glibc/sysdeps/i386/fpu/e_acosl.c

30 lines
552 B
C

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
*/
#include <math_private.h>
long double
__ieee754_acosl (long double x)
{
long double res;
/* acosl = atanl (sqrtl((1-x) (1+x)) / x) */
asm ( "fld %%st\n"
"fld1\n"
"fsubp\n"
"fld1\n"
"fadd %%st(2)\n"
"fmulp\n" /* 1 - x^2 */
"fsqrt\n" /* sqrtl (1 - x^2) */
"fabs\n"
"fxch %%st(1)\n"
"fpatan"
: "=t" (res) : "0" (x) : "st(1)");
return res;
}
strong_alias (__ieee754_acosl, __acosl_finite)