/* TI C6X disassembler.

   Copyright (C) 2010-2023 Free Software Foundation, Inc.

   Contributed by Joseph Myers <joseph@codesourcery.com>

        Bernd Schmidt  <bernds@codesourcery.com>

   This file is part of libopcodes.

   This library 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 of the License, or

   (at your option) any later version.

   It 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 this program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "sysdep.h"

#include "disassemble.h"

#include "opcode/tic6x.h"

#include "libiberty.h"

/* Define the instruction format table.  */

const tic6x_insn_format tic6x_insn_format_table[tic6x_insn_format_max] =

  {

#define FMT(name, num_bits, cst_bits, mask, fields) \

    { num_bits, cst_bits, mask, fields },

#include "opcode/tic6x-insn-formats.h"

#undef FMT

  };

/* Define the control register table.  */

const tic6x_ctrl tic6x_ctrl_table[tic6x_ctrl_max] =

  {

#define CTRL(name, isa, rw, crlo, crhi_mask)  \

    {           \

      STRINGX(name),        \

      CONCAT2(TIC6X_INSN_,isa),     \

      CONCAT2(tic6x_rw_,rw),      \

      crlo,         \

      crhi_mask         \

    },

#include "opcode/tic6x-control-registers.h"

#undef CTRL

  };

/* Define the opcode table.  */

const tic6x_opcode tic6x_opcode_table[tic6x_opcode_max] =

  {

#define INSNU(name, func_unit, format, type, isa, flags, fixed, ops, var) \

    {                 \

      STRINGX(name),              \

      CONCAT2(tic6x_func_unit_,func_unit),        \

      CONCAT3(tic6x_insn_format,_,format),              \

      CONCAT2(tic6x_pipeline_,type),          \

      CONCAT2(TIC6X_INSN_,isa),           \

      flags,                \

      fixed,                \

      ops,                \

      var               \

    },

#define INSNUE(name, e, func_unit, format, type, isa, flags, fixed, ops, var) \

    {                 \

      STRINGX(name),              \

      CONCAT2(tic6x_func_unit_,func_unit),        \

      CONCAT3(tic6x_insn_format,_,format),              \

      CONCAT2(tic6x_pipeline_,type),          \

      CONCAT2(TIC6X_INSN_,isa),           \

      flags,                \

      fixed,                \

      ops,                \

      var               \

    },

#define INSN(name, func_unit, format, type, isa, flags, fixed, ops, var) \

    {                 \

      STRINGX(name),              \

      CONCAT2(tic6x_func_unit_,func_unit),        \

      CONCAT4(tic6x_insn_format_,func_unit,_,format),     \

      CONCAT2(tic6x_pipeline_,type),          \

      CONCAT2(TIC6X_INSN_,isa),           \

      flags,                \

      fixed,                \

      ops,                \

      var               \

    },

#define INSNE(name, e, func_unit, format, type, isa, flags, fixed, ops, var) \

    {                 \

      STRINGX(name),              \

      CONCAT2(tic6x_func_unit_,func_unit),        \

      CONCAT4(tic6x_insn_format_,func_unit,_,format),     \

      CONCAT2(tic6x_pipeline_,type),          \

      CONCAT2(TIC6X_INSN_,isa),           \

      flags,                \

      fixed,                \

      ops,                \

      var               \

    },

#include "opcode/tic6x-opcode-table.h"

#undef INSN

#undef INSNE

#undef INSNU

#undef INSNUE

  };

/* If instruction format FMT has a field FIELD, return a pointer to

   the description of that field; otherwise return NULL.  */

const tic6x_insn_field *

tic6x_field_from_fmt (const tic6x_insn_format *fmt, tic6x_insn_field_id field)

{

  unsigned int f;

  for (f = 0; f < fmt->num_fields; f++)

    if (fmt->fields[f].field_id == field)

      return &fmt->fields[f];

  return NULL;

}

/* Extract the field width.  */

static unsigned int

tic6x_field_width (const tic6x_insn_field *field)

