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/* Intel 387 floating point stuff.

   Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2001

   Free Software Foundation, Inc.

   This file is part 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 2 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., 59 Temple Place - Suite 330,

   Boston, MA 02111-1307, USA.  */

#include "defs.h"

#include "frame.h"

#include "inferior.h"

#include "language.h"

#include "value.h"

#include "gdbcore.h"

#include "floatformat.h"

#include "regcache.h"

#include "gdb_assert.h"

/* FIXME: Eliminate the next two functions when we have the time to

   change all the callers.  */

void i387_to_double (char *from, char *to);

void double_to_i387 (char *from, char *to);

void

i387_to_double (char *from, char *to)

{

  floatformat_to_double (&floatformat_i387_ext, from, (double *) to);

}

void

double_to_i387 (char *from, char *to)

{

  floatformat_from_double (&floatformat_i387_ext, (double *) from, to);

}

/* FIXME: The functions on this page are used by the old `info float'

   implementations that a few of the i386 targets provide.  These

   functions should be removed if all of these have been converted to

   use the generic implementation based on the new register file

   layout.  */

static void print_387_control_bits (unsigned int control);

static void print_387_status_bits (unsigned int status);

static void

print_387_control_bits (unsigned int control)

{

  switch ((control >> 8) & 3)

    {

    case 0:

      puts_unfiltered (" 24 bit; ");

      break;

    case 1:

      puts_unfiltered (" (bad); ");

      break;

    case 2:

      puts_unfiltered (" 53 bit; ");

      break;

    case 3:

      puts_unfiltered (" 64 bit; ");

      break;

    }

  switch ((control >> 10) & 3)

    {

    case 0:

      puts_unfiltered ("NEAR; ");

      break;

    case 1:

      puts_unfiltered ("DOWN; ");

      break;

    case 2:

      puts_unfiltered ("UP; ");

      break;

    case 3:

      puts_unfiltered ("CHOP; ");

      break;

    }

  if (control & 0x3f)

    {

      puts_unfiltered ("mask");

      if (control & 0x0001)

        puts_unfiltered (" INVAL");

      if (control & 0x0002)

        puts_unfiltered (" DENOR");

      if (control & 0x0004)

        puts_unfiltered (" DIVZ");

      if (control & 0x0008)

        puts_unfiltered (" OVERF");

      if (control & 0x0010)

        puts_unfiltered (" UNDER");

      if (control & 0x0020)

        puts_unfiltered (" LOS");

      puts_unfiltered (";");

    }

  if (control & 0xe080)

    warning ("\nreserved bits on: %s",

             local_hex_string (control & 0xe080));

}

void

print_387_control_word (unsigned int control)

{

  printf_filtered ("control %s:", local_hex_string(control & 0xffff));

  print_387_control_bits (control);

  puts_unfiltered ("\n");

}

static void

print_387_status_bits (unsigned int status)

{

  printf_unfiltered (" flags %d%d%d%d; ",

                     (status & 0x4000) != 0,

                     (status & 0x0400) != 0,

                     (status & 0x0200) != 0,

                     (status & 0x0100) != 0);

  printf_unfiltered ("top %d; ", (status >> 11) & 7);

  if (status & 0xff)

    {

      puts_unfiltered ("excep");

      if (status & 0x0001) puts_unfiltered (" INVAL");

      if (status & 0x0002) puts_unfiltered (" DENOR");

      if (status & 0x0004) puts_unfiltered (" DIVZ");

      if (status & 0x0008) puts_unfiltered (" OVERF");

      if (status & 0x0010) puts_unfiltered (" UNDER");

      if (status & 0x0020) puts_unfiltered (" LOS");

      if (status & 0x0040) puts_unfiltered (" STACK");

    }

}

void

print_387_status_word (unsigned int status)

{

  printf_filtered ("status %s:", local_hex_string (status & 0xffff));

  print_387_status_bits (status);

  puts_unfiltered ("\n");

}

/* Implement the `info float' layout based on the register definitions

   in `tm-i386.h'.  */

/* Print the floating point number specified by RAW.  */

static void

print_i387_value (char *raw)

{

  DOUBLEST value;

  int len = TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT;

  char *tmp = alloca (len);

  /* This code only works on targets where ... */

  gdb_assert (TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext);

  /* Take care of the padding.  FP reg is 80 bits.  The same value in

     memory is 96 bits.  */

  gdb_assert (FPU_REG_RAW_SIZE < len);

  memcpy (&tmp, raw, FPU_REG_RAW_SIZE);

  memset (&tmp + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE);

  /* Extract the value as a DOUBLEST.  */

  /* Use extract_floating() rather than floatformat_to_doublest().

