1 /*
   2  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_ciMethod.cpp.incl"
  27 
  28 // ciMethod
  29 //
  30 // This class represents a methodOop in the HotSpot virtual
  31 // machine.
  32 
  33 
  34 // ------------------------------------------------------------------
  35 // ciMethod::ciMethod
  36 //
  37 // Loaded method.
  38 ciMethod::ciMethod(methodHandle h_m) : ciObject(h_m) {
  39   assert(h_m() != NULL, "no null method");
  40 
  41   // These fields are always filled in in loaded methods.
  42   _flags = ciFlags(h_m()->access_flags());
  43 
  44   // Easy to compute, so fill them in now.
  45   _max_stack          = h_m()->max_stack();
  46   _max_locals         = h_m()->max_locals();
  47   _code_size          = h_m()->code_size();
  48   _intrinsic_id       = h_m()->intrinsic_id();
  49   _handler_count      = h_m()->exception_table()->length() / 4;
  50   _uses_monitors      = h_m()->access_flags().has_monitor_bytecodes();
  51   _balanced_monitors  = !_uses_monitors || h_m()->access_flags().is_monitor_matching();
  52   _is_compilable      = !h_m()->is_not_compilable();
  53   // Lazy fields, filled in on demand.  Require allocation.
  54   _code               = NULL;
  55   _exception_handlers = NULL;
  56   _liveness           = NULL;
  57   _bcea = NULL;
  58   _method_blocks = NULL;
  59 #ifdef COMPILER2
  60   _flow               = NULL;
  61 #endif // COMPILER2
  62 
  63   ciEnv *env = CURRENT_ENV;
  64   if (env->jvmti_can_hotswap_or_post_breakpoint() && _is_compilable) {
  65     // 6328518 check hotswap conditions under the right lock.
  66     MutexLocker locker(Compile_lock);
  67     if (Dependencies::check_evol_method(h_m()) != NULL) {
  68       _is_compilable = false;
  69     }
  70   } else {
  71     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  72   }
  73 
  74   if (instanceKlass::cast(h_m()->method_holder())->is_linked()) {
  75     _can_be_statically_bound = h_m()->can_be_statically_bound();
  76   } else {
  77     // Have to use a conservative value in this case.
  78     _can_be_statically_bound = false;
  79   }
  80 
  81   // Adjust the definition of this condition to be more useful:
  82   // %%% take these conditions into account in vtable generation
  83   if (!_can_be_statically_bound && h_m()->is_private())
  84     _can_be_statically_bound = true;
  85   if (_can_be_statically_bound && h_m()->is_abstract())
  86     _can_be_statically_bound = false;
  87 
  88   // generating _signature may allow GC and therefore move m.
  89   // These fields are always filled in.
  90   _name = env->get_object(h_m()->name())->as_symbol();
  91   _holder = env->get_object(h_m()->method_holder())->as_instance_klass();
  92   ciSymbol* sig_symbol = env->get_object(h_m()->signature())->as_symbol();
  93   _signature = new (env->arena()) ciSignature(_holder, sig_symbol);
  94   _method_data = NULL;
  95   // Take a snapshot of these values, so they will be commensurate with the MDO.
  96   if (ProfileInterpreter) {
  97     int invcnt = h_m()->interpreter_invocation_count();
  98     // if the value overflowed report it as max int
  99     _interpreter_invocation_count = invcnt < 0 ? max_jint : invcnt ;
 100     _interpreter_throwout_count   = h_m()->interpreter_throwout_count();
 101   } else {
 102     _interpreter_invocation_count = 0;
 103     _interpreter_throwout_count = 0;
 104   }
 105   if (_interpreter_invocation_count == 0)
 106     _interpreter_invocation_count = 1;
 107 }
 108 
 109 
 110 // ------------------------------------------------------------------
 111 // ciMethod::ciMethod
 112 //
 113 // Unloaded method.
 114 ciMethod::ciMethod(ciInstanceKlass* holder,
 115                    ciSymbol* name,
 116                    ciSymbol* signature) : ciObject(ciMethodKlass::make()) {
 117   // These fields are always filled in.
 118   _name = name;
 119   _holder = holder;
 120   _signature = new (CURRENT_ENV->arena()) ciSignature(_holder, signature);
 121   _intrinsic_id = vmIntrinsics::_none;
 122   _liveness = NULL;
 123   _can_be_statically_bound = false;
 124   _bcea = NULL;
 125   _method_blocks = NULL;
 126   _method_data = NULL;
 127 #ifdef COMPILER2
 128   _flow = NULL;
 129 #endif // COMPILER2
 130 }
 131 
 132 
 133 // ------------------------------------------------------------------
 134 // ciMethod::load_code
 135 //
 136 // Load the bytecodes and exception handler table for this method.
 137 void ciMethod::load_code() {
 138   VM_ENTRY_MARK;
 139   assert(is_loaded(), "only loaded methods have code");
 140 
 141   methodOop me = get_methodOop();
 142   Arena* arena = CURRENT_THREAD_ENV->arena();
 143 
 144   // Load the bytecodes.
 145   _code = (address)arena->Amalloc(code_size());
 146   memcpy(_code, me->code_base(), code_size());
 147 
 148   // Revert any breakpoint bytecodes in ci's copy
 149   if (me->number_of_breakpoints() > 0) {
 150     BreakpointInfo* bp = instanceKlass::cast(me->method_holder())->breakpoints();
 151     for (; bp != NULL; bp = bp->next()) {
 152       if (bp->match(me)) {
 153         code_at_put(bp->bci(), bp->orig_bytecode());
 154       }
 155     }
 156   }
 157 
 158   // And load the exception table.
