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 12.6

(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 3,256
bash 118,863 1,414
osh-native 118,863 518
osh-nosouffle 118,863 480
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 6 1 9 2,698 Build.sh
osh-nosouffle 7 7 0 9 2,698 Build.sh
osh-cpython 281 267 14 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 9 8 1 9 2,512 abuild
osh-cpython 394 381 14 22 2,512 abuild
dash 7 7 0 2 20,489 configure
bash 16 16 0 4 20,489 configure
osh-native 37 30 7 22 20,489 configure
osh-nosouffle 40 36 4 23 20,489 configure
osh-cpython 1,885 1,860 22 44 20,489 configure
dash 18 17 1 2 69,779 configure-coreutils
bash 38 37 1 4 69,779 configure-coreutils
osh-native 125 107 18 52 69,779 configure-coreutils
osh-nosouffle 134 114 20 52 69,779 configure-coreutils
osh-cpython 5,399 5,349 49 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 6 3 3 9 2,029 configure-helper.sh
osh-nosouffle 6 4 3 9 2,029 configure-helper.sh
osh-cpython 274 265 9 22 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 2 1 1 3 1,733 functions
osh-native 5 2 3 9 1,733 functions
osh-nosouffle 6 4 2 9 1,733 functions
osh-cpython 265 252 13 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 8 6 2 4 9,661 ltmain.sh
osh-native 18 13 5 16 9,661 ltmain.sh
osh-nosouffle 20 17 3 16 9,661 ltmain.sh
osh-cpython 890 877 13 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 2 0 3 1,679 t4014-format-patch.sh
osh-native 3 2 1 8 1,679 t4014-format-patch.sh
osh-nosouffle 3 2 1 8 1,679 t4014-format-patch.sh
osh-cpython 97 85 12 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-nosouffle 4 2 1 8 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-cpython 105 95 10 19 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 16 2 13 5,160 test-cmd-util.sh
osh-cpython 813 787 22 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 31,591,232 2,698 Build.sh
osh-nosouffle 35,839,863 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,708,808 2,512 abuild
osh-nosouffle 52,273,700 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 221,047,067 20,489 configure
osh-nosouffle 263,041,029 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,361,107 69,779 configure-coreutils
osh-nosouffle 837,513,325 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,981,339 2,029 configure-helper.sh
osh-nosouffle 30,259,519 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,466,685 1,733 functions
osh-nosouffle 28,856,151 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,267,985 9,661 ltmain.sh
osh-nosouffle 112,478,141 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,060,969 1,679 t4014-format-patch.sh
osh-nosouffle 11,035,930 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 11,865,404 3,123 t9300-fast-import.sh
osh-nosouffle 13,015,731 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 96,171,544 5,160 test-cmd-util.sh
osh-nosouffle 112,278,795 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-80dec214
osh-native osh-e8947ed5
osh-nosouffle osh-nosouffle-7a3c7bc9
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-04__21-54-19.cachegrind.tsv
no-host.2025-12-04__21-54-19.times.csv