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 2,592
bash 118,863 1,280
osh-native 118,863 461
osh-nosouffle 118,863 438
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 7 1 9 2,698 Build.sh
osh-nosouffle 8 3 5 9 2,698 Build.sh
osh-cpython 325 310 15 21 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 9 6 4 9 2,512 abuild
osh-nosouffle 10 6 4 9 2,512 abuild
osh-cpython 458 434 24 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 22 20,489 configure
osh-nosouffle 42 31 11 23 20,489 configure
osh-cpython 2,172 2,133 39 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 145 113 32 52 69,779 configure-coreutils
osh-nosouffle 150 125 25 52 69,779 configure-coreutils
osh-cpython 6,317 6,233 81 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 3 4 9 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 326 305 21 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 2 4 9 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 304 282 23 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 14 5 15 9,661 ltmain.sh
osh-nosouffle 21 16 5 16 9,661 ltmain.sh
osh-cpython 1,029 1,009 21 30 9,661 ltmain.sh
dash 1 0 1 1 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 2 2 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 113 97 17 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 4 0 8 3,123 t9300-fast-import.sh
osh-cpython 121 101 19 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 14 3 13 5,160 test-cmd-util.sh
osh-nosouffle 18 11 7 13 5,160 test-cmd-util.sh
osh-cpython 939 919 19 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 31,600,704 2,698 Build.sh
osh-nosouffle 35,848,934 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,723,289 2,512 abuild
osh-nosouffle 52,280,078 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,575 20,489 configure
osh-nosouffle 263,062,266 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,641 69,779 configure-coreutils
osh-nosouffle 862,831,824 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,987,334 2,029 configure-helper.sh
osh-nosouffle 30,265,545 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,471,176 1,733 functions
osh-nosouffle 28,860,614 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,715 9,661 ltmain.sh
osh-nosouffle 112,485,225 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,065,206 1,679 t4014-format-patch.sh
osh-nosouffle 11,040,066 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 11,869,605 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,974 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 96,185,793 5,160 test-cmd-util.sh
osh-nosouffle 112,289,696 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-77891dd3
osh-native osh-6e28299c
osh-nosouffle osh-nosouffle-58f724d6
host label host id
no-host no-host-bba74091

Raw Data

filename
no-host.2025-12-21__06-13-20.cachegrind.tsv
no-host.2025-12-21__06-13-20.times.csv