1 /*
   2  * Copyright (c) 1998, 2016, 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 "precompiled.hpp"
  26 #include "ci/ciCallSite.hpp"
  27 #include "ci/ciMethodHandle.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "compiler/compileBroker.hpp"
  30 #include "compiler/compileLog.hpp"
  31 #include "interpreter/linkResolver.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/callGenerator.hpp"
  34 #include "opto/castnode.hpp"
  35 #include "opto/cfgnode.hpp"
  36 #include "opto/mulnode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "opto/subnode.hpp"
  41 #include "prims/nativeLookup.hpp"
  42 #include "runtime/sharedRuntime.hpp"
  43 
  44 void trace_type_profile(Compile* C, ciMethod *method, int depth, int bci, ciMethod *prof_method, ciKlass *prof_klass, int site_count, int receiver_count) {
  45   if (TraceTypeProfile || C->print_inlining()) {
  46     outputStream* out = tty;
  47     if (!C->print_inlining()) {
  48       if (!PrintOpto && !PrintCompilation) {
  49         method->print_short_name();
  50         tty->cr();
  51       }
  52       CompileTask::print_inlining_tty(prof_method, depth, bci);
  53     } else {
  54       out = C->print_inlining_stream();
  55     }
  56     CompileTask::print_inline_indent(depth, out);
  57     out->print(" \\-> TypeProfile (%d/%d counts) = ", receiver_count, site_count);
  58     stringStream ss;
  59     prof_klass->name()->print_symbol_on(&ss);
  60     out->print("%s", ss.as_string());
  61     out->cr();
  62   }
  63 }
  64 
  65 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_does_dispatch,
  66                                        JVMState* jvms, bool allow_inline,
  67                                        float prof_factor, ciKlass* speculative_receiver_type,
  68                                        bool allow_intrinsics, bool delayed_forbidden) {
  69   ciMethod*       caller   = jvms->method();
  70   int             bci      = jvms->bci();
  71   Bytecodes::Code bytecode = caller->java_code_at_bci(bci);
  72   guarantee(callee != NULL, "failed method resolution");
  73 
  74   // Dtrace currently doesn't work unless all calls are vanilla
  75   if (env()->dtrace_method_probes()) {
  76     allow_inline = false;
  77   }
  78 
  79   // Note: When we get profiling during stage-1 compiles, we want to pull
  80   // from more specific profile data which pertains to this inlining.
  81   // Right now, ignore the information in jvms->caller(), and do method[bci].
  82   ciCallProfile profile = caller->call_profile_at_bci(bci);
  83 
  84   // See how many times this site has been invoked.
  85   int site_count = profile.count();
  86   int receiver_count = -1;
  87   if (call_does_dispatch && UseTypeProfile && profile.has_receiver(0)) {
  88     // Receivers in the profile structure are ordered by call counts
  89     // so that the most called (major) receiver is profile.receiver(0).
  90     receiver_count = profile.receiver_count(0);
  91   }
  92 
  93   CompileLog* log = this->log();
  94   if (log != NULL) {
  95     int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1;
  96     int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1;
  97     log->begin_elem("call method='%d' count='%d' prof_factor='%f'",
  98                     log->identify(callee), site_count, prof_factor);
  99     if (call_does_dispatch)  log->print(" virtual='1'");
 100     if (allow_inline)     log->print(" inline='1'");
 101     if (receiver_count >= 0) {
 102       log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count);
 103       if (profile.has_receiver(1)) {
 104         log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1));
 105       }
 106     }
 107     if (callee->is_method_handle_intrinsic()) {
 108       log->print(" method_handle_intrinsic='1'");
 109     }
 110     log->end_elem();
 111   }
 112 
 113   // Special case the handling of certain common, profitable library
 114   // methods.  If these methods are replaced with specialized code,
 115   // then we return it as the inlined version of the call.
 116   // We do this before the strict f.p. check below because the
 117   // intrinsics handle strict f.p. correctly.
 118   CallGenerator* cg_intrinsic = NULL;
 119   if (allow_inline && allow_intrinsics) {
 120     CallGenerator* cg = find_intrinsic(callee, call_does_dispatch);
 121     if (cg != NULL) {
 122       if (cg->is_predicated()) {
 123         // Code without intrinsic but, hopefully, inlined.
 124         CallGenerator* inline_cg = this->call_generator(callee,
 125               vtable_index, call_does_dispatch, jvms, allow_inline, prof_factor, speculative_receiver_type, false);
 126         if (inline_cg != NULL) {
 127           cg = CallGenerator::for_predicated_intrinsic(cg, inline_cg);
 128         }
 129       }
 130 
 131       // If intrinsic does the virtual dispatch, we try to use the type profile
 132       // first, and hopefully inline it as the regular virtual call below.
 133       // We will retry the intrinsic if nothing had claimed it afterwards.
 134       if (cg->does_virtual_dispatch()) {
 135         cg_intrinsic = cg;
 136         cg = NULL;
 137       } else {
 138         return cg;
 139       }
 140     }
 141   }
 142 
 143   // Do method handle calls.
 144   // NOTE: This must happen before normal inlining logic below since
 145   // MethodHandle.invoke* are native methods which obviously don't
 146   // have bytecodes and so normal inlining fails.
 147   if (callee->is_method_handle_intrinsic()) {
 148     CallGenerator* cg = CallGenerator::for_method_handle_call(jvms, caller, callee, delayed_forbidden);
 149     assert(cg == NULL || !delayed_forbidden || !cg->is_late_inline() || cg->is_mh_late_inline(), "unexpected CallGenerator");
 150     return cg;
 151   }
 152 
 153   // Do not inline strict fp into non-strict code, or the reverse
 154   if (caller->is_strict() ^ callee->is_strict()) {
 155     allow_inline = false;
 156   }
 157 
 158   // Attempt to inline...
 159   if (allow_inline) {
 160     // The profile data is only partly attributable to this caller,
 161     // scale back the call site information.
