| Rich Felker | b69f695 | 2012-03-13 01:17:53 -0400 | [diff] [blame] | 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 |
| Szabolcs Nagy | 482ccd2 | 2012-12-11 23:06:20 +0100 | [diff] [blame] | 9 | /* acosh(x) = log(x + sqrt(x*x-1)) */ |
| Rich Felker | b69f695 | 2012-03-13 01:17:53 -0400 | [diff] [blame] | 10 | long double acoshl(long double x) |
| 11 | { |
| Szabolcs Nagy | aa0c4a2 | 2013-09-04 15:54:02 +0000 | [diff] [blame] | 12 | union ldshape u = {x}; |
| 13 | int e = u.i.se & 0x7fff; |
| Rich Felker | b69f695 | 2012-03-13 01:17:53 -0400 | [diff] [blame] | 14 | |
| Szabolcs Nagy | aa0c4a2 | 2013-09-04 15:54:02 +0000 | [diff] [blame] | 15 | if (e < 0x3fff + 1) |
| Szabolcs Nagy | 101e601 | 2013-09-05 12:26:26 +0000 | [diff] [blame] | 16 | /* |x| < 2, invalid if x < 1 or nan */ |
| Szabolcs Nagy | 482ccd2 | 2012-12-11 23:06:20 +0100 | [diff] [blame] | 17 | return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1))); |
| Szabolcs Nagy | aa0c4a2 | 2013-09-04 15:54:02 +0000 | [diff] [blame] | 18 | if (e < 0x3fff + 32) |
| Szabolcs Nagy | 101e601 | 2013-09-05 12:26:26 +0000 | [diff] [blame] | 19 | /* |x| < 0x1p32 */ |
| Szabolcs Nagy | 482ccd2 | 2012-12-11 23:06:20 +0100 | [diff] [blame] | 20 | return logl(2*x - 1/(x+sqrtl(x*x-1))); |
| 21 | return logl(x) + 0.693147180559945309417232121458176568L; |
| Rich Felker | b69f695 | 2012-03-13 01:17:53 -0400 | [diff] [blame] | 22 | } |
| Szabolcs Nagy | f4e4632 | 2015-03-10 20:01:20 +0000 | [diff] [blame] | 23 | #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
| 24 | // TODO: broken implementation to make things compile |
| 25 | long double acoshl(long double x) |
| 26 | { |
| 27 | return acosh(x); |
| 28 | } |
| Rich Felker | b69f695 | 2012-03-13 01:17:53 -0400 | [diff] [blame] | 29 | #endif |