aboutsummaryrefslogtreecommitdiff
path: root/gas/config/tc-s390.c
blob: 3eb85dde557b6283e1c3ae730866e8a6421bc28f (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
/* tc-s390.c -- Assemble for the S390
   Copyright 2000, 2001 Free Software Foundation, Inc.
   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).

   This file is part of GAS, the GNU Assembler.

   GAS 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 2, or (at your option)
   any later version.

   GAS 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 GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA. */

#include <stdio.h>
#include <ctype.h>
#include "as.h"
#include "subsegs.h"
#include "struc-symbol.h"

#include "opcode/s390.h"
#include "elf/s390.h"

/* The default architecture */
#ifndef DEFAULT_ARCH
#define DEFAULT_ARCH "s390"
#endif
static char *default_arch = DEFAULT_ARCH;
/* Either 32 or 64, selects file format.  */
static int s390_arch_size;
/* Current architecture. Start with the smallest instruction set */
static enum s390_opcode_arch_val current_architecture = S390_OPCODE_ESA;
static int current_arch_mask = 1 << S390_OPCODE_ESA;
static int current_arch_requested = 0;

/* Whether to use user friendly register names. Default is true. */
#ifndef TARGET_REG_NAMES_P
#define TARGET_REG_NAMES_P true
#endif

static boolean reg_names_p = TARGET_REG_NAMES_P;

/* Generic assembler global variables which must be defined by all
   targets.  */

const char comment_chars[] = "#";

/* Characters which start a comment at the beginning of a line.  */
const char line_comment_chars[] = "#";

/* Characters which may be used to separate multiple commands on a
   single line.  */
const char line_separator_chars[] = ";";

/* Characters which are used to indicate an exponent in a floating
   point number.  */
const char EXP_CHARS[] = "eE";

/* Characters which mean that a number is a floating point constant,
   as in 0d1.0.  */
const char FLT_CHARS[] = "dD";

/* The target specific pseudo-ops which we support.  */

/* Define the prototypes for the pseudo-ops */
static void s390_byte PARAMS ((int));
static void s390_elf_cons PARAMS ((int));
static void s390_bss PARAMS ((int));
static void s390_insn PARAMS ((int));
static void s390_literals PARAMS ((int));

const pseudo_typeS md_pseudo_table[] =
{
  { "align", s_align_bytes, 0 },
  /* Pseudo-ops which must be defined. */
  { "bss",      s390_bss,       0 }, 
  { "insn",     s390_insn,      0 },
  /* Pseudo-ops which must be overridden.  */
  { "byte",	s390_byte,	0 },
  { "short",    s390_elf_cons,  2 },
  { "long",	s390_elf_cons,	4 },
  { "quad",     s390_elf_cons,  8 },
  { "ltorg",    s390_literals,  0 },
  { "string",   stringer,       2 },
  { NULL,	NULL,		0 }
};


/* Structure to hold information about predefined registers.  */
struct pd_reg
  {
    char *name;
    int value;
  };

/* List of registers that are pre-defined:

   Each access register has a predefined name of the form:
     a<reg_num> which has the value <reg_num>.

   Each control register has a predefined name of the form:
     c<reg_num> which has the value <reg_num>.

   Each general register has a predefined name of the form:
     r<reg_num> which has the value <reg_num>.

   Each floating point register a has predefined name of the form:
     f<reg_num> which has the value <reg_num>.

   There are individual registers as well:
     sp     has the value 15
     lit    has the value 12

   The table is sorted. Suitable for searching by a binary search. */

static const struct pd_reg pre_defined_registers[] =
{
  { "a0", 0 },     /* Access registers */
  { "a1", 1 },
  { "a10", 10 },
  { "a11", 11 },
  { "a12", 12 },
  { "a13", 13 },
  { "a14", 14 },
  { "a15", 15 },
  { "a2", 2 },
  { "a3", 3 },
  { "a4", 4 },
  { "a5", 5 },
  { "a6", 6 },
  { "a7", 7 },
  { "a8", 8 },
  { "a9", 9 },

  { "c0", 0 },     /* Control registers */
  { "c1", 1 },
  { "c10", 10 },
  { "c11", 11 },
  { "c12", 12 },
  { "c13", 13 },
  { "c14", 14 },
  { "c15", 15 },
  { "c2", 2 },
  { "c3", 3 },
  { "c4", 4 },
  { "c5", 5 },
  { "c6", 6 },
  { "c7", 7 },
  { "c8", 8 },
  { "c9", 9 },

  { "f0", 0 },     /* Floating point registers */
  { "f1", 1 }, 
  { "f10", 10 }, 
  { "f11", 11 }, 
  { "f12", 12 }, 
  { "f13", 13 }, 
  { "f14", 14 }, 
  { "f15", 15 }, 
  { "f2", 2 }, 
  { "f3", 3 }, 
  { "f4", 4 }, 
  { "f5", 5 }, 
  { "f6", 6 }, 
  { "f7", 7 }, 
  { "f8", 8 }, 
  { "f9", 9 }, 

  { "lit", 13 },   /* Pointer to literal pool */

  { "r0", 0 },     /* General purpose registers */
  { "r1", 1 },
  { "r10", 10 },
  { "r11", 11 },
  { "r12", 12 },
  { "r13", 13 },
  { "r14", 14 },
  { "r15", 15 },
  { "r2", 2 },
  { "r3", 3 },
  { "r4", 4 },
  { "r5", 5 },
  { "r6", 6 },
  { "r7", 7 },
  { "r8", 8 },
  { "r9", 9 },

  { "sp", 15 },   /* Stack pointer */

};

#define REG_NAME_CNT (sizeof(pre_defined_registers) / sizeof(struct pd_reg))

/* Given NAME, find the register number associated with that name, return
   the integer value associated with the given name or -1 on failure.  */

static int
reg_name_search (regs, regcount, name)
     const struct pd_reg *regs;
     int regcount;
     const char *name;
{
  int middle, low, high;
  int cmp;

  low = 0;
  high = regcount - 1;

  do
    {
      middle = (low + high) / 2;
      cmp = strcasecmp (name, regs[middle].name);
      if (cmp < 0)
	high = middle - 1;
      else if (cmp > 0)
	low = middle + 1;
      else
	return regs[middle].value;
    }
  while (low <= high);

  return -1;
}


/*
 * Summary of register_name().
 *
 * in:	Input_line_pointer points to 1st char of operand.
 *
 * out:	A expressionS.
 *      The operand may have been a register: in this case, X_op == O_register,
 *      X_add_number is set to the register number, and truth is returned.
 *	Input_line_pointer->(next non-blank) char after operand, or is in its
 *      original state.
 */

static boolean
register_name (expressionP)
     expressionS *expressionP;
{
  int reg_number;
  char *name;
  char *start;
  char c;

  /* Find the spelling of the operand */
  start = name = input_line_pointer;
  if (name[0] == '%' && isalpha (name[1]))
    name = ++input_line_pointer;
  else
    return false;

  c = get_symbol_end ();
  reg_number = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);

  /* look to see if it's in the register table */
  if (reg_number >= 0) 
    {
      expressionP->X_op = O_register;
      expressionP->X_add_number = reg_number;
      
