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src/hotspot/share/code/compiledIC.cpp

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229 CompiledIC::CompiledIC(RelocIterator* iter)
230   : _method(iter->code())
231 {
232   _call = _method->call_wrapper_at(iter->addr());
233   address ic_call = _call->instruction_address();
234 
235   CompiledMethod* nm = iter->code();
236   assert(ic_call != nullptr, "ic_call address must be set");
237   assert(nm != nullptr, "must pass compiled method");
238   assert(nm->contains(ic_call), "must be in compiled method");
239 
240   initialize_from_iter(iter);
241 }
242 
243 // This function may fail for two reasons: either due to running out of vtable
244 // stubs, or due to running out of IC stubs in an attempted transition to a
245 // transitional state. The needs_ic_stub_refill value will be set if the failure
246 // was due to running out of IC stubs, in which case the caller will refill IC
247 // stubs and retry.
248 bool CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode,
249                                     bool& needs_ic_stub_refill, TRAPS) {
250   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
251   assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
252   assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
253 
254   address entry;
255   if (call_info->call_kind() == CallInfo::itable_call) {
256     assert(bytecode == Bytecodes::_invokeinterface, "");
257     int itable_index = call_info->itable_index();
258     entry = VtableStubs::find_itable_stub(itable_index);
259     if (entry == nullptr) {
260       return false;
261     }
262 #ifdef ASSERT
263     int index = call_info->resolved_method()->itable_index();
264     assert(index == itable_index, "CallInfo pre-computes this");
265     InstanceKlass* k = call_info->resolved_method()->method_holder();
266     assert(k->verify_itable_index(itable_index), "sanity check");
267 #endif //ASSERT
268     CompiledICHolder* holder = new CompiledICHolder(call_info->resolved_method()->method_holder(),
269                                                     call_info->resolved_klass(), false);
270     holder->claim();
271     if (!InlineCacheBuffer::create_transition_stub(this, holder, entry)) {
272       delete holder;
273       needs_ic_stub_refill = true;
274       return false;
275     }
276     // LSan appears unable to follow malloc-based memory consistently when embedded as an immediate
277     // in generated machine code. So we have to ignore it.
278     LSAN_IGNORE_OBJECT(holder);
279   } else {
280     assert(call_info->call_kind() == CallInfo::vtable_call, "either itable or vtable");
281     // Can be different than selected_method->vtable_index(), due to package-private etc.
282     int vtable_index = call_info->vtable_index();
283     assert(call_info->resolved_klass()->verify_vtable_index(vtable_index), "sanity check");
284     entry = VtableStubs::find_vtable_stub(vtable_index);
285     if (entry == nullptr) {
286       return false;
287     }
288     if (!InlineCacheBuffer::create_transition_stub(this, nullptr, entry)) {
289       needs_ic_stub_refill = true;
290       return false;
291     }
292   }
293 
294   if (TraceICs) {
295     ResourceMark rm;
296     assert(call_info->selected_method() != nullptr, "Unexpected null selected method");
297     tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
298                    p2i(instruction_address()), call_info->selected_method()->print_value_string(), p2i(entry));
299   }
300 
301   // We can't check this anymore. With lazy deopt we could have already
302   // cleaned this IC entry before we even return. This is possible if
303   // we ran out of space in the inline cache buffer trying to do the
304   // set_next and we safepointed to free up space. This is a benign

492   // cleaned this IC entry before we even return. This is possible if
493   // we ran out of space in the inline cache buffer trying to do the
494   // set_next and we safepointed to free up space. This is a benign
495   // race because the IC entry was complete when we safepointed so
496   // cleaning it immediately is harmless.
497   // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
498   return true;
499 }
500 
501 
502 // is_optimized: Compiler has generated an optimized call (i.e. fixed, no inline cache)
503 // static_bound: The call can be static bound. If it isn't also optimized, the property
504 // wasn't provable at time of compilation. An optimized call will have any necessary
505 // null check, while a static_bound won't. A static_bound (but not optimized) must
506 // therefore use the unverified entry point.
507 void CompiledIC::compute_monomorphic_entry(const methodHandle& method,
508                                            Klass* receiver_klass,
509                                            bool is_optimized,
510                                            bool static_bound,
511                                            bool caller_is_nmethod,

