8 points | by aw1621107 5 days ago
2 comments
> I have no idea what the mov rcx, rsp instruction is for. The rcx register is not read anywhere after that.
Anyone have any ideas? I’m surprised that the compiler emits a “useless” instruction at -o3.
Full title is "Why my Rust benchmarks were wrong, or how to [correctly] use std::hint::black_box?", but I had to remove something to get the title to fit.
> I have no idea what the mov rcx, rsp instruction is for. The rcx register is not read anywhere after that.
Anyone have any ideas? I’m surprised that the compiler emits a “useless” instruction at -o3.
Full title is "Why my Rust benchmarks were wrong, or how to [correctly] use std::hint::black_box?", but I had to remove something to get the title to fit.