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