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(Compile* C, 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     outputStream* out = tty;
  46     if (!PrintInlining) {
  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(ss.as_string());
  60     out->cr();
  61   }
  62 }
  63 
  64 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_is_virtual,
  65                                        JVMState* jvms, bool allow_inline,
  66                                        float prof_factor, bool allow_intrinsics) {
  67   ciMethod*       caller   = jvms->method();
  68   int             bci      = jvms->bci();
  69   Bytecodes::Code bytecode = caller->java_code_at_bci(bci);
  70   guarantee(callee != NULL, "failed method resolution");
  71 
  72   // Dtrace currently doesn't work unless all calls are vanilla
  73   if (env()->dtrace_method_probes()) {
  74     allow_inline = false;
  75   }
  76 
  77   // Note: When we get profiling during stage-1 compiles, we want to pull
  78   // from more specific profile data which pertains to this inlining.
  79   // Right now, ignore the information in jvms->caller(), and do method[bci].
  80   ciCallProfile profile = caller->call_profile_at_bci(bci);
  81 
  82   // See how many times this site has been invoked.
  83   int site_count = profile.count();
  84   int receiver_count = -1;
  85   if (call_is_virtual && UseTypeProfile && profile.has_receiver(0)) {
  86     // Receivers in the profile structure are ordered by call counts
  87     // so that the most called (major) receiver is profile.receiver(0).
  88     receiver_count = profile.receiver_count(0);
  89   }
  90 
  91   CompileLog* log = this->log();
  92   if (log != NULL) {
  93     int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1;
  94     int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1;
  95     log->begin_elem("call method='%d' count='%d' prof_factor='%g'",
  96                     log->identify(callee), site_count, prof_factor);
  97     if (call_is_virtual)  log->print(" virtual='1'");
  98     if (allow_inline)     log->print(" inline='1'");
  99     if (receiver_count >= 0) {
 100       log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count);
 101       if (profile.has_receiver(1)) {
 102         log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1));
 103       }
 104     }
 105     log->end_elem();
 106   }
 107 
 108   // Special case the handling of certain common, profitable library
 109   // methods.  If these methods are replaced with specialized code,
 110   // then we return it as the inlined version of the call.
 111   // We do this before the strict f.p. check below because the
 112   // intrinsics handle strict f.p. correctly.
 113   if (allow_inline && allow_intrinsics) {
 114     CallGenerator* cg = find_intrinsic(callee, call_is_virtual);
 115     if (cg != NULL) {
 116       if (cg->is_predicted()) {
 117         // Code without intrinsic but, hopefully, inlined.
 118         CallGenerator* inline_cg = this->call_generator(callee,
 119               vtable_index, call_is_virtual, jvms, allow_inline, prof_factor, false);
 120         if (inline_cg != NULL) {
 121           cg = CallGenerator::for_predicted_intrinsic(cg, inline_cg);
 122         }
 123       }
 124       return cg;
 125     }
 126   }
 127 
 128   // Do method handle calls.
 129   // NOTE: This must happen before normal inlining logic below since
 130   // MethodHandle.invoke* are native methods which obviously don't
 131   // have bytecodes and so normal inlining fails.
 132   if (callee->is_method_handle_intrinsic()) {
 133     return CallGenerator::for_method_handle_call(jvms, caller, callee);
 134   }
 135 
 136   // Do not inline strict fp into non-strict code, or the reverse
 137   if (caller->is_strict() ^ callee->is_strict()) {
 138     allow_inline = false;
 139   }
 140 
 141   // Attempt to inline...
 142   if (allow_inline) {
 143     // The profile data is only partly attributable to this caller,
 144     // scale back the call site information.
 145     float past_uses = jvms->method()->scale_count(site_count, prof_factor);
 146     // This is the number of times we expect the call code to be used.
 147     float expected_uses = past_uses;
 148 
 149     // Try inlining a bytecoded method:
 150     if (!call_is_virtual) {
 151       InlineTree* ilt;
 152       if (UseOldInlining) {
 153         ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method());
 154       } else {
 155         // Make a disembodied, stateless ILT.
 156         // TO DO:  When UseOldInlining is removed, copy the ILT code elsewhere.
 157         float site_invoke_ratio = prof_factor;
 158         // Note:  ilt is for the root of this parse, not the present call site.
 159         ilt = new InlineTree(this, jvms->method(), jvms->caller(), site_invoke_ratio, MaxInlineLevel);
 160       }
 161       WarmCallInfo scratch_ci;
 162       if (!UseOldInlining)
 163         scratch_ci.init(jvms, callee, profile, prof_factor);
 164       WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci);
 165       assert(ci != &scratch_ci, "do not let this pointer escape");
 166       bool allow_inline   = (ci != NULL && !ci->is_cold());
 167       bool require_inline = (allow_inline && ci->is_hot());
 168 
 169       if (allow_inline) {
 170         CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses);
 171         if (require_inline && cg != NULL && should_delay_inlining(callee, jvms)) {
 172           // Delay the inlining of this method to give us the
 173           // opportunity to perform some high level optimizations
 174           // first.
