summaryrefslogtreecommitdiff
path: root/gcc/vec.h
blob: 8858f6afea14b0a61f4cddb8a0c47f9a7555aa84 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
/* Vector API for GNU compiler.
   Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
   Free Software Foundation, Inc.
   Contributed by Nathan Sidwell <nathan@codesourcery.com>
   Re-implemented in C++ by Diego Novillo <dnovillo@google.com>

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#ifndef GCC_VEC_H
#define GCC_VEC_H

#include "statistics.h"		/* For MEM_STAT_DECL.  */

/* Templated vector type and associated interfaces.

   The interface functions are typesafe and use inline functions,
   sometimes backed by out-of-line generic functions.  The vectors are
   designed to interoperate with the GTY machinery.

   There are both 'index' and 'iterate' accessors.  The index accessor
   is implemented by operator[].  The iterator returns a boolean
   iteration condition and updates the iteration variable passed by
   reference.  Because the iterator will be inlined, the address-of
   can be optimized away.

   The vectors are implemented using the trailing array idiom, thus
   they are not resizeable without changing the address of the vector
   object itself.  This means you cannot have variables or fields of
   vector type -- always use a pointer to a vector.  The one exception
   is the final field of a structure, which could be a vector type.
   You will have to use the embedded_size & embedded_init calls to
   create such objects, and they will probably not be resizeable (so
   don't use the 'safe' allocation variants).  The trailing array
   idiom is used (rather than a pointer to an array of data), because,
   if we allow NULL to also represent an empty vector, empty vectors
   occupy minimal space in the structure containing them.

   Each operation that increases the number of active elements is
   available in 'quick' and 'safe' variants.  The former presumes that
   there is sufficient allocated space for the operation to succeed
   (it dies if there is not).  The latter will reallocate the
   vector, if needed.  Reallocation causes an exponential increase in
   vector size.  If you know you will be adding N elements, it would
   be more efficient to use the reserve operation before adding the
   elements with the 'quick' operation.  This will ensure there are at
   least as many elements as you ask for, it will exponentially
   increase if there are too few spare slots.  If you want reserve a
   specific number of slots, but do not want the exponential increase
   (for instance, you know this is the last allocation), use the
   reserve_exact operation.  You can also create a vector of a
   specific size from the get go.

   You should prefer the push and pop operations, as they append and
   remove from the end of the vector. If you need to remove several
   items in one go, use the truncate operation.  The insert and remove
   operations allow you to change elements in the middle of the
   vector.  There are two remove operations, one which preserves the
   element ordering 'ordered_remove', and one which does not
   'unordered_remove'.  The latter function copies the end element
   into the removed slot, rather than invoke a memmove operation.  The
   'lower_bound' function will determine where to place an item in the
   array using insert that will maintain sorted order.

   When a vector type is defined, first a non-memory managed version
   is created.  You can then define either or both garbage collected
   and heap allocated versions.  The allocation mechanism is specified
   when the vector is allocated.  This can occur via the VEC_alloc
   call or one of the VEC_safe_* functions that add elements to a
   vector.  If the vector is NULL, it will be allocated using the
   allocation strategy selected in the call.  The valid allocations
   are defined in enum vec_allocation_t.

   If you need to directly manipulate a vector, then the 'address'
   accessor will return the address of the start of the vector.  Also
   the 'space' predicate will tell you whether there is spare capacity
   in the vector.  You will not normally need to use these two functions.

   Variables of vector type are of type vec_t<ETYPE> where ETYPE is
   the type of the elements of the vector. Due to the way GTY works,
   you must annotate any structures you wish to insert or reference
   from a vector with a GTY(()) tag.  You need to do this even if you
   never use the GC allocated variants.

   An example of their use would be,

   struct my_struct {
     vec_t<tree> *v;      // A (pointer to) a vector of tree pointers.
   };

   struct my_struct *s;

   if (VEC_length(tree,s->v)) { we have some contents }
   VEC_safe_push(tree,gc,s->v,decl); // append some decl onto the end
   for (ix = 0; VEC_iterate(tree,s->v,ix,elt); ix++)
     { do something with elt }
*/