      /* make the rest nice */
      expressionP->X_add_symbol = NULL;
      expressionP->X_op_symbol = NULL;
      *input_line_pointer = c;   /* put back the delimiting char */
      return true;
    }
  else
    {
      /* reset the line as if we had not done anything */
      *input_line_pointer = c;   /* put back the delimiting char */
      input_line_pointer = start; /* reset input_line pointer */
      return false;
    }
}

/* Local variables.  */

/* Opformat hash table.  */
static struct hash_control *s390_opformat_hash;

/* Opcode hash table.  */
static struct hash_control *s390_opcode_hash;

/* Flags to set in the elf header */
static flagword s390_flags = 0;

symbolS *GOT_symbol;		/* Pre-defined "_GLOBAL_OFFSET_TABLE_" */

#ifndef WORKING_DOT_WORD
const int md_short_jump_size = 4;
const int md_long_jump_size = 4;
#endif

CONST char *md_shortopts = "A:m:kVQ:";
struct option md_longopts[] = {
  {NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof(md_longopts);

/* Initialize the default opcode arch and word size from the default
   architecture name.  */
static void
init_default_arch ()
{
  if (current_arch_requested)
    return;

  if (strcmp(default_arch, "s390") == 0)
    {
      s390_arch_size = 32;
      current_architecture = S390_OPCODE_ESA;
    }
  else if (strcmp(default_arch, "s390x") == 0)
    {
      s390_arch_size = 64;
      current_architecture = S390_OPCODE_ESAME;
    }
  else
    as_fatal ("Invalid default architecture, broken assembler.");
  current_arch_mask = 1 << current_architecture;
}

/* Called by TARGET_FORMAT.  */
const char *
s390_target_format ()
{
  /* We don't get a chance to initialize anything before we're called,
     so handle that now.  */
  if (! s390_arch_size)
    init_default_arch ();

  return s390_arch_size == 64 ? "elf64-s390" : "elf32-s390";
}

int
md_parse_option (c, arg)
     int c;
     char *arg;
{
  switch (c)
    {
      /* -k: Ignore for FreeBSD compatibility.  */
    case 'k':
      break;
    case 'm':
      if (arg != NULL && strcmp (arg, "regnames") == 0)
	reg_names_p = true;
    
      else if (arg != NULL && strcmp (arg, "no-regnames") == 0)
	reg_names_p = false;
    
      else
	{
	  as_bad (_("invalid switch -m%s"), arg);
	  return 0;
	}
      break;
    
    case 'A':
      if (arg != NULL && strcmp (arg, "esa") == 0)
	{
	  current_architecture = S390_OPCODE_ESA;
	  s390_arch_size = 32;
	}
      else if (arg != NULL && strcmp (arg, "esame") == 0)
	{
	  current_architecture = S390_OPCODE_ESAME;
	  s390_arch_size = 64;
	}
      else
	as_bad ("invalid architecture -A%s", arg);
      current_arch_mask = 1 << current_architecture;
      current_arch_requested = 1;
      break;

      /* -V: SVR4 argument to print version ID.  */
    case 'V':
      print_version_id ();
      break;
    
      /* -Qy, -Qn: SVR4 arguments controlling whether a .comment section
	 should be emitted or not.  FIXME: Not implemented.  */
    case 'Q':
      break;
      
    default:
      return 0;
    }
  
  return 1;
}

void
md_show_usage (stream)
     FILE *stream;
{
  fprintf (stream, _("\
          S390 options:\n\
          -mregnames   \tAllow symbolic names for registers\n\
          -mno-regnames\tDo not allow symbolic names for registers\n"));
  fprintf (stream, _("\
          -V       \tprint assembler version number\n\
          -Qy, -Qn \tignored\n"));
}

/* This function is called when the assembler starts up.  It is called
   after the options have been parsed and the output file has been
   opened. */

void
md_begin ()
{
  register const struct s390_opcode *op;
  const struct s390_opcode *op_end;
  boolean dup_insn = false;
  const char *retval;

  /* Set the ELF flags if desired. */
  if (s390_flags)
    bfd_set_private_flags (stdoutput, s390_flags);

  /* Insert the opcode formats into a hash table.  */
  s390_opformat_hash = hash_new ();

  op_end = s390_opformats + s390_num_opformats;
  for (op = s390_opformats; op < op_end; op++)
    {
      retval = hash_insert (s390_opformat_hash, op->name, (PTR) op);
      if (retval != (const char *) NULL)
	{
	  as_bad (_("Internal assembler error for instruction format %s"),
		  op->name);
	  dup_insn = true;
	}
    }

  /* Insert the opcodes into a hash table.  */
  s390_opcode_hash = hash_new ();

  op_end = s390_opcodes + s390_num_opcodes;
  for (op = s390_opcodes; op < op_end; op++)
    {
      retval = hash_insert (s390_opcode_hash, op->name, (PTR) op);
      if (retval != (const char *) NULL)
	{
	  as_bad (_("Internal assembler error for instruction %s"), op->name);
	  dup_insn = true;
	}
    }

  if (dup_insn)
    abort ();

  record_alignment (text_section, 2);
  record_alignment (data_section, 2);
  record_alignment (bss_section, 2);

}

/* Called after all assembly has been done.  */
void
s390_md_end ()
{
  if (s390_arch_size == 64)
    bfd_set_arch_mach (stdoutput, bfd_arch_s390, bfd_mach_s390_esame);
  else
    bfd_set_arch_mach (stdoutput, bfd_arch_s390, bfd_mach_s390_esa);
}

void
s390_align_code (fragP, count)
     fragS *fragP;
     int count;
{
  /* We use nop pattern 0x0707.  */
  if (count > 0)
    {
      memset(fragP->fr_literal + fragP->fr_fix, 0x07, count);
      fragP->fr_var = count;
    }
}

/* Insert an operand value into an instruction.  */

static void
s390_insert_operand (insn, operand, val, file, line)
     unsigned char *insn;
     const struct s390_operand *operand;
     offsetT val;
     char *file;
     unsigned int line;
{
  addressT uval;
  int offset;

  if (operand->flags & (S390_OPERAND_SIGNED|S390_OPERAND_PCREL))
    {
      offsetT min, max;

      max = ((offsetT) 1 << (operand->bits - 1)) - 1;
      min = - ((offsetT) 1 << (operand->bits - 1));
      /* Halve PCREL operands.  */
      if (operand->flags & S390_OPERAND_PCREL)
	val >>= 1;
      /* Check for underflow / overflow.  */
      if (val < min || val > max)
	{
	  const char *err =
	    "operand out of range (%s not between %ld and %ld)";
	  char buf[100];

	  if (operand->flags & S390_OPERAND_PCREL)
	    {
	      val <<= 1;
	      min <<= 1;
	      max <<= 1;
	    }
	  sprint_value (buf, val);
	  if (file == (char *) NULL)
	    as_bad (err, buf, (int) min, (int) max);
	  else
	    as_bad_where (file, line, err, buf, (int) min, (int) max);
	  return;
	}
      /* val is ok, now restrict it to operand->bits bits.  */
      uval = (addressT) val & ((((addressT) 1 << (operand->bits-1)) << 1) - 1);
    }
  else
    {
      addressT min, max;
      
      max = (((addressT) 1 << (operand->bits - 1))<<1) - 1;
      min = (offsetT) 0;
      uval = (addressT) val;
      /* Length x in an instructions has real length x+1.  */
      if (operand->flags & S390_OPERAND_LENGTH)
	uval--;
      /* Check for underflow / overflow.  */
      if (uval < min || uval > max)
	{
	  const char *err =
	    "operand out of range (%s not between %ld and %ld)";
	  char buf[100];
    
	  if (operand->flags & S390_OPERAND_LENGTH)
	    {
	      uval++;
	      min++;
	      max++;
	    }
	  sprint_value (buf, uval);
	  if (file == (char *) NULL)
	    as_bad (err, buf, (int) min, (int) max);
	  else
	    as_bad_where (file, line, err, buf, (int) min, (int) max);
	  return;
	}
    }

