1/*
2 * Written by J.T. Conklin <jtc@NetBSD.org>.
3 * Public domain.
4 */
5
6#include <machine/asm.h>
7
8#include "abi.h"
9
10RCSID("$NetBSD: e_acos.S,v 1.9 2014/03/03 08:00:50 dsl Exp $")
11
12/* acos = atan (sqrt(1 - x^2) / x) */
13ENTRY(__ieee754_acos)
14          XMM_ONE_ARG_DOUBLE_PROLOGUE
15          fldl      ARG_DOUBLE_ONE                /* x */
16          fld       %st(0)
17          fmul      %st(0)                        /* x^2 */
18          fld1
19          fsubp                                   /* 1 - x^2 */
20          fsqrt                                   /* sqrt (1 - x^2) */
21          fabs                                    /* Change -0.0 to +0.0 */
22          fxch      %st(1)
23          fpatan
24          XMM_DOUBLE_EPILOGUE
25          ret
26