 175           return CallGenerator::for_late_inline(callee, cg);
 176         }
 177         if (cg == NULL) {
 178           // Fall through.
 179         } else if (require_inline || !InlineWarmCalls) {
 180           return cg;
 181         } else {
 182           CallGenerator* cold_cg = call_generator(callee, vtable_index, call_is_virtual, jvms, false, prof_factor);
 183           return CallGenerator::for_warm_call(ci, cold_cg, cg);
 184         }
 185       }
 186     }
 187 
 188     // Try using the type profile.
 189     if (call_is_virtual && site_count > 0 && receiver_count > 0) {
 190       // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count.
 191       bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent);
 192       ciMethod* receiver_method = NULL;
 193       if (have_major_receiver || profile.morphism() == 1 ||
 194           (profile.morphism() == 2 && UseBimorphicInlining)) {
 195         // receiver_method = profile.method();
 196         // Profiles do not suggest methods now.  Look it up in the major receiver.
 197         receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 198                                                       profile.receiver(0));
 199       }
 200       if (receiver_method != NULL) {
 201         // The single majority receiver sufficiently outweighs the minority.
 202         CallGenerator* hit_cg = this->call_generator(receiver_method,
 203               vtable_index, !call_is_virtual, jvms, allow_inline, prof_factor);
 204         if (hit_cg != NULL) {
 205           // Look up second receiver.
 206           CallGenerator* next_hit_cg = NULL;
 207           ciMethod* next_receiver_method = NULL;
 208           if (profile.morphism() == 2 && UseBimorphicInlining) {
 209             next_receiver_method = callee->resolve_invoke(jvms->method()->holder(),
 210                                                                profile.receiver(1));
 211             if (next_receiver_method != NULL) {
 212               next_hit_cg = this->call_generator(next_receiver_method,
 213                                   vtable_index, !call_is_virtual, jvms,
 214                                   allow_inline, prof_factor);
 215               if (next_hit_cg != NULL && !next_hit_cg->is_inline() &&
 216                   have_major_receiver && UseOnlyInlinedBimorphic) {
 217                   // Skip if we can't inline second receiver's method
 218                   next_hit_cg = NULL;
 219               }
 220             }
 221           }
 222           CallGenerator* miss_cg;
 223           Deoptimization::DeoptReason reason = (profile.morphism() == 2) ?
 224                                     Deoptimization::Reason_bimorphic :
 225                                     Deoptimization::Reason_class_check;
 226           if (( profile.morphism() == 1 ||
 227                (profile.morphism() == 2 && next_hit_cg != NULL) ) &&
 228               !too_many_traps(jvms->method(), jvms->bci(), reason)
 229              ) {
 230             // Generate uncommon trap for class check failure path
 231             // in case of monomorphic or bimorphic virtual call site.
 232             miss_cg = CallGenerator::for_uncommon_trap(callee, reason,
 233                         Deoptimization::Action_maybe_recompile);
 234           } else {
 235             // Generate virtual call for class check failure path
 236             // in case of polymorphic virtual call site.
 237             miss_cg = CallGenerator::for_virtual_call(callee, vtable_index);
 238           }
 239           if (miss_cg != NULL) {
 240             if (next_hit_cg != NULL) {
 241               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1));
 242               // We don't need to record dependency on a receiver here and below.
 243               // Whenever we inline, the dependency is added by Parse::Parse().
 244               miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX);
 245             }
 246             if (miss_cg != NULL) {
 247               trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count);
 248               CallGenerator* cg = CallGenerator::for_predicted_call(profile.receiver(0), miss_cg, hit_cg, profile.receiver_prob(0));
 249               if (cg != NULL)  return cg;
 250             }
 251           }
 252         }
 253       }
 254     }
 255   }
 256 
 257   // There was no special inlining tactic, or it bailed out.
 258   // Use a more generic tactic, like a simple call.
 259   if (call_is_virtual) {
 260     return CallGenerator::for_virtual_call(callee, vtable_index);
 261   } else {
 262     // Class Hierarchy Analysis or Type Profile reveals a unique target,
 263     // or it is a static or special call.
 264     return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms));
 265   }
 266 }
 267 
 268 // Return true for methods that shouldn't be inlined early so that
 269 // they are easier to analyze and optimize as intrinsics.
