1 /*
2 * Copyright (c) 1999, 2024, 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
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #ifndef SHARE_C1_C1_VALUESTACK_HPP
26 #define SHARE_C1_C1_VALUESTACK_HPP
27
28 #include "c1/c1_Instruction.hpp"
29
30 class ValueStack: public CompilationResourceObj {
31 public:
32 enum Kind {
33 Parsing, // During abstract interpretation in GraphBuilder
34 CallerState, // Caller state when inlining
35 StateBefore, // Before before execution of instruction
36 StateAfter, // After execution of instruction
37 // Exception states for an instruction.
38 // Dead stack items or locals may be invalidated or cleared/removed.
39 // Locals are retained if needed for JVMTI.
40 // "empty" exception states are used when there is no handler,
41 // and invalidate the locals.
42 // "leaf" exception states clear the stack.
43 // "caller" exception states are used for the parent/caller,
44 // and invalidate the stack.
45 ExceptionState, // Exception state for leaf with handler, stack cleared
46 EmptyExceptionState, // Exception state for leaf w/o handler, stack cleared, locals invalidated
47 CallerExceptionState, // Exception state for parent with handler, stack invalidated
48 CallerEmptyExceptionState, // Exception state for parent w/o handler, stack+locals invalidated
49 BlockBeginState // State of BlockBegin instruction with phi functions of this block
50 };
51
52 private:
53 IRScope* _scope; // the enclosing scope
54 ValueStack* _caller_state;
55 int _bci;
56 Kind _kind;
57
58 Values _locals; // the locals
59 Values _stack; // the expression stack
60 Values* _locks; // the monitor stack (holding the locked values)
61 bool _force_reexecute; // force the reexecute flag on, used for patching stub
62
63 Value check(ValueTag tag, Value t) {
64 assert(tag == t->type()->tag() || (tag == objectTag && t->type()->tag() == addressTag), "types must correspond");
65 return t;
66 }
67
68 Value check(ValueTag tag, Value t, Value h) {
69 assert(h == nullptr, "hi-word of doubleword value must be null");
70 return check(tag, t);
71 }
72
73 // helper routine
74 static void apply(const Values& list, ValueVisitor* f);
75
76 // for simplified copying
77 ValueStack(ValueStack* copy_from, Kind kind, int bci);
78
79 int locals_size_for_copy(Kind kind) const;
80 int stack_size_for_copy(Kind kind) const;
81 public:
82 // creation
83 ValueStack(IRScope* scope, ValueStack* caller_state);
84
85 ValueStack* copy() { return new ValueStack(this, _kind, _bci); }
86 ValueStack* copy(Kind new_kind, int new_bci) { return new ValueStack(this, new_kind, new_bci); }
87 ValueStack* copy_for_parsing() { return new ValueStack(this, Parsing, -99); }
88
89 // Used when no exception handler is found
90 static Kind empty_exception_kind(bool caller = false) {
91 return Compilation::current()->env()->should_retain_local_variables() ?
92 (caller ? CallerExceptionState : ExceptionState) : // retain locals
93 (caller ? CallerEmptyExceptionState : EmptyExceptionState); // clear locals
94 }
95
96 void set_caller_state(ValueStack* s) {
97 assert(kind() == empty_exception_kind(false) || kind() == empty_exception_kind(true),
98 "only empty exception states can be modified");
99 _caller_state = s;
100 }
101
102 bool is_same(ValueStack* s); // returns true if this & s's types match (w/o checking locals)
103
104 // accessors
105 IRScope* scope() const { return _scope; }
106 ValueStack* caller_state() const { return _caller_state; }
107 int bci() const { return _bci; }
108 Kind kind() const { return _kind; }
109
110 int locals_size() const { return _locals.length(); }
111 int stack_size() const { return _stack.length(); }
112 int locks_size() const { return _locks == nullptr ? 0 : _locks->length(); }
113 bool stack_is_empty() const { return _stack.is_empty(); }
114 bool no_active_locks() const { return _locks == nullptr || _locks->is_empty(); }
115 int total_locks_size() const;
116
117 // locals access
118 void clear_locals(); // sets all locals to null;
119
120 void invalidate_local(int i) {
121 assert(!_locals.at(i)->type()->is_double_word() ||
122 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
123 _locals.at_put(i, nullptr);
124 }
125
126 Value local_at(int i) const {
127 Value x = _locals.at(i);
128 assert(x == nullptr || !x->type()->is_double_word() ||
129 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
130 return x;
131 }
132
133 void store_local(int i, Value x) {
134 // When overwriting local i, check if i - 1 was the start of a
135 // double word local and kill it.
