Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
/* tc-xgate.c -- Assembler code for Freescale XGATE
   Copyright (C) 2010-2018 Free Software Foundation, Inc.
   Contributed by Sean Keys <skeys@ipdatasys.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 3, 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, 51 Franklin Street - Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "as.h"
#include "safe-ctype.h"
#include "subsegs.h"
#include "opcode/xgate.h"
#include "dwarf2dbg.h"
#include "elf/xgate.h"

const char comment_chars[] = ";!";
const char line_comment_chars[] = "#*";
const char line_separator_chars[] = "";
const char EXP_CHARS[] = "eE";
const char FLT_CHARS[] = "dD";

/* Max opcodes per opcode handle.  */
#define MAX_OPCODES     0x05

#define SIXTEENTH_BIT		0x8000
#define N_BITS_IN_WORD		16
#define MAX_NUM_OPERANDS	3

/* #define STATE_CONDITIONAL_BRANCH		(1) */
#define STATE_PC_RELATIVE	(2)
#define REGISTER_P(ptr)		(ptr == 'r')
#define INCREMENT		01
#define DECREMENT		02
#define MAXREGISTER		07
#define MINREGISTER		00

#define OPTION_MMCU 'm'

/* This macro has no side-effects.  */
#define ENCODE_RELAX(what,length) (((what) << 2) + (length))

/* Each unique opcode name has a handle.  That handle may
   contain pointers to opcodes with the same name but
   different address modes.  */
struct xgate_opcode_handle
{
  int number_of_modes;
  char *name;
  struct xgate_opcode *opc0[MAX_OPCODES];
};

/* XGATE's registers all are 16-bit general purpose.
   They are numbered according to the specifications.  */
typedef enum register_id
{
  REG_NONE = -1,
  REG_R0 = 0,
  REG_R1 = 1,
  REG_R2 = 2,
  REG_R3 = 3,
  REG_R4 = 4,
  REG_R5 = 5,
  REG_R6 = 6,
  REG_R7 = 7,
  REG_PC = 8,
  REG_CCR = 9
} register_id;

/* Operand Modifiers */
typedef enum op_modifiers
{
  MOD_NONE = -1,
  MOD_POSTINC = 1,
  MOD_PREDEC = 2,
  MOD_CONSTANT = 3,
  MOD_LOAD_HIGH = 4,
  MOD_LOAD_LOW = 5
}op_modifiers;

typedef struct s_operand
{
  expressionS exp;
  register_id reg;
  op_modifiers mod;
} s_operand;


/* Forward declarations.  */
static inline char *skip_whitespace (char *);
static void get_default_target (void);
static char *extract_word (char *, char *, int);
static struct xgate_opcode *xgate_find_match (struct xgate_opcode_handle *,
					      int, s_operand [], unsigned int);
static int cmp_opcode (struct xgate_opcode *, struct xgate_opcode *);
static void xgate_print_table (void);
static unsigned int xgate_get_operands (char *, s_operand []);
static register_id reg_name_search (char *);
static op_modifiers xgate_determine_modifiers (char **);
static void xgate_scan_operands (struct xgate_opcode *opcode, s_operand []);
static unsigned int xgate_parse_operand (struct xgate_opcode *, int *, int,
					 char **, s_operand);

static struct hash_control *xgate_hash;

/* Previous opcode.  */
static unsigned int prev = 0;

static unsigned char fixup_required = 0;

/* Used to enable clipping of 16 bit operands into 8 bit constraints.  */
static unsigned char autoHiLo = 0;

static char oper_check;
static char flag_print_insn_syntax = 0;
static char flag_print_opcodes = 0;

static int current_architecture;
static const char *default_cpu;

/* ELF flags to set in the output file header.  */
static int elf_flags = E_XGATE_F64;

/* This table describes how you change sizes for the various types of variable
   size expressions.  This version only supports two kinds.  */

/* The fields are:
   How far Forward this mode will reach.
   How far Backward this mode will reach.
   How many bytes this mode will add to the size of the frag.
   Which mode to go to if the offset won't fit in this one.  */

relax_typeS md_relax_table[] =
{
  {1, 1, 0, 0},			/* First entries aren't used.  */
  {1, 1, 0, 0},			/* For no good reason except.  */
  {1, 1, 0, 0},			/* that the VAX doesn't either.  */
  {1, 1, 0, 0},
  /* XGATE 9 and 10 bit pc rel todo complete and test */
/*{(511), (-512), 0, ENCODE_RELAX (STATE_PC_RELATIVE, STATE_WORD)},
  {(1023), (-1024), 0, ENCODE_RELAX (STATE_PC_RELATIVE, STATE_WORD)}, */
  {0, 0, 0, 0}
};

/* This table describes all the machine specific pseudo-ops the assembler
   has to support.  The fields are: pseudo-op name without dot function to
   call to execute this pseudo-op Integer arg to pass to the function.  */
const pseudo_typeS md_pseudo_table[] =
{
  /* The following pseudo-ops are supported for MRI compatibility.  */
  {0, 0, 0}
};

const char *md_shortopts = "m:";

struct option md_longopts[] =
{
#define OPTION_PRINT_INSN_SYNTAX  (OPTION_MD_BASE + 0)
  { "print-insn-syntax", no_argument, NULL, OPTION_PRINT_INSN_SYNTAX },