 270 bool Compile::should_delay_inlining(ciMethod* call_method, JVMState* jvms) {
 271   if (has_stringbuilder()) {
 272 
 273     if ((call_method->holder() == C->env()->StringBuilder_klass() ||
 274          call_method->holder() == C->env()->StringBuffer_klass()) &&
 275         (jvms->method()->holder() == C->env()->StringBuilder_klass() ||
 276          jvms->method()->holder() == C->env()->StringBuffer_klass())) {
 277       // Delay SB calls only when called from non-SB code
 278       return false;
 279     }
 280 
 281     switch (call_method->intrinsic_id()) {
 282       case vmIntrinsics::_StringBuilder_void:
 283       case vmIntrinsics::_StringBuilder_int:
 284       case vmIntrinsics::_StringBuilder_String:
 285       case vmIntrinsics::_StringBuilder_append_char:
 286       case vmIntrinsics::_StringBuilder_append_int:
 287       case vmIntrinsics::_StringBuilder_append_String:
 288       case vmIntrinsics::_StringBuilder_toString:
 289       case vmIntrinsics::_StringBuffer_void:
 290       case vmIntrinsics::_StringBuffer_int:
 291       case vmIntrinsics::_StringBuffer_String:
 292       case vmIntrinsics::_StringBuffer_append_char:
 293       case vmIntrinsics::_StringBuffer_append_int:
 294       case vmIntrinsics::_StringBuffer_append_String:
 295       case vmIntrinsics::_StringBuffer_toString:
 296       case vmIntrinsics::_Integer_toString:
 297         return true;
 298 
 299       case vmIntrinsics::_String_String:
 300         {
 301           Node* receiver = jvms->map()->in(jvms->argoff() + 1);
 302           if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) {
 303             CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava();
 304             ciMethod* m = csj->method();
 305             if (m != NULL &&
 306                 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
 307                  m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString))
 308               // Delay String.<init>(new SB())
 309               return true;
 310           }
 311           return false;
 312         }
 313 
 314       default:
 315         return false;
 316     }
 317   }
 318   return false;
 319 }
 320 
 321 
 322 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link
 323 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) {
 324   // Additional inputs to consider...
 325   // bc      = bc()
 326   // caller  = method()
 327   // iter().get_method_holder_index()
 328   assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" );
 329   // Interface classes can be loaded & linked and never get around to
 330   // being initialized.  Uncommon-trap for not-initialized static or
 331   // v-calls.  Let interface calls happen.
 332   ciInstanceKlass* holder_klass = dest_method->holder();
 333   if (!holder_klass->is_being_initialized() &&
 334       !holder_klass->is_initialized() &&
 335       !holder_klass->is_interface()) {
 336     uncommon_trap(Deoptimization::Reason_uninitialized,
 337                   Deoptimization::Action_reinterpret,
 338                   holder_klass);
 339     return true;
 340   }
 341 
 342   assert(dest_method->is_loaded(), "dest_method: typeflow responsibility");
 343   return false;
 344 }
 345 
 346 
 347 //------------------------------do_call----------------------------------------
 348 // Handle your basic call.  Inline if we can & want to, else just setup call.
 349 void Parse::do_call() {
 350   // It's likely we are going to add debug info soon.
 351   // Also, if we inline a guy who eventually needs debug info for this JVMS,
 352   // our contribution to it is cleaned up right here.
 353   kill_dead_locals();
 354 
 355   // Set frequently used booleans
 356   const bool is_virtual = bc() == Bytecodes::_invokevirtual;
 357   const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface;
 358   const bool has_receiver = Bytecodes::has_receiver(bc());
 359 
 360   // Find target being called
 361   bool             will_link;
 362   ciSignature*     declared_signature = NULL;
 363   ciMethod*        orig_callee  = iter().get_method(will_link, &declared_signature);  // callee in the bytecode
 364   ciInstanceKlass* holder_klass = orig_callee->holder();
 365   ciKlass*         holder       = iter().get_declared_method_holder();
 366   ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder);
 367   assert(declared_signature != NULL, "cannot be null");
 368 
 369   // uncommon-trap when callee is unloaded, uninitialized or will not link
 370   // bailout when too many arguments for register representation
 371   if (!will_link || can_not_compile_call_site(orig_callee, klass)) {
 372 #ifndef PRODUCT
 373     if (PrintOpto && (Verbose || WizardMode)) {
 374       method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci());
 375       orig_callee->print_name(); tty->cr();
 376     }
 377 #endif
 378     return;
 379   }
 380   assert(holder_klass->is_loaded(), "");
 381   //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc");  // XXX invokehandle (cur_bc_raw)
 382   // Note: this takes into account invokeinterface of methods declared in java/lang/Object,
 383   // which should be invokevirtuals but according to the VM spec may be invokeinterfaces
 384   assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc");
 385   // Note:  In the absence of miranda methods, an abstract class K can perform
 386   // an invokevirtual directly on an interface method I.m if K implements I.
 387 
 388   // orig_callee is the resolved callee which's signature includes the
 389   // appendix argument.
 390   const int nargs = orig_callee->arg_size();
 391 
 392   // Push appendix argument (MethodType, CallSite, etc.), if one.
