(IEEE 754) "
IEEE Standard for Binary
Floating-Point Arithmetic (ANSI/IEEE Std 754-1985)" or
IEC
559: "Binary floating-point arithmetic for microprocessor
systems". A
standard, used by many CPUs and FPUs, which
defines formats for representing floating-point numbers;
representations of special values (e.g.
infinity, very small
values,
NaN); five exceptions, when they occur, and what
happens when they do occur; four rounding modes; and a set
of floating-point operations that will work identically on any
conforming system.
IEEE 754 specifies formats for representing floating-point
values: single-precision (32-bit) is required,
double-precision (64-bit) is optional. The standard also
mentions that some implementations may include single-extended
precision (80-bit) and double-extended precision (128-bit)
formats.