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