 393   if (iter().has_appendix()) {
 394     ciObject* appendix_arg = iter().get_appendix();
 395     const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg);
 396     Node* appendix_arg_node = _gvn.makecon(appendix_arg_type);
 397     push(appendix_arg_node);
 398   }
 399 
 400   // ---------------------
 401   // Does Class Hierarchy Analysis reveal only a single target of a v-call?
 402   // Then we may inline or make a static call, but become dependent on there being only 1 target.
 403   // Does the call-site type profile reveal only one receiver?
 404   // Then we may introduce a run-time check and inline on the path where it succeeds.
 405   // The other path may uncommon_trap, check for another receiver, or do a v-call.
 406 
 407   // Choose call strategy.
 408   bool call_is_virtual = is_virtual_or_interface;
 409   int vtable_index = Method::invalid_vtable_index;
 410   ciMethod* callee = orig_callee;
 411 
 412   // Try to get the most accurate receiver type
 413   if (is_virtual_or_interface) {
 414     Node*             receiver_node = stack(sp() - nargs);
 415     const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr();
 416     ciMethod* optimized_virtual_method = optimize_inlining(method(), bci(), klass, orig_callee, receiver_type);
 417 
 418     // Have the call been sufficiently improved such that it is no longer a virtual?
 419     if (optimized_virtual_method != NULL) {
 420       callee          = optimized_virtual_method;
 421       call_is_virtual = false;
 422     } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
 423       // We can make a vtable call at this site
 424       vtable_index = callee->resolve_vtable_index(method()->holder(), klass);
 425     }
 426   }
 427 
 428   // Note:  It's OK to try to inline a virtual call.
 429   // The call generator will not attempt to inline a polymorphic call
 430   // unless it knows how to optimize the receiver dispatch.
 431   bool try_inline = (C->do_inlining() || InlineAccessors);
 432 
 433   // ---------------------
 434   dec_sp(nargs);              // Temporarily pop args for JVM state of call
 435   JVMState* jvms = sync_jvms();
 436 
 437   // ---------------------
 438   // Decide call tactic.
 439   // This call checks with CHA, the interpreter profile, intrinsics table, etc.
 440   // It decides whether inlining is desirable or not.
 441   CallGenerator* cg = C->call_generator(callee, vtable_index, call_is_virtual, jvms, try_inline, prof_factor());
 442 
 443   // NOTE:  Don't use orig_callee and callee after this point!  Use cg->method() instead.
 444   orig_callee = callee = NULL;
 445 
 446   // ---------------------
 447   // Round double arguments before call
 448   round_double_arguments(cg->method());
 449 
 450 #ifndef PRODUCT
 451   // bump global counters for calls
 452   count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
 453 
 454   // Record first part of parsing work for this call
 455   parse_histogram()->record_change();
 456 #endif // not PRODUCT
 457 
 458   assert(jvms == this->jvms(), "still operating on the right JVMS");
 459   assert(jvms_in_sync(),       "jvms must carry full info into CG");
 460 
 461   // save across call, for a subsequent cast_not_null.
 462   Node* receiver = has_receiver ? argument(0) : NULL;
 463 
 464   // Bump method data counters (We profile *before* the call is made
 465   // because exceptions don't return to the call site.)
 466   profile_call(receiver);
 467 
 468   JVMState* new_jvms = cg->generate(jvms);
 469   if (new_jvms == NULL) {
 470     // When inlining attempt fails (e.g., too many arguments),
 471     // it may contaminate the current compile state, making it
 472     // impossible to pull back and try again.  Once we call
 473     // cg->generate(), we are committed.  If it fails, the whole
 474     // compilation task is compromised.
 475     if (failing())  return;
 476 
 477     // This can happen if a library intrinsic is available, but refuses
 478     // the call site, perhaps because it did not match a pattern the
 479     // intrinsic was expecting to optimize. Should always be possible to
 480     // get a normal java call that may inline in that case
 481     cg = C->call_generator(cg->method(), vtable_index, call_is_virtual, jvms, try_inline, prof_factor(), /* allow_intrinsics= */ false);
 482     if ((new_jvms = cg->generate(jvms)) == NULL) {
 483       guarantee(failing(), "call failed to generate:  calls should work");
 484       return;
 485     }
 486   }
 487 
 488   if (cg->is_inline()) {
 489     // Accumulate has_loops estimate
 490     C->set_has_loops(C->has_loops() || cg->method()->has_loops());
 491     C->env()->notice_inlined_method(cg->method());
 492   }
 493 
 494   // Reset parser state from [new_]jvms, which now carries results of the call.
 495   // Return value (if any) is already pushed on the stack by the cg.
 496   add_exception_states_from(new_jvms);
 497   if (new_jvms->map()->control() == top()) {
 498     stop_and_kill_map();
 499   } else {
 500     assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
 501     set_jvms(new_jvms);
 502   }
 503 
 504   if (!stopped()) {
 505     // This was some sort of virtual call, which did a null check for us.
