Floating point processor

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A floating point processor (often, technically, a floating point unit) was, until recently, an option which allowed a computer to handle floating point numbers in hardware. In architectural terms, it might be a co-processor, or on microcoded machines, it might be extra microcode, sometimes along with some additional hardware to speed up some aspects of the computation.

In early machines, the hardware involved was a complete extra set of printed circuit boards; later on, with the rise of microprocessors, it became an optional chip. Now that CPU chips typically contain extremely large numbers of transistors, floating point is usually supported in them by default.

Originally, in most CPUs with a only an integer ALU, integer multiply instructions took many CPU cycles, because they were implemented by repeated shifts and adds; similarly, divides were handled by repeated subtractions. In modern CPUs where the FPU is integrated into the CPU, there is usually a multiply network which can also be used to perform these integer operations in a few CPU cycles.

Very recently, Graphic Processing Units have been able to handle floating point operations needed for math intensive tasks such as image rendering, etc.