1 /* 2 * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "opto/addnode.hpp" 27 #include "opto/callnode.hpp" 28 #include "opto/connode.hpp" 29 #include "opto/convertnode.hpp" 30 #include "opto/phaseX.hpp" 31 #include "opto/rootnode.hpp" 32 #include "opto/subnode.hpp" 33 #include "opto/subtypenode.hpp" 34 35 const Type* SubTypeCheckNode::sub(const Type* sub_t, const Type* super_t) const { 36 const TypeKlassPtr* superk = super_t->isa_klassptr(); 37 const TypeKlassPtr* subk = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type(); 38 39 // Oop can't be a subtype of abstract type that has no subclass. 40 if (sub_t->isa_oopptr() && superk->isa_instklassptr() && superk->klass_is_exact()) { 41 ciKlass* superklass = superk->exact_klass(); 42 if (!superklass->is_interface() && superklass->is_abstract() && 43 !superklass->as_instance_klass()->has_subklass()) { 44 Compile::current()->dependencies()->assert_leaf_type(superklass); 45 return TypeInt::CC_GT; 46 } 47 } 48 49 // FIXME: shouldn't this be encoded in helper methods of the type system (maybe_java_subtype_of() etc.?) 50 // Similar to logic in CmpPNode::sub() 51 bool unrelated_classes = false; 52 // Handle inline type arrays 53 if (subk->flatten_array() && superk->not_flatten_array()) { 54 // The subtype is flattened in arrays and the supertype is not flattened in arrays. Must be unrelated. 55 unrelated_classes = true; 56 } else if (subk->is_not_flat() && superk->is_flat()) { 57 // The subtype is a non-flattened array and the supertype is a flattened array. Must be unrelated. 58 unrelated_classes = true; 59 } else if (subk->is_not_null_free() && superk->is_null_free()) { 60 // The subtype is a nullable array and the supertype is null-free array. Must be unrelated. 61 unrelated_classes = true; 62 } 63 if (unrelated_classes) { 64 TypePtr::PTR jp = sub_t->is_ptr()->join_ptr(super_t->is_ptr()->_ptr); 65 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) { 66 return TypeInt::CC_GT; 67 } 68 } 69 70 if (subk != nullptr) { 71 switch (Compile::current()->static_subtype_check(superk, subk, false)) { 72 case Compile::SSC_always_false: 73 return TypeInt::CC_GT; 74 case Compile::SSC_always_true: 75 return TypeInt::CC_EQ; 76 case Compile::SSC_easy_test: 77 case Compile::SSC_full_test: 78 break; 79 default: 80 ShouldNotReachHere(); 81 } 82 } 83 84 return bottom_type(); 85 } 86 87 Node *SubTypeCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) { 88 Node* obj_or_subklass = in(ObjOrSubKlass); 89 Node* superklass = in(SuperKlass); 90 91 if (obj_or_subklass == nullptr || 92 superklass == nullptr) { 93 return nullptr; 94 } 95 96 const Type* sub_t = phase->type(obj_or_subklass); 97 const Type* super_t = phase->type(superklass); 98 99 if (!super_t->isa_klassptr() || 100 (!sub_t->isa_klassptr() && !sub_t->isa_oopptr())) { 101 return nullptr; 102 } 103 104 Node* addr = nullptr; 105 if (obj_or_subklass->is_DecodeNKlass()) { 106 if (obj_or_subklass->in(1) != nullptr && 107 obj_or_subklass->in(1)->Opcode() == Op_LoadNKlass) { 108 addr = obj_or_subklass->in(1)->in(MemNode::Address); 109 } 110 } else if (obj_or_subklass->Opcode() == Op_LoadKlass) { 111 addr = obj_or_subklass->in(MemNode::Address); 112 } 113 114 if (addr != nullptr) { 115 intptr_t con = 0; 116 Node* obj = AddPNode::Ideal_base_and_offset(addr, phase, con); 117 if (con == oopDesc::klass_offset_in_bytes() && obj != nullptr) { 118 assert(is_oop(phase, obj), "only for oop input"); 119 set_req_X(ObjOrSubKlass, obj, phase); 120 return this; 121 } 122 } 123 124 // AllocateNode might have more accurate klass input 125 Node* allocated_klass = AllocateNode::Ideal_klass(obj_or_subklass, phase); 126 if (allocated_klass != nullptr) { 127 assert(is_oop(phase, obj_or_subklass), "only for oop input"); 128 set_req_X(ObjOrSubKlass, allocated_klass, phase); 129 return this; 130 } 131 132 // Verify that optimizing the subtype check to a simple code pattern 133 // when possible