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 2,470
bash 118,863 1,253
osh-nosouffle 118,863 425
osh-native 118,863 420
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 1 1 2 2,698 Build.sh
bash 3 2 2 3 2,698 Build.sh
osh-native 7 6 2 9 2,698 Build.sh
osh-nosouffle 8 7 1 9 2,698 Build.sh
osh-cpython 326 306 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 6 4 9 2,512 abuild
osh-nosouffle 10 7 3 9 2,512 abuild
osh-cpython 454 431 23 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-nosouffle 42 33 10 23 20,489 configure
osh-native 43 32 11 22 20,489 configure
osh-cpython 2,171 2,130 41 44 20,489 configure
dash 25 24 1 2 69,779 configure-coreutils
bash 44 41 3 3 69,779 configure-coreutils
osh-nosouffle 156 137 19 52 69,779 configure-coreutils
osh-native 165 145 20 52 69,779 configure-coreutils
osh-cpython 6,351 6,261 87 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 3 4 9 2,029 configure-helper.sh
osh-nosouffle 7 3 4 9 2,029 configure-helper.sh
osh-cpython 320 303 17 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 3 0 3 1,733 functions
osh-native 6 6 0 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 309 284 26 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 13 7 16 9,661 ltmain.sh
osh-nosouffle 22 19 3 16 9,661 ltmain.sh
osh-cpython 1,037 1,016 21 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 4 0 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 116 90 26 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 0 4 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 3 2 8 3,123 t9300-fast-import.sh
osh-cpython 125 103 22 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 17 12 6 12 5,160 test-cmd-util.sh
osh-nosouffle 19 15 3 13 5,160 test-cmd-util.sh
osh-cpython 928 903 25 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 31,530,269 2,698 Build.sh
osh-nosouffle 35,779,695 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,668,571 2,512 abuild
osh-nosouffle 52,229,056 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,613,642 20,489 configure
osh-nosouffle 252,519,618 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,276,889 69,779 configure-coreutils
osh-nosouffle 836,596,130 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 26,009,012 2,029 configure-helper.sh
osh-nosouffle 30,296,710 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,428,083 1,733 functions
osh-nosouffle 28,817,387 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,116,613 9,661 ltmain.sh
osh-nosouffle 112,325,732 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,462 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,060 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 11,849,879 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,812 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 96,108,626 5,160 test-cmd-util.sh
osh-nosouffle 112,214,748 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-c9f155b1
osh-native osh-5fd25311
osh-nosouffle osh-nosouffle-f3ca44d4
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-14__10-10-56.cachegrind.tsv
no-host.2025-11-14__10-10-56.times.csv