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 2,565
bash 118,863 1,246
osh-native 118,863 457
osh-nosouffle 118,863 432
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 7 5 2 9 2,698 Build.sh
osh-nosouffle 8 7 1 9 2,698 Build.sh
osh-cpython 329 303 26 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-native 9 5 4 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 456 427 29 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 38 26 12 22 20,489 configure
osh-nosouffle 44 32 12 23 20,489 configure
osh-cpython 2,202 2,156 46 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 44 44 0 3 69,779 configure-coreutils
osh-native 149 128 20 52 69,779 configure-coreutils
osh-nosouffle 153 132 21 52 69,779 configure-coreutils
osh-cpython 6,360 6,271 89 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 5 2 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 319 298 22 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 4 2 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 309 278 31 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 19 13 6 15 9,661 ltmain.sh
osh-nosouffle 21 19 2 16 9,661 ltmain.sh
osh-cpython 1,028 999 30 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 1 3 8 1,679 t4014-format-patch.sh
osh-cpython 115 96 19 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 1 1 3 3,123 t9300-fast-import.sh
osh-native 4 1 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 122 105 17 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 17 12 5 12 5,160 test-cmd-util.sh
osh-nosouffle 18 15 3 13 5,160 test-cmd-util.sh
osh-cpython 927 897 30 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 31,600,341 2,698 Build.sh
osh-nosouffle 35,848,581 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,722,926 2,512 abuild
osh-nosouffle 52,279,725 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,185 20,489 configure
osh-nosouffle 263,061,913 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,251 69,779 configure-coreutils
osh-nosouffle 862,831,471 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,986,971 2,029 configure-helper.sh
osh-nosouffle 30,265,192 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,470,813 1,733 functions
osh-nosouffle 28,860,261 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,352 9,661 ltmain.sh
osh-nosouffle 112,484,872 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,064,843 1,679 t4014-format-patch.sh
osh-nosouffle 11,039,686 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 11,869,242 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,621 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 96,185,430 5,160 test-cmd-util.sh
osh-nosouffle 112,289,291 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-5ace6078
osh-native osh-b110dab5
osh-nosouffle osh-nosouffle-1377f51b
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-15__00-10-43.cachegrind.tsv
no-host.2025-12-15__00-10-43.times.csv