1 /*
2 * Copyright (c) 1997, 2017, 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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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.
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23 */
24
25 #ifndef SHARE_VM_OOPS_GENERATEOOPMAP_HPP
26 #define SHARE_VM_OOPS_GENERATEOOPMAP_HPP
27
28 #include "interpreter/bytecodeStream.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/universe.inline.hpp"
31 #include "oops/method.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "runtime/signature.hpp"
34 #include "utilities/bitMap.hpp"
35
36 // Forward definition
37 class GenerateOopMap;
38 class BasicBlock;
39 class CellTypeState;
40 class StackMap;
41
42 // These two should be removed. But requires som code to be cleaned up
43 #define MAXARGSIZE 256 // This should be enough
44 #define MAX_LOCAL_VARS 65536 // 16-bit entry
45
46 typedef void (*jmpFct_t)(GenerateOopMap *c, int bcpDelta, int* data);
47
48
49 // RetTable
50 //
51 // Contains maping between jsr targets and there return addresses. One-to-many mapping
52 //
53 class RetTableEntry : public ResourceObj {
54 private:
55 static int _init_nof_jsrs; // Default size of jsrs list
56 int _target_bci; // Target PC address of jump (bytecode index)
57 GrowableArray<intptr_t> * _jsrs; // List of return addresses (bytecode index)
58 RetTableEntry *_next; // Link to next entry
59 public:
60 RetTableEntry(int target, RetTableEntry *next);
61
62 // Query
63 int target_bci() const { return _target_bci; }
64 int nof_jsrs() const { return _jsrs->length(); }
65 int jsrs(int i) const { assert(i>=0 && i<nof_jsrs(), "Index out of bounds"); return _jsrs->at(i); }
66
67 // Update entry
68 void add_jsr (int return_bci) { _jsrs->append(return_bci); }
69 void add_delta (int bci, int delta);
70 RetTableEntry * next() const { return _next; }
71 };
72
73
74 class RetTable VALUE_OBJ_CLASS_SPEC {
75 private:
76 RetTableEntry *_first;
77 static int _init_nof_entries;
78
79 void add_jsr(int return_bci, int target_bci); // Adds entry to list
80 public:
81 RetTable() { _first = NULL; }
82 void compute_ret_table(const methodHandle& method);
83 void update_ret_table(int bci, int delta);
84 RetTableEntry* find_jsrs_for_target(int targBci);
85 };
86
87 //
88 // CellTypeState
89 //
90 class CellTypeState VALUE_OBJ_CLASS_SPEC {
91 private:
92 unsigned int _state;
93
94 // Masks for separating the BITS and INFO portions of a CellTypeState
95 enum { info_mask = right_n_bits(27),
96 bits_mask = (int)(~info_mask) };
97
98 // These constant are used for manipulating the BITS portion of a
99 // CellTypeState
100 enum { uninit_bit = (int)(nth_bit(31)),
101 ref_bit = nth_bit(30),
102 val_bit = nth_bit(29),
103 addr_bit = nth_bit(28),
104 live_bits_mask = (int)(bits_mask & ~uninit_bit) };
105
106 // These constants are used for manipulating the INFO portion of a
107 // CellTypeState
108 enum { top_info_bit = nth_bit(26),
109 not_bottom_info_bit = nth_bit(25),
110 info_data_mask = right_n_bits(25),
111 info_conflict = info_mask };
112
113 // Within the INFO data, these values are used to distinguish different
114 // kinds of references.
115 enum { ref_not_lock_bit = nth_bit(24), // 0 if this reference is locked as a monitor
116 ref_slot_bit = nth_bit(23), // 1 if this reference is a "slot" reference,
117 // 0 if it is a "line" reference.
118 ref_data_mask = right_n_bits(23) };
119
120 // Within the INFO data, these values are used to distinguish different
121 // kinds of value types.
122 enum { valuetype_slot_bit = nth_bit(24), // 1 if this reference is a "slot" value type,
123 // 0 if it is a "line" value type.
124 valuetype_data_mask = right_n_bits(24) };
125
126 // These values are used to initialize commonly used CellTypeState
127 // constants.
128 enum { bottom_value = 0,
129 uninit_value = (int)(uninit_bit | info_conflict),
130 ref_value = ref_bit,
131 ref_conflict = ref_bit | info_conflict,
132 val_value = val_bit | info_conflict,
133 addr_value = addr_bit,
134 addr_conflict = addr_bit | info_conflict };
135
136 public:
137
138 // Since some C++ constructors generate poor code for declarations of the
139 // form...