#define OPTION_PRINT_OPCODES  (OPTION_MD_BASE + 1)
  { "print-opcodes", no_argument, NULL, OPTION_PRINT_OPCODES },

#define OPTION_GENERATE_EXAMPLE  (OPTION_MD_BASE + 2)
  { "generate-example", no_argument, NULL, OPTION_GENERATE_EXAMPLE },

#define OPTION_MSHORT  (OPTION_MD_BASE + 3)
  { "mshort", no_argument, NULL, OPTION_MSHORT },

#define OPTION_MLONG  (OPTION_MD_BASE + 4)
  { "mlong", no_argument, NULL, OPTION_MLONG },

#define OPTION_MSHORT_DOUBLE  (OPTION_MD_BASE + 5)
  { "mshort-double", no_argument, NULL, OPTION_MSHORT_DOUBLE },

#define OPTION_MLONG_DOUBLE  (OPTION_MD_BASE + 6)
  { "mlong-double", no_argument, NULL, OPTION_MLONG_DOUBLE },

  { NULL, no_argument, NULL, 0 }
};

size_t md_longopts_size = sizeof (md_longopts);

const char *
md_atof (int type, char *litP, int *sizeP)
{
  return ieee_md_atof (type, litP, sizeP, TRUE);
}

int
md_parse_option (int c, const char *arg)
{
  switch (c)
    {
    case OPTION_MMCU:
      if (strcasecmp (arg, "v1") == 0)
	current_architecture = XGATE_V1;
      else if (strcasecmp (arg, "v2") == 0)
	current_architecture = XGATE_V2;
      else if (strcasecmp (arg, "v3") == 0)
	current_architecture = XGATE_V3;
      else
	as_bad (_("architecture variant invalid"));
      break;

    case OPTION_PRINT_INSN_SYNTAX:
      flag_print_insn_syntax = 1;
      break;

    case OPTION_PRINT_OPCODES:
      flag_print_opcodes = 1;
      break;

    case OPTION_GENERATE_EXAMPLE:
      flag_print_opcodes = 2;
      break;

    case OPTION_MSHORT:
      elf_flags &= ~E_XGATE_I32;
      break;

    case OPTION_MLONG:
      elf_flags |= E_XGATE_I32;
      break;

    case OPTION_MSHORT_DOUBLE:
      elf_flags &= ~E_XGATE_F64;
      break;

    case OPTION_MLONG_DOUBLE:
      elf_flags |= E_XGATE_F64;
      break;

    default:
      return 0;
    }
  return 1;
}

const char *
xgate_arch_format (void)
{
  get_default_target ();

  if (current_architecture & cpuxgate)
    return "elf32-xgate";

  return "error";
}

static void
get_default_target (void)
{
  const bfd_target *target;
  bfd abfd;

  if (current_architecture != 0)
    return;

  default_cpu = "unknown";
  target = bfd_find_target (0, &abfd);

  if (target && target->name)
    {
      if (strcmp (target->name, "elf32-xgate") == 0)
	{
	  current_architecture = cpuxgate;
	  default_cpu = "XGATE V1";
	  return;
	}

      as_bad (_("Default target `%s' is not supported."), target->name);
    }
}

void
md_begin (void)
{
  struct xgate_opcode *xgate_opcode_ptr = NULL;
  struct xgate_opcode *xgate_op_table = NULL;
  struct xgate_opcode_handle *op_handles = 0;
  const char *prev_op_name = 0;
  int handle_enum = 0;
  int number_of_op_handles = 0;
  int i, j = 0;

  /* Create a local copy of our opcode table
     including an extra line for NULL termination.  */
  xgate_op_table = XNEWVEC (struct xgate_opcode, xgate_num_opcodes);

  memset (xgate_op_table, 0,
	  sizeof (struct xgate_opcode) * (xgate_num_opcodes));

  for (xgate_opcode_ptr = (struct xgate_opcode*) xgate_opcodes, i = 0;
       i < xgate_num_opcodes; i++)
    xgate_op_table[i] = xgate_opcode_ptr[i];

  qsort (xgate_op_table, xgate_num_opcodes, sizeof (struct xgate_opcode),
	 (int (*)(const void *, const void *)) cmp_opcode);

  /* Calculate number of handles since this will be
     smaller than the raw number of opcodes in the table.  */
  prev_op_name = "";
  for (xgate_opcode_ptr = xgate_op_table, i = 0;  i < xgate_num_opcodes;
       xgate_opcode_ptr++, i++)
    {
      if (strcmp (prev_op_name, xgate_opcode_ptr->name))
	number_of_op_handles++;
      prev_op_name = xgate_opcode_ptr->name;
    }

  op_handles = XNEWVEC (struct xgate_opcode_handle, number_of_op_handles);

