Modern x86 CPUs have micro instr caches to store small loops (about 50 instr) and medium loops (~2k instr). Also, the bottleneck is usually the instruction deco

Modern x86 CPUs have micro instr caches to store small loops (about 50 instr) and medium loops (~2k instr). Also, the bottleneck is usually the instruction decoding (Alder Lake made huge changes on that, so this might change). In other words, loop unrolling is, more often than not, harmful.