Hot spot (computer programming)

A hot spot in computer science is most usually defined as a region of a computer program where a high proportion of executed instructions occur or where most time is spent during the program's execution (not necessarily the same thing since some instructions are faster than others).

If a program is interrupted randomly, the program counter (the pointer to the next instruction to be executed) is frequently found to contain the address of an instruction within a certain range, possibly indicating code that is in need of optimization or even indicating the existence of a 'tight' CPU loop. This simple technique can detect highly used instructions, although more-sophisticated methods, such as instruction set simulators or performance analyzers, achieve this more accurately and consistently.