{

  unsigned int i;

  unsigned int width = 0;

  if (!field->num_bitfields)

    return field->bitfields[0].width;

  for (i = 0 ; i < field->num_bitfields ; i++)

    width += field->bitfields[i].width;

  return width;

}

/* Extract the bits corresponding to FIELD from OPCODE.  */

static unsigned int

tic6x_field_bits (unsigned int opcode, const tic6x_insn_field *field)

{

  unsigned int i;

  unsigned int val = 0;

  if (!field->num_bitfields)

    return (opcode >> field->bitfields[0].low_pos) & ((1u << field->bitfields[0].width) - 1);

  for (i = 0 ; i < field->num_bitfields ; i++)

    val |= ((opcode >> field->bitfields[i].low_pos) & ((1u << field->bitfields[i].width) - 1))

      << field->bitfields[i].pos;

  return val;

}

/* Extract a 32-bit value read from the instruction stream.  */

static unsigned int

tic6x_extract_32 (unsigned char *p, struct disassemble_info *info)

{

  if (info->endian == BFD_ENDIAN_LITTLE)

    return p[0] | (p[1] << 8) | (p[2] << 16) | ((unsigned) p[3] << 24);

  else

    return p[3] | (p[2] << 8) | (p[1] << 16) | ((unsigned) p[0] << 24);

}

/* Extract a 16-bit value read from the instruction stream.  */

static unsigned int

tic6x_extract_16 (unsigned char *p, tic6x_fetch_packet_header *header,

                  struct disassemble_info *info)

{

  unsigned int op16;

  if (info->endian == BFD_ENDIAN_LITTLE)

    op16 = (p[0]) | (p[1] << 8);

  else

    op16 = (p[1]) | (p[0] << 8);

  op16 |= (header->sat << TIC6X_COMPACT_SAT_POS);

  op16 |= (header->br << TIC6X_COMPACT_BR_POS);

  op16 |= (header->dsz << TIC6X_COMPACT_DSZ_POS);

  return op16;

}

/* FP points to a fetch packet.  Return whether it is header-based; if

   it is, fill in HEADER.  */

static bool

tic6x_check_fetch_packet_header (unsigned char *fp,

         tic6x_fetch_packet_header *header,

         struct disassemble_info *info)

{

  int i;

  header->header = tic6x_extract_32 (fp + 28, info);

  if ((header->header & 0xf0000000) != 0xe0000000)

    {

      header->prot = 0;

      header->rs = 0;

      header->dsz = 0;

      header->br = 0;

      header->sat = 0;

      for (i = 0; i < 7; i++)

  header->word_compact[i] = false;

      for (i = 0; i < 14; i++)

  header->p_bits[i] = false;

      return false;

    }

  for (i = 0; i < 7; i++)

    header->word_compact[i]

      = (header->header & (1u << (21 + i))) != 0;

  header->prot = (header->header & (1u << 20)) != 0;

  header->rs = (header->header & (1u << 19)) != 0;

  header->dsz = (header->header >> 16) & 0x7;

  header->br = (header->header & (1u << 15)) != 0;

  header->sat = (header->header & (1u << 14)) != 0;

  for (i = 0; i < 14; i++)

    header->p_bits[i] = (header->header & (1u << i)) != 0;

  return true;

}

/* Disassemble the instruction at ADDR and print it using

   INFO->FPRINTF_FUNC and INFO->STREAM, returning the number of bytes

   consumed.  */

int

print_insn_tic6x (bfd_vma addr, struct disassemble_info *info)

{

  int status;

  bfd_vma fp_addr;

  bfd_vma fp_offset;

  unsigned char fp[32];

  unsigned int opcode;

  tic6x_opcode_id opcode_id;

  bool fetch_packet_header_based;

  tic6x_fetch_packet_header header;

  unsigned int num_bits;

  bool bad_offset = false;

  fp_offset = addr & 0x1f;

  fp_addr = addr - fp_offset;

