aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/targhooks.c
blob: 4721186e5a8a50d60a344fca6bc485587e2a6327 (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
/* Default target hook functions.
   Copyright (C) 2003-2014 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/>.  */

/* The migration of target macros to target hooks works as follows:

   1. Create a target hook that uses the existing target macros to
      implement the same functionality.

   2. Convert all the MI files to use the hook instead of the macro.

   3. Repeat for a majority of the remaining target macros.  This will
      take some time.

   4. Tell target maintainers to start migrating.

   5. Eventually convert the backends to override the hook instead of
      defining the macros.  This will take some time too.

   6. TBD when, poison the macros.  Unmigrated targets will break at
      this point.

   Note that we expect steps 1-3 to be done by the people that
   understand what the MI does with each macro, and step 5 to be done
   by the target maintainers for their respective targets.

   Note that steps 1 and 2 don't have to be done together, but no
   target can override the new hook until step 2 is complete for it.

   Once the macros are poisoned, we will revert to the old migration
   rules - migrate the macro, callers, and targets all at once.  This
   comment can thus be removed at that point.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "machmode.h"
#include "rtl.h"
#include "tree.h"
#include "stor-layout.h"
#include "varasm.h"
#include "expr.h"
#include "output.h"
#include "diagnostic-core.h"
#include "function.h"
#include "target.h"
#include "tm_p.h"
#include "target-def.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "reload.h"
#include "optabs.h"
#include "recog.h"
#include "intl.h"
#include "opts.h"
#include "tree-ssa-alias.h"
#include "gimple-expr.h"
#include "gimplify.h"
#include "stringpool.h"
#include "tree-ssanames.h"
#include "insn-codes.h"


bool
default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
			      rtx addr ATTRIBUTE_UNUSED,
			      bool strict ATTRIBUTE_UNUSED)
{
#ifdef GO_IF_LEGITIMATE_ADDRESS
  /* Defer to the old implementation using a goto.  */
  if (strict)
    return strict_memory_address_p (mode, addr);
  else
    return memory_address_p (mode, addr);
#else
  gcc_unreachable ();
#endif
}

void
default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
{
#ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
#endif
}

int
default_unspec_may_trap_p (const_rtx x, unsigned flags)
{
  int i;

  /* Any floating arithmetic may trap.  */
  if ((SCALAR_FLOAT_MODE_P (GET_MODE (x)) && flag_trapping_math))
    return 1;

  for (i = 0; i < XVECLEN (x, 0); ++i)
    {
      if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
	return 1;
    }

  return 0;
}

enum machine_mode
default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
			       enum machine_mode mode,
			       int *punsignedp ATTRIBUTE_UNUSED,
			       const_tree funtype ATTRIBUTE_UNUSED,
			       int for_return ATTRIBUTE_UNUSED)
{
  if (type != NULL_TREE && for_return == 2)
    return promote_mode (type, mode, punsignedp);
  return mode;
}

enum machine_mode
default_promote_function_mode_always_promote (const_tree type,
					      enum machine_mode mode,
					      int *punsignedp,
					      const_tree funtype ATTRIBUTE_UNUSED,
					      int for_return ATTRIBUTE_UNUSED)
{
  return promote_mode (type, mode, punsignedp);
}

enum machine_mode
default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
{
  if (m1 == m2)
    return m1;
  return VOIDmode;
}

bool
default_return_in_memory (const_tree type,
			  const_tree fntype ATTRIBUTE_UNUSED)
{
  return (TYPE_MODE (type) == BLKmode);
}

rtx
default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
			    enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return x;
}

rtx
default_expand_builtin_saveregs (void)
{
  error ("__builtin_saveregs not supported by this target");
  return const0_rtx;
}

void
default_setup_incoming_varargs (cumulative_args_t ca ATTRIBUTE_UNUSED,
				enum machine_mode mode ATTRIBUTE_UNUSED,
				tree type ATTRIBUTE_UNUSED,
				int *pretend_arg_size ATTRIBUTE_UNUSED,
				int second_time ATTRIBUTE_UNUSED)
{
}

/* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */

rtx
default_builtin_setjmp_frame_value (void)
{
  return virtual_stack_vars_rtx;
}

/* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */

bool
hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED)
{
  return false;
}

bool
default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED)
{
  return (targetm.calls.setup_incoming_varargs
	  != default_setup_incoming_varargs);
}

enum machine_mode
default_eh_return_filter_mode (void)
{
  return targetm.unwind_word_mode ();
}

enum machine_mode
default_libgcc_cmp_return_mode (void)
{
  return word_mode;
}

enum machine_mode
default_libgcc_shift_count_mode (void)
{
  return word_mode;
}

enum machine_mode
default_unwind_word_mode (void)
{
  return word_mode;
}

/* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */

unsigned HOST_WIDE_INT
default_shift_truncation_mask (enum machine_mode mode)
{
  return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
}

/* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */

unsigned int
default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return have_insn_for (DIV, mode) ? 3 : 2;
}

/* The default implementation of TARGET_MODE_REP_EXTENDED.  */

int
default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
			   enum machine_mode mode_rep ATTRIBUTE_UNUSED)
{
  return UNKNOWN;
}

/* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */

bool
hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED)
{
  return true;
}

