1 /*
   2  * Copyright (c) 1998, 2014, 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/cfgnode.hpp"
  35 #include "opto/mulnode.hpp"
  36 #include "opto/parse.hpp"
  37 #include "opto/rootnode.hpp"
  38 #include "opto/runtime.hpp"
  39 #include "opto/subnode.hpp"
  40 #include "prims/nativeLookup.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 void trace_type_profile(Compile* C, ciMethod *method, int depth, int bci, ciMethod *prof_method, ciKlass *prof_klass, int site_count, int receiver_count) {
  44   if (TraceTypeProfile || C->print_inlining()) {
  45     outputStream* out = tty;
  46     if (!C->print_inlining()) {
  47       if (NOT_PRODUCT(!PrintOpto &&) !PrintCompilation) {
  48         method->print_short_name();
  49         tty->cr();
  50       }
  51       CompileTask::print_inlining(prof_method, depth, bci);
  52     } else {
  53       out = C->print_inlining_stream();
  54     }
  55     CompileTask::print_inline_indent(depth, out);
  56     out->print(" \\-> TypeProfile (%d/%d counts) = ", receiver_count, site_count);
  57     stringStream ss;
  58     prof_klass->name()->print_symbol_on(&ss);
  59     out->print("%s", ss.as_string());
  60     out->cr();
  61   }
  62 }
  63 
  64 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_does_dispatch,
  65                                        JVMState* jvms, bool allow_inline,
  66                                        float prof_factor, ciKlass* speculative_receiver_type,
  67                                        bool allow_intrinsics, bool delayed_forbidden) {
  68   ciMethod*       caller   = jvms->method();
  69   int             bci      = jvms->bci();
  70   Bytecodes::Code bytecode = caller->java_code_at_bci(bci);
  71   guarantee(callee != NULL, "failed method resolution");
  72 
  73   // Dtrace currently doesn't work unless all calls are vanilla
  74   if (env()->dtrace_method_probes()) {
  75     allow_inline = false;
  76   }
  77 
  78   // Note: When we get profiling during stage-1 compiles, we want to pull
  79   // from more specific profile data which pertains to this inlining.
  80   // Right now, ignore the information in jvms->caller(), and do method[bci].
  81   ciCallProfile profile = caller->call_profile_at_bci(bci);
  82 
  83   // See how many times this site has been invoked.
  84   int site_count = profile.count();
  85   int receiver_count = -1;
  86   if (call_does_dispatch && UseTypeProfile && profile.has_receiver(0)) {
  87     // Receivers in the profile structure are ordered by call counts
  88     // so that the most called (major) receiver is profile.receiver(0).
  89     receiver_count = profile.receiver_count(0);
  90   }
  91 
  92   CompileLog* log = this->log();
  93   if (log != NULL) {
  94     int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1;
  95     int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1;
  96     log->begin_elem("call method='%d' count='%d' prof_factor='%g'",
  97                     log->identify(callee), site_count, prof_factor);
  98     if (call_does_dispatch)  log->print(" virtual='1'");
  99     if (allow_inline)     log->print(" inline='1'");
 100     if (receiver_count >= 0) {
 101       log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count);
 102       if (profile.has_receiver(1)) {
 103         log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1));
 104       }
 105     }
 106     log->end_elem();
 107   }
 108 
 109   // Special case the handling of certain common, profitable library
 110   // methods.  If these methods are replaced with specialized code,
 111   // then we return it as the inlined version of the call.
 112   // We do this before the strict f.p. check below because the
 113   // intrinsics handle strict f.p. correctly.
 114   CallGenerator* cg_intrinsic = NULL;
 115   if (allow_inline && allow_intrinsics) {
 116     CallGenerator* cg = find_intrinsic(callee, call_does_dispatch);
 117     if (cg != NULL) {
 118       if (cg->is_predicated()) {
 119         // Code without intrinsic but, hopefully, inlined.
 120         CallGenerator* inline_cg = this->call_generator(callee,
 121               vtable_index, call_does_dispatch, jvms, allow_inline, prof_factor, speculative_receiver_type, false);
 122         if (inline_cg != NULL) {
 123           cg = CallGenerator::for_predicated_intrinsic(cg, inline_cg);
 124         }
 125       }
 126 
 127       // If intrinsic does the virtual dispatch, we try to use the type profile
 128       // first, and hopefully inline it as the regular virtual call below.
 129       // We will retry the intrinsic if nothing had claimed it afterwards.
 130       if (cg->does_virtual_dispatch()) {
 131         cg_intrinsic = cg;
 132         cg = NULL;
 133       } else {
 134         return cg;
 135       }
 136     }
 137   }
 138 
 139   // Do method handle calls.
 140   // NOTE: This must happen before normal inlining logic below since
 141   // MethodHandle.invoke* are native methods which obviously don't
 142   // have bytecodes and so normal inlining fails.
 143   if (callee->is_method_handle_intrinsic()) {
 144     CallGenerator* cg = CallGenerator::for_method_handle_call(jvms, caller, callee, delayed_forbidden);
 145     assert(cg == NULL || !delayed_forbidden || !cg->is_late_inline() || cg->is_mh_late_inline(), "unexpected CallGenerator");
 146     return cg;
 147   }
 148 
 149   // Do not inline strict fp into non-strict code, or the reverse
 150   if (caller->is_strict() ^ callee->is_strict()) {
 151     allow_inline = false;
 152   }
 153 
 154   // Attempt to inline...
 155   if (allow_inline) {
 156     // The profile data is only partly attributable to this caller,
 157     // scale back the call site information.
