1 /*
   2  * Copyright (c) 1998, 2018, 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, /* require_const= */ true);
 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   // Additional receiver subtype checks for interface calls via invokespecial or invokeinterface.
 509   ciKlass* receiver_constraint = NULL;
 510   if (iter().cur_bc_raw() == Bytecodes::_invokespecial && !orig_callee->is_object_initializer()) {
 511     ciInstanceKlass* calling_klass = method()->holder();
 512     ciInstanceKlass* sender_klass =
 513         calling_klass->is_unsafe_anonymous() ? calling_klass->unsafe_anonymous_host() :
 514                                                calling_klass;
 515     if (sender_klass->is_interface()) {
 516       receiver_constraint = sender_klass;
 517     }
 518   } else if (iter().cur_bc_raw() == Bytecodes::_invokeinterface && orig_callee->is_private()) {
 519     assert(holder->is_interface(), "How did we get a non-interface method here!");
 520     receiver_constraint = holder;
 521   }
 522 
 523   if (receiver_constraint != NULL) {
 524     Node* receiver_node = stack(sp() - nargs);
 525     Node* cls_node = makecon(TypeKlassPtr::make(receiver_constraint));
 526     Node* bad_type_ctrl = NULL;
 527     Node* casted_receiver = gen_checkcast(receiver_node, cls_node, &bad_type_ctrl);
 528     if (bad_type_ctrl != NULL) {
 529       PreserveJVMState pjvms(this);
 530       set_control(bad_type_ctrl);
 531       uncommon_trap(Deoptimization::Reason_class_check,
 532                     Deoptimization::Action_none);
 533     }
 534     if (stopped()) {
 535       return; // MUST uncommon-trap?
 536     }
 537     set_stack(sp() - nargs, casted_receiver);
 538   }
 539 
 540   // Note:  It's OK to try to inline a virtual call.
 541   // The call generator will not attempt to inline a polymorphic call
 542   // unless it knows how to optimize the receiver dispatch.
 543   bool try_inline = (C->do_inlining() || InlineAccessors);
 544 
 545   // ---------------------
 546   dec_sp(nargs);              // Temporarily pop args for JVM state of call
 547   JVMState* jvms = sync_jvms();
 548 
 549   // ---------------------
 550   // Decide call tactic.
 551   // This call checks with CHA, the interpreter profile, intrinsics table, etc.
 552   // It decides whether inlining is desirable or not.
 553   CallGenerator* cg = C->call_generator(callee, vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type);
 554 
 555   // NOTE:  Don't use orig_callee and callee after this point!  Use cg->method() instead.
 556   orig_callee = callee = NULL;
 557 
 558   // ---------------------
 559   // Round double arguments before call
 560   round_double_arguments(cg->method());
 561 
 562   // Feed profiling data for arguments to the type system so it can
 563   // propagate it as speculative types
 564   record_profiled_arguments_for_speculation(cg->method(), bc());
 565 
 566 #ifndef PRODUCT
 567   // bump global counters for calls
 568   count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
 569 
 570   // Record first part of parsing work for this call
 571   parse_histogram()->record_change();
 572 #endif // not PRODUCT
 573 
 574   assert(jvms == this->jvms(), "still operating on the right JVMS");
 575   assert(jvms_in_sync(),       "jvms must carry full info into CG");
 576 
 577   // save across call, for a subsequent cast_not_null.
 578   Node* receiver = has_receiver ? argument(0) : NULL;
 579 
 580   // The extra CheckCastPPs for speculative types mess with PhaseStringOpts
 581   if (receiver != NULL && !call_does_dispatch && !cg->is_string_late_inline()) {
 582     // Feed profiling data for a single receiver to the type system so
 583     // it can propagate it as a speculative type
 584     receiver = record_profiled_receiver_for_speculation(receiver);
 585   }
 586 
 587   // Bump method data counters (We profile *before* the call is made
 588   // because exceptions don't return to the call site.)
 589   profile_call(receiver);
 590 
 591   JVMState* new_jvms = cg->generate(jvms);
 592   if (new_jvms == NULL) {
 593     // When inlining attempt fails (e.g., too many arguments),
 594     // it may contaminate the current compile state, making it
 595     // impossible to pull back and try again.  Once we call
 596     // cg->generate(), we are committed.  If it fails, the whole
 597     // compilation task is compromised.
