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 2,593
bash 118,863 1,255
osh-native 118,863 457
osh-nosouffle 118,863 406
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 0 2 2 2,698 Build.sh
bash 3 3 0 3 2,698 Build.sh
osh-native 7 4 3 9 2,698 Build.sh
osh-nosouffle 8 5 4 9 2,698 Build.sh
osh-cpython 325 303 23 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 4 0 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 456 430 26 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 39 27 12 22 20,489 configure
osh-nosouffle 45 37 8 22 20,489 configure
osh-cpython 2,152 2,112 40 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 149 126 23 52 69,779 configure-coreutils
osh-nosouffle 164 138 26 52 69,779 configure-coreutils
osh-cpython 6,358 6,258 97 91 69,779 configure-coreutils
bash 3 2 1 3 2,029 configure-helper.sh
osh-native 6 5 1 9 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 317 292 25 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 3 0 3 1,733 functions
osh-native 6 2 4 8 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 311 291 20 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 7 2 4 9,661 ltmain.sh
osh-native 20 15 5 16 9,661 ltmain.sh
osh-nosouffle 23 17 6 16 9,661 ltmain.sh
osh-cpython 1,020 1,000 20 30 9,661 ltmain.sh
dash 1 1 0 1 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 2 2 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 101 14 19 1,679 t4014-format-patch.sh
dash 1 1 0 2 3,123 t9300-fast-import.sh
bash 2 2 0 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 121 101 20 19 3,123 t9300-fast-import.sh
bash 8 5 3 3 5,160 test-cmd-util.sh
osh-native 17 11 6 12 5,160 test-cmd-util.sh
osh-nosouffle 19 15 4 13 5,160 test-cmd-util.sh
osh-cpython 934 912 22 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 31,534,965 2,698 Build.sh
osh-nosouffle 35,785,479 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,673,773 2,512 abuild
osh-nosouffle 52,236,197 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 236,421,861 20,489 configure
osh-nosouffle 268,333,990 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,340,054 69,779 configure-coreutils
osh-nosouffle 836,512,486 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,919,175 2,029 configure-helper.sh
osh-nosouffle 30,194,412 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,431,533 1,733 functions
osh-nosouffle 28,822,600 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,097,804 9,661 ltmain.sh
osh-nosouffle 112,308,883 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,045,455 1,679 t4014-format-patch.sh
osh-nosouffle 11,020,507 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 11,850,259 3,123 t9300-fast-import.sh
osh-nosouffle 13,000,531 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 96,111,371 5,160 test-cmd-util.sh
osh-nosouffle 112,220,577 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-46038abf
osh-native osh-c11fccd1
osh-nosouffle osh-nosouffle-e6971912
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-19__06-23-15.cachegrind.tsv
no-host.2025-11-19__06-23-15.times.csv