140 //
141 // CellTypeState vector[length];
142 //
143 // ...we avoid making a constructor for this class. CellTypeState values
144 // should be constructed using one of the make_* methods:
145
146 static CellTypeState make_any(int state) {
147 CellTypeState s;
148 s._state = state;
149 // Causes SS10 warning.
150 // assert(s.is_valid_state(), "check to see if CellTypeState is valid");
151 return s;
152 }
153
154 static CellTypeState make_bottom() {
155 return make_any(0);
156 }
157
158 static CellTypeState make_top() {
159 return make_any(AllBits);
160 }
161
162 static CellTypeState make_addr(int bci) {
163 assert((bci >= 0) && (bci < info_data_mask), "check to see if ret addr is valid");
164 return make_any(addr_bit | not_bottom_info_bit | (bci & info_data_mask));
165 }
166
167 static CellTypeState make_slot_ref(int slot_num) {
168 assert(slot_num >= 0 && slot_num < ref_data_mask, "slot out of range");
169 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit | ref_slot_bit |
170 (slot_num & ref_data_mask));
171 }
172
173 static CellTypeState make_line_ref(int bci) {
174 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
175 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit |
176 (bci & ref_data_mask));
177 }
178
179 static CellTypeState make_lock_ref(int bci) {
180 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
181 return make_any(ref_bit | not_bottom_info_bit | (bci & ref_data_mask));
182 }
183
184 // Query methods:
185 bool is_bottom() const { return _state == 0; }
186 bool is_live() const { return ((_state & live_bits_mask) != 0); }
187 bool is_valid_state() const {
188 // Uninitialized and value cells must contain no data in their info field:
189 if ((can_be_uninit() || can_be_value()) && !is_info_top()) {
190 return false;
191 }
192 // The top bit is only set when all info bits are set:
193 if (is_info_top() && ((_state & info_mask) != info_mask)) {
194 return false;
195 }
196 // The not_bottom_bit must be set when any other info bit is set:
197 if (is_info_bottom() && ((_state & info_mask) != 0)) {
198 return false;
199 }
200 return true;
201 }
202
203 bool is_address() const { return ((_state & bits_mask) == addr_bit); }
204 bool is_reference() const { return ((_state & bits_mask) == ref_bit); }
205 bool is_value() const { return ((_state & bits_mask) == val_bit); }
206 bool is_uninit() const { return ((_state & bits_mask) == (uint)uninit_bit); }
207
208 bool can_be_address() const { return ((_state & addr_bit) != 0); }
209 bool can_be_reference() const { return ((_state & ref_bit) != 0); }
210 bool can_be_value() const { return ((_state & val_bit) != 0); }
211 bool can_be_uninit() const { return ((_state & uninit_bit) != 0); }
212
213 bool is_info_bottom() const { return ((_state & not_bottom_info_bit) == 0); }
214 bool is_info_top() const { return ((_state & top_info_bit) != 0); }
215 int get_info() const {
216 assert((!is_info_top() && !is_info_bottom()),
217 "check to make sure top/bottom info is not used");
218 return (_state & info_data_mask);
219 }
220
221 bool is_good_address() const { return is_address() && !is_info_top(); }
222 bool is_lock_reference() const {
223 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == ref_bit);
224 }
225 bool is_nonlock_reference() const {
226 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == (ref_bit | ref_not_lock_bit));
227 }
228
229 bool equal(CellTypeState a) const { return _state == a._state; }
230 bool equal_kind(CellTypeState a) const {
231 return (_state & bits_mask) == (a._state & bits_mask);
232 }
233
234 char to_char() const;
235
236 // Merge
237 CellTypeState merge (CellTypeState cts, int slot) const;
238
239 // Debugging output
240 void print(outputStream *os);
241
242 // Default values of common values
243 static CellTypeState bottom;
244 static CellTypeState uninit;
245 static CellTypeState ref;
246 static CellTypeState value;
247 static CellTypeState refUninit;
248 static CellTypeState varUninit;
249 static CellTypeState top;
250 static CellTypeState addr;
251 };
252
253
254 //
255 // BasicBlockStruct
256 //
257 class BasicBlock: ResourceObj {
258 private:
259 bool _changed; // Reached a fixpoint or not
260 public:
261 enum Constants {
262 _dead_basic_block = -2,
263 _unreached = -1 // Alive but not yet reached by analysis
264 // >=0 // Alive and has a merged state
265 };
266
267 int _bci; // Start of basic block
268 int _end_bci; // Bci of last instruction in basicblock
269 int _max_locals; // Determines split between vars and stack
270 int _max_stack; // Determines split between stack and monitors
271 CellTypeState* _state; // State (vars, stack) at entry.
272 int _stack_top; // -1 indicates bottom stack value.
