Subversion Repositories openrisc_2011-10-31

/* Disassembler code for CRX.

   Copyright 2004, 2005, 2006, 2007 Free Software Foundation, Inc.

   Contributed by Tomer Levi, NSC, Israel.

   Written by Tomer Levi.

   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 program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "dis-asm.h"

#include "sysdep.h"

#include "opcode/crx.h"

/* String to print when opcode was not matched.  */

#define ILLEGAL "illegal"

  /* Escape to 16-bit immediate.  */

#define ESCAPE_16_BIT  0xE

/* Extract 'n_bits' from 'a' starting from offset 'offs'.  */

#define EXTRACT(a, offs, n_bits)            \

  (n_bits == 32 ? (((a) >> (offs)) & 0xffffffffL)   \

  : (((a) >> (offs)) & ((1 << (n_bits)) -1)))

/* Set Bit Mask - a mask to set all bits starting from offset 'offs'.  */

#define SBM(offs)  ((((1 << (32 - offs)) -1) << (offs)))

typedef unsigned long dwordU;

typedef unsigned short wordU;

typedef struct

{

  dwordU val;

  int nbits;

} parameter;

/* Structure to hold valid 'cinv' instruction options.  */

typedef struct

  {

    /* Cinv printed string.  */

    char *str;

    /* Value corresponding to the string.  */

    unsigned int value;

  }

cinv_entry;

/* CRX 'cinv' options.  */

const cinv_entry crx_cinvs[] =

{

  {"[i]", 2}, {"[i,u]", 3}, {"[d]", 4}, {"[d,u]", 5},

  {"[d,i]", 6}, {"[d,i,u]", 7}, {"[b]", 8},

  {"[b,i]", 10}, {"[b,i,u]", 11}, {"[b,d]", 12},

  {"[b,d,u]", 13}, {"[b,d,i]", 14}, {"[b,d,i,u]", 15}

};

/* Enum to distinguish different registers argument types.  */

typedef enum REG_ARG_TYPE

  {

    /* General purpose register (r<N>).  */

    REG_ARG = 0,

    /* User register (u<N>).  */

    USER_REG_ARG,

    /* CO-Processor register (c<N>).  */

    COP_ARG,

    /* CO-Processor special register (cs<N>).  */

    COPS_ARG

  }

REG_ARG_TYPE;

/* Number of valid 'cinv' instruction options.  */

int NUMCINVS = ((sizeof crx_cinvs)/(sizeof crx_cinvs[0]));

/* Current opcode table entry we're disassembling.  */

const inst *instruction;

/* Current instruction we're disassembling.  */

ins currInsn;

/* The current instruction is read into 3 consecutive words.  */

wordU words[3];

/* Contains all words in appropriate order.  */

ULONGLONG allWords;

/* Holds the current processed argument number.  */

int processing_argument_number;

/* Nonzero means a CST4 instruction.  */

int cst4flag;

/* Nonzero means the instruction's original size is

   incremented (escape sequence is used).  */

int size_changed;

static int get_number_of_operands (void);

static argtype getargtype     (operand_type);

static int getbits            (operand_type);

static char *getregname       (reg);

static char *getcopregname    (copreg, reg_type);

static char * getprocregname  (int);

static char *gettrapstring    (unsigned);

static char *getcinvstring    (unsigned);

static void getregliststring  (int, char *, enum REG_ARG_TYPE);

static wordU get_word_at_PC   (bfd_vma, struct disassemble_info *);

static void get_words_at_PC   (bfd_vma, struct disassemble_info *);

static unsigned long build_mask (void);

static int powerof2           (int);

static int match_opcode       (void);

static void make_instruction  (void);

static void print_arguments   (ins *, bfd_vma, struct disassemble_info *);

static void print_arg         (argument *, bfd_vma, struct disassemble_info *);

/* Retrieve the number of operands for the current assembled instruction.  */

static int

get_number_of_operands (void)

{

  int i;

  for (i = 0; instruction->operands[i].op_type && i < MAX_OPERANDS; i++)

    ;

  return i;

}

/* Return the bit size for a given operand.  */

static int

getbits (operand_type op)

{

  if (op < MAX_OPRD)

    return crx_optab[op].bit_size;

  else

    return 0;

}

/* Return the argument type of a given operand.  */

static argtype

getargtype (operand_type op)

{

  if (op < MAX_OPRD)

    return crx_optab[op].arg_type;

  else

    return nullargs;

}

/* Given the trap index in dispatch table, return its name.