/* Return machine mode for non-standard suffix
   or VOIDmode if non-standard suffixes are unsupported.  */
enum machine_mode
default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
{
  return VOIDmode;
}

/* The generic C++ ABI specifies this is a 64-bit value.  */
tree
default_cxx_guard_type (void)
{
  return long_long_integer_type_node;
}

/* Returns the size of the cookie to use when allocating an array
   whose elements have the indicated TYPE.  Assumes that it is already
   known that a cookie is needed.  */

tree
default_cxx_get_cookie_size (tree type)
{
  tree cookie_size;

  /* We need to allocate an additional max (sizeof (size_t), alignof
     (true_type)) bytes.  */
  tree sizetype_size;
  tree type_align;

  sizetype_size = size_in_bytes (sizetype);
  type_align = size_int (TYPE_ALIGN_UNIT (type));
  if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
    cookie_size = sizetype_size;
  else
    cookie_size = type_align;

  return cookie_size;
}

/* Return true if a parameter must be passed by reference.  This version
   of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */

bool
hook_pass_by_reference_must_pass_in_stack (cumulative_args_t c ATTRIBUTE_UNUSED,
	enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
	bool named_arg ATTRIBUTE_UNUSED)
{
  return targetm.calls.must_pass_in_stack (mode, type);
}

/* Return true if a parameter follows callee copies conventions.  This
   version of the hook is true for all named arguments.  */

bool
hook_callee_copies_named (cumulative_args_t ca ATTRIBUTE_UNUSED,
			  enum machine_mode mode ATTRIBUTE_UNUSED,
			  const_tree type ATTRIBUTE_UNUSED, bool named)
{
  return named;
}

/* Emit to STREAM the assembler syntax for insn operand X.  */

void
default_print_operand (FILE *stream ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
		       int code ATTRIBUTE_UNUSED)
{
#ifdef PRINT_OPERAND
  PRINT_OPERAND (stream, x, code);
#else
  gcc_unreachable ();
#endif
}

/* Emit to STREAM the assembler syntax for an insn operand whose memory
   address is X.  */

void
default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED,
			       rtx x ATTRIBUTE_UNUSED)
{
#ifdef PRINT_OPERAND_ADDRESS
  PRINT_OPERAND_ADDRESS (stream, x);
#else
  gcc_unreachable ();
#endif
}

/* Return true if CODE is a valid punctuation character for the
   `print_operand' hook.  */

bool
default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED)
{
#ifdef PRINT_OPERAND_PUNCT_VALID_P
  return PRINT_OPERAND_PUNCT_VALID_P (code);
#else
  return false;
#endif
}

/* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME.  */
tree
default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
{
  const char *skipped = name + (*name == '*' ? 1 : 0);
  const char *stripped = targetm.strip_name_encoding (skipped);
  if (*name != '*' && user_label_prefix[0])
    stripped = ACONCAT ((user_label_prefix, stripped, NULL));
  return get_identifier (stripped);
}

/* True if MODE is valid for the target.  By "valid", we mean able to
   be manipulated in non-trivial ways.  In particular, this means all
   the arithmetic is supported.

   By default we guess this means that any C type is supported.  If
   we can't map the mode back to a type that would be available in C,
   then reject it.  Special case, here, is the double-word arithmetic
   supported by optabs.c.  */

bool
default_scalar_mode_supported_p (enum machine_mode mode)
{
  int precision = GET_MODE_PRECISION (mode);

  switch (GET_MODE_CLASS (mode))
    {
    case MODE_PARTIAL_INT:
    case MODE_INT:
      if (precision == CHAR_TYPE_SIZE)
	return true;
      if (precision == SHORT_TYPE_SIZE)
	return true;
      if (precision == INT_TYPE_SIZE)
	return true;
      if (precision == LONG_TYPE_SIZE)
	return true;
      if (precision == LONG_LONG_TYPE_SIZE)
	return true;
      if (precision == 2 * BITS_PER_WORD)
	return true;
      return false;

    case MODE_FLOAT:
      if (precision == FLOAT_TYPE_SIZE)
	return true;
      if (precision == DOUBLE_TYPE_SIZE)
	return true;
      if (precision == LONG_DOUBLE_TYPE_SIZE)
	return true;
      return false;

    case MODE_DECIMAL_FLOAT:
    case MODE_FRACT:
    case MODE_UFRACT:
    case MODE_ACCUM:
    case MODE_UACCUM:
      return false;

    default:
      gcc_unreachable ();
    }
}

/* Make some target macros useable by target-independent code.  */
bool
targhook_words_big_endian (void)
{
  return !!WORDS_BIG_ENDIAN;
}

bool
targhook_float_words_big_endian (void)
{
  return !!FLOAT_WORDS_BIG_ENDIAN;
}

/* True if the target supports floating-point exceptions and rounding
   modes.  */

bool
default_float_exceptions_rounding_supported_p (void)
{
#ifdef HAVE_adddf3
  return HAVE_adddf3;
#else
  return false;
#endif
}

/* True if the target supports decimal floating point.  */

bool
default_decimal_float_supported_p (void)
{
  return ENABLE_DECIMAL_FLOAT;
}

/* True if the target supports fixed-point arithmetic.  */

bool
default_fixed_point_supported_p (void)
{
  return ENABLE_FIXED_POINT;
}

/* True if the target supports GNU indirect functions.  */

bool
default_has_ifunc_p (void)
{
  return HAVE_GNU_INDIRECT_FUNCTION;
}

/* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
   an error message.

