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/* Assembly backend for the OpenRISC 1000.

   Copyright (C) 2002, 2003, 2005, 2007, 2009

   Copyright (C) 2010 Embecosm Limited

   Free Software Foundation, Inc.

   Contributed by Damjan Lampret <lampret@opencores.org>.

   Modified bu Johan Rydberg, <johan.rydberg@netinsight.se>.

               Gyorgy Jeney <nog@sdf.lonestar.org>

   Based upon a29k port.

   This file is part of GAS, the GNU Assembler.

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

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

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

   any later version.

   GAS is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

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

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

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

   Boston, MA 02110-1301, USA.  */

/* tc-a29k.c used as a template.  */

#include "safe-ctype.h"

#include "as.h"

#include "opcode/or32.h"

#include "struc-symbol.h"

#include "elf/or32.h"

#define DEBUG 0

#ifndef REGISTER_PREFIX

#define REGISTER_PREFIX   '%'

#endif

/* Make it easier to clone this machine desc into another one.  */

#define machine_opcode  or32_opcode

#define machine_opcodes or32_opcodes

#define machine_ip      or32_ip

#define machine_it      or32_it

/* Handle of the OPCODE hash table.  */

static struct hash_control *op_hash = NULL;

struct machine_it

{

  char *          error;

  unsigned long   opcode;

  struct nlist *  nlistp;

  expressionS     exp;

  int             pcrel;

  int             reloc;

}

the_insn;

const pseudo_typeS md_pseudo_table[] =

{

  {"align",   s_align_bytes,  4 },

  {"space",   s_space,        0 },

  {"cputype", s_ignore,       0 },

  {"reg",     s_lsym,         0 },  /* Register equate, same as equ.  */

  {"sect",    s_ignore,       0 },  /* Creation of coff sections.  */

  {"proc",    s_ignore,       0 },  /* Start of a function.  */

  {"endproc", s_ignore,       0 },  /* Function end.  */

  {"half",    cons,           2 },

  {"word",    cons,           4 },

  {NULL,      0,              0 },

};

int md_short_jump_size  = 4;

int md_long_jump_size   = 4;

/* 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[] = "#";

/* 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 like this one will always work.  */

const char line_comment_chars[] = "#";

/* We needed an unused char for line separation to work around the

   lack of macros, using sed and such.  */

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[] = "rRsSfFdDxXpP";

/* "l.jalr r9" precalculated opcode.  */

static unsigned long jalr_r9_opcode;

static void machine_ip (char *);

/* Set bits in machine opcode according to insn->encoding

   description and passed operand.  */

static void

encode (const struct machine_opcode *insn,

        unsigned long *opcode,

        signed long param_val,

        char param_ch)

{

  int opc_pos = 0;

  int param_pos = 0;

  char *enc;

#if DEBUG

  printf ("    encode:  opcode=%.8x  param_val=%.8x abs=%.8x param_ch=%c\n",

          (unsigned int) *opcode,(unsigned int) param_val, abs (param_val), param_ch);

#endif

  for (enc = insn->encoding; *enc != '\0'; enc++)

    if (*enc == param_ch)

      {

        if (enc - 2 >= insn->encoding && (*(enc - 2) == '0') && (*(enc - 1) == 'x'))

          continue;

        else

          param_pos ++;

      }

  opc_pos = 32;

  for (enc = insn->encoding; *enc != '\0';)

    {

      if ((*enc == '0') && (*(enc + 1) == 'x'))

        {

          int tmp = strtol (enc, NULL, 16);

          opc_pos -= 4;

          *opcode |= tmp << opc_pos;

          enc += 3;

        }

      else if ((*enc == '0') || (*enc == '-'))

        {

          opc_pos--;

          enc++;

        }

      else if (*enc == '1')

        {

          opc_pos--;

          *opcode |= 1 << opc_pos;

          enc++;

        }

      else if (*enc == param_ch)

        {

          opc_pos--;

          param_pos--;

          *opcode |= ((param_val >> param_pos) & 0x1) << opc_pos;

          enc++;

        }

      else if (ISALPHA (*enc))

        {

          opc_pos--;

          enc++;

        }

      else

        enc++;

    }

#if DEBUG

  printf ("    opcode=%.8lx\n", *opcode);

#endif

}

/* This function is called once, at assembler startup time.  It should

   set up all the tables, etc., that the MD part of the assembler will

   need.  */

void

md_begin (void)

{

  const char *retval = NULL;

  int lose = 0;

  int skipnext = 0;

  unsigned int i;

  /* Hash up all the opcodes for fast use later.  */

  op_hash = hash_new ();

  for (i = 0; i < or32_num_opcodes; i++)

