1 /*
   2  * Copyright (c) 1997, 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 "classfile/systemDictionary.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "interpreter/linkResolver.hpp"
  34 #include "memory/metadataFactory.hpp"
  35 #include "memory/oopFactory.hpp"
  36 #include "oops/method.hpp"
  37 #include "oops/oop.inline.hpp"
  38 #include "oops/symbol.hpp"
  39 #include "runtime/icache.hpp"
  40 #include "runtime/sharedRuntime.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "utilities/events.hpp"
  43 
  44 
  45 // Every time a compiled IC is changed or its type is being accessed,
  46 // either the CompiledIC_lock must be set or we must be at a safe point.
  47 
  48 //-----------------------------------------------------------------------------
  49 // Low-level access to an inline cache. Private, since they might not be
  50 // MT-safe to use.
  51 
  52 void* CompiledIC::cached_value() const {
  53   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  54   assert (!is_optimized(), "an optimized virtual call does not have a cached metadata");
  55 
  56   if (!is_in_transition_state()) {
  57     void* data = (void*)_value->data();
  58     // If we let the metadata value here be initialized to zero...
  59     assert(data != NULL || Universe::non_oop_word() == NULL,
  60            "no raw nulls in CompiledIC metadatas, because of patching races");
  61     return (data == (void*)Universe::non_oop_word()) ? NULL : data;
  62   } else {
  63     return InlineCacheBuffer::cached_value_for((CompiledIC *)this);
  64   }
  65 }
  66 
  67 
  68 void CompiledIC::internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder) {
  69   assert(entry_point != NULL, "must set legal entry point");
  70   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  71   assert (!is_optimized() || cache == NULL, "an optimized virtual call does not have a cached metadata");
  72   assert (cache == NULL || cache != (Metadata*)badOopVal, "invalid metadata");
  73 
  74   assert(!is_icholder || is_icholder_entry(entry_point), "must be");
  75 
  76   // Don't use ic_destination for this test since that forwards
  77   // through ICBuffer instead of returning the actual current state of
  78   // the CompiledIC.
  79   if (is_icholder_entry(_ic_call->destination())) {
  80     // When patching for the ICStub case the cached value isn't
  81     // overwritten until the ICStub copied into the CompiledIC during
  82     // the next safepoint.  Make sure that the CompiledICHolder* is
  83     // marked for release at this point since it won't be identifiable
  84     // once the entry point is overwritten.
  85     InlineCacheBuffer::queue_for_release((CompiledICHolder*)_value->data());
  86   }
  87 
  88   if (TraceCompiledIC) {
  89     tty->print("  ");
  90     print_compiled_ic();
  91     tty->print(" changing destination to " INTPTR_FORMAT, entry_point);
  92     if (!is_optimized()) {
  93       tty->print(" changing cached %s to " INTPTR_FORMAT, is_icholder ? "icholder" : "metadata", (address)cache);
  94     }
  95     if (is_icstub) {
  96       tty->print(" (icstub)");
  97     }
  98     tty->cr();
  99   }
 100 
 101   {
 102   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 103 #ifdef ASSERT
 104   CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call);
 105   assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
 106 #endif
 107   _ic_call->set_destination_mt_safe(entry_point);
 108 }
 109 
 110   if (is_optimized() || is_icstub) {
 111     // Optimized call sites don't have a cache value and ICStub call
 112     // sites only change the entry point.  Changing the value in that
 113     // case could lead to MT safety issues.