 158     float past_uses = jvms->method()->scale_count(site_count, prof_factor);
 159     // This is the number of times we expect the call code to be used.
 160     float expected_uses = past_uses;
 161 
 162     // Try inlining a bytecoded method:
 163     if (!call_does_dispatch) {
 164       InlineTree* ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method());
 165       WarmCallInfo scratch_ci;
 166       bool should_delay = false;
 167       WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci, should_delay);
 168       assert(ci != &scratch_ci, "do not let this pointer escape");
 169       bool allow_inline   = (ci != NULL && !ci->is_cold());
 170       bool require_inline = (allow_inline && ci->is_hot());
 171 
 172       if (allow_inline) {
 173         CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses);
 174 
 175         if (require_inline && cg != NULL) {
 176           // Delay the inlining of this method to give us the
 177           // opportunity to perform some high level optimizations
 178           // first.
 179           if (should_delay_string_inlining(callee, jvms)) {
 180             assert(!delayed_forbidden, "strange");
 181             return CallGenerator::for_string_late_inline(callee, cg);
 182           } else if (should_delay_boxing_inlining(callee, jvms)) {
 183             assert(!delayed_forbidden, "strange");
 184             return CallGenerator::for_boxing_late_inline(callee, cg);
 185           } else if ((should_delay || AlwaysIncrementalInline) && !delayed_forbidden) {
 186             return CallGenerator::for_late_inline(callee, cg);
 187           }
 188         }
 189         if (cg == NULL || should_delay) {
 190           // Fall through.
 191         } else if (require_inline || !InlineWarmCalls) {
 192           return cg;
 193         } else {
 194           CallGenerator* cold_cg = call_generator(callee, vtable_index, call_does_dispatch, jvms, false, prof_factor);
 195           return CallGenerator::for_warm_call(ci, cold_cg, cg);
 196         }
 197       }
 198     }
 199 
 200     // Try using the type profile.
 201     if (call_does_dispatch && site_count > 0 && receiver_count > 0) {
 202       // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count.
 203       bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent);
 204       ciMethod* receiver_method = NULL;
 205 
 206       int morphism = profile.morphism();
 207       if (speculative_receiver_type != NULL) {
 208         // We have a speculative type, we should be able to resolve
 209         // the call. We do that before looking at the profiling at
 210         // this invoke because it may lead to bimorphic inlining which
 211         // a speculative type should help us avoid.
 212         receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 213                                                  speculative_receiver_type);
 214         if (receiver_method == NULL) {
 215           speculative_receiver_type = NULL;
 216         } else {
 217           morphism = 1;
 218         }
 219       }
 220       if (receiver_method == NULL &&
 221           (have_major_receiver || morphism == 1 ||
 222            (morphism == 2 && UseBimorphicInlining))) {
 223         // receiver_method = profile.method();
 224         // Profiles do not suggest methods now.  Look it up in the major receiver.
 225         receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 226                                                       profile.receiver(0));
 227       }
 228       if (receiver_method != NULL) {
 229         // The single majority receiver sufficiently outweighs the minority.
 230         CallGenerator* hit_cg = this->call_generator(receiver_method,
 231               vtable_index, !call_does_dispatch, jvms, allow_inline, prof_factor);
 232         if (hit_cg != NULL) {
 233           // Look up second receiver.
 234           CallGenerator* next_hit_cg = NULL;
 235           ciMethod* next_receiver_method = NULL;
 236           if (morphism == 2 && UseBimorphicInlining) {
 237             next_receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 238                                                                profile.receiver(1));
 239             if (next_receiver_method != NULL) {
 240               next_hit_cg = this->call_generator(next_receiver_method,
 241                                   vtable_index, !call_does_dispatch, jvms,
 242                                   allow_inline, prof_factor);
 243               if (next_hit_cg != NULL && !next_hit_cg->is_inline() &&
 244                   have_major_receiver && UseOnlyInlinedBimorphic) {
 245                   // Skip if we can't inline second receiver's method
 246                   next_hit_cg = NULL;
 247               }
 248             }
 249           }
 250           CallGenerator* miss_cg;
 251           Deoptimization::DeoptReason reason = morphism == 2 ?
 252                                     Deoptimization::Reason_bimorphic :
 253                                     (speculative_receiver_type == NULL ? Deoptimization::Reason_class_check : Deoptimization::Reason_speculate_class_check);
 254           if ((morphism == 1 || (morphism == 2 && next_hit_cg != NULL)) &&
 255               !too_many_traps(jvms->method(), jvms->bci(), reason)
 256              ) {
 257             // Generate uncommon trap for class check failure path
 258             // in case of monomorphic or bimorphic virtual call site.
 259             miss_cg = CallGenerator::for_uncommon_trap(callee, reason,
 260                         Deoptimization::Action_maybe_recompile);
 261           } else {
 262             // Generate virtual call for class check failure path
 263             // in case of polymorphic virtual call site.
 264             miss_cg = CallGenerator::for_virtual_call(callee, vtable_index);
 265           }
 266           if (miss_cg != NULL) {
 267             if (next_hit_cg != NULL) {
 268               assert(speculative_receiver_type == NULL, "shouldn't end up here if we used speculation");
 269               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1));
 270               // We don't need to record dependency on a receiver here and below.
 271               // Whenever we inline, the dependency is added by Parse::Parse().
