/*-
 * Copyright (c) 2017,2023 Steven G. Kargl
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
/*
 * See ../src/s_cospi.c for implementation details.
 */
#define INLINE_KERNEL_SINDF
#define INLINE_KERNEL_COSDF

#include "namespace.h"
__weak_alias(cospif, _cospif)

#include "math.h"
#include "math_private.h"
#include "k_cosdf.c"
#include "k_sindf.c"

#define __kernel_cospif(x)      (__kernel_cosdf(M_PI * (x)))
#define __kernel_sinpif(x)      (__kernel_sindf(M_PI * (x)))

static volatile const float vzero = 0;

float
cospif(float x)
{
        float ax, c;
        uint32_t ix, jj0;

        GET_FLOAT_WORD(ix, x);
        ix = ix & 0x7fffffff;
        SET_FLOAT_WORD(ax, ix);

        if (ix < 0x3f800000) {                  /* |x| < 1 */
                if (ix < 0x3e800000) {          /* |x| < 0.25 */
                        if (ix < 0x38800000) {  /* |x| < 0x1p-14 */
                                /* Raise inexact iff != 0. */
                                if ((int)ax == 0)
                                        return (1);
                        }
                        return (__kernel_cospif(ax));
                }

                if (ix < 0x3f000000)            /* |x| < 0.5 */
                        c = __kernel_sinpif(0.5F - ax);
                else if (ix < 0x3f400000) {     /* |x| < 0.75 */
                        if (ix == 0x3f000000)
                                return (0);
                        c = -__kernel_sinpif(ax - 0.5F);
                } else
                        c = -__kernel_cospif(1 - ax);
                return (c);
        }

        if (ix < 0x4b000000) {          /* 1 <= |x| < 0x1p23 */
                FFLOORF(x, jj0, ix);    /* Integer part of ax. */
                ax -= x;
                GET_FLOAT_WORD(ix, ax);

                if (ix < 0x3f000000) {          /* |x| < 0.5 */
                        if (ix < 0x3e800000)    /* |x| < 0.25 */
                                c = ix == 0 ? 1 : __kernel_cospif(ax);
                        else
                                c = __kernel_sinpif(0.5F - ax);
                } else {
                        if (ix < 0x3f400000) {  /* |x| < 0.75 */
                                if (ix == 0x3f000000)
                                        return (0);
                                c = -__kernel_sinpif(ax - 0.5F);
                        } else
                                c = -__kernel_cospif(1 - ax);
                }

                jj0 = (uint32_t)x;
                return (jj0 & 1 ? -c : c);
        }

        /* x = +-inf or nan. */
        if (ix >= 0x7f800000)
                return (vzero / vzero);

        /*
         * For 0x1p23 <= |x| < 0x1p24 need to determine if x is an even
         * or odd integer to return +1 or -1.
         * For |x| >= 0x1p24, it is always an even integer, so return 1.
         */
        return (ix < 0x4b800000 ? ((ix & 1) ? -1 : 1) : 1);
}