1 /*
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  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
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 23  */
 24 
 25 #include "precompiled.hpp"
 26 #include "code/codeBehaviours.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 "memory/resourceArea.hpp"
 37 #include "memory/universe.hpp"
 38 #include "oops/klass.inline.hpp"
 39 #include "oops/method.inline.hpp"
 40 #include "oops/oop.inline.hpp"
 41 #include "oops/symbol.hpp"
 42 #include "runtime/handles.inline.hpp"
 43 #include "runtime/icache.hpp"
 44 #include "runtime/safepoint.hpp"
 45 #include "runtime/sharedRuntime.hpp"
 46 #include "runtime/stubRoutines.hpp"
 47 #include "utilities/events.hpp"
 48 
 49 
 50 // Every time a compiled IC is changed or its type is being accessed,
 51 // either the CompiledIC_lock must be set or we must be at a safe point.
 52 
 53 CompiledICLocker::CompiledICLocker(CompiledMethod* method)
 54   : _method(method),
 55     _behaviour(CompiledICProtectionBehaviour::current()),
 56     _locked(_behaviour->lock(_method)) {
 57 }
 58 
 59 CompiledICLocker::~CompiledICLocker() {
 60   if (_locked) {
 61     _behaviour->unlock(_method);
 62   }
 63 }
 64 
 65 bool CompiledICLocker::is_safe(CompiledMethod* method) {
 66   return CompiledICProtectionBehaviour::current()->is_safe(method);
 67 }
 68 
 69 bool CompiledICLocker::is_safe(address code) {
 70   CodeBlob* cb = CodeCache::find_blob_unsafe(code);
 71   assert(cb != NULL && cb->is_compiled(), "must be compiled");
 72   CompiledMethod* cm = cb->as_compiled_method();
 73   return CompiledICProtectionBehaviour::current()->is_safe(cm);
 74 }
 75 
 76 //-----------------------------------------------------------------------------
 77 // Low-level access to an inline cache. Private, since they might not be
 78 // MT-safe to use.
 79 
 80 void* CompiledIC::cached_value() const {
 81   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
 82   assert (!is_optimized(), "an optimized virtual call does not have a cached metadata");
 83 
 84   if (!is_in_transition_state()) {
 85     void* data = get_data();
 86     // If we let the metadata value here be initialized to zero...
 87     assert(data != NULL || Universe::non_oop_word() == NULL,
 88            "no raw nulls in CompiledIC metadatas, because of patching races");
 89     return (data == (void*)Universe::non_oop_word()) ? NULL : data;
 90   } else {
 91     return InlineCacheBuffer::cached_value_for((CompiledIC *)this);
 92   }
 93 }
 94 
 95 
 96 void CompiledIC::internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder) {
 97   assert(entry_point != NULL, "must set legal entry point");
 98   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
 99   assert (!is_optimized() || cache == NULL, "an optimized virtual call does not have a cached metadata");
100   assert (cache == NULL || cache != (Metadata*)badOopVal, "invalid metadata");
101 
102   assert(!is_icholder || is_icholder_entry(entry_point), "must be");
103 
104   // Don't use ic_destination for this test since that forwards
105   // through ICBuffer instead of returning the actual current state of
106   // the CompiledIC.
107   if (is_icholder_entry(_call->destination())) {
108     // When patching for the ICStub case the cached value isn't
109     // overwritten until the ICStub copied into the CompiledIC during
110     // the next safepoint.  Make sure that the CompiledICHolder* is
111     // marked for release at this point since it won't be identifiable
112     // once the entry point is overwritten.
113     InlineCacheBuffer::queue_for_release((CompiledICHolder*)get_data());
114   }
115 
116   if (TraceCompiledIC) {
117     tty->print("  ");
118     print_compiled_ic();
119     tty->print(" changing destination to " INTPTR_FORMAT, p2i(entry_point));
120     if (!is_optimized()) {
121       tty->print(" changing cached %s to " INTPTR_FORMAT, is_icholder ? "icholder" : "metadata", p2i((address)cache));
122     }
123     if (is_icstub) {
124       tty->print(" (icstub)");
125     }
126     tty->cr();
127   }
128 
129   {
130     CodeBlob* cb = CodeCache::find_blob_unsafe(_call->instruction_address());
131     assert(cb != NULL && cb->is_compiled(), "must be compiled");
132     _call->set_destination_mt_safe(entry_point);
133   }
134 
135   if (is_optimized() || is_icstub) {
136     // Optimized call sites don't have a cache value and ICStub call
137     // sites only change the entry point.  Changing the value in that
138     // case could lead to MT safety issues.
