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 2,607
bash 118,863 1,285
osh-native 118,863 484
osh-nosouffle 118,863 457
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 7 4 3 9 2,698 Build.sh
osh-nosouffle 8 5 2 9 2,698 Build.sh
osh-cpython 322 292 30 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 6 4 9 2,512 abuild
osh-cpython 445 417 27 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 38 31 7 22 20,489 configure
osh-nosouffle 41 32 9 23 20,489 configure
osh-cpython 2,150 2,113 37 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 41 1 4 69,779 configure-coreutils
osh-native 136 108 28 52 69,779 configure-coreutils
osh-nosouffle 142 118 24 52 69,779 configure-coreutils
osh-cpython 6,257 6,177 80 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 7 4 3 9 2,029 configure-helper.sh
osh-cpython 319 294 24 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 4 2 8 1,733 functions
osh-nosouffle 6 5 1 9 1,733 functions
osh-cpython 305 283 22 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 9 0 4 9,661 ltmain.sh
osh-native 19 12 7 15 9,661 ltmain.sh
osh-nosouffle 20 18 2 16 9,661 ltmain.sh
osh-cpython 1,011 981 30 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 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 112 93 19 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 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 119 92 27 19 3,123 t9300-fast-import.sh
bash 8 4 3 3 5,160 test-cmd-util.sh
osh-native 17 12 5 13 5,160 test-cmd-util.sh
osh-nosouffle 18 13 5 13 5,160 test-cmd-util.sh
osh-cpython 924 896 28 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 31,535,717 2,698 Build.sh
osh-nosouffle 35,785,401 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,901 2,512 abuild
osh-nosouffle 52,236,411 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,647,023 20,489 configure
osh-nosouffle 252,557,846 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,412,630 69,779 configure-coreutils
osh-nosouffle 836,744,278 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,946,882 2,029 configure-helper.sh
osh-nosouffle 30,224,524 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,431,937 1,733 functions
osh-nosouffle 28,822,149 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,131,013 9,661 ltmain.sh
osh-nosouffle 112,341,885 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,691 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,607 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 11,850,495 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,778 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 96,119,073 5,160 test-cmd-util.sh
osh-nosouffle 112,224,615 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-ef672410
osh-native osh-2c0af0e8
osh-nosouffle osh-nosouffle-13d478f5
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-20__17-01-08.cachegrind.tsv
no-host.2025-11-20__17-01-08.times.csv