40 // Since hashCode is usually polymorphic at call sites we can't do this
41 // optimization at the call site without a lot of work.
42 void SharedRuntime::inline_check_hashcode_from_object_header(MacroAssembler* masm,
43 const methodHandle& method,
44 Register obj_reg,
45 Register result) {
46 Label slowCase;
47
48 // Unlike for Object.hashCode, System.identityHashCode is static method and
49 // gets object as argument instead of the receiver.
50 if (method->intrinsic_id() == vmIntrinsics::_identityHashCode) {
51 Label Continue;
52 // return 0 for null reference input
53 __ cmpptr(obj_reg, NULL_WORD);
54 __ jcc(Assembler::notEqual, Continue);
55 __ xorptr(result, result);
56 __ ret(0);
57 __ bind(Continue);
58 }
59
60 __ movptr(result, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
61
62 if (!UseObjectMonitorTable) {
63 // check if monitor
64 __ testptr(result, markWord::monitor_value);
65 __ jcc(Assembler::notZero, slowCase);
66 }
67
68 // get hash
69 // Read the header and build a mask to get its hash field.
70 // Depend on hash_mask being at most 32 bits and avoid the use of hash_mask_in_place
71 // because it could be larger than 32 bits in a 64-bit vm. See markWord.hpp.
72 __ shrptr(result, markWord::hash_shift);
73 __ andptr(result, markWord::hash_mask);
74
75 // test if hashCode exists
76 __ jccb(Assembler::zero, slowCase);
77 __ ret(0);
78 __ bind(slowCase);
79 }
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40 // Since hashCode is usually polymorphic at call sites we can't do this
41 // optimization at the call site without a lot of work.
42 void SharedRuntime::inline_check_hashcode_from_object_header(MacroAssembler* masm,
43 const methodHandle& method,
44 Register obj_reg,
45 Register result) {
46 Label slowCase;
47
48 // Unlike for Object.hashCode, System.identityHashCode is static method and
49 // gets object as argument instead of the receiver.
50 if (method->intrinsic_id() == vmIntrinsics::_identityHashCode) {
51 Label Continue;
52 // return 0 for null reference input
53 __ cmpptr(obj_reg, NULL_WORD);
54 __ jcc(Assembler::notEqual, Continue);
55 __ xorptr(result, result);
56 __ ret(0);
57 __ bind(Continue);
58 }
59
60 if (UseCompactObjectHeaders) {
61 // Don't generate anything else and always take the slow-path for now.
62 return;
63 }
64
65 __ movptr(result, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
66
67 if (!UseObjectMonitorTable) {
68 // check if monitor
69 __ testptr(result, markWord::monitor_value);
70 __ jcc(Assembler::notZero, slowCase);
71 }
72
73 // get hash
74 // Read the header and build a mask to get its hash field.
75 // Depend on hash_mask being at most 32 bits and avoid the use of hash_mask_in_place
76 // because it could be larger than 32 bits in a 64-bit vm. See markWord.hpp.
77 __ shrptr(result, markWord::hash_shift);
78 __ andptr(result, markWord::hash_mask);
79
80 // test if hashCode exists
81 __ jccb(Assembler::zero, slowCase);
82 __ ret(0);
83 __ bind(slowCase);
84 }
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