1 /*
2 * Copyright (c) 1999, 2006, 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 class ValueStack: public CompilationResourceObj {
26 private:
27 IRScope* _scope; // the enclosing scope
28 bool _lock_stack; // indicates that this ValueStack is for an exception site
29 Values _locals; // the locals
30 Values _stack; // the expression stack
31 Values _locks; // the monitor stack (holding the locked values)
32
33 Value check(ValueTag tag, Value t) {
34 assert(tag == t->type()->tag() || tag == objectTag && t->type()->tag() == addressTag, "types must correspond");
35 return t;
36 }
37
38 Value check(ValueTag tag, Value t, Value h) {
39 assert(h->as_HiWord()->lo_word() == t, "incorrect stack pair");
40 return check(tag, t);
41 }
42
43 // helper routine
44 static void apply(Values list, void f(Value*));
45
46 public:
47 // creation
48 ValueStack(IRScope* scope, int locals_size, int max_stack_size);
49
50 // merging
51 ValueStack* copy(); // returns a copy of this w/ cleared locals
52 ValueStack* copy_locks(); // returns a copy of this w/ cleared locals and stack
53 // Note that when inlining of methods with exception
54 // handlers is enabled, this stack may have a
55 // non-empty expression stack (size defined by
56 // scope()->lock_stack_size())
57 bool is_same(ValueStack* s); // returns true if this & s's types match (w/o checking locals)
58 bool is_same_across_scopes(ValueStack* s); // same as is_same but returns true even if stacks are in different scopes (used for block merging w/inlining)
59
60 // accessors
61 IRScope* scope() const { return _scope; }
62 bool is_lock_stack() const { return _lock_stack; }
63 int locals_size() const { return _locals.length(); }
64 int stack_size() const { return _stack.length(); }
65 int locks_size() const { return _locks.length(); }
66 int max_stack_size() const { return _stack.capacity(); }
67 bool stack_is_empty() const { return _stack.is_empty(); }
68 bool no_active_locks() const { return _locks.is_empty(); }
69 ValueStack* caller_state() const;
70
71 // locals access
72 void clear_locals(); // sets all locals to NULL;
73
74 // Kill local i. Also kill local i+1 if i was a long or double.
75 void invalidate_local(int i) {
76 Value x = _locals.at(i);
77 if (x != NULL && x->type()->is_double_word()) {
78 assert(_locals.at(i + 1)->as_HiWord()->lo_word() == x, "locals inconsistent");
79 _locals.at_put(i + 1, NULL);
80 }
81 _locals.at_put(i, NULL);
82 }
83
84
85 Value load_local(int i) const {
86 Value x = _locals.at(i);
87 if (x != NULL && x->type()->is_illegal()) return NULL;
88 assert(x == NULL || x->as_HiWord() == NULL, "index points to hi word");
89 assert(x == NULL || x->type()->is_illegal() || x->type()->is_single_word() || x == _locals.at(i+1)->as_HiWord()->lo_word(), "locals inconsistent");
90 return x;
91 }
92
93 Value local_at(int i) const { return _locals.at(i); }
94
95 // Store x into local i.
96 void store_local(int i, Value x) {
97 // Kill the old value
98 invalidate_local(i);
99 _locals.at_put(i, x);
100
101 // Writing a double word can kill other locals
102 if (x != NULL && x->type()->is_double_word()) {
103 // If x + i was the start of a double word local then kill i + 2.
104 Value x2 = _locals.at(i + 1);
105 if (x2 != NULL && x2->type()->is_double_word()) {
106 _locals.at_put(i + 2, NULL);
107 }
108
109 // If x is a double word local, also update i + 1.
110 #ifdef ASSERT
111 _locals.at_put(i + 1, x->hi_word());
112 #else
113 _locals.at_put(i + 1, NULL);
114 #endif
115 }
116 // If x - 1 was the start of a double word local then kill i - 1.
