1 /* 2 * Copyright (c) 1998, 2021, 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 "ci/ciSymbols.hpp" 27 #include "compiler/compileLog.hpp" 28 #include "oops/objArrayKlass.hpp" 29 #include "opto/addnode.hpp" 30 #include "opto/memnode.hpp" 31 #include "opto/mulnode.hpp" 32 #include "opto/parse.hpp" 33 #include "opto/rootnode.hpp" 34 #include "opto/runtime.hpp" 35 #include "runtime/sharedRuntime.hpp" 36 37 //------------------------------make_dtrace_method_entry_exit ---------------- 38 // Dtrace -- record entry or exit of a method if compiled with dtrace support 39 void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) { 40 const TypeFunc *call_type = OptoRuntime::dtrace_method_entry_exit_Type(); 41 address call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) : 42 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit); 43 const char *call_name = is_entry ? "dtrace_method_entry" : "dtrace_method_exit"; 44 45 // Get base of thread-local storage area 46 Node* thread = _gvn.transform( new ThreadLocalNode() ); 47 48 // Get method 49 const TypePtr* method_type = TypeMetadataPtr::make(method); 50 Node *method_node = _gvn.transform(ConNode::make(method_type)); 51 52 kill_dead_locals(); 53 54 // For some reason, this call reads only raw memory. 55 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM; 56 make_runtime_call(RC_LEAF | RC_NARROW_MEM, 57 call_type, call_address, 58 call_name, raw_adr_type, 59 thread, method_node); 60 } 61 62 63 //============================================================================= 64 //------------------------------do_checkcast----------------------------------- 65 void Parse::do_checkcast() { 66 bool will_link; 67 ciKlass* klass = iter().get_klass(will_link); 68 69 Node *obj = peek(); 70 71 // Throw uncommon trap if class is not loaded or the value we are casting 72 // _from_ is not loaded, and value is not null. If the value _is_ NULL, 73 // then the checkcast does nothing. 74 const TypeOopPtr *tp = _gvn.type(obj)->isa_oopptr(); 75 if (!will_link || (tp && tp->klass() && !tp->klass()->is_loaded())) { 76 if (C->log() != NULL) { 77 if (!will_link) { 78 C->log()->elem("assert_null reason='checkcast' klass='%d'", 79 C->log()->identify(klass)); 80 } 81 if (tp && tp->klass() && !tp->klass()->is_loaded()) { 82 // %%% Cannot happen? 83 C->log()->elem("assert_null reason='checkcast source' klass='%d'", 84 C->log()->identify(tp->klass())); 85 } 86 } 87 null_assert(obj); 88 assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" ); 89 return; 90 } 91 92 Node* res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass))); 93 if (stopped()) { 94 return; 95 } 96 97 // Pop from stack AFTER gen_checkcast because it can uncommon trap and 98 // the debug info has to be correct. 99 pop(); 100 push(res); 101 } 102 103 104 //------------------------------do_instanceof---------------------------------- 105 void Parse::do_instanceof() { 106 if (stopped()) return; 107 // We would like to return false if class is not loaded, emitting a 108 // dependency, but Java requires instanceof to load its operand. 109 110 // Throw uncommon trap if class is not loaded 111 bool will_link; 112 ciKlass* klass = iter().get_klass(will_link); 113 114 if (!will_link) { 115 if (C->log() != NULL) { 116 C->log()->elem("assert_null reason='instanceof' klass='%d'", 117 C->log()->identify(klass)); 118 } 119 null_assert(peek()); 120 assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" ); 121 if (!stopped()) { 122 // The object is now known to be null. 123 // Shortcut the effect of gen_instanceof and return "false" directly. 124 pop(); // pop the null 125 push(_gvn.intcon(0)); // push false answer 126 } 127 return; 128 } 129 130 // Push the bool result back on stack 131 Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass)), true); 132 133 // Pop from stack AFTER gen_instanceof because it can uncommon trap. 134 pop(); 135 push(res); 136 } 137 138 //------------------------------array_store_check------------------------------ 139 // pull array from stack and check that the store is valid 140 void Parse::array_store_check() { 141 142 // Shorthand access to array store elements without popping them. 143 Node *obj = peek(0); 144 Node *idx = peek(1); 145 Node *ary = peek(2); 146 147 if (_gvn.type(obj) == TypePtr::NULL_PTR) { 148 // There's never a type check on null values. 149 // This cutout lets us avoid the uncommon_trap(Reason_array_check) 150 // below, which turns into a performance liability if the 151 // gen_checkcast folds up completely. 152 return; 153 } 154 155 // Extract the array klass type 156 int klass_offset = oopDesc::klass_offset_in_bytes(); 157 Node* p = basic_plus_adr( ary, ary, klass_offset ); 158 // p's type is array-of-OOPS plus klass_offset 159 Node* array_klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS)); 160 // Get the array klass 161 const TypeKlassPtr *tak = _gvn.type(array_klass)->is_klassptr(); 162 163 // The type of array_klass is usually INexact array-of-oop. Heroically 164 // cast array_klass to EXACT array and uncommon-trap if the cast fails. 