A loop buffer sits at a CPU's frontend, where it holds a small number of previously fetched instructions. Small loops can be contained within the loop buffer, after which they can be executed with some frontend stages shut off. That saves power, and can improve performance by bypassing any limitations present in prior frontend stages. It's an old but popular technique that has seen use by Intel, Arm, and AMD cores.Arm's Cortex A15 contains a 32 entry loop bufferAs far as I know, Zen 4 is the onl...