1 /*
   2  * Copyright (c) 1998, 2012, 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(ciMethod *method, int depth, int bci, ciMethod *prof_method, ciKlass *prof_klass, int site_count, int receiver_count) {
  44   if (TraceTypeProfile || PrintInlining NOT_PRODUCT(|| PrintOptoInlining)) {
  45     if (!PrintInlining) {
  46       if (NOT_PRODUCT(!PrintOpto &&) !PrintCompilation) {
  47         method->print_short_name();
  48         tty->cr();
  49       }
  50       CompileTask::print_inlining(prof_method, depth, bci);
  51     }
  52     CompileTask::print_inline_indent(depth);
  53     tty->print(" \\-> TypeProfile (%d/%d counts) = ", receiver_count, site_count);
  54     prof_klass->name()->print_symbol();
  55     tty->cr();
  56   }
  57 }
  58 
  59 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_is_virtual,
  60                                        JVMState* jvms, bool allow_inline,
  61                                        float prof_factor, bool allow_intrinsics) {
  62   ciMethod*       caller   = jvms->method();
  63   int             bci      = jvms->bci();
  64   Bytecodes::Code bytecode = caller->java_code_at_bci(bci);
  65   guarantee(callee != NULL, "failed method resolution");
  66 
  67   // Dtrace currently doesn't work unless all calls are vanilla
  68   if (env()->dtrace_method_probes()) {
  69     allow_inline = false;
  70   }
  71 
  72   // Note: When we get profiling during stage-1 compiles, we want to pull
  73   // from more specific profile data which pertains to this inlining.
  74   // Right now, ignore the information in jvms->caller(), and do method[bci].
  75   ciCallProfile profile = caller->call_profile_at_bci(bci);
  76 
  77   // See how many times this site has been invoked.
  78   int site_count = profile.count();
  79   int receiver_count = -1;
  80   if (call_is_virtual && UseTypeProfile && profile.has_receiver(0)) {
  81     // Receivers in the profile structure are ordered by call counts
  82     // so that the most called (major) receiver is profile.receiver(0).
  83     receiver_count = profile.receiver_count(0);
  84   }
  85 
  86   CompileLog* log = this->log();
  87   if (log != NULL) {
  88     int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1;
  89     int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1;
  90     log->begin_elem("call method='%d' count='%d' prof_factor='%g'",
  91                     log->identify(callee), site_count, prof_factor);
  92     if (call_is_virtual)  log->print(" virtual='1'");
  93     if (allow_inline)     log->print(" inline='1'");
  94     if (receiver_count >= 0) {
  95       log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count);
  96       if (profile.has_receiver(1)) {
  97         log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1));
  98       }
  99     }
 100     log->end_elem();
 101   }
 102 
 103   // Special case the handling of certain common, profitable library
 104   // methods.  If these methods are replaced with specialized code,
 105   // then we return it as the inlined version of the call.
 106   // We do this before the strict f.p. check below because the
 107   // intrinsics handle strict f.p. correctly.
 108   if (allow_inline && allow_intrinsics) {
 109     CallGenerator* cg = find_intrinsic(callee, call_is_virtual);
 110     if (cg != NULL) {
 111       if (cg->is_predicted()) {
 112         // Code without intrinsic but, hopefully, inlined.
 113         CallGenerator* inline_cg = this->call_generator(callee,
 114               vtable_index, call_is_virtual, jvms, allow_inline, prof_factor, false);
 115         if (inline_cg != NULL) {
 116           cg = CallGenerator::for_predicted_intrinsic(cg, inline_cg);
 117         }
 118       }
 119       return cg;
 120     }
 121   }
 122 
 123   // Do method handle calls.
 124   // NOTE: This must happen before normal inlining logic below since
 125   // MethodHandle.invoke* are native methods which obviously don't
 126   // have bytecodes and so normal inlining fails.
 127   if (callee->is_method_handle_intrinsic()) {
 128     return CallGenerator::for_method_handle_call(jvms, caller, callee);
 129   }
 130 
 131   // Do not inline strict fp into non-strict code, or the reverse
 132   if (caller->is_strict() ^ callee->is_strict()) {
 133     allow_inline = false;
 134   }
 135 
 136   // Attempt to inline...
 137   if (allow_inline) {
 138     // The profile data is only partly attributable to this caller,
 139     // scale back the call site information.
 140     float past_uses = jvms->method()->scale_count(site_count, prof_factor);
 141     // This is the number of times we expect the call code to be used.
 142     float expected_uses = past_uses;
 143 
 144     // Try inlining a bytecoded method:
 145     if (!call_is_virtual) {
 146       InlineTree* ilt;
 147       if (UseOldInlining) {
 148         ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method());
 149       } else {
 150         // Make a disembodied, stateless ILT.
 151         // TO DO:  When UseOldInlining is removed, copy the ILT code elsewhere.
 152         float site_invoke_ratio = prof_factor;
 153         // Note:  ilt is for the root of this parse, not the present call site.
