gh-100146: Steal references from stack when building a list #100147
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
lpereira
force-pushed
the
build-list-stack-steal
branch
from
d223e29 to
808385c
Compare
When executing the BUILD_LIST opcode, steal the references from the stack, in a manner similar to the BUILD_TUPLE opcode. Implement this by offloading the logic to a new private API, _PyList_FromArraySteal(), that works similarly to _PyTuple_FromArraySteal(). This way, instead of performing multiple stack pointer adjustments while the list is being initialized, the stack is adjusted only once and a fast memory copy operation is performed in one fell swoop.
lpereira
force-pushed
the
build-list-stack-steal
branch
from
808385c to
9379cd4
Compare
gvanrossum
approved these changes
Dec 10, 2022
Member
gvanrossum
left a comment
gvanrossum
left a comment
There was a problem hiding this comment.
Yeah, looks good to me. We probably won't be able to prove this improves performance, but I don't doubt that plenty of code will benefit from such a micro-optimization.
Ping me Monday about merging it.
gvanrossum
added
the
🔨 test-with-buildbots
|
🤖 New build scheduled with the buildbot fleet by @gvanrossum for commit 9379cd4 🤖 If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again. |
bedevere-bot
removed
the
🔨 test-with-buildbots
Member
|
I've requested a buildbot build to make sure there isn't some dumb issue with refleaks. |
| Improve ``BUILD_LIST`` opcode so that it works similarly to the | ||
| ``BUILD_TUPLE`` opcode, by stealing references from the stack rather than | ||
| repeatedly using stack operations to set list elements. Implementation | ||
| details are in a new private API :c:func:`_PyList_FromArraySteal`. |
Contributor
There was a problem hiding this comment.
Suggested change
| details are in a new private API :c:func:`_PyList_FromArraySteal`. | |
| details are in a new private API :c:func:`!_PyList_FromArraySteal`. |
No need to link to private functions.
kumaraditya303
approved these changes
Dec 10, 2022
iritkatriel
reviewed
Dec 10, 2022
Comment on lines
+1
to
+2
| Improve ``BUILD_LIST`` opcode so that it works similarly to the | ||
| ``BUILD_TUPLE`` opcode, by stealing references from the stack rather than |
Member
There was a problem hiding this comment.
Suggested change
| Improve ``BUILD_LIST`` opcode so that it works similarly to the | |
| ``BUILD_TUPLE`` opcode, by stealing references from the stack rather than | |
| Improve :opcode:`BUILD_LIST` so that it works similarly to | |
| :opcode:`BUILD_TUPLE`, by stealing references from the stack rather than |
Member
|
I don't know what's up with the ARM64 Windows buildbot, but it's been failing the same way for at least three days, so no need to worry that this PR could somehow have made it go red. |
markshannon
reviewed
Dec 13, 2022
Member
|
Thanks, this looks solid. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
6 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When executing the BUILD_LIST opcode, steal the references from the stack, in a manner similar to the BUILD_TUPLE opcode. Implement this by offloading the logic to a new private API, _PyList_FromArraySteal(), that works similarly to _PyTuple_FromArraySteal().
This way, instead of performing multiple stack pointer adjustments while the list is being initialized, the stack is adjusted only once and a fast memory copy operation is performed in one fell swoop.