diff options
| -rw-r--r-- | lib/CodeGen/CGExprAgg.cpp | 11 | ||||
| -rw-r--r-- | lib/CodeGen/CGExprCXX.cpp | 5 | ||||
| -rw-r--r-- | test/CodeGenCXX/value-init.cpp | 14 |
3 files changed, 27 insertions, 3 deletions
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp index 8747562ce5..87d3819e48 100644 --- a/lib/CodeGen/CGExprAgg.cpp +++ b/lib/CodeGen/CGExprAgg.cpp @@ -811,7 +811,16 @@ static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, // If the slot is already known to be zeroed, nothing to do. Don't mess with // volatile stores. if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == 0) return; - + + // C++ objects with a user-declared constructor don't need zero'ing. + if (CGF.getContext().getLangOptions().CPlusPlus) + if (const RecordType *RT = CGF.getContext() + .getBaseElementType(E->getType())->getAs<RecordType>()) { + const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->hasUserDeclaredConstructor()) + return; + } + // If the type is 16-bytes or smaller, prefer individual stores over memset. std::pair<CharUnits, CharUnits> TypeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp index 94f9505342..2f3e4680a7 100644 --- a/lib/CodeGen/CGExprCXX.cpp +++ b/lib/CodeGen/CGExprCXX.cpp @@ -370,8 +370,9 @@ CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E, // If we require zero initialization before (or instead of) calling the // constructor, as can be the case with a non-user-provided default - // constructor, emit the zero initialization now. - if (E->requiresZeroInitialization()) + // constructor, emit the zero initialization now, unless destination is + // already zeroed. + if (E->requiresZeroInitialization() && !Dest.isZeroed()) EmitNullInitialization(Dest.getAddr(), E->getType()); // If this is a call to a trivial default constructor, do nothing. diff --git a/test/CodeGenCXX/value-init.cpp b/test/CodeGenCXX/value-init.cpp index 890b144de3..a5a0b67d57 100644 --- a/test/CodeGenCXX/value-init.cpp +++ b/test/CodeGenCXX/value-init.cpp @@ -101,23 +101,37 @@ struct Test3 : public Test { }; // CHECK: define void @_ZN6PR98011fEv void f() { + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ei + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ev Test partial[3] = { 1 }; + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98014TestC1Ev Test empty[3] = {}; + // CHECK: call void @llvm.memset.p0i8.i64 + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test2C1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test2C1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test2C1Ev Test2 empty2[3] = {}; + // CHECK: call void @llvm.memset.p0i8.i64 + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test3C1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test3C1Ev + // CHECK-NOT: call void @llvm.memset.p0i8.i64 // CHECK: call void @_ZN6PR98015Test3C1Ev Test3 empty3[3] = {}; } |