165 // Make constant out of the inexact array klass, but use it only if the cast 166 // succeeds. 167 bool always_see_exact_class = false; 168 if (MonomorphicArrayCheck 169 && !too_many_traps(Deoptimization::Reason_array_check) 170 && !tak->klass_is_exact() 171 && tak != TypeInstKlassPtr::OBJECT) { 172 // Regarding the fourth condition in the if-statement from above: 173 // 174 // If the compiler has determined that the type of array 'ary' (represented 175 // by 'array_klass') is java/lang/Object, the compiler must not assume that 176 // the array 'ary' is monomorphic. 177 // 178 // If 'ary' were of type java/lang/Object, this arraystore would have to fail, 179 // because it is not possible to perform a arraystore into an object that is not 180 // a "proper" array. 181 // 182 // Therefore, let's obtain at runtime the type of 'ary' and check if we can still 183 // successfully perform the store. 184 // 185 // The implementation reasons for the condition are the following: 186 // 187 // java/lang/Object is the superclass of all arrays, but it is represented by the VM 188 // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect 189 // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses. 190 // 191 // See issue JDK-8057622 for details. 192 193 always_see_exact_class = true; 194 // (If no MDO at all, hope for the best, until a trap actually occurs.) 195 196 // Make a constant out of the inexact array klass 197 const TypeKlassPtr *extak = tak->cast_to_exactness(true)->is_klassptr(); 198 Node* con = makecon(extak); 199 Node* cmp = _gvn.transform(new CmpPNode( array_klass, con )); 200 Node* bol = _gvn.transform(new BoolNode( cmp, BoolTest::eq )); 201 Node* ctrl= control(); 202 { BuildCutout unless(this, bol, PROB_MAX); 203 uncommon_trap(Deoptimization::Reason_array_check, 204 Deoptimization::Action_maybe_recompile, 205 tak->klass()); 206 } 207 if (stopped()) { // MUST uncommon-trap? 208 set_control(ctrl); // Then Don't Do It, just fall into the normal checking 209 } else { // Cast array klass to exactness: 210 // Use the exact constant value we know it is. 211 replace_in_map(array_klass,con); 212 CompileLog* log = C->log(); 213 if (log != NULL) { 214 log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'", 215 log->identify(tak->klass())); 216 } 217 array_klass = con; // Use cast value moving forward 218 } 219 } 220 221 // Come here for polymorphic array klasses 222 223 // Extract the array element class 224 int element_klass_offset = in_bytes(ObjArrayKlass::element_klass_offset()); 225 Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset); 226 // We are allowed to use the constant type only if cast succeeded. If always_see_exact_class is true, 227 // we must set a control edge from the IfTrue node created by the uncommon_trap above to the 228 // LoadKlassNode. 229 Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, always_see_exact_class ? control() : NULL, 230 immutable_memory(), p2, tak)); 231 232 // Check (the hard way) and throw if not a subklass. 233 // Result is ignored, we just need the CFG effects. 234 gen_checkcast(obj, a_e_klass); 235 } 236 237 238 //------------------------------do_new----------------------------------------- 239 void Parse::do_new() { 240 kill_dead_locals(); 241 242 bool will_link; 243 ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass(); 244 assert(will_link, "_new: typeflow responsibility"); 245 246 // Should throw an InstantiationError? 247 if (klass->is_abstract() || klass->is_interface() || 248 klass->name() == ciSymbols::java_lang_Class() || 249 iter().is_unresolved_klass()) { 250 uncommon_trap(Deoptimization::Reason_unhandled, 251 Deoptimization::Action_none, 252 klass); 253 return; 254 } 255 256 if (C->needs_clinit_barrier(klass, method())) { 257 clinit_barrier(klass, method()); 258 if (stopped()) return; 259 } 260 261 Node* kls = makecon(TypeKlassPtr::make(klass)); 262 Node* obj = new_instance(kls); 263 264 // Push resultant oop onto stack 265 push(obj); 266 267 // Keep track of whether opportunities exist for StringBuilder 268 // optimizations. 269 if (OptimizeStringConcat && 270 (klass == C->env()->StringBuilder_klass() || 271 klass == C->env()->StringBuffer_klass())) { 272 C->set_has_stringbuilder(true); 273 } 274 275 // Keep track of boxed values for EliminateAutoBox optimizations. 276 if (C->eliminate_boxing() && klass->is_box_klass()) { 277 C->set_has_boxed_value(true); 278 } 279 } 280 281 #ifndef PRODUCT 282 //------------------------------dump_map_adr_mem------------------------------- 283 // Debug dump of the mapping from address types to MergeMemNode indices. 284 void Parse::dump_map_adr_mem() const { 285 tty->print_cr("--- Mapping from address types to memory Nodes ---"); 286 MergeMemNode *mem = map() == NULL ? NULL : (map()->memory()->is_MergeMem() ? 287 map()->memory()->as_MergeMem() : NULL); 288 for (uint i = 0; i < (uint)C->num_alias_types(); i++) { 289 C->alias_type(i)->print_on(tty); 290 tty->print("\t"); 291 // Node mapping, if any 292 if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) { 293 mem->in(i)->dump(); 294 } else { 295 tty->cr(); 296 } 297 } 298 } 299 300 #endif 301