273 int _monitor_top; // -1 indicates bottom monitor stack value.
274
275 CellTypeState* vars() { return _state; }
276 CellTypeState* stack() { return _state + _max_locals; }
277
278 bool changed() { return _changed; }
279 void set_changed(bool s) { _changed = s; }
280
281 bool is_reachable() const { return _stack_top >= 0; } // Analysis has reached this basicblock
282
283 // All basicblocks that are unreachable are going to have a _stack_top == _dead_basic_block.
284 // This info. is setup in a pre-parse before the real abstract interpretation starts.
285 bool is_dead() const { return _stack_top == _dead_basic_block; }
286 bool is_alive() const { return _stack_top != _dead_basic_block; }
287 void mark_as_alive() { assert(is_dead(), "must be dead"); _stack_top = _unreached; }
288 };
289
290
291 //
292 // GenerateOopMap
293 //
294 // Main class used to compute the pointer-maps in a Method
295 //
296 class GenerateOopMap VALUE_OBJ_CLASS_SPEC {
297 protected:
298
299 // _monitor_top is set to this constant to indicate that a monitor matching
300 // problem was encountered prior to this point in control flow.
301 enum { bad_monitors = -1 };
302
303 // Main variables
304 methodHandle _method; // The method we are examine
305 RetTable _rt; // Contains the return address mappings
306 int _max_locals; // Cached value of no. of locals
307 int _max_stack; // Cached value of max. stack depth
308 int _max_monitors; // Cached value of max. monitor stack depth
309 int _has_exceptions; // True, if exceptions exist for method
310 bool _got_error; // True, if an error occurred during interpretation.
311 Handle _exception; // Exception if got_error is true.
312 bool _did_rewriting; // was bytecodes rewritten
313 bool _did_relocation; // was relocation neccessary
314 bool _monitor_safe; // The monitors in this method have been determined
315 // to be safe.
316
317 // Working Cell type state
318 int _state_len; // Size of states
319 CellTypeState *_state; // list of states
320 char *_state_vec_buf; // Buffer used to print a readable version of a state
321 int _stack_top;
322 int _monitor_top;
323
324 // Timing and statistics
325 static elapsedTimer _total_oopmap_time; // Holds cumulative oopmap generation time
326 static long _total_byte_count; // Holds cumulative number of bytes inspected
327
328 // Cell type methods
329 void init_state();
330 void make_context_uninitialized ();
331 int methodsig_to_effect (Symbol* signature, bool isStatic, CellTypeState* effect);
332 bool merge_local_state_vectors (CellTypeState* cts, CellTypeState* bbts);
333 bool merge_monitor_state_vectors(CellTypeState* cts, CellTypeState* bbts);
334 void copy_state (CellTypeState *dst, CellTypeState *src);
335 void merge_state_into_bb (BasicBlock *bb);
336 static void merge_state (GenerateOopMap *gom, int bcidelta, int* data);
337 void set_var (int localNo, CellTypeState cts);
338 CellTypeState get_var (int localNo);
339 CellTypeState pop ();
340 void push (CellTypeState cts);
341 CellTypeState monitor_pop ();
342 void monitor_push (CellTypeState cts);
343 CellTypeState * vars () { return _state; }
344 CellTypeState * stack () { return _state+_max_locals; }
345 CellTypeState * monitors () { return _state+_max_locals+_max_stack; }
346
347 void replace_all_CTS_matches (CellTypeState match,
348 CellTypeState replace);
349 void print_states (outputStream *os, CellTypeState *vector, int num);
350 void print_current_state (outputStream *os,
351 BytecodeStream *itr,
352 bool detailed);
353 void report_monitor_mismatch (const char *msg);
354
355 // Basicblock info
356 BasicBlock * _basic_blocks; // Array of basicblock info
357 int _gc_points;
358 int _bb_count;
359 ResourceBitMap _bb_hdr_bits;
360
361 // Basicblocks methods
362 void initialize_bb ();
363 void mark_bbheaders_and_count_gc_points();
364 bool is_bb_header (int bci) const {
365 return _bb_hdr_bits.at(bci);
366 }
367 int gc_points () const { return _gc_points; }
