gas reloc rewrite.

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

/* i386.c -- Assemble code for the Intel 80386
   Copyright 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002
   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 2, or (at your option)
   any later version.

   GAS is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

/* Intel 80386 machine specific gas.
   Written by Eliot Dresselhaus (eliot@mgm.mit.edu).
   x86_64 support by Jan Hubicka (jh@suse.cz)
   Bugs & suggestions are completely welcome.  This is free software.
   Please help us make it better.  */

#include "as.h"
#include "safe-ctype.h"
#include "subsegs.h"
#include "dwarf2dbg.h"
#include "opcode/i386.h"

#ifndef REGISTER_WARNINGS
#define REGISTER_WARNINGS 1
#endif

#ifndef INFER_ADDR_PREFIX
#define INFER_ADDR_PREFIX 1
#endif

#ifndef SCALE1_WHEN_NO_INDEX
/* Specifying a scale factor besides 1 when there is no index is
   futile.  eg. `mov (%ebx,2),%al' does exactly the same as
   `mov (%ebx),%al'.  To slavishly follow what the programmer
   specified, set SCALE1_WHEN_NO_INDEX to 0.  */
#define SCALE1_WHEN_NO_INDEX 1
#endif

#ifdef BFD_ASSEMBLER
#define RELOC_ENUM enum bfd_reloc_code_real
#else
#define RELOC_ENUM int
#endif

#ifndef DEFAULT_ARCH
#define DEFAULT_ARCH "i386"
#endif

#ifndef INLINE
#if __GNUC__ >= 2
#define INLINE __inline__
#else
#define INLINE
#endif
#endif

static INLINE unsigned int mode_from_disp_size PARAMS ((unsigned int));
static INLINE int fits_in_signed_byte PARAMS ((offsetT));
static INLINE int fits_in_unsigned_byte PARAMS ((offsetT));
static INLINE int fits_in_unsigned_word PARAMS ((offsetT));
static INLINE int fits_in_signed_word PARAMS ((offsetT));
static INLINE int fits_in_unsigned_long PARAMS ((offsetT));
static INLINE int fits_in_signed_long PARAMS ((offsetT));
static int smallest_imm_type PARAMS ((offsetT));
static offsetT offset_in_range PARAMS ((offsetT, int));
static int add_prefix PARAMS ((unsigned int));
static void set_code_flag PARAMS ((int));
static void set_16bit_gcc_code_flag PARAMS ((int));
static void set_intel_syntax PARAMS ((int));
static void set_cpu_arch PARAMS ((int));
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));
static char *parse_insn PARAMS ((char *, char *));
static char *parse_operands PARAMS ((char *, const char *));
static void swap_operands PARAMS ((void));
static void optimize_imm PARAMS ((void));
static void optimize_disp PARAMS ((void));
static int match_template PARAMS ((void));
static int check_string PARAMS ((void));
static int process_suffix PARAMS ((void));
static int check_byte_reg PARAMS ((void));
static int check_long_reg PARAMS ((void));
static int check_qword_reg PARAMS ((void));
static int check_word_reg PARAMS ((void));
static int finalize_imm PARAMS ((void));
static int process_operands PARAMS ((void));
static const seg_entry *build_modrm_byte PARAMS ((void));
static void output_insn PARAMS ((void));
static void output_branch PARAMS ((void));
static void output_jump PARAMS ((void));
static void output_interseg_jump PARAMS ((void));
static void output_imm PARAMS ((fragS *insn_start_frag,
                                offsetT insn_start_off));
static void output_disp PARAMS ((fragS *insn_start_frag,
                                 offsetT insn_start_off));
#ifndef I386COFF
static void s_bss PARAMS ((int));
#endif

static const char *default_arch = DEFAULT_ARCH;

/* 'md_assemble ()' gathers together information and puts it into a
   i386_insn.  */

union i386_op
  {
    expressionS *disps;
    expressionS *imms;
    const reg_entry *regs;
  };

struct _i386_insn
  {
    /* TM holds the template for the insn were currently assembling.  */
    template tm;

    /* SUFFIX holds the instruction mnemonic suffix if given.
       (e.g. 'l' for 'movl')  */
    char suffix;

    /* OPERANDS gives the number of given operands.  */
    unsigned int operands;

    /* REG_OPERANDS, DISP_OPERANDS, MEM_OPERANDS, IMM_OPERANDS give the number
       of given register, displacement, memory operands and immediate
       operands.  */
    unsigned int reg_operands, disp_operands, mem_operands, imm_operands;

    /* TYPES [i] is the type (see above #defines) which tells us how to
       use OP[i] for the corresponding operand.  */
    unsigned int types[MAX_OPERANDS];

    /* Displacement expression, immediate expression, or register for each
       operand.  */
    union i386_op op[MAX_OPERANDS];

    /* Flags for operands.  */
    unsigned int flags[MAX_OPERANDS];
#define Operand_PCrel 1

    /* Relocation type for operand */
    RELOC_ENUM reloc[MAX_OPERANDS];

    /* BASE_REG, INDEX_REG, and LOG2_SCALE_FACTOR are used to encode
       the base index byte below.  */
    const reg_entry *base_reg;
    const reg_entry *index_reg;
    unsigned int log2_scale_factor;

    /* SEG gives the seg_entries of this insn.  They are zero unless
       explicit segment overrides are given.  */
    const seg_entry *seg[2];

    /* PREFIX holds all the given prefix opcodes (usually null).
       PREFIXES is the number of prefix opcodes.  */
    unsigned int prefixes;
    unsigned char prefix[MAX_PREFIXES];

    /* RM and SIB are the modrm byte and the sib byte where the
       addressing modes of this insn are encoded.  */

    modrm_byte rm;
    rex_byte rex;
    sib_byte sib;
  };

typedef struct _i386_insn i386_insn;

/* List of chars besides those in app.c:symbol_chars that can start an
   operand.  Used to prevent the scrubber eating vital white-space.  */
#ifdef LEX_AT
const char extra_symbol_chars[] = "*%-(@[";
#else
const char extra_symbol_chars[] = "*%-([";
#endif

#if (defined (TE_I386AIX)                               \
     || ((defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)) \
         && !defined (TE_LINUX)                         \
         && !defined (TE_FreeBSD)                       \
         && !defined (TE_NetBSD)))
/* This array holds the chars that always start a comment.  If the
   pre-processor is disabled, these aren't very useful.  */
const char comment_chars[] = "#/";
#define PREFIX_SEPARATOR '\\'

/* This array holds the chars that only start a comment at the beginning of
   a line.  If the line seems to have the form '# 123 filename'
   .line and .file directives will appear in the pre-processed output.
   Note that input_file.c hand checks for '#' at the beginning of the
   first line of the input file.  This is because the compiler outputs
   #NO_APP at the beginning of its output.
   Also note that comments started like this one will always work if
   '/' isn't otherwise defined.  */
const char line_comment_chars[] = "";

#else
/* Putting '/' here makes it impossible to use the divide operator.
   However, we need it for compatibility with SVR4 systems.  */
const char comment_chars[] = "#";
#define PREFIX_SEPARATOR '/'

const char line_comment_chars[] = "/";
#endif

const char line_separator_chars[] = ";";

/* Chars that can be used to separate mant from exp in floating point
   nums.  */
const char EXP_CHARS[] = "eE";

/* Chars that mean this number is a floating point constant
   As in 0f12.456
   or    0d1.2345e12.  */
const char FLT_CHARS[] = "fFdDxX";

/* Tables for lexical analysis.  */
static char mnemonic_chars[256];
static char register_chars[256];
static char operand_chars[256];
static char identifier_chars[256];
static char digit_chars[256];

/* Lexical macros.  */
#define is_mnemonic_char(x) (mnemonic_chars[(unsigned char) x])
#define is_operand_char(x) (operand_chars[(unsigned char) x])
#define is_register_char(x) (register_chars[(unsigned char) x])
#define is_space_char(x) ((x) == ' ')
#define is_identifier_char(x) (identifier_chars[(unsigned char) x])
#define is_digit_char(x) (digit_chars[(unsigned char) x])

/* All non-digit non-letter charcters that may occur in an operand.  */
static char operand_special_chars[] = "%$-+(,)*._~/<>|&^!:[@]";

/* md_assemble() always leaves the strings it's passed unaltered.  To
   effect this we maintain a stack of saved characters that we've smashed
   with '\0's (indicating end of strings for various sub-fields of the
   assembler instruction).  */
static char save_stack[32];
static char *save_stack_p;
#define END_STRING_AND_SAVE(s) \
        do { *save_stack_p++ = *(s); *(s) = '\0'; } while (0)
#define RESTORE_END_STRING(s) \
        do { *(s) = *--save_stack_p; } while (0)

/* The instruction we're assembling.  */
static i386_insn i;

/* Possible templates for current insn.  */
static const templates *current_templates;

/* Per instruction expressionS buffers: 2 displacements & 2 immediate max.  */
static expressionS disp_expressions[2], im_expressions[2];

/* Current operand we are working on.  */
static int this_operand;

/* We support four different modes.  FLAG_CODE variable is used to distinguish
   these.  */

enum flag_code {
        CODE_32BIT,
        CODE_16BIT,
        CODE_64BIT };
#define NUM_FLAG_CODE ((int) CODE_64BIT + 1)

static enum flag_code flag_code;
static int use_rela_relocations = 0;

/* The names used to print error messages.  */
static const char *flag_code_names[] =
  {
    "32",
    "16",
    "64"
  };

/* 1 for intel syntax,
   0 if att syntax.  */
static int intel_syntax = 0;

/* 1 if register prefix % not required.  */
static int allow_naked_reg = 0;

/* Used in 16 bit gcc mode to add an l suffix to call, ret, enter,
   leave, push, and pop instructions so that gcc has the same stack
   frame as in 32 bit mode.  */
static char stackop_size = '\0';

/* Non-zero to quieten some warnings.  */
static int quiet_warnings = 0;

/* CPU name.  */
static const char *cpu_arch_name = NULL;

/* CPU feature flags.  */
static unsigned int cpu_arch_flags = CpuUnknownFlags | CpuNo64;

/* If set, conditional jumps are not automatically promoted to handle
   larger than a byte offset.  */
static unsigned int no_cond_jump_promotion = 0;

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

/* Interface to relax_segment.
   There are 3 major relax states for 386 jump insns because the
   different types of jumps add different sizes to frags when we're
   figuring out what sort of jump to choose to reach a given label.  */

/* Types.  */
#define UNCOND_JUMP 0
#define COND_JUMP 1
#define COND_JUMP86 2

/* Sizes.  */
#define CODE16  1
#define SMALL   0
#define SMALL16 (SMALL | CODE16)
#define BIG     2
#define BIG16   (BIG | CODE16)

#ifndef INLINE
#ifdef __GNUC__
#define INLINE __inline__
#else
#define INLINE
#endif
#endif

#define ENCODE_RELAX_STATE(type, size) \
  ((relax_substateT) (((type) << 2) | (size)))
#define TYPE_FROM_RELAX_STATE(s) \
  ((s) >> 2)
#define DISP_SIZE_FROM_RELAX_STATE(s) \
    ((((s) & 3) == BIG ? 4 : (((s) & 3) == BIG16 ? 2 : 1)))

/* This table is used by relax_frag to promote short jumps to long
   ones where necessary.  SMALL (short) jumps may be promoted to BIG
   (32 bit long) ones, and SMALL16 jumps to BIG16 (16 bit long).  We
   don't allow a short jump in a 32 bit code segment to be promoted to
   a 16 bit offset jump because it's slower (requires data size
   prefix), and doesn't work, unless the destination is in the bottom
   64k of the code segment (The top 16 bits of eip are zeroed).  */

const relax_typeS md_relax_table[] =
{
  /* The fields are:
     1) most positive reach of this state,
     2) most negative reach of this state,
     3) how many bytes this mode will have in the variable part of the frag
     4) which index into the table to try if we can't fit into this one.  */

  /* UNCOND_JUMP states.  */
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (UNCOND_JUMP, BIG)},
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (UNCOND_JUMP, BIG16)},
  /* dword jmp adds 4 bytes to frag:
     0 extra opcode bytes, 4 displacement bytes.  */
  {0, 0, 4, 0},
  /* word jmp adds 2 byte2 to frag:
     0 extra opcode bytes, 2 displacement bytes.  */
  {0, 0, 2, 0},

  /* COND_JUMP states.  */
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (COND_JUMP, BIG)},
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (COND_JUMP, BIG16)},
  /* dword conditionals adds 5 bytes to frag:
     1 extra opcode byte, 4 displacement bytes.  */
  {0, 0, 5, 0},
  /* word conditionals add 3 bytes to frag:
     1 extra opcode byte, 2 displacement bytes.  */
  {0, 0, 3, 0},

  /* COND_JUMP86 states.  */
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (COND_JUMP86, BIG)},
  {127 + 1, -128 + 1, 1, ENCODE_RELAX_STATE (COND_JUMP86, BIG16)},
  /* dword conditionals adds 5 bytes to frag:
     1 extra opcode byte, 4 displacement bytes.  */
  {0, 0, 5, 0},
  /* word conditionals add 4 bytes to frag:
     1 displacement byte and a 3 byte long branch insn.  */
  {0, 0, 4, 0}
};

static const arch_entry cpu_arch[] = {
  {"i8086",     Cpu086 },
  {"i186",      Cpu086|Cpu186 },
  {"i286",      Cpu086|Cpu186|Cpu286 },
  {"i386",      Cpu086|Cpu186|Cpu286|Cpu386 },
  {"i486",      Cpu086|Cpu186|Cpu286|Cpu386|Cpu486 },
  {"i586",      Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|CpuMMX },
  {"i686",      Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|Cpu686|CpuMMX|CpuSSE },
  {"pentium",   Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|CpuMMX },
  {"pentiumpro",Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|Cpu686|CpuMMX|CpuSSE },
  {"pentium4",  Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|Cpu686|CpuP4|CpuMMX|CpuSSE|CpuSSE2 },
  {"k6",        Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|CpuK6|CpuMMX|Cpu3dnow },
  {"athlon",    Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|Cpu686|CpuK6|CpuAthlon|CpuMMX|Cpu3dnow },
  {"sledgehammer",Cpu086|Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|Cpu686|CpuK6|CpuAthlon|CpuSledgehammer|CpuMMX|Cpu3dnow|CpuSSE|CpuSSE2 },
  {NULL, 0 }
};

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", (void (*) PARAMS ((int))) 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;
\f
void
i386_align_code (fragP, count)
     fragS *fragP;
     int count;
{
  /* Various efficient no-op patterns for aligning code labels.
     Note: Don't try to assemble the instructions in the comments.
     0L and 0w are not legal.  */
  static const char f32_1[] =
    {0x90};                                     /* nop                  */
  static const char f32_2[] =
    {0x89,0xf6};                                /* movl %esi,%esi       */
  static const char f32_3[] =
    {0x8d,0x76,0x00};                           /* leal 0(%esi),%esi    */
  static const char f32_4[] =
    {0x8d,0x74,0x26,0x00};                      /* leal 0(%esi,1),%esi  */
  static const char f32_5[] =
    {0x90,                                      /* nop                  */
     0x8d,0x74,0x26,0x00};                      /* leal 0(%esi,1),%esi  */
  static const char f32_6[] =
    {0x8d,0xb6,0x00,0x00,0x00,0x00};            /* leal 0L(%esi),%esi   */
  static const char f32_7[] =
    {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00};       /* leal 0L(%esi,1),%esi */
  static const char f32_8[] =
    {0x90,                                      /* nop                  */
     0x8d,0xb4,0x26,0x00,0x00,0x00,0x00};       /* leal 0L(%esi,1),%esi */
  static const char f32_9[] =
    {0x89,0xf6,                                 /* movl %esi,%esi       */
     0x8d,0xbc,0x27,0x00,0x00,0x00,0x00};       /* leal 0L(%edi,1),%edi */
  static const char f32_10[] =
    {0x8d,0x76,0x00,                            /* leal 0(%esi),%esi    */
     0x8d,0xbc,0x27,0x00,0x00,0x00,0x00};       /* leal 0L(%edi,1),%edi */
  static const char f32_11[] =
    {0x8d,0x74,0x26,0x00,                       /* leal 0(%esi,1),%esi  */
     0x8d,0xbc,0x27,0x00,0x00,0x00,0x00};       /* leal 0L(%edi,1),%edi */
  static const char f32_12[] =
    {0x8d,0xb6,0x00,0x00,0x00,0x00,             /* leal 0L(%esi),%esi   */
     0x8d,0xbf,0x00,0x00,0x00,0x00};            /* leal 0L(%edi),%edi   */
  static const char f32_13[] =
    {0x8d,0xb6,0x00,0x00,0x00,0x00,             /* leal 0L(%esi),%esi   */
     0x8d,0xbc,0x27,0x00,0x00,0x00,0x00};       /* leal 0L(%edi,1),%edi */
  static const char f32_14[] =
    {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00,        /* leal 0L(%esi,1),%esi */
     0x8d,0xbc,0x27,0x00,0x00,0x00,0x00};       /* leal 0L(%edi,1),%edi */
  static const char f32_15[] =
    {0xeb,0x0d,0x90,0x90,0x90,0x90,0x90,        /* jmp .+15; lotsa nops */
     0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90};
  static const char f16_3[] =
    {0x8d,0x74,0x00};                           /* lea 0(%esi),%esi     */
  static const char f16_4[] =
    {0x8d,0xb4,0x00,0x00};                      /* lea 0w(%si),%si      */
  static const char f16_5[] =
    {0x90,                                      /* nop                  */
     0x8d,0xb4,0x00,0x00};                      /* lea 0w(%si),%si      */
  static const char f16_6[] =
    {0x89,0xf6,                                 /* mov %si,%si          */
     0x8d,0xbd,0x00,0x00};                      /* lea 0w(%di),%di      */
  static const char f16_7[] =
    {0x8d,0x74,0x00,                            /* lea 0(%si),%si       */
     0x8d,0xbd,0x00,0x00};                      /* lea 0w(%di),%di      */
  static const char f16_8[] =
    {0x8d,0xb4,0x00,0x00,                       /* lea 0w(%si),%si      */
     0x8d,0xbd,0x00,0x00};                      /* lea 0w(%di),%di      */
  static const char *const f32_patt[] = {
    f32_1, f32_2, f32_3, f32_4, f32_5, f32_6, f32_7, f32_8,
    f32_9, f32_10, f32_11, f32_12, f32_13, f32_14, f32_15
  };
  static const char *const f16_patt[] = {
    f32_1, f32_2, f16_3, f16_4, f16_5, f16_6, f16_7, f16_8,
    f32_15, f32_15, f32_15, f32_15, f32_15, f32_15, f32_15
  };

  if (count <= 0 || count > 15)
    return;

  /* The recommended way to pad 64bit code is to use NOPs preceded by
     maximally four 0x66 prefixes.  Balance the size of nops.  */
  if (flag_code == CODE_64BIT)
    {
      int i;
      int nnops = (count + 3) / 4;
      int len = count / nnops;
      int remains = count - nnops * len;
      int pos = 0;

      for (i = 0; i < remains; i++)
        {
          memset (fragP->fr_literal + fragP->fr_fix + pos, 0x66, len);
          fragP->fr_literal[fragP->fr_fix + pos + len] = 0x90;
          pos += len + 1;
        }
      for (; i < nnops; i++)
        {
          memset (fragP->fr_literal + fragP->fr_fix + pos, 0x66, len - 1);
          fragP->fr_literal[fragP->fr_fix + pos + len - 1] = 0x90;
          pos += len;
        }
    }
  else
    if (flag_code == CODE_16BIT)
      {
        memcpy (fragP->fr_literal + fragP->fr_fix,
                f16_patt[count - 1], count);
        if (count > 8)
          /* Adjust jump offset.  */
          fragP->fr_literal[fragP->fr_fix + 1] = count - 2;
      }
    else
      memcpy (fragP->fr_literal + fragP->fr_fix,
              f32_patt[count - 1], count);
  fragP->fr_var = count;
}

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))
    {
      /* 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 >= REX_OPCODE && prefix < REX_OPCODE + 16
      && 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] != 0)
    {
      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 ();
}

#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
\f
void
md_begin ()
{
  const char *hash_err;

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

  {
    const template *optab;
    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 ();
  {
    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.  */
  {
    int c;
    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['-'] = '-';
    identifier_chars['_'] = '_';
    identifier_chars['.'] = '.';

    for (p = operand_special_chars; *p != '\0'; p++)
      operand_chars[(unsigned char) *p] = *p;
  }

#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
  if (OUTPUT_FLAVOR == bfd_target_elf_flavour)
    {
      record_alignment (text_section, 2);
      record_alignment (data_section, 2);
      record_alignment (bss_section, 2);
    }
#endif
}

void
i386_print_statistics (file)
     FILE *file;
{
  hash_print_statistics (file, "i386 opcode", op_hash);
  hash_print_statistics (file, "i386 register", reg_hash);
}
\f
#ifdef DEBUG386

/* Debugging routines for md_assemble.  */
static void pi PARAMS ((char *, i386_insn *));
static void pte PARAMS ((template *));
static void pt PARAMS ((unsigned int));
static void pe PARAMS ((expressionS *));
static void ps PARAMS ((symbolS *));

static void
pi (line, x)
     char *line;
     i386_insn *x;
{
  unsigned int i;

  fprintf (stdout, "%s: template ", line);
  pte (&x->tm);
  fprintf (stdout, "  address: base %s  index %s  scale %x\n",
           x->base_reg ? x->base_reg->reg_name : "none",
           x->index_reg ? x->index_reg->reg_name : "none",
           x->log2_scale_factor);
  fprintf (stdout, "  modrm:  mode %x  reg %x  reg/mem %x\n",
           x->rm.mode, x->rm.reg, x->rm.regmem);
  fprintf (stdout, "  sib:  base %x  index %x  scale %x\n",
           x->sib.base, x->sib.index, x->sib.scale);
  fprintf (stdout, "  rex: 64bit %x  extX %x  extY %x  extZ %x\n",
           (x->rex & REX_MODE64) != 0,
           (x->rex & REX_EXTX) != 0,
           (x->rex & REX_EXTY) != 0,
           (x->rex & REX_EXTZ) != 0);
  for (i = 0; i < x->operands; i++)
    {
      fprintf (stdout, "    #%d:  ", i + 1);
      pt (x->types[i]);
      fprintf (stdout, "\n");
      if (x->types[i]
          & (Reg | SReg2 | SReg3 | Control | Debug | Test | RegMMX | RegXMM))
        fprintf (stdout, "%s\n", x->op[i].regs->reg_name);
      if (x->types[i] & Imm)
        pe (x->op[i].imms);
      if (x->types[i] & Disp)
        pe (x->op[i].disps);
    }
}

static void
pte (t)
     template *t;
{
  unsigned int i;
  fprintf (stdout, " %d operands ", t->operands);
  fprintf (stdout, "opcode %x ", t->base_opcode);
  if (t->extension_opcode != None)
    fprintf (stdout, "ext %x ", t->extension_opcode);
  if (t->opcode_modifier & D)
    fprintf (stdout, "D");
  if (t->opcode_modifier & W)
    fprintf (stdout, "W");
  fprintf (stdout, "\n");
  for (i = 0; i < t->operands; i++)
    {
      fprintf (stdout, "    #%d type ", i + 1);
      pt (t->operand_types[i]);
      fprintf (stdout, "\n");
    }
}

static void
pe (e)
     expressionS *e;
{
  fprintf (stdout, "    operation     %d\n", e->X_op);
  fprintf (stdout, "    add_number    %ld (%lx)\n",
           (long) e->X_add_number, (long) e->X_add_number);
  if (e->X_add_symbol)
    {
      fprintf (stdout, "    add_symbol    ");
      ps (e->X_add_symbol);
      fprintf (stdout, "\n");
    }
  if (e->X_op_symbol)
    {
      fprintf (stdout, "    op_symbol    ");
      ps (e->X_op_symbol);
      fprintf (stdout, "\n");
    }
}

static void
ps (s)
     symbolS *s;
{
  fprintf (stdout, "%s type %s%s",
           S_GET_NAME (s),
           S_IS_EXTERNAL (s) ? "EXTERNAL " : "",
           segment_name (S_GET_SEGMENT (s)));
}

struct type_name
  {
    unsigned int mask;
    char *tname;
  }

static const type_names[] =
{
  { Reg8, "r8" },
  { Reg16, "r16" },
  { Reg32, "r32" },
  { Reg64, "r64" },
  { Imm8, "i8" },
  { Imm8S, "i8s" },
  { Imm16, "i16" },
  { Imm32, "i32" },
  { Imm32S, "i32s" },
  { Imm64, "i64" },
  { Imm1, "i1" },
  { BaseIndex, "BaseIndex" },
  { Disp8, "d8" },
  { Disp16, "d16" },
  { Disp32, "d32" },
  { Disp32S, "d32s" },
  { Disp64, "d64" },
  { InOutPortReg, "InOutPortReg" },
  { ShiftCount, "ShiftCount" },
  { Control, "control reg" },
  { Test, "test reg" },
  { Debug, "debug reg" },
  { FloatReg, "FReg" },
  { FloatAcc, "FAcc" },
  { SReg2, "SReg2" },
  { SReg3, "SReg3" },
  { Acc, "Acc" },
  { JumpAbsolute, "Jump Absolute" },
  { RegMMX, "rMMX" },
  { RegXMM, "rXMM" },
  { EsSeg, "es" },
  { 0, "" }
};

static void
pt (t)
     unsigned int t;
{
  const struct type_name *ty;

  for (ty = type_names; ty->mask; ty++)
    if (t & ty->mask)
      fprintf (stdout, "%s, ", ty->tname);
  fflush (stdout);
}

#endif /* DEBUG386 */
\f
#ifdef BFD_ASSEMBLER
static bfd_reloc_code_real_type reloc
  PARAMS ((int, int, int, bfd_reloc_code_real_type));

static bfd_reloc_code_real_type
reloc (size, pcrel, sign, other)
     int size;
     int pcrel;
     int sign;
     bfd_reloc_code_real_type other;
{
  if (other != NO_RELOC)
    return other;

  if (pcrel)
    {
      if (!sign)
        as_bad (_("There are no unsigned pc-relative relocations"));
      switch (size)
        {
        case 1: return BFD_RELOC_8_PCREL;
        case 2: return BFD_RELOC_16_PCREL;
        case 4: return BFD_RELOC_32_PCREL;
        }
      as_bad (_("can not do %d byte pc-relative relocation"), size);
    }
  else
    {
      if (sign)
        switch (size)
          {
          case 4: return BFD_RELOC_X86_64_32S;
          }
      else
        switch (size)
          {
          case 1: return BFD_RELOC_8;
          case 2: return BFD_RELOC_16;
          case 4: return BFD_RELOC_32;
          case 8: return BFD_RELOC_64;
          }
      as_bad (_("can not do %s %d byte relocation"),
              sign ? "signed" : "unsigned", size);
    }

  abort ();
  return BFD_RELOC_NONE;
}

/* Here we decide which fixups can be adjusted to make them relative to
   the beginning of the section instead of the symbol.  Basically we need
   to make sure that the dynamic relocations are done correctly, so in
   some cases we force the original symbol to be used.  */

int
tc_i386_fix_adjustable (fixP)
     fixS *fixP ATTRIBUTE_UNUSED;
{
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
  if (OUTPUT_FLAVOR != bfd_target_elf_flavour)
    return 1;

  /* Don't adjust pc-relative references to merge sections in 64-bit
     mode.  */
  if (use_rela_relocations
      && (S_GET_SEGMENT (fixP->fx_addsy)->flags & SEC_MERGE) != 0
      && fixP->fx_pcrel)
    return 0;

  /* adjust_reloc_syms doesn't know about the GOT.  */
  if (fixP->fx_r_type == BFD_RELOC_386_GOTOFF
      || fixP->fx_r_type == BFD_RELOC_386_PLT32
      || fixP->fx_r_type == BFD_RELOC_386_GOT32
      || fixP->fx_r_type == BFD_RELOC_386_TLS_GD
      || fixP->fx_r_type == BFD_RELOC_386_TLS_LDM
      || fixP->fx_r_type == BFD_RELOC_386_TLS_LDO_32
      || fixP->fx_r_type == BFD_RELOC_386_TLS_IE_32
      || fixP->fx_r_type == BFD_RELOC_386_TLS_LE_32
      || fixP->fx_r_type == BFD_RELOC_386_TLS_LE
      || fixP->fx_r_type == BFD_RELOC_X86_64_PLT32
      || fixP->fx_r_type == BFD_RELOC_X86_64_GOT32
      || fixP->fx_r_type == BFD_RELOC_X86_64_GOTPCREL
      || fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
      || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    return 0;
#endif
  return 1;
}
#else
#define reloc(SIZE,PCREL,SIGN,OTHER)    0
#define BFD_RELOC_8                     0
#define BFD_RELOC_16                    0
#define BFD_RELOC_32                    0
#define BFD_RELOC_8_PCREL               0
#define BFD_RELOC_16_PCREL              0
#define BFD_RELOC_32_PCREL              0
#define BFD_RELOC_386_PLT32             0
#define BFD_RELOC_386_GOT32             0
#define BFD_RELOC_386_GOTOFF            0
#define BFD_RELOC_386_TLS_GD            0
#define BFD_RELOC_386_TLS_LDM           0
#define BFD_RELOC_386_TLS_LDO_32        0
#define BFD_RELOC_386_TLS_IE_32         0
#define BFD_RELOC_386_TLS_LE_32         0
#define BFD_RELOC_386_TLS_LE            0
#define BFD_RELOC_X86_64_PLT32          0
#define BFD_RELOC_X86_64_GOT32          0
#define BFD_RELOC_X86_64_GOTPCREL       0
#endif

static int intel_float_operand PARAMS ((const char *mnemonic));

static int
intel_float_operand (mnemonic)
     const char *mnemonic;
{
  if (mnemonic[0] == 'f' && mnemonic[1] == 'i')
    return 2;

  if (mnemonic[0] == 'f')
    return 1;

  return 0;
}

/* This is the guts of the machine-dependent assembler.  LINE points to a
   machine dependent instruction.  This function is supposed to emit
   the frags/bytes it assembles to.  */

void
md_assemble (line)
     char *line;
{
  int j;
  char mnemonic[MAX_MNEM_SIZE];

  /* Initialize globals.  */
  memset (&i, '\0', sizeof (i));
  for (j = 0; j < MAX_OPERANDS; j++)
    i.reloc[j] = NO_RELOC;
  memset (disp_expressions, '\0', sizeof (disp_expressions));
  memset (im_expressions, '\0', sizeof (im_expressions));
  save_stack_p = save_stack;

  /* First parse an instruction mnemonic & call i386_operand for the operands.
     We assume that the scrubber has arranged it so that line[0] is the valid
     start of a (possibly prefixed) mnemonic.  */

  line = parse_insn (line, mnemonic);
  if (line == NULL)
    return;

  line = parse_operands (line, mnemonic);
  if (line == NULL)
    return;

  /* Now we've parsed the mnemonic into a set of templates, and have the
     operands at hand.  */

  /* All intel opcodes have reversed operands except for "bound" and
     "enter".  We also don't reverse intersegment "jmp" and "call"
     instructions with 2 immediate operands so that the immediate segment
     precedes the offset, as it does when in AT&T mode.  "enter" and the
     intersegment "jmp" and "call" instructions are the only ones that
     have two immediate operands.  */
  if (intel_syntax && i.operands > 1
      && (strcmp (mnemonic, "bound") != 0)
      && !((i.types[0] & Imm) && (i.types[1] & Imm)))
    swap_operands ();

  if (i.imm_operands)
    optimize_imm ();

  if (i.disp_operands)
    optimize_disp ();

  /* Next, we find a template that matches the given insn,
     making sure the overlap of the given operands types is consistent
     with the template operand types.  */

  if (!match_template ())
    return;

  if (intel_syntax)
    {
      /* Undo SYSV386_COMPAT brokenness when in Intel mode.  See i386.h  */
      if (SYSV386_COMPAT
          && (i.tm.base_opcode & 0xfffffde0) == 0xdce0)
        i.tm.base_opcode ^= FloatR;

      /* Zap movzx and movsx suffix.  The suffix may have been set from
         "word ptr" or "byte ptr" on the source operand, but we'll use
         the suffix later to choose the destination register.  */
      if ((i.tm.base_opcode & ~9) == 0x0fb6)
        i.suffix = 0;
    }

  if (i.tm.opcode_modifier & FWait)
    if (!add_prefix (FWAIT_OPCODE))
      return;

  /* Check string instruction segment overrides.  */
  if ((i.tm.opcode_modifier & IsString) != 0 && i.mem_operands != 0)
    {
      if (!check_string ())
        return;
    }

  if (!process_suffix ())
    return;

  /* Make still unresolved immediate matches conform to size of immediate
     given in i.suffix.  */
  if (!finalize_imm ())
    return;

  if (i.types[0] & Imm1)
    i.imm_operands = 0; /* kludge for shift insns.  */
  if (i.types[0] & ImplicitRegister)
    i.reg_operands--;
  if (i.types[1] & ImplicitRegister)
    i.reg_operands--;
  if (i.types[2] & ImplicitRegister)
    i.reg_operands--;

  if (i.tm.opcode_modifier & ImmExt)
    {
      /* These AMD 3DNow! and Intel Katmai New Instructions have an
         opcode suffix which is coded in the same place as an 8-bit
         immediate field would be.  Here we fake an 8-bit immediate
         operand from the opcode suffix stored in tm.extension_opcode.  */

      expressionS *exp;

      assert (i.imm_operands == 0 && i.operands <= 2 && 2 < MAX_OPERANDS);

      exp = &im_expressions[i.imm_operands++];
      i.op[i.operands].imms = exp;
      i.types[i.operands++] = Imm8;
      exp->X_op = O_constant;
      exp->X_add_number = i.tm.extension_opcode;
      i.tm.extension_opcode = None;
    }

  /* For insns with operands there are more diddles to do to the opcode.  */
  if (i.operands)
    {
      if (!process_operands ())
        return;
    }
  else if (!quiet_warnings && (i.tm.opcode_modifier & Ugh) != 0)
    {
      /* UnixWare fsub no args is alias for fsubp, fadd -> faddp, etc.  */
      as_warn (_("translating to `%sp'"), i.tm.name);
    }

  /* Handle conversion of 'int $3' --> special int3 insn.  */
  if (i.tm.base_opcode == INT_OPCODE && i.op[0].imms->X_add_number == 3)
    {
      i.tm.base_opcode = INT3_OPCODE;
      i.imm_operands = 0;
    }

  if ((i.tm.opcode_modifier & (Jump | JumpByte | JumpDword))
      && i.op[0].disps->X_op == O_constant)
    {
      /* Convert "jmp constant" (and "call constant") to a jump (call) to
         the absolute address given by the constant.  Since ix86 jumps and
         calls are pc relative, we need to generate a reloc.  */
      i.op[0].disps->X_add_symbol = &abs_symbol;
      i.op[0].disps->X_op = O_symbol;
    }

  if ((i.tm.opcode_modifier & Rex64) != 0)
    i.rex |= REX_MODE64;

  /* For 8 bit registers we need an empty rex prefix.  Also if the
     instruction already has a prefix, we need to convert old
     registers to new ones.  */

  if (((i.types[0] & Reg8) != 0
       && (i.op[0].regs->reg_flags & RegRex64) != 0)
      || ((i.types[1] & Reg8) != 0
          && (i.op[1].regs->reg_flags & RegRex64) != 0)
      || (((i.types[0] & Reg8) != 0 || (i.types[1] & Reg8) != 0)
          && i.rex != 0))
    {
      int x;

      i.rex |= REX_OPCODE;
      for (x = 0; x < 2; x++)
        {
          /* Look for 8 bit operand that uses old registers.  */
          if ((i.types[x] & Reg8) != 0
              && (i.op[x].regs->reg_flags & RegRex64) == 0)
            {
              /* In case it is "hi" register, give up.  */
              if (i.op[x].regs->reg_num > 3)
                as_bad (_("can't encode register '%%%s' in an instruction requiring REX prefix.\n"),
                        i.op[x].regs->reg_name);

              /* Otherwise it is equivalent to the extended register.
                 Since the encoding doesn't change this is merely
                 cosmetic cleanup for debug output.  */

              i.op[x].regs = i.op[x].regs + 8;
            }
        }
    }

  if (i.rex != 0)
    add_prefix (REX_OPCODE | i.rex);

  /* We are ready to output the insn.  */
  output_insn ();
}

static char *
parse_insn (line, mnemonic)
     char *line;
     char *mnemonic;
{
  char *l = line;
  char *token_start = l;
  char *mnem_p;

  /* Non-zero if we found a prefix only acceptable with string insns.  */
  const char *expecting_string_instruction = NULL;

  while (1)
    {
      mnem_p = mnemonic;
      while ((*mnem_p = mnemonic_chars[(unsigned char) *l]) != 0)
        {
          mnem_p++;
          if (mnem_p >= mnemonic + MAX_MNEM_SIZE)
            {
              as_bad (_("no such instruction: `%s'"), token_start);
              return NULL;
            }
          l++;
        }
      if (!is_space_char (*l)
          && *l != END_OF_INSN
          && *l != PREFIX_SEPARATOR
          && *l != ',')
        {
          as_bad (_("invalid character %s in mnemonic"),
                  output_invalid (*l));
          return NULL;
        }
      if (token_start == l)
        {
          if (*l == PREFIX_SEPARATOR)
            as_bad (_("expecting prefix; got nothing"));
          else
            as_bad (_("expecting mnemonic; got nothing"));
          return NULL;
        }

      /* Look up instruction (or prefix) via hash table.  */
      current_templates = hash_find (op_hash, mnemonic);

      if (*l != END_OF_INSN
          && (!is_space_char (*l) || l[1] != END_OF_INSN)
          && current_templates
          && (current_templates->start->opcode_modifier & IsPrefix))
        {
          /* If we are in 16-bit mode, do not allow addr16 or data16.
             Similarly, in 32-bit mode, do not allow addr32 or data32.  */
          if ((current_templates->start->opcode_modifier & (Size16 | Size32))
              && flag_code != CODE_64BIT
              && (((current_templates->start->opcode_modifier & Size32) != 0)
                  ^ (flag_code == CODE_16BIT)))
            {
              as_bad (_("redundant %s prefix"),
                      current_templates->start->name);
              return NULL;
            }
          /* Add prefix, checking for repeated prefixes.  */
          switch (add_prefix (current_templates->start->base_opcode))
            {
            case 0:
              return NULL;
            case 2:
              expecting_string_instruction = current_templates->start->name;
              break;
            }
          /* Skip past PREFIX_SEPARATOR and reset token_start.  */
          token_start = ++l;
        }
      else
        break;
    }

  if (!current_templates)
    {
      /* See if we can get a match by trimming off a suffix.  */
      switch (mnem_p[-1])
        {
        case WORD_MNEM_SUFFIX:
        case BYTE_MNEM_SUFFIX:
        case QWORD_MNEM_SUFFIX:
          i.suffix = mnem_p[-1];
          mnem_p[-1] = '\0';
          current_templates = hash_find (op_hash, mnemonic);
          break;
        case SHORT_MNEM_SUFFIX:
        case LONG_MNEM_SUFFIX:
          if (!intel_syntax)
            {
              i.suffix = mnem_p[-1];
              mnem_p[-1] = '\0';
              current_templates = hash_find (op_hash, mnemonic);
            }
          break;

          /* Intel Syntax.  */
        case 'd':
          if (intel_syntax)
            {
              if (intel_float_operand (mnemonic))
                i.suffix = SHORT_MNEM_SUFFIX;
              else
                i.suffix = LONG_MNEM_SUFFIX;
              mnem_p[-1] = '\0';
              current_templates = hash_find (op_hash, mnemonic);
            }
          break;
        }
      if (!current_templates)
        {
          as_bad (_("no such instruction: `%s'"), token_start);
          return NULL;
        }
    }

  if (current_templates->start->opcode_modifier & (Jump | JumpByte))
    {
      /* Check for a branch hint.  We allow ",pt" and ",pn" for
         predict taken and predict not taken respectively.
         I'm not sure that branch hints actually do anything on loop
         and jcxz insns (JumpByte) for current Pentium4 chips.  They
         may work in the future and it doesn't hurt to accept them
         now.  */
      if (l[0] == ',' && l[1] == 'p')
        {
          if (l[2] == 't')
            {
              if (!add_prefix (DS_PREFIX_OPCODE))
                return NULL;
              l += 3;
            }
          else if (l[2] == 'n')
            {
              if (!add_prefix (CS_PREFIX_OPCODE))
                return NULL;
              l += 3;
            }
        }
    }
  /* Any other comma loses.  */
  if (*l == ',')
    {
      as_bad (_("invalid character %s in mnemonic"),
              output_invalid (*l));
      return NULL;
    }

  /* Check if instruction is supported on specified architecture.  */
  if ((current_templates->start->cpu_flags & ~(Cpu64 | CpuNo64))
      & ~(cpu_arch_flags & ~(Cpu64 | CpuNo64)))
    {
      as_warn (_("`%s' is not supported on `%s'"),
               current_templates->start->name, cpu_arch_name);
    }
  else if ((Cpu386 & ~cpu_arch_flags) && (flag_code != CODE_16BIT))
    {
      as_warn (_("use .code16 to ensure correct addressing mode"));
    }

  /* Check for rep/repne without a string instruction.  */
  if (expecting_string_instruction
      && !(current_templates->start->opcode_modifier & IsString))
    {
      as_bad (_("expecting string instruction after `%s'"),
              expecting_string_instruction);
      return NULL;
    }

  return l;
}

static char *
parse_operands (l, mnemonic)
     char *l;
     const char *mnemonic;
{
  char *token_start;

  /* 1 if operand is pending after ','.  */
  unsigned int expecting_operand = 0;

  /* Non-zero if operand parens not balanced.  */
  unsigned int paren_not_balanced;

  while (*l != END_OF_INSN)
    {
      /* Skip optional white space before operand.  */
      if (is_space_char (*l))
        ++l;
      if (!is_operand_char (*l) && *l != END_OF_INSN)
        {
          as_bad (_("invalid character %s before operand %d"),
                  output_invalid (*l),
                  i.operands + 1);
          return NULL;
        }
      token_start = l;  /* after white space */
      paren_not_balanced = 0;
      while (paren_not_balanced || *l != ',')
        {
          if (*l == END_OF_INSN)
            {
              if (paren_not_balanced)
                {
                  if (!intel_syntax)
                    as_bad (_("unbalanced parenthesis in operand %d."),
                            i.operands + 1);
                  else
                    as_bad (_("unbalanced brackets in operand %d."),
                            i.operands + 1);
                  return NULL;
                }
              else
                break;  /* we are done */
            }
          else if (!is_operand_char (*l) && !is_space_char (*l))
            {
              as_bad (_("invalid character %s in operand %d"),
                      output_invalid (*l),
                      i.operands + 1);
              return NULL;
            }
          if (!intel_syntax)
            {
              if (*l == '(')
                ++paren_not_balanced;
              if (*l == ')')
                --paren_not_balanced;
            }
          else
            {
              if (*l == '[')
                ++paren_not_balanced;
              if (*l == ']')
                --paren_not_balanced;
            }
          l++;
        }
      if (l != token_start)
        {                       /* Yes, we've read in another operand.  */
          unsigned int operand_ok;
          this_operand = i.operands++;
          if (i.operands > MAX_OPERANDS)
            {
              as_bad (_("spurious operands; (%d operands/instruction max)"),
                      MAX_OPERANDS);
              return NULL;
            }
          /* Now parse operand adding info to 'i' as we go along.  */
          END_STRING_AND_SAVE (l);

          if (intel_syntax)
            operand_ok =
              i386_intel_operand (token_start,
                                  intel_float_operand (mnemonic));
          else
            operand_ok = i386_operand (token_start);

          RESTORE_END_STRING (l);
          if (!operand_ok)
            return NULL;
        }
      else
        {
          if (expecting_operand)
            {
            expecting_operand_after_comma:
              as_bad (_("expecting operand after ','; got nothing"));
              return NULL;
            }
          if (*l == ',')
            {
              as_bad (_("expecting operand before ','; got nothing"));
              return NULL;
            }
        }

      /* Now *l must be either ',' or END_OF_INSN.  */
      if (*l == ',')
        {
          if (*++l == END_OF_INSN)
            {
              /* Just skip it, if it's \n complain.  */
              goto expecting_operand_after_comma;
            }
          expecting_operand = 1;
        }
    }
  return l;
}

static void
swap_operands ()
{
  union i386_op temp_op;
  unsigned int temp_type;
  RELOC_ENUM temp_reloc;
  int xchg1 = 0;
  int xchg2 = 0;

  if (i.operands == 2)
    {
      xchg1 = 0;
      xchg2 = 1;
    }
  else if (i.operands == 3)
    {
      xchg1 = 0;
      xchg2 = 2;
    }
  temp_type = i.types[xchg2];
  i.types[xchg2] = i.types[xchg1];
  i.types[xchg1] = temp_type;
  temp_op = i.op[xchg2];
  i.op[xchg2] = i.op[xchg1];
  i.op[xchg1] = temp_op;
  temp_reloc = i.reloc[xchg2];
  i.reloc[xchg2] = i.reloc[xchg1];
  i.reloc[xchg1] = temp_reloc;

  if (i.mem_operands == 2)
    {
      const seg_entry *temp_seg;
      temp_seg = i.seg[0];
      i.seg[0] = i.seg[1];
      i.seg[1] = temp_seg;
    }
}

