x86: have insns acting on segment selector values allow for consistent operands

[binutils-gdb.git] / gas / config / tc-i386-intel.c

/* tc-i386.c -- Assemble Intel syntax code for ix86/x86-64
   Copyright (C) 2009-2023 Free Software Foundation, Inc.

   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.  */

static struct
  {
    operatorT op_modifier;      /* Operand modifier.  */
    int is_mem;                 /* 1 if operand is memory reference.  */
    int is_indirect;            /* 1 if operand is indirect reference.  */
    int has_offset;             /* 1 if operand has offset.  */
    unsigned int in_offset;     /* >=1 if processing operand of offset.  */
    unsigned int in_bracket;    /* >=1 if processing operand in brackets.  */
    unsigned int in_scale;      /* >=1 if processing multiplication operand
                                 * in brackets.  */
    i386_operand_type reloc_types;      /* Value obtained from lex_got().  */
    const reg_entry *base;      /* Base register (if any).  */
    const reg_entry *index;     /* Index register (if any).  */
    offsetT scale_factor;       /* Accumulated scale factor.  */
    symbolS *seg;
  }
intel_state;

/* offset X_add_symbol */
#define O_offset O_md32
/* offset X_add_symbol */
#define O_short O_md31
/* near ptr X_add_symbol */
#define O_near_ptr O_md30
/* far ptr X_add_symbol */
#define O_far_ptr O_md29
/* byte ptr X_add_symbol */
#define O_byte_ptr O_md28
/* word ptr X_add_symbol */
#define O_word_ptr O_md27
/* dword ptr X_add_symbol */
#define O_dword_ptr O_md26
/* qword ptr X_add_symbol */
#define O_qword_ptr O_md25
/* mmword ptr X_add_symbol */
#define O_mmword_ptr O_qword_ptr
/* fword ptr X_add_symbol */
#define O_fword_ptr O_md24
/* tbyte ptr X_add_symbol */
#define O_tbyte_ptr O_md23
/* oword ptr X_add_symbol */
#define O_oword_ptr O_md22
/* xmmword ptr X_add_symbol */
#define O_xmmword_ptr O_oword_ptr
/* ymmword ptr X_add_symbol */
#define O_ymmword_ptr O_md21
/* zmmword ptr X_add_symbol */
#define O_zmmword_ptr O_md20

static struct
  {
    const char *name;
    operatorT op;
    unsigned int operands;
  }
const i386_operators[] =
  {
    { "and", O_bit_and, 2 },
    { "eq", O_eq, 2 },
    { "ge", O_ge, 2 },
    { "gt", O_gt, 2 },
    { "le", O_le, 2 },
    { "lt", O_lt, 2 },
    { "mod", O_modulus, 2 },
    { "ne", O_ne, 2 },
    { "not", O_bit_not, 1 },
    { "offset", O_offset, 1 },
    { "or", O_bit_inclusive_or, 2 },
    { "shl", O_left_shift, 2 },
    { "short", O_short, 1 },
    { "shr", O_right_shift, 2 },
    { "xor", O_bit_exclusive_or, 2 },
    { NULL, O_illegal, 0 }
  };

static struct
  {
    const char *name;
    operatorT op;
    unsigned short sz[3];
  }
const i386_types[] =
  {
#define I386_TYPE(t, n) { #t, O_##t##_ptr, { n, n, n } }
    I386_TYPE(byte, 1),
    I386_TYPE(word, 2),
    I386_TYPE(dword, 4),
    I386_TYPE(fword, 6),
    I386_TYPE(qword, 8),
    I386_TYPE(mmword, 8),
    I386_TYPE(tbyte, 10),
    I386_TYPE(oword, 16),
    I386_TYPE(xmmword, 16),
    I386_TYPE(ymmword, 32),
    I386_TYPE(zmmword, 64),
#undef I386_TYPE
    { "near", O_near_ptr, { 0xff04, 0xff02, 0xff08 } },
    { "far", O_far_ptr, { 0xff06, 0xff05, 0xff06 } },
    { NULL, O_illegal, { 0, 0, 0 } }
  };

operatorT i386_operator (const char *name, unsigned int operands, char *pc)
{
  unsigned int j;

