1 /* 2 * Copyright (c) 1999, 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 "c1/c1_IR.hpp" 27 #include "c1/c1_InstructionPrinter.hpp" 28 #include "c1/c1_ValueStack.hpp" 29 30 31 // Implementation of ValueStack 32 33 ValueStack::ValueStack(IRScope* scope, ValueStack* caller_state) 34 : _scope(scope) 35 , _caller_state(caller_state) 36 , _bci(-99) 37 , _kind(Parsing) 38 , _locals(scope->method()->max_locals(), scope->method()->max_locals(), nullptr) 39 , _stack(scope->method()->max_stack()) 40 , _locks(nullptr) 41 { 42 verify(); 43 } 44 45 ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci) 46 : _scope(copy_from->scope()) 47 , _caller_state(copy_from->caller_state()) 48 , _bci(bci) 49 , _kind(kind) 50 , _locals(copy_from->locals_size_for_copy(kind)) 51 , _stack(copy_from->stack_size_for_copy(kind)) 52 , _locks(copy_from->locks_size() == 0 ? nullptr : new Values(copy_from->locks_size())) 53 { 54 assert(kind != EmptyExceptionState || !Compilation::current()->env()->should_retain_local_variables(), "need locals"); 55 if (kind != EmptyExceptionState) { 56 _locals.appendAll(©_from->_locals); 57 } 58 59 if (kind != ExceptionState && kind != EmptyExceptionState) { 60 _stack.appendAll(©_from->_stack); 61 } 62 63 if (copy_from->locks_size() > 0) { 64 _locks->appendAll(copy_from->_locks); 65 } 66 67 verify(); 68 } 69 70 int ValueStack::locals_size_for_copy(Kind kind) const { 71 if (kind != EmptyExceptionState) { 72 return locals_size(); 73 } 74 return 0; 75 } 76 77 int ValueStack::stack_size_for_copy(Kind kind) const { 78 if (kind != ExceptionState && kind != EmptyExceptionState) { 79 if (kind == Parsing) { 80 // stack will be modified, so reserve enough space to avoid resizing 81 return scope()->method()->max_stack(); 82 } else { 83 // stack will not be modified, so do not waste space 84 return stack_size(); 85 } 86 } 87 return 0; 88 } 89 90 bool ValueStack::is_same(ValueStack* s) { 91 if (scope() != s->scope()) return false; 92 if (caller_state() != s->caller_state()) return false; 93 94 if (locals_size() != s->locals_size()) return false; 95 if (stack_size() != s->stack_size()) return false; 96 if (locks_size() != s->locks_size()) return false; 97 98 // compare each stack element with the corresponding stack element of s 99 int index; 100 Value value; 101 for_each_stack_value(this, index, value) { 102 if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false; 103 } 104 for (int i = 0; i < locks_size(); i++) { 105 value = lock_at(i); 106 if (value != nullptr && value != s->lock_at(i)) { 107 return false; 108 } 109 } 110 return true; 111 } 112 113 void ValueStack::clear_locals() { 114 for (int i = _locals.length() - 1; i >= 0; i--) { 115 _locals.at_put(i, nullptr); 116 } 117 } 118 119 120 void ValueStack::pin_stack_for_linear_scan() { 121 for_each_state_value(this, v, 122 if (v->as_Constant() == nullptr && v->as_Local() == nullptr) { 123 v->pin(Instruction::PinStackForStateSplit); 124 } 125 ); 126 } 127 128 129 // apply function to all values of a list; factored out from values_do(f) 130 void ValueStack::apply(const Values& list, ValueVisitor* f) { 131 for (int i = 0; i < list.length(); i++) { 132 Value* va = list.adr_at(i); 133 Value v0 = *va; 134 if (v0 != nullptr && !v0->type()->is_illegal()) { 135 f->visit(va); 136 #ifdef ASSERT 137 Value v1 = *va; 138 assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match"); 139 assert(!v1->type()->is_double_word() || list.at(i + 1) == nullptr, "hi-word of doubleword value must be null"); 140 #endif 141 if (v0->type()->is_double_word()) i++; 142 } 143 } 144 } 145 146 147 void ValueStack::values_do(ValueVisitor* f) { 148 ValueStack* state = this; 149 for_each_state(state) { 150 apply(state->_locals, f); 151 apply(state->_stack, f); 152 if (state->_locks != nullptr) { 153 apply(*state->_locks, f); 154 } 155 } 156 } 157 158 159 Values* ValueStack::pop_arguments(int argument_size) { 160 assert(stack_size() >= argument_size, "stack too small or too many arguments"); 161 int base = stack_size() - argument_size; 