OSH Parser Performance

We time $sh -n $file for various files under various shells, and repeat then run under cachegrind for stable metrics.

Source code: oils/benchmarks/osh-parser.sh

Raw files

Summary

Instructions Per Line (via cachegrind)

Lower numbers are generally better, but each shell recognizes a different language, and OSH uses a more thorough parsing algorithm. In thousands of "I refs".

shell label total lines thousand irefs per line
bash 118,863 7.3
dash 111,674 2.4
osh-native 105,750 10.5
osh-nosouffle 105,750 12.0

(zsh isn't measured because zsh -n unexpectedly forks.)

Average Parsing Rate, Measured on Two Machines (lines/ms)

Shell startup time is included in the elapsed time measurements, but long files are chosen to minimize its effect.

shell label total lines host no-host
dash 111,674 2,553
bash 118,863 1,253
osh-native 105,750 456
osh-nosouffle 105,750 428
osh-cpython 118,863 9

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 2 1 1 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 8 4 4 9 2,698 Build.sh
osh-nosouffle 8 4 4 9 2,698 Build.sh
osh-cpython 346 320 26 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-cpython 482 457 25 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 43 33 10 22 20,489 configure
osh-nosouffle 45 36 9 23 20,489 configure
osh-cpython 2,265 2,215 47 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 156 135 20 52 69,779 configure-coreutils
osh-nosouffle 165 131 34 52 69,779 configure-coreutils
osh-cpython 6,594 6,507 86 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-cpython 331 309 21 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-cpython 325 303 22 21 1,733 functions
dash 5 3 2 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 14 6 15 9,661 ltmain.sh
osh-nosouffle 24 20 4 16 9,661 ltmain.sh
osh-cpython 1,050 1,019 31 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-cpython 121 103 17 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 129 113 16 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-cpython 977 946 31 28 5,160 test-cmd-util.sh

Instruction Counts

shell label irefs num lines filename
dash 6,684,258 2,698 Build.sh
bash 19,403,577 2,698 Build.sh
osh-native 31,687,759 2,698 Build.sh
osh-nosouffle 36,049,399 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 221,592,897 20,489 configure
osh-nosouffle 264,250,418 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 749,804,213 69,779 configure-coreutils
osh-nosouffle 841,106,917 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,542,892 9,661 ltmain.sh
osh-nosouffle 113,080,051 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
bash 11,082,677 1,679 t4014-format-patch.sh
dash 4,585,030 3,123 t9300-fast-import.sh
osh-native 11,881,336 3,123 t9300-fast-import.sh
osh-nosouffle 13,051,131 3,123 t9300-fast-import.sh
bash 16,659,503 3,123 t9300-fast-import.sh
bash 73,195,614 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-ef16101d
osh-native osh-3acb318a
osh-nosouffle osh-nosouffle-4528e4a7
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2025-12-20__12-59-39.cachegrind.tsv
no-host.2025-12-20__12-59-39.times.csv