riccibruno created this revision.
riccibruno added a reviewer: lebedev.ri.
riccibruno added a project: clang.
Herald added a subscriber: cfe-commits.
Background:
The number of trailing `CXXBaseSpecifiers` in `CastExpr` was moved from
`CastExprBitfields` to a trailing object in r338489 (D50050
<https://reviews.llvm.org/D50050>). At this time these bit-fields
classes were only 32 bits wide. However later r345459 widened these bit-field
classes to 64 bits.
The reason for this change was that on 64 bit archs alignment requirements
caused 4 bytes of
padding after the `Stmt` sub-object in nearly all expression classes. Reusing
this padding yielded
an >10% reduction in the size used by all statement/expressions when parsing
all of Boost (on a
64 bit arch). This increased the size of statement/expressions for 32 bits
archs, but this can be
mitigated by moving more data to the bit-fields of `Stmt` (and moreover most
people now care
about 64 bits archs as a host).
Therefore move back the number of `CXXBaseSpecifiers` in `CastExpr` to the
bit-fields of `Stmt`.
This in effect mostly revert r338489 while keeping the added test.
Repository:
rC Clang
https://reviews.llvm.org/D56358
Files:
include/clang/AST/Expr.h
include/clang/AST/ExprCXX.h
include/clang/AST/ExprObjC.h
include/clang/AST/Stmt.h
lib/AST/Expr.cpp
lib/AST/ExprCXX.cpp
Index: lib/AST/ExprCXX.cpp
===================================================================
--- lib/AST/ExprCXX.cpp
+++ lib/AST/ExprCXX.cpp
@@ -694,9 +694,7 @@
SourceLocation RParenLoc,
SourceRange AngleBrackets) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
auto *E =
new (Buffer) CXXStaticCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
RParenLoc, AngleBrackets);
@@ -708,9 +706,7 @@
CXXStaticCastExpr *CXXStaticCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) CXXStaticCastExpr(EmptyShell(), PathSize);
}
@@ -723,9 +719,7 @@
SourceLocation RParenLoc,
SourceRange AngleBrackets) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
auto *E =
new (Buffer) CXXDynamicCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
RParenLoc, AngleBrackets);
@@ -737,9 +731,7 @@
CXXDynamicCastExpr *CXXDynamicCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) CXXDynamicCastExpr(EmptyShell(), PathSize);
}
@@ -784,9 +776,7 @@
SourceLocation RParenLoc,
SourceRange AngleBrackets) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
auto *E =
new (Buffer) CXXReinterpretCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
RParenLoc, AngleBrackets);
@@ -798,9 +788,7 @@
CXXReinterpretCastExpr *
CXXReinterpretCastExpr::CreateEmpty(const ASTContext &C, unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) CXXReinterpretCastExpr(EmptyShell(), PathSize);
}
@@ -823,9 +811,7 @@
const CXXCastPath *BasePath,
SourceLocation L, SourceLocation R) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
auto *E =
new (Buffer) CXXFunctionalCastExpr(T, VK, Written, K, Op, PathSize, L, R);
if (PathSize)
@@ -836,9 +822,7 @@
CXXFunctionalCastExpr *
CXXFunctionalCastExpr::CreateEmpty(const ASTContext &C, unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) CXXFunctionalCastExpr(EmptyShell(), PathSize);
}
Index: lib/AST/Expr.cpp
===================================================================
--- lib/AST/Expr.cpp
+++ lib/AST/Expr.cpp
@@ -1808,21 +1808,6 @@
return nullptr;
}
-CastExpr::BasePathSizeTy *CastExpr::BasePathSize() {
- assert(!path_empty());
- switch (getStmtClass()) {
-#define ABSTRACT_STMT(x)
-#define CASTEXPR(Type, Base) \
- case Stmt::Type##Class: \
- return static_cast<Type *>(this) \
- ->getTrailingObjects<CastExpr::BasePathSizeTy>();
-#define STMT(Type, Base)
-#include "clang/AST/StmtNodes.inc"
- default:
- llvm_unreachable("non-cast expressions not possible here");
- }
-}
-
CXXBaseSpecifier **CastExpr::path_buffer() {
switch (getStmtClass()) {
#define ABSTRACT_STMT(x)
@@ -1861,9 +1846,7 @@
const CXXCastPath *BasePath,
ExprValueKind VK) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
ImplicitCastExpr *E =
new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
if (PathSize)
@@ -1874,9 +1857,7 @@
ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
}
@@ -1887,9 +1868,7 @@
TypeSourceInfo *WrittenTy,
SourceLocation L, SourceLocation R) {
unsigned PathSize = (BasePath ? BasePath->size() : 0);
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
CStyleCastExpr *E =
new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
if (PathSize)
@@ -1900,9 +1879,7 @@
CStyleCastExpr *CStyleCastExpr::CreateEmpty(const ASTContext &C,
unsigned PathSize) {
- void *Buffer =
- C.Allocate(totalSizeToAlloc<CastExpr::BasePathSizeTy, CXXBaseSpecifier *>(
- PathSize ? 1 : 0, PathSize));
+ void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
}
Index: include/clang/AST/Stmt.h
===================================================================
--- include/clang/AST/Stmt.h
+++ include/clang/AST/Stmt.h
@@ -481,7 +481,10 @@
unsigned Kind : 6;
unsigned PartOfExplicitCast : 1; // Only set for ImplicitCastExpr.
