aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/tree-affine.c
blob: 91f9a9fee40dd2e2cf6c574bb5a4290bf7aa9646 (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
/* Operations with affine combinations of trees.
   Copyright (C) 2005-2014 Free Software Foundation, Inc.

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/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "expr.h"
#include "tree-pretty-print.h"
#include "pointer-set.h"
#include "tree-affine.h"
#include "basic-block.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "gimple-expr.h"
#include "is-a.h"
#include "gimple.h"
#include "gimplify.h"
#include "flags.h"
#include "dumpfile.h"
#include "cfgexpand.h"

/* Extends CST as appropriate for the affine combinations COMB.  */

double_int
double_int_ext_for_comb (double_int cst, aff_tree *comb)
{
  return cst.sext (TYPE_PRECISION (comb->type));
}

/* Initializes affine combination COMB so that its value is zero in TYPE.  */

static void
aff_combination_zero (aff_tree *comb, tree type)
{
  comb->type = type;
  comb->offset = double_int_zero;
  comb->n = 0;
  comb->rest = NULL_TREE;
}

/* Sets COMB to CST.  */

void
aff_combination_const (aff_tree *comb, tree type, double_int cst)
{
  aff_combination_zero (comb, type);
  comb->offset = double_int_ext_for_comb (cst, comb);
}

/* Sets COMB to single element ELT.  */

void
aff_combination_elt (aff_tree *comb, tree type, tree elt)
{
  aff_combination_zero (comb, type);

  comb->n = 1;
  comb->elts[0].val = elt;
  comb->elts[0].coef = double_int_one;
}

/* Scales COMB by SCALE.  */

void
aff_combination_scale (aff_tree *comb, double_int scale)
{
  unsigned i, j;

  scale = double_int_ext_for_comb (scale, comb);
  if (scale.is_one ())
    return;

  if (scale.is_zero ())
    {
      aff_combination_zero (comb, comb->type);
      return;
    }

  comb->offset
    = double_int_ext_for_comb (scale * comb->offset, comb);
  for (i = 0, j = 0; i < comb->n; i++)
    {
      double_int new_coef;

      new_coef
	= double_int_ext_for_comb (scale * comb->elts[i].coef, comb);
      /* A coefficient may become zero due to overflow.  Remove the zero
	 elements.  */
      if (new_coef.is_zero ())
	continue;
      comb->elts[j].coef = new_coef;
      comb->elts[j].val = comb->elts[i].val;
      j++;
    }
  comb->n = j;

  if (comb->rest)
    {
      tree type = comb->type;
      if (POINTER_TYPE_P (type))
	type = sizetype;
      if (comb->n < MAX_AFF_ELTS)
	{
	  comb->elts[comb->n].coef = scale;
	  comb->elts[comb->n].val = comb->rest;
	  comb->rest = NULL_TREE;
	  comb->n++;
	}
      else
	comb->rest = fold_build2 (MULT_EXPR, type, comb->rest,
				  double_int_to_tree (type, scale));
    }
}

/* Adds ELT * SCALE to COMB.  */

void
aff_combination_add_elt (aff_tree *comb, tree elt, double_int scale)
{
  unsigned i;
  tree type;

  scale = double_int_ext_for_comb (scale, comb);
  if (scale.is_zero ())
    return;

  for (i = 0; i < comb->n; i++)
    if (operand_equal_p (comb->elts[i].val, elt, 0))
      {
	double_int new_coef;

	new_coef = comb->elts[i].coef + scale;
	new_coef = double_int_ext_for_comb (new_coef, comb);
	if (!new_coef.is_zero ())
	  {
	    comb->elts[i].coef = new_coef;
	    return;
	  }

	comb->n--;
	comb->elts[i] = comb->elts[comb->n];

	if (comb->rest)
	  {
	    gcc_assert (comb->n == MAX_AFF_ELTS - 1);
	    comb->elts[comb->n].coef = double_int_one;
	    comb->elts[comb->n].val = comb->rest;
	    comb->rest = NULL_TREE;
	    comb->n++;
	  }
	return;
      }
  if (comb->n < MAX_AFF_ELTS)
    {
      comb->elts[comb->n].coef = scale;
      comb->elts[comb->n].val = elt;
      comb->n++;
      return;
    }

  type = comb->type;
  if (POINTER_TYPE_P (type))
    type = sizetype;

  if (scale.is_one ())
    elt = fold_convert (type, elt);
  else
    elt = fold_build2 (MULT_EXPR, type,
		       fold_convert (type, elt),
		       double_int_to_tree (type, scale));

  if (comb->rest)
    comb->rest = fold_build2 (PLUS_EXPR, type, comb->rest,
			      elt);
  else
    comb->rest = elt;
}

