Author: higher-performance Date: 2025-03-13T16:02:39-04:00 New Revision: 8c7f0eaa6ee3f84e3d8260535cced234bed4fa28
URL: https://github.com/llvm/llvm-project/commit/8c7f0eaa6ee3f84e3d8260535cced234bed4fa28 DIFF: https://github.com/llvm/llvm-project/commit/8c7f0eaa6ee3f84e3d8260535cced234bed4fa28.diff LOG: Reduce memory usage in AST parent map generation by lazily checking if nodes have been seen (#129934) This mitigates a regression introduced in #87824. The mitigation here is to store pointers the deduplicated AST nodes, rather than copies of the nodes themselves. This allows a pointer-optimized set to be used and saves a lot of memory because `clang::DynTypedNode` is ~5 times larger than a pointer. Fixes #129808. Added: Modified: clang/lib/AST/ParentMapContext.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ParentMapContext.cpp b/clang/lib/AST/ParentMapContext.cpp index e9387ec79c373..6337605a07738 100644 --- a/clang/lib/AST/ParentMapContext.cpp +++ b/clang/lib/AST/ParentMapContext.cpp @@ -12,10 +12,11 @@ //===----------------------------------------------------------------------===// #include "clang/AST/ParentMapContext.h" -#include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/Decl.h" #include "clang/AST/Expr.h" +#include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/TemplateBase.h" +#include "llvm/ADT/SmallPtrSet.h" using namespace clang; @@ -69,17 +70,21 @@ class ParentMapContext::ParentMap { for (; N > 0; --N) push_back(Value); } - bool contains(const DynTypedNode &Value) { - return Seen.contains(Value); + bool contains(const DynTypedNode &Value) const { + const void *Identity = Value.getMemoizationData(); + assert(Identity); + return Dedup.contains(Identity); } void push_back(const DynTypedNode &Value) { - if (!Value.getMemoizationData() || Seen.insert(Value).second) + const void *Identity = Value.getMemoizationData(); + if (!Identity || Dedup.insert(Identity).second) { Items.push_back(Value); + } } llvm::ArrayRef<DynTypedNode> view() const { return Items; } private: - llvm::SmallVector<DynTypedNode, 2> Items; - llvm::SmallDenseSet<DynTypedNode, 2> Seen; + llvm::SmallVector<DynTypedNode, 1> Items; + llvm::SmallPtrSet<const void *, 2> Dedup; }; /// Maps from a node to its parents. This is used for nodes that have _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
