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 2,511
bash 118,863 1,255
osh-native 118,863 452
osh-nosouffle 118,863 423
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 1 2 3 2,698 Build.sh
osh-native 8 7 1 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 326 307 19 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 9 0 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 457 426 31 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 40 31 8 22 20,489 configure
osh-nosouffle 43 35 8 23 20,489 configure
osh-cpython 2,143 2,094 46 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 40 2 3 69,779 configure-coreutils
osh-native 147 125 22 52 69,779 configure-coreutils
osh-nosouffle 157 133 24 52 69,779 configure-coreutils
osh-cpython 6,353 6,275 77 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 7 6 1 9 2,029 configure-helper.sh
osh-nosouffle 7 6 1 9 2,029 configure-helper.sh
osh-cpython 324 298 26 22 2,029 configure-helper.sh
dash 1 0 1 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 6 0 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 310 294 16 21 1,733 functions
dash 5 4 1 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 15 6 16 9,661 ltmain.sh
osh-nosouffle 22 18 4 16 9,661 ltmain.sh
osh-cpython 1,037 1,002 36 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-nosouffle 4 1 3 8 1,679 t4014-format-patch.sh
osh-native 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 97 18 19 1,679 t4014-format-patch.sh
dash 2 2 0 2 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 124 98 26 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 18 12 6 12 5,160 test-cmd-util.sh
osh-nosouffle 19 16 3 13 5,160 test-cmd-util.sh
osh-cpython 929 900 29 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 31,595,735 2,698 Build.sh
osh-nosouffle 35,843,398 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,713,578 2,512 abuild
osh-nosouffle 52,278,437 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,139,803 20,489 configure
osh-nosouffle 263,051,962 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,356,344 69,779 configure-coreutils
osh-nosouffle 837,536,108 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,983,697 2,029 configure-helper.sh
osh-nosouffle 30,261,700 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,004 1,733 functions
osh-nosouffle 28,858,422 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,272,734 9,661 ltmain.sh
osh-nosouffle 112,483,403 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,130 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,980 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 11,866,607 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,774 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 96,177,399 5,160 test-cmd-util.sh
osh-nosouffle 112,284,686 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-85dd8730
osh-native osh-f1ed1352
osh-nosouffle osh-nosouffle-1f613f0b
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-08__19-12-34.cachegrind.tsv
no-host.2025-12-08__19-12-34.times.csv