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src/hotspot/share/opto/library_call.cpp

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4648     // and skip a call to MH.linkTo*/invokeBasic adapter, additional information
4649     // about the method being invoked should be attached to the call site to
4650     // make resolution logic work (see SharedRuntime::resolve_{virtual,opt_virtual}_call_C).
4651     slow_call->set_override_symbolic_info(true);
4652   }
4653   set_arguments_for_java_call(slow_call);
4654   set_edges_for_java_call(slow_call);
4655   return slow_call;
4656 }
4657 
4658 
4659 /**
4660  * Build special case code for calls to hashCode on an object. This call may
4661  * be virtual (invokevirtual) or bound (invokespecial). For each case we generate
4662  * slightly different code.
4663  */
4664 bool LibraryCallKit::inline_native_hashcode(bool is_virtual, bool is_static) {
4665   assert(is_static == callee()->is_static(), "correct intrinsic selection");
4666   assert(!(is_virtual && is_static), "either virtual, special, or static");
4667 
4668   enum { _slow_path = 1, _fast_path, _null_path, PATH_LIMIT };
4669 
4670   RegionNode* result_reg = new RegionNode(PATH_LIMIT);
4671   PhiNode*    result_val = new PhiNode(result_reg, TypeInt::INT);
4672   PhiNode*    result_io  = new PhiNode(result_reg, Type::ABIO);
4673   PhiNode*    result_mem = new PhiNode(result_reg, Type::MEMORY, TypePtr::BOTTOM);
4674   Node* obj = nullptr;
4675   if (!is_static) {
4676     // Check for hashing null object
4677     obj = null_check_receiver();
4678     if (stopped())  return true;        // unconditionally null
4679     result_reg->init_req(_null_path, top());
4680     result_val->init_req(_null_path, top());
4681   } else {
4682     // Do a null check, and return zero if null.
4683     // System.identityHashCode(null) == 0
4684     obj = argument(0);
4685     Node* null_ctl = top();
4686     obj = null_check_oop(obj, &null_ctl);
4687     result_reg->init_req(_null_path, null_ctl);
4688     result_val->init_req(_null_path, _gvn.intcon(0));

4696     return true;
4697   }
4698 
4699   // We only go to the fast case code if we pass a number of guards.  The
4700   // paths which do not pass are accumulated in the slow_region.
4701   RegionNode* slow_region = new RegionNode(1);
4702   record_for_igvn(slow_region);
4703 
4704   // If this is a virtual call, we generate a funny guard.  We pull out
4705   // the vtable entry corresponding to hashCode() from the target object.
4706   // If the target method which we are calling happens to be the native
4707   // Object hashCode() method, we pass the guard.  We do not need this
4708   // guard for non-virtual calls -- the caller is known to be the native
4709   // Object hashCode().
4710   if (is_virtual) {
4711     // After null check, get the object's klass.
4712     Node* obj_klass = load_object_klass(obj);
4713     generate_virtual_guard(obj_klass, slow_region);
4714   }
4715 
4716   // Get the header out of the object, use LoadMarkNode when available
4717   Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4718   // The control of the load must be null. Otherwise, the load can move before
4719   // the null check after castPP removal.
4720   Node* no_ctrl = nullptr;
4721   Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);




























4722 
4723   if (!UseObjectMonitorTable) {
4724     // Test the header to see if it is safe to read w.r.t. locking.
4725     Node *lock_mask      = _gvn.MakeConX(markWord::lock_mask_in_place);
4726     Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4727     if (LockingMode == LM_LIGHTWEIGHT) {
4728       Node *monitor_val   = _gvn.MakeConX(markWord::monitor_value);
4729       Node *chk_monitor   = _gvn.transform(new CmpXNode(lmasked_header, monitor_val));
4730       Node *test_monitor  = _gvn.transform(new BoolNode(chk_monitor, BoolTest::eq));











