real.c

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      emul (d2, d1, v);
      break;

    case RDIV_EXPR:
#ifndef REAL_INFINITY
      if (ecmp (d2, ezero) == 0)
	{
#ifdef NANS
	enan (v, eisneg (d1) ^ eisneg (d2));
	break;
#else
	abort ();
#endif
	}
#endif
      ediv (d2, d1, v);	/* d1/d2 */
      break;

    case MIN_EXPR:		/* min (d1,d2) */
      if (ecmp (d1, d2) < 0)
	emov (d1, v);
      else
	emov (d2, v);
      break;

    case MAX_EXPR:		/* max (d1,d2) */
      if (ecmp (d1, d2) > 0)
	emov (d1, v);
      else
	emov (d2, v);
      break;
    default:
      emov (ezero, v);
      break;
    }
PUT_REAL (v, value);
}


/* Truncate REAL_VALUE_TYPE toward zero to signed HOST_WIDE_INT.
   implements REAL_VALUE_RNDZINT (x) (etrunci (x)).  */

REAL_VALUE_TYPE 
etrunci (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT f[NE], g[NE];
  REAL_VALUE_TYPE r;
  HOST_WIDE_INT l;

  GET_REAL (&x, g);
#ifdef NANS
  if (eisnan (g))
    return (x);
#endif
  eifrac (g, &l, f);
  ltoe (&l, g);
  PUT_REAL (g, &r);
  return (r);
}


/* Truncate REAL_VALUE_TYPE toward zero to unsigned HOST_WIDE_INT;
   implements REAL_VALUE_UNSIGNED_RNDZINT (x) (etruncui (x)).  */

REAL_VALUE_TYPE 
etruncui (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT f[NE], g[NE];
  REAL_VALUE_TYPE r;
  unsigned HOST_WIDE_INT l;

  GET_REAL (&x, g);
#ifdef NANS
  if (eisnan (g))
    return (x);
#endif
  euifrac (g, &l, f);
  ultoe (&l, g);
  PUT_REAL (g, &r);
  return (r);
}


/* This is the REAL_VALUE_ATOF function.  It converts a decimal string to
   binary, rounding off as indicated by the machine_mode argument.  Then it
   promotes the rounded value to REAL_VALUE_TYPE.  */

REAL_VALUE_TYPE 
ereal_atof (s, t)
     char *s;
     enum machine_mode t;
{
  unsigned EMUSHORT tem[NE], e[NE];
  REAL_VALUE_TYPE r;

  switch (t)
    {
    case HFmode:
    case SFmode:
      asctoe24 (s, tem);
      e24toe (tem, e);
      break;
    case DFmode:
      asctoe53 (s, tem);
      e53toe (tem, e);
      break;
    case XFmode:
      asctoe64 (s, tem);
      e64toe (tem, e);
      break;
    case TFmode:
      asctoe113 (s, tem);
      e113toe (tem, e);
      break;
    default:
      asctoe (s, e);
    }
  PUT_REAL (e, &r);
  return (r);
}


/* Expansion of REAL_NEGATE.  */

REAL_VALUE_TYPE 
ereal_negate (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT e[NE];
  REAL_VALUE_TYPE r;

  GET_REAL (&x, e);
  eneg (e);
  PUT_REAL (e, &r);
  return (r);
}


/* Round real toward zero to HOST_WIDE_INT;
   implements REAL_VALUE_FIX (x).  */

HOST_WIDE_INT
efixi (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT f[NE], g[NE];
  HOST_WIDE_INT l;

  GET_REAL (&x, f);
#ifdef NANS
  if (eisnan (f))
    {
      warning ("conversion from NaN to int");
      return (-1);
    }
#endif
  eifrac (f, &l, g);
  return l;
}

/* Round real toward zero to unsigned HOST_WIDE_INT
   implements  REAL_VALUE_UNSIGNED_FIX (x).
   Negative input returns zero.  */

unsigned HOST_WIDE_INT
efixui (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT f[NE], g[NE];
  unsigned HOST_WIDE_INT l;

  GET_REAL (&x, f);
#ifdef NANS
  if (eisnan (f))
    {
      warning ("conversion from NaN to unsigned int");
      return (-1);
    }
#endif
  euifrac (f, &l, g);
  return l;
}


