xref: /netbsd-src/lib/libm/arch/i387/e_acos.S (revision c41a4eebefede43f6950f838a387dc18c6a431bf)
1/*
2 * Written by J.T. Conklin <jtc@netbsd.org>.
3 * Public domain.
4 */
5
6#include <machine/asm.h>
7
8RCSID("$NetBSD: e_acos.S,v 1.4 1995/05/08 23:44:37 jtc Exp $")
9
10/* acos = atan (sqrt(1 - x^2) / x) */
11ENTRY(__ieee754_acos)
12	fldl	4(%esp)			/* x */
13	fst	%st(1)
14	fmul	%st(0)			/* x^2 */
15	fld1
16	fsubp				/* 1 - x^2 */
17	fsqrt				/* sqrt (1 - x^2) */
18	fxch	%st(1)
19	fpatan
20	ret
21