4731 
4732       generate_slow_guard(test_monitor, slow_region);
4733     } else {
4734       Node *unlocked_val      = _gvn.MakeConX(markWord::unlocked_value);
4735       Node *chk_unlocked      = _gvn.transform(new CmpXNode(lmasked_header, unlocked_val));
4736       Node *test_not_unlocked = _gvn.transform(new BoolNode(chk_unlocked, BoolTest::ne));

















4737 
4738       generate_slow_guard(test_not_unlocked, slow_region);













































































4739     }
4740   }
4741 
4742   // Get the hash value and check to see that it has been properly assigned.
4743   // We depend on hash_mask being at most 32 bits and avoid the use of
4744   // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4745   // vm: see markWord.hpp.
4746   Node *hash_mask      = _gvn.intcon(markWord::hash_mask);
4747   Node *hash_shift     = _gvn.intcon(markWord::hash_shift);
4748   Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4749   // This hack lets the hash bits live anywhere in the mark object now, as long
4750   // as the shift drops the relevant bits into the low 32 bits.  Note that
4751   // Java spec says that HashCode is an int so there's no point in capturing
4752   // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4753   hshifted_header      = ConvX2I(hshifted_header);
4754   Node *hash_val       = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4755 
4756   Node *no_hash_val    = _gvn.intcon(markWord::no_hash);
4757   Node *chk_assigned   = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4758   Node *test_assigned  = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4759 
4760   generate_slow_guard(test_assigned, slow_region);









4761 
4762   Node* init_mem = reset_memory();
4763   // fill in the rest of the null path:
4764   result_io ->init_req(_null_path, i_o());
4765   result_mem->init_req(_null_path, init_mem);
4766 
4767   result_val->init_req(_fast_path, hash_val);
4768   result_reg->init_req(_fast_path, control());
4769   result_io ->init_req(_fast_path, i_o());
4770   result_mem->init_req(_fast_path, init_mem);
4771 





4772   // Generate code for the slow case.  We make a call to hashCode().

4773   set_control(_gvn.transform(slow_region));
4774   if (!stopped()) {
4775     // No need for PreserveJVMState, because we're using up the present state.
4776     set_all_memory(init_mem);
4777     vmIntrinsics::ID hashCode_id = is_static ? vmIntrinsics::_identityHashCode : vmIntrinsics::_hashCode;
4778     CallJavaNode* slow_call = generate_method_call(hashCode_id, is_virtual, is_static, false);
4779     Node* slow_result = set_results_for_java_call(slow_call);
4780     // this->control() comes from set_results_for_java_call
4781     result_reg->init_req(_slow_path, control());
4782     result_val->init_req(_slow_path, slow_result);
4783     result_io  ->set_req(_slow_path, i_o());
4784     result_mem ->set_req(_slow_path, reset_memory());
4785   }
4786 
4787   // Return the combined state.
4788   set_i_o(        _gvn.transform(result_io)  );
4789   set_all_memory( _gvn.transform(result_mem));
4790 
4791   set_result(result_reg, result_val);
4792   return true;

