< prev index next > src/hotspot/share/opto/library_call.cpp
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*/
bool LibraryCallKit::inline_native_hashcode(bool is_virtual, bool is_static) {
assert(is_static == callee()->is_static(), "correct intrinsic selection");
assert(!(is_virtual && is_static), "either virtual, special, or static");
- enum { _slow_path = 1, _fast_path, _null_path, PATH_LIMIT };
+ enum { _slow_path = 1, _null_path, _fast_path, _fast_path2, PATH_LIMIT };
RegionNode* result_reg = new RegionNode(PATH_LIMIT);
PhiNode* result_val = new PhiNode(result_reg, TypeInt::INT);
PhiNode* result_io = new PhiNode(result_reg, Type::ABIO);
PhiNode* result_mem = new PhiNode(result_reg, Type::MEMORY, TypePtr::BOTTOM);
// After null check, get the object's klass.
Node* obj_klass = load_object_klass(obj);
generate_virtual_guard(obj_klass, slow_region);
}
- // Get the header out of the object, use LoadMarkNode when available
- Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
- // The control of the load must be null. Otherwise, the load can move before
- // the null check after castPP removal.
- Node* no_ctrl = nullptr;
- Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
+ if (UseCompactObjectHeaders) {
+ // Get the header out of the object.
+ Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
+ // The control of the load must be null. Otherwise, the load can move before
+ // the null check after castPP removal.
+ Node* no_ctrl = nullptr;
+ Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
+
+ // Test the header to see if the object is in hashed or copied state.
+ Node* hashctrl_mask = _gvn.MakeConX(markWord::hashctrl_mask_in_place);
+ Node* masked_header = _gvn.transform(new AndXNode(header, hashctrl_mask));
+
+ // Take slow-path when the object has not been hashed.
+ Node* not_hashed_val = _gvn.MakeConX(0);
+ Node* chk_hashed = _gvn.transform(new CmpXNode(masked_header, not_hashed_val));
+ Node* test_hashed = _gvn.transform(new BoolNode(chk_hashed, BoolTest::eq));
+
+ generate_slow_guard(test_hashed, slow_region);
+
+ // Test whether the object is hashed or hashed&copied.
+ Node* hashed_copied = _gvn.MakeConX(markWord::hashctrl_expanded_mask_in_place | markWord::hashctrl_hashed_mask_in_place);
+ Node* chk_copied = _gvn.transform(new CmpXNode(masked_header, hashed_copied));
+ // If true, then object has been hashed&copied, otherwise it's only hashed.
+ Node* test_copied = _gvn.transform(new BoolNode(chk_copied, BoolTest::eq));
+ IfNode* if_copied = create_and_map_if(control(), test_copied, PROB_FAIR, COUNT_UNKNOWN);
+ Node* if_true = _gvn.transform(new IfTrueNode(if_copied));
+ Node* if_false = _gvn.transform(new IfFalseNode(if_copied));
+
+ // Hashed&Copied path: read hash-code out of the object.
+ set_control(if_true);
+ // result_val->del_req(_fast_path2);
+ // result_reg->del_req(_fast_path2);
+ // result_io->del_req(_fast_path2);
+ // result_mem->del_req(_fast_path2);
- if (!UseObjectMonitorTable) {
- // Test the header to see if it is safe to read w.r.t. locking.
- Node *lock_mask = _gvn.MakeConX(markWord::lock_mask_in_place);
- Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
- if (LockingMode == LM_LIGHTWEIGHT) {
- Node *monitor_val = _gvn.MakeConX(markWord::monitor_value);
- Node *chk_monitor = _gvn.transform(new CmpXNode(lmasked_header, monitor_val));
- Node *test_monitor = _gvn.transform(new BoolNode(chk_monitor, BoolTest::eq));
+ Node* obj_klass = load_object_klass(obj);
+ Node* hash_addr;
+ const TypeKlassPtr* klass_t = _gvn.type(obj_klass)->isa_klassptr();
+ bool load_offset_runtime = true;
+
+ if (klass_t != nullptr) {
+ if (klass_t->klass_is_exact() && klass_t->isa_instklassptr()) {
+ ciInstanceKlass* ciKlass = reinterpret_cast<ciInstanceKlass*>(klass_t->is_instklassptr()->exact_klass());
+ if (!ciKlass->is_mirror_instance_klass() && !ciKlass->is_reference_instance_klass()) {
+ // We know the InstanceKlass, load hash_offset from there at compile-time.
+ int hash_offset = ciKlass->hash_offset_in_bytes();
+ hash_addr = basic_plus_adr(obj, hash_offset);
+ Node* loaded_hash = make_load(control(), hash_addr, TypeInt::INT, T_INT, MemNode::unordered);
+ result_val->init_req(_fast_path2, loaded_hash);
+ result_reg->init_req(_fast_path2, control());
+ load_offset_runtime = false;
+ }
+ }
+ }
- generate_slow_guard(test_monitor, slow_region);
- } else {
- Node *unlocked_val = _gvn.MakeConX(markWord::unlocked_value);
- Node *chk_unlocked = _gvn.transform(new CmpXNode(lmasked_header, unlocked_val));
- Node *test_not_unlocked = _gvn.transform(new BoolNode(chk_unlocked, BoolTest::ne));
+ //tty->print_cr("Load hash-offset at runtime: %s", BOOL_TO_STR(load_offset_runtime));
+
+ if (load_offset_runtime) {
+ // We don't know if it is an array or an exact type, figure it out at run-time.
+ // If not an ordinary instance, then we need to take slow-path.
+ Node* kind_addr = basic_plus_adr(obj_klass, Klass::kind_offset_in_bytes());
+ Node* kind = make_load(control(), kind_addr, TypeInt::INT, T_INT, MemNode::unordered);
+ Node* instance_val = _gvn.intcon(Klass::InstanceKlassKind);
+ Node* chk_inst = _gvn.transform(new CmpINode(kind, instance_val));
+ Node* test_inst = _gvn.transform(new BoolNode(chk_inst, BoolTest::ne));
+ generate_slow_guard(test_inst, slow_region);
+
+ // Otherwise it's an instance and we can read the hash_offset from the InstanceKlass.
+ Node* hash_offset_addr = basic_plus_adr(obj_klass, InstanceKlass::hash_offset_offset_in_bytes());
+ Node* hash_offset = make_load(control(), hash_offset_addr, TypeInt::INT, T_INT, MemNode::unordered);
+ // hash_offset->dump();
+ Node* hash_addr = basic_plus_adr(obj, ConvI2X(hash_offset));
+ Compile::current()->set_has_unsafe_access(true);
+ Node* loaded_hash = make_load(control(), hash_addr, TypeInt::INT, T_INT, MemNode::unordered);
+ result_val->init_req(_fast_path2, loaded_hash);
+ result_reg->init_req(_fast_path2, control());
+ }
- generate_slow_guard(test_not_unlocked, slow_region);
+ // Hashed-only path: recompute hash-code from object address.
+ set_control(if_false);
+ // Our constants.
+ Node* M = _gvn.intcon(0x337954D5);
+ Node* A = _gvn.intcon(0xAAAAAAAA);
+ // Split object address into lo and hi 32 bits.
+ Node* obj_addr = _gvn.transform(new CastP2XNode(nullptr, obj));
+ Node* x = _gvn.transform(new ConvL2INode(obj_addr));
+ Node* upper_addr = _gvn.transform(new URShiftLNode(obj_addr, _gvn.intcon(32)));
+ Node* y = _gvn.transform(new ConvL2INode(upper_addr));
+
+ Node* H0 = _gvn.transform(new XorINode(x, y));
+ Node* L0 = _gvn.transform(new XorINode(x, A));
+
+ // Full multiplication of two 32 bit values L0 and M into a hi/lo result in two 32 bit values V0 and U0.
+ Node* L0_64 = _gvn.transform(new ConvI2LNode(L0));
+ L0_64 = _gvn.transform(new AndLNode(L0_64, _gvn.longcon(0xFFFFFFFF)));
+ Node* M_64 = _gvn.transform(new ConvI2LNode(M));
+ // M_64 = _gvn.transform(new AndLNode(M_64, _gvn.longcon(0xFFFFFFFF)));
+ Node* prod64 = _gvn.transform(new MulLNode(L0_64, M_64));
+ Node* V0 = _gvn.transform(new ConvL2INode(prod64));
+ Node* prod_upper = _gvn.transform(new URShiftLNode(prod64, _gvn.intcon(32)));
+ Node* U0 = _gvn.transform(new ConvL2INode(prod_upper));
+
+ Node* Q0 = _gvn.transform(new MulINode(H0, M));
+ Node* L1 = _gvn.transform(new XorINode(Q0, U0));
+
+ // Full multiplication of two 32 bit values L1 and M into a hi/lo result in two 32 bit values V1 and U1.
+ Node* L1_64 = _gvn.transform(new ConvI2LNode(L1));
+ L1_64 = _gvn.transform(new AndLNode(L1_64, _gvn.longcon(0xFFFFFFFF)));
+ prod64 = _gvn.transform(new MulLNode(L1_64, M_64));
+ Node* V1 = _gvn.transform(new ConvL2INode(prod64));
+ prod_upper = _gvn.transform(new URShiftLNode(prod64, _gvn.intcon(32)));
+ Node* U1 = _gvn.transform(new ConvL2INode(prod_upper));
+
+ Node* P1 = _gvn.transform(new XorINode(V0, M));
+
+ // Right rotate P1 by distance L1.
+ Node* distance = _gvn.transform(new AndINode(L1, _gvn.intcon(32 - 1)));
+ Node* inverse_distance = _gvn.transform(new SubINode(_gvn.intcon(32), distance));
+ Node* ror_part1 = _gvn.transform(new URShiftINode(P1, distance));
+ Node* ror_part2 = _gvn.transform(new LShiftINode(P1, inverse_distance));
+ Node* Q1 = _gvn.transform(new OrINode(ror_part1, ror_part2));
+
+ Node* L2 = _gvn.transform(new XorINode(Q1, U1));
+ Node* hash = _gvn.transform(new XorINode(V1, L2));
+ Node* hash_truncated = _gvn.transform(new AndINode(hash, _gvn.intcon(markWord::hash_mask)));
+
+ // TODO: We could generate a fast case here under the following conditions:
+ // - The hashctrl is set to hash_is_copied (see markWord::hash_is_copied())
+ // - The type of the object is known
+ // Then we can load the identity hashcode from the int field at Klass::hash_offset_in_bytes() of the object.
+ result_val->init_req(_fast_path, hash_truncated);
+ } else {
+ // Get the header out of the object, use LoadMarkNode when available
+ Node* header_addr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
+ // The control of the load must be null. Otherwise, the load can move before
+ // the null check after castPP removal.
+ Node* no_ctrl = nullptr;
+ Node* header = make_load(no_ctrl, header_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
+
+ if (!UseObjectMonitorTable) {
+ // Test the header to see if it is safe to read w.r.t. locking.
+ Node *lock_mask = _gvn.MakeConX(markWord::lock_mask_in_place);
+ Node *lmasked_header = _gvn.transform(new AndXNode(header, lock_mask));
+ if (LockingMode == LM_LIGHTWEIGHT) {
+ Node *monitor_val = _gvn.MakeConX(markWord::monitor_value);
+ Node *chk_monitor = _gvn.transform(new CmpXNode(lmasked_header, monitor_val));
+ Node *test_monitor = _gvn.transform(new BoolNode(chk_monitor, BoolTest::eq));
+
+ generate_slow_guard(test_monitor, slow_region);
+ } else {
+ Node *unlocked_val = _gvn.MakeConX(markWord::unlocked_value);
+ Node *chk_unlocked = _gvn.transform(new CmpXNode(lmasked_header, unlocked_val));
+ Node *test_not_unlocked = _gvn.transform(new BoolNode(chk_unlocked, BoolTest::ne));
+
+ generate_slow_guard(test_not_unlocked, slow_region);
+ }
}
- }
- // Get the hash value and check to see that it has been properly assigned.
- // We depend on hash_mask being at most 32 bits and avoid the use of
- // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
- // vm: see markWord.hpp.
- Node *hash_mask = _gvn.intcon(markWord::hash_mask);
- Node *hash_shift = _gvn.intcon(markWord::hash_shift);
- Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
- // This hack lets the hash bits live anywhere in the mark object now, as long
- // as the shift drops the relevant bits into the low 32 bits. Note that
- // Java spec says that HashCode is an int so there's no point in capturing
- // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
- hshifted_header = ConvX2I(hshifted_header);
- Node *hash_val = _gvn.transform(new AndINode(hshifted_header, hash_mask));
+ // Get the hash value and check to see that it has been properly assigned.
+ // We depend on hash_mask being at most 32 bits and avoid the use of
+ // hash_mask_in_place because it could be larger than 32 bits in a 64-bit
+ // vm: see markWord.hpp.
+ Node *hash_mask = _gvn.intcon(markWord::hash_mask);
+ Node *hash_shift = _gvn.intcon(markWord::hash_shift);
+ Node *hshifted_header= _gvn.transform(new URShiftXNode(header, hash_shift));
+ // This hack lets the hash bits live anywhere in the mark object now, as long
+ // as the shift drops the relevant bits into the low 32 bits. Note that
+ // Java spec says that HashCode is an int so there's no point in capturing
+ // an 'X'-sized hashcode (32 in 32-bit build or 64 in 64-bit build).
+ hshifted_header = ConvX2I(hshifted_header);
+ Node *hash_val = _gvn.transform(new AndINode(hshifted_header, hash_mask));
- Node *no_hash_val = _gvn.intcon(markWord::no_hash);
- Node *chk_assigned = _gvn.transform(new CmpINode( hash_val, no_hash_val));
- Node *test_assigned = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
+ Node *no_hash_val = _gvn.intcon(markWord::no_hash);
+ Node *chk_assigned = _gvn.transform(new CmpINode( hash_val, no_hash_val));
+ Node *test_assigned = _gvn.transform(new BoolNode( chk_assigned, BoolTest::eq));
- generate_slow_guard(test_assigned, slow_region);
+ generate_slow_guard(test_assigned, slow_region);
+
+ result_val->init_req(_fast_path, hash_val);
+
+ // _fast_path2 is not used here.
+ result_val->del_req(_fast_path2);
+ result_reg->del_req(_fast_path2);
+ result_io->del_req(_fast_path2);
+ result_mem->del_req(_fast_path2);
+ }
Node* init_mem = reset_memory();
// fill in the rest of the null path:
result_io ->init_req(_null_path, i_o());
result_mem->init_req(_null_path, init_mem);
- result_val->init_req(_fast_path, hash_val);
result_reg->init_req(_fast_path, control());
result_io ->init_req(_fast_path, i_o());
result_mem->init_req(_fast_path, init_mem);
+ if (UseCompactObjectHeaders) {
+ result_io->init_req(_fast_path2, i_o());
+ result_mem->init_req(_fast_path2, init_mem);
+ }
+
// Generate code for the slow case. We make a call to hashCode().
+ assert(slow_region != nullptr, "must have slow_region");
set_control(_gvn.transform(slow_region));
if (!stopped()) {
// No need for PreserveJVMState, because we're using up the present state.
set_all_memory(init_mem);
vmIntrinsics::ID hashCode_id = is_static ? vmIntrinsics::_identityHashCode : vmIntrinsics::_hashCode;
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