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 3,180
bash 118,863 1,413
osh-native 118,863 504
osh-nosouffle 118,863 463
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 0 2 2,698 Build.sh
bash 3 3 0 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 283 271 12 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 9 4 5 9 2,512 abuild
osh-nosouffle 9 8 1 9 2,512 abuild
osh-cpython 395 378 17 22 2,512 abuild
dash 7 7 0 2 20,489 configure
bash 16 15 1 4 20,489 configure
osh-native 38 35 3 23 20,489 configure
osh-nosouffle 42 36 6 23 20,489 configure
osh-cpython 1,883 1,859 24 44 20,489 configure
dash 18 18 0 2 69,779 configure-coreutils
bash 38 37 1 4 69,779 configure-coreutils
osh-native 131 112 19 52 69,779 configure-coreutils
osh-nosouffle 142 127 15 52 69,779 configure-coreutils
osh-cpython 5,448 5,405 43 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 5 1 9 2,029 configure-helper.sh
osh-cpython 275 259 17 22 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 5 4 1 9 1,733 functions
osh-nosouffle 6 5 1 9 1,733 functions
osh-cpython 266 257 8 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 8 6 2 4 9,661 ltmain.sh
osh-native 18 15 3 15 9,661 ltmain.sh
osh-nosouffle 20 15 5 16 9,661 ltmain.sh
osh-cpython 899 882 17 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 3 0 7 1,679 t4014-format-patch.sh
osh-nosouffle 3 3 0 8 1,679 t4014-format-patch.sh
osh-cpython 100 87 13 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-native 4 1 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 4 0 8 3,123 t9300-fast-import.sh
osh-cpython 104 92 13 19 3,123 t9300-fast-import.sh
bash 7 5 2 3 5,160 test-cmd-util.sh
osh-native 16 11 5 12 5,160 test-cmd-util.sh
osh-nosouffle 18 14 4 13 5,160 test-cmd-util.sh
osh-cpython 825 806 17 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 31,532,038 2,698 Build.sh
osh-nosouffle 35,781,274 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,672,166 2,512 abuild
osh-nosouffle 52,232,519 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,622,858 20,489 configure
osh-nosouffle 252,531,123 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,299,967 69,779 configure-coreutils
osh-nosouffle 836,628,932 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,939,746 2,029 configure-helper.sh
osh-nosouffle 30,217,001 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,429,938 1,733 functions
osh-nosouffle 28,819,253 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,119,776 9,661 ltmain.sh
osh-nosouffle 112,329,560 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,609 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,221 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 11,850,027 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,919 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 96,107,044 5,160 test-cmd-util.sh
osh-nosouffle 112,211,369 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-7cbbadf1
osh-native osh-837fcf4e
osh-nosouffle osh-nosouffle-e326900c
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-15__16-27-48.cachegrind.tsv
no-host.2025-11-15__16-27-48.times.csv