Fast path

Fast path is a term used in computer science to describe a path with shorter instruction path length through a program compared to the 'normal' path. For a fast path to be effective it must handle the most commonly occuring tasks more efficiently than the 'normal' path, leaving the latter to handle uncommon cases, corner cases, error handling, and other anomalies. Fast paths are a form of optimization.

For example dedicated packet routing hardware used to build computer networks will often sport hardware dedicated to handling the most common kinds of packets, with other kinds, for example with control information or packets directed at the device itself instead of to be routed elsewhere, put on the metaphorical "slow path", in this example usually implemented by software running on the control processor.

Origin

A fast path is analogous to a short cut (generic meaning: a shorter route or smaller effort).