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
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.
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20 * or visit www.oracle.com if you need additional information or have any
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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 bool _should_reexecute;
58
59 Values _locals; // the locals
60 Values _stack; // the expression stack
61 Values* _locks; // the monitor stack (holding the locked values)
62 bool _force_reexecute; // force the reexecute flag on, used for patching stub
63
64 Value check(ValueTag tag, Value t) {
65 assert(tag == t->type()->tag() || (tag == objectTag && t->type()->tag() == addressTag), "types must correspond");
66 return t;
67 }
68
69 Value check(ValueTag tag, Value t, Value h) {
70 assert(h == nullptr, "hi-word of doubleword value must be null");
71 return check(tag, t);
72 }
73
74 // helper routine
75 static void apply(const Values& list, ValueVisitor* f);
76
77 // for simplified copying
78 ValueStack(ValueStack* copy_from, Kind kind, int bci, bool reexecute);
79
80 int locals_size_for_copy(Kind kind) const;
81 int stack_size_for_copy(Kind kind) const;
82 public:
83 // creation
84 ValueStack(IRScope* scope, ValueStack* caller_state);
85
86 ValueStack* copy() { return new ValueStack(this, _kind, _bci, _should_reexecute); }
87 ValueStack* copy(Kind new_kind, int new_bci) { return new ValueStack(this, new_kind, new_bci, _should_reexecute); }
88 ValueStack* copy_for_parsing() { return new ValueStack(this, Parsing, -99, false); }
89
90 // Used when no exception handler is found
91 static Kind empty_exception_kind(bool caller = false) {
92 return Compilation::current()->env()->should_retain_local_variables() ?
93 (caller ? CallerExceptionState : ExceptionState) : // retain locals
94 (caller ? CallerEmptyExceptionState : EmptyExceptionState); // clear locals
95 }
96
97 void set_caller_state(ValueStack* s) {
98 assert(kind() == empty_exception_kind(false) || kind() == empty_exception_kind(true),
99 "only empty exception states can be modified");
100 _caller_state = s;
101 }
102
103 bool is_same(ValueStack* s); // returns true if this & s's types match (w/o checking locals)
104
105 // accessors
106 IRScope* scope() const { return _scope; }
107 ValueStack* caller_state() const { return _caller_state; }
108 int bci() const { return _bci; }
109 Kind kind() const { return _kind; }
110 bool should_reexecute() const { return _should_reexecute; }
111 void set_should_reexecute(bool reexec) { _should_reexecute = reexec; }
112
113 int locals_size() const { return _locals.length(); }
114 int stack_size() const { return _stack.length(); }
115 int locks_size() const { return _locks == nullptr ? 0 : _locks->length(); }
116 bool stack_is_empty() const { return _stack.is_empty(); }
117 bool no_active_locks() const { return _locks == nullptr || _locks->is_empty(); }
118 int total_locks_size() const;
119
120 // locals access
121 void clear_locals(); // sets all locals to null;
122
123 void invalidate_local(int i) {
124 assert(!_locals.at(i)->type()->is_double_word() ||
125 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
126 _locals.at_put(i, nullptr);
127 }
128
129 Value local_at(int i) const {
130 Value x = _locals.at(i);
131 assert(x == nullptr || !x->type()->is_double_word() ||
132 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
133 return x;
134 }
135
136 void store_local(int i, Value x) {
137 // When overwriting local i, check if i - 1 was the start of a
138 // double word local and kill it.
139 if (i > 0) {
140 Value prev = _locals.at(i - 1);
141 if (prev != nullptr && prev->type()->is_double_word()) {
142 _locals.at_put(i - 1, nullptr);
143 }
144 }
145
146 _locals.at_put(i, x);
147 if (x->type()->is_double_word()) {
148 // hi-word of doubleword value is always null
149 _locals.at_put(i + 1, nullptr);
150 }
151 }
152
153 // stack access
154 Value stack_at(int i) const {
155 Value x = _stack.at(i);
156 assert(x == nullptr || !x->type()->is_double_word() ||
157 _stack.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
158 return x;
159 }
160
161 Value stack_at_inc(int& i) const {
162 Value x = stack_at(i);
163 i += ((x == nullptr) ? 1 : x->type()->size());
164 return x;
165 }
166
167 void stack_at_put(int i, Value x) {
168 _stack.at_put(i, x);
169 }
170
171 // pinning support
172 void pin_stack_for_linear_scan();
173
174 // iteration
175 void values_do(ValueVisitor* f);
176
177 // untyped manipulation (for dup_x1, etc.)