 114     assert(cache == NULL, "must be null");
 115     return;
 116   }
 117 
 118   if (cache == NULL)  cache = (void*)Universe::non_oop_word();
 119 
 120   _value->set_data((intptr_t)cache);
 121 }
 122 
 123 
 124 void CompiledIC::set_ic_destination(ICStub* stub) {
 125   internal_set_ic_destination(stub->code_begin(), true, NULL, false);
 126 }
 127 
 128 
 129 
 130 address CompiledIC::ic_destination() const {
 131  assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 132  if (!is_in_transition_state()) {
 133    return _ic_call->destination();
 134  } else {
 135    return InlineCacheBuffer::ic_destination_for((CompiledIC *)this);
 136  }
 137 }
 138 
 139 
 140 bool CompiledIC::is_in_transition_state() const {
 141   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 142   return InlineCacheBuffer::contains(_ic_call->destination());
 143 }
 144 
 145 
 146 bool CompiledIC::is_icholder_call() const {
 147   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 148   return !_is_optimized && is_icholder_entry(ic_destination());
 149 }
 150 
 151 // Returns native address of 'call' instruction in inline-cache. Used by
 152 // the InlineCacheBuffer when it needs to find the stub.
 153 address CompiledIC::stub_address() const {
 154   assert(is_in_transition_state(), "should only be called when we are in a transition state");
 155   return _ic_call->destination();
 156 }
 157 
 158 
 159 //-----------------------------------------------------------------------------
 160 // High-level access to an inline cache. Guaranteed to be MT-safe.
 161 
 162 
 163 void CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS) {
 164   methodHandle method = call_info->selected_method();
 165   bool is_invoke_interface = (bytecode == Bytecodes::_invokeinterface && !call_info->has_vtable_index());
 166   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 167   assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
 168   assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
 169 
 170   address entry;
 171   if (is_invoke_interface) {
 172     int index = klassItable::compute_itable_index(call_info->resolved_method()());
 173     entry = VtableStubs::create_stub(false, index, method());
 174     assert(entry != NULL, "entry not computed");
 175     InstanceKlass* k = call_info->resolved_method()->method_holder();
 176     assert(k->is_interface(), "sanity check");
 177     InlineCacheBuffer::create_transition_stub(this, k, entry);
 178   } else {
 179     // Can be different than method->vtable_index(), due to package-private etc.
 180     int vtable_index = call_info->vtable_index();
 181     entry = VtableStubs::create_stub(true, vtable_index, method());
 182     InlineCacheBuffer::create_transition_stub(this, method(), entry);
 183   }
 184 
 185   if (TraceICs) {
 186     ResourceMark rm;
 187     tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
 188                    instruction_address(), method->print_value_string(), entry);
 189   }
 190 
 191   // We can't check this anymore. With lazy deopt we could have already
 192   // cleaned this IC entry before we even return. This is possible if
 193   // we ran out of space in the inline cache buffer trying to do the
 194   // set_next and we safepointed to free up space. This is a benign
 195   // race because the IC entry was complete when we safepointed so
 196   // cleaning it immediately is harmless.
 197   // assert(is_megamorphic(), "sanity check");
 198 }
 199 
 200 
 201 // true if destination is megamorphic stub
 202 bool CompiledIC::is_megamorphic() const {
 203   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 204   assert(!is_optimized(), "an optimized call cannot be megamorphic");
 205 
 206   // Cannot rely on cached_value. It is either an interface or a method.
 207   return VtableStubs::is_entry_point(ic_destination());
 208 }
 209 
 210 bool CompiledIC::is_call_to_compiled() const {
 211   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 212 
 213   // Use unsafe, since an inline cache might point to a zombie method. However, the zombie
 214   // method is guaranteed to still exist, since we only remove methods after all inline caches
 215   // has been cleaned up
 216   CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
 217   bool is_monomorphic = (cb != NULL && cb->is_nmethod());
 218   // Check that the cached_value is a klass for non-optimized monomorphic calls
 219   // This assertion is invalid for compiler1: a call that does not look optimized (no static stub) can be used
 220   // for calling directly to vep without using the inline cache (i.e., cached_value == NULL)
 221 #ifdef ASSERT
 222   CodeBlob* caller = CodeCache::find_blob_unsafe(instruction_address());
 223   bool is_c1_method = caller->is_compiled_by_c1();
 224   assert( is_c1_method ||
 225          !is_monomorphic ||
 226          is_optimized() ||
 227          (cached_metadata() != NULL && cached_metadata()->is_klass()), "sanity check");
 228 #endif // ASSERT
 229   return is_monomorphic;
 230 }
 231 
 232 
 233 bool CompiledIC::is_call_to_interpreted() const {
 234   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 235   // Call to interpreter if destination is either calling to a stub (if it
 236   // is optimized), or calling to an I2C blob
 237   bool is_call_to_interpreted = false;
 238   if (!is_optimized()) {
 239     // must use unsafe because the destination can be a zombie (and we're cleaning)
 240     // and the print_compiled_ic code wants to know if site (in the non-zombie)
 241     // is to the interpreter.