 162     float past_uses = jvms->method()->scale_count(site_count, prof_factor);
 163     // This is the number of times we expect the call code to be used.
 164     float expected_uses = past_uses;
 165 
 166     // Try inlining a bytecoded method:
 167     if (!call_does_dispatch) {
 168       InlineTree* ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method());
 169       WarmCallInfo scratch_ci;
 170       bool should_delay = false;
 171       WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci, should_delay);
 172       assert(ci != &scratch_ci, "do not let this pointer escape");
 173       bool allow_inline   = (ci != NULL && !ci->is_cold());
 174       bool require_inline = (allow_inline && ci->is_hot());
 175 
 176       if (allow_inline) {
 177         CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses);
 178 
 179         if (require_inline && cg != NULL) {
 180           // Delay the inlining of this method to give us the
 181           // opportunity to perform some high level optimizations
 182           // first.
 183           if (should_delay_string_inlining(callee, jvms)) {
 184             assert(!delayed_forbidden, "strange");
 185             return CallGenerator::for_string_late_inline(callee, cg);
 186           } else if (should_delay_boxing_inlining(callee, jvms)) {
 187             assert(!delayed_forbidden, "strange");
 188             return CallGenerator::for_boxing_late_inline(callee, cg);
 189           } else if ((should_delay || AlwaysIncrementalInline) && !delayed_forbidden) {
 190             return CallGenerator::for_late_inline(callee, cg);
 191           }
 192         }
 193         if (cg == NULL || should_delay) {
 194           // Fall through.
 195         } else if (require_inline || !InlineWarmCalls) {
 196           return cg;
 197         } else {
 198           CallGenerator* cold_cg = call_generator(callee, vtable_index, call_does_dispatch, jvms, false, prof_factor);
 199           return CallGenerator::for_warm_call(ci, cold_cg, cg);
 200         }
 201       }
 202     }
 203 
 204     // Try using the type profile.
 205     if (call_does_dispatch && site_count > 0 && receiver_count > 0) {
 206       // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count.
 207       bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent);
 208       ciMethod* receiver_method = NULL;
 209 
 210       int morphism = profile.morphism();
 211       if (speculative_receiver_type != NULL) {
 212         if (!too_many_traps(caller, bci, Deoptimization::Reason_speculate_class_check)) {
 213           // We have a speculative type, we should be able to resolve
 214           // the call. We do that before looking at the profiling at
 215           // this invoke because it may lead to bimorphic inlining which
 216           // a speculative type should help us avoid.
 217           receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 218                                                    speculative_receiver_type);
 219           if (receiver_method == NULL) {
 220             speculative_receiver_type = NULL;
 221           } else {
 222             morphism = 1;
 223           }
 224         } else {
 225           // speculation failed before. Use profiling at the call
 226           // (could allow bimorphic inlining for instance).
 227           speculative_receiver_type = NULL;
 228         }
 229       }
 230       if (receiver_method == NULL &&
 231           (have_major_receiver || morphism == 1 ||
 232            (morphism == 2 && UseBimorphicInlining))) {
 233         // receiver_method = profile.method();
 234         // Profiles do not suggest methods now.  Look it up in the major receiver.
 235         receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 236                                                       profile.receiver(0));
 237       }
 238       if (receiver_method != NULL) {
 239         // The single majority receiver sufficiently outweighs the minority.
 240         CallGenerator* hit_cg = this->call_generator(receiver_method,
 241               vtable_index, !call_does_dispatch, jvms, allow_inline, prof_factor);
 242         if (hit_cg != NULL) {
 243           // Look up second receiver.
 244           CallGenerator* next_hit_cg = NULL;
 245           ciMethod* next_receiver_method = NULL;
 246           if (morphism == 2 && UseBimorphicInlining) {
 247             next_receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 248                                                                profile.receiver(1));
 249             if (next_receiver_method != NULL) {
 250               next_hit_cg = this->call_generator(next_receiver_method,
 251                                   vtable_index, !call_does_dispatch, jvms,
 252                                   allow_inline, prof_factor);
 253               if (next_hit_cg != NULL && !next_hit_cg->is_inline() &&
 254                   have_major_receiver && UseOnlyInlinedBimorphic) {
 255                   // Skip if we can't inline second receiver's method
 256                   next_hit_cg = NULL;
 257               }
 258             }
 259           }
 260           CallGenerator* miss_cg;
 261           Deoptimization::DeoptReason reason = morphism == 2 ?
 262             Deoptimization::Reason_bimorphic : Deoptimization::reason_class_check(speculative_receiver_type != NULL);
 263           if ((morphism == 1 || (morphism == 2 && next_hit_cg != NULL)) &&
 264               !too_many_traps(caller, bci, reason)
 265              ) {
 266             // Generate uncommon trap for class check failure path
 267             // in case of monomorphic or bimorphic virtual call site.
 268             miss_cg = CallGenerator::for_uncommon_trap(callee, reason,
 269                         Deoptimization::Action_maybe_recompile);
 270           } else {
 271             // Generate virtual call for class check failure path
 272             // in case of polymorphic virtual call site.
 273             miss_cg = CallGenerator::for_virtual_call(callee, vtable_index);
 274           }
 275           if (miss_cg != NULL) {
 276             if (next_hit_cg != NULL) {
 277               assert(speculative_receiver_type == NULL, "shouldn't end up here if we used speculation");
 278               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1));
 279               // We don't need to record dependency on a receiver here and below.
 280               // Whenever we inline, the dependency is added by Parse::Parse().
 281               miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX);
 282             }
 283             if (miss_cg != NULL) {
 284               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count);
 285               ciKlass* k = speculative_receiver_type != NULL ? speculative_receiver_type : profile.receiver(0);
 286               float hit_prob = speculative_receiver_type != NULL ? 1.0 : profile.receiver_prob(0);
 287               CallGenerator* cg = CallGenerator::for_predicted_call(k, miss_cg, hit_cg, hit_prob);
 288               if (cg != NULL)  return cg;
 289             }
 290           }
 291         }
 292       }
 293     }
 294   }
 295 
 296   // Nothing claimed the intrinsic, we go with straight-forward inlining
 297   // for already discovered intrinsic.
