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 2,585
bash 118,863 1,268
osh-native 105,750 508
osh-nosouffle 105,750 492
osh-cpython 118,863 10

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 7 2 5 9 2,698 Build.sh
osh-nosouffle 7 6 1 9 2,698 Build.sh
osh-cpython 331 309 22 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-cpython 464 438 26 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 40 33 7 23 20,489 configure
osh-nosouffle 41 28 13 23 20,489 configure
osh-cpython 2,207 2,165 42 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 137 115 22 52 69,779 configure-coreutils
osh-nosouffle 142 122 20 52 69,779 configure-coreutils
osh-cpython 6,359 6,279 78 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-cpython 318 296 22 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-cpython 314 288 26 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 12 8 15 9,661 ltmain.sh
osh-nosouffle 20 16 4 16 9,661 ltmain.sh
osh-cpython 1,045 1,011 34 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-cpython 114 93 21 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 1 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 122 99 23 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-cpython 961 940 21 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 841,106,944 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-d676c076
osh-native osh-f3ff8b3e
osh-nosouffle osh-nosouffle-a371db6e
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2025-12-19__17-01-00.cachegrind.tsv
no-host.2025-12-19__17-01-00.times.csv