summaryrefslogtreecommitdiff
path: root/gcc/vr-values.cc
blob: 86c1bf8ebc66c73d0655d218cda090b336ae7101 (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
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
/* Support routines for Value Range Propagation (VRP).
   Copyright (C) 2005-2023 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 "backend.h"
#include "insn-codes.h"
#include "tree.h"
#include "gimple.h"
#include "ssa.h"
#include "optabs-tree.h"
#include "gimple-pretty-print.h"
#include "diagnostic-core.h"
#include "flags.h"
#include "fold-const.h"
#include "calls.h"
#include "cfganal.h"
#include "gimple-iterator.h"
#include "gimple-fold.h"
#include "tree-cfg.h"
#include "tree-ssa-loop-niter.h"
#include "tree-ssa-loop.h"
#include "intl.h"
#include "cfgloop.h"
#include "tree-scalar-evolution.h"
#include "tree-ssa-propagate.h"
#include "tree-chrec.h"
#include "omp-general.h"
#include "case-cfn-macros.h"
#include "alloc-pool.h"
#include "attribs.h"
#include "range.h"
#include "vr-values.h"
#include "cfghooks.h"
#include "range-op.h"
#include "gimple-range.h"

/* Return true if op is in a boolean [0, 1] value-range.  */

bool
simplify_using_ranges::op_with_boolean_value_range_p (tree op, gimple *s)
{
  if (TYPE_PRECISION (TREE_TYPE (op)) == 1)
    return true;

  if (integer_zerop (op)
      || integer_onep (op))
    return true;

  if (TREE_CODE (op) != SSA_NAME)
    return false;

  /* ?? Errr, this should probably check for [0,0] and [1,1] as well
     as [0,1].  */
  value_range vr;
  return (query->range_of_expr (vr, op, s)
	  && vr == range_true_and_false (TREE_TYPE (op)));
}

/* Helper function for simplify_internal_call_using_ranges and
   extract_range_basic.  Return true if OP0 SUBCODE OP1 for
   SUBCODE {PLUS,MINUS,MULT}_EXPR is known to never overflow or
   always overflow.  Set *OVF to true if it is known to always
   overflow.  */

static bool
check_for_binary_op_overflow (range_query *query,
			      enum tree_code subcode, tree type,
			      tree op0, tree op1, bool *ovf, gimple *s = NULL)
{
  value_range vr0, vr1;
  if (!query->range_of_expr (vr0, op0, s) || vr0.undefined_p ())
    vr0.set_varying (TREE_TYPE (op0));
  if (!query->range_of_expr (vr1, op1, s) || vr1.undefined_p ())
    vr1.set_varying (TREE_TYPE (op1));

  tree vr0min = wide_int_to_tree (TREE_TYPE (op0), vr0.lower_bound ());
  tree vr0max = wide_int_to_tree (TREE_TYPE (op0), vr0.upper_bound ());
  tree vr1min = wide_int_to_tree (TREE_TYPE (op1), vr1.lower_bound ());
  tree vr1max = wide_int_to_tree (TREE_TYPE (op1), vr1.upper_bound ());

  *ovf = arith_overflowed_p (subcode, type, vr0min,
			     subcode == MINUS_EXPR ? vr1max : vr1min);
  if (arith_overflowed_p (subcode, type, vr0max,
			  subcode == MINUS_EXPR ? vr1min : vr1max) != *ovf)
    return false;
  if (subcode == MULT_EXPR)
    {
      if (arith_overflowed_p (subcode, type, vr0min, vr1max) != *ovf
	  || arith_overflowed_p (subcode, type, vr0max, vr1min) != *ovf)
	return false;
    }
  if (*ovf)
    {
      /* So far we found that there is an overflow on the boundaries.
	 That doesn't prove that there is an overflow even for all values
	 in between the boundaries.  For that compute widest_int range
	 of the result and see if it doesn't overlap the range of
	 type.  */
      widest_int wmin, wmax;
      widest_int w[4];
      int i;
      signop sign0 = TYPE_SIGN (TREE_TYPE (op0));
      signop sign1 = TYPE_SIGN (TREE_TYPE (op1));
      w[0] = widest_int::from (vr0.lower_bound (), sign0);
      w[1] = widest_int::from (vr0.upper_bound (), sign0);
      w[2] = widest_int::from (vr1.lower_bound (), sign1);
      w[3] = widest_int::from (vr1.upper_bound (), sign1);
      for (i = 0; i < 4; i++)
	{
	  widest_int wt;
	  switch (subcode)
	    {
	    case PLUS_EXPR:
	      wt = wi::add (w[i & 1], w[2 + (i & 2) / 2]);
	      break;
	    case MINUS_EXPR:
	      wt = wi::sub (w[i & 1], w[2 + (i & 2) / 2]);
	      break;
	    case MULT_EXPR:
	      wt = wi::mul (w[i & 1], w[2 + (i & 2) / 2]);
	      break;
	    default:
	      gcc_unreachable ();
	    }
	  if (i == 0)
	    {
	      wmin = wt;
	      wmax = wt;
	    }
	  else
	    {
	      wmin = wi::smin (wmin, wt);
	      wmax = wi::smax (wmax, wt);
	    }
	}
      /* The result of op0 CODE op1 is known to be in range
	 [wmin, wmax].  */
      widest_int wtmin
	= widest_int::from (irange_val_min (type), TYPE_SIGN (type));
      widest_int wtmax
	= widest_int::from (irange_val_max (type), TYPE_SIGN (type));
      /* If all values in [wmin, wmax] are smaller than
	 [wtmin, wtmax] or all are larger than [wtmin, wtmax],
	 the arithmetic operation will always overflow.  */
      if (wmax < wtmin || wmin > wtmax)
	return true;
      return false;
    }
  return true;
}

/* Set INIT, STEP, and DIRECTION the the corresponding values of NAME
   within LOOP, and return TRUE.  Otherwise return FALSE, and set R to
   the conservative range of NAME within the loop.  */

static bool
get_scev_info (vrange &r, tree name, gimple *stmt, class loop *l,
	       tree &init, tree &step, enum ev_direction &dir)
{
  tree ev = analyze_scalar_evolution (l, name);
  tree chrec = instantiate_parameters (l, ev);
  tree type = TREE_TYPE (name);
  if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
    {
      r.set_varying (type);
      return false;
    }
  if (is_gimple_min_invariant (chrec))
    {
      if (is_gimple_constant (chrec))
	r.set (chrec, chrec);
      else
	r.set_varying (type);
      return false;
    }

  init = initial_condition_in_loop_num (chrec, l->num);
  step = evolution_part_in_loop_num (chrec, l->num);
  if (!init || !step)
    {
      r.set_varying (type);
      return false;
    }
  dir = scev_direction (chrec);
  if (dir == EV_DIR_UNKNOWN
      || scev_probably_wraps_p (NULL, init, step, stmt,
				get_chrec_loop (chrec), true))
    {
      r.set_varying (type);
      return false;
    }
  return true;
}

/* Return TRUE if STEP * NIT may overflow when calculated in TYPE.  */

static bool
induction_variable_may_overflow_p (tree type,
				   const wide_int &step, const widest_int &nit)
{
  wi::overflow_type ovf;
  signop sign = TYPE_SIGN (type);
  widest_int max_step = wi::mul (widest_int::from (step, sign),
				 nit, sign, &ovf);

  if (ovf || !wi::fits_to_tree_p (max_step, type))
    return true;

  /* For a signed type we have to check whether the result has the
     expected signedness which is that of the step as number of
     iterations is unsigned.  */
  return (sign == SIGNED
	  && wi::gts_p (max_step, 0) != wi::gts_p (step, 0));
}

/* Set R to the range from BEGIN to END, assuming the direction of the
   loop is DIR.  */

static void
range_from_loop_direction (irange &r, tree type,
			   const irange &begin, const irange &end,
			   ev_direction dir)
{
  signop sign = TYPE_SIGN (type);

  if (begin.undefined_p () || end.undefined_p ())
    r.set_varying (type);
  else if (dir == EV_DIR_GROWS)
    {
      if (wi::gt_p (begin.lower_bound (), end.upper_bound (), sign))
	r.set_varying (type);
      else
	r = int_range<1> (type, begin.lower_bound (), end.upper_bound ());
    }
  else
    {
      if (wi::gt_p (end.lower_bound (), begin.upper_bound (), sign))
	r.set_varying (type);
      else
	r = int_range<1> (type, end.lower_bound (), begin.upper_bound ());
    }
}

