1/*
2 * Copyright (c) 1999, 2016, 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
33ValueStack::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(), NULL)
39, _stack(scope->method()->max_stack())
40, _locks(NULL)
41{
42 verify();
43}
44
45
46ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci)
47 : _scope(copy_from->scope())
48 , _caller_state(copy_from->caller_state())
49 , _bci(bci)
50 , _kind(kind)
51 , _locals()
52 , _stack()
53 , _locks(copy_from->locks_size() == 0 ? NULL : new Values(copy_from->locks_size()))
54{
55 assert(kind != EmptyExceptionState || !Compilation::current()->env()->should_retain_local_variables(), "need locals");
56 if (kind != EmptyExceptionState) {
57 // only allocate space if we need to copy the locals-array
58 _locals = Values(copy_from->locals_size());
59 _locals.appendAll(&copy_from->_locals);
60 }
61
62 if (kind != ExceptionState && kind != EmptyExceptionState) {
63 if (kind == Parsing) {
64 // stack will be modified, so reserve enough space to avoid resizing
65 _stack = Values(scope()->method()->max_stack());
66 } else {
67 // stack will not be modified, so do not waste space
68 _stack = Values(copy_from->stack_size());
69 }
70 _stack.appendAll(&copy_from->_stack);
71 }
72
73 if (copy_from->locks_size() > 0) {
74 _locks->appendAll(copy_from->_locks);
75 }
76
77 verify();
78}
79
80
81bool ValueStack::is_same(ValueStack* s) {
82 if (scope() != s->scope()) return false;
83 if (caller_state() != s->caller_state()) return false;
84
85 if (locals_size() != s->locals_size()) return false;
86 if (stack_size() != s->stack_size()) return false;
87 if (locks_size() != s->locks_size()) return false;
88
89 // compare each stack element with the corresponding stack element of s
90 int index;
91 Value value;
92 for_each_stack_value(this, index, value) {
93 if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;
94 }
95 for (int i = 0; i < locks_size(); i++) {
96 value = lock_at(i);
97 if (value != NULL && value != s->lock_at(i)) {
98 return false;
99 }
100 }
101 return true;
102}
103
104void ValueStack::clear_locals() {
105 for (int i = _locals.length() - 1; i >= 0; i--) {
106 _locals.at_put(i, NULL);
107 }
108}
109
110
111void ValueStack::pin_stack_for_linear_scan() {
112 for_each_state_value(this, v,
113 if (v->as_Constant() == NULL && v->as_Local() == NULL) {
114 v->pin(Instruction::PinStackForStateSplit);
115 }
116 );
117}
118
119
120// apply function to all values of a list; factored out from values_do(f)
121void ValueStack::apply(const Values& list, ValueVisitor* f) {
122 for (int i = 0; i < list.length(); i++) {
123 Value* va = list.adr_at(i);
124 Value v0 = *va;
125 if (v0 != NULL && !v0->type()->is_illegal()) {
126 f->visit(va);
127#ifdef ASSERT
128 Value v1 = *va;
129 assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");
130 assert(!v1->type()->is_double_word() || list.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
131#endif
132 if (v0->type()->is_double_word()) i++;
133 }
134 }
135}
136
137
138void ValueStack::values_do(ValueVisitor* f) {
139 ValueStack* state = this;
140 for_each_state(state) {
141 apply(state->_locals, f);
142 apply(state->_stack, f);
143 if (state->_locks != NULL) {
144 apply(*state->_locks, f);
145 }
146 }
147}
148
149
150Values* ValueStack::pop_arguments(int argument_size) {
151 assert(stack_size() >= argument_size, "stack too small or too many arguments");
152 int base = stack_size() - argument_size;
153 Values* args = new Values(argument_size);
154 for (int i = base; i < stack_size();) args->push(stack_at_inc(i));
155 truncate_stack(base);
156 return args;
157}
158
159
160int ValueStack::total_locks_size() const {
161 int num_locks = 0;