139     assert(cache == NULL, "must be null");
140     return;
141   }
142 
143   if (cache == NULL)  cache = Universe::non_oop_word();
144 
145   set_data((intptr_t)cache);
146 }
147 
148 
149 void CompiledIC::set_ic_destination(ICStub* stub) {
150   internal_set_ic_destination(stub->code_begin(), true, NULL, false);
151 }
152 
153 
154 
155 address CompiledIC::ic_destination() const {
156   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
157   if (!is_in_transition_state()) {
158     return _call->destination();
159   } else {
160     return InlineCacheBuffer::ic_destination_for((CompiledIC *)this);
161   }
162 }
163 
164 
165 bool CompiledIC::is_in_transition_state() const {
166   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
167   return InlineCacheBuffer::contains(_call->destination());;
168 }
169 
170 
171 bool CompiledIC::is_icholder_call() const {
172   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
173   return !_is_optimized && is_icholder_entry(ic_destination());
174 }
175 
176 // Returns native address of 'call' instruction in inline-cache. Used by
177 // the InlineCacheBuffer when it needs to find the stub.
178 address CompiledIC::stub_address() const {
179   assert(is_in_transition_state(), "should only be called when we are in a transition state");
180   return _call->destination();
181 }
182 
183 // Clears the IC stub if the compiled IC is in transition state
184 void CompiledIC::clear_ic_stub() {
185   if (is_in_transition_state()) {
186     ICStub* stub = ICStub_from_destination_address(stub_address());
187     stub->clear();
188   }
189 }
190 
191 //-----------------------------------------------------------------------------
192 // High-level access to an inline cache. Guaranteed to be MT-safe.
193 
194 void CompiledIC::initialize_from_iter(RelocIterator* iter) {
195   assert(iter->addr() == _call->instruction_address(), "must find ic_call");
196 
197   if (iter->type() == relocInfo::virtual_call_type) {
198     virtual_call_Relocation* r = iter->virtual_call_reloc();
199     _is_optimized = false;
200     _value = _call->get_load_instruction(r);
201   } else {
202     assert(iter->type() == relocInfo::opt_virtual_call_type, "must be a virtual call");
203     _is_optimized = true;
204     _value = NULL;
205   }
206 }
207 
208 CompiledIC::CompiledIC(CompiledMethod* cm, NativeCall* call)
209   : _method(cm)
210 {
211   _call = _method->call_wrapper_at((address) call);
212   address ic_call = _call->instruction_address();
213 
214   assert(ic_call != NULL, "ic_call address must be set");
215   assert(cm != NULL, "must pass compiled method");
216   assert(cm->contains(ic_call), "must be in compiled method");
217 
218   // Search for the ic_call at the given address.
219   RelocIterator iter(cm, ic_call, ic_call+1);
220   bool ret = iter.next();
221   assert(ret == true, "relocInfo must exist at this address");
222   assert(iter.addr() == ic_call, "must find ic_call");
223 
224   initialize_from_iter(&iter);
225 }
226 
227 CompiledIC::CompiledIC(RelocIterator* iter)
228   : _method(iter->code())
229 {
230   _call = _method->call_wrapper_at(iter->addr());
231   address ic_call = _call->instruction_address();
232 
233   CompiledMethod* nm = iter->code();
234   assert(ic_call != NULL, "ic_call address must be set");
235   assert(nm != NULL, "must pass compiled method");
236   assert(nm->contains(ic_call), "must be in compiled method");
237 
238   initialize_from_iter(iter);
239 }
240 
241 // This function may fail for two reasons: either due to running out of vtable
242 // stubs, or due to running out of IC stubs in an attempted transition to a
243 // transitional state. The needs_ic_stub_refill value will be set if the failure
244 // was due to running out of IC stubs, in which case the caller will refill IC
245 // stubs and retry.