/* Set V to the range of NAME in STMT within LOOP.  Return TRUE if a
   range was found.  */

bool
range_of_var_in_loop (vrange &v, tree name, class loop *l, gimple *stmt,
		      range_query *query)
{
  tree init, step;
  enum ev_direction dir;
  if (!get_scev_info (v, name, stmt, l, init, step, dir))
    return true;

  // Calculate ranges for the values from SCEV.
  irange &r = as_a <irange> (v);
  tree type = TREE_TYPE (init);
  int_range<2> rinit (type), rstep (type), max_init (type);
  if (!query->range_of_expr (rinit, init, stmt)
      || !query->range_of_expr (rstep, step, stmt))
    return false;

  // Calculate the final range of NAME if possible.
  if (rinit.singleton_p () && rstep.singleton_p ())
    {
      widest_int nit;
      if (!max_loop_iterations (l, &nit))
	return false;

      if (!induction_variable_may_overflow_p (type, rstep.lower_bound (), nit))
	{
	  // Calculate the max bounds for init (init + niter * step).
	  wide_int w = wide_int::from (nit, TYPE_PRECISION (type), TYPE_SIGN (type));
	  int_range<1> niter (type, w, w);
	  int_range_max max_step;
	  range_op_handler mult_handler (MULT_EXPR, type);
	  range_op_handler plus_handler (PLUS_EXPR, type);
	  if (!mult_handler.fold_range (max_step, type, niter, rstep)
	      || !plus_handler.fold_range (max_init, type, rinit, max_step))
	    return false;
	}
    }
  range_from_loop_direction (r, type, rinit, max_init, dir);
  return true;
}

/* Helper function for vrp_evaluate_conditional_warnv & other
   optimizers.  */

tree
simplify_using_ranges::fold_cond_with_ops (enum tree_code code,
					   tree op0, tree op1, gimple *s)
{
  int_range_max r0, r1;
  if (!query->range_of_expr (r0, op0, s)
      || !query->range_of_expr (r1, op1, s))
    return NULL_TREE;

  tree type = TREE_TYPE (op0);
  int_range<1> res;
  range_op_handler handler (code, type);
  if (handler && handler.fold_range (res, type, r0, r1))
    {
      if (res == range_true (type))
	return boolean_true_node;
      if (res == range_false (type))
	return boolean_false_node;
    }
  return NULL;
}

/* Helper function for legacy_fold_cond.  */

tree
simplify_using_ranges::legacy_fold_cond_overflow (gimple *stmt)
{
  tree ret;
  tree_code code = gimple_cond_code (stmt);
  tree op0 = gimple_cond_lhs (stmt);
  tree op1 = gimple_cond_rhs (stmt);

  /* We only deal with integral and pointer types.  */
  if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
      && !POINTER_TYPE_P (TREE_TYPE (op0)))
    return NULL_TREE;

  /* If OP0 CODE OP1 is an overflow comparison, if it can be expressed
     as a simple equality test, then prefer that over its current form
     for evaluation.

     An overflow test which collapses to an equality test can always be
     expressed as a comparison of one argument against zero.  Overflow
     occurs when the chosen argument is zero and does not occur if the
     chosen argument is not zero.  */
  tree x;
  if (overflow_comparison_p (code, op0, op1, &x))
    {
      wide_int max = wi::max_value (TYPE_PRECISION (TREE_TYPE (op0)), UNSIGNED);
      /* B = A - 1; if (A < B) -> B = A - 1; if (A == 0)
         B = A - 1; if (A > B) -> B = A - 1; if (A != 0)
         B = A + 1; if (B < A) -> B = A + 1; if (B == 0)
         B = A + 1; if (B > A) -> B = A + 1; if (B != 0) */
      if (integer_zerop (x))
	{
	  op1 = x;
	  code = (code == LT_EXPR || code == LE_EXPR) ? EQ_EXPR : NE_EXPR;
	}
      /* B = A + 1; if (A > B) -> B = A + 1; if (B == 0)
         B = A + 1; if (A < B) -> B = A + 1; if (B != 0)
         B = A - 1; if (B > A) -> B = A - 1; if (A == 0)
         B = A - 1; if (B < A) -> B = A - 1; if (A != 0) */
      else if (wi::to_wide (x) == max - 1)
	{
	  op0 = op1;
	  op1 = wide_int_to_tree (TREE_TYPE (op0), 0);
	  code = (code == GT_EXPR || code == GE_EXPR) ? EQ_EXPR : NE_EXPR;
	}
      else
	{
	  value_range vro, vri;
	  tree type = TREE_TYPE (op0);
	  if (code == GT_EXPR || code == GE_EXPR)
	    {
	      vro.set (type,
		       wi::to_wide (TYPE_MIN_VALUE (type)),
		       wi::to_wide (x), VR_ANTI_RANGE);
	      vri.set (type,
		       wi::to_wide (TYPE_MIN_VALUE (type)),
		       wi::to_wide (x));
	    }
	  else if (code == LT_EXPR || code == LE_EXPR)
	    {
	      vro.set (type,
		       wi::to_wide (TYPE_MIN_VALUE (type)),
		       wi::to_wide (x));
	      vri.set (type,
		       wi::to_wide (TYPE_MIN_VALUE (type)),
		       wi::to_wide (x),
		       VR_ANTI_RANGE);
	    }
	  else
	    gcc_unreachable ();
	  value_range vr0;
	  if (!query->range_of_expr (vr0, op0, stmt))
	    vr0.set_varying (TREE_TYPE (op0));
	  /* If vro, the range for OP0 to pass the overflow test, has
	     no intersection with *vr0, OP0's known range, then the
	     overflow test can't pass, so return the node for false.
	     If it is the inverted range, vri, that has no
	     intersection, then the overflow test must pass, so return
	     the node for true.  In other cases, we could proceed with
	     a simplified condition comparing OP0 and X, with LE_EXPR
	     for previously LE_ or LT_EXPR and GT_EXPR otherwise, but
	     the comments next to the enclosing if suggest it's not
	     generally profitable to do so.  */
	  vro.intersect (vr0);
	  if (vro.undefined_p ())
	    return boolean_false_node;
	  vri.intersect (vr0);
	  if (vri.undefined_p ())
	    return boolean_true_node;
	}
    }

  if ((ret = fold_cond_with_ops (code, op0, op1, stmt)))
    return ret;
  return NULL_TREE;
}

/* Visit conditional statement STMT.  If we can determine which edge
   will be taken out of STMT's basic block, record it in
   *TAKEN_EDGE_P.  Otherwise, set *TAKEN_EDGE_P to NULL.  */

void
simplify_using_ranges::legacy_fold_cond (gcond *stmt, edge *taken_edge_p)
{
  tree val;

  *taken_edge_p = NULL;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      tree use;
      ssa_op_iter i;

      fprintf (dump_file, "\nVisiting conditional with predicate: ");
      print_gimple_stmt (dump_file, stmt, 0);
      fprintf (dump_file, "\nWith known ranges\n");

      FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
	{
	  fprintf (dump_file, "\t");
	  print_generic_expr (dump_file, use);
	  fprintf (dump_file, ": ");
	  Value_Range r (TREE_TYPE (use));
	  query->range_of_expr (r, use, stmt);
	  r.dump (dump_file);
	}

      fprintf (dump_file, "\n");
    }

  val = legacy_fold_cond_overflow (stmt);
  if (val)
    *taken_edge_p = find_taken_edge (gimple_bb (stmt), val);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\nPredicate evaluates to: ");
      if (val == NULL_TREE)
	fprintf (dump_file, "DON'T KNOW\n");
      else
	print_generic_stmt (dump_file, val);
    }
}

/* Searches the case label vector VEC for the ranges of CASE_LABELs that are
   used in range VR.  The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
   MAX_IDX2.  If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
   Returns true if the default label is not needed.  */

static bool
find_case_label_ranges (gswitch *stmt, const value_range *vr,
			size_t *min_idx1, size_t *max_idx1,
			size_t *min_idx2, size_t *max_idx2)
{
  size_t i, j, k, l;
  unsigned int n = gimple_switch_num_labels (stmt);
  bool take_default;
  tree case_low, case_high;
  tree min, max;
  value_range_kind kind = get_legacy_range (*vr, min, max);

  gcc_checking_assert (!vr->varying_p () && !vr->undefined_p ());

  take_default = !find_case_label_range (stmt, min, max, &i, &j);

