generateOopMap.hpp revision 1472:c18cbe5936b8
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
26class MethodOopMap;
27class GenerateOopMap;
28class BasicBlock;
29class CellTypeState;
30class 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
36typedef 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//
43class 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
64class 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//
80class 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//
242class 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//
281class 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//
506class 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//
541class 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};
560