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 2,545
bash 118,863 1,239
osh-native 118,863 419
osh-nosouffle 118,863 402
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 8 5 2 8 2,698 Build.sh
osh-nosouffle 8 4 4 9 2,698 Build.sh
osh-cpython 338 319 19 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 7 2 9 2,512 abuild
osh-nosouffle 10 7 3 9 2,512 abuild
osh-cpython 469 455 15 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 18 17 1 4 20,489 configure
osh-native 42 34 8 23 20,489 configure
osh-nosouffle 46 37 9 23 20,489 configure
osh-cpython 2,205 2,170 35 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 43 42 1 3 69,779 configure-coreutils
osh-native 165 144 21 52 69,779 configure-coreutils
osh-nosouffle 166 144 22 52 69,779 configure-coreutils
osh-cpython 6,480 6,389 89 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 7 2 5 8 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 328 313 15 21 2,029 configure-helper.sh
dash 2 1 1 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 2 4 9 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 318 293 25 21 1,733 functions
dash 5 2 3 2 9,661 ltmain.sh
bash 9 7 3 4 9,661 ltmain.sh
osh-native 21 16 5 16 9,661 ltmain.sh
osh-nosouffle 23 19 4 16 9,661 ltmain.sh
osh-cpython 1,080 1,047 33 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 4 1 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 4 0 8 1,679 t4014-format-patch.sh
osh-cpython 121 94 27 19 1,679 t4014-format-patch.sh
dash 1 0 1 2 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 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 126 107 19 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 13 4 13 5,160 test-cmd-util.sh
osh-nosouffle 20 15 5 13 5,160 test-cmd-util.sh
osh-cpython 968 931 38 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 31,535,722 2,698 Build.sh
osh-nosouffle 35,785,347 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,675,906 2,512 abuild
osh-nosouffle 52,236,357 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,647,001 20,489 configure
osh-nosouffle 252,557,819 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,412,608 69,779 configure-coreutils
osh-nosouffle 836,744,251 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,946,887 2,029 configure-helper.sh
osh-nosouffle 30,224,470 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,432,732 1,733 functions
osh-nosouffle 28,822,122 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,131,018 9,661 ltmain.sh
osh-nosouffle 112,341,831 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,669 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,580 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 11,850,500 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,724 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 96,119,078 5,160 test-cmd-util.sh
osh-nosouffle 112,224,601 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-30c08d6b
osh-native osh-55531c6d
osh-nosouffle osh-nosouffle-f46fbbf5
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-20__18-53-29.cachegrind.tsv
no-host.2025-11-20__18-53-29.times.csv