  /* Set second range to empty.  */
  *min_idx2 = 1;
  *max_idx2 = 0;

  if (kind == VR_RANGE)
    {
      *min_idx1 = i;
      *max_idx1 = j;
      return !take_default;
    }

  /* Set first range to all case labels.  */
  *min_idx1 = 1;
  *max_idx1 = n - 1;

  if (i > j)
    return false;

  /* Make sure all the values of case labels [i , j] are contained in
     range [MIN, MAX].  */
  case_low = CASE_LOW (gimple_switch_label (stmt, i));
  case_high = CASE_HIGH (gimple_switch_label (stmt, j));
  if (tree_int_cst_compare (case_low, min) < 0)
    i += 1;
  if (case_high != NULL_TREE
      && tree_int_cst_compare (max, case_high) < 0)
    j -= 1;

  if (i > j)
    return false;

  /* If the range spans case labels [i, j], the corresponding anti-range spans
     the labels [1, i - 1] and [j + 1, n -  1].  */
  k = j + 1;
  l = n - 1;
  if (k > l)
    {
      k = 1;
      l = 0;
    }

  j = i - 1;
  i = 1;
  if (i > j)
    {
      i = k;
      j = l;
      k = 1;
      l = 0;
    }

  *min_idx1 = i;
  *max_idx1 = j;
  *min_idx2 = k;
  *max_idx2 = l;
  return false;
}

/* Simplify boolean operations if the source is known
   to be already a boolean.  */
bool
simplify_using_ranges::simplify_truth_ops_using_ranges
					(gimple_stmt_iterator *gsi,
					 gimple *stmt)
{
  enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
  tree lhs, op0, op1;
  bool need_conversion;

  /* We handle only !=/== case here.  */
  gcc_assert (rhs_code == EQ_EXPR || rhs_code == NE_EXPR);

  op0 = gimple_assign_rhs1 (stmt);
  if (!op_with_boolean_value_range_p (op0, stmt))
    return false;

  op1 = gimple_assign_rhs2 (stmt);
  if (!op_with_boolean_value_range_p (op1, stmt))
    return false;

  /* Reduce number of cases to handle to NE_EXPR.  As there is no
     BIT_XNOR_EXPR we cannot replace A == B with a single statement.  */
  if (rhs_code == EQ_EXPR)
    {
      if (TREE_CODE (op1) == INTEGER_CST)
	op1 = int_const_binop (BIT_XOR_EXPR, op1,
			       build_int_cst (TREE_TYPE (op1), 1));
      else
	return false;
    }

  lhs = gimple_assign_lhs (stmt);
  need_conversion
    = !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0));

  /* Make sure to not sign-extend a 1-bit 1 when converting the result.  */
  if (need_conversion
      && !TYPE_UNSIGNED (TREE_TYPE (op0))
      && TYPE_PRECISION (TREE_TYPE (op0)) == 1
      && TYPE_PRECISION (TREE_TYPE (lhs)) > 1)
    return false;

  /* For A != 0 we can substitute A itself.  */
  if (integer_zerop (op1))
    gimple_assign_set_rhs_with_ops (gsi,
				    need_conversion
				    ? NOP_EXPR : TREE_CODE (op0), op0);
  /* For A != B we substitute A ^ B.  Either with conversion.  */
  else if (need_conversion)
    {
      tree tem = make_ssa_name (TREE_TYPE (op0));
      gassign *newop
	= gimple_build_assign (tem, BIT_XOR_EXPR, op0, op1);
      gsi_insert_before (gsi, newop, GSI_SAME_STMT);
      if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
	  && TYPE_PRECISION (TREE_TYPE (tem)) > 1)
	{
	  value_range vr (TREE_TYPE (tem),
			  wi::zero (TYPE_PRECISION (TREE_TYPE (tem))),
			  wi::one (TYPE_PRECISION (TREE_TYPE (tem))));
	  set_range_info (tem, vr);
	}
      gimple_assign_set_rhs_with_ops (gsi, NOP_EXPR, tem);
    }
  /* Or without.  */
  else
    gimple_assign_set_rhs_with_ops (gsi, BIT_XOR_EXPR, op0, op1);
  update_stmt (gsi_stmt (*gsi));
  fold_stmt (gsi, follow_single_use_edges);

  return true;
}

/* Simplify a division or modulo operator to a right shift or bitwise and
   if the first operand is unsigned or is greater than zero and the second
   operand is an exact power of two.  For TRUNC_MOD_EXPR op0 % op1 with
   constant op1 (op1min = op1) or with op1 in [op1min, op1max] range,
   optimize it into just op0 if op0's range is known to be a subset of
   [-op1min + 1, op1min - 1] for signed and [0, op1min - 1] for unsigned
   modulo.  */

bool
simplify_using_ranges::simplify_div_or_mod_using_ranges
					(gimple_stmt_iterator *gsi,
					 gimple *stmt)
{
  enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
  tree val = NULL;
  tree op0 = gimple_assign_rhs1 (stmt);
  tree op1 = gimple_assign_rhs2 (stmt);
  tree op0min = NULL_TREE, op0max = NULL_TREE;
  tree op1min = op1;
  value_range vr;

  if (TREE_CODE (op0) == INTEGER_CST)
    {
      op0min = op0;
      op0max = op0;
    }
  else
    {
      if (!query->range_of_expr (vr, op0, stmt))
	vr.set_varying (TREE_TYPE (op0));
      if (!vr.varying_p () && !vr.undefined_p ())
	{
	  tree type = vr.type ();
	  op0min = wide_int_to_tree (type, vr.lower_bound ());
	  op0max = wide_int_to_tree (type, vr.upper_bound ());
	}
    }

  if (rhs_code == TRUNC_MOD_EXPR
      && TREE_CODE (op1) == SSA_NAME)
    {
      value_range vr1;
      if (!query->range_of_expr (vr1, op1, stmt))
	vr1.set_varying (TREE_TYPE (op1));
      if (!vr1.varying_p () && !vr1.undefined_p ())
	op1min = wide_int_to_tree (vr1.type (), vr1.lower_bound ());
    }
  if (rhs_code == TRUNC_MOD_EXPR
      && TREE_CODE (op1min) == INTEGER_CST
      && tree_int_cst_sgn (op1min) == 1
      && op0max
      && tree_int_cst_lt (op0max, op1min))
    {
      if (TYPE_UNSIGNED (TREE_TYPE (op0))
	  || tree_int_cst_sgn (op0min) >= 0
	  || tree_int_cst_lt (fold_unary (NEGATE_EXPR, TREE_TYPE (op1min), op1min),
			      op0min))
	{
	  /* If op0 already has the range op0 % op1 has,
	     then TRUNC_MOD_EXPR won't change anything.  */
	  gimple_assign_set_rhs_from_tree (gsi, op0);
	  return true;
	}
    }

  if (TREE_CODE (op0) != SSA_NAME)
    return false;

  if (!integer_pow2p (op1))
    {
      /* X % -Y can be only optimized into X % Y either if
	 X is not INT_MIN, or Y is not -1.  Fold it now, as after
	 remove_range_assertions the range info might be not available
	 anymore.  */
      if (rhs_code == TRUNC_MOD_EXPR
	  && fold_stmt (gsi, follow_single_use_edges))
	return true;
      return false;
    }

  if (TYPE_UNSIGNED (TREE_TYPE (op0)))
    val = integer_one_node;
  else
    {
      tree zero = build_zero_cst (TREE_TYPE (op0));
      val = fold_cond_with_ops (GE_EXPR, op0, zero, stmt);
    }

  if (val && integer_onep (val))
    {
      tree t;

      if (rhs_code == TRUNC_DIV_EXPR)
	{
	  t = build_int_cst (integer_type_node, tree_log2 (op1));
	  gimple_assign_set_rhs_code (stmt, RSHIFT_EXPR);
	  gimple_assign_set_rhs1 (stmt, op0);
	  gimple_assign_set_rhs2 (stmt, t);
	}
      else
	{
	  t = build_int_cst (TREE_TYPE (op1), 1);
	  t = int_const_binop (MINUS_EXPR, op1, t);
	  t = fold_convert (TREE_TYPE (op0), t);

	  gimple_assign_set_rhs_code (stmt, BIT_AND_EXPR);
	  gimple_assign_set_rhs1 (stmt, op0);
	  gimple_assign_set_rhs2 (stmt, t);
	}