#if ENABLE_CHECKING
#define ALONE_VEC_CHECK_INFO __FILE__, __LINE__, __FUNCTION__
#define VEC_CHECK_INFO , ALONE_VEC_CHECK_INFO
#define ALONE_VEC_CHECK_DECL const char *file_, unsigned line_, const char *function_
#define VEC_CHECK_DECL , ALONE_VEC_CHECK_DECL
#define ALONE_VEC_CHECK_PASS file_, line_, function_
#define VEC_CHECK_PASS , ALONE_VEC_CHECK_PASS

#define VEC_ASSERT(EXPR,OP,T,A) \
  (void)((EXPR) ? 0 : (VEC_ASSERT_FAIL(OP,VEC(T,A)), 0))

extern void vec_assert_fail (const char *, const char * VEC_CHECK_DECL)
     ATTRIBUTE_NORETURN;
#define VEC_ASSERT_FAIL(OP,VEC) vec_assert_fail (OP,#VEC VEC_CHECK_PASS)
#else
#define ALONE_VEC_CHECK_INFO
#define VEC_CHECK_INFO
#define ALONE_VEC_CHECK_DECL void
#define VEC_CHECK_DECL
#define ALONE_VEC_CHECK_PASS
#define VEC_CHECK_PASS
#define VEC_ASSERT(EXPR,OP,T,A) (void)(EXPR)
#endif

#define VEC(T,A) vec_t<T>

enum vec_allocation_t { heap, gc, stack };

struct vec_prefix
{
  unsigned num_;
  unsigned alloc_;
};

/* Vector type, user visible.  */
template<typename T>
struct GTY(()) vec_t
{
  unsigned length (void) const;
  bool empty (void) const;
  T *address (void);
  T &last (ALONE_VEC_CHECK_DECL);
  const T &operator[] (unsigned) const;
  T &operator[] (unsigned);
  void embedded_init (int, int = 0);

  template<enum vec_allocation_t A>
  vec_t<T> *copy (ALONE_MEM_STAT_DECL);

  bool space (int VEC_CHECK_DECL);
  void splice (vec_t<T> * VEC_CHECK_DECL);
  T *quick_push (const T & VEC_CHECK_DECL);
  T &pop (ALONE_VEC_CHECK_DECL);
  void truncate (unsigned VEC_CHECK_DECL);
  void replace (unsigned, const T & VEC_CHECK_DECL);
  void quick_insert (unsigned, const T & VEC_CHECK_DECL);
  void ordered_remove (unsigned VEC_CHECK_DECL);
  void unordered_remove (unsigned VEC_CHECK_DECL);
  void block_remove (unsigned, unsigned VEC_CHECK_DECL);
  unsigned lower_bound (T, bool (*)(const T &, const T &)) const;

  /* Class-static member functions.  Some of these will become member
     functions of a future handler class wrapping vec_t.  */
  static size_t embedded_size (int);

  template<enum vec_allocation_t A>
  static vec_t<T> *alloc (int MEM_STAT_DECL);

  static vec_t<T> *alloc (int, vec_t<T> *);

  template<enum vec_allocation_t A>
  static void free (vec_t<T> **);

  template<enum vec_allocation_t A>
  static vec_t<T> *reserve_exact (vec_t<T> *, int MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static bool reserve_exact (vec_t<T> **, int VEC_CHECK_DECL MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static vec_t<T> *reserve (vec_t<T> *, int MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static bool reserve (vec_t<T> **, int VEC_CHECK_DECL MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static void safe_splice (vec_t<T> **, vec_t<T> * VEC_CHECK_DECL
			   MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static T *safe_push (vec_t<T> **, const T & VEC_CHECK_DECL MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static void safe_grow (vec_t<T> **, int VEC_CHECK_DECL MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static void safe_grow_cleared (vec_t<T> **, int VEC_CHECK_DECL MEM_STAT_DECL);

  template<enum vec_allocation_t A>
  static void safe_insert (vec_t<T> **, unsigned, const T & VEC_CHECK_DECL
			   MEM_STAT_DECL);

  static bool iterate (const vec_t<T> *, unsigned, T *);
  static bool iterate (const vec_t<T> *, unsigned, T **);

  vec_prefix prefix_;
  T vec_[1];
};


/* Garbage collection support for vec_t.  */

template<typename T>
void
gt_ggc_mx (vec_t<T> *v)
{
  extern void gt_ggc_mx (T &);
  for (unsigned i = 0; i < v->length (); i++)
    gt_ggc_mx ((*v)[i]);
}


