Benchmarking for checking if one array contains another in Ruby

results.txt

Warming up --------------------------------------
            subtract   233.432k i/100ms # higher is better
        bitwise & ==   164.352k i/100ms
      bitwise & size   218.548k i/100ms
        bitwise & []   200.794k i/100ms
        contains_all    74.648k i/100ms
  contains_all_count   112.634k i/100ms
                 set    19.238k i/100ms
          set cached   194.675k i/100ms
       all? include?   144.048k i/100ms
Calculating -------------------------------------
            subtract      5.723M (± 6.7%) i/s -     28.479M in   5.002088s
        bitwise & ==      2.752M (± 3.3%) i/s -     13.806M in   5.022462s
      bitwise & size      4.803M (± 6.2%) i/s -     24.040M in   5.027104s
        bitwise & []      3.990M (± 4.7%) i/s -     20.079M in   5.043979s
        contains_all    912.814k (± 4.9%) i/s -      4.554M in   5.002096s
  contains_all_count      1.589M (± 6.2%) i/s -      7.997M in   5.057523s
                 set    206.133k (± 2.9%) i/s -      1.039M in   5.043780s
          set cached      3.847M (± 4.4%) i/s -     19.273M in   5.020417s
       all? include?      2.183M (± 3.3%) i/s -     10.948M in   5.021192s

Comparison: (higher is better)
            subtract:  5723282.1 i/s 
      bitwise & size:  4803227.2 i/s - 1.19x  slower
        bitwise & []:  3990081.0 i/s - 1.43x  slower
          set cached:  3846838.4 i/s - 1.49x  slower
        bitwise & ==:  2751914.6 i/s - 2.08x  slower
       all? include?:  2182757.5 i/s - 2.62x  slower
  contains_all_count:  1588738.7 i/s - 3.60x  slower
        contains_all:   912813.5 i/s - 6.27x  slower
                 set:   206133.5 i/s - 27.76x  slower

subset_benchmark.rb

# Collecting the solutions from Stack Overflow
# https://stackoverflow.com/questions/7387937/how-to-determine-if-one-array-contains-all-elements-of-another-array

require 'set'
require 'benchmark/ips'

sub_array = %i[alpha omega]
main_array = %i[alpha beta omega zeta shoe]

sub_array_set = Set.new(sub_array)
main_array_set = Set.new(main_array)

class Array
  def contains_all?(ary)
    ary.uniq.all? { |x| count(x) >= ary.count(x) }
  end
end

def contains_all_count?(a, b)
  b.all? { |x| a.count(x) >= b.count(x) }
end

Benchmark.ips do |x|
  # this is the selected answer and it's the fastest
  x.report('subtract') { (sub_array - main_array).empty? }

  x.report('bitwise & ==') { (sub_array & main_array) == sub_array }
  x.report('bitwise & size') { (sub_array & main_array).size == sub_array.size }
  x.report('bitwise & []') { (sub_array & main_array) == [] }

  x.report('contains_all') { main_array.contains_all?(sub_array) }
  x.report('contains_all_count') { contains_all_count?(main_array, sub_array) }

  x.report('set') { Set.new(main_array).subset?(Set.new(sub_array)) }
  x.report('set cached') { main_array_set.subset?(sub_array_set) }

  x.report('all? include?') { sub_array.all? { |e| main_array.include?(e) } }

  x.compare!
end