/* tc-xstormy16.c -- Assembler for the Sanyo XSTORMY16.
   Copyright (C) 2000, 2001, 2002 Free Software Foundation.

   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.  */

#include <stdio.h>
#include "as.h"
#include "subsegs.h"     
#include "symcat.h"
#include "opcodes/xstormy16-desc.h"
#include "opcodes/xstormy16-opc.h"
#include "cgen.h"

/* Structure to hold all of the different components describing
   an individual instruction.  */
typedef struct
{
  const CGEN_INSN *	insn;
  const CGEN_INSN *	orig_insn;
  CGEN_FIELDS		fields;
#if CGEN_INT_INSN_P
  CGEN_INSN_INT         buffer [1];
#define INSN_VALUE(buf) (*(buf))
#else
  unsigned char         buffer [CGEN_MAX_INSN_SIZE];
#define INSN_VALUE(buf) (buf)
#endif
  char *		addr;
  fragS *		frag;
  int                   num_fixups;
  fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
  int                   indices [MAX_OPERAND_INSTANCES];
}
xstormy16_insn;

const char comment_chars[]        = ";";
const char line_comment_chars[]   = "#";
const char line_separator_chars[] = "|";
const char EXP_CHARS[]            = "eE";
const char FLT_CHARS[]            = "dD";

#define O_fptr_symbol	(O_max + 1)

#define XSTORMY16_SHORTOPTS ""
const char * md_shortopts = XSTORMY16_SHORTOPTS;

struct option md_longopts[] =
{
  {NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof (md_longopts);

int
md_parse_option (c, arg)
     int    c ATTRIBUTE_UNUSED;
     char * arg ATTRIBUTE_UNUSED;
{
  return 0;
}

void
md_show_usage (stream)
  FILE * stream;
{
  fprintf (stream, _(" XSTORMY16 specific command line options:\n"));
} 

/* The target specific pseudo-ops which we support.  */
const pseudo_typeS md_pseudo_table[] =
{
  { "word",	cons,		4 },
  { NULL, 	NULL, 		0 }
};


void
md_begin ()
{
  /* Initialize the `cgen' interface.  */
  
  /* Set the machine number and endian.  */
  gas_cgen_cpu_desc = xstormy16_cgen_cpu_open (CGEN_CPU_OPEN_MACHS, 0,
					  CGEN_CPU_OPEN_ENDIAN,
					  CGEN_ENDIAN_LITTLE,
					  CGEN_CPU_OPEN_END);
  xstormy16_cgen_init_asm (gas_cgen_cpu_desc);

  /* This is a callback from cgen to gas to parse operands.  */
  cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
}

void
md_assemble (str)
     char * str;
{
  xstormy16_insn insn;
  char *    errmsg;

  /* Initialize GAS's cgen interface for a new instruction.  */
  gas_cgen_init_parse ();

  insn.insn = xstormy16_cgen_assemble_insn
    (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
  
  if (!insn.insn)
    {
      as_bad (errmsg);
      return;
    }

  /* Doesn't really matter what we pass for RELAX_P here.  */
  gas_cgen_finish_insn (insn.insn, insn.buffer,
			CGEN_FIELDS_BITSIZE (& insn.fields), 0, NULL);
}

void 
md_operand (e)
     expressionS * e;
{
  if (*input_line_pointer != '@')
    return;

  if (strncmp (input_line_pointer+1, "fptr", 4) == 0)
    {
      input_line_pointer += 5;
      SKIP_WHITESPACE ();
      if (*input_line_pointer != '(')
	{
	  as_bad ("Expected '('");
	  goto err;
	}
      input_line_pointer++;

      expression (e);

      if (*input_line_pointer != ')')
	{
	  as_bad ("Missing ')'");
	  goto err;
	}
      input_line_pointer++;

      if (e->X_op != O_symbol)
	as_bad ("Not a symbolic expression");
      else
        e->X_op = O_fptr_symbol;
    }

  return;
 err:
  ignore_rest_of_line ();
}

/* Called while parsing data to create a fixup.
   Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */

void
xstormy16_cons_fix_new (f, where, nbytes, exp)
     fragS *f;
     int where;
     int nbytes;
     expressionS *exp;
{
  bfd_reloc_code_real_type code;
  fixS *fix;

  if (exp->X_op == O_fptr_symbol)
    {
      if (nbytes != 2)
	{
	  as_bad ("unsupported fptr fixup size %d", nbytes);
	  return;
	}
      exp->X_op = O_symbol;
      code = BFD_RELOC_XSTORMY16_FPTR16;
    }
  else if (nbytes == 1)
    code = BFD_RELOC_8;
  else if (nbytes == 2)
    code = BFD_RELOC_16;
  else if (nbytes == 4)
    code = BFD_RELOC_32;
  else
    {
      as_bad ("unsupported fixup size %d", nbytes);
      return;
    }

