[AST] Only store the needed data in IfStmt
Only store the needed data in IfStmt. This cuts the size of IfStmt
by up to 3 pointers + 1 SourceLocation. The order of the children
is intentionally kept the same even though it would be more
convenient to put the optional trailing objects last. Additionally
use the newly available space in the bit-fields of Stmt to store
the location of the "if".
The result of this is that for the common case of an
if statement of the form:
if (some_cond)
some_statement
the size of IfStmt is brought down to 8 bytes + 2 pointers,
instead of 8 bytes + 5 pointers + 2 SourceLocation.
Differential Revision: https://reviews.llvm.org/D53607
Reviewed By: rjmccall
llvm-svn: 345464
diff --git a/clang/lib/AST/ASTDumper.cpp b/clang/lib/AST/ASTDumper.cpp
index b2ba2dd..4bac6d8 100644
--- a/clang/lib/AST/ASTDumper.cpp
+++ b/clang/lib/AST/ASTDumper.cpp
@@ -511,6 +511,7 @@
void VisitStmt(const Stmt *Node);
void VisitDeclStmt(const DeclStmt *Node);
void VisitAttributedStmt(const AttributedStmt *Node);
+ void VisitIfStmt(const IfStmt *Node);
void VisitLabelStmt(const LabelStmt *Node);
void VisitGotoStmt(const GotoStmt *Node);
void VisitCXXCatchStmt(const CXXCatchStmt *Node);
@@ -2020,6 +2021,16 @@
dumpAttr(*I);
}
+void ASTDumper::VisitIfStmt(const IfStmt *Node) {
+ VisitStmt(Node);
+ if (Node->hasInitStorage())
+ OS << " has_init";
+ if (Node->hasVarStorage())
+ OS << " has_var";
+ if (Node->hasElseStorage())
+ OS << " has_else";
+}
+
void ASTDumper::VisitLabelStmt(const LabelStmt *Node) {
VisitStmt(Node);
OS << " '" << Node->getName() << "'";
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 6262ad3..10f58ab 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -5772,10 +5772,9 @@
ToIfLoc, ToInit, ToConditionVariable, ToCond, ToThen, ToElseLoc, ToElse) =
*Imp;
- return new (Importer.getToContext()) IfStmt(
- Importer.getToContext(),
- ToIfLoc, S->isConstexpr(), ToInit, ToConditionVariable, ToCond,
- ToThen, ToElseLoc, ToElse);
+ return IfStmt::Create(Importer.getToContext(), ToIfLoc, S->isConstexpr(),
+ ToInit, ToConditionVariable, ToCond, ToThen, ToElseLoc,
+ ToElse);
}
ExpectedStmt ASTNodeImporter::VisitSwitchStmt(SwitchStmt *S) {
diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index 8e1a2b0..9ae514c 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -799,39 +799,86 @@
});
}
-IfStmt::IfStmt(const ASTContext &C, SourceLocation IL, bool IsConstexpr,
- Stmt *init, VarDecl *var, Expr *cond, Stmt *then,
- SourceLocation EL, Stmt *elsev)
- : Stmt(IfStmtClass), IfLoc(IL), ElseLoc(EL) {
+IfStmt::IfStmt(const ASTContext &Ctx, SourceLocation IL, bool IsConstexpr,
+ Stmt *Init, VarDecl *Var, Expr *Cond, Stmt *Then,
+ SourceLocation EL, Stmt *Else)
+ : Stmt(IfStmtClass) {
+ bool HasElse = Else != nullptr;
+ bool HasVar = Var != nullptr;
+ bool HasInit = Init != nullptr;
+ IfStmtBits.HasElse = HasElse;
+ IfStmtBits.HasVar = HasVar;
+ IfStmtBits.HasInit = HasInit;
+
setConstexpr(IsConstexpr);
- setConditionVariable(C, var);
- SubExprs[INIT] = init;
- SubExprs[COND] = cond;
- SubExprs[THEN] = then;
- SubExprs[ELSE] = elsev;
+
+ setCond(Cond);
+ setThen(Then);
+ if (HasElse)
+ setElse(Else);
+ if (HasVar)
+ setConditionVariable(Ctx, Var);
+ if (HasInit)
+ setInit(Init);
+
+ setIfLoc(IL);
+ if (HasElse)
+ setElseLoc(EL);
}
-VarDecl *IfStmt::getConditionVariable() const {
- if (!SubExprs[VAR])
- return nullptr;
+IfStmt::IfStmt(EmptyShell Empty, bool HasElse, bool HasVar, bool HasInit)
+ : Stmt(IfStmtClass, Empty) {
+ IfStmtBits.HasElse = HasElse;
+ IfStmtBits.HasVar = HasVar;
+ IfStmtBits.HasInit = HasInit;
+}
- auto *DS = cast<DeclStmt>(SubExprs[VAR]);
+IfStmt *IfStmt::Create(const ASTContext &Ctx, SourceLocation IL,
+ bool IsConstexpr, Stmt *Init, VarDecl *Var, Expr *Cond,
+ Stmt *Then, SourceLocation EL, Stmt *Else) {
+ bool HasElse = Else != nullptr;
+ bool HasVar = Var != nullptr;
+ bool HasInit = Init != nullptr;
+ void *Mem = Ctx.Allocate(
+ totalSizeToAlloc<Stmt *, SourceLocation>(
+ NumMandatoryStmtPtr + HasElse + HasVar + HasInit, HasElse),
+ alignof(IfStmt));
+ return new (Mem)
+ IfStmt(Ctx, IL, IsConstexpr, Init, Var, Cond, Then, EL, Else);
+}
+
+IfStmt *IfStmt::CreateEmpty(const ASTContext &Ctx, bool HasElse, bool HasVar,
+ bool HasInit) {
+ void *Mem = Ctx.Allocate(
+ totalSizeToAlloc<Stmt *, SourceLocation>(
+ NumMandatoryStmtPtr + HasElse + HasVar + HasInit, HasElse),
+ alignof(IfStmt));
+ return new (Mem) IfStmt(EmptyShell(), HasElse, HasVar, HasInit);
+}
+
+VarDecl *IfStmt::getConditionVariable() {
+ auto *DS = getConditionVariableDeclStmt();
+ if (!DS)
+ return nullptr;
return cast<VarDecl>(DS->getSingleDecl());
}
-void IfStmt::setConditionVariable(const ASTContext &C, VarDecl *V) {
+void IfStmt::setConditionVariable(const ASTContext &Ctx, VarDecl *V) {
+ assert(hasVarStorage() &&
+ "This if statement has no storage for a condition variable!");
+
if (!V) {
- SubExprs[VAR] = nullptr;
+ getTrailingObjects<Stmt *>()[varOffset()] = nullptr;
return;
}
SourceRange VarRange = V->getSourceRange();
- SubExprs[VAR] = new (C) DeclStmt(DeclGroupRef(V), VarRange.getBegin(),
- VarRange.getEnd());
+ getTrailingObjects<Stmt *>()[varOffset()] = new (Ctx)
+ DeclStmt(DeclGroupRef(V), VarRange.getBegin(), VarRange.getEnd());
}
bool IfStmt::isObjCAvailabilityCheck() const {
- return isa<ObjCAvailabilityCheckExpr>(SubExprs[COND]);
+ return isa<ObjCAvailabilityCheckExpr>(getCond());
}
ForStmt::ForStmt(const ASTContext &C, Stmt *Init, Expr *Cond, VarDecl *condVar,