   This function checks whether a given INSN is valid within a low-overhead
   loop.  If INSN is invalid it returns the reason for that, otherwise it
   returns NULL. A called function may clobber any special registers required
   for low-overhead looping. Additionally, some targets (eg, PPC) use the count
   register for branch on table instructions. We reject the doloop pattern in
   these cases.  */

const char *
default_invalid_within_doloop (const_rtx insn)
{
  if (CALL_P (insn))
    return "Function call in loop.";

  if (tablejump_p (insn, NULL, NULL) || computed_jump_p (insn))
    return "Computed branch in the loop.";

  return NULL;
}

/* Mapping of builtin functions to vectorized variants.  */

tree
default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
				     tree type_out ATTRIBUTE_UNUSED,
				     tree type_in ATTRIBUTE_UNUSED)
{
  return NULL_TREE;
}

/* Vectorized conversion.  */

tree
default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
				       tree dest_type ATTRIBUTE_UNUSED,
				       tree src_type ATTRIBUTE_UNUSED)
{
  return NULL_TREE;
}

/* Default vectorizer cost model values.  */

int
default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
                                    tree vectype,
                                    int misalign ATTRIBUTE_UNUSED)
{
  unsigned elements;

  switch (type_of_cost)
    {
      case scalar_stmt:
      case scalar_load:
      case scalar_store:
      case vector_stmt:
      case vector_load:
      case vector_store:
      case vec_to_scalar:
      case scalar_to_vec:
      case cond_branch_not_taken:
      case vec_perm:
      case vec_promote_demote:
        return 1;

      case unaligned_load:
      case unaligned_store:
        return 2;

      case cond_branch_taken:
        return 3;

      case vec_construct:
	elements = TYPE_VECTOR_SUBPARTS (vectype);
	return elements / 2 + 1;

      default:
        gcc_unreachable ();
    }
}

/* Reciprocal.  */

tree
default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
			    bool md_fn ATTRIBUTE_UNUSED,
			    bool sqrt ATTRIBUTE_UNUSED)
{
  return NULL_TREE;
}

bool
hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
	cumulative_args_t ca ATTRIBUTE_UNUSED,
	enum machine_mode mode ATTRIBUTE_UNUSED,
	const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
{
  return false;
}

bool
hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
	cumulative_args_t ca ATTRIBUTE_UNUSED,
	enum machine_mode mode ATTRIBUTE_UNUSED,
	const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
{
  return true;
}

int
hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
	cumulative_args_t ca ATTRIBUTE_UNUSED,
	enum machine_mode mode ATTRIBUTE_UNUSED,
	tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
{
  return 0;
}

void
default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
			      enum machine_mode mode ATTRIBUTE_UNUSED,
			      const_tree type ATTRIBUTE_UNUSED,
			      bool named ATTRIBUTE_UNUSED)
{
  gcc_unreachable ();
}

rtx
default_function_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
		      enum machine_mode mode ATTRIBUTE_UNUSED,
		      const_tree type ATTRIBUTE_UNUSED,
		      bool named ATTRIBUTE_UNUSED)
{
  gcc_unreachable ();
}

rtx
default_function_incoming_arg (cumulative_args_t ca ATTRIBUTE_UNUSED,
			       enum machine_mode mode ATTRIBUTE_UNUSED,
			       const_tree type ATTRIBUTE_UNUSED,
			       bool named ATTRIBUTE_UNUSED)
{
  gcc_unreachable ();
}

unsigned int
default_function_arg_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
			       const_tree type ATTRIBUTE_UNUSED)
{
  return PARM_BOUNDARY;
}

unsigned int
default_function_arg_round_boundary (enum machine_mode mode ATTRIBUTE_UNUSED,
				     const_tree type ATTRIBUTE_UNUSED)
{
  return PARM_BOUNDARY;
}

void
hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
{
}

const char *
hook_invalid_arg_for_unprototyped_fn (
	const_tree typelist ATTRIBUTE_UNUSED,
	const_tree funcdecl ATTRIBUTE_UNUSED,
	const_tree val ATTRIBUTE_UNUSED)
{
  return NULL;
}

/* Initialize the stack protection decls.  */

/* Stack protection related decls living in libgcc.  */
static GTY(()) tree stack_chk_guard_decl;

tree
default_stack_protect_guard (void)
{
  tree t = stack_chk_guard_decl;

  if (t == NULL)
    {
      rtx x;

      t = build_decl (UNKNOWN_LOCATION,
		      VAR_DECL, get_identifier ("__stack_chk_guard"),
		      ptr_type_node);
      TREE_STATIC (t) = 1;
      TREE_PUBLIC (t) = 1;
      DECL_EXTERNAL (t) = 1;
      TREE_USED (t) = 1;
      TREE_THIS_VOLATILE (t) = 1;
      DECL_ARTIFICIAL (t) = 1;
      DECL_IGNORED_P (t) = 1;

