/* Adapteva epiphany opcode support.  -*- C -*-

   Copyright 2011 Free Software Foundation, Inc.

   Contributed by Embecosm on behalf of Adapteva, Inc.

   This file is part of the GNU Binutils and of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

/*
   Each section is delimited with start and end markers.

   <arch>-opc.h additions use: "-- opc.h"
   <arch>-opc.c additions use: "-- opc.c"
   <arch>-asm.c additions use: "-- asm.c"
   <arch>-dis.c additions use: "-- dis.c"
   <arch>-ibd.h additions use: "-- ibd.h".  */

/* -- opc.h */

/* enumerate relaxation types for gas. */
typedef enum epiphany_relax_types
{
  EPIPHANY_RELAX_NONE=0,
  EPIPHANY_RELAX_NEED_RELAXING,

  EPIPHANY_RELAX_BRANCH_SHORT,	/* Fits into +127..-128 */
  EPIPHANY_RELAX_BRANCH_LONG,	/* b/bl/b<cond> +-2*16 */

  EPIPHANY_RELAX_ARITH_SIMM3,	/* add/sub -7..3 */
  EPIPHANY_RELAX_ARITH_SIMM11,	/* add/sub -2**11-1 .. 2**10-1 */

  EPIPHANY_RELAX_MOV_IMM8,		/* mov r,imm8 */
  EPIPHANY_RELAX_MOV_IMM16,	/* mov r,imm16 */

  EPIPHANY_RELAX_LDST_IMM3,	/* (ldr|str)* r,[r,disp3] */
  EPIPHANY_RELAX_LDST_IMM11	/* (ldr|str)* r,[r,disp11] */

} EPIPHANY_RELAX_TYPES;

/* Override disassembly hashing... */

/* Can only depend on instruction having 4 decode bits which gets us to the
   major groups of 16/32 instructions. */
#undef CGEN_DIS_HASH_SIZE
#if 1

/* hash code on the 4 LSBs */
#define CGEN_DIS_HASH_SIZE 16

#define CGEN_DIS_HASH(buf, value) ((*buf) & 0xf)
#else
#define CGEN_DIS_HASH_SIZE 1
#define CGEN_DIS_HASH(buf, value) 0
#endif

extern const char * parse_shortregs (CGEN_CPU_DESC cd,
				     const char ** strp,
				     CGEN_KEYWORD * keywords,
				     long * valuep);

extern const char * parse_branch_addr (CGEN_CPU_DESC cd,
				       const char ** strp,
				       int opindex,
				       int opinfo,
				       enum cgen_parse_operand_result * resultp,
				       bfd_vma *valuep);

/* Allows reason codes to be output when assembler errors occur.  */
#define CGEN_VERBOSE_ASSEMBLER_ERRORS


/* -- opc.c */



/* -- asm.c */
const char *
parse_shortregs (CGEN_CPU_DESC cd,
		 const char ** strp,
		 CGEN_KEYWORD * keywords,
		 long * regno)
{
  const char * errmsg;

  /* Parse register.  */
  errmsg = cgen_parse_keyword (cd, strp, keywords, regno);

  if (errmsg)
    return errmsg;

  if (*regno > 7)
    errmsg = _("register unavailable for short instructions");

  return errmsg;
}

static const char * parse_simm_not_reg (CGEN_CPU_DESC, const char **, int,
					long *);

static const char *
parse_uimm_not_reg (CGEN_CPU_DESC cd,
		    const char ** strp,
		    int opindex,
		    unsigned long * valuep)
{
  long * svalp = (void *) valuep;
  return parse_simm_not_reg (cd, strp, opindex, svalp);
}

/* Handle simm3/simm11/imm3/imm12.  */

static const char *
parse_simm_not_reg (CGEN_CPU_DESC cd,
		   const char ** strp,
		   int opindex,
		   long * valuep)
{
  const char * errmsg;

  int   sign = 0;
  int   bits = 0;

  switch (opindex)
    {
    case EPIPHANY_OPERAND_SIMM3:
      sign = 1; bits = 3; break;
    case EPIPHANY_OPERAND_SIMM11:
      sign = 1; bits = 11; break;
    case EPIPHANY_OPERAND_DISP3:
      sign = 0; bits = 3; break;
    case EPIPHANY_OPERAND_DISP11:
      /* Load/store displacement is a sign-magnitude 12 bit value.  */
      sign = 0; bits = 11; break;
    }

