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 2,576
bash 118,863 1,256
osh-native 118,863 439
osh-nosouffle 118,863 418
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 2 3 2,698 Build.sh
osh-native 8 5 3 9 2,698 Build.sh
osh-nosouffle 8 5 3 9 2,698 Build.sh
osh-cpython 330 311 19 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 7 3 9 2,512 abuild
osh-cpython 461 431 30 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 17 15 2 4 20,489 configure
osh-native 40 34 6 23 20,489 configure
osh-nosouffle 44 36 8 23 20,489 configure
osh-cpython 2,214 2,176 38 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 42 40 2 3 69,779 configure-coreutils
osh-native 153 131 22 52 69,779 configure-coreutils
osh-nosouffle 158 136 22 52 69,779 configure-coreutils
osh-cpython 6,240 6,153 86 91 69,779 configure-coreutils
bash 3 3 0 3 2,029 configure-helper.sh
osh-native 7 4 3 9 2,029 configure-helper.sh
osh-nosouffle 7 4 3 9 2,029 configure-helper.sh
osh-cpython 324 298 26 21 2,029 configure-helper.sh
dash 1 1 0 2 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 7 5 2 9 1,733 functions
osh-nosouffle 7 4 3 9 1,733 functions
osh-cpython 308 278 30 21 1,733 functions
dash 5 5 0 2 9,661 ltmain.sh
bash 9 8 1 4 9,661 ltmain.sh
osh-native 20 14 6 15 9,661 ltmain.sh
osh-nosouffle 22 18 4 16 9,661 ltmain.sh
osh-cpython 1,039 1,006 31 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 1 3 8 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 115 94 21 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 1 2 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 5 2 2 8 3,123 t9300-fast-import.sh
osh-cpython 128 110 18 19 3,123 t9300-fast-import.sh
bash 8 6 2 3 5,160 test-cmd-util.sh
osh-native 19 15 4 13 5,160 test-cmd-util.sh
osh-nosouffle 19 16 3 13 5,160 test-cmd-util.sh
osh-cpython 941 898 42 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 31,594,510 2,698 Build.sh
osh-nosouffle 35,843,131 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,713,433 2,512 abuild
osh-nosouffle 52,277,472 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,139,452 20,489 configure
osh-nosouffle 263,055,818 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,359,338 69,779 configure-coreutils
osh-nosouffle 837,534,176 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,983,395 2,029 configure-helper.sh
osh-nosouffle 30,261,562 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,468,727 1,733 functions
osh-nosouffle 28,858,163 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,272,474 9,661 ltmain.sh
osh-nosouffle 112,483,121 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,061,803 1,679 t4014-format-patch.sh
osh-nosouffle 11,036,718 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 11,866,243 3,123 t9300-fast-import.sh
osh-nosouffle 13,016,690 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 96,177,266 5,160 test-cmd-util.sh
osh-nosouffle 112,284,507 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-a42a5d0a
osh-native osh-022ae1a3
osh-nosouffle osh-nosouffle-99bc4f5a
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-08__17-37-02.cachegrind.tsv
no-host.2025-12-08__17-37-02.times.csv