  /* Insert unique opcode names into hash table, aliasing duplicates.  */
  xgate_hash = hash_new ();

  prev_op_name = "";
  for (xgate_opcode_ptr = xgate_op_table, i = 0, j = 0; i < xgate_num_opcodes;
       i++, xgate_opcode_ptr++)
    {
      if (!strcmp (prev_op_name, xgate_opcode_ptr->name))
	{
	  handle_enum++;
	  op_handles[j].opc0[handle_enum] = xgate_opcode_ptr;
	}
      else
	{
	  handle_enum = 0;
	  if (i)
	    j++;
	  op_handles[j].name = xgate_opcode_ptr->name;
	  op_handles[j].opc0[0] = xgate_opcode_ptr;
	  hash_insert (xgate_hash, (char *) op_handles[j].name,
		       (char *) &(op_handles[j]));
	}
      op_handles[j].number_of_modes = handle_enum;
      prev_op_name = op_handles[j].name;
    }

  if (flag_print_opcodes)
    {
      xgate_print_table ();
      exit (EXIT_SUCCESS);
    }
}

void
xgate_init_after_args (void)
{
}

void
md_show_usage (FILE * stream)
{
  get_default_target ();

  fprintf (stream,
	   _("\
Freescale XGATE co-processor options:\n\
  -mshort                 use 16-bit int ABI (default)\n\
  -mlong                  use 32-bit int ABI\n\
  -mshort-double          use 32-bit double ABI\n\
  -mlong-double           use 64-bit double ABI (default)\n\
  --mxgate                specify the processor variant [default %s]\n\
  --print-insn-syntax     print the syntax of instruction in case of error\n\
  --print-opcodes         print the list of instructions with syntax\n\
  --generate-example      generate an example of each instruction"),
	   default_cpu);
}

enum bfd_architecture
xgate_arch (void)
{
  get_default_target ();
  return bfd_arch_xgate;
}

int
xgate_mach (void)
{
  return 0;
}

static void
xgate_print_syntax (char *name)
{
  int i;

  for (i = 0; i < xgate_num_opcodes; i++)
    {
      if (!strcmp (xgate_opcodes[i].name, name))
	{
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IDR))
	    printf ("\tFormat is %s\tRx, Rx, Rx+|-Rx|Rx\n",
		    xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_INH))
	    printf ("\tFormat is %s\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_TRI))
	    printf ("\tFormat is %s\tRx, Rx, Rx\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_DYA))
	    printf ("\tFormat is %s\tRx, Rx\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IMM3))
	    printf ("\tFormat is %s\t<3-bit value>\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IMM4))
	    printf ("\tFormat is %s\t<4 -bit value>\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IMM8))
	    printf ("\tFormat is %s\tRx, <8-bit value>\n",
		    xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IMM16))
	    printf ("\tFormat is %s\tRx, <16-bit value>\n",
		    xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_MON_R_C))
	    printf ("\tFormat is %s\tRx, CCR\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_MON_C_R))
	    printf ("\tFormat is %s\tCCR, Rx\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_MON_R_P))
	    printf ("\tFormat is %s\tRx, PC\n", xgate_opcodes[i].name);
	  if (!strcmp (xgate_opcodes[i].constraints, XGATE_OP_IMM16mLDW))
	    printf ("\tFormat is %s\tRx, <16-bit value>\n",
		    xgate_opcodes[i].name);
	}
    }
}

static void
xgate_print_table (void)
{
  int i;

  for (i = 0; i < xgate_num_opcodes; i++)
    xgate_print_syntax (xgate_opcodes[i].name);

  return;
}

const char *
xgate_listing_header (void)
{
  if (current_architecture & cpuxgate)
    return "XGATE GAS ";

  return "ERROR MC9S12X GAS ";
}

symbolS *
md_undefined_symbol (char *name ATTRIBUTE_UNUSED)
{
  return NULL;
}

/* GAS will call this function for each section at the end of the assembly,
   to permit the CPU backend to adjust the alignment of a section.  */

valueT
md_section_align (asection * seg, valueT addr)
{
  int align = bfd_get_section_alignment (stdoutput, seg);
  return ((addr + (1 << align) - 1) & -(1 << align));
}

void
md_assemble (char *input_line)
{
  struct xgate_opcode *opcode = 0;
  struct xgate_opcode *macro_opcode = 0;
  struct xgate_opcode_handle *opcode_handle = 0;
  /* Caller expects it to be returned as it was passed.  */
  char *saved_input_line = input_line;
  char op_name[9] =  { 0 };
  unsigned int operandCount = 0;
  char *p = 0;

  s_operand new_operands[MAX_NUM_OPERANDS];

  fixup_required = 0;
  oper_check = 0; /* set error flags */
  input_line = extract_word (input_line, op_name, sizeof (op_name));

  /* Check to make sure we are not reading a bogus line.  */
  if (!op_name[0])
    as_bad (_("opcode missing or not found on input line"));

  if (!(opcode_handle = (struct xgate_opcode_handle *) hash_find (xgate_hash,
								  op_name)))
    {
      as_bad (_("opcode %s not found in opcode hash table"), op_name);
    }
  else
    {
      /* Parse operands so we can find the proper opcode bin.  */

      operandCount = xgate_get_operands (input_line, new_operands);

      opcode = xgate_find_match (opcode_handle, opcode_handle->number_of_modes,
				 new_operands, operandCount);

      if (!opcode)
	{
	  as_bad (_("matching operands to opcode"));
	  xgate_print_syntax (opcode_handle->opc0[0]->name);
	}
      else if (opcode->size == 2)
	{
	  /* Size is one word - assemble that native insn.  */
	  xgate_scan_operands (opcode, new_operands);
	}
      else
	{
	  /* Insn is a simplified instruction - expand it out.  */
	  autoHiLo = 1;
	  unsigned int i;

