cosmopolitan/libc/math/coshl.c

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2020-06-15 14:18:57 +00:00
#include "libc/math/libm.h"
#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double coshl(long double x)
{
return cosh(x);
}
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
long double coshl(long double x)
{
union ldshape u = {x};
unsigned ex = u.i.se & 0x7fff;
uint32_t w;
long double t;
/* |x| */
u.i.se = ex;
x = u.f;
w = u.i.m >> 32;
/* |x| < log(2) */
if (ex < 0x3fff-1 || (ex == 0x3fff-1 && w < 0xb17217f7)) {
if (ex < 0x3fff-32) {
FORCE_EVAL(x + 0x1p120f);
return 1;
}
t = expm1l(x);
return 1 + t*t/(2*(1+t));
}
/* |x| < log(LDBL_MAX) */
if (ex < 0x3fff+13 || (ex == 0x3fff+13 && w < 0xb17217f7)) {
t = expl(x);
return 0.5*(t + 1/t);
}
/* |x| > log(LDBL_MAX) or nan */
t = expl(0.5*x);
return 0.5*t*t;
}
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
// TODO: broken implementation to make things compile
long double coshl(long double x)
{
return cosh(x);
}
#endif