      /* Do not share RTL as the declaration is visible outside of
	 current function.  */
      x = DECL_RTL (t);
      RTX_FLAG (x, used) = 1;

      stack_chk_guard_decl = t;
    }

  return t;
}

static GTY(()) tree stack_chk_fail_decl;

tree
default_external_stack_protect_fail (void)
{
  tree t = stack_chk_fail_decl;

  if (t == NULL_TREE)
    {
      t = build_function_type_list (void_type_node, NULL_TREE);
      t = build_decl (UNKNOWN_LOCATION,
		      FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
      TREE_STATIC (t) = 1;
      TREE_PUBLIC (t) = 1;
      DECL_EXTERNAL (t) = 1;
      TREE_USED (t) = 1;
      TREE_THIS_VOLATILE (t) = 1;
      TREE_NOTHROW (t) = 1;
      DECL_ARTIFICIAL (t) = 1;
      DECL_IGNORED_P (t) = 1;
      DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
      DECL_VISIBILITY_SPECIFIED (t) = 1;

      stack_chk_fail_decl = t;
    }

  return build_call_expr (t, 0);
}

tree
default_hidden_stack_protect_fail (void)
{
#ifndef HAVE_GAS_HIDDEN
  return default_external_stack_protect_fail ();
#else
  tree t = stack_chk_fail_decl;

  if (!flag_pic)
    return default_external_stack_protect_fail ();

  if (t == NULL_TREE)
    {
      t = build_function_type_list (void_type_node, NULL_TREE);
      t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
		      get_identifier ("__stack_chk_fail_local"), t);
      TREE_STATIC (t) = 1;
      TREE_PUBLIC (t) = 1;
      DECL_EXTERNAL (t) = 1;
      TREE_USED (t) = 1;
      TREE_THIS_VOLATILE (t) = 1;
      TREE_NOTHROW (t) = 1;
      DECL_ARTIFICIAL (t) = 1;
      DECL_IGNORED_P (t) = 1;
      DECL_VISIBILITY_SPECIFIED (t) = 1;
      DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;

      stack_chk_fail_decl = t;
    }

  return build_call_expr (t, 0);
#endif
}

bool
hook_bool_const_rtx_commutative_p (const_rtx x,
				   int outer_code ATTRIBUTE_UNUSED)
{
  return COMMUTATIVE_P (x);
}

rtx
default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
			const_tree fn_decl_or_type,
			bool outgoing ATTRIBUTE_UNUSED)
{
  /* The old interface doesn't handle receiving the function type.  */
  if (fn_decl_or_type
      && !DECL_P (fn_decl_or_type))
    fn_decl_or_type = NULL;

#ifdef FUNCTION_VALUE
  return FUNCTION_VALUE (ret_type, fn_decl_or_type);
#else
  gcc_unreachable ();
#endif
}

rtx
default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
		       const_rtx fun ATTRIBUTE_UNUSED)
{
#ifdef LIBCALL_VALUE
  return LIBCALL_VALUE (mode);
#else
  gcc_unreachable ();
#endif
}

/* The default hook for TARGET_FUNCTION_VALUE_REGNO_P.  */

bool
default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED)
{
#ifdef FUNCTION_VALUE_REGNO_P
  return FUNCTION_VALUE_REGNO_P (regno);
#else
  gcc_unreachable ();
#endif
}

rtx
default_internal_arg_pointer (void)
{
  /* If the reg that the virtual arg pointer will be translated into is
     not a fixed reg or is the stack pointer, make a copy of the virtual
     arg pointer, and address parms via the copy.  The frame pointer is
     considered fixed even though it is not marked as such.  */
  if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
       || ! (fixed_regs[ARG_POINTER_REGNUM]
	     || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
    return copy_to_reg (virtual_incoming_args_rtx);
  else
    return virtual_incoming_args_rtx;
}

rtx
default_static_chain (const_tree fndecl, bool incoming_p)
{
  if (!DECL_STATIC_CHAIN (fndecl))
    return NULL;

  if (incoming_p)
    {
#ifdef STATIC_CHAIN_INCOMING_REGNUM
      return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
#endif
    }

#ifdef STATIC_CHAIN_REGNUM
  return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
#endif

  {
    static bool issued_error;
    if (!issued_error)
      {
	issued_error = true;
	sorry ("nested functions not supported on this target");
      }

    /* It really doesn't matter what we return here, so long at it
       doesn't cause the rest of the compiler to crash.  */
    return gen_rtx_MEM (Pmode, stack_pointer_rtx);
  }
}

void
default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
			 rtx ARG_UNUSED (r_chain))
{
  sorry ("nested function trampolines not supported on this target");
}

int
default_return_pops_args (tree fundecl ATTRIBUTE_UNUSED,
			  tree funtype ATTRIBUTE_UNUSED,
			  int size ATTRIBUTE_UNUSED)
{
  return 0;
}

reg_class_t
default_branch_target_register_class (void)
{
  return NO_REGS;
}

extern bool
default_lra_p (void)
{
  return false;
}

int
default_register_priority (int hard_regno ATTRIBUTE_UNUSED)
{
  return 0;
}

extern bool
default_register_usage_leveling_p (void)
{
  return false;
}

extern bool
default_different_addr_displacement_p (void)
{
  return false;
}

reg_class_t
default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
			  reg_class_t reload_class_i ATTRIBUTE_UNUSED,
			  enum machine_mode reload_mode ATTRIBUTE_UNUSED,
			  secondary_reload_info *sri)
{
  enum reg_class rclass = NO_REGS;
  enum reg_class reload_class = (enum reg_class) reload_class_i;

