Set and use Elidable in elimination of copy ctors.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78331 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 567c583..0d51c03 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -258,16 +258,10 @@
// Code gen optimization to eliminate copy constructor and return
// its first argument instead.
- const CXXConstructorDecl *CDecl = E->getConstructor();
- if (E->getNumArgs() == 1 &&
- CDecl->isCopyConstructor(getContext())) {
+ if (E->isElidable()) {
CXXConstructExpr::const_arg_iterator i = E->arg_begin();
- const Expr *SubExpr = (*i);
- // FIXME. Any other cases can be optimized away?
- if (isa<CallExpr>(SubExpr) || isa<CXXTemporaryObjectExpr>(SubExpr)) {
- EmitAggExpr(SubExpr, Dest, false);
- return;
- }
+ EmitAggExpr((*i), Dest, false);
+ return;
}
// Call the constructor.
EmitCXXConstructorCall(E->getConstructor(), Ctor_Complete, Dest,
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 7e0422e..5b74938 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -911,8 +911,10 @@
assert(!ToType->isReferenceType());
// FIXME: Keep track of whether the copy constructor is elidable or not.
- From = BuildCXXConstructExpr(Context,
- ToType, SCS.CopyConstructor, false, &From, 1);
+ bool Elidable = (isa<CallExpr>(From) ||
+ isa<CXXTemporaryObjectExpr>(From));
+ From = BuildCXXConstructExpr(Context, ToType,
+ SCS.CopyConstructor, Elidable, &From, 1);
return false;
}
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 445cd69..2911382 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -176,9 +176,10 @@
DirectInit? IK_Direct : IK_Copy);
if (!Constructor)
return true;
-
+ bool Elidable = (isa<CallExpr>(Init) ||
+ isa<CXXTemporaryObjectExpr>(Init));
Init = BuildCXXConstructExpr(Context,
- DeclType, Constructor, false, &Init, 1);
+ DeclType, Constructor, Elidable, &Init, 1);
Init = MaybeCreateCXXExprWithTemporaries(Init, /*DestroyTemps=*/true);
return false;
}