	  /* skip past our ';' separator.  */
	  for (i = strlen (opcode->constraints), p = opcode->constraints; i > 0;
	       i--, p++)
	    {
	      if (*p == ';')
		{
		  p++;
		  break;
		}
	    }
	  input_line = skip_whitespace (input_line);
	  char *macro_inline = input_line;

	  /* Loop though the macro's opcode list and apply operands to
	     each real opcode. */
	  for (i = 0; *p && i < (opcode->size / 2); i++)
	    {
	      /* Loop though macro operand list.  */
	      input_line = macro_inline; /* Rewind.  */
	      p = extract_word (p, op_name, 10);

	      if (!(opcode_handle = (struct xgate_opcode_handle *)
		    hash_find (xgate_hash, op_name)))
		{
		  as_bad (_(": processing macro, real opcode handle"
			    " not found in hash"));
		  break;
		}
	      else
		{
		  operandCount = xgate_get_operands (input_line, new_operands);
		  macro_opcode = xgate_find_match (opcode_handle,
						   opcode_handle->number_of_modes, new_operands,
						   operandCount);
		  xgate_scan_operands (macro_opcode, new_operands);
		}
	    }
	}
    }
  autoHiLo = 0;
  input_line = saved_input_line;
}

/* Force truly undefined symbols to their maximum size, and generally set up
   the frag list to be relaxed.  */

int
md_estimate_size_before_relax (fragS *fragp, asection *seg)
{
  /* If symbol is undefined or located in a different section,
     select the largest supported relocation.  */
  relax_substateT subtype;
  relax_substateT rlx_state[] = { 0, 2 };

  for (subtype = 0; subtype < ARRAY_SIZE (rlx_state); subtype += 2)
    {
      if (fragp->fr_subtype == rlx_state[subtype]
	  && (!S_IS_DEFINED (fragp->fr_symbol)
	      || seg != S_GET_SEGMENT (fragp->fr_symbol)))
	{
	  fragp->fr_subtype = rlx_state[subtype + 1];
	  break;
	}
    }

  if (fragp->fr_subtype >= ARRAY_SIZE (md_relax_table))
    abort ();

  return md_relax_table[fragp->fr_subtype].rlx_length;
}


/* Relocation, relaxation and frag conversions.  */

/* PC-relative offsets are relative to the start of the
   next instruction.  That is, the address of the offset, plus its
   size, since the offset is always the last part of the insn.  */

long
md_pcrel_from (fixS * fixP)
{
  return fixP->fx_size + fixP->fx_where + fixP->fx_frag->fr_address;
}

/* If while processing a fixup, a reloc really needs to be created
   then it is done here.  */

arelent *
tc_gen_reloc (asection * section ATTRIBUTE_UNUSED, fixS * fixp)
{
  arelent * reloc;

  reloc = XNEW (arelent);
  reloc->sym_ptr_ptr = XNEW (asymbol *);
  *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;

  if (fixp->fx_r_type == 0)
    reloc->howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_16);
  else
    reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);

  if (reloc->howto == (reloc_howto_type *) NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line, _
		    ("Relocation %d is not supported by object file format."),
		    (int) fixp->fx_r_type);
      return NULL;
    }

  /* Since we use Rel instead of Rela, encode the vtable entry to be
     used in the relocation's section offset.  */
  if (fixp->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    reloc->address = fixp->fx_offset;
  reloc->addend = 0;
  return reloc;
}

/* Patch the instruction with the resolved operand.  Elf relocation
   info will also be generated to take care of linker/loader fixups.
   The XGATE addresses only 16-bit addresses.The BFD_RELOC_32 is necessary
   for the support of --gstabs.  */

void
md_apply_fix (fixS * fixP, valueT * valP, segT seg ATTRIBUTE_UNUSED)
{
  char *where;
  long value = *valP;
  int opcode = 0;
  ldiv_t result;

  /* If the fixup is done mark it done so no further symbol resolution
     will take place.  */
  if (fixP->fx_addsy == (symbolS *) NULL)
    fixP->fx_done = 1;

  /* We don't actually support subtracting a symbol.  */
  if (fixP->fx_subsy != (symbolS *) NULL)
    as_bad_where (fixP->fx_file, fixP->fx_line, _("Expression too complex."));

  where = fixP->fx_frag->fr_literal + fixP->fx_where;
  opcode = bfd_getl16 (where);
  int mask = 0;

