mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-05-23 05:42:29 +00:00
Initial import
This commit is contained in:
commit
c91b3c5006
14915 changed files with 590219 additions and 0 deletions
24
libc/math/acosh.c
Normal file
24
libc/math/acosh.c
Normal file
|
@ -0,0 +1,24 @@
|
|||
#include "libc/math/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;
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue