newlib-cygwin/winsup/cygwin/math/acosl.c

24 lines
582 B
C

/**
* This file has no copyright assigned and is placed in the Public Domain.
* This file is part of the mingw-w64 runtime package.
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
*/
long double acosl (long double x);
long double acosl (long double x)
{
long double res = 0.0L;
/* acosl = atanl (sqrtl(1 - x^2) / x) */
asm volatile (
"fld %%st\n\t"
"fmul %%st(0)\n\t" /* x^2 */
"fld1\n\t"
"fsubp\n\t" /* 1 - x^2 */
"fsqrt\n\t" /* sqrtl (1 - x^2) */
"fxch %%st(1)\n\t"
"fpatan"
: "=t" (res) : "0" (x) : "st(1)");
return res;
}