/* PCH support for vec_t.  */

template<typename T>
void
gt_pch_nx (vec_t<T> *v)
{
  extern void gt_pch_nx (T &);
  for (unsigned i = 0; i < v->length (); i++)
    gt_pch_nx ((*v)[i]);
}

template<typename T>
void
gt_pch_nx (vec_t<T *> *v, gt_pointer_operator op, void *cookie)
{
  for (unsigned i = 0; i < v->length (); i++)
    op (&((*v)[i]), cookie);
}

template<typename T>
void
gt_pch_nx (vec_t<T> *v, gt_pointer_operator op, void *cookie)
{
  extern void gt_pch_nx (T *, gt_pointer_operator, void *);
  for (unsigned i = 0; i < v->length (); i++)
    gt_pch_nx (&((*v)[i]), op, cookie);
}


/* FIXME.  Remove these definitions and update all calling sites after
   the handler class for vec_t is implemented.  */

/* Vector of integer-like object.  */
#define DEF_VEC_I(T)			struct vec_swallow_trailing_semi
#define DEF_VEC_ALLOC_I(T,A)		struct vec_swallow_trailing_semi

/* Vector of pointer to object.  */
#define DEF_VEC_P(T)			struct vec_swallow_trailing_semi
#define DEF_VEC_ALLOC_P(T,A)		struct vec_swallow_trailing_semi

/* Vector of object.  */
#define DEF_VEC_O(T)			struct vec_swallow_trailing_semi
#define DEF_VEC_ALLOC_O(T,A)		struct vec_swallow_trailing_semi

/* Vectors on the stack.  */
#define DEF_VEC_ALLOC_P_STACK(T)	struct vec_swallow_trailing_semi
#define DEF_VEC_ALLOC_O_STACK(T)	struct vec_swallow_trailing_semi
#define DEF_VEC_ALLOC_I_STACK(T)	struct vec_swallow_trailing_semi

/* Vectors of atomic types.  Atomic types do not need to have its
   elements marked for GC and PCH.  To avoid unnecessary traversals,
   we provide template instantiations for the GC/PCH functions that
   do not traverse the vector.

   FIXME cxx-conversion - Once vec_t users are converted this can
   be provided in some other way (e.g., adding an additional template
   parameter to the vec_t class).  */
#define DEF_VEC_A(TYPE)						\
template<typename T>						\
void								\
gt_ggc_mx (vec_t<TYPE> *v ATTRIBUTE_UNUSED)			\
{								\
}								\
								\
template<typename T>						\
void								\
gt_pch_nx (vec_t<TYPE> *v ATTRIBUTE_UNUSED)			\
{								\
}								\
								\
template<typename T>						\
void								\
gt_pch_nx (vec_t<TYPE> *v ATTRIBUTE_UNUSED,			\
	   gt_pointer_operator op ATTRIBUTE_UNUSED,		\
	   void *cookie ATTRIBUTE_UNUSED)			\
{								\
}								\
struct vec_swallow_trailing_semi

#define DEF_VEC_ALLOC_A(T,A)		struct vec_swallow_trailing_semi

/* Support functions for stack vectors.  */
extern void *vec_stack_p_reserve_exact_1 (int, void *);
extern void *vec_stack_o_reserve (void *, int, size_t, size_t MEM_STAT_DECL);
extern void *vec_stack_o_reserve_exact (void *, int, size_t, size_t
					 MEM_STAT_DECL);
extern void vec_stack_free (void *);

extern void dump_vec_loc_statistics (void);
extern void ggc_free (void *);
extern void vec_heap_free (void *);


/* API compatibility macros (to be removed).  */
#define VEC_length(T,V)							\
	((V) ? (V)->length () : 0)

#define VEC_empty(T,V)							\
	((V) ? (V)->empty () : true)

#define VEC_address(T,V)						\
	vec_address<T> (V)

/* FIXME.  For now, we need to continue expanding VEC_address into a
   function call.  Otherwise, the warning machinery for -Wnonnull gets
   confused thinking that VEC_address may return null in calls to
   memcpy and qsort.  This will disappear once vec_address becomes
   a member function for a handler class wrapping vec_t.  */

template<typename T>
static inline T *
vec_address (vec_t<T> *vec)
{
  return vec ? vec->address() : NULL;
}

#define VEC_last(T,V)							\
	((V)->last (ALONE_VEC_CHECK_INFO))

#define VEC_index(T,V,I)						\
	((*(V))[I])