    {

      const char *name = machine_opcodes[i].name;

      if (skipnext)

        {

          skipnext = 0;

          continue;

        }

      retval = hash_insert (op_hash, name, (void *) &machine_opcodes[i]);

      if (retval != NULL)

        {

          fprintf (stderr, "internal error: can't hash `%s': %s\n",

                   machine_opcodes[i].name, retval);

          lose = 1;

        }

    }

  if (lose)

    as_fatal (_("Broken assembler.  No assembly attempted."));

  encode (&machine_opcodes[insn_index ("l.jalr")], &jalr_r9_opcode, 9, 'B');

}

/* Returns non zero if instruction is to be used.  */

static int

check_invalid_opcode (unsigned long opcode)

{

  return opcode == jalr_r9_opcode;

}

/* Assemble a single instruction.  Its label has already been handled

   by the generic front end.  We just parse opcode and operands, and

   produce the bytes of data and relocation.  */

void

md_assemble (char *str)

{

  char *toP;

#if DEBUG

  printf ("NEW INSTRUCTION\n");

#endif

  know (str);

  machine_ip (str);

  toP = frag_more (4);

  /* Put out the opcode.  */

  md_number_to_chars (toP, the_insn.opcode, 4);

  /* Put out the symbol-dependent stuff.  */

  if (the_insn.reloc != BFD_RELOC_NONE)

    {

      fix_new_exp (frag_now,

                   (toP - frag_now->fr_literal),

                   4,   /* size */

                   &the_insn.exp,

                   the_insn.pcrel,

                   the_insn.reloc);

    }

}

static int mask_or_shift = 0;

/*----------------------------------------------------------------------------*/

/*!Parse an operand

   We use some semantic information about the operand to determine its type.

   @param[in]  s         Pointer to start of the operand string

   @param[out] operandp  The parsed operand expression

   @param[in]  opt       Non-zero (TRUE) if this operand is optional, zero

                         (FALSE) otherwise.

   @param[in]  is_reg    Non-zero (TRUE) if this operand is a register, zero

                         (FALSE) otherwise.

   @return  Pointer to the operand string immediately after the operand just

            parsed.                                                           */

/*----------------------------------------------------------------------------*/

static char *

parse_operand (char        *s,

               expressionS *operandp,

               int          opt,

               int          is_reg)

{

  char *save = input_line_pointer;

  char *new_pointer;

#if DEBUG

  printf ("  PROCESS NEW OPERAND(%s): %s, %s\n", s,

          opt ? "optional" : "not optional",

          is_reg ? "register", "not register");

#endif

  input_line_pointer = s;

  if (strncasecmp (s, "HI(", 3) == 0)

    {

      mask_or_shift = BFD_RELOC_HI16;

      input_line_pointer += 3;

    }

  else if (strncasecmp (s, "LO(", 3) == 0)

    {

      mask_or_shift = BFD_RELOC_LO16;

      input_line_pointer += 3;

    }

  else

    mask_or_shift = 0;

  if ((*s == '(') && (*(s+1) == 'r'))

    s++;

  /* JPB 18-Aug-10: The old assumption was that any symbol starting with 'r'

     and followed by a digit was a register. That was fine when we prepended

     underscores, but not when that was dropped. We need to makes sure that

     this is a register operand. */

  if (is_reg)

    {

      if ((*s == 'r') && ISDIGIT (*(s + 1)))

        {

          operandp->X_add_number = strtol (s + 1, NULL, 10);

          operandp->X_op = O_register;

          operandp->X_add_symbol = NULL;// Added to stop know() in machine_ip()

          operandp->X_op_symbol = NULL; // Added to stop know() in machine_ip()

                                        // erroring out - it appears this

                                        // wasn't getting cleared sometimes. -

                                        // JB 100718

        }

      else

        {

          as_bad (_("register expected"));

        }

      /* Skip the argument */

      for (; (*s != ',') && (*s != '\0');)

        s++;

      input_line_pointer = save;

      return s;

    }

  expression (operandp);

  if (operandp->X_op == O_absent)

    {

      if (! opt)

        as_bad (_("missing operand"));

      else

        {

          operandp->X_add_number = 0;

          operandp->X_op = O_constant;

        }

    }

  new_pointer = input_line_pointer;

  input_line_pointer = save;

#if DEBUG

  printf ("  %s=parse_operand(%s): operandp->X_op = %u\n", new_pointer, s,

          operandp->X_op);

#endif

  return new_pointer;

}

/* Instruction parsing.  Takes a string containing the opcode.

   Operands are at input_line_pointer.  Output is in the_insn.

