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 11.5
osh-nosouffle 118,863 12.9

(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 3,277
bash 118,863 1,427
osh-native 118,863 115
osh-nosouffle 118,863 112
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 0 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 24 6 18 9 2,698 Build.sh
osh-nosouffle 24 11 13 9 2,698 Build.sh
osh-cpython 281 267 14 22 2,698 Build.sh
dash 1 1 1 2 2,512 abuild
bash 3 3 0 3 2,512 abuild
osh-native 24 8 15 9 2,512 abuild
osh-nosouffle 25 10 15 10 2,512 abuild
osh-cpython 391 379 12 23 2,512 abuild
dash 7 5 2 2 20,489 configure
bash 15 15 0 4 20,489 configure
osh-native 190 57 134 23 20,489 configure
osh-nosouffle 193 64 129 24 20,489 configure
osh-cpython 1,885 1,856 25 44 20,489 configure
dash 18 16 2 2 69,779 configure-coreutils
bash 38 36 2 3 69,779 configure-coreutils
osh-native 557 175 382 52 69,779 configure-coreutils
osh-nosouffle 572 203 369 53 69,779 configure-coreutils
osh-cpython 5,404 5,357 45 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 25 5 20 9 2,029 configure-helper.sh
osh-nosouffle 26 5 21 10 2,029 configure-helper.sh
osh-cpython 276 260 16 21 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 2 1 1 3 1,733 functions
osh-native 16 7 9 9 1,733 functions
osh-nosouffle 16 4 13 9 1,733 functions
osh-cpython 273 252 21 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 8 8 0 4 9,661 ltmain.sh
osh-native 87 24 63 16 9,661 ltmain.sh
osh-nosouffle 89 21 68 17 9,661 ltmain.sh
osh-cpython 895 880 15 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 2 0 3 1,679 t4014-format-patch.sh
osh-native 15 3 11 8 1,679 t4014-format-patch.sh
osh-nosouffle 15 1 14 9 1,679 t4014-format-patch.sh
osh-cpython 99 88 11 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 20 4 16 8 3,123 t9300-fast-import.sh
osh-nosouffle 21 2 19 9 3,123 t9300-fast-import.sh
osh-cpython 105 96 8 19 3,123 t9300-fast-import.sh
bash 7 6 1 3 5,160 test-cmd-util.sh
osh-native 76 29 47 13 5,160 test-cmd-util.sh
osh-nosouffle 78 23 55 14 5,160 test-cmd-util.sh
osh-cpython 816 803 14 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 33,025,495 2,698 Build.sh
osh-nosouffle 37,273,643 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 46,034,476 2,512 abuild
osh-nosouffle 53,599,729 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 230,742,870 20,489 configure
osh-nosouffle 262,650,648 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 771,429,223 69,779 configure-coreutils
osh-nosouffle 860,750,377 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 27,856,213 2,029 configure-helper.sh
osh-nosouffle 32,136,405 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 25,494,048 1,733 functions
osh-nosouffle 29,883,072 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 100,898,397 9,661 ltmain.sh
osh-nosouffle 117,108,217 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
bash 11,082,677 1,679 t4014-format-patch.sh
osh-native 11,245,643 1,679 t4014-format-patch.sh
osh-nosouffle 12,220,193 1,679 t4014-format-patch.sh
dash 4,585,030 3,123 t9300-fast-import.sh
osh-native 13,221,411 3,123 t9300-fast-import.sh
osh-nosouffle 14,371,319 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 101,376,064 5,160 test-cmd-util.sh
osh-nosouffle 117,478,476 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-cd0ae5ac
osh-native osh-dfadf10f
osh-nosouffle osh-nosouffle-067693f2
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-12__20-17-49.cachegrind.tsv
no-host.2025-11-12__20-17-49.times.csv