xref: /openjdk10/hotspot/src/share/vm/ci/ciMethod.cpp

/*
 * Copyright 1999-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_ciMethod.cpp.incl"

// ciMethod
//
// This class represents a methodOop in the HotSpot virtual
// machine.


// ------------------------------------------------------------------
// ciMethod::ciMethod
//
// Loaded method.
ciMethod::ciMethod(methodHandle h_m) : ciObject(h_m) {
  assert(h_m() != NULL, "no null method");

  // These fields are always filled in in loaded methods.
  _flags = ciFlags(h_m()->access_flags());

  // Easy to compute, so fill them in now.
  _max_stack          = h_m()->max_stack();
  _max_locals         = h_m()->max_locals();
  _code_size          = h_m()->code_size();
  _intrinsic_id       = h_m()->intrinsic_id();
  _handler_count      = h_m()->exception_table()->length() / 4;
  _uses_monitors      = h_m()->access_flags().has_monitor_bytecodes();
  _balanced_monitors  = !_uses_monitors || h_m()->access_flags().is_monitor_matching();
  _is_compilable      = !h_m()->is_not_compilable();
  // Lazy fields, filled in on demand.  Require allocation.
  _code               = NULL;
  _exception_handlers = NULL;
  _liveness           = NULL;
  _bcea = NULL;
  _method_blocks = NULL;
#ifdef COMPILER2
  _flow               = NULL;
#endif // COMPILER2

  if (JvmtiExport::can_hotswap_or_post_breakpoint() && _is_compilable) {
    // 6328518 check hotswap conditions under the right lock.
    MutexLocker locker(Compile_lock);
    if (Dependencies::check_evol_method(h_m()) != NULL) {
      _is_compilable = false;
    }
  } else {
    CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  }

  if (instanceKlass::cast(h_m()->method_holder())->is_linked()) {
    _can_be_statically_bound = h_m()->can_be_statically_bound();
  } else {
    // Have to use a conservative value in this case.
    _can_be_statically_bound = false;
  }

  // Adjust the definition of this condition to be more useful:
  // %%% take these conditions into account in vtable generation
  if (!_can_be_statically_bound && h_m()->is_private())
    _can_be_statically_bound = true;
  if (_can_be_statically_bound && h_m()->is_abstract())
    _can_be_statically_bound = false;

  ciEnv *env = CURRENT_ENV;
  // generating _signature may allow GC and therefore move m.
  // These fields are always filled in.
  _name = env->get_object(h_m()->name())->as_symbol();
  _holder = env->get_object(h_m()->method_holder())->as_instance_klass();
  ciSymbol* sig_symbol = env->get_object(h_m()->signature())->as_symbol();
  _signature = new (env->arena()) ciSignature(_holder, sig_symbol);
  _method_data = NULL;
  // Take a snapshot of these values, so they will be commensurate with the MDO.
  if (ProfileInterpreter) {
    int invcnt = h_m()->interpreter_invocation_count();
    // if the value overflowed report it as max int
    _interpreter_invocation_count = invcnt < 0 ? max_jint : invcnt ;
    _interpreter_throwout_count   = h_m()->interpreter_throwout_count();
  } else {
    _interpreter_invocation_count = 0;
    _interpreter_throwout_count = 0;
  }
  if (_interpreter_invocation_count == 0)
    _interpreter_invocation_count = 1;
}


// ------------------------------------------------------------------
// ciMethod::ciMethod
//
// Unloaded method.
ciMethod::ciMethod(ciInstanceKlass* holder,
                   ciSymbol* name,
                   ciSymbol* signature) : ciObject(ciMethodKlass::make()) {
  // These fields are always filled in.
  _name = name;
  _holder = holder;
  _signature = new (CURRENT_ENV->arena()) ciSignature(_holder, signature);
  _intrinsic_id = vmIntrinsics::_none;
  _liveness = NULL;
  _can_be_statically_bound = false;
  _bcea = NULL;
  _method_blocks = NULL;
  _method_data = NULL;
#ifdef COMPILER2
  _flow = NULL;
#endif // COMPILER2
}


// ------------------------------------------------------------------
// ciMethod::load_code
//
// Load the bytecodes and exception handler table for this method.
void ciMethod::load_code() {
  VM_ENTRY_MARK;
  assert(is_loaded(), "only loaded methods have code");

  methodOop me = get_methodOop();
  Arena* arena = CURRENT_THREAD_ENV->arena();