  if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
    {
      sri->icode = sri->prev_sri->t_icode;
      return NO_REGS;
    }
#ifdef SECONDARY_INPUT_RELOAD_CLASS
  if (in_p)
    rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
#endif
#ifdef SECONDARY_OUTPUT_RELOAD_CLASS
  if (! in_p)
    rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
#endif
  if (rclass != NO_REGS)
    {
      enum insn_code icode
	= direct_optab_handler (in_p ? reload_in_optab : reload_out_optab,
				reload_mode);

      if (icode != CODE_FOR_nothing
	  && !insn_operand_matches (icode, in_p, x))
	icode = CODE_FOR_nothing;
      else if (icode != CODE_FOR_nothing)
	{
	  const char *insn_constraint, *scratch_constraint;
	  char insn_letter, scratch_letter;
	  enum reg_class insn_class, scratch_class;

	  gcc_assert (insn_data[(int) icode].n_operands == 3);
	  insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
	  if (!*insn_constraint)
	    insn_class = ALL_REGS;
	  else
	    {
	      if (in_p)
		{
		  gcc_assert (*insn_constraint == '=');
		  insn_constraint++;
		}
	      insn_letter = *insn_constraint;
	      insn_class
		= (insn_letter == 'r' ? GENERAL_REGS
		   : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
						insn_constraint));
	      gcc_assert (insn_class != NO_REGS);
	    }

	  scratch_constraint = insn_data[(int) icode].operand[2].constraint;
	  /* The scratch register's constraint must start with "=&",
	     except for an input reload, where only "=" is necessary,
	     and where it might be beneficial to re-use registers from
	     the input.  */
	  gcc_assert (scratch_constraint[0] == '='
		      && (in_p || scratch_constraint[1] == '&'));
	  scratch_constraint++;
	  if (*scratch_constraint == '&')
	    scratch_constraint++;
	  scratch_letter = *scratch_constraint;
	  scratch_class
	    = (scratch_letter == 'r' ? GENERAL_REGS
	       : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
					    scratch_constraint));

	  if (reg_class_subset_p (reload_class, insn_class))
	    {
	      gcc_assert (scratch_class == rclass);
	      rclass = NO_REGS;
	    }
	  else
	    rclass = insn_class;

        }
      if (rclass == NO_REGS)
	sri->icode = icode;
      else
	sri->t_icode = icode;
    }
  return rclass;
}

/* By default, if flag_pic is true, then neither local nor global relocs
   should be placed in readonly memory.  */

int
default_reloc_rw_mask (void)
{
  return flag_pic ? 3 : 0;
}

/* By default, do no modification. */
tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
					 tree id)
{
   return id;
}

/* Default to natural alignment for vector types.  */
HOST_WIDE_INT
default_vector_alignment (const_tree type)
{
  return tree_to_shwi (TYPE_SIZE (type));
}

bool
default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
{
  if (is_packed)
    return false;

  /* Assuming that types whose size is > pointer-size are not guaranteed to be
     naturally aligned.  */
  if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
    return false;

  /* Assuming that types whose size is <= pointer-size
     are naturally aligned.  */
  return true;
}

/* By default, assume that a target supports any factor of misalignment
   memory access if it supports movmisalign patten.
   is_packed is true if the memory access is defined in a packed struct.  */
bool
default_builtin_support_vector_misalignment (enum machine_mode mode,
					     const_tree type
					     ATTRIBUTE_UNUSED,
					     int misalignment
					     ATTRIBUTE_UNUSED,
					     bool is_packed
					     ATTRIBUTE_UNUSED)
{
  if (optab_handler (movmisalign_optab, mode) != CODE_FOR_nothing)
    return true;
  return false;
}

/* By default, only attempt to parallelize bitwise operations, and
   possibly adds/subtracts using bit-twiddling.  */

enum machine_mode
default_preferred_simd_mode (enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return word_mode;
}

/* By default only the size derived from the preferred vector mode
   is tried.  */

unsigned int
default_autovectorize_vector_sizes (void)
{
  return 0;
}

/* By default, the cost model accumulates three separate costs (prologue,
   loop body, and epilogue) for a vectorized loop or block.  So allocate an
   array of three unsigned ints, set it to zero, and return its address.  */

void *
default_init_cost (struct loop *loop_info ATTRIBUTE_UNUSED)
{
  unsigned *cost = XNEWVEC (unsigned, 3);
  cost[vect_prologue] = cost[vect_body] = cost[vect_epilogue] = 0;
  return cost;
}

/* By default, the cost model looks up the cost of the given statement
   kind and mode, multiplies it by the occurrence count, accumulates
   it into the cost specified by WHERE, and returns the cost added.  */

unsigned
default_add_stmt_cost (void *data, int count, enum vect_cost_for_stmt kind,
		       struct _stmt_vec_info *stmt_info, int misalign,
		       enum vect_cost_model_location where)
{
  unsigned *cost = (unsigned *) data;
  unsigned retval = 0;

  tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
  int stmt_cost = default_builtin_vectorization_cost (kind, vectype,
							  misalign);
   /* Statements in an inner loop relative to the loop being
      vectorized are weighted more heavily.  The value here is
      arbitrary and could potentially be improved with analysis.  */
  if (where == vect_body && stmt_info && stmt_in_inner_loop_p (stmt_info))
    count *= 50;  /* FIXME.  */

  retval = (unsigned) (count * stmt_cost);
  cost[where] += retval;

  return retval;
}

/* By default, the cost model just returns the accumulated costs.  */

void
default_finish_cost (void *data, unsigned *prologue_cost,
		     unsigned *body_cost, unsigned *epilogue_cost)
{
  unsigned *cost = (unsigned *) data;
  *prologue_cost = cost[vect_prologue];
  *body_cost     = cost[vect_body];
  *epilogue_cost = cost[vect_epilogue];
}

/* Free the cost data.  */

void
default_destroy_cost_data (void *data)
{
  free (data);
}

/* Determine whether or not a pointer mode is valid. Assume defaults
   of ptr_mode or Pmode - can be overridden.  */
bool
default_valid_pointer_mode (enum machine_mode mode)
{
  return (mode == ptr_mode || mode == Pmode);
}

/* Determine whether the memory reference specified by REF may alias
   the C libraries errno location.  */
bool
default_ref_may_alias_errno (ao_ref *ref)
{
  tree base = ao_ref_base (ref);
  /* The default implementation assumes the errno location is
     a declaration of type int or is always accessed via a
     pointer to int.  We assume that accesses to errno are
     not deliberately obfuscated (even in conforming ways).  */
  if (TYPE_UNSIGNED (TREE_TYPE (base))
      || TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
    return false;
  /* The default implementation assumes an errno location
     declaration is never defined in the current compilation unit.  */
  if (DECL_P (base)
      && !TREE_STATIC (base))
    return true;
  else if (TREE_CODE (base) == MEM_REF
	   && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
    {
      struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
      return !pi || pi->pt.anything || pi->pt.nonlocal;
    }
  return false;
}

/* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
   for the generic address space only.  */

enum machine_mode
default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
{
  gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
  return ptr_mode;
}

/* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
   for the generic address space only.  */

enum machine_mode
default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
{
  gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
  return Pmode;
}

/* Named address space version of valid_pointer_mode.  */

bool
default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
{
  if (!ADDR_SPACE_GENERIC_P (as))
    return (mode == targetm.addr_space.pointer_mode (as)
	    || mode == targetm.addr_space.address_mode (as));

  return targetm.valid_pointer_mode (mode);
}

/* Some places still assume that all pointer or address modes are the
   standard Pmode and ptr_mode.  These optimizations become invalid if
   the target actually supports multiple different modes.  For now,
   we disable such optimizations on such targets, using this function.  */

bool
target_default_pointer_address_modes_p (void)
{
  if (targetm.addr_space.address_mode != default_addr_space_address_mode)
    return false;
  if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
    return false;

  return true;
}

/* Named address space version of legitimate_address_p.  */

bool
default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
					 bool strict, addr_space_t as)
{
  if (!ADDR_SPACE_GENERIC_P (as))
    gcc_unreachable ();

  return targetm.legitimate_address_p (mode, mem, strict);
}

/* Named address space version of LEGITIMIZE_ADDRESS.  */

rtx
default_addr_space_legitimize_address (rtx x, rtx oldx,
				       enum machine_mode mode, addr_space_t as)
{
  if (!ADDR_SPACE_GENERIC_P (as))
    return x;

  return targetm.legitimize_address (x, oldx, mode);
}

/* The default hook for determining if one named address space is a subset of
   another and to return which address space to use as the common address
   space.  */

bool
default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
{
  return (subset == superset);
}

/* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
   called for targets with only a generic address space.  */

rtx
default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
			    tree from_type ATTRIBUTE_UNUSED,
			    tree to_type ATTRIBUTE_UNUSED)
{
  gcc_unreachable ();
}

bool
default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
{
  return true;
}

/* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P.  */

bool
default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED,
				  addr_space_t addrspace ATTRIBUTE_UNUSED)
{
  return false;
}

bool
default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
					 tree ARG_UNUSED (name),
					 tree ARG_UNUSED (args),
					 int ARG_UNUSED (flags))
{
  warning (OPT_Wattributes,
	   "target attribute is not supported on this machine");

  return false;
}

bool
default_target_option_pragma_parse (tree ARG_UNUSED (args),
				    tree ARG_UNUSED (pop_target))
{
  warning (OPT_Wpragmas,
	   "#pragma GCC target is not supported for this machine");

  return false;
}

bool
default_target_can_inline_p (tree caller, tree callee)
{
  bool ret = false;
  tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
  tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);

  /* If callee has no option attributes, then it is ok to inline */
  if (!callee_opts)
    ret = true;

  /* If caller has no option attributes, but callee does then it is not ok to
     inline */
  else if (!caller_opts)
    ret = false;

  /* If both caller and callee have attributes, assume that if the
     pointer is different, the two functions have different target
     options since build_target_option_node uses a hash table for the
     options.  */
  else
    ret = (callee_opts == caller_opts);

  return ret;
}

#ifndef HAVE_casesi
# define HAVE_casesi 0
#endif

/* If the machine does not have a case insn that compares the bounds,
   this means extra overhead for dispatch tables, which raises the
   threshold for using them.  */

unsigned int
default_case_values_threshold (void)
{
  return (HAVE_casesi ? 4 : 5);
}

bool
default_have_conditional_execution (void)
{
#ifdef HAVE_conditional_execution
  return HAVE_conditional_execution;
#else
  return false;
#endif
}

tree
default_builtin_tm_load_store (tree ARG_UNUSED (type))
{
  return NULL_TREE;
}

