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 2,551
bash 118,863 1,237
osh-native 118,863 417
osh-nosouffle 118,863 353
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 2 0 2 2,698 Build.sh
bash 3 2 2 3 2,698 Build.sh
osh-native 8 5 3 9 2,698 Build.sh
osh-nosouffle 9 7 1 9 2,698 Build.sh
osh-cpython 339 319 20 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 9 7 3 9 2,512 abuild
osh-nosouffle 11 9 3 9 2,512 abuild
osh-cpython 464 441 22 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 18 17 1 4 20,489 configure
osh-native 42 31 11 23 20,489 configure
osh-nosouffle 48 40 8 23 20,489 configure
osh-cpython 2,216 2,160 56 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 43 43 0 3 69,779 configure-coreutils
osh-native 165 141 24 52 69,779 configure-coreutils
osh-nosouffle 202 174 28 52 69,779 configure-coreutils
osh-cpython 6,505 6,423 82 91 69,779 configure-coreutils
bash 4 3 1 3 2,029 configure-helper.sh
osh-native 7 4 3 9 2,029 configure-helper.sh
osh-nosouffle 8 6 1 9 2,029 configure-helper.sh
osh-cpython 327 299 28 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 7 4 3 9 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 323 299 24 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 10 10 0 4 9,661 ltmain.sh
osh-native 22 16 6 16 9,661 ltmain.sh
osh-nosouffle 24 17 6 16 9,661 ltmain.sh
osh-cpython 1,045 1,010 34 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 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 122 96 26 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-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 4 1 8 3,123 t9300-fast-import.sh
osh-cpython 129 113 16 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 16 3 13 5,160 test-cmd-util.sh
osh-cpython 939 911 29 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 31,600,727 2,698 Build.sh
osh-nosouffle 35,848,956 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,303 2,512 abuild
osh-nosouffle 52,280,091 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,535 20,489 configure
osh-nosouffle 263,062,264 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,613 69,779 configure-coreutils
osh-nosouffle 862,831,882 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,329 2,029 configure-helper.sh
osh-nosouffle 30,265,545 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,163 1,733 functions
osh-nosouffle 28,860,627 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,729 9,661 ltmain.sh
osh-nosouffle 112,485,246 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,176 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,039 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 11,868,802 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,992 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 96,185,823 5,160 test-cmd-util.sh
osh-nosouffle 112,289,654 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-894592e0
osh-native osh-6bbe7583
osh-nosouffle osh-nosouffle-9e8f8068
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2025-12-26__05-47-29.cachegrind.tsv
no-host.2025-12-26__05-47-29.times.csv