 159   typeArrayOop exc_table = me->exception_table();
 160 
 161   // Allocate one extra spot in our list of exceptions.  This
 162   // last entry will be used to represent the possibility that
 163   // an exception escapes the method.  See ciExceptionHandlerStream
 164   // for details.
 165   _exception_handlers =
 166     (ciExceptionHandler**)arena->Amalloc(sizeof(ciExceptionHandler*)
 167                                          * (_handler_count + 1));
 168   if (_handler_count > 0) {
 169     for (int i=0; i<_handler_count; i++) {
 170       int base = i*4;
 171       _exception_handlers[i] = new (arena) ciExceptionHandler(
 172                                 holder(),
 173             /* start    */      exc_table->int_at(base),
 174             /* limit    */      exc_table->int_at(base+1),
 175             /* goto pc  */      exc_table->int_at(base+2),
 176             /* cp index */      exc_table->int_at(base+3));
 177     }
 178   }
 179 
 180   // Put an entry at the end of our list to represent the possibility
 181   // of exceptional exit.
 182   _exception_handlers[_handler_count] =
 183     new (arena) ciExceptionHandler(holder(), 0, code_size(), -1, 0);
 184 
 185   if (CIPrintMethodCodes) {
 186     print_codes();
 187   }
 188 }
 189 
 190 
 191 // ------------------------------------------------------------------
 192 // ciMethod::has_linenumber_table
 193 //
 194 // length unknown until decompression
 195 bool    ciMethod::has_linenumber_table() const {
 196   check_is_loaded();
 197   VM_ENTRY_MARK;
 198   return get_methodOop()->has_linenumber_table();
 199 }
 200 
 201 
 202 // ------------------------------------------------------------------
 203 // ciMethod::compressed_linenumber_table
 204 u_char* ciMethod::compressed_linenumber_table() const {
 205   check_is_loaded();
 206   VM_ENTRY_MARK;
 207   return get_methodOop()->compressed_linenumber_table();
 208 }
 209 
 210 
 211 // ------------------------------------------------------------------
 212 // ciMethod::line_number_from_bci
 213 int ciMethod::line_number_from_bci(int bci) const {
 214   check_is_loaded();
 215   VM_ENTRY_MARK;
 216   return get_methodOop()->line_number_from_bci(bci);
 217 }
 218 
 219 
 220 // ------------------------------------------------------------------
 221 // ciMethod::vtable_index
 222 //
 223 // Get the position of this method's entry in the vtable, if any.
 224 int ciMethod::vtable_index() {
 225   check_is_loaded();
 226   assert(holder()->is_linked(), "must be linked");
 227   VM_ENTRY_MARK;
 228   return get_methodOop()->vtable_index();
 229 }
 230 
 231 
 232 // ------------------------------------------------------------------
 233 // ciMethod::native_entry
 234 //
 235 // Get the address of this method's native code, if any.
 236 address ciMethod::native_entry() {
 237   check_is_loaded();
 238   assert(flags().is_native(), "must be native method");
 239   VM_ENTRY_MARK;
 240   methodOop method = get_methodOop();
 241   address entry = method->native_function();
 242   assert(entry != NULL, "must be valid entry point");
 243   return entry;
 244 }
 245 
 246 
 247 // ------------------------------------------------------------------
 248 // ciMethod::interpreter_entry
 249 //
 250 // Get the entry point for running this method in the interpreter.
 251 address ciMethod::interpreter_entry() {
 252   check_is_loaded();
 253   VM_ENTRY_MARK;
 254   methodHandle mh(THREAD, get_methodOop());
 255   return Interpreter::entry_for_method(mh);
 256 }
 257 
 258 
 259 // ------------------------------------------------------------------
 260 // ciMethod::uses_balanced_monitors
 261 //
 262 // Does this method use monitors in a strict stack-disciplined manner?
 263 bool ciMethod::has_balanced_monitors() {
 264   check_is_loaded();
 265   if (_balanced_monitors) return true;
 266 
 267   // Analyze the method to see if monitors are used properly.
 268   VM_ENTRY_MARK;
 269   methodHandle method(THREAD, get_methodOop());
 270   assert(method->has_monitor_bytecodes(), "should have checked this");
 271 
 272   // Check to see if a previous compilation computed the
 273   // monitor-matching analysis.