/* Adds CST to C.  */

static void
aff_combination_add_cst (aff_tree *c, double_int cst)
{
  c->offset = double_int_ext_for_comb (c->offset + cst, c);
}

/* Adds COMB2 to COMB1.  */

void
aff_combination_add (aff_tree *comb1, aff_tree *comb2)
{
  unsigned i;

  aff_combination_add_cst (comb1, comb2->offset);
  for (i = 0; i < comb2->n; i++)
    aff_combination_add_elt (comb1, comb2->elts[i].val, comb2->elts[i].coef);
  if (comb2->rest)
    aff_combination_add_elt (comb1, comb2->rest, double_int_one);
}

/* Converts affine combination COMB to TYPE.  */

void
aff_combination_convert (aff_tree *comb, tree type)
{
  unsigned i, j;
  tree comb_type = comb->type;

  if  (TYPE_PRECISION (type) > TYPE_PRECISION (comb_type))
    {
      tree val = fold_convert (type, aff_combination_to_tree (comb));
      tree_to_aff_combination (val, type, comb);
      return;
    }

  comb->type = type;
  if (comb->rest && !POINTER_TYPE_P (type))
    comb->rest = fold_convert (type, comb->rest);

  if (TYPE_PRECISION (type) == TYPE_PRECISION (comb_type))
    return;

  comb->offset = double_int_ext_for_comb (comb->offset, comb);
  for (i = j = 0; i < comb->n; i++)
    {
      double_int new_coef = double_int_ext_for_comb (comb->elts[i].coef, comb);
      if (new_coef.is_zero ())
	continue;
      comb->elts[j].coef = new_coef;
      comb->elts[j].val = fold_convert (type, comb->elts[i].val);
      j++;
    }

  comb->n = j;
  if (comb->n < MAX_AFF_ELTS && comb->rest)
    {
      comb->elts[comb->n].coef = double_int_one;
      comb->elts[comb->n].val = comb->rest;
      comb->rest = NULL_TREE;
      comb->n++;
    }
}

/* Splits EXPR into an affine combination of parts.  */

void
tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
{
  aff_tree tmp;
  enum tree_code code;
  tree cst, core, toffset;
  HOST_WIDE_INT bitpos, bitsize;
  enum machine_mode mode;
  int unsignedp, volatilep;

  STRIP_NOPS (expr);

  code = TREE_CODE (expr);
  switch (code)
    {
    case INTEGER_CST:
      aff_combination_const (comb, type, tree_to_double_int (expr));
      return;

    case POINTER_PLUS_EXPR:
      tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
      tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp);
      aff_combination_add (comb, &tmp);
      return;

    case PLUS_EXPR:
    case MINUS_EXPR:
      tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
      tree_to_aff_combination (TREE_OPERAND (expr, 1), type, &tmp);
      if (code == MINUS_EXPR)
	aff_combination_scale (&tmp, double_int_minus_one);
      aff_combination_add (comb, &tmp);
      return;

    case MULT_EXPR:
      cst = TREE_OPERAND (expr, 1);
      if (TREE_CODE (cst) != INTEGER_CST)
	break;
      tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
      aff_combination_scale (comb, tree_to_double_int (cst));
      return;

    case NEGATE_EXPR:
      tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
      aff_combination_scale (comb, double_int_minus_one);
      return;

    case BIT_NOT_EXPR:
      /* ~x = -x - 1 */
      tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
      aff_combination_scale (comb, double_int_minus_one);
      aff_combination_add_cst (comb, double_int_minus_one);
      return;

    case ADDR_EXPR:
      /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR.  */
      if (TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF)
	{
	  expr = TREE_OPERAND (expr, 0);
	  tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
	  tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp);
	  aff_combination_add (comb, &tmp);
	  return;
	}
      core = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, &bitpos,
				  &toffset, &mode, &unsignedp, &volatilep,
				  false);
      if (bitpos % BITS_PER_UNIT != 0)
	break;
      aff_combination_const (comb, type,
			     double_int::from_uhwi (bitpos / BITS_PER_UNIT));
      core = build_fold_addr_expr (core);
      if (TREE_CODE (core) == ADDR_EXPR)
	aff_combination_add_elt (comb, core, double_int_one);
      else
	{
	  tree_to_aff_combination (core, type, &tmp);
	  aff_combination_add (comb, &tmp);
	}
      if (toffset)
	{
	  tree_to_aff_combination (toffset, type, &tmp);
	  aff_combination_add (comb, &tmp);
	}
      return;

