hotspot/src/share/vm/ci/ciMethod.cpp
changeset 1 489c9b5090e2
child 200 88d83617f912
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/ci/ciMethod.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1042 @@
+/*
+ * Copyright 1999-2007 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 (_is_compilable && 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_size();
+  )
+}
+
+// ------------------------------------------------------------------
+// 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");
+  }
+}