4648     // and skip a call to MH.linkTo*/invokeBasic adapter, additional information
4649     // about the method being invoked should be attached to the call site to
4650     // make resolution logic work (see SharedRuntime::resolve_{virtual,opt_virtual}_call_C).
4651     slow_call->set_override_symbolic_info(true);
4652   }
4653   set_arguments_for_java_call(slow_call);
4654   set_edges_for_java_call(slow_call);
4655   return slow_call;
4656 }
4657 
4658 
4659 /**
4660  * Build special case code for calls to hashCode on an object. This call may
4661  * be virtual (invokevirtual) or bound (invokespecial). For each case we generate
4662  * slightly different code.
4663  */
4664 bool LibraryCallKit::inline_native_hashcode(bool is_virtual, bool is_static) {
4665   assert(is_static == callee()->is_static(), "correct intrinsic selection");
4666   assert(!(is_virtual && is_static), "either virtual, special, or static");
4667 
4668   enum { _slow_path = 1, _null_path, _fast_path, _fast_path2, PATH_LIMIT };
4669 
4670   RegionNode* result_reg = new RegionNode(PATH_LIMIT);
4671   PhiNode*    result_val = new PhiNode(result_reg, TypeInt::INT);
4672   PhiNode*    result_io  = new PhiNode(result_reg, Type::ABIO);
4673   PhiNode*    result_mem = new PhiNode(result_reg, Type::MEMORY, TypePtr::BOTTOM);
4674   Node* obj = nullptr;
4675   if (!is_static) {
4676     // Check for hashing null object
4677     obj = null_check_receiver();
4678     if (stopped())  return true;        // unconditionally null
4679     result_reg->init_req(_null_path, top());
4680     result_val->init_req(_null_path, top());
4681   } else {
4682     // Do a null check, and return zero if null.
4683     // System.identityHashCode(null) == 0
4684     obj = argument(0);
4685     Node* null_ctl = top();
4686     obj = null_check_oop(obj, &null_ctl);
4687     result_reg->init_req(_null_path, null_ctl);
4688     result_val->init_req(_null_path, _gvn.intcon(0));

