third_party/ulib/musl/src/math/sinhf.c

#include "libm.h"

float sinhf(float x) {
    union {
        float f;
        uint32_t i;
    } u = {.f = x};
    uint32_t w;
    float t, h, absx;

    h = 0.5;
    if (u.i >> 31)
        h = -h;
    /* |x| */
    u.i &= 0x7fffffff;
    absx = u.f;
    w = u.i;

    /* |x| < log(FLT_MAX) */
    if (w < 0x42b17217) {
        t = expm1f(absx);
        if (w < 0x3f800000) {
            if (w < 0x3f800000 - (12 << 23))
                return x;
            return h * (2 * t - t * t / (t + 1));
        }
        return h * (t + t / (t + 1));
    }

    /* |x| > logf(FLT_MAX) or nan */
    t = 2 * h * __expo2f(absx);
    return t;
}