github.com/afumu/libc@v0.0.6/musl/src/math/asinhl.c (about)

     1  #include "libm.h"
     2  
     3  #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
     4  long double asinhl(long double x)
     5  {
     6  	return asinh(x);
     7  }
     8  #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
     9  /* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */
    10  long double asinhl(long double x)
    11  {
    12  	union ldshape u = {x};
    13  	unsigned e = u.i.se & 0x7fff;
    14  	unsigned s = u.i.se >> 15;
    15  
    16  	/* |x| */
    17  	u.i.se = e;
    18  	x = u.f;
    19  
    20  	if (e >= 0x3fff + 32) {
    21  		/* |x| >= 0x1p32 or inf or nan */
    22  		x = logl(x) + 0.693147180559945309417232121458176568L;
    23  	} else if (e >= 0x3fff + 1) {
    24  		/* |x| >= 2 */
    25  		x = logl(2*x + 1/(sqrtl(x*x+1)+x));
    26  	} else if (e >= 0x3fff - 32) {
    27  		/* |x| >= 0x1p-32 */
    28  		x = log1pl(x + x*x/(sqrtl(x*x+1)+1));
    29  	} else {
    30  		/* |x| < 0x1p-32, raise inexact if x!=0 */
    31  		FORCE_EVAL(x + 0x1p120f);
    32  	}
    33  	return s ? -x : x;
    34  }
    35  #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
    36  // TODO: broken implementation to make things compile
    37  long double asinhl(long double x)
    38  {
    39  	return asinh(x);
    40  }
    41  #endif