Function UnityPrintFloat

src/unity.c:334–491

* This function prints a floating-point value in a format similar to * printf("%.7g") on a single-precision machine or printf("%.9g") on a * double-precision machine. The 7th digit won't always be totally correct * in single-precision operation (for that level of accuracy, a more * complicated algorithm would be needed). */

 * complicated algorithm would be needed).
 */
void UnityPrintFloat(const UNITY_DOUBLE input_number)
{
#ifdef UNITY_INCLUDE_DOUBLE
    static const int sig_digits = 9;
    static const UNITY_INT32 min_scaled = 100000000;
    static const UNITY_INT32 max_scaled = 1000000000;
#else
    static const int sig_digits = 7;
    static const UNITY_INT32 min_scaled = 1000000;
    static const UNITY_INT32 max_scaled = 10000000;
#endif

    UNITY_DOUBLE number = input_number;

    /* print minus sign (does not handle negative zero) */
    if (number < 0.0f)
    {
        UNITY_OUTPUT_CHAR('-');
        number = -number;
    }

    /* handle zero, NaN, and +/- infinity */
    if (number == 0.0f)
    {
        UnityPrint("0");
    }
    else if (UNITY_IS_NAN(number))
    {
        UnityPrint("nan");
    }
    else if (UNITY_IS_INF(number))
    {
        UnityPrint("inf");
    }
    else
    {
        UNITY_INT32 n_int = 0;
        UNITY_INT32 n;
        int         exponent = 0;
        int         decimals;
        int         digits;
        char        buf[16] = {0};

        /*
         * Scale up or down by powers of 10.  To minimize rounding error,
         * start with a factor/divisor of 10^10, which is the largest
         * power of 10 that can be represented exactly.  Finally, compute
         * (exactly) the remaining power of 10 and perform one more
         * multiplication or division.
         */
        if (number < 1.0f)
        {
            UNITY_DOUBLE factor = 1.0f;

            while (number < (UNITY_DOUBLE)max_scaled / 1e10f)  { number *= 1e10f; exponent -= 10; }
            while (number * factor < (UNITY_DOUBLE)min_scaled) { factor *= 10.0f; exponent--; }

            number *= factor;