 272               miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX);
 273             }
 274             if (miss_cg != NULL) {
 275               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count);
 276               ciKlass* k = speculative_receiver_type != NULL ? speculative_receiver_type : profile.receiver(0);
 277               float hit_prob = speculative_receiver_type != NULL ? 1.0 : profile.receiver_prob(0);
 278               CallGenerator* cg = CallGenerator::for_predicted_call(k, miss_cg, hit_cg, hit_prob);
 279               if (cg != NULL)  return cg;
 280             }
 281           }
 282         }
 283       }
 284     }
 285   }
 286 
 287   // Nothing claimed the intrinsic, we go with straight-forward inlining
 288   // for already discovered intrinsic.
 289   if (allow_inline && allow_intrinsics && cg_intrinsic != NULL) {
 290     assert(cg_intrinsic->does_virtual_dispatch(), "sanity");
 291     return cg_intrinsic;
 292   }
 293 
 294   // There was no special inlining tactic, or it bailed out.
 295   // Use a more generic tactic, like a simple call.
 296   if (call_does_dispatch) {
 297     return CallGenerator::for_virtual_call(callee, vtable_index);
 298   } else {
 299     // Class Hierarchy Analysis or Type Profile reveals a unique target,
 300     // or it is a static or special call.
 301     return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms));
 302   }
 303 }
 304 
 305 // Return true for methods that shouldn't be inlined early so that
 306 // they are easier to analyze and optimize as intrinsics.
 307 bool Compile::should_delay_string_inlining(ciMethod* call_method, JVMState* jvms) {
 308   if (has_stringbuilder()) {
 309 
 310     if ((call_method->holder() == C->env()->StringBuilder_klass() ||
 311          call_method->holder() == C->env()->StringBuffer_klass()) &&
 312         (jvms->method()->holder() == C->env()->StringBuilder_klass() ||
 313          jvms->method()->holder() == C->env()->StringBuffer_klass())) {
 314       // Delay SB calls only when called from non-SB code
 315       return false;
 316     }
 317 
 318     switch (call_method->intrinsic_id()) {
 319       case vmIntrinsics::_StringBuilder_void:
 320       case vmIntrinsics::_StringBuilder_int:
 321       case vmIntrinsics::_StringBuilder_String:
 322       case vmIntrinsics::_StringBuilder_append_char:
 323       case vmIntrinsics::_StringBuilder_append_int:
 324       case vmIntrinsics::_StringBuilder_append_String:
 325       case vmIntrinsics::_StringBuilder_toString:
 326       case vmIntrinsics::_StringBuffer_void:
 327       case vmIntrinsics::_StringBuffer_int:
 328       case vmIntrinsics::_StringBuffer_String:
 329       case vmIntrinsics::_StringBuffer_append_char:
 330       case vmIntrinsics::_StringBuffer_append_int:
 331       case vmIntrinsics::_StringBuffer_append_String:
 332       case vmIntrinsics::_StringBuffer_toString:
 333       case vmIntrinsics::_Integer_toString:
 334         return true;
 335 
 336       case vmIntrinsics::_String_String:
 337         {
 338           Node* receiver = jvms->map()->in(jvms->argoff() + 1);
 339           if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) {
 340             CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava();
 341             ciMethod* m = csj->method();
 342             if (m != NULL &&
 343                 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
 344                  m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString))
 345               // Delay String.<init>(new SB())
 346               return true;
 347           }
 348           return false;
 349         }
 350 
 351       default:
 352         return false;
 353     }
 354   }
 355   return false;
 356 }
 357 
 358 bool Compile::should_delay_boxing_inlining(ciMethod* call_method, JVMState* jvms) {
 359   if (eliminate_boxing() && call_method->is_boxing_method()) {
 360     set_has_boxed_value(true);
 361     return aggressive_unboxing();
 362   }
 363   return false;
 364 }
 365 
 366 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link
 367 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) {
 368   // Additional inputs to consider...
 369   // bc      = bc()
 370   // caller  = method()
 371   // iter().get_method_holder_index()
 372   assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" );
 373   // Interface classes can be loaded & linked and never get around to
 374   // being initialized.  Uncommon-trap for not-initialized static or
 375   // v-calls.  Let interface calls happen.
 376   ciInstanceKlass* holder_klass = dest_method->holder();
 377   if (!holder_klass->is_being_initialized() &&
 378       !holder_klass->is_initialized() &&
 379       !holder_klass->is_interface()) {
 380     uncommon_trap(Deoptimization::Reason_uninitialized,
 381                   Deoptimization::Action_reinterpret,
 382                   holder_klass);
 383     return true;
 384   }
 385 
 386   assert(dest_method->is_loaded(), "dest_method: typeflow responsibility");
 387   return false;
 388 }
 389 
 390 
 391 //------------------------------do_call----------------------------------------
 392 // Handle your basic call.  Inline if we can & want to, else just setup call.
 393 void Parse::do_call() {
 394   // It's likely we are going to add debug info soon.
 395   // Also, if we inline a guy who eventually needs debug info for this JVMS,
 396   // our contribution to it is cleaned up right here.