 598     if (failing())  return;
 599 
 600     // This can happen if a library intrinsic is available, but refuses
 601     // the call site, perhaps because it did not match a pattern the
 602     // intrinsic was expecting to optimize. Should always be possible to
 603     // get a normal java call that may inline in that case
 604     cg = C->call_generator(cg->method(), vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type, /* allow_intrinsics= */ false);
 605     new_jvms = cg->generate(jvms);
 606     if (new_jvms == NULL) {
 607       guarantee(failing(), "call failed to generate:  calls should work");
 608       return;
 609     }
 610   }
 611 
 612   if (cg->is_inline()) {
 613     // Accumulate has_loops estimate
 614     C->set_has_loops(C->has_loops() || cg->method()->has_loops());
 615     C->env()->notice_inlined_method(cg->method());
 616   }
 617 
 618   // Reset parser state from [new_]jvms, which now carries results of the call.
 619   // Return value (if any) is already pushed on the stack by the cg.
 620   add_exception_states_from(new_jvms);
 621   if (new_jvms->map()->control() == top()) {
 622     stop_and_kill_map();
 623   } else {
 624     assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
 625     set_jvms(new_jvms);
 626   }
 627 
 628   assert(check_call_consistency(jvms, cg), "inconsistent info");
 629 
 630   if (!stopped()) {
 631     // This was some sort of virtual call, which did a null check for us.
 632     // Now we can assert receiver-not-null, on the normal return path.
 633     if (receiver != NULL && cg->is_virtual()) {
 634       Node* cast = cast_not_null(receiver);
 635       // %%% assert(receiver == cast, "should already have cast the receiver");
 636     }
 637 
 638     // Round double result after a call from strict to non-strict code
 639     round_double_result(cg->method());
 640 
 641     ciType* rtype = cg->method()->return_type();
 642     ciType* ctype = declared_signature->return_type();
 643 
 644     if (Bytecodes::has_optional_appendix(iter().cur_bc_raw()) || is_signature_polymorphic) {
 645       // Be careful here with return types.
 646       if (ctype != rtype) {
 647         BasicType rt = rtype->basic_type();
 648         BasicType ct = ctype->basic_type();
 649         if (ct == T_VOID) {
 650           // It's OK for a method  to return a value that is discarded.
 651           // The discarding does not require any special action from the caller.
 652           // The Java code knows this, at VerifyType.isNullConversion.
 653           pop_node(rt);  // whatever it was, pop it
 654         } else if (rt == T_INT || is_subword_type(rt)) {
 655           // Nothing.  These cases are handled in lambda form bytecode.
 656           assert(ct == T_INT || is_subword_type(ct), "must match: rt=%s, ct=%s", type2name(rt), type2name(ct));
 657         } else if (rt == T_OBJECT || rt == T_ARRAY) {
 658           assert(ct == T_OBJECT || ct == T_ARRAY, "rt=%s, ct=%s", type2name(rt), type2name(ct));
 659           if (ctype->is_loaded()) {
 660             const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
 661             const Type*       sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
 662             if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
 663               Node* retnode = pop();
 664               Node* cast_obj = _gvn.transform(new CheckCastPPNode(control(), retnode, sig_type));
 665               push(cast_obj);
 666             }
 667           }
 668         } else {
 669           assert(rt == ct, "unexpected mismatch: rt=%s, ct=%s", type2name(rt), type2name(ct));
 670           // push a zero; it's better than getting an oop/int mismatch
 671           pop_node(rt);
 672           Node* retnode = zerocon(ct);
 673           push_node(ct, retnode);
 674         }
 675         // Now that the value is well-behaved, continue with the call-site type.
 676         rtype = ctype;
 677       }
 678     } else {
 679       // Symbolic resolution enforces the types to be the same.
 680       // NOTE: We must relax the assert for unloaded types because two
 681       // different ciType instances of the same unloaded class type
 682       // can appear to be "loaded" by different loaders (depending on
 683       // the accessing class).
 684       assert(!rtype->is_loaded() || !ctype->is_loaded() || rtype == ctype,
 685              "mismatched return types: rtype=%s, ctype=%s", rtype->name(), ctype->name());
 686     }
 687 
 688     // If the return type of the method is not loaded, assert that the
 689     // value we got is a null.  Otherwise, we need to recompile.
