/* ia64-opc.c -- Functions to access the compacted opcode table

   Copyright (C) 1999-2025 Free Software Foundation, Inc.

   Written by Bob Manson of Cygnus Solutions, <manson@cygnus.com>

   This file is part of the GNU opcodes library.

   This library is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   It is distributed in the hope that it will be useful, but WITHOUT

   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public

   License for more details.

   You should have received a copy of the GNU General Public License

   along with this file; see the file COPYING.  If not, write to the

   Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "sysdep.h"

#include "libiberty.h"

#include "ia64-asmtab.h"

#include "ia64-asmtab.c"

static void get_opc_prefix (const char **, char *);

static short int find_string_ent (const char *);

static short int find_main_ent (short int);

static short int find_completer (short int, short int, const char *);

static ia64_insn apply_completer (ia64_insn, int);

static int extract_op_bits (int, int, int);

static int extract_op (int, int *, unsigned int *);

static int opcode_verify (ia64_insn, int, enum ia64_insn_type);

static int locate_opcode_ent (ia64_insn, enum ia64_insn_type);

static struct ia64_opcode *make_ia64_opcode

  (ia64_insn, const char *, int, int);

static struct ia64_opcode *ia64_find_matching_opcode

  (const char *, short int);

const struct ia64_templ_desc ia64_templ_desc[16] =

  {

    { 0, { IA64_UNIT_M, IA64_UNIT_I, IA64_UNIT_I }, "MII" },  /* 0 */

    { 2, { IA64_UNIT_M, IA64_UNIT_I, IA64_UNIT_I }, "MII" },

    { 0, { IA64_UNIT_M, IA64_UNIT_L, IA64_UNIT_X }, "MLX" },

    { 0, { 0, },            "-3-" },

    { 0, { IA64_UNIT_M, IA64_UNIT_M, IA64_UNIT_I }, "MMI" },  /* 4 */

    { 1, { IA64_UNIT_M, IA64_UNIT_M, IA64_UNIT_I }, "MMI" },

    { 0, { IA64_UNIT_M, IA64_UNIT_F, IA64_UNIT_I }, "MFI" },

    { 0, { IA64_UNIT_M, IA64_UNIT_M, IA64_UNIT_F }, "MMF" },

    { 0, { IA64_UNIT_M, IA64_UNIT_I, IA64_UNIT_B }, "MIB" },  /* 8 */

    { 0, { IA64_UNIT_M, IA64_UNIT_B, IA64_UNIT_B }, "MBB" },

    { 0, { 0, },            "-a-" },

    { 0, { IA64_UNIT_B, IA64_UNIT_B, IA64_UNIT_B }, "BBB" },

    { 0, { IA64_UNIT_M, IA64_UNIT_M, IA64_UNIT_B }, "MMB" },  /* c */

    { 0, { 0, },            "-d-" },

    { 0, { IA64_UNIT_M, IA64_UNIT_F, IA64_UNIT_B }, "MFB" },

    { 0, { 0, },            "-f-" },

  };

/* Copy the prefix contained in *PTR (up to a '.' or a NUL) to DEST.

   PTR will be adjusted to point to the start of the next portion

   of the opcode, or at the NUL character. */

static void

get_opc_prefix (const char **ptr, char *dest)

{

  char *c = strchr (*ptr, '.');

  if (c != NULL)

    {

      memcpy (dest, *ptr, c - *ptr);

      dest[c - *ptr] = '\0';

      *ptr = c + 1;

    }

  else

    {

      int l = strlen (*ptr);

      memcpy (dest, *ptr, l);

      dest[l] = '\0';

      *ptr += l;

    }

}

/* Find the index of the entry in the string table corresponding to

   STR; return -1 if one does not exist. */

static short

find_string_ent (const char *str)

{

  short start = 0;

  short end = sizeof (ia64_strings) / sizeof (const char *);

  short i = (start + end) / 2;

  if (strcmp (str, ia64_strings[end - 1]) > 0)

    {

      return -1;

    }

  while (start <= end)

    {

      int c = strcmp (str, ia64_strings[i]);

      if (c < 0)