 506     // Now we can assert receiver-not-null, on the normal return path.
 507     if (receiver != NULL && cg->is_virtual()) {
 508       Node* cast = cast_not_null(receiver);
 509       // %%% assert(receiver == cast, "should already have cast the receiver");
 510     }
 511 
 512     // Round double result after a call from strict to non-strict code
 513     round_double_result(cg->method());
 514 
 515     ciType* rtype = cg->method()->return_type();
 516     if (Bytecodes::has_optional_appendix(iter().cur_bc_raw())) {
 517       // Be careful here with return types.
 518       ciType* ctype = declared_signature->return_type();
 519       if (ctype != rtype) {
 520         BasicType rt = rtype->basic_type();
 521         BasicType ct = ctype->basic_type();
 522         Node* retnode = peek();
 523         if (ct == T_VOID) {
 524           // It's OK for a method  to return a value that is discarded.
 525           // The discarding does not require any special action from the caller.
 526           // The Java code knows this, at VerifyType.isNullConversion.
 527           pop_node(rt);  // whatever it was, pop it
 528           retnode = top();
 529         } else if (rt == T_INT || is_subword_type(rt)) {
 530           // FIXME: This logic should be factored out.
 531           if (ct == T_BOOLEAN) {
 532             retnode = _gvn.transform( new (C) AndINode(retnode, intcon(0x1)) );
 533           } else if (ct == T_CHAR) {
 534             retnode = _gvn.transform( new (C) AndINode(retnode, intcon(0xFFFF)) );
 535           } else if (ct == T_BYTE) {
 536             retnode = _gvn.transform( new (C) LShiftINode(retnode, intcon(24)) );
 537             retnode = _gvn.transform( new (C) RShiftINode(retnode, intcon(24)) );
 538           } else if (ct == T_SHORT) {
 539             retnode = _gvn.transform( new (C) LShiftINode(retnode, intcon(16)) );
 540             retnode = _gvn.transform( new (C) RShiftINode(retnode, intcon(16)) );
 541           } else {
 542             assert(ct == T_INT, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
 543           }
 544         } else if (rt == T_OBJECT || rt == T_ARRAY) {
 545           assert(ct == T_OBJECT || ct == T_ARRAY, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
 546           if (ctype->is_loaded()) {
 547             const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
 548             const Type*       sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
 549             if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
 550               Node* cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(), retnode, sig_type));
 551               pop();
 552               push(cast_obj);
 553             }
 554           }
 555         } else {
 556           assert(ct == rt, err_msg("unexpected mismatch rt=%d, ct=%d", rt, ct));
 557           // push a zero; it's better than getting an oop/int mismatch
 558           retnode = pop_node(rt);
 559           retnode = zerocon(ct);
 560           push_node(ct, retnode);
 561         }
 562         // Now that the value is well-behaved, continue with the call-site type.
 563         rtype = ctype;
 564       }
 565     }
 566 
 567     // If the return type of the method is not loaded, assert that the
 568     // value we got is a null.  Otherwise, we need to recompile.
 569     if (!rtype->is_loaded()) {
 570 #ifndef PRODUCT
 571       if (PrintOpto && (Verbose || WizardMode)) {
 572         method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
 573         cg->method()->print_name(); tty->cr();
 574       }
 575 #endif
 576       if (C->log() != NULL) {
 577         C->log()->elem("assert_null reason='return' klass='%d'",
 578                        C->log()->identify(rtype));
 579       }
 580       // If there is going to be a trap, put it at the next bytecode:
 581       set_bci(iter().next_bci());
 582       null_assert(peek());
 583       set_bci(iter().cur_bci()); // put it back
 584     }
 585   }
 586 
 587   // Restart record of parsing work after possible inlining of call
 588 #ifndef PRODUCT
 589   parse_histogram()->set_initial_state(bc());
 590 #endif
 591 }
 592 
 593 //---------------------------catch_call_exceptions-----------------------------
 594 // Put a Catch and CatchProj nodes behind a just-created call.
 595 // Send their caught exceptions to the proper handler.
 596 // This may be used after a call to the rethrow VM stub,
 597 // when it is needed to process unloaded exception classes.
 598 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
 599   // Exceptions are delivered through this channel:
 600   Node* i_o = this->i_o();
 601 
 602   // Add a CatchNode.
 603   GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
 604   GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
 605   GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
 606 
 607   for (; !handlers.is_done(); handlers.next()) {
 608     ciExceptionHandler* h        = handlers.handler();
 609     int                 h_bci    = h->handler_bci();
 610     ciInstanceKlass*    h_klass  = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
 611     // Do not introduce unloaded exception types into the graph:
 612     if (!h_klass->is_loaded()) {
 613       if (saw_unloaded->contains(h_bci)) {
 614         /* We've already seen an unloaded exception with h_bci,
 615            so don't duplicate. Duplication will cause the CatchNode to be
 616            unnecessarily large. See 4713716. */
 617         continue;
 618       } else {
 619         saw_unloaded->append(h_bci);
 620       }
 621     }
 622     const Type*         h_extype = TypeOopPtr::make_from_klass(h_klass);
 623     // (We use make_from_klass because it respects UseUniqueSubclasses.)
