truly correct. Correct the value here.
    if (extra_locals != 0 &&
        interpreter_frame->sender_sp() ==
        interpreter_frame->interpreter_frame_sender_sp()) {
      interpreter_frame->set_interpreter_frame_sender_sp(caller->sp() +
                                                         extra_locals);
    }
    *interpreter_frame->interpreter_frame_cache_addr() =
      method->constants()->cache();
  }
  return size;
}

//-----------------------------------------------------------------------------
// Exceptions

void TemplateInterpreterGenerator::generate_throw_exception() {
  // Entry point in previous activation (i.e., if the caller was
  // interpreted)
  Interpreter::_rethrow_exception_entry = __ pc();
  // Restore sp to interpreter_frame_last_sp even though we are going
  // to empty the expression stack for the exception processing.
  __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);
  // rax: exception
  // rdx: return address/pc that threw exception
  __ restore_bcp();    // r13 points to call/send
  __ restore_locals();
  __ reinit_heapbase();  // restore r12 as heapbase.
  // Entry point for exceptions thrown within interpreter code
  Interpreter::_throw_exception_entry = __ pc();
  // expression stack is undefined here
  // rax: exception
  // r13: exception bcp
  __ verify_oop(rax);
  __ mov(c_rarg1, rax);

  // expression stack must be empty before entering the VM in case of
  // an exception
  __ empty_expression_stack();
  // find exception handler address and preserve exception oop
  __ call_VM(rdx,
             CAST_FROM_FN_PTR(address,
                          InterpreterRuntime::exception_handler_for_exception),
             c_rarg1);
  // rax: exception handler entry point
  // rdx: preserved exception oop
  // r13: bcp for exception handler
  __ push_ptr(rdx); // push exception which is now the only value on the stack
  __ jmp(rax); // jump to exception handler (may be _remove_activation_entry!)

  // If the exception is not handled in the current frame the frame is
  // removed and the exception is rethrown (i.e. exception
  // continuation is _rethrow_exception).
  //
  // Note: At this point the bci is still the bxi for the instruction
  // which caused the exception and the expression stack is
  // empty. Thus, for any VM calls at this point, GC will find a legal
  // oop map (with empty expression stack).

  // In current activation
  // tos: exception
  // esi: exception bcp

  //
  // JVMTI PopFrame support
  //

  Interpreter::_remove_activation_preserving_args_entry = __ pc();
  __ empty_expression_stack();
  // Set the popframe_processing bit in pending_popframe_condition
  // indicating that we are currently handling popframe, so that
  // call_VMs that may happen later do not trigger new popframe
  // handling cycles.
  __ movl(rdx, Address(r15_thread, JavaThread::popframe_condition_offset()));
  __ orl(rdx, JavaThread::popframe_processing_bit);
  __ movl(Address(r15_thread, JavaThread::popframe_condition_offset()), rdx);

  {
    // Check to see whether we are returning to a deoptimized frame.
    // (The PopFrame call ensures that the caller of the popped frame is
    // either interpreted or compiled and deoptimizes it if compiled.)
    // In this case, we can't call dispatch_next() after the frame is
    // popped, but instead must save the incoming arguments and restore
    // them after deoptimization has occurred.
    //
    // Note that we don't compare the return PC against the
    // deoptimization blob's unpack entry because of the presence of
    // adapter frames in C2.
    Label caller_not_deoptimized;
    __ movptr(c_rarg1, Address(rbp, frame::return_addr_offset * wordSize));
    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address,
                               InterpreterRuntime::interpreter_contains), c_rarg1);
    __ testl(rax, rax);
    __ jcc(Assembler::notZero, caller_not_deoptimized);

    // Compute size of arguments for saving when returning to
    // deoptimized caller
    __ get_method(rax);
    __ load_unsigned_short(rax, Address(rax, in_bytes(methodOopDesc::
                                                size_of_parameters_offset())));
    __ shll(rax, Interpreter::logStackElementSize);
    __ restore_locals(); // XXX do we need this?
    __ subptr(r14, rax);
    __ addptr(r14, wordSize);
    // Save these arguments
    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address,
                                           Deoptimization::
                                           popframe_preserve_args),
                          r15_thread, rax, r14);

