Author: d0k Date: Wed Oct 21 11:33:15 2015 New Revision: 250905 URL: http://llvm.org/viewvc/llvm-project?rev=250905&view=rev Log: Shrink DynTypedNode by one pointer from 40 to 32 bytes (on x86_64).
The MemoizationData cache was introduced to avoid a series of enum compares at the cost of making DynTypedNode bigger. This change reverts to using an enum compare but instead of building a chain of comparison the enum values are reordered so the check can be performed with a simple greater than. The alternative would be to steal a bit from the enum but I think that's a more complex solution and not really needed here. I tried this on several large .cpp files with clang-tidy and didn't notice any performance difference. The test change is due to matchers being sorted by their node kind. Differential Revision: http://reviews.llvm.org/D13946 Modified: cfe/trunk/include/clang/AST/ASTTypeTraits.h cfe/trunk/unittests/ASTMatchers/Dynamic/RegistryTest.cpp Modified: cfe/trunk/include/clang/AST/ASTTypeTraits.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/ASTTypeTraits.h?rev=250905&r1=250904&r2=250905&view=diff ============================================================================== --- cfe/trunk/include/clang/AST/ASTTypeTraits.h (original) +++ cfe/trunk/include/clang/AST/ASTTypeTraits.h Wed Oct 21 11:33:15 2015 @@ -106,18 +106,25 @@ public: } }; + /// Check if the given ASTNodeKind identifies a type that offers pointer + /// identity. This is useful for the fast path in DynTypedNode. + bool hasPointerIdentity() const { + return KindId > NKI_LastKindWithoutPointerIdentity; + } + private: /// \brief Kind ids. /// /// Includes all possible base and derived kinds. enum NodeKindId { NKI_None, - NKI_CXXCtorInitializer, NKI_TemplateArgument, - NKI_NestedNameSpecifier, NKI_NestedNameSpecifierLoc, NKI_QualType, NKI_TypeLoc, + NKI_LastKindWithoutPointerIdentity = NKI_TypeLoc, + NKI_CXXCtorInitializer, + NKI_NestedNameSpecifier, NKI_Decl, #define DECL(DERIVED, BASE) NKI_##DERIVED##Decl, #include "clang/AST/DeclNodes.inc" @@ -238,7 +245,11 @@ public: /// Note that this is not supported by all AST nodes. For AST nodes /// that don't have a pointer-defined identity inside the AST, this /// method returns NULL. - const void *getMemoizationData() const { return MemoizationData; } + const void *getMemoizationData() const { + return NodeKind.hasPointerIdentity() + ? *reinterpret_cast<void *const *>(Storage.buffer) + : nullptr; + } /// \brief Prints the node to the given output stream. void print(llvm::raw_ostream &OS, const PrintingPolicy &PP) const; @@ -286,18 +297,18 @@ private: template <typename T, typename BaseT> struct DynCastPtrConverter { static const T *get(ASTNodeKind NodeKind, const char Storage[]) { if (ASTNodeKind::getFromNodeKind<T>().isBaseOf(NodeKind)) - return cast<T>(*reinterpret_cast<BaseT *const *>(Storage)); + return &getUnchecked(NodeKind, Storage); return nullptr; } static const T &getUnchecked(ASTNodeKind NodeKind, const char Storage[]) { assert(ASTNodeKind::getFromNodeKind<T>().isBaseOf(NodeKind)); - return *cast<T>(*reinterpret_cast<BaseT *const *>(Storage)); + return *cast<T>(static_cast<const BaseT *>( + *reinterpret_cast<const void *const *>(Storage))); } static DynTypedNode create(const BaseT &Node) { DynTypedNode Result; Result.NodeKind = ASTNodeKind::getFromNode(Node); - Result.MemoizationData = &Node; - new (Result.Storage.buffer) const BaseT * (&Node); + new (Result.Storage.buffer) const void *(&Node); return Result; } }; @@ -306,18 +317,18 @@ private: template <typename T> struct PtrConverter { static const T *get(ASTNodeKind NodeKind, const char Storage[]) { if (ASTNodeKind::getFromNodeKind<T>().isSame(NodeKind)) - return *reinterpret_cast<T *const *>(Storage); + return &getUnchecked(NodeKind, Storage); return nullptr; } static const T &getUnchecked(ASTNodeKind NodeKind, const char Storage[]) { assert(ASTNodeKind::getFromNodeKind<T>().isSame(NodeKind)); - return **reinterpret_cast<T *const *>(Storage); + return *static_cast<const T *>( + *reinterpret_cast<const void *const *>(Storage)); } static DynTypedNode create(const T &Node) { DynTypedNode Result; Result.NodeKind = ASTNodeKind::getFromNodeKind<T>(); - Result.MemoizationData = &Node; - new (Result.Storage.buffer) const T * (&Node); + new (Result.Storage.buffer) const void *(&Node); return Result; } }; @@ -336,14 +347,12 @@ private: static DynTypedNode create(const T &Node) { DynTypedNode Result; Result.NodeKind = ASTNodeKind::getFromNodeKind<T>(); - Result.MemoizationData = nullptr; new (Result.Storage.buffer) T(Node); return Result; } }; ASTNodeKind NodeKind; - const void *MemoizationData; /// \brief Stores the data of the node. /// @@ -353,12 +362,9 @@ private: /// \c QualTypes, \c NestedNameSpecifierLocs, \c TypeLocs and /// \c TemplateArguments on the other hand do not have storage or unique /// pointers and thus need to be stored by value. - typedef llvm::AlignedCharArrayUnion< - Decl *, Stmt *, Type *, NestedNameSpecifier *, CXXCtorInitializer *> - KindsByPointer; - llvm::AlignedCharArrayUnion<KindsByPointer, TemplateArgument, - NestedNameSpecifierLoc, QualType, TypeLoc> - Storage; + llvm::AlignedCharArrayUnion<const void *, TemplateArgument, + NestedNameSpecifierLoc, QualType, + TypeLoc> Storage; }; template <typename T> Modified: cfe/trunk/unittests/ASTMatchers/Dynamic/RegistryTest.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/ASTMatchers/Dynamic/RegistryTest.cpp?rev=250905&r1=250904&r2=250905&view=diff ============================================================================== --- cfe/trunk/unittests/ASTMatchers/Dynamic/RegistryTest.cpp (original) +++ cfe/trunk/unittests/ASTMatchers/Dynamic/RegistryTest.cpp Wed Oct 21 11:33:15 2015 @@ -455,8 +455,8 @@ TEST_F(RegistryTest, Completion) { // Polymorphic. EXPECT_TRUE(hasCompletion( Comps, "hasDescendant(", - "Matcher<NestedNameSpecifier|NestedNameSpecifierLoc|QualType|...> " - "hasDescendant(Matcher<CXXCtorInitializer|NestedNameSpecifier|" + "Matcher<TemplateArgument|NestedNameSpecifier|NestedNameSpecifierLoc|...>" + " hasDescendant(Matcher<TemplateArgument|NestedNameSpecifier|" "NestedNameSpecifierLoc|...>)")); CompVector WhileComps = getCompletions("whileStmt", 0); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits