The only stack-specific special optimization that's done is fusing the decrement/increment of esp/rsp with the store µop. And that's done mainly since push/pop

The only stack-specific special optimization that's done is fusing the decrement/increment of esp/rsp with the store µop. And that's done mainly since push/pop are one byte opcodes, unlike general load/store. Everything else is general memory optimizations that apply for everything like the aforementioned store forwarding. It's still expensive if the CPU can't use them (mismatched load/store size, incorrect speculation, etc.)