Julia 全部直接引数わたしと構造体わたし，どっちが早いか

概要

Juliaで複数の配列を関数に渡すときに直接引数として渡すのと，構造体でまとめてから渡すので，どっちが早いか。

結論，変数が増えると構造体わたしのほうが遅い。

コード

using Parameters
using BenchmarkTools

@with_kw struct Param{T1}

    n::T1 = 100
end

struct vars
    u::Array{Float64, 2}
    v::Array{Float64, 2}
    p::Array{Float64, 2}
    T::Array{Float64, 2}
    u1::Array{Float64, 2}
    u2::Array{Float64, 2}
    u3::Array{Float64, 2}
end

#vars(para::Param) = vars(zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n))

function main(para)
    @unpack n = para

    u = zeros(Float64, n, n)
    v = zeros(Float64, n, n)
    p = zeros(Float64, n, n)
    T = zeros(Float64, n, n)
    u1 = zeros(Float64, n, n)
    u2 = zeros(Float64, n, n)
    u3 = zeros(Float64, n, n)

    #Var = vars(para)
    Var = vars(zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n), zeros(Float64, para.n, para.n))
    #Var = vars()

    @time for i=1:1000
        test_arg(para, u, v, p, T, u1, u2, u3)
    end
    println(u[1:5,1])
    @time for i=1:1000
        test_struct(para, Var)
    end
    println(Var.u[1:5,1])
end

function test_arg(para, u, v, p, T, u1, u2, u3)
    @unpack n = para 

    for j=1:n
        for i=1:n
            u[i,j] = 2*i+j*1.5
            v[i,j] = sin(i*j)
            p[i,j] = i-j*0.1 
            T[i,j] = 0.2i^2-j
            u1[i,j] = 0.2*i+j
            u2[i,j] = 0.2*i+j
            u3[i,j] = 0.2*i+j
        end
    end
end

function test_struct(para, Var)
    @unpack n = para 

    for j=1:n
        for i=1:n
            Var.u[i,j] = 2*i+j*1.5
            Var.v[i,j] = sin(i*j)
            Var.p[i,j] = i-j*0.1 
            Var.T[i,j] = 0.2i^2-j
            Var.u1[i,j] = 0.2*i+j
            Var.u2[i,j] = 0.2*i+j
            Var.u3[i,j] = 0.2*i+j
        end
    end
end

結果

julia> include("struct-arg-test.jl")
julia> para = Param(n=500)
julia> main(para)
 4.876456 seconds
[3.5, 5.5, 7.5, 9.5, 11.5]
  5.039125 seconds
[3.5, 5.5, 7.5, 9.5, 11.5]

前半が直接引数渡しで，後半が構造体で引数渡しの場合。