512                                            CompiledICInfo& info,
513                                            TRAPS) {
514   CompiledMethod* method_code = method->code();
515 
516   address entry = nullptr;
517   if (method_code != nullptr && method_code->is_in_use() && !method_code->is_unloading()) {
518     assert(method_code->is_compiled(), "must be compiled");
519     // Call to compiled code
520     //
521     // Note: the following problem exists with Compiler1:
522     //   - at compile time we may or may not know if the destination is final
523     //   - if we know that the destination is final (is_optimized), we will emit
524     //     an optimized virtual call (no inline cache), and need a Method* to make
525     //     a call to the interpreter
526     //   - if we don't know if the destination is final, we emit a standard
527     //     virtual call, and use CompiledICHolder to call interpreted code
528     //     (no static call stub has been generated)
529     //   - In the case that we here notice the call is static bound we
530     //     convert the call into what looks to be an optimized virtual call,
531     //     but we must use the unverified entry point (since there will be no
532     //     null check on a call when the target isn't loaded).
533     //     This causes problems when verifying the IC because
534     //     it looks vanilla but is optimized. Code in is_call_to_interpreted
535     //     is aware of this and weakens its asserts.
536     if (is_optimized) {
537       entry      = method_code->verified_entry_point();
538     } else {
539       entry      = method_code->entry_point();
540     }
541   }
542   if (entry != nullptr) {
543     // Call to near compiled code.
544     info.set_compiled_entry(entry, is_optimized ? nullptr : receiver_klass, is_optimized);
545   } else {
546     if (is_optimized) {
547       // Use stub entry
548       info.set_interpreter_entry(method()->get_c2i_entry(), method());

549     } else {
550       // Use icholder entry
551       assert(method_code == nullptr || method_code->is_compiled(), "must be compiled");
552       CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass);
553       info.set_icholder_entry(method()->get_c2i_unverified_entry(), holder);

554     }
555   }
556   assert(info.is_optimized() == is_optimized, "must agree");
557 }
558 
559 
560 bool CompiledIC::is_icholder_entry(address entry) {
561   CodeBlob* cb = CodeCache::find_blob(entry);
562   if (cb == nullptr) {
563     return false;
564   }
565   if (cb->is_adapter_blob()) {
566     return true;
567   } else if (cb->is_vtable_blob()) {
568     return VtableStubs::is_icholder_entry(entry);
569   }
570   return false;
571 }
572 
573 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site, const CompiledMethod* cm) {

619 }
620 
621 void CompiledStaticCall::set(const StaticCallInfo& info) {
622   assert(CompiledICLocker::is_safe(instruction_address()), "mt unsafe call");
623   // Updating a cache to the wrong entry can cause bugs that are very hard
624   // to track down - if cache entry gets invalid - we just clean it. In
625   // this way it is always the same code path that is responsible for
626   // updating and resolving an inline cache
627   assert(is_clean(), "do not update a call entry - use clean");
628 
629   if (info._to_interpreter) {
630     // Call to interpreted code
631     set_to_interpreted(info.callee(), info.entry());
632   } else {
633     set_to_compiled(info.entry());
634   }
635 }
636 
637 // Compute settings for a CompiledStaticCall. Since we might have to set
638 // the stub when calling to the interpreter, we need to return arguments.
639 void CompiledStaticCall::compute_entry(const methodHandle& m, bool caller_is_nmethod, StaticCallInfo& info) {


640   CompiledMethod* m_code = m->code();
641   info._callee = m;
642   if (m_code != nullptr && m_code->is_in_use() && !m_code->is_unloading()) {
643     info._to_interpreter = false;
644     info._entry  = m_code->verified_entry_point();




645   } else {
646     // Callee is interpreted code.  In any case entering the interpreter
647     // puts a converter-frame on the stack to save arguments.
648     assert(!m->is_method_handle_intrinsic(), "Compiled code should never call interpreter MH intrinsics");
649     info._to_interpreter = true;
650     info._entry      = m()->get_c2i_entry();






651   }
652 }
653 
654 void CompiledStaticCall::compute_entry_for_continuation_entry(const methodHandle& m, StaticCallInfo& info) {
655   if (ContinuationEntry::is_interpreted_call(instruction_address())) {
656     info._to_interpreter = true;
657     info._entry = m()->get_c2i_entry();
658   }
659 }
660 
661 address CompiledDirectStaticCall::find_stub_for(address instruction) {
662   // Find reloc. information containing this call-site
663   RelocIterator iter((nmethod*)nullptr, instruction);
664   while (iter.next()) {
665     if (iter.addr() == instruction) {
666       switch(iter.type()) {
667         case relocInfo::static_call_type:
668           return iter.static_call_reloc()->static_stub();
669         // We check here for opt_virtual_call_type, since we reuse the code
670         // from the CompiledIC implementation

