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