This benchmark requires https://github.com/JuliaLang/julia/pull/5355. Try flog(1000,1000000,30)

gistfile1.txt

function inner( x, y )
    s = zero(eltype(x))
    @simd for i=1:length(x)
        @inbounds s += x[i]*y[i]
    end
    s
end

function flog( n, reps, tolerance )
    x = rand(Float32,n)
    y = rand(Float32,n)
    s = zero(Float64)
    time = @elapsed for j in 1:reps
        s+=inner(x,y)
    end
    println("GFlop = ",2.0*n*reps/time*1E-9)
    t = dot(x,y)
    err = abs(s-t*reps)
    if err>tolerance
        println(STDERR,"err = $err")
    end
end