source: azure_iot_hub/trunk/musl-1.1.18/src/math/sincosl.c@ 388

#define _GNU_SOURCE
#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
void sincosl(long double x, long double *sin, long double *cos)
{
        double sind, cosd;
        sincos(x, &sind, &cosd);
        *sin = sind;
        *cos = cosd;
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
void sincosl(long double x, long double *sin, long double *cos)
{
        union ldshape u = {x};
        unsigned n;
        long double y[2], s, c;

        u.i.se &= 0x7fff;
        if (u.i.se == 0x7fff) {
                *sin = *cos = x - x;
                return;
        }
        if (u.f < M_PI_4) {
                if (u.i.se < 0x3fff - LDBL_MANT_DIG) {
                        /* raise underflow if subnormal */
                        if (u.i.se == 0) FORCE_EVAL(x*0x1p-120f);
                        *sin = x;
                        /* raise inexact if x!=0 */
                        *cos = 1.0 + x;
                        return;
                }
                *sin = __sinl(x, 0, 0);
                *cos = __cosl(x, 0);
                return;
        }
        n = __rem_pio2l(x, y);
        s = __sinl(y[0], y[1], 1);
        c = __cosl(y[0], y[1]);
        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;
        }
}
#endif