 274   if (method->guaranteed_monitor_matching()) {
 275     _balanced_monitors = true;
 276     return true;
 277   }
 278 
 279   {
 280     EXCEPTION_MARK;
 281     ResourceMark rm(THREAD);
 282     GeneratePairingInfo gpi(method);
 283     gpi.compute_map(CATCH);
 284     if (!gpi.monitor_safe()) {
 285       return false;
 286     }
 287     method->set_guaranteed_monitor_matching();
 288     _balanced_monitors = true;
 289   }
 290   return true;
 291 }
 292 
 293 
 294 // ------------------------------------------------------------------
 295 // ciMethod::get_flow_analysis
 296 ciTypeFlow* ciMethod::get_flow_analysis() {
 297 #ifdef COMPILER2
 298   if (_flow == NULL) {
 299     ciEnv* env = CURRENT_ENV;
 300     _flow = new (env->arena()) ciTypeFlow(env, this);
 301     _flow->do_flow();
 302   }
 303   return _flow;
 304 #else // COMPILER2
 305   ShouldNotReachHere();
 306   return NULL;
 307 #endif // COMPILER2
 308 }
 309 
 310 
 311 // ------------------------------------------------------------------
 312 // ciMethod::get_osr_flow_analysis
 313 ciTypeFlow* ciMethod::get_osr_flow_analysis(int osr_bci) {
 314 #ifdef COMPILER2
 315   // OSR entry points are always place after a call bytecode of some sort
 316   assert(osr_bci >= 0, "must supply valid OSR entry point");
 317   ciEnv* env = CURRENT_ENV;
 318   ciTypeFlow* flow = new (env->arena()) ciTypeFlow(env, this, osr_bci);
 319   flow->do_flow();
 320   return flow;
 321 #else // COMPILER2
 322   ShouldNotReachHere();
 323   return NULL;
 324 #endif // COMPILER2
 325 }
 326 
 327 // ------------------------------------------------------------------
 328 // ciMethod::raw_liveness_at_bci
 329 //
 330 // Which local variables are live at a specific bci?
 331 MethodLivenessResult ciMethod::raw_liveness_at_bci(int bci) {
 332   check_is_loaded();
 333   if (_liveness == NULL) {
 334     // Create the liveness analyzer.
 335     Arena* arena = CURRENT_ENV->arena();
 336     _liveness = new (arena) MethodLiveness(arena, this);
 337     _liveness->compute_liveness();
 338   }
 339   return _liveness->get_liveness_at(bci);
 340 }
 341 
 342 // ------------------------------------------------------------------
 343 // ciMethod::liveness_at_bci
 344 //
 345 // Which local variables are live at a specific bci?  When debugging
 346 // will return true for all locals in some cases to improve debug
 347 // information.
 348 MethodLivenessResult ciMethod::liveness_at_bci(int bci) {
 349   MethodLivenessResult result = raw_liveness_at_bci(bci);
 350   if (CURRENT_ENV->jvmti_can_access_local_variables() || DeoptimizeALot || CompileTheWorld) {
 351     // Keep all locals live for the user's edification and amusement.
 352     result.at_put_range(0, result.size(), true);
 353   }
 354   return result;
 355 }
 356 
 357 // ciMethod::live_local_oops_at_bci
 358 //
 359 // find all the live oops in the locals array for a particular bci
 360 // Compute what the interpreter believes by using the interpreter
 361 // oopmap generator. This is used as a double check during osr to
 362 // guard against conservative result from MethodLiveness making us
 363 // think a dead oop is live.  MethodLiveness is conservative in the
 364 // sense that it may consider locals to be live which cannot be live,
 365 // like in the case where a local could contain an oop or  a primitive
 366 // along different paths.  In that case the local must be dead when
 367 // those paths merge. Since the interpreter's viewpoint is used when
 368 // gc'ing an interpreter frame we need to use its viewpoint  during
 369 // OSR when loading the locals.
 370 
 371 BitMap ciMethod::live_local_oops_at_bci(int bci) {
 372   VM_ENTRY_MARK;
 373   InterpreterOopMap mask;
 374   OopMapCache::compute_one_oop_map(get_methodOop(), bci, &mask);
 375   int mask_size = max_locals();
 376   BitMap result(mask_size);
 377   result.clear();
 378   int i;
 379   for (i = 0; i < mask_size ; i++ ) {
 380     if (mask.is_oop(i)) result.set_bit(i);
 381   }
 382   return result;
 383 }
 384 
 385 
 386 #ifdef COMPILER1
 387 // ------------------------------------------------------------------
 388 // ciMethod::bci_block_start
 389 //
 390 // Marks all bcis where a new basic block starts
 391 const BitMap ciMethod::bci_block_start() {
 392   check_is_loaded();
 393   if (_liveness == NULL) {
 394     // Create the liveness analyzer.
 395     Arena* arena = CURRENT_ENV->arena();
 396     _liveness = new (arena) MethodLiveness(arena, this);
 397     _liveness->compute_liveness();
 398   }
 399 
 400   return _liveness->get_bci_block_start();
 401 }
 402 #endif // COMPILER1
 403 
 404 
 405 // ------------------------------------------------------------------
 406 // ciMethod::call_profile_at_bci
 407 //
 408 // Get the ciCallProfile for the invocation of this method.
 409 // Also reports receiver types for non-call type checks (if TypeProfileCasts).
 410 ciCallProfile ciMethod::call_profile_at_bci(int bci) {
 411   ResourceMark rm;
 412   ciCallProfile result;
 413   if (method_data() != NULL && method_data()->is_mature()) {
 414     ciProfileData* data = method_data()->bci_to_data(bci);
 415     if (data != NULL && data->is_CounterData()) {
 416       // Every profiled call site has a counter.
 417       int count = data->as_CounterData()->count();
 418 
 419       if (!data->is_ReceiverTypeData()) {
 420         result._receiver_count[0] = 0;  // that's a definite zero
 421       } else { // ReceiverTypeData is a subclass of CounterData
 422         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
 423         // In addition, virtual call sites have receiver type information
 424         int receivers_count_total = 0;
 425         int morphism = 0;
 426         for (uint i = 0; i < call->row_limit(); i++) {
 427           ciKlass* receiver = call->receiver(i);
 428           if (receiver == NULL)  continue;
 429           morphism += 1;
 430           int rcount = call->receiver_count(i);
 431           if (rcount == 0) rcount = 1; // Should be valid value
 432           receivers_count_total += rcount;
 433           // Add the receiver to result data.