  /* Insert fragments of the operand byte for byte.  */
  offset = operand->shift + operand->bits;
  uval <<= (-offset) & 7;
  insn += (offset - 1)/8;
  while (uval != 0)
    {
      *insn-- |= uval;
      uval >>= 8;
    }
}

/* Structure used to hold suffixes.  */
typedef enum
  {
    ELF_SUFFIX_NONE = 0,
    ELF_SUFFIX_GOT,
    ELF_SUFFIX_PLT,
    ELF_SUFFIX_GOTENT
  }
elf_suffix_type;

struct map_bfd
  {
    char *string;
    int length;
    elf_suffix_type suffix;
  };

/* Parse @got/@plt/@gotoff. and return the desired relocation.  */
static elf_suffix_type
s390_elf_suffix (str_p, exp_p)
     char **str_p;
     expressionS *exp_p;
{
  static struct map_bfd mapping[] =
  {
    { "got", 3, ELF_SUFFIX_GOT  },
    { "got12", 5, ELF_SUFFIX_GOT  },
    { "plt", 3, ELF_SUFFIX_PLT  },
    { "gotent", 6, ELF_SUFFIX_GOTENT },
    { NULL,  0, ELF_SUFFIX_NONE }
  };

  struct map_bfd *ptr;
  char *str = *str_p;
  char *ident;
  int len;

  if (*str++ != '@')
    return ELF_SUFFIX_NONE;

  ident = str;
  while (isalnum(*str))
    str++;
  len = str - ident;

  for (ptr = &mapping[0]; ptr->length > 0; ptr++)
    if (len == ptr->length &&
	strncasecmp(ident, ptr->string, ptr->length) == 0)
      {
	if (exp_p->X_add_number != 0)
	  as_warn (_("identifier+constant@%s means identifier@%s+constant"),
		   ptr->string, ptr->string);
	/* Now check for identifier@suffix+constant.  */
	if (*str == '-' || *str == '+')
	  {
	    char *orig_line = input_line_pointer;
	    expressionS new_exp;

	    input_line_pointer = str;
	    expression (&new_exp);

	    switch (new_exp.X_op)
	      {
	      case O_constant: /* X_add_number (a constant expression).  */
		exp_p->X_add_number += new_exp.X_add_number;
		str = input_line_pointer;
		break;
	      case O_symbol:   /* X_add_symbol + X_add_number.  */
		/* this case is used for e.g. xyz@PLT+.Label.  */
		exp_p->X_add_number += new_exp.X_add_number;
		exp_p->X_op_symbol = new_exp.X_add_symbol;
		exp_p->X_op = O_add;
		str = input_line_pointer;
		break;
	      case O_uminus:   /* (- X_add_symbol) + X_add_number.  */
		/* this case is used for e.g. xyz@PLT-.Label.  */
		exp_p->X_add_number += new_exp.X_add_number;
		exp_p->X_op_symbol = new_exp.X_add_symbol;
		exp_p->X_op = O_subtract;
		str = input_line_pointer;
		break;
	      default:
		break;
	      }

	    /* If s390_elf_suffix has not been called with
	       &input_line_pointer as first parameter, we have
	       clobbered the input_line_pointer. We have to
	       undo that.  */
	    if (&input_line_pointer != str_p)
	      input_line_pointer = orig_line;
	  }
	*str_p = str;
	return ptr->suffix;
      }

  return BFD_RELOC_UNUSED;
}

/* Structure used to hold a literal pool entry.  */
struct s390_lpe
  {
    struct s390_lpe *next;
    expressionS ex;
    FLONUM_TYPE floatnum;     /* used if X_op == O_big && X_add_number <= 0 */
    LITTLENUM_TYPE bignum[4]; /* used if X_op == O_big && X_add_number > 0  */
    int nbytes;
    bfd_reloc_code_real_type reloc;
    symbolS *sym;
  };

static struct s390_lpe *lpe_free_list = NULL;
static struct s390_lpe *lpe_list = NULL;
static struct s390_lpe *lpe_list_tail = NULL;
static symbolS *lp_sym = NULL;
static int lp_count = 0;
static int lpe_count = 0;

static int
s390_exp_compare(exp1, exp2)
     expressionS *exp1;
     expressionS *exp2;
{
  if (exp1->X_op != exp2->X_op)
    return 0;

  switch (exp1->X_op)
    {
    case O_constant:   /* X_add_number must be equal.  */
    case O_register:
      return exp1->X_add_number == exp2->X_add_number;

    case O_big:
      as_bad(_("Can't handle O_big in s390_exp_compare")); 

    case O_symbol:     /* X_add_symbol & X_add_number must be equal.  */
    case O_symbol_rva:
    case O_uminus:
    case O_bit_not:
    case O_logical_not:
      return (exp1->X_add_symbol == exp2->X_add_symbol) &&
	(exp1->X_add_number == exp2->X_add_number);

    case O_multiply:   /* X_add_symbol,X_op_symbol&X_add_number must be equal.  */
    case O_divide:
    case O_modulus:
    case O_left_shift:
    case O_right_shift:
    case O_bit_inclusive_or:
    case O_bit_or_not:
    case O_bit_exclusive_or:
    case O_bit_and:
    case O_add:
    case O_subtract:
    case O_eq:
    case O_ne:
    case O_lt:
    case O_le:
    case O_ge:
    case O_gt:
    case O_logical_and:
    case O_logical_or:
      return (exp1->X_add_symbol == exp2->X_add_symbol) &&
	     (exp1->X_op_symbol == exp2->X_op_symbol) &&
	     (exp1->X_add_number == exp2->X_add_number);
    default:
    return 0;
  }
}