178 void truncate_stack(int size) { _stack.trunc_to(size); }
179 void raw_push(Value t) { _stack.push(t); }
180 Value raw_pop() { return _stack.pop(); }
181
182 // typed manipulation
183 void ipush(Value t) { _stack.push(check(intTag , t)); }
184 void fpush(Value t) { _stack.push(check(floatTag , t)); }
185 void apush(Value t) { _stack.push(check(objectTag , t)); }
186 void rpush(Value t) { _stack.push(check(addressTag, t)); }
187 void lpush(Value t) { _stack.push(check(longTag , t)); _stack.push(nullptr); }
188 void dpush(Value t) { _stack.push(check(doubleTag , t)); _stack.push(nullptr); }
189
190 void push(ValueType* type, Value t) {
191 switch (type->tag()) {
192 case intTag : ipush(t); return;
193 case longTag : lpush(t); return;
194 case floatTag : fpush(t); return;
195 case doubleTag : dpush(t); return;
196 case objectTag : apush(t); return;
197 case addressTag: rpush(t); return;
198 default : ShouldNotReachHere(); return;
199 }
200 }
201
202 Value ipop() { return check(intTag , _stack.pop()); }
203 Value fpop() { return check(floatTag , _stack.pop()); }
204 Value apop() { return check(objectTag , _stack.pop()); }
205 Value rpop() { return check(addressTag, _stack.pop()); }
206 Value lpop() { Value h = _stack.pop(); return check(longTag , _stack.pop(), h); }
207 Value dpop() { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
208
209 Value pop(ValueType* type) {
210 switch (type->tag()) {
211 case intTag : return ipop();
212 case longTag : return lpop();
213 case floatTag : return fpop();
214 case doubleTag : return dpop();
215 case objectTag : return apop();
216 case addressTag: return rpop();
217 default : ShouldNotReachHere(); return nullptr;
218 }
219 }
220
221 Values* pop_arguments(int argument_size);
222
223 // locks access
224 int lock (Value obj);
225 int unlock();
226 Value lock_at(int i) const { return _locks->at(i); }
227
228 // SSA form IR support
229 void setup_phi_for_stack(BlockBegin* b, int index);
230 void setup_phi_for_local(BlockBegin* b, int index);
231
232 bool force_reexecute() const { return _force_reexecute; }
233 void set_force_reexecute() { _force_reexecute = true; }
234
235 // debugging
236 void print() PRODUCT_RETURN;
237 void verify() PRODUCT_RETURN;
238 };
239
240
241
242 // Macro definitions for simple iteration of stack and local values of a ValueStack
243 // The macros can be used like a for-loop. All variables (state, index and value)
244 // must be defined before the loop.
245 // When states are nested because of inlining, the stack of the innermost state
246 // cumulates also the stack of the nested states. In contrast, the locals of all
247 // states must be iterated each.
248 // Use the following code pattern to iterate all stack values and all nested local values:
249 //
250 // ValueStack* state = ... // state that is iterated
251 // int index; // current loop index (overwritten in loop)
252 // Value value; // value at current loop index (overwritten in loop)
253 //
254 // for_each_stack_value(state, index, value {
255 // do something with value and index
256 // }
257 //
258 // for_each_state(state) {
259 // for_each_local_value(state, index, value) {
260 // do something with value and index
261 // }
262 // }
263 // as an invariant, state is null now
264
265
266 // construct a unique variable name with the line number where the macro is used
267 #define temp_var3(x) temp__ ## x
268 #define temp_var2(x) temp_var3(x)
269 #define temp_var temp_var2(__LINE__)
270
271 #define for_each_state(state) \
272 for (; state != nullptr; state = state->caller_state())
273
274 #define for_each_local_value(state, index, value) \
275 int temp_var = state->locals_size(); \
276 for (index = 0; \
277 index < temp_var && (value = state->local_at(index), true); \
278 index += (value == nullptr || value->type()->is_illegal() ? 1 : value->type()->size())) \
279 if (value != nullptr)
280
281
282 #define for_each_stack_value(state, index, value) \
283 int temp_var = state->stack_size(); \
284 for (index = 0; \
285 index < temp_var && (value = state->stack_at(index), true); \
286 index += (value == nullptr ? 1 : value->type()->size())) \
287 if (value != nullptr)
288
289
290 #define for_each_lock_value(state, index, value) \
291 int temp_var = state->locks_size(); \
292 for (index = 0; \
293 index < temp_var && (value = state->lock_at(index), true); \
294 index++) \
295 if (value != nullptr)
296
297
298 // Macro definition for simple iteration of all state values of a ValueStack
299 // Because the code cannot be executed in a single loop, the code must be passed
300 // as a macro parameter.
301 // Use the following code pattern to iterate all stack values and all nested local values:
302 //
303 // ValueStack* state = ... // state that is iterated
304 // for_each_state_value(state, value,
305 // do something with value (note that this is a macro parameter)
306 // );
307
308 #define for_each_state_value(v_state, v_value, v_code) \
309 { \
310 int cur_index; \
311 ValueStack* cur_state = v_state; \
312 Value v_value; \
313 for_each_state(cur_state) { \
314 { \
315 for_each_local_value(cur_state, cur_index, v_value) { \
316 v_code; \
317 } \
318 } \
319 { \
320 for_each_stack_value(cur_state, cur_index, v_value) { \
321 v_code; \
322 } \
323 } \
324 } \
325 }
326
327
328 // Macro definition for simple iteration of all phi functions of a block, i.e all
329 // phi functions of the ValueStack where the block matches.
330 // Use the following code pattern to iterate all phi functions of a block:
331 //
332 // BlockBegin* block = ... // block that is iterated
333 // for_each_phi_function(block, phi,
334 // do something with the phi function phi (note that this is a macro parameter)
335 // );
336
337 #define for_each_phi_fun(v_block, v_phi, v_code) \
338 { \
339 int cur_index; \
340 ValueStack* cur_state = v_block->state(); \
341 Value value; \
342 { \
343 for_each_stack_value(cur_state, cur_index, value) { \
344 Phi* v_phi = value->as_Phi(); \
345 if (v_phi != nullptr && v_phi->block() == v_block) { \
346 v_code; \
347 } \
348 } \
349 } \
350 { \
351 for_each_local_value(cur_state, cur_index, value) { \
352 Phi* v_phi = value->as_Phi(); \
353 if (v_phi != nullptr && v_phi->block() == v_block) { \
354 v_code; \
355 } \
356 } \
357 } \
358 }
359
360 #endif // SHARE_C1_C1_VALUESTACK_HPP