Extend `FOR_ITER` specializations to cover other indexable sequences
还没有人认领这个 Issue。
- 主要语言
- Python
- 星标
- 77.2k
- 派生
- 35.9k
- PR 合并指标
- PR 指标待抓取
描述
Currently, we specialize FOR_ITER for both tuple and list. We also handle tuple and lists specially in GET_ITER to support this specialization.
We should extend this specialization of iteration over sequences, using virtual iterators to bytes, str, bytesarray and others.
To do this, we should:
- Add a
tp_getiteritemslots toPyTypeObjectfor sequences that can be efficiently indexed and cannot raise except for out-of-bounds access. - Add a specialization of
FOR_ITERfor these classes. - Specialize
GET_ITERfor:- iterators
- indexable sequences (those classes with a
tp_getiteritemslot)
- Specialize
SENDfor indexable sequences which should also improve JIT coverage, as unspecialized_SENDis currently a major cause of jit optimization failures.
Combined with https://github.com/python/cpython/issues/145667 this will allow effective specialization of a wider range of iterables and allow that specialization not only for for loops, but also for yield from loops.
It will add 3 instructions (4 new, 1 removed) which a reasonable
Linked PRs
- gh-145670
- gh-147967
贡献指南
从这里开始
- 先读完整个 Issue,再读项目的贡献指南。
- 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
- Fork 仓库,在一个分支上完成修改。
- 提交 Pull Request,并在描述里引用这个 Issue 编号。
调研方向
首先阅读现有的 FOR_ITER 和 GET_ITER 特化,然后检查 PyTypeObject 和 SEND 特化。当 bytes 和 str 等可索引序列在 for 循环和 yield from 循环中使用虚拟迭代器,并完成所请求的新指令覆盖时,这项工作就完成了。
由索引模型根据 Issue 内容生成。
评估
- 技术栈
- python
- 领域
- compilers, performance
- Issue 类型
- 功能
- 难度
- 5/5
- 预计耗时
- 一周以上
- 活跃度
- 停滞
- 描述清晰度
- 需要澄清
- 新手友好度
- 20/100