tc-i386.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 2,311 行 · 第 1/5 页

      else
	memcpy (fragP->fr_literal + fragP->fr_fix,
		f32_patt[count - 1], count);
      fragP->fr_var = count;
    }
}

static char *output_invalid PARAMS ((int c));
static int i386_operand PARAMS ((char *operand_string));
static int i386_intel_operand PARAMS ((char *operand_string, int got_a_float));
static const reg_entry *parse_register PARAMS ((char *reg_string,
						char **end_op));

#ifndef I386COFF
static void s_bss PARAMS ((int));
#endif

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

static INLINE unsigned int
mode_from_disp_size (t)
     unsigned int t;
{
  return (t & Disp8) ? 1 : (t & (Disp16 | Disp32 | Disp32S)) ? 2 : 0;
}

static INLINE int
fits_in_signed_byte (num)
     offsetT num;
{
  return (num >= -128) && (num <= 127);
}

static INLINE int
fits_in_unsigned_byte (num)
     offsetT num;
{
  return (num & 0xff) == num;
}

static INLINE int
fits_in_unsigned_word (num)
     offsetT num;
{
  return (num & 0xffff) == num;
}

static INLINE int
fits_in_signed_word (num)
     offsetT num;
{
  return (-32768 <= num) && (num <= 32767);
}
static INLINE int
fits_in_signed_long (num)
     offsetT num ATTRIBUTE_UNUSED;
{
#ifndef BFD64
  return 1;
#else
  return (!(((offsetT) -1 << 31) & num)
	  || (((offsetT) -1 << 31) & num) == ((offsetT) -1 << 31));
#endif
}				/* fits_in_signed_long() */
static INLINE int
fits_in_unsigned_long (num)
     offsetT num ATTRIBUTE_UNUSED;
{
#ifndef BFD64
  return 1;
#else
  return (num & (((offsetT) 2 << 31) - 1)) == num;
#endif
}				/* fits_in_unsigned_long() */

static int
smallest_imm_type (num)
     offsetT num;
{
  if (cpu_arch_flags != (Cpu086 | Cpu186 | Cpu286 | Cpu386 | Cpu486 | CpuNo64)
      && !(cpu_arch_flags & (CpuUnknown)))
    {
      /* This code is disabled on the 486 because all the Imm1 forms
	 in the opcode table are slower on the i486.  They're the
	 versions with the implicitly specified single-position
	 displacement, which has another syntax if you really want to
	 use that form.  */
      if (num == 1)
	return Imm1 | Imm8 | Imm8S | Imm16 | Imm32 | Imm32S | Imm64;
    }
  return (fits_in_signed_byte (num)
	  ? (Imm8S | Imm8 | Imm16 | Imm32 | Imm32S | Imm64)
	  : fits_in_unsigned_byte (num)
	  ? (Imm8 | Imm16 | Imm32 | Imm32S | Imm64)
	  : (fits_in_signed_word (num) || fits_in_unsigned_word (num))
	  ? (Imm16 | Imm32 | Imm32S | Imm64)
	  : fits_in_signed_long (num)
	  ? (Imm32 | Imm32S | Imm64)
	  : fits_in_unsigned_long (num)
	  ? (Imm32 | Imm64)
	  : Imm64);
}

static offsetT
offset_in_range (val, size)
     offsetT val;
     int size;
{
  addressT mask;

  switch (size)
    {
    case 1: mask = ((addressT) 1 <<  8) - 1; break;
    case 2: mask = ((addressT) 1 << 16) - 1; break;
    case 4: mask = ((addressT) 2 << 31) - 1; break;
#ifdef BFD64
    case 8: mask = ((addressT) 2 << 63) - 1; break;
#endif
    default: abort ();
    }

  /* If BFD64, sign extend val.  */
  if (!use_rela_relocations)
    if ((val & ~(((addressT) 2 << 31) - 1)) == 0)
      val = (val ^ ((addressT) 1 << 31)) - ((addressT) 1 << 31);

  if ((val & ~mask) != 0 && (val & ~mask) != ~mask)
    {
      char buf1[40], buf2[40];

      sprint_value (buf1, val);
      sprint_value (buf2, val & mask);
      as_warn (_("%s shortened to %s"), buf1, buf2);
    }
  return val & mask;
}

