sysdeps/i386/fpu/e_acosl.c

   1 /*
   2  * Written by J.T. Conklin <jtc@netbsd.org>.
   3  * Public domain.
   4  *
   5  * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
   6  */
   7
   8 #include <math_private.h>
   9
  10 long double
  11 __ieee754_acosl (long double x)
  12 {
  13   long double res;
  14
  15   /* acosl = atanl (sqrtl((1-x) (1+x)) / x) */
  16   asm ( "fld    %%st\n"
  17         "fld1\n"
  18         "fsubp\n"
  19         "fld1\n"
  20         "fadd   %%st(2)\n"
  21         "fmulp\n"                       /* 1 - x^2 */
  22         "fsqrt\n"                       /* sqrtl (1 - x^2) */
  23         "fabs\n"
  24         "fxch   %%st(1)\n"
  25         "fpatan"
  26         : "=t" (res) : "0" (x) : "st(1)");
  27   return res;
  28 }
  29 strong_alias (__ieee754_acosl, __acosl_finite)