162 Values* args = new Values(argument_size); 163 for (int i = base; i < stack_size();) args->push(stack_at_inc(i)); 164 truncate_stack(base); 165 return args; 166 } 167 168 169 int ValueStack::total_locks_size() const { 170 int num_locks = 0; 171 const ValueStack* state = this; 172 for_each_state(state) { 173 num_locks += state->locks_size(); 174 } 175 return num_locks; 176 } 177 178 int ValueStack::lock(Value obj) { 179 if (_locks == nullptr) { 180 _locks = new Values(); 181 } 182 _locks->push(obj); 183 int num_locks = total_locks_size(); 184 scope()->set_min_number_of_locks(num_locks); 185 return num_locks - 1; 186 } 187 188 189 int ValueStack::unlock() { 190 assert(locks_size() > 0, "sanity"); 191 _locks->pop(); 192 return total_locks_size(); 193 } 194 195 196 void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) { 197 assert(stack_at(index)->as_Phi() == nullptr || stack_at(index)->as_Phi()->block() != b, "phi function already created"); 198 199 ValueType* t = stack_at(index)->type(); 200 Value phi = new Phi(t, b, -index - 1); 201 _stack.at_put(index, phi); 202 203 assert(!t->is_double_word() || _stack.at(index + 1) == nullptr, "hi-word of doubleword value must be null"); 204 } 205 206 void ValueStack::setup_phi_for_local(BlockBegin* b, int index) { 207 assert(local_at(index)->as_Phi() == nullptr || local_at(index)->as_Phi()->block() != b, "phi function already created"); 208 209 ValueType* t = local_at(index)->type(); 210 Value phi = new Phi(t, b, index); 211 store_local(index, phi); 212 } 213 214 #ifndef PRODUCT 215 216 void ValueStack::print() { 217 scope()->method()->print_name(); 218 tty->cr(); 219 if (stack_is_empty()) { 220 tty->print_cr("empty stack"); 221 } else { 222 InstructionPrinter ip; 223 for (int i = 0; i < stack_size();) { 224 Value t = stack_at_inc(i); 225 tty->print("%2d ", i); 226 tty->print("%c%d ", t->type()->tchar(), t->id()); 227 ip.print_instr(t); 228 tty->cr(); 229 } 230 } 231 if (!no_active_locks()) { 232 InstructionPrinter ip; 233 for (int i = 0; i < locks_size(); i++) { 234 Value t = lock_at(i); 235 tty->print("lock %2d ", i); 236 if (t == nullptr) { 237 tty->print("this"); 238 } else { 239 tty->print("%c%d ", t->type()->tchar(), t->id()); 240 ip.print_instr(t); 241 } 242 tty->cr(); 243 } 244 } 245 if (locals_size() > 0) { 246 InstructionPrinter ip; 247 for (int i = 0; i < locals_size();) { 248 Value l = _locals.at(i); 249 tty->print("local %d ", i); 250 if (l == nullptr) { 251 tty->print("null"); 252 i ++; 253 } else { 254 tty->print("%c%d ", l->type()->tchar(), l->id()); 255 ip.print_instr(l); 256 if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2; 257 } 258 tty->cr(); 259 } 260 } 261 262 if (caller_state() != nullptr) { 263 caller_state()->print(); 264 } 265 } 266 267 268 void ValueStack::verify() { 269 assert(scope() != nullptr, "scope must exist"); 270 if (caller_state() != nullptr) { 271 assert(caller_state()->scope() == scope()->caller(), "invalid caller scope"); 272 caller_state()->verify(); 273 } 274 275 if (kind() == Parsing) { 276 assert(bci() == -99, "bci not defined during parsing"); 277 } else { 278 assert(bci() >= -1, "bci out of range"); 279 assert(bci() < scope()->method()->code_size(), "bci out of range"); 280 assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode"); 281 assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid"); 282 } 283 284 int i; 285 for (i = 0; i < stack_size(); i++) { 286 Value v = _stack.at(i); 287 if (v == nullptr) { 288 assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are null on stack"); 289 } else if (v->type()->is_double_word()) { 290 assert(_stack.at(i + 1) == nullptr, "hi-word must be null"); 291 } 292 } 293 294 for (i = 0; i < locals_size(); i++) { 295 Value v = _locals.at(i); 296 if (v != nullptr && v->type()->is_double_word()) { 297 assert(_locals.at(i + 1) == nullptr, "hi-word must be null"); 298 } 299 } 300 301 for_each_state_value(this, v, 302 assert(v != nullptr, "just test if state-iteration succeeds"); 303 ); 304 } 305 #endif // PRODUCT