glibc/sysdeps/i386/fpu/e_acosl.c
Ulrich Drepper 0ac5ae2335 Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
2011-10-12 11:27:51 -04:00

27 lines
528 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^2) / x) */
asm ( "fld %%st\n"
"fmul %%st(0)\n" /* x^2 */
"fld1\n"
"fsubp\n" /* 1 - x^2 */
"fsqrt\n" /* sqrtl (1 - x^2) */
"fxch %%st(1)\n"
"fpatan"
: "=t" (res) : "0" (x) : "st(1)");
return res;
}
strong_alias (__ieee754_acosl, __acosl_finite)