#define VEC_iterate(T,V,I,P)						\
	(vec_t<T>::iterate(V, I, &(P)))

#define VEC_embedded_size(T,N)						\
	(vec_t<T>::embedded_size (N))

#define VEC_embedded_init(T,V,N)					\
	((V)->embedded_init (N))

#define VEC_free(T,A,V)							\
	(vec_t<T>::free<A> (&(V)))

#define VEC_copy(T,A,V)							\
	((V)->copy<A> (ALONE_MEM_STAT_INFO))

#define VEC_space(T,V,R)						\
	((V) ? (V)->space (R VEC_CHECK_INFO) : (R) == 0)

#define VEC_reserve(T,A,V,R)						\
	(vec_t<T>::reserve<A> (&(V), (int)(R) VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_reserve_exact(T,A,V,R)					\
	(vec_t<T>::reserve_exact<A> (&(V), R VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_splice(T,DST,SRC)	        				\
	(DST)->splice (SRC VEC_CHECK_INFO)

#define VEC_safe_splice(T,A,DST,SRC)					\
	 vec_t<T>::safe_splice<A> (&(DST), SRC VEC_CHECK_INFO MEM_STAT_INFO)

#define VEC_quick_push(T,V,O)						\
	((V)->quick_push (O VEC_CHECK_INFO))

#define VEC_safe_push(T,A,V,O)						\
	(vec_t<T>::safe_push<A> (&(V), O VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_pop(T,V)							\
	((V)->pop (ALONE_VEC_CHECK_INFO))

#define VEC_truncate(T,V,I)						\
	(V								\
	 ? (V)->truncate ((unsigned)(I) VEC_CHECK_INFO)			\
	 : gcc_assert ((I) == 0))

#define VEC_safe_grow(T,A,V,I)						\
	(vec_t<T>::safe_grow<A> (&(V), (int)(I) VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_safe_grow_cleared(T,A,V,I)					\
	(vec_t<T>::safe_grow_cleared<A> (&(V), (int)(I)			\
				         VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_replace(T,V,I,O)						\
	((V)->replace ((unsigned)(I), O VEC_CHECK_INFO))

#define VEC_quick_insert(T,V,I,O)					\
	((V)->quick_insert (I,O VEC_CHECK_INFO))

#define VEC_safe_insert(T,A,V,I,O)					\
	(vec_t<T>::safe_insert<A> (&(V), I, O VEC_CHECK_INFO MEM_STAT_INFO))

#define VEC_ordered_remove(T,V,I)					\
	((V)->ordered_remove (I VEC_CHECK_INFO))

#define VEC_unordered_remove(T,V,I)					\
	((V)->unordered_remove (I VEC_CHECK_INFO))

#define VEC_block_remove(T,V,I,L)					\
	((V)->block_remove (I, L VEC_CHECK_INFO))

#define VEC_lower_bound(T,V,O,LT)					\
	((V)->lower_bound (O, LT))


/* Return the number of active elements in this vector.  */

template<typename T>
inline unsigned
vec_t<T>::length (void) const
{
  return prefix_.num_;
}


/* Return true if this vector has no active elements.  */

template<typename T>
inline bool
vec_t<T>::empty (void) const
{
  return length () == 0;
}


/* Return the address of the array of elements.  If you need to
   directly manipulate the array (for instance, you want to feed it
   to qsort), use this accessor.  */

template<typename T>
inline T *
vec_t<T>::address (void)
{
  return vec_;
}


/* Get the final element of the vector, which must not be empty.  */

template<typename T>
T &
vec_t<T>::last (ALONE_VEC_CHECK_DECL)
{
  VEC_ASSERT (prefix_.num_, "last", T, base);
  return (*this)[prefix_.num_ - 1];
}


/* Index into vector.  Return the IX'th element.  IX must be in the
   domain of the vector.  */

template<typename T>
const T &
vec_t<T>::operator[] (unsigned ix) const
{
  gcc_assert (ix < prefix_.num_);
  return vec_[ix];
}

template<typename T>
T &
vec_t<T>::operator[] (unsigned ix)
{
  gcc_assert (ix < prefix_.num_);
  return vec_[ix];
}


/* Return iteration condition and update PTR to point to the IX'th
   element of VEC.  Use this to iterate over the elements of a vector
   as follows,

     for (ix = 0; vec_t<T>::iterate(v, ix, &ptr); ix++)
       continue;
   
