Comparison of implementations of zeros

zeros_test.jl

using BenchmarkTools

function zeros_calloc{S, N}(T::Type, dims::Vararg{S, N})
    data = ccall((:calloc, "libc"),
                 Ptr{Void},
                 (Csize_t, Csize_t),
                 prod(dims), sizeof(T))
    data == C_NULL && error("Failed to allocate memory")
    ccall(:jl_ptr_to_array,
          Array{T, N},
          (Any, Ptr{Void}, Any, Cint),
          Array{T, N}, data, dims, 1)
end

zeros_mmap{S, N}(T::Type, dims::Vararg{S, N}) = Mmap.mmap(Array{T, N}, dims)

@show @benchmark zeros(Float64, 10)
@show @benchmark zeros_calloc(Float64, 10)
@show @benchmark zeros_mmap(Float64, 10)

@show @benchmark zeros(Float64, 1000, 1000)
@show @benchmark zeros_calloc(Float64, 1000, 1000)
@show @benchmark zeros_mmap(Float64, 1000, 1000)

function zeros_then_fill(f, T, dims...)
    A = f(T, dims...)
    fill!(A, 1.0)
    A
end

@show @benchmark zeros_then_fill(zeros, Float64, 1000, 1000)
@show @benchmark zeros_then_fill(zeros_calloc, Float64, 1000, 1000)
@show @benchmark zeros_then_fill(zeros_mmap, Float64, 1000, 1000)