 154         ilt = new InlineTree(this, jvms->method(), jvms->caller(), site_invoke_ratio, MaxInlineLevel);
 155       }
 156       WarmCallInfo scratch_ci;
 157       if (!UseOldInlining)
 158         scratch_ci.init(jvms, callee, profile, prof_factor);
 159       WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci);
 160       assert(ci != &scratch_ci, "do not let this pointer escape");
 161       bool allow_inline   = (ci != NULL && !ci->is_cold());
 162       bool require_inline = (allow_inline && ci->is_hot());
 163 
 164       if (allow_inline) {
 165         CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses);
 166         if (require_inline && cg != NULL && should_delay_inlining(callee, jvms)) {
 167           // Delay the inlining of this method to give us the
 168           // opportunity to perform some high level optimizations
 169           // first.
 170           return CallGenerator::for_late_inline(callee, cg);
 171         }
 172         if (cg == NULL) {
 173           // Fall through.
 174         } else if (require_inline || !InlineWarmCalls) {
 175           return cg;
 176         } else {
 177           CallGenerator* cold_cg = call_generator(callee, vtable_index, call_is_virtual, jvms, false, prof_factor);
 178           return CallGenerator::for_warm_call(ci, cold_cg, cg);
 179         }
 180       }
 181     }
 182 
 183     // Try using the type profile.
 184     if (call_is_virtual && site_count > 0 && receiver_count > 0) {
 185       // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count.
 186       bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent);
 187       ciMethod* receiver_method = NULL;
 188       if (have_major_receiver || profile.morphism() == 1 ||
 189           (profile.morphism() == 2 && UseBimorphicInlining)) {
 190         // receiver_method = profile.method();
 191         // Profiles do not suggest methods now.  Look it up in the major receiver.
 192         receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 193                                                       profile.receiver(0));
 194       }
 195       if (receiver_method != NULL) {
 196         // The single majority receiver sufficiently outweighs the minority.
 197         CallGenerator* hit_cg = this->call_generator(receiver_method,
 198               vtable_index, !call_is_virtual, jvms, allow_inline, prof_factor);
 199         if (hit_cg != NULL) {
 200           // Look up second receiver.
 201           CallGenerator* next_hit_cg = NULL;
 202           ciMethod* next_receiver_method = NULL;
 203           if (profile.morphism() == 2 && UseBimorphicInlining) {
 204             next_receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 205                                                                profile.receiver(1));
 206             if (next_receiver_method != NULL) {
 207               next_hit_cg = this->call_generator(next_receiver_method,
 208                                   vtable_index, !call_is_virtual, jvms,
 209                                   allow_inline, prof_factor);
 210               if (next_hit_cg != NULL && !next_hit_cg->is_inline() &&
 211                   have_major_receiver && UseOnlyInlinedBimorphic) {
 212                   // Skip if we can't inline second receiver's method
 213                   next_hit_cg = NULL;
 214               }
 215             }
 216           }
 217           CallGenerator* miss_cg;
 218           Deoptimization::DeoptReason reason = (profile.morphism() == 2) ?
 219                                     Deoptimization::Reason_bimorphic :
 220                                     Deoptimization::Reason_class_check;
 221           if (( profile.morphism() == 1 ||
 222                (profile.morphism() == 2 && next_hit_cg != NULL) ) &&
 223               !too_many_traps(jvms->method(), jvms->bci(), reason)
 224              ) {
 225             // Generate uncommon trap for class check failure path
 226             // in case of monomorphic or bimorphic virtual call site.
 227             miss_cg = CallGenerator::for_uncommon_trap(callee, reason,
 228                         Deoptimization::Action_maybe_recompile);
 229           } else {
 230             // Generate virtual call for class check failure path
 231             // in case of polymorphic virtual call site.
 232             miss_cg = CallGenerator::for_virtual_call(callee, vtable_index);
 233           }
 234           if (miss_cg != NULL) {
 235             if (next_hit_cg != NULL) {
 236               trace_type_profile(jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1));
 237               // We don't need to record dependency on a receiver here and below.
 238               // Whenever we inline, the dependency is added by Parse::Parse().
 239               miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX);
 240             }
 241             if (miss_cg != NULL) {
 242               trace_type_profile(jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count);
 243               CallGenerator* cg = CallGenerator::for_predicted_call(profile.receiver(0), miss_cg, hit_cg, profile.receiver_prob(0));
 244               if (cg != NULL)  return cg;
 245             }
 246           }
 247         }
 248       }
 249     }
 250   }
 251 
 252   // There was no special inlining tactic, or it bailed out.
 253   // Use a more generic tactic, like a simple call.
 254   if (call_is_virtual) {
 255     return CallGenerator::for_virtual_call(callee, vtable_index);
 256   } else {
 257     // Class Hierarchy Analysis or Type Profile reveals a unique target,
 258     // or it is a static or special call.