  // Load the bytecodes.
  _code = (address)arena->Amalloc(code_size());
  memcpy(_code, me->code_base(), code_size());

  // Revert any breakpoint bytecodes in ci's copy
  if (me->number_of_breakpoints() > 0) {
    BreakpointInfo* bp = instanceKlass::cast(me->method_holder())->breakpoints();
    for (; bp != NULL; bp = bp->next()) {
      if (bp->match(me)) {
        code_at_put(bp->bci(), bp->orig_bytecode());
      }
    }
  }

  // And load the exception table.
  typeArrayOop exc_table = me->exception_table();

  // Allocate one extra spot in our list of exceptions.  This
  // last entry will be used to represent the possibility that
  // an exception escapes the method.  See ciExceptionHandlerStream
  // for details.
  _exception_handlers =
    (ciExceptionHandler**)arena->Amalloc(sizeof(ciExceptionHandler*)
                                         * (_handler_count + 1));
  if (_handler_count > 0) {
    for (int i=0; i<_handler_count; i++) {
      int base = i*4;
      _exception_handlers[i] = new (arena) ciExceptionHandler(
                                holder(),
            /* start    */      exc_table->int_at(base),
            /* limit    */      exc_table->int_at(base+1),
            /* goto pc  */      exc_table->int_at(base+2),
            /* cp index */      exc_table->int_at(base+3));
    }
  }

  // Put an entry at the end of our list to represent the possibility
  // of exceptional exit.
  _exception_handlers[_handler_count] =
    new (arena) ciExceptionHandler(holder(), 0, code_size(), -1, 0);

  if (CIPrintMethodCodes) {
    print_codes();
  }
}


// ------------------------------------------------------------------
// ciMethod::has_linenumber_table
//
// length unknown until decompression
bool    ciMethod::has_linenumber_table() const {
  check_is_loaded();
  VM_ENTRY_MARK;
  return get_methodOop()->has_linenumber_table();
}


// ------------------------------------------------------------------
// ciMethod::compressed_linenumber_table
u_char* ciMethod::compressed_linenumber_table() const {
  check_is_loaded();
  VM_ENTRY_MARK;
  return get_methodOop()->compressed_linenumber_table();
}


// ------------------------------------------------------------------
// ciMethod::line_number_from_bci
int ciMethod::line_number_from_bci(int bci) const {
  check_is_loaded();
  VM_ENTRY_MARK;
  return get_methodOop()->line_number_from_bci(bci);
}


// ------------------------------------------------------------------
// ciMethod::vtable_index
//
// Get the position of this method's entry in the vtable, if any.
int ciMethod::vtable_index() {
  check_is_loaded();
  assert(holder()->is_linked(), "must be linked");
  VM_ENTRY_MARK;
  return get_methodOop()->vtable_index();
}


// ------------------------------------------------------------------
// ciMethod::native_entry
//
// Get the address of this method's native code, if any.
address ciMethod::native_entry() {
  check_is_loaded();
  assert(flags().is_native(), "must be native method");
  VM_ENTRY_MARK;
  methodOop method = get_methodOop();
  address entry = method->native_function();
  assert(entry != NULL, "must be valid entry point");
  return entry;
}


// ------------------------------------------------------------------
// ciMethod::interpreter_entry
//
// Get the entry point for running this method in the interpreter.
address ciMethod::interpreter_entry() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return Interpreter::entry_for_method(mh);
}


// ------------------------------------------------------------------
// ciMethod::uses_balanced_monitors
//
// Does this method use monitors in a strict stack-disciplined manner?
bool ciMethod::has_balanced_monitors() {
  check_is_loaded();
  if (_balanced_monitors) return true;

  // Analyze the method to see if monitors are used properly.
  VM_ENTRY_MARK;
  methodHandle method(THREAD, get_methodOop());
  assert(method->has_monitor_bytecodes(), "should have checked this");

  // Check to see if a previous compilation computed the
  // monitor-matching analysis.
  if (method->guaranteed_monitor_matching()) {
    _balanced_monitors = true;
    return true;
  }