     The latter is lossy in nature.  Once GDB gets a host/target

     independent and non-lossy FP it will become possible to bypass

     extract_floating() and call floatformat*() directly.  Note also

     the assumptions about TARGET_LONG_DOUBLE above.  */

  value = extract_floating (tmp, len);

  /* We try to print 19 digits.  The last digit may or may not contain

     garbage, but we'd better print one too many.  We need enough room

     to print the value, 1 position for the sign, 1 for the decimal

     point, 19 for the digits and 6 for the exponent adds up to 27.  */

#ifdef PRINTF_HAS_LONG_DOUBLE

  printf_filtered (" %-+27.19Lg", (long double) value);

#else

  printf_filtered (" %-+27.19g", (double) value);

#endif

}

/* Print the classification for the register contents RAW.  */

static void

print_i387_ext (unsigned char *raw)

{

  int sign;

  int integer;

  unsigned int exponent;

  unsigned long fraction[2];

  sign = raw[9] & 0x80;

  integer = raw[7] & 0x80;

  exponent = (((raw[9] & 0x7f) << 8) | raw[8]);

  fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);

  fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)

                 | (raw[5] << 8) | raw[4]);

  if (exponent == 0x7fff && integer)

    {

      if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000)

        /* Infinity.  */

        printf_filtered (" %cInf", (sign ? '-' : '+'));

      else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000)

        /* Real Indefinite (QNaN).  */

        puts_unfiltered (" Real Indefinite (QNaN)");

      else if (fraction[1] & 0x40000000)

        /* QNaN.  */

        puts_filtered (" QNaN");

      else

        /* SNaN.  */

        puts_filtered (" SNaN");

    }

  else if (exponent < 0x7fff && exponent > 0x0000 && integer)

    /* Normal.  */

    print_i387_value (raw);

  else if (exponent == 0x0000)

    {

      /* Denormal or zero.  */

      print_i387_value (raw);

      if (integer)

        /* Pseudo-denormal.  */

        puts_filtered (" Pseudo-denormal");

      else if (fraction[0] || fraction[1])

        /* Denormal.  */

        puts_filtered (" Denormal");

    }

  else

    /* Unsupported.  */

    puts_filtered (" Unsupported");

}

/* Print the status word STATUS.  */

static void

print_i387_status_word (unsigned int status)

{

  printf_filtered ("Status Word:         %s",

                   local_hex_string_custom (status, "04"));

  puts_filtered ("  ");

  printf_filtered (" %s", (status & 0x0001) ? "IE" : "  ");

  printf_filtered (" %s", (status & 0x0002) ? "DE" : "  ");

  printf_filtered (" %s", (status & 0x0004) ? "ZE" : "  ");

  printf_filtered (" %s", (status & 0x0008) ? "OE" : "  ");

  printf_filtered (" %s", (status & 0x0010) ? "UE" : "  ");

  printf_filtered (" %s", (status & 0x0020) ? "PE" : "  ");

  puts_filtered ("  ");

  printf_filtered (" %s", (status & 0x0080) ? "ES" : "  ");

  puts_filtered ("  ");

  printf_filtered (" %s", (status & 0x0040) ? "SF" : "  ");

  puts_filtered ("  ");

  printf_filtered (" %s", (status & 0x0100) ? "C0" : "  ");

  printf_filtered (" %s", (status & 0x0200) ? "C1" : "  ");

  printf_filtered (" %s", (status & 0x0400) ? "C2" : "  ");

  printf_filtered (" %s", (status & 0x4000) ? "C3" : "  ");

  puts_filtered ("\n");

  printf_filtered ("                       TOP: %d\n", ((status >> 11) & 7));

