1 /*
2 * Copyright (c) 1999, 2024, 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 , _force_reexecute(false)
43 {
44 verify();
45 }
46
47 ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci, bool reexecute)
48 : _scope(copy_from->scope())
49 , _caller_state(copy_from->caller_state())
50 , _bci(bci)
51 , _kind(kind)
52 , _should_reexecute(reexecute)
53 , _locals(copy_from->locals_size_for_copy(kind))
54 , _stack(copy_from->stack_size_for_copy(kind))
55 , _locks(copy_from->locks_size() == 0 ? nullptr : new Values(copy_from->locks_size()))
56 , _force_reexecute(false)
57 {
58 switch (kind) {
59 case EmptyExceptionState:
60 case CallerEmptyExceptionState:
61 assert(!Compilation::current()->env()->should_retain_local_variables(), "need locals");
62 // set to all nulls, like clear_locals()
63 for (int i = 0; i < copy_from->locals_size(); ++i) {
64 _locals.append(nullptr);
65 }
66 break;
67 default:
68 _locals.appendAll(©_from->_locals);
69 }
70
71 switch (kind) {
72 case ExceptionState:
73 case EmptyExceptionState:
74 assert(stack_size() == 0, "fix stack_size_for_copy");
75 break;
76 case CallerExceptionState:
77 case CallerEmptyExceptionState:
78 // set to all nulls
79 for (int i = 0; i < copy_from->stack_size(); ++i) {
80 _stack.append(nullptr);
81 }
82 break;
83 default:
84 _stack.appendAll(©_from->_stack);
85 }
86
87 if (copy_from->locks_size() > 0) {
88 _locks->appendAll(copy_from->_locks);
89 }
90
91 verify();
92 }
93
94 int ValueStack::locals_size_for_copy(Kind kind) const {
95 return locals_size();
96 }
97
98 int ValueStack::stack_size_for_copy(Kind kind) const {
99 if (kind != ExceptionState && kind != EmptyExceptionState) {
100 if (kind == Parsing) {
101 // stack will be modified, so reserve enough space to avoid resizing
102 return scope()->method()->max_stack();
103 } else {
104 // stack will not be modified, so do not waste space
105 return stack_size();
106 }
107 }
108 return 0;
109 }
110
111 bool ValueStack::is_same(ValueStack* s) {
112 if (scope() != s->scope()) return false;
113 if (caller_state() != s->caller_state()) return false;
114
115 if (locals_size() != s->locals_size()) return false;
116 if (stack_size() != s->stack_size()) return false;
117 if (locks_size() != s->locks_size()) return false;
118
119 // compare each stack element with the corresponding stack element of s
120 int index;
121 Value value;
122 for_each_stack_value(this, index, value) {
123 if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;
124 }
125 for (int i = 0; i < locks_size(); i++) {
126 value = lock_at(i);
127 if (value != nullptr && value != s->lock_at(i)) {
128 return false;
129 }
130 }
131 return true;
132 }
133
134 void ValueStack::clear_locals() {
135 for (int i = _locals.length() - 1; i >= 0; i--) {
136 _locals.at_put(i, nullptr);
137 }
138 }
139
140
141 void ValueStack::pin_stack_for_linear_scan() {
142 for_each_state_value(this, v,
143 if (v->as_Constant() == nullptr && v->as_Local() == nullptr) {
144 v->pin(Instruction::PinStackForStateSplit);
145 }
146 );
147 }
148
149
150 // apply function to all values of a list; factored out from values_do(f)
151 void ValueStack::apply(const Values& list, ValueVisitor* f) {
152 for (int i = 0; i < list.length(); i++) {
153 Value* va = list.adr_at(i);
154 Value v0 = *va;
155 if (v0 != nullptr && !v0->type()->is_illegal()) {
156 f->visit(va);
157 #ifdef ASSERT
158 Value v1 = *va;
159 assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");
160 assert(!v1->type()->is_double_word() || list.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
161 #endif
162 if (v0->type()->is_double_word()) i++;
163 }
164 }
165 }
166
167
168 void ValueStack::values_do(ValueVisitor* f) {
169 ValueStack* state = this;
170 for_each_state(state) {
171 apply(state->_locals, f);
172 apply(state->_stack, f);
173 if (state->_locks != nullptr) {
174 apply(*state->_locks, f);
175 }
176 }
177 }
178
179
180 Values* ValueStack::pop_arguments(int argument_size) {
181 assert(stack_size() >= argument_size, "stack too small or too many arguments");
182 int base = stack_size() - argument_size;
183 Values* args = new Values(argument_size);
184 for (int i = base; i < stack_size();) args->push(stack_at_inc(i));
