1 /*
2 * Copyright (c) 1997, 2005, 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.
22 *
23 */
24
25 // Forward definition
26 class MethodOopMap;
27 class GenerateOopMap;
28 class BasicBlock;
29 class CellTypeState;
30 class StackMap;
31
32 // These two should be removed. But requires som code to be cleaned up
33 #define MAXARGSIZE 256 // This should be enough
34 #define MAX_LOCAL_VARS 65536 // 16-bit entry
35
36 typedef void (*jmpFct_t)(GenerateOopMap *c, int bcpDelta, int* data);
37
38
39 // RetTable
40 //
41 // Contains maping between jsr targets and there return addresses. One-to-many mapping
42 //
43 class RetTableEntry : public ResourceObj {
44 private:
45 static int _init_nof_jsrs; // Default size of jsrs list
46 int _target_bci; // Target PC address of jump (bytecode index)
47 GrowableArray<intptr_t> * _jsrs; // List of return addresses (bytecode index)
48 RetTableEntry *_next; // Link to next entry
49 public:
50 RetTableEntry(int target, RetTableEntry *next) { _target_bci=target; _jsrs = new GrowableArray<intptr_t>(_init_nof_jsrs); _next = next; }
51
52 // Query
53 int target_bci() const { return _target_bci; }
54 int nof_jsrs() const { return _jsrs->length(); }
55 int jsrs(int i) const { assert(i>=0 && i<nof_jsrs(), "Index out of bounds"); return _jsrs->at(i); }
56
57 // Update entry
58 void add_jsr (int return_bci) { _jsrs->append(return_bci); }
59 void add_delta (int bci, int delta);
60 RetTableEntry * next() const { return _next; }
61 };
62
63
64 class RetTable VALUE_OBJ_CLASS_SPEC {
65 private:
66 RetTableEntry *_first;
67 static int _init_nof_entries;
68
69 void add_jsr(int return_bci, int target_bci); // Adds entry to list
70 public:
71 RetTable() { _first = NULL; }
72 void compute_ret_table(methodHandle method);
73 void update_ret_table(int bci, int delta);
74 RetTableEntry* find_jsrs_for_target(int targBci);
75 };
76
77 //
78 // CellTypeState
79 //
80 class CellTypeState VALUE_OBJ_CLASS_SPEC {
81 private:
82 unsigned int _state;
83
84 // Masks for separating the BITS and INFO portions of a CellTypeState
85 enum { info_mask = right_n_bits(28),
86 bits_mask = (int)(~info_mask) };
87
88 // These constant are used for manipulating the BITS portion of a
89 // CellTypeState
90 enum { uninit_bit = (int)(nth_bit(31)),
91 ref_bit = nth_bit(30),
92 val_bit = nth_bit(29),
93 addr_bit = nth_bit(28),
94 live_bits_mask = (int)(bits_mask & ~uninit_bit) };
95
96 // These constants are used for manipulating the INFO portion of a
97 // CellTypeState
98 enum { top_info_bit = nth_bit(27),
99 not_bottom_info_bit = nth_bit(26),
100 info_data_mask = right_n_bits(26),
101 info_conflict = info_mask };
102
103 // Within the INFO data, these values are used to distinguish different
104 // kinds of references.
105 enum { ref_not_lock_bit = nth_bit(25), // 0 if this reference is locked as a monitor
106 ref_slot_bit = nth_bit(24), // 1 if this reference is a "slot" reference,
107 // 0 if it is a "line" reference.
108 ref_data_mask = right_n_bits(24) };
109
110
111 // These values are used to initialize commonly used CellTypeState
112 // constants.
113 enum { bottom_value = 0,
114 uninit_value = (int)(uninit_bit | info_conflict),
115 ref_value = ref_bit,
116 ref_conflict = ref_bit | info_conflict,
117 val_value = val_bit | info_conflict,
118 addr_value = addr_bit,
119 addr_conflict = addr_bit | info_conflict };
120
121 public:
122
123 // Since some C++ constructors generate poor code for declarations of the
124 // form...
125 //
126 // CellTypeState vector[length];
127 //
128 // ...we avoid making a constructor for this class. CellTypeState values
129 // should be constructed using one of the make_* methods:
130
131 static CellTypeState make_any(int state) {
132 CellTypeState s;
133 s._state = state;
134 // Causes SS10 warning.
