/* 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;
        }
}