 434           result.add_receiver(receiver, rcount);
 435           // If we extend profiling to record methods,
 436           // we will set result._method also.
 437         }
 438         // Determine call site's morphism.
 439         // The call site count is 0 with known morphism (onlt 1 or 2 receivers)
 440         // or < 0 in the case of a type check failured for checkcast, aastore, instanceof.
 441         // The call site count is > 0 in the case of a polymorphic virtual call.
 442         if (morphism > 0 && morphism == result._limit) {
 443            // The morphism <= MorphismLimit.
 444            if ((morphism <  ciCallProfile::MorphismLimit) ||
 445                (morphism == ciCallProfile::MorphismLimit && count == 0)) {
 446 #ifdef ASSERT
 447              if (count > 0) {
 448                this->print_short_name(tty);
 449                tty->print_cr(" @ bci:%d", bci);
 450                this->print_codes();
 451                assert(false, "this call site should not be polymorphic");
 452              }
 453 #endif
 454              result._morphism = morphism;
 455            }
 456         }
 457         // Make the count consistent if this is a call profile. If count is
 458         // zero or less, presume that this is a typecheck profile and
 459         // do nothing.  Otherwise, increase count to be the sum of all
 460         // receiver's counts.
 461         if (count >= 0) {
 462           count += receivers_count_total;
 463         }
 464       }
 465       result._count = count;
 466     }
 467   }
 468   return result;
 469 }
 470 
 471 // ------------------------------------------------------------------
 472 // Add new receiver and sort data by receiver's profile count.
 473 void ciCallProfile::add_receiver(ciKlass* receiver, int receiver_count) {
 474   // Add new receiver and sort data by receiver's counts when we have space
 475   // for it otherwise replace the less called receiver (less called receiver
 476   // is placed to the last array element which is not used).
 477   // First array's element contains most called receiver.
 478   int i = _limit;
 479   for (; i > 0 && receiver_count > _receiver_count[i-1]; i--) {
 480     _receiver[i] = _receiver[i-1];
 481     _receiver_count[i] = _receiver_count[i-1];
 482   }
 483   _receiver[i] = receiver;
 484   _receiver_count[i] = receiver_count;
 485   if (_limit < MorphismLimit) _limit++;
 486 }
 487 
 488 // ------------------------------------------------------------------
 489 // ciMethod::find_monomorphic_target
 490 //
 491 // Given a certain calling environment, find the monomorphic target
 492 // for the call.  Return NULL if the call is not monomorphic in
 493 // its calling environment, or if there are only abstract methods.
 494 // The returned method is never abstract.
 495 // Note: If caller uses a non-null result, it must inform dependencies
 496 // via assert_unique_concrete_method or assert_leaf_type.
 497 ciMethod* ciMethod::find_monomorphic_target(ciInstanceKlass* caller,
 498                                             ciInstanceKlass* callee_holder,
 499                                             ciInstanceKlass* actual_recv) {
 500   check_is_loaded();
 501 
 502   if (actual_recv->is_interface()) {
 503     // %%% We cannot trust interface types, yet.  See bug 6312651.
 504     return NULL;
 505   }
 506 
 507   ciMethod* root_m = resolve_invoke(caller, actual_recv);
 508   if (root_m == NULL) {
 509     // Something went wrong looking up the actual receiver method.
 510     return NULL;
 511   }
 512   assert(!root_m->is_abstract(), "resolve_invoke promise");
 513 
 514   // Make certain quick checks even if UseCHA is false.
 515 
 516   // Is it private or final?
 517   if (root_m->can_be_statically_bound()) {
 518     return root_m;
 519   }
 520 
 521   if (actual_recv->is_leaf_type() && actual_recv == root_m->holder()) {
 522     // Easy case.  There is no other place to put a method, so don't bother
 523     // to go through the VM_ENTRY_MARK and all the rest.
 524     return root_m;
 525   }
 526 
 527   // Array methods (clone, hashCode, etc.) are always statically bound.
 528   // If we were to see an array type here, we'd return root_m.
 529   // However, this method processes only ciInstanceKlasses.  (See 4962591.)
 530   // The inline_native_clone intrinsic narrows Object to T[] properly,
 531   // so there is no need to do the same job here.
 532 
 533   if (!UseCHA)  return NULL;
 534 
 535   VM_ENTRY_MARK;
 536 
 537   methodHandle target;
 538   {
 539     MutexLocker locker(Compile_lock);
 540     klassOop context = actual_recv->get_klassOop();
 541     target = Dependencies::find_unique_concrete_method(context,
 542                                                        root_m->get_methodOop());
 543     // %%% Should upgrade this ciMethod API to look for 1 or 2 concrete methods.
 544   }
 545 
 546 #ifndef PRODUCT
 547   if (TraceDependencies && target() != NULL && target() != root_m->get_methodOop()) {
 548     tty->print("found a non-root unique target method");
 549     tty->print_cr("  context = %s", instanceKlass::cast(actual_recv->get_klassOop())->external_name());
 550     tty->print("  method  = ");
 551     target->print_short_name(tty);
 552     tty->cr();
 553   }
 554 #endif //PRODUCT
 555 
 556   if (target() == NULL) {
 557     return NULL;
 558   }
 559   if (target() == root_m->get_methodOop()) {
 560     return root_m;
 561   }
 562   if (!root_m->is_public() &&
 563       !root_m->is_protected()) {
 564     // If we are going to reason about inheritance, it's easiest
 565     // if the method in question is public, protected, or private.