 242     CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
 243     is_call_to_interpreted = (cb != NULL && cb->is_adapter_blob());
 244     assert(!is_call_to_interpreted || (is_icholder_call() && cached_icholder() != NULL), "sanity check");
 245   } else {
 246     // Check if we are calling into our own codeblob (i.e., to a stub)
 247     CodeBlob* cb = CodeCache::find_blob(_ic_call->instruction_address());
 248     address dest = ic_destination();
 249 #ifdef ASSERT
 250     {
 251       CodeBlob* db = CodeCache::find_blob_unsafe(dest);
 252       assert(!db->is_adapter_blob(), "must use stub!");
 253     }
 254 #endif /* ASSERT */
 255     is_call_to_interpreted = cb->contains(dest);
 256   }
 257   return is_call_to_interpreted;
 258 }
 259 
 260 
 261 void CompiledIC::set_to_clean() {
 262   assert(SafepointSynchronize::is_at_safepoint() || CompiledIC_lock->is_locked() , "MT-unsafe call");
 263   if (TraceInlineCacheClearing || TraceICs) {
 264     tty->print_cr("IC@" INTPTR_FORMAT ": set to clean", instruction_address());
 265     print();
 266   }
 267 
 268   address entry;
 269   if (is_optimized()) {
 270     entry = SharedRuntime::get_resolve_opt_virtual_call_stub();
 271   } else {
 272     entry = SharedRuntime::get_resolve_virtual_call_stub();
 273   }
 274 
 275   // A zombie transition will always be safe, since the metadata has already been set to NULL, so
 276   // we only need to patch the destination
 277   bool safe_transition = is_optimized() || SafepointSynchronize::is_at_safepoint();
 278 
 279   if (safe_transition) {
 280     // Kill any leftover stub we might have too
 281     if (is_in_transition_state()) {
 282       ICStub* old_stub = ICStub_from_destination_address(stub_address());
 283       old_stub->clear();
 284     }
 285     if (is_optimized()) {
 286     set_ic_destination(entry);
 287   } else {
 288       set_ic_destination_and_value(entry, (void*)NULL);
 289     }
 290   } else {
 291     // Unsafe transition - create stub.
 292     InlineCacheBuffer::create_transition_stub(this, NULL, entry);
 293   }
 294   // We can't check this anymore. With lazy deopt we could have already
 295   // cleaned this IC entry before we even return. This is possible if
 296   // we ran out of space in the inline cache buffer trying to do the
 297   // set_next and we safepointed to free up space. This is a benign
 298   // race because the IC entry was complete when we safepointed so
 299   // cleaning it immediately is harmless.
 300   // assert(is_clean(), "sanity check");
 301 }
 302 
 303 
 304 bool CompiledIC::is_clean() const {
 305   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 306   bool is_clean = false;
 307   address dest = ic_destination();
 308   is_clean = dest == SharedRuntime::get_resolve_opt_virtual_call_stub() ||
 309              dest == SharedRuntime::get_resolve_virtual_call_stub();
 310   assert(!is_clean || is_optimized() || cached_value() == NULL, "sanity check");
 311   return is_clean;
 312 }
 313 
 314 
 315 void CompiledIC::set_to_monomorphic(CompiledICInfo& info) {
 316   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 317   // Updating a cache to the wrong entry can cause bugs that are very hard
 318   // to track down - if cache entry gets invalid - we just clean it. In
 319   // this way it is always the same code path that is responsible for
 320   // updating and resolving an inline cache
 321   //
 322   // The above is no longer true. SharedRuntime::fixup_callers_callsite will change optimized
 323   // callsites. In addition ic_miss code will update a site to monomorphic if it determines
 324   // that an monomorphic call to the interpreter can now be monomorphic to compiled code.
