*/

#if defined(__GNUC__)
typedef unsigned int	fpu_control_t __attribute__ ((__mode__ (__HI__)));

#define _FPU_GETCW(cw)	__asm__ __volatile__ ("fnstcw %0" : "=m" (*&cw))
#define _FPU_SETCW(cw)	__asm__ __volatile__ ("fldcw %0" : : "m" (*&cw))
#   define FPU_IEEE_ROUNDING	0x027f
#   define ADJUST_FPU_CONTROL_WORD
#define TCL_IEEE_DOUBLE_ROUNDING \
    fpu_control_t roundTo53Bits = FPU_IEEE_ROUNDING;	\
    fpu_control_t oldRoundingMode;			\
    _FPU_GETCW(oldRoundingMode);			\
    _FPU_SETCW(roundTo53Bits)
#define TCL_DEFAULT_DOUBLE_ROUNDING \

/*
 * HP's PA_RISC architecture uses 7ff4000000000000 to represent a quiet NaN.
 * Everyone else uses 7ff8000000000000. (Why, HP, why?)
 */

#ifdef __hppa
#   define NAN_START	0x7ff4
#   define NAN_MASK	(((Tcl_WideUInt) 1) << 50)
#else
#   define NAN_START	0x7ff8
#   define NAN_MASK	(((Tcl_WideUInt) 1) << 51)
#endif

/*
 * Constants used by this file (most of which are only ever calculated at
 * runtime).
 */

/*
 * Definitions of the parts of an IEEE754-format floating point number.
 */

#define SIGN_BIT 	0x80000000
				/* Mask for the sign bit in the first word of
				 * a double. */
#define EXP_MASK	0x7ff00000
				/* Mask for the exponent field in the first
				 * word of a double. */
#define EXP_SHIFT	20	/* Shift count to make the exponent an
				 * integer. */
#define HIDDEN_BIT	(((Tcl_WideUInt) 0x00100000) << 32)
				/* Hidden 1 bit for the significand. */
#define HI_ORDER_SIG_MASK 0x000fffff
				/* Mask for the high-order part of the
				 * significand in the first word of a
				 * double. */
#define SIG_MASK	(((Tcl_WideUInt) HI_ORDER_SIG_MASK << 32) \
			| 0xffffffff)
				/* Mask for the 52-bit significand. */
#define FP_PRECISION	53	/* Number of bits of significand plus the
				 * hidden bit. */
#define EXPONENT_BIAS	0x3ff	/* Bias of the exponent 0. */

/*
 * Derived quantities.
 */

#define TEN_PMAX	22	/* floor(FP_PRECISION*log(2)/log(5)) */
#define QUICK_MAX	14	/* floor((FP_PRECISION-1)*log(2)/log(10))-1 */

static inline int
NormalizeRightward(
    Tcl_WideUInt *wPtr)		/* INOUT: Number to shift. */
{
    int rv = 0;
    Tcl_WideUInt w = *wPtr;

    if (!(w & (Tcl_WideUInt) 0xffffffff)) {
	w >>= 32; rv += 32;
    }
    if (!(w & (Tcl_WideUInt) 0xffff)) {
	w >>= 16; rv += 16;
    }
    if (!(w & (Tcl_WideUInt) 0xff)) {
	w >>= 8; rv += 8;
    }
    if (!(w & (Tcl_WideUInt) 0xf)) {
	w >>= 4; rv += 4;
    }
    if (!(w & 0x3)) {
	w >>= 2; rv += 2;
    }
    if (!(w & 0x1)) {
	w >>= 1; ++rv;

static int
RequiredPrecision(
    Tcl_WideUInt w)		/* Number to interrogate. */
{
    int rv;
    unsigned long wi;

    if (w & ((Tcl_WideUInt) 0xffffffff << 32)) {
	wi = (unsigned long) (w >> 32); rv = 32;
    } else {
	wi = (unsigned long) w; rv = 0;
    }
    if (wi & 0xffff0000) {
	wi >>= 16; rv += 16;
    }
    if (wi & 0xff00) {
	wi >>= 8; rv += 8;
    }
    if (wi & 0xf0) {
	wi >>= 4; rv += 4;
    }
    if (wi & 0xc) {
	wi >>= 2; rv += 2;
    }
    if (wi & 0x2) {
	wi >>= 1; ++rv;
    }
    if (wi & 0x1) {
	++rv;

    ieps = 2;

    if (k > 0) {
	/*
	 * The number must be reduced to bring it into range.
	 */

	ds = tens[k & 0xf];
	j = k >> 4;
	if (j & BLETCH) {
	    j &= (BLETCH-1);
	    d /= bigtens[N_BIGTENS - 1];
	    ieps++;
	}
	i = 0;
	for (; j != 0; j>>=1) {
	    if (j & 1) {
		ds *= bigtens[i];
		++ieps;
	    }
	    ++i;
	}
	d /= ds;
    } else if ((j1 = -k) != 0) {
	/*
	 * The number must be increased to bring it into range.
	 */

	d *= tens[j1 & 0xf];
	i = 0;
	for (j = j1>>4; j; j>>=1) {
	    if (j & 1) {
		ieps++;
		d *= bigtens[i];
	    }
	    ++i;

     * integers), but the two words of a 'double' are presented most
     * significant word first.
     */

#ifdef IEEE_FLOATING_POINT
    bitwhack.dv = 1.000000238418579;
				/* 3ff0 0000 4000 0000 */
    if ((bitwhack.iv >> 32) == 0x3ff00000) {
	n770_fp = 0;
    } else if ((bitwhack.iv & 0xffffffff) == 0x3ff00000) {
	n770_fp = 1;
    } else {
	Tcl_Panic("unknown floating point word order on this machine");
    }
#endif
}


    double retval = fraction;

    if (exponent > 0) {
	/*
	 * Multiply by 10**exponent.
	 */

	retval = frexp(retval * pow10vals[exponent & 0xf], &j);
	expt += j;
	for (i=4; i<9; ++i) {
	    if (exponent & (1<<i)) {
		retval = frexp(retval * pow_10_2_n[i], &j);
		expt += j;
	    }
	}
    } else if (exponent < 0) {
	/*
	 * Divide by 10**-exponent.
	 */

	retval = frexp(retval / pow10vals[(-exponent) & 0xf], &j);
	expt += j;
	for (i=4; i<9; ++i) {
	    if ((-exponent) & (1<<i)) {
		retval = frexp(retval / pow_10_2_n[i], &j);
		expt += j;
	    }
	}

 *----------------------------------------------------------------------
 */
#ifdef IEEE_FLOATING_POINT
static Tcl_WideUInt
Nokia770Twiddle(
    Tcl_WideUInt w)		/* Number to transpose. */
{
    return (((w >> 32) & 0xffffffff) | (w << 32));
}
#endif

/*
 *----------------------------------------------------------------------
 *
 * TclNokia770Doubles --