4499
4500 // If this is a virtual call, we generate a funny guard. We pull out
4501 // the vtable entry corresponding to hashCode() from the target object.
4502 // If the target method which we are calling happens to be the native
4503 // Object hashCode() method, we pass the guard. We do not need this
4504 // guard for non-virtual calls -- the caller is known to be the native
4505 // Object hashCode().
4506 if (is_virtual) {
4507 // After null check, get the object's klass.
4508 Node* obj_klass = load_object_klass(obj);
4509 generate_virtual_guard(obj_klass, slow_region);
4510 }
4511
4512 // Get the header out of the object, use LoadMarkNode when available
4513 Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4514 // The control of the load must be null. Otherwise, the load can move before
4515 // the null check after castPP removal.
4516 Node* no_ctrl = nullptr;
4517 Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4518
4519 // Test the header to see if it is unlocked.
4520 Node *lock_mask = _gvn.MakeConX(markWord::lock_mask_in_place);
4521 Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4522 Node *unlocked_val = _gvn.MakeConX(markWord::unlocked_value);
4523 Node *chk_unlocked = _gvn.transform(new CmpXNode( lmasked_header, unlocked_val));
4524 Node *test_unlocked = _gvn.transform(new BoolNode( chk_unlocked, BoolTest::ne));
4525
4526 generate_slow_guard(test_unlocked, slow_region);
4527
4528 // Get the hash value and check to see that it has been properly assigned.
4529 // We depend on hash_mask being at most 32 bits and avoid the use of
4530 // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4531 // vm: see markWord.hpp.
4532 Node *hash_mask = _gvn.intcon(markWord::hash_mask);
4533 Node *hash_shift = _gvn.intcon(markWord::hash_shift);
4534 Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4535 // This hack lets the hash bits live anywhere in the mark object now, as long
4536 // as the shift drops the relevant bits into the low 32 bits. Note that
4537 // Java spec says that HashCode is an int so there's no point in capturing
4538 // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4539 hshifted_header = ConvX2I(hshifted_header);
4540 Node *hash_val = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4541
4542 Node *no_hash_val = _gvn.intcon(markWord::no_hash);
4543 Node *chk_assigned = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4544 Node *test_assigned = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4545
4546 generate_slow_guard(test_assigned, slow_region);
4547
4548 Node* init_mem = reset_memory();
4549 // fill in the rest of the null path:
4550 result_io ->init_req(_null_path, i_o());
4551 result_mem->init_req(_null_path, init_mem);
4552
4553 result_val->init_req(_fast_path, hash_val);
|
4499
4500 // If this is a virtual call, we generate a funny guard. We pull out
4501 // the vtable entry corresponding to hashCode() from the target object.
4502 // If the target method which we are calling happens to be the native
4503 // Object hashCode() method, we pass the guard. We do not need this
4504 // guard for non-virtual calls -- the caller is known to be the native
4505 // Object hashCode().
4506 if (is_virtual) {
4507 // After null check, get the object's klass.
4508 Node* obj_klass = load_object_klass(obj);
4509 generate_virtual_guard(obj_klass, slow_region);
4510 }
4511
4512 // Get the header out of the object, use LoadMarkNode when available
4513 Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4514 // The control of the load must be null. Otherwise, the load can move before
4515 // the null check after castPP removal.
4516 Node* no_ctrl = nullptr;
4517 Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4518
4519 // Test the header to see if it is safe to read w.r.t. locking.
4520 Node *lock_mask = _gvn.MakeConX(markWord::lock_mask_in_place);
4521 Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4522 if (LockingMode == LM_LIGHTWEIGHT) {
4523 Node *monitor_val = _gvn.MakeConX(markWord::monitor_value);
4524 Node *chk_monitor = _gvn.transform(new CmpXNode(lmasked_header, monitor_val));
4525 Node *test_monitor = _gvn.transform(new BoolNode(chk_monitor, BoolTest::eq));
4526
4527 generate_slow_guard(test_monitor, slow_region);
4528 } else {
4529 Node *unlocked_val = _gvn.MakeConX(markWord::unlocked_value);
4530 Node *chk_unlocked = _gvn.transform(new CmpXNode(lmasked_header, unlocked_val));
4531 Node *test_not_unlocked = _gvn.transform(new BoolNode(chk_unlocked, BoolTest::ne));
4532
4533 generate_slow_guard(test_not_unlocked, slow_region);
4534 }
4535
4536 // Get the hash value and check to see that it has been properly assigned.
4537 // We depend on hash_mask being at most 32 bits and avoid the use of
4538 // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4539 // vm: see markWord.hpp.
4540 Node *hash_mask = _gvn.intcon(UseCompactObjectHeaders ? markWord::hash_mask_compact : markWord::hash_mask);
4541 Node *hash_shift = _gvn.intcon(UseCompactObjectHeaders ? markWord::hash_shift_compact : markWord::hash_shift);
4542 Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4543 // This hack lets the hash bits live anywhere in the mark object now, as long
4544 // as the shift drops the relevant bits into the low 32 bits. Note that
4545 // Java spec says that HashCode is an int so there's no point in capturing
4546 // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4547 hshifted_header = ConvX2I(hshifted_header);
4548 Node *hash_val = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4549
4550 Node *no_hash_val = _gvn.intcon(markWord::no_hash);
4551 Node *chk_assigned = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4552 Node *test_assigned = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4553
4554 generate_slow_guard(test_assigned, slow_region);
4555
4556 Node* init_mem = reset_memory();
4557 // fill in the rest of the null path:
4558 result_io ->init_req(_null_path, i_o());
4559 result_mem->init_req(_null_path, init_mem);
4560
4561 result_val->init_req(_fast_path, hash_val);
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