117 if (i > 0) {
118 Value prev = _locals.at(i - 1);
119 if (prev != NULL && prev->type()->is_double_word()) {
120 _locals.at_put(i - 1, NULL);
121 }
122 }
123 }
124
125 void replace_locals(ValueStack* with);
126
127 // stack access
128 Value stack_at(int i) const {
129 Value x = _stack.at(i);
130 assert(x->as_HiWord() == NULL, "index points to hi word");
131 assert(x->type()->is_single_word() ||
132 x->subst() == _stack.at(i+1)->as_HiWord()->lo_word(), "stack inconsistent");
133 return x;
134 }
135
136 Value stack_at_inc(int& i) const {
137 Value x = stack_at(i);
138 i += x->type()->size();
139 return x;
140 }
141
142 // pinning support
143 void pin_stack_for_linear_scan();
144
145 // iteration
146 void values_do(void f(Value*));
147
148 // untyped manipulation (for dup_x1, etc.)
149 void clear_stack() { _stack.clear(); }
150 void truncate_stack(int size) { _stack.trunc_to(size); }
151 void raw_push(Value t) { _stack.push(t); }
152 Value raw_pop() { return _stack.pop(); }
153
154 // typed manipulation
155 void ipush(Value t) { _stack.push(check(intTag , t)); }
156 void fpush(Value t) { _stack.push(check(floatTag , t)); }
157 void apush(Value t) { _stack.push(check(objectTag , t)); }
158 void rpush(Value t) { _stack.push(check(addressTag, t)); }
159 #ifdef ASSERT
160 // in debug mode, use HiWord for 2-word values
161 void lpush(Value t) { _stack.push(check(longTag , t)); _stack.push(new HiWord(t)); }
162 void dpush(Value t) { _stack.push(check(doubleTag , t)); _stack.push(new HiWord(t)); }
163 #else
164 // in optimized mode, use NULL for 2-word values
165 void lpush(Value t) { _stack.push(check(longTag , t)); _stack.push(NULL); }
166 void dpush(Value t) { _stack.push(check(doubleTag , t)); _stack.push(NULL); }
167 #endif // ASSERT
168
169 void push(ValueType* type, Value t) {
170 switch (type->tag()) {
171 case intTag : ipush(t); return;
172 case longTag : lpush(t); return;
173 case floatTag : fpush(t); return;
174 case doubleTag : dpush(t); return;
175 case objectTag : apush(t); return;
176 case addressTag: rpush(t); return;
177 }
178 ShouldNotReachHere();
179 }
180
181 Value ipop() { return check(intTag , _stack.pop()); }
182 Value fpop() { return check(floatTag , _stack.pop()); }
183 Value apop() { return check(objectTag , _stack.pop()); }
184 Value rpop() { return check(addressTag, _stack.pop()); }
185 #ifdef ASSERT
186 // in debug mode, check for HiWord consistency
187 Value lpop() { Value h = _stack.pop(); return check(longTag , _stack.pop(), h); }
188 Value dpop() { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
189 #else
190 // in optimized mode, ignore HiWord since it is NULL
191 Value lpop() { _stack.pop(); return check(longTag , _stack.pop()); }
192 Value dpop() { _stack.pop(); return check(doubleTag, _stack.pop()); }
193 #endif // ASSERT
194
195 Value pop(ValueType* type) {
196 switch (type->tag()) {
197 case intTag : return ipop();
198 case longTag : return lpop();
199 case floatTag : return fpop();
200 case doubleTag : return dpop();
201 case objectTag : return apop();
202 case addressTag: return rpop();
203 }
204 ShouldNotReachHere();
205 return NULL;
206 }
207
208 Values* pop_arguments(int argument_size);
209
210 // locks access
211 int lock (IRScope* scope, Value obj);
212 int unlock();
213 Value lock_at(int i) const { return _locks.at(i); }
214
215 // Inlining support
216 ValueStack* push_scope(IRScope* scope); // "Push" new scope, returning new resulting stack
217 // Preserves stack and locks, destroys locals
218 ValueStack* pop_scope(); // "Pop" topmost scope, returning new resulting stack
219 // Preserves stack and locks, destroys locals
220
221 // SSA form IR support
222 void setup_phi_for_stack(BlockBegin* b, int index);
223 void setup_phi_for_local(BlockBegin* b, int index);
224
225 // debugging
226 void print() PRODUCT_RETURN;
227 void verify() PRODUCT_RETURN;
228 };
229
230
231
232 // Macro definitions for simple iteration of stack and local values of a ValueStack
233 // The macros can be used like a for-loop. All variables (state, index and value)
234 // must be defined before the loop.
