_CRTIMP2 short __cdecl _Exp(double *px, double y, short eoff)
{ /* compute y*e^(*px), (*px) finite, |y| not huge */
if (*px < -hugexp || y == 0)
{ /* certain underflow */
*px = 0;
return (0);
}
else if (hugexp < *px)
{ /* certain overflow */
*px = _Inf._D;
return (INF);
}
else
{ /* xexp won't overflow */
double g = *px * invln2;
short xexp = g + (g < 0 ? - 0.5 : + 0.5);
g = xexp;
g = (*px - g * c1) - g * c2;
if (-_Eps._D < g && g < _Eps._D)
*px = y;
else
{ /* g*g worth computing */
const double z = g * g;
const double w = (q[0] * z + q[1]) * z + q[2];
g *= (z + p[1]) * z + p[2];
*px = (w + g) / (w - g) * 2 * y;
--xexp;
}
return (_Dscale(px, (long)xexp + eoff));
}
}
_C_STD_BEGIN
#if _DLONG == 0
short _LDscale(long double *px, long lexp)
{ /* scale *px by 2^lexp with checking -- 64-bit */
return (_Dscale((double *)px, lexp));
}
_C_STD_BEGIN
#if _DLONG == 0
_MRTIMP2_NCEEPURE short __CLRCALL_PURE_OR_CDECL _LDscale(long double *px, long lexp)
{ /* scale *px by 2^lexp with checking -- 64-bit */
return (_Dscale((double *)px, lexp));
}
_STD_BEGIN
#if !_DLONG
_CRTIMP2 short _LDscale(long double *px, long lexp)
{ /* scale *px by 2^lexp with checking */
return (_Dscale((double *)px, lexp));
}
_MRTIMP2_NCEEPURE short __CLRCALL_PURE_OR_CDECL _Exp(double *px, double y, short eoff)
{ /* compute y*e^(*px), (*px) finite, |y| not huge */
if (*px < -hugexp || y == 0.0)
{ /* certain underflow */
*px = 0.0;
return (0);
}
else if (hugexp < *px)
{ /* certain overflow */
*px = _Inf._Double;
return (_INFCODE);
}
else
{ /* xexp won't overflow */
double g = *px * invln2;
short xexp = (short)(g + (g < 0.0 ? - 0.5 : + 0.5));
g = xexp;
g = (*px - g * c1) - g * c2;
if (-_Eps._Double < g && g < _Eps._Double)
*px = y;
else
{ /* g*g worth computing */
const double z = g * g;
const double w = (q[0] * z + q[1]) * z + q[2];
g *= (z + p[1]) * z + p[2];
*px = (w + g) / (w - g) * 2.0 * y;
--xexp;
}
return (_Dscale(px, (long)xexp + eoff));
}
}
double (fmod)(double x, double y)
{ /* compute fmod(x, y) */
const short errx = _Dtest(&x);
const short erry = _Dtest(&y);
if (errx == NAN || erry == NAN || errx == INF || erry == 0)
{ /* fmod undefined */
errno = EDOM;
return (errx == NAN ? x : erry == NAN ? y : _Nan._D);
}
else if (errx == 0 || erry == INF)
return (x); /* fmod(0,nonzero) or fmod(finite,INF) */
else
{ /* fmod(finite,finite) */
double t;
short n, neg, ychar;
if (y < 0.0)
y = -y;
if (x < 0.0)
x = -x, neg = 1;
else
neg = 0;
for (t = y, _Dunscale(&ychar, &t), n = 0; ; )
{ /* subtract |y| until |x|<|y| */
short xchar;
t = x;
if (n < 0 || _Dunscale(&xchar, &t) == 0
|| (n = xchar - ychar) < 0)
return (neg ? -x : x);
for (; 0 <= n; --n)
{ /* try to subtract |y|*2^n */
t = y, _Dscale(&t, n);
if (t <= x)
{
x -= t;
break;
}
}
}
}
}