 624     h_extype = h_extype->join(TypeInstPtr::NOTNULL);
 625     assert(!h_extype->empty(), "sanity");
 626     // Note:  It's OK if the BCIs repeat themselves.
 627     bcis->append(h_bci);
 628     extypes->append(h_extype);
 629   }
 630 
 631   int len = bcis->length();
 632   CatchNode *cn = new (C) CatchNode(control(), i_o, len+1);
 633   Node *catch_ = _gvn.transform(cn);
 634 
 635   // now branch with the exception state to each of the (potential)
 636   // handlers
 637   for(int i=0; i < len; i++) {
 638     // Setup JVM state to enter the handler.
 639     PreserveJVMState pjvms(this);
 640     // Locals are just copied from before the call.
 641     // Get control from the CatchNode.
 642     int handler_bci = bcis->at(i);
 643     Node* ctrl = _gvn.transform( new (C) CatchProjNode(catch_, i+1,handler_bci));
 644     // This handler cannot happen?
 645     if (ctrl == top())  continue;
 646     set_control(ctrl);
 647 
 648     // Create exception oop
 649     const TypeInstPtr* extype = extypes->at(i)->is_instptr();
 650     Node *ex_oop = _gvn.transform(new (C) CreateExNode(extypes->at(i), ctrl, i_o));
 651 
 652     // Handle unloaded exception classes.
 653     if (saw_unloaded->contains(handler_bci)) {
 654       // An unloaded exception type is coming here.  Do an uncommon trap.
 655 #ifndef PRODUCT
 656       // We do not expect the same handler bci to take both cold unloaded
 657       // and hot loaded exceptions.  But, watch for it.
 658       if ((Verbose || WizardMode) && extype->is_loaded()) {
 659         tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
 660         method()->print_name(); tty->cr();
 661       } else if (PrintOpto && (Verbose || WizardMode)) {
 662         tty->print("Bailing out on unloaded exception type ");
 663         extype->klass()->print_name();
 664         tty->print(" at bci:%d in ", bci());
 665         method()->print_name(); tty->cr();
 666       }
 667 #endif
 668       // Emit an uncommon trap instead of processing the block.
 669       set_bci(handler_bci);
 670       push_ex_oop(ex_oop);
 671       uncommon_trap(Deoptimization::Reason_unloaded,
 672                     Deoptimization::Action_reinterpret,
 673                     extype->klass(), "!loaded exception");
 674       set_bci(iter().cur_bci()); // put it back
 675       continue;
 676     }
 677 
 678     // go to the exception handler
 679     if (handler_bci < 0) {     // merge with corresponding rethrow node
 680       throw_to_exit(make_exception_state(ex_oop));
 681     } else {                      // Else jump to corresponding handle
 682       push_ex_oop(ex_oop);        // Clear stack and push just the oop.
 683       merge_exception(handler_bci);
 684     }
 685   }
 686 
 687   // The first CatchProj is for the normal return.
 688   // (Note:  If this is a call to rethrow_Java, this node goes dead.)
 689   set_control(_gvn.transform( new (C) CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
 690 }
 691 
 692 
 693 //----------------------------catch_inline_exceptions--------------------------
 694 // Handle all exceptions thrown by an inlined method or individual bytecode.
 695 // Common case 1: we have no handler, so all exceptions merge right into
 696 // the rethrow case.
 697 // Case 2: we have some handlers, with loaded exception klasses that have
 698 // no subklasses.  We do a Deutsch-Shiffman style type-check on the incoming
 699 // exception oop and branch to the handler directly.
 700 // Case 3: We have some handlers with subklasses or are not loaded at
 701 // compile-time.  We have to call the runtime to resolve the exception.
 702 // So we insert a RethrowCall and all the logic that goes with it.
 703 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
 704   // Caller is responsible for saving away the map for normal control flow!
 705   assert(stopped(), "call set_map(NULL) first");
 706   assert(method()->has_exception_handlers(), "don't come here w/o work to do");
 707 
 708   Node* ex_node = saved_ex_oop(ex_map);
 709   if (ex_node == top()) {
 710     // No action needed.
 711     return;
 712   }
 713   const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
 714   NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
 715   if (ex_type == NULL)
 716     ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
 717 
 718   // determine potential exception handlers
 719   ciExceptionHandlerStream handlers(method(), bci(),
 720                                     ex_type->klass()->as_instance_klass(),
 721                                     ex_type->klass_is_exact());
 722 
 723   // Start executing from the given throw state.  (Keep its stack, for now.)
 724   // Get the exception oop as known at compile time.
