Description

markshannon

opened on Jun 14, 2024

Issue body actions

With the JIT and better tier 2 optimizations, effective specialization is becoming more important that plain speed in tier 1.

BEFORE_WITH and BEFORE_ASYNC_WITH could be specialized, but they are bulky and won't optimize well in tier 2.
Instead, we should lower them to attribute lookups and calls which can then be optimized.
We should add a LOAD_SPECIAL instruction for loading dunder methods and replace BEFORE_WITH as follows:

    COPY 1
    LOAD_SPECIAL __enter__ + NULL|self
    SWAP 3
    LOAD_SPECIAL __exit__
    SWAP 3
    CALL 0

Likewise for BEFORE_ASYNC_WITH.

Even without any specialization of LOAD_SPECIAL, the CALL will be specialized and the JIT can eliminate the COPY and SWAPs.

Linked PRs

• GH-120507: Lower the BEFORE_WITH and BEFORE_ASYNC_WITH instructions. #120640
• gh-120507: Double WASI memory #120648

Activity

1. markshannon commented on Jun 17, 2024

   

   markshannon

   on Jun 17, 2024

   MemberAuthor

   More actions

   No performance impact
   https://github.com/faster-cpython/benchmarking-public/tree/main/results/bm-20240617-3.14.0a0-68df0a5
2. vstinner

   added 2 commits that reference this issue on Jun 17, 2024

   pythongh-120507: Double WASI memory

   24bb60d

   gh-120507: Double WASI memory (#120648)

   6acf777
3. markshannon

   added a commit that references this issue on Jun 18, 2024

   GH-120507: Lower the `BEFORE_WITH` and `BEFORE_ASYNC_WITH` instructio…

   9cefcc0
4. brandtbucher

   closed this as completedon Jun 18, 2024
5. picnixz

   added a commit that references this issue on Jun 19, 2024

   pythonGH-120507: Lower the `BEFORE_WITH` and `BEFORE_ASYNC_WITH` inst…

   d3107d4
6. mrahtz

   added 2 commits that reference this issue on Jun 30, 2024

   pythongh-120507: Double WASI memory (python#120648)

   c565073

   pythonGH-120507: Lower the `BEFORE_WITH` and `BEFORE_ASYNC_WITH` inst…

   81ea6ea
7. estyxx

   added 2 commits that reference this issue on Jul 17, 2024

   pythongh-120507: Double WASI memory (python#120648)

   7b46d07

   pythonGH-120507: Lower the `BEFORE_WITH` and `BEFORE_ASYNC_WITH` inst…

   d831a39

Issue actions