In loop jamming, the bodies of the two loops are merged together to form a single loop provided that they do not make any references to each other.
In loop concatenation, the bodies of the two loops are concatenated together to form a series of loop, loop concatenation, some times help to reduce complexity.
In loop unrolling, we try to optimize a program's execution speed. It is also known as space–time tradeoff.
In strength reduction compiler optimize expensive operations with equivalent but less expensive operations.