  {

    end = i - 1;

  }

      else if (c == 0)

  {

    return i;

  }

      else

  {

    start = i + 1;

  }

      i = (start + end) / 2;

    }

  return -1;

}

/* Find the opcode in the main opcode table whose name is STRINGINDEX, or

   return -1 if one does not exist. */

static short

find_main_ent (short nameindex)

{

  short start = 0;

  short end = ARRAY_SIZE (main_table);

  short i = (start + end) / 2;

  if (nameindex < main_table[0].name_index

      || nameindex > main_table[end - 1].name_index)

    {

      return -1;

    }

  while (start <= end)

    {

      if (nameindex < main_table[i].name_index)

  {

    end = i - 1;

  }

      else if (nameindex == main_table[i].name_index)

  {

    while (i > 0 && main_table[i - 1].name_index == nameindex)

      {

        i--;

      }

    return i;

  }

      else

  {

    start = i + 1;

  }

      i = (start + end) / 2;

    }

  return -1;

}

/* Find the index of the entry in the completer table that is part of

   MAIN_ENT (starting from PREV_COMPLETER) that matches NAME, or

   return -1 if one does not exist. */

static short

find_completer (short main_ent, short prev_completer, const char *name)

{

  short name_index = find_string_ent (name);

  if (name_index < 0)

    {

      return -1;

    }

  if (prev_completer == -1)

    {

      prev_completer = main_table[main_ent].completers;

    }

  else

    {

      prev_completer = completer_table[prev_completer].subentries;

    }

  while (prev_completer != -1)

    {

      if (completer_table[prev_completer].name_index == name_index)

  {

    return prev_completer;

  }

      prev_completer = completer_table[prev_completer].alternative;

    }

  return -1;

}

/* Apply the completer referred to by COMPLETER_INDEX to OPCODE, and

   return the result. */

static ia64_insn

apply_completer (ia64_insn opcode, int completer_index)

{

  ia64_insn mask = completer_table[completer_index].mask;

  ia64_insn bits = completer_table[completer_index].bits;

  int shiftamt = (completer_table[completer_index].offset & 63);

  mask = mask << shiftamt;

  bits = bits << shiftamt;

  opcode = (opcode & ~mask) | bits;

  return opcode;

}

/* Extract BITS number of bits starting from OP_POINTER + BITOFFSET in

   the dis_table array, and return its value.  (BITOFFSET is numbered

   starting from MSB to LSB, so a BITOFFSET of 0 indicates the MSB of the

   first byte in OP_POINTER.) */

static int

extract_op_bits (int op_pointer, int bitoffset, int bits)

{

  int res = 0;

  op_pointer += (bitoffset / 8);

  if (bitoffset % 8)

    {

      unsigned int op = dis_table[op_pointer++];

      int numb = 8 - (bitoffset % 8);

      int mask = (1 << numb) - 1;

      int bata = (bits < numb) ? bits : numb;

      int delta = numb - bata;

      res = (res << bata) | ((op & mask) >> delta);

      bitoffset += bata;

      bits -= bata;

    }

  while (bits >= 8)

    {

      res = (res << 8) | (dis_table[op_pointer++] & 255);

      bits -= 8;

    }

  if (bits > 0)

    {

      unsigned int op = (dis_table[op_pointer++] & 255);

      res = (res << bits) | (op >> (8 - bits));

    }

  return res;

}

/* Examine the state machine entry at OP_POINTER in the dis_table

   array, and extract its values into OPVAL and OP.  The length of the

   state entry in bits is returned. */

static int

extract_op (int op_pointer, int *opval, unsigned int *op)

{

  int oplen = 5;

  *op = dis_table[op_pointer];

  if ((*op) & 0x40)

    {

      opval[0] = extract_op_bits (op_pointer, oplen, 5);

      oplen += 5;

    }

  switch ((*op) & 0x30)

    {

    case 0x10:

      {

  opval[1] = extract_op_bits (op_pointer, oplen, 8);

  oplen += 8;

  opval[1] += op_pointer;

  break;

      }

    case 0x20:

      {

  opval[1] = extract_op_bits (op_pointer, oplen, 16);

  if (! (opval[1] & 32768))

    {

      opval[1] += op_pointer;

    }

  oplen += 16;

  break;

      }

    case 0x30:

      {

  oplen--;

  opval[2] = extract_op_bits (op_pointer, oplen, 12);

  oplen += 12;

  opval[2] |= 32768;

  break;

      }

    }

  if (((*op) & 0x08) && (((*op) & 0x30) != 0x30))

    {

      opval[2] = extract_op_bits (op_pointer, oplen, 16);

      oplen += 16;

      if (! (opval[2] & 32768))

  {

    opval[2] += op_pointer;

  }

    }

  return oplen;

}

/* Returns a non-zero value if the opcode in the main_table list at

   PLACE matches OPCODE and is of type TYPE. */

static int

opcode_verify (ia64_insn opcode, int place, enum ia64_insn_type type)

{

  if (main_table[place].opcode_type != type)

    {

      return 0;

    }

  if (main_table[place].flags

      & (IA64_OPCODE_F2_EQ_F3 | IA64_OPCODE_LEN_EQ_64MCNT))

    {

      const struct ia64_operand *o1, *o2;

      ia64_insn f2, f3;

      if (main_table[place].flags & IA64_OPCODE_F2_EQ_F3)

  {

    o1 = elf64_ia64_operands + IA64_OPND_F2;

    o2 = elf64_ia64_operands + IA64_OPND_F3;

    (*o1->extract) (o1, opcode, &f2);

    (*o2->extract) (o2, opcode, &f3);

    if (f2 != f3)

      return 0;

  }

      else

  {

    ia64_insn len, count;

    /* length must equal 64-count: */

    o1 = elf64_ia64_operands + IA64_OPND_LEN6;

    o2 = elf64_ia64_operands + main_table[place].operands[2];

    (*o1->extract) (o1, opcode, &len);

    (*o2->extract) (o2, opcode, &count);

    if (len != 64 - count)

      return 0;

  }

    }

  return 1;

}

/* Find an instruction entry in the ia64_dis_names array that matches

   opcode OPCODE and is of type TYPE.  Returns either a positive index

   into the array, or a negative value if an entry for OPCODE could

   not be found.  Checks all matches and returns the one with the highest

   priority. */

static int

locate_opcode_ent (ia64_insn opcode, enum ia64_insn_type type)

{

  int currtest[41];

  int bitpos[41];

  int op_ptr[41];

  int currstatenum = 0;

  short found_disent = -1;

  short found_priority = -1;

  currtest[currstatenum] = 0;

  op_ptr[currstatenum] = 0;

  bitpos[currstatenum] = 40;

  while (1)

    {

      int op_pointer = op_ptr[currstatenum];

      unsigned int op;

      int currbitnum = bitpos[currstatenum];

      int oplen;

      int opval[3] = {0};

      int next_op;

      int currbit;

      oplen = extract_op (op_pointer, opval, &op);

      bitpos[currstatenum] = currbitnum;

      /* Skip opval[0] bits in the instruction.  */

      if (op & 0x40)

  {

    currbitnum -= opval[0];

  }

      if (currbitnum < 0)

  currbitnum = 0;

      /* The value of the current bit being tested.  */

      currbit = opcode & (((ia64_insn) 1) << currbitnum) ? 1 : 0;

      next_op = -1;

      /* We always perform the tests specified in the current state in

   a particular order, falling through to the next test if the

   previous one failed. */

      switch (currtest[currstatenum])

  {

  case 0:

    currtest[currstatenum]++;

    if (currbit == 0 && (op & 0x80))

      {

        /* Check for a zero bit.  If this test solely checks for

     a zero bit, we can check for up to 8 consecutive zero

     bits (the number to check is specified by the lower 3

     bits in the state code.)