 397   kill_dead_locals();
 398 
 399   // Set frequently used booleans
 400   const bool is_virtual = bc() == Bytecodes::_invokevirtual;
 401   const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface;
 402   const bool has_receiver = Bytecodes::has_receiver(bc());
 403 
 404   // Find target being called
 405   bool             will_link;
 406   ciSignature*     declared_signature = NULL;
 407   ciMethod*        orig_callee  = iter().get_method(will_link, &declared_signature);  // callee in the bytecode
 408   ciInstanceKlass* holder_klass = orig_callee->holder();
 409   ciKlass*         holder       = iter().get_declared_method_holder();
 410   ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder);
 411   assert(declared_signature != NULL, "cannot be null");
 412 
 413   // Bump max node limit for JSR292 users
 414   if (bc() == Bytecodes::_invokedynamic || orig_callee->is_method_handle_intrinsic()) {
 415     C->set_max_node_limit(3*MaxNodeLimit);
 416   }
 417 
 418   // uncommon-trap when callee is unloaded, uninitialized or will not link
 419   // bailout when too many arguments for register representation
 420   if (!will_link || can_not_compile_call_site(orig_callee, klass)) {
 421 #ifndef PRODUCT
 422     if (PrintOpto && (Verbose || WizardMode)) {
 423       method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci());
 424       orig_callee->print_name(); tty->cr();
 425     }
 426 #endif
 427     return;
 428   }
 429   assert(holder_klass->is_loaded(), "");
 430   //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc");  // XXX invokehandle (cur_bc_raw)
 431   // Note: this takes into account invokeinterface of methods declared in java/lang/Object,
 432   // which should be invokevirtuals but according to the VM spec may be invokeinterfaces
 433   assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc");
 434   // Note:  In the absence of miranda methods, an abstract class K can perform
 435   // an invokevirtual directly on an interface method I.m if K implements I.
 436 
 437   // orig_callee is the resolved callee which's signature includes the
 438   // appendix argument.
 439   const int nargs = orig_callee->arg_size();
 440   const bool is_signature_polymorphic = MethodHandles::is_signature_polymorphic(orig_callee->intrinsic_id());
 441 
 442   // Push appendix argument (MethodType, CallSite, etc.), if one.
 443   if (iter().has_appendix()) {
 444     ciObject* appendix_arg = iter().get_appendix();
 445     const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg);
 446     Node* appendix_arg_node = _gvn.makecon(appendix_arg_type);
 447     push(appendix_arg_node);
 448   }
 449 
 450   // ---------------------
 451   // Does Class Hierarchy Analysis reveal only a single target of a v-call?
 452   // Then we may inline or make a static call, but become dependent on there being only 1 target.
 453   // Does the call-site type profile reveal only one receiver?
 454   // Then we may introduce a run-time check and inline on the path where it succeeds.
 455   // The other path may uncommon_trap, check for another receiver, or do a v-call.
 456 
 457   // Try to get the most accurate receiver type
 458   ciMethod* callee             = orig_callee;
 459   int       vtable_index       = Method::invalid_vtable_index;
 460   bool      call_does_dispatch = false;
 461 
 462   // Speculative type of the receiver if any
 463   ciKlass* speculative_receiver_type = NULL;
 464   if (is_virtual_or_interface) {
 465     Node* receiver_node             = stack(sp() - nargs);
 466     const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr();
 467     // call_does_dispatch and vtable_index are out-parameters.  They might be changed.
 468     // For arrays, klass below is Object. When vtable calls are used,
 469     // resolving the call with Object would allow an illegal call to
 470     // finalize() on an array. We use holder instead: illegal calls to
 471     // finalize() won't be compiled as vtable calls (IC call
 472     // resolution will catch the illegal call) and the few legal calls
 473     // on array types won't be either.
 474     callee = C->optimize_virtual_call(method(), bci(), klass, holder, orig_callee,
 475                                       receiver_type, is_virtual,
 476                                       call_does_dispatch, vtable_index);  // out-parameters
 477     speculative_receiver_type = receiver_type != NULL ? receiver_type->speculative_type() : NULL;
 478   }
 479 
 480   // Note:  It's OK to try to inline a virtual call.
 481   // The call generator will not attempt to inline a polymorphic call
 482   // unless it knows how to optimize the receiver dispatch.
 483   bool try_inline = (C->do_inlining() || InlineAccessors);
 484 
 485   // ---------------------
 486   dec_sp(nargs);              // Temporarily pop args for JVM state of call
 487   JVMState* jvms = sync_jvms();
 488 
 489   // ---------------------
 490   // Decide call tactic.
 491   // This call checks with CHA, the interpreter profile, intrinsics table, etc.
 492   // It decides whether inlining is desirable or not.
 493   CallGenerator* cg = C->call_generator(callee, vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type);
 494 
 495   // NOTE:  Don't use orig_callee and callee after this point!  Use cg->method() instead.
 496   orig_callee = callee = NULL;
 497 
 498   // ---------------------
 499   // Round double arguments before call
 500   round_double_arguments(cg->method());
 501 
 502   // Feed profiling data for arguments to the type system so it can
 503   // propagate it as speculative types
 504   record_profiled_arguments_for_speculation(cg->method(), bc());
 505 
 506 #ifndef PRODUCT
 507   // bump global counters for calls
 508   count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
 509 
 510   // Record first part of parsing work for this call
 511   parse_histogram()->record_change();
 512 #endif // not PRODUCT
 513 
 514   assert(jvms == this->jvms(), "still operating on the right JVMS");
 515   assert(jvms_in_sync(),       "jvms must carry full info into CG");
 516 
 517   // save across call, for a subsequent cast_not_null.
 518   Node* receiver = has_receiver ? argument(0) : NULL;
 519 
 520   // The extra CheckCastPP for speculative types mess with PhaseStringOpts
 521   if (receiver != NULL && !call_does_dispatch && !cg->is_string_late_inline()) {
 522     // Feed profiling data for a single receiver to the type system so
 523     // it can propagate it as a speculative type
 524     receiver = record_profiled_receiver_for_speculation(receiver);
 525   }
 526 
 527   // Bump method data counters (We profile *before* the call is made
 528   // because exceptions don't return to the call site.)
 529   profile_call(receiver);
 530 
 531   JVMState* new_jvms = cg->generate(jvms);
 532   if (new_jvms == NULL) {
 533     // When inlining attempt fails (e.g., too many arguments),
 534     // it may contaminate the current compile state, making it
 535     // impossible to pull back and try again.  Once we call
 536     // cg->generate(), we are committed.  If it fails, the whole
 537     // compilation task is compromised.
 538     if (failing())  return;
 539 
 540     // This can happen if a library intrinsic is available, but refuses
 541     // the call site, perhaps because it did not match a pattern the
 542     // intrinsic was expecting to optimize. Should always be possible to
 543     // get a normal java call that may inline in that case
 544     cg = C->call_generator(cg->method(), vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type, /* allow_intrinsics= */ false);
 545     if ((new_jvms = cg->generate(jvms)) == NULL) {
 546       guarantee(failing(), "call failed to generate:  calls should work");
 547       return;
 548     }
 549   }
 550 
 551   if (cg->is_inline()) {
 552     // Accumulate has_loops estimate
 553     C->set_has_loops(C->has_loops() || cg->method()->has_loops());
 554     C->env()->notice_inlined_method(cg->method());
 555   }
 556 
 557   // Reset parser state from [new_]jvms, which now carries results of the call.
 558   // Return value (if any) is already pushed on the stack by the cg.
 559   add_exception_states_from(new_jvms);
 560   if (new_jvms->map()->control() == top()) {
 561     stop_and_kill_map();
 562   } else {
 563     assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
 564     set_jvms(new_jvms);
 565   }
 566 
 567   if (!stopped()) {
 568     // This was some sort of virtual call, which did a null check for us.
 569     // Now we can assert receiver-not-null, on the normal return path.
 570     if (receiver != NULL && cg->is_virtual()) {
 571       Node* cast = cast_not_null(receiver);
 572       // %%% assert(receiver == cast, "should already have cast the receiver");
 573     }
 574 
 575     // Round double result after a call from strict to non-strict code
 576     round_double_result(cg->method());
 577 
 578     ciType* rtype = cg->method()->return_type();
 579     ciType* ctype = declared_signature->return_type();
 580 
 581     if (Bytecodes::has_optional_appendix(iter().cur_bc_raw()) || is_signature_polymorphic) {
 582       // Be careful here with return types.
 583       if (ctype != rtype) {
 584         BasicType rt = rtype->basic_type();
 585         BasicType ct = ctype->basic_type();
 586         if (ct == T_VOID) {
 587           // It's OK for a method  to return a value that is discarded.
 588           // The discarding does not require any special action from the caller.
 589           // The Java code knows this, at VerifyType.isNullConversion.
 590           pop_node(rt);  // whatever it was, pop it
 591         } else if (rt == T_INT || is_subword_type(rt)) {
 592           // Nothing.  These cases are handled in lambda form bytecode.
 593           assert(ct == T_INT || is_subword_type(ct), err_msg_res("must match: rt=%s, ct=%s", type2name(rt), type2name(ct)));
 594         } else if (rt == T_OBJECT || rt == T_ARRAY) {
 595           assert(ct == T_OBJECT || ct == T_ARRAY, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
 596           if (ctype->is_loaded()) {
 597             const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
 598             const Type*       sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
 599             if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
 600               Node* retnode = pop();
 601               Node* cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(), retnode, sig_type));
 602               push(cast_obj);
 603             }
 604           }
 605         } else {
 606           assert(rt == ct, err_msg_res("unexpected mismatch: rt=%s, ct=%s", type2name(rt), type2name(ct)));
 607           // push a zero; it's better than getting an oop/int mismatch
 608           pop_node(rt);
 609           Node* retnode = zerocon(ct);
 610           push_node(ct, retnode);
 611         }
 612         // Now that the value is well-behaved, continue with the call-site type.
 613         rtype = ctype;
 614       }
 615     } else {
 616       // Symbolic resolution enforces the types to be the same.
 617       // NOTE: We must relax the assert for unloaded types because two
 618       // different ciType instances of the same unloaded class type
 619       // can appear to be "loaded" by different loaders (depending on
 620       // the accessing class).
 621       assert(!rtype->is_loaded() || !ctype->is_loaded() || rtype == ctype,
 622              err_msg_res("mismatched return types: rtype=%s, ctype=%s", rtype->name(), ctype->name()));
 623     }
 624 
 625     // If the return type of the method is not loaded, assert that the
 626     // value we got is a null.  Otherwise, we need to recompile.
 627     if (!rtype->is_loaded()) {
 628 #ifndef PRODUCT
 629       if (PrintOpto && (Verbose || WizardMode)) {
 630         method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
 631         cg->method()->print_name(); tty->cr();
 632       }
 633 #endif
 634       if (C->log() != NULL) {
 635         C->log()->elem("assert_null reason='return' klass='%d'",
 636                        C->log()->identify(rtype));
 637       }
 638       // If there is going to be a trap, put it at the next bytecode:
 639       set_bci(iter().next_bci());
 640       null_assert(peek());
 641       set_bci(iter().cur_bci()); // put it back
 642     }
 643     BasicType ct = ctype->basic_type();
 644     if (ct == T_OBJECT || ct == T_ARRAY) {
 645       ciKlass* better_type = method()->return_profiled_type(bci());
 646       if (UseTypeSpeculation && better_type != NULL) {
 647         // If profiling reports a single type for the return value,
 648         // feed it to the type system so it can propagate it as a
 649         // speculative type
 650         record_profile_for_speculation(stack(sp()-1), better_type);
 651       }
 652     }
 653   }
 654 
 655   // Restart record of parsing work after possible inlining of call
 656 #ifndef PRODUCT
 657   parse_histogram()->set_initial_state(bc());
 658 #endif
 659 }
 660 
 661 //---------------------------catch_call_exceptions-----------------------------
 662 // Put a Catch and CatchProj nodes behind a just-created call.
