[#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:114906] [Ruby master Bug#19875] Ruby 3.0 -> 3.1 Performance regression in String#count
From:
"Freaky (Thomas Hurst) via ruby-core" <ruby-core@...>
Date:
2023-09-27 18:52:30 UTC
List:
ruby-core #114906
Issue #19875 has been updated by Freaky (Thomas Hurst).
ahorek (Pavel Rosick=FD) wrote in #note-18:
> I think if the platform support is sufficient, there are multiple places =
where this feature could be beneficial.
I think the platform support covers the major bases. I'm testing a PHP bui=
ld with ifunc and target support enabled, after it was disabled for FreeBSD=
in 2018 and nobody thought to try turning it back on.
> Even without explicit SIMD code, some existing C code could be autovector=
ized by the compiler itself for the AVX2 target while keeping the binary co=
mpatibility with platforms that don't support these instructions.
Yes - `__attribute__((target_clones(..))` makes this particularly easy to d=
o -- the difficulty lies in using it appropriately.
> You can always recompile Ruby with optimization flags for your own platfo=
rm, but most users use precompiled binaries that can't benefit from it now.
It would be interesting to see some benchmarks comparing Ruby (and other th=
ings) targetting basline x86-64, and the -v2, -v3, and -v4 profiles.
> could prepare a proof of concept PR for the Ruby repo?
This is what I'm working towards, yes.
> also, see the previous discussion #16487 there are already other existing=
examples where this feature could help.
Thanks.
----------------------------------------
Bug #19875: Ruby 3.0 -> 3.1 Performance regression in String#count
https://bugs.ruby-lang.org/issues/19875#change-104772
* 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/
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