/* Test for @lit and if its present make an entry in the literal pool and
   modify the current expression to be an offset into the literal pool.  */
static elf_suffix_type
s390_lit_suffix (str_p, exp_p, suffix)
     char **str_p;
     expressionS *exp_p;
     elf_suffix_type suffix;
{
  bfd_reloc_code_real_type reloc;
  char tmp_name[64];
  char *str = *str_p;
  char *ident;
  struct s390_lpe *lpe;
  int nbytes, len;

  if (*str++ != ':')
    return suffix;       /* No modification.  */
 
  /* We look for a suffix of the form "@lit1", "@lit2", "@lit4" or "@lit8".  */
  ident = str;
  while (isalnum(*str))
    str++;
  len = str - ident;
  if (len != 4 || strncasecmp(ident, "lit", 3) != 0 ||
      (ident[3]!='1' && ident[3]!='2' && ident[3]!='4' && ident[3]!='8'))
    return suffix;      /* no modification */
  nbytes = ident[3] - '0';

  reloc = BFD_RELOC_UNUSED;
  if (suffix == ELF_SUFFIX_GOT)
    {
      if (nbytes == 2)
	reloc = BFD_RELOC_390_GOT16;
      else if (nbytes == 4)
	reloc = BFD_RELOC_32_GOT_PCREL;
      else if (nbytes == 8)
	reloc = BFD_RELOC_390_GOT64;
    }
  else if (suffix == ELF_SUFFIX_PLT)
    {
      if (nbytes == 4)
	reloc = BFD_RELOC_390_PLT32;
      else if (nbytes == 8)
	reloc = BFD_RELOC_390_PLT64;
    }

  if (suffix != ELF_SUFFIX_NONE && reloc == BFD_RELOC_UNUSED)
    as_bad (_("Invalid suffix for literal pool entry"));

  /* Search the pool if the new entry is a duplicate.  */
  if (exp_p->X_op == O_big)
    {
      /* Special processing for big numbers.  */
      for (lpe = lpe_list; lpe != NULL; lpe = lpe->next)
	{
	  if (lpe->ex.X_op == O_big)
	    {
	      if (exp_p->X_add_number <= 0 && lpe->ex.X_add_number <= 0)
		{
		  if (memcmp (&generic_floating_point_number, &lpe->floatnum,
			      sizeof (FLONUM_TYPE)) == 0)
		    break;
		}
	      else if (exp_p->X_add_number == lpe->ex.X_add_number)
		{
		  if (memcmp (generic_bignum, lpe->bignum,
			      sizeof (LITTLENUM_TYPE)*exp_p->X_add_number) == 0)
		    break;
		}
	    }
	}
    }
  else
    {
      /* Processing for 'normal' data types.  */
      for (lpe = lpe_list; lpe != NULL; lpe = lpe->next)
	if (lpe->nbytes == nbytes && lpe->reloc == reloc &&
	    s390_exp_compare(exp_p, &lpe->ex) != 0)
	  break;
    }

  if (lpe == NULL)
    {
      /* A new literal.  */
      if (lpe_free_list != NULL)
	{
	  lpe = lpe_free_list;
	  lpe_free_list = lpe_free_list->next;
	}
      else
	{
	  lpe = (struct s390_lpe *) xmalloc(sizeof(struct s390_lpe));
	}

      lpe->ex = *exp_p;

      if (exp_p->X_op == O_big)
	{
	  if (exp_p->X_add_number <= 0)
	    lpe->floatnum = generic_floating_point_number;
	  else if (exp_p->X_add_number <= 4)
	    memcpy (lpe->bignum, generic_bignum,
		    exp_p->X_add_number*sizeof(LITTLENUM_TYPE));
	  else
	    as_bad (_("Big number is too big"));
	}

      lpe->nbytes = nbytes;
      lpe->reloc = reloc;
      /* Literal pool name defined ?  */
      if (lp_sym == NULL)
	{
	  sprintf(tmp_name, ".L\001%i", lp_count);
	  lp_sym = symbol_make(tmp_name);
	}

      /* Make name for literal pool entry.  */
      sprintf(tmp_name, ".L\001%i\002%i", lp_count, lpe_count);
      lpe_count++;
      lpe->sym = symbol_make(tmp_name);

      /* Add to literal pool list.  */
      lpe->next = NULL;
      if (lpe_list_tail != NULL)
	{
	  lpe_list_tail->next = lpe;
	  lpe_list_tail = lpe;
	}
      else
	lpe_list = lpe_list_tail = lpe;
    }
  
  /* Now change exp_p to the offset into the literal pool.
     Thats the expression: .L^Ax^By-.L^Ax   */
  exp_p->X_add_symbol = lpe->sym;
  exp_p->X_op_symbol = lp_sym;
  exp_p->X_op = O_subtract;
  exp_p->X_add_number = 0;

  *str_p = str;

  /* We change the suffix type to ELF_SUFFIX_NONE, because
     the difference of two local labels is just a number.  */
  return ELF_SUFFIX_NONE;
}

/* Like normal .long/.short/.word, except support @got, etc.
   clobbers input_line_pointer, checks end-of-line.  */
static void
s390_elf_cons (nbytes)
     register int nbytes;	/* 1=.byte, 2=.word, 4=.long */
{
  expressionS exp;
  elf_suffix_type suffix;

  if (is_it_end_of_statement ())
    {
      demand_empty_rest_of_line ();
      return;
    }

  do
    {
      expression (&exp);

      if (exp.X_op == O_symbol
	  && *input_line_pointer == '@'
	  && (suffix = s390_elf_suffix (&input_line_pointer, &exp)) != ELF_SUFFIX_NONE)
	{
	  bfd_reloc_code_real_type reloc;
	  reloc_howto_type *reloc_howto;
	  int size;
	  char *where;

	  if (nbytes == 2 && suffix == ELF_SUFFIX_GOT)
	    reloc = BFD_RELOC_390_GOT16;
	  else if (nbytes == 4 && suffix == ELF_SUFFIX_GOT)
	    reloc = BFD_RELOC_32_GOT_PCREL;
	  else if (nbytes == 8 && suffix == ELF_SUFFIX_GOT)
	    reloc = BFD_RELOC_390_GOT64;
	  else if (nbytes == 4 && suffix == ELF_SUFFIX_PLT)
	    reloc = BFD_RELOC_390_PLT32;
	  else if (nbytes == 8 && suffix == ELF_SUFFIX_PLT)
	    reloc = BFD_RELOC_390_PLT64;
	  else
	    reloc = BFD_RELOC_UNUSED;

	  if (reloc != BFD_RELOC_UNUSED)
	    {
	      reloc_howto = bfd_reloc_type_lookup (stdoutput, reloc);
	      size = bfd_get_reloc_size (reloc_howto);
	      if (size > nbytes)
		as_bad (_("%s relocations do not fit in %d bytes"),
			reloc_howto->name, nbytes);
	      where = frag_more(nbytes);
	      md_number_to_chars (where, 0, size);
	      fix_new_exp (frag_now, where - frag_now->fr_literal, 
			   size, &exp, reloc_howto->pc_relative, reloc);
	    }
	  else
	    as_bad (_("relocation not applicable"));
	}
      else
	emit_expr (&exp, (unsigned int) nbytes);
    }
  while (*input_line_pointer++ == ',');

  input_line_pointer--;		/* Put terminator back into stream. */
  demand_empty_rest_of_line ();
}

/* We need to keep a list of fixups.  We can't simply generate them as
   we go, because that would require us to first create the frag, and
   that would screw up references to ``.''.  */

struct s390_fixup
  {
    expressionS exp;
    int opindex;
    bfd_reloc_code_real_type reloc;
  };

#define MAX_INSN_FIXUPS (4)

