Skip to content

Speed up min, max #1266

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Merged
merged 1 commit into from
Aug 22, 2023
Merged

Speed up min, max #1266

merged 1 commit into from
Aug 22, 2023

Conversation

primo-ppcg
Copy link
Contributor

Creates a helper macro so that the primitive comparators compile to vm ops directly. The boiler plating is approximately the same as would be generated by each, except that the key is advanced before the loop to avoid unnecessarily comparing the first value with itself. The result is approximately 4x faster for min and max, 5x faster for min-of and max-of, and roughly unchanged for extreme.

(use spork/test)
(use spork/misc)

(def rng (math/rng 12345))
(def a (randomize-array (range 100) rng))

(timeit-loop [:timeout 1] "min    " (min ;a))
(timeit-loop [:timeout 1] "max    " (max ;a))
(timeit-loop [:timeout 1] "min-of " (min-of a))
(timeit-loop [:timeout 1] "max-of " (max-of a))
(timeit-loop [:timeout 1] "extreme" (extreme < a))

master:

min     1.000s, 9.145µs/body
max     1.001s, 9.146µs/body
min-of  1.000s, 8.959µs/body
max-of  1.000s, 8.962µs/body
extreme 1.000s, 9.012µs/body

branch:

min     1.000s, 2.101µs/body
max     1.000s, 2.172µs/body
min-of  1.000s, 1.816µs/body
max-of  1.000s, 1.854µs/body
extreme 1.000s, 8.888µs/body

The stray comma before not= is necessary, oddly. With, it compiles to a single jmpni instruction. Without, it compiles to ldn, neq, jmpno.

@sogaiu
Copy link
Contributor

sogaiu commented Aug 22, 2023 •
edited
Loading

Here are my numbers:

master (ee01045):

$ JANET_PATH=~/src/spork/jpm_tree/lib ~/src/janet/build/janet ~/scratch/min-max.janet 
min     1.000s, 13.23µs/body
max     1.000s, 13.04µs/body
min-of  1.000s, 12.67µs/body
max-of  1.000s, 12.57µs/body
extreme 1.000s, 12.6µs/body

branch (6e89793):

$ JANET_PATH=~/src/spork/jpm_tree/lib ~/src/janet.primo-ppcg/build/janet ~/scratch/min-max.janet 
min     1.000s, 3.313µs/body
max     1.000s, 3.18µs/body
min-of  1.000s, 2.767µs/body
max-of  1.000s, 2.679µs/body
extreme 1.000s, 12.37µs/body

Test from various repositories were fine too 👍

@primo-ppcg
Copy link
Contributor Author

Here are my numbers:

Appreciated, as always 😄

@bakpakin bakpakin merged commit 70a467d into janet-lang:master Aug 22, 2023
@primo-ppcg primo-ppcg deleted the min-max branch August 22, 2023 03:37
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers
No reviews
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
3 participants
@primo-ppcg @sogaiu @bakpakin