 566     // If the answer is not root_m, it is conservatively correct
 567     // to return NULL, even if the CHA encountered irrelevant
 568     // methods in other packages.
 569     // %%% TO DO: Work out logic for package-private methods
 570     // with the same name but different vtable indexes.
 571     return NULL;
 572   }
 573   return CURRENT_THREAD_ENV->get_object(target())->as_method();
 574 }
 575 
 576 // ------------------------------------------------------------------
 577 // ciMethod::resolve_invoke
 578 //
 579 // Given a known receiver klass, find the target for the call.
 580 // Return NULL if the call has no target or the target is abstract.
 581 ciMethod* ciMethod::resolve_invoke(ciKlass* caller, ciKlass* exact_receiver) {
 582    check_is_loaded();
 583    VM_ENTRY_MARK;
 584 
 585    KlassHandle caller_klass (THREAD, caller->get_klassOop());
 586    KlassHandle h_recv       (THREAD, exact_receiver->get_klassOop());
 587    KlassHandle h_resolved   (THREAD, holder()->get_klassOop());
 588    symbolHandle h_name      (THREAD, name()->get_symbolOop());
 589    symbolHandle h_signature (THREAD, signature()->get_symbolOop());
 590 
 591    methodHandle m;
 592    // Only do exact lookup if receiver klass has been linked.  Otherwise,
 593    // the vtable has not been setup, and the LinkResolver will fail.
 594    if (h_recv->oop_is_javaArray()
 595         ||
 596        instanceKlass::cast(h_recv())->is_linked() && !exact_receiver->is_interface()) {
 597      if (holder()->is_interface()) {
 598        m = LinkResolver::resolve_interface_call_or_null(h_recv, h_resolved, h_name, h_signature, caller_klass);
 599      } else {
 600        m = LinkResolver::resolve_virtual_call_or_null(h_recv, h_resolved, h_name, h_signature, caller_klass);
 601      }
 602    }
 603 
 604    if (m.is_null()) {
 605      // Return NULL only if there was a problem with lookup (uninitialized class, etc.)
 606      return NULL;
 607    }
 608 
 609    ciMethod* result = this;
 610    if (m() != get_methodOop()) {
 611      result = CURRENT_THREAD_ENV->get_object(m())->as_method();
 612    }
 613 
 614    // Don't return abstract methods because they aren't
 615    // optimizable or interesting.
 616    if (result->is_abstract()) {
 617      return NULL;
 618    } else {
 619      return result;
 620    }
 621 }
 622 
 623 // ------------------------------------------------------------------
 624 // ciMethod::resolve_vtable_index
 625 //
 626 // Given a known receiver klass, find the vtable index for the call.
 627 // Return methodOopDesc::invalid_vtable_index if the vtable_index is unknown.
 628 int ciMethod::resolve_vtable_index(ciKlass* caller, ciKlass* receiver) {
 629    check_is_loaded();
 630 
 631    int vtable_index = methodOopDesc::invalid_vtable_index;
 632    // Only do lookup if receiver klass has been linked.  Otherwise,
 633    // the vtable has not been setup, and the LinkResolver will fail.
 634    if (!receiver->is_interface()
 635        && (!receiver->is_instance_klass() ||
 636            receiver->as_instance_klass()->is_linked())) {
 637      VM_ENTRY_MARK;
 638 
 639      KlassHandle caller_klass (THREAD, caller->get_klassOop());
 640      KlassHandle h_recv       (THREAD, receiver->get_klassOop());
 641      symbolHandle h_name      (THREAD, name()->get_symbolOop());
 642      symbolHandle h_signature (THREAD, signature()->get_symbolOop());
 643 
 644      vtable_index = LinkResolver::resolve_virtual_vtable_index(h_recv, h_recv, h_name, h_signature, caller_klass);
 645      if (vtable_index == methodOopDesc::nonvirtual_vtable_index) {
 646        // A statically bound method.  Return "no such index".
 647        vtable_index = methodOopDesc::invalid_vtable_index;
 648      }
 649    }
 650 
 651    return vtable_index;
 652 }
 653 
 654 // ------------------------------------------------------------------
 655 // ciMethod::interpreter_call_site_count
 656 int ciMethod::interpreter_call_site_count(int bci) {
 657   if (method_data() != NULL) {
 658     ResourceMark rm;
 659     ciProfileData* data = method_data()->bci_to_data(bci);
 660     if (data != NULL && data->is_CounterData()) {
 661       return scale_count(data->as_CounterData()->count());
 662     }
 663   }
 664   return -1;  // unknown
 665 }
 666 
 667 // ------------------------------------------------------------------
 668 // Adjust a CounterData count to be commensurate with
 669 // interpreter_invocation_count.  If the MDO exists for
 670 // only 25% of the time the method exists, then the
 671 // counts in the MDO should be scaled by 4X, so that
 672 // they can be usefully and stably compared against the
 673 // invocation counts in methods.
