Repository navigation
[llvm] Clean backport of upstream PR183272 - #23284
Merged
Merged
Conversation
Test Results 24 files 24 suites 3d 20h 59m 5s ⏱️ For more details on these failures, see this check. Results for commit 3b692372. ♻️ This comment has been updated with latest results. |
vepadulano
added a commit
to vepadulano/root
that referenced
this pull request
Sep 11, 2026
The test is disabled as it sporadically fails due to a performance degradation in LLVM22. That could be fixed by backporting patches from LLVM23, e.g. as done by root-project#23284. The test coverage for the "unorderedMap" test is kept via "unorderedMapTests", a fully-compiled googletest-based rewrite which had already been added to the test suite. The "Names" test is currently not being replaced.
vepadulano
added a commit
that referenced
this pull request
Sep 12, 2026
The test is disabled as it sporadically fails due to a performance degradation in LLVM22. That could be fixed by backporting patches from LLVM23, e.g. as done by #23284. The test coverage for the "unorderedMap" test is kept via "unorderedMapTests", a fully-compiled googletest-based rewrite which had already been added to the test suite. The "Names" test is currently not being replaced.
ferdymercury
pushed a commit
to ferdymercury/root
that referenced
this pull request
Oct 16, 2026
The test is disabled as it sporadically fails due to a performance degradation in LLVM22. That could be fixed by backporting patches from LLVM23, e.g. as done by root-project#23284. The test coverage for the "unorderedMap" test is kept via "unorderedMapTests", a fully-compiled googletest-based rewrite which had already been added to the test suite. The "Names" test is currently not being replaced.
pcanal
self-requested a review
October 27, 2026 18:29
pcanal
approved these changes
Oct 27, 2026
pcanal
left a comment
pcanal
left a comment
Member
There was a problem hiding this comment.
This bring WaitingOnGraph.h on part which the tip of LLVM except for NFC refactors after db5ffb04: (#184775, #184955, #185001, #185152, #185242, #185275, #185388, #194297).
pcanal
marked this pull request as ready for review
October 27, 2026 18:40
hahnjo
marked this pull request as draft
October 27, 2026 19:12
Member
|
Putting back in draft as it must not be merged as-is/yet as we need an LLVM tag. |
This reapplies 85354c6d8bc, which was reverted in d7347c0b81a due to bot failures. In this commit further changes are made to address the bot failure, and general readability. WaitingOnGraph::Coalescer::remove is renamed WaitingOnGraph::Coalescer::erase, since its behavior is now similar to common container erase operations. WaitingOnGraph::Coalescer::clear is provided to enable a fast reset of Coalescer state. SuperNodeBuilder::takeSuperNodes is updated to clear the Coalescer state before returning the SuperNodes, ensuring that future calls to SuperNodeBuilder::add do not trip the assert that caused the builder failures. Backport of root-project/llvm-project@55ce4b7
This commit replaces the core dependence propagation algorithm in WaitingOnGraph to avoid worst-case behavior in the common case where dependence graphs are sparse. This algorithm showed up as the underlying cause of the bug in llvm/llvm-project#179611. For each call to MaterializationResponsibility::notifyEmitted, WaitingOnGraph would build the transitive closure of all SuperNodes whose "waiting on" relationships were affected by the newly emitted symbols, then propagate any remaining unemitted dependencies through this transitive closure graph. This approach is simple, but pushes the algorithm towards n^2 complexity even for sparse dependence graphs. The new propagation algorithm: 1. Inverts the edge direction in the SymbolDependenceMap data structure: SymbolDepMap[SN] now contains the set of SuperNodes that depend on SN, rather than the set that SN depends upon. 2. Pushes dependencies through the SymbolDepMap iteratively until it reaches a fixed point. This updated algorithm converges much more quickly than the original for the testcase reported in the issue, and for other cases tested so far. No testcase yet, as this only affects performance. I've filed a follow-up issue, llvm/llvm-project#183251, to track construction of performance testing infrastructure for WaitingOnGraph. Should fix llvm/llvm-project#179611 Backport of root-project/llvm-project@db5ffb0
hahnjo
force-pushed
the
backport-llvm-PR183272
branch
from
October 28, 2026 07:47
cf31254 to
462d55c
Compare
hahnjo
marked this pull request as ready for review
October 28, 2026 07:54
hahnjo
force-pushed
the
backport-llvm-PR183272
branch
from
October 28, 2026 11:56
462d55c to
3b69237
Compare
dpiparo
approved these changes
Oct 28, 2026
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
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.
Backport llvm/llvm-project@55ce4b7 as a dependency of llvm/llvm-project@db5ffb0 (llvm/llvm-project#183272)
(Clean) alternative to #23249