  {
    EXCEPTION_MARK;
    ResourceMark rm(THREAD);
    GeneratePairingInfo gpi(method);
    gpi.compute_map(CATCH);
    if (!gpi.monitor_safe()) {
      return false;
    }
    method->set_guaranteed_monitor_matching();
    _balanced_monitors = true;
  }
  return true;
}


// ------------------------------------------------------------------
// ciMethod::get_flow_analysis
ciTypeFlow* ciMethod::get_flow_analysis() {
#ifdef COMPILER2
  if (_flow == NULL) {
    ciEnv* env = CURRENT_ENV;
    _flow = new (env->arena()) ciTypeFlow(env, this);
    _flow->do_flow();
  }
  return _flow;
#else // COMPILER2
  ShouldNotReachHere();
  return NULL;
#endif // COMPILER2
}


// ------------------------------------------------------------------
// ciMethod::get_osr_flow_analysis
ciTypeFlow* ciMethod::get_osr_flow_analysis(int osr_bci) {
#ifdef COMPILER2
  // OSR entry points are always place after a call bytecode of some sort
  assert(osr_bci >= 0, "must supply valid OSR entry point");
  ciEnv* env = CURRENT_ENV;
  ciTypeFlow* flow = new (env->arena()) ciTypeFlow(env, this, osr_bci);
  flow->do_flow();
  return flow;
#else // COMPILER2
  ShouldNotReachHere();
  return NULL;
#endif // COMPILER2
}

// ------------------------------------------------------------------
// ciMethod::liveness_at_bci
//
// Which local variables are live at a specific bci?
MethodLivenessResult ciMethod::liveness_at_bci(int bci) {
  check_is_loaded();
  if (_liveness == NULL) {
    // Create the liveness analyzer.
    Arena* arena = CURRENT_ENV->arena();
    _liveness = new (arena) MethodLiveness(arena, this);
    _liveness->compute_liveness();
  }
  MethodLivenessResult result = _liveness->get_liveness_at(bci);
  if (JvmtiExport::can_access_local_variables() || DeoptimizeALot || CompileTheWorld) {
    // Keep all locals live for the user's edification and amusement.
    result.at_put_range(0, result.size(), true);
  }
  return result;
}

// ciMethod::live_local_oops_at_bci
//
// find all the live oops in the locals array for a particular bci
// Compute what the interpreter believes by using the interpreter
// oopmap generator. This is used as a double check during osr to
// guard against conservative result from MethodLiveness making us
// think a dead oop is live.  MethodLiveness is conservative in the
// sense that it may consider locals to be live which cannot be live,
// like in the case where a local could contain an oop or  a primitive
// along different paths.  In that case the local must be dead when
// those paths merge. Since the interpreter's viewpoint is used when
// gc'ing an interpreter frame we need to use its viewpoint  during
// OSR when loading the locals.

BitMap ciMethod::live_local_oops_at_bci(int bci) {
  VM_ENTRY_MARK;
  InterpreterOopMap mask;
  OopMapCache::compute_one_oop_map(get_methodOop(), bci, &mask);
  int mask_size = max_locals();
  BitMap result(mask_size);
  result.clear();
  int i;
  for (i = 0; i < mask_size ; i++ ) {
    if (mask.is_oop(i)) result.set_bit(i);
  }
  return result;
}


#ifdef COMPILER1
// ------------------------------------------------------------------
// ciMethod::bci_block_start
//
// Marks all bcis where a new basic block starts
const BitMap ciMethod::bci_block_start() {
  check_is_loaded();
  if (_liveness == NULL) {
    // Create the liveness analyzer.
    Arena* arena = CURRENT_ENV->arena();
    _liveness = new (arena) MethodLiveness(arena, this);
    _liveness->compute_liveness();
  }

  return _liveness->get_bci_block_start();
}
#endif // COMPILER1


// ------------------------------------------------------------------
// ciMethod::call_profile_at_bci
//
// Get the ciCallProfile for the invocation of this method.
// Also reports receiver types for non-call type checks (if TypeProfileCasts).
ciCallProfile ciMethod::call_profile_at_bci(int bci) {
  ResourceMark rm;
  ciCallProfile result;
  if (method_data() != NULL && method_data()->is_mature()) {
    ciProfileData* data = method_data()->bci_to_data(bci);
    if (data != NULL && data->is_CounterData()) {
      // Every profiled call site has a counter.
      int count = data->as_CounterData()->count();

