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 2,589
bash 118,863 1,278
osh-native 118,863 484
osh-nosouffle 118,863 447
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 3 4 9 2,698 Build.sh
osh-nosouffle 8 4 4 9 2,698 Build.sh
osh-cpython 328 311 17 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 10 6 4 9 2,512 abuild
osh-cpython 455 428 27 23 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 40 33 7 23 20,489 configure
osh-nosouffle 42 30 12 23 20,489 configure
osh-cpython 2,128 2,085 42 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 133 109 24 52 69,779 configure-coreutils
osh-nosouffle 145 122 23 52 69,779 configure-coreutils
osh-cpython 6,220 6,144 76 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 1 5 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 318 299 19 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 4 2 9 1,733 functions
osh-nosouffle 7 3 3 9 1,733 functions
osh-cpython 302 277 25 21 1,733 functions
dash 4 2 3 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 13 7 16 9,661 ltmain.sh
osh-nosouffle 21 16 5 16 9,661 ltmain.sh
osh-cpython 1,024 1,000 24 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 0 2 3 1,679 t4014-format-patch.sh
osh-native 4 1 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 94 21 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 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 120 101 19 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 17 9 8 12 5,160 test-cmd-util.sh
osh-nosouffle 19 17 2 13 5,160 test-cmd-util.sh
osh-cpython 918 889 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 31,601,418 2,698 Build.sh
osh-nosouffle 35,849,686 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,994 2,512 abuild
osh-nosouffle 52,280,821 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,144,253 20,489 configure
osh-nosouffle 263,062,967 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,387,317 69,779 configure-coreutils
osh-nosouffle 862,832,563 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,988,006 2,029 configure-helper.sh
osh-nosouffle 30,266,253 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,881 1,733 functions
osh-nosouffle 28,861,357 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,275,420 9,661 ltmain.sh
osh-nosouffle 112,485,949 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,826 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,688 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 11,870,249 3,123 t9300-fast-import.sh
osh-nosouffle 13,020,668 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 96,186,392 5,160 test-cmd-util.sh
osh-nosouffle 112,290,313 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-6a76879a
osh-native osh-06bcc766
osh-nosouffle osh-nosouffle-c2f31f66
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-25__12-01-10.cachegrind.tsv
no-host.2026-01-25__12-01-10.times.csv