/* Try to ensure constant immediates are represented in the smallest
   opcode possible.  */
static void
optimize_imm ()
{
  char guess_suffix = 0;
  int op;

  if (i.suffix)
    guess_suffix = i.suffix;
  else if (i.reg_operands)
    {
      /* Figure out a suffix from the last register operand specified.
         We can't do this properly yet, ie. excluding InOutPortReg,
         but the following works for instructions with immediates.
         In any case, we can't set i.suffix yet.  */
      for (op = i.operands; --op >= 0;)
        if (i.types[op] & Reg)
          {
            if (i.types[op] & Reg8)
              guess_suffix = BYTE_MNEM_SUFFIX;
            else if (i.types[op] & Reg16)
              guess_suffix = WORD_MNEM_SUFFIX;
            else if (i.types[op] & Reg32)
              guess_suffix = LONG_MNEM_SUFFIX;
            else if (i.types[op] & Reg64)
              guess_suffix = QWORD_MNEM_SUFFIX;
            break;
          }
    }
  else if ((flag_code == CODE_16BIT) ^ (i.prefix[DATA_PREFIX] != 0))
    guess_suffix = WORD_MNEM_SUFFIX;

  for (op = i.operands; --op >= 0;)
    if (i.types[op] & Imm)
      {
        switch (i.op[op].imms->X_op)
          {
          case O_constant:
            /* If a suffix is given, this operand may be shortened.  */
            switch (guess_suffix)
              {
              case LONG_MNEM_SUFFIX:
                i.types[op] |= Imm32 | Imm64;
                break;
              case WORD_MNEM_SUFFIX:
                i.types[op] |= Imm16 | Imm32S | Imm32 | Imm64;
                break;
              case BYTE_MNEM_SUFFIX:
                i.types[op] |= Imm16 | Imm8 | Imm8S | Imm32S | Imm32 | Imm64;
                break;
              }

            /* If this operand is at most 16 bits, convert it
               to a signed 16 bit number before trying to see
               whether it will fit in an even smaller size.
               This allows a 16-bit operand such as $0xffe0 to
               be recognised as within Imm8S range.  */
            if ((i.types[op] & Imm16)
                && (i.op[op].imms->X_add_number & ~(offsetT) 0xffff) == 0)
              {
                i.op[op].imms->X_add_number =
                  (((i.op[op].imms->X_add_number & 0xffff) ^ 0x8000) - 0x8000);
              }
            if ((i.types[op] & Imm32)
                && ((i.op[op].imms->X_add_number & ~(((offsetT) 2 << 31) - 1))
                    == 0))
              {
                i.op[op].imms->X_add_number = ((i.op[op].imms->X_add_number
                                                ^ ((offsetT) 1 << 31))
                                               - ((offsetT) 1 << 31));
              }
            i.types[op] |= smallest_imm_type (i.op[op].imms->X_add_number);

            /* We must avoid matching of Imm32 templates when 64bit
               only immediate is available.  */
            if (guess_suffix == QWORD_MNEM_SUFFIX)
              i.types[op] &= ~Imm32;
            break;

          case O_absent:
          case O_register:
            abort ();

            /* Symbols and expressions.  */
          default:
            /* Convert symbolic operand to proper sizes for matching.  */
            switch (guess_suffix)
              {
              case QWORD_MNEM_SUFFIX:
                i.types[op] = Imm64 | Imm32S;
                break;
              case LONG_MNEM_SUFFIX:
                i.types[op] = Imm32 | Imm64;
                break;
              case WORD_MNEM_SUFFIX:
                i.types[op] = Imm16 | Imm32 | Imm64;
                break;
                break;
              case BYTE_MNEM_SUFFIX:
                i.types[op] = Imm8 | Imm8S | Imm16 | Imm32S | Imm32;
                break;
                break;
              }
            break;
          }
      }
}

/* Try to use the smallest displacement type too.  */
static void
optimize_disp ()
{
  int op;

  for (op = i.operands; --op >= 0;)
    if ((i.types[op] & Disp) && i.op[op].disps->X_op == O_constant)
      {
        offsetT disp = i.op[op].disps->X_add_number;

        if (i.types[op] & Disp16)
          {
            /* We know this operand is at most 16 bits, so
               convert to a signed 16 bit number before trying
               to see whether it will fit in an even smaller
               size.  */

            disp = (((disp & 0xffff) ^ 0x8000) - 0x8000);
          }
        else if (i.types[op] & Disp32)
          {
            /* We know this operand is at most 32 bits, so convert to a
               signed 32 bit number before trying to see whether it will
               fit in an even smaller size.  */
            disp &= (((offsetT) 2 << 31) - 1);
            disp = (disp ^ ((offsetT) 1 << 31)) - ((addressT) 1 << 31);
          }
        if (flag_code == CODE_64BIT)
          {
            if (fits_in_signed_long (disp))
              i.types[op] |= Disp32S;
            if (fits_in_unsigned_long (disp))
              i.types[op] |= Disp32;
          }
        if ((i.types[op] & (Disp32 | Disp32S | Disp16))
            && fits_in_signed_byte (disp))
          i.types[op] |= Disp8;
      }
}

static int
match_template ()
{
  /* Points to template once we've found it.  */
  const template *t;
  unsigned int overlap0, overlap1, overlap2;
  unsigned int found_reverse_match;
  int suffix_check;

#define MATCH(overlap, given, template)                         \
  ((overlap & ~JumpAbsolute)                                    \
   && (((given) & (BaseIndex | JumpAbsolute))                   \
       == ((overlap) & (BaseIndex | JumpAbsolute))))

  /* If given types r0 and r1 are registers they must be of the same type
     unless the expected operand type register overlap is null.
     Note that Acc in a template matches every size of reg.  */
#define CONSISTENT_REGISTER_MATCH(m0, g0, t0, m1, g1, t1)       \
  (((g0) & Reg) == 0 || ((g1) & Reg) == 0                       \
   || ((g0) & Reg) == ((g1) & Reg)                              \
   || ((((m0) & Acc) ? Reg : (t0)) & (((m1) & Acc) ? Reg : (t1)) & Reg) == 0 )

  overlap0 = 0;
  overlap1 = 0;
  overlap2 = 0;
  found_reverse_match = 0;
  suffix_check = (i.suffix == BYTE_MNEM_SUFFIX
                  ? No_bSuf
                  : (i.suffix == WORD_MNEM_SUFFIX
                     ? No_wSuf
                     : (i.suffix == SHORT_MNEM_SUFFIX
                        ? No_sSuf
                        : (i.suffix == LONG_MNEM_SUFFIX
                           ? No_lSuf
                           : (i.suffix == QWORD_MNEM_SUFFIX
                              ? No_qSuf
                              : (i.suffix == LONG_DOUBLE_MNEM_SUFFIX
                                 ? No_xSuf : 0))))));

  for (t = current_templates->start;
       t < current_templates->end;
       t++)
    {
      /* Must have right number of operands.  */
      if (i.operands != t->operands)
        continue;

      /* Check the suffix, except for some instructions in intel mode.  */
      if ((t->opcode_modifier & suffix_check)
          && !(intel_syntax
               && (t->opcode_modifier & IgnoreSize))
          && !(intel_syntax
               && t->base_opcode == 0xd9
               && (t->extension_opcode == 5          /* 0xd9,5 "fldcw"  */
                   || t->extension_opcode == 7)))  /* 0xd9,7 "f{n}stcw"  */
        continue;

      /* Do not verify operands when there are none.  */
      else if (!t->operands)
        {
          if (t->cpu_flags & ~cpu_arch_flags)
            continue;
          /* We've found a match; break out of loop.  */
          break;
        }

      overlap0 = i.types[0] & t->operand_types[0];
      switch (t->operands)
        {
        case 1:
          if (!MATCH (overlap0, i.types[0], t->operand_types[0]))
            continue;
          break;
        case 2:
        case 3:
          overlap1 = i.types[1] & t->operand_types[1];
          if (!MATCH (overlap0, i.types[0], t->operand_types[0])
              || !MATCH (overlap1, i.types[1], t->operand_types[1])
              || !CONSISTENT_REGISTER_MATCH (overlap0, i.types[0],
                                             t->operand_types[0],
                                             overlap1, i.types[1],
                                             t->operand_types[1]))
            {
              /* Check if other direction is valid ...  */
              if ((t->opcode_modifier & (D | FloatD)) == 0)
                continue;

              /* Try reversing direction of operands.  */
              overlap0 = i.types[0] & t->operand_types[1];
              overlap1 = i.types[1] & t->operand_types[0];
              if (!MATCH (overlap0, i.types[0], t->operand_types[1])
                  || !MATCH (overlap1, i.types[1], t->operand_types[0])
                  || !CONSISTENT_REGISTER_MATCH (overlap0, i.types[0],
                                                 t->operand_types[1],
                                                 overlap1, i.types[1],
                                                 t->operand_types[0]))
                {
                  /* Does not match either direction.  */
                  continue;
                }
              /* found_reverse_match holds which of D or FloatDR
                 we've found.  */
              found_reverse_match = t->opcode_modifier & (D | FloatDR);
            }
          /* Found a forward 2 operand match here.  */
          else if (t->operands == 3)
            {
              /* Here we make use of the fact that there are no
                 reverse match 3 operand instructions, and all 3
                 operand instructions only need to be checked for
                 register consistency between operands 2 and 3.  */
              overlap2 = i.types[2] & t->operand_types[2];
              if (!MATCH (overlap2, i.types[2], t->operand_types[2])
                  || !CONSISTENT_REGISTER_MATCH (overlap1, i.types[1],
                                                 t->operand_types[1],
                                                 overlap2, i.types[2],
                                                 t->operand_types[2]))

                continue;
            }
          /* Found either forward/reverse 2 or 3 operand match here:
             slip through to break.  */
        }
      if (t->cpu_flags & ~cpu_arch_flags)
        {
          found_reverse_match = 0;
          continue;
        }
      /* We've found a match; break out of loop.  */
      break;
    }

  if (t == current_templates->end)
    {
      /* We found no match.  */
      as_bad (_("suffix or operands invalid for `%s'"),
              current_templates->start->name);
      return 0;
    }

  if (!quiet_warnings)
    {
      if (!intel_syntax
          && ((i.types[0] & JumpAbsolute)
              != (t->operand_types[0] & JumpAbsolute)))
        {
          as_warn (_("indirect %s without `*'"), t->name);
        }

      if ((t->opcode_modifier & (IsPrefix | IgnoreSize))
          == (IsPrefix | IgnoreSize))
        {
          /* Warn them that a data or address size prefix doesn't
             affect assembly of the next line of code.  */
          as_warn (_("stand-alone `%s' prefix"), t->name);
        }
    }

  /* Copy the template we found.  */
  i.tm = *t;
  if (found_reverse_match)
    {
      /* If we found a reverse match we must alter the opcode
         direction bit.  found_reverse_match holds bits to change
         (different for int & float insns).  */

      i.tm.base_opcode ^= found_reverse_match;

      i.tm.operand_types[0] = t->operand_types[1];
      i.tm.operand_types[1] = t->operand_types[0];
    }

  return 1;
}

static int
check_string ()
{
  int mem_op = (i.types[0] & AnyMem) ? 0 : 1;
  if ((i.tm.operand_types[mem_op] & EsSeg) != 0)
    {
      if (i.seg[0] != NULL && i.seg[0] != &es)
        {
          as_bad (_("`%s' operand %d must use `%%es' segment"),
                  i.tm.name,
                  mem_op + 1);
          return 0;
        }
      /* There's only ever one segment override allowed per instruction.
         This instruction possibly has a legal segment override on the
         second operand, so copy the segment to where non-string
         instructions store it, allowing common code.  */
      i.seg[0] = i.seg[1];
    }
  else if ((i.tm.operand_types[mem_op + 1] & EsSeg) != 0)
    {
      if (i.seg[1] != NULL && i.seg[1] != &es)
        {
          as_bad (_("`%s' operand %d must use `%%es' segment"),
                  i.tm.name,
                  mem_op + 2);
          return 0;
        }
    }
  return 1;
}

static int
process_suffix ()
{
  /* If matched instruction specifies an explicit instruction mnemonic
     suffix, use it.  */
  if (i.tm.opcode_modifier & (Size16 | Size32 | Size64))
    {
      if (i.tm.opcode_modifier & Size16)
        i.suffix = WORD_MNEM_SUFFIX;
      else if (i.tm.opcode_modifier & Size64)
        i.suffix = QWORD_MNEM_SUFFIX;
      else
        i.suffix = LONG_MNEM_SUFFIX;
    }
  else if (i.reg_operands)
    {
      /* If there's no instruction mnemonic suffix we try to invent one
         based on register operands.  */
      if (!i.suffix)
        {
          /* We take i.suffix from the last register operand specified,
             Destination register type is more significant than source
             register type.  */
          int op;
          for (op = i.operands; --op >= 0;)
            if ((i.types[op] & Reg)
                && !(i.tm.operand_types[op] & InOutPortReg))
              {
                i.suffix = ((i.types[op] & Reg8) ? BYTE_MNEM_SUFFIX :
                            (i.types[op] & Reg16) ? WORD_MNEM_SUFFIX :
                            (i.types[op] & Reg64) ? QWORD_MNEM_SUFFIX :
                            LONG_MNEM_SUFFIX);
                break;
              }
        }
      else if (i.suffix == BYTE_MNEM_SUFFIX)
        {
          if (!check_byte_reg ())
            return 0;
        }
      else if (i.suffix == LONG_MNEM_SUFFIX)
        {
          if (!check_long_reg ())
            return 0;
        }
      else if (i.suffix == QWORD_MNEM_SUFFIX)
        {
          if (!check_qword_reg ())
            return 0;
        }
      else if (i.suffix == WORD_MNEM_SUFFIX)
        {
          if (!check_word_reg ())
            return 0;
        }
      else if (intel_syntax && (i.tm.opcode_modifier & IgnoreSize))
        /* Do nothing if the instruction is going to ignore the prefix.  */
        ;
      else
        abort ();
    }
  else if ((i.tm.opcode_modifier & DefaultSize) && !i.suffix)
    {
      i.suffix = stackop_size;
    }

  /* Change the opcode based on the operand size given by i.suffix;
     We need not change things for byte insns.  */

  if (!i.suffix && (i.tm.opcode_modifier & W))
    {
      as_bad (_("no instruction mnemonic suffix given and no register operands; can't size instruction"));
      return 0;
    }

  if (i.suffix && i.suffix != BYTE_MNEM_SUFFIX)
    {
      /* It's not a byte, select word/dword operation.  */
      if (i.tm.opcode_modifier & W)
        {
          if (i.tm.opcode_modifier & ShortForm)
            i.tm.base_opcode |= 8;
          else
            i.tm.base_opcode |= 1;
        }

      /* Now select between word & dword operations via the operand
         size prefix, except for instructions that will ignore this
         prefix anyway.  */
      if (i.suffix != QWORD_MNEM_SUFFIX
          && !(i.tm.opcode_modifier & IgnoreSize)
          && ((i.suffix == LONG_MNEM_SUFFIX) == (flag_code == CODE_16BIT)
              || (flag_code == CODE_64BIT
                  && (i.tm.opcode_modifier & JumpByte))))
        {
          unsigned int prefix = DATA_PREFIX_OPCODE;
          if (i.tm.opcode_modifier & JumpByte) /* jcxz, loop */
            prefix = ADDR_PREFIX_OPCODE;

          if (!add_prefix (prefix))
            return 0;
        }

      /* Set mode64 for an operand.  */
      if (i.suffix == QWORD_MNEM_SUFFIX
          && flag_code == CODE_64BIT
          && (i.tm.opcode_modifier & NoRex64) == 0)
        i.rex |= REX_MODE64;

      /* Size floating point instruction.  */
      if (i.suffix == LONG_MNEM_SUFFIX)
        {
          if (i.tm.opcode_modifier & FloatMF)
            i.tm.base_opcode ^= 4;
        }
    }

  return 1;
}

static int
check_byte_reg ()
{
  int op;
  for (op = i.operands; --op >= 0;)
    {
      /* If this is an eight bit register, it's OK.  If it's the 16 or
         32 bit version of an eight bit register, we will just use the
         low portion, and that's OK too.  */
      if (i.types[op] & Reg8)
        continue;

      /* movzx and movsx should not generate this warning.  */
      if (intel_syntax
          && (i.tm.base_opcode == 0xfb7
              || i.tm.base_opcode == 0xfb6
              || i.tm.base_opcode == 0x63
              || i.tm.base_opcode == 0xfbe
              || i.tm.base_opcode == 0xfbf))
        continue;

      if ((i.types[op] & WordReg) && i.op[op].regs->reg_num < 4
#if 0
          /* Check that the template allows eight bit regs.  This
             kills insns such as `orb $1,%edx', which maybe should be
             allowed.  */
          && (i.tm.operand_types[op] & (Reg8 | InOutPortReg))
#endif
          )
        {
          /* Prohibit these changes in the 64bit mode, since the
             lowering is more complicated.  */
          if (flag_code == CODE_64BIT
              && (i.tm.operand_types[op] & InOutPortReg) == 0)
            {
              as_bad (_("Incorrect register `%%%s' used with `%c' suffix"),
                      i.op[op].regs->reg_name,
                      i.suffix);
              return 0;
            }
#if REGISTER_WARNINGS
          if (!quiet_warnings
              && (i.tm.operand_types[op] & InOutPortReg) == 0)
            as_warn (_("using `%%%s' instead of `%%%s' due to `%c' suffix"),
                     (i.op[op].regs + (i.types[op] & Reg16
                                       ? REGNAM_AL - REGNAM_AX
                                       : REGNAM_AL - REGNAM_EAX))->reg_name,
                     i.op[op].regs->reg_name,
                     i.suffix);
#endif
          continue;
        }
      /* Any other register is bad.  */
      if (i.types[op] & (Reg | RegMMX | RegXMM
                         | SReg2 | SReg3
                         | Control | Debug | Test
                         | FloatReg | FloatAcc))
        {
          as_bad (_("`%%%s' not allowed with `%s%c'"),
                  i.op[op].regs->reg_name,
                  i.tm.name,
                  i.suffix);
          return 0;
        }
    }
  return 1;
}

static int
check_long_reg ()
{
  int op;

  for (op = i.operands; --op >= 0;)
    /* Reject eight bit registers, except where the template requires
       them. (eg. movzb)  */
    if ((i.types[op] & Reg8) != 0
        && (i.tm.operand_types[op] & (Reg16 | Reg32 | Acc)) != 0)
      {
        as_bad (_("`%%%s' not allowed with `%s%c'"),
                i.op[op].regs->reg_name,
                i.tm.name,
                i.suffix);
        return 0;
      }
  /* Warn if the e prefix on a general reg is missing.  */
    else if ((!quiet_warnings || flag_code == CODE_64BIT)
             && (i.types[op] & Reg16) != 0
             && (i.tm.operand_types[op] & (Reg32 | Acc)) != 0)
      {
        /* Prohibit these changes in the 64bit mode, since the
           lowering is more complicated.  */
        if (flag_code == CODE_64BIT)
          {
            as_bad (_("Incorrect register `%%%s' used with `%c' suffix"),
                    i.op[op].regs->reg_name,
                    i.suffix);
            return 0;
          }
#if REGISTER_WARNINGS
        else
          as_warn (_("using `%%%s' instead of `%%%s' due to `%c' suffix"),
                   (i.op[op].regs + REGNAM_EAX - REGNAM_AX)->reg_name,
                   i.op[op].regs->reg_name,
                   i.suffix);
#endif
      }
  /* Warn if the r prefix on a general reg is missing.  */
    else if ((i.types[op] & Reg64) != 0
             && (i.tm.operand_types[op] & (Reg32 | Acc)) != 0)
      {
        as_bad (_("Incorrect register `%%%s' used with `%c' suffix"),
                i.op[op].regs->reg_name,
                i.suffix);
        return 0;
      }
  return 1;
}

static int
check_qword_reg ()
{
  int op;

  for (op = i.operands; --op >= 0; )
    /* Reject eight bit registers, except where the template requires
       them. (eg. movzb)  */
    if ((i.types[op] & Reg8) != 0
        && (i.tm.operand_types[op] & (Reg16 | Reg32 | Acc)) != 0)
      {
        as_bad (_("`%%%s' not allowed with `%s%c'"),
                i.op[op].regs->reg_name,
                i.tm.name,
                i.suffix);
        return 0;
      }
  /* Warn if the e prefix on a general reg is missing.  */
    else if (((i.types[op] & Reg16) != 0
              || (i.types[op] & Reg32) != 0)
             && (i.tm.operand_types[op] & (Reg32 | Acc)) != 0)
      {
        /* Prohibit these changes in the 64bit mode, since the
           lowering is more complicated.  */
        as_bad (_("Incorrect register `%%%s' used with `%c' suffix"),
                i.op[op].regs->reg_name,
                i.suffix);
        return 0;
      }
  return 1;
}

static int
check_word_reg ()
{
  int op;
  for (op = i.operands; --op >= 0;)
    /* Reject eight bit registers, except where the template requires
       them. (eg. movzb)  */
    if ((i.types[op] & Reg8) != 0
        && (i.tm.operand_types[op] & (Reg16 | Reg32 | Acc)) != 0)
      {
        as_bad (_("`%%%s' not allowed with `%s%c'"),
                i.op[op].regs->reg_name,
                i.tm.name,
                i.suffix);
        return 0;
      }
  /* Warn if the e prefix on a general reg is present.  */
    else if ((!quiet_warnings || flag_code == CODE_64BIT)
             && (i.types[op] & Reg32) != 0
             && (i.tm.operand_types[op] & (Reg16 | Acc)) != 0)
      {
        /* Prohibit these changes in the 64bit mode, since the
           lowering is more complicated.  */
        if (flag_code == CODE_64BIT)
          {
            as_bad (_("Incorrect register `%%%s' used with `%c' suffix"),
                    i.op[op].regs->reg_name,
                    i.suffix);
            return 0;
          }
        else
#if REGISTER_WARNINGS
          as_warn (_("using `%%%s' instead of `%%%s' due to `%c' suffix"),
                   (i.op[op].regs + REGNAM_AX - REGNAM_EAX)->reg_name,
                   i.op[op].regs->reg_name,
                   i.suffix);
#endif
      }
  return 1;
}

static int
finalize_imm ()
{
  unsigned int overlap0, overlap1, overlap2;

  overlap0 = i.types[0] & i.tm.operand_types[0];
  if ((overlap0 & (Imm8 | Imm8S | Imm16 | Imm32 | Imm32S))
      && overlap0 != Imm8 && overlap0 != Imm8S
      && overlap0 != Imm16 && overlap0 != Imm32S
      && overlap0 != Imm32 && overlap0 != Imm64)
    {
      if (i.suffix)
        {
          overlap0 &= (i.suffix == BYTE_MNEM_SUFFIX
                       ? Imm8 | Imm8S
                       : (i.suffix == WORD_MNEM_SUFFIX
                          ? Imm16
                          : (i.suffix == QWORD_MNEM_SUFFIX
                             ? Imm64 | Imm32S
                             : Imm32)));
        }
      else if (overlap0 == (Imm16 | Imm32S | Imm32)
               || overlap0 == (Imm16 | Imm32)
               || overlap0 == (Imm16 | Imm32S))
        {
          overlap0 = ((flag_code == CODE_16BIT) ^ (i.prefix[DATA_PREFIX] != 0)
                      ? Imm16 : Imm32S);
        }
      if (overlap0 != Imm8 && overlap0 != Imm8S
          && overlap0 != Imm16 && overlap0 != Imm32S
          && overlap0 != Imm32 && overlap0 != Imm64)
        {
          as_bad (_("no instruction mnemonic suffix given; can't determine immediate size"));
          return 0;
        }
    }
  i.types[0] = overlap0;

  overlap1 = i.types[1] & i.tm.operand_types[1];
  if ((overlap1 & (Imm8 | Imm8S | Imm16 | Imm32S | Imm32))
      && overlap1 != Imm8 && overlap1 != Imm8S
      && overlap1 != Imm16 && overlap1 != Imm32S
      && overlap1 != Imm32 && overlap1 != Imm64)
    {
      if (i.suffix)
        {
          overlap1 &= (i.suffix == BYTE_MNEM_SUFFIX
                       ? Imm8 | Imm8S
                       : (i.suffix == WORD_MNEM_SUFFIX
                          ? Imm16
                          : (i.suffix == QWORD_MNEM_SUFFIX
                             ? Imm64 | Imm32S
                             : Imm32)));
        }
      else if (overlap1 == (Imm16 | Imm32 | Imm32S)
               || overlap1 == (Imm16 | Imm32)
               || overlap1 == (Imm16 | Imm32S))
        {
          overlap1 = ((flag_code == CODE_16BIT) ^ (i.prefix[DATA_PREFIX] != 0)
                      ? Imm16 : Imm32S);
        }
      if (overlap1 != Imm8 && overlap1 != Imm8S
          && overlap1 != Imm16 && overlap1 != Imm32S
          && overlap1 != Imm32 && overlap1 != Imm64)
        {
          as_bad (_("no instruction mnemonic suffix given; can't determine immediate size %x %c"),overlap1, i.suffix);
          return 0;
        }
    }
  i.types[1] = overlap1;

  overlap2 = i.types[2] & i.tm.operand_types[2];
  assert ((overlap2 & Imm) == 0);
  i.types[2] = overlap2;

  return 1;
}

static int
process_operands ()
{
  /* Default segment register this instruction will use for memory
     accesses.  0 means unknown.  This is only for optimizing out
     unnecessary segment overrides.  */
  const seg_entry *default_seg = 0;

