function testVec(t,v,k,n)
    for i=1:n
        t .= v .* 3 .+ k .* 4;
    end
end

module params
r = 3;
end

function testVec2(t,v,k,n)
    for i=1:n
        t .= v .* params.r .+ k .* 4;
    end
end

@time testVec([1 2 3 4], [2 3 4 5], [3 4 5 6], 1000)
0.000036 seconds (7 allocations: 496 bytes)

@time testVec2([1 2 3 4], [2 3 4 5], [3 4 5 6], 1000)
0.003180 seconds (4.01 k allocations: 141.109 KiB)