   This routine is used when disassembling the 'excp' instruction.  */

static char *

gettrapstring (unsigned int trap_index)

{

  const trap_entry *trap;

  for (trap = crx_traps; trap < crx_traps + NUMTRAPS; trap++)

    if (trap->entry == trap_index)

      return trap->name;

  return ILLEGAL;

}

/* Given a 'cinv' instruction constant operand, return its corresponding string.

   This routine is used when disassembling the 'cinv' instruction.  */

static char *

getcinvstring (unsigned int num)

{

  const cinv_entry *cinv;

  for (cinv = crx_cinvs; cinv < (crx_cinvs + NUMCINVS); cinv++)

    if (cinv->value == num)

      return cinv->str;

  return ILLEGAL;

}

/* Given a register enum value, retrieve its name.  */

char *

getregname (reg r)

{

  const reg_entry * regentry = &crx_regtab[r];

  if (regentry->type != CRX_R_REGTYPE)

    return ILLEGAL;

  else

    return regentry->name;

}

/* Given a coprocessor register enum value, retrieve its name.  */

char *

getcopregname (copreg r, reg_type type)

{

  const reg_entry * regentry;

  if (type == CRX_C_REGTYPE)

    regentry = &crx_copregtab[r];

  else if (type == CRX_CS_REGTYPE)

    regentry = &crx_copregtab[r+(cs0-c0)];

  else

    return ILLEGAL;

  return regentry->name;

}

/* Getting a processor register name.  */

static char *

getprocregname (int reg_index)

{

  const reg_entry *r;

  for (r = crx_regtab; r < crx_regtab + NUMREGS; r++)

    if (r->image == reg_index)

      return r->name;

  return "ILLEGAL REGISTER";

}

/* Get the power of two for a given integer.  */

static int

powerof2 (int x)

{

  int product, i;

  for (i = 0, product = 1; i < x; i++)

    product *= 2;

  return product;

}

/* Transform a register bit mask to a register list.  */

void

getregliststring (int mask, char *string, enum REG_ARG_TYPE core_cop)

{

  char temp_string[5];

  int i;

  string[0] = '{';

  string[1] = '\0';

  /* A zero mask means HI/LO registers.  */

  if (mask == 0)

    {

      if (core_cop == USER_REG_ARG)

        strcat (string, "ulo,uhi");

      else

        strcat (string, "lo,hi");

    }

  else

    {

      for (i = 0; i < 16; i++)

        {

          if (mask & 0x1)

            {

              switch (core_cop)

              {

              case REG_ARG:

                sprintf (temp_string, "r%d", i);

                break;

              case USER_REG_ARG:

                sprintf (temp_string, "u%d", i);

                break;

              case COP_ARG:

                sprintf (temp_string, "c%d", i);

                break;

              case COPS_ARG:

                sprintf (temp_string, "cs%d", i);

                break;

              default:

                break;

              }

              strcat (string, temp_string);

              if (mask & 0xfffe)

                strcat (string, ",");

            }

          mask >>= 1;

        }

    }

  strcat (string, "}");

}

/* START and END are relating 'allWords' struct, which is 48 bits size.

                          START|--------|END

            +---------+---------+---------+---------+

            |         |    V    |     A   |   L     |

            +---------+---------+---------+---------+

    words                 [0]       [1]       [2]       */

static parameter

makelongparameter (ULONGLONG val, int start, int end)

{

  parameter p;

  p.val = (dwordU) EXTRACT(val, 48 - end, end - start);

  p.nbits = end - start;

  return p;

}

/* Build a mask of the instruction's 'constant' opcode,

   based on the instruction's printing flags.  */

static unsigned long

build_mask (void)

{

  unsigned int print_flags;

  unsigned long mask;

  print_flags = instruction->flags & FMT_CRX;

  switch (print_flags)

    {

      case FMT_1:

        mask = 0xF0F00000;

        break;

      case FMT_2:

        mask = 0xFFF0FF00;

        break;

      case FMT_3:

        mask = 0xFFF00F00;

        break;

      case FMT_4:

        mask = 0xFFF0F000;

        break;

      case FMT_5:

        mask = 0xFFF0FFF0;

        break;

      default:

        mask = SBM(instruction->match_bits);

        break;

    }

  return mask;

}

/* Search for a matching opcode. Return 1 for success, 0 for failure.  */

static int

match_opcode (void)

{

  unsigned long mask;

  /* The instruction 'constant' opcode doewsn't exceed 32 bits.  */

  unsigned long doubleWord = (words[1] + (words[0] << 16)) & 0xffffffff;