/* REAL_VALUE_FROM_INT macro.  */

void 
ereal_from_int (d, i, j, mode)
     REAL_VALUE_TYPE *d;
     HOST_WIDE_INT i, j;
     enum machine_mode mode;
{
  unsigned EMUSHORT df[NE], dg[NE];
  HOST_WIDE_INT low, high;
  int sign;

  if (GET_MODE_CLASS (mode) != MODE_FLOAT)
    abort ();
  sign = 0;
  low = i;
  if ((high = j) < 0)
    {
      sign = 1;
      /* complement and add 1 */
      high = ~high;
      if (low)
	low = -low;
      else
	high += 1;
    }
  eldexp (eone, HOST_BITS_PER_WIDE_INT, df);
  ultoe ((unsigned HOST_WIDE_INT *) &high, dg);
  emul (dg, df, dg);
  ultoe ((unsigned HOST_WIDE_INT *) &low, df);
  eadd (df, dg, dg);
  if (sign)
    eneg (dg);

  /* A REAL_VALUE_TYPE may not be wide enough to hold the two HOST_WIDE_INTS.
     Avoid double-rounding errors later by rounding off now from the
     extra-wide internal format to the requested precision.  */
  switch (GET_MODE_BITSIZE (mode))
    {
    case 32:
      etoe24 (dg, df);
      e24toe (df, dg);
      break;

    case 64:
      etoe53 (dg, df);
      e53toe (df, dg);
      break;

    case 96:
      etoe64 (dg, df);
      e64toe (df, dg);
      break;

    case 128:
      etoe113 (dg, df);
      e113toe (df, dg);
      break;

    default:
      abort ();
  }

  PUT_REAL (dg, d);
}


/* REAL_VALUE_FROM_UNSIGNED_INT macro.   */

void 
ereal_from_uint (d, i, j, mode)
     REAL_VALUE_TYPE *d;
     unsigned HOST_WIDE_INT i, j;
     enum machine_mode mode;
{
  unsigned EMUSHORT df[NE], dg[NE];
  unsigned HOST_WIDE_INT low, high;

  if (GET_MODE_CLASS (mode) != MODE_FLOAT)
    abort ();
  low = i;
  high = j;
  eldexp (eone, HOST_BITS_PER_WIDE_INT, df);
  ultoe (&high, dg);
  emul (dg, df, dg);
  ultoe (&low, df);
  eadd (df, dg, dg);

  /* A REAL_VALUE_TYPE may not be wide enough to hold the two HOST_WIDE_INTS.
     Avoid double-rounding errors later by rounding off now from the
     extra-wide internal format to the requested precision.  */
  switch (GET_MODE_BITSIZE (mode))
    {
    case 32:
      etoe24 (dg, df);
      e24toe (df, dg);
      break;

    case 64:
      etoe53 (dg, df);
      e53toe (df, dg);
      break;

    case 96:
      etoe64 (dg, df);
      e64toe (df, dg);
      break;

    case 128:
      etoe113 (dg, df);
      e113toe (df, dg);
      break;

    default:
      abort ();
  }

  PUT_REAL (dg, d);
}


/* REAL_VALUE_TO_INT macro.  */

void 
ereal_to_int (low, high, rr)
     HOST_WIDE_INT *low, *high;
     REAL_VALUE_TYPE rr;
{
  unsigned EMUSHORT d[NE], df[NE], dg[NE], dh[NE];
  int s;

  GET_REAL (&rr, d);
#ifdef NANS
  if (eisnan (d))
    {
      warning ("conversion from NaN to int");
      *low = -1;
      *high = -1;
      return;
    }
#endif
  /* convert positive value */
  s = 0;
  if (eisneg (d))
    {
      eneg (d);
      s = 1;
    }
  eldexp (eone, HOST_BITS_PER_WIDE_INT, df);
  ediv (df, d, dg);		/* dg = d / 2^32 is the high word */
  euifrac (dg, (unsigned HOST_WIDE_INT *) high, dh);
  emul (df, dh, dg);		/* fractional part is the low word */
  euifrac (dg, (unsigned HOST_WIDE_INT *)low, dh);
  if (s)
    {
      /* complement and add 1 */
      *high = ~(*high);
      if (*low)
	*low = -(*low);
      else
	*high += 1;
    }
}


/* REAL_VALUE_LDEXP macro.  */

REAL_VALUE_TYPE
ereal_ldexp (x, n)
     REAL_VALUE_TYPE x;
     int n;
{
  unsigned EMUSHORT e[NE], y[NE];
  REAL_VALUE_TYPE r;

  GET_REAL (&x, e);
#ifdef NANS
  if (eisnan (e))
    return (x);
#endif
  eldexp (e, n, y);
  PUT_REAL (y, &r);
  return (r);
}

/* These routines are conditionally compiled because functions
   of the same names may be defined in fold-const.c.  */

#ifdef REAL_ARITHMETIC

/* Check for infinity in a REAL_VALUE_TYPE.  */

int
target_isinf (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT e[NE];

#ifdef INFINITY
  GET_REAL (&x, e);
  return (eisinf (e));
#else
  return 0;
#endif
}