 690     if (!rtype->is_loaded()) {
 691       if (PrintOpto && (Verbose || WizardMode)) {
 692         method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
 693         cg->method()->print_name(); tty->cr();
 694       }
 695       if (C->log() != NULL) {
 696         C->log()->elem("assert_null reason='return' klass='%d'",
 697                        C->log()->identify(rtype));
 698       }
 699       // If there is going to be a trap, put it at the next bytecode:
 700       set_bci(iter().next_bci());
 701       null_assert(peek());
 702       set_bci(iter().cur_bci()); // put it back
 703     }
 704     BasicType ct = ctype->basic_type();
 705     if (ct == T_OBJECT || ct == T_ARRAY) {
 706       record_profiled_return_for_speculation();
 707     }
 708   }
 709 
 710   // Restart record of parsing work after possible inlining of call
 711 #ifndef PRODUCT
 712   parse_histogram()->set_initial_state(bc());
 713 #endif
 714 }
 715 
 716 //---------------------------catch_call_exceptions-----------------------------
 717 // Put a Catch and CatchProj nodes behind a just-created call.
 718 // Send their caught exceptions to the proper handler.
 719 // This may be used after a call to the rethrow VM stub,
 720 // when it is needed to process unloaded exception classes.
 721 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
 722   // Exceptions are delivered through this channel:
 723   Node* i_o = this->i_o();
 724 
 725   // Add a CatchNode.
 726   GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
 727   GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
 728   GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
 729 
 730   bool default_handler = false;
 731   for (; !handlers.is_done(); handlers.next()) {
 732     ciExceptionHandler* h        = handlers.handler();
 733     int                 h_bci    = h->handler_bci();
 734     ciInstanceKlass*    h_klass  = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
 735     // Do not introduce unloaded exception types into the graph:
 736     if (!h_klass->is_loaded()) {
 737       if (saw_unloaded->contains(h_bci)) {
 738         /* We've already seen an unloaded exception with h_bci,
 739            so don't duplicate. Duplication will cause the CatchNode to be
 740            unnecessarily large. See 4713716. */
 741         continue;
 742       } else {
 743         saw_unloaded->append(h_bci);
 744       }
 745     }
 746     const Type*         h_extype = TypeOopPtr::make_from_klass(h_klass);
 747     // (We use make_from_klass because it respects UseUniqueSubclasses.)
 748     h_extype = h_extype->join(TypeInstPtr::NOTNULL);
 749     assert(!h_extype->empty(), "sanity");
 750     // Note:  It's OK if the BCIs repeat themselves.
 751     bcis->append(h_bci);
 752     extypes->append(h_extype);
 753     if (h_bci == -1) {
 754       default_handler = true;
 755     }
 756   }
 757 
 758   if (!default_handler) {
 759     bcis->append(-1);
 760     extypes->append(TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr());
 761   }
 762 
 763   int len = bcis->length();
 764   CatchNode *cn = new CatchNode(control(), i_o, len+1);
 765   Node *catch_ = _gvn.transform(cn);
 766 
 767   // now branch with the exception state to each of the (potential)
 768   // handlers
 769   for(int i=0; i < len; i++) {
 770     // Setup JVM state to enter the handler.
 771     PreserveJVMState pjvms(this);
 772     // Locals are just copied from before the call.
 773     // Get control from the CatchNode.
 774     int handler_bci = bcis->at(i);
 775     Node* ctrl = _gvn.transform( new CatchProjNode(catch_, i+1,handler_bci));
 776     // This handler cannot happen?
 777     if (ctrl == top())  continue;
 778     set_control(ctrl);
 779 
 780     // Create exception oop
 781     const TypeInstPtr* extype = extypes->at(i)->is_instptr();
 782     Node *ex_oop = _gvn.transform(new CreateExNode(extypes->at(i), ctrl, i_o));
 783 
 784     // Handle unloaded exception classes.
 785     if (saw_unloaded->contains(handler_bci)) {
 786       // An unloaded exception type is coming here.  Do an uncommon trap.
 787 #ifndef PRODUCT
 788       // We do not expect the same handler bci to take both cold unloaded
 789       // and hot loaded exceptions.  But, watch for it.
 790       if ((Verbose || WizardMode) && extype->is_loaded()) {
 791         tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
 792         method()->print_name(); tty->cr();
 793       } else if (PrintOpto && (Verbose || WizardMode)) {
 794         tty->print("Bailing out on unloaded exception type ");
 795         extype->klass()->print_name();
 796         tty->print(" at bci:%d in ", bci());
 797         method()->print_name(); tty->cr();
 798       }
 799 #endif
 800       // Emit an uncommon trap instead of processing the block.
