+ with many arguments

[vtjnash]

This function allocates large numbers of gc roots:

function laplace2 (del_x::Array{Float64, 3}, x::Array{Float64, 3})

               n1, n2, n3 = size (x)
               for i1 = 1:n1, i2 = 1:n2, i3 = 1:n3
                       del_x[i1,i2,i3] =
                               x[i1,i2,i3] + x[i1,i2,i3] +
                               x[i1,i2,i3] + x[i1,i2,i3] +
                               x[i1,i2,i3] + x[i1,i2,i3]
               end

       end

while this function does not:

function laplace2 (del_x::Array{Float64, 3}, x::Array{Float64, 3})

               n1, n2, n3 = size (x)
               for i1 = 1:n1, i2 = 1:n2, i3 = 1:n3
                       del_x[i1,i2,i3] =
                               x[i1,i2,i3] + x[i1,i2,i3] +
                               x[i1,i2,i3] + x[i1,i2,i3]
               end

       end

[andrioni]

Maybe it's because the first one calls the varargs + method, while the second one not?