 259     return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms));
 260   }
 261 }
 262 
 263 // Return true for methods that shouldn't be inlined early so that
 264 // they are easier to analyze and optimize as intrinsics.
 265 bool Compile::should_delay_inlining(ciMethod* call_method, JVMState* jvms) {
 266   if (has_stringbuilder()) {
 267 
 268     if ((call_method->holder() == C->env()->StringBuilder_klass() ||
 269          call_method->holder() == C->env()->StringBuffer_klass()) &&
 270         (jvms->method()->holder() == C->env()->StringBuilder_klass() ||
 271          jvms->method()->holder() == C->env()->StringBuffer_klass())) {
 272       // Delay SB calls only when called from non-SB code
 273       return false;
 274     }
 275 
 276     switch (call_method->intrinsic_id()) {
 277       case vmIntrinsics::_StringBuilder_void:
 278       case vmIntrinsics::_StringBuilder_int:
 279       case vmIntrinsics::_StringBuilder_String:
 280       case vmIntrinsics::_StringBuilder_append_char:
 281       case vmIntrinsics::_StringBuilder_append_int:
 282       case vmIntrinsics::_StringBuilder_append_String:
 283       case vmIntrinsics::_StringBuilder_toString:
 284       case vmIntrinsics::_StringBuffer_void:
 285       case vmIntrinsics::_StringBuffer_int:
 286       case vmIntrinsics::_StringBuffer_String:
 287       case vmIntrinsics::_StringBuffer_append_char:
 288       case vmIntrinsics::_StringBuffer_append_int:
 289       case vmIntrinsics::_StringBuffer_append_String:
 290       case vmIntrinsics::_StringBuffer_toString:
 291       case vmIntrinsics::_Integer_toString:
 292         return true;
 293 
 294       case vmIntrinsics::_String_String:
 295         {
 296           Node* receiver = jvms->map()->in(jvms->argoff() + 1);
 297           if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) {
 298             CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava();
 299             ciMethod* m = csj->method();
 300             if (m != NULL &&
 301                 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
 302                  m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString))
 303               // Delay String.<init>(new SB())
 304               return true;
 305           }
 306           return false;
 307         }
 308 
 309       default:
 310         return false;
 311     }
 312   }
 313   return false;
 314 }
 315 
 316 
 317 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link
 318 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) {
 319   // Additional inputs to consider...
 320   // bc      = bc()
 321   // caller  = method()
 322   // iter().get_method_holder_index()
 323   assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" );
 324   // Interface classes can be loaded & linked and never get around to
 325   // being initialized.  Uncommon-trap for not-initialized static or
 326   // v-calls.  Let interface calls happen.
 327   ciInstanceKlass* holder_klass = dest_method->holder();
 328   if (!holder_klass->is_being_initialized() &&
 329       !holder_klass->is_initialized() &&
 330       !holder_klass->is_interface()) {
 331     uncommon_trap(Deoptimization::Reason_uninitialized,
 332                   Deoptimization::Action_reinterpret,
 333                   holder_klass);
 334     return true;
 335   }
 336 
 337   assert(dest_method->is_loaded(), "dest_method: typeflow responsibility");
 338   return false;
 339 }
 340 
 341 
 342 //------------------------------do_call----------------------------------------
 343 // Handle your basic call.  Inline if we can & want to, else just setup call.
 344 void Parse::do_call() {
 345   // It's likely we are going to add debug info soon.
 346   // Also, if we inline a guy who eventually needs debug info for this JVMS,
 347   // our contribution to it is cleaned up right here.
 348   kill_dead_locals();
 349 
 350   // Set frequently used booleans
 351   const bool is_virtual = bc() == Bytecodes::_invokevirtual;
 352   const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface;
 353   const bool has_receiver = Bytecodes::has_receiver(bc());
 354 
 355   // Find target being called
 356   bool             will_link;
 357   ciSignature*     declared_signature = NULL;
 358   ciMethod*        orig_callee  = iter().get_method(will_link, &declared_signature);  // callee in the bytecode
 359   ciInstanceKlass* holder_klass = orig_callee->holder();
 360   ciKlass*         holder       = iter().get_declared_method_holder();
 361   ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder);
 362   assert(declared_signature != NULL, "cannot be null");
 363 
 364   // uncommon-trap when callee is unloaded, uninitialized or will not link
 365   // bailout when too many arguments for register representation
 366   if (!will_link || can_not_compile_call_site(orig_callee, klass)) {
 367 #ifndef PRODUCT
 368     if (PrintOpto && (Verbose || WizardMode)) {
 369       method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci());
 370       orig_callee->print_name(); tty->cr();
 371     }
 372 #endif
 373     return;
 374   }
 375   assert(holder_klass->is_loaded(), "");
 376   //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc");  // XXX invokehandle (cur_bc_raw)
 377   // Note: this takes into account invokeinterface of methods declared in java/lang/Object,
 378   // which should be invokevirtuals but according to the VM spec may be invokeinterfaces
 379   assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc");
 380   // Note:  In the absence of miranda methods, an abstract class K can perform
 381   // an invokevirtual directly on an interface method I.m if K implements I.
