[cfe-commits] r111779 - in /cfe/trunk: lib/CodeGen/CGExprAgg.cpp lib/CodeGen/CGExprCXX.cpp test/CodeGenCXX/value-init.cpp
Douglas Gregor
dgregor at apple.com
Sun Aug 22 09:15:35 PDT 2010
Author: dgregor
Date: Sun Aug 22 11:15:35 2010
New Revision: 111779
URL: http://llvm.org/viewvc/llvm-project?rev=111779&view=rev
Log:
When performing value-initialization for a class with a non-trivial,
implicitly-defined default constructor, zero-initialize the memory
before calling the default constructor. Previously, we would only
zero-initialize in the case of a trivial default constructor.
Also, simplify the hideous logic that determines when we have a
trivial default constructor and, therefore, don't need to emit any
call at all.
Modified:
cfe/trunk/lib/CodeGen/CGExprAgg.cpp
cfe/trunk/lib/CodeGen/CGExprCXX.cpp
cfe/trunk/test/CodeGenCXX/value-init.cpp
Modified: cfe/trunk/lib/CodeGen/CGExprAgg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprAgg.cpp?rev=111779&r1=111778&r2=111779&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprAgg.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprAgg.cpp Sun Aug 22 11:15:35 2010
@@ -450,10 +450,6 @@
if (!Val) // Create a temporary variable.
Val = CGF.CreateMemTemp(E->getType(), "tmp");
- if (E->requiresZeroInitialization())
- EmitNullInitializationToLValue(CGF.MakeAddrLValue(Val, E->getType()),
- E->getType());
-
CGF.EmitCXXConstructExpr(Val, E);
}
Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=111779&r1=111778&r2=111779&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Sun Aug 22 11:15:35 2010
@@ -248,25 +248,18 @@
const CXXConstructExpr *E) {
assert(Dest && "Must have a destination!");
const CXXConstructorDecl *CD = E->getConstructor();
- const ConstantArrayType *Array =
- getContext().getAsConstantArrayType(E->getType());
- // For a copy constructor, even if it is trivial, must fall thru so
- // its argument is code-gen'ed.
- if (!CD->isCopyConstructor()) {
- QualType InitType = E->getType();
- if (Array)
- InitType = getContext().getBaseElementType(Array);
- const CXXRecordDecl *RD =
- cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl());
- if (RD->hasTrivialConstructor()) {
- // The constructor is trivial, but we may still need to zero-initialize
- // the class.
- if (E->requiresZeroInitialization())
- EmitNullInitialization(Dest, E->getType());
-
- return;
- }
- }
+
+ // 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())
+ EmitNullInitialization(Dest, E->getType());
+
+
+ // If this is a call to a trivial default constructor, do nothing.
+ if (CD->isTrivial() && CD->isDefaultConstructor())
+ return;
+
// Code gen optimization to eliminate copy constructor and return
// its first argument instead, if in fact that argument is a temporary
// object.
@@ -276,6 +269,9 @@
return;
}
}
+
+ const ConstantArrayType *Array
+ = getContext().getAsConstantArrayType(E->getType());
if (Array) {
QualType BaseElementTy = getContext().getBaseElementType(Array);
const llvm::Type *BasePtr = ConvertType(BaseElementTy);
Modified: cfe/trunk/test/CodeGenCXX/value-init.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/value-init.cpp?rev=111779&r1=111778&r2=111779&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/value-init.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/value-init.cpp Sun Aug 22 11:15:35 2010
@@ -93,4 +93,22 @@
// CHECK: ret i32
return S().i;
}
+
+ struct X0 {
+ X0() { }
+ int x;
+ };
+
+ struct X1 : X0 {
+ int x1;
+ void f();
+ };
+
+ // CHECK: define void @_ZN8zeroinit9testX0_X1Ev
+ void testX0_X1() {
+ // CHECK: call void @llvm.memset.p0i8.i64
+ // CHECK-NEXT: call void @_ZN8zeroinit2X1C1Ev
+ // CHECK-NEXT: call void @_ZN8zeroinit2X11fEv
+ X1().f();
+ }
}
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