      if (!data->is_ReceiverTypeData()) {
        result._receiver_count[0] = 0;  // that's a definite zero
      } else { // ReceiverTypeData is a subclass of CounterData
        ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
        // In addition, virtual call sites have receiver type information
        int receivers_count_total = 0;
        int morphism = 0;
        for (uint i = 0; i < call->row_limit(); i++) {
          ciKlass* receiver = call->receiver(i);
          if (receiver == NULL)  continue;
          morphism += 1;
          int rcount = call->receiver_count(i);
          if (rcount == 0) rcount = 1; // Should be valid value
          receivers_count_total += rcount;
          // Add the receiver to result data.
          result.add_receiver(receiver, rcount);
          // If we extend profiling to record methods,
          // we will set result._method also.
        }
        // Determine call site's morphism.
        // The call site count could be == (receivers_count_total + 1)
        // not only in the case of a polymorphic call but also in the case
        // when a method data snapshot is taken after the site count was updated
        // but before receivers counters were updated.
        if (morphism == result._limit) {
           // There were no array klasses and morphism <= MorphismLimit.
           if (morphism <  ciCallProfile::MorphismLimit ||
               morphism == ciCallProfile::MorphismLimit &&
               (receivers_count_total+1) >= count) {
             result._morphism = morphism;
           }
        }
        // Make the count consistent if this is a call profile. If count is
        // zero or less, presume that this is a typecheck profile and
        // do nothing.  Otherwise, increase count to be the sum of all
        // receiver's counts.
        if (count > 0) {
          if (count < receivers_count_total) {
            count = receivers_count_total;
          }
        }
      }
      result._count = count;
    }
  }
  return result;
}

// ------------------------------------------------------------------
// Add new receiver and sort data by receiver's profile count.
void ciCallProfile::add_receiver(ciKlass* receiver, int receiver_count) {
  // Add new receiver and sort data by receiver's counts when we have space
  // for it otherwise replace the less called receiver (less called receiver
  // is placed to the last array element which is not used).
  // First array's element contains most called receiver.
  int i = _limit;
  for (; i > 0 && receiver_count > _receiver_count[i-1]; i--) {
    _receiver[i] = _receiver[i-1];
    _receiver_count[i] = _receiver_count[i-1];
  }
  _receiver[i] = receiver;
  _receiver_count[i] = receiver_count;
  if (_limit < MorphismLimit) _limit++;
}

// ------------------------------------------------------------------
// ciMethod::find_monomorphic_target
//
// Given a certain calling environment, find the monomorphic target
// for the call.  Return NULL if the call is not monomorphic in
// its calling environment, or if there are only abstract methods.
// The returned method is never abstract.
// Note: If caller uses a non-null result, it must inform dependencies
// via assert_unique_concrete_method or assert_leaf_type.
ciMethod* ciMethod::find_monomorphic_target(ciInstanceKlass* caller,
                                            ciInstanceKlass* callee_holder,
                                            ciInstanceKlass* actual_recv) {
  check_is_loaded();

  if (actual_recv->is_interface()) {
    // %%% We cannot trust interface types, yet.  See bug 6312651.
    return NULL;
  }

  ciMethod* root_m = resolve_invoke(caller, actual_recv);
  if (root_m == NULL) {
    // Something went wrong looking up the actual receiver method.
    return NULL;
  }
  assert(!root_m->is_abstract(), "resolve_invoke promise");

  // Make certain quick checks even if UseCHA is false.

  // Is it private or final?
  if (root_m->can_be_statically_bound()) {
    return root_m;
  }

  if (actual_recv->is_leaf_type() && actual_recv == root_m->holder()) {
    // Easy case.  There is no other place to put a method, so don't bother
    // to go through the VM_ENTRY_MARK and all the rest.
    return root_m;
  }

  // Array methods (clone, hashCode, etc.) are always statically bound.
  // If we were to see an array type here, we'd return root_m.
  // However, this method processes only ciInstanceKlasses.  (See 4962591.)
  // The inline_native_clone intrinsic narrows Object to T[] properly,
  // so there is no need to do the same job here.

  if (!UseCHA)  return NULL;