 382 
 383   // orig_callee is the resolved callee which's signature includes the
 384   // appendix argument.
 385   const int nargs = orig_callee->arg_size();
 386 
 387   // Push appendix argument (MethodType, CallSite, etc.), if one.
 388   if (iter().has_appendix()) {
 389     ciObject* appendix_arg = iter().get_appendix();
 390     const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg);
 391     Node* appendix_arg_node = _gvn.makecon(appendix_arg_type);
 392     push(appendix_arg_node);
 393   }
 394 
 395   // ---------------------
 396   // Does Class Hierarchy Analysis reveal only a single target of a v-call?
 397   // Then we may inline or make a static call, but become dependent on there being only 1 target.
 398   // Does the call-site type profile reveal only one receiver?
 399   // Then we may introduce a run-time check and inline on the path where it succeeds.
 400   // The other path may uncommon_trap, check for another receiver, or do a v-call.
 401 
 402   // Choose call strategy.
 403   bool call_is_virtual = is_virtual_or_interface;
 404   int vtable_index = Method::invalid_vtable_index;
 405   ciMethod* callee = orig_callee;
 406 
 407   // Try to get the most accurate receiver type
 408   if (is_virtual_or_interface) {
 409     Node*             receiver_node = stack(sp() - nargs);
 410     const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr();
 411     ciMethod* optimized_virtual_method = optimize_inlining(method(), bci(), klass, orig_callee, receiver_type);
 412 
 413     // Have the call been sufficiently improved such that it is no longer a virtual?
 414     if (optimized_virtual_method != NULL) {
 415       callee          = optimized_virtual_method;
 416       call_is_virtual = false;
 417     } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
 418       // We can make a vtable call at this site
 419       vtable_index = callee->resolve_vtable_index(method()->holder(), klass);
 420     }
 421   }
 422 
 423   // Note:  It's OK to try to inline a virtual call.
 424   // The call generator will not attempt to inline a polymorphic call
 425   // unless it knows how to optimize the receiver dispatch.
 426   bool try_inline = (C->do_inlining() || InlineAccessors);
 427 
 428   // ---------------------
 429   dec_sp(nargs);              // Temporarily pop args for JVM state of call
 430   JVMState* jvms = sync_jvms();
 431 
 432   // ---------------------
 433   // Decide call tactic.
 434   // This call checks with CHA, the interpreter profile, intrinsics table, etc.
 435   // It decides whether inlining is desirable or not.
 436   CallGenerator* cg = C->call_generator(callee, vtable_index, call_is_virtual, jvms, try_inline, prof_factor());
 437 
 438   // NOTE:  Don't use orig_callee and callee after this point!  Use cg->method() instead.
 439   orig_callee = callee = NULL;
 440 
 441   // ---------------------
 442   // Round double arguments before call
 443   round_double_arguments(cg->method());
 444 
 445 #ifndef PRODUCT
 446   // bump global counters for calls
 447   count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
 448 
 449   // Record first part of parsing work for this call
 450   parse_histogram()->record_change();
 451 #endif // not PRODUCT
 452 
 453   assert(jvms == this->jvms(), "still operating on the right JVMS");
 454   assert(jvms_in_sync(),       "jvms must carry full info into CG");
 455 
 456   // save across call, for a subsequent cast_not_null.
 457   Node* receiver = has_receiver ? argument(0) : NULL;
 458 
 459   // Bump method data counters (We profile *before* the call is made
 460   // because exceptions don't return to the call site.)
 461   profile_call(receiver);
 462 
 463   JVMState* new_jvms = cg->generate(jvms);
 464   if (new_jvms == NULL) {
 465     // When inlining attempt fails (e.g., too many arguments),
 466     // it may contaminate the current compile state, making it
 467     // impossible to pull back and try again.  Once we call
 468     // cg->generate(), we are committed.  If it fails, the whole
 469     // compilation task is compromised.
 470     if (failing())  return;
 471 
 472     // This can happen if a library intrinsic is available, but refuses
 473     // the call site, perhaps because it did not match a pattern the
 474     // intrinsic was expecting to optimize. Should always be possible to
 475     // get a normal java call that may inline in that case
 476     cg = C->call_generator(cg->method(), vtable_index, call_is_virtual, jvms, try_inline, prof_factor(), /* allow_intrinsics= */ false);
 477     if ((new_jvms = cg->generate(jvms)) == NULL) {
 478       guarantee(failing(), "call failed to generate:  calls should work");
 479       return;
 480     }
 481   }
 482 
 483   if (cg->is_inline()) {
 484     // Accumulate has_loops estimate
 485     C->set_has_loops(C->has_loops() || cg->method()->has_loops());
 486     C->env()->notice_inlined_method(cg->method());
 487   }
 488 
 489   // Reset parser state from [new_]jvms, which now carries results of the call.
