Floating-point unit

A floating-point unit (FPU, colloquially a math co-processor) is a part of a computer system specially designed to carry out operations on numbers. Typical operations are, , , , and. Some FPUs can also perform various s such as or  calculations, but the accuracy can be very low,  so that some systems prefer to compute these functions in software.

In general-purpose s, one or more FPUs may be integrated as s within the central processing unit; however, many s do not have hardware support for floating-point operations (while they increasingly have them as standard, at least 32-bit ones).

Types
When a CPU is executing a program that calls for a floating-point operation, there are three ways to carry it out:
 * A floating-point unit emulator (or floating-point library), such as SANE, SoftwareFPU, or PowerFPU.
 * An add-on FPU, a dedicated hardware unit such as the Motorola 68881 or 68882.
 * An integrated FPU, included in processors such as the Motorola 68040, and all PowerPC and Intel processors used by Apple, which made separate add-on FPUs obsolete.