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 *
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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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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
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, bool reexecute);
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, _should_reexecute); }
86 ValueStack* copy(Kind new_kind, int new_bci) { return new ValueStack(this, new_kind, new_bci, _should_reexecute); }
87 ValueStack* copy_for_parsing() { return new ValueStack(this, Parsing, -99, false); }
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 bool should_reexecute() const { return _should_reexecute; }
110 void set_should_reexecute(bool reexec) { _should_reexecute = reexec; }
111
112 int locals_size() const { return _locals.length(); }
113 int stack_size() const { return _stack.length(); }
114 int locks_size() const { return _locks == nullptr ? 0 : _locks->length(); }
115 bool stack_is_empty() const { return _stack.is_empty(); }
116 bool no_active_locks() const { return _locks == nullptr || _locks->is_empty(); }
117 int total_locks_size() const;
118
119 // locals access
120 void clear_locals(); // sets all locals to null;
121
122 void invalidate_local(int i) {
123 assert(!_locals.at(i)->type()->is_double_word() ||
124 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
125 _locals.at_put(i, nullptr);
126 }
127
128 Value local_at(int i) const {
129 Value x = _locals.at(i);
130 assert(x == nullptr || !x->type()->is_double_word() ||
131 _locals.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
132 return x;
133 }
134
135 void store_local(int i, Value x) {
136 // When overwriting local i, check if i - 1 was the start of a
137 // double word local and kill it.
138 if (i > 0) {
139 Value prev = _locals.at(i - 1);
140 if (prev != nullptr && prev->type()->is_double_word()) {
141 _locals.at_put(i - 1, nullptr);
142 }
143 }
144
145 _locals.at_put(i, x);
146 if (x->type()->is_double_word()) {
147 // hi-word of doubleword value is always null
148 _locals.at_put(i + 1, nullptr);
149 }
150 }
151
152 // stack access
153 Value stack_at(int i) const {
154 Value x = _stack.at(i);
155 assert(x == nullptr || !x->type()->is_double_word() ||
156 _stack.at(i + 1) == nullptr, "hi-word of doubleword value must be null");
157 return x;
158 }
159
160 Value stack_at_inc(int& i) const {
161 Value x = stack_at(i);
162 i += ((x == nullptr) ? 1 : x->type()->size());
163 return x;
164 }
165
166 void stack_at_put(int i, Value x) {
167 _stack.at_put(i, x);
168 }
169
170 // pinning support
171 void pin_stack_for_linear_scan();
172
173 // iteration
174 void values_do(ValueVisitor* f);
175
176 // untyped manipulation (for dup_x1, etc.)
177 void truncate_stack(int size) { _stack.trunc_to(size); }
178 void raw_push(Value t) { _stack.push(t); }
179 Value raw_pop() { return _stack.pop(); }
180
181 // typed manipulation
182 void ipush(Value t) { _stack.push(check(intTag , t)); }
183 void fpush(Value t) { _stack.push(check(floatTag , t)); }
184 void apush(Value t) { _stack.push(check(objectTag , t)); }
185 void rpush(Value t) { _stack.push(check(addressTag, t)); }
186 void lpush(Value t) { _stack.push(check(longTag , t)); _stack.push(nullptr); }
187 void dpush(Value t) { _stack.push(check(doubleTag , t)); _stack.push(nullptr); }
188
189 void push(ValueType* type, Value t) {
190 switch (type->tag()) {
191 case intTag : ipush(t); return;
192 case longTag : lpush(t); return;
193 case floatTag : fpush(t); return;
194 case doubleTag : dpush(t); return;
195 case objectTag : apush(t); return;
196 case addressTag: rpush(t); return;
197 default : ShouldNotReachHere(); return;
198 }
199 }
200
201 Value ipop() { return check(intTag , _stack.pop()); }
202 Value fpop() { return check(floatTag , _stack.pop()); }
203 Value apop() { return check(objectTag , _stack.pop()); }
204 Value rpop() { return check(addressTag, _stack.pop()); }
205 Value lpop() { Value h = _stack.pop(); return check(longTag , _stack.pop(), h); }
206 Value dpop() { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
207
208 Value pop(ValueType* type) {
209 switch (type->tag()) {
210 case intTag : return ipop();
211 case longTag : return lpop();
212 case floatTag : return fpop();
213 case doubleTag : return dpop();
214 case objectTag : return apop();
215 case addressTag: return rpop();
216 default : ShouldNotReachHere(); return nullptr;
217 }
218 }
219
220 Values* pop_arguments(int argument_size);
221
222 // locks access
223 int lock (Value obj);
224 int unlock();
225 Value lock_at(int i) const { return _locks->at(i); }
226
227 // SSA form IR support
228 void setup_phi_for_stack(BlockBegin* b, int index);
229 void setup_phi_for_local(BlockBegin* b, int index);
230
231 // debugging
232 void print() PRODUCT_RETURN;
233 void verify() PRODUCT_RETURN;
234 };
235
236
237
238 // Macro definitions for simple iteration of stack and local values of a ValueStack
239 // The macros can be used like a for-loop. All variables (state, index and value)
240 // must be defined before the loop.
