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 3,260
bash 118,863 1,423
osh-native 118,863 520
osh-nosouffle 118,863 492
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 1 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 6 5 1 9 2,698 Build.sh
osh-nosouffle 7 5 2 9 2,698 Build.sh
osh-cpython 281 269 13 22 2,698 Build.sh
dash 1 1 0 2 2,512 abuild
bash 3 2 1 3 2,512 abuild
osh-native 8 7 1 9 2,512 abuild
osh-nosouffle 9 7 2 9 2,512 abuild
osh-cpython 390 378 12 22 2,512 abuild
dash 7 7 0 2 20,489 configure
bash 15 13 2 4 20,489 configure
osh-native 36 24 12 22 20,489 configure
osh-nosouffle 39 33 6 23 20,489 configure
osh-cpython 1,859 1,838 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 125 108 17 52 69,779 configure-coreutils
osh-nosouffle 131 112 19 52 69,779 configure-coreutils
osh-cpython 5,399 5,344 53 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 4 2 9 2,029 configure-helper.sh
osh-nosouffle 6 4 2 9 2,029 configure-helper.sh
osh-cpython 275 263 12 22 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 5 3 3 9 1,733 functions
osh-nosouffle 6 5 1 9 1,733 functions
osh-cpython 264 250 14 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 8 7 1 4 9,661 ltmain.sh
osh-nosouffle 19 11 9 16 9,661 ltmain.sh
osh-native 20 17 3 16 9,661 ltmain.sh
osh-cpython 881 863 18 30 9,661 ltmain.sh
dash 1 1 0 2 1,679 t4014-format-patch.sh
bash 2 2 0 3 1,679 t4014-format-patch.sh
osh-native 3 3 0 8 1,679 t4014-format-patch.sh
osh-nosouffle 3 1 2 8 1,679 t4014-format-patch.sh
osh-cpython 97 86 11 19 1,679 t4014-format-patch.sh
dash 1 0 1 2 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-native 3 2 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 3 1 9 3,123 t9300-fast-import.sh
osh-cpython 104 92 12 19 3,123 t9300-fast-import.sh
bash 7 7 0 3 5,160 test-cmd-util.sh
osh-native 15 12 3 13 5,160 test-cmd-util.sh
osh-nosouffle 17 14 3 13 5,160 test-cmd-util.sh
osh-cpython 811 795 16 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 31,595,766 2,698 Build.sh
osh-nosouffle 35,843,442 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,713,610 2,512 abuild
osh-nosouffle 52,278,481 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,139,861 20,489 configure
osh-nosouffle 263,052,006 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,356,402 69,779 configure-coreutils
osh-nosouffle 837,536,158 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,983,728 2,029 configure-helper.sh
osh-nosouffle 30,261,777 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,035 1,733 functions
osh-nosouffle 28,858,493 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,272,792 9,661 ltmain.sh
osh-nosouffle 112,483,447 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,161 1,679 t4014-format-patch.sh
osh-nosouffle 11,037,051 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 11,866,638 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,818 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 96,177,457 5,160 test-cmd-util.sh
osh-nosouffle 112,284,776 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-0621d9cb
osh-native osh-96ba6c5d
osh-nosouffle osh-nosouffle-c0454cf4
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-08__22-20-17.cachegrind.tsv
no-host.2025-12-08__22-20-17.times.csv