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 12.5

(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 2,562
bash 118,863 1,247
osh-native 118,863 455
osh-nosouffle 118,863 423
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 4 4 9 2,698 Build.sh
osh-nosouffle 8 5 3 9 2,698 Build.sh
osh-cpython 331 313 18 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 1 3 2,512 abuild
osh-native 9 6 4 9 2,512 abuild
osh-nosouffle 10 5 5 9 2,512 abuild
osh-cpython 455 429 26 22 2,512 abuild
dash 9 7 2 2 20,489 configure
bash 18 18 0 4 20,489 configure
osh-native 38 29 9 23 20,489 configure
osh-nosouffle 42 32 10 23 20,489 configure
osh-cpython 2,164 2,119 45 44 20,489 configure
dash 23 23 0 2 69,779 configure-coreutils
bash 43 42 1 3 69,779 configure-coreutils
osh-native 148 119 29 52 69,779 configure-coreutils
osh-nosouffle 157 130 27 52 69,779 configure-coreutils
osh-cpython 6,381 6,305 75 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 4 9 2,029 configure-helper.sh
osh-cpython 322 296 26 22 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 1 1 3 1,733 functions
osh-native 6 5 1 8 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 316 291 25 21 1,733 functions
dash 5 4 1 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 21 16 5 16 9,661 ltmain.sh
osh-cpython 1,029 996 32 30 9,661 ltmain.sh
dash 1 1 0 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 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 121 98 23 19 1,679 t4014-format-patch.sh
dash 1 1 1 1 3,123 t9300-fast-import.sh
bash 3 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 3 1 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 2 3 8 3,123 t9300-fast-import.sh
osh-cpython 126 102 24 19 3,123 t9300-fast-import.sh
bash 8 7 1 3 5,160 test-cmd-util.sh
osh-native 17 12 5 13 5,160 test-cmd-util.sh
osh-nosouffle 19 17 2 13 5,160 test-cmd-util.sh
osh-cpython 958 918 40 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 31,532,405 2,698 Build.sh
osh-nosouffle 35,781,665 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,672,180 2,512 abuild
osh-nosouffle 52,232,584 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 220,622,874 20,489 configure
osh-nosouffle 252,531,162 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 747,299,982 69,779 configure-coreutils
osh-nosouffle 836,628,971 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,999,237 2,029 configure-helper.sh
osh-nosouffle 30,279,480 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,429,953 1,733 functions
osh-nosouffle 28,819,319 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,119,791 9,661 ltmain.sh
osh-nosouffle 112,329,599 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,044,624 1,679 t4014-format-patch.sh
osh-nosouffle 11,019,287 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 11,850,042 3,123 t9300-fast-import.sh
osh-nosouffle 12,999,985 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 96,120,814 5,160 test-cmd-util.sh
osh-nosouffle 112,226,570 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-9874749b
osh-native osh-8363900b
osh-nosouffle osh-nosouffle-cba71576
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-11-10__17-04-10.cachegrind.tsv
no-host.2025-11-10__17-04-10.times.csv