apache / apache/arrow

[C++][SIMD] Avoid one-definition-rule violation of `arrow::internal::BitmapWriter` without depending on `-O2`

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Component: C++ Type: enhancement
主要言語
C++
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マージ済み PR(30日)
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説明

### Describe the enhancement requested

Contexts:

* https://github.com/apache/arrow/issues/31132#issuecomment-1378082076
* GH-14342
* GH-36685

We have runtime SIMD dispatch feature. For example, it's used in `cpp/src/parquet/level_conversion.cc` to run BMI2 based `DefLevelsToBitmap` implementation if available.

`DefLevelsToBitmap` (`DefLevelsToBitmapSimd`) is implemented in `cpp/src/parquet/level_conversion_inc.h` and it's built with/without BMI2. `DefLevelsToBitmapSimd` uses `arrow::internal::BitmapWriter`. If `arrow::internal::BitmapWriter` in `DefLevelsToBitmapSimd` is not inlined, one-definition-rule violation is happen. If it's happen, `libparquet.dylib` has two `BitmapWriter` definitions for with/without BMI2. If BMI2 version `BitmapWriter` is used on BMI2 unavailable machine, "illegal opcode" is happen.

GH-14342 resolved this by forcing to use `-O2` to enforce inlining. But it doesn't work with Homebrew. Because Homebrew overrides `-O*` specified by us.

If we can avoid one-definition-rule violation of `arrow::internal::BitmapWriter` without depending on `-O2`, we can provide a Homebrew bottle that can use the BMI2 based implementation on machines that support BMI2.

### Component(s)

C++

コントリビューションガイド

コントリビューションガイドを開く

調査の方向性

Start with cpp/src/parquet/level_conversion.cc and cpp/src/parquet/level_conversion_inc.h, focusing on DefLevelsToBitmap, DefLevelsToBitmapSimd, and their use of arrow::internal::BitmapWriter. Check how the BMI2 and non-BMI2 variants are built and dispatched. Done means avoiding duplicate BitmapWriter definitions and illegal opcodes without depending on -O2, including for Homebrew builds.

索引モデルが issue の本文から書いたものです。

評価

技術スタック
cpp
領域
build-system, performance
issue の種類
バグ
難易度
4/5
見積もり時間
3〜5日
活発さ
停滞
明瞭さ
おおむね明確
初心者へのやさしさ
35/100

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