When emitting a multidimensional array copy, only emit a single flattened
cleanup loop for exception handling.
llvm-svn: 289623
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 9ead6b8..35148be 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -164,7 +164,8 @@
void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
void VisitChooseExpr(const ChooseExpr *CE);
void VisitInitListExpr(InitListExpr *E);
- void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
+ void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
+ llvm::Value *outerBegin = nullptr);
void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
@@ -1309,7 +1310,8 @@
cleanupDominator->eraseFromParent();
}
-void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
+void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
+ llvm::Value *outerBegin) {
// Emit the common subexpression.
CodeGenFunction::OpaqueValueMapping binding(CGF, E->getCommonExpr());
@@ -1319,15 +1321,18 @@
if (!numElements)
return;
- // FIXME: Dig through nested ArrayInitLoopExprs to find the overall array
- // size, and only emit a single loop for a multidimensional array.
-
// destPtr is an array*. Construct an elementType* by drilling down a level.
llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
llvm::Value *indices[] = {zero, zero};
llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices,
"arrayinit.begin");
+ // Prepare to special-case multidimensional array initialization: we avoid
+ // emitting multiple destructor loops in that case.
+ if (!outerBegin)
+ outerBegin = begin;
+ ArrayInitLoopExpr *InnerLoop = dyn_cast<ArrayInitLoopExpr>(E->getSubExpr());
+
QualType elementType =
CGF.getContext().getAsArrayType(E->getType())->getElementType();
CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
@@ -1347,9 +1352,12 @@
// Prepare for a cleanup.
QualType::DestructionKind dtorKind = elementType.isDestructedType();
EHScopeStack::stable_iterator cleanup;
- if (CGF.needsEHCleanup(dtorKind)) {
- CGF.pushRegularPartialArrayCleanup(
- begin, element, elementType, elementAlign, CGF.getDestroyer(dtorKind));
+ if (CGF.needsEHCleanup(dtorKind) && !InnerLoop) {
+ if (outerBegin->getType() != element->getType())
+ outerBegin = Builder.CreateBitCast(outerBegin, element->getType());
+ CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType,
+ elementAlign,
+ CGF.getDestroyer(dtorKind));
cleanup = CGF.EHStack.stable_begin();
} else {
dtorKind = QualType::DK_none;
@@ -1363,7 +1371,16 @@
CodeGenFunction::ArrayInitLoopExprScope Scope(CGF, index);
LValue elementLV =
CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
- EmitInitializationToLValue(E->getSubExpr(), elementLV);
+
+ if (InnerLoop) {
+ // If the subexpression is an ArrayInitLoopExpr, share its cleanup.
+ auto elementSlot = AggValueSlot::forLValue(
+ elementLV, AggValueSlot::IsDestructed,
+ AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased);
+ AggExprEmitter(CGF, elementSlot, false)
+ .VisitArrayInitLoopExpr(InnerLoop, outerBegin);
+ } else
+ EmitInitializationToLValue(E->getSubExpr(), elementLV);
}
// Move on to the next element.