gsub benchmark TruffleRuby (19.2.0) vs MRI (Ruby 2.6.2)

gsub.rb

str1 = 'white chocolate'
str2 = 'a1'
str3 = 'dog'

regex2 = /\d/
regex3 = /\w+/

benchmark 'gsub-string' do
  r1 = str1.gsub('white', 'dark')
end

benchmark "gsub-regex" do
  r2 = str2.gsub(regex2, '2')
end

benchmark "gsub-regex-block" do
  r3 = str3.gsub(regex3) { |animal| animal == 'dog' ? 'cat' : 'dog' }
end

mri-ruby-2.6.2.txt

Warming up --------------------------------------
         gsub-string   133.332k i/100ms
          gsub-regex   109.422k i/100ms
    gsub-regex-block   100.462k i/100ms
         gsub-string   133.908k i/100ms
          gsub-regex   109.548k i/100ms
    gsub-regex-block   100.390k i/100ms
         gsub-string   134.102k i/100ms
          gsub-regex   110.124k i/100ms
    gsub-regex-block   100.716k i/100ms
Calculating -------------------------------------
         gsub-string      1.604M (± 4.4%) i/s -      8.046M in   5.027993s
          gsub-regex      1.275M (± 1.1%) i/s -      6.387M in   5.008714s
    gsub-regex-block      1.196M (± 0.9%) i/s -      6.043M in   5.052229s
         gsub-string      1.640M (± 2.0%) i/s -      8.314M in   5.072339s
          gsub-regex      1.268M (± 1.9%) i/s -      6.387M in   5.039050s
    gsub-regex-block      1.191M (± 1.9%) i/s -      6.043M in   5.075145s
         gsub-string      1.616M (± 1.7%) i/s -      8.180M in   5.064058s
          gsub-regex      1.271M (± 1.3%) i/s -      6.387M in   5.024287s
    gsub-regex-block      1.202M (± 1.1%) i/s -      6.043M in   5.030043s

Comparison:
         gsub-string:  1615810.2 i/s
          gsub-regex:  1271467.8 i/s - 1.27x  slower
    gsub-regex-block:  1201523.3 i/s - 1.34x  slower

truffleruby-19.2.0.txt

Warming up --------------------------------------
         gsub-string    29.634k i/100ms
          gsub-regex   154.576k i/100ms
    gsub-regex-block   123.275k i/100ms
         gsub-string    39.857k i/100ms
          gsub-regex   227.180k i/100ms
    gsub-regex-block   188.622k i/100ms
         gsub-string    38.142k i/100ms
          gsub-regex   218.579k i/100ms
    gsub-regex-block   200.674k i/100ms
Calculating -------------------------------------
         gsub-string    387.474k (±30.6%) i/s -      1.640M in   5.051508s
          gsub-regex      2.225M (±21.4%) i/s -     10.055M in   4.999286s
    gsub-regex-block      2.093M (±23.3%) i/s -      9.432M in   5.053969s
         gsub-string    426.231k (±20.2%) i/s -      1.983M in   5.024651s
          gsub-regex      2.327M (±18.8%) i/s -     10.710M in   5.008312s
    gsub-regex-block      2.283M (±22.1%) i/s -     10.435M in   5.057132s
         gsub-string    447.039k (±22.2%) i/s -      2.060M in   5.107442s
          gsub-regex      2.362M (±18.3%) i/s -     10.929M in   5.029235s
    gsub-regex-block      2.288M (±22.0%) i/s -     10.435M in   5.041204s

Comparison:
          gsub-regex:  2361636.1 i/s
    gsub-regex-block:  2288310.2 i/s - same-ish: difference falls within error
         gsub-string:   447039.4 i/s - 5.28x  slower