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 12.6

(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 2,548
bash 118,863 1,253
osh-native 118,863 408
osh-nosouffle 118,863 393
osh-cpython 118,863 9

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 2 1 3 2,698 Build.sh
osh-native 8 6 2 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 343 322 22 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-native 10 5 5 9 2,512 abuild
osh-nosouffle 11 8 3 9 2,512 abuild
osh-cpython 470 448 22 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 16 2 4 20,489 configure
osh-native 43 31 12 23 20,489 configure
osh-nosouffle 47 37 10 23 20,489 configure
osh-cpython 2,264 2,215 49 44 20,489 configure
dash 23 21 2 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 168 140 28 52 69,779 configure-coreutils
osh-nosouffle 170 150 20 52 69,779 configure-coreutils
osh-cpython 6,590 6,503 85 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 5 2 9 2,029 configure-helper.sh
osh-nosouffle 7 4 4 9 2,029 configure-helper.sh
osh-cpython 325 299 27 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 7 3 4 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 317 292 26 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 9 6 3 4 9,661 ltmain.sh
osh-native 21 15 6 15 9,661 ltmain.sh
osh-nosouffle 23 19 4 16 9,661 ltmain.sh
osh-cpython 1,076 1,038 38 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 3 1 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 122 103 19 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 3 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 3 2 8 3,123 t9300-fast-import.sh
osh-cpython 132 117 15 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 19 15 4 12 5,160 test-cmd-util.sh
osh-nosouffle 20 15 5 13 5,160 test-cmd-util.sh
osh-cpython 967 941 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 31,593,702 2,698 Build.sh
osh-nosouffle 35,841,465 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,711,216 2,512 abuild
osh-nosouffle 52,275,940 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,135,271 20,489 configure
osh-nosouffle 263,051,596 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,351,879 69,779 configure-coreutils
osh-nosouffle 837,525,759 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,982,278 2,029 configure-helper.sh
osh-nosouffle 30,259,499 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,467,590 1,733 functions
osh-nosouffle 28,857,043 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,270,218 9,661 ltmain.sh
osh-nosouffle 112,481,156 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,061,190 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,127 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 11,864,869 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,102 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 96,174,873 5,160 test-cmd-util.sh
osh-nosouffle 112,282,043 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-694f3a87
osh-native osh-982ff90a
osh-nosouffle osh-nosouffle-e8f343cc
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-04__09-44-06.cachegrind.tsv
no-host.2025-12-04__09-44-06.times.csv