4696     return true;
4697   }
4698 
4699   // We only go to the fast case code if we pass a number of guards.  The
4700   // paths which do not pass are accumulated in the slow_region.
4701   RegionNode* slow_region = new RegionNode(1);
4702   record_for_igvn(slow_region);
4703 
4704   // If this is a virtual call, we generate a funny guard.  We pull out
4705   // the vtable entry corresponding to hashCode() from the target object.
4706   // If the target method which we are calling happens to be the native
4707   // Object hashCode() method, we pass the guard.  We do not need this
4708   // guard for non-virtual calls -- the caller is known to be the native
4709   // Object hashCode().
4710   if (is_virtual) {
4711     // After null check, get the object's klass.
4712     Node* obj_klass = load_object_klass(obj);
4713     generate_virtual_guard(obj_klass, slow_region);
4714   }
4715 
4716   if (UseCompactObjectHeaders) {
4717     // Get the header out of the object.
4718     Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4719     // The control of the load must be null. Otherwise, the load can move before
4720     // the null check after castPP removal.
4721     Node* no_ctrl = nullptr;
4722     Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4723 
4724     // Test the header to see if the object is in hashed or copied state.
4725     Node* hashctrl_mask  = _gvn.MakeConX(markWord::hashctrl_mask_in_place);
4726     Node* masked_header  = _gvn.transform(new AndXNode(header, hashctrl_mask));
4727 
4728     // Take slow-path when the object has not been hashed.
4729     Node* not_hashed_val = _gvn.MakeConX(0);
4730     Node* chk_hashed     = _gvn.transform(new CmpXNode(masked_header, not_hashed_val));
4731     Node* test_hashed    = _gvn.transform(new BoolNode(chk_hashed, BoolTest::eq));
4732 
4733     generate_slow_guard(test_hashed, slow_region);
4734 
4735     // Test whether the object is hashed or hashed&copied.
4736     Node* hashed_copied = _gvn.MakeConX(markWord::hashctrl_expanded_mask_in_place | markWord::hashctrl_hashed_mask_in_place);
4737     Node* chk_copied    = _gvn.transform(new CmpXNode(masked_header, hashed_copied));
4738     // If true, then object has been hashed&copied, otherwise it's only hashed.
4739     Node* test_copied   = _gvn.transform(new BoolNode(chk_copied, BoolTest::eq));
4740     IfNode* if_copied   = create_and_map_if(control(), test_copied, PROB_FAIR, COUNT_UNKNOWN);
4741     Node* if_true = _gvn.transform(new IfTrueNode(if_copied));
4742     Node* if_false = _gvn.transform(new IfFalseNode(if_copied));
4743 
4744     // Hashed&Copied path: read hash-code out of the object.
4745     set_control(if_true);
4746     // result_val->del_req(_fast_path2);
4747     // result_reg->del_req(_fast_path2);
4748     // result_io->del_req(_fast_path2);
4749     // result_mem->del_req(_fast_path2);
4750 
4751     Node* obj_klass = load_object_klass(obj);
4752     Node* hash_addr;
4753     const TypeKlassPtr* klass_t = _gvn.type(obj_klass)->isa_klassptr();
4754     bool load_offset_runtime = true;
4755 
4756     if (klass_t != nullptr) {
4757       if (klass_t->klass_is_exact()  && klass_t->isa_instklassptr()) {
4758         ciInstanceKlass* ciKlass = reinterpret_cast<ciInstanceKlass*>(klass_t->is_instklassptr()->exact_klass());
4759         if (!ciKlass->is_mirror_instance_klass() && !ciKlass->is_reference_instance_klass()) {
4760           // We know the InstanceKlass, load hash_offset from there at compile-time.
4761           int hash_offset = ciKlass->hash_offset_in_bytes();
4762           hash_addr = basic_plus_adr(obj, hash_offset);
4763           Node* loaded_hash = make_load(control(), hash_addr, TypeInt::INT, T_INT, MemNode::unordered);
4764           result_val->init_req(_fast_path2, loaded_hash);
4765           result_reg->init_req(_fast_path2, control());
4766           load_offset_runtime = false;
4767         }
4768       }
4769     }
4770 
4771     //tty->print_cr("Load hash-offset at runtime: %s", BOOL_TO_STR(load_offset_runtime));
4772 
4773     if (load_offset_runtime) {
4774       // We don't know if it is an array or an exact type, figure it out at run-time.
4775       // If not an ordinary instance, then we need to take slow-path.
4776       Node* kind_addr = basic_plus_adr(obj_klass, Klass::kind_offset_in_bytes());
4777       Node* kind = make_load(control(), kind_addr, TypeInt::INT, T_INT, MemNode::unordered);
4778       Node* instance_val = _gvn.intcon(Klass::InstanceKlassKind);
4779       Node* chk_inst     = _gvn.transform(new CmpINode(kind, instance_val));
4780       Node* test_inst    = _gvn.transform(new BoolNode(chk_inst, BoolTest::ne));
4781       generate_slow_guard(test_inst, slow_region);
4782 
4783       // Otherwise it's an instance and we can read the hash_offset from the InstanceKlass.
4784       Node* hash_offset_addr = basic_plus_adr(obj_klass, InstanceKlass::hash_offset_offset_in_bytes());
4785       Node* hash_offset = make_load(control(), hash_offset_addr, TypeInt::INT, T_INT, MemNode::unordered);
4786       // hash_offset->dump();
4787       Node* hash_addr = basic_plus_adr(obj, ConvI2X(hash_offset));
4788       Compile::current()->set_has_unsafe_access(true);
4789       Node* loaded_hash = make_load(control(), hash_addr, TypeInt::INT, T_INT, MemNode::unordered);
4790       result_val->init_req(_fast_path2, loaded_hash);
4791       result_reg->init_req(_fast_path2, control());
4792     }
4793 
4794     // Hashed-only path: recompute hash-code from object address.
4795     set_control(if_false);
4796     // Our constants.
4797     Node* M = _gvn.intcon(0x337954D5);
4798     Node* A = _gvn.intcon(0xAAAAAAAA);
4799     // Split object address into lo and hi 32 bits.
4800     Node* obj_addr = _gvn.transform(new CastP2XNode(nullptr, obj));
4801     Node* x = _gvn.transform(new ConvL2INode(obj_addr));
4802     Node* upper_addr = _gvn.transform(new URShiftLNode(obj_addr, _gvn.intcon(32)));
4803     Node* y = _gvn.transform(new ConvL2INode(upper_addr));
4804 
4805     Node* H0 = _gvn.transform(new XorINode(x, y));
4806     Node* L0 = _gvn.transform(new XorINode(x, A));
4807 
4808     // Full multiplication of two 32 bit values L0 and M into a hi/lo result in two 32 bit values V0 and U0.
4809     Node* L0_64 = _gvn.transform(new ConvI2LNode(L0));
4810     L0_64 = _gvn.transform(new AndLNode(L0_64, _gvn.longcon(0xFFFFFFFF)));
4811     Node* M_64 = _gvn.transform(new ConvI2LNode(M));
4812     // M_64 = _gvn.transform(new AndLNode(M_64, _gvn.longcon(0xFFFFFFFF)));
4813     Node* prod64 = _gvn.transform(new MulLNode(L0_64, M_64));
4814     Node* V0 = _gvn.transform(new ConvL2INode(prod64));
4815     Node* prod_upper = _gvn.transform(new URShiftLNode(prod64, _gvn.intcon(32)));
4816     Node* U0 = _gvn.transform(new ConvL2INode(prod_upper));
4817 
4818     Node* Q0 = _gvn.transform(new MulINode(H0, M));
4819     Node* L1 = _gvn.transform(new XorINode(Q0, U0));
4820 
4821     // Full multiplication of two 32 bit values L1 and M into a hi/lo result in two 32 bit values V1 and U1.
4822     Node* L1_64 = _gvn.transform(new ConvI2LNode(L1));
4823     L1_64 = _gvn.transform(new AndLNode(L1_64, _gvn.longcon(0xFFFFFFFF)));
4824     prod64 = _gvn.transform(new MulLNode(L1_64, M_64));
4825     Node* V1 = _gvn.transform(new ConvL2INode(prod64));
4826     prod_upper = _gvn.transform(new URShiftLNode(prod64, _gvn.intcon(32)));
4827     Node* U1 = _gvn.transform(new ConvL2INode(prod_upper));
4828 
4829     Node* P1 = _gvn.transform(new XorINode(V0, M));
4830 
4831     // Right rotate P1 by distance L1.
4832     Node* distance = _gvn.transform(new AndINode(L1, _gvn.intcon(32 - 1)));
4833     Node* inverse_distance = _gvn.transform(new SubINode(_gvn.intcon(32), distance));
4834     Node* ror_part1 = _gvn.transform(new URShiftINode(P1, distance));
4835     Node* ror_part2 = _gvn.transform(new LShiftINode(P1, inverse_distance));
4836     Node* Q1 = _gvn.transform(new OrINode(ror_part1, ror_part2));
4837 
4838     Node* L2 = _gvn.transform(new XorINode(Q1, U1));
4839     Node* hash = _gvn.transform(new XorINode(V1, L2));
4840     Node* hash_truncated = _gvn.transform(new AndINode(hash, _gvn.intcon(markWord::hash_mask)));
4841 
4842     // TODO: We could generate a fast case here under the following conditions:
4843     // - The hashctrl is set to hash_is_copied (see markWord::hash_is_copied())
4844     // - The type of the object is known
4845     // Then we can load the identity hashcode from the int field at Klass::hash_offset_in_bytes() of the object.
4846     result_val->init_req(_fast_path, hash_truncated);
4847   } else {
4848     // Get the header out of the object, use LoadMarkNode when available
4849     Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4850     // The control of the load must be null. Otherwise, the load can move before
4851     // the null check after castPP removal.
4852     Node* no_ctrl = nullptr;
4853     Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4854 
4855     if (!UseObjectMonitorTable) {
4856       // Test the header to see if it is safe to read w.r.t. locking.
4857       Node *lock_mask      = _gvn.MakeConX(markWord::lock_mask_in_place);
4858       Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4859       if (LockingMode == LM_LIGHTWEIGHT) {
4860         Node *monitor_val   = _gvn.MakeConX(markWord::monitor_value);
4861         Node *chk_monitor   = _gvn.transform(new CmpXNode(lmasked_header, monitor_val));
4862         Node *test_monitor  = _gvn.transform(new BoolNode(chk_monitor, BoolTest::eq));
4863 
4864         generate_slow_guard(test_monitor, slow_region);
4865       } else {
4866         Node *unlocked_val      = _gvn.MakeConX(markWord::unlocked_value);
4867         Node *chk_unlocked      = _gvn.transform(new CmpXNode(lmasked_header, unlocked_val));
4868         Node *test_not_unlocked = _gvn.transform(new BoolNode(chk_unlocked, BoolTest::ne));
4869 
4870         generate_slow_guard(test_not_unlocked, slow_region);
4871       }
4872     }