  /* The imul $imm, %reg instruction is converted into
     imul $imm, %reg, %reg, and the clr %reg instruction
     is converted into xor %reg, %reg.  */
  if (i.tm.opcode_modifier & regKludge)
    {
      unsigned int first_reg_op = (i.types[0] & Reg) ? 0 : 1;
      /* Pretend we saw the extra register operand.  */
      assert (i.op[first_reg_op + 1].regs == 0);
      i.op[first_reg_op + 1].regs = i.op[first_reg_op].regs;
      i.types[first_reg_op + 1] = i.types[first_reg_op];
      i.reg_operands = 2;
    }

  if (i.tm.opcode_modifier & ShortForm)
    {
      /* The register or float register operand is in operand 0 or 1.  */
      unsigned int op = (i.types[0] & (Reg | FloatReg)) ? 0 : 1;
      /* Register goes in low 3 bits of opcode.  */
      i.tm.base_opcode |= i.op[op].regs->reg_num;
      if ((i.op[op].regs->reg_flags & RegRex) != 0)
        i.rex |= REX_EXTZ;
      if (!quiet_warnings && (i.tm.opcode_modifier & Ugh) != 0)
        {
          /* Warn about some common errors, but press on regardless.
             The first case can be generated by gcc (<= 2.8.1).  */
          if (i.operands == 2)
            {
              /* Reversed arguments on faddp, fsubp, etc.  */
              as_warn (_("translating to `%s %%%s,%%%s'"), i.tm.name,
                       i.op[1].regs->reg_name,
                       i.op[0].regs->reg_name);
            }
          else
            {
              /* Extraneous `l' suffix on fp insn.  */
              as_warn (_("translating to `%s %%%s'"), i.tm.name,
                       i.op[0].regs->reg_name);
            }
        }
    }
  else if (i.tm.opcode_modifier & Modrm)
    {
      /* The opcode is completed (modulo i.tm.extension_opcode which
         must be put into the modrm byte).
         Now, we make the modrm & index base bytes based on all the
         info we've collected.  */

      default_seg = build_modrm_byte ();
    }
  else if (i.tm.opcode_modifier & (Seg2ShortForm | Seg3ShortForm))
    {
      if (i.tm.base_opcode == POP_SEG_SHORT
          && i.op[0].regs->reg_num == 1)
        {
          as_bad (_("you can't `pop %%cs'"));
          return 0;
        }
      i.tm.base_opcode |= (i.op[0].regs->reg_num << 3);
      if ((i.op[0].regs->reg_flags & RegRex) != 0)
        i.rex |= REX_EXTZ;
    }
  else if ((i.tm.base_opcode & ~(D | W)) == MOV_AX_DISP32)
    {
      default_seg = &ds;
    }
  else if ((i.tm.opcode_modifier & IsString) != 0)
    {
      /* For the string instructions that allow a segment override
         on one of their operands, the default segment is ds.  */
      default_seg = &ds;
    }

  /* If a segment was explicitly specified,
     and the specified segment is not the default,
     use an opcode prefix to select it.
     If we never figured out what the default segment is,
     then default_seg will be zero at this point,
     and the specified segment prefix will always be used.  */
  if ((i.seg[0]) && (i.seg[0] != default_seg))
    {
      if (!add_prefix (i.seg[0]->seg_prefix))
        return 0;
    }
  return 1;
}

static const seg_entry *
build_modrm_byte ()
{
  const seg_entry *default_seg = 0;

  /* i.reg_operands MUST be the number of real register operands;
     implicit registers do not count.  */
  if (i.reg_operands == 2)
    {
      unsigned int source, dest;
      source = ((i.types[0]
                 & (Reg | RegMMX | RegXMM
                    | SReg2 | SReg3
                    | Control | Debug | Test))
                ? 0 : 1);
      dest = source + 1;

      i.rm.mode = 3;
      /* One of the register operands will be encoded in the i.tm.reg
         field, the other in the combined i.tm.mode and i.tm.regmem
         fields.  If no form of this instruction supports a memory
         destination operand, then we assume the source operand may
         sometimes be a memory operand and so we need to store the
         destination in the i.rm.reg field.  */
      if ((i.tm.operand_types[dest] & AnyMem) == 0)
        {
          i.rm.reg = i.op[dest].regs->reg_num;
          i.rm.regmem = i.op[source].regs->reg_num;
          if ((i.op[dest].regs->reg_flags & RegRex) != 0)
            i.rex |= REX_EXTX;
          if ((i.op[source].regs->reg_flags & RegRex) != 0)
            i.rex |= REX_EXTZ;
        }
      else
        {
          i.rm.reg = i.op[source].regs->reg_num;
          i.rm.regmem = i.op[dest].regs->reg_num;
          if ((i.op[dest].regs->reg_flags & RegRex) != 0)
            i.rex |= REX_EXTZ;
          if ((i.op[source].regs->reg_flags & RegRex) != 0)
            i.rex |= REX_EXTX;
        }
    }
  else
    {                   /* If it's not 2 reg operands...  */
      if (i.mem_operands)
        {
          unsigned int fake_zero_displacement = 0;
          unsigned int op = ((i.types[0] & AnyMem)
                             ? 0
                             : (i.types[1] & AnyMem) ? 1 : 2);

          default_seg = &ds;

          if (i.base_reg == 0)
            {
              i.rm.mode = 0;
              if (!i.disp_operands)
                fake_zero_displacement = 1;
              if (i.index_reg == 0)
                {
                  /* Operand is just <disp>  */
                  if ((flag_code == CODE_16BIT) ^ (i.prefix[ADDR_PREFIX] != 0)
                      && (flag_code != CODE_64BIT))
                    {
                      i.rm.regmem = NO_BASE_REGISTER_16;
                      i.types[op] &= ~Disp;
                      i.types[op] |= Disp16;
                    }
                  else if (flag_code != CODE_64BIT
                           || (i.prefix[ADDR_PREFIX] != 0))
                    {
                      i.rm.regmem = NO_BASE_REGISTER;
                      i.types[op] &= ~Disp;
                      i.types[op] |= Disp32;
                    }
                  else
                    {
                      /* 64bit mode overwrites the 32bit absolute
                         addressing by RIP relative addressing and
                         absolute addressing is encoded by one of the
                         redundant SIB forms.  */
                      i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
                      i.sib.base = NO_BASE_REGISTER;
                      i.sib.index = NO_INDEX_REGISTER;
                      i.types[op] &= ~Disp;
                      i.types[op] |= Disp32S;
                    }
                }
              else /* !i.base_reg && i.index_reg  */
                {
                  i.sib.index = i.index_reg->reg_num;
                  i.sib.base = NO_BASE_REGISTER;
                  i.sib.scale = i.log2_scale_factor;
                  i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
                  i.types[op] &= ~Disp;
                  if (flag_code != CODE_64BIT)
                    i.types[op] |= Disp32;      /* Must be 32 bit */
                  else
                    i.types[op] |= Disp32S;
                  if ((i.index_reg->reg_flags & RegRex) != 0)
                    i.rex |= REX_EXTY;
                }
            }
          /* RIP addressing for 64bit mode.  */
          else if (i.base_reg->reg_type == BaseIndex)
            {
              i.rm.regmem = NO_BASE_REGISTER;
              i.types[op] &= ~Disp;
              i.types[op] |= Disp32S;
              i.flags[op] = Operand_PCrel;
            }
          else if (i.base_reg->reg_type & Reg16)
            {
              switch (i.base_reg->reg_num)
                {
                case 3: /* (%bx)  */
                  if (i.index_reg == 0)
                    i.rm.regmem = 7;
                  else /* (%bx,%si) -> 0, or (%bx,%di) -> 1  */
                    i.rm.regmem = i.index_reg->reg_num - 6;
                  break;
                case 5: /* (%bp)  */
                  default_seg = &ss;
                  if (i.index_reg == 0)
                    {
                      i.rm.regmem = 6;
                      if ((i.types[op] & Disp) == 0)
                        {
                          /* fake (%bp) into 0(%bp)  */
                          i.types[op] |= Disp8;
                          fake_zero_displacement = 1;
                        }
                    }
                  else /* (%bp,%si) -> 2, or (%bp,%di) -> 3  */
                    i.rm.regmem = i.index_reg->reg_num - 6 + 2;
                  break;
                default: /* (%si) -> 4 or (%di) -> 5  */
                  i.rm.regmem = i.base_reg->reg_num - 6 + 4;
                }
              i.rm.mode = mode_from_disp_size (i.types[op]);
            }
          else /* i.base_reg and 32/64 bit mode  */
            {
              if (flag_code == CODE_64BIT
                  && (i.types[op] & Disp))
                {
                  if (i.types[op] & Disp8)
                    i.types[op] = Disp8 | Disp32S;
                  else
                    i.types[op] = Disp32S;
                }
              i.rm.regmem = i.base_reg->reg_num;
              if ((i.base_reg->reg_flags & RegRex) != 0)
                i.rex |= REX_EXTZ;
              i.sib.base = i.base_reg->reg_num;
              /* x86-64 ignores REX prefix bit here to avoid decoder
                 complications.  */
              if ((i.base_reg->reg_num & 7) == EBP_REG_NUM)
                {
                  default_seg = &ss;
                  if (i.disp_operands == 0)
                    {
                      fake_zero_displacement = 1;
                      i.types[op] |= Disp8;
                    }
                }
              else if (i.base_reg->reg_num == ESP_REG_NUM)
                {
                  default_seg = &ss;
                }
              i.sib.scale = i.log2_scale_factor;
              if (i.index_reg == 0)
                {
                  /* <disp>(%esp) becomes two byte modrm with no index
                     register.  We've already stored the code for esp
                     in i.rm.regmem ie. ESCAPE_TO_TWO_BYTE_ADDRESSING.
                     Any base register besides %esp will not use the
                     extra modrm byte.  */
                  i.sib.index = NO_INDEX_REGISTER;
#if !SCALE1_WHEN_NO_INDEX
                  /* Another case where we force the second modrm byte.  */
                  if (i.log2_scale_factor)
                    i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
#endif
                }
              else
                {
                  i.sib.index = i.index_reg->reg_num;
                  i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
                  if ((i.index_reg->reg_flags & RegRex) != 0)
                    i.rex |= REX_EXTY;
                }
              i.rm.mode = mode_from_disp_size (i.types[op]);
            }

          if (fake_zero_displacement)
            {
              /* Fakes a zero displacement assuming that i.types[op]
                 holds the correct displacement size.  */
              expressionS *exp;

              assert (i.op[op].disps == 0);
              exp = &disp_expressions[i.disp_operands++];
              i.op[op].disps = exp;
              exp->X_op = O_constant;
              exp->X_add_number = 0;
              exp->X_add_symbol = (symbolS *) 0;
              exp->X_op_symbol = (symbolS *) 0;
            }
        }

      /* Fill in i.rm.reg or i.rm.regmem field with register operand
         (if any) based on i.tm.extension_opcode.  Again, we must be
         careful to make sure that segment/control/debug/test/MMX
         registers are coded into the i.rm.reg field.  */
      if (i.reg_operands)
        {
          unsigned int op =
            ((i.types[0]
              & (Reg | RegMMX | RegXMM
                 | SReg2 | SReg3
                 | Control | Debug | Test))
             ? 0
             : ((i.types[1]
                 & (Reg | RegMMX | RegXMM
                    | SReg2 | SReg3
                    | Control | Debug | Test))
                ? 1
                : 2));
          /* If there is an extension opcode to put here, the register
             number must be put into the regmem field.  */
          if (i.tm.extension_opcode != None)
            {
              i.rm.regmem = i.op[op].regs->reg_num;
              if ((i.op[op].regs->reg_flags & RegRex) != 0)
                i.rex |= REX_EXTZ;
            }
          else
            {
              i.rm.reg = i.op[op].regs->reg_num;
              if ((i.op[op].regs->reg_flags & RegRex) != 0)
                i.rex |= REX_EXTX;
            }

          /* Now, if no memory operand has set i.rm.mode = 0, 1, 2 we
             must set it to 3 to indicate this is a register operand
             in the regmem field.  */
          if (!i.mem_operands)
            i.rm.mode = 3;
        }

      /* Fill in i.rm.reg field with extension opcode (if any).  */
      if (i.tm.extension_opcode != None)
        i.rm.reg = i.tm.extension_opcode;
    }
  return default_seg;
}

static void
output_branch ()
{
  char *p;
  int code16;
  int prefix;
  relax_substateT subtype;
  symbolS *sym;
  offsetT off;

  code16 = 0;
  if (flag_code == CODE_16BIT)
    code16 = CODE16;

  prefix = 0;
  if (i.prefix[DATA_PREFIX] != 0)
    {
      prefix = 1;
      i.prefixes -= 1;
      code16 ^= CODE16;
    }
  /* Pentium4 branch hints.  */
  if (i.prefix[SEG_PREFIX] == CS_PREFIX_OPCODE /* not taken */
      || i.prefix[SEG_PREFIX] == DS_PREFIX_OPCODE /* taken */)
    {
      prefix++;
      i.prefixes--;
    }
  if (i.prefix[REX_PREFIX] != 0)
    {
      prefix++;
      i.prefixes--;
    }

  if (i.prefixes != 0 && !intel_syntax)
    as_warn (_("skipping prefixes on this instruction"));

  /* It's always a symbol;  End frag & setup for relax.
     Make sure there is enough room in this frag for the largest
     instruction we may generate in md_convert_frag.  This is 2
     bytes for the opcode and room for the prefix and largest
     displacement.  */
  frag_grow (prefix + 2 + 4);
  /* Prefix and 1 opcode byte go in fr_fix.  */
  p = frag_more (prefix + 1);
  if (i.prefix[DATA_PREFIX] != 0)
    *p++ = DATA_PREFIX_OPCODE;
  if (i.prefix[SEG_PREFIX] == CS_PREFIX_OPCODE
      || i.prefix[SEG_PREFIX] == DS_PREFIX_OPCODE)
    *p++ = i.prefix[SEG_PREFIX];
  if (i.prefix[REX_PREFIX] != 0)
    *p++ = i.prefix[REX_PREFIX];
  *p = i.tm.base_opcode;

  if ((unsigned char) *p == JUMP_PC_RELATIVE)
    subtype = ENCODE_RELAX_STATE (UNCOND_JUMP, SMALL);
  else if ((cpu_arch_flags & Cpu386) != 0)
    subtype = ENCODE_RELAX_STATE (COND_JUMP, SMALL);
  else
    subtype = ENCODE_RELAX_STATE (COND_JUMP86, SMALL);
  subtype |= code16;

  sym = i.op[0].disps->X_add_symbol;
  off = i.op[0].disps->X_add_number;

  if (i.op[0].disps->X_op != O_constant
      && i.op[0].disps->X_op != O_symbol)
    {
      /* Handle complex expressions.  */
      sym = make_expr_symbol (i.op[0].disps);
      off = 0;
    }

  /* 1 possible extra opcode + 4 byte displacement go in var part.
     Pass reloc in fr_var.  */
  frag_var (rs_machine_dependent, 5, i.reloc[0], subtype, sym, off, p);
}

static void
output_jump ()
{
  char *p;
  int size;

  if (i.tm.opcode_modifier & JumpByte)
    {
      /* This is a loop or jecxz type instruction.  */
      size = 1;
      if (i.prefix[ADDR_PREFIX] != 0)
        {
          FRAG_APPEND_1_CHAR (ADDR_PREFIX_OPCODE);
          i.prefixes -= 1;
        }
      /* Pentium4 branch hints.  */
      if (i.prefix[SEG_PREFIX] == CS_PREFIX_OPCODE /* not taken */
          || i.prefix[SEG_PREFIX] == DS_PREFIX_OPCODE /* taken */)
        {
          FRAG_APPEND_1_CHAR (i.prefix[SEG_PREFIX]);
          i.prefixes--;
        }
    }
  else
    {
      int code16;

      code16 = 0;
      if (flag_code == CODE_16BIT)
        code16 = CODE16;

      if (i.prefix[DATA_PREFIX] != 0)
        {
          FRAG_APPEND_1_CHAR (DATA_PREFIX_OPCODE);
          i.prefixes -= 1;
          code16 ^= CODE16;
        }

      size = 4;
      if (code16)
        size = 2;
    }

  if (i.prefix[REX_PREFIX] != 0)
    {
      FRAG_APPEND_1_CHAR (i.prefix[REX_PREFIX]);
      i.prefixes -= 1;
    }

  if (i.prefixes != 0 && !intel_syntax)
    as_warn (_("skipping prefixes on this instruction"));

  p = frag_more (1 + size);
  *p++ = i.tm.base_opcode;

  fix_new_exp (frag_now, p - frag_now->fr_literal, size,
               i.op[0].disps, 1, reloc (size, 1, 1, i.reloc[0]));
}

static void
output_interseg_jump ()
{
  char *p;
  int size;
  int prefix;
  int code16;

  code16 = 0;
  if (flag_code == CODE_16BIT)
    code16 = CODE16;

  prefix = 0;
  if (i.prefix[DATA_PREFIX] != 0)
    {
      prefix = 1;
      i.prefixes -= 1;
      code16 ^= CODE16;
    }
  if (i.prefix[REX_PREFIX] != 0)
    {
      prefix++;
      i.prefixes -= 1;
    }

  size = 4;
  if (code16)
    size = 2;

  if (i.prefixes != 0 && !intel_syntax)
    as_warn (_("skipping prefixes on this instruction"));

  /* 1 opcode; 2 segment; offset  */
  p = frag_more (prefix + 1 + 2 + size);

  if (i.prefix[DATA_PREFIX] != 0)
    *p++ = DATA_PREFIX_OPCODE;

  if (i.prefix[REX_PREFIX] != 0)
    *p++ = i.prefix[REX_PREFIX];

  *p++ = i.tm.base_opcode;
  if (i.op[1].imms->X_op == O_constant)
    {
      offsetT n = i.op[1].imms->X_add_number;

      if (size == 2
          && !fits_in_unsigned_word (n)
          && !fits_in_signed_word (n))
        {
          as_bad (_("16-bit jump out of range"));
          return;
        }
      md_number_to_chars (p, n, size);
    }
  else
    fix_new_exp (frag_now, p - frag_now->fr_literal, size,
                 i.op[1].imms, 0, reloc (size, 0, 0, i.reloc[1]));
  if (i.op[0].imms->X_op != O_constant)
    as_bad (_("can't handle non absolute segment in `%s'"),
            i.tm.name);
  md_number_to_chars (p + size, (valueT) i.op[0].imms->X_add_number, 2);
}


static void
output_insn ()
{
  fragS *insn_start_frag;
  offsetT insn_start_off;

  /* Tie dwarf2 debug info to the address at the start of the insn.
     We can't do this after the insn has been output as the current
     frag may have been closed off.  eg. by frag_var.  */
  dwarf2_emit_insn (0);

  insn_start_frag = frag_now;
  insn_start_off = frag_now_fix ();

  /* Output jumps.  */
  if (i.tm.opcode_modifier & Jump)
    output_branch ();
  else if (i.tm.opcode_modifier & (JumpByte | JumpDword))
    output_jump ();
  else if (i.tm.opcode_modifier & JumpInterSegment)
    output_interseg_jump ();
  else
    {
      /* Output normal instructions here.  */
      char *p;
      unsigned char *q;

      /* All opcodes on i386 have either 1 or 2 bytes.  We may use third
         byte for the SSE instructions to specify a prefix they require.  */
      if (i.tm.base_opcode & 0xff0000)
        add_prefix ((i.tm.base_opcode >> 16) & 0xff);

