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 12.5

(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 2,549
bash 118,863 1,250
osh-native 118,863 447
osh-nosouffle 118,863 404
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 2 0 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 7 5 2 8 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 333 306 27 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 7 4 9 2,512 abuild
osh-cpython 456 438 18 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 40 33 7 22 20,489 configure
osh-nosouffle 46 37 9 23 20,489 configure
osh-cpython 2,233 2,187 46 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 43 41 2 3 69,779 configure-coreutils
osh-native 151 133 18 52 69,779 configure-coreutils
osh-nosouffle 164 136 28 52 69,779 configure-coreutils
osh-cpython 6,529 6,438 91 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 7 4 2 9 2,029 configure-helper.sh
osh-nosouffle 7 3 4 9 2,029 configure-helper.sh
osh-cpython 322 294 28 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 5 2 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 313 287 26 21 1,733 functions
dash 5 3 1 2 9,661 ltmain.sh
bash 9 7 3 4 9,661 ltmain.sh
osh-native 20 14 6 15 9,661 ltmain.sh
osh-nosouffle 22 13 9 16 9,661 ltmain.sh
osh-cpython 1,060 1,032 28 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 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 116 97 20 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 1 3 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 3 2 8 3,123 t9300-fast-import.sh
osh-cpython 124 105 20 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 13 4 12 5,160 test-cmd-util.sh
osh-nosouffle 21 16 5 13 5,160 test-cmd-util.sh
osh-cpython 950 922 28 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 31,535,735 2,698 Build.sh
osh-nosouffle 35,785,374 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,919 2,512 abuild
osh-nosouffle 52,236,384 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,647,014 20,489 configure
osh-nosouffle 252,557,846 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,412,621 69,779 configure-coreutils
osh-nosouffle 836,744,278 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,946,900 2,029 configure-helper.sh
osh-nosouffle 30,224,497 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,432,772 1,733 functions
osh-nosouffle 28,822,149 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,131,004 9,661 ltmain.sh
osh-nosouffle 112,341,858 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,682 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,607 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 11,850,513 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,751 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 96,119,091 5,160 test-cmd-util.sh
osh-nosouffle 112,224,628 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-22a37f8c
osh-native osh-d9efba04
osh-nosouffle osh-nosouffle-5506077e
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-22__16-07-31.cachegrind.tsv
no-host.2025-11-22__16-07-31.times.csv