 325   //
 326   // In both of these cases the only thing being modifed is the jump/call target and these
 327   // transitions are mt_safe
 328 
 329   Thread *thread = Thread::current();
 330   if (info.to_interpreter()) {
 331     // Call to interpreter
 332     if (info.is_optimized() && is_optimized()) {
 333        assert(is_clean(), "unsafe IC path");
 334        MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 335       // the call analysis (callee structure) specifies that the call is optimized
 336       // (either because of CHA or the static target is final)
 337       // At code generation time, this call has been emitted as static call
 338       // Call via stub
 339       assert(info.cached_metadata() != NULL && info.cached_metadata()->is_method(), "sanity check");
 340       CompiledStaticCall* csc = compiledStaticCall_at(instruction_address());
 341       methodHandle method (thread, (Method*)info.cached_metadata());
 342       csc->set_to_interpreted(method, info.entry());
 343       if (TraceICs) {
 344          ResourceMark rm(thread);
 345          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s",
 346            instruction_address(),
 347            method->print_value_string());
 348       }
 349     } else {
 350       // Call via method-klass-holder
 351       InlineCacheBuffer::create_transition_stub(this, info.claim_cached_icholder(), info.entry());
 352       if (TraceICs) {
 353          ResourceMark rm(thread);
 354          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via icholder ", instruction_address());
 355       }
 356     }
 357   } else {
 358     // Call to compiled code
 359     bool static_bound = info.is_optimized() || (info.cached_metadata() == NULL);
 360 #ifdef ASSERT
 361     CodeBlob* cb = CodeCache::find_blob_unsafe(info.entry());
 362     assert (cb->is_nmethod(), "must be compiled!");
 363 #endif /* ASSERT */
 364 
 365     // This is MT safe if we come from a clean-cache and go through a
 366     // non-verified entry point
 367     bool safe = SafepointSynchronize::is_at_safepoint() ||
 368                 (!is_in_transition_state() && (info.is_optimized() || static_bound || is_clean()));
 369 
 370     if (!safe) {
 371       InlineCacheBuffer::create_transition_stub(this, info.cached_metadata(), info.entry());
 372     } else {
 373       if (is_optimized()) {
 374       set_ic_destination(info.entry());
 375       } else {
 376         set_ic_destination_and_value(info.entry(), info.cached_metadata());
 377       }
 378     }
 379 
 380     if (TraceICs) {
 381       ResourceMark rm(thread);
 382       assert(info.cached_metadata() == NULL || info.cached_metadata()->is_klass(), "must be");
 383       tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass) %s: %s",
 384         instruction_address(),
 385         ((Klass*)info.cached_metadata())->print_value_string(),
 386         (safe) ? "" : "via stub");
 387     }
 388   }
 389   // We can't check this anymore. With lazy deopt we could have already
 390   // cleaned this IC entry before we even return. This is possible if
 391   // we ran out of space in the inline cache buffer trying to do the
 392   // set_next and we safepointed to free up space. This is a benign
 393   // race because the IC entry was complete when we safepointed so
 394   // cleaning it immediately is harmless.