246 bool CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode,
247                                     bool& needs_ic_stub_refill, TRAPS) {
248   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
249   assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
250   assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
251 
252   address entry;
253   if (call_info->call_kind() == CallInfo::itable_call) {
254     assert(bytecode == Bytecodes::_invokeinterface, "");
255     int itable_index = call_info->itable_index();
256     entry = VtableStubs::find_itable_stub(itable_index);
257     if (entry == NULL) {
258       return false;
259     }
260 #ifdef ASSERT
261     int index = call_info->resolved_method()->itable_index();
262     assert(index == itable_index, "CallInfo pre-computes this");
263     InstanceKlass* k = call_info->resolved_method()->method_holder();
264     assert(k->verify_itable_index(itable_index), "sanity check");
265 #endif //ASSERT
266     CompiledICHolder* holder = new CompiledICHolder(call_info->resolved_method()->method_holder(),
267                                                     call_info->resolved_klass(), false);
268     holder->claim();
269     if (!InlineCacheBuffer::create_transition_stub(this, holder, entry)) {
270       delete holder;
271       needs_ic_stub_refill = true;
272       return false;
273     }
274   } else {
275     assert(call_info->call_kind() == CallInfo::vtable_call, "either itable or vtable");
276     // Can be different than selected_method->vtable_index(), due to package-private etc.
277     int vtable_index = call_info->vtable_index();
278     assert(call_info->resolved_klass()->verify_vtable_index(vtable_index), "sanity check");
279     entry = VtableStubs::find_vtable_stub(vtable_index);
280     if (entry == NULL) {
281       return false;
282     }
283     if (!InlineCacheBuffer::create_transition_stub(this, NULL, entry)) {
284       needs_ic_stub_refill = true;
285       return false;
286     }
287   }
288 
289   if (TraceICs) {
290     ResourceMark rm;
291     assert(call_info->selected_method() != NULL, "Unexpected null selected method");
292     tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
293                    p2i(instruction_address()), call_info->selected_method()->print_value_string(), p2i(entry));
294   }
295 
296   // We can't check this anymore. With lazy deopt we could have already
297   // cleaned this IC entry before we even return. This is possible if
298   // we ran out of space in the inline cache buffer trying to do the
299   // set_next and we safepointed to free up space. This is a benign
300   // race because the IC entry was complete when we safepointed so
301   // cleaning it immediately is harmless.
302   // assert(is_megamorphic(), "sanity check");
303   return true;
304 }
305 
306 
307 // true if destination is megamorphic stub
308 bool CompiledIC::is_megamorphic() const {
309   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
310   assert(!is_optimized(), "an optimized call cannot be megamorphic");
311 
312   // Cannot rely on cached_value. It is either an interface or a method.
313   return VtableStubs::entry_point(ic_destination()) != NULL;
314 }
315 
316 bool CompiledIC::is_call_to_compiled() const {
317   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
318 
319   // Use unsafe, since an inline cache might point to a zombie method. However, the zombie
320   // method is guaranteed to still exist, since we only remove methods after all inline caches
321   // has been cleaned up
322   CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
323   bool is_monomorphic = (cb != NULL && cb->is_compiled());
324   // Check that the cached_value is a klass for non-optimized monomorphic calls
325   // This assertion is invalid for compiler1: a call that does not look optimized (no static stub) can be used
326   // for calling directly to vep without using the inline cache (i.e., cached_value == NULL).
327   // For JVMCI this occurs because CHA is only used to improve inlining so call sites which could be optimized
328   // virtuals because there are no currently loaded subclasses of a type are left as virtual call sites.