135 // assert(s.is_valid_state(), "check to see if CellTypeState is valid");
136 return s;
137 }
138
139 static CellTypeState make_bottom() {
140 return make_any(0);
141 }
142
143 static CellTypeState make_top() {
144 return make_any(AllBits);
145 }
146
147 static CellTypeState make_addr(int bci) {
148 assert((bci >= 0) && (bci < info_data_mask), "check to see if ret addr is valid");
149 return make_any(addr_bit | not_bottom_info_bit | (bci & info_data_mask));
150 }
151
152 static CellTypeState make_slot_ref(int slot_num) {
153 assert(slot_num >= 0 && slot_num < ref_data_mask, "slot out of range");
154 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit | ref_slot_bit |
155 (slot_num & ref_data_mask));
156 }
157
158 static CellTypeState make_line_ref(int bci) {
159 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
160 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit |
161 (bci & ref_data_mask));
162 }
163
164 static CellTypeState make_lock_ref(int bci) {
165 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
166 return make_any(ref_bit | not_bottom_info_bit | (bci & ref_data_mask));
167 }
168
169 // Query methods:
170 bool is_bottom() const { return _state == 0; }
171 bool is_live() const { return ((_state & live_bits_mask) != 0); }
172 bool is_valid_state() const {
173 // Uninitialized and value cells must contain no data in their info field:
174 if ((can_be_uninit() || can_be_value()) && !is_info_top()) {
175 return false;
176 }
177 // The top bit is only set when all info bits are set:
178 if (is_info_top() && ((_state & info_mask) != info_mask)) {
179 return false;
180 }
181 // The not_bottom_bit must be set when any other info bit is set:
182 if (is_info_bottom() && ((_state & info_mask) != 0)) {
183 return false;
184 }
185 return true;
186 }
187
188 bool is_address() const { return ((_state & bits_mask) == addr_bit); }
189 bool is_reference() const { return ((_state & bits_mask) == ref_bit); }
190 bool is_value() const { return ((_state & bits_mask) == val_bit); }
191 bool is_uninit() const { return ((_state & bits_mask) == (uint)uninit_bit); }
192
193 bool can_be_address() const { return ((_state & addr_bit) != 0); }
194 bool can_be_reference() const { return ((_state & ref_bit) != 0); }
195 bool can_be_value() const { return ((_state & val_bit) != 0); }
196 bool can_be_uninit() const { return ((_state & uninit_bit) != 0); }
197
198 bool is_info_bottom() const { return ((_state & not_bottom_info_bit) == 0); }
199 bool is_info_top() const { return ((_state & top_info_bit) != 0); }
200 int get_info() const {
201 assert((!is_info_top() && !is_info_bottom()),
202 "check to make sure top/bottom info is not used");
203 return (_state & info_data_mask);
204 }
205
206 bool is_good_address() const { return is_address() && !is_info_top(); }
207 bool is_lock_reference() const {
208 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == ref_bit);
209 }
210 bool is_nonlock_reference() const {
211 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == (ref_bit | ref_not_lock_bit));
212 }
213
214 bool equal(CellTypeState a) const { return _state == a._state; }
215 bool equal_kind(CellTypeState a) const {
216 return (_state & bits_mask) == (a._state & bits_mask);
217 }
218
219 char to_char() const;
220
221 // Merge
222 CellTypeState merge (CellTypeState cts, int slot) const;
223
224 // Debugging output
225 void print(outputStream *os);
226
227 // Default values of common values
228 static CellTypeState bottom;
229 static CellTypeState uninit;
230 static CellTypeState ref;
231 static CellTypeState value;
232 static CellTypeState refUninit;
233 static CellTypeState varUninit;
234 static CellTypeState top;
235 static CellTypeState addr;
236 };
237
238
239 //
240 // BasicBlockStruct
241 //
242 class BasicBlock: ResourceObj {
243 private:
244 bool _changed; // Reached a fixpoint or not
245 public:
246 enum Constants {
247 _dead_basic_block = -2,
248 _unreached = -1 // Alive but not yet reached by analysis
249 // >=0 // Alive and has a merged state
250 };
251
252 int _bci; // Start of basic block
253 int _end_bci; // Bci of last instruction in basicblock
254 int _max_locals; // Determines split between vars and stack
255 int _max_stack; // Determines split between stack and monitors
256 CellTypeState* _state; // State (vars, stack) at entry.
257 int _stack_top; // -1 indicates bottom stack value.