/* Check whether a REAL_VALUE_TYPE item is a NaN.  */

int
target_isnan (x)
     REAL_VALUE_TYPE x;
{
  unsigned EMUSHORT e[NE];

#ifdef NANS
  GET_REAL (&x, e);
  return (eisnan (e));
#else
  return (0);
#endif
}


/* Check for a negative REAL_VALUE_TYPE number.
   This just checks the sign bit, so that -0 counts as negative.  */

int
target_negative (x)
     REAL_VALUE_TYPE x;
{
  return ereal_isneg (x);
}

/* Expansion of REAL_VALUE_TRUNCATE.
   The result is in floating point, rounded to nearest or even.  */

REAL_VALUE_TYPE
real_value_truncate (mode, arg)
     enum machine_mode mode;
     REAL_VALUE_TYPE arg;
{
  unsigned EMUSHORT e[NE], t[NE];
  REAL_VALUE_TYPE r;

  GET_REAL (&arg, e);
#ifdef NANS
  if (eisnan (e))
    return (arg);
#endif
  eclear (t);
  switch (mode)
    {
    case TFmode:
      etoe113 (e, t);
      e113toe (t, t);
      break;

    case XFmode:
      etoe64 (e, t);
      e64toe (t, t);
      break;

    case DFmode:
      etoe53 (e, t);
      e53toe (t, t);
      break;

    case HFmode:
    case SFmode:
      etoe24 (e, t);
      e24toe (t, t);
      break;

    case SImode:
      r = etrunci (arg);
      return (r);

    /* If an unsupported type was requested, presume that
       the machine files know something useful to do with
       the unmodified value.  */

    default:
      return (arg);
    }
  PUT_REAL (t, &r);
  return (r);
}

/* Try to change R into its exact multiplicative inverse in machine mode
   MODE.  Return nonzero function value if successful.  */

int
exact_real_inverse (mode, r)
     enum machine_mode mode;
     REAL_VALUE_TYPE *r;
{
  unsigned EMUSHORT e[NE], einv[NE];
  REAL_VALUE_TYPE rinv;
  int i;

  GET_REAL (r, e);

  /* Test for input in range.  Don't transform IEEE special values.  */
  if (eisinf (e) || eisnan (e) || (ecmp (e, ezero) == 0))
    return 0;

  /* Test for a power of 2: all significand bits zero except the MSB.
     We are assuming the target has binary (or hex) arithmetic.  */
  if (e[NE - 2] != 0x8000)
    return 0;

  for (i = 0; i < NE - 2; i++)
    {
      if (e[i] != 0)
	return 0;
    }

  /* Compute the inverse and truncate it to the required mode.  */
  ediv (e, eone, einv);
  PUT_REAL (einv, &rinv);
  rinv = real_value_truncate (mode, rinv);

#ifdef CHECK_FLOAT_VALUE
  /* This check is not redundant.  It may, for example, flush
     a supposedly IEEE denormal value to zero.  */
  i = 0;
  if (CHECK_FLOAT_VALUE (mode, rinv, i))
    return 0;
#endif
  GET_REAL (&rinv, einv);

  /* Check the bits again, because the truncation might have
     generated an arbitrary saturation value on overflow.  */
  if (einv[NE - 2] != 0x8000)
    return 0;

  for (i = 0; i < NE - 2; i++)
    {
      if (einv[i] != 0)
	return 0;
    }

  /* Fail if the computed inverse is out of range.  */
  if (eisinf (einv) || eisnan (einv) || (ecmp (einv, ezero) == 0))
    return 0;

  /* Output the reciprocal and return success flag.  */
  PUT_REAL (einv, r);
  return 1;
}
#endif /* REAL_ARITHMETIC defined */

/* Used for debugging--print the value of R in human-readable format
   on stderr.  */

void
debug_real (r)
     REAL_VALUE_TYPE r;
{
  char dstr[30];

  REAL_VALUE_TO_DECIMAL (r, "%.20g", dstr);
  fprintf (stderr, "%s", dstr);
}  


/* The following routines convert REAL_VALUE_TYPE to the various floating
   point formats that are meaningful to supported computers.

   The results are returned in 32-bit pieces, each piece stored in a `long'.  
   This is so they can be printed by statements like
 
      fprintf (file, "%lx, %lx", L[0],  L[1]);

   that will work on both narrow- and wide-word host computers.  */

/* Convert R to a 128-bit long double precision value.  The output array L
   contains four 32-bit pieces of the result, in the order they would appear
   in memory.  */

void 
etartdouble (r, l)
     REAL_VALUE_TYPE r;
     long l[];
{
  unsigned EMUSHORT e[NE];

  GET_REAL (&r, e);
  etoe113 (e, e);