 674 int ciMethod::scale_count(int count, float prof_factor) {
 675   if (count > 0 && method_data() != NULL) {
 676     int current_mileage = method_data()->current_mileage();
 677     int creation_mileage = method_data()->creation_mileage();
 678     int counter_life = current_mileage - creation_mileage;
 679     int method_life = interpreter_invocation_count();
 680     // counter_life due to backedge_counter could be > method_life
 681     if (counter_life > method_life)
 682       counter_life = method_life;
 683     if (0 < counter_life && counter_life <= method_life) {
 684       count = (int)((double)count * prof_factor * method_life / counter_life + 0.5);
 685       count = (count > 0) ? count : 1;
 686     }
 687   }
 688   return count;
 689 }
 690 
 691 // ------------------------------------------------------------------
 692 // invokedynamic support
 693 
 694 // ------------------------------------------------------------------
 695 // ciMethod::is_method_handle_invoke
 696 //
 697 // Return true if the method is a MethodHandle target.
 698 bool ciMethod::is_method_handle_invoke() const {
 699   bool flag = (holder()->name() == ciSymbol::java_dyn_MethodHandle() &&
 700                methodOopDesc::is_method_handle_invoke_name(name()->sid()));
 701 #ifdef ASSERT
 702   if (is_loaded()) {
 703     bool flag2 = ((flags().as_int() & JVM_MH_INVOKE_BITS) == JVM_MH_INVOKE_BITS);
 704     {
 705       VM_ENTRY_MARK;
 706       bool flag3 = get_methodOop()->is_method_handle_invoke();
 707       assert(flag2 == flag3, "consistent");
 708       assert(flag  == flag3, "consistent");
 709     }
 710   }
 711 #endif //ASSERT
 712   return flag;
 713 }
 714 
 715 // ------------------------------------------------------------------
 716 // ciMethod::is_method_handle_adapter
 717 //
 718 // Return true if the method is a generated MethodHandle adapter.
 719 bool ciMethod::is_method_handle_adapter() const {
 720   check_is_loaded();
 721   VM_ENTRY_MARK;
 722   return get_methodOop()->is_method_handle_adapter();
 723 }
 724 
 725 ciInstance* ciMethod::method_handle_type() {
 726   check_is_loaded();
 727   VM_ENTRY_MARK;
 728   oop mtype = get_methodOop()->method_handle_type();
 729   return CURRENT_THREAD_ENV->get_object(mtype)->as_instance();
 730 }
 731 
 732 
 733 // ------------------------------------------------------------------
 734 // ciMethod::build_method_data
 735 //
 736 // Generate new methodDataOop objects at compile time.
 737 void ciMethod::build_method_data(methodHandle h_m) {
 738   EXCEPTION_CONTEXT;
 739   if (is_native() || is_abstract() || h_m()->is_accessor()) return;
 740   if (h_m()->method_data() == NULL) {
 741     methodOopDesc::build_interpreter_method_data(h_m, THREAD);
 742     if (HAS_PENDING_EXCEPTION) {
 743       CLEAR_PENDING_EXCEPTION;
 744     }
 745   }
 746   if (h_m()->method_data() != NULL) {
 747     _method_data = CURRENT_ENV->get_object(h_m()->method_data())->as_method_data();
 748     _method_data->load_data();
 749   } else {
 750     _method_data = CURRENT_ENV->get_empty_methodData();
 751   }
 752 }
 753 
 754 // public, retroactive version
 755 void ciMethod::build_method_data() {
 756   if (_method_data == NULL || _method_data->is_empty()) {
 757     GUARDED_VM_ENTRY({
 758       build_method_data(get_methodOop());
 759     });
 760   }
 761 }
 762 
 763 
 764 // ------------------------------------------------------------------
 765 // ciMethod::method_data
 766 //
 767 ciMethodData* ciMethod::method_data() {
 768   if (_method_data != NULL) {
 769     return _method_data;
 770   }
 771   VM_ENTRY_MARK;
 772   ciEnv* env = CURRENT_ENV;
 773   Thread* my_thread = JavaThread::current();
 774   methodHandle h_m(my_thread, get_methodOop());
 775 
 776   if (Tier1UpdateMethodData && is_tier1_compile(env->comp_level())) {
 777     build_method_data(h_m);
 778   }
 779 
 780   if (h_m()->method_data() != NULL) {
 781     _method_data = CURRENT_ENV->get_object(h_m()->method_data())->as_method_data();
 782     _method_data->load_data();
 783   } else {
 784     _method_data = CURRENT_ENV->get_empty_methodData();
 785   }
 786   return _method_data;
 787 
 788 }
 789 
 790 
 791 // ------------------------------------------------------------------
 792 // ciMethod::will_link
 793 //
 794 // Will this method link in a specific calling context?
 795 bool ciMethod::will_link(ciKlass* accessing_klass,
 796                          ciKlass* declared_method_holder,
 797                          Bytecodes::Code bc) {
 798   if (!is_loaded()) {
 799     // Method lookup failed.
 800     return false;
 801   }
 802 
 803   // The link checks have been front-loaded into the get_method
 804   // call.  This method (ciMethod::will_link()) will be removed
 805   // in the future.
 806 
 807   return true;
 808 }
 809 
 810 // ------------------------------------------------------------------
 811 // ciMethod::should_exclude
 812 //
 813 // Should this method be excluded from compilation?
 814 bool ciMethod::should_exclude() {
 815   check_is_loaded();
 816   VM_ENTRY_MARK;
 817   methodHandle mh(THREAD, get_methodOop());
 818   bool ignore;
 819   return CompilerOracle::should_exclude(mh, ignore);
 820 }
 821 
 822 // ------------------------------------------------------------------
 823 // ciMethod::should_inline
 824 //
 825 // Should this method be inlined during compilation?
