Track whether an AggValueSlot is potentially aliased, and do not
emit call results into potentially aliased slots.  This allows us
to properly mark indirect return slots as noalias, at the cost
of requiring an extra memcpy when assigning an aggregate call
result into a l-value.  It also brings us into compliance with
the x86-64 ABI.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138599 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index da892c7..1ed24cc 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -360,7 +360,8 @@
         = AggValueSlot::IsDestructed_t(InitializedDecl != 0);
       AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Qualifiers(),
                                       isDestructed,
-                                      AggValueSlot::DoesNotNeedGCBarriers);
+                                      AggValueSlot::DoesNotNeedGCBarriers,
+                                      AggValueSlot::IsNotAliased);
     }
     
     if (InitializedDecl) {