Class SmallFloat


  • public class SmallFloat
    extends Object
    Floating point numbers smaller than 32 bits.
    NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
    • Method Detail

      • floatToByte

        public static byte floatToByte​(float f,
                                       int numMantissaBits,
                                       int zeroExp)
        Converts a 32 bit float to an 8 bit float.
        Values less than zero are all mapped to zero.
        Values are truncated (rounded down) to the nearest 8 bit value.
        Values between zero and the smallest representable value are rounded up.
        Parameters:
        f - the 32 bit float to be converted to an 8 bit float (byte)
        numMantissaBits - the number of mantissa bits to use in the byte, with the remainder to be used in the exponent
        zeroExp - the zero-point in the range of exponent values
        Returns:
        the 8 bit float representation
      • byteToFloat

        public static float byteToFloat​(byte b,
                                        int numMantissaBits,
                                        int zeroExp)
        Converts an 8 bit float to a 32 bit float.
      • floatToByte315

        public static byte floatToByte315​(float f)
        floatToByte(b, mantissaBits=3, zeroExponent=15)
        smallest non-zero value = 5.820766E-10
        largest value = 7.5161928E9
        epsilon = 0.125
      • byte315ToFloat

        public static float byte315ToFloat​(byte b)
        byteToFloat(b, mantissaBits=3, zeroExponent=15)
      • longToInt4

        public static int longToInt4​(long i)
        Float-like encoding for positive longs that preserves ordering and 4 significant bits.
      • int4ToLong

        public static final long int4ToLong​(int i)
        Decode values encoded with longToInt4(long).
      • intToByte4

        public static byte intToByte4​(int i)
        Encode an integer to a byte. It is built upon longToInt4(long) and leverages the fact that longToInt4(Integer.MAX_VALUE) is less than 255 to encode low values more accurately.
      • byte4ToInt

        public static int byte4ToInt​(byte b)
        Decode values that have been encoded with intToByte4(int).