    __ remove_activation(vtos, rdx,
                         /* throw_monitor_exception */ false,
                         /* install_monitor_exception */ false,
                         /* notify_jvmdi */ false);

    // Inform deoptimization that it is responsible for restoring
    // these arguments
    __ movl(Address(r15_thread, JavaThread::popframe_condition_offset()),
            JavaThread::popframe_force_deopt_reexecution_bit);

    // Continue in deoptimization handler
    __ jmp(rdx);

    __ bind(caller_not_deoptimized);
  }

  __ remove_activation(vtos, rdx, /* rdx result (retaddr) is not used */
                       /* throw_monitor_exception */ false,
                       /* install_monitor_exception */ false,
                       /* notify_jvmdi */ false);

  // Finish with popframe handling
  // A previous I2C followed by a deoptimization might have moved the
  // outgoing arguments further up the stack. PopFrame expects the
  // mutations to those outgoing arguments to be preserved and other
  // constraints basically require this frame to look exactly as
  // though it had previously invoked an interpreted activation with
  // no space between the top of the expression stack (current
  // last_sp) and the top of stack. Rather than force deopt to
  // maintain this kind of invariant all the time we call a small
  // fixup routine to move the mutated arguments onto the top of our
  // expression stack if necessary.
  __ mov(c_rarg1, rsp);
  __ movptr(c_rarg2, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
  // PC must point into interpreter here
  __ set_last_Java_frame(noreg, rbp, __ pc());
  __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::popframe_move_outgoing_args), r15_thread, c_rarg1, c_rarg2);
  __ reset_last_Java_frame(true, true);
  // Restore the last_sp and null it out
  __ movptr(rsp, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
  __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);

  __ restore_bcp();  // XXX do we need this?
  __ restore_locals(); // XXX do we need this?
  // The method data pointer was incremented already during
  // call profiling. We have to restore the mdp for the current bcp.
  if (ProfileInterpreter) {
    __ set_method_data_pointer_for_bcp();
  }

  // Clear the popframe condition flag
  __ movl(Address(r15_thread, JavaThread::popframe_condition_offset()),
          JavaThread::popframe_inactive);

  __ dispatch_next(vtos);
  // end of PopFrame support

  Interpreter::_remove_activation_entry = __ pc();

  // preserve exception over this code sequence
  __ pop_ptr(rax);
  __ movptr(Address(r15_thread, JavaThread::vm_result_offset()), rax);
  // remove the activation (without doing throws on illegalMonitorExceptions)
  __ remove_activation(vtos, rdx, false, true, false);
  // restore exception
  __ movptr(rax, Address(r15_thread, JavaThread::vm_result_offset()));
  __ movptr(Address(r15_thread, JavaThread::vm_result_offset()), (int32_t)NULL_WORD);
  __ verify_oop(rax);

  // In between activations - previous activation type unknown yet
  // compute continuation point - the continuation point expects the
  // following registers set up:
  //
  // rax: exception
  // rdx: return address/pc that threw exception
  // rsp: expression stack of caller
  // rbp: ebp of caller
  __ push(rax);                                  // save exception
  __ push(rdx);                                  // save return address
  __ super_call_VM_leaf(CAST_FROM_FN_PTR(address,
                          SharedRuntime::exception_handler_for_return_address),
                        r15_thread, rdx);
  __ mov(rbx, rax);                              // save exception handler
  __ pop(rdx);                                   // restore return address
  __ pop(rax);                                   // restore exception
  // Note that an "issuing PC" is actually the next PC after the call
  __ jmp(rbx);                                   // jump to exception
                                                 // handler of caller
}


//
// JVMTI ForceEarlyReturn support
//
address TemplateInterpreterGenerator::generate_earlyret_entry_for(TosState state) {
  address entry = __ pc();

  __ restore_bcp();
  __ restore_locals();
  __ empty_expression_stack();
  __ load_earlyret_value(state);

  __ movptr(rdx, Address(r15_thread, JavaThread::jvmti_thread_state_offset()));
  Address cond_addr(rdx, JvmtiThreadState::earlyret_state_offset());