368 int bb_count () const { return _bb_count; }
369 void set_bbmark_bit (int bci);
370 BasicBlock * get_basic_block_at (int bci) const;
371 BasicBlock * get_basic_block_containing (int bci) const;
372 void interp_bb (BasicBlock *bb);
373 void restore_state (BasicBlock *bb);
374 int next_bb_start_pc (BasicBlock *bb);
375 void update_basic_blocks (int bci, int delta, int new_method_size);
376 static void bb_mark_fct (GenerateOopMap *c, int deltaBci, int *data);
377
378 // Dead code detection
379 void mark_reachable_code();
380 static void reachable_basicblock (GenerateOopMap *c, int deltaBci, int *data);
381
382 // Interpretation methods (primary)
383 void do_interpretation ();
384 void init_basic_blocks ();
385 void setup_method_entry_state ();
386 void interp_all ();
387
388 // Interpretation methods (secondary)
389 void interp1 (BytecodeStream *itr);
390 void do_exception_edge (BytecodeStream *itr);
391 void check_type (CellTypeState expected, CellTypeState actual);
392 void ppstore (CellTypeState *in, int loc_no);
393 void ppload (CellTypeState *out, int loc_no);
394 void ppush1 (CellTypeState in);
395 void ppush (CellTypeState *in);
396 void ppop1 (CellTypeState out);
397 void ppop (CellTypeState *out);
398 void ppop_any (int poplen);
399 void pp (CellTypeState *in, CellTypeState *out);
400 void pp_new_ref (CellTypeState *in, int bci);
401 void ppdupswap (int poplen, const char *out);
402 void do_ldc (int bci);
403 void do_astore (int idx);
404 void do_jsr (int delta);
405 void do_field (int is_get, int is_static, int idx, int bci);
406 void do_method (int is_static, int idx, int bci);
407 void do_withfield (int idx, int bci);
408 void do_multianewarray (int dims, int bci);
409 void do_monitorenter (int bci);
410 void do_monitorexit (int bci);
411 void do_return_monitor_check ();
412 void do_checkcast ();
413 CellTypeState *sigchar_to_effect (char sigch, int bci, CellTypeState *out);
414 int copy_cts (CellTypeState *dst, CellTypeState *src);
415
416 // Error handling
417 void error_work (const char *format, va_list ap) ATTRIBUTE_PRINTF(2, 0);
418 void report_error (const char *format, ...) ATTRIBUTE_PRINTF(2, 3);
419 void verify_error (const char *format, ...) ATTRIBUTE_PRINTF(2, 3);
420 bool got_error() { return _got_error; }
421
422 // Create result set
423 bool _report_result;
424 bool _report_result_for_send; // Unfortunatly, stackmaps for sends are special, so we need some extra
425 BytecodeStream *_itr_send; // variables to handle them properly.
426
427 void report_result ();
428
429 // Initvars
430 GrowableArray<intptr_t> * _init_vars;
431
432 void initialize_vars ();
433 void add_to_ref_init_set (int localNo);
434
435 // Conflicts rewrite logic
436 bool _conflict; // True, if a conflict occurred during interpretation
437 int _nof_refval_conflicts; // No. of conflicts that require rewrites
438 int * _new_var_map;
439
440 void record_refval_conflict (int varNo);
441 void rewrite_refval_conflicts ();
442 void rewrite_refval_conflict (int from, int to);
443 bool rewrite_refval_conflict_inst (BytecodeStream *i, int from, int to);
444 bool rewrite_load_or_store (BytecodeStream *i, Bytecodes::Code bc, Bytecodes::Code bc0, unsigned int varNo);
445
446 void expand_current_instr (int bci, int ilen, int newIlen, u_char inst_buffer[]);
447 bool is_astore (BytecodeStream *itr, int *index);
448 bool is_aload (BytecodeStream *itr, int *index);
449
450 // List of bci's where a return address is on top of the stack
451 GrowableArray<intptr_t> *_ret_adr_tos;
452
453 bool stack_top_holds_ret_addr (int bci);
454 void compute_ret_adr_at_TOS ();
455 void update_ret_adr_at_TOS (int bci, int delta);
456
457 int binsToHold (int no) { return ((no+(BitsPerWord-1))/BitsPerWord); }
458 char *state_vec_to_string (CellTypeState* vec, int len);
459
460 // Helper method. Can be used in subclasses to fx. calculate gc_points. If the current instuction
461 // is a control transfer, then calls the jmpFct all possible destinations.