      update_stmt (stmt);
      fold_stmt (gsi, follow_single_use_edges);
      return true;
    }

  return false;
}

/* Simplify a min or max if the ranges of the two operands are
   disjoint.   Return true if we do simplify.  */

bool
simplify_using_ranges::simplify_min_or_max_using_ranges
				(gimple_stmt_iterator *gsi,
				 gimple *stmt)
{
  tree op0 = gimple_assign_rhs1 (stmt);
  tree op1 = gimple_assign_rhs2 (stmt);
  tree val;

  val = fold_cond_with_ops (LE_EXPR, op0, op1, stmt);
  if (!val)
    val = fold_cond_with_ops (LT_EXPR, op0, op1, stmt);

  if (val)
    {
      /* VAL == TRUE -> OP0 < or <= op1
	 VAL == FALSE -> OP0 > or >= op1.  */
      tree res = ((gimple_assign_rhs_code (stmt) == MAX_EXPR)
		  == integer_zerop (val)) ? op0 : op1;
      gimple_assign_set_rhs_from_tree (gsi, res);
      return true;
    }

  return false;
}

/* If the operand to an ABS_EXPR is >= 0, then eliminate the
   ABS_EXPR.  If the operand is <= 0, then simplify the
   ABS_EXPR into a NEGATE_EXPR.  */

bool
simplify_using_ranges::simplify_abs_using_ranges (gimple_stmt_iterator *gsi,
						  gimple *stmt)
{
  tree op = gimple_assign_rhs1 (stmt);
  tree zero = build_zero_cst (TREE_TYPE (op));
  tree val = fold_cond_with_ops (LE_EXPR, op, zero, stmt);

  if (!val)
    {
      /* The range is neither <= 0 nor > 0.  Now see if it is
	 either < 0 or >= 0.  */
      val = fold_cond_with_ops (LT_EXPR, op, zero, stmt);
    }
  if (val)
    {
      gimple_assign_set_rhs1 (stmt, op);
      if (integer_zerop (val))
	gimple_assign_set_rhs_code (stmt, SSA_NAME);
      else
	gimple_assign_set_rhs_code (stmt, NEGATE_EXPR);
      update_stmt (stmt);
      fold_stmt (gsi, follow_single_use_edges);
      return true;
    }
  return false;
}

/* value_range wrapper for wi_set_zero_nonzero_bits.

   Return TRUE if VR was a constant range and we were able to compute
   the bit masks.  */

static bool
vr_set_zero_nonzero_bits (const tree expr_type,
			  const irange *vr,
			  wide_int *may_be_nonzero,
			  wide_int *must_be_nonzero)
{
  if (vr->varying_p () || vr->undefined_p ())
    {
      *may_be_nonzero = wi::minus_one (TYPE_PRECISION (expr_type));
      *must_be_nonzero = wi::zero (TYPE_PRECISION (expr_type));
      return false;
    }
  wi_set_zero_nonzero_bits (expr_type, vr->lower_bound (), vr->upper_bound (),
			    *may_be_nonzero, *must_be_nonzero);
  return true;
}

/* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
   If all the bits that are being cleared by & are already
   known to be zero from VR, or all the bits that are being
   set by | are already known to be one from VR, the bit
   operation is redundant.  */

bool
simplify_using_ranges::simplify_bit_ops_using_ranges
				(gimple_stmt_iterator *gsi,
				 gimple *stmt)
{
  tree op0 = gimple_assign_rhs1 (stmt);
  tree op1 = gimple_assign_rhs2 (stmt);
  tree op = NULL_TREE;
  value_range vr0, vr1;
  wide_int may_be_nonzero0, may_be_nonzero1;
  wide_int must_be_nonzero0, must_be_nonzero1;
  wide_int mask;

  if (!query->range_of_expr (vr0, op0, stmt)
      || vr0.undefined_p ())
    return false;
  if (!query->range_of_expr (vr1, op1, stmt)
      || vr1.undefined_p ())
    return false;

  if (!vr_set_zero_nonzero_bits (TREE_TYPE (op0), &vr0, &may_be_nonzero0,
				 &must_be_nonzero0))
    return false;
  if (!vr_set_zero_nonzero_bits (TREE_TYPE (op1), &vr1, &may_be_nonzero1,
				 &must_be_nonzero1))
    return false;

  switch (gimple_assign_rhs_code (stmt))
    {
    case BIT_AND_EXPR:
      mask = wi::bit_and_not (may_be_nonzero0, must_be_nonzero1);
      if (mask == 0)
	{
	  op = op0;
	  break;
	}
      mask = wi::bit_and_not (may_be_nonzero1, must_be_nonzero0);
      if (mask == 0)
	{
	  op = op1;
	  break;
	}
      break;
    case BIT_IOR_EXPR:
      mask = wi::bit_and_not (may_be_nonzero0, must_be_nonzero1);
      if (mask == 0)
	{
	  op = op1;
	  break;
	}
      mask = wi::bit_and_not (may_be_nonzero1, must_be_nonzero0);
      if (mask == 0)
	{
	  op = op0;
	  break;
	}
      break;
    default:
      gcc_unreachable ();
    }

  if (op == NULL_TREE)
    return false;

  gimple_assign_set_rhs_with_ops (gsi, TREE_CODE (op), op);
  update_stmt (gsi_stmt (*gsi));
  return true;
}

/* We are comparing trees OP0 and OP1 using COND_CODE.  OP0 has
   a known value range VR.

   If there is one and only one value which will satisfy the
   conditional, then return that value.  Else return NULL.

   If signed overflow must be undefined for the value to satisfy
   the conditional, then set *STRICT_OVERFLOW_P to true.  */

static tree
test_for_singularity (enum tree_code cond_code, tree op0,
		      tree op1, const value_range *vr)
{
  tree min = NULL;
  tree max = NULL;

  /* Extract minimum/maximum values which satisfy the conditional as it was
     written.  */
  if (cond_code == LE_EXPR || cond_code == LT_EXPR)
    {
      min = TYPE_MIN_VALUE (TREE_TYPE (op0));

      max = op1;
      if (cond_code == LT_EXPR)
	{
	  tree one = build_int_cst (TREE_TYPE (op0), 1);
	  max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
	  /* Signal to compare_values_warnv this expr doesn't overflow.  */
	  if (EXPR_P (max))
	    suppress_warning (max, OPT_Woverflow);
	}
    }
  else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
    {
      max = TYPE_MAX_VALUE (TREE_TYPE (op0));

      min = op1;
      if (cond_code == GT_EXPR)
	{
	  tree one = build_int_cst (TREE_TYPE (op0), 1);
	  min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
	  /* Signal to compare_values_warnv this expr doesn't overflow.  */
	  if (EXPR_P (min))
	    suppress_warning (min, OPT_Woverflow);
	}
    }

  /* Now refine the minimum and maximum values using any
     value range information we have for op0.  */
  if (min && max)
    {
      tree type = TREE_TYPE (op0);
      tree tmin = wide_int_to_tree (type, vr->lower_bound ());
      tree tmax = wide_int_to_tree (type, vr->upper_bound ());
      if (compare_values (tmin, min) == 1)
	min = tmin;
      if (compare_values (tmax, max) == -1)
	max = tmax;

      /* If the new min/max values have converged to a single value,
	 then there is only one value which can satisfy the condition,
	 return that value.  */
      if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
	return min;
    }
  return NULL;
}

/* Return whether the value range *VR fits in an integer type specified
   by PRECISION and UNSIGNED_P.  */

bool
range_fits_type_p (const irange *vr,
		   unsigned dest_precision, signop dest_sgn)
{
  tree src_type;
  unsigned src_precision;
  widest_int tem;
  signop src_sgn;

  /* We can only handle integral and pointer types.  */
  src_type = vr->type ();
  if (!INTEGRAL_TYPE_P (src_type)
      && !POINTER_TYPE_P (src_type))
    return false;

  /* An extension is fine unless VR is SIGNED and dest_sgn is UNSIGNED,
     and so is an identity transform.  */
  src_precision = TYPE_PRECISION (vr->type ());
  src_sgn = TYPE_SIGN (src_type);
  if ((src_precision < dest_precision
       && !(dest_sgn == UNSIGNED && src_sgn == SIGNED))
      || (src_precision == dest_precision && src_sgn == dest_sgn))
    return true;

