FP80

FP80 is most commonly known as x86 extended precision, and is defined by IEEE 754 as 10 bytes (80 bits) of memory space. The x86 extended precision format was first implemented in the Intel 8087 math coprocessor and is supported by all processors based on the x86 design that incorporate a floating-point unit (FPU).

Anatomy of an FP80

• 1 bit for sign
• 15 bits for exponent
• 64 bits for significand/mantissa