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 2,573
bash 118,863 1,276
osh-native 118,863 445
osh-nosouffle 118,863 428
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 8 6 2 9 2,698 Build.sh
osh-nosouffle 8 7 1 9 2,698 Build.sh
osh-cpython 323 302 22 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 9 7 3 9 2,512 abuild
osh-nosouffle 10 6 4 9 2,512 abuild
osh-cpython 452 434 18 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 17 0 4 20,489 configure
osh-native 41 35 6 23 20,489 configure
osh-nosouffle 42 33 9 23 20,489 configure
osh-cpython 2,143 2,104 38 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 156 132 23 52 69,779 configure-coreutils
osh-cpython 6,389 6,284 102 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 7 5 2 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 315 292 23 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 7 4 3 9 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 308 278 30 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 13 7 16 9,661 ltmain.sh
osh-nosouffle 21 14 7 16 9,661 ltmain.sh
osh-cpython 1,029 996 33 30 9,661 ltmain.sh
dash 1 0 1 2 1,679 t4014-format-patch.sh
bash 2 1 1 3 1,679 t4014-format-patch.sh
osh-native 4 1 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 0 4 8 1,679 t4014-format-patch.sh
osh-cpython 114 90 24 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 2 0 3 3,123 t9300-fast-import.sh
osh-nosouffle 4 1 3 9 3,123 t9300-fast-import.sh
osh-native 5 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 120 102 18 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 18 10 8 13 5,160 test-cmd-util.sh
osh-nosouffle 18 13 6 13 5,160 test-cmd-util.sh
osh-cpython 911 884 27 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 31,596,933 2,698 Build.sh
osh-nosouffle 35,844,625 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,715,180 2,512 abuild
osh-nosouffle 52,275,127 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,142,344 20,489 configure
osh-nosouffle 263,054,850 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,401,065 69,779 configure-coreutils
osh-nosouffle 837,539,813 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,984,571 2,029 configure-helper.sh
osh-nosouffle 30,262,642 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,878 1,733 functions
osh-nosouffle 28,859,325 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,283 9,661 ltmain.sh
osh-nosouffle 112,484,920 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,680 1,679 t4014-format-patch.sh
osh-nosouffle 11,037,539 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 11,867,040 3,123 t9300-fast-import.sh
osh-nosouffle 13,017,482 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 96,178,762 5,160 test-cmd-util.sh
osh-nosouffle 112,286,785 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-55ce9732
osh-native osh-1bc8ce04
osh-nosouffle osh-nosouffle-c9475275
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-14__07-56-10.cachegrind.tsv
no-host.2025-12-14__07-56-10.times.csv