- unsigned BasePathIsEmpty : 1;
+
+ /// The number of CXXBaseSpecifiers in the cast. 16 bits would be enough
+ /// here. ([implimits] Direct and indirect base classes [16384]).
+ unsigned BasePathSize;
};
class BinaryOperatorBitfields {
Index: include/clang/AST/ExprObjC.h
===================================================================
--- include/clang/AST/ExprObjC.h
+++ include/clang/AST/ExprObjC.h
@@ -1574,8 +1574,7 @@
/// \endcode
class ObjCBridgedCastExpr final
: public ExplicitCastExpr,
- private llvm::TrailingObjects<
- ObjCBridgedCastExpr, CastExpr::BasePathSizeTy, CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<ObjCBridgedCastExpr, CXXBaseSpecifier *> {
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend class CastExpr;
@@ -1585,10 +1584,6 @@
SourceLocation BridgeKeywordLoc;
unsigned Kind : 2;
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
ObjCBridgedCastExpr(SourceLocation LParenLoc, ObjCBridgeCastKind Kind,
CastKind CK, SourceLocation BridgeKeywordLoc,
Index: include/clang/AST/ExprCXX.h
===================================================================
--- include/clang/AST/ExprCXX.h
+++ include/clang/AST/ExprCXX.h
@@ -325,8 +325,7 @@
/// \c static_cast<int>(1.0).
class CXXStaticCastExpr final
: public CXXNamedCastExpr,
- private llvm::TrailingObjects<CXXStaticCastExpr, CastExpr::BasePathSizeTy,
- CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<CXXStaticCastExpr, CXXBaseSpecifier *> {
CXXStaticCastExpr(QualType ty, ExprValueKind vk, CastKind kind, Expr *op,
unsigned pathSize, TypeSourceInfo *writtenTy,
SourceLocation l, SourceLocation RParenLoc,
@@ -337,10 +336,6 @@
explicit CXXStaticCastExpr(EmptyShell Empty, unsigned PathSize)
: CXXNamedCastExpr(CXXStaticCastExprClass, Empty, PathSize) {}
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
friend class CastExpr;
friend TrailingObjects;
@@ -366,8 +361,7 @@
/// check to determine how to perform the type conversion.
class CXXDynamicCastExpr final
: public CXXNamedCastExpr,
- private llvm::TrailingObjects<
- CXXDynamicCastExpr, CastExpr::BasePathSizeTy, CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<CXXDynamicCastExpr, CXXBaseSpecifier *> {
CXXDynamicCastExpr(QualType ty, ExprValueKind VK, CastKind kind,
Expr *op, unsigned pathSize, TypeSourceInfo *writtenTy,
SourceLocation l, SourceLocation RParenLoc,
@@ -378,10 +372,6 @@
explicit CXXDynamicCastExpr(EmptyShell Empty, unsigned pathSize)
: CXXNamedCastExpr(CXXDynamicCastExprClass, Empty, pathSize) {}
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
friend class CastExpr;
friend TrailingObjects;
@@ -414,7 +404,6 @@
class CXXReinterpretCastExpr final
: public CXXNamedCastExpr,
private llvm::TrailingObjects<CXXReinterpretCastExpr,
- CastExpr::BasePathSizeTy,
CXXBaseSpecifier *> {
CXXReinterpretCastExpr(QualType ty, ExprValueKind vk, CastKind kind,
Expr *op, unsigned pathSize,
@@ -427,10 +416,6 @@
CXXReinterpretCastExpr(EmptyShell Empty, unsigned pathSize)
: CXXNamedCastExpr(CXXReinterpretCastExprClass, Empty, pathSize) {}
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
friend class CastExpr;
friend TrailingObjects;
@@ -458,8 +443,7 @@
/// value.
class CXXConstCastExpr final
: public CXXNamedCastExpr,
- private llvm::TrailingObjects<CXXConstCastExpr, CastExpr::BasePathSizeTy,
- CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<CXXConstCastExpr, CXXBaseSpecifier *> {
CXXConstCastExpr(QualType ty, ExprValueKind VK, Expr *op,
TypeSourceInfo *writtenTy, SourceLocation l,
SourceLocation RParenLoc, SourceRange AngleBrackets)
@@ -469,10 +453,6 @@
explicit CXXConstCastExpr(EmptyShell Empty)
: CXXNamedCastExpr(CXXConstCastExprClass, Empty, 0) {}
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
friend class CastExpr;
friend TrailingObjects;
@@ -1538,8 +1518,7 @@
/// \endcode
class CXXFunctionalCastExpr final
: public ExplicitCastExpr,
- private llvm::TrailingObjects<
- CXXFunctionalCastExpr, CastExpr::BasePathSizeTy, CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<CXXFunctionalCastExpr, CXXBaseSpecifier *> {
SourceLocation LParenLoc;
SourceLocation RParenLoc;
@@ -1554,10 +1533,6 @@
explicit CXXFunctionalCastExpr(EmptyShell Shell, unsigned PathSize)
: ExplicitCastExpr(CXXFunctionalCastExprClass, Shell, PathSize) {}
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
friend class CastExpr;
friend TrailingObjects;
Index: include/clang/AST/Expr.h
===================================================================
--- include/clang/AST/Expr.h
+++ include/clang/AST/Expr.h
@@ -2995,28 +2995,15 @@
/// representation in the source code (ExplicitCastExpr's derived
/// classes).
