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 , _should_reexecute(false)
39 , _locals(scope->method()->max_locals(), scope->method()->max_locals(), nullptr)
40 , _stack(scope->method()->max_stack())
41 , _locks(nullptr)
42 {
43 verify();
44 }
45
46 ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci, bool reexecute)
47 : _scope(copy_from->scope())
48 , _caller_state(copy_from->caller_state())
49 , _bci(bci)
50 , _kind(kind)
51 , _should_reexecute(reexecute)
52 , _locals(copy_from->locals_size_for_copy(kind))
53 , _stack(copy_from->stack_size_for_copy(kind))
54 , _locks(copy_from->locks_size() == 0 ? nullptr : new Values(copy_from->locks_size()))
55 {
56 switch (kind) {
57 case EmptyExceptionState:
58 case CallerEmptyExceptionState:
59 assert(!Compilation::current()->env()->should_retain_local_variables(), "need locals");
60 // set to all nulls, like clear_locals()
61 for (int i = 0; i < copy_from->locals_size(); ++i) {
62 _locals.append(nullptr);
63 }
64 break;
65 default:
66 _locals.appendAll(©_from->_locals);
67 }
68
69 switch (kind) {
70 case ExceptionState:
71 case EmptyExceptionState:
72 assert(stack_size() == 0, "fix stack_size_for_copy");
73 break;
74 case CallerExceptionState:
75 case CallerEmptyExceptionState:
76 // set to all nulls
77 for (int i = 0; i < copy_from->stack_size(); ++i) {
78 _stack.append(nullptr);
79 }
80 break;
81 default:
82 _stack.appendAll(©_from->_stack);
83 }
84
85 if (copy_from->locks_size() > 0) {
86 _locks->appendAll(copy_from->_locks);
87 }
88
89 verify();
90 }
91
92 int ValueStack::locals_size_for_copy(Kind kind) const {
93 return locals_size();
94 }
95
96 int ValueStack::stack_size_for_copy(Kind kind) const {
97 if (kind != ExceptionState && kind != EmptyExceptionState) {
98 if (kind == Parsing) {
99 // stack will be modified, so reserve enough space to avoid resizing
100 return scope()->method()->max_stack();
101 } else {
102 // stack will not be modified, so do not waste space
103 return stack_size();
104 }
105 }
106 return 0;
107 }
108
109 bool ValueStack::is_same(ValueStack* s) {
110 if (scope() != s->scope()) return false;
111 if (caller_state() != s->caller_state()) return false;
112
113 if (locals_size() != s->locals_size()) return false;
114 if (stack_size() != s->stack_size()) return false;
115 if (locks_size() != s->locks_size()) return false;
116
117 // compare each stack element with the corresponding stack element of s
118 int index;
119 Value value;
120 for_each_stack_value(this, index, value) {
121 if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;
122 }
123 for (int i = 0; i < locks_size(); i++) {
124 value = lock_at(i);
125 if (value != nullptr && value != s->lock_at(i)) {
126 return false;
127 }
128 }
129 return true;
130 }
131
132 void ValueStack::clear_locals() {
133 for (int i = _locals.length() - 1; i >= 0; i--) {
134 _locals.at_put(i, nullptr);
135 }
136 }
137
138
139 void ValueStack::pin_stack_for_linear_scan() {
140 for_each_state_value(this, v,
141 if (v->as_Constant() == nullptr && v->as_Local() == nullptr) {
142 v->pin(Instruction::PinStackForStateSplit);
143 }
144 );
145 }
146
147
148 // apply function to all values of a list; factored out from values_do(f)
149 void ValueStack::apply(const Values& list, ValueVisitor* f) {
150 for (int i = 0; i < list.length(); i++) {
151 Value* va = list.adr_at(i);
152 Value v0 = *va;
153 if (v0 != nullptr && !v0->type()->is_illegal()) {
154 f->visit(va);
155 #ifdef ASSERT
156 Value v1 = *va;
157 assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");
158 assert(!v1->type()->is_double_word() || list.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
159 #endif
160 if (v0->type()->is_double_word()) i++;
161 }
162 }
163 }
164
165
166 void ValueStack::values_do(ValueVisitor* f) {
167 ValueStack* state = this;
168 for_each_state(state) {
169 apply(state->_locals, f);
170 apply(state->_stack, f);
171 if (state->_locks != nullptr) {
172 apply(*state->_locks, f);
173 }
174 }
175 }
176
177
178 Values* ValueStack::pop_arguments(int argument_size) {
179 assert(stack_size() >= argument_size, "stack too small or too many arguments");
180 int base = stack_size() - argument_size;
181 Values* args = new Values(argument_size);
