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 3,219
bash 118,863 1,404
osh-native 118,863 497
osh-nosouffle 118,863 447
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 2 1 3 2,698 Build.sh
osh-native 7 7 0 9 2,698 Build.sh
osh-nosouffle 7 2 6 9 2,698 Build.sh
osh-cpython 284 270 13 22 2,698 Build.sh
dash 1 1 1 2 2,512 abuild
bash 3 3 0 3 2,512 abuild
osh-native 8 8 0 9 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-cpython 398 390 8 23 2,512 abuild
dash 7 6 1 2 20,489 configure
bash 15 15 0 4 20,489 configure
osh-native 37 28 8 22 20,489 configure
osh-nosouffle 42 38 4 23 20,489 configure
osh-cpython 1,902 1,873 29 44 20,489 configure
dash 18 18 0 2 69,779 configure-coreutils
bash 39 37 1 4 69,779 configure-coreutils
osh-native 136 113 23 52 69,779 configure-coreutils
osh-nosouffle 148 129 19 52 69,779 configure-coreutils
osh-cpython 5,448 5,399 48 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 6 0 9 2,029 configure-helper.sh
osh-cpython 275 263 12 22 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 2 1 3 1,733 functions
osh-native 6 6 0 8 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 266 255 11 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 8 5 4 4 9,661 ltmain.sh
osh-native 18 14 4 16 9,661 ltmain.sh
osh-nosouffle 20 15 5 16 9,661 ltmain.sh
osh-cpython 897 879 18 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 8 1,679 t4014-format-patch.sh
osh-nosouffle 3 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 98 83 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 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 106 92 13 19 3,123 t9300-fast-import.sh
bash 7 6 1 3 5,160 test-cmd-util.sh
osh-native 16 11 5 13 5,160 test-cmd-util.sh
osh-nosouffle 18 13 5 13 5,160 test-cmd-util.sh
osh-cpython 815 802 13 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 31,535,451 2,698 Build.sh
osh-nosouffle 35,785,118 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,636 2,512 abuild
osh-nosouffle 52,236,129 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,646,757 20,489 configure
osh-nosouffle 252,557,617 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,412,364 69,779 configure-coreutils
osh-nosouffle 836,744,049 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,946,616 2,029 configure-helper.sh
osh-nosouffle 30,224,241 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,432,488 1,733 functions
osh-nosouffle 28,821,893 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,130,747 9,661 ltmain.sh
osh-nosouffle 112,341,629 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,425 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,351 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 11,850,229 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,495 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 96,118,807 5,160 test-cmd-util.sh
osh-nosouffle 112,224,308 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-823f331e
osh-native osh-f86bb45f
osh-nosouffle osh-nosouffle-d9952f81
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-20__15-38-02.cachegrind.tsv
no-host.2025-11-20__15-38-02.times.csv