    case MEM_REF:
      if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
	tree_to_aff_combination (TREE_OPERAND (TREE_OPERAND (expr, 0), 0),
				 type, comb);
      else if (integer_zerop (TREE_OPERAND (expr, 1)))
	{
	  aff_combination_elt (comb, type, expr);
	  return;
	}
      else
	aff_combination_elt (comb, type,
			     build2 (MEM_REF, TREE_TYPE (expr),
				     TREE_OPERAND (expr, 0),
				     build_int_cst
				      (TREE_TYPE (TREE_OPERAND (expr, 1)), 0)));
      tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp);
      aff_combination_add (comb, &tmp);
      return;

    default:
      break;
    }

  aff_combination_elt (comb, type, expr);
}

/* Creates EXPR + ELT * SCALE in TYPE.  EXPR is taken from affine
   combination COMB.  */

static tree
add_elt_to_tree (tree expr, tree type, tree elt, double_int scale,
		 aff_tree *comb)
{
  enum tree_code code;
  tree type1 = type;
  if (POINTER_TYPE_P (type))
    type1 = sizetype;

  scale = double_int_ext_for_comb (scale, comb);

  if (scale.is_minus_one ()
      && POINTER_TYPE_P (TREE_TYPE (elt)))
    {
      elt = convert_to_ptrofftype (elt);
      elt = fold_build1 (NEGATE_EXPR, TREE_TYPE (elt), elt);
      scale = double_int_one;
    }

  if (scale.is_one ())
    {
      if (!expr)
	{
	  if (POINTER_TYPE_P (TREE_TYPE (elt)))
	    return elt;
	  else
	    return fold_convert (type1, elt);
	}

      if (POINTER_TYPE_P (TREE_TYPE (expr)))
	return fold_build_pointer_plus (expr, elt);
      if (POINTER_TYPE_P (TREE_TYPE (elt)))
	return fold_build_pointer_plus (elt, expr);
      return fold_build2 (PLUS_EXPR, type1,
			  expr, fold_convert (type1, elt));
    }

  if (scale.is_minus_one ())
    {
      if (!expr)
	return fold_build1 (NEGATE_EXPR, type1,
			    fold_convert (type1, elt));

      if (POINTER_TYPE_P (TREE_TYPE (expr)))
	{
	  elt = convert_to_ptrofftype (elt);
	  elt = fold_build1 (NEGATE_EXPR, TREE_TYPE (elt), elt);
	  return fold_build_pointer_plus (expr, elt);
	}
      return fold_build2 (MINUS_EXPR, type1,
			  expr, fold_convert (type1, elt));
    }

  elt = fold_convert (type1, elt);
  if (!expr)
    return fold_build2 (MULT_EXPR, type1, elt,
			double_int_to_tree (type1, scale));

  if (scale.is_negative ())
    {
      code = MINUS_EXPR;
      scale = -scale;
    }
  else
    code = PLUS_EXPR;

  elt = fold_build2 (MULT_EXPR, type1, elt,
		     double_int_to_tree (type1, scale));
  if (POINTER_TYPE_P (TREE_TYPE (expr)))
    {
      if (code == MINUS_EXPR)
        elt = fold_build1 (NEGATE_EXPR, type1, elt);
      return fold_build_pointer_plus (expr, elt);
    }
  return fold_build2 (code, type1, expr, elt);
}

/* Makes tree from the affine combination COMB.  */

tree
aff_combination_to_tree (aff_tree *comb)
{
  tree type = comb->type;
  tree expr = NULL_TREE;
  unsigned i;
  double_int off, sgn;
  tree type1 = type;
  if (POINTER_TYPE_P (type))
    type1 = sizetype;

  gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE);

  for (i = 0; i < comb->n; i++)
    expr = add_elt_to_tree (expr, type, comb->elts[i].val, comb->elts[i].coef,
			    comb);

  if (comb->rest)
    expr = add_elt_to_tree (expr, type, comb->rest, double_int_one, comb);

  /* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is
     unsigned.  */
  if (comb->offset.is_negative ())
    {
      off = -comb->offset;
      sgn = double_int_minus_one;
    }
  else
    {
      off = comb->offset;
      sgn = double_int_one;
    }
  return add_elt_to_tree (expr, type, double_int_to_tree (type1, off), sgn,
			  comb);
}

