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 12.6

(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 2,569
bash 118,863 1,268
osh-native 118,863 435
osh-nosouffle 118,863 405
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-nosouffle 8 7 1 9 2,698 Build.sh
osh-native 8 6 2 9 2,698 Build.sh
osh-cpython 325 300 25 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 3 1 3 2,512 abuild
osh-native 10 7 3 9 2,512 abuild
osh-nosouffle 10 8 2 9 2,512 abuild
osh-cpython 463 445 18 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 43 38 5 23 20,489 configure
osh-nosouffle 45 35 10 23 20,489 configure
osh-cpython 2,146 2,111 35 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 41 1 3 69,779 configure-coreutils
osh-native 152 121 31 52 69,779 configure-coreutils
osh-nosouffle 164 136 28 52 69,779 configure-coreutils
osh-cpython 6,283 6,206 73 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 7 4 2 9 2,029 configure-helper.sh
osh-nosouffle 7 4 4 9 2,029 configure-helper.sh
osh-cpython 319 298 21 21 2,029 configure-helper.sh
dash 1 1 1 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 7 5 2 8 1,733 functions
osh-nosouffle 7 5 3 9 1,733 functions
osh-cpython 304 290 15 21 1,733 functions
dash 4 3 2 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 13 7 15 9,661 ltmain.sh
osh-nosouffle 23 17 6 16 9,661 ltmain.sh
osh-cpython 1,020 983 36 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 3 1 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 3 1 8 1,679 t4014-format-patch.sh
osh-cpython 115 103 13 19 1,679 t4014-format-patch.sh
dash 1 0 1 1 3,123 t9300-fast-import.sh
bash 3 1 2 3 3,123 t9300-fast-import.sh
osh-native 4 0 4 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 121 101 20 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 20 11 9 13 5,160 test-cmd-util.sh
osh-cpython 939 904 34 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 31,591,956 2,698 Build.sh
osh-nosouffle 35,839,729 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,708,667 2,512 abuild
osh-nosouffle 52,273,535 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 221,046,776 20,489 configure
osh-nosouffle 263,040,740 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,360,634 69,779 configure-coreutils
osh-nosouffle 837,512,881 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,981,261 2,029 configure-helper.sh
osh-nosouffle 30,259,416 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,466,607 1,733 functions
osh-nosouffle 28,856,021 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,267,818 9,661 ltmain.sh
osh-nosouffle 112,477,976 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,060,922 1,679 t4014-format-patch.sh
osh-nosouffle 11,035,831 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 11,865,330 3,123 t9300-fast-import.sh
osh-nosouffle 13,015,659 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 96,171,538 5,160 test-cmd-util.sh
osh-nosouffle 112,278,471 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-af0718cd
osh-native osh-1f91a24a
osh-nosouffle osh-nosouffle-c58d940e
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-25__17-35-37.cachegrind.tsv
no-host.2025-11-25__17-35-37.times.csv