4873 
4874     // Get the hash value and check to see that it has been properly assigned.
4875     // We depend on hash_mask being at most 32 bits and avoid the use of
4876     // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4877     // vm: see markWord.hpp.
4878     Node *hash_mask      = _gvn.intcon(markWord::hash_mask);
4879     Node *hash_shift     = _gvn.intcon(markWord::hash_shift);
4880     Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4881     // This hack lets the hash bits live anywhere in the mark object now, as long
4882     // as the shift drops the relevant bits into the low 32 bits.  Note that
4883     // Java spec says that HashCode is an int so there's no point in capturing
4884     // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4885     hshifted_header      = ConvX2I(hshifted_header);
4886     Node *hash_val       = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4887 
4888     Node *no_hash_val    = _gvn.intcon(markWord::no_hash);
4889     Node *chk_assigned   = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4890     Node *test_assigned  = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4891 
4892     generate_slow_guard(test_assigned, slow_region);
4893 
4894     result_val->init_req(_fast_path, hash_val);
4895 
4896     // _fast_path2 is not used here.
4897     result_val->del_req(_fast_path2);
4898     result_reg->del_req(_fast_path2);
4899     result_io->del_req(_fast_path2);
4900     result_mem->del_req(_fast_path2);
4901   }
4902 
4903   Node* init_mem = reset_memory();
4904   // fill in the rest of the null path:
4905   result_io ->init_req(_null_path, i_o());
4906   result_mem->init_req(_null_path, init_mem);
4907 