258 int _monitor_top; // -1 indicates bottom monitor stack value.
259
260 CellTypeState* vars() { return _state; }
261 CellTypeState* stack() { return _state + _max_locals; }
262
263 bool changed() { return _changed; }
264 void set_changed(bool s) { _changed = s; }
265
266 bool is_reachable() const { return _stack_top >= 0; } // Analysis has reached this basicblock
267
268 // All basicblocks that are unreachable are going to have a _stack_top == _dead_basic_block.
269 // This info. is setup in a pre-parse before the real abstract interpretation starts.
270 bool is_dead() const { return _stack_top == _dead_basic_block; }
271 bool is_alive() const { return _stack_top != _dead_basic_block; }
272 void mark_as_alive() { assert(is_dead(), "must be dead"); _stack_top = _unreached; }
273 };
274
275
276 //
277 // GenerateOopMap
278 //
279 // Main class used to compute the pointer-maps in a MethodOop
280 //
281 class GenerateOopMap VALUE_OBJ_CLASS_SPEC {
282 protected:
283
284 // _monitor_top is set to this constant to indicate that a monitor matching
285 // problem was encountered prior to this point in control flow.
286 enum { bad_monitors = -1 };
287
288 // Main variables
289 methodHandle _method; // The method we are examine
290 RetTable _rt; // Contains the return address mappings
291 int _max_locals; // Cached value of no. of locals
292 int _max_stack; // Cached value of max. stack depth
293 int _max_monitors; // Cached value of max. monitor stack depth
294 int _has_exceptions; // True, if exceptions exist for method
295 bool _got_error; // True, if an error occurred during interpretation.
296 Handle _exception; // Exception if got_error is true.
297 bool _did_rewriting; // was bytecodes rewritten
298 bool _did_relocation; // was relocation neccessary
299 bool _monitor_safe; // The monitors in this method have been determined
300 // to be safe.
301
302 // Working Cell type state
303 int _state_len; // Size of states
304 CellTypeState *_state; // list of states
305 char *_state_vec_buf; // Buffer used to print a readable version of a state
306 int _stack_top;
307 int _monitor_top;
308
309 // Timing and statistics
310 static elapsedTimer _total_oopmap_time; // Holds cumulative oopmap generation time
311 static long _total_byte_count; // Holds cumulative number of bytes inspected
312
313 // Cell type methods
314 void init_state();
315 void make_context_uninitialized ();
316 int methodsig_to_effect (symbolOop signature, bool isStatic, CellTypeState* effect);
317 bool merge_local_state_vectors (CellTypeState* cts, CellTypeState* bbts);
318 bool merge_monitor_state_vectors(CellTypeState* cts, CellTypeState* bbts);
319 void copy_state (CellTypeState *dst, CellTypeState *src);
320 void merge_state_into_bb (BasicBlock *bb);
321 static void merge_state (GenerateOopMap *gom, int bcidelta, int* data);
322 void set_var (int localNo, CellTypeState cts);
323 CellTypeState get_var (int localNo);
324 CellTypeState pop ();
325 void push (CellTypeState cts);
326 CellTypeState monitor_pop ();
327 void monitor_push (CellTypeState cts);
328 CellTypeState * vars () { return _state; }
329 CellTypeState * stack () { return _state+_max_locals; }
330 CellTypeState * monitors () { return _state+_max_locals+_max_stack; }
331
332 void replace_all_CTS_matches (CellTypeState match,
333 CellTypeState replace);
334 void print_states (outputStream *os, CellTypeState *vector, int num);
335 void print_current_state (outputStream *os,
336 BytecodeStream *itr,
337 bool detailed);
338 void report_monitor_mismatch (const char *msg);
339
340 // Basicblock info
341 BasicBlock * _basic_blocks; // Array of basicblock info
342 int _gc_points;
343 int _bb_count;
344 BitMap _bb_hdr_bits;
345
346 // Basicblocks methods
347 void initialize_bb ();
348 void mark_bbheaders_and_count_gc_points();
349 bool is_bb_header (int bci) const {
350 return _bb_hdr_bits.at(bci);
351 }
352 int gc_points () const { return _gc_points; }
353 int bb_count () const { return _bb_count; }
