double
j0(double x) /* wrapper j0 */
{
#ifdef _IEEE_LIBM
return __ieee754_j0(x);
#else
double z = __ieee754_j0(x);
if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
if(fabs(x)>X_TLOSS) {
return __kernel_standard(x,x,34); /* j0(|x|>X_TLOSS) */
} else
return z;
#endif
}
double j0(double x)
{
double z = __ieee754_j0(x);
if (_LIB_VERSION == _IEEE_ || isnan(x))
return z;
if (fabs(x) > X_TLOSS)
return __kernel_standard(x, x, 34); /* j0(|x|>X_TLOSS) */
return z;
}
void
Math_j0(void *fp)
{
F_Math_j0 *f;
f = fp;
*f->ret = __ieee754_j0(f->x);
}
/* wrapper j0 */
double
j0 (double x)
{
if (__builtin_expect (isgreater (fabs (x), X_TLOSS), 0)
&& _LIB_VERSION != _IEEE_ && _LIB_VERSION != _POSIX_)
/* j0(|x|>X_TLOSS) */
return __kernel_standard (x, x, 34);
return __ieee754_j0 (x);
}
/* wrapper j0l */
long double
j0l (long double x)
{
# if defined(__UCLIBC_HAS_FENV__)
if (__builtin_expect (isgreater (fabsl (x), X_TLOSS), 0)
&& _LIB_VERSION != _IEEE_ && _LIB_VERSION != _POSIX_)
/* j0(|x|>X_TLOSS) */
return __kernel_standard_l (x, x, 234);
# endif /* __UCLIBC_HAS_FENV__ */
return (long double) __ieee754_j0 ((double)x);
}
double
__ieee754_y0(double x)
{
double z, s,c,ss,cc,u,v;
int32_t hx,ix,lx;
EXTRACT_WORDS(hx,lx,x);
ix = 0x7fffffff&hx;
/* Y0(NaN) is NaN, y0(-inf) is Nan, y0(inf) is 0 */
if(ix>=0x7ff00000) return one/(x+x*x);
if((ix|lx)==0) return -one/zero;
if(hx<0) return zero/zero;
if(ix >= 0x40000000) { /* |x| >= 2.0 */
/* y0(x) = sqrt(2/(pi*x))*(p0(x)*sin(x0)+q0(x)*cos(x0))
* where x0 = x-pi/4
* Better formula:
* cos(x0) = cos(x)cos(pi/4)+sin(x)sin(pi/4)
* = 1/sqrt(2) * (sin(x) + cos(x))
* sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4)
* = 1/sqrt(2) * (sin(x) - cos(x))
* To avoid cancellation, use
* sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x))
* to compute the worse one.
*/
s = sin(x);
c = cos(x);
ss = s-c;
cc = s+c;
/*
* j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
* y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x)
*/
if(ix<0x7fe00000) { /* make sure x+x not overflow */
z = -cos(x+x);
if ((s*c)<zero) cc = z/ss;
else ss = z/cc;
}
if(ix>0x48000000) z = (invsqrtpi*ss)/sqrt(x);
else {
u = pzero(x);
v = qzero(x);
z = invsqrtpi*(u*ss+v*cc)/sqrt(x);
}
return z;
}
if(ix<=0x3e400000) { /* x < 2**-27 */
return(u00 + tpi*__ieee754_log(x));
}
z = x*x;
u = u00+z*(u01+z*(u02+z*(u03+z*(u04+z*(u05+z*u06)))));
v = one+z*(v01+z*(v02+z*(v03+z*v04)));
return(u/v + tpi*(__ieee754_j0(x)*__ieee754_log(x)));
}
