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 3,269
bash 118,863 1,431
osh-native 118,863 511
osh-nosouffle 118,863 462
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 1 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 6 1 9 2,698 Build.sh
osh-cpython 282 272 10 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 2 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 9 10 0 9 2,512 abuild
osh-cpython 394 381 13 23 2,512 abuild
dash 7 6 2 2 20,489 configure
bash 16 16 0 4 20,489 configure
osh-native 37 27 9 23 20,489 configure
osh-nosouffle 46 37 9 23 20,489 configure
osh-cpython 1,860 1,837 23 44 20,489 configure
dash 18 18 0 2 69,779 configure-coreutils
bash 38 37 1 3 69,779 configure-coreutils
osh-native 130 106 24 52 69,779 configure-coreutils
osh-nosouffle 136 119 17 52 69,779 configure-coreutils
osh-cpython 5,501 5,450 50 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 6 0 9 2,029 configure-helper.sh
osh-nosouffle 6 4 3 9 2,029 configure-helper.sh
osh-cpython 276 257 18 21 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 6 3 2 9 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 267 252 15 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 8 6 2 4 9,661 ltmain.sh
osh-native 17 12 6 15 9,661 ltmain.sh
osh-nosouffle 21 16 5 16 9,661 ltmain.sh
osh-cpython 887 864 23 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 0 2 3 1,679 t4014-format-patch.sh
osh-native 3 1 2 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 100 85 15 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 3 2 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 106 90 16 19 3,123 t9300-fast-import.sh
bash 7 6 1 3 5,160 test-cmd-util.sh
osh-native 16 13 3 13 5,160 test-cmd-util.sh
osh-nosouffle 18 10 7 13 5,160 test-cmd-util.sh
osh-cpython 808 783 25 29 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 31,601,337 2,698 Build.sh
osh-nosouffle 35,848,911 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,913 2,512 abuild
osh-nosouffle 52,280,748 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,339 20,489 configure
osh-nosouffle 263,062,893 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,237 69,779 configure-coreutils
osh-nosouffle 862,832,489 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,926 2,029 configure-helper.sh
osh-nosouffle 30,266,179 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,800 1,733 functions
osh-nosouffle 28,861,283 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,339 9,661 ltmain.sh
osh-nosouffle 112,485,875 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,752 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,641 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 11,870,175 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,594 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 96,186,312 5,160 test-cmd-util.sh
osh-nosouffle 112,290,267 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-ac75ab0b
osh-native osh-316cc692
osh-nosouffle osh-nosouffle-4d8ba6df
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-15__20-25-11.cachegrind.tsv
no-host.2026-01-15__20-25-11.times.csv