/* s_cosf.c -- float version of s_cos.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: s_cosf.c,v 1.10 2024/05/08 01:40:27 riastradh Exp $");
#endif

#include "namespace.h"
#include "math.h"
#include "math_private.h"

__weak_alias(cosf, _cosf)

float
cosf(float x)
{
        float y[2],z=0.0;
        int32_t n,ix;

        GET_FLOAT_WORD(ix,x);

    /* |x| ~< pi/4 */
        ix &= 0x7fffffff;
        if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);

    /* cos(Inf or NaN) is NaN */
        else if (ix>=0x7f800000) return x-x;

    /* argument reduction needed */
        else {
            n = __ieee754_rem_pio2f(x,y);
            switch(n&3) {
                case 0: return  __kernel_cosf(y[0],y[1]);
                case 1: return -__kernel_sinf(y[0],y[1],1);
                case 2: return -__kernel_cosf(y[0],y[1]);
                default:
                        return  __kernel_sinf(y[0],y[1],1);
            }
        }
}