  // Clear the earlyret state
  __ movl(cond_addr, JvmtiThreadState::earlyret_inactive);

  __ remove_activation(state, rsi,
                       false, /* throw_monitor_exception */
                       false, /* install_monitor_exception */
                       true); /* notify_jvmdi */
  __ jmp(rsi);

  return entry;
} // end of ForceEarlyReturn support


//-----------------------------------------------------------------------------
// Helper for vtos entry point generation

void TemplateInterpreterGenerator::set_vtos_entry_points(Template* t,
                                                         address& bep,
                                                         address& cep,
                                                         address& sep,
                                                         address& aep,
                                                         address& iep,
                                                         address& lep,
                                                         address& fep,
                                                         address& dep,
                                                         address& vep) {
  assert(t->is_valid() && t->tos_in() == vtos, "illegal template");
  Label L;
  aep = __ pc();  __ push_ptr();  __ jmp(L);
  fep = __ pc();  __ push_f();    __ jmp(L);
  dep = __ pc();  __ push_d();    __ jmp(L);
  lep = __ pc();  __ push_l();    __ jmp(L);
  bep = cep = sep =
  iep = __ pc();  __ push_i();
  vep = __ pc();
  __ bind(L);
  generate_and_dispatch(t);
}


//-----------------------------------------------------------------------------
// Generation of individual instructions

// helpers for generate_and_dispatch


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

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

// Non-product code
#ifndef PRODUCT
address TemplateInterpreterGenerator::generate_trace_code(TosState state) {
  address entry = __ pc();

  __ push(state);
  __ push(c_rarg0);
  __ push(c_rarg1);
  __ push(c_rarg2);
  __ push(c_rarg3);
  __ mov(c_rarg2, rax);  // Pass itos
#ifdef _WIN64
  __ movflt(xmm3, xmm0); // Pass ftos
#endif
  __ call_VM(noreg,
             CAST_FROM_FN_PTR(address, SharedRuntime::trace_bytecode),
             c_rarg1, c_rarg2, c_rarg3);
  __ pop(c_rarg3);
  __ pop(c_rarg2);
  __ pop(c_rarg1);
  __ pop(c_rarg0);
  __ pop(state);
  __ ret(0);                                   // return from result handler

  return entry;
}

void TemplateInterpreterGenerator::count_bytecode() {
  __ incrementl(ExternalAddress((address) &BytecodeCounter::_counter_value));
}

void TemplateInterpreterGenerator::histogram_bytecode(Template* t) {
  __ incrementl(ExternalAddress((address) &BytecodeHistogram::_counters[t->bytecode()]));
}

void TemplateInterpreterGenerator::histogram_bytecode_pair(Template* t) {
  __ mov32(rbx, ExternalAddress((address) &BytecodePairHistogram::_index));
  __ shrl(rbx, BytecodePairHistogram::log2_number_of_codes);
  __ orl(rbx,
         ((int) t->bytecode()) <<
         BytecodePairHistogram::log2_number_of_codes);
  __ mov32(ExternalAddress((address) &BytecodePairHistogram::_index), rbx);
  __ lea(rscratch1, ExternalAddress((address) BytecodePairHistogram::_counters));
  __ incrementl(Address(rscratch1, rbx, Address::times_4));
}


void TemplateInterpreterGenerator::trace_bytecode(Template* t) {
  // Call a little run-time stub to avoid blow-up for each bytecode.
  // The run-time runtime saves the right registers, depending on
  // the tosca in-state for the given template.

  assert(Interpreter::trace_code(t->tos_in()) != NULL,
         "entry must have been generated");
  __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
  __ andptr(rsp, -16); // align stack as required by ABI
  __ call(RuntimeAddress(Interpreter::trace_code(t->tos_in())));
  __ mov(rsp, r12); // restore sp
  __ reinit_heapbase();
}


void TemplateInterpreterGenerator::stop_interpreter_at() {
  Label L;
  __ cmp32(ExternalAddress((address) &BytecodeCounter::_counter_value),
           StopInterpreterAt);
  __ jcc(Assembler::notEqual, L);
  __ int3();
  __ bind(L);
}
#endif // !PRODUCT
#endif // ! CC_INTERP