 826 bool ciMethod::should_inline() {
 827   check_is_loaded();
 828   VM_ENTRY_MARK;
 829   methodHandle mh(THREAD, get_methodOop());
 830   return CompilerOracle::should_inline(mh);
 831 }
 832 
 833 // ------------------------------------------------------------------
 834 // ciMethod::should_not_inline
 835 //
 836 // Should this method be disallowed from inlining during compilation?
 837 bool ciMethod::should_not_inline() {
 838   check_is_loaded();
 839   VM_ENTRY_MARK;
 840   methodHandle mh(THREAD, get_methodOop());
 841   return CompilerOracle::should_not_inline(mh);
 842 }
 843 
 844 // ------------------------------------------------------------------
 845 // ciMethod::should_print_assembly
 846 //
 847 // Should the compiler print the generated code for this method?
 848 bool ciMethod::should_print_assembly() {
 849   check_is_loaded();
 850   VM_ENTRY_MARK;
 851   methodHandle mh(THREAD, get_methodOop());
 852   return CompilerOracle::should_print(mh);
 853 }
 854 
 855 // ------------------------------------------------------------------
 856 // ciMethod::break_at_execute
 857 //
 858 // Should the compiler insert a breakpoint into the generated code
 859 // method?
 860 bool ciMethod::break_at_execute() {
 861   check_is_loaded();
 862   VM_ENTRY_MARK;
 863   methodHandle mh(THREAD, get_methodOop());
 864   return CompilerOracle::should_break_at(mh);
 865 }
 866 
 867 // ------------------------------------------------------------------
 868 // ciMethod::has_option
 869 //
 870 bool ciMethod::has_option(const char* option) {
 871   check_is_loaded();
 872   VM_ENTRY_MARK;
 873   methodHandle mh(THREAD, get_methodOop());
 874   return CompilerOracle::has_option_string(mh, option);
 875 }
 876 
 877 // ------------------------------------------------------------------
 878 // ciMethod::can_be_compiled
 879 //
 880 // Have previous compilations of this method succeeded?
 881 bool ciMethod::can_be_compiled() {
 882   check_is_loaded();
 883   return _is_compilable;
 884 }
 885 
 886 // ------------------------------------------------------------------
 887 // ciMethod::set_not_compilable
 888 //
 889 // Tell the VM that this method cannot be compiled at all.
 890 void ciMethod::set_not_compilable() {
 891   check_is_loaded();
 892   VM_ENTRY_MARK;
 893   _is_compilable = false;
 894   get_methodOop()->set_not_compilable();
 895 }
 896 
 897 // ------------------------------------------------------------------
 898 // ciMethod::can_be_osr_compiled
 899 //
 900 // Have previous compilations of this method succeeded?
 901 //
 902 // Implementation note: the VM does not currently keep track
 903 // of failed OSR compilations per bci.  The entry_bci parameter
 904 // is currently unused.
 905 bool ciMethod::can_be_osr_compiled(int entry_bci) {
 906   check_is_loaded();
 907   VM_ENTRY_MARK;
 908   return !get_methodOop()->access_flags().is_not_osr_compilable();
 909 }
 910 
 911 // ------------------------------------------------------------------
 912 // ciMethod::has_compiled_code
 913 bool ciMethod::has_compiled_code() {
 914   VM_ENTRY_MARK;
 915   return get_methodOop()->code() != NULL;
 916 }
 917 
 918 // ------------------------------------------------------------------
 919 // ciMethod::instructions_size
 920 // This is a rough metric for "fat" methods, compared
 921 // before inlining with InlineSmallCode.
 922 // The CodeBlob::instructions_size accessor includes
 923 // junk like exception handler, stubs, and constant table,
 924 // which are not highly relevant to an inlined method.
 925 // So we use the more specific accessor nmethod::code_size.
 926 int ciMethod::instructions_size() {
 927   GUARDED_VM_ENTRY(
 928     nmethod* code = get_methodOop()->code();
 929     // if there's no compiled code or the code was produced by the
 930     // tier1 profiler return 0 for the code size.  This should
 931     // probably be based on the compilation level of the nmethod but
 932     // that currently isn't properly recorded.
