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 3,295
bash 118,863 1,620
osh-native 118,863 567
osh-nosouffle 118,863 532
osh-cpython 118,863 14

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 2 2 0 3 2,698 Build.sh
osh-native 6 5 1 9 2,698 Build.sh
osh-nosouffle 6 5 2 9 2,698 Build.sh
osh-cpython 234 215 19 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 8 7 1 9 2,512 abuild
osh-nosouffle 8 7 1 9 2,512 abuild
osh-cpython 324 298 26 23 2,512 abuild
dash 7 7 0 2 20,489 configure
bash 14 10 3 4 20,489 configure
osh-native 32 22 10 23 20,489 configure
osh-nosouffle 35 30 5 23 20,489 configure
osh-cpython 1,509 1,466 43 44 20,489 configure
dash 18 17 1 2 69,779 configure-coreutils
bash 33 33 0 4 69,779 configure-coreutils
osh-native 115 91 24 52 69,779 configure-coreutils
osh-nosouffle 123 97 26 52 69,779 configure-coreutils
osh-cpython 4,486 4,412 74 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 5 3 3 9 2,029 configure-helper.sh
osh-nosouffle 6 3 3 9 2,029 configure-helper.sh
osh-cpython 228 214 14 22 2,029 configure-helper.sh
dash 1 0 1 1 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 5 2 3 8 1,733 functions
osh-nosouffle 5 4 1 9 1,733 functions
osh-cpython 220 206 14 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 7 7 0 4 9,661 ltmain.sh
osh-native 16 11 5 16 9,661 ltmain.sh
osh-nosouffle 18 8 10 16 9,661 ltmain.sh
osh-cpython 720 699 21 30 9,661 ltmain.sh
dash 1 0 1 1 1,679 t4014-format-patch.sh
bash 2 2 0 3 1,679 t4014-format-patch.sh
osh-native 4 3 1 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 90 70 20 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 4 0 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 93 75 18 19 3,123 t9300-fast-import.sh
bash 6 5 1 4 5,160 test-cmd-util.sh
osh-native 14 11 3 13 5,160 test-cmd-util.sh
osh-nosouffle 15 10 5 13 5,160 test-cmd-util.sh
osh-cpython 659 629 29 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 31,601,615 2,698 Build.sh
osh-nosouffle 35,849,894 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,724,175 2,512 abuild
osh-nosouffle 52,281,013 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,978 20,489 configure
osh-nosouffle 263,063,757 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,388,540 69,779 configure-coreutils
osh-nosouffle 862,833,857 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,988,167 2,029 configure-helper.sh
osh-nosouffle 30,266,431 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,472,070 1,733 functions
osh-nosouffle 28,861,557 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,677 9,661 ltmain.sh
osh-nosouffle 112,486,271 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,970 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,876 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 11,870,393 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,829 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 96,187,207 5,160 test-cmd-util.sh
osh-nosouffle 112,291,020 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-f6c05a8b
osh-native osh-acb28860
osh-nosouffle osh-nosouffle-fce4fb50
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-26__17-50-15.cachegrind.tsv
no-host.2026-01-26__17-50-15.times.csv