329 #ifdef ASSERT
330   CodeBlob* caller = CodeCache::find_blob_unsafe(instruction_address());
331   bool is_c1_or_jvmci_method = caller->is_compiled_by_c1() || caller->is_compiled_by_jvmci();
332   assert( is_c1_or_jvmci_method ||
333          !is_monomorphic ||
334          is_optimized() ||
335          !caller->is_alive() ||
336          (cached_metadata() != NULL && cached_metadata()->is_klass()), "sanity check");
337 #endif // ASSERT
338   return is_monomorphic;
339 }
340 
341 
342 bool CompiledIC::is_call_to_interpreted() const {
343   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
344   // Call to interpreter if destination is either calling to a stub (if it
345   // is optimized), or calling to an I2C blob
346   bool is_call_to_interpreted = false;
347   if (!is_optimized()) {
348     // must use unsafe because the destination can be a zombie (and we're cleaning)
349     // and the print_compiled_ic code wants to know if site (in the non-zombie)
350     // is to the interpreter.
351     CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
352     is_call_to_interpreted = (cb != NULL && cb->is_adapter_blob());
353     assert(!is_call_to_interpreted || (is_icholder_call() && cached_icholder() != NULL), "sanity check");
354   } else {
355     // Check if we are calling into our own codeblob (i.e., to a stub)
356     address dest = ic_destination();
357 #ifdef ASSERT
358     {
359       _call->verify_resolve_call(dest);
360     }
361 #endif /* ASSERT */
362     is_call_to_interpreted = _call->is_call_to_interpreted(dest);
363   }
364   return is_call_to_interpreted;
365 }
366 
367 bool CompiledIC::set_to_clean(bool in_use) {
368   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
369   if (TraceInlineCacheClearing || TraceICs) {
370     tty->print_cr("IC@" INTPTR_FORMAT ": set to clean", p2i(instruction_address()));
371     print();
372   }
373 
374   address entry = _call->get_resolve_call_stub(is_optimized());
375 
376   // A zombie transition will always be safe, since the metadata has already been set to NULL, so
377   // we only need to patch the destination
378   bool safe_transition = _call->is_safe_for_patching() || !in_use || is_optimized() || SafepointSynchronize::is_at_safepoint();
379 
380   if (safe_transition) {
381     // Kill any leftover stub we might have too
382     clear_ic_stub();
383     if (is_optimized()) {
384       set_ic_destination(entry);
385     } else {
386       set_ic_destination_and_value(entry, (void*)NULL);
387     }
388   } else {
389     // Unsafe transition - create stub.
390     if (!InlineCacheBuffer::create_transition_stub(this, NULL, entry)) {
391       return false;
392     }
393   }
394   // We can't check this anymore. With lazy deopt we could have already
395   // cleaned this IC entry before we even return. This is possible if
396   // we ran out of space in the inline cache buffer trying to do the
397   // set_next and we safepointed to free up space. This is a benign
398   // race because the IC entry was complete when we safepointed so
399   // cleaning it immediately is harmless.
400   // assert(is_clean(), "sanity check");
401   return true;
402 }
403 
404 bool CompiledIC::is_clean() const {
405   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
406   bool is_clean = false;
407   address dest = ic_destination();
408   is_clean = dest == _call->get_resolve_call_stub(is_optimized());
409   assert(!is_clean || is_optimized() || cached_value() == NULL, "sanity check");
410   return is_clean;
411 }
412 
413 bool CompiledIC::set_to_monomorphic(CompiledICInfo& info) {
414   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
415   // Updating a cache to the wrong entry can cause bugs that are very hard
416   // to track down - if cache entry gets invalid - we just clean it. In
417   // this way it is always the same code path that is responsible for
418   // updating and resolving an inline cache
419   //
420   // The above is no longer true. SharedRuntime::fixup_callers_callsite will change optimized
421   // callsites. In addition ic_miss code will update a site to monomorphic if it determines
422   // that an monomorphic call to the interpreter can now be monomorphic to compiled code.