462 void ret_jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int varNo,int *data);
463 bool jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int *data);
464
465 friend class RelocCallback;
466 public:
467 GenerateOopMap(const methodHandle& method);
468
469 // Compute the map.
470 void compute_map(TRAPS);
471 void result_for_basicblock(int bci); // Do a callback on fill_stackmap_for_opcodes for basicblock containing bci
472
473 // Query
474 int max_locals() const { return _max_locals; }
475 Method* method() const { return _method(); }
476 methodHandle method_as_handle() const { return _method; }
477
478 bool did_rewriting() { return _did_rewriting; }
479 bool did_relocation() { return _did_relocation; }
480
481 static void print_time();
482
483 // Monitor query
484 bool monitor_safe() { return _monitor_safe; }
485
486 // Specialization methods. Intended use:
487 // - possible_gc_point must return true for every bci for which the stackmaps must be returned
488 // - fill_stackmap_prolog is called just before the result is reported. The arguments tells the estimated
489 // number of gc points
490 // - fill_stackmap_for_opcodes is called once for each bytecode index in order (0...code_length-1)
491 // - fill_stackmap_epilog is called after all results has been reported. Note: Since the algorithm does not report
492 // stackmaps for deadcode, fewer gc_points might have been encounted than assumed during the epilog. It is the
493 // responsibility of the subclass to count the correct number.
494 // - fill_init_vars are called once with the result of the init_vars computation
495 //
496 // All these methods are used during a call to: compute_map. Note: Non of the return results are valid
497 // after compute_map returns, since all values are allocated as resource objects.
498 //
499 // All virtual method must be implemented in subclasses
500 virtual bool allow_rewrites () const { return false; }
501 virtual bool report_results () const { return true; }
502 virtual bool report_init_vars () const { return true; }
503 virtual bool possible_gc_point (BytecodeStream *bcs) { ShouldNotReachHere(); return false; }
504 virtual void fill_stackmap_prolog (int nof_gc_points) { ShouldNotReachHere(); }
505 virtual void fill_stackmap_epilog () { ShouldNotReachHere(); }
506 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
507 CellTypeState* vars,
508 CellTypeState* stack,
509 int stackTop) { ShouldNotReachHere(); }
510 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { ShouldNotReachHere();; }
511 };
512
513 //
514 // Subclass of the GenerateOopMap Class that just do rewrites of the method, if needed.
515 // It does not store any oopmaps.
516 //
517 class ResolveOopMapConflicts: public GenerateOopMap {
518 private:
519
520 bool _must_clear_locals;
521
522 virtual bool report_results() const { return false; }
523 virtual bool report_init_vars() const { return true; }
524 virtual bool allow_rewrites() const { return true; }
525 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
526 virtual void fill_stackmap_prolog (int nof_gc_points) {}
527 virtual void fill_stackmap_epilog () {}
528 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
529 CellTypeState* vars,
530 CellTypeState* stack,
531 int stack_top) {}
532 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { _must_clear_locals = init_vars->length() > 0; }
533
534 #ifndef PRODUCT
535 // Statistics
536 static int _nof_invocations;
537 static int _nof_rewrites;
538 static int _nof_relocations;
539 #endif
540
541 public:
542 ResolveOopMapConflicts(const methodHandle& method) : GenerateOopMap(method) { _must_clear_locals = false; };
543
544 methodHandle do_potential_rewrite(TRAPS);
545 bool must_clear_locals() const { return _must_clear_locals; }
546 };
547
548
549 //
550 // Subclass used by the compiler to generate pairing infomation
551 //
552 class GeneratePairingInfo: public GenerateOopMap {
553 private:
554
555 virtual bool report_results() const { return false; }
556 virtual bool report_init_vars() const { return false; }
557 virtual bool allow_rewrites() const { return false; }
558 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
559 virtual void fill_stackmap_prolog (int nof_gc_points) {}
560 virtual void fill_stackmap_epilog () {}
561 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
562 CellTypeState* vars,
563 CellTypeState* stack,
564 int stack_top) {}
565 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) {}
566 public:
567 GeneratePairingInfo(const methodHandle& method) : GenerateOopMap(method) {};
568
569 // Call compute_map(CHECK) to generate info.
570 };
571
572 #endif // SHARE_VM_OOPS_GENERATEOOPMAP_HPP