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[clang][NFC] Specify Type and ExtQuals as having 16-byte alignment #68377

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Merged
Endilll merged 3 commits into from
Oct 12, 2023
Merged

[clang][NFC] Specify Type and ExtQuals as having 16-byte alignment #68377

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8503ff3
[clang] Align Type and ExtQuals on 16-byte boundary
Endilll Oct 5, 2023
d08f8f9
Run clang-format
Endilll Oct 6, 2023
d117d28
Address review feedback
Endilll Oct 7, 2023
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21 changes: 10 additions & 11 deletions clang/include/clang/AST/Type.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1482,7 +1482,8 @@ class ExtQualsTypeCommonBase {
/// in three low bits on the QualType pointer; a fourth bit records whether
/// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
/// Objective-C GC attributes) are much more rare.
class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
class alignas(TypeAlignment) ExtQuals : public ExtQualsTypeCommonBase,
public llvm::FoldingSetNode {
// NOTE: changing the fast qualifiers should be straightforward as
// long as you don't make 'const' non-fast.
// 1. Qualifiers:
Expand Down Expand Up @@ -1594,7 +1595,7 @@ enum class AutoTypeKeyword {
///
/// Types, once created, are immutable.
///
class alignas(8) Type : public ExtQualsTypeCommonBase {
class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
public:
enum TypeClass {
#define TYPE(Class, Base) Class,
Expand Down Expand Up @@ -1982,9 +1983,10 @@ class alignas(8) Type : public ExtQualsTypeCommonBase {
Type(TypeClass tc, QualType canon, TypeDependence Dependence)
: ExtQualsTypeCommonBase(this,
canon.isNull() ? QualType(this_(), 0) : canon) {
static_assert(sizeof(*this) <= 8 + sizeof(ExtQualsTypeCommonBase),
static_assert(sizeof(*this) <=
alignof(decltype(*this)) + sizeof(ExtQualsTypeCommonBase),
"changing bitfields changed sizeof(Type)!");
static_assert(alignof(decltype(*this)) % sizeof(void *) == 0,
static_assert(alignof(decltype(*this)) % TypeAlignment == 0,
"Insufficient alignment!");
TypeBits.TC = tc;
TypeBits.Dependence = static_cast<unsigned>(Dependence);
Expand Down Expand Up @@ -5348,7 +5350,7 @@ class DeducedType : public Type {

/// Represents a C++11 auto or C++14 decltype(auto) type, possibly constrained
/// by a type-constraint.
class alignas(8) AutoType : public DeducedType, public llvm::FoldingSetNode {
class AutoType : public DeducedType, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

ConceptDecl *TypeConstraintConcept;
Expand Down Expand Up @@ -5456,9 +5458,7 @@ class DeducedTemplateSpecializationType : public DeducedType,
/// TemplateArguments, followed by a QualType representing the
/// non-canonical aliased type when the template is a type alias
/// template.
class alignas(8) TemplateSpecializationType
: public Type,
public llvm::FoldingSetNode {
class TemplateSpecializationType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The name of the template being specialized. This is
Expand Down Expand Up @@ -5872,9 +5872,8 @@ class DependentNameType : public TypeWithKeyword, public llvm::FoldingSetNode {
/// Represents a template specialization type whose template cannot be
/// resolved, e.g.
/// A<T>::template B<T>
class alignas(8) DependentTemplateSpecializationType
: public TypeWithKeyword,
public llvm::FoldingSetNode {
class DependentTemplateSpecializationType : public TypeWithKeyword,
public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The nested name specifier containing the qualifier.
Expand Down