      /* The prefix bytes.  */
      for (q = i.prefix;
           q < i.prefix + sizeof (i.prefix) / sizeof (i.prefix[0]);
           q++)
        {
          if (*q)
            {
              p = frag_more (1);
              md_number_to_chars (p, (valueT) *q, 1);
            }
        }

      /* Now the opcode; be careful about word order here!  */
      if (fits_in_unsigned_byte (i.tm.base_opcode))
        {
          FRAG_APPEND_1_CHAR (i.tm.base_opcode);
        }
      else
        {
          p = frag_more (2);
          /* Put out high byte first: can't use md_number_to_chars!  */
          *p++ = (i.tm.base_opcode >> 8) & 0xff;
          *p = i.tm.base_opcode & 0xff;
        }

      /* Now the modrm byte and sib byte (if present).  */
      if (i.tm.opcode_modifier & Modrm)
        {
          p = frag_more (1);
          md_number_to_chars (p,
                              (valueT) (i.rm.regmem << 0
                                        | i.rm.reg << 3
                                        | i.rm.mode << 6),
                              1);
          /* If i.rm.regmem == ESP (4)
             && i.rm.mode != (Register mode)
             && not 16 bit
             ==> need second modrm byte.  */
          if (i.rm.regmem == ESCAPE_TO_TWO_BYTE_ADDRESSING
              && i.rm.mode != 3
              && !(i.base_reg && (i.base_reg->reg_type & Reg16) != 0))
            {
              p = frag_more (1);
              md_number_to_chars (p,
                                  (valueT) (i.sib.base << 0
                                            | i.sib.index << 3
                                            | i.sib.scale << 6),
                                  1);
            }
        }

      if (i.disp_operands)
        output_disp (insn_start_frag, insn_start_off);

      if (i.imm_operands)
        output_imm (insn_start_frag, insn_start_off);
    }

#ifdef DEBUG386
  if (flag_debug)
    {
      pi (line, &i);
    }
#endif /* DEBUG386  */
}

static void
output_disp (insn_start_frag, insn_start_off)
    fragS *insn_start_frag;
    offsetT insn_start_off;
{
  char *p;
  unsigned int n;

  for (n = 0; n < i.operands; n++)
    {
      if (i.types[n] & Disp)
        {
          if (i.op[n].disps->X_op == O_constant)
            {
              int size;
              offsetT val;

              size = 4;
              if (i.types[n] & (Disp8 | Disp16 | Disp64))
                {
                  size = 2;
                  if (i.types[n] & Disp8)
                    size = 1;
                  if (i.types[n] & Disp64)
                    size = 8;
                }
              val = offset_in_range (i.op[n].disps->X_add_number,
                                     size);
              p = frag_more (size);
              md_number_to_chars (p, val, size);
            }
          else
            {
              RELOC_ENUM reloc_type;
              int size = 4;
              int sign = 0;
              int pcrel = (i.flags[n] & Operand_PCrel) != 0;

              /* The PC relative address is computed relative
                 to the instruction boundary, so in case immediate
                 fields follows, we need to adjust the value.  */
              if (pcrel && i.imm_operands)
                {
                  int imm_size = 4;
                  unsigned int n1;

                  for (n1 = 0; n1 < i.operands; n1++)
                    if (i.types[n1] & Imm)
                      {
                        if (i.types[n1] & (Imm8 | Imm8S | Imm16 | Imm64))
                          {
                            imm_size = 2;
                            if (i.types[n1] & (Imm8 | Imm8S))
                              imm_size = 1;
                            if (i.types[n1] & Imm64)
                              imm_size = 8;
                          }
                        break;
                      }
                  /* We should find the immediate.  */
                  if (n1 == i.operands)
                    abort ();
                  i.op[n].disps->X_add_number -= imm_size;
                }

              if (i.types[n] & Disp32S)
                sign = 1;

              if (i.types[n] & (Disp16 | Disp64))
                {
                  size = 2;
                  if (i.types[n] & Disp64)
                    size = 8;
                }

              p = frag_more (size);
              reloc_type = reloc (size, pcrel, sign, i.reloc[n]);
#ifdef BFD_ASSEMBLER
              if (reloc_type == BFD_RELOC_32
                  && GOT_symbol
                  && GOT_symbol == i.op[n].disps->X_add_symbol
                  && (i.op[n].disps->X_op == O_symbol
                      || (i.op[n].disps->X_op == O_add
                          && ((symbol_get_value_expression
                               (i.op[n].disps->X_op_symbol)->X_op)
                              == O_subtract))))
                {
                  offsetT add;

                  if (insn_start_frag == frag_now)
                    add = (p - frag_now->fr_literal) - insn_start_off;
                  else
                    {
                      fragS *fr;

                      add = insn_start_frag->fr_fix - insn_start_off;
                      for (fr = insn_start_frag->fr_next;
                           fr && fr != frag_now; fr = fr->fr_next)
                        add += fr->fr_fix;
                      add += p - frag_now->fr_literal;
                    }

                  /* We don't support dynamic linking on x86-64 yet.  */
                  if (flag_code == CODE_64BIT)
                    abort ();
                  reloc_type = BFD_RELOC_386_GOTPC;
                  i.op[n].disps->X_add_number += add;
                }
#endif
              fix_new_exp (frag_now, p - frag_now->fr_literal, size,
                           i.op[n].disps, pcrel, reloc_type);
            }
        }
    }
}

static void
output_imm (insn_start_frag, insn_start_off)
    fragS *insn_start_frag;
    offsetT insn_start_off;
{
  char *p;
  unsigned int n;

  for (n = 0; n < i.operands; n++)
    {
      if (i.types[n] & Imm)
        {
          if (i.op[n].imms->X_op == O_constant)
            {
              int size;
              offsetT val;

              size = 4;
              if (i.types[n] & (Imm8 | Imm8S | Imm16 | Imm64))
                {
                  size = 2;
                  if (i.types[n] & (Imm8 | Imm8S))
                    size = 1;
                  else if (i.types[n] & Imm64)
                    size = 8;
                }
              val = offset_in_range (i.op[n].imms->X_add_number,
                                     size);
              p = frag_more (size);
              md_number_to_chars (p, val, size);
            }
          else
            {
              /* Not absolute_section.
                 Need a 32-bit fixup (don't support 8bit
                 non-absolute imms).  Try to support other
                 sizes ...  */
              RELOC_ENUM reloc_type;
              int size = 4;
              int sign = 0;

              if ((i.types[n] & (Imm32S))
                  && i.suffix == QWORD_MNEM_SUFFIX)
                sign = 1;
              if (i.types[n] & (Imm8 | Imm8S | Imm16 | Imm64))
                {
                  size = 2;
                  if (i.types[n] & (Imm8 | Imm8S))
                    size = 1;
                  if (i.types[n] & Imm64)
                    size = 8;
                }

              p = frag_more (size);
              reloc_type = reloc (size, 0, sign, i.reloc[n]);
#ifdef BFD_ASSEMBLER
              /*   This is tough to explain.  We end up with this one if we
               * have operands that look like
               * "_GLOBAL_OFFSET_TABLE_+[.-.L284]".  The goal here is to
               * obtain the absolute address of the GOT, and it is strongly
               * preferable from a performance point of view to avoid using
               * a runtime relocation for this.  The actual sequence of
               * instructions often look something like:
               *
               *        call    .L66
               * .L66:
               *        popl    %ebx
               *        addl    $_GLOBAL_OFFSET_TABLE_+[.-.L66],%ebx
               *
               *   The call and pop essentially return the absolute address
               * of the label .L66 and store it in %ebx.  The linker itself
               * will ultimately change the first operand of the addl so
               * that %ebx points to the GOT, but to keep things simple, the
               * .o file must have this operand set so that it generates not
               * the absolute address of .L66, but the absolute address of
               * itself.  This allows the linker itself simply treat a GOTPC
               * relocation as asking for a pcrel offset to the GOT to be
               * added in, and the addend of the relocation is stored in the
               * operand field for the instruction itself.
               *
               *   Our job here is to fix the operand so that it would add
               * the correct offset so that %ebx would point to itself.  The
               * thing that is tricky is that .-.L66 will point to the
               * beginning of the instruction, so we need to further modify
               * the operand so that it will point to itself.  There are
               * other cases where you have something like:
               *
               *        .long   $_GLOBAL_OFFSET_TABLE_+[.-.L66]
               *
               * and here no correction would be required.  Internally in
               * the assembler we treat operands of this form as not being
               * pcrel since the '.' is explicitly mentioned, and I wonder
               * whether it would simplify matters to do it this way.  Who
               * knows.  In earlier versions of the PIC patches, the
               * pcrel_adjust field was used to store the correction, but
               * since the expression is not pcrel, I felt it would be
               * confusing to do it this way.  */

              if (reloc_type == BFD_RELOC_32
                  && GOT_symbol
                  && GOT_symbol == i.op[n].imms->X_add_symbol
                  && (i.op[n].imms->X_op == O_symbol
                      || (i.op[n].imms->X_op == O_add
                          && ((symbol_get_value_expression
                               (i.op[n].imms->X_op_symbol)->X_op)
                              == O_subtract))))
                {
                  offsetT add;

                  if (insn_start_frag == frag_now)
                    add = (p - frag_now->fr_literal) - insn_start_off;
                  else
                    {
                      fragS *fr;

                      add = insn_start_frag->fr_fix - insn_start_off;
                      for (fr = insn_start_frag->fr_next;
                           fr && fr != frag_now; fr = fr->fr_next)
                        add += fr->fr_fix;
                      add += p - frag_now->fr_literal;
                    }

                  /* We don't support dynamic linking on x86-64 yet.  */
                  if (flag_code == CODE_64BIT)
                    abort ();
                  reloc_type = BFD_RELOC_386_GOTPC;
                  i.op[n].imms->X_add_number += add;
                }
#endif
              fix_new_exp (frag_now, p - frag_now->fr_literal, size,
                           i.op[n].imms, 0, reloc_type);
            }
        }
    }
}
\f
#ifndef LEX_AT
static char *lex_got PARAMS ((RELOC_ENUM *, int *));

/* Parse operands of the form
   <symbol>@GOTOFF+<nnn>
   and similar .plt or .got references.

   If we find one, set up the correct relocation in RELOC and copy the
   input string, minus the `@GOTOFF' into a malloc'd buffer for
   parsing by the calling routine.  Return this buffer, and if ADJUST
   is non-null set it to the length of the string we removed from the
   input line.  Otherwise return NULL.  */
static char *
lex_got (reloc, adjust)
     RELOC_ENUM *reloc;
     int *adjust;
{
  static const char * const mode_name[NUM_FLAG_CODE] = { "32", "16", "64" };
  static const struct {
    const char *str;
    const RELOC_ENUM rel[NUM_FLAG_CODE];
  } gotrel[] = {
    { "PLT",      { BFD_RELOC_386_PLT32,      0, BFD_RELOC_X86_64_PLT32    } },
    { "GOTOFF",   { BFD_RELOC_386_GOTOFF,     0, 0                         } },
    { "GOTPCREL", { 0,                        0, BFD_RELOC_X86_64_GOTPCREL } },
    { "TLSGD",    { BFD_RELOC_386_TLS_GD,     0, 0                         } },
    { "TLSLDM",   { BFD_RELOC_386_TLS_LDM,    0, 0                         } },
    { "GOTTPOFF", { BFD_RELOC_386_TLS_IE_32,  0, 0                         } },
    { "TPOFF",    { BFD_RELOC_386_TLS_LE_32,  0, 0                         } },
    { "NTPOFF",   { BFD_RELOC_386_TLS_LE,     0, 0                         } },
    { "DTPOFF",   { BFD_RELOC_386_TLS_LDO_32, 0, 0                         } },
    { "GOT",      { BFD_RELOC_386_GOT32,      0, BFD_RELOC_X86_64_GOT32    } }
  };
  char *cp;
  unsigned int j;

  for (cp = input_line_pointer; *cp != '@'; cp++)
    if (is_end_of_line[(unsigned char) *cp])
      return NULL;

  for (j = 0; j < sizeof (gotrel) / sizeof (gotrel[0]); j++)
    {
      int len;

      len = strlen (gotrel[j].str);
      if (strncasecmp (cp + 1, gotrel[j].str, len) == 0)
        {
          if (gotrel[j].rel[(unsigned int) flag_code] != 0)
            {
              int first, second;
              char *tmpbuf, *past_reloc;

              *reloc = gotrel[j].rel[(unsigned int) flag_code];
              if (adjust)
                *adjust = len;

              if (GOT_symbol == NULL)
                GOT_symbol = symbol_find_or_make (GLOBAL_OFFSET_TABLE_NAME);

              /* Replace the relocation token with ' ', so that
                 errors like foo@GOTOFF1 will be detected.  */

              /* The length of the first part of our input line.  */
              first = cp - input_line_pointer;

              /* The second part goes from after the reloc token until
                 (and including) an end_of_line char.  Don't use strlen
                 here as the end_of_line char may not be a NUL.  */
              past_reloc = cp + 1 + len;
              for (cp = past_reloc; !is_end_of_line[(unsigned char) *cp++]; )
                ;
              second = cp - past_reloc;

              /* Allocate and copy string.  The trailing NUL shouldn't
                 be necessary, but be safe.  */
              tmpbuf = xmalloc (first + second + 2);
              memcpy (tmpbuf, input_line_pointer, first);
              tmpbuf[first] = ' ';
              memcpy (tmpbuf + first + 1, past_reloc, second);
              tmpbuf[first + second + 1] = '\0';
              return tmpbuf;
            }

          as_bad (_("@%s reloc is not supported in %s bit mode"),
                  gotrel[j].str, mode_name[(unsigned int) flag_code]);
          return NULL;
        }
    }

  /* Might be a symbol version string.  Don't as_bad here.  */
  return NULL;
}

/* x86_cons_fix_new is called via the expression parsing code when a
   reloc is needed.  We use this hook to get the correct .got reloc.  */
static RELOC_ENUM got_reloc = NO_RELOC;

void
x86_cons_fix_new (frag, off, len, exp)
     fragS *frag;
     unsigned int off;
     unsigned int len;
     expressionS *exp;
{
  RELOC_ENUM r = reloc (len, 0, 0, got_reloc);
  got_reloc = NO_RELOC;
  fix_new_exp (frag, off, len, exp, 0, r);
}

void
x86_cons (exp, size)
     expressionS *exp;
     int size;
{
  if (size == 4)
    {
      /* Handle @GOTOFF and the like in an expression.  */
      char *save;
      char *gotfree_input_line;
      int adjust;

      save = input_line_pointer;
      gotfree_input_line = lex_got (&got_reloc, &adjust);
      if (gotfree_input_line)
        input_line_pointer = gotfree_input_line;

      expression (exp);

      if (gotfree_input_line)
        {
          /* expression () has merrily parsed up to the end of line,
             or a comma - in the wrong buffer.  Transfer how far
             input_line_pointer has moved to the right buffer.  */
          input_line_pointer = (save
                                + (input_line_pointer - gotfree_input_line)
                                + adjust);
          free (gotfree_input_line);
        }
    }
  else
    expression (exp);
}
#endif

static int i386_immediate PARAMS ((char *));

static int
i386_immediate (imm_start)
     char *imm_start;
{
  char *save_input_line_pointer;
#ifndef LEX_AT
  char *gotfree_input_line;
#endif
  segT exp_seg = 0;
  expressionS *exp;

  if (i.imm_operands == MAX_IMMEDIATE_OPERANDS)
    {
      as_bad (_("only 1 or 2 immediate operands are allowed"));
      return 0;
    }

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

  if (is_space_char (*imm_start))
    ++imm_start;

  save_input_line_pointer = input_line_pointer;
  input_line_pointer = imm_start;

#ifndef LEX_AT
  gotfree_input_line = lex_got (&i.reloc[this_operand], NULL);
  if (gotfree_input_line)
    input_line_pointer = gotfree_input_line;
#endif

  exp_seg = expression (exp);

  SKIP_WHITESPACE ();
  if (*input_line_pointer)
    as_bad (_("junk `%s' after expression"), input_line_pointer);

  input_line_pointer = save_input_line_pointer;
#ifndef LEX_AT
  if (gotfree_input_line)
    free (gotfree_input_line);
#endif

  if (exp->X_op == O_absent || exp->X_op == O_big)
    {
      /* Missing or bad expr becomes absolute 0.  */
      as_bad (_("missing or invalid immediate expression `%s' taken as 0"),
              imm_start);
      exp->X_op = O_constant;
      exp->X_add_number = 0;
      exp->X_add_symbol = (symbolS *) 0;
      exp->X_op_symbol = (symbolS *) 0;
    }
  else if (exp->X_op == O_constant)
    {
      /* Size it properly later.  */
      i.types[this_operand] |= Imm64;
      /* If BFD64, sign extend val.  */
      if (!use_rela_relocations)
        if ((exp->X_add_number & ~(((addressT) 2 << 31) - 1)) == 0)
          exp->X_add_number = (exp->X_add_number ^ ((addressT) 1 << 31)) - ((addressT) 1 << 31);
    }
#if (defined (OBJ_AOUT) || defined (OBJ_MAYBE_AOUT))
  else if (1
#ifdef BFD_ASSEMBLER
           && OUTPUT_FLAVOR == bfd_target_aout_flavour
#endif
           && exp_seg != absolute_section
           && exp_seg != text_section
           && exp_seg != data_section
           && exp_seg != bss_section
           && exp_seg != undefined_section
#ifdef BFD_ASSEMBLER
           && !bfd_is_com_section (exp_seg)
#endif
           )
    {
#ifdef BFD_ASSEMBLER
      as_bad (_("unimplemented segment %s in operand"), exp_seg->name);
#else
      as_bad (_("unimplemented segment type %d in operand"), exp_seg);
#endif
      return 0;
    }
#endif
  else
    {
      /* This is an address.  The size of the address will be
         determined later, depending on destination register,
         suffix, or the default for the section.  */
      i.types[this_operand] |= Imm8 | Imm16 | Imm32 | Imm32S | Imm64;
    }

  return 1;
}

static char *i386_scale PARAMS ((char *));

static char *
i386_scale (scale)
     char *scale;
{
  offsetT val;
  char *save = input_line_pointer;

  input_line_pointer = scale;
  val = get_absolute_expression ();

  switch (val)
    {
    case 0:
    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:
      as_bad (_("expecting scale factor of 1, 2, 4, or 8: got `%s'"),
              scale);
      input_line_pointer = save;
      return NULL;
    }
  if (i.log2_scale_factor != 0 && i.index_reg == 0)
    {
      as_warn (_("scale factor of %d without an index register"),
               1 << i.log2_scale_factor);
#if SCALE1_WHEN_NO_INDEX
      i.log2_scale_factor = 0;
#endif
    }
  scale = input_line_pointer;
  input_line_pointer = save;
  return scale;
}

static int i386_displacement PARAMS ((char *, char *));

static int
i386_displacement (disp_start, disp_end)
     char *disp_start;
     char *disp_end;
{
  expressionS *exp;
  segT exp_seg = 0;
  char *save_input_line_pointer;
#ifndef LEX_AT
  char *gotfree_input_line;
#endif
  int bigdisp = Disp32;

  if (flag_code == CODE_64BIT)
    {
      if (i.prefix[ADDR_PREFIX] == 0)
        bigdisp = Disp64;
    }
  else if ((flag_code == CODE_16BIT) ^ (i.prefix[ADDR_PREFIX] != 0))
    bigdisp = Disp16;
  i.types[this_operand] |= bigdisp;

  exp = &disp_expressions[i.disp_operands];
  i.op[this_operand].disps = exp;
  i.disp_operands++;
  save_input_line_pointer = input_line_pointer;
  input_line_pointer = disp_start;
  END_STRING_AND_SAVE (disp_end);

#ifndef GCC_ASM_O_HACK
#define GCC_ASM_O_HACK 0
#endif
#if GCC_ASM_O_HACK
  END_STRING_AND_SAVE (disp_end + 1);
  if ((i.types[this_operand] & BaseIndex) != 0
      && displacement_string_end[-1] == '+')
    {
      /* This hack is to avoid a warning when using the "o"
         constraint within gcc asm statements.
         For instance:

         #define _set_tssldt_desc(n,addr,limit,type) \
         __asm__ __volatile__ ( \
         "movw %w2,%0\n\t" \
         "movw %w1,2+%0\n\t" \
         "rorl $16,%1\n\t" \
         "movb %b1,4+%0\n\t" \
         "movb %4,5+%0\n\t" \
         "movb $0,6+%0\n\t" \
         "movb %h1,7+%0\n\t" \
         "rorl $16,%1" \
         : "=o"(*(n)) : "q" (addr), "ri"(limit), "i"(type))

         This works great except that the output assembler ends
         up looking a bit weird if it turns out that there is
         no offset.  You end up producing code that looks like:

         #APP
         movw $235,(%eax)
         movw %dx,2+(%eax)
         rorl $16,%edx
         movb %dl,4+(%eax)
         movb $137,5+(%eax)
         movb $0,6+(%eax)
         movb %dh,7+(%eax)
         rorl $16,%edx
         #NO_APP

         So here we provide the missing zero.  */

      *displacement_string_end = '0';
    }
#endif
#ifndef LEX_AT
  gotfree_input_line = lex_got (&i.reloc[this_operand], NULL);
  if (gotfree_input_line)
    input_line_pointer = gotfree_input_line;
#endif

  exp_seg = expression (exp);

  SKIP_WHITESPACE ();
  if (*input_line_pointer)
    as_bad (_("junk `%s' after expression"), input_line_pointer);
#if GCC_ASM_O_HACK
  RESTORE_END_STRING (disp_end + 1);
#endif
  RESTORE_END_STRING (disp_end);
  input_line_pointer = save_input_line_pointer;
#ifndef LEX_AT
  if (gotfree_input_line)
    free (gotfree_input_line);
#endif

#ifdef BFD_ASSEMBLER
  /* We do this to make sure that the section symbol is in
     the symbol table.  We will ultimately change the relocation
     to be relative to the beginning of the section.  */
  if (i.reloc[this_operand] == BFD_RELOC_386_GOTOFF
      || i.reloc[this_operand] == BFD_RELOC_X86_64_GOTPCREL)
    {
      if (exp->X_op != O_symbol)
        {
          as_bad (_("bad expression used with @%s"),
                  (i.reloc[this_operand] == BFD_RELOC_X86_64_GOTPCREL
                   ? "GOTPCREL"
                   : "GOTOFF"));
          return 0;
        }

      if (S_IS_LOCAL (exp->X_add_symbol)
          && S_GET_SEGMENT (exp->X_add_symbol) != undefined_section)
        section_symbol (S_GET_SEGMENT (exp->X_add_symbol));
      exp->X_op = O_subtract;
      exp->X_op_symbol = GOT_symbol;
      if (i.reloc[this_operand] == BFD_RELOC_X86_64_GOTPCREL)
        i.reloc[this_operand] = BFD_RELOC_32_PCREL;
      else
        i.reloc[this_operand] = BFD_RELOC_32;
    }
#endif

  if (exp->X_op == O_absent || exp->X_op == O_big)
    {
      /* Missing or bad expr becomes absolute 0.  */
      as_bad (_("missing or invalid displacement expression `%s' taken as 0"),
              disp_start);
      exp->X_op = O_constant;
      exp->X_add_number = 0;
      exp->X_add_symbol = (symbolS *) 0;
      exp->X_op_symbol = (symbolS *) 0;
    }