   FIXME.  This is a static member function because if VEC is NULL,
   PTR should be initialized to NULL.  This will become a regular
   member function of the handler class.  */

template<typename T>
bool
vec_t<T>::iterate (const vec_t<T> *vec, unsigned ix, T *ptr)
{
  if (vec && ix < vec->prefix_.num_)
    {
      *ptr = vec->vec_[ix];
      return true;
    }
  else
    {
      *ptr = 0;
      return false;
    }
}


/* Return iteration condition and update *PTR to point to the
   IX'th element of VEC.  Use this to iterate over the elements of a
   vector as follows,

     for (ix = 0; v->iterate(ix, &ptr); ix++)
       continue;

   This variant is for vectors of objects.  FIXME, to be removed
   once the distinction between vec_t<T> and vec_t<T *> disappears.  */

template<typename T>
bool
vec_t<T>::iterate (const vec_t<T> *vec, unsigned ix, T **ptr)
{
  if (vec && ix < vec->prefix_.num_)
    {
      *ptr = CONST_CAST (T *, &vec->vec_[ix]);
      return true;
    }
  else
    {
      *ptr = 0;
      return false;
    }
}


/* Convenience macro for forward iteration.  */

#define FOR_EACH_VEC_ELT(T, V, I, P)			\
  for (I = 0; VEC_iterate (T, (V), (I), (P)); ++(I))

/* Likewise, but start from FROM rather than 0.  */

#define FOR_EACH_VEC_ELT_FROM(T, V, I, P, FROM)		\
  for (I = (FROM); VEC_iterate (T, (V), (I), (P)); ++(I))

/* Convenience macro for reverse iteration.  */

#define FOR_EACH_VEC_ELT_REVERSE(T, V, I, P)		\
  for (I = VEC_length (T, (V)) - 1;			\
       VEC_iterate (T, (V), (I), (P));			\
       (I)--)


/* Return the number of bytes needed to embed an instance of vec_t inside
   another data structure.

   Use these methods to determine the required size and initialization
   of a vector V of type T embedded within another structure (as the
   final member):

   size_t vec_t<T>::embedded_size<T> (int reserve);
   void v->embedded_init(int reserve, int active);

   These allow the caller to perform the memory allocation.  */

template<typename T>
size_t
vec_t<T>::embedded_size (int nelems)
{
  return offsetof (vec_t<T>, vec_) + nelems * sizeof (T);
}


/* Initialize the vector to contain room for NELEMS elements and
   ACTIVE active elements.  */

template<typename T>
void
vec_t<T>::embedded_init (int nelems, int active)
{
  prefix_.num_ = active;
  prefix_.alloc_ = nelems;
}


/* Allocate a new vector with space for RESERVE objects.  If RESERVE
   is zero, NO vector is created.

   Note that this allocator must always be a macro:

   We support a vector which starts out with space on the stack and
   switches to heap space when forced to reallocate.  This works a
   little differently.  In the case of stack vectors, vec_alloc will
   expand to a call to vec_alloc_1 that calls XALLOCAVAR to request the
   initial allocation.  This uses alloca to get the initial space.
   Since alloca can not be usefully called in an inline function,
   vec_alloc must always be a macro.

   Important limitations of stack vectors:

   - Only the initial allocation will be made using alloca, so pass a
     reasonable estimate that doesn't use too much stack space; don't
     pass zero.

   - Don't return a stack-allocated vector from the function which
     allocated it.  */

#define VEC_alloc(T,A,N)						\
  ((A == stack)								\
    ? vec_t<T>::alloc (N, XALLOCAVAR (vec_t<T>, vec_t<T>::embedded_size (N)))\
    : vec_t<T>::alloc<A> (N MEM_STAT_INFO))

template<typename T>
template<enum vec_allocation_t A>
vec_t<T> *
vec_t<T>::alloc (int nelems MEM_STAT_DECL)
{
  return reserve_exact<A> ((vec_t<T> *) NULL, nelems PASS_MEM_STAT);
}

template<typename T>
vec_t<T> *
vec_t<T>::alloc (int nelems, vec_t<T> *space)
{
  return static_cast <vec_t<T> *> (vec_stack_p_reserve_exact_1 (nelems, space));
}