235 // When states are nested because of inlining, the stack of the innermost state
236 // cumulates also the stack of the nested states. In contrast, the locals of all
237 // states must be iterated each.
238 // Use the following code pattern to iterate all stack values and all nested local values:
239 //
240 // ValueStack* state = ... // state that is iterated
241 // int index; // current loop index (overwritten in loop)
242 // Value value; // value at current loop index (overwritten in loop)
243 //
244 // for_each_stack_value(state, index, value {
245 // do something with value and index
246 // }
247 //
248 // for_each_state(state) {
249 // for_each_local_value(state, index, value) {
250 // do something with value and index
251 // }
252 // }
253 // as an invariant, state is NULL now
254
255
256 // construct a unique variable name with the line number where the macro is used
257 #define temp_var3(x) temp__ ## x
258 #define temp_var2(x) temp_var3(x)
259 #define temp_var temp_var2(__LINE__)
260
261 #define for_each_state(state) \
262 for (; state != NULL; state = state->caller_state())
263
264 #define for_each_local_value(state, index, value) \
265 int temp_var = state->locals_size(); \
266 for (index = 0; \
267 index < temp_var && (value = state->local_at(index), true); \
268 index += (value == NULL || value->type()->is_illegal() ? 1 : value->type()->size())) \
269 if (value != NULL)
270
271
272 #define for_each_stack_value(state, index, value) \
273 int temp_var = state->stack_size(); \
274 for (index = 0; \
275 index < temp_var && (value = state->stack_at(index), true); \
276 index += value->type()->size())
277
278
279 #define for_each_lock_value(state, index, value) \
280 int temp_var = state->locks_size(); \
281 for (index = 0; \
282 index < temp_var && (value = state->lock_at(index), true); \
283 index++) \
284 if (value != NULL)
285
286
287 // Macro definition for simple iteration of all state values of a ValueStack
288 // Because the code cannot be executed in a single loop, the code must be passed
289 // as a macro parameter.
290 // Use the following code pattern to iterate all stack values and all nested local values:
291 //
292 // ValueStack* state = ... // state that is iterated
293 // for_each_state_value(state, value,
294 // do something with value (note that this is a macro parameter)
295 // );
296
297 #define for_each_state_value(v_state, v_value, v_code) \
298 { \
299 int cur_index; \
300 ValueStack* cur_state = v_state; \
301 Value v_value; \
302 { \
303 for_each_stack_value(cur_state, cur_index, v_value) { \
304 v_code; \
305 } \
306 } \
307 for_each_state(cur_state) { \
308 for_each_local_value(cur_state, cur_index, v_value) { \
309 v_code; \
310 } \
311 } \
312 }
313
314
315 // Macro definition for simple iteration of all phif functions of a block, i.e all
316 // phi functions of the ValueStack where the block matches.
317 // Use the following code pattern to iterate all phi functions of a block:
318 //
319 // BlockBegin* block = ... // block that is iterated
320 // for_each_phi_function(block, phi,
321 // do something with the phi function phi (note that this is a macro parameter)
322 // );
323
324 #define for_each_phi_fun(v_block, v_phi, v_code) \
325 { \
326 int cur_index; \
327 ValueStack* cur_state = v_block->state(); \
328 Value value; \
329 { \
330 for_each_stack_value(cur_state, cur_index, value) { \
331 Phi* v_phi = value->as_Phi(); \
332 if (v_phi != NULL && v_phi->block() == v_block) { \
333 v_code; \
334 } \
335 } \
336 } \
337 { \
338 for_each_local_value(cur_state, cur_index, value) { \
339 Phi* v_phi = value->as_Phi(); \
340 if (v_phi != NULL && v_phi->block() == v_block) { \
341 v_code; \
342 } \
343 } \
344 } \
345 }