https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/147909
>From b23c75ff781875da10baa9e6f033ed5358c0cf02 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbae...@redhat.com> Date: Thu, 10 Jul 2025 09:21:57 +0200 Subject: [PATCH] [clang][bytecode] Allocate Record Fields and bases via Program Records have Program-lifetime, but we used to allocate their fields, bases and virtual bases using llvm::SmallVector. However, after creating a Record, it doesn't change and we know all the number of elements beforehand. So, allocate the lists via the BumpPtrAllocator we already have in Program. This results in slight compile-time improvements: https://llvm-compile-time-tracker.com/compare.php?from=3a3d55705b0f69f3ef5bed0b0211e7c884001842&to=e0fede973116c4d43e9883586c737c3d0bb99c3e&stat=instructions:u Unfortunately, we still have the three DenseMaps in Record, so they still heap-allocate memory on their own. --- clang/lib/AST/ByteCode/Program.cpp | 33 +++++++++++++++------ clang/lib/AST/ByteCode/Record.cpp | 21 ++++++++------ clang/lib/AST/ByteCode/Record.h | 46 ++++++++++++++---------------- 3 files changed, 58 insertions(+), 42 deletions(-) diff --git a/clang/lib/AST/ByteCode/Program.cpp b/clang/lib/AST/ByteCode/Program.cpp index 5ac0f59f32d4e..de9008f0512e6 100644 --- a/clang/lib/AST/ByteCode/Program.cpp +++ b/clang/lib/AST/ByteCode/Program.cpp @@ -315,9 +315,17 @@ Record *Program::getOrCreateRecord(const RecordDecl *RD) { }; // Reserve space for base classes. - Record::BaseList Bases; - Record::VirtualBaseList VirtBases; + Record::Base *Bases = nullptr; + Record::Base *VBases = nullptr; + unsigned NumRecordBases = 0; + unsigned NumRecordVBases = 0; if (const auto *CD = dyn_cast<CXXRecordDecl>(RD)) { + unsigned NumBases = CD->getNumBases(); + unsigned NumVBases = CD->getNumVBases(); + + Bases = new (*this) Record::Base[NumBases]; + VBases = new (*this) Record::Base[NumVBases]; + for (const CXXBaseSpecifier &Spec : CD->bases()) { if (Spec.isVirtual()) continue; @@ -334,9 +342,11 @@ Record *Program::getOrCreateRecord(const RecordDecl *RD) { return nullptr; BaseSize += align(sizeof(InlineDescriptor)); - Bases.push_back({BD, BaseSize, Desc, BR}); + new (&Bases[NumRecordBases]) Record::Base{BD, BaseSize, Desc, BR}; BaseSize += align(BR->getSize()); + ++NumRecordBases; } + assert(NumRecordBases <= NumBases); for (const CXXBaseSpecifier &Spec : CD->vbases()) { const auto *RT = Spec.getType()->getAs<RecordType>(); @@ -351,13 +361,17 @@ Record *Program::getOrCreateRecord(const RecordDecl *RD) { return nullptr; VirtSize += align(sizeof(InlineDescriptor)); - VirtBases.push_back({BD, VirtSize, Desc, BR}); + new (&VBases[NumRecordVBases]) Record::Base{BD, VirtSize, Desc, BR}; VirtSize += align(BR->getSize()); + ++NumRecordVBases; } + assert(NumRecordVBases <= NumVBases); } // Reserve space for fields. - Record::FieldList Fields; + unsigned NumFields = std::distance(RD->field_begin(), RD->field_end()); + unsigned NumRecordFields = 0; + Record::Field *Fields = new (*this) Record::Field[NumFields]; for (const FieldDecl *FD : RD->fields()) { FD = FD->getFirstDecl(); // Note that we DO create fields and descriptors @@ -382,12 +396,15 @@ Record *Program::getOrCreateRecord(const RecordDecl *RD) { } if (!Desc) return nullptr; - Fields.push_back({FD, BaseSize, Desc}); + + new (&Fields[NumRecordFields]) Record::Field{FD, BaseSize, Desc}; BaseSize += align(Desc->getAllocSize()); + ++NumRecordFields; } - Record *R = new (Allocator) Record(RD, std::move(Bases), std::move(Fields), - std::move(VirtBases), VirtSize, BaseSize); + Record *R = + new (Allocator) Record(RD, Bases, NumRecordBases, Fields, NumRecordFields, + VBases, NumRecordVBases, VirtSize, BaseSize); Records[RD] = R; return R; } diff --git a/clang/lib/AST/ByteCode/Record.cpp b/clang/lib/AST/ByteCode/Record.cpp index 1d4ac7103cb76..e40fb63914b61 100644 --- a/clang/lib/AST/ByteCode/Record.cpp +++ b/clang/lib/AST/ByteCode/Record.cpp @@ -12,20 +12,23 @@ using namespace clang; using namespace clang::interp; -Record::Record(const RecordDecl *Decl, BaseList &&SrcBases, - FieldList &&SrcFields, VirtualBaseList &&SrcVirtualBases, - unsigned VirtualSize, unsigned BaseSize) - : Decl(Decl), Bases(std::move(SrcBases)), Fields(std::move(SrcFields)), +Record::Record(const RecordDecl *Decl, const Base *SrcBases, unsigned NumBases, + const Field *Fields, unsigned NumFields, Base *VBases, + unsigned NumVBases, unsigned VirtualSize, unsigned