 725   ex_node = use_exception_state(ex_map);
 726 
 727   // Get the exception oop klass from its header
 728   Node* ex_klass_node = NULL;
 729   if (has_ex_handler() && !ex_type->klass_is_exact()) {
 730     Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
 731     ex_klass_node = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
 732 
 733     // Compute the exception klass a little more cleverly.
 734     // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
 735     // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
 736     // each arm of the Phi.  If I know something clever about the exceptions
 737     // I'm loading the class from, I can replace the LoadKlass with the
 738     // klass constant for the exception oop.
 739     if( ex_node->is_Phi() ) {
 740       ex_klass_node = new (C) PhiNode( ex_node->in(0), TypeKlassPtr::OBJECT );
 741       for( uint i = 1; i < ex_node->req(); i++ ) {
 742         Node* p = basic_plus_adr( ex_node->in(i), ex_node->in(i), oopDesc::klass_offset_in_bytes() );
 743         Node* k = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
 744         ex_klass_node->init_req( i, k );
 745       }
 746       _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
 747 
 748     }
 749   }
 750 
 751   // Scan the exception table for applicable handlers.
 752   // If none, we can call rethrow() and be done!
 753   // If precise (loaded with no subklasses), insert a D.S. style
 754   // pointer compare to the correct handler and loop back.
 755   // If imprecise, switch to the Rethrow VM-call style handling.
 756 
 757   int remaining = handlers.count_remaining();
 758 
 759   // iterate through all entries sequentially
 760   for (;!handlers.is_done(); handlers.next()) {
 761     ciExceptionHandler* handler = handlers.handler();
 762 
 763     if (handler->is_rethrow()) {
 764       // If we fell off the end of the table without finding an imprecise
 765       // exception klass (and without finding a generic handler) then we
 766       // know this exception is not handled in this method.  We just rethrow
 767       // the exception into the caller.
 768       throw_to_exit(make_exception_state(ex_node));
 769       return;
 770     }
 771 
 772     // exception handler bci range covers throw_bci => investigate further
 773     int handler_bci = handler->handler_bci();
 774 
 775     if (remaining == 1) {
 776       push_ex_oop(ex_node);        // Push exception oop for handler
 777 #ifndef PRODUCT
 778       if (PrintOpto && WizardMode) {
 779         tty->print_cr("  Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
 780       }
 781 #endif
 782       merge_exception(handler_bci); // jump to handler
 783       return;                   // No more handling to be done here!
 784     }
 785 
 786     // Get the handler's klass
 787     ciInstanceKlass* klass = handler->catch_klass();
 788 
 789     if (!klass->is_loaded()) {  // klass is not loaded?
 790       // fall through into catch_call_exceptions which will emit a
 791       // handler with an uncommon trap.
 792       break;
 793     }
 794 
 795     if (klass->is_interface())  // should not happen, but...
 796       break;                    // bail out
 797 
 798     // Check the type of the exception against the catch type
 799     const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
 800     Node* con = _gvn.makecon(tk);
 801     Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
 802     if (!stopped()) {
 803       PreserveJVMState pjvms(this);
 804       const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
 805       assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
 806       Node* ex_oop = _gvn.transform(new (C) CheckCastPPNode(control(), ex_node, tinst));
 807       push_ex_oop(ex_oop);      // Push exception oop for handler
 808 #ifndef PRODUCT
 809       if (PrintOpto && WizardMode) {
 810         tty->print("  Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
 811         klass->print_name();
 812         tty->cr();
 813       }
 814 #endif
 815       merge_exception(handler_bci);
 816     }
 817     set_control(not_subtype_ctrl);
 818 
 819     // Come here if exception does not match handler.
 820     // Carry on with more handler checks.
 821     --remaining;
 822   }
 823 
 824   assert(!stopped(), "you should return if you finish the chain");
 825 
 826   // Oops, need to call into the VM to resolve the klasses at runtime.
 827   // Note:  This call must not deoptimize, since it is not a real at this bci!
 828   kill_dead_locals();
 829 
 830   make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
 831                     OptoRuntime::rethrow_Type(),
 832                     OptoRuntime::rethrow_stub(),
 833                     NULL, NULL,
 834                     ex_node);
 835 
 836   // Rethrow is a pure call, no side effects, only a result.
 837   // The result cannot be allocated, so we use I_O
 838 
 839   // Catch exceptions from the rethrow
 840   catch_call_exceptions(handlers);
 841 }
 842 
 843 
 844 // (Note:  Moved add_debug_info into GraphKit::add_safepoint_edges.)