  VM_ENTRY_MARK;

  methodHandle target;
  {
    MutexLocker locker(Compile_lock);
    klassOop context = actual_recv->get_klassOop();
    target = Dependencies::find_unique_concrete_method(context,
                                                       root_m->get_methodOop());
    // %%% Should upgrade this ciMethod API to look for 1 or 2 concrete methods.
  }

#ifndef PRODUCT
  if (TraceDependencies && target() != NULL && target() != root_m->get_methodOop()) {
    tty->print("found a non-root unique target method");
    tty->print_cr("  context = %s", instanceKlass::cast(actual_recv->get_klassOop())->external_name());
    tty->print("  method  = ");
    target->print_short_name(tty);
    tty->cr();
  }
#endif //PRODUCT

  if (target() == NULL) {
    return NULL;
  }
  if (target() == root_m->get_methodOop()) {
    return root_m;
  }
  if (!root_m->is_public() &&
      !root_m->is_protected()) {
    // If we are going to reason about inheritance, it's easiest
    // if the method in question is public, protected, or private.
    // If the answer is not root_m, it is conservatively correct
    // to return NULL, even if the CHA encountered irrelevant
    // methods in other packages.
    // %%% TO DO: Work out logic for package-private methods
    // with the same name but different vtable indexes.
    return NULL;
  }
  return CURRENT_THREAD_ENV->get_object(target())->as_method();
}

// ------------------------------------------------------------------
// ciMethod::resolve_invoke
//
// Given a known receiver klass, find the target for the call.
// Return NULL if the call has no target or the target is abstract.
ciMethod* ciMethod::resolve_invoke(ciKlass* caller, ciKlass* exact_receiver) {
   check_is_loaded();
   VM_ENTRY_MARK;

   KlassHandle caller_klass (THREAD, caller->get_klassOop());
   KlassHandle h_recv       (THREAD, exact_receiver->get_klassOop());
   KlassHandle h_resolved   (THREAD, holder()->get_klassOop());
   symbolHandle h_name      (THREAD, name()->get_symbolOop());
   symbolHandle h_signature (THREAD, signature()->get_symbolOop());

   methodHandle m;
   // Only do exact lookup if receiver klass has been linked.  Otherwise,
   // the vtable has not been setup, and the LinkResolver will fail.
   if (h_recv->oop_is_javaArray()
        ||
       instanceKlass::cast(h_recv())->is_linked() && !exact_receiver->is_interface()) {
     if (holder()->is_interface()) {
       m = LinkResolver::resolve_interface_call_or_null(h_recv, h_resolved, h_name, h_signature, caller_klass);
     } else {
       m = LinkResolver::resolve_virtual_call_or_null(h_recv, h_resolved, h_name, h_signature, caller_klass);
     }
   }

   if (m.is_null()) {
     // Return NULL only if there was a problem with lookup (uninitialized class, etc.)
     return NULL;
   }

   ciMethod* result = this;
   if (m() != get_methodOop()) {
     result = CURRENT_THREAD_ENV->get_object(m())->as_method();
   }

   // Don't return abstract methods because they aren't
   // optimizable or interesting.
   if (result->is_abstract()) {
     return NULL;
   } else {
     return result;
   }
}

// ------------------------------------------------------------------
// ciMethod::resolve_vtable_index
//
// Given a known receiver klass, find the vtable index for the call.
// Return methodOopDesc::invalid_vtable_index if the vtable_index is unknown.
int ciMethod::resolve_vtable_index(ciKlass* caller, ciKlass* receiver) {
   check_is_loaded();

   int vtable_index = methodOopDesc::invalid_vtable_index;
   // Only do lookup if receiver klass has been linked.  Otherwise,
   // the vtable has not been setup, and the LinkResolver will fail.
   if (!receiver->is_interface()
       && (!receiver->is_instance_klass() ||
           receiver->as_instance_klass()->is_linked())) {
     VM_ENTRY_MARK;