 933     if (code == NULL ||
 934         (TieredCompilation && code->compiler() != NULL && code->compiler()->is_c1())) {
 935       return 0;
 936     }
 937     return code->code_end() - code->verified_entry_point();
 938   )
 939 }
 940 
 941 // ------------------------------------------------------------------
 942 // ciMethod::log_nmethod_identity
 943 void ciMethod::log_nmethod_identity(xmlStream* log) {
 944   GUARDED_VM_ENTRY(
 945     nmethod* code = get_methodOop()->code();
 946     if (code != NULL) {
 947       code->log_identity(log);
 948     }
 949   )
 950 }
 951 
 952 // ------------------------------------------------------------------
 953 // ciMethod::is_not_reached
 954 bool ciMethod::is_not_reached(int bci) {
 955   check_is_loaded();
 956   VM_ENTRY_MARK;
 957   return Interpreter::is_not_reached(
 958                methodHandle(THREAD, get_methodOop()), bci);
 959 }
 960 
 961 // ------------------------------------------------------------------
 962 // ciMethod::was_never_executed
 963 bool ciMethod::was_executed_more_than(int times) {
 964   VM_ENTRY_MARK;
 965   return get_methodOop()->was_executed_more_than(times);
 966 }
 967 
 968 // ------------------------------------------------------------------
 969 // ciMethod::has_unloaded_classes_in_signature
 970 bool ciMethod::has_unloaded_classes_in_signature() {
 971   VM_ENTRY_MARK;
 972   {
 973     EXCEPTION_MARK;
 974     methodHandle m(THREAD, get_methodOop());
 975     bool has_unloaded = methodOopDesc::has_unloaded_classes_in_signature(m, (JavaThread *)THREAD);
 976     if( HAS_PENDING_EXCEPTION ) {
 977       CLEAR_PENDING_EXCEPTION;
 978       return true;     // Declare that we may have unloaded classes
 979     }
 980     return has_unloaded;
 981   }
 982 }
 983 
 984 // ------------------------------------------------------------------
 985 // ciMethod::is_klass_loaded
 986 bool ciMethod::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 987   VM_ENTRY_MARK;
 988   return get_methodOop()->is_klass_loaded(refinfo_index, must_be_resolved);
 989 }
 990 
 991 // ------------------------------------------------------------------
 992 // ciMethod::check_call
 993 bool ciMethod::check_call(int refinfo_index, bool is_static) const {
 994   VM_ENTRY_MARK;
 995   {
 996     EXCEPTION_MARK;
 997     HandleMark hm(THREAD);
 998     constantPoolHandle pool (THREAD, get_methodOop()->constants());
 999     methodHandle spec_method;
1000     KlassHandle  spec_klass;
1001     LinkResolver::resolve_method(spec_method, spec_klass, pool, refinfo_index, THREAD);
1002     if (HAS_PENDING_EXCEPTION) {
1003       CLEAR_PENDING_EXCEPTION;
1004       return false;
1005     } else {
1006       return (spec_method->is_static() == is_static);
1007     }
1008   }
1009   return false;
1010 }
1011 
1012 // ------------------------------------------------------------------
1013 // ciMethod::print_codes
1014 //
1015 // Print the bytecodes for this method.
1016 void ciMethod::print_codes_on(outputStream* st) {
1017   check_is_loaded();
1018   GUARDED_VM_ENTRY(get_methodOop()->print_codes_on(st);)
1019 }
1020 
1021 
1022 #define FETCH_FLAG_FROM_VM(flag_accessor) { \
1023   check_is_loaded(); \
1024   VM_ENTRY_MARK; \
1025   return get_methodOop()->flag_accessor(); \
1026 }
1027 
1028 bool ciMethod::is_empty_method() const {         FETCH_FLAG_FROM_VM(is_empty_method); }
1029 bool ciMethod::is_vanilla_constructor() const {  FETCH_FLAG_FROM_VM(is_vanilla_constructor); }
1030 bool ciMethod::has_loops      () const {         FETCH_FLAG_FROM_VM(has_loops); }
1031 bool ciMethod::has_jsrs       () const {         FETCH_FLAG_FROM_VM(has_jsrs);  }
1032 bool ciMethod::is_accessor    () const {         FETCH_FLAG_FROM_VM(is_accessor); }
1033 bool ciMethod::is_initializer () const {         FETCH_FLAG_FROM_VM(is_initializer); }
1034 
1035 BCEscapeAnalyzer  *ciMethod::get_bcea() {
1036   if (_bcea == NULL) {
1037     _bcea = new (CURRENT_ENV->arena()) BCEscapeAnalyzer(this, NULL);
1038   }
1039   return _bcea;
1040 }
1041 
1042 ciMethodBlocks  *ciMethod::get_method_blocks() {
1043   Arena *arena = CURRENT_ENV->arena();
1044   if (_method_blocks == NULL) {
1045     _method_blocks = new (arena) ciMethodBlocks(arena, this);
1046   }
1047   return _method_blocks;
1048 }
1049 
1050 #undef FETCH_FLAG_FROM_VM
1051 
1052 
1053 // ------------------------------------------------------------------
1054 // ciMethod::print_codes
1055 //
1056 // Print a range of the bytecodes for this method.
1057 void ciMethod::print_codes_on(int from, int to, outputStream* st) {
1058   check_is_loaded();
1059   GUARDED_VM_ENTRY(get_methodOop()->print_codes_on(from, to, st);)
1060 }
1061 
1062 // ------------------------------------------------------------------
1063 // ciMethod::print_name
1064 //
1065 // Print the name of this method, including signature and some flags.
1066 void ciMethod::print_name(outputStream* st) {
1067   check_is_loaded();
1068   GUARDED_VM_ENTRY(get_methodOop()->print_name(st);)
1069 }
1070 
1071 // ------------------------------------------------------------------
1072 // ciMethod::print_short_name
1073 //
1074 // Print the name of this method, without signature.
1075 void ciMethod::print_short_name(outputStream* st) {
1076   check_is_loaded();
1077   GUARDED_VM_ENTRY(get_methodOop()->print_short_name(st);)
1078 }
1079 
1080 // ------------------------------------------------------------------
1081 // ciMethod::print_impl
1082 //
1083 // Implementation of the print method.
1084 void ciMethod::print_impl(outputStream* st) {
1085   ciObject::print_impl(st);
1086   st->print(" name=");
1087   name()->print_symbol_on(st);
1088   st->print(" holder=");
1089   holder()->print_name_on(st);
1090   st->print(" signature=");
1091   signature()->as_symbol()->print_symbol_on(st);
1092   if (is_loaded()) {
1093     st->print(" loaded=true flags=");
1094     flags().print_member_flags(st);
1095   } else {
1096     st->print(" loaded=false");
1097   }
1098 }