 395   // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
 396 }
 397 
 398 
 399 // is_optimized: Compiler has generated an optimized call (i.e., no inline
 400 // cache) static_bound: The call can be static bound (i.e, no need to use
 401 // inline cache)
 402 void CompiledIC::compute_monomorphic_entry(methodHandle method,
 403                                            KlassHandle receiver_klass,
 404                                            bool is_optimized,
 405                                            bool static_bound,
 406                                            CompiledICInfo& info,
 407                                            TRAPS) {
 408   nmethod* method_code = method->code();
 409   address entry = NULL;
 410   if (method_code != NULL) {
 411     // Call to compiled code
 412     if (static_bound || is_optimized) {
 413       entry      = method_code->verified_entry_point();
 414     } else {
 415       entry      = method_code->entry_point();
 416     }
 417   }
 418   if (entry != NULL) {
 419     // Call to compiled code
 420     info.set_compiled_entry(entry, (static_bound || is_optimized) ? NULL : receiver_klass(), is_optimized);
 421   } else {
 422     // Note: the following problem exists with Compiler1:
 423     //   - at compile time we may or may not know if the destination is final
 424     //   - if we know that the destination is final, we will emit an optimized
 425     //     virtual call (no inline cache), and need a Method* to make a call
 426     //     to the interpreter
 427     //   - if we do not know if the destination is final, we emit a standard
 428     //     virtual call, and use CompiledICHolder to call interpreted code
 429     //     (no static call stub has been generated)
 430     //     However in that case we will now notice it is static_bound
 431     //     and convert the call into what looks to be an optimized
 432     //     virtual call. This causes problems in verifying the IC because
 433     //     it look vanilla but is optimized. Code in is_call_to_interpreted
 434     //     is aware of this and weakens its asserts.
 435 
 436     // static_bound should imply is_optimized -- otherwise we have a
 437     // performance bug (statically-bindable method is called via
 438     // dynamically-dispatched call note: the reverse implication isn't
 439     // necessarily true -- the call may have been optimized based on compiler
 440     // analysis (static_bound is only based on "final" etc.)
 441 #ifdef COMPILER2
 442 #ifdef TIERED
 443 #if defined(ASSERT)
 444     // can't check the assert because we don't have the CompiledIC with which to
 445     // find the address if the call instruction.
 446     //
 447     // CodeBlob* cb = find_blob_unsafe(instruction_address());
 448     // assert(cb->is_compiled_by_c1() || !static_bound || is_optimized, "static_bound should imply is_optimized");
 449 #endif // ASSERT
 450 #else
 451     assert(!static_bound || is_optimized, "static_bound should imply is_optimized");
 452 #endif // TIERED
 453 #endif // COMPILER2
 454     if (is_optimized) {
 455       // Use stub entry
 456       info.set_interpreter_entry(method()->get_c2i_entry(), method());
 457     } else {
 458       // Use icholder entry
 459       CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass());
 460       info.set_icholder_entry(method()->get_c2i_unverified_entry(), holder);
 461     }
 462   }
 463   assert(info.is_optimized() == is_optimized, "must agree");
 464 }
 465 
 466 
 467 bool CompiledIC::is_icholder_entry(address entry) {
 468   CodeBlob* cb = CodeCache::find_blob_unsafe(entry);
 469   return (cb != NULL && cb->is_adapter_blob());
 470 }
 471 
 472 // ----------------------------------------------------------------------------
 473 
 474 void CompiledStaticCall::set_to_clean() {
 475   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 476   // Reset call site
 477   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 478 #ifdef ASSERT
 479   CodeBlob* cb = CodeCache::find_blob_unsafe(this);
 480   assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
 481 #endif
 482   set_destination_mt_safe(SharedRuntime::get_resolve_static_call_stub());
 483 
 484   // Do not reset stub here:  It is too expensive to call find_stub.
 485   // Instead, rely on caller (nmethod::clear_inline_caches) to clear
 486   // both the call and its stub.