/* Free vector *V and set it to NULL.  */

template<typename T>
template<enum vec_allocation_t A>
void
vec_t<T>::free (vec_t<T> **v)
{
  if (*v)
    {
      if (A == heap)
	vec_heap_free (*v);
      else if (A == gc)
	ggc_free (*v);
      else if (A == stack)
	vec_stack_free (*v);
    }
  *v = NULL;
}


/* Return a copy of this vector.  The new and old vectors need not be
   allocated by the same mechanism.  */

template<typename T>
template<enum vec_allocation_t A>
vec_t<T> *
vec_t<T>::copy (ALONE_MEM_STAT_DECL)
{
  unsigned len = VEC_length (T, this);
  vec_t<T> *new_vec = NULL;

  if (len)
    {
      new_vec = reserve_exact<A> (static_cast<vec_t<T> *> (NULL),
				  len PASS_MEM_STAT);
      new_vec->embedded_init (len, len);
      memcpy (new_vec->address (), vec_, sizeof (T) * len);
    }

  return new_vec;
}


/* If this vector has space for RESERVE additional entries, return
   true.  You usually only need to use this if you are doing your
   own vector reallocation, for instance on an embedded vector.  This
   returns true in exactly the same circumstances that vec_reserve
   will.  */

template<typename T>
bool
vec_t<T>::space (int nelems VEC_CHECK_DECL)
{
  VEC_ASSERT (nelems >= 0, "space", T, base);
  return prefix_.alloc_ - prefix_.num_ >= static_cast <unsigned> (nelems);
}


/* Ensure that the vector **VEC has at least RESERVE slots available.  This
   will create additional headroom.  Note this can cause **VEC to
   be reallocated.  Returns true iff reallocation actually occurred.  */

template<typename T>
template<enum vec_allocation_t A>
bool
vec_t<T>::reserve (vec_t<T> **vec, int nelems VEC_CHECK_DECL MEM_STAT_DECL)
{
  bool extend = (*vec) ? !(*vec)->space (nelems VEC_CHECK_PASS) : nelems != 0;

  if (extend)
    *vec = reserve<A> (*vec, nelems PASS_MEM_STAT);

  return extend;
}


/* Ensure that **VEC has at least NELEMS slots available.  This will not
   create additional headroom.  Note this can cause VEC to be
   reallocated.  Returns true iff reallocation actually occurred.  */

template<typename T>
template<enum vec_allocation_t A>
bool
vec_t<T>::reserve_exact (vec_t<T> **vec, int nelems VEC_CHECK_DECL
			 MEM_STAT_DECL)
{
  bool extend = (*vec) ? !(*vec)->space (nelems VEC_CHECK_PASS) : nelems != 0;

  if (extend)
    *vec = reserve_exact<A> (*vec, nelems PASS_MEM_STAT);

  return extend;
}


/* Copy the elements from SRC to the end of this vector as if by memcpy.
   SRC and this vector need not be allocated with the same mechanism,
   although they most often will be.  This vector is assumed to have
   sufficient headroom available.  */

template<typename T>
void
vec_t<T>::splice (vec_t<T> *src VEC_CHECK_DECL)
{
  if (src)
    {
      unsigned len = VEC_length (T, src);
      VEC_ASSERT (VEC_length (T, this) + len <= prefix_.alloc_, "splice", T,
		  base);
      memcpy (address () + VEC_length (T, this),
	      src->address (),
	      len * sizeof (T));
      prefix_.num_ += len;
    }
}


/* Copy the elements in SRC to the end of DST as if by memcpy.  DST and
   SRC need not be allocated with the same mechanism, although they most
   often will be.  DST need not have sufficient headroom and will be
   reallocated if needed.  */

template<typename T>
template<enum vec_allocation_t A>
void
vec_t<T>::safe_splice (vec_t<T> **dst, vec_t<T> *src VEC_CHECK_DECL
		       MEM_STAT_DECL)
{
  if (src)
    {
      reserve_exact<A> (dst, VEC_length (T, src) VEC_CHECK_PASS MEM_STAT_INFO);
      (*dst)->splice (src VEC_CHECK_PASS);
    }
}

  
/* Push OBJ (a new element) onto the end of the vector.  There must be
   sufficient space in the vector.  Return a pointer to the slot
   where OBJ was inserted.  */


template<typename T>
T *
vec_t<T>::quick_push (const T &obj VEC_CHECK_DECL)
{
  VEC_ASSERT (prefix_.num_ < prefix_.alloc_, "push", T, base);
  T *slot = &vec_[prefix_.num_++];
  *slot = obj;
  return slot;
}


