/*
 * Written by J.T. Conklin <jtc@NetBSD.org>.
 * Public domain.
 */

#include <machine/asm.h>

#include "abi.h"

RCSID("$NetBSD: e_acos.S,v 1.9 2014/03/03 08:00:50 dsl Exp $")

/* acos = atan (sqrt(1 - x^2) / x) */
ENTRY(__ieee754_acos)
        XMM_ONE_ARG_DOUBLE_PROLOGUE
        fldl    ARG_DOUBLE_ONE          /* x */
        fld     %st(0)
        fmul    %st(0)                  /* x^2 */
        fld1
        fsubp                           /* 1 - x^2 */
        fsqrt                           /* sqrt (1 - x^2) */
        fabs                            /* Change -0.0 to +0.0 */
        fxch    %st(1)
        fpatan
        XMM_DOUBLE_EPILOGUE
        ret