423   //
424   // In both of these cases the only thing being modifed is the jump/call target and these
425   // transitions are mt_safe
426 
427   Thread *thread = Thread::current();
428   if (info.to_interpreter()) {
429     // Call to interpreter
430     if (info.is_optimized() && is_optimized()) {
431       assert(is_clean(), "unsafe IC path");
432       // the call analysis (callee structure) specifies that the call is optimized
433       // (either because of CHA or the static target is final)
434       // At code generation time, this call has been emitted as static call
435       // Call via stub
436       assert(info.cached_metadata() != NULL && info.cached_metadata()->is_method(), "sanity check");
437       methodHandle method (thread, (Method*)info.cached_metadata());
438       _call->set_to_interpreted(method, info);
439 
440       if (TraceICs) {
441          ResourceMark rm(thread);
442          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s",
443            p2i(instruction_address()),
444            method->print_value_string());
445       }
446     } else {
447       // Call via method-klass-holder
448       CompiledICHolder* holder = info.claim_cached_icholder();
449       if (!InlineCacheBuffer::create_transition_stub(this, holder, info.entry())) {
450         delete holder;
451         return false;
452       }
453       if (TraceICs) {
454          ResourceMark rm(thread);
455          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via icholder ", p2i(instruction_address()));
456       }
457     }
458   } else {
459     // Call to compiled code
460     bool static_bound = info.is_optimized() || (info.cached_metadata() == NULL);
461 #ifdef ASSERT
462     CodeBlob* cb = CodeCache::find_blob_unsafe(info.entry());
463     assert (cb != NULL && cb->is_compiled(), "must be compiled!");
464 #endif /* ASSERT */
465 
466     // This is MT safe if we come from a clean-cache and go through a
467     // non-verified entry point
468     bool safe = SafepointSynchronize::is_at_safepoint() ||
469                 (!is_in_transition_state() && (info.is_optimized() || static_bound || is_clean()));
470 
471     if (!safe) {
472       if (!InlineCacheBuffer::create_transition_stub(this, info.cached_metadata(), info.entry())) {
473         return false;
474       }
475     } else {
476       if (is_optimized()) {
477         set_ic_destination(info.entry());
478       } else {
479         set_ic_destination_and_value(info.entry(), info.cached_metadata());
480       }
481     }
482 
483     if (TraceICs) {
484       ResourceMark rm(thread);
485       assert(info.cached_metadata() == NULL || info.cached_metadata()->is_klass(), "must be");
486       tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass = %s) %s",
487         p2i(instruction_address()),
488         (info.cached_metadata() != NULL) ? ((Klass*)info.cached_metadata())->print_value_string() : "NULL",
489         (safe) ? "" : " via stub");
490     }
491   }
492   // We can't check this anymore. With lazy deopt we could have already
493   // cleaned this IC entry before we even return. This is possible if
494   // we ran out of space in the inline cache buffer trying to do the
495   // set_next and we safepointed to free up space. This is a benign
496   // race because the IC entry was complete when we safepointed so
497   // cleaning it immediately is harmless.
498   // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
499   return true;
500 }
501 
502 
503 // is_optimized: Compiler has generated an optimized call (i.e. fixed, no inline cache)
504 // static_bound: The call can be static bound. If it isn't also optimized, the property
505 // wasn't provable at time of compilation. An optimized call will have any necessary
506 // null check, while a static_bound won't. A static_bound (but not optimized) must
507 // therefore use the unverified entry point.
508 void CompiledIC::compute_monomorphic_entry(const methodHandle& method,
509                                            Klass* receiver_klass,
510                                            bool is_optimized,
511                                            bool static_bound,
512                                            bool caller_is_nmethod,
513                                            CompiledICInfo& info,
514                                            TRAPS) {
515   CompiledMethod* method_code = method->code();
516 
517   address entry = NULL;
518   if (method_code != NULL && method_code->is_in_use() && !method_code->is_unloading()) {
519     assert(method_code->is_compiled(), "must be compiled");
520     // Call to compiled code
521     //
522     // Note: the following problem exists with Compiler1:
523     //   - at compile time we may or may not know if the destination is final
524     //   - if we know that the destination is final (is_optimized), we will emit
525     //     an optimized virtual call (no inline cache), and need a Method* to make
526     //     a call to the interpreter
527     //   - if we don't know if the destination is final, we emit a standard
528     //     virtual call, and use CompiledICHolder to call interpreted code
529     //     (no static call stub has been generated)
530     //   - In the case that we here notice the call is static bound we
531     //     convert the call into what looks to be an optimized virtual call,
532     //     but we must use the unverified entry point (since there will be no
533     //     null check on a call when the target isn't loaded).
534     //     This causes problems when verifying the IC because
535     //     it looks vanilla but is optimized. Code in is_call_to_interpreted
536     //     is aware of this and weakens its asserts.
