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