 663 // Send their caught exceptions to the proper handler.
 664 // This may be used after a call to the rethrow VM stub,
 665 // when it is needed to process unloaded exception classes.
 666 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
 667   // Exceptions are delivered through this channel:
 668   Node* i_o = this->i_o();
 669 
 670   // Add a CatchNode.
 671   GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
 672   GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
 673   GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
 674 
 675   for (; !handlers.is_done(); handlers.next()) {
 676     ciExceptionHandler* h        = handlers.handler();
 677     int                 h_bci    = h->handler_bci();
 678     ciInstanceKlass*    h_klass  = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
 679     // Do not introduce unloaded exception types into the graph:
 680     if (!h_klass->is_loaded()) {
 681       if (saw_unloaded->contains(h_bci)) {
 682         /* We've already seen an unloaded exception with h_bci,
 683            so don't duplicate. Duplication will cause the CatchNode to be
 684            unnecessarily large. See 4713716. */
 685         continue;
 686       } else {
 687         saw_unloaded->append(h_bci);
 688       }
 689     }
 690     const Type*         h_extype = TypeOopPtr::make_from_klass(h_klass);
 691     // (We use make_from_klass because it respects UseUniqueSubclasses.)
 692     h_extype = h_extype->join(TypeInstPtr::NOTNULL);
 693     assert(!h_extype->empty(), "sanity");
 694     // Note:  It's OK if the BCIs repeat themselves.
 695     bcis->append(h_bci);
 696     extypes->append(h_extype);
 697   }
 698 
 699   int len = bcis->length();
 700   CatchNode *cn = new (C) CatchNode(control(), i_o, len+1);
 701   Node *catch_ = _gvn.transform(cn);
 702 
 703   // now branch with the exception state to each of the (potential)
 704   // handlers
 705   for(int i=0; i < len; i++) {
 706     // Setup JVM state to enter the handler.
 707     PreserveJVMState pjvms(this);
 708     // Locals are just copied from before the call.
 709     // Get control from the CatchNode.
 710     int handler_bci = bcis->at(i);
 711     Node* ctrl = _gvn.transform( new (C) CatchProjNode(catch_, i+1,handler_bci));
 712     // This handler cannot happen?
 713     if (ctrl == top())  continue;
 714     set_control(ctrl);
 715 
 716     // Create exception oop
 717     const TypeInstPtr* extype = extypes->at(i)->is_instptr();
 718     Node *ex_oop = _gvn.transform(new (C) CreateExNode(extypes->at(i), ctrl, i_o));
 719 
 720     // Handle unloaded exception classes.
 721     if (saw_unloaded->contains(handler_bci)) {
 722       // An unloaded exception type is coming here.  Do an uncommon trap.
 723 #ifndef PRODUCT
 724       // We do not expect the same handler bci to take both cold unloaded
 725       // and hot loaded exceptions.  But, watch for it.
 726       if ((Verbose || WizardMode) && extype->is_loaded()) {
 727         tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
 728         method()->print_name(); tty->cr();
 729       } else if (PrintOpto && (Verbose || WizardMode)) {
 730         tty->print("Bailing out on unloaded exception type ");
 731         extype->klass()->print_name();
 732         tty->print(" at bci:%d in ", bci());
 733         method()->print_name(); tty->cr();
 734       }
 735 #endif
 736       // Emit an uncommon trap instead of processing the block.
 737       set_bci(handler_bci);
 738       push_ex_oop(ex_oop);
 739       uncommon_trap(Deoptimization::Reason_unloaded,
 740                     Deoptimization::Action_reinterpret,
 741                     extype->klass(), "!loaded exception");
 742       set_bci(iter().cur_bci()); // put it back
 743       continue;
 744     }
 745 
 746     // go to the exception handler
 747     if (handler_bci < 0) {     // merge with corresponding rethrow node
 748       throw_to_exit(make_exception_state(ex_oop));
 749     } else {                      // Else jump to corresponding handle
 750       push_ex_oop(ex_oop);        // Clear stack and push just the oop.
 751       merge_exception(handler_bci);
 752     }
 753   }
 754 
 755   // The first CatchProj is for the normal return.
 756   // (Note:  If this is a call to rethrow_Java, this node goes dead.)
 757   set_control(_gvn.transform( new (C) CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
 758 }
 759 
 760 
 761 //----------------------------catch_inline_exceptions--------------------------
 762 // Handle all exceptions thrown by an inlined method or individual bytecode.
 763 // Common case 1: we have no handler, so all exceptions merge right into
 764 // the rethrow case.
 765 // Case 2: we have some handlers, with loaded exception klasses that have
 766 // no subklasses.  We do a Deutsch-Shiffman style type-check on the incoming
 767 // exception oop and branch to the handler directly.
 768 // Case 3: We have some handlers with subklasses or are not loaded at
 769 // compile-time.  We have to call the runtime to resolve the exception.
 770 // So we insert a RethrowCall and all the logic that goes with it.
 771 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
 772   // Caller is responsible for saving away the map for normal control flow!
 773   assert(stopped(), "call set_map(NULL) first");
 774   assert(method()->has_exception_handlers(), "don't come here w/o work to do");
 775 
 776   Node* ex_node = saved_ex_oop(ex_map);
 777   if (ex_node == top()) {
 778     // No action needed.