  /* Start searching from end of instruction table.  */

  instruction = &crx_instruction[NUMOPCODES - 2];

  /* Loop over instruction table until a full match is found.  */

  while (instruction >= crx_instruction)

    {

      mask = build_mask ();

      if ((doubleWord & mask) == BIN(instruction->match, instruction->match_bits))

        return 1;

      else

        instruction--;

    }

  return 0;

}

/* Set the proper parameter value for different type of arguments.  */

static void

make_argument (argument * a, int start_bits)

{

  int inst_bit_size, total_size;

  parameter p;

  if ((instruction->size == 3) && a->size >= 16)

    inst_bit_size = 48;

  else

    inst_bit_size = 32;

  switch (a->type)

    {

    case arg_copr:

    case arg_copsr:

      p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),

                             inst_bit_size - start_bits);

      a->cr = p.val;

      break;

    case arg_r:

      p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),

                             inst_bit_size - start_bits);

      a->r = p.val;

      break;

    case arg_ic:

      p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),

                             inst_bit_size - start_bits);

      if ((p.nbits == 4) && cst4flag)

        {

          if (IS_INSN_TYPE (CMPBR_INS) && (p.val == ESCAPE_16_BIT))

            {

              /* A special case, where the value is actually stored

                 in the last 4 bits.  */

              p = makelongparameter (allWords, 44, 48);

              /* The size of the instruction should be incremented.  */

              size_changed = 1;

            }

          if (p.val == 6)

            p.val = -1;

          else if (p.val == 13)

            p.val = 48;

          else if (p.val == 5)

            p.val = -4;

          else if (p.val == 10)

            p.val = 32;

          else if (p.val == 11)

            p.val = 20;

          else if (p.val == 9)

            p.val = 16;

        }

      a->constant = p.val;

      break;

    case arg_idxr:

      a->scale = 0;

      total_size = a->size + 10;  /* sizeof(rbase + ridx + scl2) = 10.  */

      p = makelongparameter (allWords, inst_bit_size - total_size,

                             inst_bit_size - (total_size - 4));

      a->r = p.val;

      p = makelongparameter (allWords, inst_bit_size - (total_size - 4),

                             inst_bit_size - (total_size - 8));

      a->i_r = p.val;

      p = makelongparameter (allWords, inst_bit_size - (total_size - 8),

                             inst_bit_size - (total_size - 10));

      a->scale = p.val;

      p = makelongparameter (allWords, inst_bit_size - (total_size - 10),

                             inst_bit_size);

      a->constant = p.val;

      break;

    case arg_rbase:

      p = makelongparameter (allWords, inst_bit_size - (start_bits + 4),

                             inst_bit_size - start_bits);

      a->r = p.val;

      break;

    case arg_cr:

      if (a->size <= 8)

        {

          p = makelongparameter (allWords, inst_bit_size - (start_bits + 4),

                                 inst_bit_size - start_bits);

          a->r = p.val;

          /* Case for opc4 r dispu rbase.  */

          p = makelongparameter (allWords, inst_bit_size - (start_bits + 8),

                                 inst_bit_size - (start_bits + 4));

        }

      else

        {

          /* The 'rbase' start_bits is always relative to a 32-bit data type.  */

          p = makelongparameter (allWords, 32 - (start_bits + 4),

                                 32 - start_bits);

          a->r = p.val;

          p = makelongparameter (allWords, 32 - start_bits,

                                 inst_bit_size);

        }

      if ((p.nbits == 4) && cst4flag)

        {

          if (instruction->flags & DISPUW4)

            p.val *= 2;

          else if (instruction->flags & DISPUD4)

            p.val *= 4;

        }

      a->constant = p.val;

      break;

    case arg_c:

      p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),

                             inst_bit_size - start_bits);

      a->constant = p.val;

      break;

    default:

      break;

    }

}

/*  Print a single argument.  */

static void

print_arg (argument *a, bfd_vma memaddr, struct disassemble_info *info)

{

  LONGLONG longdisp, mask;

  int sign_flag = 0;

  int relative = 0;

  bfd_vma number;

  int op_index = 0;

  char string[200];

  PTR stream = info->stream;

  fprintf_ftype func = info->fprintf_func;

  switch (a->type)

    {

    case arg_copr:

      func (stream, "%s", getcopregname (a->cr, CRX_C_REGTYPE));

      break;

    case arg_copsr:

      func (stream, "%s", getcopregname (a->cr, CRX_CS_REGTYPE));

      break;

    case arg_r:

      if (IS_INSN_MNEMONIC ("mtpr") || IS_INSN_MNEMONIC ("mfpr"))

        func (stream, "%s", getprocregname (a->r));

      else

        func (stream, "%s", getregname (a->r));

      break;

    case arg_ic:

      if (IS_INSN_MNEMONIC ("excp"))

        func (stream, "%s", gettrapstring (a->constant));

      else if (IS_INSN_MNEMONIC ("cinv"))

        func (stream, "%s", getcinvstring (a->constant));

      else if (INST_HAS_REG_LIST)

        {

          REG_ARG_TYPE reg_arg_type = IS_INSN_TYPE (COP_REG_INS) ?