4908   result_reg->init_req(_fast_path, control());
4909   result_io ->init_req(_fast_path, i_o());
4910   result_mem->init_req(_fast_path, init_mem);
4911 
4912   if (UseCompactObjectHeaders) {
4913     result_io->init_req(_fast_path2, i_o());
4914     result_mem->init_req(_fast_path2, init_mem);
4915   }
4916 
4917   // Generate code for the slow case.  We make a call to hashCode().
4918   assert(slow_region != nullptr, "must have slow_region");
4919   set_control(_gvn.transform(slow_region));
4920   if (!stopped()) {
4921     // No need for PreserveJVMState, because we're using up the present state.
4922     set_all_memory(init_mem);
4923     vmIntrinsics::ID hashCode_id = is_static ? vmIntrinsics::_identityHashCode : vmIntrinsics::_hashCode;
4924     CallJavaNode* slow_call = generate_method_call(hashCode_id, is_virtual, is_static, false);
4925     Node* slow_result = set_results_for_java_call(slow_call);
4926     // this->control() comes from set_results_for_java_call
4927     result_reg->init_req(_slow_path, control());
4928     result_val->init_req(_slow_path, slow_result);
4929     result_io  ->set_req(_slow_path, i_o());
4930     result_mem ->set_req(_slow_path, reset_memory());
4931   }
4932 
4933   // Return the combined state.
4934   set_i_o(        _gvn.transform(result_io)  );
4935   set_all_memory( _gvn.transform(result_mem));
4936 
4937   set_result(result_reg, result_val);
4938   return true;
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