/* Copies the tree elements of COMB to ensure that they are not shared.  */

void
unshare_aff_combination (aff_tree *comb)
{
  unsigned i;

  for (i = 0; i < comb->n; i++)
    comb->elts[i].val = unshare_expr (comb->elts[i].val);
  if (comb->rest)
    comb->rest = unshare_expr (comb->rest);
}

/* Remove M-th element from COMB.  */

void
aff_combination_remove_elt (aff_tree *comb, unsigned m)
{
  comb->n--;
  if (m <= comb->n)
    comb->elts[m] = comb->elts[comb->n];
  if (comb->rest)
    {
      comb->elts[comb->n].coef = double_int_one;
      comb->elts[comb->n].val = comb->rest;
      comb->rest = NULL_TREE;
      comb->n++;
    }
}

/* Adds C * COEF * VAL to R.  VAL may be NULL, in that case only
   C * COEF is added to R.  */


static void
aff_combination_add_product (aff_tree *c, double_int coef, tree val,
			     aff_tree *r)
{
  unsigned i;
  tree aval, type;

  for (i = 0; i < c->n; i++)
    {
      aval = c->elts[i].val;
      if (val)
	{
	  type = TREE_TYPE (aval);
	  aval = fold_build2 (MULT_EXPR, type, aval,
			      fold_convert (type, val));
	}

      aff_combination_add_elt (r, aval, coef * c->elts[i].coef);
    }

  if (c->rest)
    {
      aval = c->rest;
      if (val)
	{
	  type = TREE_TYPE (aval);
	  aval = fold_build2 (MULT_EXPR, type, aval,
			      fold_convert (type, val));
	}

      aff_combination_add_elt (r, aval, coef);
    }

  if (val)
    aff_combination_add_elt (r, val, coef * c->offset);
  else
    aff_combination_add_cst (r, coef * c->offset);
}

/* Multiplies C1 by C2, storing the result to R  */

void
aff_combination_mult (aff_tree *c1, aff_tree *c2, aff_tree *r)
{
  unsigned i;
  gcc_assert (TYPE_PRECISION (c1->type) == TYPE_PRECISION (c2->type));

  aff_combination_zero (r, c1->type);

  for (i = 0; i < c2->n; i++)
    aff_combination_add_product (c1, c2->elts[i].coef, c2->elts[i].val, r);
  if (c2->rest)
    aff_combination_add_product (c1, double_int_one, c2->rest, r);
  aff_combination_add_product (c1, c2->offset, NULL, r);
}

/* Returns the element of COMB whose value is VAL, or NULL if no such
   element exists.  If IDX is not NULL, it is set to the index of VAL in
   COMB.  */

static struct aff_comb_elt *
aff_combination_find_elt (aff_tree *comb, tree val, unsigned *idx)
{
  unsigned i;

  for (i = 0; i < comb->n; i++)
    if (operand_equal_p (comb->elts[i].val, val, 0))
      {
	if (idx)
	  *idx = i;

	return &comb->elts[i];
      }

  return NULL;
}

/* Element of the cache that maps ssa name NAME to its expanded form
   as an affine expression EXPANSION.  */

struct name_expansion
{
  aff_tree expansion;

  /* True if the expansion for the name is just being generated.  */
  unsigned in_progress : 1;
};

/* Expands SSA names in COMB recursively.  CACHE is used to cache the
   results.  */

void
aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED,
			struct pointer_map_t **cache ATTRIBUTE_UNUSED)
{
  unsigned i;
  aff_tree to_add, current, curre;
  tree e, rhs;
  gimple def;
  double_int scale;
  void **slot;
  struct name_expansion *exp;

  aff_combination_zero (&to_add, comb->type);
  for (i = 0; i < comb->n; i++)
    {
      tree type, name;
      enum tree_code code;

      e = comb->elts[i].val;
      type = TREE_TYPE (e);
      name = e;
      /* Look through some conversions.  */
      if (TREE_CODE (e) == NOP_EXPR
          && (TYPE_PRECISION (type)
	      >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (e, 0)))))
	name = TREE_OPERAND (e, 0);
      if (TREE_CODE (name) != SSA_NAME)
	continue;
      def = SSA_NAME_DEF_STMT (name);
      if (!is_gimple_assign (def) || gimple_assign_lhs (def) != name)
	continue;

      code = gimple_assign_rhs_code (def);
      if (code != SSA_NAME
	  && !IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
	  && (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
	      || !is_gimple_min_invariant (gimple_assign_rhs1 (def))))
	continue;