241 // When states are nested because of inlining, the stack of the innermost state
242 // cumulates also the stack of the nested states. In contrast, the locals of all
243 // states must be iterated each.
244 // Use the following code pattern to iterate all stack values and all nested local values:
245 //
246 // ValueStack* state = ... // state that is iterated
247 // int index; // current loop index (overwritten in loop)
248 // Value value; // value at current loop index (overwritten in loop)
249 //
250 // for_each_stack_value(state, index, value {
251 // do something with value and index
252 // }
253 //
254 // for_each_state(state) {
255 // for_each_local_value(state, index, value) {
256 // do something with value and index
257 // }
258 // }
259 // as an invariant, state is null now
260
261
262 // construct a unique variable name with the line number where the macro is used
263 #define temp_var3(x) temp__ ## x
264 #define temp_var2(x) temp_var3(x)
265 #define temp_var temp_var2(__LINE__)
266
267 #define for_each_state(state) \
268 for (; state != nullptr; state = state->caller_state())
269
270 #define for_each_local_value(state, index, value) \
271 int temp_var = state->locals_size(); \
272 for (index = 0; \
273 index < temp_var && (value = state->local_at(index), true); \
274 index += (value == nullptr || value->type()->is_illegal() ? 1 : value->type()->size())) \
275 if (value != nullptr)
276
277
278 #define for_each_stack_value(state, index, value) \
279 int temp_var = state->stack_size(); \
280 for (index = 0; \
281 index < temp_var && (value = state->stack_at(index), true); \
282 index += (value == nullptr ? 1 : value->type()->size())) \
283 if (value != nullptr)
284
285
286 #define for_each_lock_value(state, index, value) \
287 int temp_var = state->locks_size(); \
288 for (index = 0; \
289 index < temp_var && (value = state->lock_at(index), true); \
290 index++) \
291 if (value != nullptr)
292
293
294 // Macro definition for simple iteration of all state values of a ValueStack
295 // Because the code cannot be executed in a single loop, the code must be passed
296 // as a macro parameter.
297 // Use the following code pattern to iterate all stack values and all nested local values:
298 //
299 // ValueStack* state = ... // state that is iterated
300 // for_each_state_value(state, value,
301 // do something with value (note that this is a macro parameter)
302 // );
303
304 #define for_each_state_value(v_state, v_value, v_code) \
305 { \
306 int cur_index; \
307 ValueStack* cur_state = v_state; \
308 Value v_value; \
309 for_each_state(cur_state) { \
310 { \
311 for_each_local_value(cur_state, cur_index, v_value) { \
312 v_code; \
313 } \
314 } \
315 { \
316 for_each_stack_value(cur_state, cur_index, v_value) { \
317 v_code; \
318 } \
319 } \
320 } \
321 }
322
323
324 // Macro definition for simple iteration of all phi functions of a block, i.e all
325 // phi functions of the ValueStack where the block matches.
326 // Use the following code pattern to iterate all phi functions of a block:
327 //
328 // BlockBegin* block = ... // block that is iterated
329 // for_each_phi_function(block, phi,
330 // do something with the phi function phi (note that this is a macro parameter)
331 // );
332
333 #define for_each_phi_fun(v_block, v_phi, v_code) \
334 { \
335 int cur_index; \
336 ValueStack* cur_state = v_block->state(); \
337 Value value; \
338 { \
339 for_each_stack_value(cur_state, cur_index, value) { \
340 Phi* v_phi = value->as_Phi(); \
341 if (v_phi != nullptr && v_phi->block() == v_block) { \
342 v_code; \
343 } \
344 } \
345 } \
346 { \
347 for_each_local_value(cur_state, cur_index, value) { \
348 Phi* v_phi = value->as_Phi(); \
349 if (v_phi != nullptr && v_phi->block() == v_block) { \
350 v_code; \
351 } \
352 } \
353 } \
354 }
355
356 #endif // SHARE_C1_C1_VALUESTACK_HPP