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 2,588
bash 118,863 1,270
osh-native 118,863 448
osh-nosouffle 118,863 423
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 1 3 2,698 Build.sh
osh-native 8 5 3 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 323 302 22 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 10 6 3 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 452 430 22 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 40 29 11 23 20,489 configure
osh-nosouffle 43 34 9 23 20,489 configure
osh-cpython 2,128 2,088 40 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 42 0 3 69,779 configure-coreutils
osh-native 147 121 26 52 69,779 configure-coreutils
osh-nosouffle 157 130 26 52 69,779 configure-coreutils
osh-cpython 6,295 6,231 64 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 5 2 9 2,029 configure-helper.sh
osh-nosouffle 7 2 5 9 2,029 configure-helper.sh
osh-cpython 316 291 25 22 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-nosouffle 7 6 1 9 1,733 functions
osh-native 9 6 3 8 1,733 functions
osh-cpython 309 290 19 21 1,733 functions
dash 4 2 2 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 12 9 15 9,661 ltmain.sh
osh-nosouffle 22 15 7 16 9,661 ltmain.sh
osh-cpython 1,015 989 24 30 9,661 ltmain.sh
dash 1 0 1 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 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 93 22 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 124 100 24 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 13 5 12 5,160 test-cmd-util.sh
osh-nosouffle 19 14 5 13 5,160 test-cmd-util.sh
osh-cpython 936 903 33 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 31,596,835 2,698 Build.sh
osh-nosouffle 35,844,535 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,715,082 2,512 abuild
osh-nosouffle 52,275,010 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,142,246 20,489 configure
osh-nosouffle 263,054,787 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,400,971 69,779 configure-coreutils
osh-nosouffle 837,539,710 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,984,477 2,029 configure-helper.sh
osh-nosouffle 30,262,512 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,780 1,733 functions
osh-nosouffle 28,859,208 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,185 9,661 ltmain.sh
osh-nosouffle 112,484,857 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,586 1,679 t4014-format-patch.sh
osh-nosouffle 11,037,438 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 11,866,946 3,123 t9300-fast-import.sh
osh-nosouffle 13,017,381 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 96,179,629 5,160 test-cmd-util.sh
osh-nosouffle 112,286,638 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-f62e92c9
osh-native osh-c6ca0c1a
osh-nosouffle osh-nosouffle-2cc905a7
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-10__21-36-05.cachegrind.tsv
no-host.2025-12-10__21-36-05.times.csv