[llvm-branch-commits] [clang] [LifetimeSafety] Disable canonicalization in immutable collections (PR #159850)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-analysis

Author: Utkarsh Saxena (usx95)

<details>
<summary>Changes</summary>

Disable canonicalization in immutable collections for lifetime analysis.

Modified the `LifetimeFactory` struct in `LifetimeSafety.cpp` to explicitly initialize the immutable collection factories with `canonicalize=false`. This prevents the factories from canonicalizing their data structures, which can improve performance by avoiding unnecessary comparisons and digest computations.

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Full diff: https://github.com/llvm/llvm-project/pull/159850.diff


1 Files Affected:

- (modified) clang/lib/Analysis/LifetimeSafety.cpp (+6-3) 


``````````diff
diff --git a/clang/lib/Analysis/LifetimeSafety.cpp b/clang/lib/Analysis/LifetimeSafety.cpp
index 0dd5716d93fb6..43cab406a9dc3 100644
--- a/clang/lib/Analysis/LifetimeSafety.cpp
+++ b/clang/lib/Analysis/LifetimeSafety.cpp
@@ -966,9 +966,12 @@ using ExpiredLoanMap = llvm::ImmutableMap<LoanID, const ExpireFact *>;
 /// An object to hold the factories for immutable collections, ensuring
 /// that all created states share the same underlying memory management.
 struct LifetimeFactory {
-  OriginLoanMap::Factory OriginMapFactory;
-  LoanSet::Factory LoanSetFactory;
-  ExpiredLoanMap::Factory ExpiredLoanMapFactory;
+  // Avoid canonicalising
+  OriginLoanMap::Factory OriginMapFactory =
+      OriginLoanMap::Factory(/*canonicalize=*/false);
+  LoanSet::Factory LoanSetFactory = LoanSet::Factory(/*canonicalize=*/false);
+  ExpiredLoanMap::Factory ExpiredLoanMapFactory =
+      ExpiredLoanMap::Factory(/*canonicalize=*/false);
 };
 
 /// Represents the dataflow lattice for loan propagation.

``````````

</details>


https://github.com/llvm/llvm-project/pull/159850