  /* Read in a block of instructions.  Since there might be a

     symbol in the middle of this block, disable stop_vma.  */

  info->stop_vma = 0;

  status = info->read_memory_func (fp_addr, fp, 32, info);

  if (status)

    {

      info->memory_error_func (status, addr, info);

      return -1;

    }

  fetch_packet_header_based

    = tic6x_check_fetch_packet_header (fp, &header, info);

  if (fetch_packet_header_based)

    {

      if (fp_offset & 0x1)

  bad_offset = true;

      if ((fp_offset & 0x3) && (fp_offset >= 28

        || !header.word_compact[fp_offset >> 2]))

  bad_offset = true;

      if (fp_offset == 28)

  {

    info->bytes_per_chunk = 4;

    info->fprintf_func (info->stream, "<fetch packet header 0x%.8x>",

            header.header);

    return 4;

  }

      num_bits = (header.word_compact[fp_offset >> 2] ? 16 : 32);

    }

  else

    {

      num_bits = 32;

      if (fp_offset & 0x3)

  bad_offset = true;

    }

  if (bad_offset)

    {

      info->bytes_per_chunk = 1;

      info->fprintf_func (info->stream, ".byte 0x%.2x", fp[fp_offset]);

      return 1;

    }

  if (num_bits == 16)

    {

      /* The least-significant part of a 32-bit word comes logically

   before the most-significant part.  For big-endian, follow the

   TI assembler in showing instructions in logical order by

   pretending that the two halves of the word are in opposite

   locations to where they actually are.  */

      if (info->endian == BFD_ENDIAN_LITTLE)

  opcode = tic6x_extract_16 (fp + fp_offset, &header, info);

      else

  opcode = tic6x_extract_16 (fp + (fp_offset ^ 2), &header, info);

    }

  else

    opcode = tic6x_extract_32 (fp + fp_offset, info);

  for (opcode_id = 0; opcode_id < tic6x_opcode_max; opcode_id++)

    {

      const tic6x_opcode *const opc = &tic6x_opcode_table[opcode_id];

      const tic6x_insn_format *const fmt

  = &tic6x_insn_format_table[opc->format];

      const tic6x_insn_field *creg_field;

      bool p_bit;

      const char *parallel;

      const char *cond = "";

      const char *func_unit;

      char func_unit_buf[8];

      unsigned int func_unit_side = 0;

      unsigned int func_unit_data_side = 0;

      unsigned int func_unit_cross = 0;

      unsigned int t_val = 0;

      /* The maximum length of the text of a non-PC-relative operand

   is 24 bytes (SPMASK masking all eight functional units, with

   separating commas and trailing NUL).  */

      char operands[TIC6X_MAX_OPERANDS][24] = { { 0 } };

      bfd_vma operands_addresses[TIC6X_MAX_OPERANDS] = { 0 };

      bool operands_text[TIC6X_MAX_OPERANDS] = { false };

      bool operands_pcrel[TIC6X_MAX_OPERANDS] = { false };

      unsigned int fix;

      unsigned int num_operands;

      unsigned int op_num;

      bool fixed_ok;

      bool operands_ok;

      bool have_t = false;

      if (opc->flags & TIC6X_FLAG_MACRO)

  continue;

      if (fmt->num_bits != num_bits)

  continue;

      if ((opcode & fmt->mask) != fmt->cst_bits)

  continue;

      /* If the format has a creg field, it is only a candidate for a

   match if the creg and z fields have values indicating a valid

   condition; reserved values indicate either an instruction

   format without a creg field, or an invalid instruction.  */

      creg_field = tic6x_field_from_fmt (fmt, tic6x_field_creg);

      if (creg_field)

  {

    const tic6x_insn_field *z_field;

    unsigned int creg_value, z_value;

    static const char *const conds[8][2] =

      {

        { "", NULL },

        { "[b0] ", "[!b0] " },

        { "[b1] ", "[!b1] " },

        { "[b2] ", "[!b2] " },

        { "[a1] ", "[!a1] " },

        { "[a2] ", "[!a2] " },

        { "[a0] ", "[!a0] " },

        { NULL, NULL }

      };

