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 11.0
osh-nosouffle 118,863 12.5

(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 2,597
bash 118,863 1,268
osh-native 118,863 472
osh-nosouffle 118,863 413
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 5 2 9 2,698 Build.sh
osh-nosouffle 8 5 3 9 2,698 Build.sh
osh-cpython 323 301 22 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 10 6 4 9 2,512 abuild
osh-cpython 450 430 20 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 38 31 7 22 20,489 configure
osh-nosouffle 45 38 7 23 20,489 configure
osh-cpython 2,135 2,096 38 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 4 69,779 configure-coreutils
osh-native 140 118 21 52 69,779 configure-coreutils
osh-nosouffle 162 133 29 52 69,779 configure-coreutils
osh-cpython 6,301 6,235 65 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 3 4 9 2,029 configure-helper.sh
osh-nosouffle 7 3 4 9 2,029 configure-helper.sh
osh-cpython 312 290 22 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 5 1 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 304 282 23 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 15 5 15 9,661 ltmain.sh
osh-nosouffle 23 22 1 16 9,661 ltmain.sh
osh-cpython 1,013 988 23 30 9,661 ltmain.sh
dash 1 0 1 1 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 1 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 114 92 22 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 1 2 3 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 119 100 20 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 13 4 13 5,160 test-cmd-util.sh
osh-nosouffle 19 14 5 13 5,160 test-cmd-util.sh
osh-cpython 927 906 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 31,530,048 2,698 Build.sh
osh-nosouffle 35,779,369 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,668,592 2,512 abuild
osh-nosouffle 52,229,080 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,613,663 20,489 configure
osh-nosouffle 252,519,642 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,276,910 69,779 configure-coreutils
osh-nosouffle 836,596,127 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,992,425 2,029 configure-helper.sh
osh-nosouffle 30,272,602 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,428,104 1,733 functions
osh-nosouffle 28,817,411 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,116,634 9,661 ltmain.sh
osh-nosouffle 112,325,756 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,483 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,084 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 11,849,900 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,836 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 96,107,456 5,160 test-cmd-util.sh
osh-nosouffle 112,211,619 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-1f5ee437
osh-native osh-7647b828
osh-nosouffle osh-nosouffle-95904462
host label host id
no-host no-host-44ad0cc8

Raw Data

filename
no-host.2025-11-07__16-24-49.cachegrind.tsv
no-host.2025-11-07__16-24-49.times.csv