#if (defined (OBJ_AOUT) || defined (OBJ_MAYBE_AOUT))
  if (exp->X_op != O_constant
#ifdef BFD_ASSEMBLER
      && OUTPUT_FLAVOR == bfd_target_aout_flavour
#endif
      && exp_seg != absolute_section
      && exp_seg != text_section
      && exp_seg != data_section
      && exp_seg != bss_section
      && exp_seg != undefined_section
#ifdef BFD_ASSEMBLER
      && !bfd_is_com_section (exp_seg)
#endif
      )
    {
#ifdef BFD_ASSEMBLER
      as_bad (_("unimplemented segment %s in operand"), exp_seg->name);
#else
      as_bad (_("unimplemented segment type %d in operand"), exp_seg);
#endif
      return 0;
    }
#endif
  else if (flag_code == CODE_64BIT)
    i.types[this_operand] |= Disp32S | Disp32;
  return 1;
}

static int i386_index_check PARAMS ((const char *));

/* Make sure the memory operand we've been dealt is valid.
   Return 1 on success, 0 on a failure.  */

static int
i386_index_check (operand_string)
     const char *operand_string;
{
  int ok;
#if INFER_ADDR_PREFIX
  int fudged = 0;

 tryprefix:
#endif
  ok = 1;
  if (flag_code == CODE_64BIT)
    {
      if (i.prefix[ADDR_PREFIX] == 0)
        {
          /* 64bit checks.  */
          if ((i.base_reg
               && ((i.base_reg->reg_type & Reg64) == 0)
                   && (i.base_reg->reg_type != BaseIndex
                       || i.index_reg))
              || (i.index_reg
                  && ((i.index_reg->reg_type & (Reg64 | BaseIndex))
                      != (Reg64 | BaseIndex))))
            ok = 0;
        }
      else
        {
          /* 32bit checks.  */
          if ((i.base_reg
               && (i.base_reg->reg_type & (Reg32 | RegRex)) != Reg32)
              || (i.index_reg
                  && ((i.index_reg->reg_type & (Reg32 | BaseIndex | RegRex))
                      != (Reg32 | BaseIndex))))
            ok = 0;
        }
    }
  else
    {
      if ((flag_code == CODE_16BIT) ^ (i.prefix[ADDR_PREFIX] != 0))
        {
          /* 16bit checks.  */
          if ((i.base_reg
               && ((i.base_reg->reg_type & (Reg16 | BaseIndex | RegRex))
                   != (Reg16 | BaseIndex)))
              || (i.index_reg
                  && (((i.index_reg->reg_type & (Reg16 | BaseIndex))
                       != (Reg16 | BaseIndex))
                      || !(i.base_reg
                           && i.base_reg->reg_num < 6
                           && i.index_reg->reg_num >= 6
                           && i.log2_scale_factor == 0))))
            ok = 0;
        }
      else
        {
          /* 32bit checks.  */
          if ((i.base_reg
               && (i.base_reg->reg_type & (Reg32 | RegRex)) != Reg32)
              || (i.index_reg
                  && ((i.index_reg->reg_type & (Reg32 | BaseIndex | RegRex))
                      != (Reg32 | BaseIndex))))
            ok = 0;
        }
    }
  if (!ok)
    {
#if INFER_ADDR_PREFIX
      if (flag_code != CODE_64BIT
          && i.prefix[ADDR_PREFIX] == 0 && stackop_size != '\0')
        {
          i.prefix[ADDR_PREFIX] = ADDR_PREFIX_OPCODE;
          i.prefixes += 1;
          /* Change the size of any displacement too.  At most one of
             Disp16 or Disp32 is set.
             FIXME.  There doesn't seem to be any real need for separate
             Disp16 and Disp32 flags.  The same goes for Imm16 and Imm32.
             Removing them would probably clean up the code quite a lot.  */
          if (i.types[this_operand] & (Disp16 | Disp32))
             i.types[this_operand] ^= (Disp16 | Disp32);
          fudged = 1;
          goto tryprefix;
        }
      if (fudged)
        as_bad (_("`%s' is not a valid base/index expression"),
                operand_string);
      else
#endif
        as_bad (_("`%s' is not a valid %s bit base/index expression"),
                operand_string,
                flag_code_names[flag_code]);
      return 0;
    }
  return 1;
}

/* Parse OPERAND_STRING into the i386_insn structure I.  Returns non-zero
   on error.  */

static int
i386_operand (operand_string)
     char *operand_string;
{
  const reg_entry *r;
  char *end_op;
  char *op_string = operand_string;

  if (is_space_char (*op_string))
    ++op_string;

  /* We check for an absolute prefix (differentiating,
     for example, 'jmp pc_relative_label' from 'jmp *absolute_label'.  */
  if (*op_string == ABSOLUTE_PREFIX)
    {
      ++op_string;
      if (is_space_char (*op_string))
        ++op_string;
      i.types[this_operand] |= JumpAbsolute;
    }

  /* Check if operand is a register.  */
  if ((*op_string == REGISTER_PREFIX || allow_naked_reg)
      && (r = parse_register (op_string, &end_op)) != NULL)
    {
      /* Check for a segment override by searching for ':' after a
         segment register.  */
      op_string = end_op;
      if (is_space_char (*op_string))
        ++op_string;
      if (*op_string == ':' && (r->reg_type & (SReg2 | SReg3)))
        {
          switch (r->reg_num)
            {
            case 0:
              i.seg[i.mem_operands] = &es;
              break;
            case 1:
              i.seg[i.mem_operands] = &cs;
              break;
            case 2:
              i.seg[i.mem_operands] = &ss;
              break;
            case 3:
              i.seg[i.mem_operands] = &ds;
              break;
            case 4:
              i.seg[i.mem_operands] = &fs;
              break;
            case 5:
              i.seg[i.mem_operands] = &gs;
              break;
            }

          /* Skip the ':' and whitespace.  */
          ++op_string;
          if (is_space_char (*op_string))
            ++op_string;

          if (!is_digit_char (*op_string)
              && !is_identifier_char (*op_string)
              && *op_string != '('
              && *op_string != ABSOLUTE_PREFIX)
            {
              as_bad (_("bad memory operand `%s'"), op_string);
              return 0;
            }
          /* Handle case of %es:*foo.  */
          if (*op_string == ABSOLUTE_PREFIX)
            {
              ++op_string;
              if (is_space_char (*op_string))
                ++op_string;
              i.types[this_operand] |= JumpAbsolute;
            }
          goto do_memory_reference;
        }
      if (*op_string)
        {
          as_bad (_("junk `%s' after register"), op_string);
          return 0;
        }
      i.types[this_operand] |= r->reg_type & ~BaseIndex;
      i.op[this_operand].regs = r;
      i.reg_operands++;
    }
  else if (*op_string == REGISTER_PREFIX)
    {
      as_bad (_("bad register name `%s'"), op_string);
      return 0;
    }
  else if (*op_string == IMMEDIATE_PREFIX)
    {
      ++op_string;
      if (i.types[this_operand] & JumpAbsolute)
        {
          as_bad (_("immediate operand illegal with absolute jump"));
          return 0;
        }
      if (!i386_immediate (op_string))
        return 0;
    }
  else if (is_digit_char (*op_string)
           || is_identifier_char (*op_string)
           || *op_string == '(')
    {
      /* This is a memory reference of some sort.  */
      char *base_string;

      /* Start and end of displacement string expression (if found).  */
      char *displacement_string_start;
      char *displacement_string_end;

    do_memory_reference:
      if ((i.mem_operands == 1
           && (current_templates->start->opcode_modifier & IsString) == 0)
          || i.mem_operands == 2)
        {
          as_bad (_("too many memory references for `%s'"),
                  current_templates->start->name);
          return 0;
        }

      /* Check for base index form.  We detect the base index form by
         looking for an ')' at the end of the operand, searching
         for the '(' matching it, and finding a REGISTER_PREFIX or ','
         after the '('.  */
      base_string = op_string + strlen (op_string);

      --base_string;
      if (is_space_char (*base_string))
        --base_string;

      /* If we only have a displacement, set-up for it to be parsed later.  */
      displacement_string_start = op_string;
      displacement_string_end = base_string + 1;

      if (*base_string == ')')
        {
          char *temp_string;
          unsigned int parens_balanced = 1;
          /* We've already checked that the number of left & right ()'s are
             equal, so this loop will not be infinite.  */
          do
            {
              base_string--;
              if (*base_string == ')')
                parens_balanced++;
              if (*base_string == '(')
                parens_balanced--;
            }
          while (parens_balanced);

          temp_string = base_string;

          /* Skip past '(' and whitespace.  */
          ++base_string;
          if (is_space_char (*base_string))
            ++base_string;

          if (*base_string == ','
              || ((*base_string == REGISTER_PREFIX || allow_naked_reg)
                  && (i.base_reg = parse_register (base_string, &end_op)) != NULL))
            {
              displacement_string_end = temp_string;

              i.types[this_operand] |= BaseIndex;

              if (i.base_reg)
                {
                  base_string = end_op;
                  if (is_space_char (*base_string))
                    ++base_string;
                }

              /* There may be an index reg or scale factor here.  */
              if (*base_string == ',')
                {
                  ++base_string;
                  if (is_space_char (*base_string))
                    ++base_string;

                  if ((*base_string == REGISTER_PREFIX || allow_naked_reg)
                      && (i.index_reg = parse_register (base_string, &end_op)) != NULL)
                    {
                      base_string = end_op;
                      if (is_space_char (*base_string))
                        ++base_string;
                      if (*base_string == ',')
                        {
                          ++base_string;
                          if (is_space_char (*base_string))
                            ++base_string;
                        }
                      else if (*base_string != ')')
                        {
                          as_bad (_("expecting `,' or `)' after index register in `%s'"),
                                  operand_string);
                          return 0;
                        }
                    }
                  else if (*base_string == REGISTER_PREFIX)
                    {
                      as_bad (_("bad register name `%s'"), base_string);
                      return 0;
                    }

                  /* Check for scale factor.  */
                  if (*base_string != ')')
                    {
                      char *end_scale = i386_scale (base_string);

                      if (!end_scale)
                        return 0;

                      base_string = end_scale;
                      if (is_space_char (*base_string))
                        ++base_string;
                      if (*base_string != ')')
                        {
                          as_bad (_("expecting `)' after scale factor in `%s'"),
                                  operand_string);
                          return 0;
                        }
                    }
                  else if (!i.index_reg)
                    {
                      as_bad (_("expecting index register or scale factor after `,'; got '%c'"),
                              *base_string);
                      return 0;
                    }
                }
              else if (*base_string != ')')
                {
                  as_bad (_("expecting `,' or `)' after base register in `%s'"),
                          operand_string);
                  return 0;
                }
            }
          else if (*base_string == REGISTER_PREFIX)
            {
              as_bad (_("bad register name `%s'"), base_string);
              return 0;
            }
        }

      /* If there's an expression beginning the operand, parse it,
         assuming displacement_string_start and
         displacement_string_end are meaningful.  */
      if (displacement_string_start != displacement_string_end)
        {
          if (!i386_displacement (displacement_string_start,
                                  displacement_string_end))
            return 0;
        }

      /* Special case for (%dx) while doing input/output op.  */
      if (i.base_reg
          && i.base_reg->reg_type == (Reg16 | InOutPortReg)
          && i.index_reg == 0
          && i.log2_scale_factor == 0
          && i.seg[i.mem_operands] == 0
          && (i.types[this_operand] & Disp) == 0)
        {
          i.types[this_operand] = InOutPortReg;
          return 1;
        }

      if (i386_index_check (operand_string) == 0)
        return 0;
      i.mem_operands++;
    }
  else
    {
      /* It's not a memory operand; argh!  */
      as_bad (_("invalid char %s beginning operand %d `%s'"),
              output_invalid (*op_string),
              this_operand + 1,
              op_string);
      return 0;
    }
  return 1;                     /* Normal return.  */
}
\f
/* md_estimate_size_before_relax()

   Called just before relax() for rs_machine_dependent frags.  The x86
   assembler uses these frags to handle variable size jump
   instructions.

   Any symbol that is now undefined will not become defined.
   Return the correct fr_subtype in the frag.
   Return the initial "guess for variable size of frag" to caller.
   The guess is actually the growth beyond the fixed part.  Whatever
   we do to grow the fixed or variable part contributes to our
   returned value.  */

int
md_estimate_size_before_relax (fragP, segment)
     fragS *fragP;
     segT segment;
{
  /* We've already got fragP->fr_subtype right;  all we have to do is
     check for un-relaxable symbols.  On an ELF system, we can't relax
     an externally visible symbol, because it may be overridden by a
     shared library.  */
  if (S_GET_SEGMENT (fragP->fr_symbol) != segment
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
      || (OUTPUT_FLAVOR == bfd_target_elf_flavour
          && (S_IS_EXTERNAL (fragP->fr_symbol)
              || S_IS_WEAK (fragP->fr_symbol)))
#endif
      )
    {
      /* Symbol is undefined in this segment, or we need to keep a
         reloc so that weak symbols can be overridden.  */
      int size = (fragP->fr_subtype & CODE16) ? 2 : 4;
      RELOC_ENUM reloc_type;
      unsigned char *opcode;
      int old_fr_fix;

      if (fragP->fr_var != NO_RELOC)
        reloc_type = fragP->fr_var;
      else if (size == 2)
        reloc_type = BFD_RELOC_16_PCREL;
      else
        reloc_type = BFD_RELOC_32_PCREL;

      old_fr_fix = fragP->fr_fix;
      opcode = (unsigned char *) fragP->fr_opcode;

      switch (TYPE_FROM_RELAX_STATE (fragP->fr_subtype))
        {
        case UNCOND_JUMP:
          /* Make jmp (0xeb) a (d)word displacement jump.  */
          opcode[0] = 0xe9;
          fragP->fr_fix += size;
          fix_new (fragP, old_fr_fix, size,
                   fragP->fr_symbol,
                   fragP->fr_offset, 1,
                   reloc_type);
          break;

        case COND_JUMP86:
          if (size == 2
              && (!no_cond_jump_promotion || fragP->fr_var != NO_RELOC))
            {
              /* Negate the condition, and branch past an
                 unconditional jump.  */
              opcode[0] ^= 1;
              opcode[1] = 3;
              /* Insert an unconditional jump.  */
              opcode[2] = 0xe9;
              /* We added two extra opcode bytes, and have a two byte
                 offset.  */
              fragP->fr_fix += 2 + 2;
              fix_new (fragP, old_fr_fix + 2, 2,
                       fragP->fr_symbol,
                       fragP->fr_offset, 1,
                       reloc_type);
              break;
            }
          /* Fall through.  */

        case COND_JUMP:
          if (no_cond_jump_promotion && fragP->fr_var == NO_RELOC)
            {
              fragP->fr_fix += 1;
              fix_new (fragP, old_fr_fix, 1,
                       fragP->fr_symbol,
                       fragP->fr_offset, 1,
                       BFD_RELOC_8_PCREL);
              break;
            }

          /* This changes the byte-displacement jump 0x7N
             to the (d)word-displacement jump 0x0f,0x8N.  */
          opcode[1] = opcode[0] + 0x10;
          opcode[0] = TWO_BYTE_OPCODE_ESCAPE;
          /* We've added an opcode byte.  */
          fragP->fr_fix += 1 + size;
          fix_new (fragP, old_fr_fix + 1, size,
                   fragP->fr_symbol,
                   fragP->fr_offset, 1,
                   reloc_type);
          break;

        default:
          BAD_CASE (fragP->fr_subtype);
          break;
        }
      frag_wane (fragP);
      return fragP->fr_fix - old_fr_fix;
    }

  /* Guess size depending on current relax state.  Initially the relax
     state will correspond to a short jump and we return 1, because
     the variable part of the frag (the branch offset) is one byte
     long.  However, we can relax a section more than once and in that
     case we must either set fr_subtype back to the unrelaxed state,
     or return the value for the appropriate branch.  */
  return md_relax_table[fragP->fr_subtype].rlx_length;
}

/* Called after relax() is finished.

   In:  Address of frag.
        fr_type == rs_machine_dependent.
        fr_subtype is what the address relaxed to.

   Out: Any fixSs and constants are set up.
        Caller will turn frag into a ".space 0".  */

#ifndef BFD_ASSEMBLER
void
md_convert_frag (headers, sec, fragP)
     object_headers *headers ATTRIBUTE_UNUSED;
     segT sec ATTRIBUTE_UNUSED;
     fragS *fragP;
#else
void
md_convert_frag (abfd, sec, fragP)
     bfd *abfd ATTRIBUTE_UNUSED;
     segT sec ATTRIBUTE_UNUSED;
     fragS *fragP;
#endif
{
  unsigned char *opcode;
  unsigned char *where_to_put_displacement = NULL;
  offsetT target_address;
  offsetT opcode_address;
  unsigned int extension = 0;
  offsetT displacement_from_opcode_start;

  opcode = (unsigned char *) fragP->fr_opcode;

  /* Address we want to reach in file space.  */
  target_address = S_GET_VALUE (fragP->fr_symbol) + fragP->fr_offset;

  /* Address opcode resides at in file space.  */
  opcode_address = fragP->fr_address + fragP->fr_fix;

  /* Displacement from opcode start to fill into instruction.  */
  displacement_from_opcode_start = target_address - opcode_address;

  if ((fragP->fr_subtype & BIG) == 0)
    {
      /* Don't have to change opcode.  */
      extension = 1;            /* 1 opcode + 1 displacement  */
      where_to_put_displacement = &opcode[1];
    }
  else
    {
      if (no_cond_jump_promotion
          && TYPE_FROM_RELAX_STATE (fragP->fr_subtype) != UNCOND_JUMP)
        as_warn_where (fragP->fr_file, fragP->fr_line, _("long jump required"));

      switch (fragP->fr_subtype)
        {
        case ENCODE_RELAX_STATE (UNCOND_JUMP, BIG):
          extension = 4;                /* 1 opcode + 4 displacement  */
          opcode[0] = 0xe9;
          where_to_put_displacement = &opcode[1];
          break;

        case ENCODE_RELAX_STATE (UNCOND_JUMP, BIG16):
          extension = 2;                /* 1 opcode + 2 displacement  */
          opcode[0] = 0xe9;
          where_to_put_displacement = &opcode[1];
          break;

        case ENCODE_RELAX_STATE (COND_JUMP, BIG):
        case ENCODE_RELAX_STATE (COND_JUMP86, BIG):
          extension = 5;                /* 2 opcode + 4 displacement  */
          opcode[1] = opcode[0] + 0x10;
          opcode[0] = TWO_BYTE_OPCODE_ESCAPE;
          where_to_put_displacement = &opcode[2];
          break;

        case ENCODE_RELAX_STATE (COND_JUMP, BIG16):
          extension = 3;                /* 2 opcode + 2 displacement  */
          opcode[1] = opcode[0] + 0x10;
          opcode[0] = TWO_BYTE_OPCODE_ESCAPE;
          where_to_put_displacement = &opcode[2];
          break;

        case ENCODE_RELAX_STATE (COND_JUMP86, BIG16):
          extension = 4;
          opcode[0] ^= 1;
          opcode[1] = 3;
          opcode[2] = 0xe9;
          where_to_put_displacement = &opcode[3];
          break;

        default:
          BAD_CASE (fragP->fr_subtype);
          break;
        }
    }

  /* Now put displacement after opcode.  */
  md_number_to_chars ((char *) where_to_put_displacement,
                      (valueT) (displacement_from_opcode_start - extension),
                      DISP_SIZE_FROM_RELAX_STATE (fragP->fr_subtype));
  fragP->fr_fix += extension;
}
\f
/* Size of byte displacement jmp.  */
int md_short_jump_size = 2;

/* Size of dword displacement jmp.  */
int md_long_jump_size = 5;

/* Size of relocation record.  */
const int md_reloc_size = 8;

void
md_create_short_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr;
     addressT from_addr, to_addr;
     fragS *frag ATTRIBUTE_UNUSED;
     symbolS *to_symbol ATTRIBUTE_UNUSED;
{
  offsetT offset;

  offset = to_addr - (from_addr + 2);
  /* Opcode for byte-disp jump.  */
  md_number_to_chars (ptr, (valueT) 0xeb, 1);
  md_number_to_chars (ptr + 1, (valueT) offset, 1);
}

void
md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol)
     char *ptr;
     addressT from_addr, to_addr;
     fragS *frag ATTRIBUTE_UNUSED;
     symbolS *to_symbol ATTRIBUTE_UNUSED;
{
  offsetT offset;

  offset = to_addr - (from_addr + 5);
  md_number_to_chars (ptr, (valueT) 0xe9, 1);
  md_number_to_chars (ptr + 1, (valueT) offset, 4);
}
\f
/* Apply a fixup (fixS) to segment data, once it has been determined
   by our caller that we have all the info we need to fix it up.