354 void set_bbmark_bit (int bci) {
355 _bb_hdr_bits.at_put(bci, true);
356 }
357 void clear_bbmark_bit (int bci) {
358 _bb_hdr_bits.at_put(bci, false);
359 }
360 BasicBlock * get_basic_block_at (int bci) const;
361 BasicBlock * get_basic_block_containing (int bci) const;
362 void interp_bb (BasicBlock *bb);
363 void restore_state (BasicBlock *bb);
364 int next_bb_start_pc (BasicBlock *bb);
365 void update_basic_blocks (int bci, int delta, int new_method_size);
366 static void bb_mark_fct (GenerateOopMap *c, int deltaBci, int *data);
367
368 // Dead code detection
369 void mark_reachable_code();
370 static void reachable_basicblock (GenerateOopMap *c, int deltaBci, int *data);
371
372 // Interpretation methods (primary)
373 void do_interpretation ();
374 void init_basic_blocks ();
375 void setup_method_entry_state ();
376 void interp_all ();
377
378 // Interpretation methods (secondary)
379 void interp1 (BytecodeStream *itr);
380 void do_exception_edge (BytecodeStream *itr);
381 void check_type (CellTypeState expected, CellTypeState actual);
382 void ppstore (CellTypeState *in, int loc_no);
383 void ppload (CellTypeState *out, int loc_no);
384 void ppush1 (CellTypeState in);
385 void ppush (CellTypeState *in);
386 void ppop1 (CellTypeState out);
387 void ppop (CellTypeState *out);
388 void ppop_any (int poplen);
389 void pp (CellTypeState *in, CellTypeState *out);
390 void pp_new_ref (CellTypeState *in, int bci);
391 void ppdupswap (int poplen, const char *out);
392 void do_ldc (int idx, int bci);
393 void do_astore (int idx);
394 void do_jsr (int delta);
395 void do_field (int is_get, int is_static, int idx, int bci);
396 void do_method (int is_static, int is_interface, int idx, int bci);
397 void do_multianewarray (int dims, int bci);
398 void do_monitorenter (int bci);
399 void do_monitorexit (int bci);
400 void do_return_monitor_check ();
401 void do_checkcast ();
402 CellTypeState *sigchar_to_effect (char sigch, int bci, CellTypeState *out);
403 int copy_cts (CellTypeState *dst, CellTypeState *src);
404
405 // Error handling
406 void error_work (const char *format, va_list ap);
407 void report_error (const char *format, ...);
408 void verify_error (const char *format, ...);
409 bool got_error() { return _got_error; }
410
411 // Create result set
412 bool _report_result;
413 bool _report_result_for_send; // Unfortunatly, stackmaps for sends are special, so we need some extra
414 BytecodeStream *_itr_send; // variables to handle them properly.
415
416 void report_result ();
417
418 // Initvars
419 GrowableArray<intptr_t> * _init_vars;
420
421 void initialize_vars ();
422 void add_to_ref_init_set (int localNo);
423
424 // Conflicts rewrite logic
425 bool _conflict; // True, if a conflict occurred during interpretation
426 int _nof_refval_conflicts; // No. of conflicts that require rewrites
427 int * _new_var_map;
428
429 void record_refval_conflict (int varNo);
430 void rewrite_refval_conflicts ();
431 void rewrite_refval_conflict (int from, int to);
432 bool rewrite_refval_conflict_inst (BytecodeStream *i, int from, int to);
433 bool rewrite_load_or_store (BytecodeStream *i, Bytecodes::Code bc, Bytecodes::Code bc0, unsigned int varNo);
434
435 void expand_current_instr (int bci, int ilen, int newIlen, u_char inst_buffer[]);
436 bool is_astore (BytecodeStream *itr, int *index);
437 bool is_aload (BytecodeStream *itr, int *index);
438
439 // List of bci's where a return address is on top of the stack
440 GrowableArray<intptr_t> *_ret_adr_tos;
441
442 bool stack_top_holds_ret_addr (int bci);
443 void compute_ret_adr_at_TOS ();
444 void update_ret_adr_at_TOS (int bci, int delta);
445
446 int binsToHold (int no) { return ((no+(BitsPerWord-1))/BitsPerWord); }
447 char *state_vec_to_string (CellTypeState* vec, int len);
448
449 // Helper method. Can be used in subclasses to fx. calculate gc_points. If the current instuction
450 // is a control transfer, then calls the jmpFct all possible destinations.