   Warnings or errors are generated.  */

static void

machine_ip (char *str)

{

  char *s;

  const char *args;

  const struct machine_opcode *insn;

  unsigned long opcode;

  expressionS operand;

  int reloc = BFD_RELOC_NONE;

#if DEBUG

  printf ("machine_ip(%s)\n", str);

#endif

  s = str;

  for (; ISALNUM (*s) || *s == '.' || *s == '_'; ++s)

    if (ISUPPER (*s))

      *s = TOLOWER (*s);

  switch (*s)

    {

    case '\0':

      break;

    case ' ':     /* FIXME-SOMEDAY more whitespace.  */

      *s++ = '\0';

      break;

    default:

      as_bad (_("unknown opcode1: `%s'"), str);

      return;

    }

  if ((insn = (struct machine_opcode *) hash_find (op_hash, str)) == NULL)

    {

      as_bad (_("unknown opcode2 `%s'."), str);

      return;

    }

  opcode = 0;

  memset (&the_insn, '\0', sizeof (the_insn));

  the_insn.reloc = BFD_RELOC_NONE;

  reloc = BFD_RELOC_NONE;

  /* Build the opcode, checking as we go to make sure that the

     operands match.

     If an operand matches, we modify the_insn or opcode appropriately,

     and do a "continue".  If an operand fails to match, we "break".  */

  if (insn->args[0] != '\0')

    /* Prime the pump.  */

    s = parse_operand (s,

                       &operand,

                       (insn->args[0] == 'I') ||

                       (strcmp(insn->name, "l.nop") == 0),

                       'r' == insn->args[0]);

  for (args = insn->args;; ++args)

    {

#if DEBUG

      printf ("  args = %s\n", args);

#endif

      switch (*args)

        {

        case '\0':    /* End of args.  */

          /* We have have 0 args, do the bazoooka!  */

          if (args == insn->args)

            encode (insn, &opcode, 0, 0);

          if (*s == '\0')

            {

              /* We are truly done.  */

              the_insn.opcode = opcode;

              if (check_invalid_opcode (opcode))

                as_bad (_("instruction not allowed: %s"), str);

              return;

            }

          as_bad (_("too many operands: %s"), s);

          break;

        case ',':   /* Must match a comma.  */

          if (*s++ == ',')

            {

              reloc = BFD_RELOC_NONE;

              /* Parse next operand.  */

              s = parse_operand (s, &operand, args[1] == 'I', 'r' == args[1]);

#if DEBUG

              printf ("    ',' case: operand->X_add_number = %d, *args = %s, *s = %s\n",

                      (int) operand.X_add_number, args, s);

#endif

              continue;

            }

          break;

        case '(':   /* Must match a (.  */

          s = parse_operand (s, &operand, args[1] == 'I', 'r' == args[1]);

          continue;

        case ')':   /* Must match a ).  */

          continue;

        case 'r':   /* A general register.  */

          args++;

          if (operand.X_op != O_register)

            break;    /* Only registers.  */

#if DEBUG

          printf("   (operand.X_add_symbol == 0)=%d",

                 (operand.X_add_symbol == NULL));

          printf("   (operand.X_op_symbol(%x) == 0)=%d",

                 (unsigned int)operand.X_op_symbol,

                 (operand.X_op_symbol == NULL));

#endif    

          know (operand.X_add_symbol == NULL);

          know (operand.X_op_symbol == NULL);

          encode (insn, &opcode, operand.X_add_number, *args);

#if DEBUG

          printf ("    r: operand->X_op = %d\n", operand.X_op);

#endif

          continue;

        default:

          if (mask_or_shift)

            {

#if DEBUG

              printf ("mask_or_shift = %d\n", mask_or_shift);

#endif

              reloc = mask_or_shift;

            }

          mask_or_shift = 0;

          if (*s == '(')

            operand.X_op = O_constant;

          else if (*s == ')')

            s += 1;

#if DEBUG

          printf ("    default case: operand->X_add_number = %d, *args = %s, *s = %s\n",(int) operand.X_add_number, args, s);

#endif

          if (operand.X_op == O_constant)

            {

            unsigned long add = operand.X_add_number;

              if (reloc == BFD_RELOC_NONE)

                {

                  bfd_vma v, mask;

                  mask = 0x3ffffff;

                  v = abs (operand.X_add_number) & ~ mask;

                  if (v)

                    as_bad (_("call/jmp target out of range (1)"));

                }

              if (reloc == BFD_RELOC_HI16)

                add = ((operand.X_add_number >> 16) & 0xffff);

              the_insn.pcrel = 0;

              encode (insn, &opcode, add, *args);

              continue;

            }

          if (reloc == BFD_RELOC_NONE)

            the_insn.reloc = BFD_RELOC_28_PCREL_S2;

          else

            the_insn.reloc = reloc;