  switch (fixP->fx_r_type)
    {
    case R_XGATE_PCREL_9:
      if (value < -512 || value > 511)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value %ld too large for 9-bit PC-relative branch."),
		      value);
      result = ldiv (value, 2); /* from bytes to words */
      value = result.quot;
      if (result.rem)
	as_bad_where (fixP->fx_file, fixP->fx_line, _
		      ("Value %ld not aligned by 2 for 9-bit"
		       " PC-relative branch."), value);
      /* Clip into 8-bit field.
	 FIXME I'm sure there is a more proper place for this.  */
      mask = 0x1FF;
      value &= mask;
      number_to_chars_bigendian (where, (opcode | value), 2);
      break;
    case R_XGATE_PCREL_10:
      if (value < -1024 || value > 1023)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value %ld too large for 10-bit PC-relative branch."),
		      value);
      result = ldiv (value, 2); /* from bytes to words */
      value = result.quot;
      if (result.rem)
	as_bad_where (fixP->fx_file, fixP->fx_line, _
		      ("Value %ld not aligned by 2 for 10-bit"
		       " PC-relative branch."), value);
      /* Clip into 9-bit field.
	 FIXME I'm sure there is a more proper place for this.  */
      mask = 0x3FF;
      value &= mask;
      number_to_chars_bigendian (where, (opcode | value), 2);
      break;
    case BFD_RELOC_XGATE_IMM8_HI:
      if (value < -65537 || value > 65535)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value out of 16-bit range."));
      value >>= 8;
      value &= 0x00ff;
      bfd_putb16 ((bfd_vma) value | opcode, (void *) where);
      break;
    case BFD_RELOC_XGATE_24:
    case BFD_RELOC_XGATE_IMM8_LO:
      if (value < -65537 || value > 65535)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value out of 16-bit range."));
      value &= 0x00ff;
      bfd_putb16 ((bfd_vma) value | opcode, (void *) where);
      break;
    case BFD_RELOC_XGATE_IMM3:
      if (value < 0 || value > 7)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value out of 3-bit range."));
      value <<= 8; /* make big endian */
      number_to_chars_bigendian (where, (opcode | value), 2);
      break;
    case BFD_RELOC_XGATE_IMM4:
      if (value < 0 || value > 15)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value out of 4-bit range."));
      value <<= 4; /* align the operand bits */
      number_to_chars_bigendian (where, (opcode | value), 2);
      break;
    case BFD_RELOC_XGATE_IMM5:
      if (value < 0 || value > 31)
	as_bad_where (fixP->fx_file, fixP->fx_line,
		      _("Value out of 5-bit range."));
      value <<= 5; /* align the operand bits */
      number_to_chars_bigendian (where, (opcode | value), 2);
      break;
    case BFD_RELOC_8:
      ((bfd_byte *) where)[0] = (bfd_byte) value;
      break;
    case BFD_RELOC_32:
      bfd_putb32 ((bfd_vma) value, (unsigned char *) where);
      break;
    case BFD_RELOC_16:
      bfd_putb16 ((bfd_vma) value, (unsigned char *) where);
      break;
    default:
      as_fatal (_("Line %d: unknown relocation type: 0x%x."), fixP->fx_line,
		fixP->fx_r_type);
      break;
    }
}

/* See whether we need to force a relocation into the output file.  */

int
tc_xgate_force_relocation (fixS * fixP)
{
  if (fixP->fx_r_type == BFD_RELOC_XGATE_RL_GROUP)
    return 1;
  return generic_force_reloc (fixP);
}

/* 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 linker relaxation is done
   correctly, so in some cases we force the original symbol to be
   used.  */

int
tc_xgate_fix_adjustable (fixS * fixP)
{
  switch (fixP->fx_r_type)
    {
      /* For the linker relaxation to work correctly, these relocs
	 need to be on the symbol itself.  */
    case BFD_RELOC_16:
    case BFD_RELOC_XGATE_RL_JUMP:
    case BFD_RELOC_XGATE_RL_GROUP:
    case BFD_RELOC_VTABLE_INHERIT:
    case BFD_RELOC_VTABLE_ENTRY:
    case BFD_RELOC_32:
      return 0;
    default:
      return 1;
    }
}

void
md_convert_frag (bfd * abfd ATTRIBUTE_UNUSED,
		 asection * sec ATTRIBUTE_UNUSED,
		 fragS * fragP ATTRIBUTE_UNUSED)
{
  as_bad (("md_convert_frag not implemented yet"));
  abort ();
}

/* Set the ELF specific flags.  */

void
xgate_elf_final_processing (void)
{
  elf_flags |= EF_XGATE_MACH;
  elf_elfheader (stdoutput)->e_flags &= ~EF_XGATE_ABI;
  elf_elfheader (stdoutput)->e_flags |= elf_flags;
}

static inline char *
skip_whitespace (char *s)
{
  while (*s == ' ' || *s == '\t' || *s == '(' || *s == ')')
    s++;

  return s;
}

/* Extract a word (continuous alpha-numeric chars) from the input line.  */

static char *
extract_word (char *from, char *to, int limit)
{
  char *op_end;
  int size = 0;

  /* Drop leading whitespace.  */
  from = skip_whitespace (from);
  *to = 0;
  /* Find the op code end.  */
  for (op_end = from; *op_end != 0 && is_part_of_name (*op_end);)
    {
      to[size++] = *op_end++;
      if (size + 1 >= limit)
	break;
    }
  to[size] = 0;
  return op_end;
}

static char *
xgate_new_instruction (int size)
{
  char *f = frag_more (size);
  dwarf2_emit_insn (size);
  return f;
}

static unsigned short
xgate_apply_operand (unsigned short new_mask,
		     unsigned short *availiable_mask_bits,
		     unsigned short mask,
		     unsigned char n_bits)
{
  unsigned short n_shifts;
  unsigned int n_drop_bits;

