loop: a series of instructions that is repeated until a terminating condition is reached
Loops are pervasive in computer programs, and a great proportion of the execution time of a typical program is spent in one loop or another. Hence it is worthwhile devising optimizations to make loops go faster. Intuitively, a loop is a sequence of instructions that ends by jumping back to the beginning. But to be able to optimize loops effectively we will use a more precise definition.
A loop in a control-flow graph ...