/* Returns 0 if attempting to add a prefix where one from the same
   class already exists, 1 if non rep/repne added, 2 if rep/repne
   added.  */
static int
add_prefix (prefix)
     unsigned int prefix;
{
  int ret = 1;
  int q;

  if (prefix >= 0x40 && prefix < 0x50 && flag_code == CODE_64BIT)
    q = REX_PREFIX;
  else
    switch (prefix)
      {
      default:
	abort ();

      case CS_PREFIX_OPCODE:
      case DS_PREFIX_OPCODE:
      case ES_PREFIX_OPCODE:
      case FS_PREFIX_OPCODE:
      case GS_PREFIX_OPCODE:
      case SS_PREFIX_OPCODE:
	q = SEG_PREFIX;
	break;

      case REPNE_PREFIX_OPCODE:
      case REPE_PREFIX_OPCODE:
	ret = 2;
	/* fall thru */
      case LOCK_PREFIX_OPCODE:
	q = LOCKREP_PREFIX;
	break;

      case FWAIT_OPCODE:
	q = WAIT_PREFIX;
	break;

      case ADDR_PREFIX_OPCODE:
	q = ADDR_PREFIX;
	break;

      case DATA_PREFIX_OPCODE:
	q = DATA_PREFIX;
	break;
      }

  if (i.prefix[q])
    {
      as_bad (_("same type of prefix used twice"));
      return 0;
    }

  i.prefixes += 1;
  i.prefix[q] = prefix;
  return ret;
}

static void
set_code_flag (value)
     int value;
{
  flag_code = value;
  cpu_arch_flags &= ~(Cpu64 | CpuNo64);
  cpu_arch_flags |= (flag_code == CODE_64BIT ? Cpu64 : CpuNo64);
  if (value == CODE_64BIT && !(cpu_arch_flags & CpuSledgehammer))
    {
      as_bad (_("64bit mode not supported on this CPU."));
    }
  if (value == CODE_32BIT && !(cpu_arch_flags & Cpu386))
    {
      as_bad (_("32bit mode not supported on this CPU."));
    }
  stackop_size = '\0';
}

static void
set_16bit_gcc_code_flag (new_code_flag)
     int new_code_flag;
{
  flag_code = new_code_flag;
  cpu_arch_flags &= ~(Cpu64 | CpuNo64);
  cpu_arch_flags |= (flag_code == CODE_64BIT ? Cpu64 : CpuNo64);
  stackop_size = 'l';
}

static void
set_intel_syntax (syntax_flag)
     int syntax_flag;
{
  /* Find out if register prefixing is specified.  */
  int ask_naked_reg = 0;

  SKIP_WHITESPACE ();
  if (! is_end_of_line[(unsigned char) *input_line_pointer])
    {
      char *string = input_line_pointer;
      int e = get_symbol_end ();

      if (strcmp (string, "prefix") == 0)
	ask_naked_reg = 1;
      else if (strcmp (string, "noprefix") == 0)
	ask_naked_reg = -1;
      else
	as_bad (_("bad argument to syntax directive."));
      *input_line_pointer = e;
    }
  demand_empty_rest_of_line ();

  intel_syntax = syntax_flag;

  if (ask_naked_reg == 0)
    {
#ifdef BFD_ASSEMBLER
      allow_naked_reg = (intel_syntax
			 && (bfd_get_symbol_leading_char (stdoutput) != '\0'));
#else
      /* Conservative default.  */
      allow_naked_reg = 0;
#endif
    }
  else
    allow_naked_reg = (ask_naked_reg < 0);
}

static void
set_cpu_arch (dummy)
     int dummy ATTRIBUTE_UNUSED;
{
  SKIP_WHITESPACE ();

  if (! is_end_of_line[(unsigned char) *input_line_pointer])
    {
      char *string = input_line_pointer;
      int e = get_symbol_end ();
      int i;

      for (i = 0; cpu_arch[i].name; i++)
	{
	  if (strcmp (string, cpu_arch[i].name) == 0)
	    {
	      cpu_arch_name = cpu_arch[i].name;
	      cpu_arch_flags = (cpu_arch[i].flags
				| (flag_code == CODE_64BIT ? Cpu64 : CpuNo64));
	      break;
	    }
	}
      if (!cpu_arch[i].name)
	as_bad (_("no such architecture: `%s'"), string);

      *input_line_pointer = e;
    }
  else
    as_bad (_("missing cpu architecture"));

  no_cond_jump_promotion = 0;
  if (*input_line_pointer == ','
      && ! is_end_of_line[(unsigned char) input_line_pointer[1]])
    {
      char *string = ++input_line_pointer;
      int e = get_symbol_end ();

      if (strcmp (string, "nojumps") == 0)
	no_cond_jump_promotion = 1;
      else if (strcmp (string, "jumps") == 0)
	;
      else
	as_bad (_("no such architecture modifier: `%s'"), string);