class CastExpr : public Expr {
-public:
- using BasePathSizeTy = unsigned int;
- static_assert(std::numeric_limits<BasePathSizeTy>::max() >= 16384,
- "[implimits] Direct and indirect base classes [16384].");
-
-private:
Stmt *Op;
bool CastConsistency() const;
- BasePathSizeTy *BasePathSize();
-
const CXXBaseSpecifier * const *path_buffer() const {
return const_cast<CastExpr*>(this)->path_buffer();
}
CXXBaseSpecifier **path_buffer();
- void setBasePathSize(BasePathSizeTy basePathSize) {
- assert(!path_empty() && basePathSize != 0);
- *(BasePathSize()) = basePathSize;
- }
-
protected:
CastExpr(StmtClass SC, QualType ty, ExprValueKind VK, const CastKind kind,
Expr *op, unsigned BasePathSize)
@@ -3037,9 +3024,9 @@
Op(op) {
CastExprBits.Kind = kind;
CastExprBits.PartOfExplicitCast = false;
- CastExprBits.BasePathIsEmpty = BasePathSize == 0;
- if (!path_empty())
- setBasePathSize(BasePathSize);
+ CastExprBits.BasePathSize = BasePathSize;
+ assert((CastExprBits.BasePathSize == BasePathSize) &&
+ "BasePathSize overflow!");
assert(CastConsistency());
}
@@ -3047,9 +3034,9 @@
CastExpr(StmtClass SC, EmptyShell Empty, unsigned BasePathSize)
: Expr(SC, Empty) {
CastExprBits.PartOfExplicitCast = false;
- CastExprBits.BasePathIsEmpty = BasePathSize == 0;
- if (!path_empty())
- setBasePathSize(BasePathSize);
+ CastExprBits.BasePathSize = BasePathSize;
+ assert((CastExprBits.BasePathSize == BasePathSize) &&
+ "BasePathSize overflow!");
}
public:
@@ -3076,13 +3063,9 @@
NamedDecl *getConversionFunction() const;
typedef CXXBaseSpecifier **path_iterator;
- typedef const CXXBaseSpecifier * const *path_const_iterator;
- bool path_empty() const { return CastExprBits.BasePathIsEmpty; }
- unsigned path_size() const {
- if (path_empty())
- return 0U;
- return *(const_cast<CastExpr *>(this)->BasePathSize());
- }
+ typedef const CXXBaseSpecifier *const *path_const_iterator;
+ bool path_empty() const { return path_size() == 0; }
+ unsigned path_size() const { return CastExprBits.BasePathSize; }
path_iterator path_begin() { return path_buffer(); }
path_iterator path_end() { return path_buffer() + path_size(); }
path_const_iterator path_begin() const { return path_buffer(); }
@@ -3130,13 +3113,8 @@
/// @endcode
class ImplicitCastExpr final
: public CastExpr,
- private llvm::TrailingObjects<ImplicitCastExpr, CastExpr::BasePathSizeTy,
- CXXBaseSpecifier *> {
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
+ private llvm::TrailingObjects<ImplicitCastExpr, CXXBaseSpecifier *> {
-private:
ImplicitCastExpr(QualType ty, CastKind kind, Expr *op,
unsigned BasePathLength, ExprValueKind VK)
: CastExpr(ImplicitCastExprClass, ty, VK, kind, op, BasePathLength) { }
@@ -3244,8 +3222,7 @@
/// (Type)expr. For example: @c (int)f.
class CStyleCastExpr final
: public ExplicitCastExpr,
- private llvm::TrailingObjects<CStyleCastExpr, CastExpr::BasePathSizeTy,
- CXXBaseSpecifier *> {
+ private llvm::TrailingObjects<CStyleCastExpr, CXXBaseSpecifier *> {
SourceLocation LPLoc; // the location of the left paren
SourceLocation RPLoc; // the location of the right paren
@@ -3259,10 +3236,6 @@
explicit CStyleCastExpr(EmptyShell Shell, unsigned PathSize)
: ExplicitCastExpr(CStyleCastExprClass, Shell, PathSize) { }
- size_t numTrailingObjects(OverloadToken<CastExpr::BasePathSizeTy>) const {
- return path_empty() ? 0 : 1;
- }
-
public:
static CStyleCastExpr *Create(const ASTContext &Context, QualType T,
ExprValueKind VK, CastKind K,
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