162 const ValueStack* state = this;
163 for_each_state(state) {
164 num_locks += state->locks_size();
165 }
166 return num_locks;
167}
168
169int ValueStack::lock(Value obj) {
170 if (_locks == NULL) {
171 _locks = new Values();
172 }
173 _locks->push(obj);
174 int num_locks = total_locks_size();
175 scope()->set_min_number_of_locks(num_locks);
176 return num_locks - 1;
177}
178
179
180int ValueStack::unlock() {
181 assert(locks_size() > 0, "sanity");
182 _locks->pop();
183 return total_locks_size();
184}
185
186
187void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {
188 assert(stack_at(index)->as_Phi() == NULL || stack_at(index)->as_Phi()->block() != b, "phi function already created");
189
190 ValueType* t = stack_at(index)->type();
191 Value phi = new Phi(t, b, -index - 1);
192 _stack.at_put(index, phi);
193
194 assert(!t->is_double_word() || _stack.at(index + 1) == NULL, "hi-word of doubleword value must be NULL");
195}
196
197void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {
198 assert(local_at(index)->as_Phi() == NULL || local_at(index)->as_Phi()->block() != b, "phi function already created");
199
200 ValueType* t = local_at(index)->type();
201 Value phi = new Phi(t, b, index);
202 store_local(index, phi);
203}
204
205#ifndef PRODUCT
206
207void ValueStack::print() {
208 scope()->method()->print_name();
209 tty->cr();
210 if (stack_is_empty()) {
211 tty->print_cr("empty stack");
212 } else {
213 InstructionPrinter ip;
214 for (int i = 0; i < stack_size();) {
215 Value t = stack_at_inc(i);
216 tty->print("%2d ", i);
217 tty->print("%c%d ", t->type()->tchar(), t->id());
218 ip.print_instr(t);
219 tty->cr();
220 }
221 }
222 if (!no_active_locks()) {
223 InstructionPrinter ip;
224 for (int i = 0; i < locks_size(); i++) {
225 Value t = lock_at(i);
226 tty->print("lock %2d ", i);
227 if (t == NULL) {
228 tty->print("this");
229 } else {
230 tty->print("%c%d ", t->type()->tchar(), t->id());
231 ip.print_instr(t);
232 }
233 tty->cr();
234 }
235 }
236 if (locals_size() > 0) {
237 InstructionPrinter ip;
238 for (int i = 0; i < locals_size();) {
239 Value l = _locals.at(i);
240 tty->print("local %d ", i);
241 if (l == NULL) {
242 tty->print("null");
243 i ++;
244 } else {
245 tty->print("%c%d ", l->type()->tchar(), l->id());
246 ip.print_instr(l);
247 if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;
248 }
249 tty->cr();
250 }
251 }
252
253 if (caller_state() != NULL) {
254 caller_state()->print();
255 }
256}
257
258
259void ValueStack::verify() {
260 assert(scope() != NULL, "scope must exist");
261 if (caller_state() != NULL) {
262 assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");
263 caller_state()->verify();
264 }
265
266 if (kind() == Parsing) {
267 assert(bci() == -99, "bci not defined during parsing");
268 } else {
269 assert(bci() >= -1, "bci out of range");
270 assert(bci() < scope()->method()->code_size(), "bci out of range");
271 assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");
272 assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");
273 }
274
275 int i;
276 for (i = 0; i < stack_size(); i++) {
277 Value v = _stack.at(i);
278 if (v == NULL) {
279 assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are NULL on stack");
280 } else if (v->type()->is_double_word()) {
281 assert(_stack.at(i + 1) == NULL, "hi-word must be NULL");
282 }
283 }
284
285 for (i = 0; i < locals_size(); i++) {
286 Value v = _locals.at(i);
287 if (v != NULL && v->type()->is_double_word()) {
288 assert(_locals.at(i + 1) == NULL, "hi-word must be NULL");
289 }
290 }
291
292 for_each_state_value(this, v,
293 assert(v != NULL, "just test if state-iteration succeeds");
294 );
295}
296#endif // PRODUCT
297