  /* Shift until you find an available operand bit "1" and record
     the number of shifts.  */
  for (n_shifts = 0;
       !(*availiable_mask_bits & SIXTEENTH_BIT) && n_shifts < 16;
       n_shifts++)
    *availiable_mask_bits <<= 1;

  /* Shift for the number of bits your operand requires while bits
     are available.  */
  for (n_drop_bits = n_bits;
       n_drop_bits && (*availiable_mask_bits & SIXTEENTH_BIT);
       --n_drop_bits)
    *availiable_mask_bits <<= 1;

  if (n_drop_bits)
    as_bad (_(":operand has too many bits"));
  *availiable_mask_bits >>= n_shifts + n_bits;
  if ((n_drop_bits == 0) && (*availiable_mask_bits == 0))
    {
      oper_check = 1; /* flag operand check as good */
    }
  new_mask <<= N_BITS_IN_WORD - (n_shifts + n_bits);
  mask |= new_mask;
  return mask;
}

/* Parse ordinary expression.  */

static char *
xgate_parse_exp (char *s, expressionS * op)
{
  input_line_pointer = s;

  expression (op);
  if (op->X_op == O_absent)
    as_bad (_("missing operand"));
  return input_line_pointer;
}

static int
cmp_opcode (struct xgate_opcode *op1, struct xgate_opcode *op2)
{
  return strcmp (op1->name, op2->name);
}

static struct xgate_opcode *
xgate_find_match (struct xgate_opcode_handle *opcode_handle,
		  int numberOfModes, s_operand oprs[], unsigned int operandCount)
{
  int i;

  if (numberOfModes == 0)
    return opcode_handle->opc0[0];

  for (i = 0; i <= numberOfModes; i++)
    {
      switch (operandCount)
        {
      case 0:
        if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_INH))
          return opcode_handle->opc0[i];
        break;
      case 1:
        if (oprs[0].reg >= REG_R0 && oprs[0].reg <= REG_R7)
	  {
	    if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_MON))
	      return opcode_handle->opc0[i];
	    if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_DYA_MON))
	      return opcode_handle->opc0[i];
	  }
        if (oprs[0].reg == REG_NONE)
          if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_IMM3))
            return opcode_handle->opc0[i];
        break;
      case 2:
        if (oprs[0].reg >= REG_R0 && oprs[0].reg <= REG_R7)
          {
            if (oprs[1].reg >= REG_R0 && oprs[1].reg <= REG_R7)
	      {
		if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_DYA))
		  return opcode_handle->opc0[i];
	      }
            if (oprs[1].reg == REG_CCR)
              if (!strcmp (opcode_handle->opc0[i]->constraints,
                  XGATE_OP_MON_R_C))
                return opcode_handle->opc0[i];
            if (oprs[1].reg == REG_PC)
              if (!strcmp (opcode_handle->opc0[i]->constraints,
                  XGATE_OP_MON_R_P))
                return opcode_handle->opc0[i];
            if (oprs[1].reg == REG_NONE)
              if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_IMM16)
                  || !strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_IMM8)
                  || !strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_IMM4)
                  || !strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IMM16mADD)
                  || !strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IMM16mAND)
                  || !strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IMM16mCPC)
                  || !strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IMM16mSUB)
                  || !strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IMM16mLDW))
                return opcode_handle->opc0[i];
          }
        if (oprs[0].reg == REG_CCR)
          if (!strcmp (opcode_handle->opc0[i]->constraints, XGATE_OP_MON_C_R))
            return opcode_handle->opc0[i];
        break;
      case 3:
        if (oprs[0].reg >= REG_R0 && oprs[0].reg <= REG_R7)
          {
            if (oprs[1].reg >= REG_R0 && oprs[1].reg <= REG_R7)
              {
                if (oprs[2].reg >= REG_R0 && oprs[2].reg <= REG_R7)
                  {
                    if (!strcmp (opcode_handle->opc0[i]->constraints,
                        XGATE_OP_IDR)
                        || !strcmp (opcode_handle->opc0[i]->constraints,
                            XGATE_OP_TRI))
                      return opcode_handle->opc0[i];
                  }

                if (oprs[2].reg == REG_NONE)
                  if (!strcmp (opcode_handle->opc0[i]->constraints,
                      XGATE_OP_IDO5))
                    return opcode_handle->opc0[i];
              }
          }
        break;
      default:
        as_bad (_("unknown operand count"));
        break;
        }
    }
  return NULL ;
}

/* Because we are dealing with two different core that view the system
   memory with different offsets, we must differentiate what core a
   symbol belongs to, in order for the linker to cross-link.  */

int
xgate_frob_symbol (symbolS *sym)
{
  asymbol *bfdsym;
  elf_symbol_type *elfsym;

  bfdsym = symbol_get_bfdsym (sym);
  elfsym = elf_symbol_from (bfd_asymbol_bfd (bfdsym), bfdsym);

  gas_assert (elfsym);

  /* Mark the symbol as being *from XGATE  */
  elfsym->internal_elf_sym.st_target_internal = 1;

  return 0;
}

static unsigned int
xgate_get_operands (char *line, s_operand oprs[])
{
  int num_operands;