  fix = fix_new_exp (f, where, nbytes, exp, 0, code);
}

/* Called while parsing an instruction to create a fixup. 
   Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */

fixS *
xstormy16_cgen_record_fixup_exp (frag, where, insn, length, operand, opinfo, exp)
     fragS *              frag;
     int                  where;
     const CGEN_INSN *    insn;
     int                  length;
     const CGEN_OPERAND * operand;
     int                  opinfo;
     expressionS *        exp;
{
  fixS *fixP;
  operatorT op = exp->X_op;
  
  if (op == O_fptr_symbol)
    exp->X_op = O_symbol;

  fixP = gas_cgen_record_fixup_exp (frag, where, insn, length,
				    operand, opinfo, exp);

  if (op == O_fptr_symbol)
    {
      if (operand->type != XSTORMY16_OPERAND_IMM16)
	as_bad ("unsupported fptr fixup");
      else
	{
	  fixP->fx_r_type = BFD_RELOC_XSTORMY16_FPTR16;
	  fixP->fx_where += 2;
	}
    }

  return fixP;
}

valueT
md_section_align (segment, size)
     segT   segment;
     valueT size;
{
  int align = bfd_get_section_alignment (stdoutput, segment);
  return ((size + (1 << align) - 1) & (-1 << align));
}

symbolS *
md_undefined_symbol (name)
  char * name ATTRIBUTE_UNUSED;
{
  return 0;
}

/* Return an initial guess of the length by which a fragment must grow to
   hold a branch to reach its destination.
   Also updates fr_type/fr_subtype as necessary.

   Called just before doing relaxation.
   Any symbol that is now undefined will not become defined.
   The guess for fr_var is ACTUALLY the growth beyond fr_fix.
   Whatever we do to grow fr_fix or fr_var contributes to our returned value.
   Although it may not be explicit in the frag, pretend fr_var starts with a
   0 value.  */

int
md_estimate_size_before_relax (fragP, segment)
     fragS * fragP ATTRIBUTE_UNUSED;
     segT    segment ATTRIBUTE_UNUSED;
{
  /* No assembler relaxation is defined (or necessary) for this port.  */
  abort ();
} 

/* *fragP has been relaxed to its final size, and now needs to have
   the bytes inside it modified to conform to the new size.

   Called after relaxation is finished.
   fragP->fr_type == rs_machine_dependent.
   fragP->fr_subtype is the subtype of what the address relaxed to.  */

void
md_convert_frag (abfd, sec, fragP)
  bfd *   abfd ATTRIBUTE_UNUSED;
  segT    sec ATTRIBUTE_UNUSED;
  fragS * fragP ATTRIBUTE_UNUSED;
{
  /* No assembler relaxation is defined (or necessary) for this port.  */
  abort ();
}

/* Functions concerning relocs.  */

/* The location from which a PC relative jump should be calculated,
   given a PC relative reloc.  */

long
md_pcrel_from_section (fixP, sec)
     fixS * fixP;
     segT   sec;
{
  if (fixP->fx_addsy != (symbolS *) NULL
      && (! S_IS_DEFINED (fixP->fx_addsy)
	  || S_GET_SEGMENT (fixP->fx_addsy) != sec))
    {
      /* The symbol is undefined (or is defined but not in this section).
	 Let the linker figure it out.  */
      return 0;
    }

  return fixP->fx_frag->fr_address + fixP->fx_where;
}

/* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
   Returns BFD_RELOC_NONE if no reloc type can be found.
   *FIXP may be modified if desired.  */

bfd_reloc_code_real_type
md_cgen_lookup_reloc (insn, operand, fixP)
     const CGEN_INSN *    insn ATTRIBUTE_UNUSED;
     const CGEN_OPERAND * operand;
     fixS *               fixP;
{
  switch (operand->type)
    {
    case XSTORMY16_OPERAND_IMM2:
    case XSTORMY16_OPERAND_IMM3:
    case XSTORMY16_OPERAND_IMM3B:
    case XSTORMY16_OPERAND_IMM4:
    case XSTORMY16_OPERAND_IMM12:
    case XSTORMY16_OPERAND_HMEM8:
      return BFD_RELOC_NONE;
      
    case XSTORMY16_OPERAND_IMM8:
    case XSTORMY16_OPERAND_LMEM8:
      return fixP->fx_pcrel ? BFD_RELOC_8_PCREL : BFD_RELOC_8;
      