    /* A creg field is not meaningful without a z field, so if

       the z field is not present this is an error in the format

       table.  */

    z_field = tic6x_field_from_fmt (fmt, tic6x_field_z);

    if (!z_field)

      {

        printf ("*** opcode %x: missing z field", opcode);

        abort ();

      }

    creg_value = tic6x_field_bits (opcode, creg_field);

    z_value = tic6x_field_bits (opcode, z_field);

    cond = conds[creg_value][z_value];

    if (cond == NULL)

      continue;

  }

      if (opc->flags & TIC6X_FLAG_INSN16_SPRED)

  {

    const tic6x_insn_field *cc_field;

          unsigned int s_value = 0;

          unsigned int z_value = 0;

          bool cond_known = false;

          static const char *const conds[2][2] =

            {

              { "[a0] ", "[!a0] " },

              { "[b0] ", "[!b0] " }

            };

          cc_field = tic6x_field_from_fmt (fmt, tic6x_field_cc);

          if (cc_field)

      {

        unsigned int cc_value;

        cc_value = tic6x_field_bits (opcode, cc_field);

        s_value = (cc_value & 0x2) >> 1;

        z_value = (cc_value & 0x1);

        cond_known = true;

      }

    else

      {

        const tic6x_insn_field *z_field;

        const tic6x_insn_field *s_field;

        s_field = tic6x_field_from_fmt (fmt, tic6x_field_s);

        if (!s_field)

    {

      printf ("opcode %x: missing compact insn predicate register field (s field)\n",

        opcode);

      abort ();

    }

        s_value = tic6x_field_bits (opcode, s_field);

        z_field = tic6x_field_from_fmt (fmt, tic6x_field_z);

        if (!z_field)

    {

      printf ("opcode %x: missing compact insn predicate z_value (z field)\n", opcode);

      abort ();

    }

        z_value = tic6x_field_bits (opcode, z_field);

        cond_known = true;

      }

          if (!cond_known)

      {

        printf ("opcode %x: unspecified ompact insn predicate\n", opcode);

        abort ();

      }

          cond = conds[s_value][z_value];

  }

      /* All fixed fields must have matching values; all fields with

   restricted ranges must have values within those ranges.  */

      fixed_ok = true;

      for (fix = 0; fix < opc->num_fixed_fields; fix++)

  {

    unsigned int field_bits;

    const tic6x_insn_field *const field

      = tic6x_field_from_fmt (fmt, opc->fixed_fields[fix].field_id);

    if (!field)

      {

        printf ("opcode %x: missing field #%d for FIX #%d\n",

          opcode, opc->fixed_fields[fix].field_id, fix);

        abort ();

      }

    field_bits = tic6x_field_bits (opcode, field);

    if (field_bits < opc->fixed_fields[fix].min_val

        || field_bits > opc->fixed_fields[fix].max_val)

      {

        fixed_ok = false;

        break;

      }

  }

      if (!fixed_ok)

  continue;

      /* The instruction matches.  */

      /* The p-bit indicates whether this instruction is in parallel

   with the *next* instruction, whereas the parallel bars

   indicate the instruction is in parallel with the *previous*

   instruction.  Thus, we must find the p-bit for the previous

   instruction.  */

      if (num_bits == 16 && (fp_offset & 0x2) == 2)

  {

    /* This is the logically second (most significant; second in

       fp_offset terms because fp_offset relates to logical not

       physical addresses) instruction of a compact pair; find

       the p-bit for the first (least significant).  */

    p_bit = header.p_bits[(fp_offset >> 2) << 1];

  }

      else if (fp_offset >= 4)