  /* If there are no operands, then it must be inherent.  */
  if (*line == 0 || *line == '\n' || *line == '\r')
    return 0;

  for (num_operands = 0; strlen (line) && (num_operands < MAX_NUM_OPERANDS);
       num_operands++)
    {
      line = skip_whitespace (line);
      if (*line == '#')
	line++;

      oprs[num_operands].mod = xgate_determine_modifiers (&line);

      if ((oprs[num_operands].reg = reg_name_search (line)) == REG_NONE)
	line = xgate_parse_exp (line, &oprs[num_operands].exp);

      /* skip to next operand */
      while (*line != 0)
	{
	  if (*line == ',')
	    {
	      line++;
	      break;
	    }
	  line++;
	}
    }
  if (num_operands > MAX_NUM_OPERANDS)
    return 0;
  return num_operands;
}

/* reg_name_search() finds the register number given its name.
   Returns the register number or REG_NONE on failure.  */

static register_id
reg_name_search (char *name)
{
  if (strncasecmp (name, "r0", 2) == 0)
    return REG_R0;
  if (strncasecmp (name, "r1", 2) == 0)
    return REG_R1;
  if (strncasecmp (name, "r2", 2) == 0)
    return REG_R2;
  if (strncasecmp (name, "r3", 2) == 0)
    return REG_R3;
  if (strncasecmp (name, "r4", 2) == 0)
    return REG_R4;
  if (strncasecmp (name, "r5", 2) == 0)
    return REG_R5;
  if (strncasecmp (name, "r6", 2) == 0)
    return REG_R6;
  if (strncasecmp (name, "r7", 2) == 0)
    return REG_R7;
  if (strncasecmp (name, "pc", 2) == 0)
    return REG_PC;
  if (strncasecmp (name, "ccr", 3) == 0)
    return REG_CCR;
  return REG_NONE;
}

/* Parse operand modifiers such as inc/dec/hi/low.  */

static op_modifiers
xgate_determine_modifiers (char **line)
{
  char *local_line = line[0];

  if (strncasecmp (local_line, "%hi", 3) == 0)
    {
      *line += 3;
      return MOD_LOAD_HIGH;
    }
  if (strncasecmp (local_line, "%lo", 3) == 0)
    {
      *line += 3;
      return MOD_LOAD_LOW;
    }
  if (*(local_line + 2) == '+')
    return MOD_POSTINC;
  if (strncasecmp (local_line, "-r", 2) == 0)
    {
      *line += 1;
      return MOD_PREDEC;
    }
  return MOD_NONE;
}

/* Parse instruction operands.  */

static void
xgate_scan_operands (struct xgate_opcode *opcode, s_operand oprs[])
{
  char *frag = xgate_new_instruction (opcode->size);
  int where = frag - frag_now->fr_literal;
  char *op = opcode->constraints;
  unsigned int bin = (int) opcode->bin_opcode;
  unsigned short oper_mask = 0;
  int operand_bit_length = 0;
  unsigned int operand = 0;
  char n_operand_bits = 0;
  char first_operand_equals_second = 0;
  int i = 0;
  char c = 0;

  /* Generate available operand bits mask.  */
  for (i = 0; (c = opcode->format[i]); i++)
    {
      if (ISDIGIT (c) || (c == 's'))
	{
	  oper_mask <<= 1;
	}
      else
	{
	  oper_mask <<= 1;
	  oper_mask += 1;
	  n_operand_bits++;
	}
    }

  /* Parse first operand.  */
  if (*op)
    {
      if (*op == '=')
	{
	  first_operand_equals_second = 1;
	  ++op;
	}
      operand = xgate_parse_operand (opcode, &operand_bit_length, where,
				     &op, oprs[0]);
      ++op;
      bin = xgate_apply_operand (operand, &oper_mask, bin, operand_bit_length);

      if (first_operand_equals_second)
	bin = xgate_apply_operand (operand, &oper_mask, bin,
				   operand_bit_length);
      /* Parse second operand.  */
      if (*op)
	{
	  if (*op == ',')
	    ++op;
	  if (first_operand_equals_second)
	    {
	      bin = xgate_apply_operand (operand, &oper_mask, bin,
					 operand_bit_length);
	      ++op;
	    }
	  else
	    {
	      operand = xgate_parse_operand (opcode, &operand_bit_length, where,
					     &op, oprs[1]);
	      bin = xgate_apply_operand (operand, &oper_mask, bin,
					 operand_bit_length);
	      ++op;
	    }
	}
      /* Parse the third register.  */
      if (*op)
	{
	  if (*op == ',')
	    ++op;
	  operand = xgate_parse_operand (opcode, &operand_bit_length, where,
					 &op, oprs[2]);
	  bin = xgate_apply_operand (operand, &oper_mask, bin,
				     operand_bit_length);
	}
    }
  if (opcode->size == 2 && fixup_required)
    {
      bfd_putl16 (bin, frag);
    }
  else if ( !strcmp (opcode->constraints, XGATE_OP_REL9)
      || !strcmp (opcode->constraints, XGATE_OP_REL10))
    {
      /* Write our data to a frag for further processing.  */
      bfd_putl16 (opcode->bin_opcode, frag);
    }
  else
    {
      /* Apply operand mask(s)to bin opcode and write the output.  */
      /* Since we are done write this frag in xgate BE format.  */
      number_to_chars_bigendian (frag, bin, opcode->size);
    }
  prev = bin;
  return;
}

static unsigned int
xgate_parse_operand (struct xgate_opcode *opcode,
		     int *bit_width,
		     int where,
		     char **op_con,
		     s_operand operand)
{
  char *op_constraint = *op_con;
  unsigned int op_mask = 0;
  unsigned int pp_fix = 0;
  unsigned short max_size = 0;
  int i;

