Well, at least division isn&#x27;t. On reasonable recent Intel Broadwell, signed 64-bit division (IDIV) takes 59 cycles, while signed 32-bit division takes just 9 cycles.<p>Granted, divisions are rare, but that&#x27;s still nearly an order of magnitude difference in that corner case.<p>32-bit and 64-bit addition, multiplication, comparison, logical operations etc. are in almost all cases just as fast.<p>You&#x27;ll still need more storage on the stack for 64-bit variables. So more cache misses (and perhaps TLB misses and page faults) when corresponding boundary is crossed.