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#include "libm.h"
#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double acoshl(long double x)
{
return acosh(x);
}
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
/* acosh(x) = log(x + sqrt(x*x-1)) */
long double acoshl(long double x)
{
union ldshape u = {x};
int e = u.i.se & 0x7fff;
if (e < 0x3fff + 1)
/* x < 2, invalid if x < 1 or nan */
return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1)));
if (e < 0x3fff + 32)
/* x < 0x1p32 */
return logl(2*x - 1/(x+sqrtl(x*x-1)));
return logl(x) + 0.693147180559945309417232121458176568L;
}
#endif
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