  {

    /* Find the last instruction of the previous word in this

       fetch packet.  For compact instructions, this is the most

       significant 16 bits.  */

    if (fetch_packet_header_based

        && header.word_compact[(fp_offset >> 2) - 1])

      p_bit = header.p_bits[(fp_offset >> 1) - 1];

    else

      {

        unsigned int prev_opcode

    = tic6x_extract_32 (fp + (fp_offset & 0x1c) - 4, info);

        p_bit = (prev_opcode & 0x1) != 0;

      }

  }

      else

  {

    /* Find the last instruction of the previous fetch

       packet.  */

    unsigned char fp_prev[32];

    status = info->read_memory_func (fp_addr - 32, fp_prev, 32, info);

    if (status)

      /* No previous instruction to be parallel with.  */

      p_bit = false;

    else

      {

        bool prev_header_based;

        tic6x_fetch_packet_header prev_header;

        prev_header_based

    = tic6x_check_fetch_packet_header (fp_prev, &prev_header, info);

        if (prev_header_based)

    {

      if (prev_header.word_compact[6])

        p_bit = prev_header.p_bits[13];

      else

        {

          unsigned int prev_opcode = tic6x_extract_32 (fp_prev + 24,

                   info);

          p_bit = (prev_opcode & 0x1) != 0;

        }

    }

        else

    {

      unsigned int prev_opcode = tic6x_extract_32 (fp_prev + 28,

                     info);

      p_bit = (prev_opcode & 0x1) != 0;

    }

      }

  }

      parallel = p_bit ? "|| " : "";

      if (opc->func_unit == tic6x_func_unit_nfu)

  func_unit = "";

      else

  {

    unsigned int fld_num;

    char func_unit_char;

    const char *data_str;

    bool have_areg = false;

    bool have_cross = false;

    func_unit_side = (opc->flags & TIC6X_FLAG_SIDE_B_ONLY) ? 2 : 0;

    func_unit_cross = 0;

    func_unit_data_side = (opc->flags & TIC6X_FLAG_SIDE_T2_ONLY) ? 2 : 0;

    for (fld_num = 0; fld_num < opc->num_variable_fields; fld_num++)

      {

        const tic6x_coding_field *const enc = &opc->variable_fields[fld_num];

        const tic6x_insn_field *field;

        unsigned int fld_val;

        field = tic6x_field_from_fmt (fmt, enc->field_id);

        if (!field)

    {

      printf ("opcode %x: could not retrieve field (field_id:%d)\n",

        opcode, fld_num);

      abort ();

    }

        fld_val = tic6x_field_bits (opcode, field);

        switch (enc->coding_method)

    {

    case tic6x_coding_fu:

      /* The side must be specified exactly once.  */

      if (func_unit_side)

        {

          printf ("opcode %x: field #%d use tic6x_coding_fu, but func_unit_side is already set!\n",

            opcode, fld_num);

          abort ();

        }

      func_unit_side = (fld_val ? 2 : 1);

      break;

    case tic6x_coding_data_fu:

      /* The data side must be specified exactly once.  */

      if (func_unit_data_side)

        {

          printf ("opcode %x: field #%d use tic6x_coding_fu, but func_unit_side is already set!\n",

            opcode, fld_num);

          abort ();

        }

      func_unit_data_side = (fld_val ? 2 : 1);

      break;

    case tic6x_coding_xpath:

      /* Cross path use must be specified exactly

         once.  */

      if (have_cross)

        {

          printf ("opcode %x: field #%d use tic6x_coding_xpath, have_cross is already set!\n",

            opcode, fld_num);

          abort ();

        }

      have_cross = true;

      func_unit_cross = fld_val;

      break;

                case tic6x_coding_rside:

                  /* If the format has a t field, use it for src/dst register side.  */

                  have_t = true;

                  t_val = fld_val;

                  func_unit_data_side = (t_val ? 2 : 1);

                  break;

    case tic6x_coding_areg:

      have_areg = true;

      break;

    default:

      /* Don't relate to functional units.  */

      break;

    }

      }

    /* The side of the functional unit used must now have been

       determined either from the flags or from an instruction

       field.  */

    if (func_unit_side != 1 && func_unit_side != 2)