/* Push a new element OBJ onto the end of VEC.  Reallocates VEC, if
   needed.  Return a pointer to the slot where OBJ was inserted.  */

template<typename T>
template<enum vec_allocation_t A>
T *
vec_t<T>::safe_push (vec_t<T> **vec, const T &obj VEC_CHECK_DECL MEM_STAT_DECL)
{
  reserve<A> (vec, 1 VEC_CHECK_PASS PASS_MEM_STAT);
  return (*vec)->quick_push (obj VEC_CHECK_PASS);
}


/* Pop and return the last element off the end of the vector.  */


template<typename T>
T &
vec_t<T>::pop (ALONE_VEC_CHECK_DECL)
{
  VEC_ASSERT (prefix_.num_, "pop", T, base);
  return vec_[--prefix_.num_];
}


/* Set the length of the vector to LEN.  The new length must be less
   than or equal to the current length.  This is an O(1) operation.  */

template<typename T>
void
vec_t<T>::truncate (unsigned size VEC_CHECK_DECL)
{
  VEC_ASSERT (prefix_.num_ >= size, "truncate", T, base);
  prefix_.num_ = size;
}


/* Grow the vector VEC to a specific length.  The LEN must be as
   long or longer than the current length.  The new elements are
   uninitialized.  */

template<typename T>
template<enum vec_allocation_t A>
void
vec_t<T>::safe_grow (vec_t<T> **vec, int size VEC_CHECK_DECL MEM_STAT_DECL)
{
  VEC_ASSERT (size >= 0 && VEC_length (T, *vec) <= (unsigned)size,
	      "grow", T, A);
  reserve_exact<A> (vec, size - (int)VEC_length (T, *vec)
		    VEC_CHECK_PASS PASS_MEM_STAT);
  (*vec)->prefix_.num_ = size;
}


/* Grow the vector *VEC to a specific length.  The LEN must be as
   long or longer than the current length.  The new elements are
   initialized to zero.  */

template<typename T>
template<enum vec_allocation_t A>
void
vec_t<T>::safe_grow_cleared (vec_t<T> **vec, int size VEC_CHECK_DECL
			     MEM_STAT_DECL)
{
  int oldsize = VEC_length (T, *vec);
  safe_grow<A> (vec, size VEC_CHECK_PASS PASS_MEM_STAT);
  memset (&((*vec)->address ()[oldsize]), 0, sizeof (T) * (size - oldsize));
}


/* Replace the IXth element of this vector with a new value, VAL.  */

template<typename T>
void
vec_t<T>::replace (unsigned ix, const T &obj VEC_CHECK_DECL)
{
  VEC_ASSERT (ix < prefix_.num_, "replace", T, base);
  vec_[ix] = obj;
}


/* Insert an element, OBJ, at the IXth position of VEC.  There must be
   sufficient space.  */

template<typename T>
void
vec_t<T>::quick_insert (unsigned ix, const T &obj VEC_CHECK_DECL)
{
  VEC_ASSERT (prefix_.num_ < prefix_.alloc_, "insert", T, base);
  VEC_ASSERT (ix <= prefix_.num_, "insert", T, base);
  T *slot = &vec_[ix];
  memmove (slot + 1, slot, (prefix_.num_++ - ix) * sizeof (T));
  *slot = obj;
}


/* Insert an element, OBJ, at the IXth position of VEC. Reallocate
   VEC, if necessary.  */

template<typename T>
template<enum vec_allocation_t A>
void
vec_t<T>::safe_insert (vec_t<T> **vec, unsigned ix, const T &obj VEC_CHECK_DECL
		       MEM_STAT_DECL)
{
  reserve<A> (vec, 1 VEC_CHECK_PASS PASS_MEM_STAT);
  (*vec)->quick_insert (ix, obj VEC_CHECK_PASS);
}


/* Remove an element from the IXth position of this vector.  Ordering of
   remaining elements is preserved.  This is an O(N) operation due to
   a memmove.  */

template<typename T>
void
vec_t<T>::ordered_remove (unsigned ix VEC_CHECK_DECL)
{
  VEC_ASSERT (ix < prefix_.num_, "remove", T, base);
  T *slot = &vec_[ix];
  memmove (slot, slot + 1, (--prefix_.num_ - ix) * sizeof (T));
}