 487 }
 488 
 489 
 490 bool CompiledStaticCall::is_clean() const {
 491   return destination() == SharedRuntime::get_resolve_static_call_stub();
 492 }
 493 
 494 bool CompiledStaticCall::is_call_to_compiled() const {
 495   return CodeCache::contains(destination());
 496 }
 497 
 498 
 499 bool CompiledStaticCall::is_call_to_interpreted() const {
 500   // It is a call to interpreted, if it calls to a stub. Hence, the destination
 501   // must be in the stub part of the nmethod that contains the call
 502   nmethod* nm = CodeCache::find_nmethod(instruction_address());
 503   return nm->stub_contains(destination());
 504 }
 505 
 506 void CompiledStaticCall::set(const StaticCallInfo& info) {
 507   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 508   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 509   // Updating a cache to the wrong entry can cause bugs that are very hard
 510   // to track down - if cache entry gets invalid - we just clean it. In
 511   // this way it is always the same code path that is responsible for
 512   // updating and resolving an inline cache
 513   assert(is_clean(), "do not update a call entry - use clean");
 514 
 515   if (info._to_interpreter) {
 516     // Call to interpreted code
 517     set_to_interpreted(info.callee(), info.entry());
 518   } else {
 519     if (TraceICs) {
 520       ResourceMark rm;
 521       tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_compiled " INTPTR_FORMAT,
 522                     instruction_address(),
 523                     info.entry());
 524     }
 525     // Call to compiled code
 526     assert (CodeCache::contains(info.entry()), "wrong entry point");
 527     set_destination_mt_safe(info.entry());
 528   }
 529 }
 530 
 531 
 532 // Compute settings for a CompiledStaticCall. Since we might have to set
 533 // the stub when calling to the interpreter, we need to return arguments.
 534 void CompiledStaticCall::compute_entry(methodHandle m, StaticCallInfo& info) {
 535   nmethod* m_code = m->code();
 536   info._callee = m;
 537   if (m_code != NULL) {
 538     info._to_interpreter = false;
 539     info._entry  = m_code->verified_entry_point();
 540   } else {
 541     // Callee is interpreted code.  In any case entering the interpreter
 542     // puts a converter-frame on the stack to save arguments.
 543     info._to_interpreter = true;
 544     info._entry      = m()->get_c2i_entry();
 545   }
 546 }
 547 
 548 address CompiledStaticCall::find_stub() {
 549   // Find reloc. information containing this call-site
 550   RelocIterator iter((nmethod*)NULL, instruction_address());
 551   while (iter.next()) {
 552     if (iter.addr() == instruction_address()) {
 553       switch(iter.type()) {
 554         case relocInfo::static_call_type:
 555           return iter.static_call_reloc()->static_stub();
 556         // We check here for opt_virtual_call_type, since we reuse the code
 557         // from the CompiledIC implementation
 558         case relocInfo::opt_virtual_call_type:
 559           return iter.opt_virtual_call_reloc()->static_stub();
 560         case relocInfo::poll_type:
 561         case relocInfo::poll_return_type: // A safepoint can't overlap a call.
 562         default:
 563           ShouldNotReachHere();
 564       }
 565     }
 566   }
 567   return NULL;
 568 }
 569 
 570 
 571 //-----------------------------------------------------------------------------
 572 // Non-product mode code
 573 #ifndef PRODUCT
 574 
 575 void CompiledIC::verify() {
 576   // make sure code pattern is actually a call imm32 instruction
 577   _ic_call->verify();
 578   if (os::is_MP()) {
 579     _ic_call->verify_alignment();
 580   }
 581   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted()
 582           || is_optimized() || is_megamorphic(), "sanity check");
 583 }
 584 
 585 void CompiledIC::print() {
 586   print_compiled_ic();
 587   tty->cr();
 588 }
 589 
 590 void CompiledIC::print_compiled_ic() {
 591   tty->print("Inline cache at " INTPTR_FORMAT ", calling %s " INTPTR_FORMAT " cached_value " INTPTR_FORMAT,
 592              instruction_address(), is_call_to_interpreted() ? "interpreted " : "", ic_destination(), is_optimized() ? NULL : cached_value());
 593 }
 594 
 595 void CompiledStaticCall::print() {
 596   tty->print("static call at " INTPTR_FORMAT " -> ", instruction_address());
 597   if (is_clean()) {
 598     tty->print("clean");
 599   } else if (is_call_to_compiled()) {
 600     tty->print("compiled");
 601   } else if (is_call_to_interpreted()) {
 602     tty->print("interpreted");
 603   }
 604   tty->cr();
 605 }
 606 
 607 #endif // !PRODUCT