Floating-Point Representations

float, double, and long double data elements are represented according to the ANSI/ISO IEEE 754-1985 standard. The representation is:

(-1)^s(e ^- bias⁾¥2 j.f

where:

• s = sign

• e = biased exponent

• j is the leading bit, determined by the value of e. In the case of long double (Intel), the leading bit is explicit; in all other cases, it is implicit.

• f = fraction

• u means that the bit can be either 0 or 1.

The following tables show the position of the bits.

Table A-6 float Representation

Bits	Name
31	Sign
23 - 30	Exponent
0 - 22	Fraction

Table A-7 double Representation

Bits	Name
63	Sign
52 - 62	Exponent
0 - 51	Fraction

Table A-8 long double Representation (SPARC)

Bits	Name
127	Sign
112 - 126	Exponent
0 - 111	Fraction

Table A-9 long double Representation (Intel)

Bits	Name
80 - 95	Unused
79	Sign
64 - 78	Exponent
63	Leading bit
0 - 62	Fraction

For further information, refer to the Numerical Computation Guide.