     KlassHandle caller_klass (THREAD, caller->get_klassOop());
     KlassHandle h_recv       (THREAD, receiver->get_klassOop());
     symbolHandle h_name      (THREAD, name()->get_symbolOop());
     symbolHandle h_signature (THREAD, signature()->get_symbolOop());

     vtable_index = LinkResolver::resolve_virtual_vtable_index(h_recv, h_recv, h_name, h_signature, caller_klass);
     if (vtable_index == methodOopDesc::nonvirtual_vtable_index) {
       // A statically bound method.  Return "no such index".
       vtable_index = methodOopDesc::invalid_vtable_index;
     }
   }

   return vtable_index;
}

// ------------------------------------------------------------------
// ciMethod::interpreter_call_site_count
int ciMethod::interpreter_call_site_count(int bci) {
  if (method_data() != NULL) {
    ResourceMark rm;
    ciProfileData* data = method_data()->bci_to_data(bci);
    if (data != NULL && data->is_CounterData()) {
      return scale_count(data->as_CounterData()->count());
    }
  }
  return -1;  // unknown
}

// ------------------------------------------------------------------
// Adjust a CounterData count to be commensurate with
// interpreter_invocation_count.  If the MDO exists for
// only 25% of the time the method exists, then the
// counts in the MDO should be scaled by 4X, so that
// they can be usefully and stably compared against the
// invocation counts in methods.
int ciMethod::scale_count(int count, float prof_factor) {
  if (count > 0 && method_data() != NULL) {
    int current_mileage = method_data()->current_mileage();
    int creation_mileage = method_data()->creation_mileage();
    int counter_life = current_mileage - creation_mileage;
    int method_life = interpreter_invocation_count();
    // counter_life due to backedge_counter could be > method_life
    if (counter_life > method_life)
      counter_life = method_life;
    if (0 < counter_life && counter_life <= method_life) {
      count = (int)((double)count * prof_factor * method_life / counter_life + 0.5);
      count = (count > 0) ? count : 1;
    }
  }
  return count;
}

// ------------------------------------------------------------------
// ciMethod::build_method_data
//
// Generate new methodDataOop objects at compile time.
void ciMethod::build_method_data(methodHandle h_m) {
  EXCEPTION_CONTEXT;
  if (is_native() || is_abstract() || h_m()->is_accessor()) return;
  if (h_m()->method_data() == NULL) {
    methodOopDesc::build_interpreter_method_data(h_m, THREAD);
    if (HAS_PENDING_EXCEPTION) {
      CLEAR_PENDING_EXCEPTION;
    }
  }
  if (h_m()->method_data() != NULL) {
    _method_data = CURRENT_ENV->get_object(h_m()->method_data())->as_method_data();
    _method_data->load_data();
  } else {
    _method_data = CURRENT_ENV->get_empty_methodData();
  }
}

// public, retroactive version
void ciMethod::build_method_data() {
  if (_method_data == NULL || _method_data->is_empty()) {
    GUARDED_VM_ENTRY({
      build_method_data(get_methodOop());
    });
  }
}


// ------------------------------------------------------------------
// ciMethod::method_data
//
ciMethodData* ciMethod::method_data() {
  if (_method_data != NULL) {
    return _method_data;
  }
  VM_ENTRY_MARK;
  ciEnv* env = CURRENT_ENV;
  Thread* my_thread = JavaThread::current();
  methodHandle h_m(my_thread, get_methodOop());

  if (Tier1UpdateMethodData && is_tier1_compile(env->comp_level())) {
    build_method_data(h_m);
  }

  if (h_m()->method_data() != NULL) {
    _method_data = CURRENT_ENV->get_object(h_m()->method_data())->as_method_data();
    _method_data->load_data();
  } else {
    _method_data = CURRENT_ENV->get_empty_methodData();
  }
  return _method_data;

}


// ------------------------------------------------------------------
// ciMethod::will_link
//
// Will this method link in a specific calling context?
bool ciMethod::will_link(ciKlass* accessing_klass,
                         ciKlass* declared_method_holder,
                         Bytecodes::Code bc) {
  if (!is_loaded()) {
    // Method lookup failed.
    return false;
  }

  // The link checks have been front-loaded into the get_method
  // call.  This method (ciMethod::will_link()) will be removed
  // in the future.

  return true;
}

// ------------------------------------------------------------------
// ciMethod::should_exclude
//
// Should this method be excluded from compilation?
bool ciMethod::should_exclude() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  bool ignore;
  return CompilerOracle::should_exclude(mh, ignore);
}

// ------------------------------------------------------------------
// ciMethod::should_inline
//
// Should this method be inlined during compilation?
bool ciMethod::should_inline() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return CompilerOracle::should_inline(mh);
}

