diff options
| author | Ian Moffett <ian@osmora.org> | 2025-07-14 22:39:34 -0400 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-07-14 23:27:58 -0400 |
| commit | 30634165980deaeead9f4e71e0ff6a5c9d897776 (patch) | |
| tree | 18546a9d493a699eb3ea23ab5cc792d40cf82d7d /lib/libc/src/musl-math/acosh.c | |
| parent | 83acdbef7ae961c2ae296835df3f368573c89eeb (diff) | |
usr: libc: Add math.h + musl math impl portexpt
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'lib/libc/src/musl-math/acosh.c')
| -rw-r--r-- | lib/libc/src/musl-math/acosh.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/lib/libc/src/musl-math/acosh.c b/lib/libc/src/musl-math/acosh.c new file mode 100644 index 0000000..badbf90 --- /dev/null +++ b/lib/libc/src/musl-math/acosh.c @@ -0,0 +1,24 @@ +#include "libm.h" + +#if FLT_EVAL_METHOD==2 +#undef sqrt +#define sqrt sqrtl +#endif + +/* acosh(x) = log(x + sqrt(x*x-1)) */ +double acosh(double x) +{ + union {double f; uint64_t i;} u = {.f = x}; + unsigned e = u.i >> 52 & 0x7ff; + + /* x < 1 domain error is handled in the called functions */ + + if (e < 0x3ff + 1) + /* |x| < 2, up to 2ulp error in [1,1.125] */ + return log1p(x-1 + sqrt((x-1)*(x-1)+2*(x-1))); + if (e < 0x3ff + 26) + /* |x| < 0x1p26 */ + return log(2*x - 1/(x+sqrt(x*x-1))); + /* |x| >= 0x1p26 or nan */ + return log(x) + 0.693147180559945309417232121458176568; +} |