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 3,218
bash 118,863 1,405
osh-native 118,863 516
osh-nosouffle 118,863 471
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 1 2 3 2,698 Build.sh
osh-native 7 5 1 9 2,698 Build.sh
osh-nosouffle 7 5 2 9 2,698 Build.sh
osh-cpython 283 267 16 22 2,698 Build.sh
dash 1 0 1 2 2,512 abuild
bash 3 3 0 3 2,512 abuild
osh-native 8 6 2 9 2,512 abuild
osh-nosouffle 9 6 3 9 2,512 abuild
osh-cpython 398 382 15 22 2,512 abuild
dash 7 6 1 2 20,489 configure
bash 16 16 0 4 20,489 configure
osh-native 37 33 4 22 20,489 configure
osh-nosouffle 41 35 6 23 20,489 configure
osh-cpython 1,877 1,858 18 44 20,489 configure
dash 18 17 1 2 69,779 configure-coreutils
bash 38 37 1 4 69,779 configure-coreutils
osh-native 127 113 13 52 69,779 configure-coreutils
osh-nosouffle 141 124 17 52 69,779 configure-coreutils
osh-cpython 5,397 5,337 57 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 5 1 9 2,029 configure-helper.sh
osh-nosouffle 6 2 4 9 2,029 configure-helper.sh
osh-cpython 277 258 20 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 5 5 1 8 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 268 256 12 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 8 6 3 4 9,661 ltmain.sh
osh-native 18 12 6 16 9,661 ltmain.sh
osh-nosouffle 19 17 2 16 9,661 ltmain.sh
osh-cpython 897 881 15 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 7 1,679 t4014-format-patch.sh
osh-nosouffle 3 1 2 8 1,679 t4014-format-patch.sh
osh-cpython 101 88 14 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-nosouffle 4 4 0 8 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 107 93 15 19 3,123 t9300-fast-import.sh
bash 7 7 0 3 5,160 test-cmd-util.sh
osh-native 16 13 3 13 5,160 test-cmd-util.sh
osh-nosouffle 17 17 0 13 5,160 test-cmd-util.sh
osh-cpython 811 797 14 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 31,601,367 2,698 Build.sh
osh-nosouffle 35,849,615 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,944 2,512 abuild
osh-nosouffle 52,280,751 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,202 20,489 configure
osh-nosouffle 263,062,923 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,267 69,779 configure-coreutils
osh-nosouffle 862,832,519 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,983 2,029 configure-helper.sh
osh-nosouffle 30,266,182 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,857 1,733 functions
osh-nosouffle 28,861,286 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,369 9,661 ltmain.sh
osh-nosouffle 112,485,905 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,809 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,644 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 11,870,205 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,597 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 96,186,342 5,160 test-cmd-util.sh
osh-nosouffle 112,290,270 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-70d85774
osh-native osh-ee8e5e23
osh-nosouffle osh-nosouffle-629c11d2
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-15__02-48-39.cachegrind.tsv
no-host.2026-01-15__02-48-39.times.csv