checked_var_overhead.jl

using Images

data = rand(10, 10)
image = Image(data)

immutable Point{T}
    i::T
    j::T
end

function foobar_image(input::Image{Float64}, i::Int, j::Int)
    @inbounds return input.data[i, j]
end

function interpolate_image(input::Image{Float64}, p::Point{Float64})
    # Get fractional and integral part of the coordinates
    p_int::Point{Int} = Point(ifloor(p.i), ifloor(p.j))
    p_fract::Point{Float64} = Point(p.i-p_int.i, p.j-p_int.j)

    # Bilinear interpolation
    @inbounds return (input[p_int.i,   p_int.j]   * (1-p_fract.j) * (1-p_fract.i) +
                      input[p_int.i,   p_int.j+1] * p_fract.j     * (1-p_fract.i) +
                      input[p_int.i+1, p_int.j]   * (1-p_fract.j) * p_fract.i +
                      input[p_int.i+1, p_int.j+1] * p_fract.j     * p_fract.i)
end

function foobar_array(input::Array{Float64, 2}, i::Int, j::Int)
    @inbounds return input[i, j]
end

function interpolate_array(input::Array{Float64, 2}, p::Point{Float64})
    # Get fractional and integral part of the coordinates
    p_int::Point{Int} = Point(ifloor(p.i), ifloor(p.j))
    p_fract::Point{Float64} = Point(p.i-p_int.i, p.j-p_int.j)

    # Bilinear interpolation
    @inbounds return (input[p_int.i,   p_int.j]   * (1-p_fract.j) * (1-p_fract.i) +
                      input[p_int.i,   p_int.j+1] * p_fract.j     * (1-p_fract.i) +
                      input[p_int.i+1, p_int.j]   * (1-p_fract.j) * p_fract.i +
                      input[p_int.i+1, p_int.j+1] * p_fract.j     * p_fract.i)
end

code_native(interpolate_image, (Image{Float64}, Point{Float64}))
interpolate_image(image, Point(0.0, 0.0))
gc_disable() 
@time [interpolate_image(image, Point(0.0, 0.0)) for i in 1:100000];
gc_enable()

println()
println()
println()

code_native(interpolate_array, (Array{Float64, 2}, Point{Float64}))
interpolate_array(image.data, Point(0.0, 0.0))
gc_disable() 
@time [interpolate_array(image.data, Point(0.0, 0.0)) for i in 1:100000];
gc_enable()