136 if (i > 0) {
137 Value prev = _locals.at(i - 1);
138 if (prev != nullptr && prev->type()->is_double_word()) {
139 _locals.at_put(i - 1, nullptr);
140 }
141 }
142
143 _locals.at_put(i, x);
144 if (x->type()->is_double_word()) {
145 // hi-word of doubleword value is always null
146 _locals.at_put(i + 1, nullptr);
147 }
148 }
149
150 // stack access
151 Value stack_at(int i) const {
152 Value x = _stack.at(i);
153 assert(x == nullptr || !x->type()->is_double_word() ||
154 _stack.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
155 return x;
156 }
157
158 Value stack_at_inc(int& i) const {
159 Value x = stack_at(i);
160 i += ((x == nullptr) ? 1 : x->type()->size());
161 return x;
162 }
163
164 void stack_at_put(int i, Value x) {
165 _stack.at_put(i, x);
166 }
167
168 // pinning support
169 void pin_stack_for_linear_scan();
170
171 // iteration
172 void values_do(ValueVisitor* f);
173
174 // untyped manipulation (for dup_x1, etc.)
175 void truncate_stack(int size) { _stack.trunc_to(size); }
176 void raw_push(Value t) { _stack.push(t); }
177 Value raw_pop() { return _stack.pop(); }
178
179 // typed manipulation
180 void ipush(Value t) { _stack.push(check(intTag , t)); }
181 void fpush(Value t) { _stack.push(check(floatTag , t)); }
182 void apush(Value t) { _stack.push(check(objectTag , t)); }
183 void rpush(Value t) { _stack.push(check(addressTag, t)); }
184 void lpush(Value t) { _stack.push(check(longTag , t)); _stack.push(nullptr); }
185 void dpush(Value t) { _stack.push(check(doubleTag , t)); _stack.push(nullptr); }
186
187 void push(ValueType* type, Value t) {
188 switch (type->tag()) {
189 case intTag : ipush(t); return;
190 case longTag : lpush(t); return;
191 case floatTag : fpush(t); return;
192 case doubleTag : dpush(t); return;
193 case objectTag : apush(t); return;
194 case addressTag: rpush(t); return;
195 default : ShouldNotReachHere(); return;
196 }
197 }
198
199 Value ipop() { return check(intTag , _stack.pop()); }
200 Value fpop() { return check(floatTag , _stack.pop()); }
201 Value apop() { return check(objectTag , _stack.pop()); }
202 Value rpop() { return check(addressTag, _stack.pop()); }
203 Value lpop() { Value h = _stack.pop(); return check(longTag , _stack.pop(), h); }
204 Value dpop() { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
205
206 Value pop(ValueType* type) {
207 switch (type->tag()) {
208 case intTag : return ipop();
209 case longTag : return lpop();
210 case floatTag : return fpop();
211 case doubleTag : return dpop();
212 case objectTag : return apop();
213 case addressTag: return rpop();
214 default : ShouldNotReachHere(); return nullptr;
215 }
216 }
217
218 Values* pop_arguments(int argument_size);
219
220 // locks access
221 int lock (Value obj);
222 int unlock();
223 Value lock_at(int i) const { return _locks->at(i); }
224
225 // SSA form IR support
226 void setup_phi_for_stack(BlockBegin* b, int index);
227 void setup_phi_for_local(BlockBegin* b, int index);
228
229 bool force_reexecute() const { return _force_reexecute; }
230 void set_force_reexecute() { _force_reexecute = true; }
231
232 // debugging
233 void print() PRODUCT_RETURN;
234 void verify() PRODUCT_RETURN;
235 };
236
237
238
239 // Macro definitions for simple iteration of stack and local values of a ValueStack
240 // The macros can be used like a for-loop. All variables (state, index and value)
241 // must be defined before the loop.