   On the 386, immediates, displacements, and data pointers are all in
   the same (little-endian) format, so we don't need to care about which
   we are handling.  */

void
md_apply_fix3 (fixP, valP, seg)
     /* The fix we're to put in.  */
     fixS *fixP;
     /* Pointer to the value of the bits.  */
     valueT *valP;
     /* Segment fix is from.  */
     segT seg ATTRIBUTE_UNUSED;
{
  char *p = fixP->fx_where + fixP->fx_frag->fr_literal;
  valueT value = *valP;

#if defined (BFD_ASSEMBLER) && !defined (TE_Mach)
  if (fixP->fx_pcrel)
    {
      switch (fixP->fx_r_type)
        {
        default:
          break;

        case BFD_RELOC_32:
          fixP->fx_r_type = BFD_RELOC_32_PCREL;
          break;
        case BFD_RELOC_16:
          fixP->fx_r_type = BFD_RELOC_16_PCREL;
          break;
        case BFD_RELOC_8:
          fixP->fx_r_type = BFD_RELOC_8_PCREL;
          break;
        }
    }

  if (fixP->fx_addsy != NULL
      && (fixP->fx_r_type == BFD_RELOC_32_PCREL
          || fixP->fx_r_type == BFD_RELOC_16_PCREL
          || fixP->fx_r_type == BFD_RELOC_8_PCREL)
      && !use_rela_relocations)
    {
      /* This is a hack.  There should be a better way to handle this.
         This covers for the fact that bfd_install_relocation will
         subtract the current location (for partial_inplace, PC relative
         relocations); see more below.  */
#ifndef OBJ_AOUT
      if (OUTPUT_FLAVOR == bfd_target_elf_flavour
#ifdef TE_PE
          || OUTPUT_FLAVOR == bfd_target_coff_flavour
#endif
          )
        value += fixP->fx_where + fixP->fx_frag->fr_address;
#endif
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
      if (OUTPUT_FLAVOR == bfd_target_elf_flavour)
        {
          segT fseg = S_GET_SEGMENT (fixP->fx_addsy);

          if ((fseg == seg
               || (symbol_section_p (fixP->fx_addsy)
                   && fseg != absolute_section))
              && !S_IS_EXTERNAL (fixP->fx_addsy)
              && !S_IS_WEAK (fixP->fx_addsy)
              && S_IS_DEFINED (fixP->fx_addsy)
              && !S_IS_COMMON (fixP->fx_addsy))
            {
              /* Yes, we add the values in twice.  This is because
                 bfd_perform_relocation subtracts them out again.  I think
                 bfd_perform_relocation is broken, but I don't dare change
                 it.  FIXME.  */
              value += fixP->fx_where + fixP->fx_frag->fr_address;
            }
        }
#endif
#if defined (OBJ_COFF) && defined (TE_PE)
      /* For some reason, the PE format does not store a section
         address offset for a PC relative symbol.  */
      if (S_GET_SEGMENT (fixP->fx_addsy) != seg)
        value += md_pcrel_from (fixP);
#endif
    }

  /* Fix a few things - the dynamic linker expects certain values here,
     and we must not dissappoint it.  */
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
  if (OUTPUT_FLAVOR == bfd_target_elf_flavour
      && fixP->fx_addsy)
    switch (fixP->fx_r_type)
      {
      case BFD_RELOC_386_PLT32:
      case BFD_RELOC_X86_64_PLT32:
        /* Make the jump instruction point to the address of the operand.  At
           runtime we merely add the offset to the actual PLT entry.  */
        value = -4;
        break;

      case BFD_RELOC_386_GOT32:
      case BFD_RELOC_386_TLS_GD:
      case BFD_RELOC_386_TLS_LDM:
      case BFD_RELOC_386_TLS_LDO_32:
      case BFD_RELOC_386_TLS_IE_32:
      case BFD_RELOC_386_TLS_LE_32:
      case BFD_RELOC_386_TLS_LE:
      case BFD_RELOC_X86_64_GOT32:
        value = 0; /* Fully resolved at runtime.  No addend.  */
        break;

      case BFD_RELOC_VTABLE_INHERIT:
      case BFD_RELOC_VTABLE_ENTRY:
        fixP->fx_done = 0;
        return;

      default:
        break;
      }
#endif /* defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)  */
  *valP = value;
#endif /* defined (BFD_ASSEMBLER) && !defined (TE_Mach)  */

  /* Are we finished with this relocation now?  */
  if (fixP->fx_addsy == NULL)
    fixP->fx_done = 1;
#ifdef BFD_ASSEMBLER
  else if (use_rela_relocations)
    {
      fixP->fx_no_overflow = 1;
      /* Remember value for tc_gen_reloc.  */
      fixP->fx_addnumber = value;
      value = 0;
    }
#endif
  md_number_to_chars (p, value, fixP->fx_size);
}
\f
#define MAX_LITTLENUMS 6

/* Turn the string pointed to by litP into a floating point constant
   of type TYPE, and emit the appropriate bytes.  The number of
   LITTLENUMS emitted is stored in *SIZEP.  An error message is
   returned, or NULL on OK.  */

char *
md_atof (type, litP, sizeP)
     int type;
     char *litP;
     int *sizeP;
{
  int prec;
  LITTLENUM_TYPE words[MAX_LITTLENUMS];
  LITTLENUM_TYPE *wordP;
  char *t;

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

    case 'd':
    case 'D':
      prec = 4;
      break;

    case 'x':
    case 'X':
      prec = 5;
      break;

    default:
      *sizeP = 0;
      return _("Bad call to md_atof ()");
    }
  t = atof_ieee (input_line_pointer, type, words);
  if (t)
    input_line_pointer = t;

  *sizeP = prec * sizeof (LITTLENUM_TYPE);
  /* This loops outputs the LITTLENUMs in REVERSE order; in accord with
     the bigendian 386.  */
  for (wordP = words + prec - 1; prec--;)
    {
      md_number_to_chars (litP, (valueT) (*wordP--), sizeof (LITTLENUM_TYPE));
      litP += sizeof (LITTLENUM_TYPE);
    }
  return 0;
}
\f
char output_invalid_buf[8];

static char *
output_invalid (c)
     int c;
{
  if (ISPRINT (c))
    sprintf (output_invalid_buf, "'%c'", c);
  else
    sprintf (output_invalid_buf, "(0x%x)", (unsigned) c);
  return output_invalid_buf;
}

/* REG_STRING starts *before* REGISTER_PREFIX.  */

static const reg_entry *
parse_register (reg_string, end_op)
     char *reg_string;
     char **end_op;
{
  char *s = reg_string;
  char *p;
  char reg_name_given[MAX_REG_NAME_SIZE + 1];
  const reg_entry *r;

  /* Skip possible REGISTER_PREFIX and possible whitespace.  */
  if (*s == REGISTER_PREFIX)
    ++s;

  if (is_space_char (*s))
    ++s;

  p = reg_name_given;
  while ((*p++ = register_chars[(unsigned char) *s]) != '\0')
    {
      if (p >= reg_name_given + MAX_REG_NAME_SIZE)
        return (const reg_entry *) NULL;
      s++;
    }

  /* For naked regs, make sure that we are not dealing with an identifier.
     This prevents confusing an identifier like `eax_var' with register
     `eax'.  */
  if (allow_naked_reg && identifier_chars[(unsigned char) *s])
    return (const reg_entry *) NULL;

  *end_op = s;

  r = (const reg_entry *) hash_find (reg_hash, reg_name_given);

  /* Handle floating point regs, allowing spaces in the (i) part.  */
  if (r == i386_regtab /* %st is first entry of table  */)
    {
      if (is_space_char (*s))
        ++s;
      if (*s == '(')
        {
          ++s;
          if (is_space_char (*s))
            ++s;
          if (*s >= '0' && *s <= '7')
            {
              r = &i386_float_regtab[*s - '0'];
              ++s;
              if (is_space_char (*s))
                ++s;
              if (*s == ')')
                {
                  *end_op = s + 1;
                  return r;
                }
            }
          /* We have "%st(" then garbage.  */
          return (const reg_entry *) NULL;
        }
    }

  if (r != NULL
      && (r->reg_flags & (RegRex64 | RegRex)) != 0
      && flag_code != CODE_64BIT)
    {
      return (const reg_entry *) NULL;
    }

  return r;
}
\f
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
const char *md_shortopts = "kVQ:sq";
#else
const char *md_shortopts = "q";
#endif

struct option md_longopts[] = {
#define OPTION_32 (OPTION_MD_BASE + 0)
  {"32", no_argument, NULL, OPTION_32},
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
#define OPTION_64 (OPTION_MD_BASE + 1)
  {"64", no_argument, NULL, OPTION_64},
#endif
  {NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof (md_longopts);

int
md_parse_option (c, arg)
     int c;
     char *arg ATTRIBUTE_UNUSED;
{
  switch (c)
    {
    case 'q':
      quiet_warnings = 1;
      break;

#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
      /* -Qy, -Qn: SVR4 arguments controlling whether a .comment section
         should be emitted or not.  FIXME: Not implemented.  */
    case 'Q':
      break;

      /* -V: SVR4 argument to print version ID.  */
    case 'V':
      print_version_id ();
      break;

      /* -k: Ignore for FreeBSD compatibility.  */
    case 'k':
      break;

    case 's':
      /* -s: On i386 Solaris, this tells the native assembler to use
         .stab instead of .stab.excl.  We always use .stab anyhow.  */
      break;

    case OPTION_64:
      {
        const char **list, **l;

        list = bfd_target_list ();
        for (l = list; *l != NULL; l++)
          if (strcmp (*l, "elf64-x86-64") == 0)
            {
              default_arch = "x86_64";
              break;
            }
        if (*l == NULL)
          as_fatal (_("No compiled in support for x86_64"));
        free (list);
      }
      break;
#endif

    case OPTION_32:
      default_arch = "i386";
      break;

    default:
      return 0;
    }
  return 1;
}

void
md_show_usage (stream)
     FILE *stream;
{
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
  fprintf (stream, _("\
  -Q                      ignored\n\
  -V                      print assembler version number\n\
  -k                      ignored\n\
  -q                      quieten some warnings\n\
  -s                      ignored\n"));
#else
  fprintf (stream, _("\
  -q                      quieten some warnings\n"));
#endif
}

#ifdef BFD_ASSEMBLER
#if ((defined (OBJ_MAYBE_COFF) && defined (OBJ_MAYBE_AOUT)) \
     || defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF))

/* Pick the target format to use.  */

const char *
i386_target_format ()
{
  if (!strcmp (default_arch, "x86_64"))
    set_code_flag (CODE_64BIT);
  else if (!strcmp (default_arch, "i386"))
    set_code_flag (CODE_32BIT);
  else
    as_fatal (_("Unknown architecture"));
  switch (OUTPUT_FLAVOR)
    {
#ifdef OBJ_MAYBE_AOUT
    case bfd_target_aout_flavour:
      return AOUT_TARGET_FORMAT;
#endif
#ifdef OBJ_MAYBE_COFF
    case bfd_target_coff_flavour:
      return "coff-i386";
#endif
#if defined (OBJ_MAYBE_ELF) || defined (OBJ_ELF)
    case bfd_target_elf_flavour:
      {
        if (flag_code == CODE_64BIT)
          use_rela_relocations = 1;
        return flag_code == CODE_64BIT ? "elf64-x86-64" : "elf32-i386";
      }
#endif
    default:
      abort ();
      return NULL;
    }
}

#endif /* OBJ_MAYBE_ more than one  */

#if (defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF))
void i386_elf_emit_arch_note ()
{
  if (OUTPUT_FLAVOR == bfd_target_elf_flavour
      && cpu_arch_name != NULL)
    {
      char *p;
      asection *seg = now_seg;
      subsegT subseg = now_subseg;
      Elf_Internal_Note i_note;
      Elf_External_Note e_note;
      asection *note_secp;
      int len;

      /* Create the .note section.  */
      note_secp = subseg_new (".note", 0);
      bfd_set_section_flags (stdoutput,
                             note_secp,
                             SEC_HAS_CONTENTS | SEC_READONLY);

      /* Process the arch string.  */
      len = strlen (cpu_arch_name);

      i_note.namesz = len + 1;
      i_note.descsz = 0;
      i_note.type = NT_ARCH;
      p = frag_more (sizeof (e_note.namesz));
      md_number_to_chars (p, (valueT) i_note.namesz, sizeof (e_note.namesz));
      p = frag_more (sizeof (e_note.descsz));
      md_number_to_chars (p, (valueT) i_note.descsz, sizeof (e_note.descsz));
      p = frag_more (sizeof (e_note.type));
      md_number_to_chars (p, (valueT) i_note.type, sizeof (e_note.type));
      p = frag_more (len + 1);
      strcpy (p, cpu_arch_name);

      frag_align (2, 0, 0);

      subseg_set (seg, subseg);
    }
}
#endif
#endif /* BFD_ASSEMBLER  */
\f
symbolS *
md_undefined_symbol (name)
     char *name;
{
  if (name[0] == GLOBAL_OFFSET_TABLE_NAME[0]
      && name[1] == GLOBAL_OFFSET_TABLE_NAME[1]
      && name[2] == GLOBAL_OFFSET_TABLE_NAME[2]
      && strcmp (name, GLOBAL_OFFSET_TABLE_NAME) == 0)
    {
      if (!GOT_symbol)
        {
          if (symbol_find (name))
            as_bad (_("GOT already in symbol table"));
          GOT_symbol = symbol_new (name, undefined_section,
                                   (valueT) 0, &zero_address_frag);
        };
      return GOT_symbol;
    }
  return 0;
}

/* Round up a section size to the appropriate boundary.  */

valueT
md_section_align (segment, size)
     segT segment ATTRIBUTE_UNUSED;
     valueT size;
{
#ifdef BFD_ASSEMBLER
#if (defined (OBJ_AOUT) || defined (OBJ_MAYBE_AOUT))
  if (OUTPUT_FLAVOR == bfd_target_aout_flavour)
    {
      /* For a.out, force the section size to be aligned.  If we don't do
         this, BFD will align it for us, but it will not write out the
         final bytes of the section.  This may be a bug in BFD, but it is
         easier to fix it here since that is how the other a.out targets
         work.  */
      int align;

      align = bfd_get_section_alignment (stdoutput, segment);
      size = ((size + (1 << align) - 1) & ((valueT) -1 << align));
    }
#endif
#endif

  return size;
}

/* On the i386, 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 (fixP)
     fixS *fixP;
{
  return fixP->fx_size + fixP->fx_where + fixP->fx_frag->fr_address;
}

#ifndef I386COFF

static void
s_bss (ignore)
     int ignore ATTRIBUTE_UNUSED;
{
  int temp;

  temp = get_absolute_expression ();
  subseg_set (bss_section, (subsegT) temp);
  demand_empty_rest_of_line ();
}

#endif

#ifdef BFD_ASSEMBLER

void
i386_validate_fix (fixp)
     fixS *fixp;
{
  if (fixp->fx_subsy && fixp->fx_subsy == GOT_symbol)
    {
      /* GOTOFF relocation are nonsense in 64bit mode.  */
      if (fixp->fx_r_type == BFD_RELOC_32_PCREL)
        {
          if (flag_code != CODE_64BIT)
            abort ();
          fixp->fx_r_type = BFD_RELOC_X86_64_GOTPCREL;
        }
      else
        {
          if (flag_code == CODE_64BIT)
            abort ();
          fixp->fx_r_type = BFD_RELOC_386_GOTOFF;
        }
      fixp->fx_subsy = 0;
    }
}

boolean
i386_force_relocation (fixp)
     fixS *fixp;
{
  if (fixp->fx_r_type == BFD_RELOC_VTABLE_INHERIT
      || fixp->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    return 1;

  return S_FORCE_RELOC (fixp->fx_addsy);
}

arelent *
tc_gen_reloc (section, fixp)
     asection *section ATTRIBUTE_UNUSED;
     fixS *fixp;
{
  arelent *rel;
  bfd_reloc_code_real_type code;

  switch (fixp->fx_r_type)
    {
    case BFD_RELOC_X86_64_PLT32:
    case BFD_RELOC_X86_64_GOT32:
    case BFD_RELOC_X86_64_GOTPCREL:
    case BFD_RELOC_386_PLT32:
    case BFD_RELOC_386_GOT32:
    case BFD_RELOC_386_GOTOFF:
    case BFD_RELOC_386_GOTPC:
    case BFD_RELOC_386_TLS_GD:
    case BFD_RELOC_386_TLS_LDM:
    case BFD_RELOC_386_TLS_LDO_32:
    case BFD_RELOC_386_TLS_IE_32:
    case BFD_RELOC_386_TLS_LE_32:
    case BFD_RELOC_386_TLS_LE:
    case BFD_RELOC_X86_64_32S:
    case BFD_RELOC_RVA:
    case BFD_RELOC_VTABLE_ENTRY:
    case BFD_RELOC_VTABLE_INHERIT:
      code = fixp->fx_r_type;
      break;
    default:
      if (fixp->fx_pcrel)
        {
          switch (fixp->fx_size)
            {
            default:
              as_bad_where (fixp->fx_file, fixp->fx_line,
                            _("can not do %d byte pc-relative relocation"),
                            fixp->fx_size);
              code = BFD_RELOC_32_PCREL;
              break;
            case 1: code = BFD_RELOC_8_PCREL;  break;
            case 2: code = BFD_RELOC_16_PCREL; break;
            case 4: code = BFD_RELOC_32_PCREL; break;
            }
        }
      else
        {
          switch (fixp->fx_size)
            {
            default:
              as_bad_where (fixp->fx_file, fixp->fx_line,
                            _("can not do %d byte relocation"),
                            fixp->fx_size);
              code = BFD_RELOC_32;
              break;
            case 1: code = BFD_RELOC_8;  break;
            case 2: code = BFD_RELOC_16; break;
            case 4: code = BFD_RELOC_32; break;
#ifdef BFD64
            case 8: code = BFD_RELOC_64; break;
#endif
            }
        }
      break;
    }

  if (code == BFD_RELOC_32
      && GOT_symbol
      && fixp->fx_addsy == GOT_symbol)
    {
      /* We don't support GOTPC on 64bit targets.  */
      if (flag_code == CODE_64BIT)
        abort ();
      code = BFD_RELOC_386_GOTPC;
    }

  rel = (arelent *) xmalloc (sizeof (arelent));
  rel->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
  *rel->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);

  rel->address = fixp->fx_frag->fr_address + fixp->fx_where;
  if (!use_rela_relocations)
    {
      /* HACK: Since i386 ELF uses 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)
        rel->address = fixp->fx_offset;

      rel->addend = 0;
    }
  /* Use the rela in 64bit mode.  */
  else
    {
      if (!fixp->fx_pcrel)
        rel->addend = fixp->fx_offset;
      else
        switch (code)
          {
          case BFD_RELOC_X86_64_PLT32:
          case BFD_RELOC_X86_64_GOT32:
          case BFD_RELOC_X86_64_GOTPCREL:
            rel->addend = fixp->fx_offset - fixp->fx_size;
            break;
          default:
            rel->addend = (section->vma
                           - fixp->fx_size
                           + fixp->fx_addnumber
                           + md_pcrel_from (fixp));
            break;
          }
    }

  rel->howto = bfd_reloc_type_lookup (stdoutput, code);
  if (rel->howto == NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
                    _("cannot represent relocation type %s"),
                    bfd_get_reloc_code_name (code));
      /* Set howto to a garbage value so that we can keep going.  */
      rel->howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_32);
      assert (rel->howto != NULL);
    }

  return rel;
}

#else /* !BFD_ASSEMBLER  */

#if (defined(OBJ_AOUT) | defined(OBJ_BOUT))
void
tc_aout_fix_to_chars (where, fixP, segment_address_in_file)
     char *where;
     fixS *fixP;
     relax_addressT segment_address_in_file;
{
  /* In:  length of relocation (or of address) in chars: 1, 2 or 4.
     Out: GNU LD relocation length code: 0, 1, or 2.  */

  static const unsigned char nbytes_r_length[] = { 42, 0, 1, 42, 2 };
  long r_symbolnum;

  know (fixP->fx_addsy != NULL);

  md_number_to_chars (where,
                      (valueT) (fixP->fx_frag->fr_address
                                + fixP->fx_where - segment_address_in_file),
                      4);

  r_symbolnum = (S_IS_DEFINED (fixP->fx_addsy)
                 ? S_GET_TYPE (fixP->fx_addsy)
                 : fixP->fx_addsy->sy_number);

  where[6] = (r_symbolnum >> 16) & 0x0ff;
  where[5] = (r_symbolnum >> 8) & 0x0ff;
  where[4] = r_symbolnum & 0x0ff;
  where[7] = ((((!S_IS_DEFINED (fixP->fx_addsy)) << 3) & 0x08)
              | ((nbytes_r_length[fixP->fx_size] << 1) & 0x06)
              | (((fixP->fx_pcrel << 0) & 0x01) & 0x0f));
}

#endif /* OBJ_AOUT or OBJ_BOUT.  */

#if defined (I386COFF)

short
tc_coff_fix2rtype (fixP)
     fixS *fixP;
{
  if (fixP->fx_r_type == R_IMAGEBASE)
    return R_IMAGEBASE;

  return (fixP->fx_pcrel ?
          (fixP->fx_size == 1 ? R_PCRBYTE :
           fixP->fx_size == 2 ? R_PCRWORD :
           R_PCRLONG) :
          (fixP->fx_size == 1 ? R_RELBYTE :
           fixP->fx_size == 2 ? R_RELWORD :
           R_DIR32));
}

int
tc_coff_sizemachdep (frag)
     fragS *frag;
{
  if (frag->fr_next)
    return (frag->fr_next->fr_address - frag->fr_address);
  else
    return 0;
}

#endif /* I386COFF  */

#endif /* !BFD_ASSEMBLER  */
\f
/* Parse operands using Intel syntax. This implements a recursive descent
   parser based on the BNF grammar published in Appendix B of the MASM 6.1
   Programmer's Guide.

   FIXME: We do not recognize the full operand grammar defined in the MASM
          documentation.  In particular, all the structure/union and
          high-level macro operands are missing.

   Uppercase words are terminals, lower case words are non-terminals.
   Objects surrounded by double brackets '[[' ']]' are optional. Vertical
   bars '|' denote choices. Most grammar productions are implemented in
   functions called 'intel_<production>'.