185 truncate_stack(base);
186 return args;
187 }
188
189
190 int ValueStack::total_locks_size() const {
191 int num_locks = 0;
192 const ValueStack* state = this;
193 for_each_state(state) {
194 num_locks += state->locks_size();
195 }
196 return num_locks;
197 }
198
199 int ValueStack::lock(Value obj) {
200 if (_locks == nullptr) {
201 _locks = new Values();
202 }
203 _locks->push(obj);
204 int num_locks = total_locks_size();
205 scope()->set_min_number_of_locks(num_locks);
206 return num_locks - 1;
207 }
208
209
210 int ValueStack::unlock() {
211 assert(locks_size() > 0, "sanity");
212 _locks->pop();
213 return total_locks_size();
214 }
215
216 void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {
217 assert(stack_at(index)->as_Phi() == nullptr || stack_at(index)->as_Phi()->block() != b, "phi function already created");
218
219 ValueType* t = stack_at(index)->type();
220 Value phi = new Phi(t, b, -index - 1);
221 _stack.at_put(index, phi);
222
223 assert(!t->is_double_word() || _stack.at(index + 1) == nullptr, "hi-word of doubleword value must be null");
224 }
225
226 void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {
227 assert(local_at(index)->as_Phi() == nullptr || local_at(index)->as_Phi()->block() != b, "phi function already created");
228
229 ValueType* t = local_at(index)->type();
230 Value phi = new Phi(t, b, index);
231 store_local(index, phi);
232 }
233
234 #ifndef PRODUCT
235
236 void ValueStack::print() {
237 scope()->method()->print_name();
238 tty->cr();
239 if (stack_is_empty()) {
240 tty->print_cr("empty stack");
241 } else {
242 InstructionPrinter ip;
243 for (int i = 0; i < stack_size();) {
244 tty->print("stack %d ", i);
245 Value t = stack_at_inc(i);
246 if (t == nullptr) {
247 tty->print("null");
248 } else {
249 tty->print("%2d ", i);
250 tty->print("%c%d ", t->type()->tchar(), t->id());
251 ip.print_instr(t);
252 }
253 tty->cr();
254 }
255 }
256 if (!no_active_locks()) {
257 InstructionPrinter ip;
258 for (int i = 0; i < locks_size(); i++) {
259 Value t = lock_at(i);
260 tty->print("lock %2d ", i);
261 if (t == nullptr) {
262 tty->print("this");
263 } else {
264 tty->print("%c%d ", t->type()->tchar(), t->id());
265 ip.print_instr(t);
266 }
267 tty->cr();
268 }
269 }
270 if (locals_size() > 0) {
271 InstructionPrinter ip;
272 for (int i = 0; i < locals_size();) {
273 Value l = _locals.at(i);
274 tty->print("local %d ", i);
275 if (l == nullptr) {
276 tty->print("null");
277 i ++;
278 } else {
279 tty->print("%c%d ", l->type()->tchar(), l->id());
280 ip.print_instr(l);
281 if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;
282 }
283 tty->cr();
284 }
285 }
286
287 if (caller_state() != nullptr) {
288 caller_state()->print();
289 }
290 }
291
292
293 void ValueStack::verify() {
294 assert(scope() != nullptr, "scope must exist");
295 if (caller_state() != nullptr) {
296 assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");
297 caller_state()->verify();
298 }
299
300 if (kind() == Parsing) {
301 assert(bci() == -99, "bci not defined during parsing");
302 } else {
303 assert(bci() >= -1, "bci out of range");
304 assert(bci() < scope()->method()->code_size(), "bci out of range");
305 assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");
306 assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");
307 }
308
309 int i;
310 for (i = 0; i < stack_size(); i++) {
311 Value v = _stack.at(i);
312 if (kind() == empty_exception_kind(true /* caller */)) {
313 assert(v == nullptr, "should be empty");
314 } else if (v == nullptr) {
315 assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are null on stack");
316 } else if (v->type()->is_double_word()) {
317 assert(_stack.at(i + 1) == nullptr, "hi-word must be null");
318 }
319 }
320
321 for (i = 0; i < locals_size(); i++) {
322 Value v = _locals.at(i);
323 if (kind() == EmptyExceptionState) {
324 assert(v == nullptr, "should be empty");
325 } else if (v != nullptr && v->type()->is_double_word()) {
326 assert(_locals.at(i + 1) == nullptr, "hi-word must be null");
327 }
328 }
329
330 for_each_state_value(this, v,
331 assert(v != nullptr, "just test if state-iteration succeeds");
332 );
333 }
334 #endif // PRODUCT