      {

        printf ("opcode %x: func_unit_side is not encoded!\n", opcode);

        abort ();

      }

    /* Cross paths are not applicable when sides are specified

       for both address and data paths.  */

    if (func_unit_data_side && have_cross)

      {

        printf ("opcode %x: xpath not applicable when side are specified both for address and data!\n",

          opcode);

        abort ();

      }

    /* Separate address and data paths are only applicable for

       the D unit.  */

    if (func_unit_data_side && opc->func_unit != tic6x_func_unit_d)

      {

        printf ("opcode %x: separate address and data paths only applicable for D unit!\n",

          opcode);

        abort ();

          }

    /* If an address register is being used but in ADDA rather

       than a load or store, it uses a cross path for side-A

       instructions, and the cross path use is not specified by

       an instruction field.  */

    if (have_areg && !func_unit_data_side)

      {

        if (have_cross)

    {

      printf ("opcode %x: illegal cross path specifier in adda opcode!\n", opcode);

      abort ();

    }

        func_unit_cross = func_unit_side == 1;

      }

    switch (opc->func_unit)

      {

      case tic6x_func_unit_d:

        func_unit_char = 'D';

        break;

      case tic6x_func_unit_l:

        func_unit_char = 'L';

        break;

      case tic6x_func_unit_m:

        func_unit_char = 'M';

        break;

      case tic6x_func_unit_s:

        func_unit_char = 'S';

        break;

      default:

              printf ("opcode %x: illegal func_unit specifier %d\n", opcode, opc->func_unit);

        abort ();

      }

    switch (func_unit_data_side)

      {

      case 0:

        data_str = "";

        break;

      case 1:

        data_str = "T1";

        break;

      case 2:

        data_str = "T2";

        break;

      default:

              printf ("opcode %x: illegal data func_unit specifier %d\n",

          opcode, func_unit_data_side);

        abort ();

      }

    if (opc->flags & TIC6X_FLAG_INSN16_BSIDE && func_unit_side == 1)

        func_unit_cross = 1;

    snprintf (func_unit_buf, sizeof func_unit_buf, " .%c%u%s%s",

        func_unit_char, func_unit_side,

        (func_unit_cross ? "X" : ""), data_str);

    func_unit = func_unit_buf;

  }

      /* For each operand there must be one or more fields set based

   on that operand, that can together be used to derive the

   operand value.  */

      operands_ok = true;

      num_operands = opc->num_operands;

      for (op_num = 0; op_num < num_operands; op_num++)

  {

    unsigned int fld_num;

    unsigned int mem_base_reg = 0;

    bool mem_base_reg_known = false;

    bool mem_base_reg_known_long = false;

    unsigned int mem_offset = 0;

    bool mem_offset_known = false;

    bool mem_offset_known_long = false;

    unsigned int mem_mode = 0;

    bool mem_mode_known = false;

    unsigned int mem_scaled = 0;

    bool mem_scaled_known = false;

    unsigned int crlo = 0;

    bool crlo_known = false;

    unsigned int crhi = 0;

    bool crhi_known = false;

    bool spmask_skip_operand = false;

    unsigned int fcyc_bits = 0;

    bool prev_sploop_found = false;

    switch (opc->operand_info[op_num].form)

      {

      case tic6x_operand_b15reg:

        /* Fully determined by the functional unit.  */

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "b15");

        continue;

      case tic6x_operand_zreg:

        /* Fully determined by the functional unit.  */

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "%c0",

      (func_unit_side == 2 ? 'b' : 'a'));

        continue;

      case tic6x_operand_retreg:

        /* Fully determined by the functional unit.  */

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "%c3",

      (func_unit_side == 2 ? 'b' : 'a'));

        continue;

      case tic6x_operand_irp:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "irp");

        continue;

      case tic6x_operand_nrp:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "nrp");

        continue;

      case tic6x_operand_ilc:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "ilc");

        continue;

      case tic6x_operand_hw_const_minus_1:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "-1");

        continue;

      case tic6x_operand_hw_const_0:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "0");

        continue;

      case tic6x_operand_hw_const_1:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "1");

        continue;

      case tic6x_operand_hw_const_5:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "5");

        continue;

      case tic6x_operand_hw_const_16:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "16");

        continue;

      case tic6x_operand_hw_const_24:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "24");

        continue;

      case tic6x_operand_hw_const_31:

        operands_text[op_num] = true;

        snprintf (operands[op_num], 24, "31");

        continue;

      default:

        break;

      }

    for (fld_num = 0; fld_num < opc->num_variable_fields; fld_num++)

      {

        const tic6x_coding_field *const enc

    = &opc->variable_fields[fld_num];

        const tic6x_insn_field *field;

        unsigned int fld_val;

        unsigned int reg_base = 0;

        signed int signed_fld_val;

              char reg_side = '?';

        if (enc->operand_num != op_num)

    continue;

        field = tic6x_field_from_fmt (fmt, enc->field_id);

        if (!field)

    {

      printf ("opcode %x: missing field (field_id:%d) in format\n", opcode, enc->field_id);

      abort ();

    }

              fld_val = tic6x_field_bits (opcode, field);

        switch (enc->coding_method)

    {

                case tic6x_coding_cst_s3i:

                  (fld_val == 0x00) && (fld_val = 0x10);

                  (fld_val == 0x07) && (fld_val = 0x08);

                  /* Fall through.  */

    case tic6x_coding_ucst:

    case tic6x_coding_ulcst_dpr_byte:

    case tic6x_coding_ulcst_dpr_half:

    case tic6x_coding_ulcst_dpr_word:

    case tic6x_coding_lcst_low16:

      switch (opc->operand_info[op_num].form)

        {

        case tic6x_operand_asm_const:

        case tic6x_operand_link_const:

          operands_text[op_num] = true;

          snprintf (operands[op_num], 24, "%u", fld_val);

          break;

        case tic6x_operand_mem_long:

          mem_offset = fld_val;

          mem_offset_known_long = true;

          break;

        default:

                      printf ("opcode %x: illegal operand form for operand#%d\n", opcode, op_num);

          abort ();

        }

      break;

    case tic6x_coding_lcst_high16:

      operands_text[op_num] = true;

      snprintf (operands[op_num], 24, "%u", fld_val << 16);

      break;

                case tic6x_coding_scst_l3i:

      operands_text[op_num] = true;

                  if (fld_val == 0)

        {

          signed_fld_val = 8;

        }

      else

        {

          signed_fld_val = (signed int) fld_val;

          signed_fld_val ^= (1 << (tic6x_field_width (field) - 1));

          signed_fld_val -= (1 << (tic6x_field_width (field) - 1));

        }

      snprintf (operands[op_num], 24, "%d", signed_fld_val);

      break;

    case tic6x_coding_scst:

      operands_text[op_num] = true;

      signed_fld_val = (signed int) fld_val;

      signed_fld_val ^= (1 << (tic6x_field_width (field) - 1));

      signed_fld_val -= (1 << (tic6x_field_width (field) - 1));

      snprintf (operands[op_num], 24, "%d", signed_fld_val);

      break;

    case tic6x_coding_ucst_minus_one:

      operands_text[op_num] = true;

      snprintf (operands[op_num], 24, "%u", fld_val + 1);

      break;

    case tic6x_coding_pcrel:

    case tic6x_coding_pcrel_half:

      signed_fld_val = (signed int) fld_val;

      signed_fld_val ^= (1 << (tic6x_field_width (field) - 1));

      signed_fld_val -= (1 << (tic6x_field_width (field) - 1));

      if (fetch_packet_header_based

          && enc->coding_method == tic6x_coding_pcrel_half)

        signed_fld_val *= 2;

      else

        signed_fld_val *= 4;

      operands_pcrel[op_num] = true;

      operands_addresses[op_num] = fp_addr + signed_fld_val;