          /* the_insn.reloc = insn->reloc;  */

#if DEBUG

          printf ("    reloc sym=%d\n", the_insn.reloc);

          printf ("    BFD_RELOC_NONE=%d\n", BFD_RELOC_NONE);

#endif

          the_insn.exp = operand;

          /*  the_insn.reloc_offset = 1;  */

          the_insn.pcrel = 1; /* Assume PC-relative jump.  */

          /* FIXME-SOON, Do we figure out whether abs later, after

             know sym val?  */

          if (reloc == BFD_RELOC_LO16 || reloc == BFD_RELOC_HI16)

            the_insn.pcrel = 0;

          if (reloc == BFD_RELOC_NONE)

            encode (insn, &opcode, operand.X_add_number, *args);

          else

            encode (insn, &opcode, 0, *args);

          continue;

        }

      /* Types or values of args don't match.  */

      as_bad (_("invalid operands"));

      return;

    }

}

char *

md_atof (int type, char * litP, int *  sizeP)

{

  return ieee_md_atof (type, litP, sizeP, TRUE);

}

/* Write out big-endian.  */

void

md_number_to_chars (char *buf, valueT val, int n)

{

  number_to_chars_bigendian (buf, val, n);

}

void

md_apply_fix (fixS * fixP, valueT * val, segT seg ATTRIBUTE_UNUSED)

{

  bfd_byte *buf;

  long insn;

  buf = (bfd_byte *) (fixP->fx_where + fixP->fx_frag->fr_literal);

#if DEBUG

  printf ("md_apply_fix *val=%x fixP->fx_r_type=%i sym=%s\n",(unsigned int)*val,

           fixP->fx_r_type, fixP->fx_addsy ? fixP->fx_addsy->bsym->name : "(none)");

#endif

  if ((fixP->fx_addsy == (symbolS *) NULL) && !fixP->fx_pcrel)

    fixP->fx_done = 1;

  switch (fixP->fx_r_type)

    {

    case BFD_RELOC_32:      /* XXXXXXXX pattern in a word.  */

#if DEBUG

      printf ("reloc_const: val=%x\n", (unsigned int) *val);

#endif

      /* If we are deleting this reloc entry, we must fill in the

               value now.  This can happen if we have a .word which is not

               resolved when it appears but is later defined.  We also need

               to fill in the value if this is an embedded PIC switch table

               entry.  */

      if (fixP->fx_done)

        md_number_to_chars ((char *) buf, *val, 4);

      break;

    case BFD_RELOC_16:      /* XXXX0000 pattern in a word.  */

#if DEBUG

      printf ("reloc_const: val=%x\n", (unsigned int)*val);

#endif

      /* If we are deleting this reloc entry, we must fill in the

         value now.  */

      gas_assert (fixP->fx_size == 2);

      if (fixP->fx_done)

              md_number_to_chars ((char *) buf, *val, 2);

      break;

    case BFD_RELOC_8:      /* XX000000 pattern in a word.  */

    case BFD_RELOC_LO16:      /* 0000XXXX pattern in a word.  */

#if DEBUG

      printf ("reloc_const: val=%x\n", (unsigned int)*val);

#endif

      break;

    case BFD_RELOC_HI16:    /* 0000XXXX pattern in a word.  */

#if DEBUG

      printf ("reloc_consth: val=%x\n", (unsigned int)*val);

#endif

      break;

    case BFD_RELOC_28_PCREL_S2:  /* 0000XXXX pattern in a word.  */

#if DEBUG

      printf("reloc_pcrel: *val=%x done=%d fixP->fx_pcrel=%i line=%i\n",

             (unsigned int) *val, fixP->fx_done, fixP->fx_pcrel, fixP->fx_line);

#endif

      if ((*val & 0x3) != 0)

        as_bad_where (fixP->fx_file, fixP->fx_line,

                      _("Branch to odd address (%lx)"), (long) *val);

      /*

       * We need to save the bits in the instruction since fixup_segment()

       * might be deleting the relocation entry (i.e., a branch within

       * the current segment).

       */

      if (! fixP->fx_done)

        break;

      /* update old instruction data */

      if (target_big_endian)

        insn = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

      else

        insn = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];

      insn |= (*val >> 2) & 0x03ffffff;

      md_number_to_chars ((char *) buf, insn, 4);

#if DEBUG

      printf("Resulting instruction: %08x\n", (unsigned int)insn);

#endif

      break;

    case BFD_RELOC_VTABLE_INHERIT:

    case BFD_RELOC_VTABLE_ENTRY:

      fixP->fx_done = 0;

      break;

    case BFD_RELOC_NONE:

    default: