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 2,608
bash 118,863 1,277
osh-native 118,863 485
osh-nosouffle 118,863 455
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 0 2 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 7 5 2 9 2,698 Build.sh
osh-nosouffle 8 4 3 9 2,698 Build.sh
osh-cpython 327 306 20 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 5 5 9 2,512 abuild
osh-cpython 451 428 23 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 38 24 14 22 20,489 configure
osh-nosouffle 41 27 14 23 20,489 configure
osh-cpython 2,132 2,085 47 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 42 0 4 69,779 configure-coreutils
osh-native 134 117 17 52 69,779 configure-coreutils
osh-nosouffle 144 123 21 52 69,779 configure-coreutils
osh-cpython 6,264 6,203 60 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 3 4 9 2,029 configure-helper.sh
osh-nosouffle 7 2 5 9 2,029 configure-helper.sh
osh-cpython 318 292 26 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 3 0 3 1,733 functions
osh-native 6 3 3 8 1,733 functions
osh-nosouffle 6 3 4 9 1,733 functions
osh-cpython 307 282 26 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 15 4 16 9,661 ltmain.sh
osh-nosouffle 20 11 9 16 9,661 ltmain.sh
osh-cpython 1,014 988 26 30 9,661 ltmain.sh
dash 1 1 0 1 1,679 t4014-format-patch.sh
bash 2 0 2 3 1,679 t4014-format-patch.sh
osh-native 4 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 114 86 28 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 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 121 103 18 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 16 14 3 13 5,160 test-cmd-util.sh
osh-nosouffle 18 12 6 13 5,160 test-cmd-util.sh
osh-cpython 920 887 31 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 31,530,075 2,698 Build.sh
osh-nosouffle 35,779,396 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,668,619 2,512 abuild
osh-nosouffle 52,229,107 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,613,690 20,489 configure
osh-nosouffle 252,519,669 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,276,937 69,779 configure-coreutils
osh-nosouffle 836,596,154 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,992,452 2,029 configure-helper.sh
osh-nosouffle 30,272,629 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,428,158 1,733 functions
osh-nosouffle 28,817,438 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,116,661 9,661 ltmain.sh
osh-nosouffle 112,325,783 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,537 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,111 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 11,849,927 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,863 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 96,107,483 5,160 test-cmd-util.sh
osh-nosouffle 112,213,019 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-344f6e55
osh-native osh-e76a3222
osh-nosouffle osh-nosouffle-717188f1
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-09__17-07-41.cachegrind.tsv
no-host.2025-11-09__17-07-41.times.csv