 779     return;
 780   }
 781   const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
 782   NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
 783   if (ex_type == NULL)
 784     ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
 785 
 786   // determine potential exception handlers
 787   ciExceptionHandlerStream handlers(method(), bci(),
 788                                     ex_type->klass()->as_instance_klass(),
 789                                     ex_type->klass_is_exact());
 790 
 791   // Start executing from the given throw state.  (Keep its stack, for now.)
 792   // Get the exception oop as known at compile time.
 793   ex_node = use_exception_state(ex_map);
 794 
 795   // Get the exception oop klass from its header
 796   Node* ex_klass_node = NULL;
 797   if (has_ex_handler() && !ex_type->klass_is_exact()) {
 798     Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
 799     ex_klass_node = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 800 
 801     // Compute the exception klass a little more cleverly.
 802     // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
 803     // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
 804     // each arm of the Phi.  If I know something clever about the exceptions
 805     // I'm loading the class from, I can replace the LoadKlass with the
 806     // klass constant for the exception oop.
 807     if (ex_node->is_Phi()) {
 808       ex_klass_node = new (C) PhiNode(ex_node->in(0), TypeKlassPtr::OBJECT);
 809       for (uint i = 1; i < ex_node->req(); i++) {
 810         Node* ex_in = ex_node->in(i);
 811         if (ex_in == top() || ex_in == NULL) {
 812           // This path was not taken.
 813           ex_klass_node->init_req(i, top());
 814           continue;
 815         }
 816         Node* p = basic_plus_adr(ex_in, ex_in, oopDesc::klass_offset_in_bytes());
 817         Node* k = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT));
 818         ex_klass_node->init_req( i, k );
 819       }
 820       _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
 821 
 822     }
 823   }
 824 
 825   // Scan the exception table for applicable handlers.
 826   // If none, we can call rethrow() and be done!
 827   // If precise (loaded with no subklasses), insert a D.S. style
 828   // pointer compare to the correct handler and loop back.
 829   // If imprecise, switch to the Rethrow VM-call style handling.
 830 
 831   int remaining = handlers.count_remaining();
 832 
 833   // iterate through all entries sequentially
 834   for (;!handlers.is_done(); handlers.next()) {
 835     ciExceptionHandler* handler = handlers.handler();
 836 
 837     if (handler->is_rethrow()) {
 838       // If we fell off the end of the table without finding an imprecise
 839       // exception klass (and without finding a generic handler) then we
 840       // know this exception is not handled in this method.  We just rethrow
 841       // the exception into the caller.
 842       throw_to_exit(make_exception_state(ex_node));
 843       return;
 844     }
 845 
 846     // exception handler bci range covers throw_bci => investigate further
 847     int handler_bci = handler->handler_bci();
 848 
 849     if (remaining == 1) {
 850       push_ex_oop(ex_node);        // Push exception oop for handler
 851 #ifndef PRODUCT
 852       if (PrintOpto && WizardMode) {
 853         tty->print_cr("  Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
 854       }
 855 #endif
 856       merge_exception(handler_bci); // jump to handler
 857       return;                   // No more handling to be done here!
 858     }
 859 
 860     // Get the handler's klass
 861     ciInstanceKlass* klass = handler->catch_klass();
 862 
 863     if (!klass->is_loaded()) {  // klass is not loaded?
 864       // fall through into catch_call_exceptions which will emit a
 865       // handler with an uncommon trap.
 866       break;
 867     }
 868 
 869     if (klass->is_interface())  // should not happen, but...
 870       break;                    // bail out
 871 
 872     // Check the type of the exception against the catch type
 873     const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
 874     Node* con = _gvn.makecon(tk);
 875     Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
 876     if (!stopped()) {
 877       PreserveJVMState pjvms(this);
 878       const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
 879       assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
 880       Node* ex_oop = _gvn.transform(new (C) CheckCastPPNode(control(), ex_node, tinst));
 881       push_ex_oop(ex_oop);      // Push exception oop for handler
 882 #ifndef PRODUCT
 883       if (PrintOpto && WizardMode) {
 884         tty->print("  Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
 885         klass->print_name();
 886         tty->cr();
 887       }
 888 #endif
 889       merge_exception(handler_bci);
 890     }
 891     set_control(not_subtype_ctrl);
 892 
 893     // Come here if exception does not match handler.
 894     // Carry on with more handler checks.
 895     --remaining;
 896   }
 897 
 898   assert(!stopped(), "you should return if you finish the chain");
 899 
 900   // Oops, need to call into the VM to resolve the klasses at runtime.
 901   // Note:  This call must not deoptimize, since it is not a real at this bci!
 902   kill_dead_locals();
 903 
 904   make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
 905                     OptoRuntime::rethrow_Type(),
 906                     OptoRuntime::rethrow_stub(),
 907                     NULL, NULL,
 908                     ex_node);
 909 
 910   // Rethrow is a pure call, no side effects, only a result.
 911   // The result cannot be allocated, so we use I_O
 912 
 913   // Catch exceptions from the rethrow
 914   catch_call_exceptions(handlers);
 915 }
 916 
 917 
 918 // (Note:  Moved add_debug_info into GraphKit::add_safepoint_edges.)