537     if (is_optimized) {
538       entry      = method_code->verified_entry_point();
539     } else {
540       entry      = method_code->entry_point();
541     }
542   }
543   if (entry != NULL) {
544     // Call to near compiled code.
545     info.set_compiled_entry(entry, is_optimized ? NULL : receiver_klass, is_optimized);
546   } else {
547     if (is_optimized) {
548       // Use stub entry
549       info.set_interpreter_entry(method()->get_c2i_entry(), method());
550     } else {
551       // Use icholder entry
552       assert(method_code == NULL || method_code->is_compiled(), "must be compiled");
553       CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass);
554       info.set_icholder_entry(method()->get_c2i_unverified_entry(), holder);
555     }
556   }
557   assert(info.is_optimized() == is_optimized, "must agree");
558 }
559 
560 
561 bool CompiledIC::is_icholder_entry(address entry) {
562   CodeBlob* cb = CodeCache::find_blob_unsafe(entry);
563   if (cb != NULL && cb->is_adapter_blob()) {
564     return true;
565   }
566   // itable stubs also use CompiledICHolder
567   if (cb != NULL && cb->is_vtable_blob()) {
568     VtableStub* s = VtableStubs::entry_point(entry);
569     return (s != NULL) && s->is_itable_stub();
570   }
571 
572   return false;
573 }
574 
575 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site, const CompiledMethod* cm) {
576   // This call site might have become stale so inspect it carefully.
577   address dest = cm->call_wrapper_at(call_site->addr())->destination();
578   return is_icholder_entry(dest);
579 }
580 
581 // ----------------------------------------------------------------------------
582 
583 bool CompiledStaticCall::set_to_clean(bool in_use) {
584   // in_use is unused but needed to match template function in CompiledMethod
585   assert(CompiledICLocker::is_safe(instruction_address()), "mt unsafe call");
586   // Reset call site
587   set_destination_mt_safe(resolve_call_stub());
588 
589   // Do not reset stub here:  It is too expensive to call find_stub.
590   // Instead, rely on caller (nmethod::clear_inline_caches) to clear
591   // both the call and its stub.
592   return true;
593 }
594 
595 bool CompiledStaticCall::is_clean() const {
596   return destination() == resolve_call_stub();
597 }
598 
599 bool CompiledStaticCall::is_call_to_compiled() const {
600   return CodeCache::contains(destination());
601 }
602 
603 bool CompiledDirectStaticCall::is_call_to_interpreted() const {
604   // It is a call to interpreted, if it calls to a stub. Hence, the destination
605   // must be in the stub part of the nmethod that contains the call
606   CompiledMethod* cm = CodeCache::find_compiled(instruction_address());
607   return cm->stub_contains(destination());
608 }
609 
610 void CompiledStaticCall::set_to_compiled(address entry) {
611   if (TraceICs) {
612     ResourceMark rm;
613     tty->print_cr("%s@" INTPTR_FORMAT ": set_to_compiled " INTPTR_FORMAT,
614         name(),
615         p2i(instruction_address()),
616         p2i(entry));
617   }
618   // Call to compiled code
619   assert(CodeCache::contains(entry), "wrong entry point");
620   set_destination_mt_safe(entry);
621 }
622 
623 void CompiledStaticCall::set(const StaticCallInfo& info) {
624   assert(CompiledICLocker::is_safe(instruction_address()), "mt unsafe call");
625   // Updating a cache to the wrong entry can cause bugs that are very hard
626   // to track down - if cache entry gets invalid - we just clean it. In
627   // this way it is always the same code path that is responsible for
628   // updating and resolving an inline cache
629   assert(is_clean(), "do not update a call entry - use clean");
630 
631   if (info._to_interpreter) {
632     // Call to interpreted code
633     set_to_interpreted(info.callee(), info.entry());
634   } else {
635     set_to_compiled(info.entry());
636   }
637 }
638 
639 // Compute settings for a CompiledStaticCall. Since we might have to set
640 // the stub when calling to the interpreter, we need to return arguments.