  /* Now we can only handle ranges with constant bounds.  */
  if (vr->undefined_p () || vr->varying_p ())
    return false;

  wide_int vrmin = vr->lower_bound ();
  wide_int vrmax = vr->upper_bound ();

  /* For sign changes, the MSB of the wide_int has to be clear.
     An unsigned value with its MSB set cannot be represented by
     a signed wide_int, while a negative value cannot be represented
     by an unsigned wide_int.  */
  if (src_sgn != dest_sgn
      && (wi::lts_p (vrmin, 0) || wi::lts_p (vrmax, 0)))
    return false;

  /* Then we can perform the conversion on both ends and compare
     the result for equality.  */
  signop sign = TYPE_SIGN (vr->type ());
  tem = wi::ext (widest_int::from (vrmin, sign), dest_precision, dest_sgn);
  if (tem != widest_int::from (vrmin, sign))
    return false;
  tem = wi::ext (widest_int::from (vrmax, sign), dest_precision, dest_sgn);
  if (tem != widest_int::from (vrmax, sign))
    return false;

  return true;
}

// Clear edge E of EDGE_EXECUTABLE (it is unexecutable). If it wasn't
// previously clear, propagate to successor blocks if appropriate.

void
simplify_using_ranges::set_and_propagate_unexecutable (edge e)
{
  // If not_executable is already set, we're done.
  // This works in the absence of a flag as well.
  if ((e->flags & m_not_executable_flag) == m_not_executable_flag)
    return;

  e->flags |= m_not_executable_flag;
  m_flag_set_edges.safe_push (e);

  // Check if the destination block needs to propagate the property.
  basic_block bb = e->dest;

  // If any incoming edge is executable, we are done.
  edge_iterator ei;
  FOR_EACH_EDGE (e, ei, bb->preds)
    if ((e->flags & m_not_executable_flag) == 0)
      return;

  // This block is also unexecutable, propagate to all exit edges as well.
  FOR_EACH_EDGE (e, ei, bb->succs)
    set_and_propagate_unexecutable (e);
}

/* If COND can be folded entirely as TRUE or FALSE, rewrite the
   conditional as such, and return TRUE.  */

bool
simplify_using_ranges::fold_cond (gcond *cond)
{
  int_range_max r;
  if (query->range_of_stmt (r, cond) && r.singleton_p ())
    {
      // COND has already been folded if arguments are constant.
      if (TREE_CODE (gimple_cond_lhs (cond)) != SSA_NAME
	  && TREE_CODE (gimple_cond_rhs (cond)) != SSA_NAME)
	return false;
      if (dump_file)
	{
	  fprintf (dump_file, "Folding predicate ");
	  print_gimple_expr (dump_file, cond, 0);
	  fprintf (dump_file, " to ");
	}
      edge e0 = EDGE_SUCC (gimple_bb (cond), 0);
      edge e1 = EDGE_SUCC (gimple_bb (cond), 1);
      if (r.zero_p ())
	{
	  if (dump_file)
	    fprintf (dump_file, "0\n");
	  gimple_cond_make_false (cond);
	  if (e0->flags & EDGE_TRUE_VALUE)
	    set_and_propagate_unexecutable (e0);
	  else
	    set_and_propagate_unexecutable (e1);
	}
      else
	{
	  if (dump_file)
	    fprintf (dump_file, "1\n");
	  gimple_cond_make_true (cond);
	  if (e0->flags & EDGE_FALSE_VALUE)
	    set_and_propagate_unexecutable (e0);
	  else
	    set_and_propagate_unexecutable (e1);
	}
      update_stmt (cond);
      return true;
    }

  // FIXME: Audit the code below and make sure it never finds anything.
  edge taken_edge;
  legacy_fold_cond (cond, &taken_edge);

  if (taken_edge)
    {
      if (taken_edge->flags & EDGE_TRUE_VALUE)
	{
	  if (dump_file && (dump_flags & TDF_DETAILS))
	    fprintf (dump_file, "\nVRP Predicate evaluates to: 1\n");
	  gimple_cond_make_true (cond);
	}
      else if (taken_edge->flags & EDGE_FALSE_VALUE)
	{
	  if (dump_file && (dump_flags & TDF_DETAILS))
	    fprintf (dump_file, "\nVRP Predicate evaluates to: 0\n");
	  gimple_cond_make_false (cond);
	}
      else
       gcc_unreachable ();
      update_stmt (cond);
      return true;
    }
  return false;
}

/* Simplify a conditional using a relational operator to an equality
   test if the range information indicates only one value can satisfy
   the original conditional.  */

bool
simplify_using_ranges::simplify_cond_using_ranges_1 (gcond *stmt)
{
  tree op0 = gimple_cond_lhs (stmt);
  tree op1 = gimple_cond_rhs (stmt);
  enum tree_code cond_code = gimple_cond_code (stmt);

  if (fold_cond (stmt))
    return true;

  if (cond_code != NE_EXPR
      && cond_code != EQ_EXPR
      && TREE_CODE (op0) == SSA_NAME
      && INTEGRAL_TYPE_P (TREE_TYPE (op0))
      && is_gimple_min_invariant (op1))
    {
      value_range vr;

      if (!query->range_of_expr (vr, op0, stmt))
	vr.set_undefined ();

      /* If we have range information for OP0, then we might be
	 able to simplify this conditional. */
      if (!vr.undefined_p () && !vr.varying_p ())
	{
	  tree new_tree = test_for_singularity (cond_code, op0, op1, &vr);
	  if (new_tree)
	    {
	      if (dump_file)
		{
		  fprintf (dump_file, "Simplified relational ");
		  print_gimple_stmt (dump_file, stmt, 0);
		  fprintf (dump_file, " into ");
		}

	      gimple_cond_set_code (stmt, EQ_EXPR);
	      gimple_cond_set_lhs (stmt, op0);
	      gimple_cond_set_rhs (stmt, new_tree);

	      update_stmt (stmt);

	      if (dump_file)
		{
		  print_gimple_stmt (dump_file, stmt, 0);
		  fprintf (dump_file, "\n");
		}

	      return true;
	    }

	  /* Try again after inverting the condition.  We only deal
	     with integral types here, so no need to worry about
	     issues with inverting FP comparisons.  */
	  new_tree = test_for_singularity
		       (invert_tree_comparison (cond_code, false),
			op0, op1, &vr);
	  if (new_tree)
	    {
	      if (dump_file)
		{
		  fprintf (dump_file, "Simplified relational ");
		  print_gimple_stmt (dump_file, stmt, 0);
		  fprintf (dump_file, " into ");
		}

	      gimple_cond_set_code (stmt, NE_EXPR);
	      gimple_cond_set_lhs (stmt, op0);
	      gimple_cond_set_rhs (stmt, new_tree);

	      update_stmt (stmt);

	      if (dump_file)
		{
		  print_gimple_stmt (dump_file, stmt, 0);
		  fprintf (dump_file, "\n");
		}

	      return true;
	    }
	}
    }
  // Try to simplify casted conditions.
  return simplify_casted_cond (stmt);
}

/* STMT is a conditional at the end of a basic block.

   If the conditional is of the form SSA_NAME op constant and the SSA_NAME
   was set via a type conversion, try to replace the SSA_NAME with the RHS
   of the type conversion.  Doing so makes the conversion dead which helps
   subsequent passes.  */

bool
simplify_using_ranges::simplify_casted_cond (gcond *stmt)
{
  tree op0 = gimple_cond_lhs (stmt);
  tree op1 = gimple_cond_rhs (stmt);

  /* If we have a comparison of an SSA_NAME (OP0) against a constant,
     see if OP0 was set by a type conversion where the source of
     the conversion is another SSA_NAME with a range that fits
     into the range of OP0's type.

