This makes verbose comparison of 37MB completely different files 2.34x
faster than our own baseline, putting our cmp at almost 6x faster than
GNU cmp (/opt/homebrew/bin/cmp) on my M4 Pro Mac. The output remains
identical to that of GNU cmp. Mostly equal and smaller files do not
regress.
Benchmark 1: ./bin/baseline/diffutils cmp -lb t/huge t/eguh
Time (mean ± σ): 1.669 s ± 0.011 s [User: 1.594 s, System: 0.073 s]
Range (min … max): 1.654 s … 1.689 s 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 2: ./target/release/diffutils cmp -lb t/huge t/eguh
Time (mean ± σ): 714.2 ms ± 4.1 ms [User: 629.3 ms, System: 82.7 ms]
Range (min … max): 707.2 ms … 721.5 ms 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 3: /opt/homebrew/bin/cmp -lb t/huge t/eguh
Time (mean ± σ): 4.213 s ± 0.050 s [User: 4.128 s, System: 0.081 s]
Range (min … max): 4.160 s … 4.316 s 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 4: /usr/bin/cmp -lb t/huge t/eguh
Time (mean ± σ): 3.892 s ± 0.048 s [User: 3.819 s, System: 0.070 s]
Range (min … max): 3.808 s … 3.976 s 10 runs
Warning: Ignoring non-zero exit code.
Summary
./target/release/diffutils cmp -lb t/huge t/eguh ran
2.34 ± 0.02 times faster than ./bin/baseline/diffutils cmp -lb t/huge t/eguh
5.45 ± 0.07 times faster than /usr/bin/cmp -lb t/huge t/eguh
5.90 ± 0.08 times faster than /opt/homebrew/bin/cmp -lb t/huge t/eguh
This makes verbose comparison of 37MB completely different files 2.34x
faster than our own baseline, putting our cmp at almost 6x faster than
GNU cmp (/opt/homebrew/bin/cmp) on my M4 Pro Mac. The output remains
identical to that of GNU cmp. Mostly equal and smaller files do not
regress.
Benchmark 1: ./bin/baseline/diffutils cmp -lb t/huge t/eguh
Time (mean ± σ): 1.669 s ± 0.011 s [User: 1.594 s, System: 0.073 s]
Range (min … max): 1.654 s … 1.689 s 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 2: ./target/release/diffutils cmp -lb t/huge t/eguh
Time (mean ± σ): 714.2 ms ± 4.1 ms [User: 629.3 ms, System: 82.7 ms]
Range (min … max): 707.2 ms … 721.5 ms 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 3: /opt/homebrew/bin/cmp -lb t/huge t/eguh
Time (mean ± σ): 4.213 s ± 0.050 s [User: 4.128 s, System: 0.081 s]
Range (min … max): 4.160 s … 4.316 s 10 runs
Warning: Ignoring non-zero exit code.
Benchmark 4: /usr/bin/cmp -lb t/huge t/eguh
Time (mean ± σ): 3.892 s ± 0.048 s [User: 3.819 s, System: 0.070 s]
Range (min … max): 3.808 s … 3.976 s 10 runs
Warning: Ignoring non-zero exit code.
Summary
./target/release/diffutils cmp -lb t/huge t/eguh ran
2.34 ± 0.02 times faster than ./bin/baseline/diffutils cmp -lb t/huge t/eguh
5.45 ± 0.07 times faster than /usr/bin/cmp -lb t/huge t/eguh
5.90 ± 0.08 times faster than /opt/homebrew/bin/cmp -lb t/huge t/eguh
On my Mac I see this test fail quite consistently. This change makes it
more resilient in systems with slower startup times, while still
allowing faster systems to finish as soon as possible.
The test was failing in the regular MacOS terminal due to it defaulting
to LC_ALL=C. Best to standardize like the other tests that check for
locale-dependent output.