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 118,863 11.1
osh-nosouffle 118,863 12.8

(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 3,269
bash 118,863 1,435
osh-native 118,863 538
osh-nosouffle 118,863 478
osh-cpython 118,863 11

Per-File Measurements

Time and Memory

shell label elapsed ms user ms sys ms max rss MB num lines filename
dash 1 1 1 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 6 5 1 9 2,698 Build.sh
osh-nosouffle 7 6 1 9 2,698 Build.sh
osh-cpython 282 268 14 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 8 5 3 9 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-cpython 392 379 13 23 2,512 abuild
dash 7 6 1 2 20,489 configure
bash 15 12 3 4 20,489 configure
osh-native 35 25 10 23 20,489 configure
osh-nosouffle 40 34 6 23 20,489 configure
osh-cpython 1,847 1,819 25 44 20,489 configure
dash 18 17 1 2 69,779 configure-coreutils
bash 38 37 1 3 69,779 configure-coreutils
osh-native 122 101 21 52 69,779 configure-coreutils
osh-nosouffle 136 117 19 52 69,779 configure-coreutils
osh-cpython 5,417 5,356 61 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 5 4 2 9 2,029 configure-helper.sh
osh-nosouffle 6 5 1 9 2,029 configure-helper.sh
osh-cpython 273 261 12 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 1 3 1,733 functions
osh-native 5 3 3 9 1,733 functions
osh-nosouffle 6 3 3 9 1,733 functions
osh-cpython 263 252 11 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 8 7 1 4 9,661 ltmain.sh
osh-native 17 14 3 16 9,661 ltmain.sh
osh-nosouffle 20 15 5 16 9,661 ltmain.sh
osh-cpython 882 859 24 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-native 3 2 1 8 1,679 t4014-format-patch.sh
osh-nosouffle 3 3 0 8 1,679 t4014-format-patch.sh
osh-cpython 97 86 11 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 3 2 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 4 0 8 3,123 t9300-fast-import.sh
osh-cpython 104 91 14 19 3,123 t9300-fast-import.sh
bash 7 7 0 3 5,160 test-cmd-util.sh
osh-native 15 13 2 13 5,160 test-cmd-util.sh
osh-nosouffle 18 16 1 13 5,160 test-cmd-util.sh
osh-cpython 808 793 15 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 31,600,243 2,698 Build.sh
osh-nosouffle 35,848,468 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,722,828 2,512 abuild
osh-nosouffle 52,279,613 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,087 20,489 configure
osh-nosouffle 263,061,800 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,153 69,779 configure-coreutils
osh-nosouffle 862,831,355 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,986,873 2,029 configure-helper.sh
osh-nosouffle 30,265,076 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,470,715 1,733 functions
osh-nosouffle 28,860,148 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,254 9,661 ltmain.sh
osh-nosouffle 112,484,759 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,064,745 1,679 t4014-format-patch.sh
osh-nosouffle 11,039,579 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 11,869,144 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,514 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
osh-native 96,185,341 5,160 test-cmd-util.sh
osh-nosouffle 112,289,235 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-31afb5a7
osh-native osh-692fd2fb
osh-nosouffle osh-nosouffle-65f14ee7
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-14__16-53-52.cachegrind.tsv
no-host.2025-12-14__16-53-52.times.csv