 845 
 846 
 847 #ifndef PRODUCT
 848 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
 849   if( CountCompiledCalls ) {
 850     if( at_method_entry ) {
 851       // bump invocation counter if top method (for statistics)
 852       if (CountCompiledCalls && depth() == 1) {
 853         const TypePtr* addr_type = TypeMetadataPtr::make(method());
 854         Node* adr1 = makecon(addr_type);
 855         Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
 856         increment_counter(adr2);
 857       }
 858     } else if (is_inline) {
 859       switch (bc()) {
 860       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
 861       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
 862       case Bytecodes::_invokestatic:
 863       case Bytecodes::_invokedynamic:
 864       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
 865       default: fatal("unexpected call bytecode");
 866       }
 867     } else {
 868       switch (bc()) {
 869       case Bytecodes::_invokevirtual:   increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
 870       case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
 871       case Bytecodes::_invokestatic:
 872       case Bytecodes::_invokedynamic:
 873       case Bytecodes::_invokespecial:   increment_counter(SharedRuntime::nof_static_calls_addr()); break;
 874       default: fatal("unexpected call bytecode");
 875       }
 876     }
 877   }
 878 }
 879 #endif //PRODUCT
 880 
 881 
 882 // Identify possible target method and inlining style
 883 ciMethod* Parse::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
 884                                    ciMethod *dest_method, const TypeOopPtr* receiver_type) {
 885   // only use for virtual or interface calls
 886 
 887   // If it is obviously final, do not bother to call find_monomorphic_target,
 888   // because the class hierarchy checks are not needed, and may fail due to
 889   // incompletely loaded classes.  Since we do our own class loading checks
 890   // in this module, we may confidently bind to any method.
 891   if (dest_method->can_be_statically_bound()) {
 892     return dest_method;
 893   }
 894 
 895   // Attempt to improve the receiver
 896   bool actual_receiver_is_exact = false;
 897   ciInstanceKlass* actual_receiver = klass;
 898   if (receiver_type != NULL) {
 899     // Array methods are all inherited from Object, and are monomorphic.
 900     if (receiver_type->isa_aryptr() &&
 901         dest_method->holder() == env()->Object_klass()) {
 902       return dest_method;
 903     }
 904 
 905     // All other interesting cases are instance klasses.
 906     if (!receiver_type->isa_instptr()) {
 907       return NULL;
 908     }
 909 
 910     ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
 911     if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
 912         (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
 913       // ikl is a same or better type than the original actual_receiver,
 914       // e.g. static receiver from bytecodes.
 915       actual_receiver = ikl;
 916       // Is the actual_receiver exact?
 917       actual_receiver_is_exact = receiver_type->klass_is_exact();
 918     }
 919   }
 920 
 921   ciInstanceKlass*   calling_klass = caller->holder();
 922   ciMethod* cha_monomorphic_target = dest_method->find_monomorphic_target(calling_klass, klass, actual_receiver);
 923   if (cha_monomorphic_target != NULL) {
 924     assert(!cha_monomorphic_target->is_abstract(), "");
 925     // Look at the method-receiver type.  Does it add "too much information"?
 926     ciKlass*    mr_klass = cha_monomorphic_target->holder();
 927     const Type* mr_type  = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
 928     if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
 929       // Calling this method would include an implicit cast to its holder.
 930       // %%% Not yet implemented.  Would throw minor asserts at present.
 931       // %%% The most common wins are already gained by +UseUniqueSubclasses.
 932       // To fix, put the higher_equal check at the call of this routine,
 933       // and add a CheckCastPP to the receiver.
 934       if (TraceDependencies) {
 935         tty->print_cr("found unique CHA method, but could not cast up");
 936         tty->print("  method  = ");
 937         cha_monomorphic_target->print();
 938         tty->cr();
 939       }
 940       if (C->log() != NULL) {
 941         C->log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
 942                        C->log()->identify(klass),
 943                        C->log()->identify(cha_monomorphic_target));
 944       }
 945       cha_monomorphic_target = NULL;
 946     }
 947   }
 948   if (cha_monomorphic_target != NULL) {
 949     // Hardwiring a virtual.
 950     // If we inlined because CHA revealed only a single target method,
 951     // then we are dependent on that target method not getting overridden
 952     // by dynamic class loading.  Be sure to test the "static" receiver
 953     // dest_method here, as opposed to the actual receiver, which may
 954     // falsely lead us to believe that the receiver is final or private.
 955     C->dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
 956     return cha_monomorphic_target;
 957   }
 958 
 959   // If the type is exact, we can still bind the method w/o a vcall.
 960   // (This case comes after CHA so we can see how much extra work it does.)
 961   if (actual_receiver_is_exact) {
 962     // In case of evolution, there is a dependence on every inlined method, since each
 963     // such method can be changed when its class is redefined.
 964     ciMethod* exact_method = dest_method->resolve_invoke(calling_klass, actual_receiver);
 965     if (exact_method != NULL) {
 966 #ifndef PRODUCT
 967       if (PrintOpto) {
 968         tty->print("  Calling method via exact type @%d --- ", bci);
 969         exact_method->print_name();
 970         tty->cr();
 971       }
 972 #endif
 973       return exact_method;
 974     }
 975   }
 976 
 977   return NULL;
 978 }