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 2,601
bash 118,863 1,274
osh-native 118,863 474
osh-nosouffle 118,863 438
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 2 0 2 2,698 Build.sh
bash 3 2 1 3 2,698 Build.sh
osh-native 7 5 2 9 2,698 Build.sh
osh-nosouffle 7 5 2 9 2,698 Build.sh
osh-cpython 330 308 22 22 2,698 Build.sh
dash 2 1 1 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 9 6 3 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 457 436 22 22 2,512 abuild
dash 9 8 1 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 38 31 6 22 20,489 configure
osh-nosouffle 42 34 8 23 20,489 configure
osh-cpython 2,156 2,112 42 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 42 0 3 69,779 configure-coreutils
osh-native 142 121 21 52 69,779 configure-coreutils
osh-nosouffle 149 120 29 52 69,779 configure-coreutils
osh-cpython 6,362 6,279 82 91 69,779 configure-coreutils
bash 3 2 2 3 2,029 configure-helper.sh
osh-native 6 4 2 9 2,029 configure-helper.sh
osh-nosouffle 7 5 2 9 2,029 configure-helper.sh
osh-cpython 315 299 17 21 2,029 configure-helper.sh
dash 1 0 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 5 1 8 1,733 functions
osh-nosouffle 7 6 1 9 1,733 functions
osh-cpython 305 285 20 21 1,733 functions
dash 4 4 0 2 9,661 ltmain.sh
bash 9 9 0 4 9,661 ltmain.sh
osh-native 18 13 5 16 9,661 ltmain.sh
osh-nosouffle 24 17 7 16 9,661 ltmain.sh
osh-cpython 1,014 991 23 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 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 113 85 28 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 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 119 101 18 19 3,123 t9300-fast-import.sh
bash 8 8 0 3 5,160 test-cmd-util.sh
osh-native 16 10 7 12 5,160 test-cmd-util.sh
osh-nosouffle 18 14 4 13 5,160 test-cmd-util.sh
osh-cpython 938 912 26 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 31,595,797 2,698 Build.sh
osh-nosouffle 35,843,472 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,713,640 2,512 abuild
osh-nosouffle 52,278,510 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,139,892 20,489 configure
osh-nosouffle 263,052,063 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,356,433 69,779 configure-coreutils
osh-nosouffle 837,536,215 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,983,759 2,029 configure-helper.sh
osh-nosouffle 30,261,780 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,469,066 1,733 functions
osh-nosouffle 28,858,496 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,272,823 9,661 ltmain.sh
osh-nosouffle 112,483,504 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,062,192 1,679 t4014-format-patch.sh
osh-nosouffle 11,037,054 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 11,866,669 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,848 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 96,177,488 5,160 test-cmd-util.sh
osh-nosouffle 112,284,833 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-b41a1ed1
osh-native osh-f349a2b3
osh-nosouffle osh-nosouffle-e43190a4
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-08__22-01-02.cachegrind.tsv
no-host.2025-12-08__22-01-02.times.csv