bench_blas.jl

using BenchmarkTools, Plots


function bench_dot(N :: Int)
  T1 = zeros(N, 3)
  T2 = zeros(N, 3)
  T3 = zeros(N, 3)
  for i = 1:N
    n = 2^i
    println("Running for $n")
    x = rand(n)
    y = rand(n)
    t1 = @benchmark BLAS.dot($n, $x, 1, $y, 1)
    t2 = @benchmark BLAS.dot($x, $y)
    t3 = @benchmark dot($x,$y)
    t1 = t1.times
    t2 = t2.times
    t3 = t3.times
    T1[i,:] = [minimum(t1), mean(t1), maximum(t1)]
    T2[i,:] = [minimum(t2), mean(t2), maximum(t2)]
    T3[i,:] = [minimum(t3), mean(t3), maximum(t3)]
  end
  return T1, T2, T3
end


function bench_norm(N :: Int)
  T1 = zeros(N, 3)
  T2 = zeros(N, 3)
  T3 = zeros(N, 3)
  for i = 1:N
    n = 2^i
    println("Running for $n")
    x = rand(n)
    t1 = @benchmark BLAS.nrm2($n, $x, 1)
    t2 = @benchmark BLAS.nrm2($x)
    t3 = @benchmark norm($x)
    t1 = t1.times
    t2 = t2.times
    t3 = t3.times
    T1[i,:] = [minimum(t1), mean(t1), maximum(t1)]
    T2[i,:] = [minimum(t2), mean(t2), maximum(t2)]
    T3[i,:] = [minimum(t3), mean(t3), maximum(t3)]
  end
  return T1, T2, T3
end


function plotbench(T1, T2, T3, name1, name2, name3)
  N = size(T1, 1)
  t = 2.^(1:N)
  plot(xaxis = :log, yaxis=:log, reuse=false)
  plot!(t, T1[:,1], color=:red, l=:dash, lab="$name1 min")
  plot!(t, T1[:,2], color=:red, l=:solid, lab="$name1 mean")
  plot!(t, T1[:,3], color=:red, l=:dot, lab="$name1 max")
  plot!(t, T2[:,1], color=:blue, l=:dash, lab="$name2 min")
  plot!(t, T2[:,2], color=:blue, l=:solid, lab="$name2 mean")
  plot!(t, T2[:,3], color=:blue, l=:dot, lab="$name2 max")
  plot!(t, T3[:,1], color=:green, l=:dash, lab="$name3 min")
  plot!(t, T3[:,2], color=:green, l=:solid, lab="$name3 mean")
  plot!(t, T3[:,3], color=:green, l=:dot, lab="$name3 max")
  title!("$name1 vs $name2 vs $name3")
  xlabel!("Dimension")
  ylabel!("Time")
  png("$(name1)_vs_$(name2)_vs_$(name3)")

  plot(t, T2[:,2]./T1[:,2], xaxis=:log, lab="$name2/$name1", reuse=false)
  plot!(t, T3[:,2]./T1[:,2], xaxis=:log, lab="$name3/$name1")
  title!("How much better is $name1?")
  xlabel!("Dimension")
  png("$(name1)_$(name2)_$(name3)_ratio")
end

T1, T2, T3 = bench_dot(10)
plotbench(T1, T2, T3, "BLAS.dot", "BLAS.dot (simple)", "dot")
T1, T2, T3 = bench_norm(10)
plotbench(T1, T2, T3, "BLAS.nrm2", "BLAS.nrm2 (simple)", "norm")