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 2,569
bash 118,863 1,264
osh-native 118,863 436
osh-nosouffle 118,863 424
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 2 3 2,698 Build.sh
osh-native 8 6 2 9 2,698 Build.sh
osh-nosouffle 8 6 3 9 2,698 Build.sh
osh-cpython 327 302 26 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 10 5 6 9 2,512 abuild
osh-cpython 459 435 24 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 43 32 10 22 20,489 configure
osh-nosouffle 43 33 10 23 20,489 configure
osh-cpython 2,140 2,092 48 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 153 122 31 52 69,779 configure-coreutils
osh-nosouffle 153 130 23 52 69,779 configure-coreutils
osh-cpython 6,391 6,308 82 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 7 4 3 9 2,029 configure-helper.sh
osh-nosouffle 7 6 1 9 2,029 configure-helper.sh
osh-cpython 321 301 20 21 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 3 0 3 1,733 functions
osh-native 7 2 4 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 320 297 24 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 15 5 16 9,661 ltmain.sh
osh-nosouffle 23 16 7 16 9,661 ltmain.sh
osh-cpython 1,018 990 29 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 4 4 0 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 100 16 19 1,679 t4014-format-patch.sh
dash 1 0 1 2 3,123 t9300-fast-import.sh
bash 2 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 2 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 120 99 21 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 18 11 7 12 5,160 test-cmd-util.sh
osh-nosouffle 19 13 6 13 5,160 test-cmd-util.sh
osh-cpython 946 913 32 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 31,530,078 2,698 Build.sh
osh-nosouffle 35,779,399 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,668,622 2,512 abuild
osh-nosouffle 52,229,137 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,613,693 20,489 configure
osh-nosouffle 252,519,672 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,258,698 69,779 configure-coreutils
osh-nosouffle 836,596,157 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,992,455 2,029 configure-helper.sh
osh-nosouffle 30,272,659 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,428,134 1,733 functions
osh-nosouffle 28,817,468 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,116,664 9,661 ltmain.sh
osh-nosouffle 112,325,786 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,513 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,141 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 11,849,930 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,866 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 96,107,486 5,160 test-cmd-util.sh
osh-nosouffle 112,213,022 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-f6817cf2
osh-native osh-6aff9066
osh-nosouffle osh-nosouffle-8af3c5f6
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-13__04-05-16.cachegrind.tsv
no-host.2025-11-13__04-05-16.times.csv