小编mjo*_*lka的帖子

计算机语言基准测试游戏对于Threadring的F#条目包含一条看似无用的行:if false then ().当我注释掉这一行时,程序运行得更快(对于50000000的输入,~2s vs~55s)并产生相同的结果.这是如何运作的？为什么这条线路在那里？编译器到底做了什么似乎是无操作？

代码:

let ringLength = 503

let cells = Array.zeroCreate ringLength
let threads = Array.zeroCreate ringLength
let answer = ref -1

let createWorker i = 
    let next = (i+1)%ringLength
    async { let value = cells.[i]
            if false then () 
            match value with
            | 0 -> answer := i+1
            | _ -> 
                cells.[next] <- value - 1 
                return! threads.[next] }

[<EntryPoint>]
let main args = 
    cells.[0] <- if args.Length>0 then int …