 919 
 920 
 921 #ifndef PRODUCT
 922 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
 923   if( CountCompiledCalls ) {
 924     if( at_method_entry ) {
 925       // bump invocation counter if top method (for statistics)
 926       if (CountCompiledCalls && depth() == 1) {
 927         const TypePtr* addr_type = TypeMetadataPtr::make(method());
 928         Node* adr1 = makecon(addr_type);
 929         Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
 930         increment_counter(adr2);
 931       }
 932     } else if (is_inline) {
 933       switch (bc()) {
 934       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
 935       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
 936       case Bytecodes::_invokestatic:
 937       case Bytecodes::_invokedynamic:
 938       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
 939       default: fatal("unexpected call bytecode");
 940       }
 941     } else {
 942       switch (bc()) {
 943       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
 944       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
 945       case Bytecodes::_invokestatic:
 946       case Bytecodes::_invokedynamic:
 947       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_static_calls_addr()); break;
 948       default: fatal("unexpected call bytecode");
 949       }
 950     }
 951   }
 952 }
 953 #endif //PRODUCT
 954 
 955 
 956 ciMethod* Compile::optimize_virtual_call(ciMethod* caller, int bci, ciInstanceKlass* klass,
 957                                          ciKlass* holder, ciMethod* callee,
 958                                          const TypeOopPtr* receiver_type, bool is_virtual,
 959                                          bool& call_does_dispatch, int& vtable_index) {
 960   // Set default values for out-parameters.
 961   call_does_dispatch = true;
 962   vtable_index       = Method::invalid_vtable_index;
 963 
 964   // Choose call strategy.
 965   ciMethod* optimized_virtual_method = optimize_inlining(caller, bci, klass, callee, receiver_type);
 966 
 967   // Have the call been sufficiently improved such that it is no longer a virtual?
 968   if (optimized_virtual_method != NULL) {
 969     callee             = optimized_virtual_method;
 970     call_does_dispatch = false;
 971   } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
 972     // We can make a vtable call at this site
 973     vtable_index = callee->resolve_vtable_index(caller->holder(), holder);
 974   }
 975   return callee;
 976 }
 977 
 978 // Identify possible target method and inlining style
 979 ciMethod* Compile::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
 980                                      ciMethod* callee, const TypeOopPtr* receiver_type) {
 981   // only use for virtual or interface calls
 982 
 983   // If it is obviously final, do not bother to call find_monomorphic_target,
 984   // because the class hierarchy checks are not needed, and may fail due to
 985   // incompletely loaded classes.  Since we do our own class loading checks
 986   // in this module, we may confidently bind to any method.
 987   if (callee->can_be_statically_bound()) {
 988     return callee;
 989   }
 990 
 991   // Attempt to improve the receiver
 992   bool actual_receiver_is_exact = false;
 993   ciInstanceKlass* actual_receiver = klass;
 994   if (receiver_type != NULL) {
 995     // Array methods are all inherited from Object, and are monomorphic.
 996     // finalize() call on array is not allowed.
 997     if (receiver_type->isa_aryptr() &&
 998         callee->holder() == env()->Object_klass() &&
 999         callee->name() != ciSymbol::finalize_method_name()) {
1000       return callee;
1001     }
1002 
1003     // All other interesting cases are instance klasses.
1004     if (!receiver_type->isa_instptr()) {
1005       return NULL;
1006     }
1007 
1008     ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
1009     if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
1010         (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
1011       // ikl is a same or better type than the original actual_receiver,
1012       // e.g. static receiver from bytecodes.
1013       actual_receiver = ikl;
1014       // Is the actual_receiver exact?
1015       actual_receiver_is_exact = receiver_type->klass_is_exact();
1016     }
1017   }
1018 
1019   ciInstanceKlass*   calling_klass = caller->holder();
1020   ciMethod* cha_monomorphic_target = callee->find_monomorphic_target(calling_klass, klass, actual_receiver);
1021   if (cha_monomorphic_target != NULL) {
1022     assert(!cha_monomorphic_target->is_abstract(), "");
1023     // Look at the method-receiver type.  Does it add "too much information"?
1024     ciKlass*    mr_klass = cha_monomorphic_target->holder();
1025     const Type* mr_type  = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
1026     if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
1027       // Calling this method would include an implicit cast to its holder.
1028       // %%% Not yet implemented.  Would throw minor asserts at present.
1029       // %%% The most common wins are already gained by +UseUniqueSubclasses.
1030       // To fix, put the higher_equal check at the call of this routine,
1031       // and add a CheckCastPP to the receiver.
1032       if (TraceDependencies) {
1033         tty->print_cr("found unique CHA method, but could not cast up");
1034         tty->print("  method  = ");
1035         cha_monomorphic_target->print();
1036         tty->cr();
1037       }
1038       if (log() != NULL) {
1039         log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
1040                        log()->identify(klass),
1041                        log()->identify(cha_monomorphic_target));
1042       }
1043       cha_monomorphic_target = NULL;
1044     }
1045   }
1046   if (cha_monomorphic_target != NULL) {
1047     // Hardwiring a virtual.
1048     // If we inlined because CHA revealed only a single target method,
1049     // then we are dependent on that target method not getting overridden
1050     // by dynamic class loading.  Be sure to test the "static" receiver
1051     // dest_method here, as opposed to the actual receiver, which may
1052     // falsely lead us to believe that the receiver is final or private.
1053     dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
1054     return cha_monomorphic_target;
1055   }
1056 
1057   // If the type is exact, we can still bind the method w/o a vcall.
1058   // (This case comes after CHA so we can see how much extra work it does.)
1059   if (actual_receiver_is_exact) {
1060     // In case of evolution, there is a dependence on every inlined method, since each
1061     // such method can be changed when its class is redefined.
1062     ciMethod* exact_method = callee->resolve_invoke(calling_klass, actual_receiver);
1063     if (exact_method != NULL) {
1064 #ifndef PRODUCT
1065       if (PrintOpto) {
1066         tty->print("  Calling method via exact type @%d --- ", bci);
1067         exact_method->print_name();
1068         tty->cr();
1069       }
1070 #endif
1071       return exact_method;
1072     }
1073   }
1074 
1075   return NULL;
1076 }