 298   if (allow_inline && allow_intrinsics && cg_intrinsic != NULL) {
 299     assert(cg_intrinsic->does_virtual_dispatch(), "sanity");
 300     return cg_intrinsic;
 301   }
 302 
 303   // There was no special inlining tactic, or it bailed out.
 304   // Use a more generic tactic, like a simple call.
 305   if (call_does_dispatch) {
 306     const char* msg = "virtual call";
 307     if (PrintInlining) print_inlining(callee, jvms->depth() - 1, jvms->bci(), msg);
 308     C->log_inline_failure(msg);
 309     return CallGenerator::for_virtual_call(callee, vtable_index);
 310   } else {
 311     // Class Hierarchy Analysis or Type Profile reveals a unique target,
 312     // or it is a static or special call.
 313     return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms));
 314   }
 315 }
 316 
 317 // Return true for methods that shouldn't be inlined early so that
 318 // they are easier to analyze and optimize as intrinsics.
 319 bool Compile::should_delay_string_inlining(ciMethod* call_method, JVMState* jvms) {
 320   if (has_stringbuilder()) {
 321 
 322     if ((call_method->holder() == C->env()->StringBuilder_klass() ||
 323          call_method->holder() == C->env()->StringBuffer_klass()) &&
 324         (jvms->method()->holder() == C->env()->StringBuilder_klass() ||
 325          jvms->method()->holder() == C->env()->StringBuffer_klass())) {
 326       // Delay SB calls only when called from non-SB code
 327       return false;
 328     }
 329 
 330     switch (call_method->intrinsic_id()) {
 331       case vmIntrinsics::_StringBuilder_void:
 332       case vmIntrinsics::_StringBuilder_int:
 333       case vmIntrinsics::_StringBuilder_String:
 334       case vmIntrinsics::_StringBuilder_append_char:
 335       case vmIntrinsics::_StringBuilder_append_int:
 336       case vmIntrinsics::_StringBuilder_append_String:
 337       case vmIntrinsics::_StringBuilder_toString:
 338       case vmIntrinsics::_StringBuffer_void:
 339       case vmIntrinsics::_StringBuffer_int:
 340       case vmIntrinsics::_StringBuffer_String:
 341       case vmIntrinsics::_StringBuffer_append_char:
 342       case vmIntrinsics::_StringBuffer_append_int:
 343       case vmIntrinsics::_StringBuffer_append_String:
 344       case vmIntrinsics::_StringBuffer_toString:
 345       case vmIntrinsics::_Integer_toString:
 346         return true;
 347 
 348       case vmIntrinsics::_String_String:
 349         {
 350           Node* receiver = jvms->map()->in(jvms->argoff() + 1);
 351           if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) {
 352             CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava();
 353             ciMethod* m = csj->method();
 354             if (m != NULL &&
 355                 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
 356                  m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString))
 357               // Delay String.<init>(new SB())
 358               return true;
 359           }
 360           return false;
 361         }
 362 
 363       default:
 364         return false;
 365     }
 366   }
 367   return false;
 368 }
 369 
 370 bool Compile::should_delay_boxing_inlining(ciMethod* call_method, JVMState* jvms) {
 371   if (eliminate_boxing() && call_method->is_boxing_method()) {
 372     set_has_boxed_value(true);
 373     return aggressive_unboxing();
 374   }
 375   return false;
 376 }
 377 
 378 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link
 379 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) {
 380   // Additional inputs to consider...
 381   // bc      = bc()
 382   // caller  = method()
 383   // iter().get_method_holder_index()
 384   assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" );
 385   // Interface classes can be loaded & linked and never get around to
 386   // being initialized.  Uncommon-trap for not-initialized static or
 387   // v-calls.  Let interface calls happen.
 388   ciInstanceKlass* holder_klass = dest_method->holder();
 389   if (!holder_klass->is_being_initialized() &&
 390       !holder_klass->is_initialized() &&
 391       !holder_klass->is_interface()) {
 392     uncommon_trap(Deoptimization::Reason_uninitialized,
 393                   Deoptimization::Action_reinterpret,
 394                   holder_klass);
 395     return true;
 396   }
 397 
 398   assert(dest_method->is_loaded(), "dest_method: typeflow responsibility");
 399   return false;
 400 }
 401 
 402 #ifdef ASSERT
 403 static bool check_call_consistency(JVMState* jvms, CallGenerator* cg) {
 404   ciMethod* symbolic_info = jvms->method()->get_method_at_bci(jvms->bci());
 405   ciMethod* resolved_method = cg->method();
 406   if (!ciMethod::is_consistent_info(symbolic_info, resolved_method)) {
 407     tty->print_cr("JVMS:");
 408     jvms->dump();
 409     tty->print_cr("Bytecode info:");
 410     jvms->method()->get_method_at_bci(jvms->bci())->print(); tty->cr();
 411     tty->print_cr("Resolved method:");
 412     cg->method()->print(); tty->cr();
 413     return false;
 414   }
 415   return true;
 416 }
 417 #endif // ASSERT
 418 
 419 //------------------------------do_call----------------------------------------
 420 // Handle your basic call.  Inline if we can & want to, else just setup call.
 421 void Parse::do_call() {
 422   // It's likely we are going to add debug info soon.
 423   // Also, if we inline a guy who eventually needs debug info for this JVMS,
 424   // our contribution to it is cleaned up right here.
 425   kill_dead_locals();
 426 
 427   C->print_inlining_assert_ready();
 428 
 429   // Set frequently used booleans
 430   const bool is_virtual = bc() == Bytecodes::_invokevirtual;
 431   const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface;
 432   const bool has_receiver = Bytecodes::has_receiver(bc());
 433 
 434   // Find target being called
 435   bool             will_link;
 436   ciSignature*     declared_signature = NULL;
 437   ciMethod*        orig_callee  = iter().get_method(will_link, &declared_signature);  // callee in the bytecode
 438   ciInstanceKlass* holder_klass = orig_callee->holder();
 439   ciKlass*         holder       = iter().get_declared_method_holder();
 440   ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder);
 441   assert(declared_signature != NULL, "cannot be null");
 442 
 443   // Bump max node limit for JSR292 users
 444   if (bc() == Bytecodes::_invokedynamic || orig_callee->is_method_handle_intrinsic()) {
 445     C->set_max_node_limit(3*MaxNodeLimit);
 446   }
 447 
 448   // uncommon-trap when callee is unloaded, uninitialized or will not link
 449   // bailout when too many arguments for register representation
 450   if (!will_link || can_not_compile_call_site(orig_callee, klass)) {
 451     if (PrintOpto && (Verbose || WizardMode)) {
 452       method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci());
 453       orig_callee->print_name(); tty->cr();
 454     }
 455     return;
 456   }
 457   assert(holder_klass->is_loaded(), "");
 458   //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc");  // XXX invokehandle (cur_bc_raw)
 459   // Note: this takes into account invokeinterface of methods declared in java/lang/Object,
 460   // which should be invokevirtuals but according to the VM spec may be invokeinterfaces
 461   assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc");
 462   // Note:  In the absence of miranda methods, an abstract class K can perform
 463   // an invokevirtual directly on an interface method I.m if K implements I.
 464 
 465   // orig_callee is the resolved callee which's signature includes the
 466   // appendix argument.
 467   const int nargs = orig_callee->arg_size();
 468   const bool is_signature_polymorphic = MethodHandles::is_signature_polymorphic(orig_callee->intrinsic_id());
 469 
 470   // Push appendix argument (MethodType, CallSite, etc.), if one.
 471   if (iter().has_appendix()) {
 472     ciObject* appendix_arg = iter().get_appendix();
 473     const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg);
 474     Node* appendix_arg_node = _gvn.makecon(appendix_arg_type);
 475     push(appendix_arg_node);
 476   }
 477 
 478   // ---------------------
 479   // Does Class Hierarchy Analysis reveal only a single target of a v-call?
 480   // Then we may inline or make a static call, but become dependent on there being only 1 target.
 481   // Does the call-site type profile reveal only one receiver?
 482   // Then we may introduce a run-time check and inline on the path where it succeeds.
 483   // The other path may uncommon_trap, check for another receiver, or do a v-call.
 484 
 485   // Try to get the most accurate receiver type
 486   ciMethod* callee             = orig_callee;
 487   int       vtable_index       = Method::invalid_vtable_index;
 488   bool      call_does_dispatch = false;
 489 
 490   // Speculative type of the receiver if any
 491   ciKlass* speculative_receiver_type = NULL;
 492   if (is_virtual_or_interface) {
 493     Node* receiver_node             = stack(sp() - nargs);
 494     const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr();
 495     // call_does_dispatch and vtable_index are out-parameters.  They might be changed.
 496     // For arrays, klass below is Object. When vtable calls are used,
 497     // resolving the call with Object would allow an illegal call to
 498     // finalize() on an array. We use holder instead: illegal calls to
 499     // finalize() won't be compiled as vtable calls (IC call
 500     // resolution will catch the illegal call) and the few legal calls
 501     // on array types won't be either.
 502     callee = C->optimize_virtual_call(method(), bci(), klass, holder, orig_callee,
 503                                       receiver_type, is_virtual,
 504                                       call_does_dispatch, vtable_index);  // out-parameters
 505     speculative_receiver_type = receiver_type != NULL ? receiver_type->speculative_type() : NULL;
 506   }
 507 
 508   // invoke-super-special
 509   if (iter().cur_bc_raw() == Bytecodes::_invokespecial && !orig_callee->is_object_initializer()) {
 510     ciInstanceKlass* calling_klass = method()->holder();
 511     ciInstanceKlass* sender_klass =
 512         calling_klass->is_anonymous() ? calling_klass->host_klass() :
 513                                         calling_klass;
 514     if (sender_klass->is_interface()) {
 515       Node* receiver_node = stack(sp() - nargs);
 516       Node* cls_node = makecon(TypeKlassPtr::make(sender_klass));
 517       Node* bad_type_ctrl = NULL;
 518       Node* casted_receiver = gen_checkcast(receiver_node, cls_node, &bad_type_ctrl);
 519       if (bad_type_ctrl != NULL) {
 520         PreserveJVMState pjvms(this);
 521         set_control(bad_type_ctrl);
 522         uncommon_trap(Deoptimization::Reason_class_check,
 523                       Deoptimization::Action_none);
 524       }
 525       if (stopped()) {
 526         return; // MUST uncommon-trap?
 527       }
 528       set_stack(sp() - nargs, casted_receiver);
 529     }
 530   }
 531 
 532   // Note:  It's OK to try to inline a virtual call.
 533   // The call generator will not attempt to inline a polymorphic call
 534   // unless it knows how to optimize the receiver dispatch.
 535   bool try_inline = (C->do_inlining() || InlineAccessors);
 536 
 537   // ---------------------
 538   dec_sp(nargs);              // Temporarily pop args for JVM state of call
 539   JVMState* jvms = sync_jvms();
 540 
 541   // ---------------------
 542   // Decide call tactic.
 543   // This call checks with CHA, the interpreter profile, intrinsics table, etc.
 544   // It decides whether inlining is desirable or not.
 545   CallGenerator* cg = C->call_generator(callee, vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type);
 546 
 547   // NOTE:  Don't use orig_callee and callee after this point!  Use cg->method() instead.