      break;

    case tic6x_coding_regpair_msb:

      if (opc->operand_info[op_num].form != tic6x_operand_regpair)

        abort ();

      operands_text[op_num] = true;

      snprintf (operands[op_num], 24, "%c%u:%c%u",

          (func_unit_side == 2 ? 'b' : 'a'), (fld_val | 0x1),

          (func_unit_side == 2 ? 'b' : 'a'), (fld_val | 0x1) - 1);

      break;

    case tic6x_coding_pcrel_half_unsigned:

      operands_pcrel[op_num] = true;

      operands_addresses[op_num] = fp_addr + 2 * fld_val;

      break;

    case tic6x_coding_reg_shift:

      fld_val <<= 1;

      /* Fall through.  */

    case tic6x_coding_reg:

                  if (num_bits == 16 && header.rs && !(opc->flags & TIC6X_FLAG_INSN16_NORS))

                    {

          reg_base = 16;

                    }

      switch (opc->operand_info[op_num].form)

        {

        case tic6x_operand_treg:

                      if (!have_t)

      {

        printf ("opcode %x: operand treg but missing t field\n", opcode);

        abort ();

      }

          operands_text[op_num] = true;

                      reg_side = t_val ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u", reg_side, reg_base + fld_val);

          break;

        case tic6x_operand_reg:

          operands_text[op_num] = true;

                      reg_side = (func_unit_side == 2) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u", reg_side,  reg_base + fld_val);

          break;

        case tic6x_operand_reg_nors:

          operands_text[op_num] = true;

                      reg_side = (func_unit_side == 2) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u", reg_side, fld_val);

          break;

        case tic6x_operand_reg_bside:

          operands_text[op_num] = true;

          snprintf (operands[op_num], 24, "b%u", reg_base + fld_val);

          break;

        case tic6x_operand_reg_bside_nors:

          operands_text[op_num] = true;

          snprintf (operands[op_num], 24, "b%u", fld_val);

          break;

        case tic6x_operand_xreg:

          operands_text[op_num] = true;

                      reg_side = ((func_unit_side == 2) ^ func_unit_cross) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u", reg_side,  reg_base + fld_val);

          break;

        case tic6x_operand_dreg:

          operands_text[op_num] = true;

                      reg_side = (func_unit_data_side == 2) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u", reg_side,  reg_base + fld_val);

          break;

        case tic6x_operand_regpair:

          operands_text[op_num] = true;

          if (fld_val & 1)

      operands_ok = false;

                      reg_side = (func_unit_side == 2) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u:%c%u",

                                reg_side, reg_base + fld_val + 1,

        reg_side, reg_base + fld_val);

          break;

        case tic6x_operand_xregpair:

          operands_text[op_num] = true;

          if (fld_val & 1)

      operands_ok = false;

                      reg_side = ((func_unit_side == 2) ^ func_unit_cross) ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u:%c%u",

        reg_side, reg_base + fld_val + 1,

        reg_side, reg_base + fld_val);

          break;

        case tic6x_operand_tregpair:

                      if (!have_t)

      {

        printf ("opcode %x: operand tregpair but missing t field\n", opcode);

        abort ();

      }

          operands_text[op_num] = true;

          if (fld_val & 1)

      operands_ok = false;

                      reg_side = t_val ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u:%c%u",

        reg_side, reg_base + fld_val + 1,

        reg_side, reg_base + fld_val);

          break;

        case tic6x_operand_dregpair:

          operands_text[op_num] = true;

          if (fld_val & 1)

      operands_ok = false;

                      reg_side = (func_unit_data_side) == 2 ? 'b' : 'a';

          snprintf (operands[op_num], 24, "%c%u:%c%u",

        reg_side, reg_base + fld_val + 1,

        reg_side, reg_base + fld_val);

          break;

        case tic6x_operand_mem_deref:

          operands_text[op_num] = true;

                      reg_side = func_unit_side == 2 ? 'b' : 'a';