#ifdef SVR4_COMMENT_CHARS
  if (!name && operands == 2 && *input_line_pointer == '\\')
    switch (input_line_pointer[1])
      {
      case '/': input_line_pointer += 2; return O_divide;
      case '%': input_line_pointer += 2; return O_modulus;
      case '*': input_line_pointer += 2; return O_multiply;
      }
#endif

  if (!intel_syntax)
    return O_absent;

  if (!name)
    {
      if (operands != 2)
        return O_illegal;
      switch (*input_line_pointer)
        {
        case ':':
          ++input_line_pointer;
          return O_full_ptr;
        case '[':
          ++input_line_pointer;
          return O_index;
        case '@':
          if (this_operand >= 0 && i.reloc[this_operand] == NO_RELOC)
            {
              int adjust = 0;
              char *gotfree_input_line = lex_got (&i.reloc[this_operand],
                                                  &adjust,
                                                  &intel_state.reloc_types);

              if (!gotfree_input_line)
                break;
              free (gotfree_input_line);
              *input_line_pointer++ = '+';
              memset (input_line_pointer, '0', adjust - 1);
              input_line_pointer[adjust - 1] = ' ';
              return O_add;
            }
          break;
        }
      return O_illegal;
    }

  for (j = 0; i386_operators[j].name; ++j)
    if (strcasecmp (i386_operators[j].name, name) == 0)
      {
        if (i386_operators[j].operands
            && i386_operators[j].operands != operands)
          return O_illegal;
        return i386_operators[j].op;
      }

  for (j = 0; i386_types[j].name; ++j)
    if (strcasecmp (i386_types[j].name, name) == 0)
      break;

  if (i386_types[j].name && *pc == ' ')
    {
      char *pname;
      char c;

      ++input_line_pointer;
      c = get_symbol_name (&pname);

      if (strcasecmp (pname, "ptr") == 0)
        {
          /* FIXME: What if c == '"' ?  */
          pname[-1] = *pc;
          *pc = c;
          if (intel_syntax > 0 || operands != 1)
            return O_illegal;
          return i386_types[j].op;
        }

      if (strcasecmp (pname, "bcst") == 0)
        {
          /* FIXME: Again, what if c == '"' ?  */
          pname[-1] = *pc;
          *pc = c;
          if (intel_syntax > 0 || operands != 1
              || i386_types[j].sz[0] > 8
              || (i386_types[j].sz[0] & (i386_types[j].sz[0] - 1)))
            return O_illegal;
          if (!i.broadcast.bytes && !i.broadcast.type)
            {
              i.broadcast.bytes = i386_types[j].sz[0];
              i.broadcast.operand = this_operand;
            }
          return i386_types[j].op;
        }

      (void) restore_line_pointer (c);
      input_line_pointer = pname - 1;
    }

  return O_absent;
}

static int i386_intel_parse_name (const char *name, expressionS *e)
{
  unsigned int j;

  if (! strcmp (name, "$"))
    {
      current_location (e);
      return 1;
    }

  for (j = 0; i386_types[j].name; ++j)
    if (strcasecmp(i386_types[j].name, name) == 0)
      {
        e->X_op = O_constant;
        e->X_add_number = i386_types[j].sz[flag_code];
        e->X_add_symbol = NULL;
        e->X_op_symbol = NULL;
        return 1;
      }

  return 0;
}

static INLINE int i386_intel_check (const reg_entry *rreg,
                                    const reg_entry *base,
                                    const reg_entry *iindex)
{
  if ((this_operand >= 0
       && rreg != i.op[this_operand].regs)
      || base != intel_state.base
      || iindex != intel_state.index)
    {
      as_bad (_("invalid use of register"));
      return 0;
    }
  return 1;
}

static INLINE void i386_intel_fold (expressionS *e, symbolS *sym)
{
  expressionS *exp = symbol_get_value_expression (sym);
  if (S_GET_SEGMENT (sym) == absolute_section)
    {
      offsetT val = e->X_add_number;

      *e = *exp;
      e->X_add_number += val;
    }
  else
    {
      if (exp->X_op == O_symbol
          && strcmp (S_GET_NAME (exp->X_add_symbol),
                     GLOBAL_OFFSET_TABLE_NAME) == 0)
        sym = exp->X_add_symbol;
      e->X_add_symbol = sym;
      e->X_op_symbol = NULL;
      e->X_op = O_symbol;
    }
}

static int
i386_intel_simplify_register (expressionS *e)
{
  int reg_num;

  if (this_operand < 0 || intel_state.in_offset)
    {
      as_bad (_("invalid use of register"));
      return 0;
    }

  if (e->X_op == O_register)
    reg_num = e->X_add_number;
  else
    reg_num = e->X_md - 1;

  if (reg_num < 0 || reg_num >= (int) i386_regtab_size)
    {
      as_bad (_("invalid register number"));
      return 0;
    }

  if (!check_register (&i386_regtab[reg_num]))
    {
      as_bad (_("register '%s%s' cannot be used here"),
              register_prefix, i386_regtab[reg_num].reg_name);
      return 0;
    }

  if (!intel_state.in_bracket)
    {
      if (i.op[this_operand].regs)
        {
          as_bad (_("invalid use of register"));
          return 0;
        }
      if (i386_regtab[reg_num].reg_type.bitfield.class == SReg
          && i386_regtab[reg_num].reg_num == RegFlat)
        {
          as_bad (_("invalid use of pseudo-register"));
          return 0;
        }
      i.op[this_operand].regs = i386_regtab + reg_num;
    }
  else if (!intel_state.index
           && (i386_regtab[reg_num].reg_type.bitfield.xmmword
               || i386_regtab[reg_num].reg_type.bitfield.ymmword
               || i386_regtab[reg_num].reg_type.bitfield.zmmword
               || i386_regtab[reg_num].reg_num == RegIZ))
    intel_state.index = i386_regtab + reg_num;
  else if (!intel_state.base && !intel_state.in_scale)
    intel_state.base = i386_regtab + reg_num;
  else if (!intel_state.index)
    {
      const insn_template *t = current_templates->start;

      if (intel_state.in_scale
          || i386_regtab[reg_num].reg_type.bitfield.baseindex
          || t->mnem_off == MN_bndmk
          || t->mnem_off == MN_bndldx
          || t->mnem_off == MN_bndstx)
        intel_state.index = i386_regtab + reg_num;
      else
        {
          /* Convert base to index and make ESP/RSP the base.  */
          intel_state.index = intel_state.base;
          intel_state.base = i386_regtab + reg_num;
        }
    }
  else
    {
      /* esp is invalid as index */
      intel_state.index = reg_eax + ESP_REG_NUM;
    }
  return 2;
}

static int i386_intel_simplify (expressionS *);

static INLINE int i386_intel_simplify_symbol(symbolS *sym)
{
  int ret = i386_intel_simplify (symbol_get_value_expression (sym));

  if (ret == 2)
  {
    S_SET_SEGMENT(sym, absolute_section);
    ret = 1;
  }
  return ret;
}

static int i386_intel_simplify (expressionS *e)
{
  const reg_entry *the_reg = (this_operand >= 0
                              ? i.op[this_operand].regs : NULL);
  const reg_entry *base = intel_state.base;
  const reg_entry *state_index = intel_state.index;
  int ret;

  if (!intel_syntax)
    return 1;

  switch (e->X_op)
    {
    case O_index:
      if (e->X_add_symbol)
        {
          if (!i386_intel_simplify_symbol (e->X_add_symbol)
              || !i386_intel_check(the_reg, intel_state.base,
                                   intel_state.index))
            return 0;
        }
      if (!intel_state.in_offset)
        ++intel_state.in_bracket;
      ret = i386_intel_simplify_symbol (e->X_op_symbol);
      if (!intel_state.in_offset)
        --intel_state.in_bracket;
      if (!ret)
        return 0;
      if (e->X_add_symbol)
        e->X_op = O_add;
      else
        i386_intel_fold (e, e->X_op_symbol);
      break;

    case O_offset:
      intel_state.has_offset = 1;
      ++intel_state.in_offset;
      ret = i386_intel_simplify_symbol (e->X_add_symbol);
      --intel_state.in_offset;
      if (!ret || !i386_intel_check(the_reg, base, state_index))
        return 0;
      i386_intel_fold (e, e->X_add_symbol);
      return ret;

    case O_byte_ptr:
    case O_word_ptr:
    case O_dword_ptr:
    case O_fword_ptr:
    case O_qword_ptr: /* O_mmword_ptr */
    case O_tbyte_ptr:
    case O_oword_ptr: /* O_xmmword_ptr */
    case O_ymmword_ptr:
    case O_zmmword_ptr:
    case O_near_ptr:
    case O_far_ptr:
      if (intel_state.op_modifier == O_absent)
        intel_state.op_modifier = e->X_op;
      /* FALLTHROUGH */
    case O_short:
      if (symbol_get_value_expression (e->X_add_symbol)->X_op
          == O_register)
        {
          as_bad (_("invalid use of register"));
          return 0;
        }
      if (!i386_intel_simplify_symbol (e->X_add_symbol))
        return 0;
      i386_intel_fold (e, e->X_add_symbol);
      break;

    case O_full_ptr:
      if (symbol_get_value_expression (e->X_op_symbol)->X_op
          == O_register)
        {
          as_bad (_("invalid use of register"));
          return 0;
        }
      if (!i386_intel_simplify_symbol (e->X_op_symbol)
          || !i386_intel_check(the_reg, intel_state.base,
                               intel_state.index))
        return 0;
      if (!intel_state.in_offset)
        {
          if (!intel_state.seg)
            intel_state.seg = e->X_add_symbol;
          else
            {
              expressionS exp;

              exp.X_op = O_full_ptr;
              exp.X_add_symbol = e->X_add_symbol;
              exp.X_op_symbol = intel_state.seg;
              intel_state.seg = make_expr_symbol (&exp);
            }
        }
      i386_intel_fold (e, e->X_op_symbol);
      break;

    case O_multiply:
      if (this_operand >= 0 && intel_state.in_bracket)
        {
          expressionS *scale = NULL;
          int has_index = (intel_state.index != NULL);

          if (!intel_state.in_scale++)
            intel_state.scale_factor = 1;

          ret = i386_intel_simplify_symbol (e->X_add_symbol);
          if (ret && !has_index && intel_state.index)
            scale = symbol_get_value_expression (e->X_op_symbol);

          if (ret)
            ret = i386_intel_simplify_symbol (e->X_op_symbol);
          if (ret && !scale && !has_index && intel_state.index)
            scale = symbol_get_value_expression (e->X_add_symbol);

          if (ret && scale)
            {
              resolve_expression (scale);
              if (scale->X_op != O_constant
                  || intel_state.index->reg_type.bitfield.word)
                scale->X_add_number = 0;
              intel_state.scale_factor *= scale->X_add_number;
            }

          --intel_state.in_scale;
          if (!ret)
            return 0;

          if (!intel_state.in_scale)
            switch (intel_state.scale_factor)
              {
              case 1:
                i.log2_scale_factor = 0;
                break;
              case 2:
                i.log2_scale_factor = 1;
                break;
              case 4:
                i.log2_scale_factor = 2;
                break;
              case 8:
                i.log2_scale_factor = 3;
                break;
              default:
                /* esp is invalid as index */
                intel_state.index = reg_eax + ESP_REG_NUM;
                break;
              }

          break;
        }
      goto fallthrough;

    case O_register:
      ret = i386_intel_simplify_register (e);
      if (ret == 2)
        {
          gas_assert (e->X_add_number < (unsigned short) -1);
          e->X_md = (unsigned short) e->X_add_number + 1;
          e->X_op = O_constant;
          e->X_add_number = 0;
        }
      return ret;

    case O_constant:
      if (e->X_md)
        return i386_intel_simplify_register (e);

      /* FALLTHROUGH */
    default:
    fallthrough:
      if (e->X_add_symbol
          && !i386_intel_simplify_symbol (e->X_add_symbol))
        return 0;
      if (!the_reg && this_operand >= 0
          && e->X_op == O_symbol && !e->X_add_number)
        the_reg = i.op[this_operand].regs;
      if (e->X_op == O_add || e->X_op == O_subtract)
        {
          base = intel_state.base;
          state_index = intel_state.index;
        }
      if (!i386_intel_check (the_reg, base, state_index)
          || (e->X_op_symbol
              && !i386_intel_simplify_symbol (e->X_op_symbol))
          || !i386_intel_check (the_reg,
                                (e->X_op != O_add
                                 ? base : intel_state.base),
                                (e->X_op != O_add
                                 ? state_index : intel_state.index)))
        return 0;
      break;
    }

  if (this_operand >= 0
      && e->X_op == O_symbol
      && !intel_state.in_offset)
    {
      segT seg = S_GET_SEGMENT (e->X_add_symbol);

      if (seg != absolute_section
          && seg != reg_section
          && seg != expr_section)
        intel_state.is_mem |= 2 - !intel_state.in_bracket;
    }

  return 1;
}

int i386_need_index_operator (void)
{
  return intel_syntax < 0;
}

static int
i386_intel_operand (char *operand_string, int got_a_float)
{
  char *saved_input_line_pointer, *buf;
  segT exp_seg;
  expressionS exp, *expP;
  char suffix = 0;
  bool rc_sae_modifier = i.rounding.type != rc_none && i.rounding.modifier;
  int ret;

  /* Handle vector immediates.  */
  if (RC_SAE_immediate (operand_string))
    {
      if (i.imm_operands)
        {
          as_bad (_("`%s': RC/SAE operand must precede immediate operands"),
                  insn_name (current_templates->start));
          return 0;
        }

      return 1;
    }

  /* Initialize state structure.  */
  intel_state.op_modifier = O_absent;
  intel_state.is_mem = 0;
  intel_state.is_indirect = 0;
  intel_state.has_offset = 0;
  intel_state.base = NULL;
  intel_state.index = NULL;
  intel_state.seg = NULL;
  operand_type_set (&intel_state.reloc_types, ~0);
  gas_assert (!intel_state.in_offset);
  gas_assert (!intel_state.in_bracket);
  gas_assert (!intel_state.in_scale);

  saved_input_line_pointer = input_line_pointer;
  input_line_pointer = buf = xstrdup (operand_string);

  intel_syntax = -1;
  memset (&exp, 0, sizeof(exp));
  exp_seg = expression (&exp);
  ret = i386_intel_simplify (&exp);
  intel_syntax = 1;

  SKIP_WHITESPACE ();

  /* Handle vector operations.  */
  if (*input_line_pointer == '{')
    {
      char *end = check_VecOperations (input_line_pointer);
      if (end)
        input_line_pointer = end;
      else
        ret = 0;
    }

  if (!is_end_of_line[(unsigned char) *input_line_pointer])
    {
      if (ret)
        as_bad (_("junk `%s' after expression"), input_line_pointer);
      ret = 0;
    }
  else if (exp.X_op == O_illegal || exp.X_op == O_absent)
    {
      if (ret)
        as_bad (_("invalid expression"));
      ret = 0;
    }
  else if (!intel_state.has_offset
           && input_line_pointer > buf
           && *(input_line_pointer - 1) == ']')
    {
      intel_state.is_mem |= 1;
      intel_state.is_indirect = 1;
    }

  input_line_pointer = saved_input_line_pointer;
  free (buf);

  gas_assert (!intel_state.in_offset);
  gas_assert (!intel_state.in_bracket);
  gas_assert (!intel_state.in_scale);

  if (!ret)
    return 0;

  if (intel_state.op_modifier != O_absent
      && current_templates->start->mnem_off != MN_lea)
    {
      i.types[this_operand].bitfield.unspecified = 0;

      switch (intel_state.op_modifier)
        {
        case O_byte_ptr:
          i.types[this_operand].bitfield.byte = 1;
          suffix = BYTE_MNEM_SUFFIX;
          break;

        case O_word_ptr:
          i.types[this_operand].bitfield.word = 1;
          if (got_a_float == 2) /* "fi..." */
            suffix = SHORT_MNEM_SUFFIX;
          else if (current_templates->start->mnem_off != MN_lar
                   && current_templates->start->mnem_off != MN_lsl
                   && current_templates->start->mnem_off != MN_arpl)
            suffix = WORD_MNEM_SUFFIX;
          break;

        case O_dword_ptr:
          i.types[this_operand].bitfield.dword = 1;
          if ((insn_name (current_templates->start)[0] == 'l'
               && insn_name (current_templates->start)[2] == 's'
               && insn_name (current_templates->start)[3] == 0)
              || current_templates->start->mnem_off == MN_bound)
            suffix = WORD_MNEM_SUFFIX;
          else if (flag_code != CODE_32BIT
                   && (current_templates->start->opcode_modifier.jump == JUMP
                       || current_templates->start->opcode_modifier.jump
                          == JUMP_DWORD))
            {
              i.far_branch = true;
              suffix = WORD_MNEM_SUFFIX;
            }
          else if (got_a_float == 1)    /* "f..." */
            suffix = SHORT_MNEM_SUFFIX;
          else
            suffix = LONG_MNEM_SUFFIX;
          break;

        case O_fword_ptr:
          i.types[this_operand].bitfield.fword = 1;
          if (current_templates->start->mnem_off == MN_les
              || current_templates->start->mnem_off == MN_lds
              || current_templates->start->mnem_off == MN_lss
              || current_templates->start->mnem_off == MN_lfs
              || current_templates->start->mnem_off == MN_lgs)
            suffix = LONG_MNEM_SUFFIX;
          else if (!got_a_float)
            {
              if (flag_code == CODE_16BIT)
                add_prefix (DATA_PREFIX_OPCODE);
              i.far_branch = true;
            }
          break;

        case O_qword_ptr: /* O_mmword_ptr */
          i.types[this_operand].bitfield.qword = 1;
          if (current_templates->start->mnem_off == MN_bound
              || got_a_float == 1)      /* "f..." */
            suffix = LONG_MNEM_SUFFIX;
          else
            suffix = QWORD_MNEM_SUFFIX;
          break;

