[#114774] [Ruby master Feature#19884] Make Safe Navigation Operator work on classes — "p8 (Petrik de Heus) via ruby-core" <ruby-core@...>
Issue #19884 has been reported by p8 (Petrik de Heus).
13 messages
2023/09/15
[ruby-core:114823] [Ruby master Bug#19875] Ruby 3.0 -> 3.1 Performance regression in String#count
From:
"Freaky (Thomas Hurst) via ruby-core" <ruby-core@...>
Date:
2023-09-19 23:15:21 UTC
List:
ruby-core #114823
Issue #19875 has been updated by Freaky (Thomas Hurst).
File bytecount.c added
nobu (Nobuyoshi Nakada) wrote in #note-13:
> Freaky (Thomas Hurst) wrote in #note-12:
> > I see a difference if I configure with cflags=3D-msse4.2 - it's off by =
default. We probably want some runtime CPU feature detection if people are=
actually going to use it.
>=20
> Who/what do you mean by "we"?
> It feels like a compiler's (or optimizer's) job.
If only!
I've added an AVX2 path and worked on getting runtime dispatch working on b=
oth clang and gcc. I've combined the result into a single file suitable to=
drop straight over the top of your `missing/bytecount.c`, which yields thi=
s on my Zen 3:
```
'./ruby test.rb' ran
22.37 =B1 1.03 times faster than './ruby.master test.rb'
```
And this - using exactly the same binary - on an old K8 machine which lacks=
AVX2 and SSE4:
```
./ruby test.rb ran
2.97 =B1 0.02 times faster than ./ruby.master test.rb
```
----------------------------------------
Bug #19875: Ruby 3.0 -> 3.1 Performance regression in String#count
https://bugs.ruby-lang.org/issues/19875#change-104667
* Author: iz (Illia Zub)
* Status: Open
* Priority: Normal
* ruby -v: 3.2.2
* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN
----------------------------------------
`String#count` became slower since Ruby 3.1. Originally found by `@Freaky`:=
https://github.com/ruby/ruby/pull/4001#issuecomment-1714779781
Compared using the [`benchmark-driver` gem](https://github.com/benchmark-dr=
iver/benchmark-driver).
```
$ benchmark-driver tmp/string_count_benchmark_driver.yml --rbenv '3.1.1;3.1=
.4;2.7.2;3.2.2;3.0.6' =20
Calculating -------------------------------------
3.1.1 3.1.4 2.7.2 3.2.2 3=
.0.6
count 465.804 463.741 865.783 462.711 857=
.395 i/s - 10.000k times in 21.468251s 21.563768s 11.550239s 21.611783s=
11.663235s
Comparison:
count
2.7.2: 865.8 i/s=20
3.0.6: 857.4 i/s - 1.01x slower
3.1.1: 465.8 i/s - 1.86x slower
3.1.4: 463.7 i/s - 1.87x slower
3.2.2: 462.7 i/s - 1.87x slower
```
Benchmark:
```yml
$ cat ./tmp/string_count_benchmark_driver.yml=20
loop_count: 10_000
prelude: |
html =3D "\nruby\n" * 1024 * 1024
benchmark:
count: html.count($/)
```
---
*Initially, I noticed the difference between `str.count($/)` and `str.lines=
.size` when working on the performance improvement: https://serpapi.com/blo=
g/lines-count-failed-deployments/*
---Files--------------------------------
rb_str_len.fast (31.9 KB)
rb_str_len.slow (34 KB)
revert-4001.patch (1.71 KB)
rb_str_count.S (11.8 KB)
bytecount.c (7.23 KB)
--=20
https://bugs.ruby-lang.org/
______________________________________________
ruby-core mailing list -- ruby-core@ml.ruby-lang.org
To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-c=
ore.ml.ruby-lang.org/