     If the state instruction matches, we go to the very

     next state instruction; otherwise, try the next test. */

        if ((op & 0xf8) == 0x80)

    {

      int count = op & 0x7;

      int x;

      for (x = 0; x <= count; x++)

        {

          int i =

      opcode & (((ia64_insn) 1) << (currbitnum - x)) ? 1 : 0;

          if (i)

      {

        break;

      }

        }

      if (x > count)

        {

          next_op = op_pointer + ((oplen + 7) / 8);

          currbitnum -= count;

          break;

        }

    }

        else if (! currbit)

    {

      next_op = op_pointer + ((oplen + 7) / 8);

      break;

    }

      }

    /* FALLTHROUGH */

  case 1:

    /* If the bit in the instruction is one, go to the state

       instruction specified by opval[1]. */

    currtest[currstatenum]++;

    if (currbit && (op & 0x30) != 0 && ((op & 0x30) != 0x30))

      {

        next_op = opval[1];

        break;

      }

    /* FALLTHROUGH */

  case 2:

    /* Don't care.  Skip the current bit and go to the state

       instruction specified by opval[2].

       An encoding of 0x30 is special; this means that a 12-bit

       offset into the ia64_dis_names[] array is specified.  */

    currtest[currstatenum]++;

    if ((op & 0x08) || ((op & 0x30) == 0x30))

      {

        next_op = opval[2];

        break;

      }

  }

      /* If bit 15 is set in the address of the next state, an offset

   in the ia64_dis_names array was specified instead.  We then

   check to see if an entry in the list of opcodes matches the

   opcode we were given; if so, we have succeeded.  */

      if ((next_op >= 0) && (next_op & 32768))

  {

    short disent = next_op & 32767;

          short priority = -1;

    if (next_op > 65535)

      {

        return -1;

      }

    /* Run through the list of opcodes to check, trying to find

       one that matches.  */

    while (disent >= 0)

      {

        int place = ia64_dis_names[disent].insn_index;

              priority = ia64_dis_names[disent].priority;

        if (opcode_verify (opcode, place, type)

                  && priority > found_priority)

    {

      break;

    }

        if (ia64_dis_names[disent].next_flag)

    {

      disent++;

    }

        else

    {

      disent = -1;

    }

      }

    if (disent >= 0)

      {

              found_disent = disent;

              found_priority = priority;

      }

          /* Try the next test in this state, regardless of whether a match

             was found. */

          next_op = -2;

  }

      /* next_op == -1 is "back up to the previous state".

   next_op == -2 is "stay in this state and try the next test".

   Otherwise, transition to the state indicated by next_op. */

      if (next_op == -1)

  {

    currstatenum--;

    if (currstatenum < 0)

      {

              return found_disent;

      }

  }

      else if (next_op >= 0)

  {

    currstatenum++;

    bitpos[currstatenum] = currbitnum - 1;

    op_ptr[currstatenum] = next_op;

    currtest[currstatenum] = 0;

  }

    }

}

/* Construct an ia64_opcode entry based on OPCODE, NAME and PLACE. */

static struct ia64_opcode *

make_ia64_opcode (ia64_insn opcode, const char *name, int place, int depind)

{

  struct ia64_opcode *res =

    (struct ia64_opcode *) xmalloc (sizeof (struct ia64_opcode));

  res->name = xstrdup (name);

  res->type = main_table[place].opcode_type;

  res->num_outputs = main_table[place].num_outputs;

  res->opcode = opcode;

  res->mask = main_table[place].mask;

  res->operands[0] = main_table[place].operands[0];

  res->operands[1] = main_table[place].operands[1];

  res->operands[2] = main_table[place].operands[2];

  res->operands[3] = main_table[place].operands[3];

  res->operands[4] = main_table[place].operands[4];

  res->flags = main_table[place].flags;

  res->ent_index = place;

  res->dependencies = &op_dependencies[depind];

  return res;

}

/* Determine the ia64_opcode entry for the opcode specified by INSN

   and TYPE.  If a valid entry is not found, return NULL. */

struct ia64_opcode *

ia64_dis_opcode (ia64_insn insn, enum ia64_insn_type type)

{

  int disent = locate_opcode_ent (insn, type);

  if (disent < 0)

    {

      return NULL;

