Native IEEE Floating-Point Representations

The REAL(4) (S_floating) and REAL(8) (T_floating) formats are stored in standard little endian IEEE binary floating-point notation. (See IEEE Standard 754 for additional information about IEEE binary floating point notation.) COMPLEX() and COMPLEX() formats use a pair of REAL(KIND=4) or REAL(8) values to denote the real and imaginary parts of the data.

For IEEE S_floating and T_floating formats, fractions are represented in sign-magnitude notation, with the binary radix point to the right of the most-significant bit. Fractions are assumed to be normalized, and therefore the most-significant bit is not stored (this is called "hidden bit normalization"). This bit is assumed to be 1 unless the exponent is 0. If the exponent equals 0, then the value represented is denormalized (subnormal) or plus or minus zero.

The following sections discuss floating-point data:

• REAL(KIND=4) (REAL) Representation
• REAL(KIND=8) (DOUBLE PRECISION) Representation
• COMPLEX(KIND=4) (COMPLEX) Representation
• COMPLEX(KIND=8) (DOUBLE COMPLEX) Representation

For more information:

• On using the BitViewer tool, see Viewing Floating-Point Representations with BitViewer.
• Reading or writing floating-point data other than native IEEE little endian data, see Converting Unformatted Numeric Data.
• Using floating-point numbers, see The Floating-Point Environment.