/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */
/*
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 * Optimized by Bruce D. Evans.
 */
/*
 * ====================================================
 * 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.
 * ====================================================
 */

#define _GNU_SOURCE
#include "libm.h"

/* Small multiples of pi/2 rounded to double precision. */
static const double s1pio2 = 1 * M_PI_2, /* 0x3FF921FB, 0x54442D18 */
    s2pio2 = 2 * M_PI_2,                 /* 0x400921FB, 0x54442D18 */
    s3pio2 = 3 * M_PI_2,                 /* 0x4012D97C, 0x7F3321D2 */
    s4pio2 = 4 * M_PI_2;                 /* 0x401921FB, 0x54442D18 */

void sincosf(float x, float* sin, float* cos) {
    double y;
    float_t s, c;
    uint32_t ix;
    unsigned n, sign;

    GET_FLOAT_WORD(ix, x);
    sign = ix >> 31;
    ix &= 0x7fffffff;

    /* |x| ~<= pi/4 */
    if (ix <= 0x3f490fda) {
        /* |x| < 2**-12 */
        if (ix < 0x39800000) {
            /* raise inexact if x!=0 and underflow if subnormal */
            FORCE_EVAL(ix < 0x00100000 ? x / 0x1p120f : x + 0x1p120f);
            *sin = x;
            *cos = 1.0f;
            return;
        }
        *sin = __sindf(x);
        *cos = __cosdf(x);
        return;
    }

    /* |x| ~<= 5*pi/4 */
    if (ix <= 0x407b53d1) {
        if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
            if (sign) {
                *sin = -__cosdf(x + s1pio2);
                *cos = __sindf(x + s1pio2);
            } else {
                *sin = __cosdf(s1pio2 - x);
                *cos = __sindf(s1pio2 - x);
            }
            return;
        }
        /* -sin(x+c) is not correct if x+c could be 0: -0 vs +0 */
        *sin = -__sindf(sign ? x + s2pio2 : x - s2pio2);
        *cos = -__cosdf(sign ? x + s2pio2 : x - s2pio2);
        return;
    }

    /* |x| ~<= 9*pi/4 */
    if (ix <= 0x40e231d5) {
        if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
            if (sign) {
                *sin = __cosdf(x + s3pio2);
                *cos = -__sindf(x + s3pio2);
            } else {
                *sin = -__cosdf(x - s3pio2);
                *cos = __sindf(x - s3pio2);
            }
            return;
        }
        *sin = __sindf(sign ? x + s4pio2 : x - s4pio2);
        *cos = __cosdf(sign ? x + s4pio2 : x - s4pio2);
        return;
    }

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

    /* general argument reduction needed */
    n = __rem_pio2f(x, &y);
    s = __sindf(y);
    c = __cosdf(y);
    switch (n & 3) {
    case 0:
        *sin = s;
        *cos = c;
        break;
    case 1:
        *sin = c;
        *cos = -s;
        break;
    case 2:
        *sin = -s;
        *cos = -c;
        break;
    case 3:
    default:
        *sin = -c;
        *cos = s;
        break;
    }
}