BaseSize) + : Decl(Decl), Bases(SrcBases), NumBases(NumBases), Fields(Fields), + NumFields(NumFields), VBases(VBases), NumVBases(NumVBases), BaseSize(BaseSize), VirtualSize(VirtualSize), IsUnion(Decl->isUnion()), IsAnonymousUnion(IsUnion && Decl->isAnonymousStructOrUnion()) { - for (Base &V : SrcVirtualBases) - VirtualBases.push_back({V.Decl, V.Offset + BaseSize, V.Desc, V.R}); - for (Base &B : Bases) + for (unsigned I = 0; I != NumVBases; ++I) { + VBases[I].Offset += BaseSize; + } + + for (const Base &B : bases()) BaseMap[B.Decl] = &B; - for (Field &F : Fields) + for (const Field &F : fields()) FieldMap[F.Decl] = &F; - for (Base &V : VirtualBases) + for (const Base &V : virtual_bases()) VirtualBaseMap[V.Decl] = &V; } diff --git a/clang/lib/AST/ByteCode/Record.h b/clang/lib/AST/ByteCode/Record.h index 93ca43046180a..f70f22e8c56e0 100644 --- a/clang/lib/AST/ByteCode/Record.h +++ b/clang/lib/AST/ByteCode/Record.h @@ -41,13 +41,6 @@ class Record final { const Record *R; }; - /// Mapping from identifiers to field descriptors. - using FieldList = llvm::SmallVector<Field, 8>; - /// Mapping from identifiers to base classes. - using BaseList = llvm::SmallVector<Base, 8>; - /// List of virtual base classes. - using VirtualBaseList = llvm::SmallVector<Base, 2>; - public: /// Returns the underlying declaration. const RecordDecl *getDecl() const { return Decl; } @@ -76,32 +69,32 @@ class Record final { return nullptr; } - using const_field_iter = FieldList::const_iterator; + using const_field_iter = ArrayRef<Field>::const_iterator; llvm::iterator_range<const_field_iter> fields() const { - return llvm::make_range(Fields.begin(), Fields.end()); + return llvm::make_range(Fields, Fields + NumFields); } - unsigned getNumFields() const { return Fields.size(); } + unsigned getNumFields() const { return NumFields; } const Field *getField(unsigned I) const { return &Fields[I]; } - using const_base_iter = BaseList::const_iterator; + using const_base_iter = ArrayRef<Base>::const_iterator; llvm::iterator_range<const_base_iter> bases() const { - return llvm::make_range(Bases.begin(), Bases.end()); + return llvm::make_range(Bases, Bases + NumBases); } - unsigned getNumBases() const { return Bases.size(); } + unsigned getNumBases() const { return NumBases; } const Base *getBase(unsigned I) const { assert(I < getNumBases()); return &Bases[I]; } - using const_virtual_iter = VirtualBaseList::const_iterator; + using const_virtual_iter = ArrayRef<Base>::const_iterator; llvm::iterator_range<const_virtual_iter> virtual_bases() const { - return llvm::make_range(VirtualBases.begin(), VirtualBases.end()); + return llvm::make_range(VBases, VBases + NumVBases); } - unsigned getNumVirtualBases() const { return VirtualBases.size(); } - const Base *getVirtualBase(unsigned I) const { return &VirtualBases[I]; } + unsigned getNumVirtualBases() const { return NumVBases; } + const Base *getVirtualBase(unsigned I) const { return &VBases[I]; } void dump(llvm::raw_ostream &OS, unsigned Indentation = 0, unsigned Offset = 0) const; @@ -109,9 +102,9 @@ class Record final { private: /// Constructor used by Program to create record descriptors. - Record(const RecordDecl *, BaseList &&Bases, FieldList &&Fields, - VirtualBaseList &&VirtualBases, unsigned VirtualSize, - unsigned BaseSize); + Record(const RecordDecl *, const Base *Bases, unsigned NumBases, + const Field *Fields, unsigned NumFields, Base *VBases, + unsigned NumVBases, unsigned VirtualSize, unsigned BaseSize); private: friend class Program; @@ -119,18 +112,21 @@ class Record final { /// Original declaration. const RecordDecl *Decl; /// List of all base classes. - BaseList Bases; + const Base *Bases; + unsigned NumBases; /// List of all the fields in the record. - FieldList Fields; - /// List o fall virtual bases. - VirtualBaseList VirtualBases; + const Field *Fields; + unsigned NumFields; + /// List of all virtual bases. + Base *VBases; + unsigned NumVBases; /// Mapping from declarations to bases. llvm::DenseMap<const RecordDecl *, const Base *> BaseMap; /// Mapping from field identifiers to descriptors. llvm::DenseMap<const FieldDecl *, const Field *> FieldMap; /// Mapping from declarations to virtual bases. - llvm::DenseMap<const RecordDecl *, Base *> VirtualBaseMap; + llvm::DenseMap<const RecordDecl *, const Base *> VirtualBaseMap; /// Size of the structure. unsigned BaseSize; /// Size of all virtual bases. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
