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 12.6

(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 2,584
bash 118,863 1,222
osh-native 118,863 464
osh-nosouffle 118,863 445
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 8 4 3 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 327 313 14 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 5 4 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 454 429 25 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 39 27 12 22 20,489 configure
osh-nosouffle 43 29 14 23 20,489 configure
osh-cpython 2,118 2,070 47 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 141 115 27 52 69,779 configure-coreutils
osh-nosouffle 145 124 21 52 69,779 configure-coreutils
osh-cpython 6,284 6,207 77 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 7 0 9 2,029 configure-helper.sh
osh-nosouffle 7 4 4 9 2,029 configure-helper.sh
osh-cpython 323 306 17 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-native 6 5 2 9 1,733 functions
osh-nosouffle 7 5 1 9 1,733 functions
osh-cpython 309 288 22 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 13 11 2 4 9,661 ltmain.sh
osh-native 20 13 7 15 9,661 ltmain.sh
osh-nosouffle 21 13 8 16 9,661 ltmain.sh
osh-cpython 1,039 1,015 24 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 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 116 99 17 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 2 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 119 97 23 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 12 6 13 5,160 test-cmd-util.sh
osh-nosouffle 19 16 3 13 5,160 test-cmd-util.sh
osh-cpython 935 904 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 31,593,805 2,698 Build.sh
osh-nosouffle 35,841,504 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,711,030 2,512 abuild
osh-nosouffle 52,275,868 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,134,084 20,489 configure
osh-nosouffle 263,045,573 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,366,705 69,779 configure-coreutils
osh-nosouffle 837,521,081 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,982,509 2,029 configure-helper.sh
osh-nosouffle 30,260,637 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,467,840 1,733 functions
osh-nosouffle 28,857,228 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,270,388 9,661 ltmain.sh
osh-nosouffle 112,480,613 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,061,602 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,475 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 11,866,028 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,303 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 96,173,997 5,160 test-cmd-util.sh
osh-nosouffle 112,280,739 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-b3db5b15
osh-native osh-7975364e
osh-nosouffle osh-nosouffle-3e34b56e
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-07__11-21-33.cachegrind.tsv
no-host.2025-12-07__11-21-33.times.csv