      /* We do not know whether the reference retains its value at the
	 place where the expansion is used.  */
      if (TREE_CODE_CLASS (code) == tcc_reference)
	continue;

      if (!*cache)
	*cache = pointer_map_create ();
      slot = pointer_map_insert (*cache, e);
      exp = (struct name_expansion *) *slot;

      if (!exp)
	{
	  exp = XNEW (struct name_expansion);
	  exp->in_progress = 1;
	  *slot = exp;
	  /* In principle this is a generally valid folding, but
	     it is not unconditionally an optimization, so do it
	     here and not in fold_unary.  */
	  /* Convert (T1)(X *+- CST) into (T1)X *+- (T1)CST if T1 is wider
	     than the type of X and overflow for the type of X is
	     undefined.  */
	  if (e != name
	      && INTEGRAL_TYPE_P (type)
	      && INTEGRAL_TYPE_P (TREE_TYPE (name))
	      && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (name))
	      && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (name))
	      && (code == PLUS_EXPR || code == MINUS_EXPR || code == MULT_EXPR)
	      && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST)
	    rhs = fold_build2 (code, type,
			       fold_convert (type, gimple_assign_rhs1 (def)),
			       fold_convert (type, gimple_assign_rhs2 (def)));
	  else
	    {
	      rhs = gimple_assign_rhs_to_tree (def);
	      if (e != name)
		rhs = fold_convert (type, rhs);
	    }
	  tree_to_aff_combination_expand (rhs, comb->type, &current, cache);
	  exp->expansion = current;
	  exp->in_progress = 0;
	}
      else
	{
	  /* Since we follow the definitions in the SSA form, we should not
	     enter a cycle unless we pass through a phi node.  */
	  gcc_assert (!exp->in_progress);
	  current = exp->expansion;
	}

      /* Accumulate the new terms to TO_ADD, so that we do not modify
	 COMB while traversing it; include the term -coef * E, to remove
         it from COMB.  */
      scale = comb->elts[i].coef;
      aff_combination_zero (&curre, comb->type);
      aff_combination_add_elt (&curre, e, -scale);
      aff_combination_scale (&current, scale);
      aff_combination_add (&to_add, &current);
      aff_combination_add (&to_add, &curre);
    }
  aff_combination_add (comb, &to_add);
}

/* Similar to tree_to_aff_combination, but follows SSA name definitions
   and expands them recursively.  CACHE is used to cache the expansions
   of the ssa names, to avoid exponential time complexity for cases
   like

   a1 = a0 + a0;
   a2 = a1 + a1;
   a3 = a2 + a2;
   ...  */

void
tree_to_aff_combination_expand (tree expr, tree type, aff_tree *comb,
				struct pointer_map_t **cache)
{
  tree_to_aff_combination (expr, type, comb);
  aff_combination_expand (comb, cache);
}

/* Frees memory occupied by struct name_expansion in *VALUE.  Callback for
   pointer_map_traverse.  */

static bool
free_name_expansion (const void *key ATTRIBUTE_UNUSED, void **value,
		     void *data ATTRIBUTE_UNUSED)
{
  struct name_expansion *const exp = (struct name_expansion *) *value;

  free (exp);
  return true;
}

/* Frees memory allocated for the CACHE used by
   tree_to_aff_combination_expand.  */

void
free_affine_expand_cache (struct pointer_map_t **cache)
{
  if (!*cache)
    return;

  pointer_map_traverse (*cache, free_name_expansion, NULL);
  pointer_map_destroy (*cache);
  *cache = NULL;
}

/* If VAL != CST * DIV for any constant CST, returns false.
   Otherwise, if *MULT_SET is true, additionally compares CST and MULT,
   and if they are different, returns false.  Finally, if neither of these
   two cases occur, true is returned, and CST is stored to MULT and MULT_SET
   is set to true.  */

static bool
double_int_constant_multiple_p (double_int val, double_int div,
				bool *mult_set, double_int *mult)
{
  double_int rem, cst;

  if (val.is_zero ())
    {
      if (*mult_set && !mult->is_zero ())
	return false;
      *mult_set = true;
      *mult = double_int_zero;
      return true;
    }

  if (div.is_zero ())
    return false;

  cst = val.sdivmod (div, FLOOR_DIV_EXPR, &rem);
  if (!rem.is_zero ())
    return false;

  if (*mult_set && *mult != cst)
    return false;