// ------------------------------------------------------------------
// ciMethod::should_not_inline
//
// Should this method be disallowed from inlining during compilation?
bool ciMethod::should_not_inline() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return CompilerOracle::should_not_inline(mh);
}

// ------------------------------------------------------------------
// ciMethod::should_print_assembly
//
// Should the compiler print the generated code for this method?
bool ciMethod::should_print_assembly() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return CompilerOracle::should_print(mh);
}

// ------------------------------------------------------------------
// ciMethod::break_at_execute
//
// Should the compiler insert a breakpoint into the generated code
// method?
bool ciMethod::break_at_execute() {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return CompilerOracle::should_break_at(mh);
}

// ------------------------------------------------------------------
// ciMethod::has_option
//
bool ciMethod::has_option(const char* option) {
  check_is_loaded();
  VM_ENTRY_MARK;
  methodHandle mh(THREAD, get_methodOop());
  return CompilerOracle::has_option_string(mh, option);
}

// ------------------------------------------------------------------
// ciMethod::can_be_compiled
//
// Have previous compilations of this method succeeded?
bool ciMethod::can_be_compiled() {
  check_is_loaded();
  return _is_compilable;
}

// ------------------------------------------------------------------
// ciMethod::set_not_compilable
//
// Tell the VM that this method cannot be compiled at all.
void ciMethod::set_not_compilable() {
  check_is_loaded();
  VM_ENTRY_MARK;
  _is_compilable = false;
  get_methodOop()->set_not_compilable();
}

// ------------------------------------------------------------------
// ciMethod::can_be_osr_compiled
//
// Have previous compilations of this method succeeded?
//
// Implementation note: the VM does not currently keep track
// of failed OSR compilations per bci.  The entry_bci parameter
// is currently unused.
bool ciMethod::can_be_osr_compiled(int entry_bci) {
  check_is_loaded();
  VM_ENTRY_MARK;
  return !get_methodOop()->access_flags().is_not_osr_compilable();
}

// ------------------------------------------------------------------
// ciMethod::has_compiled_code
bool ciMethod::has_compiled_code() {
  VM_ENTRY_MARK;
  return get_methodOop()->code() != NULL;
}

// ------------------------------------------------------------------
// ciMethod::instructions_size
// This is a rough metric for "fat" methods, compared
// before inlining with InlineSmallCode.
// The CodeBlob::instructions_size accessor includes
// junk like exception handler, stubs, and constant table,
// which are not highly relevant to an inlined method.
// So we use the more specific accessor nmethod::code_size.
int ciMethod::instructions_size() {
  GUARDED_VM_ENTRY(
    nmethod* code = get_methodOop()->code();
    // if there's no compiled code or the code was produced by the
    // tier1 profiler return 0 for the code size.  This should
    // probably be based on the compilation level of the nmethod but
    // that currently isn't properly recorded.
    if (code == NULL ||
        (TieredCompilation && code->compiler() != NULL && code->compiler()->is_c1())) {
      return 0;
    }
    return code->code_end() - code->verified_entry_point();
  )
}

// ------------------------------------------------------------------
// ciMethod::log_nmethod_identity
void ciMethod::log_nmethod_identity(xmlStream* log) {
  GUARDED_VM_ENTRY(
    nmethod* code = get_methodOop()->code();
    if (code != NULL) {
      code->log_identity(log);
    }
  )
}

// ------------------------------------------------------------------
// ciMethod::is_not_reached
bool ciMethod::is_not_reached(int bci) {
  check_is_loaded();
  VM_ENTRY_MARK;
  return Interpreter::is_not_reached(
               methodHandle(THREAD, get_methodOop()), bci);
}

// ------------------------------------------------------------------
// ciMethod::was_never_executed
bool ciMethod::was_executed_more_than(int times) {
  VM_ENTRY_MARK;
  return get_methodOop()->was_executed_more_than(times);
}

// ------------------------------------------------------------------
// ciMethod::has_unloaded_classes_in_signature
bool ciMethod::has_unloaded_classes_in_signature() {
  VM_ENTRY_MARK;
  {
    EXCEPTION_MARK;
    methodHandle m(THREAD, get_methodOop());
    bool has_unloaded = methodOopDesc::has_unloaded_classes_in_signature(m, (JavaThread *)THREAD);
    if( HAS_PENDING_EXCEPTION ) {
      CLEAR_PENDING_EXCEPTION;
      return true;     // Declare that we may have unloaded classes
    }
    return has_unloaded;
  }
}

