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 3,223
bash 118,863 1,215
osh-native 118,863 504
osh-nosouffle 118,863 459
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 7 3 3 9 2,698 Build.sh
osh-nosouffle 7 4 3 9 2,698 Build.sh
osh-cpython 283 268 14 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 3 3 1 3 2,512 abuild
osh-native 8 7 1 9 2,512 abuild
osh-nosouffle 9 8 1 9 2,512 abuild
osh-cpython 403 388 15 23 2,512 abuild
dash 7 7 0 2 20,489 configure
bash 17 14 3 4 20,489 configure
osh-native 37 28 9 23 20,489 configure
osh-nosouffle 41 35 6 23 20,489 configure
osh-cpython 1,886 1,854 32 45 20,489 configure
dash 18 16 2 2 69,779 configure-coreutils
bash 45 43 2 3 69,779 configure-coreutils
osh-native 130 112 18 52 69,779 configure-coreutils
osh-nosouffle 144 128 16 52 69,779 configure-coreutils
osh-cpython 5,481 5,424 57 92 69,779 configure-coreutils
bash 5 3 0 3 2,029 configure-helper.sh
osh-native 6 2 4 9 2,029 configure-helper.sh
osh-nosouffle 6 5 1 9 2,029 configure-helper.sh
osh-cpython 325 306 19 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 2 2 0 3 1,733 functions
osh-native 6 4 2 9 1,733 functions
osh-nosouffle 6 5 1 9 1,733 functions
osh-cpython 270 254 16 22 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 12 8 5 4 9,661 ltmain.sh
osh-native 18 12 7 16 9,661 ltmain.sh
osh-nosouffle 20 14 6 16 9,661 ltmain.sh
osh-cpython 889 867 22 31 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-nosouffle 3 1 2 8 1,679 t4014-format-patch.sh
osh-native 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 102 90 11 20 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 4 1 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 108 96 12 20 3,123 t9300-fast-import.sh
bash 7 6 1 3 5,160 test-cmd-util.sh
osh-native 16 10 6 13 5,160 test-cmd-util.sh
osh-nosouffle 18 13 5 13 5,160 test-cmd-util.sh
osh-cpython 816 797 18 29 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 31,540,047 2,698 Build.sh
osh-nosouffle 35,789,574 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,680,175 2,512 abuild
osh-nosouffle 52,240,819 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,630,868 20,489 configure
osh-nosouffle 252,539,423 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,307,976 69,779 configure-coreutils
osh-nosouffle 836,637,238 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,947,755 2,029 configure-helper.sh
osh-nosouffle 30,225,307 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,437,947 1,733 functions
osh-nosouffle 28,827,553 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,127,785 9,661 ltmain.sh
osh-nosouffle 112,337,860 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,052,618 1,679 t4014-format-patch.sh
osh-nosouffle 11,027,521 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 11,858,036 3,123 t9300-fast-import.sh
osh-nosouffle 13,008,219 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 96,114,809 5,160 test-cmd-util.sh
osh-nosouffle 112,219,479 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-cd2f85a6
osh-native osh-1449c97f
osh-nosouffle osh-nosouffle-6ccbc11c
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-16__19-24-43.cachegrind.tsv
no-host.2025-11-16__19-24-43.times.csv