 548   orig_callee = callee = NULL;
 549 
 550   // ---------------------
 551   // Round double arguments before call
 552   round_double_arguments(cg->method());
 553 
 554   // Feed profiling data for arguments to the type system so it can
 555   // propagate it as speculative types
 556   record_profiled_arguments_for_speculation(cg->method(), bc());
 557 
 558 #ifndef PRODUCT
 559   // bump global counters for calls
 560   count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
 561 
 562   // Record first part of parsing work for this call
 563   parse_histogram()->record_change();
 564 #endif // not PRODUCT
 565 
 566   assert(jvms == this->jvms(), "still operating on the right JVMS");
 567   assert(jvms_in_sync(),       "jvms must carry full info into CG");
 568 
 569   // save across call, for a subsequent cast_not_null.
 570   Node* receiver = has_receiver ? argument(0) : NULL;
 571 
 572   // The extra CheckCastPPs for speculative types mess with PhaseStringOpts
 573   if (receiver != NULL && !call_does_dispatch && !cg->is_string_late_inline()) {
 574     // Feed profiling data for a single receiver to the type system so
 575     // it can propagate it as a speculative type
 576     receiver = record_profiled_receiver_for_speculation(receiver);
 577   }
 578 
 579   // Bump method data counters (We profile *before* the call is made
 580   // because exceptions don't return to the call site.)
 581   profile_call(receiver);
 582 
 583   JVMState* new_jvms = cg->generate(jvms);
 584   if (new_jvms == NULL) {
 585     // When inlining attempt fails (e.g., too many arguments),
 586     // it may contaminate the current compile state, making it
 587     // impossible to pull back and try again.  Once we call
 588     // cg->generate(), we are committed.  If it fails, the whole
 589     // compilation task is compromised.
 590     if (failing())  return;
 591 
 592     // This can happen if a library intrinsic is available, but refuses
 593     // the call site, perhaps because it did not match a pattern the
 594     // intrinsic was expecting to optimize. Should always be possible to
 595     // get a normal java call that may inline in that case
 596     cg = C->call_generator(cg->method(), vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type, /* allow_intrinsics= */ false);
 597     new_jvms = cg->generate(jvms);
 598     if (new_jvms == NULL) {
 599       guarantee(failing(), "call failed to generate:  calls should work");
 600       return;
 601     }
 602   }
 603 
 604   if (cg->is_inline()) {
 605     // Accumulate has_loops estimate
 606     C->set_has_loops(C->has_loops() || cg->method()->has_loops());
 607     C->env()->notice_inlined_method(cg->method());
 608   }
 609 
 610   // Reset parser state from [new_]jvms, which now carries results of the call.
 611   // Return value (if any) is already pushed on the stack by the cg.
 612   add_exception_states_from(new_jvms);
 613   if (new_jvms->map()->control() == top()) {
 614     stop_and_kill_map();
 615   } else {
 616     assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
 617     set_jvms(new_jvms);
 618   }
 619 
 620   assert(check_call_consistency(jvms, cg), "inconsistent info");
 621 
 622   if (!stopped()) {
 623     // This was some sort of virtual call, which did a null check for us.
 624     // Now we can assert receiver-not-null, on the normal return path.
 625     if (receiver != NULL && cg->is_virtual()) {
 626       Node* cast = cast_not_null(receiver);
 627       // %%% assert(receiver == cast, "should already have cast the receiver");
 628     }
 629 
 630     // Round double result after a call from strict to non-strict code
 631     round_double_result(cg->method());
 632 
 633     ciType* rtype = cg->method()->return_type();
 634     ciType* ctype = declared_signature->return_type();
 635 
 636     if (Bytecodes::has_optional_appendix(iter().cur_bc_raw()) || is_signature_polymorphic) {
 637       // Be careful here with return types.
 638       if (ctype != rtype) {
 639         BasicType rt = rtype->basic_type();
 640         BasicType ct = ctype->basic_type();
 641         if (ct == T_VOID) {
 642           // It's OK for a method  to return a value that is discarded.
 643           // The discarding does not require any special action from the caller.
 644           // The Java code knows this, at VerifyType.isNullConversion.
 645           pop_node(rt);  // whatever it was, pop it
 646         } else if (rt == T_INT || is_subword_type(rt)) {
 647           // Nothing.  These cases are handled in lambda form bytecode.
 648           assert(ct == T_INT || is_subword_type(ct), "must match: rt=%s, ct=%s", type2name(rt), type2name(ct));
 649         } else if (rt == T_OBJECT || rt == T_ARRAY) {
 650           assert(ct == T_OBJECT || ct == T_ARRAY, "rt=%s, ct=%s", type2name(rt), type2name(ct));
 651           if (ctype->is_loaded()) {
 652             const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
 653             const Type*       sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
 654             if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
 655               Node* retnode = pop();
 656               Node* cast_obj = _gvn.transform(new CheckCastPPNode(control(), retnode, sig_type));
 657               push(cast_obj);
 658             }
 659           }
 660         } else {
 661           assert(rt == ct, "unexpected mismatch: rt=%s, ct=%s", type2name(rt), type2name(ct));
 662           // push a zero; it's better than getting an oop/int mismatch
 663           pop_node(rt);
 664           Node* retnode = zerocon(ct);
 665           push_node(ct, retnode);
 666         }
 667         // Now that the value is well-behaved, continue with the call-site type.
 668         rtype = ctype;
 669       }
 670     } else {
 671       // Symbolic resolution enforces the types to be the same.
 672       // NOTE: We must relax the assert for unloaded types because two
 673       // different ciType instances of the same unloaded class type
 674       // can appear to be "loaded" by different loaders (depending on
 675       // the accessing class).
 676       assert(!rtype->is_loaded() || !ctype->is_loaded() || rtype == ctype,
 677              "mismatched return types: rtype=%s, ctype=%s", rtype->name(), ctype->name());
 678     }
 679 
 680     // If the return type of the method is not loaded, assert that the
 681     // value we got is a null.  Otherwise, we need to recompile.
