Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -10979,6 +10979,15 @@
     // Unions aren't eligible unless they're empty (which is caught above).
     if (RD->isUnion())
       return false;
+    // If this is a C++ record, check the bases first.
+    if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
+      for (const CXXBaseSpecifier &B : CXXRD->bases()) {
+        bool Ret = detectFPCCEligibleStructHelper(
+            B.getType(), CurOff, Field1Ty, Field1Off, Field2Ty, Field2Off);
+        if (!Ret)
+          return false;
+      }
+    }
     int ZeroWidthBitFieldCount = 0;
     for (const FieldDecl *FD : RD->fields()) {
       const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);