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 12.8

(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 2,597
bash 118,863 1,267
osh-native 118,863 479
osh-nosouffle 118,863 435
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 1 2 3 2,698 Build.sh
osh-native 7 4 3 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 322 304 19 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 6 4 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 454 432 21 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 39 31 8 23 20,489 configure
osh-nosouffle 44 37 7 23 20,489 configure
osh-cpython 2,149 2,106 43 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 135 115 20 52 69,779 configure-coreutils
osh-nosouffle 149 133 16 52 69,779 configure-coreutils
osh-cpython 6,174 6,099 74 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 7 4 3 9 2,029 configure-helper.sh
osh-nosouffle 7 3 4 9 2,029 configure-helper.sh
osh-cpython 314 303 11 22 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 3 1 2 3 1,733 functions
osh-native 6 5 1 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 304 283 21 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 9 0 4 9,661 ltmain.sh
osh-native 19 13 6 15 9,661 ltmain.sh
osh-nosouffle 21 16 5 16 9,661 ltmain.sh
osh-cpython 1,022 984 36 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 1 3 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 115 92 23 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 1 3 8 3,123 t9300-fast-import.sh
osh-cpython 121 104 17 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 11 6 13 5,160 test-cmd-util.sh
osh-nosouffle 19 18 1 13 5,160 test-cmd-util.sh
osh-cpython 923 897 26 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 31,597,785 2,698 Build.sh
osh-nosouffle 35,846,084 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,720,345 2,512 abuild
osh-nosouffle 52,277,203 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,141,175 20,489 configure
osh-nosouffle 263,059,920 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,384,750 69,779 configure-coreutils
osh-nosouffle 862,830,029 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,984,350 2,029 configure-helper.sh
osh-nosouffle 30,262,630 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,468,240 1,733 functions
osh-nosouffle 28,857,747 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,271,874 9,661 ltmain.sh
osh-nosouffle 112,482,434 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,209 1,679 t4014-format-patch.sh
osh-nosouffle 11,037,116 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 11,866,632 3,123 t9300-fast-import.sh
osh-nosouffle 13,017,069 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 96,183,167 5,160 test-cmd-util.sh
osh-nosouffle 112,287,083 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-f6cffb81
osh-native osh-80865b73
osh-nosouffle osh-nosouffle-9798a836
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2026-01-26__22-24-24.cachegrind.tsv
no-host.2026-01-26__22-24-24.times.csv