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 12.8

(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 2,606
bash 118,863 1,282
osh-native 118,863 487
osh-nosouffle 118,863 449
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 3 0 3 2,698 Build.sh
osh-native 7 4 4 9 2,698 Build.sh
osh-nosouffle 8 6 2 9 2,698 Build.sh
osh-cpython 323 304 19 22 2,698 Build.sh
dash 2 2 0 2 2,512 abuild
bash 4 2 2 3 2,512 abuild
osh-native 9 5 4 9 2,512 abuild
osh-nosouffle 10 9 1 9 2,512 abuild
osh-cpython 455 431 23 22 2,512 abuild
dash 9 9 0 2 20,489 configure
bash 17 16 1 4 20,489 configure
osh-native 39 29 10 23 20,489 configure
osh-nosouffle 42 32 10 23 20,489 configure
osh-cpython 2,171 2,137 34 44 20,489 configure
dash 23 22 1 2 69,779 configure-coreutils
bash 42 40 2 3 69,779 configure-coreutils
osh-native 132 110 22 52 69,779 configure-coreutils
osh-nosouffle 144 117 27 52 69,779 configure-coreutils
osh-cpython 6,165 6,086 78 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 3 3 9 2,029 configure-helper.sh
osh-cpython 320 296 24 21 2,029 configure-helper.sh
dash 1 1 0 1 1,733 functions
bash 3 2 1 3 1,733 functions
osh-native 6 2 4 9 1,733 functions
osh-nosouffle 7 5 2 9 1,733 functions
osh-cpython 306 287 19 21 1,733 functions
dash 4 2 2 2 9,661 ltmain.sh
bash 9 6 3 4 9,661 ltmain.sh
osh-native 20 18 2 16 9,661 ltmain.sh
osh-nosouffle 21 17 4 16 9,661 ltmain.sh
osh-cpython 1,035 1,004 31 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 7 1,679 t4014-format-patch.sh
osh-nosouffle 4 2 2 8 1,679 t4014-format-patch.sh
osh-cpython 113 94 20 19 1,679 t4014-format-patch.sh
dash 1 1 0 1 3,123 t9300-fast-import.sh
bash 2 2 1 3 3,123 t9300-fast-import.sh
osh-native 4 2 2 8 3,123 t9300-fast-import.sh
osh-nosouffle 4 1 3 8 3,123 t9300-fast-import.sh
osh-cpython 121 102 19 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 18 15 3 13 5,160 test-cmd-util.sh
osh-cpython 931 906 24 29 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 31,600,328 2,698 Build.sh
osh-nosouffle 35,848,525 2,698 Build.sh
dash 7,346,197 2,512 abuild
bash 23,586,858 2,512 abuild
osh-native 44,722,913 2,512 abuild
osh-nosouffle 52,279,669 2,512 abuild
dash 55,988,490 20,489 configure
bash 166,013,802 20,489 configure
osh-native 231,143,172 20,489 configure
osh-nosouffle 263,061,857 20,489 configure
dash 161,016,284 69,779 configure-coreutils
bash 440,767,942 69,779 configure-coreutils
osh-native 748,386,211 69,779 configure-coreutils
osh-nosouffle 862,831,412 69,779 configure-coreutils
bash 22,799,636 2,029 configure-helper.sh
osh-native 25,986,931 2,029 configure-helper.sh
osh-nosouffle 30,265,133 2,029 configure-helper.sh
dash 4,811,799 1,733 functions
bash 15,312,098 1,733 functions
osh-native 24,470,773 1,733 functions
osh-nosouffle 28,860,205 1,733 functions
dash 24,904,718 9,661 ltmain.sh
bash 80,310,064 9,661 ltmain.sh
osh-native 96,274,339 9,661 ltmain.sh
osh-nosouffle 112,484,816 9,661 ltmain.sh
dash 3,294,377 1,679 t4014-format-patch.sh
osh-native 10,064,803 1,679 t4014-format-patch.sh
osh-nosouffle 11,039,636 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 11,869,229 3,123 t9300-fast-import.sh
osh-nosouffle 13,019,571 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 96,185,425 5,160 test-cmd-util.sh
osh-nosouffle 112,289,292 5,160 test-cmd-util.sh

Shell and Host Details

shell label shell id
bash bash-36833674
dash dash-cea41b3e
osh-cpython osh-6ba00ec4
osh-native osh-6d42922d
osh-nosouffle osh-nosouffle-2e7f582d
host label host id
no-host no-host-9c670df1

Raw Data

filename
no-host.2025-12-15__16-39-28.cachegrind.tsv
no-host.2025-12-15__16-39-28.times.csv