}

/* Print the control word CONTROL.  */

static void

print_i387_control_word (unsigned int control)

{

  printf_filtered ("Control Word:        %s",

                   local_hex_string_custom (control, "04"));

  puts_filtered ("  ");

  printf_filtered (" %s", (control & 0x0001) ? "IM" : "  ");

  printf_filtered (" %s", (control & 0x0002) ? "DM" : "  ");

  printf_filtered (" %s", (control & 0x0004) ? "ZM" : "  ");

  printf_filtered (" %s", (control & 0x0008) ? "OM" : "  ");

  printf_filtered (" %s", (control & 0x0010) ? "UM" : "  ");

  printf_filtered (" %s", (control & 0x0020) ? "PM" : "  ");

  puts_filtered ("\n");

  puts_filtered ("                       PC: ");

  switch ((control >> 8) & 3)

    {

    case 0:

      puts_filtered ("Single Precision (24-bits)\n");

      break;

    case 1:

      puts_filtered ("Reserved\n");

      break;

    case 2:

      puts_filtered ("Double Precision (53-bits)\n");

      break;

    case 3:

      puts_filtered ("Extended Precision (64-bits)\n");

      break;

    }

  puts_filtered ("                       RC: ");

  switch ((control >> 10) & 3)

    {

    case 0:

      puts_filtered ("Round to nearest\n");

      break;

    case 1:

      puts_filtered ("Round down\n");

      break;

    case 2:

      puts_filtered ("Round up\n");

      break;

    case 3:

      puts_filtered ("Round toward zero\n");

      break;

    }

}

/* Print out the i387 floating poin state.  */

void

i387_float_info (void)

{

  unsigned int fctrl;

  unsigned int fstat;

  unsigned int ftag;

  unsigned int fiseg;

  unsigned int fioff;

  unsigned int foseg;

  unsigned int fooff;

  unsigned int fop;

  int fpreg;

  int top;

  fctrl = read_register (FCTRL_REGNUM);

  fstat = read_register (FSTAT_REGNUM);

  ftag  = read_register (FTAG_REGNUM);

  fiseg = read_register (FCS_REGNUM);

  fioff = read_register (FCOFF_REGNUM);

  foseg = read_register (FDS_REGNUM);

  fooff = read_register (FDOFF_REGNUM);

  fop   = read_register (FOP_REGNUM);

  top = ((fstat >> 11) & 7);

  for (fpreg = 7; fpreg >= 0; fpreg--)

    {

      unsigned char raw[FPU_REG_RAW_SIZE];

      int tag = (ftag >> (fpreg * 2)) & 3;

      int i;

      printf_filtered ("%sR%d: ", fpreg == top ? "=>" : "  ", fpreg);

      switch (tag)

        {

        case 0:

          puts_filtered ("Valid   ");

          break;

        case 1:

          puts_filtered ("Zero    ");

          break;

        case 2:

          puts_filtered ("Special ");

          break;

        case 3:

          puts_filtered ("Empty   ");

          break;

        }

      read_register_gen ((fpreg + 8 - top) % 8 + FP0_REGNUM, raw);

      puts_filtered ("0x");

      for (i = 9; i >= 0; i--)

        printf_filtered ("%02x", raw[i]);

      if (tag != 3)

        print_i387_ext (raw);

      puts_filtered ("\n");

    }

  puts_filtered ("\n");

  print_i387_status_word (fstat);

  print_i387_control_word (fctrl);

  printf_filtered ("Tag Word:            %s\n",

                   local_hex_string_custom (ftag, "04"));

  printf_filtered ("Instruction Pointer: %s:",

                   local_hex_string_custom (fiseg, "02"));

  printf_filtered ("%s\n", local_hex_string_custom (fioff, "08"));

  printf_filtered ("Operand Pointer:     %s:",

                   local_hex_string_custom (foseg, "02"));

  printf_filtered ("%s\n", local_hex_string_custom (fooff, "08"));

  printf_filtered ("Opcode:              %s\n",

                   local_hex_string_custom (fop ? (fop | 0xd800) : 0, "04"));

}