/* This routine is called for each instruction to be assembled.  */

char *
md_gather_operands (str, insn, opcode)
     char *str;
     unsigned char *insn;
     const struct s390_opcode *opcode;
{
  struct s390_fixup fixups[MAX_INSN_FIXUPS];
  const struct s390_operand *operand;
  const unsigned char *opindex_ptr;
  elf_suffix_type suffix;
  bfd_reloc_code_real_type reloc;
  int skip_optional;
  int parentheses;
  char *f;
  int fc, i;

  while (isspace(*str)) str++;

  parentheses = 0;
  skip_optional = 0;

  /* Gather the operands.  */
  fc = 0;
  for (opindex_ptr = opcode->operands; *opindex_ptr != 0; opindex_ptr++)
    {
      expressionS ex;
      char *hold;

      operand = s390_operands + *opindex_ptr;
    
      if (skip_optional && (operand->flags & S390_OPERAND_INDEX))
	{
	  /* We do an early skip. For D(X,B) constructions the index
	     register is skipped (X is optional). For D(L,B) the base  
	     register will be the skipped operand, because L is NOT
	     optional.  */
	  skip_optional = 0;
	  continue;
	}
    
      /* Gather the operand.  */
      hold = input_line_pointer;
      input_line_pointer = str;

      if (! register_name (&ex))    /* parse the operand */
	expression (&ex);
    
      str = input_line_pointer;
      input_line_pointer = hold;
    
      /* Write the operand to the insn.  */
      if (ex.X_op == O_illegal)
	as_bad (_("illegal operand"));
      else if (ex.X_op == O_absent)
	as_bad (_("missing operand"));
      else if (ex.X_op == O_register || ex.X_op == O_constant)
	{
	  s390_lit_suffix (&str, &ex, ELF_SUFFIX_NONE);

	  if (ex.X_op != O_register && ex.X_op != O_constant)
	    {
	      /* We need to generate a fixup for the
		 expression returned by s390_lit_suffix.  */
	      if (fc >= MAX_INSN_FIXUPS)
		as_fatal (_("too many fixups"));
	      fixups[fc].exp = ex;
	      fixups[fc].opindex = *opindex_ptr;
	      fixups[fc].reloc = BFD_RELOC_UNUSED;
	      ++fc;
	    }
	  else
	    {
	      if ((operand->flags & S390_OPERAND_INDEX) && ex.X_add_number == 0)
		as_warn("index register specified but zero");
	      if ((operand->flags & S390_OPERAND_BASE) && ex.X_add_number == 0)
		as_warn("base register specified but zero");
	      s390_insert_operand (insn, operand, ex.X_add_number, NULL, 0);
	    }
	}
      else
	{
	  suffix = s390_elf_suffix (&str, &ex);
	  suffix = s390_lit_suffix (&str, &ex, suffix);
	  reloc = BFD_RELOC_UNUSED;

	  if (suffix == ELF_SUFFIX_GOT)
	    {
	      if (operand->flags & S390_OPERAND_DISP)
		reloc = BFD_RELOC_390_GOT12;
	      else if ((operand->flags & S390_OPERAND_SIGNED) &&
		       (operand->bits == 16))
		reloc = BFD_RELOC_390_GOT16;
	      else if ((operand->flags & S390_OPERAND_PCREL) &&
		       (operand->bits == 32))
		reloc = BFD_RELOC_390_GOTENT;
	    }
	  else if (suffix == ELF_SUFFIX_PLT)
	    {
	      if ((operand->flags & S390_OPERAND_PCREL) &&
		  (operand->bits == 16))
		reloc = BFD_RELOC_390_PLT16DBL;
	      else if ((operand->flags & S390_OPERAND_PCREL) &&
		       (operand->bits == 32))
		reloc = BFD_RELOC_390_PLT32DBL;
	    }
	  else if (suffix == ELF_SUFFIX_GOTENT)
	    {
	      if ((operand->flags & S390_OPERAND_PCREL) &&
		  (operand->bits == 32))
		reloc = BFD_RELOC_390_GOTENT;
	    }

	  if (suffix != ELF_SUFFIX_NONE && reloc == BFD_RELOC_UNUSED)
	    as_bad (_("invalid operand suffix"));
	  /* We need to generate a fixup of type 'reloc' for this
	     expression.  */
	  if (fc >= MAX_INSN_FIXUPS)
	    as_fatal (_("too many fixups"));
	  fixups[fc].exp = ex;
	  fixups[fc].opindex = *opindex_ptr;
	  fixups[fc].reloc = reloc;
	  ++fc;
	}
 
      /* Check the next character. The call to expression has advanced
	 str past any whitespace.  */
      if (operand->flags & S390_OPERAND_DISP)
	{
	  /* After a displacement a block in parentheses can start.  */
	  if (*str != '(')
	    {
	      /* Check if parethesed block can be skipped. If the next
		 operand is neiter an optional operand nor a base register
		 then we have a syntax error.  */
	      operand = s390_operands + *(++opindex_ptr);
	      if (!(operand->flags & (S390_OPERAND_INDEX|S390_OPERAND_BASE)))
		as_bad (_("syntax error; missing '(' after displacement"));

	      /* Ok, skip all operands until S390_OPERAND_BASE.  */
	      while (!(operand->flags & S390_OPERAND_BASE))
		operand = s390_operands + *(++opindex_ptr);
	
	      /* If there is a next operand it must be seperated by a comma.  */
	      if (opindex_ptr[1] != '\0')
		{
		  if (*str++ != ',')
		    as_bad(_("syntax error; expected ,"));
		}
	    }
	  else
	    {
	      /* We found an opening parentheses.  */
	      str++;
	      for (f = str; *f != '\0'; f++)
		if (*f == ',' || *f == ')')
		  break;
	      /* If there is no comma until the closing parentheses OR
		 there is a comma right after the opening parentheses,
		 we have to skip optional operands.  */
	      if (*f == ',' && f == str)
		{
		  /* comma directly after '(' ? */
		  skip_optional = 1;
		  str++;
		}
	      else
		skip_optional = (*f != ',');
	    }
	}
      else if (operand->flags & S390_OPERAND_BASE)
	{
	  /* After the base register the parenthesed block ends.  */
	  if (*str++ != ')')
	    as_bad (_("syntax error; missing ')' after base register"));
	  skip_optional = 0;
	  /* If there is a next operand it must be seperated by a comma.  */
	  if (opindex_ptr[1] != '\0')
	    {
	      if (*str++ != ',')
		as_bad (_("syntax error; expected ,"));
	    }
	}
      else
	{
	  /* We can find an 'early' closing parentheses in e.g. D(L) instead
	     of D(L,B).  In this case the base register has to be skipped.  */
	  if (*str == ')')
	    {
	      operand = s390_operands + *(++opindex_ptr);

	      if (!(operand->flags & S390_OPERAND_BASE))
		as_bad (_("syntax error; ')' not allowed here"));
	      str++;
	    }
	  /* If there is a next operand it must be seperated by a comma.  */
	  if (opindex_ptr[1] != '\0')
	    {
	      if (*str++ != ',')
		as_bad(_("syntax error; expected ,"));
	    }
	}
    }

  while (isspace (*str))
    ++str;

  if (*str != '\0')
    {
      char *linefeed;

      if ((linefeed = strchr(str, '\n')) != NULL)
	*linefeed = '\0';
      as_bad (_("junk at end of line: `%s'"), str);
      if (linefeed != NULL)
	*linefeed = '\n';
    }