  /* First try to parse as a register name and reject the operand.  */
  errmsg = cgen_parse_keyword (cd, strp, & epiphany_cgen_opval_gr_names,valuep);
  if (!errmsg)
    return _("register name used as immediate value");

  errmsg = (sign ? cgen_parse_signed_integer (cd, strp, opindex, valuep)
	    : cgen_parse_unsigned_integer (cd, strp, opindex,
					  (unsigned long *) valuep));
  if (errmsg)
    return errmsg;

  if (sign)
    errmsg = cgen_validate_signed_integer (*valuep,
					  -((1L << bits) - 1), (1 << (bits - 1)) - 1);
  else
    errmsg = cgen_validate_unsigned_integer (*valuep, 0, (1L << bits) - 1);

  return errmsg;
}

static const char *
parse_postindex (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
		 const char ** strp,
		 int opindex ATTRIBUTE_UNUSED,
		 unsigned long *valuep)
{
  if (**strp == '#')
    ++*strp;			/* Skip leading hashes.  */

  if (**strp == '-')
    {
      *valuep = 1;
      ++*strp;
    }
  else if (**strp == '+')
    {
      *valuep = 0;
      ++*strp;
    }
  else
    *valuep = 0;

  return NULL;
}

static const char *
parse_imm8 (CGEN_CPU_DESC cd,
	    const char ** strp,
	    int opindex,
	    bfd_reloc_code_real_type code,
	    enum cgen_parse_operand_result * result_type,
	    bfd_vma * valuep)
{
  const char * errmsg;
  enum cgen_parse_operand_result rt;
  long dummyval;

  if (!result_type)
    result_type = &rt;

  code = BFD_RELOC_NONE;

  if (!cgen_parse_keyword (cd, strp, &epiphany_cgen_opval_gr_names, &dummyval)
      || !cgen_parse_keyword (cd, strp, &epiphany_cgen_opval_cr_names,
			      &dummyval))
    /* Don't treat "mov ip,ip" as a move-immediate.  */
    return _("register source in immediate move");

  errmsg = cgen_parse_address (cd, strp, opindex, code, result_type, valuep);
  if (errmsg)
    return errmsg;

  if (*result_type == CGEN_PARSE_OPERAND_RESULT_NUMBER)
    errmsg = cgen_validate_unsigned_integer (*valuep, 0, 0xff);
  else
    errmsg = _("byte relocation unsupported");

  *valuep &= 0xff;
  return errmsg;
}

static const char * MISSING_CLOSE_PARENTHESIS = N_("missing `)'");

static const char *
parse_imm16 (CGEN_CPU_DESC cd,
	     const char ** strp,
	     int opindex,
	     bfd_reloc_code_real_type code ATTRIBUTE_UNUSED,
	     enum cgen_parse_operand_result * result_type,
	     bfd_vma * valuep)
{
  const char * errmsg;
  enum cgen_parse_operand_result rt;
  long dummyval;

  if (!result_type)
    result_type = &rt;

  if (strncasecmp (*strp, "%high(", 6) == 0)
    {
      *strp += 6;
      errmsg = cgen_parse_address (cd, strp, opindex, BFD_RELOC_EPIPHANY_HIGH,
				   result_type, valuep);
      if (**strp != ')')
	return MISSING_CLOSE_PARENTHESIS;
      ++*strp;
      *valuep >>= 16;
    }
  else if (strncasecmp (*strp, "%low(", 5) == 0)
    {
      *strp += 5;
      errmsg = cgen_parse_address (cd, strp, opindex, BFD_RELOC_EPIPHANY_LOW,
				   result_type, valuep);
      if (**strp != ')')
	return MISSING_CLOSE_PARENTHESIS;
      ++*strp;
    }
  else if (!cgen_parse_keyword (cd, strp, &epiphany_cgen_opval_gr_names,
				&dummyval)
	   || !cgen_parse_keyword (cd, strp, &epiphany_cgen_opval_cr_names,
				   &dummyval))
    /* Don't treat "mov ip,ip" as a move-immediate.  */
    return _("register source in immediate move");
  else
    errmsg = cgen_parse_address (cd, strp, opindex, BFD_RELOC_16,
				 result_type, valuep);

  if (!errmsg && result_type == CGEN_PARSE_OPERAND_RESULT_NUMBER)
    errmsg = cgen_validate_unsigned_integer (*valuep, 0, 0xffff);

