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 2,589
bash 118,863 1,261
osh-native 118,863 458
osh-nosouffle 118,863 410
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 8 0 8 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 330 314 16 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 2 9 2,512 abuild
osh-nosouffle 10 7 4 9 2,512 abuild
osh-cpython 456 427 29 23 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 39 29 10 23 20,489 configure
osh-nosouffle 46 33 13 23 20,489 configure
osh-cpython 2,177 2,128 49 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 41 1 4 69,779 configure-coreutils
osh-native 147 126 20 52 69,779 configure-coreutils
osh-nosouffle 163 135 27 52 69,779 configure-coreutils
osh-cpython 6,279 6,207 69 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 7 5 2 9 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 315 291 24 22 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 3 3 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 312 292 20 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 19 15 5 16 9,661 ltmain.sh
osh-nosouffle 22 17 5 16 9,661 ltmain.sh
osh-cpython 1,017 990 28 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 3 1 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 116 100 16 19 1,679 t4014-format-patch.sh
dash 1 1 0 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 4 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 125 95 30 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 14 3 12 5,160 test-cmd-util.sh
osh-nosouffle 19 13 6 13 5,160 test-cmd-util.sh
osh-cpython 934 909 25 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 31,573,769 2,698 Build.sh
osh-nosouffle 35,823,498 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,695,259 2,512 abuild
osh-nosouffle 52,255,841 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,998,587 20,489 configure
osh-nosouffle 252,909,249 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,150,106 69,779 configure-coreutils
osh-nosouffle 837,482,529 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,966,277 2,029 configure-helper.sh
osh-nosouffle 30,243,919 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,449,639 1,733 functions
osh-nosouffle 28,839,106 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,249,986 9,661 ltmain.sh
osh-nosouffle 112,460,924 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,047,991 1,679 t4014-format-patch.sh
osh-nosouffle 11,023,024 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 11,852,460 3,123 t9300-fast-import.sh
osh-nosouffle 13,002,779 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 96,151,039 5,160 test-cmd-util.sh
osh-nosouffle 112,256,644 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-4f5983df
osh-native osh-c2102b77
osh-nosouffle osh-nosouffle-e42c34f5
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-23__13-58-15.cachegrind.tsv
no-host.2025-11-23__13-58-15.times.csv