[ruby-core:117266] [Ruby master Bug#20203] `TestEnumerable` test failures with GCC 14

["alanwu (Alan Wu) via ruby-core" <ruby-core@ml.ruby-lang.org>]

Issue #20203 has been updated by alanwu (Alan Wu).

File sort-benchmark-ubuntu.png added
File sort-benchmark-macos.png added

I ran some benchmarks comparing the builtin `ruby_qsort()` and `qsort_r()` on macOS with an M1 chip and on Ubuntu 22.04 (glibc 2.35) wtih a Xeon Platinum 8000 chip. The rubies are built off of commit:3f5f04afa7 and the `ruby_qsort()` one is built with `configure ac_cv_func_qsort_r=no` to use the builtin sort (verified with a debugger). Note that I used `benchmark-driver` in `time` mode, which picks the number times to repeat based on the workload, so larger input size doesn't necessarily run longer.

![](sort-benchmark-ubuntu.png)
![](sort-benchmark-macos.png)

With shuffled inputs, the builtin sort is about 5% faster on macOS but 10 to 20% slower on Ubuntu. The builtin sort seems very good with ordered inputs and outperforms `qsort_r()` across the board.

Considering it's faster on macOS, I think the builtin sort has acceptable performance.

----------------------------------------
Bug #20203: `TestEnumerable` test failures with GCC 14
https://bugs.ruby-lang.org/issues/20203#change-107391

* Author: vo.x (Vit Ondruch)
* Status: Open
* ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-linux]
* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
There is ongoing mass rebuild in Fedora and that is first time GCC 14 is used and we observe test failures in `TestEnumerable`. Here are a few examples:

~~~
[ 3000/26419] TestEnumerable#test_transient_heap_sort_bymalloc_consolidate(): unaligned fastbin chunk detected
~~~

~~~
[ 2455/26535] TestEnumerable#test_transient_heap_sort_bycorrupted size vs. prev_size in fastbins
~~~

~~~
[ 9716/26532] TestEnumerable#test_any_with_unused_blockdouble free or corruption (fasttop)
~~~

The full logs are accessible [here](https://koji.fedoraproject.org/koji/taskinfo?taskID=112176941). Please drill through `Descendants` and `build.log`

---Files--------------------------------
sort-benchmark-ubuntu.png (233 KB)
sort-benchmark-macos.png (232 KB)


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