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 2,547
bash 118,863 1,242
osh-nosouffle 105,750 415
osh-native 105,750 399
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 3 0 3 2,698 Build.sh
osh-native 8 6 2 9 2,698 Build.sh
osh-nosouffle 9 6 3 9 2,698 Build.sh
osh-cpython 342 323 19 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-cpython 476 444 30 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 18 17 1 4 20,489 configure
osh-nosouffle 45 35 10 23 20,489 configure
osh-native 45 34 11 22 20,489 configure
osh-cpython 2,280 2,240 39 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 43 40 3 3 69,779 configure-coreutils
osh-nosouffle 174 152 22 52 69,779 configure-coreutils
osh-native 185 157 27 52 69,779 configure-coreutils
osh-cpython 6,706 6,605 98 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-cpython 328 306 23 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-cpython 319 297 22 21 1,733 functions
dash 5 3 2 2 9,661 ltmain.sh
bash 9 8 2 4 9,661 ltmain.sh
osh-native 22 16 6 16 9,661 ltmain.sh
osh-nosouffle 23 17 6 16 9,661 ltmain.sh
osh-cpython 1,087 1,059 27 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 122 102 20 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 3 2 1 3 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 3 8 3,123 t9300-fast-import.sh
osh-native 5 3 2 8 3,123 t9300-fast-import.sh
osh-cpython 130 106 24 19 3,123 t9300-fast-import.sh
bash 8 6 2 3 5,160 test-cmd-util.sh
osh-cpython 984 951 33 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 36,049,426 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 13,051,158 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-118da5b4
osh-native osh-9b64e30d
osh-nosouffle osh-nosouffle-f470d47a
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2025-12-19__17-03-12.cachegrind.tsv
no-host.2025-12-19__17-03-12.times.csv