 682     if (!rtype->is_loaded()) {
 683       if (PrintOpto && (Verbose || WizardMode)) {
 684         method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
 685         cg->method()->print_name(); tty->cr();
 686       }
 687       if (C->log() != NULL) {
 688         C->log()->elem("assert_null reason='return' klass='%d'",
 689                        C->log()->identify(rtype));
 690       }
 691       // If there is going to be a trap, put it at the next bytecode:
 692       set_bci(iter().next_bci());
 693       null_assert(peek());
 694       set_bci(iter().cur_bci()); // put it back
 695     }
 696     BasicType ct = ctype->basic_type();
 697     if (ct == T_OBJECT || ct == T_ARRAY) {
 698       record_profiled_return_for_speculation();
 699     }
 700   }
 701 
 702   // Restart record of parsing work after possible inlining of call
 703 #ifndef PRODUCT
 704   parse_histogram()->set_initial_state(bc());
 705 #endif
 706 }
 707 
 708 //---------------------------catch_call_exceptions-----------------------------
 709 // Put a Catch and CatchProj nodes behind a just-created call.
 710 // Send their caught exceptions to the proper handler.
 711 // This may be used after a call to the rethrow VM stub,
 712 // when it is needed to process unloaded exception classes.
 713 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
 714   // Exceptions are delivered through this channel:
 715   Node* i_o = this->i_o();
 716 
 717   // Add a CatchNode.
 718   GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
 719   GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
 720   GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
 721 
 722   bool default_handler = false;
 723   for (; !handlers.is_done(); handlers.next()) {
 724     ciExceptionHandler* h        = handlers.handler();
 725     int                 h_bci    = h->handler_bci();
 726     ciInstanceKlass*    h_klass  = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
 727     // Do not introduce unloaded exception types into the graph:
 728     if (!h_klass->is_loaded()) {
 729       if (saw_unloaded->contains(h_bci)) {
 730         /* We've already seen an unloaded exception with h_bci,
 731            so don't duplicate. Duplication will cause the CatchNode to be
 732            unnecessarily large. See 4713716. */
 733         continue;
 734       } else {
 735         saw_unloaded->append(h_bci);
 736       }
 737     }
 738     const Type*         h_extype = TypeOopPtr::make_from_klass(h_klass);
 739     // (We use make_from_klass because it respects UseUniqueSubclasses.)
 740     h_extype = h_extype->join(TypeInstPtr::NOTNULL);
 741     assert(!h_extype->empty(), "sanity");
 742     // Note:  It's OK if the BCIs repeat themselves.
 743     bcis->append(h_bci);
 744     extypes->append(h_extype);
 745     if (h_bci == -1) {
 746       default_handler = true;
 747     }
 748   }
 749 
 750   if (!default_handler) {
 751     bcis->append(-1);
 752     extypes->append(TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr());
 753   }
 754 
 755   int len = bcis->length();
 756   CatchNode *cn = new CatchNode(control(), i_o, len+1);
 757   Node *catch_ = _gvn.transform(cn);
 758 
 759   // now branch with the exception state to each of the (potential)
 760   // handlers
 761   for(int i=0; i < len; i++) {
 762     // Setup JVM state to enter the handler.
 763     PreserveJVMState pjvms(this);
 764     // Locals are just copied from before the call.
 765     // Get control from the CatchNode.
 766     int handler_bci = bcis->at(i);
 767     Node* ctrl = _gvn.transform( new CatchProjNode(catch_, i+1,handler_bci));
 768     // This handler cannot happen?
 769     if (ctrl == top())  continue;
 770     set_control(ctrl);
 771 
 772     // Create exception oop
 773     const TypeInstPtr* extype = extypes->at(i)->is_instptr();
 774     Node *ex_oop = _gvn.transform(new CreateExNode(extypes->at(i), ctrl, i_o));
 775 
 776     // Handle unloaded exception classes.
 777     if (saw_unloaded->contains(handler_bci)) {
 778       // An unloaded exception type is coming here.  Do an uncommon trap.
 779 #ifndef PRODUCT
 780       // We do not expect the same handler bci to take both cold unloaded
 781       // and hot loaded exceptions.  But, watch for it.
 782       if ((Verbose || WizardMode) && extype->is_loaded()) {
 783         tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
 784         method()->print_name(); tty->cr();
 785       } else if (PrintOpto && (Verbose || WizardMode)) {
 786         tty->print("Bailing out on unloaded exception type ");
 787         extype->klass()->print_name();
 788         tty->print(" at bci:%d in ", bci());
 789         method()->print_name(); tty->cr();
 790       }
 791 #endif
 792       // Emit an uncommon trap instead of processing the block.
 793       set_bci(handler_bci);
 794       push_ex_oop(ex_oop);
 795       uncommon_trap(Deoptimization::Reason_unloaded,
 796                     Deoptimization::Action_reinterpret,
 797                     extype->klass(), "!loaded exception");
 798       set_bci(iter().cur_bci()); // put it back
 799       continue;
 800     }
 801 
 802     // go to the exception handler
 803     if (handler_bci < 0) {     // merge with corresponding rethrow node
 804       throw_to_exit(make_exception_state(ex_oop));
 805     } else {                      // Else jump to corresponding handle
 806       push_ex_oop(ex_oop);        // Clear stack and push just the oop.
 807       merge_exception(handler_bci);
 808     }
 809   }
 810 
 811   // The first CatchProj is for the normal return.
 812   // (Note:  If this is a call to rethrow_Java, this node goes dead.)
 813   set_control(_gvn.transform( new CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
 814 }
 815 
 816 
 817 //----------------------------catch_inline_exceptions--------------------------
 818 // Handle all exceptions thrown by an inlined method or individual bytecode.
 819 // Common case 1: we have no handler, so all exceptions merge right into
 820 // the rethrow case.
 821 // Case 2: we have some handlers, with loaded exception klasses that have
 822 // no subklasses.  We do a Deutsch-Shiffman style type-check on the incoming
 823 // exception oop and branch to the handler directly.