 490   // Return value (if any) is already pushed on the stack by the cg.
 491   add_exception_states_from(new_jvms);
 492   if (new_jvms->map()->control() == top()) {
 493     stop_and_kill_map();
 494   } else {
 495     assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
 496     set_jvms(new_jvms);
 497   }
 498 
 499   if (!stopped()) {
 500     // This was some sort of virtual call, which did a null check for us.
 501     // Now we can assert receiver-not-null, on the normal return path.
 502     if (receiver != NULL && cg->is_virtual()) {
 503       Node* cast = cast_not_null(receiver);
 504       // %%% assert(receiver == cast, "should already have cast the receiver");
 505     }
 506 
 507     // Round double result after a call from strict to non-strict code
 508     round_double_result(cg->method());
 509 
 510     ciType* rtype = cg->method()->return_type();
 511     if (Bytecodes::has_optional_appendix(iter().cur_bc_raw())) {
 512       // Be careful here with return types.
 513       ciType* ctype = declared_signature->return_type();
 514       if (ctype != rtype) {
 515         BasicType rt = rtype->basic_type();
 516         BasicType ct = ctype->basic_type();
 517         Node* retnode = peek();
 518         if (ct == T_VOID) {
 519           // It's OK for a method  to return a value that is discarded.
 520           // The discarding does not require any special action from the caller.
 521           // The Java code knows this, at VerifyType.isNullConversion.
 522           pop_node(rt);  // whatever it was, pop it
 523           retnode = top();
 524         } else if (rt == T_INT || is_subword_type(rt)) {
 525           // FIXME: This logic should be factored out.
 526           if (ct == T_BOOLEAN) {
 527             retnode = _gvn.transform( new (C) AndINode(retnode, intcon(0x1)) );
 528           } else if (ct == T_CHAR) {
 529             retnode = _gvn.transform( new (C) AndINode(retnode, intcon(0xFFFF)) );
 530           } else if (ct == T_BYTE) {
 531             retnode = _gvn.transform( new (C) LShiftINode(retnode, intcon(24)) );
 532             retnode = _gvn.transform( new (C) RShiftINode(retnode, intcon(24)) );
 533           } else if (ct == T_SHORT) {
 534             retnode = _gvn.transform( new (C) LShiftINode(retnode, intcon(16)) );
 535             retnode = _gvn.transform( new (C) RShiftINode(retnode, intcon(16)) );
 536           } else {
 537             assert(ct == T_INT, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
 538           }
 539         } else if (rt == T_OBJECT || rt == T_ARRAY) {
 540           assert(ct == T_OBJECT || ct == T_ARRAY, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
 541           if (ctype->is_loaded()) {
 542             const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
 543             const Type*       sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
 544             if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
 545               Node* cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(), retnode, sig_type));
 546               pop();
 547               push(cast_obj);
 548             }
 549           }
 550         } else {
 551           assert(ct == rt, err_msg("unexpected mismatch rt=%d, ct=%d", rt, ct));
 552           // push a zero; it's better than getting an oop/int mismatch
 553           retnode = pop_node(rt);
 554           retnode = zerocon(ct);
 555           push_node(ct, retnode);
 556         }
 557         // Now that the value is well-behaved, continue with the call-site type.
 558         rtype = ctype;
 559       }
 560     }
 561 
 562     // If the return type of the method is not loaded, assert that the
 563     // value we got is a null.  Otherwise, we need to recompile.
 564     if (!rtype->is_loaded()) {
 565 #ifndef PRODUCT
 566       if (PrintOpto && (Verbose || WizardMode)) {
 567         method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
 568         cg->method()->print_name(); tty->cr();
 569       }
 570 #endif
 571       if (C->log() != NULL) {
 572         C->log()->elem("assert_null reason='return' klass='%d'",
 573                        C->log()->identify(rtype));
 574       }
 575       // If there is going to be a trap, put it at the next bytecode:
 576       set_bci(iter().next_bci());
 577       null_assert(peek());
 578       set_bci(iter().cur_bci()); // put it back
 579     }
 580   }
 581 
 582   // Restart record of parsing work after possible inlining of call
 583 #ifndef PRODUCT
 584   parse_histogram()->set_initial_state(bc());
 585 #endif
 586 }
 587 
 588 //---------------------------catch_call_exceptions-----------------------------
 589 // Put a Catch and CatchProj nodes behind a just-created call.
 590 // Send their caught exceptions to the proper handler.
 591 // This may be used after a call to the rethrow VM stub,
 592 // when it is needed to process unloaded exception classes.
 593 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
 594   // Exceptions are delivered through this channel:
 595   Node* i_o = this->i_o();
 596 
 597   // Add a CatchNode.
 598   GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
 599   GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
 600   GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
 601 
 602   for (; !handlers.is_done(); handlers.next()) {
 603     ciExceptionHandler* h        = handlers.handler();
 604     int                 h_bci    = h->handler_bci();
 605     ciInstanceKlass*    h_klass  = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
 606     // Do not introduce unloaded exception types into the graph:
 607     if (!h_klass->is_loaded()) {
 608       if (saw_unloaded->contains(h_bci)) {
 609         /* We've already seen an unloaded exception with h_bci,
 610            so don't duplicate. Duplication will cause the CatchNode to be
 611            unnecessarily large. See 4713716. */
 612         continue;
 613       } else {
 614         saw_unloaded->append(h_bci);
 615       }
 616     }
 617     const Type*         h_extype = TypeOopPtr::make_from_klass(h_klass);
 618     // (We use make_from_klass because it respects UseUniqueSubclasses.)
 619     h_extype = h_extype->join(TypeInstPtr::NOTNULL);
 620     assert(!h_extype->empty(), "sanity");
 621     // Note:  It's OK if the BCIs repeat themselves.
 622     bcis->append(h_bci);
 623     extypes->append(h_extype);
 624   }
 625 
 626   int len = bcis->length();
 627   CatchNode *cn = new (C) CatchNode(control(), i_o, len+1);
 628   Node *catch_ = _gvn.transform(cn);
 629 
 630   // now branch with the exception state to each of the (potential)
 631   // handlers
 632   for(int i=0; i < len; i++) {
 633     // Setup JVM state to enter the handler.
 634     PreserveJVMState pjvms(this);
 635     // Locals are just copied from before the call.
 636     // Get control from the CatchNode.
 637     int handler_bci = bcis->at(i);
 638     Node* ctrl = _gvn.transform( new (C) CatchProjNode(catch_, i+1,handler_bci));
 639     // This handler cannot happen?
 640     if (ctrl == top())  continue;
 641     set_control(ctrl);
 642 
 643     // Create exception oop
 644     const TypeInstPtr* extype = extypes->at(i)->is_instptr();
 645     Node *ex_oop = _gvn.transform(new (C) CreateExNode(extypes->at(i), ctrl, i_o));
 646 
 647     // Handle unloaded exception classes.
 648     if (saw_unloaded->contains(handler_bci)) {
 649       // An unloaded exception type is coming here.  Do an uncommon trap.
 650 #ifndef PRODUCT
 651       // We do not expect the same handler bci to take both cold unloaded
 652       // and hot loaded exceptions.  But, watch for it.
 653       if ((Verbose || WizardMode) && extype->is_loaded()) {
 654         tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
 655         method()->print_name(); tty->cr();
 656       } else if (PrintOpto && (Verbose || WizardMode)) {
 657         tty->print("Bailing out on unloaded exception type ");
 658         extype->klass()->print_name();
 659         tty->print(" at bci:%d in ", bci());
 660         method()->print_name(); tty->cr();
 661       }
 662 #endif
 663       // Emit an uncommon trap instead of processing the block.
 664       set_bci(handler_bci);
 665       push_ex_oop(ex_oop);
 666       uncommon_trap(Deoptimization::Reason_unloaded,
 667                     Deoptimization::Action_reinterpret,
 668                     extype->klass(), "!loaded exception");
 669       set_bci(iter().cur_bci()); // put it back
 670       continue;
 671     }
 672 
 673     // go to the exception handler
 674     if (handler_bci < 0) {     // merge with corresponding rethrow node
 675       throw_to_exit(make_exception_state(ex_oop));
 676     } else {                      // Else jump to corresponding handle
 677       push_ex_oop(ex_oop);        // Clear stack and push just the oop.
 678       merge_exception(handler_bci);
 679     }
 680   }
 681 
 682   // The first CatchProj is for the normal return.
 683   // (Note:  If this is a call to rethrow_Java, this node goes dead.)
 684   set_control(_gvn.transform( new (C) CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
 685 }
 686 
 687 
 688 //----------------------------catch_inline_exceptions--------------------------
 689 // Handle all exceptions thrown by an inlined method or individual bytecode.
 690 // Common case 1: we have no handler, so all exceptions merge right into
 691 // the rethrow case.
 692 // Case 2: we have some handlers, with loaded exception klasses that have
 693 // no subklasses.  We do a Deutsch-Shiffman style type-check on the incoming
 694 // exception oop and branch to the handler directly.
 695 // Case 3: We have some handlers with subklasses or are not loaded at
 696 // compile-time.  We have to call the runtime to resolve the exception.
 697 // So we insert a RethrowCall and all the logic that goes with it.
 698 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
 699   // Caller is responsible for saving away the map for normal control flow!
 700   assert(stopped(), "call set_map(NULL) first");
 701   assert(method()->has_exception_handlers(), "don't come here w/o work to do");
 702 
 703   Node* ex_node = saved_ex_oop(ex_map);
 704   if (ex_node == top()) {
 705     // No action needed.
 706     return;
 707   }
 708   const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
 709   NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
 710   if (ex_type == NULL)
 711     ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
 712 
 713   // determine potential exception handlers
 714   ciExceptionHandlerStream handlers(method(), bci(),
 715                                     ex_type->klass()->as_instance_klass(),
 716                                     ex_type->klass_is_exact());
 717 
 718   // Start executing from the given throw state.  (Keep its stack, for now.)
