_C_STD_BEGIN
_CRTIMP2_PURE double __CLRCALL_PURE_OR_CDECL _Cosh(double x, double y)
{ /* compute y * cosh(x), |y| <= 1 */
switch (_Dtest(&x))
{ /* test for special codes */
case _NANCODE:
case _INFCODE:
return (x);
case 0:
return (y);
default: /* finite */
if (y == 0.0)
return (y);
if (x < 0.0)
x = -x;
if (x < _Xbig)
{ /* worth adding in exp(-x) */
_Exp(&x, 1.0, -1);
return (y * (x + 0.25 / x));
}
switch (_Exp(&x, y, -1))
{ /* report over/underflow */
case 0:
_Feraise(_FE_UNDERFLOW);
break;
case _INFCODE:
_Feraise(_FE_OVERFLOW);
}
return (x);
}
}
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;
}
}
}
}
}
double (atan2)(double y, double x)
{ /* compute atan(y/x) */
double z;
const short errx = _Dtest(&x);
const short erry = _Dtest(&y);
unsigned short hex;
if (errx <= 0 && erry <= 0)
{ /* x & y both finite or 0 */
if (y < 0.0)
y = -y, hex = 0x8;
else
hex = 0x0;
if (x < 0.0)
x = -x, hex ^= 0x6;
if (x < y)
z = x / y, hex ^= 0x2;
else if (0.0 < x)
z = y / x;
else
return (0.0); /* atan(0, 0) */
}
else if (errx == NAN || erry == NAN)
{ /* return one of the NaNs */
errno = EDOM;
return (errx == NAN ? x : y);
}
else
{ /* at least one INF */
z = errx == erry ? 1.0 : 0.0;
hex = DSIGN(y) ? 0x8 : 0x0;
if (DSIGN(x))
hex ^= 0x6;
if (erry == INF)
hex ^= 0x2;
}
return (_Atan(z, hex));
}
double (exp)(double x)
{ /* compute exp(x) */
switch (_Dtest(&x))
{ /* test for special codes */
case NAN:
errno = EDOM;
return (x);
case INF:
errno = ERANGE;
return (DSIGN(x) ? 0.0 : _Inf._D);
case 0:
return (1.0);
default: /* finite */
if (0 <= _Exp(&x, 0))
errno = ERANGE;
return (x);
}
}
double (tan)(double x)
{ /* compute tan(x) */
double g, gd;
long quad;
switch (_Dtest(&x))
{
case NAN:
errno = EDOM;
return (x);
case INF:
errno = EDOM;
return (_Nan._D);
case 0:
return (0.0);
default: /* finite */
if (x < -HUGE_RAD || HUGE_RAD < x)
{ /* x huge, sauve qui peut */
g = x / twopi;
_Dint(&g, 0);
x -= g * twopi;
}
g = x * twobypi;
quad = (long)(0 < g ? g + 0.5 : g - 0.5);
g = (double)quad;
g = (x - g * c1) - g * c2;
gd = 1.0;
if (_Rteps._D < (g < 0.0 ? -g : g))
{ /* g*g worth computing */
double y = g * g;
gd += (((q[0] * y + q[1]) * y + q[2]) * y + q[3]) * y;
g += ((p[0] * y + p[1]) * y + p[2]) * y * g;
}
return ((unsigned int)quad & 0x1 ? -gd / g : g / gd);
}
}
double (atan)(double x)
{ /* compute atan(x) */
unsigned short hex;
static const double piby2 = 1.57079632679489661923;
switch (_Dtest(&x))
{ /* test for special codes */
case NAN:
errno = EDOM;
return (x);
case INF:
return (DSIGN(x) ? -piby2 : piby2);
case 0:
return (0.0);
default: /* finite */
if (x < 0.0)
x = -x, hex = 0x8;
else
hex = 0x0;
if (1.0 < x)
x = 1.0 / x, hex ^= 0x2;
return (_Atan(x, hex));
}
}