    case XSTORMY16_OPERAND_IMM16:
      fixP->fx_where += 2;
      return fixP->fx_pcrel ? BFD_RELOC_16_PCREL : BFD_RELOC_16;

    case XSTORMY16_OPERAND_ABS24:
      return BFD_RELOC_XSTORMY16_24;

    case XSTORMY16_OPERAND_REL8_2:
    case XSTORMY16_OPERAND_REL8_4:
      fixP->fx_pcrel = 1;
      return BFD_RELOC_8_PCREL;

    case XSTORMY16_OPERAND_REL12:
      fixP->fx_where += 2;
      /* Fall through... */
    case XSTORMY16_OPERAND_REL12A:
      fixP->fx_pcrel = 1;
      return BFD_RELOC_XSTORMY16_REL_12;

    default : /* avoid -Wall warning */
      abort ();
    }
}

/* See whether we need to force a relocation into the output file.
   This is used to force out switch and PC relative relocations when
   relaxing.  */

int
xstormy16_force_relocation (fix)
     fixS * fix;
{
  switch (fix->fx_r_type)
    {
    case BFD_RELOC_XSTORMY16_FPTR16:
    case BFD_RELOC_VTABLE_INHERIT:
    case BFD_RELOC_VTABLE_ENTRY:
      return 1;

    default:
      return 0;
    }
}

/* Return true if a relocation against a symbol may be replaced with
   a relocation against section+offset.  */

boolean
xstormy16_fix_adjustable (fixP)
   fixS * fixP;
{
  if (fixP->fx_addsy == NULL)
    return 1;
  
  /* Prevent all adjustments to global symbols. */
  if (S_IS_EXTERN (fixP->fx_addsy))
    return 0;
  
  if (S_IS_WEAK (fixP->fx_addsy))
    return 0;
  
  /* We need the symbol name for the VTABLE entries.  */
  if (   fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
      || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
    return 0;

  return ! xstormy16_force_relocation (fixP);
}

/* This is a copy of gas_cgen_md_apply_fix3, with some enhancements to
   do various things that would not be valid for all ports.  */

void
xstormy16_md_apply_fix3 (fixP, valueP, seg)
     fixS *   fixP;
     valueT * valueP;
     segT     seg ATTRIBUTE_UNUSED;
{
  char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
  valueT value;
  /* Canonical name, since used a lot.  */
  CGEN_CPU_DESC cd = gas_cgen_cpu_desc;

  /* This port has pc-relative relocs and DIFF_EXPR_OK defined, so
     it must deal with turning a BFD_RELOC_{8,16,32,64} into a
     BFD_RELOC_*_PCREL for the case of

	.word something-.
  */
  if (fixP->fx_pcrel)
    switch (fixP->fx_r_type)
      {
      case BFD_RELOC_8:
	fixP->fx_r_type = BFD_RELOC_8_PCREL;
	break;
      case BFD_RELOC_16:
	fixP->fx_r_type = BFD_RELOC_16_PCREL;
	break;
      case BFD_RELOC_32:
	fixP->fx_r_type = BFD_RELOC_32_PCREL;
	break;
      case BFD_RELOC_64:
	fixP->fx_r_type = BFD_RELOC_64_PCREL;
	break;
      default:
	break;
      }
  
  /* FIXME FIXME FIXME: The value we are passed in *valuep includes
     the symbol values.  Since we are using BFD_ASSEMBLER, if we are
     doing this relocation the code in write.c is going to call
     bfd_install_relocation, which is also going to use the symbol
     value.  That means that if the reloc is fully resolved we want to
     use *valuep since bfd_install_relocation is not being used.
     However, if the reloc is not fully resolved we do not want to use
     *valuep, and must use fx_offset instead.  However, if the reloc
     is PC relative, we do want to use *valuep since it includes the
     result of md_pcrel_from.  This is confusing.  */

  if (fixP->fx_addsy == (symbolS *) NULL)
    {
      value = *valueP;
      fixP->fx_done = 1;
    }
  else if (fixP->fx_pcrel)
    value = *valueP;
  else
    {
      value = fixP->fx_offset;
      if (fixP->fx_subsy != (symbolS *) NULL)
	{
	  if (S_GET_SEGMENT (fixP->fx_subsy) == absolute_section)
	    value -= S_GET_VALUE (fixP->fx_subsy);
	  else
	    {
	      /* We don't actually support subtracting a symbol.  */
	      as_bad_where (fixP->fx_file, fixP->fx_line,
			    _("expression too complex"));
	    }
	}
    }

  if ((int) fixP->fx_r_type >= (int) BFD_RELOC_UNUSED)
    {
      int opindex = (int) fixP->fx_r_type - (int) BFD_RELOC_UNUSED;
      const CGEN_OPERAND *operand = cgen_operand_lookup_by_num (cd, opindex);
      const char *errmsg;
      bfd_reloc_code_real_type reloc_type;
      CGEN_FIELDS *fields = alloca (CGEN_CPU_SIZEOF_FIELDS (cd));
      const CGEN_INSN *insn = fixP->fx_cgen.insn;