 801       set_bci(handler_bci);
 802       push_ex_oop(ex_oop);
 803       uncommon_trap(Deoptimization::Reason_unloaded,
 804                     Deoptimization::Action_reinterpret,
 805                     extype->klass(), "!loaded exception");
 806       set_bci(iter().cur_bci()); // put it back
 807       continue;
 808     }
 809 
 810     // go to the exception handler
 811     if (handler_bci < 0) {     // merge with corresponding rethrow node
 812       throw_to_exit(make_exception_state(ex_oop));
 813     } else {                      // Else jump to corresponding handle
 814       push_ex_oop(ex_oop);        // Clear stack and push just the oop.
 815       merge_exception(handler_bci);
 816     }
 817   }
 818 
 819   // The first CatchProj is for the normal return.
 820   // (Note:  If this is a call to rethrow_Java, this node goes dead.)
 821   set_control(_gvn.transform( new CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
 822 }
 823 
 824 
 825 //----------------------------catch_inline_exceptions--------------------------
 826 // Handle all exceptions thrown by an inlined method or individual bytecode.
 827 // Common case 1: we have no handler, so all exceptions merge right into
 828 // the rethrow case.
 829 // Case 2: we have some handlers, with loaded exception klasses that have
 830 // no subklasses.  We do a Deutsch-Shiffman style type-check on the incoming
 831 // exception oop and branch to the handler directly.
 832 // Case 3: We have some handlers with subklasses or are not loaded at
 833 // compile-time.  We have to call the runtime to resolve the exception.
 834 // So we insert a RethrowCall and all the logic that goes with it.
 835 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
 836   // Caller is responsible for saving away the map for normal control flow!
 837   assert(stopped(), "call set_map(NULL) first");
 838   assert(method()->has_exception_handlers(), "don't come here w/o work to do");
 839 
 840   Node* ex_node = saved_ex_oop(ex_map);
 841   if (ex_node == top()) {
 842     // No action needed.
 843     return;
 844   }
 845   const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
 846   NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
 847   if (ex_type == NULL)
 848     ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
 849 
 850   // determine potential exception handlers
 851   ciExceptionHandlerStream handlers(method(), bci(),
 852                                     ex_type->klass()->as_instance_klass(),
 853                                     ex_type->klass_is_exact());
 854 
 855   // Start executing from the given throw state.  (Keep its stack, for now.)
 856   // Get the exception oop as known at compile time.
 857   ex_node = use_exception_state(ex_map);
 858 
 859   // Get the exception oop klass from its header
 860   Node* ex_klass_node = NULL;
 861   if (has_ex_handler() && !ex_type->klass_is_exact()) {
 862     Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
 863     ex_klass_node = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 864 
 865     // Compute the exception klass a little more cleverly.
 866     // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
 867     // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
 868     // each arm of the Phi.  If I know something clever about the exceptions
 869     // I'm loading the class from, I can replace the LoadKlass with the
 870     // klass constant for the exception oop.
 871     if (ex_node->is_Phi()) {
 872       ex_klass_node = new PhiNode(ex_node->in(0), TypeKlassPtr::OBJECT);
 873       for (uint i = 1; i < ex_node->req(); i++) {
 874         Node* ex_in = ex_node->in(i);
 875         if (ex_in == top() || ex_in == NULL) {
 876           // This path was not taken.
 877           ex_klass_node->init_req(i, top());
 878           continue;
 879         }
 880         Node* p = basic_plus_adr(ex_in, ex_in, oopDesc::klass_offset_in_bytes());
 881         Node* k = _gvn.transform( LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 882         ex_klass_node->init_req( i, k );
 883       }
 884       _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
 885 
 886     }
 887   }
 888 
 889   // Scan the exception table for applicable handlers.
 890   // If none, we can call rethrow() and be done!
 891   // If precise (loaded with no subklasses), insert a D.S. style
 892   // pointer compare to the correct handler and loop back.
 893   // If imprecise, switch to the Rethrow VM-call style handling.
 894 
 895   int remaining = handlers.count_remaining();
 896 
 897   // iterate through all entries sequentially
 898   for (;!handlers.is_done(); handlers.next()) {
 899     ciExceptionHandler* handler = handlers.handler();
 900 
 901     if (handler->is_rethrow()) {
 902       // If we fell off the end of the table without finding an imprecise
 903       // exception klass (and without finding a generic handler) then we
 904       // know this exception is not handled in this method.  We just rethrow
 905       // the exception into the caller.