  *mult_set = true;
  *mult = cst;
  return true;
}

/* Returns true if VAL = X * DIV for some constant X.  If this is the case,
   X is stored to MULT.  */

bool
aff_combination_constant_multiple_p (aff_tree *val, aff_tree *div,
				     double_int *mult)
{
  bool mult_set = false;
  unsigned i;

  if (val->n == 0 && val->offset.is_zero ())
    {
      *mult = double_int_zero;
      return true;
    }
  if (val->n != div->n)
    return false;

  if (val->rest || div->rest)
    return false;

  if (!double_int_constant_multiple_p (val->offset, div->offset,
				       &mult_set, mult))
    return false;

  for (i = 0; i < div->n; i++)
    {
      struct aff_comb_elt *elt
	      = aff_combination_find_elt (val, div->elts[i].val, NULL);
      if (!elt)
	return false;
      if (!double_int_constant_multiple_p (elt->coef, div->elts[i].coef,
					   &mult_set, mult))
	return false;
    }

  gcc_assert (mult_set);
  return true;
}

/* Prints the affine VAL to the FILE. */

static void
print_aff (FILE *file, aff_tree *val)
{
  unsigned i;
  bool uns = TYPE_UNSIGNED (val->type);
  if (POINTER_TYPE_P (val->type))
    uns = false;
  fprintf (file, "{\n  type = ");
  print_generic_expr (file, val->type, TDF_VOPS|TDF_MEMSYMS);
  fprintf (file, "\n  offset = ");
  dump_double_int (file, val->offset, uns);
  if (val->n > 0)
    {
      fprintf (file, "\n  elements = {\n");
      for (i = 0; i < val->n; i++)
	{
	  fprintf (file, "    [%d] = ", i);
	  print_generic_expr (file, val->elts[i].val, TDF_VOPS|TDF_MEMSYMS);

	  fprintf (file, " * ");
	  dump_double_int (file, val->elts[i].coef, uns);
	  if (i != val->n - 1)
	    fprintf (file, ", \n");
	}
      fprintf (file, "\n  }");
  }
  if (val->rest)
    {
      fprintf (file, "\n  rest = ");
      print_generic_expr (file, val->rest, TDF_VOPS|TDF_MEMSYMS);
    }
  fprintf (file, "\n}");
}

/* Prints the affine VAL to the standard error, used for debugging.  */

DEBUG_FUNCTION void
debug_aff (aff_tree *val)
{
  print_aff (stderr, val);
  fprintf (stderr, "\n");
}

/* Computes address of the reference REF in ADDR.  The size of the accessed
   location is stored to SIZE.  Returns the ultimate containing object to
   which REF refers.  */

tree
get_inner_reference_aff (tree ref, aff_tree *addr, double_int *size)
{
  HOST_WIDE_INT bitsize, bitpos;
  tree toff;
  enum machine_mode mode;
  int uns, vol;
  aff_tree tmp;
  tree base = get_inner_reference (ref, &bitsize, &bitpos, &toff, &mode,
				   &uns, &vol, false);
  tree base_addr = build_fold_addr_expr (base);

  /* ADDR = &BASE + TOFF + BITPOS / BITS_PER_UNIT.  */

  tree_to_aff_combination (base_addr, sizetype, addr);

  if (toff)
    {
      tree_to_aff_combination (toff, sizetype, &tmp);
      aff_combination_add (addr, &tmp);
    }

  aff_combination_const (&tmp, sizetype,
			 double_int::from_shwi (bitpos / BITS_PER_UNIT));
  aff_combination_add (addr, &tmp);

  *size = double_int::from_shwi ((bitsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT);

  return base;
}

/* Returns true if a region of size SIZE1 at position 0 and a region of
   size SIZE2 at position DIFF cannot overlap.  */

bool
aff_comb_cannot_overlap_p (aff_tree *diff, double_int size1, double_int size2)
{
  double_int d, bound;

  /* Unless the difference is a constant, we fail.  */
  if (diff->n != 0)
    return false;

  d = diff->offset;
  if (d.is_negative ())
    {
      /* The second object is before the first one, we succeed if the last
	 element of the second object is before the start of the first one.  */
      bound = d + size2 + double_int_minus_one;
      return bound.is_negative ();
    }
  else
    {
      /* We succeed if the second object starts after the first one ends.  */
      return size1.sle (d);
    }
}