/* Compute cost of moving registers to/from memory.  */

int
default_memory_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
			  reg_class_t rclass ATTRIBUTE_UNUSED,
			  bool in ATTRIBUTE_UNUSED)
{
#ifndef MEMORY_MOVE_COST
    return (4 + memory_move_secondary_cost (mode, (enum reg_class) rclass, in));
#else
    return MEMORY_MOVE_COST (mode, (enum reg_class) rclass, in);
#endif
}

/* Compute cost of moving data from a register of class FROM to one of
   TO, using MODE.  */

int
default_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
                            reg_class_t from ATTRIBUTE_UNUSED,
                            reg_class_t to ATTRIBUTE_UNUSED)
{
#ifndef REGISTER_MOVE_COST
  return 2;
#else
  return REGISTER_MOVE_COST (mode, (enum reg_class) from, (enum reg_class) to);
#endif
}

bool
default_profile_before_prologue (void)
{
#ifdef PROFILE_BEFORE_PROLOGUE
  return true;
#else
  return false;
#endif
}

rtx
default_set_fp_insn (void)
{
  return NULL;
}

/* The default implementation of TARGET_PREFERRED_RELOAD_CLASS.  */

reg_class_t
default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED,
			        reg_class_t rclass)
{
#ifdef PREFERRED_RELOAD_CLASS 
  return (reg_class_t) PREFERRED_RELOAD_CLASS (x, (enum reg_class) rclass);
#else
  return rclass;
#endif
}

/* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS.  */

reg_class_t
default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED,
				       reg_class_t rclass)
{
  return rclass;
}

/* The default implementation of TARGET_PREFERRED_RENAME_CLASS.  */
reg_class_t
default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED)
{
  return NO_REGS;
}

/* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P.  */

bool
default_class_likely_spilled_p (reg_class_t rclass)
{
  return (reg_class_size[(int) rclass] == 1);
}

/* The default implementation of TARGET_CLASS_MAX_NREGS.  */

unsigned char
default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED,
			 enum machine_mode mode ATTRIBUTE_UNUSED)
{
#ifdef CLASS_MAX_NREGS
  return (unsigned char) CLASS_MAX_NREGS ((enum reg_class) rclass, mode);
#else
  return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
#endif
}

/* Determine the debugging unwind mechanism for the target.  */

enum unwind_info_type
default_debug_unwind_info (void)
{
  /* If the target wants to force the use of dwarf2 unwind info, let it.  */
  /* ??? Change all users to the hook, then poison this.  */
#ifdef DWARF2_FRAME_INFO
  if (DWARF2_FRAME_INFO)
    return UI_DWARF2;
#endif

  /* Otherwise, only turn it on if dwarf2 debugging is enabled.  */
#ifdef DWARF2_DEBUGGING_INFO
  if (write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
    return UI_DWARF2;
#endif

  return UI_NONE;
}

/* Determine the correct mode for a Dwarf frame register that represents
   register REGNO.  */

enum machine_mode
default_dwarf_frame_reg_mode (int regno)
{
  enum machine_mode save_mode = reg_raw_mode[regno];

  if (HARD_REGNO_CALL_PART_CLOBBERED (regno, save_mode))
    save_mode = choose_hard_reg_mode (regno, 1, true);
  return save_mode;
}

/* To be used by targets where reg_raw_mode doesn't return the right
   mode for registers used in apply_builtin_return and apply_builtin_arg.  */

enum machine_mode
default_get_reg_raw_mode (int regno)
{
  return reg_raw_mode[regno];
}

/* Return true if the state of option OPTION should be stored in PCH files
   and checked by default_pch_valid_p.  Store the option's current state
   in STATE if so.  */

static inline bool
option_affects_pch_p (int option, struct cl_option_state *state)
{
  if ((cl_options[option].flags & CL_TARGET) == 0)
    return false;
  if ((cl_options[option].flags & CL_PCH_IGNORE) != 0)
    return false;
  if (option_flag_var (option, &global_options) == &target_flags)
    if (targetm.check_pch_target_flags)
      return false;
  return get_option_state (&global_options, option, state);
}

/* Default version of get_pch_validity.
   By default, every flag difference is fatal; that will be mostly right for
   most targets, but completely right for very few.  */

void *
default_get_pch_validity (size_t *sz)
{
  struct cl_option_state state;
  size_t i;
  char *result, *r;

  *sz = 2;
  if (targetm.check_pch_target_flags)
    *sz += sizeof (target_flags);
  for (i = 0; i < cl_options_count; i++)
    if (option_affects_pch_p (i, &state))
      *sz += state.size;

  result = r = XNEWVEC (char, *sz);
  r[0] = flag_pic;
  r[1] = flag_pie;
  r += 2;
  if (targetm.check_pch_target_flags)
    {
      memcpy (r, &target_flags, sizeof (target_flags));
      r += sizeof (target_flags);
    }

  for (i = 0; i < cl_options_count; i++)
    if (option_affects_pch_p (i, &state))
      {
	memcpy (r, state.data, state.size);
	r += state.size;
      }

  return result;
}

/* Return a message which says that a PCH file was created with a different
   setting of OPTION.  */

static const char *
pch_option_mismatch (const char *option)
{
  char *r;

  asprintf (&r, _("created and used with differing settings of '%s'"), option);
  if (r == NULL)
    return _("out of memory");
  return r;
}

