require "benchmark/ips"

Benchmark.ips do |x|
  x.config(time: 5, warmup: 2)

  index     = 42
  page_size = 10

  x.report("separate") do |times|
    1.upto(times) do
      page   = index / page_size
      offset = index % page_size
    end
  end

  x.report("separate i-assign") do |times|
    1.upto(times) do
      page, offset = index / page_size, index % page_size
    end
  end

  x.report("divmod") do |times|
    1.upto(times) do
      page, offset = index.divmod(page_size)
    end
  end

  x.report("divmod no i-assign") do |times|
    1.upto(times) do
      page_and_offset = index.divmod(page_size)
    end
  end

  x.report("separate no-assign") do |times|
    1.upto(times) do
      index / page_size
      index % page_size
    end
  end

  x.report("divmod no-assign") do |times|
    1.upto(times) do
      index.divmod(page_size)
    end
  end

  x.compare!
end

# >> Calculating -------------------------------------
# >>             separate   109.038k i/100ms
# >>    separate i-assign   102.224k i/100ms
# >>               divmod   101.067k i/100ms
# >>   divmod no i-assign   103.093k i/100ms
# >>   separate no-assign   112.813k i/100ms
# >>     divmod no-assign   105.110k i/100ms
# >> -------------------------------------------------
# >>             separate     12.945M (± 5.8%) i/s -     64.550M
# >>    separate i-assign      8.062M (± 2.9%) i/s -     40.276M
# >>               divmod      8.049M (± 2.5%) i/s -     40.225M
# >>   divmod no i-assign      8.001M (± 1.1%) i/s -     40.000M
# >>   separate no-assign     14.208M (± 3.0%) i/s -     70.959M
# >>     divmod no-assign      9.148M (± 1.1%) i/s -     45.828M
# >>
# >> Comparison:
# >>   separate no-assign: 14207716.5 i/s
# >>             separate: 12944759.7 i/s - 1.10x slower
# >>     divmod no-assign:  9148332.3 i/s - 1.55x slower
# >>    separate i-assign:  8062392.9 i/s - 1.76x slower
# >>               divmod:  8048842.0 i/s - 1.77x slower
# >>   divmod no i-assign:  8001018.8 i/s - 1.78x slower
# >>