// ------------------------------------------------------------------
// ciMethod::is_klass_loaded
bool ciMethod::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
  VM_ENTRY_MARK;
  return get_methodOop()->is_klass_loaded(refinfo_index, must_be_resolved);
}

// ------------------------------------------------------------------
// ciMethod::check_call
bool ciMethod::check_call(int refinfo_index, bool is_static) const {
  VM_ENTRY_MARK;
  {
    EXCEPTION_MARK;
    HandleMark hm(THREAD);
    constantPoolHandle pool (THREAD, get_methodOop()->constants());
    methodHandle spec_method;
    KlassHandle  spec_klass;
    LinkResolver::resolve_method(spec_method, spec_klass, pool, refinfo_index, THREAD);
    if (HAS_PENDING_EXCEPTION) {
      CLEAR_PENDING_EXCEPTION;
      return false;
    } else {
      return (spec_method->is_static() == is_static);
    }
  }
  return false;
}

// ------------------------------------------------------------------
// ciMethod::print_codes
//
// Print the bytecodes for this method.
void ciMethod::print_codes_on(outputStream* st) {
  check_is_loaded();
  GUARDED_VM_ENTRY(get_methodOop()->print_codes_on(st);)
}


#define FETCH_FLAG_FROM_VM(flag_accessor) { \
  check_is_loaded(); \
  VM_ENTRY_MARK; \
  return get_methodOop()->flag_accessor(); \
}

bool ciMethod::is_empty_method() const {         FETCH_FLAG_FROM_VM(is_empty_method); }
bool ciMethod::is_vanilla_constructor() const {  FETCH_FLAG_FROM_VM(is_vanilla_constructor); }
bool ciMethod::has_loops      () const {         FETCH_FLAG_FROM_VM(has_loops); }
bool ciMethod::has_jsrs       () const {         FETCH_FLAG_FROM_VM(has_jsrs);  }
bool ciMethod::is_accessor    () const {         FETCH_FLAG_FROM_VM(is_accessor); }
bool ciMethod::is_initializer () const {         FETCH_FLAG_FROM_VM(is_initializer); }

BCEscapeAnalyzer  *ciMethod::get_bcea() {
  if (_bcea == NULL) {
    _bcea = new (CURRENT_ENV->arena()) BCEscapeAnalyzer(this, NULL);
  }
  return _bcea;
}

ciMethodBlocks  *ciMethod::get_method_blocks() {
  Arena *arena = CURRENT_ENV->arena();
  if (_method_blocks == NULL) {
    _method_blocks = new (arena) ciMethodBlocks(arena, this);
  }
  return _method_blocks;
}

#undef FETCH_FLAG_FROM_VM


// ------------------------------------------------------------------
// ciMethod::print_codes
//
// Print a range of the bytecodes for this method.
void ciMethod::print_codes_on(int from, int to, outputStream* st) {
  check_is_loaded();
  GUARDED_VM_ENTRY(get_methodOop()->print_codes_on(from, to, st);)
}

// ------------------------------------------------------------------
// ciMethod::print_name
//
// Print the name of this method, including signature and some flags.
void ciMethod::print_name(outputStream* st) {
  check_is_loaded();
  GUARDED_VM_ENTRY(get_methodOop()->print_name(st);)
}

// ------------------------------------------------------------------
// ciMethod::print_short_name
//
// Print the name of this method, without signature.
void ciMethod::print_short_name(outputStream* st) {
  check_is_loaded();
  GUARDED_VM_ENTRY(get_methodOop()->print_short_name(st);)
}

// ------------------------------------------------------------------
// ciMethod::print_impl
//
// Implementation of the print method.
void ciMethod::print_impl(outputStream* st) {
  ciObject::print_impl(st);
  st->print(" name=");
  name()->print_symbol_on(st);
  st->print(" holder=");
  holder()->print_name_on(st);
  st->print(" signature=");
  signature()->as_symbol()->print_symbol_on(st);
  if (is_loaded()) {
    st->print(" loaded=true flags=");
    flags().print_member_flags(st);
  } else {
    st->print(" loaded=false");
  }
}