      /* If the reloc has been fully resolved finish the operand here.  */
      /* FIXME: This duplicates the capabilities of code in BFD.  */
      if (fixP->fx_done)
	{
	  CGEN_CPU_SET_FIELDS_BITSIZE (cd) (fields, CGEN_INSN_BITSIZE (insn));
	  CGEN_CPU_SET_VMA_OPERAND (cd) (cd, opindex, fields, (bfd_vma) value);

#if CGEN_INT_INSN_P
	  {
	    CGEN_INSN_INT insn_value =
	      cgen_get_insn_value (cd, where, CGEN_INSN_BITSIZE (insn));

	    /* ??? 0 is passed for `pc'.  */
	    errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
						   &insn_value, (bfd_vma) 0);
	    cgen_put_insn_value (cd, where, CGEN_INSN_BITSIZE (insn),
				 insn_value);
	  }
#else
	  /* ??? 0 is passed for `pc'.  */
	  errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields, where,
						 (bfd_vma) 0);
#endif
	  if (errmsg)
	    as_bad_where (fixP->fx_file, fixP->fx_line, "%s", errmsg);
	}

      if (fixP->fx_done)
	return;

      /* The operand isn't fully resolved.  Determine a BFD reloc value
	 based on the operand information and leave it to
	 bfd_install_relocation.  Note that this doesn't work when
	 partial_inplace == false.  */

      reloc_type = md_cgen_lookup_reloc (insn, operand, fixP);
      if (reloc_type != BFD_RELOC_NONE)
	{
	  fixP->fx_r_type = reloc_type;
	}
      else
	{
	  as_bad_where (fixP->fx_file, fixP->fx_line,
			_("unresolved expression that must be resolved"));
	  fixP->fx_done = 1;
	  return;
	}
    }
  else if (fixP->fx_done)
    {
      /* We're finished with this fixup.  Install it because
	 bfd_install_relocation won't be called to do it.  */
      switch (fixP->fx_r_type)
	{
	case BFD_RELOC_8:
	  md_number_to_chars (where, value, 1);
	  break;
	case BFD_RELOC_16:
	  md_number_to_chars (where, value, 2);
	  break;
	case BFD_RELOC_32:
	  md_number_to_chars (where, value, 4);
	  break;
	case BFD_RELOC_64:
	  md_number_to_chars (where, value, 8);
	  break;
	default:
	  as_bad_where (fixP->fx_file, fixP->fx_line,
			_("internal error: can't install fix for reloc type %d (`%s')"),
			fixP->fx_r_type, bfd_get_reloc_code_name (fixP->fx_r_type));
	  break;
	}
    }
  else
    {
      /* bfd_install_relocation will be called to finish things up.  */
    }

  /* This is a RELA port.  Thus, it does not need to store a
     value if it is going to make a reloc.  What's more, when
     assembling a line like
     
     .byte global-0x7f00
     
     we'll get a spurious error message if we try to stuff 0x7f00 into
     the byte.  */
  if (! fixP->fx_done)
    *valueP = 0;

  /* Tuck `value' away for use by tc_gen_reloc.
     See the comment describing fx_addnumber in write.h.
     This field is misnamed (or misused :-).  */
  fixP->fx_addnumber = value;
}


/* Write a value out to the object file, using the appropriate endianness.  */

void
md_number_to_chars (buf, val, n)
     char * buf;
     valueT val;
     int    n;
{
  number_to_chars_littleendian (buf, val, n);
}

/* Turn a string in input_line_pointer into a floating point constant of type
   type, and store the appropriate bytes in *litP.  The number of LITTLENUMS
   emitted is stored in *sizeP .  An error message is returned, or NULL on OK.
*/

/* Equal to MAX_PRECISION in atof-ieee.c */
#define MAX_LITTLENUMS 6

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

   /* FIXME: Some targets allow other format chars for bigger sizes here.  */

    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);

  *sizeP = prec * sizeof (LITTLENUM_TYPE);
  /* This loops outputs the LITTLENUMs in REVERSE order; in accord with
     the littleendianness of the processor.  */
  for (wordP = words + prec - 1; prec--;)
    {
      md_number_to_chars (litP, (valueT) (*wordP--), sizeof (LITTLENUM_TYPE));
      litP += sizeof (LITTLENUM_TYPE);
    }
     
  return 0;
}