        case O_tbyte_ptr:
          i.types[this_operand].bitfield.tbyte = 1;
          if (got_a_float)
            break;
          if (flag_code == CODE_64BIT
              && (current_templates->start->operand_types[0].bitfield.fword
                  || current_templates->start->operand_types[0].bitfield.tbyte
                  || current_templates->start->opcode_modifier.jump == JUMP_DWORD
                  || current_templates->start->opcode_modifier.jump == JUMP))
            suffix = QWORD_MNEM_SUFFIX; /* l[fgs]s, [ls][gi]dt, call, jmp */
          else
            i.types[this_operand].bitfield.byte = 1; /* cause an error */
          break;

        case O_oword_ptr: /* O_xmmword_ptr */
          i.types[this_operand].bitfield.xmmword = 1;
          break;

        case O_ymmword_ptr:
          i.types[this_operand].bitfield.ymmword = 1;
          break;

        case O_zmmword_ptr:
          i.types[this_operand].bitfield.zmmword = 1;
          break;

        case O_far_ptr:
          i.far_branch = true;
          /* FALLTHROUGH */
        case O_near_ptr:
          if (current_templates->start->opcode_modifier.jump != JUMP
              && current_templates->start->opcode_modifier.jump != JUMP_DWORD)
            {
              /* cause an error */
              i.types[this_operand].bitfield.byte = 1;
              i.types[this_operand].bitfield.tbyte = 1;
              suffix = i.suffix;
            }
          break;

        default:
          BAD_CASE (intel_state.op_modifier);
          break;
        }

      /* Now check whether we actually want to infer an AT&T-like suffix.
         We really only need to do this when operand size determination (incl.
         REX.W) is going to be derived from it.  For this we check whether the
         given suffix is valid for any of the candidate templates.  */
      if (suffix && suffix != i.suffix
          && current_templates->start->mnem_off != MN_bound)
        {
          const insn_template *t;

          for (t = current_templates->start; t < current_templates->end; ++t)
            {
              /* Operands haven't been swapped yet.  */
              unsigned int op = t->operands - 1 - this_operand;

              /* Easy checks to skip templates which won't match anyway.  */
              if (this_operand >= t->operands || t->opcode_modifier.attsyntax)
                continue;

              switch (suffix)
                {
                case BYTE_MNEM_SUFFIX:
                  if (t->opcode_modifier.no_bsuf)
                    continue;
                  break;
                case WORD_MNEM_SUFFIX:
                  if (t->opcode_modifier.no_wsuf)
                    continue;
                  break;
                case LONG_MNEM_SUFFIX:
                  if (t->opcode_modifier.no_lsuf)
                    continue;
                  break;
                case QWORD_MNEM_SUFFIX:
                  if (t->opcode_modifier.no_qsuf || !q_suffix_allowed (t))
                    continue;
                  break;
                case SHORT_MNEM_SUFFIX:
                  if (t->opcode_modifier.no_ssuf)
                    continue;
                  break;
                default:
                  abort ();
                }

              /* We can skip templates with swappable operands here, as one
                 operand will be a register, which operand size can be
                 determined from.  */
              if (t->opcode_modifier.d)
                continue;

              /* In a few cases suffixes are permitted, but we can nevertheless
                 derive that these aren't going to be needed.  This is only of
                 interest for insns using ModR/M.  */
              if (!t->opcode_modifier.modrm)
                break;

              if (!t->operand_types[op].bitfield.baseindex)
                continue;

              switch (t->operand_types[op].bitfield.class)
                {
                case RegMMX:
                case RegSIMD:
                case RegMask:
                  continue;
                }

              break;
            }

          if (t == current_templates->end)
            suffix = 0;
        }

      if (!i.suffix)
        i.suffix = suffix;
      else if (suffix && i.suffix != suffix)
        {
          as_bad (_("conflicting operand size modifiers"));
          return 0;
        }
    }