 824 // Case 3: We have some handlers with subklasses or are not loaded at
 825 // compile-time.  We have to call the runtime to resolve the exception.
 826 // So we insert a RethrowCall and all the logic that goes with it.
 827 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
 828   // Caller is responsible for saving away the map for normal control flow!
 829   assert(stopped(), "call set_map(NULL) first");
 830   assert(method()->has_exception_handlers(), "don't come here w/o work to do");
 831 
 832   Node* ex_node = saved_ex_oop(ex_map);
 833   if (ex_node == top()) {
 834     // No action needed.
 835     return;
 836   }
 837   const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
 838   NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
 839   if (ex_type == NULL)
 840     ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
 841 
 842   // determine potential exception handlers
 843   ciExceptionHandlerStream handlers(method(), bci(),
 844                                     ex_type->klass()->as_instance_klass(),
 845                                     ex_type->klass_is_exact());
 846 
 847   // Start executing from the given throw state.  (Keep its stack, for now.)
 848   // Get the exception oop as known at compile time.
 849   ex_node = use_exception_state(ex_map);
 850 
 851   // Get the exception oop klass from its header
 852   Node* ex_klass_node = NULL;
 853   if (has_ex_handler() && !ex_type->klass_is_exact()) {
 854     Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
 855     ex_klass_node = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 856 
 857     // Compute the exception klass a little more cleverly.
 858     // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
 859     // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
 860     // each arm of the Phi.  If I know something clever about the exceptions
 861     // I'm loading the class from, I can replace the LoadKlass with the
 862     // klass constant for the exception oop.
 863     if (ex_node->is_Phi()) {
 864       ex_klass_node = new PhiNode(ex_node->in(0), TypeKlassPtr::OBJECT);
 865       for (uint i = 1; i < ex_node->req(); i++) {
 866         Node* ex_in = ex_node->in(i);
 867         if (ex_in == top() || ex_in == NULL) {
 868           // This path was not taken.
 869           ex_klass_node->init_req(i, top());
 870           continue;
 871         }
 872         Node* p = basic_plus_adr(ex_in, ex_in, oopDesc::klass_offset_in_bytes());
 873         Node* k = _gvn.transform( LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 874         ex_klass_node->init_req( i, k );
 875       }
 876       _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
 877 
 878     }
 879   }
 880 
 881   // Scan the exception table for applicable handlers.
 882   // If none, we can call rethrow() and be done!
 883   // If precise (loaded with no subklasses), insert a D.S. style
 884   // pointer compare to the correct handler and loop back.
 885   // If imprecise, switch to the Rethrow VM-call style handling.
 886 
 887   int remaining = handlers.count_remaining();
 888 
 889   // iterate through all entries sequentially
 890   for (;!handlers.is_done(); handlers.next()) {
 891     ciExceptionHandler* handler = handlers.handler();
 892 
 893     if (handler->is_rethrow()) {
 894       // If we fell off the end of the table without finding an imprecise
 895       // exception klass (and without finding a generic handler) then we
 896       // know this exception is not handled in this method.  We just rethrow
 897       // the exception into the caller.
 898       throw_to_exit(make_exception_state(ex_node));
 899       return;
 900     }
 901 
 902     // exception handler bci range covers throw_bci => investigate further
 903     int handler_bci = handler->handler_bci();
 904 
 905     if (remaining == 1) {
 906       push_ex_oop(ex_node);        // Push exception oop for handler
 907       if (PrintOpto && WizardMode) {
 908         tty->print_cr("  Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
 909       }
 910       merge_exception(handler_bci); // jump to handler
 911       return;                   // No more handling to be done here!
 912     }
 913 
 914     // Get the handler's klass
 915     ciInstanceKlass* klass = handler->catch_klass();
 916 
 917     if (!klass->is_loaded()) {  // klass is not loaded?
 918       // fall through into catch_call_exceptions which will emit a
 919       // handler with an uncommon trap.
 920       break;
 921     }
 922 
 923     if (klass->is_interface())  // should not happen, but...
 924       break;                    // bail out
 925 
 926     // Check the type of the exception against the catch type
 927     const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
 928     Node* con = _gvn.makecon(tk);
 929     Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
 930     if (!stopped()) {
 931       PreserveJVMState pjvms(this);
 932       const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
 933       assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
 934       Node* ex_oop = _gvn.transform(new CheckCastPPNode(control(), ex_node, tinst));
 935       push_ex_oop(ex_oop);      // Push exception oop for handler
 936       if (PrintOpto && WizardMode) {
 937         tty->print("  Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
 938         klass->print_name();
 939         tty->cr();
 940       }
 941       merge_exception(handler_bci);
 942     }
 943     set_control(not_subtype_ctrl);
 944 
 945     // Come here if exception does not match handler.
 946     // Carry on with more handler checks.
 947     --remaining;
 948   }
 949 
 950   assert(!stopped(), "you should return if you finish the chain");
 951 
 952   // Oops, need to call into the VM to resolve the klasses at runtime.
 953   // Note:  This call must not deoptimize, since it is not a real at this bci!
 954   kill_dead_locals();
 955 
 956   make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
 957                     OptoRuntime::rethrow_Type(),
 958                     OptoRuntime::rethrow_stub(),
 959                     NULL, NULL,
 960                     ex_node);
 961 
 962   // Rethrow is a pure call, no side effects, only a result.
 963   // The result cannot be allocated, so we use I_O
 964 
 965   // Catch exceptions from the rethrow
 966   catch_call_exceptions(handlers);
 967 }
 968 
 969 
 970 // (Note:  Moved add_debug_info into GraphKit::add_safepoint_edges.)
