Remove sort_key attribute from DAGNode #13736
Merged
Conversation
This file contains 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
Prior to having the DAGCircuit in rust the `sort_key` attribute was added as a cache to speed up the lexicographical topological sort. Prior to having this attribute the topological sort method would compute the sort key as a string on the fly which ended up being a large bottleneck in transpilation (see: Qiskit#4040 for more details). However, since migrating the DAGCircuit implementation to Rust this sort_key attribute isn't needed anymore because we call the rustworkx-core function with a tuple of bit objects instead of a string. The `sort_key` atribute was left on in place for backwards compatibility (it shouldn't have been public, this was a mistake in Qiskit#4040) and when we create a python DAGNode object that will be returned to Python the creation of the sort key is unnecessary overhead (it takes roughly 1% of profile time to format the sort_key string during transpilation). Since nothing in DAGCircuit is actually using it this commit removes it to save the CPU cycles creating the string on each dag creation. We will need to add a deprecation to 1.4.0 to mark this removal for 2.0.0 since this was missed in 1.3.0.
mtreinish
added
the
Changelog: Removal
|
One or more of the following people are relevant to this code:
|
Pull Request Test Coverage Report for Build 12999233331Warning: This coverage report may be inaccurate.This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.
Details
💛 - Coveralls |
kevinhartman
previously approved these changes
Jan 27, 2025
| @@ -114,8 +114,6 @@ impl DAGNode { | |||
| #[pyclass(module = "qiskit._accelerate.circuit", extends=DAGNode)] | |||
| pub struct DAGOpNode { | |||
| pub instruction: CircuitInstruction, | |||
There was a problem hiding this comment.
Nice! Maybe this should become a tuple struct now. Feel free to leave as is if that's your preference.
There was a problem hiding this comment.
I kept it this way for simplicity since I just deleted the lines with the previous attribute. I did overlook there is only a single field now. But I think I'd probably rather keep it the same because I feel like there are a few places we do node.instruction/self.instruction and that feels a bit more ergonomic than node.0
mtreinish
added a commit
to mtreinish/qiskit-core
that referenced
this pull request
Jan 27, 2025
Prior to having the DAGCircuit in rust the sort_key attribute was added as a cache to speed up the lexicographical topological sort. Prior to having this attribute the topological sort method would compute the sort key as a string on the fly which ended up being a large bottleneck in transpilation (see: Qiskit#4040 for more details). However, since migrating the DAGCircuit implementation to Rust this sort_key attribute isn't needed anymore because we call the rustworkx-core function with a tuple of bit objects instead of a string. The sort_key atribute was left on in place for backwards compatibility (it shouldn't have been public, this was a mistake in Qiskit#4040) and when we create a python DAGNode object that will be returned to Python the creation of the sort key is unnecessary overhead (it takes roughly 1% of profile time to format the sort_key string during transpilation). Since nothing in DAGCircuit is actually using it this commit removes it to save the CPU cycles creating the string on each dag creation. This attribute is removed in Qiskit 2.0.0 in Qiskit#13736
kevinhartman
approved these changes
Jan 27, 2025
github-merge-queue bot
pushed a commit
that referenced
this pull request
Jan 27, 2025
Prior to having the DAGCircuit in rust the sort_key attribute was added as a cache to speed up the lexicographical topological sort. Prior to having this attribute the topological sort method would compute the sort key as a string on the fly which ended up being a large bottleneck in transpilation (see: #4040 for more details). However, since migrating the DAGCircuit implementation to Rust this sort_key attribute isn't needed anymore because we call the rustworkx-core function with a tuple of bit objects instead of a string. The sort_key atribute was left on in place for backwards compatibility (it shouldn't have been public, this was a mistake in #4040) and when we create a python DAGNode object that will be returned to Python the creation of the sort key is unnecessary overhead (it takes roughly 1% of profile time to format the sort_key string during transpilation). Since nothing in DAGCircuit is actually using it this commit removes it to save the CPU cycles creating the string on each dag creation. This attribute is removed in Qiskit 2.0.0 in #13736
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
Summary
Prior to having the DAGCircuit in rust the
sort_keyattribute was added as a cache to speed up the lexicographical topological sort. Prior to having this attribute the topological sort method would compute the sort key as a string on the fly which ended up being a large bottleneck in transpilation (see: #4040 for more details). However, since migrating the DAGCircuit implementation to Rust this sort_key attribute isn't needed anymore because we call the rustworkx-core function with a tuple of bit objects instead of a string. Thesort_keyatribute was left on in place for backwards compatibility (it shouldn't have been public, this was a mistake in #4040) and when we create a python DAGNode object that will be returned to Python the creation of the sort key is unnecessary overhead (it takes roughly 1% of profile time to format the sort_key string during transpilation). Since nothing in DAGCircuit is actually using it this commit removes it to save the CPU cycles creating the string on each dag creation. We will need to add a deprecation to 1.4.0 to mark this removal for 2.0.0 since this was missed in 1.3.0.Details and comments
Deprecation in: #13744