641 void CompiledStaticCall::compute_entry(const methodHandle& m, bool caller_is_nmethod, StaticCallInfo& info) {
642   CompiledMethod* m_code = m->code();
643   info._callee = m;
644   if (m_code != NULL && m_code->is_in_use() && !m_code->is_unloading()) {
645     info._to_interpreter = false;
646     info._entry  = m_code->verified_entry_point();
647   } else {
648     // Callee is interpreted code.  In any case entering the interpreter
649     // puts a converter-frame on the stack to save arguments.
650     assert(!m->is_method_handle_intrinsic(), "Compiled code should never call interpreter MH intrinsics");
651     info._to_interpreter = true;
652     info._entry      = m()->get_c2i_entry();
653   }
654 }
655 
656 address CompiledDirectStaticCall::find_stub_for(address instruction) {
657   // Find reloc. information containing this call-site
658   RelocIterator iter((nmethod*)NULL, instruction);
659   while (iter.next()) {
660     if (iter.addr() == instruction) {
661       switch(iter.type()) {
662         case relocInfo::static_call_type:
663           return iter.static_call_reloc()->static_stub();
664         // We check here for opt_virtual_call_type, since we reuse the code
665         // from the CompiledIC implementation
666         case relocInfo::opt_virtual_call_type:
667           return iter.opt_virtual_call_reloc()->static_stub();
668         case relocInfo::poll_type:
669         case relocInfo::poll_return_type: // A safepoint can't overlap a call.
670         default:
671           ShouldNotReachHere();
672       }
673     }
674   }
675   return NULL;
676 }
677 
678 address CompiledDirectStaticCall::find_stub() {
679   return CompiledDirectStaticCall::find_stub_for(instruction_address());
680 }
681 
682 address CompiledDirectStaticCall::resolve_call_stub() const {
683   return SharedRuntime::get_resolve_static_call_stub();
684 }
685 
686 //-----------------------------------------------------------------------------
687 // Non-product mode code
688 #ifndef PRODUCT
689 
690 void CompiledIC::verify() {
691   _call->verify();
692   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted()
693           || is_optimized() || is_megamorphic(), "sanity check");
694 }
695 
696 void CompiledIC::print() {
697   print_compiled_ic();
698   tty->cr();
699 }
700 
701 void CompiledIC::print_compiled_ic() {
702   tty->print("Inline cache at " INTPTR_FORMAT ", calling %s " INTPTR_FORMAT " cached_value " INTPTR_FORMAT,
703              p2i(instruction_address()), is_call_to_interpreted() ? "interpreted " : "", p2i(ic_destination()), p2i(is_optimized() ? NULL : cached_value()));
704 }
705 
706 void CompiledDirectStaticCall::print() {
707   tty->print("static call at " INTPTR_FORMAT " -> ", p2i(instruction_address()));
708   if (is_clean()) {
709     tty->print("clean");
710   } else if (is_call_to_compiled()) {
711     tty->print("compiled");
712   } else if (is_call_to_interpreted()) {
713     tty->print("interpreted");
714   }
715   tty->cr();
716 }
717 
718 void CompiledDirectStaticCall::verify_mt_safe(const methodHandle& callee, address entry,
719                                               NativeMovConstReg* method_holder,
720                                               NativeJump*        jump) {
721   // A generated lambda form might be deleted from the Lambdaform
722   // cache in MethodTypeForm.  If a jit compiled lambdaform method
723   // becomes not entrant and the cache access returns null, the new
724   // resolve will lead to a new generated LambdaForm.
725   Method* old_method = reinterpret_cast<Method*>(method_holder->data());
726   assert(old_method == NULL || old_method == callee() ||
727          callee->is_compiled_lambda_form() ||
728          !old_method->method_holder()->is_loader_alive() ||
729          old_method->is_old(),  // may be race patching deoptimized nmethod due to redefinition.
730          "a) MT-unsafe modification of inline cache");
731 
732   address destination = jump->jump_destination();
733   assert(destination == (address)-1 || destination == entry
734          || old_method == NULL || !old_method->method_holder()->is_loader_alive() // may have a race due to class unloading.
735          || old_method->is_old(),  // may be race patching deoptimized nmethod due to redefinition.
736          "b) MT-unsafe modification of inline cache");
737 }
738 #endif // !PRODUCT