 906       throw_to_exit(make_exception_state(ex_node));
 907       return;
 908     }
 909 
 910     // exception handler bci range covers throw_bci => investigate further
 911     int handler_bci = handler->handler_bci();
 912 
 913     if (remaining == 1) {
 914       push_ex_oop(ex_node);        // Push exception oop for handler
 915       if (PrintOpto && WizardMode) {
 916         tty->print_cr("  Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
 917       }
 918       merge_exception(handler_bci); // jump to handler
 919       return;                   // No more handling to be done here!
 920     }
 921 
 922     // Get the handler's klass
 923     ciInstanceKlass* klass = handler->catch_klass();
 924 
 925     if (!klass->is_loaded()) {  // klass is not loaded?
 926       // fall through into catch_call_exceptions which will emit a
 927       // handler with an uncommon trap.
 928       break;
 929     }
 930 
 931     if (klass->is_interface())  // should not happen, but...
 932       break;                    // bail out
 933 
 934     // Check the type of the exception against the catch type
 935     const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
 936     Node* con = _gvn.makecon(tk);
 937     Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
 938     if (!stopped()) {
 939       PreserveJVMState pjvms(this);
 940       const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
 941       assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
 942       Node* ex_oop = _gvn.transform(new CheckCastPPNode(control(), ex_node, tinst));
 943       push_ex_oop(ex_oop);      // Push exception oop for handler
 944       if (PrintOpto && WizardMode) {
 945         tty->print("  Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
 946         klass->print_name();
 947         tty->cr();
 948       }
 949       merge_exception(handler_bci);
 950     }
 951     set_control(not_subtype_ctrl);
 952 
 953     // Come here if exception does not match handler.
 954     // Carry on with more handler checks.
 955     --remaining;
 956   }
 957 
 958   assert(!stopped(), "you should return if you finish the chain");
 959 
 960   // Oops, need to call into the VM to resolve the klasses at runtime.
 961   // Note:  This call must not deoptimize, since it is not a real at this bci!
 962   kill_dead_locals();
 963 
 964   make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
 965                     OptoRuntime::rethrow_Type(),
 966                     OptoRuntime::rethrow_stub(),
 967                     NULL, NULL,
 968                     ex_node);
 969 
 970   // Rethrow is a pure call, no side effects, only a result.
 971   // The result cannot be allocated, so we use I_O
 972 
 973   // Catch exceptions from the rethrow
 974   catch_call_exceptions(handlers);
 975 }
 976 
 977 
 978 // (Note:  Moved add_debug_info into GraphKit::add_safepoint_edges.)
 979 
 980 
 981 #ifndef PRODUCT
 982 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
 983   if( CountCompiledCalls ) {
 984     if( at_method_entry ) {
 985       // bump invocation counter if top method (for statistics)
 986       if (CountCompiledCalls && depth() == 1) {
 987         const TypePtr* addr_type = TypeMetadataPtr::make(method());
 988         Node* adr1 = makecon(addr_type);
 989         Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
 990         increment_counter(adr2);
 991       }
 992     } else if (is_inline) {
 993       switch (bc()) {
 994       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
 995       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
 996       case Bytecodes::_invokestatic:
 997       case Bytecodes::_invokedynamic:
 998       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
 999       default: fatal("unexpected call bytecode");
1000       }
1001     } else {
1002       switch (bc()) {
1003       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
1004       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
1005       case Bytecodes::_invokestatic:
1006       case Bytecodes::_invokedynamic:
1007       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_static_calls_addr()); break;
1008       default: fatal("unexpected call bytecode");
1009       }
1010     }
1011   }
1012 }
1013 #endif //PRODUCT
1014 
1015 
1016 ciMethod* Compile::optimize_virtual_call(ciMethod* caller, int bci, ciInstanceKlass* klass,
1017                                          ciKlass* holder, ciMethod* callee,
1018                                          const TypeOopPtr* receiver_type, bool is_virtual,
1019                                          bool& call_does_dispatch, int& vtable_index,
1020                                          bool check_access) {
1021   // Set default values for out-parameters.
1022   call_does_dispatch = true;
1023   vtable_index       = Method::invalid_vtable_index;
1024 
1025   // Choose call strategy.
1026   ciMethod* optimized_virtual_method = optimize_inlining(caller, bci, klass, callee,
1027                                                          receiver_type, check_access);
1028 
1029   // Have the call been sufficiently improved such that it is no longer a virtual?