  *bit_width = 0;
  /* Reset.  */

  switch (*op_constraint)
    {
    case '+': /* Indexed register operand +/- or plain r.  */
      /* Default to neither inc or dec.  */
      pp_fix = 0;
      *bit_width = 5;

      if (operand.reg == REG_NONE)
	as_bad (_(": expected register name r0-r7 ") );
      op_mask = operand.reg;
      if (operand.mod == MOD_POSTINC)
	pp_fix = INCREMENT;
      if (operand.mod == MOD_PREDEC)
	pp_fix = DECREMENT;
      op_mask <<= 2;
      op_mask |= pp_fix;
      break;

    case 'r': /* Register operand.  */
      if (operand.reg == REG_NONE)
	as_bad (_(": expected register name r0-r7 "));

      *bit_width = 3;

      op_mask = operand.reg;
      break;

    case 'i': /* Immediate value or expression expected.  */
      /* Advance the original format pointer.  */
      (*op_con)++;
      op_constraint++;
      if (ISDIGIT (*op_constraint))
	*bit_width = (int) *op_constraint - '0';
      else if (*op_constraint == 'a')
	*bit_width = 0x0A;
      else if (*op_constraint == 'f')
	*bit_width = 0x0F;

      /* http://tigcc.ticalc.org/doc/gnuasm.html#SEC31 */
      if (operand.exp.X_op == O_constant)
	{
	  op_mask = operand.exp.X_add_number;
	  if (((opcode->name[strlen (opcode->name) - 1] == 'l') && autoHiLo)
	      || operand.mod == MOD_LOAD_LOW)
	    op_mask &= 0x00FF;
	  else if (((opcode->name[strlen (opcode->name) - 1]) == 'h'
		    && autoHiLo) || operand.mod == MOD_LOAD_HIGH)
	    op_mask >>= 8;

	  /* Make sure it fits.  */
	  for (i = *bit_width; i; i--)
	    {
	      max_size <<= 1;
	      max_size += 1;
	    }
	  if (op_mask > max_size)
	    as_bad (_(":operand value(%d) too big for constraint"), op_mask);
	}
      else
	{
	  /* Should be BFD_RELOC_XGATE_IMM8_LO instead of BFD_RELOC_XGATE_24
	     TODO fix.  */
	  fixup_required = 1;
	  if (*op_constraint == '8')
	    {
	      if (((opcode->name[strlen (opcode->name) - 1] == 'l')
		   && autoHiLo) || operand.mod == MOD_LOAD_LOW)
		fix_new_exp (frag_now, where, 2, &operand.exp, FALSE,
			     BFD_RELOC_XGATE_24);
	      else if (((opcode->name[strlen (opcode->name) - 1]) == 'h'
			&& autoHiLo) || operand.mod == MOD_LOAD_HIGH )
		fix_new_exp (frag_now, where, 2, &operand.exp, FALSE,
			     BFD_RELOC_XGATE_IMM8_HI);
	      else
		as_bad (_("you must use a hi/lo directive or 16-bit macro "
			  "to load a 16-bit value."));
	    }
	  else if (*op_constraint == '5')
	    fix_new_exp (frag_now, where, 2, &operand.exp, FALSE,
			 BFD_RELOC_XGATE_IMM5);
	  else if (*op_constraint == '4')
	    fix_new_exp (frag_now, where, 2, &operand.exp, FALSE,
			 BFD_RELOC_XGATE_IMM4);
	  else if (*op_constraint == '3')
	    fix_new_exp (frag_now, where, 2, &operand.exp, FALSE,
			 BFD_RELOC_XGATE_IMM3);
	  else
	    as_bad (_(":unknown relocation constraint size"));
	}
      break;

    case 'c': /* CCR register expected.  */
      *bit_width = 0;
      if (operand.reg != REG_CCR)
	as_bad (_(": expected register name ccr "));
      break;

    case 'p': /* PC register expected.  */
      *bit_width = 0;
      if (operand.reg != REG_PC)
	as_bad (_(": expected register name pc "));
      break;

    case 'b': /* Branch expected.  */
      (*op_con)++;
      op_constraint++;

      if (operand.exp.X_op != O_register)
	{
	  if (*op_constraint == '9')
	    fix_new_exp (frag_now, where, 2, &operand.exp, TRUE,
			 R_XGATE_PCREL_9);
	  else if (*op_constraint == 'a')
	    fix_new_exp (frag_now, where, 2, &operand.exp, TRUE,
			 R_XGATE_PCREL_10);
	}
      else
	as_fatal (_("Operand `%x' not recognized in fixup8."),
		  operand.exp.X_op);
      break;
    case '?':
      break;

    default:
      as_bad (_("unknown constraint `%c'"), *op_constraint);
      break;
    }
  return op_mask;
}