[boyter]

A rather nice ~10% speed boost for my tool scc from this just with a simple recompile against some input sets.

    $ hyperfine 'scc' './scc'
    Benchmark #1: scc
      Time (mean ± σ):      43.5 ms ±   1.7 ms    [User: 30.4 ms, System: 88.2 ms]
      Range (min … max):    40.5 ms …  48.9 ms

    Benchmark #2: ./scc
      Time (mean ± σ):      39.6 ms ±   1.3 ms    [User: 46.1 ms, System: 89.7 ms]
      Range (min … max):    35.9 ms …  42.5 ms

    Summary
      './scc' ran
        1.10 ± 0.06 times faster than 'scc'

Trying it on various other inputs it seems to be somewhere between 3% and 10%

I am surprised they are still getting these sort of gains to be honest. From memory 1.13 for the same workload came with a ~3% improvement over 1.12. This is purely in terms of wall clock time to run the same code over the same inputs. Have not had a look at the impact of a long running process or memory yet.