    }

  else

    {

      unsigned int cb = ia64_dis_names[disent].completer_index;

      static char name[128];

      int place = ia64_dis_names[disent].insn_index;

      int ci = main_table[place].completers;

      ia64_insn tinsn = main_table[place].opcode;

      strcpy (name, ia64_strings [main_table[place].name_index]);

      while (cb)

  {

    if (cb & 1)

      {

        int cname = completer_table[ci].name_index;

        tinsn = apply_completer (tinsn, ci);

        if (ia64_strings[cname][0] != '\0')

    {

      strcat (name, ".");

      strcat (name, ia64_strings[cname]);

    }

        if (cb != 1)

    {

      ci = completer_table[ci].subentries;

    }

      }

    else

      {

        ci = completer_table[ci].alternative;

      }

    if (ci < 0)

      {

        abort ();

      }

    cb = cb >> 1;

  }

      if (tinsn != (insn & main_table[place].mask))

  {

    abort ();

  }

      return make_ia64_opcode (insn, name, place,

                               completer_table[ci].dependencies);

    }

}

/* Search the main_opcode table starting from PLACE for an opcode that

   matches NAME.  Return NULL if one is not found. */

static struct ia64_opcode *

ia64_find_matching_opcode (const char *name, short place)

{

  char op[129];

  const char *suffix;

  short name_index;

  if ((unsigned) place >= ARRAY_SIZE (main_table))

    return NULL;

  if (strlen (name) > 128)

    {

      return NULL;

    }

  suffix = name;

  get_opc_prefix (&suffix, op);

  name_index = find_string_ent (op);

  if (name_index < 0)

    {

      return NULL;

    }

  while (main_table[place].name_index == name_index)

    {

      const char *curr_suffix = suffix;

      ia64_insn curr_insn = main_table[place].opcode;

      short completer = -1;

      do {

  if (suffix[0] == '\0')

    {

      completer = find_completer (place, completer, suffix);

    }

  else

    {

      get_opc_prefix (&curr_suffix, op);

      completer = find_completer (place, completer, op);

    }

  if (completer != -1)

    {

      curr_insn = apply_completer (curr_insn, completer);

    }

      } while (completer != -1 && curr_suffix[0] != '\0');

      if (completer != -1 && curr_suffix[0] == '\0'

    && completer_table[completer].terminal_completer)

  {

          int depind = completer_table[completer].dependencies;

    return make_ia64_opcode (curr_insn, name, place, depind);

  }

      else

  {

    place++;

  }

    }

  return NULL;

}

/* Find the next opcode after PREV_ENT that matches PREV_ENT, or return NULL

   if one does not exist.

   It is the caller's responsibility to invoke ia64_free_opcode () to

   release any resources used by the returned entry. */

struct ia64_opcode *

ia64_find_next_opcode (struct ia64_opcode *prev_ent)

{

  return ia64_find_matching_opcode (prev_ent->name,

            prev_ent->ent_index + 1);

}

/* Find the first opcode that matches NAME, or return NULL if it does

   not exist.

   It is the caller's responsibility to invoke ia64_free_opcode () to

   release any resources used by the returned entry. */

struct ia64_opcode *

ia64_find_opcode (const char *name)

{

  char op[129];

  const char *suffix;

  short place;

  short name_index;

  if (strlen (name) > 128)

    {

      return NULL;

    }

  suffix = name;

  get_opc_prefix (&suffix, op);

  name_index = find_string_ent (op);

  if (name_index < 0)

    {

      return NULL;

    }

  place = find_main_ent (name_index);

  if (place < 0)

    {

      return NULL;

    }

  return ia64_find_matching_opcode (name, place);

}

/* Free any resources used by ENT. */

void

ia64_free_opcode (struct ia64_opcode *ent)

{

  free ((void *)ent->name);

  free (ent);

}

const struct ia64_dependency *

ia64_find_dependency (int dep_index)

{

  dep_index = DEP(dep_index);

  if (dep_index < 0

      || dep_index >= (int) ARRAY_SIZE (dependencies))

    return NULL;

  return &dependencies[dep_index];

}