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src/hotspot/share/opto/library_call.cpp

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4542   // Get the header out of the object, use LoadMarkNode when available
4543   Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4544   // The control of the load must be null. Otherwise, the load can move before
4545   // the null check after castPP removal.
4546   Node* no_ctrl = nullptr;
4547   Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4548 
4549   // Test the header to see if it is unlocked.
4550   Node *lock_mask      = _gvn.MakeConX(markWord::lock_mask_in_place);
4551   Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4552   Node *unlocked_val   = _gvn.MakeConX(markWord::unlocked_value);
4553   Node *chk_unlocked   = _gvn.transform(new CmpXNode( lmasked_header, unlocked_val));
4554   Node *test_unlocked  = _gvn.transform(new BoolNode( chk_unlocked, BoolTest::ne));
4555 
4556   generate_slow_guard(test_unlocked, slow_region);
4557 
4558   // Get the hash value and check to see that it has been properly assigned.
4559   // We depend on hash_mask being at most 32 bits and avoid the use of
4560   // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4561   // vm: see markWord.hpp.
4562   Node *hash_mask      = _gvn.intcon(markWord::hash_mask);
4563   Node *hash_shift     = _gvn.intcon(markWord::hash_shift);
4564   Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4565   // This hack lets the hash bits live anywhere in the mark object now, as long
4566   // as the shift drops the relevant bits into the low 32 bits.  Note that
4567   // Java spec says that HashCode is an int so there's no point in capturing
4568   // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4569   hshifted_header      = ConvX2I(hshifted_header);
4570   Node *hash_val       = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4571 
4572   Node *no_hash_val    = _gvn.intcon(markWord::no_hash);
4573   Node *chk_assigned   = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4574   Node *test_assigned  = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4575 
4576   generate_slow_guard(test_assigned, slow_region);
4577 
4578   Node* init_mem = reset_memory();
4579   // fill in the rest of the null path:
4580   result_io ->init_req(_null_path, i_o());
4581   result_mem->init_req(_null_path, init_mem);
4582 
4583   result_val->init_req(_fast_path, hash_val);

4542   // Get the header out of the object, use LoadMarkNode when available
4543   Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
4544   // The control of the load must be null. Otherwise, the load can move before
4545   // the null check after castPP removal.
4546   Node* no_ctrl = nullptr;
4547   Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
4548 
4549   // Test the header to see if it is unlocked.
4550   Node *lock_mask      = _gvn.MakeConX(markWord::lock_mask_in_place);
4551   Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
4552   Node *unlocked_val   = _gvn.MakeConX(markWord::unlocked_value);
4553   Node *chk_unlocked   = _gvn.transform(new CmpXNode( lmasked_header, unlocked_val));
4554   Node *test_unlocked  = _gvn.transform(new BoolNode( chk_unlocked, BoolTest::ne));
4555 
4556   generate_slow_guard(test_unlocked, slow_region);
4557 
4558   // Get the hash value and check to see that it has been properly assigned.
4559   // We depend on hash_mask being at most 32 bits and avoid the use of
4560   // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
4561   // vm: see markWord.hpp.
4562   Node *hash_mask      = _gvn.intcon(UseCompactObjectHeaders ? markWord::hash_mask_compact  : markWord::hash_mask);
4563   Node *hash_shift     = _gvn.intcon(UseCompactObjectHeaders ? markWord::hash_shift_compact : markWord::hash_shift);
4564   Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
4565   // This hack lets the hash bits live anywhere in the mark object now, as long
4566   // as the shift drops the relevant bits into the low 32 bits.  Note that
4567   // Java spec says that HashCode is an int so there's no point in capturing
4568   // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
4569   hshifted_header      = ConvX2I(hshifted_header);
4570   Node *hash_val       = _gvn.transform(new AndINode(hshifted_header, hash_mask));
4571 
4572   Node *no_hash_val    = _gvn.intcon(markWord::no_hash);
4573   Node *chk_assigned   = _gvn.transform(new CmpINode( hash_val, no_hash_val));
4574   Node *test_assigned  = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
4575 
4576   generate_slow_guard(test_assigned, slow_region);
4577 
4578   Node* init_mem = reset_memory();
4579   // fill in the rest of the null path:
4580   result_io ->init_req(_null_path, i_o());
4581   result_mem->init_req(_null_path, init_mem);
4582 
4583   result_val->init_req(_fast_path, hash_val);
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