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 12.6

(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 2,589
bash 118,863 1,262
osh-native 118,863 440
osh-nosouffle 118,863 428
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 6 2 8 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 325 300 25 21 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 7 4 9 2,512 abuild
osh-cpython 460 433 27 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 13 4 4 20,489 configure
osh-native 41 30 10 22 20,489 configure
osh-nosouffle 41 31 10 23 20,489 configure
osh-cpython 2,151 2,111 40 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 43 42 1 3 69,779 configure-coreutils
osh-native 153 125 28 52 69,779 configure-coreutils
osh-nosouffle 154 131 23 52 69,779 configure-coreutils
osh-cpython 6,284 6,194 88 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 4 3 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 315 298 18 21 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 3 1 1 3 1,733 functions
osh-native 6 2 4 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 314 283 31 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 6 3 4 9,661 ltmain.sh
osh-native 21 18 3 15 9,661 ltmain.sh
osh-nosouffle 22 15 6 16 9,661 ltmain.sh
osh-cpython 1,028 1,005 23 30 9,661 ltmain.sh
dash 1 1 0 1 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 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 118 101 17 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 4 4 0 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 122 106 17 19 3,123 t9300-fast-import.sh
bash 8 6 2 3 5,160 test-cmd-util.sh
osh-native 18 12 6 12 5,160 test-cmd-util.sh
osh-nosouffle 19 15 5 13 5,160 test-cmd-util.sh
osh-cpython 933 908 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 31,592,024 2,698 Build.sh
osh-nosouffle 35,839,793 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,708,739 2,512 abuild
osh-nosouffle 52,273,629 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 221,047,026 20,489 configure
osh-nosouffle 263,040,959 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,361,039 69,779 configure-coreutils
osh-nosouffle 837,513,255 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,981,271 2,029 configure-helper.sh
osh-nosouffle 30,259,449 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,466,617 1,733 functions
osh-nosouffle 28,856,054 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,267,944 9,661 ltmain.sh
osh-nosouffle 112,478,071 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,060,901 1,679 t4014-format-patch.sh
osh-nosouffle 11,035,833 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 11,865,336 3,123 t9300-fast-import.sh
osh-nosouffle 13,015,661 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 96,171,332 5,160 test-cmd-util.sh
osh-nosouffle 112,278,513 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-f5069e26
osh-native osh-29092dfd
osh-nosouffle osh-nosouffle-8f9311b5
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-30__19-48-22.cachegrind.tsv
no-host.2025-11-30__19-48-22.times.csv