|  | #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; | 
|  | } | 
|  | #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 | 
|  | // TODO: broken implementation to make things compile | 
|  | long double acoshl(long double x) | 
|  | { | 
|  | return acosh(x); | 
|  | } | 
|  | #endif |