  /* Write out the instruction.  */
  f = frag_more (opcode->oplen);
  memcpy (f, insn, opcode->oplen);

  /* Create any fixups.  At this point we do not use a
     bfd_reloc_code_real_type, but instead just use the
     BFD_RELOC_UNUSED plus the operand index.  This lets us easily
     handle fixups for any operand type, although that is admittedly
     not a very exciting feature.  We pick a BFD reloc type in
     md_apply_fix3.  */
  for (i = 0; i < fc; i++)
    {
      operand = s390_operands + fixups[i].opindex;

      if (fixups[i].reloc != BFD_RELOC_UNUSED)
	{
	  reloc_howto_type *reloc_howto;
	  fixS *fixP;
	  int size;
      
	  reloc_howto = bfd_reloc_type_lookup (stdoutput, fixups[i].reloc);
	  if (!reloc_howto)
	    abort ();
      
	  size = bfd_get_reloc_size (reloc_howto);

	  if (size < 1 || size > 4)
	    abort ();
      
	  fixP = fix_new_exp (frag_now, 
			      f - frag_now->fr_literal + (operand->shift/8), 
			      size, &fixups[i].exp, reloc_howto->pc_relative,
			      fixups[i].reloc);
	  /* Turn off overflow checking in fixup_segment. This is necessary
	     because fixup_segment will signal an overflow for large 4 byte
	     quantities for GOT12 relocations.  */
	  if (fixups[i].reloc == BFD_RELOC_390_GOT12 ||
	      fixups[i].reloc == BFD_RELOC_390_GOT16)
	    fixP->fx_no_overflow = 1;
	}
      else
	fix_new_exp (frag_now, f - frag_now->fr_literal, 4, &fixups[i].exp,
		     (operand->flags & S390_OPERAND_PCREL) != 0,
		     ((bfd_reloc_code_real_type)
		      (fixups[i].opindex + (int) BFD_RELOC_UNUSED)));
    }
  return str;
}

/* This routine is called for each instruction to be assembled.  */

void
md_assemble (str)
     char *str;
{
  const struct s390_opcode *opcode;
  unsigned char insn[6];
  char *s;

  /* Get the opcode.  */
  for (s = str; *s != '\0' && ! isspace (*s); s++)
    ;
  if (*s != '\0')
    *s++ = '\0';

  /* Look up the opcode in the hash table.  */
  opcode = (struct s390_opcode *) hash_find (s390_opcode_hash, str);
  if (opcode == (const struct s390_opcode *) NULL)
    {
      as_bad (_("Unrecognized opcode: `%s'"), str);
      return;
    }
  else if (!(opcode->architecture & current_arch_mask))
    {
      as_bad("Opcode %s not available in this architecture", str);
      return;
    }

  memcpy (insn, opcode->opcode, sizeof(insn));
  md_gather_operands (s, insn, opcode);
}

#ifndef WORKING_DOT_WORD
/* Handle long and short jumps. We don't support these */
void
md_create_short_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr;
     addressT from_addr, to_addr;
     fragS *frag;
     symbolS *to_symbol;
{
  abort ();
}

void
md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr;
     addressT from_addr, to_addr;
     fragS *frag;
     symbolS *to_symbol;
{
  abort ();
}
#endif

void
s390_bss (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  /* We don't support putting frags in the BSS segment, we fake it
     by marking in_bss, then looking at s_skip for clues.  */

  subseg_set (bss_section, 0);
  demand_empty_rest_of_line ();
}

/* Pseudo-op handling.  */

void
s390_insn(ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  expressionS exp;
  const struct s390_opcode *opformat;
  unsigned char insn[6];
  char *s;

  /* Get the opcode format.  */
  s = input_line_pointer;
  while (*s != '\0' && *s != ',' && ! isspace (*s))
    s++;
  if (*s != ',')
    as_bad (_("Invalid .insn format\n"));
  *s++ = '\0';

  /* Look up the opcode in the hash table.  */
  opformat = (struct s390_opcode *)
    hash_find (s390_opformat_hash, input_line_pointer);
  if (opformat == (const struct s390_opcode *) NULL)
    {
      as_bad (_("Unrecognized opcode format: `%s'"), input_line_pointer);
      return;
    }
  input_line_pointer = s;
  expression (&exp);
  if (exp.X_op == O_constant)
    {
      if (opformat->oplen == 4 ||
	  (opformat->oplen == 2 && exp.X_op < 0x10000))
	md_number_to_chars (insn, exp.X_add_number, opformat->oplen);
      else
	as_bad(_("Invalid .insn format\n"));
    }
  else if (exp.X_op == O_big)
    {
      if (exp.X_add_number > 0 && 
	  opformat->oplen == 6 &&
	  generic_bignum[3] == 0)
	{
	  md_number_to_chars (insn, generic_bignum[2], 2);
	  md_number_to_chars (&insn[2], generic_bignum[1], 2);
	  md_number_to_chars (&insn[4], generic_bignum[0], 2);
	}
      else
	as_bad(_("Invalid .insn format\n"));
    }
  else
    as_bad (_("second operand of .insn not a constant\n"));
  if (*input_line_pointer++ != ',')
    as_bad (_("missing comma after insn constant\n"));

  if ((s = strchr(input_line_pointer, '\n')) != NULL)
    *s = '\0';
  input_line_pointer = md_gather_operands (input_line_pointer, insn, opformat);
  if (s != NULL)
    *s = '\n';
  demand_empty_rest_of_line ();
}

/* The .byte pseudo-op.  This is similar to the normal .byte
   pseudo-op, but it can also take a single ASCII string.  */

static void
s390_byte (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  if (*input_line_pointer != '\"')
    {
      cons (1);
      return;
    }

  /* Gather characters.  A real double quote is doubled.  Unusual
     characters are not permitted.  */
  ++input_line_pointer;
  while (1)
    {
      char c;

      c = *input_line_pointer++;

      if (c == '\"')
	{
	  if (*input_line_pointer != '\"')
	    break;
	  ++input_line_pointer;
	}

      FRAG_APPEND_1_CHAR (c);
    }

  demand_empty_rest_of_line ();
}

/* The .ltorg pseudo-op.This emits all literals defined since the last
   .ltorg or the invocation of gas. Literals are defined with the 
   @lit suffix.  */

static void
s390_literals (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  struct s390_lpe *lpe;

  if (lp_sym == NULL || lpe_count == 0)
    return;     /* nothing to be done */

  /* Emit symbol for start of literal pool.  */
  S_SET_SEGMENT (lp_sym, now_seg);
  S_SET_VALUE (lp_sym, (valueT) frag_now_fix ());
  lp_sym->sy_frag = frag_now;

  while (lpe_list)
    {
      lpe = lpe_list;
      lpe_list = lpe_list->next;
      S_SET_SEGMENT (lpe->sym, now_seg);
      S_SET_VALUE (lpe->sym, (valueT) frag_now_fix ());
      lpe->sym->sy_frag = frag_now;