                                 COP_ARG : IS_INSN_TYPE (COPS_REG_INS) ?

                                 COPS_ARG : (instruction->flags & USER_REG) ?

                                 USER_REG_ARG : REG_ARG;

          if ((reg_arg_type == COP_ARG) || (reg_arg_type == COPS_ARG))

            {

                /*  Check for proper argument number.  */

                if (processing_argument_number == 2)

                  {

                    getregliststring (a->constant, string, reg_arg_type);

                    func (stream, "%s", string);

                  }

                else

                  func (stream, "$0x%lx", a->constant);

            }

          else

            {

              getregliststring (a->constant, string, reg_arg_type);

              func (stream, "%s", string);

            }

        }

      else

        func (stream, "$0x%lx", a->constant);

      break;

    case arg_idxr:

      func (stream, "0x%lx(%s,%s,%d)", a->constant, getregname (a->r),

            getregname (a->i_r), powerof2 (a->scale));

      break;

    case arg_rbase:

      func (stream, "(%s)", getregname (a->r));

      break;

    case arg_cr:

      func (stream, "0x%lx(%s)", a->constant, getregname (a->r));

      if (IS_INSN_TYPE (LD_STOR_INS_INC))

        func (stream, "+");

      break;

    case arg_c:

      /* Removed the *2 part as because implicit zeros are no more required.

         Have to fix this as this needs a bit of extension in terms of branchins.

         Have to add support for cmp and branch instructions.  */

      if (IS_INSN_TYPE (BRANCH_INS) || IS_INSN_MNEMONIC ("bal")

          || IS_INSN_TYPE (CMPBR_INS) || IS_INSN_TYPE (DCR_BRANCH_INS)

          || IS_INSN_TYPE (COP_BRANCH_INS))

        {

          relative = 1;

          longdisp = a->constant;

          longdisp <<= 1;

          switch (a->size)

            {

            case 8:

            case 16:

            case 24:

            case 32:

              mask = ((LONGLONG)1 << a->size) - 1;

              if (longdisp & ((LONGLONG)1 << a->size))

                {

                  sign_flag = 1;

                  longdisp = ~(longdisp) + 1;

                }

              a->constant = (unsigned long int) (longdisp & mask);

              break;

            default:

              func (stream,

                    "Wrong offset used in branch/bal instruction");

              break;

            }

        }

      /* For branch Neq instruction it is 2*offset + 2.  */

      else if (IS_INSN_TYPE (BRANCH_NEQ_INS))

        a->constant = 2 * a->constant + 2;

      else if (IS_INSN_TYPE (LD_STOR_INS_INC)

          || IS_INSN_TYPE (LD_STOR_INS)

          || IS_INSN_TYPE (STOR_IMM_INS)

          || IS_INSN_TYPE (CSTBIT_INS))

        {

          op_index = instruction->flags & REVERSE_MATCH ? 0 : 1;

          if (instruction->operands[op_index].op_type == abs16)

            a->constant |= 0xFFFF0000;

        }

      func (stream, "%s", "0x");

      number = (relative ? memaddr : 0)

               + (sign_flag ? -a->constant : a->constant);

      (*info->print_address_func) (number, info);

      break;

    default:

      break;

    }

}

/* Print all the arguments of CURRINSN instruction.  */

static void

print_arguments (ins *currentInsn, bfd_vma memaddr, struct disassemble_info *info)

{

  int i;

  for (i = 0; i < currentInsn->nargs; i++)

    {

      processing_argument_number = i;

      print_arg (&currentInsn->arg[i], memaddr, info);

      if (i != currentInsn->nargs - 1)

        info->fprintf_func (info->stream, ", ");

    }

}

/* Build the instruction's arguments.  */

static void

make_instruction (void)

{

  int i;

  unsigned int shift;

  for (i = 0; i < currInsn.nargs; i++)

    {

      argument a;

      memset (&a, 0, sizeof (a));