would not constant fold better 134 assert(verify(phase), "missing Value() optimization"); 135 136 return nullptr; 137 } 138 139 #ifdef ASSERT 140 bool SubTypeCheckNode::is_oop(PhaseGVN* phase, Node* n) { 141 const Type* t = phase->type(n); 142 if (!t->isa_oopptr() && t != Type::TOP) { 143 n->dump(); 144 t->dump(); tty->cr(); 145 return false; 146 } 147 return true; 148 } 149 150 static Node* record_for_cleanup(Node* n, PhaseGVN* phase) { 151 if (phase->is_IterGVN()) { 152 phase->is_IterGVN()->_worklist.push(n); // record for cleanup 153 } 154 return n; 155 } 156 bool SubTypeCheckNode::verify_helper(PhaseGVN* phase, Node* subklass, const Type* cached_t) { 157 Node* cmp = phase->transform(new CmpPNode(subklass, in(SuperKlass))); 158 record_for_cleanup(cmp, phase); 159 160 const Type* cmp_t = phase->type(cmp); 161 const Type* t = Value(phase); 162 163 if (t == cmp_t || 164 t != cached_t || // previous observations don't hold anymore 165 (cmp_t != TypeInt::CC_GT && cmp_t != TypeInt::CC_EQ)) { 166 return true; 167 } else { 168 t->dump(); tty->cr(); 169 this->dump(2); tty->cr(); 170 cmp_t->dump(); tty->cr(); 171 subklass->dump(2); tty->cr(); 172 tty->print_cr("=============================="); 173 phase->C->root()->dump(9999); 174 return false; 175 } 176 } 177 178 // Verify that optimizing the subtype check to a simple code pattern when possible would not constant fold better. 179 bool SubTypeCheckNode::verify(PhaseGVN* phase) { 180 Compile* C = phase->C; 181 Node* obj_or_subklass = in(ObjOrSubKlass); 182 Node* superklass = in(SuperKlass); 183 184 const Type* sub_t = phase->type(obj_or_subklass); 185 const Type* super_t = phase->type(superklass); 186 187 const TypeKlassPtr* superk = super_t->isa_klassptr(); 188 const TypeKlassPtr* subk = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type(); 189 190 if (super_t->singleton() && subk != nullptr) { 191 const Type* cached_t = Value(phase); // cache the type to validate consistency 192 switch (C->static_subtype_check(superk, subk)) { 193 case Compile::SSC_easy_test: { 194 return verify_helper(phase, load_klass(phase), cached_t); 195 } 196 case Compile::SSC_full_test: { 197 Node* p1 = phase->transform(new AddPNode(superklass, superklass, phase->MakeConX(in_bytes(Klass::super_check_offset_offset())))); 198 Node* chk_off = phase->transform(new LoadINode(nullptr, C->immutable_memory(), p1, phase->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered)); 199 record_for_cleanup(chk_off, phase); 200 201 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset()); 202 bool might_be_cache = (phase->find_int_con(chk_off, cacheoff_con) == cacheoff_con); 203 if (!might_be_cache) { 204 Node* subklass = load_klass(phase); 205 Node* chk_off_X = chk_off; 206 #ifdef _LP64 207 chk_off_X = phase->transform(new ConvI2LNode(chk_off_X)); 208 #endif 209 Node* p2 = phase->transform(new AddPNode(subklass, subklass, chk_off_X)); 210 Node* nkls = phase->transform(LoadKlassNode::make(*phase, nullptr, C->immutable_memory(), p2, phase->type(p2)->is_ptr(), TypeInstKlassPtr::OBJECT_OR_NULL)); 211 212 return verify_helper(phase, nkls, cached_t); 213 } 214 break; 215 } 216 case Compile::SSC_always_false: 217 case Compile::SSC_always_true: 218 default: { 219 break; // nothing to do 220 } 221 } 222 } 223 224 return true; 225 } 226 227 Node* SubTypeCheckNode::load_klass(PhaseGVN* phase) const { 228 Node* obj_or_subklass = in(ObjOrSubKlass); 229 const Type* sub_t = phase->type(obj_or_subklass); 230 Node* subklass = nullptr; 231 if (sub_t->isa_oopptr()) { 232 Node* adr = phase->transform(new AddPNode(obj_or_subklass, obj_or_subklass, phase->MakeConX(oopDesc::klass_offset_in_bytes()))); 233 subklass = phase->transform(LoadKlassNode::make(*phase, nullptr, phase->C->immutable_memory(), adr, TypeInstPtr::KLASS)); 234 record_for_cleanup(subklass, phase); 235 } else { 236 subklass = obj_or_subklass; 237 } 238 return subklass; 239 } 240 241 #endif