229 CompiledIC::CompiledIC(RelocIterator* iter)
230   : _method(iter->code())
231 {
232   _call = _method->call_wrapper_at(iter->addr());
233   address ic_call = _call->instruction_address();
234 
235   CompiledMethod* nm = iter->code();
236   assert(ic_call != nullptr, "ic_call address must be set");
237   assert(nm != nullptr, "must pass compiled method");
238   assert(nm->contains(ic_call), "must be in compiled method");
239 
240   initialize_from_iter(iter);
241 }
242 
243 // This function may fail for two reasons: either due to running out of vtable
244 // stubs, or due to running out of IC stubs in an attempted transition to a
245 // transitional state. The needs_ic_stub_refill value will be set if the failure
246 // was due to running out of IC stubs, in which case the caller will refill IC
247 // stubs and retry.
248 bool CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode,
249                                     bool& needs_ic_stub_refill, bool caller_is_c1, TRAPS) {
250   assert(CompiledICLocker::is_safe(_method), "mt unsafe call");
251   assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
252   assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
253 
254   address entry;
255   if (call_info->call_kind() == CallInfo::itable_call) {
256     assert(bytecode == Bytecodes::_invokeinterface, "");
257     int itable_index = call_info->itable_index();
258     entry = VtableStubs::find_itable_stub(itable_index, caller_is_c1);
259     if (entry == nullptr) {
260       return false;
261     }
262 #ifdef ASSERT
263     int index = call_info->resolved_method()->itable_index();
264     assert(index == itable_index, "CallInfo pre-computes this");
265     InstanceKlass* k = call_info->resolved_method()->method_holder();
266     assert(k->verify_itable_index(itable_index), "sanity check");
267 #endif //ASSERT
268     CompiledICHolder* holder = new CompiledICHolder(call_info->resolved_method()->method_holder(),
269                                                     call_info->resolved_klass(), false);
270     holder->claim();
271     if (!InlineCacheBuffer::create_transition_stub(this, holder, entry)) {
272       delete holder;
273       needs_ic_stub_refill = true;
274       return false;
275     }
276     // LSan appears unable to follow malloc-based memory consistently when embedded as an immediate
277     // in generated machine code. So we have to ignore it.
278     LSAN_IGNORE_OBJECT(holder);
279   } else {
280     assert(call_info->call_kind() == CallInfo::vtable_call, "either itable or vtable");
281     // Can be different than selected_method->vtable_index(), due to package-private etc.
282     int vtable_index = call_info->vtable_index();
283     assert(call_info->resolved_klass()->verify_vtable_index(vtable_index), "sanity check");
284     entry = VtableStubs::find_vtable_stub(vtable_index, caller_is_c1);
285     if (entry == nullptr) {
286       return false;
287     }
288     if (!InlineCacheBuffer::create_transition_stub(this, nullptr, entry)) {
289       needs_ic_stub_refill = true;
290       return false;
291     }
292   }
293 
294   if (TraceICs) {
295     ResourceMark rm;
296     assert(call_info->selected_method() != nullptr, "Unexpected null selected method");
297     tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
298                    p2i(instruction_address()), call_info->selected_method()->print_value_string(), p2i(entry));
299   }
300 
301   // We can't check this anymore. With lazy deopt we could have already
302   // cleaned this IC entry before we even return. This is possible if
303   // we ran out of space in the inline cache buffer trying to do the
304   // set_next and we safepointed to free up space. This is a benign