     If so, the conversion is redundant as the earlier SSA_NAME can be
     used for the comparison directly if we just massage the constant in the
     comparison.  */
  if (TREE_CODE (op0) == SSA_NAME
      && TREE_CODE (op1) == INTEGER_CST)
    {
      gimple *def_stmt = SSA_NAME_DEF_STMT (op0);
      tree innerop;

      if (!is_gimple_assign (def_stmt))
	return false;

      switch (gimple_assign_rhs_code (def_stmt))
	{
	CASE_CONVERT:
	  innerop = gimple_assign_rhs1 (def_stmt);
	  break;
	case VIEW_CONVERT_EXPR:
	  innerop = TREE_OPERAND (gimple_assign_rhs1 (def_stmt), 0);
	  if (!INTEGRAL_TYPE_P (TREE_TYPE (innerop)))
	    return false;
	  break;
	default:
	  return false;
	}

      if (TREE_CODE (innerop) == SSA_NAME
	  && !POINTER_TYPE_P (TREE_TYPE (innerop))
	  && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop)
	  && desired_pro_or_demotion_p (TREE_TYPE (innerop), TREE_TYPE (op0)))
	{
	  value_range vr;

	  if (query->range_of_expr (vr, innerop)
	      && !vr.varying_p ()
	      && !vr.undefined_p ()
	      && range_fits_type_p (&vr,
				    TYPE_PRECISION (TREE_TYPE (op0)),
				    TYPE_SIGN (TREE_TYPE (op0)))
	      && int_fits_type_p (op1, TREE_TYPE (innerop)))
	    {
	      tree newconst = fold_convert (TREE_TYPE (innerop), op1);
	      gimple_cond_set_lhs (stmt, innerop);
	      gimple_cond_set_rhs (stmt, newconst);
	      update_stmt (stmt);
	      return true;
	    }
	}
    }
  return false;
}

/* Simplify a switch statement using the value range of the switch
   argument.  */

bool
simplify_using_ranges::simplify_switch_using_ranges (gswitch *stmt)
{
  tree op = gimple_switch_index (stmt);
  value_range vr;
  bool take_default;
  edge e;
  edge_iterator ei;
  size_t i = 0, j = 0, n, n2;
  tree vec2;
  switch_update su;
  size_t k = 1, l = 0;

  if (TREE_CODE (op) == SSA_NAME)
    {
      if (!query->range_of_expr (vr, op, stmt)
	  || vr.varying_p () || vr.undefined_p ())
	return false;

      /* Find case label for min/max of the value range.  */
      take_default = !find_case_label_ranges (stmt, &vr, &i, &j, &k, &l);
    }
  else if (TREE_CODE (op) == INTEGER_CST)
    {
      take_default = !find_case_label_index (stmt, 1, op, &i);
      if (take_default)
	{
	  i = 1;
	  j = 0;
	}
      else
	{
	  j = i;
	}
    }
  else
    return false;

  n = gimple_switch_num_labels (stmt);

  /* We can truncate the case label ranges that partially overlap with OP's
     value range.  */
  size_t min_idx = 1, max_idx = 0;
  tree min, max;
  value_range_kind kind = get_legacy_range (vr, min, max);
  if (!vr.undefined_p ())
    find_case_label_range (stmt, min, max, &min_idx, &max_idx);
  if (min_idx <= max_idx)
    {
      tree min_label = gimple_switch_label (stmt, min_idx);
      tree max_label = gimple_switch_label (stmt, max_idx);

      /* Avoid changing the type of the case labels when truncating.  */
      tree case_label_type = TREE_TYPE (CASE_LOW (min_label));
      tree vr_min = fold_convert (case_label_type, min);
      tree vr_max = fold_convert (case_label_type, max);

      if (kind == VR_RANGE)
	{
	  /* If OP's value range is [2,8] and the low label range is
	     0 ... 3, truncate the label's range to 2 .. 3.  */
	  if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
	      && CASE_HIGH (min_label) != NULL_TREE
	      && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
	    CASE_LOW (min_label) = vr_min;

	  /* If OP's value range is [2,8] and the high label range is
	     7 ... 10, truncate the label's range to 7 .. 8.  */
	  if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
	      && CASE_HIGH (max_label) != NULL_TREE
	      && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
	    CASE_HIGH (max_label) = vr_max;
	}
      else if (kind == VR_ANTI_RANGE)
	{
	  tree one_cst = build_one_cst (case_label_type);

	  if (min_label == max_label)
	    {
	      /* If OP's value range is ~[7,8] and the label's range is
		 7 ... 10, truncate the label's range to 9 ... 10.  */
	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) == 0
		  && CASE_HIGH (min_label) != NULL_TREE
		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) > 0)
		CASE_LOW (min_label)
		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);

	      /* If OP's value range is ~[7,8] and the label's range is
		 5 ... 8, truncate the label's range to 5 ... 6.  */
	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
		  && CASE_HIGH (min_label) != NULL_TREE
		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) == 0)
		CASE_HIGH (min_label)
		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);
	    }
	  else
	    {
	      /* If OP's value range is ~[2,8] and the low label range is
		 0 ... 3, truncate the label's range to 0 ... 1.  */
	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
		  && CASE_HIGH (min_label) != NULL_TREE
		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
		CASE_HIGH (min_label)
		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);

	      /* If OP's value range is ~[2,8] and the high label range is
		 7 ... 10, truncate the label's range to 9 ... 10.  */
	      if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
		  && CASE_HIGH (max_label) != NULL_TREE
		  && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
		CASE_LOW (max_label)
		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);
	    }
	}

      /* Canonicalize singleton case ranges.  */
      if (tree_int_cst_equal (CASE_LOW (min_label), CASE_HIGH (min_label)))
	CASE_HIGH (min_label) = NULL_TREE;
      if (tree_int_cst_equal (CASE_LOW (max_label), CASE_HIGH (max_label)))
	CASE_HIGH (max_label) = NULL_TREE;
    }

  /* We can also eliminate case labels that lie completely outside OP's value
     range.  */

  /* Bail out if this is just all edges taken.  */
  if (i == 1
      && j == n - 1
      && take_default)
    return false;

  /* Build a new vector of taken case labels.  */
  vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default);
  n2 = 0;

  /* Add the default edge, if necessary.  */
  if (take_default)
    TREE_VEC_ELT (vec2, n2++) = gimple_switch_default_label (stmt);

  for (; i <= j; ++i, ++n2)
    TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i);

  for (; k <= l; ++k, ++n2)
    TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k);

  /* Mark needed edges.  */
  for (i = 0; i < n2; ++i)
    {
      e = find_edge (gimple_bb (stmt),
		     label_to_block (cfun,
				     CASE_LABEL (TREE_VEC_ELT (vec2, i))));
      e->aux = (void *)-1;
    }

  /* Queue not needed edges for later removal.  */
  FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
    {
      if (e->aux == (void *)-1)
	{
	  e->aux = NULL;
	  continue;
	}

      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "removing unreachable case label\n");
	}
      to_remove_edges.safe_push (e);
      set_and_propagate_unexecutable (e);
      e->flags &= ~EDGE_EXECUTABLE;
      e->flags |= EDGE_IGNORE;
    }

  /* And queue an update for the stmt.  */
  su.stmt = stmt;
  su.vec = vec2;
  to_update_switch_stmts.safe_push (su);
  return true;
}

void
simplify_using_ranges::cleanup_edges_and_switches (void)
{
  int i;
  edge e;
  switch_update *su;

  /* Clear any edges marked as not executable.  */
  if (m_not_executable_flag)
    {
      FOR_EACH_VEC_ELT (m_flag_set_edges, i, e)
	e->flags &= ~m_not_executable_flag;
    }
  /* Remove dead edges from SWITCH_EXPR optimization.  This leaves the
     CFG in a broken state and requires a cfg_cleanup run.  */
  FOR_EACH_VEC_ELT (to_remove_edges, i, e)
    remove_edge (e);

  /* Update SWITCH_EXPR case label vector.  */
  FOR_EACH_VEC_ELT (to_update_switch_stmts, i, su)
    {
      size_t j;
      size_t n = TREE_VEC_LENGTH (su->vec);
      tree label;
      gimple_switch_set_num_labels (su->stmt, n);
      for (j = 0; j < n; j++)
	gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j));
      /* As we may have replaced the default label with a regular one
	 make sure to make it a real default label again.  This ensures
	 optimal expansion.  */
      label = gimple_switch_label (su->stmt, 0);
      CASE_LOW (label) = NULL_TREE;
      CASE_HIGH (label) = NULL_TREE;
    }

  if (!to_remove_edges.is_empty ())
    {
      free_dominance_info (CDI_DOMINATORS);
      loops_state_set (LOOPS_NEED_FIXUP);
    }

  to_remove_edges.release ();
  to_update_switch_stmts.release ();
}

/* Simplify an integral conversion from an SSA name in STMT.  */

static bool
simplify_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple *stmt)
{
  tree innerop, middleop, finaltype;
  gimple *def_stmt;
  signop inner_sgn, middle_sgn, final_sgn;
  unsigned inner_prec, middle_prec, final_prec;
  widest_int innermin, innermed, innermax, middlemin, middlemed, middlemax;

  finaltype = TREE_TYPE (gimple_assign_lhs (stmt));
  if (!INTEGRAL_TYPE_P (finaltype))
    return false;
  middleop = gimple_assign_rhs1 (stmt);
  def_stmt = SSA_NAME_DEF_STMT (middleop);
  if (!is_gimple_assign (def_stmt)
      || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
    return false;
  innerop = gimple_assign_rhs1 (def_stmt);
  if (TREE_CODE (innerop) != SSA_NAME
      || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop))
    return false;