451 void ret_jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int varNo,int *data);
452 bool jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int *data);
453
454 friend class RelocCallback;
455 public:
456 GenerateOopMap(methodHandle method);
457
458 // Compute the map.
459 void compute_map(TRAPS);
460 void result_for_basicblock(int bci); // Do a callback on fill_stackmap_for_opcodes for basicblock containing bci
461
462 // Query
463 int max_locals() const { return _max_locals; }
464 methodOop method() const { return _method(); }
465 methodHandle method_as_handle() const { return _method; }
466
467 bool did_rewriting() { return _did_rewriting; }
468 bool did_relocation() { return _did_relocation; }
469
470 static void print_time();
471
472 // Monitor query
473 bool monitor_safe() { return _monitor_safe; }
474
475 // Specialization methods. Intended use:
476 // - possible_gc_point must return true for every bci for which the stackmaps must be returned
477 // - fill_stackmap_prolog is called just before the result is reported. The arguments tells the estimated
478 // number of gc points
479 // - fill_stackmap_for_opcodes is called once for each bytecode index in order (0...code_length-1)
480 // - fill_stackmap_epilog is called after all results has been reported. Note: Since the algorithm does not report
481 // stackmaps for deadcode, fewer gc_points might have been encounted than assumed during the epilog. It is the
482 // responsibility of the subclass to count the correct number.
483 // - fill_init_vars are called once with the result of the init_vars computation
484 //
485 // All these methods are used during a call to: compute_map. Note: Non of the return results are valid
486 // after compute_map returns, since all values are allocated as resource objects.
487 //
488 // All virtual method must be implemented in subclasses
489 virtual bool allow_rewrites () const { return false; }
490 virtual bool report_results () const { return true; }
491 virtual bool report_init_vars () const { return true; }
492 virtual bool possible_gc_point (BytecodeStream *bcs) { ShouldNotReachHere(); return false; }
493 virtual void fill_stackmap_prolog (int nof_gc_points) { ShouldNotReachHere(); }
494 virtual void fill_stackmap_epilog () { ShouldNotReachHere(); }
495 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
496 CellTypeState* vars,
497 CellTypeState* stack,
498 int stackTop) { ShouldNotReachHere(); }
499 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { ShouldNotReachHere();; }
500 };
501
502 //
503 // Subclass of the GenerateOopMap Class that just do rewrites of the method, if needed.
504 // It does not store any oopmaps.
505 //
506 class ResolveOopMapConflicts: public GenerateOopMap {
507 private:
508
509 bool _must_clear_locals;
510
511 virtual bool report_results() const { return false; }
512 virtual bool report_init_vars() const { return true; }
513 virtual bool allow_rewrites() const { return true; }
514 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
515 virtual void fill_stackmap_prolog (int nof_gc_points) {}
516 virtual void fill_stackmap_epilog () {}
517 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
518 CellTypeState* vars,
519 CellTypeState* stack,
520 int stack_top) {}
521 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { _must_clear_locals = init_vars->length() > 0; }
522
523 #ifndef PRODUCT
524 // Statistics
525 static int _nof_invocations;
526 static int _nof_rewrites;
527 static int _nof_relocations;
528 #endif
529
530 public:
531 ResolveOopMapConflicts(methodHandle method) : GenerateOopMap(method) { _must_clear_locals = false; };
532
533 methodHandle do_potential_rewrite(TRAPS);
534 bool must_clear_locals() const { return _must_clear_locals; }
535 };
536
537
538 //
539 // Subclass used by the compiler to generate pairing infomation
540 //
541 class GeneratePairingInfo: public GenerateOopMap {
542 private:
543
544 virtual bool report_results() const { return false; }
545 virtual bool report_init_vars() const { return false; }
546 virtual bool allow_rewrites() const { return false; }
547 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
548 virtual void fill_stackmap_prolog (int nof_gc_points) {}
549 virtual void fill_stackmap_epilog () {}
550 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
551 CellTypeState* vars,
552 CellTypeState* stack,
553 int stack_top) {}
554 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) {}
555 public:
556 GeneratePairingInfo(methodHandle method) : GenerateOopMap(method) {};
557
558 // Call compute_map(CHECK) to generate info.
559 };