/*
 * gcc on x86 needs access to rounding controls, because of a questionable
 * feature where it retains intermediate results as IEEE 'long double' values
 * somewhat unpredictably. It is tempting to include fpu_control.h, but that
 * file exists only on Linux; it is missing on Cygwin and MinGW. Most gcc-isms
 * and ix86-isms are factored out here.
 */

# 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_DECL \
    fpu_control_t roundTo53Bits = FPU_IEEE_ROUNDING;	\
    fpu_control_t oldRoundingMode;
#  define TCL_IEEE_DOUBLE_ROUNDING \
    _FPU_GETCW(oldRoundingMode);			\
    _FPU_SETCW(roundTo53Bits)
#  define TCL_DEFAULT_DOUBLE_ROUNDING \
    _FPU_SETCW(oldRoundingMode)

/*
 * Sun ProC needs sunmath for rounding control on x86 like gcc above.
 */
# elif defined(__sun)
#  include <sunmath.h>
#  define TCL_IEEE_DOUBLE_ROUNDING_DECL
#  define TCL_IEEE_DOUBLE_ROUNDING \
    ieee_flags("set","precision","double",NULL)
#  define TCL_DEFAULT_DOUBLE_ROUNDING \
    ieee_flags("clear","precision",NULL,NULL)

# endif
#endif
/*
 * Other platforms are assumed to always operate in full IEEE mode, so we make
 * the macros to go in and out of that mode do nothing.
 */
#ifndef TCL_IEEE_DOUBLE_ROUNDING /* !__i386 || (!__GNUC__ && !__sun) */

#  define TCL_IEEE_DOUBLE_ROUNDING_DECL



#  define TCL_IEEE_DOUBLE_ROUNDING	((void) 0)
#  define TCL_DEFAULT_DOUBLE_ROUNDING	((void) 0)
#endif

/*
 * MIPS floating-point units need special settings in control registers to use
 * gradual underflow as we expect.  This fix is for the MIPSpro compiler.
 */

#endif

	case sINFINITY:
	    acceptState = state;
	    acceptPoint = p;
	    acceptLen = len;
	    goto endgame;

	}
	p++;
	len--;
    }

  endgame:
    if (acceptState == INITIAL) {

static double
MakeLowPrecisionDouble(
    int signum,			/* 1 if the number is negative, 0 otherwise */
    Tcl_WideUInt significand,	/* Significand of the number */
    int numSigDigs,		/* Number of digits in the significand */
    long exponent)		/* Power of ten */
{
    TCL_IEEE_DOUBLE_ROUNDING_DECL

    mp_int significandBig;	/* Significand expressed as a bignum. */

    /*
     * With gcc on x86, the floating point rounding mode is double-extended.
     * This causes the result of double-precision calculations to be rounded
     * twice: once to the precision of double-extended and then again to the
     * precision of double. Double-rounding introduces gratuitous errors of 1

static double
MakeHighPrecisionDouble(
    int signum,			/* 1=negative, 0=nonnegative */
    mp_int *significand,	/* Exact significand of the number */
    int numSigDigs,		/* Number of significant digits */
    long exponent)		/* Power of 10 by which to multiply */
{
    TCL_IEEE_DOUBLE_ROUNDING_DECL

    int machexp = 0;		/* Machine exponent of a power of 10. */

    /*
     * With gcc on x86, the floating point rounding mode is double-extended.
     * This causes the result of double-precision calculations to be rounded
     * twice: once to the precision of double-extended and then again to the
     * precision of double. Double-rounding introduces gratuitous errors of 1