CodeGen: Copy-ctorm must obey the destination's alignment requirement

We would synthesize memcpy intrinsics when emitting calls to trivial C++
constructors but we wouldn't take into account the alignment of the
destination.

llvm-svn: 228061

clang/lib/CodeGen/CodeGenFunction.h

@@ -1559,6 +1559,15 @@ public:
                       true);
   }
 
+  void EmitAggregateCopyCtor(llvm::Value *DestPtr, llvm::Value *SrcPtr,
+                           QualType DestTy, QualType SrcTy) {
+    CharUnits DestTypeAlign = getContext().getTypeAlignInChars(DestTy);
+    CharUnits SrcTypeAlign = getContext().getTypeAlignInChars(SrcTy);
+    EmitAggregateCopy(DestPtr, SrcPtr, SrcTy, /*IsVolatile=*/false,
+                      std::min(DestTypeAlign, SrcTypeAlign),
+                      /*IsAssignment=*/false);
+  }
+
   /// EmitAggregateCopy - Emit an aggregate copy.
   ///
   /// \param isVolatile - True iff either the source or the destination is