 719   // Get the exception oop as known at compile time.
 720   ex_node = use_exception_state(ex_map);
 721 
 722   // Get the exception oop klass from its header
 723   Node* ex_klass_node = NULL;
 724   if (has_ex_handler() && !ex_type->klass_is_exact()) {
 725     Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
 726     ex_klass_node = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
 727 
 728     // Compute the exception klass a little more cleverly.
 729     // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
 730     // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
 731     // each arm of the Phi.  If I know something clever about the exceptions
 732     // I'm loading the class from, I can replace the LoadKlass with the
 733     // klass constant for the exception oop.
 734     if( ex_node->is_Phi() ) {
 735       ex_klass_node = new (C) PhiNode( ex_node->in(0), TypeKlassPtr::OBJECT );
 736       for( uint i = 1; i < ex_node->req(); i++ ) {
 737         Node* p = basic_plus_adr( ex_node->in(i), ex_node->in(i), oopDesc::klass_offset_in_bytes() );
 738         Node* k = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
 739         ex_klass_node->init_req( i, k );
 740       }
 741       _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
 742 
 743     }
 744   }
 745 
 746   // Scan the exception table for applicable handlers.
 747   // If none, we can call rethrow() and be done!
 748   // If precise (loaded with no subklasses), insert a D.S. style
 749   // pointer compare to the correct handler and loop back.
 750   // If imprecise, switch to the Rethrow VM-call style handling.
 751 
 752   int remaining = handlers.count_remaining();
 753 
 754   // iterate through all entries sequentially
 755   for (;!handlers.is_done(); handlers.next()) {
 756     ciExceptionHandler* handler = handlers.handler();
 757 
 758     if (handler->is_rethrow()) {
 759       // If we fell off the end of the table without finding an imprecise
 760       // exception klass (and without finding a generic handler) then we
 761       // know this exception is not handled in this method.  We just rethrow
 762       // the exception into the caller.
 763       throw_to_exit(make_exception_state(ex_node));
 764       return;
 765     }
 766 
 767     // exception handler bci range covers throw_bci => investigate further
 768     int handler_bci = handler->handler_bci();
 769 
 770     if (remaining == 1) {
 771       push_ex_oop(ex_node);        // Push exception oop for handler
 772 #ifndef PRODUCT
 773       if (PrintOpto && WizardMode) {
 774         tty->print_cr("  Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
 775       }
 776 #endif
 777       merge_exception(handler_bci); // jump to handler
 778       return;                   // No more handling to be done here!
 779     }
 780 
 781     // Get the handler's klass
 782     ciInstanceKlass* klass = handler->catch_klass();
 783 
 784     if (!klass->is_loaded()) {  // klass is not loaded?
 785       // fall through into catch_call_exceptions which will emit a
 786       // handler with an uncommon trap.
 787       break;
 788     }
 789 
 790     if (klass->is_interface())  // should not happen, but...
 791       break;                    // bail out
 792 
 793     // Check the type of the exception against the catch type
 794     const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
 795     Node* con = _gvn.makecon(tk);
 796     Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
 797     if (!stopped()) {
 798       PreserveJVMState pjvms(this);
 799       const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
 800       assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
 801       Node* ex_oop = _gvn.transform(new (C) CheckCastPPNode(control(), ex_node, tinst));
 802       push_ex_oop(ex_oop);      // Push exception oop for handler
 803 #ifndef PRODUCT
 804       if (PrintOpto && WizardMode) {
 805         tty->print("  Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
 806         klass->print_name();
 807         tty->cr();
 808       }
 809 #endif
 810       merge_exception(handler_bci);
 811     }
 812     set_control(not_subtype_ctrl);
 813 
 814     // Come here if exception does not match handler.
 815     // Carry on with more handler checks.
 816     --remaining;
 817   }
 818 
 819   assert(!stopped(), "you should return if you finish the chain");
 820 
 821   // Oops, need to call into the VM to resolve the klasses at runtime.
 822   // Note:  This call must not deoptimize, since it is not a real at this bci!
 823   kill_dead_locals();
 824 
 825   make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
 826                     OptoRuntime::rethrow_Type(),
 827                     OptoRuntime::rethrow_stub(),
 828                     NULL, NULL,
 829                     ex_node);
 830 
 831   // Rethrow is a pure call, no side effects, only a result.
 832   // The result cannot be allocated, so we use I_O
 833 
 834   // Catch exceptions from the rethrow
 835   catch_call_exceptions(handlers);
 836 }
 837 
 838 
 839 // (Note:  Moved add_debug_info into GraphKit::add_safepoint_edges.)