   Initial production is 'expr'.

    addOp               + | -

    alpha               [a-zA-Z]

    byteRegister        AL | AH | BL | BH | CL | CH | DL | DH

    constant            digits [[ radixOverride ]]

    dataType            BYTE | WORD | DWORD | QWORD | XWORD

    digits              decdigit
                        | digits decdigit
                        | digits hexdigit

    decdigit            [0-9]

    e05                 e05 addOp e06
                        | e06

    e06                 e06 mulOp e09
                        | e09

    e09                 OFFSET e10
                        | e09 PTR e10
                        | e09 : e10
                        | e10

    e10                 e10 [ expr ]
                        | e11

    e11                 ( expr )
                        | [ expr ]
                        | constant
                        | dataType
                        | id
                        | $
                        | register

 => expr                SHORT e05
                        | e05

    gpRegister          AX | EAX | BX | EBX | CX | ECX | DX | EDX
                        | BP | EBP | SP | ESP | DI | EDI | SI | ESI

    hexdigit            a | b | c | d | e | f
                        | A | B | C | D | E | F

    id                  alpha
                        | id alpha
                        | id decdigit

    mulOp               * | / | MOD

    quote               " | '

    register            specialRegister
                        | gpRegister
                        | byteRegister

    segmentRegister     CS | DS | ES | FS | GS | SS

    specialRegister     CR0 | CR2 | CR3
                        | DR0 | DR1 | DR2 | DR3 | DR6 | DR7
                        | TR3 | TR4 | TR5 | TR6 | TR7

    We simplify the grammar in obvious places (e.g., register parsing is
    done by calling parse_register) and eliminate immediate left recursion
    to implement a recursive-descent parser.

    expr        SHORT e05
                | e05

    e05         e06 e05'

    e05'        addOp e06 e05'
                | Empty

    e06         e09 e06'

    e06'        mulOp e09 e06'
                | Empty

    e09         OFFSET e10 e09'
                | e10 e09'

    e09'        PTR e10 e09'
                | : e10 e09'
                | Empty

    e10         e11 e10'

    e10'        [ expr ] e10'
                | Empty

    e11         ( expr )
                | [ expr ]
                | BYTE
                | WORD
                | DWORD
                | QWORD
                | XWORD
                | .
                | $
                | register
                | id
                | constant  */

/* Parsing structure for the intel syntax parser. Used to implement the
   semantic actions for the operand grammar.  */
struct intel_parser_s
  {
    char *op_string;            /* The string being parsed.  */
    int got_a_float;            /* Whether the operand is a float.  */
    int op_modifier;            /* Operand modifier.  */
    int is_mem;                 /* 1 if operand is memory reference.  */
    const reg_entry *reg;       /* Last register reference found.  */
    char *disp;                 /* Displacement string being built.  */
  };

static struct intel_parser_s intel_parser;

/* Token structure for parsing intel syntax.  */
struct intel_token
  {
    int code;                   /* Token code.  */
    const reg_entry *reg;       /* Register entry for register tokens.  */
    char *str;                  /* String representation.  */
  };

static struct intel_token cur_token, prev_token;

/* Token codes for the intel parser. Since T_SHORT is already used
   by COFF, undefine it first to prevent a warning.  */
#define T_NIL           -1
#define T_CONST         1
#define T_REG           2
#define T_BYTE          3
#define T_WORD          4
#define T_DWORD         5
#define T_QWORD         6
#define T_XWORD         7
#undef  T_SHORT
#define T_SHORT         8
#define T_OFFSET        9
#define T_PTR           10
#define T_ID            11

/* Prototypes for intel parser functions.  */
static int intel_match_token    PARAMS ((int code));
static void intel_get_token     PARAMS ((void));
static void intel_putback_token PARAMS ((void));
static int intel_expr           PARAMS ((void));
static int intel_e05            PARAMS ((void));
static int intel_e05_1          PARAMS ((void));
static int intel_e06            PARAMS ((void));
static int intel_e06_1          PARAMS ((void));
static int intel_e09            PARAMS ((void));
static int intel_e09_1          PARAMS ((void));
static int intel_e10            PARAMS ((void));
static int intel_e10_1          PARAMS ((void));
static int intel_e11            PARAMS ((void));

static int
i386_intel_operand (operand_string, got_a_float)
     char *operand_string;
     int got_a_float;
{
  int ret;
  char *p;

  /* Initialize token holders.  */
  cur_token.code = prev_token.code = T_NIL;
  cur_token.reg = prev_token.reg = NULL;
  cur_token.str = prev_token.str = NULL;

  /* Initialize parser structure.  */
  p = intel_parser.op_string = (char *) malloc (strlen (operand_string) + 1);
  if (p == NULL)
    abort ();
  strcpy (intel_parser.op_string, operand_string);
  intel_parser.got_a_float = got_a_float;
  intel_parser.op_modifier = -1;
  intel_parser.is_mem = 0;
  intel_parser.reg = NULL;
  intel_parser.disp = (char *) malloc (strlen (operand_string) + 1);
  if (intel_parser.disp == NULL)
    abort ();
  intel_parser.disp[0] = '\0';

  /* Read the first token and start the parser.  */
  intel_get_token ();
  ret = intel_expr ();

  if (ret)
    {
      /* If we found a memory reference, hand it over to i386_displacement
         to fill in the rest of the operand fields.  */
      if (intel_parser.is_mem)
        {
          if ((i.mem_operands == 1
               && (current_templates->start->opcode_modifier & IsString) == 0)
              || i.mem_operands == 2)
            {
              as_bad (_("too many memory references for '%s'"),
                      current_templates->start->name);
              ret = 0;
            }
          else
            {
              char *s = intel_parser.disp;
              i.mem_operands++;

              /* Add the displacement expression.  */
              if (*s != '\0')
                ret = i386_displacement (s, s + strlen (s))
                      && i386_index_check (s);
            }
        }

      /* Constant and OFFSET expressions are handled by i386_immediate.  */
      else if (intel_parser.op_modifier == OFFSET_FLAT
               || intel_parser.reg == NULL)
        ret = i386_immediate (intel_parser.disp);
    }

  free (p);
  free (intel_parser.disp);

  return ret;
}

/* expr SHORT e05
        | e05  */
static int
intel_expr ()
{
  /* expr  SHORT e05  */
  if (cur_token.code == T_SHORT)
    {
      intel_parser.op_modifier = SHORT;
      intel_match_token (T_SHORT);

      return (intel_e05 ());
    }

  /* expr  e05  */
  else
    return intel_e05 ();
}

/* e05  e06 e05'

   e05' addOp e06 e05'
        | Empty  */
static int
intel_e05 ()
{
  return (intel_e06 () && intel_e05_1 ());
}

static int
intel_e05_1 ()
{
  /* e05'  addOp e06 e05'  */
  if (cur_token.code == '+' || cur_token.code == '-')
    {
      strcat (intel_parser.disp, cur_token.str);
      intel_match_token (cur_token.code);

      return (intel_e06 () && intel_e05_1 ());
    }

  /* e05'  Empty  */
  else
    return 1;
}

/* e06  e09 e06'

   e06' mulOp e09 e06'
        | Empty  */
static int
intel_e06 ()
{
  return (intel_e09 () && intel_e06_1 ());
}

static int
intel_e06_1 ()
{
  /* e06'  mulOp e09 e06'  */
  if (cur_token.code == '*' || cur_token.code == '/')
    {
      strcat (intel_parser.disp, cur_token.str);
      intel_match_token (cur_token.code);

      return (intel_e09 () && intel_e06_1 ());
    }

  /* e06'  Empty  */
  else
    return 1;
}

/* e09  OFFSET e10 e09'
        | e10 e09'

   e09' PTR e10 e09'
        | : e10 e09'
        | Empty */
static int
intel_e09 ()
{
  /* e09  OFFSET e10 e09'  */
  if (cur_token.code == T_OFFSET)
    {
      intel_parser.is_mem = 0;
      intel_parser.op_modifier = OFFSET_FLAT;
      intel_match_token (T_OFFSET);

      return (intel_e10 () && intel_e09_1 ());
    }

  /* e09  e10 e09'  */
  else
    return (intel_e10 () && intel_e09_1 ());
}

static int
intel_e09_1 ()
{
  /* e09'  PTR e10 e09' */
  if (cur_token.code == T_PTR)
    {
      if (prev_token.code == T_BYTE)
        i.suffix = BYTE_MNEM_SUFFIX;

      else if (prev_token.code == T_WORD)
        {
          if (intel_parser.got_a_float == 2)    /* "fi..." */
            i.suffix = SHORT_MNEM_SUFFIX;
          else
            i.suffix = WORD_MNEM_SUFFIX;
        }

      else if (prev_token.code == T_DWORD)
        {
          if (intel_parser.got_a_float == 1)    /* "f..." */
            i.suffix = SHORT_MNEM_SUFFIX;
          else
            i.suffix = LONG_MNEM_SUFFIX;
        }

      else if (prev_token.code == T_QWORD)
        {
          if (intel_parser.got_a_float == 1)    /* "f..." */
            i.suffix = LONG_MNEM_SUFFIX;
          else
            i.suffix = QWORD_MNEM_SUFFIX;
        }

      else if (prev_token.code == T_XWORD)
        i.suffix = LONG_DOUBLE_MNEM_SUFFIX;

      else
        {
          as_bad (_("Unknown operand modifier `%s'\n"), prev_token.str);
          return 0;
        }

      intel_match_token (T_PTR);

      return (intel_e10 () && intel_e09_1 ());
    }

  /* e09  : e10 e09'  */
  else if (cur_token.code == ':')
    {
      /* Mark as a memory operand only if it's not already known to be an
         offset expression.  */
      if (intel_parser.op_modifier != OFFSET_FLAT)
        intel_parser.is_mem = 1;

      return (intel_match_token (':') && intel_e10 () && intel_e09_1 ());
    }

  /* e09'  Empty  */
  else
    return 1;
}

/* e10  e11 e10'

   e10' [ expr ] e10'
        | Empty  */
static int
intel_e10 ()
{
  return (intel_e11 () && intel_e10_1 ());
}

static int
intel_e10_1 ()
{
  /* e10'  [ expr ]  e10'  */
  if (cur_token.code == '[')
    {
      intel_match_token ('[');

      /* Mark as a memory operand only if it's not already known to be an
         offset expression.  If it's an offset expression, we need to keep
         the brace in.  */
      if (intel_parser.op_modifier != OFFSET_FLAT)
        intel_parser.is_mem = 1;
      else
        strcat (intel_parser.disp, "[");

      /* Add a '+' to the displacement string if necessary.  */
      if (*intel_parser.disp != '\0'
          && *(intel_parser.disp + strlen (intel_parser.disp) - 1) != '+')
        strcat (intel_parser.disp, "+");

      if (intel_expr () && intel_match_token (']'))
        {
          /* Preserve brackets when the operand is an offset expression.  */
          if (intel_parser.op_modifier == OFFSET_FLAT)
            strcat (intel_parser.disp, "]");

          return intel_e10_1 ();
        }
      else
        return 0;
    }

  /* e10'  Empty  */
  else
    return 1;
}

/* e11  ( expr )
        | [ expr ]
        | BYTE
        | WORD
        | DWORD
        | QWORD
        | XWORD
        | $
        | .
        | register
        | id
        | constant  */
static int
intel_e11 ()
{
  /* e11  ( expr ) */
  if (cur_token.code == '(')
    {
      intel_match_token ('(');
      strcat (intel_parser.disp, "(");

      if (intel_expr () && intel_match_token (')'))
        {
          strcat (intel_parser.disp, ")");
          return 1;
        }
      else
        return 0;
    }

  /* e11  [ expr ] */
  else if (cur_token.code == '[')
    {
      intel_match_token ('[');

      /* Mark as a memory operand only if it's not already known to be an
         offset expression.  If it's an offset expression, we need to keep
         the brace in.  */
      if (intel_parser.op_modifier != OFFSET_FLAT)
        intel_parser.is_mem = 1;
      else
        strcat (intel_parser.disp, "[");

      /* Operands for jump/call inside brackets denote absolute addresses.  */
      if (current_templates->start->opcode_modifier & Jump
          || current_templates->start->opcode_modifier & JumpDword
          || current_templates->start->opcode_modifier & JumpByte
          || current_templates->start->opcode_modifier & JumpInterSegment)
        i.types[this_operand] |= JumpAbsolute;

      /* Add a '+' to the displacement string if necessary.  */
      if (*intel_parser.disp != '\0'
          && *(intel_parser.disp + strlen (intel_parser.disp) - 1) != '+')
        strcat (intel_parser.disp, "+");

      if (intel_expr () && intel_match_token (']'))
        {
          /* Preserve brackets when the operand is an offset expression.  */
          if (intel_parser.op_modifier == OFFSET_FLAT)
            strcat (intel_parser.disp, "]");

          return 1;
        }
      else
        return 0;
    }

  /* e11  BYTE
          | WORD
          | DWORD
          | QWORD
          | XWORD  */
  else if (cur_token.code == T_BYTE
           || cur_token.code == T_WORD
           || cur_token.code == T_DWORD
           || cur_token.code == T_QWORD
           || cur_token.code == T_XWORD)
    {
      intel_match_token (cur_token.code);

      return 1;
    }

  /* e11  $
          | .  */
  else if (cur_token.code == '$' || cur_token.code == '.')
    {
      strcat (intel_parser.disp, cur_token.str);
      intel_match_token (cur_token.code);

      /* Mark as a memory operand only if it's not already known to be an
         offset expression.  */
      if (intel_parser.op_modifier != OFFSET_FLAT)
        intel_parser.is_mem = 1;

      return 1;
    }

  /* e11  register  */
  else if (cur_token.code == T_REG)
    {
      const reg_entry *reg = intel_parser.reg = cur_token.reg;

      intel_match_token (T_REG);

      /* Check for segment change.  */
      if (cur_token.code == ':')
        {
          if (reg->reg_type & (SReg2 | SReg3))
            {
              switch (reg->reg_num)
                {
                case 0:
                  i.seg[i.mem_operands] = &es;
                  break;
                case 1:
                  i.seg[i.mem_operands] = &cs;
                  break;
                case 2:
                  i.seg[i.mem_operands] = &ss;
                  break;
                case 3:
                  i.seg[i.mem_operands] = &ds;
                  break;
                case 4:
                  i.seg[i.mem_operands] = &fs;
                  break;
                case 5:
                  i.seg[i.mem_operands] = &gs;
                  break;
                }
            }
          else
            {
              as_bad (_("`%s' is not a valid segment register"), reg->reg_name);
              return 0;
            }
        }

      /* Not a segment register. Check for register scaling.  */
      else if (cur_token.code == '*')
        {
          if (!intel_parser.is_mem)
            {
              as_bad (_("Register scaling only allowed in memory operands."));
              return 0;
            }

          /* What follows must be a valid scale.  */
          if (intel_match_token ('*')
              && strchr ("01248", *cur_token.str))
            {
              i.index_reg = reg;
              i.types[this_operand] |= BaseIndex;

              /* Set the scale after setting the register (otherwise,
                 i386_scale will complain)  */
              i386_scale (cur_token.str);
              intel_match_token (T_CONST);
            }
          else
            {
              as_bad (_("expecting scale factor of 1, 2, 4, or 8: got `%s'"),
                      cur_token.str);
              return 0;
            }
        }

      /* No scaling. If this is a memory operand, the register is either a
         base register (first occurrence) or an index register (second
         occurrence).  */
      else if (intel_parser.is_mem && !(reg->reg_type & (SReg2 | SReg3)))
        {
          if (i.base_reg && i.index_reg)
            {
              as_bad (_("Too many register references in memory operand.\n"));
              return 0;
            }

          if (i.base_reg == NULL)
            i.base_reg = reg;
          else
            i.index_reg = reg;

          i.types[this_operand] |= BaseIndex;
        }

      /* Offset modifier. Add the register to the displacement string to be
         parsed as an immediate expression after we're done.  */
      else if (intel_parser.op_modifier == OFFSET_FLAT)
        strcat (intel_parser.disp, reg->reg_name);

      /* It's neither base nor index nor offset.  */
      else
        {
          i.types[this_operand] |= reg->reg_type & ~BaseIndex;
          i.op[this_operand].regs = reg;
          i.reg_operands++;
        }

      /* Since registers are not part of the displacement string (except
         when we're parsing offset operands), we may need to remove any
         preceding '+' from the displacement string.  */
      if (*intel_parser.disp != '\0'
          && intel_parser.op_modifier != OFFSET_FLAT)
        {
          char *s = intel_parser.disp;
          s += strlen (s) - 1;
          if (*s == '+')
            *s = '\0';
        }

      return 1;
    }

  /* e11  id  */
  else if (cur_token.code == T_ID)
    {
      /* Add the identifier to the displacement string.  */
      strcat (intel_parser.disp, cur_token.str);
      intel_match_token (T_ID);

      /* The identifier represents a memory reference only if it's not
         preceded by an offset modifier.  */
      if (intel_parser.op_modifier != OFFSET_FLAT)
        intel_parser.is_mem = 1;

      return 1;
    }

  /* e11  constant  */
  else if (cur_token.code == T_CONST
           || cur_token.code == '-'
           || cur_token.code == '+')
    {
      char *save_str;

      /* Allow constants that start with `+' or `-'.  */
      if (cur_token.code == '-' || cur_token.code == '+')
        {
          strcat (intel_parser.disp, cur_token.str);
          intel_match_token (cur_token.code);
          if (cur_token.code != T_CONST)
            {
              as_bad (_("Syntax error. Expecting a constant. Got `%s'.\n"),
                      cur_token.str);
              return 0;
            }
        }

      save_str = (char *) malloc (strlen (cur_token.str) + 1);
      if (save_str == NULL)
        abort ();
      strcpy (save_str, cur_token.str);

      /* Get the next token to check for register scaling.  */
      intel_match_token (cur_token.code);

      /* Check if this constant is a scaling factor for an index register.  */
      if (cur_token.code == '*')
        {
          if (intel_match_token ('*') && cur_token.code == T_REG)
            {
              if (!intel_parser.is_mem)
                {
                  as_bad (_("Register scaling only allowed in memory operands."));
                  return 0;
                }

              /* The constant is followed by `* reg', so it must be
                 a valid scale.  */
              if (strchr ("01248", *save_str))
                {
                  i.index_reg = cur_token.reg;
                  i.types[this_operand] |= BaseIndex;

                  /* Set the scale after setting the register (otherwise,
                     i386_scale will complain)  */
                  i386_scale (save_str);
                  intel_match_token (T_REG);

                  /* Since registers are not part of the displacement
                     string, we may need to remove any preceding '+' from
                     the displacement string.  */
                  if (*intel_parser.disp != '\0')
                    {
                      char *s = intel_parser.disp;
                      s += strlen (s) - 1;
                      if (*s == '+')
                        *s = '\0';
                    }

                  free (save_str);

                  return 1;
                }
              else
                return 0;
            }

          /* The constant was not used for register scaling. Since we have
             already consumed the token following `*' we now need to put it
             back in the stream.  */
          else
            intel_putback_token ();
        }

      /* Add the constant to the displacement string.  */
      strcat (intel_parser.disp, save_str);
      free (save_str);

      return 1;
    }

  as_bad (_("Unrecognized token '%s'"), cur_token.str);
  return 0;
}

/* Match the given token against cur_token. If they match, read the next
   token from the operand string.  */
static int
intel_match_token (code)
     int code;
{
  if (cur_token.code == code)
    {
      intel_get_token ();
      return 1;
    }
  else
    {
      as_bad (_("Unexpected token `%s'\n"), cur_token.str);
      return 0;
    }
}

/* Read a new token from intel_parser.op_string and store it in cur_token.  */
static void
intel_get_token ()
{
  char *end_op;
  const reg_entry *reg;
  struct intel_token new_token;

  new_token.code = T_NIL;
  new_token.reg = NULL;
  new_token.str = NULL;

  /* Free the memory allocated to the previous token and move
     cur_token to prev_token.  */
  if (prev_token.str)
    free (prev_token.str);

  prev_token = cur_token;

  /* Skip whitespace.  */
  while (is_space_char (*intel_parser.op_string))
    intel_parser.op_string++;

  /* Return an empty token if we find nothing else on the line.  */
  if (*intel_parser.op_string == '\0')
    {
      cur_token = new_token;
      return;
    }

  /* The new token cannot be larger than the remainder of the operand
     string.  */
  new_token.str = (char *) malloc (strlen (intel_parser.op_string) + 1);
  if (new_token.str == NULL)
    abort ();
  new_token.str[0] = '\0';

  if (strchr ("0123456789", *intel_parser.op_string))
    {
      char *p = new_token.str;
      char *q = intel_parser.op_string;
      new_token.code = T_CONST;

      /* Allow any kind of identifier char to encompass floating point and
         hexadecimal numbers.  */
      while (is_identifier_char (*q))
        *p++ = *q++;
      *p = '\0';

      /* Recognize special symbol names [0-9][bf].  */
      if (strlen (intel_parser.op_string) == 2
          && (intel_parser.op_string[1] == 'b'
              || intel_parser.op_string[1] == 'f'))
        new_token.code = T_ID;
    }

  else if (strchr ("+-/*:[]()", *intel_parser.op_string))
    {
      new_token.code = *intel_parser.op_string;
      new_token.str[0] = *intel_parser.op_string;
      new_token.str[1] = '\0';
    }

  else if ((*intel_parser.op_string == REGISTER_PREFIX || allow_naked_reg)
           && ((reg = parse_register (intel_parser.op_string, &end_op)) != NULL))
    {
      new_token.code = T_REG;
      new_token.reg = reg;

      if (*intel_parser.op_string == REGISTER_PREFIX)
        {
          new_token.str[0] = REGISTER_PREFIX;
          new_token.str[1] = '\0';
        }

      strcat (new_token.str, reg->reg_name);
    }

  else if (is_identifier_char (*intel_parser.op_string))
    {
      char *p = new_token.str;
      char *q = intel_parser.op_string;

      /* A '.' or '$' followed by an identifier char is an identifier.
         Otherwise, it's operator '.' followed by an expression.  */
      if ((*q == '.' || *q == '$') && !is_identifier_char (*(q + 1)))
        {
          new_token.code = *q;
          new_token.str[0] = *q;
          new_token.str[1] = '\0';
        }
      else
        {
          while (is_identifier_char (*q) || *q == '@')
            *p++ = *q++;
          *p = '\0';

          if (strcasecmp (new_token.str, "BYTE") == 0)
            new_token.code = T_BYTE;

          else if (strcasecmp (new_token.str, "WORD") == 0)
            new_token.code = T_WORD;

          else if (strcasecmp (new_token.str, "DWORD") == 0)
            new_token.code = T_DWORD;

          else if (strcasecmp (new_token.str, "QWORD") == 0)
            new_token.code = T_QWORD;

          else if (strcasecmp (new_token.str, "XWORD") == 0)
            new_token.code = T_XWORD;

          else if (strcasecmp (new_token.str, "PTR") == 0)
            new_token.code = T_PTR;

          else if (strcasecmp (new_token.str, "SHORT") == 0)
            new_token.code = T_SHORT;

          else if (strcasecmp (new_token.str, "OFFSET") == 0)
            {
              new_token.code = T_OFFSET;

              /* ??? This is not mentioned in the MASM grammar but gcc
                     makes use of it with -mintel-syntax.  OFFSET may be
                     followed by FLAT:  */
              if (strncasecmp (q, " FLAT:", 6) == 0)
                strcat (new_token.str, " FLAT:");
            }

          /* ??? This is not mentioned in the MASM grammar.  */
          else if (strcasecmp (new_token.str, "FLAT") == 0)
            new_token.code = T_OFFSET;

          else
            new_token.code = T_ID;
        }
    }

  else
    as_bad (_("Unrecognized token `%s'\n"), intel_parser.op_string);

  intel_parser.op_string += strlen (new_token.str);
  cur_token = new_token;
}

/* Put cur_token back into the token stream and make cur_token point to
   prev_token.  */
static void
intel_putback_token ()
{
  intel_parser.op_string -= strlen (cur_token.str);
  free (cur_token.str);
  cur_token = prev_token;

  /* Forget prev_token.  */
  prev_token.code = T_NIL;
  prev_token.reg = NULL;
  prev_token.str = NULL;
}