182 for (int i = base; i < stack_size();) args->push(stack_at_inc(i));
183 truncate_stack(base);
184 return args;
185 }
186
187
188 int ValueStack::total_locks_size() const {
189 int num_locks = 0;
190 const ValueStack* state = this;
191 for_each_state(state) {
192 num_locks += state->locks_size();
193 }
194 return num_locks;
195 }
196
197 int ValueStack::lock(Value obj) {
198 if (_locks == nullptr) {
199 _locks = new Values();
200 }
201 _locks->push(obj);
202 int num_locks = total_locks_size();
203 scope()->set_min_number_of_locks(num_locks);
204 return num_locks - 1;
205 }
206
207
208 int ValueStack::unlock() {
209 assert(locks_size() > 0, "sanity");
210 _locks->pop();
211 return total_locks_size();
212 }
213
214 void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {
215 assert(stack_at(index)->as_Phi() == nullptr || stack_at(index)->as_Phi()->block() != b, "phi function already created");
216
217 ValueType* t = stack_at(index)->type();
218 Value phi = new Phi(t, b, -index - 1);
219 _stack.at_put(index, phi);
220
221 assert(!t->is_double_word() || _stack.at(index + 1) == nullptr, "hi-word of doubleword value must be null");
222 }
223
224 void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {
225 assert(local_at(index)->as_Phi() == nullptr || local_at(index)->as_Phi()->block() != b, "phi function already created");
226
227 ValueType* t = local_at(index)->type();
228 Value phi = new Phi(t, b, index);
229 store_local(index, phi);
230 }
231
232 #ifndef PRODUCT
233
234 void ValueStack::print() {
235 scope()->method()->print_name();
236 tty->cr();
237 if (stack_is_empty()) {
238 tty->print_cr("empty stack");
239 } else {
240 InstructionPrinter ip;
241 for (int i = 0; i < stack_size();) {
242 tty->print("stack %d ", i);
243 Value t = stack_at_inc(i);
244 if (t == nullptr) {
245 tty->print("null");
246 } else {
247 tty->print("%2d ", i);
248 tty->print("%c%d ", t->type()->tchar(), t->id());
249 ip.print_instr(t);
250 }
251 tty->cr();
252 }
253 }
254 if (!no_active_locks()) {
255 InstructionPrinter ip;
256 for (int i = 0; i < locks_size(); i++) {
257 Value t = lock_at(i);
258 tty->print("lock %2d ", i);
259 if (t == nullptr) {
260 tty->print("this");
261 } else {
262 tty->print("%c%d ", t->type()->tchar(), t->id());
263 ip.print_instr(t);
264 }
265 tty->cr();
266 }
267 }
268 if (locals_size() > 0) {
269 InstructionPrinter ip;
270 for (int i = 0; i < locals_size();) {
271 Value l = _locals.at(i);
272 tty->print("local %d ", i);
273 if (l == nullptr) {
274 tty->print("null");
275 i ++;
276 } else {
277 tty->print("%c%d ", l->type()->tchar(), l->id());
278 ip.print_instr(l);
279 if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;
280 }
281 tty->cr();
282 }
283 }
284
285 if (caller_state() != nullptr) {
286 caller_state()->print();
287 }
288 }
289
290
291 void ValueStack::verify() {
292 assert(scope() != nullptr, "scope must exist");
293 if (caller_state() != nullptr) {
294 assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");
295 caller_state()->verify();
296 }
297
298 if (kind() == Parsing) {
299 assert(bci() == -99, "bci not defined during parsing");
300 } else {
301 assert(bci() >= -1, "bci out of range");
302 assert(bci() < scope()->method()->code_size(), "bci out of range");
303 assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");
304 assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");
305 }
306
307 int i;
308 for (i = 0; i < stack_size(); i++) {
309 Value v = _stack.at(i);
310 if (kind() == empty_exception_kind(true /* caller */)) {
311 assert(v == nullptr, "should be empty");
312 } else if (v == nullptr) {
313 assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are null on stack");
314 } else if (v->type()->is_double_word()) {
315 assert(_stack.at(i + 1) == nullptr, "hi-word must be null");
316 }
317 }
318
319 for (i = 0; i < locals_size(); i++) {
320 Value v = _locals.at(i);
321 if (kind() == EmptyExceptionState) {
322 assert(v == nullptr, "should be empty");
323 } else if (v != nullptr && v->type()->is_double_word()) {
324 assert(_locals.at(i + 1) == nullptr, "hi-word must be null");
325 }
326 }
327
328 for_each_state_value(this, v,
329 assert(v != nullptr, "just test if state-iteration succeeds");
330 );
331 }
332 #endif // PRODUCT