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 2,568
bash 118,863 1,250
osh-native 118,863 446
osh-nosouffle 118,863 417
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 1 3 2,698 Build.sh
osh-native 8 5 3 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 335 315 20 21 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 4 5 9 2,512 abuild
osh-nosouffle 10 7 3 9 2,512 abuild
osh-cpython 460 444 16 22 2,512 abuild
dash 9 6 3 2 20,489 configure
bash 17 14 3 4 20,489 configure
osh-native 40 31 9 23 20,489 configure
osh-nosouffle 43 29 14 23 20,489 configure
osh-cpython 2,213 2,154 56 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 43 42 1 4 69,779 configure-coreutils
osh-native 152 130 22 52 69,779 configure-coreutils
osh-nosouffle 160 134 26 52 69,779 configure-coreutils
osh-cpython 6,415 6,323 91 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 7 4 3 9 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 323 302 22 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 4 2 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 309 294 15 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 19 17 3 15 9,661 ltmain.sh
osh-nosouffle 22 16 6 16 9,661 ltmain.sh
osh-cpython 1,044 1,007 35 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-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-native 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 120 97 23 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 1 2 3 3,123 t9300-fast-import.sh
osh-native 4 3 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 130 105 25 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 13 4 12 5,160 test-cmd-util.sh
osh-nosouffle 19 18 1 13 5,160 test-cmd-util.sh
osh-cpython 939 896 43 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 31,600,243 2,698 Build.sh
osh-nosouffle 35,848,468 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,722,828 2,512 abuild
osh-nosouffle 52,279,612 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,087 20,489 configure
osh-nosouffle 263,061,800 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,153 69,779 configure-coreutils
osh-nosouffle 862,831,355 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,986,873 2,029 configure-helper.sh
osh-nosouffle 30,265,076 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,470,715 1,733 functions
osh-nosouffle 28,860,148 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,254 9,661 ltmain.sh
osh-nosouffle 112,484,759 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,064,745 1,679 t4014-format-patch.sh
osh-nosouffle 11,039,579 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 11,869,144 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,514 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 96,185,340 5,160 test-cmd-util.sh
osh-nosouffle 112,289,235 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-6433e72c
osh-native osh-38964d46
osh-nosouffle osh-nosouffle-3a0e57a9
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-17__16-55-48.cachegrind.tsv
no-host.2025-12-17__16-55-48.times.csv