Index: lldb/source/Core/Value.cpp
===================================================================
--- lldb/source/Core/Value.cpp
+++ lldb/source/Core/Value.cpp
@@ -222,6 +222,11 @@
   case eContextTypeLLDBType: // Type *
   case eContextTypeVariable: // Variable *
   {
+    // The size of this Value may be less than the size of the type of its
+    // source variable due to truncating operations such as DW_OP_piece.
+    if (m_value_type == eValueTypeHostAddress)
+      return GetBuffer().GetByteSize();
+
     auto *scope = exe_ctx ? exe_ctx->GetBestExecutionContextScope() : nullptr;
     if (llvm::Optional<uint64_t> size = GetCompilerType().GetByteSize(scope)) {
       if (error_ptr)
Index: lldb/unittests/Expression/DWARFExpressionTest.cpp
===================================================================
--- lldb/unittests/Expression/DWARFExpressionTest.cpp
+++ lldb/unittests/Expression/DWARFExpressionTest.cpp
@@ -360,4 +360,16 @@
       // Note that the "00" should really be "undef", but we can't
       // represent that yet.
       llvm::HasValue(GetScalar(16, 0xff00, true)));
+
+  for (unsigned char ByteSize = 1; ByteSize <= 8; ++ByteSize) {
+    llvm::Expected<Scalar> empty = Evaluate({DW_OP_piece, ByteSize});
+    // Note that the "00" should really be "undef", but we can't
+    // represent that yet.
+    EXPECT_THAT_EXPECTED(empty,
+                         llvm::HasValue(GetScalar(ByteSize * 8, 0, true)));
+
+    Value pieces;
+    ASSERT_EQ(pieces.AppendDataToHostBuffer(empty.get()), ByteSize);
+    ASSERT_EQ(pieces.GetValueByteSize(nullptr, nullptr), ByteSize);
+  }
 }