      /* Emit literal pool entry.  */
      if (lpe->reloc != BFD_RELOC_UNUSED)
	{
	  reloc_howto_type *reloc_howto = 
	    bfd_reloc_type_lookup (stdoutput, lpe->reloc);
	  int size = bfd_get_reloc_size (reloc_howto);
	  char *where;

	  if (size > lpe->nbytes)
	    as_bad (_("%s relocations do not fit in %d bytes"),
		    reloc_howto->name, lpe->nbytes);
	  where = frag_more(lpe->nbytes);
	  md_number_to_chars (where, 0, size);
	  fix_new_exp (frag_now, where - frag_now->fr_literal,
		       size, &lpe->ex, reloc_howto->pc_relative, lpe->reloc);
	}
      else
	{
	  if (lpe->ex.X_op == O_big)
	    {
	      if (lpe->ex.X_add_number <= 0)
		generic_floating_point_number = lpe->floatnum;
	      else
		memcpy (generic_bignum, lpe->bignum,
			lpe->ex.X_add_number*sizeof(LITTLENUM_TYPE));
	    }
	  emit_expr (&lpe->ex, lpe->nbytes);
	}

      lpe->next = lpe_free_list;
      lpe_free_list = lpe;
    }
  lpe_list_tail = NULL;
  lp_sym = NULL;
  lp_count++;
  lpe_count = 0;
}

/* Turn a string in input_line_pointer into a floating point constant
   of type type, and store the appropriate bytes in *litp.  The number
   of LITTLENUMS emitted is stored in *sizep .  An error message is
   returned, or NULL on OK.  */

char *
md_atof (type, litp, sizep)
     int type;
     char *litp;
     int *sizep;
{
  int prec;
  LITTLENUM_TYPE words[4];
  char *t;
  int i;

  switch (type)
    {
    case 'f':
      prec = 2;
      break;

    case 'd':
      prec = 4;
      break;

    default:
      *sizep = 0;
      return "bad call to md_atof";
    }

  t = atof_ieee (input_line_pointer, type, words);
  if (t)
    input_line_pointer = t;

  *sizep = prec * 2;

  for (i = 0; i < prec; i++)
    {
      md_number_to_chars (litp, (valueT) words[i], 2);
      litp += 2;
    }
     
  return NULL;
}

/* Align a section (I don't know why this is machine dependent).  */

valueT
md_section_align (seg, addr)
     asection *seg;
     valueT addr;
{
  int align = bfd_get_section_alignment (stdoutput, seg);

  return ((addr + (1 << align) - 1) & (-1 << align));
}

/* We don't have any form of relaxing.  */

int
md_estimate_size_before_relax (fragp, seg)
     fragS *fragp ATTRIBUTE_UNUSED;
     asection *seg ATTRIBUTE_UNUSED;
{
  abort ();
  return 0;
}

/* Convert a machine dependent frag.  We never generate these.  */

void
md_convert_frag (abfd, sec, fragp)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
     fragS *fragp ATTRIBUTE_UNUSED;
{
  abort ();
}

symbolS *
md_undefined_symbol (name)
     char *name;
{
  if (*name == '_' && *(name+1) == 'G'
      && strcmp(name, "_GLOBAL_OFFSET_TABLE_") == 0)
   {
     if(!GOT_symbol)
      {
        if(symbol_find(name))
          as_bad(_("GOT already in symbol table"));
        GOT_symbol = symbol_new (name, undefined_section,
                                 (valueT) 0, &zero_address_frag);
      }
     return GOT_symbol;
   }
  return 0;
}

/* Functions concerning relocs.  */

/* The location from which a PC relative jump should be calculated,
   given a PC relative reloc.  */

long
md_pcrel_from_section (fixp, sec)
     fixS *fixp;
     segT sec ATTRIBUTE_UNUSED;
{
  return fixp->fx_frag->fr_address + fixp->fx_where;
}

/* Here we decide which fixups can be adjusted to make them relative to
   the beginning of the section instead of the symbol.  Basically we need
   to make sure that the dynamic relocations are done correctly, so in
   some cases we force the original symbol to be used.  */
int
tc_s390_fix_adjustable(fixP)
     fixS * fixP;
{
  /* Prevent all adjustments to global symbols.  */
  if (S_IS_EXTERN (fixP->fx_addsy))
    return 0;
  if (S_IS_WEAK (fixP->fx_addsy))
    return 0;
  /* adjust_reloc_syms doesn't know about the GOT.  */
  if (fixP->fx_r_type == BFD_RELOC_32_GOTOFF
      || fixP->fx_r_type == BFD_RELOC_390_PLT16DBL
      || fixP->fx_r_type == BFD_RELOC_390_PLT32
      || fixP->fx_r_type == BFD_RELOC_390_PLT32DBL
      || fixP->fx_r_type == BFD_RELOC_390_PLT64
      || fixP->fx_r_type == BFD_RELOC_390_GOT12
      || fixP->fx_r_type == BFD_RELOC_390_GOT16
      || fixP->fx_r_type == BFD_RELOC_32_GOT_PCREL
      || fixP->fx_r_type == BFD_RELOC_390_GOT64
      || fixP->fx_r_type == BFD_RELOC_390_GOTENT
      || fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
      || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    return 0;
  return 1;
}

/* Apply a fixup to the object code.  This is called for all the
   fixups we generated by the call to fix_new_exp, above.  In the call
   above we used a reloc code which was the largest legal reloc code
   plus the operand index.  Here we undo that to recover the operand
   index.  At this point all symbol values should be fully resolved,
   and we attempt to completely resolve the reloc.  If we can not do
   that, we determine the correct reloc code and put it back in the
   fixup.  */

int
md_apply_fix3 (fixp, valuep, seg)
     fixS *fixp;
     valueT *valuep;
     segT seg ATTRIBUTE_UNUSED;
{
  char *where;
  valueT value;

  value = *valuep;
  where = fixp->fx_frag->fr_literal + fixp->fx_where;

  if (fixp->fx_subsy != NULL)
    {
      if (!S_IS_DEFINED (fixp->fx_subsy))
	as_bad_where (fixp->fx_file, fixp->fx_line,
		      _("unresolved fx_subsy symbol that must be resolved"));
      value -= S_GET_VALUE(fixp->fx_subsy);
    }

  if (fixp->fx_addsy != NULL)
    {
      /* `*valuep' may contain the value of the symbol on which the reloc
	 will be based; we have to remove it.  */
      if (fixp->fx_addsy->sy_used_in_reloc
	  && S_GET_SEGMENT (fixp->fx_addsy) != absolute_section
	  && S_GET_SEGMENT (fixp->fx_addsy) != undefined_section
	  && ! bfd_is_com_section (S_GET_SEGMENT (fixp->fx_addsy)))
	value -= S_GET_VALUE (fixp->fx_addsy);
      
      if (fixp->fx_pcrel)
	value += fixp->fx_frag->fr_address + fixp->fx_where;
    }
  else
    fixp->fx_done = 1;

  if ((int) fixp->fx_r_type >= (int) BFD_RELOC_UNUSED)
    {
      const struct s390_operand *operand;
      int opindex;
    
      opindex = (int) fixp->fx_r_type - (int) BFD_RELOC_UNUSED;
      operand = &s390_operands[opindex];
      