/* Default version of pch_valid_p.  */

const char *
default_pch_valid_p (const void *data_p, size_t len)
{
  struct cl_option_state state;
  const char *data = (const char *)data_p;
  size_t i;

  /* -fpic and -fpie also usually make a PCH invalid.  */
  if (data[0] != flag_pic)
    return _("created and used with different settings of -fpic");
  if (data[1] != flag_pie)
    return _("created and used with different settings of -fpie");
  data += 2;

  /* Check target_flags.  */
  if (targetm.check_pch_target_flags)
    {
      int tf;
      const char *r;

      memcpy (&tf, data, sizeof (target_flags));
      data += sizeof (target_flags);
      len -= sizeof (target_flags);
      r = targetm.check_pch_target_flags (tf);
      if (r != NULL)
	return r;
    }

  for (i = 0; i < cl_options_count; i++)
    if (option_affects_pch_p (i, &state))
      {
	if (memcmp (data, state.data, state.size) != 0)
	  return pch_option_mismatch (cl_options[i].opt_text);
	data += state.size;
	len -= state.size;
      }

  return NULL;
}

/* Default version of cstore_mode.  */

enum machine_mode
default_cstore_mode (enum insn_code icode)
{
  return insn_data[(int) icode].operand[0].mode;
}

/* Default version of member_type_forces_blk.  */

bool
default_member_type_forces_blk (const_tree, enum machine_mode)
{
  return false;
}

/* Default version of canonicalize_comparison.  */

void
default_canonicalize_comparison (int *, rtx *, rtx *, bool)
{
}

/* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV.  */

void
default_atomic_assign_expand_fenv (tree *, tree *, tree *)
{
}

#ifndef PAD_VARARGS_DOWN
#define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
#endif

/* Build an indirect-ref expression over the given TREE, which represents a
   piece of a va_arg() expansion.  */
tree
build_va_arg_indirect_ref (tree addr)
{
  addr = build_simple_mem_ref_loc (EXPR_LOCATION (addr), addr);
  return addr;
}

/* The "standard" implementation of va_arg: read the value from the
   current (padded) address and increment by the (padded) size.  */

tree
std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
			  gimple_seq *post_p)
{
  tree addr, t, type_size, rounded_size, valist_tmp;
  unsigned HOST_WIDE_INT align, boundary;
  bool indirect;

#ifdef ARGS_GROW_DOWNWARD
  /* All of the alignment and movement below is for args-grow-up machines.
     As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
     implement their own specialized gimplify_va_arg_expr routines.  */
  gcc_unreachable ();
#endif

  indirect = pass_by_reference (NULL, TYPE_MODE (type), type, false);
  if (indirect)
    type = build_pointer_type (type);

  align = PARM_BOUNDARY / BITS_PER_UNIT;
  boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);

  /* When we align parameter on stack for caller, if the parameter
     alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
     aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
     here with caller.  */
  if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
    boundary = MAX_SUPPORTED_STACK_ALIGNMENT;

  boundary /= BITS_PER_UNIT;

  /* Hoist the valist value into a temporary for the moment.  */
  valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);

  /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
     requires greater alignment, we must perform dynamic alignment.  */
  if (boundary > align
      && !integer_zerop (TYPE_SIZE (type)))
    {
      t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
		  fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
      gimplify_and_add (t, pre_p);

      t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
		  fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
			       valist_tmp,
			       build_int_cst (TREE_TYPE (valist), -boundary)));
      gimplify_and_add (t, pre_p);
    }
  else
    boundary = align;

  /* If the actual alignment is less than the alignment of the type,
     adjust the type accordingly so that we don't assume strict alignment
     when dereferencing the pointer.  */
  boundary *= BITS_PER_UNIT;
  if (boundary < TYPE_ALIGN (type))
    {
      type = build_variant_type_copy (type);
      TYPE_ALIGN (type) = boundary;
    }

  /* Compute the rounded size of the type.  */
  type_size = size_in_bytes (type);
  rounded_size = round_up (type_size, align);

  /* Reduce rounded_size so it's sharable with the postqueue.  */
  gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);

  /* Get AP.  */
  addr = valist_tmp;
  if (PAD_VARARGS_DOWN && !integer_zerop (rounded_size))
    {
      /* Small args are padded downward.  */
      t = fold_build2_loc (input_location, GT_EXPR, sizetype,
		       rounded_size, size_int (align));
      t = fold_build3 (COND_EXPR, sizetype, t, size_zero_node,
		       size_binop (MINUS_EXPR, rounded_size, type_size));
      addr = fold_build_pointer_plus (addr, t);
    }

  /* Compute new value for AP.  */
  t = fold_build_pointer_plus (valist_tmp, rounded_size);
  t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
  gimplify_and_add (t, pre_p);

  addr = fold_convert (build_pointer_type (type), addr);

  if (indirect)
    addr = build_va_arg_indirect_ref (addr);

  return build_va_arg_indirect_ref (addr);
}

/* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
   not support nested low-overhead loops.  */

bool
can_use_doloop_if_innermost (double_int, double_int,
			     unsigned int loop_depth, bool)
{
  return loop_depth == 1;
}

#include "gt-targhooks.h"