versions/v1_4_0/mynewt-core/encoding/tinycbor/include/tinycbor/math_support_p.h

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#ifndef MATH_SUPPORT_H
#define MATH_SUPPORT_H

#include <math.h>

#ifdef __cplusplus
extern "C" {
#endif

/* this function was copied & adapted from RFC 7049 Appendix D */
static inline double decode_half(unsigned short half)
{
#ifdef __F16C__
    return _cvtsh_ss(half);
#else
    int exp = (half >> 10) & 0x1f;
    int mant = half & 0x3ff;
    double val;
    if (exp == 0) val = ldexp(mant, -24);
    else if (exp != 31) val = ldexp(mant + 1024, exp - 25);
    else val = mant == 0 ? INFINITY : NAN;
    return half & 0x8000 ? -val : val;
#endif
}

#ifdef __cplusplus
}
#endif

#endif // MATH_SUPPORT_H