/* Remove an element from the IXth position of VEC.  Ordering of
   remaining elements is destroyed.  This is an O(1) operation.  */

template<typename T>
void
vec_t<T>::unordered_remove (unsigned ix VEC_CHECK_DECL)
{
  VEC_ASSERT (ix < prefix_.num_, "remove", T, base);
  vec_[ix] = vec_[--prefix_.num_];
}


/* Remove LEN elements starting at the IXth.  Ordering is retained.
   This is an O(N) operation due to memmove.  */

template<typename T>
void
vec_t<T>::block_remove (unsigned ix, unsigned len VEC_CHECK_DECL)
{
  VEC_ASSERT (ix + len <= prefix_.num_, "block_remove", T, base);
  T *slot = &vec_[ix];
  prefix_.num_ -= len;
  memmove (slot, slot + len, (prefix_.num_ - ix) * sizeof (T));
}

/* Sort the contents of V with qsort.  Use CMP as the comparison function.  */
#define VEC_qsort(T,V,CMP)						\
	qsort (VEC_address (T, V), VEC_length (T, V), sizeof (T), CMP)


/* Find and return the first position in which OBJ could be inserted
   without changing the ordering of this vector.  LESSTHAN is a
   function that returns true if the first argument is strictly less
   than the second.  */

template<typename T>
unsigned
vec_t<T>::lower_bound (T obj, bool (*lessthan)(const T &, const T &)) const
{
  unsigned int len = VEC_length (T, this);
  unsigned int half, middle;
  unsigned int first = 0;
  while (len > 0)
    {
      half = len / 2;
      middle = first;
      middle += half;
      T middle_elem = (*this)[middle];
      if (lessthan (middle_elem, obj))
	{
	  first = middle;
	  ++first;
	  len = len - half - 1;
	}
      else
	len = half;
    }
  return first;
}


void *vec_heap_o_reserve_1 (void *, int, size_t, size_t, bool MEM_STAT_DECL);
void *vec_gc_o_reserve_1 (void *, int, size_t, size_t, bool MEM_STAT_DECL);

/* Ensure there are at least RESERVE free slots in VEC_, growing
   exponentially.  If RESERVE < 0 grow exactly, else grow
   exponentially.  As a special case, if VEC_ is NULL, and RESERVE is
   0, no vector will be created. */

template<typename T>
template<enum vec_allocation_t A>
vec_t<T> *
vec_t<T>::reserve (vec_t<T> *vec, int reserve MEM_STAT_DECL)
{
  void *res = NULL;
  size_t off = offsetof (vec_t<T>, vec_);
  size_t sz = sizeof (T);

  switch (A)
    {
      case gc:
	res = vec_gc_o_reserve_1 (vec, reserve, off, sz, false PASS_MEM_STAT);
	break;
      case heap:
	res = vec_heap_o_reserve_1 (vec, reserve, off, sz, false PASS_MEM_STAT);
	break;
      case stack:
	res = vec_stack_o_reserve (vec, reserve, off, sz PASS_MEM_STAT);
	break;
    }

  return static_cast <vec_t<T> *> (res);
}


/* Ensure there are at least RESERVE free slots in VEC, growing
   exactly.  If RESERVE < 0 grow exactly, else grow exponentially.  As
   a special case, if VEC is NULL, and RESERVE is 0, no vector will be
   created. */

template<typename T>
template<enum vec_allocation_t A>
vec_t<T> *
vec_t<T>::reserve_exact (vec_t<T> *vec, int reserve MEM_STAT_DECL)
{
  void *res = NULL;
  size_t off = sizeof (struct vec_prefix);
  size_t sz = sizeof (T);

  gcc_assert (offsetof (vec_t<T>, vec_) == sizeof (struct vec_prefix));

  switch (A)
    {
      case gc:
	res = vec_gc_o_reserve_1 (vec, reserve, off, sz, true PASS_MEM_STAT);
	break;
      case heap:
	res = vec_heap_o_reserve_1 (vec, reserve, off, sz, true PASS_MEM_STAT);
	break;
      case stack:
	res = vec_stack_o_reserve_exact (vec, reserve, off, sz PASS_MEM_STAT);
	break;
    }

  return static_cast <vec_t<T> *> (res);
}

#endif /* GCC_VEC_H */