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 11.3
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 2,590
bash 118,863 1,267
osh-native 118,863 54
osh-nosouffle 118,863 52
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 48 10 38 9 2,698 Build.sh
osh-nosouffle 50 11 39 9 2,698 Build.sh
osh-cpython 322 298 25 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-native 46 10 36 9 2,512 abuild
osh-nosouffle 48 10 38 10 2,512 abuild
osh-cpython 460 431 29 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 408 81 327 23 20,489 configure
osh-nosouffle 428 94 334 23 20,489 configure
osh-cpython 2,097 2,049 47 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 1,189 284 904 52 69,779 configure-coreutils
osh-nosouffle 1,231 318 913 53 69,779 configure-coreutils
osh-cpython 6,267 6,182 84 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 51 10 42 9 2,029 configure-helper.sh
osh-nosouffle 54 15 39 10 2,029 configure-helper.sh
osh-cpython 318 296 22 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 31 4 27 9 1,733 functions
osh-nosouffle 32 7 25 9 1,733 functions
osh-cpython 308 280 27 21 1,733 functions
dash 4 3 1 2 9,661 ltmain.sh
bash 9 9 0 4 9,661 ltmain.sh
osh-native 187 43 144 16 9,661 ltmain.sh
osh-nosouffle 193 44 149 16 9,661 ltmain.sh
osh-cpython 1,030 994 36 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 31 7 24 8 1,679 t4014-format-patch.sh
osh-nosouffle 32 4 28 9 1,679 t4014-format-patch.sh
osh-cpython 116 91 25 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 45 10 35 8 3,123 t9300-fast-import.sh
osh-nosouffle 46 1 45 9 3,123 t9300-fast-import.sh
osh-cpython 125 107 19 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 166 29 137 13 5,160 test-cmd-util.sh
osh-nosouffle 172 50 122 14 5,160 test-cmd-util.sh
osh-cpython 930 898 32 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 32,744,636 2,698 Build.sh
osh-nosouffle 36,992,784 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 45,782,132 2,512 abuild
osh-nosouffle 53,347,385 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 228,224,542 20,489 configure
osh-nosouffle 260,132,292 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 764,385,232 69,779 configure-coreutils
osh-nosouffle 853,706,359 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 27,542,770 2,029 configure-helper.sh
osh-nosouffle 31,822,962 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 25,326,605 1,733 functions
osh-nosouffle 29,715,629 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 99,763,685 9,661 ltmain.sh
osh-nosouffle 115,973,478 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 11,058,396 1,679 t4014-format-patch.sh
bash 11,082,677 1,679 t4014-format-patch.sh
osh-nosouffle 12,032,946 1,679 t4014-format-patch.sh
dash 4,585,030 3,123 t9300-fast-import.sh
osh-native 12,939,203 3,123 t9300-fast-import.sh
osh-nosouffle 14,089,084 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 100,341,771 5,160 test-cmd-util.sh
osh-nosouffle 116,444,156 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-9b7fefe6
osh-native osh-547c00e4
osh-nosouffle osh-nosouffle-858bd111
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-12__22-57-20.cachegrind.tsv
no-host.2025-11-12__22-57-20.times.csv