492   // cleaned this IC entry before we even return. This is possible if
493   // we ran out of space in the inline cache buffer trying to do the
494   // set_next and we safepointed to free up space. This is a benign
495   // race because the IC entry was complete when we safepointed so
496   // cleaning it immediately is harmless.
497   // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
498   return true;
499 }
500 
501 
502 // is_optimized: Compiler has generated an optimized call (i.e. fixed, no inline cache)
503 // static_bound: The call can be static bound. If it isn't also optimized, the property
504 // wasn't provable at time of compilation. An optimized call will have any necessary
505 // null check, while a static_bound won't. A static_bound (but not optimized) must
506 // therefore use the unverified entry point.
507 void CompiledIC::compute_monomorphic_entry(const methodHandle& method,
508                                            Klass* receiver_klass,
509                                            bool is_optimized,
510                                            bool static_bound,
511                                            bool caller_is_nmethod,
512                                            bool caller_is_c1,
513                                            CompiledICInfo& info,
514                                            TRAPS) {
515   CompiledMethod* method_code = method->code();
516 
517   address entry = nullptr;
518   if (method_code != nullptr && 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      = caller_is_c1 ? method_code->verified_inline_entry_point() : method_code->verified_entry_point();
539     } else {
540       entry      = caller_is_c1 ? method_code->inline_entry_point() : method_code->entry_point();
541     }
542   }
543   if (entry != nullptr) {
544     // Call to near compiled code.
545     info.set_compiled_entry(entry, is_optimized ? nullptr : receiver_klass, is_optimized);
546   } else {
547     if (is_optimized) {
548       // Use stub entry
549       address entry = caller_is_c1 ? method()->get_c2i_inline_entry() : method()->get_c2i_entry();
550       info.set_interpreter_entry(entry, method());
551     } else {
552       // Use icholder entry
553       assert(method_code == nullptr || method_code->is_compiled(), "must be compiled");
554       CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass);
555       entry = (caller_is_c1)? method()->get_c2i_unverified_inline_entry() : method()->get_c2i_unverified_entry();
556       info.set_icholder_entry(entry, holder);
557     }
558   }
559   assert(info.is_optimized() == is_optimized, "must agree");
560 }
561 
562 
563 bool CompiledIC::is_icholder_entry(address entry) {
564   CodeBlob* cb = CodeCache::find_blob(entry);
565   if (cb == nullptr) {
566     return false;
567   }
568   if (cb->is_adapter_blob()) {
569     return true;
570   } else if (cb->is_vtable_blob()) {
571     return VtableStubs::is_icholder_entry(entry);
572   }
573   return false;
574 }
575 
576 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site, const CompiledMethod* cm) {

622 }
623 
624 void CompiledStaticCall::set(const StaticCallInfo& info) {
625   assert(CompiledICLocker::is_safe(instruction_address()), "mt unsafe call");
626   // Updating a cache to the wrong entry can cause bugs that are very hard
627   // to track down - if cache entry gets invalid - we just clean it. In
628   // this way it is always the same code path that is responsible for
629   // updating and resolving an inline cache
630   assert(is_clean(), "do not update a call entry - use clean");
631 
632   if (info._to_interpreter) {
633     // Call to interpreted code
634     set_to_interpreted(info.callee(), info.entry());
635   } else {
636     set_to_compiled(info.entry());
637   }
638 }
639 
640 // Compute settings for a CompiledStaticCall. Since we might have to set
641 // the stub when calling to the interpreter, we need to return arguments.
642 void CompiledStaticCall::compute_entry(const methodHandle& m, CompiledMethod* caller_nm, StaticCallInfo& info) {
643   assert(!m->mismatch(), "Mismatch for static call");
644   bool caller_is_nmethod = caller_nm->is_nmethod();
645   CompiledMethod* m_code = m->code();
646   info._callee = m;
647   if (m_code != nullptr && m_code->is_in_use() && !m_code->is_unloading()) {
648     info._to_interpreter = false;
649     if (caller_nm->is_compiled_by_c1()) {
650       info._entry = m_code->verified_inline_entry_point();
651     } else {
652       info._entry = m_code->verified_entry_point();
653     }
654   } else {
655     // Callee is interpreted code.  In any case entering the interpreter
656     // puts a converter-frame on the stack to save arguments.
657     assert(!m->is_method_handle_intrinsic(), "Compiled code should never call interpreter MH intrinsics");
658     info._to_interpreter = true;
659     if (caller_nm->is_compiled_by_c1()) {
660       // C1 -> interp: values passed as oops
661       info._entry = m()->get_c2i_inline_entry();
662     } else {
663       // C2 -> interp: values passed as fields
664       info._entry = m()->get_c2i_entry();
665     }
666   }
667 }
668 
669 void CompiledStaticCall::compute_entry_for_continuation_entry(const methodHandle& m, StaticCallInfo& info) {
670   if (ContinuationEntry::is_interpreted_call(instruction_address())) {
671     info._to_interpreter = true;
672     info._entry = m()->get_c2i_entry();
673   }
674 }
675 
676 address CompiledDirectStaticCall::find_stub_for(address instruction) {
677   // Find reloc. information containing this call-site
678   RelocIterator iter((nmethod*)nullptr, instruction);
679   while (iter.next()) {
680     if (iter.addr() == instruction) {
681       switch(iter.type()) {
682         case relocInfo::static_call_type:
683           return iter.static_call_reloc()->static_stub();
684         // We check here for opt_virtual_call_type, since we reuse the code
685         // from the CompiledIC implementation
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