  /* Operands for jump/call need special consideration.  */
  if (current_templates->start->opcode_modifier.jump == JUMP
      || current_templates->start->opcode_modifier.jump == JUMP_DWORD
      || current_templates->start->opcode_modifier.jump == JUMP_INTERSEGMENT)
    {
      bool jumpabsolute = false;

      if (i.op[this_operand].regs
          || intel_state.base
          || intel_state.index
          || intel_state.is_mem > 1)
        jumpabsolute = true;
      else
        switch (intel_state.op_modifier)
          {
          case O_near_ptr:
            if (intel_state.seg)
              jumpabsolute = true;
            else
              intel_state.is_mem = 1;
            break;
          case O_far_ptr:
          case O_absent:
            if (!intel_state.seg)
              {
                intel_state.is_mem = 1;
                if (intel_state.op_modifier == O_absent)
                  {
                    if (intel_state.is_indirect == 1)
                      jumpabsolute = true;
                    break;
                  }
                as_bad (_("cannot infer the segment part of the operand"));
                return 0;
              }
            else if (S_GET_SEGMENT (intel_state.seg) == reg_section)
              {
                jumpabsolute = true;
                if (intel_state.op_modifier == O_far_ptr)
                  i.far_branch = true;
              }
            else
              {
                i386_operand_type types;

                if (i.imm_operands >= MAX_IMMEDIATE_OPERANDS)
                  {
                    as_bad (_("at most %d immediate operands are allowed"),
                            MAX_IMMEDIATE_OPERANDS);
                    return 0;
                  }
                expP = &im_expressions[i.imm_operands++];
                memset (expP, 0, sizeof(*expP));
                expP->X_op = O_symbol;
                expP->X_add_symbol = intel_state.seg;
                i.op[this_operand].imms = expP;

                resolve_expression (expP);
                operand_type_set (&types, ~0);
                if (!i386_finalize_immediate (S_GET_SEGMENT (intel_state.seg),
                                              expP, types, operand_string))
                  return 0;
                if (i.operands < MAX_OPERANDS)
                  {
                    this_operand = i.operands++;
                    i.types[this_operand].bitfield.unspecified = 1;
                  }
                intel_state.seg = NULL;
                intel_state.is_mem = 0;
              }
            break;
          default:
            jumpabsolute = true;
            break;
          }
      if (jumpabsolute)
        {
          i.jumpabsolute = true;
          intel_state.is_mem |= 1;
        }
    }
  else if (intel_state.seg)
    intel_state.is_mem |= 1;

  if (i.op[this_operand].regs)
    {
      i386_operand_type temp;

      /* Register operand.  */
      if (intel_state.base || intel_state.index || intel_state.seg)
        {
          as_bad (_("invalid operand"));
          return 0;
        }

      temp = i.op[this_operand].regs->reg_type;
      temp.bitfield.baseindex = 0;
      i.types[this_operand] = operand_type_or (i.types[this_operand],
                                               temp);
      i.types[this_operand].bitfield.unspecified = 0;
      ++i.reg_operands;

      if ((i.rounding.type != rc_none && !i.rounding.modifier
           && temp.bitfield.class != Reg)
          || rc_sae_modifier)
        {
          unsigned int j;

          for (j = 0; j < ARRAY_SIZE (RC_NamesTable); ++j)
            if (i.rounding.type == RC_NamesTable[j].type)
              break;
          as_bad (_("`%s': misplaced `{%s}'"),
                  insn_name (current_templates->start), RC_NamesTable[j].name);
          return 0;
        }
    }
  else if (intel_state.base
           || intel_state.index
           || intel_state.seg
           || intel_state.is_mem)
    {
      /* Memory operand.  */
      if (i.mem_operands)
        {
          /* Handle

             call       0x9090,0x90909090
             lcall      0x9090,0x90909090
             jmp        0x9090,0x90909090
             ljmp       0x9090,0x90909090
           */

          if ((current_templates->start->opcode_modifier.jump == JUMP_INTERSEGMENT
               || current_templates->start->opcode_modifier.jump == JUMP_DWORD
               || current_templates->start->opcode_modifier.jump == JUMP)
              && this_operand == 1
              && intel_state.seg == NULL
              && i.mem_operands == 1
              && i.disp_operands == 1
              && intel_state.op_modifier == O_absent)
            {
              /* Try to process the first operand as immediate,  */
              this_operand = 0;
              if (i386_finalize_immediate (exp_seg, i.op[0].imms,
                                           intel_state.reloc_types,
                                           NULL))
                {
                  this_operand = 1;
                  expP = &im_expressions[0];
                  i.op[this_operand].imms = expP;
                  *expP = exp;

                  /* Try to process the second operand as immediate,  */
                  if (i386_finalize_immediate (exp_seg, expP,
                                               intel_state.reloc_types,
                                               NULL))
                    {
                      i.mem_operands = 0;
                      i.disp_operands = 0;
                      i.imm_operands = 2;
                      i.flags[0] &= ~Operand_Mem;
                      i.types[0].bitfield.disp16 = 0;
                      i.types[0].bitfield.disp32 = 0;
                      return 1;
                    }
                }
            }
        }