242 // When states are nested because of inlining, the stack of the innermost state
243 // cumulates also the stack of the nested states. In contrast, the locals of all
244 // states must be iterated each.
245 // Use the following code pattern to iterate all stack values and all nested local values:
246 //
247 // ValueStack* state = ... // state that is iterated
248 // int index; // current loop index (overwritten in loop)
249 // Value value; // value at current loop index (overwritten in loop)
250 //
251 // for_each_stack_value(state, index, value {
252 // do something with value and index
253 // }
254 //
255 // for_each_state(state) {
256 // for_each_local_value(state, index, value) {
257 // do something with value and index
258 // }
259 // }
260 // as an invariant, state is null now
261
262
263 // construct a unique variable name with the line number where the macro is used
264 #define temp_var3(x) temp__ ## x
265 #define temp_var2(x) temp_var3(x)
266 #define temp_var temp_var2(__LINE__)
267
268 #define for_each_state(state) \
269 for (; state != nullptr; state = state->caller_state())
270
271 #define for_each_local_value(state, index, value) \
272 int temp_var = state->locals_size(); \
273 for (index = 0; \
274 index < temp_var && (value = state->local_at(index), true); \
275 index += (value == nullptr || value->type()->is_illegal() ? 1 : value->type()->size())) \
276 if (value != nullptr)
277
278
279 #define for_each_stack_value(state, index, value) \
280 int temp_var = state->stack_size(); \
281 for (index = 0; \
282 index < temp_var && (value = state->stack_at(index), true); \
283 index += (value == nullptr ? 1 : value->type()->size())) \
284 if (value != nullptr)
285
286
287 #define for_each_lock_value(state, index, value) \
288 int temp_var = state->locks_size(); \
289 for (index = 0; \
290 index < temp_var && (value = state->lock_at(index), true); \
291 index++) \
292 if (value != nullptr)
293
294
295 // Macro definition for simple iteration of all state values of a ValueStack
296 // Because the code cannot be executed in a single loop, the code must be passed
297 // as a macro parameter.
298 // Use the following code pattern to iterate all stack values and all nested local values:
299 //
300 // ValueStack* state = ... // state that is iterated
301 // for_each_state_value(state, value,
302 // do something with value (note that this is a macro parameter)
303 // );
304
305 #define for_each_state_value(v_state, v_value, v_code) \
306 { \
307 int cur_index; \
308 ValueStack* cur_state = v_state; \
309 Value v_value; \
310 for_each_state(cur_state) { \
311 { \
312 for_each_local_value(cur_state, cur_index, v_value) { \
313 v_code; \
314 } \
315 } \
316 { \
317 for_each_stack_value(cur_state, cur_index, v_value) { \
318 v_code; \
319 } \
320 } \
321 } \
322 }
323
324
325 // Macro definition for simple iteration of all phi functions of a block, i.e all
326 // phi functions of the ValueStack where the block matches.
327 // Use the following code pattern to iterate all phi functions of a block:
328 //
329 // BlockBegin* block = ... // block that is iterated
330 // for_each_phi_function(block, phi,
331 // do something with the phi function phi (note that this is a macro parameter)
332 // );
333
334 #define for_each_phi_fun(v_block, v_phi, v_code) \
335 { \
336 int cur_index; \
337 ValueStack* cur_state = v_block->state(); \
338 Value value; \
339 { \
340 for_each_stack_value(cur_state, cur_index, value) { \
341 Phi* v_phi = value->as_Phi(); \
342 if (v_phi != nullptr && v_phi->block() == v_block) { \
343 v_code; \
344 } \
345 } \
346 } \
347 { \
348 for_each_local_value(cur_state, cur_index, value) { \
349 Phi* v_phi = value->as_Phi(); \
350 if (v_phi != nullptr && v_phi->block() == v_block) { \
351 v_code; \
352 } \
353 } \
354 } \
355 }
356
357 #endif // SHARE_C1_C1_VALUESTACK_HPP