[DAG] SDPatternMatch - Replace runtime data structures with lengths known at compile time#172064
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…ngth is known at compile time
ContributorAuthor
bermondd commented Dec 12, 2025
I don't think I can select reviewers yet, but as these changes are relevant to a previous PR, CC @RKSimon@mshockwave |
Collaborator
RKSimon commented Dec 12, 2025
If we hoist NumPatterns out of match() and make a static class value then we can avoid having to pass it as a template argument. |
ContributorAuthor
bermondd commented Dec 12, 2025
Hmm, true. I'll make that change in a next commit. |
… template arguments
bermondd changed the title 
Member
mgorny commented Dec 13, 2025
I can confirm this change fixes the crash I'm seeing on x86, as I've reported in #169644 (comment). |
RKSimon merged commit 755a693 into llvm:main 9 of 10 checks passed
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Collaborator
llvm-ci commented Dec 14, 2025
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/186/builds/14708 Here is the relevant piece of the build log for the reference |
Collaborator
llvm-ci commented Dec 14, 2025
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/110/builds/6795 Here is the relevant piece of the build log for the reference |
ContributorAuthor
I have no idea what might be causing these issues, but I'll look into it. Should we revert this commit while I try to find what's wrong? |
ContributorAuthor
This one's interesting. One of the lines say Edit:
And all of these fail because the builder can't find |
Collaborator
RKSimon commented Dec 14, 2025
Both are intermittent failures on more "exotic" buildbots - the trick is to check if they go green again the following build without a relevant commit fix :) |
ContributorAuthor
bermondd commented Dec 14, 2025
Ah, I see. Thanks for the clarification! :) |
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Following the suggestions in #170061, I replaced
SmallVector<SDValue>withstd::array<SDValue, NumPatterns>andSmallBitVectorwithBitset<NumPatterns>.I had to make some changes to the
collectLeavesandreassociatableMatchHelperfunctions. IncollectLeavesspecifically, I changed the return type so I could propagate a failure in case the number of found leaves is greater than the number of expected patterns. I also added a new unit test that, together with the one already present in the previous line, checks if the matching fails in the cases where the number of patterns is less or more than the number of leaves.I don't think this is going to completely address the increased compile time reported in #169644, but hopefully it leads to an improvement.