| 1 | #include "libm.h" |
| 2 | |
| 3 | #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 |
| 4 | long double acoshl(long double x) |
| 5 | { |
| 6 | return acosh(x); |
| 7 | } |
| 8 | #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 |
| 9 | /* acosh(x) = log(x + sqrt(x*x-1)) */ |
| 10 | long double acoshl(long double x) |
| 11 | { |
| 12 | union ldshape u = {x}; |
| 13 | int e = u.i.se; |
| 14 | |
| 15 | if (e < 0x3fff + 1) |
| 16 | /* 0 <= x < 2, invalid if x < 1 */ |
| 17 | return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1))); |
| 18 | if (e < 0x3fff + 32) |
| 19 | /* 2 <= x < 0x1p32 */ |
| 20 | return logl(2*x - 1/(x+sqrtl(x*x-1))); |
| 21 | if (e & 0x8000) |
| 22 | /* x < 0 or x = -0, invalid */ |
| 23 | return (x - x) / (x - x); |
| 24 | /* 0x1p32 <= x or nan */ |
| 25 | return logl(x) + 0.693147180559945309417232121458176568L; |
| 26 | } |
| 27 | #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
| 28 | // TODO: broken implementation to make things compile |
| 29 | long double acoshl(long double x) |
| 30 | { |
| 31 | return acosh(x); |
| 32 | } |
| 33 | #endif |