 971 
 972 
 973 #ifndef PRODUCT
 974 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
 975   if( CountCompiledCalls ) {
 976     if( at_method_entry ) {
 977       // bump invocation counter if top method (for statistics)
 978       if (CountCompiledCalls && depth() == 1) {
 979         const TypePtr* addr_type = TypeMetadataPtr::make(method());
 980         Node* adr1 = makecon(addr_type);
 981         Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
 982         increment_counter(adr2);
 983       }
 984     } else if (is_inline) {
 985       switch (bc()) {
 986       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
 987       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
 988       case Bytecodes::_invokestatic:
 989       case Bytecodes::_invokedynamic:
 990       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
 991       default: fatal("unexpected call bytecode");
 992       }
 993     } else {
 994       switch (bc()) {
 995       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
 996       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
 997       case Bytecodes::_invokestatic:
 998       case Bytecodes::_invokedynamic:
 999       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_static_calls_addr()); break;
1000       default: fatal("unexpected call bytecode");
1001       }
1002     }
1003   }
1004 }
1005 #endif //PRODUCT
1006 
1007 
1008 ciMethod* Compile::optimize_virtual_call(ciMethod* caller, int bci, ciInstanceKlass* klass,
1009                                          ciKlass* holder, ciMethod* callee,
1010                                          const TypeOopPtr* receiver_type, bool is_virtual,
1011                                          bool& call_does_dispatch, int& vtable_index,
1012                                          bool check_access) {
1013   // Set default values for out-parameters.
1014   call_does_dispatch = true;
1015   vtable_index       = Method::invalid_vtable_index;
1016 
1017   // Choose call strategy.
1018   ciMethod* optimized_virtual_method = optimize_inlining(caller, bci, klass, callee,
1019                                                          receiver_type, check_access);
1020 
1021   // Have the call been sufficiently improved such that it is no longer a virtual?
1022   if (optimized_virtual_method != NULL) {
1023     callee             = optimized_virtual_method;
1024     call_does_dispatch = false;
1025   } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
1026     // We can make a vtable call at this site
1027     vtable_index = callee->resolve_vtable_index(caller->holder(), holder);
1028   }
1029   return callee;
1030 }
1031 
1032 // Identify possible target method and inlining style
1033 ciMethod* Compile::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
1034                                      ciMethod* callee, const TypeOopPtr* receiver_type,
1035                                      bool check_access) {
1036   // only use for virtual or interface calls
1037 
1038   // If it is obviously final, do not bother to call find_monomorphic_target,
1039   // because the class hierarchy checks are not needed, and may fail due to
1040   // incompletely loaded classes.  Since we do our own class loading checks
1041   // in this module, we may confidently bind to any method.
1042   if (callee->can_be_statically_bound()) {
1043     return callee;
1044   }
1045 
1046   // Attempt to improve the receiver
1047   bool actual_receiver_is_exact = false;
1048   ciInstanceKlass* actual_receiver = klass;
1049   if (receiver_type != NULL) {
1050     // Array methods are all inherited from Object, and are monomorphic.
1051     // finalize() call on array is not allowed.
1052     if (receiver_type->isa_aryptr() &&
1053         callee->holder() == env()->Object_klass() &&
1054         callee->name() != ciSymbol::finalize_method_name()) {
1055       return callee;
1056     }
1057 
1058     // All other interesting cases are instance klasses.
1059     if (!receiver_type->isa_instptr()) {
1060       return NULL;
1061     }
1062 
1063     ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
1064     if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
1065         (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
1066       // ikl is a same or better type than the original actual_receiver,
1067       // e.g. static receiver from bytecodes.
1068       actual_receiver = ikl;
1069       // Is the actual_receiver exact?
1070       actual_receiver_is_exact = receiver_type->klass_is_exact();
1071     }
1072   }
1073 
1074   ciInstanceKlass*   calling_klass = caller->holder();
1075   ciMethod* cha_monomorphic_target = callee->find_monomorphic_target(calling_klass, klass, actual_receiver, check_access);
1076   if (cha_monomorphic_target != NULL) {
1077     assert(!cha_monomorphic_target->is_abstract(), "");
1078     // Look at the method-receiver type.  Does it add "too much information"?
1079     ciKlass*    mr_klass = cha_monomorphic_target->holder();
1080     const Type* mr_type  = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
1081     if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
1082       // Calling this method would include an implicit cast to its holder.
1083       // %%% Not yet implemented.  Would throw minor asserts at present.
1084       // %%% The most common wins are already gained by +UseUniqueSubclasses.
1085       // To fix, put the higher_equal check at the call of this routine,
1086       // and add a CheckCastPP to the receiver.
1087       if (TraceDependencies) {
1088         tty->print_cr("found unique CHA method, but could not cast up");
1089         tty->print("  method  = ");
1090         cha_monomorphic_target->print();
1091         tty->cr();
1092       }
1093       if (log() != NULL) {
1094         log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
1095                        log()->identify(klass),
1096                        log()->identify(cha_monomorphic_target));
1097       }
1098       cha_monomorphic_target = NULL;
1099     }
1100   }
1101   if (cha_monomorphic_target != NULL) {
1102     // Hardwiring a virtual.
1103     // If we inlined because CHA revealed only a single target method,
1104     // then we are dependent on that target method not getting overridden
1105     // by dynamic class loading.  Be sure to test the "static" receiver
1106     // dest_method here, as opposed to the actual receiver, which may
1107     // falsely lead us to believe that the receiver is final or private.
1108     dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
1109     return cha_monomorphic_target;
1110   }
1111 
1112   // If the type is exact, we can still bind the method w/o a vcall.
1113   // (This case comes after CHA so we can see how much extra work it does.)
1114   if (actual_receiver_is_exact) {
1115     // In case of evolution, there is a dependence on every inlined method, since each
1116     // such method can be changed when its class is redefined.
1117     ciMethod* exact_method = callee->resolve_invoke(calling_klass, actual_receiver);
1118     if (exact_method != NULL) {
1119       if (PrintOpto) {
1120         tty->print("  Calling method via exact type @%d --- ", bci);
1121         exact_method->print_name();
1122         tty->cr();
1123       }
1124       return exact_method;
1125     }
1126   }
1127 
1128   return NULL;
1129 }