Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -1860,6 +1860,25 @@
   CharUnits FieldAlign = CharUnits::fromQuantity(4);
 
   assert(StackOffset.isMultipleOf(FieldAlign) && "unaligned inalloca struct");
+  CharUnits FieldStart = StackOffset;
+  unsigned StackArgTypeAlignment = getContext().getTypeAlign(Type) / 8;
+  // if the type contains an SSE vector type, the alignment has to be 16.
+  StackArgTypeAlignment = (StackArgTypeAlignment >= 16 &&
+                           (isSSEVectorType(getContext(), Type) ||
+                            isRecordWithSSEVectorType(getContext(), Type)))
+                              ? 16
+                              : MinABIStackAlignInBytes;
+
+  CharUnits argAlign = CharUnits::fromQuantity(StackArgTypeAlignment);
+
+  StackOffset = FieldStart.alignTo(argAlign);
+  if (StackOffset != FieldStart) {
+    CharUnits NumBytes = StackOffset - FieldStart;
+    llvm::Type *Ty = llvm::Type::getInt8Ty(getVMContext());
+    Ty = llvm::ArrayType::get(Ty, NumBytes.getQuantity());
+    FrameFields.push_back(Ty);
+  }
+
   Info = ABIArgInfo::getInAlloca(FrameFields.size());
   FrameFields.push_back(CGT.ConvertTypeForMem(Type));
   StackOffset += getContext().getTypeSizeInChars(Type);