      /* Swap base and index in 16-bit memory operands like
         [si+bx]. Since i386_index_check is also used in AT&T
         mode we have to do this here.  */
      if (intel_state.base
          && intel_state.index
          && intel_state.base->reg_type.bitfield.word
          && intel_state.index->reg_type.bitfield.word
          && intel_state.base->reg_num >= 6
          && intel_state.index->reg_num < 6)
        {
          i.base_reg = intel_state.index;
          i.index_reg = intel_state.base;
        }
      else
        {
          i.base_reg = intel_state.base;
          i.index_reg = intel_state.index;
        }

      if (i.base_reg || i.index_reg)
        i.types[this_operand].bitfield.baseindex = 1;

      expP = &disp_expressions[i.disp_operands];
      memcpy (expP, &exp, sizeof(exp));
      resolve_expression (expP);

      if (expP->X_op != O_constant
          || expP->X_add_number
          || !i.types[this_operand].bitfield.baseindex)
        {
          i.op[this_operand].disps = expP;
          i.disp_operands++;

          i386_addressing_mode ();

          if (flag_code == CODE_64BIT)
            {
              i.types[this_operand].bitfield.disp32 = 1;
              if (!i.prefix[ADDR_PREFIX])
                i.types[this_operand].bitfield.disp64 = 1;
            }
          else if (!i.prefix[ADDR_PREFIX] ^ (flag_code == CODE_16BIT))
            i.types[this_operand].bitfield.disp32 = 1;
          else
            i.types[this_operand].bitfield.disp16 = 1;

#if defined (OBJ_AOUT) || defined (OBJ_MAYBE_AOUT)
          /*
           * exp_seg is used only for verification in
           * i386_finalize_displacement, and we can end up seeing reg_section
           * here - but we know we removed all registers from the expression
           * (or error-ed on any remaining ones) in i386_intel_simplify.  I
           * consider the check in i386_finalize_displacement bogus anyway, in
           * particular because it doesn't allow for expr_section, so I'd
           * rather see that check (and the similar one in
           * i386_finalize_immediate) use SEG_NORMAL(), but not being an a.out
           * expert I can't really say whether that would have other bad side
           * effects.
           */
          if (OUTPUT_FLAVOR == bfd_target_aout_flavour
              && exp_seg == reg_section)
            exp_seg = expP->X_op != O_constant ? undefined_section
                                               : absolute_section;
#endif

          if (!i386_finalize_displacement (exp_seg, expP,
                                           intel_state.reloc_types,
                                           operand_string))
            return 0;
        }

      if (intel_state.seg)
        {
          for (ret = check_none; ; ret = operand_check)
            {
              expP = symbol_get_value_expression (intel_state.seg);
              if (expP->X_op != O_full_ptr 
                  || symbol_get_value_expression (expP->X_op_symbol)->X_op
                     != O_register)
                break;
              intel_state.seg = expP->X_add_symbol;
            }
          if (expP->X_op != O_register)
            {
              as_bad (_("segment register name expected"));
              return 0;
            }
          if (i386_regtab[expP->X_add_number].reg_type.bitfield.class != SReg)
            {
              as_bad (_("invalid use of register"));
              return 0;
            }
          switch (ret)
            {
            case check_error:
              as_bad (_("redundant segment overrides"));
              return 0;
            case check_warning:
              as_warn (_("redundant segment overrides"));
              break;
            }
          if (i386_regtab[expP->X_add_number].reg_num == RegFlat)
            i.seg[i.mem_operands] = NULL;
          else
            i.seg[i.mem_operands] = &i386_regtab[expP->X_add_number];
        }

      if (!i386_index_check (operand_string))
        return 0;

      i.flags[this_operand] |= Operand_Mem;
      ++i.mem_operands;
    }
  else
    {
      /* Immediate.  */
      if (i.imm_operands >= MAX_IMMEDIATE_OPERANDS)
        {
          as_bad (_("at most %d immediate operands are allowed"),
                  MAX_IMMEDIATE_OPERANDS);
          return 0;
        }

      expP = &im_expressions[i.imm_operands++];
      i.op[this_operand].imms = expP;
      *expP = exp;

      return i386_finalize_immediate (exp_seg, expP, intel_state.reloc_types,
                                      operand_string);
    }

  return 1;
}