 840 
 841 
 842 #ifndef PRODUCT
 843 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
 844   if( CountCompiledCalls ) {
 845     if( at_method_entry ) {
 846       // bump invocation counter if top method (for statistics)
 847       if (CountCompiledCalls && depth() == 1) {
 848         const TypePtr* addr_type = TypeMetadataPtr::make(method());
 849         Node* adr1 = makecon(addr_type);
 850         Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
 851         increment_counter(adr2);
 852       }
 853     } else if (is_inline) {
 854       switch (bc()) {
 855       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
 856       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
 857       case Bytecodes::_invokestatic:
 858       case Bytecodes::_invokedynamic:
 859       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
 860       default: fatal("unexpected call bytecode");
 861       }
 862     } else {
 863       switch (bc()) {
 864       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
 865       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
 866       case Bytecodes::_invokestatic:
 867       case Bytecodes::_invokedynamic:
 868       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_static_calls_addr()); break;
 869       default: fatal("unexpected call bytecode");
 870       }
 871     }
 872   }
 873 }
 874 #endif //PRODUCT
 875 
 876 
 877 // Identify possible target method and inlining style
 878 ciMethod* Parse::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
 879                                    ciMethod *dest_method, const TypeOopPtr* receiver_type) {
 880   // only use for virtual or interface calls
 881 
 882   // If it is obviously final, do not bother to call find_monomorphic_target,
 883   // because the class hierarchy checks are not needed, and may fail due to
 884   // incompletely loaded classes.  Since we do our own class loading checks
 885   // in this module, we may confidently bind to any method.
 886   if (dest_method->can_be_statically_bound()) {
 887     return dest_method;
 888   }
 889 
 890   // Attempt to improve the receiver
 891   bool actual_receiver_is_exact = false;
 892   ciInstanceKlass* actual_receiver = klass;
 893   if (receiver_type != NULL) {
 894     // Array methods are all inherited from Object, and are monomorphic.
 895     if (receiver_type->isa_aryptr() &&
 896         dest_method->holder() == env()->Object_klass()) {
 897       return dest_method;
 898     }
 899 
 900     // All other interesting cases are instance klasses.
 901     if (!receiver_type->isa_instptr()) {
 902       return NULL;
 903     }
 904 
 905     ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
 906     if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
 907         (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
 908       // ikl is a same or better type than the original actual_receiver,
 909       // e.g. static receiver from bytecodes.
 910       actual_receiver = ikl;
 911       // Is the actual_receiver exact?
 912       actual_receiver_is_exact = receiver_type->klass_is_exact();
 913     }
 914   }
 915 
 916   ciInstanceKlass*   calling_klass = caller->holder();
 917   ciMethod* cha_monomorphic_target = dest_method->find_monomorphic_target(calling_klass, klass, actual_receiver);
 918   if (cha_monomorphic_target != NULL) {
 919     assert(!cha_monomorphic_target->is_abstract(), "");
 920     // Look at the method-receiver type.  Does it add "too much information"?
 921     ciKlass*    mr_klass = cha_monomorphic_target->holder();
 922     const Type* mr_type  = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
 923     if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
 924       // Calling this method would include an implicit cast to its holder.
 925       // %%% Not yet implemented.  Would throw minor asserts at present.
 926       // %%% The most common wins are already gained by +UseUniqueSubclasses.
 927       // To fix, put the higher_equal check at the call of this routine,
 928       // and add a CheckCastPP to the receiver.
 929       if (TraceDependencies) {
 930         tty->print_cr("found unique CHA method, but could not cast up");
 931         tty->print("  method  = ");
 932         cha_monomorphic_target->print();
 933         tty->cr();
 934       }
 935       if (C->log() != NULL) {
 936         C->log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
 937                        C->log()->identify(klass),
 938                        C->log()->identify(cha_monomorphic_target));
 939       }
 940       cha_monomorphic_target = NULL;
 941     }
 942   }
 943   if (cha_monomorphic_target != NULL) {
 944     // Hardwiring a virtual.
 945     // If we inlined because CHA revealed only a single target method,
 946     // then we are dependent on that target method not getting overridden
 947     // by dynamic class loading.  Be sure to test the "static" receiver
 948     // dest_method here, as opposed to the actual receiver, which may
 949     // falsely lead us to believe that the receiver is final or private.
 950     C->dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
 951     return cha_monomorphic_target;
 952   }
 953 
 954   // If the type is exact, we can still bind the method w/o a vcall.
 955   // (This case comes after CHA so we can see how much extra work it does.)
 956   if (actual_receiver_is_exact) {
 957     // In case of evolution, there is a dependence on every inlined method, since each
 958     // such method can be changed when its class is redefined.
 959     ciMethod* exact_method = dest_method->resolve_invoke(calling_klass, actual_receiver);
 960     if (exact_method != NULL) {
 961 #ifndef PRODUCT
 962       if (PrintOpto) {
 963         tty->print("  Calling method via exact type @%d --- ", bci);
 964         exact_method->print_name();
 965         tty->cr();
 966       }
 967 #endif
 968       return exact_method;
 969     }
 970   }
 971 
 972   return NULL;
 973 }