      if (fixp->fx_done)
	{
	  /* Insert the fully resolved operand value.  */
	  s390_insert_operand (where, operand, (offsetT) value,
			       fixp->fx_file, fixp->fx_line);

	  return 1;
	}
    
      /* Determine a BFD reloc value based on the operand information.
	 We are only prepared to turn a few of the operands into
	 relocs.  */
      fixp->fx_offset = value;
      if (operand->bits == 12 && operand->shift == 20)
	{
	  fixp->fx_size = 2;
	  fixp->fx_where += 2;
	  fixp->fx_r_type = BFD_RELOC_390_12;
	}
      else if (operand->bits == 12 && operand->shift == 36)
	{
	  fixp->fx_size = 2;
	  fixp->fx_where += 4;
	  fixp->fx_r_type = BFD_RELOC_390_12;
	}
      else if (operand->bits == 8 && operand->shift == 8)
	{
	  fixp->fx_size = 1;
	  fixp->fx_where += 1;
	  fixp->fx_r_type = BFD_RELOC_8;
	}
      else if (operand->bits == 16 && operand->shift == 16)
	{
	  fixp->fx_size = 2;
	  fixp->fx_where += 2;
	  if (operand->flags & S390_OPERAND_PCREL)
	    {
	      fixp->fx_r_type = BFD_RELOC_390_PC16DBL;
	      fixp->fx_offset += 2;
	    }
	  else
	    fixp->fx_r_type = BFD_RELOC_16;
	}
      else if (operand->bits == 32 && operand->shift == 16 &&
	       (operand->flags & S390_OPERAND_PCREL))
	{
	  fixp->fx_size = 4;
	  fixp->fx_where += 2;
	  fixp->fx_offset += 2;
	  fixp->fx_r_type = BFD_RELOC_390_PC32DBL;
	}
      else
	{
	  char *sfile;
	  unsigned int sline;
      
	  /* Use expr_symbol_where to see if this is an expression
	     symbol.  */
	  if (expr_symbol_where (fixp->fx_addsy, &sfile, &sline))
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  _("unresolved expression that must be resolved"));
	  else
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  _("unsupported relocation type"));
	  fixp->fx_done = 1;
	  return 1;
	}
    }
  else
    {
      switch (fixp->fx_r_type)
	{
	case BFD_RELOC_8:
	  if (fixp->fx_pcrel)
	    abort ();
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 1);
	  break;
	case BFD_RELOC_390_12:
	case BFD_RELOC_390_GOT12:
	  if (fixp->fx_done)
	    {
	      unsigned short mop;

	      mop = bfd_getb16 ((unsigned char *) where);
	      mop |= (unsigned short) (value & 0xfff);
	      bfd_putb16 ((bfd_vma) mop, (unsigned char *) where);
	    } 
	  break;
    
	case BFD_RELOC_16:
	case BFD_RELOC_GPREL16:
	case BFD_RELOC_16_GOT_PCREL:
	case BFD_RELOC_16_GOTOFF:
	  if (fixp->fx_pcrel)
	    as_bad_where (fixp->fx_file, fixp->fx_line,
			  "cannot emit PC relative %s relocation%s%s",
			  bfd_get_reloc_code_name (fixp->fx_r_type),
			  fixp->fx_addsy != NULL ? " against " : "",
			  (fixp->fx_addsy != NULL
			   ? S_GET_NAME (fixp->fx_addsy)
			   : ""));
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 2);
	  break;
	case BFD_RELOC_390_GOT16:
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 2);
	  break;
	case BFD_RELOC_390_PC16DBL:
	case BFD_RELOC_390_PLT16DBL:
	  value += 2;
	  if (fixp->fx_done)
	    md_number_to_chars (where, (offsetT) value >> 1, 2);
	  break;

	case BFD_RELOC_32:
	  if (fixp->fx_pcrel)
	    fixp->fx_r_type = BFD_RELOC_32_PCREL;
	  else
	    fixp->fx_r_type = BFD_RELOC_32;
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 4);
	  break;
	case BFD_RELOC_32_PCREL:
	case BFD_RELOC_32_BASEREL:
	  fixp->fx_r_type = BFD_RELOC_32_PCREL;
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 4);
	  break;
	case BFD_RELOC_32_GOT_PCREL:
	case BFD_RELOC_390_PLT32:
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 4);
	  break;
	case BFD_RELOC_390_PC32DBL:
	case BFD_RELOC_390_PLT32DBL:
	case BFD_RELOC_390_GOTPCDBL:
	case BFD_RELOC_390_GOTENT:
	  value += 2;
	  if (fixp->fx_done)
	    md_number_to_chars (where, (offsetT) value >> 1, 4);
	  break;

	case BFD_RELOC_32_GOTOFF:
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, sizeof(int));
	  break;

	case BFD_RELOC_390_GOT64:
	case BFD_RELOC_390_PLT64:
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 8);
	  break;

	case BFD_RELOC_64:
	  if (fixp->fx_pcrel)
	    fixp->fx_r_type = BFD_RELOC_64_PCREL;
	  else
	    fixp->fx_r_type = BFD_RELOC_64;
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 8);
	  break;

	case BFD_RELOC_64_PCREL:
	  fixp->fx_r_type = BFD_RELOC_64_PCREL;
	  if (fixp->fx_done)
	    md_number_to_chars (where, value, 8);
	  break;

	case BFD_RELOC_VTABLE_INHERIT:
	case BFD_RELOC_VTABLE_ENTRY:
	  fixp->fx_done = 0;
	  return 1;

	default:
	  {
	    const char *reloc_name = bfd_get_reloc_code_name (fixp->fx_r_type);
	    
	    if (reloc_name != NULL)
	      fprintf (stderr, "Gas failure, reloc type %s\n", reloc_name);
	    else
	      fprintf (stderr, "Gas failure, reloc type #%i\n", fixp->fx_r_type);
	    fflush (stderr);
	    abort ();
	  }
	}

      fixp->fx_offset = value;
    }

  return 1;
}

/* Generate a reloc for a fixup.  */

arelent *
tc_gen_reloc (seg, fixp)
     asection *seg ATTRIBUTE_UNUSED;
     fixS *fixp;
{
  bfd_reloc_code_real_type code;
  arelent *reloc;

  code = fixp->fx_r_type;
  if (GOT_symbol && fixp->fx_addsy == GOT_symbol)
    {
      if ((s390_arch_size == 32 && code == BFD_RELOC_32_PCREL) ||
	  (s390_arch_size == 64 && code == BFD_RELOC_64_PCREL))
	code = BFD_RELOC_390_GOTPC;
      if (code == BFD_RELOC_390_PC32DBL)
	code = BFD_RELOC_390_GOTPCDBL;
    }

  reloc = (arelent *) xmalloc (sizeof (arelent));
  reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
  *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
  reloc->howto = bfd_reloc_type_lookup (stdoutput, code);
  if (reloc->howto == NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
                    _("cannot represent relocation type %s"),
                    bfd_get_reloc_code_name (code));
      /* Set howto to a garbage value so that we can keep going.  */
      reloc->howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_32);
      assert (reloc->howto != NULL);
    }
  reloc->addend = fixp->fx_offset;

  return reloc;
}