  *valuep &= 0xffff;
  return errmsg;
}

const char *
parse_branch_addr (CGEN_CPU_DESC cd,
		   const char ** strp,
		   int opindex,
		   int opinfo ATTRIBUTE_UNUSED,
		   enum cgen_parse_operand_result * resultp ATTRIBUTE_UNUSED,
		   bfd_vma *valuep ATTRIBUTE_UNUSED)
{
  const char * errmsg;
  enum cgen_parse_operand_result result_type;
  bfd_reloc_code_real_type code = BFD_RELOC_NONE;
  bfd_vma value;

  switch (opindex)
    {
    case EPIPHANY_OPERAND_SIMM24:
      code = BFD_RELOC_EPIPHANY_SIMM24;
      break;

    case EPIPHANY_OPERAND_SIMM8:
      code = BFD_RELOC_EPIPHANY_SIMM8;
      break;

    default:
      errmsg = _("ABORT: unknown operand");
      return errmsg;
    }

  errmsg = cgen_parse_address (cd, strp, opindex, code,
			       &result_type, &value);
  if (errmsg == NULL)
    {
      if (result_type == CGEN_PARSE_OPERAND_RESULT_NUMBER)
	{
	  /* Act as if we had done a PC-relative branch, ala .+num.  */
	  char buf[20];
	  const char * bufp = (const char *) buf;

	  sprintf (buf, ".+%ld", (long) value);
	  errmsg = cgen_parse_address (cd, &bufp, opindex, code, &result_type,
				       &value);
	}

      if (result_type == CGEN_PARSE_OPERAND_RESULT_QUEUED)
	{
	  /* This will happen for things like (s2-s1) where s2 and s1
	     are labels.  */
	  /* Nothing further to be done.  */
	}
      else
	errmsg = _("Not a pc-relative address.");
    }
  return errmsg;
}

/* -- dis.c */

#define CGEN_PRINT_INSN epiphany_print_insn

static int
epiphany_print_insn (CGEN_CPU_DESC cd, bfd_vma pc, disassemble_info *info)
{
  bfd_byte buf[CGEN_MAX_INSN_SIZE];
  int buflen;
  int status;

  info->bytes_per_chunk = 2;

  /* Attempt to read the base part of the insn.  */
  info->bytes_per_line = buflen = cd->base_insn_bitsize / 8;
  status = (*info->read_memory_func) (pc, buf, buflen, info);

  /* Try again with the minimum part, if min < base.  */
  if (status != 0 && (cd->min_insn_bitsize < cd->base_insn_bitsize))
    {
      info->bytes_per_line = buflen = cd->min_insn_bitsize / 8;
      status = (*info->read_memory_func) (pc, buf, buflen, info);
    }

  if (status != 0)
    {
      (*info->memory_error_func) (status, pc, info);
      return -1;
    }

  return print_insn (cd, pc, info, buf, buflen);
}


static void
print_postindex (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
		 void * dis_info,
		 long value,
		 unsigned int attrs ATTRIBUTE_UNUSED,
		 bfd_vma pc ATTRIBUTE_UNUSED,
		 int length ATTRIBUTE_UNUSED)
{
  disassemble_info *info = (disassemble_info *) dis_info;
  (*info->fprintf_func) (info->stream, value ? "-" : "+");
}

static void
print_simm_not_reg (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
		    void * dis_info,
		    long value,
		    unsigned int attrs ATTRIBUTE_UNUSED,
		    bfd_vma pc ATTRIBUTE_UNUSED,
		    int length ATTRIBUTE_UNUSED)
{
  print_address (cd, dis_info, value, attrs, pc, length);
}

static void
print_uimm_not_reg (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
		    void * dis_info,
		    unsigned long value,
		    unsigned int attrs ATTRIBUTE_UNUSED,
		    bfd_vma pc ATTRIBUTE_UNUSED,
		    int length ATTRIBUTE_UNUSED)
{
  disassemble_info *info = (disassemble_info *)dis_info;

  if (value & 0x800)
    (*info->fprintf_func) (info->stream, "-");

  value &= 0x7ff;
  print_address (cd, dis_info, value, attrs, pc, length);
}


/* -- */