testlog.jl

julia> type A{S<:AbstractArray}
       data::S
       end

julia> type B{T,N}
       data::AbstractArray{T,N}
       end

julia> type C{T}
       data::AbstractMatrix{T}
       end

julia> type D{T,N}
       data::Array{T,N}
       end

julia> type E{T}
       data::Matrix{T}
       end

julia> function test(x)
       tmpA = A(x)
       tmpB = B(x)
       tmpC = C(x)
       tmpD = D(x)
       tmpE = E(x)
       @time for i = 1:10^7; tmpA.data[1,1]; end
       @time for i = 1:10^7; tmpB.data[1,1]; end
       @time for i = 1:10^7; tmpC.data[1,1]; end
       @time for i = 1:10^7; tmpD.data[1,1]; end
       @time for i = 1:10^7; tmpE.data[1,1]; end
       end
test (generic function with 1 method)

julia> function test2(x)
       tmpA = A(x)
       tmpB = B(x)
       tmpC = C(x)
       tmpD = D(x)
       tmpE = E(x)
       @time for i = 1:10^7; sum(tmpA.data); end
       @time for i = 1:10^7; sum(tmpB.data); end
       @time for i = 1:10^7; sum(tmpC.data); end
       @time for i = 1:10^7; sum(tmpD.data); end
       @time for i = 1:10^7; sum(tmpE.data); end
       end
test2 (generic function with 1 method)

julia> x = randn(10,10);

julia> test(x)
  0.009130 seconds
  0.311626 seconds (10.00 M allocations: 152.606 MB, 9.83% gc time)
  0.283041 seconds (10.00 M allocations: 152.588 MB, 2.81% gc time)
  0.006136 seconds
  0.006092 seconds

julia> test(x)
  0.032918 seconds
  0.344165 seconds (10.00 M allocations: 152.588 MB, 2.26% gc time)
  0.280957 seconds (10.00 M allocations: 152.588 MB, 2.64% gc time)
  0.006105 seconds
  0.006092 seconds

julia> test(x)
  0.032655 seconds
  0.347223 seconds (10.00 M allocations: 152.588 MB, 2.26% gc time)
  0.288612 seconds (10.00 M allocations: 152.588 MB, 2.60% gc time)
  0.006276 seconds
  0.006306 seconds

julia> test2(x)
  0.290332 seconds
  0.951569 seconds (10.00 M allocations: 152.588 MB, 1.06% gc time)
  0.958516 seconds (10.00 M allocations: 152.588 MB, 0.79% gc time)
  0.280691 seconds
  0.279666 seconds

julia> test2(x)
  0.361693 seconds
  0.950392 seconds (10.00 M allocations: 152.588 MB, 0.80% gc time)
  0.955537 seconds (10.00 M allocations: 152.588 MB, 0.80% gc time)
  0.277672 seconds
  0.278493 seconds

julia> test2(x)
  0.377770 seconds
  0.948726 seconds (10.00 M allocations: 152.588 MB, 0.81% gc time)
  0.958683 seconds (10.00 M allocations: 152.588 MB, 0.80% gc time)
  0.280095 seconds
  0.279119 seconds

julia> x = randn(1000,10);

julia> test2(x)
 27.034179 seconds
 28.241048 seconds (10.00 M allocations: 152.588 MB, 0.04% gc time)
 29.013901 seconds (10.00 M allocations: 152.588 MB, 0.02% gc time)
 29.141071 seconds
 28.600888 seconds
 
julia> @time sum(x)
  0.000028 seconds (61 allocations: 3.672 KB)
86.11169337777784

julia> @time sum(x);
  0.000025 seconds (5 allocations: 176 bytes)
  
julia> @time for i = 1:10^7; sum(x); end;
 27.637227 seconds (10.00 M allocations: 152.588 MB, 0.04% gc time)