  /* Get the value-range of the inner operand.  Use global ranges in
     case innerop was created during substitute-and-fold.  */
  wide_int imin, imax;
  value_range vr;
  if (!INTEGRAL_TYPE_P (TREE_TYPE (innerop)))
    return false;
  get_range_query (cfun)->range_of_expr (vr, innerop, stmt);
  if (vr.undefined_p () || vr.varying_p ())
    return false;
  innermin = widest_int::from (vr.lower_bound (), TYPE_SIGN (TREE_TYPE (innerop)));
  innermax = widest_int::from (vr.upper_bound (), TYPE_SIGN (TREE_TYPE (innerop)));

  /* Simulate the conversion chain to check if the result is equal if
     the middle conversion is removed.  */
  inner_prec = TYPE_PRECISION (TREE_TYPE (innerop));
  middle_prec = TYPE_PRECISION (TREE_TYPE (middleop));
  final_prec = TYPE_PRECISION (finaltype);

  /* If the first conversion is not injective, the second must not
     be widening.  */
  if (wi::gtu_p (innermax - innermin,
		 wi::mask <widest_int> (middle_prec, false))
      && middle_prec < final_prec)
    return false;
  /* We also want a medium value so that we can track the effect that
     narrowing conversions with sign change have.  */
  inner_sgn = TYPE_SIGN (TREE_TYPE (innerop));
  if (inner_sgn == UNSIGNED)
    innermed = wi::shifted_mask <widest_int> (1, inner_prec - 1, false);
  else
    innermed = 0;
  if (wi::cmp (innermin, innermed, inner_sgn) >= 0
      || wi::cmp (innermed, innermax, inner_sgn) >= 0)
    innermed = innermin;

  middle_sgn = TYPE_SIGN (TREE_TYPE (middleop));
  middlemin = wi::ext (innermin, middle_prec, middle_sgn);
  middlemed = wi::ext (innermed, middle_prec, middle_sgn);
  middlemax = wi::ext (innermax, middle_prec, middle_sgn);

  /* Require that the final conversion applied to both the original
     and the intermediate range produces the same result.  */
  final_sgn = TYPE_SIGN (finaltype);
  if (wi::ext (middlemin, final_prec, final_sgn)
	 != wi::ext (innermin, final_prec, final_sgn)
      || wi::ext (middlemed, final_prec, final_sgn)
	 != wi::ext (innermed, final_prec, final_sgn)
      || wi::ext (middlemax, final_prec, final_sgn)
	 != wi::ext (innermax, final_prec, final_sgn))
    return false;

  gimple_assign_set_rhs1 (stmt, innerop);
  fold_stmt (gsi, follow_single_use_edges);
  return true;
}

/* Simplify a conversion from integral SSA name to float in STMT.  */

bool
simplify_using_ranges::simplify_float_conversion_using_ranges
					(gimple_stmt_iterator *gsi,
					 gimple *stmt)
{
  tree rhs1 = gimple_assign_rhs1 (stmt);
  value_range vr;
  scalar_float_mode fltmode
    = SCALAR_FLOAT_TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt)));
  scalar_int_mode mode;
  tree tem;
  gassign *conv;

  /* We can only handle constant ranges.  */
  if (!query->range_of_expr (vr, rhs1, stmt)
      || vr.varying_p ()
      || vr.undefined_p ())
    return false;

  /* First check if we can use a signed type in place of an unsigned.  */
  scalar_int_mode rhs_mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (rhs1));
  if (TYPE_UNSIGNED (TREE_TYPE (rhs1))
      && can_float_p (fltmode, rhs_mode, 0) != CODE_FOR_nothing
      && range_fits_type_p (&vr, TYPE_PRECISION (TREE_TYPE (rhs1)), SIGNED))
    mode = rhs_mode;
  /* If we can do the conversion in the current input mode do nothing.  */
  else if (can_float_p (fltmode, rhs_mode,
			TYPE_UNSIGNED (TREE_TYPE (rhs1))) != CODE_FOR_nothing)
    return false;
  /* Otherwise search for a mode we can use, starting from the narrowest
     integer mode available.  */
  else
    {
      mode = NARROWEST_INT_MODE;
      for (;;)
	{
	  /* If we cannot do a signed conversion to float from mode
	     or if the value-range does not fit in the signed type
	     try with a wider mode.  */
	  if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing
	      && range_fits_type_p (&vr, GET_MODE_PRECISION (mode), SIGNED))
	    break;

	  /* But do not widen the input.  Instead leave that to the
	     optabs expansion code.  */
	  if (!GET_MODE_WIDER_MODE (mode).exists (&mode)
	      || GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1)))
	    return false;
	}
    }

  /* It works, insert a truncation or sign-change before the
     float conversion.  */
  tem = make_ssa_name (build_nonstandard_integer_type
			  (GET_MODE_PRECISION (mode), 0));
  conv = gimple_build_assign (tem, NOP_EXPR, rhs1);
  gsi_insert_before (gsi, conv, GSI_SAME_STMT);
  gimple_assign_set_rhs1 (stmt, tem);
  fold_stmt (gsi, follow_single_use_edges);

  return true;
}

/* Simplify an internal fn call using ranges if possible.  */

bool
simplify_using_ranges::simplify_internal_call_using_ranges
					(gimple_stmt_iterator *gsi,
					 gimple *stmt)
{
  enum tree_code subcode;
  bool is_ubsan = false;
  bool ovf = false;
  switch (gimple_call_internal_fn (stmt))
    {
    case IFN_UBSAN_CHECK_ADD:
      subcode = PLUS_EXPR;
      is_ubsan = true;
      break;
    case IFN_UBSAN_CHECK_SUB:
      subcode = MINUS_EXPR;
      is_ubsan = true;
      break;
    case IFN_UBSAN_CHECK_MUL:
      subcode = MULT_EXPR;
      is_ubsan = true;
      break;
    case IFN_ADD_OVERFLOW:
      subcode = PLUS_EXPR;
      break;
    case IFN_SUB_OVERFLOW:
      subcode = MINUS_EXPR;
      break;
    case IFN_MUL_OVERFLOW:
      subcode = MULT_EXPR;
      break;
    default:
      return false;
    }

  tree op0 = gimple_call_arg (stmt, 0);
  tree op1 = gimple_call_arg (stmt, 1);
  tree type;
  if (is_ubsan)
    {
      type = TREE_TYPE (op0);
      if (VECTOR_TYPE_P (type))
	return false;
    }
  else if (gimple_call_lhs (stmt) == NULL_TREE)
    return false;
  else
    type = TREE_TYPE (TREE_TYPE (gimple_call_lhs (stmt)));
  if (!check_for_binary_op_overflow (query, subcode, type, op0, op1, &ovf, stmt)
      || (is_ubsan && ovf))
    return false;

  gimple *g;
  location_t loc = gimple_location (stmt);
  if (is_ubsan)
    g = gimple_build_assign (gimple_call_lhs (stmt), subcode, op0, op1);
  else
    {
      int prec = TYPE_PRECISION (type);
      tree utype = type;
      if (ovf
	  || !useless_type_conversion_p (type, TREE_TYPE (op0))
	  || !useless_type_conversion_p (type, TREE_TYPE (op1)))
	utype = build_nonstandard_integer_type (prec, 1);
      if (TREE_CODE (op0) == INTEGER_CST)
	op0 = fold_convert (utype, op0);
      else if (!useless_type_conversion_p (utype, TREE_TYPE (op0)))
	{
	  g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op0);
	  gimple_set_location (g, loc);
	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
	  op0 = gimple_assign_lhs (g);
	}
      if (TREE_CODE (op1) == INTEGER_CST)
	op1 = fold_convert (utype, op1);
      else if (!useless_type_conversion_p (utype, TREE_TYPE (op1)))
	{
	  g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op1);
	  gimple_set_location (g, loc);
	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
	  op1 = gimple_assign_lhs (g);
	}
      g = gimple_build_assign (make_ssa_name (utype), subcode, op0, op1);
      gimple_set_location (g, loc);
      gsi_insert_before (gsi, g, GSI_SAME_STMT);
      if (utype != type)
	{
	  g = gimple_build_assign (make_ssa_name (type), NOP_EXPR,
				   gimple_assign_lhs (g));
	  gimple_set_location (g, loc);
	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
	}
      g = gimple_build_assign (gimple_call_lhs (stmt), COMPLEX_EXPR,
			       gimple_assign_lhs (g),
			       build_int_cst (type, ovf));
    }
  gimple_set_location (g, loc);
  gsi_replace (gsi, g, false);
  return true;
}