1030   if (optimized_virtual_method != NULL) {
1031     callee             = optimized_virtual_method;
1032     call_does_dispatch = false;
1033   } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
1034     // We can make a vtable call at this site
1035     vtable_index = callee->resolve_vtable_index(caller->holder(), holder);
1036   }
1037   return callee;
1038 }
1039 
1040 // Identify possible target method and inlining style
1041 ciMethod* Compile::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
1042                                      ciMethod* callee, const TypeOopPtr* receiver_type,
1043                                      bool check_access) {
1044   // only use for virtual or interface calls
1045 
1046   // If it is obviously final, do not bother to call find_monomorphic_target,
1047   // because the class hierarchy checks are not needed, and may fail due to
1048   // incompletely loaded classes.  Since we do our own class loading checks
1049   // in this module, we may confidently bind to any method.
1050   if (callee->can_be_statically_bound()) {
1051     return callee;
1052   }
1053 
1054   // Attempt to improve the receiver
1055   bool actual_receiver_is_exact = false;
1056   ciInstanceKlass* actual_receiver = klass;
1057   if (receiver_type != NULL) {
1058     // Array methods are all inherited from Object, and are monomorphic.
1059     // finalize() call on array is not allowed.
1060     if (receiver_type->isa_aryptr() &&
1061         callee->holder() == env()->Object_klass() &&
1062         callee->name() != ciSymbol::finalize_method_name()) {
1063       return callee;
1064     }
1065 
1066     // All other interesting cases are instance klasses.
1067     if (!receiver_type->isa_instptr()) {
1068       return NULL;
1069     }
1070 
1071     ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
1072     if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
1073         (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
1074       // ikl is a same or better type than the original actual_receiver,
1075       // e.g. static receiver from bytecodes.
1076       actual_receiver = ikl;
1077       // Is the actual_receiver exact?
1078       actual_receiver_is_exact = receiver_type->klass_is_exact();
1079     }
1080   }
1081 
1082   ciInstanceKlass*   calling_klass = caller->holder();
1083   ciMethod* cha_monomorphic_target = callee->find_monomorphic_target(calling_klass, klass, actual_receiver, check_access);
1084   if (cha_monomorphic_target != NULL) {
1085     assert(!cha_monomorphic_target->is_abstract(), "");
1086     // Look at the method-receiver type.  Does it add "too much information"?
1087     ciKlass*    mr_klass = cha_monomorphic_target->holder();
1088     const Type* mr_type  = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
1089     if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
1090       // Calling this method would include an implicit cast to its holder.
1091       // %%% Not yet implemented.  Would throw minor asserts at present.
1092       // %%% The most common wins are already gained by +UseUniqueSubclasses.
1093       // To fix, put the higher_equal check at the call of this routine,
1094       // and add a CheckCastPP to the receiver.
1095       if (TraceDependencies) {
1096         tty->print_cr("found unique CHA method, but could not cast up");
1097         tty->print("  method  = ");
1098         cha_monomorphic_target->print();
1099         tty->cr();
1100       }
1101       if (log() != NULL) {
1102         log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
1103                        log()->identify(klass),
1104                        log()->identify(cha_monomorphic_target));
1105       }
1106       cha_monomorphic_target = NULL;
1107     }
1108   }
1109   if (cha_monomorphic_target != NULL) {
1110     // Hardwiring a virtual.
1111     // If we inlined because CHA revealed only a single target method,
1112     // then we are dependent on that target method not getting overridden
1113     // by dynamic class loading.  Be sure to test the "static" receiver
1114     // dest_method here, as opposed to the actual receiver, which may
1115     // falsely lead us to believe that the receiver is final or private.
1116     dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
1117     return cha_monomorphic_target;
1118   }
1119 
1120   // If the type is exact, we can still bind the method w/o a vcall.
1121   // (This case comes after CHA so we can see how much extra work it does.)
1122   if (actual_receiver_is_exact) {
1123     // In case of evolution, there is a dependence on every inlined method, since each
1124     // such method can be changed when its class is redefined.
1125     ciMethod* exact_method = callee->resolve_invoke(calling_klass, actual_receiver);
1126     if (exact_method != NULL) {
1127       if (PrintOpto) {
1128         tty->print("  Calling method via exact type @%d --- ", bci);
1129         exact_method->print_name();
1130         tty->cr();
1131       }
1132       return exact_method;
1133     }
1134   }
1135 
1136   return NULL;
1137 }