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| author | Vladimir Azarov <avm@intermediate-node.net> | 2024-10-01 15:47:05 +0200 |
|---|---|---|
| committer | Vladimir Azarov <avm@intermediate-node.net> | 2024-10-01 15:47:05 +0200 |
| commit | 4abab5ad6c8465a7528ccdd5f49367da05f78bbd (patch) | |
| tree | ebf009bf1376a5a223a915bc27cbbd791a1316bc /src/math/acoshl.c | |
Initial version
Diffstat (limited to 'src/math/acoshl.c')
| -rw-r--r-- | src/math/acoshl.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/math/acoshl.c b/src/math/acoshl.c new file mode 100644 index 0000000..943cec1 --- /dev/null +++ b/src/math/acoshl.c @@ -0,0 +1,33 @@ +#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; + + if (e < 0x3fff + 1) + /* 0 <= x < 2, invalid if x < 1 */ + return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1))); + if (e < 0x3fff + 32) + /* 2 <= x < 0x1p32 */ + return logl(2*x - 1/(x+sqrtl(x*x-1))); + if (e & 0x8000) + /* x < 0 or x = -0, invalid */ + return (x - x) / (x - x); + /* 0x1p32 <= x or nan */ + 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 |