/* Return true if VAR is a two-valued variable.  Set a and b with the
   two-values when it is true.  Return false otherwise.  */

bool
simplify_using_ranges::two_valued_val_range_p (tree var, tree *a, tree *b,
					       gimple *s)
{
  value_range vr;
  if (!query->range_of_expr (vr, var, s))
    return false;
  if (vr.varying_p () || vr.undefined_p ())
    return false;

  if ((vr.num_pairs () == 1 && vr.upper_bound () - vr.lower_bound () == 1)
      || (vr.num_pairs () == 2
	  && vr.lower_bound (0) == vr.upper_bound (0)
	  && vr.lower_bound (1) == vr.upper_bound (1)))
    {
      *a = wide_int_to_tree (TREE_TYPE (var), vr.lower_bound ());
      *b = wide_int_to_tree (TREE_TYPE (var), vr.upper_bound ());
      return true;
    }
  return false;
}

simplify_using_ranges::simplify_using_ranges (range_query *query,
					      int not_executable_flag)
  : query (query)
{
  to_remove_edges = vNULL;
  to_update_switch_stmts = vNULL;
  m_not_executable_flag = not_executable_flag;
  m_flag_set_edges = vNULL;
}

simplify_using_ranges::~simplify_using_ranges ()
{
  cleanup_edges_and_switches ();
  m_flag_set_edges.release ();
}

/* Simplify STMT using ranges if possible.  */

bool
simplify_using_ranges::simplify (gimple_stmt_iterator *gsi)
{
  gcc_checking_assert (query);

  gimple *stmt = gsi_stmt (*gsi);
  if (is_gimple_assign (stmt))
    {
      enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
      tree rhs1 = gimple_assign_rhs1 (stmt);
      tree rhs2 = gimple_assign_rhs2 (stmt);
      tree lhs = gimple_assign_lhs (stmt);
      tree val1 = NULL_TREE, val2 = NULL_TREE;
      use_operand_p use_p;
      gimple *use_stmt;

      /* Convert:
	 LHS = CST BINOP VAR
	 Where VAR is two-valued and LHS is used in GIMPLE_COND only
	 To:
	 LHS = VAR == VAL1 ? (CST BINOP VAL1) : (CST BINOP VAL2)

	 Also handles:
	 LHS = VAR BINOP CST
	 Where VAR is two-valued and LHS is used in GIMPLE_COND only
	 To:
	 LHS = VAR == VAL1 ? (VAL1 BINOP CST) : (VAL2 BINOP CST) */

      if (TREE_CODE_CLASS (rhs_code) == tcc_binary
	  && INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
	  && ((TREE_CODE (rhs1) == INTEGER_CST
	       && TREE_CODE (rhs2) == SSA_NAME)
	      || (TREE_CODE (rhs2) == INTEGER_CST
		  && TREE_CODE (rhs1) == SSA_NAME))
	  && single_imm_use (lhs, &use_p, &use_stmt)
	  && gimple_code (use_stmt) == GIMPLE_COND)

	{
	  tree new_rhs1 = NULL_TREE;
	  tree new_rhs2 = NULL_TREE;
	  tree cmp_var = NULL_TREE;

	  if (TREE_CODE (rhs2) == SSA_NAME
	      && two_valued_val_range_p (rhs2, &val1, &val2, stmt))
	    {
	      /* Optimize RHS1 OP [VAL1, VAL2].  */
	      new_rhs1 = int_const_binop (rhs_code, rhs1, val1);
	      new_rhs2 = int_const_binop (rhs_code, rhs1, val2);
	      cmp_var = rhs2;
	    }
	  else if (TREE_CODE (rhs1) == SSA_NAME
		   && two_valued_val_range_p (rhs1, &val1, &val2, stmt))
	    {
	      /* Optimize [VAL1, VAL2] OP RHS2.  */
	      new_rhs1 = int_const_binop (rhs_code, val1, rhs2);
	      new_rhs2 = int_const_binop (rhs_code, val2, rhs2);
	      cmp_var = rhs1;
	    }

	  /* If we could not find two-vals or the optimzation is invalid as
	     in divide by zero, new_rhs1 / new_rhs will be NULL_TREE.  */
	  if (new_rhs1 && new_rhs2)
	    {
	      tree cond = gimple_build (gsi, true, GSI_SAME_STMT,
					UNKNOWN_LOCATION,
					EQ_EXPR, boolean_type_node,
					cmp_var, val1);
	      gimple_assign_set_rhs_with_ops (gsi,
					      COND_EXPR, cond,
					      new_rhs1,
					      new_rhs2);
	      update_stmt (gsi_stmt (*gsi));
	      fold_stmt (gsi, follow_single_use_edges);
	      return true;
	    }
	}

      switch (rhs_code)
	{
	case EQ_EXPR:
	case NE_EXPR:
          /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
	     if the RHS is zero or one, and the LHS are known to be boolean
	     values.  */
	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_truth_ops_using_ranges (gsi, stmt);
	  break;

      /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
	 and BIT_AND_EXPR respectively if the first operand is greater
	 than zero and the second operand is an exact power of two.
	 Also optimize TRUNC_MOD_EXPR away if the second operand is
	 constant and the first operand already has the right value
	 range.  */
	case TRUNC_DIV_EXPR:
	case TRUNC_MOD_EXPR:
	  if ((TREE_CODE (rhs1) == SSA_NAME
	       || TREE_CODE (rhs1) == INTEGER_CST)
	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_div_or_mod_using_ranges (gsi, stmt);
	  break;

      /* Transform ABS (X) into X or -X as appropriate.  */
	case ABS_EXPR:
	  if (TREE_CODE (rhs1) == SSA_NAME
	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_abs_using_ranges (gsi, stmt);
	  break;

	case BIT_AND_EXPR:
	case BIT_IOR_EXPR:
	  /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
	     if all the bits being cleared are already cleared or
	     all the bits being set are already set.  */
	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_bit_ops_using_ranges (gsi, stmt);
	  break;

	CASE_CONVERT:
	  if (TREE_CODE (rhs1) == SSA_NAME
	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_conversion_using_ranges (gsi, stmt);
	  break;

	case FLOAT_EXPR:
	  if (TREE_CODE (rhs1) == SSA_NAME
	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_float_conversion_using_ranges (gsi, stmt);
	  break;

	case MIN_EXPR:
	case MAX_EXPR:
	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
	    return simplify_min_or_max_using_ranges (gsi, stmt);
	  break;

	case RSHIFT_EXPR:
	  {
	    tree op0 = gimple_assign_rhs1 (stmt);
	    tree type = TREE_TYPE (op0);
	    int_range_max range;
	    if (TYPE_SIGN (type) == SIGNED
		&& query->range_of_expr (range, op0, stmt))
	      {
		unsigned prec = TYPE_PRECISION (TREE_TYPE (op0));
		int_range<2> nzm1 (type, wi::minus_one (prec), wi::zero (prec),
				   VR_ANTI_RANGE);
		range.intersect (nzm1);
		// If there are no ranges other than [-1, 0] remove the shift.
		if (range.undefined_p ())
		  {
		    gimple_assign_set_rhs_from_tree (gsi, op0);
		    return true;
		  }
		return false;
	      }
	    break;
	  }
	default:
	  break;
	}
    }
  else if (gimple_code (stmt) == GIMPLE_COND)
    return simplify_cond_using_ranges_1 (as_a <gcond *> (stmt));
  else if (gimple_code (stmt) == GIMPLE_SWITCH)
    return simplify_switch_using_ranges (as_a <gswitch *> (stmt));
  else if (is_gimple_call (stmt)
	   && gimple_call_internal_p (stmt))
    return simplify_internal_call_using_ranges (gsi, stmt);

  return false;
}