      *input_line_pointer = e;
    }

  demand_empty_rest_of_line ();
}

const pseudo_typeS md_pseudo_table[] =
{
#if !defined(OBJ_AOUT) && !defined(USE_ALIGN_PTWO)
  {"align", s_align_bytes, 0},
#else
  {"align", s_align_ptwo, 0},
#endif
  {"arch", set_cpu_arch, 0},
#ifndef I386COFF
  {"bss", s_bss, 0},
#endif
  {"ffloat", float_cons, 'f'},
  {"dfloat", float_cons, 'd'},
  {"tfloat", float_cons, 'x'},
  {"value", cons, 2},
  {"noopt", s_ignore, 0},
  {"optim", s_ignore, 0},
  {"code16gcc", set_16bit_gcc_code_flag, CODE_16BIT},
  {"code16", set_code_flag, CODE_16BIT},
  {"code32", set_code_flag, CODE_32BIT},
  {"code64", set_code_flag, CODE_64BIT},
  {"intel_syntax", set_intel_syntax, 1},
  {"att_syntax", set_intel_syntax, 0},
  {"file", dwarf2_directive_file, 0},
  {"loc", dwarf2_directive_loc, 0},
  {0, 0, 0}
};

/* For interface with expression ().  */
extern char *input_line_pointer;

/* Hash table for instruction mnemonic lookup.  */
static struct hash_control *op_hash;

/* Hash table for register lookup.  */
static struct hash_control *reg_hash;

#ifdef BFD_ASSEMBLER
unsigned long
i386_mach ()
{
  if (!strcmp (default_arch, "x86_64"))
    return bfd_mach_x86_64;
  else if (!strcmp (default_arch, "i386"))
    return bfd_mach_i386_i386;
  else
    as_fatal (_("Unknown architecture"));
}
#endif

void
md_begin ()
{
  const char *hash_err;

  /* Initialize op_hash hash table.  */
  op_hash = hash_new ();

  {
    register const template *optab;
    register templates *core_optab;

    /* Setup for loop.  */
    optab = i386_optab;
    core_optab = (templates *) xmalloc (sizeof (templates));
    core_optab->start = optab;

    while (1)
      {
	++optab;
	if (optab->name == NULL
	    || strcmp (optab->name, (optab - 1)->name) != 0)
	  {
	    /* different name --> ship out current template list;
	       add to hash table; & begin anew.  */
	    core_optab->end = optab;
	    hash_err = hash_insert (op_hash,
				    (optab - 1)->name,
				    (PTR) core_optab);
	    if (hash_err)
	      {
		as_fatal (_("Internal Error:  Can't hash %s: %s"),
			  (optab - 1)->name,
			  hash_err);
	      }
	    if (optab->name == NULL)
	      break;
	    core_optab = (templates *) xmalloc (sizeof (templates));
	    core_optab->start = optab;
	  }
      }
  }

  /* Initialize reg_hash hash table.  */
  reg_hash = hash_new ();
  {
    register const reg_entry *regtab;

    for (regtab = i386_regtab;
	 regtab < i386_regtab + sizeof (i386_regtab) / sizeof (i386_regtab[0]);
	 regtab++)
      {
	hash_err = hash_insert (reg_hash, regtab->reg_name, (PTR) regtab);
	if (hash_err)
	  as_fatal (_("Internal Error:  Can't hash %s: %s"),
		    regtab->reg_name,
		    hash_err);
      }
  }

  /* Fill in lexical tables:  mnemonic_chars, operand_chars.  */
  {
    register int c;
    register char *p;

    for (c = 0; c < 256; c++)
      {
	if (isdigit (c))
	  {
	    digit_chars[c] = c;
	    mnemonic_chars[c] = c;
	    register_chars[c] = c;
	    operand_chars[c] = c;
	  }
	else if (islower (c))
	  {
	    mnemonic_chars[c] = c;
	    register_chars[c] = c;
	    operand_chars[c] = c;
	  }
	else if (isupper (c))
	  {
	    mnemonic_chars[c] = tolower (c);
	    register_chars[c] = mnemonic_chars[c];
	    operand_chars[c] = c;
	  }

	if (isalpha (c) || isdigit (c))
	  identifier_chars[c] = c;
	else if (c >= 128)
	  {
	    identifier_chars[c] = c;
	    operand_chars[c] = c;
	  }
      }

#ifdef LEX_AT
    identifier_chars['@'] = '@';
#endif
    digit_chars['-'] = '-';