2 files changed, 3 insertions, 2 deletions
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 64414c91675..b782c184b96 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -529,8 +529,8 @@ IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
   Bits >>= 1;
   bool hasMacroDefinition = Bits & 0x01;
   Bits >>= 1;
-  unsigned ObjCOrBuiltinID = Bits & 0x3FF;
-  Bits >>= 10;
+  unsigned ObjCOrBuiltinID = Bits & 0x7FF;
+  Bits >>= 11;
 
   assert(Bits == 0 && "Extra bits in the identifier?");
   DataLen -= 6;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index bb2b1cb5b08..e1af601614d 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -2519,6 +2519,7 @@ public:
     uint32_t Bits = 0;
     bool HasMacroDefinition = hasMacroDefinition(II, Macro);
     Bits = (uint32_t)II->getObjCOrBuiltinID();
+    assert((Bits & 0x7ff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
     Bits = (Bits << 1) | unsigned(HasMacroDefinition);
     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
     Bits = (Bits << 1) | unsigned(II->isPoisoned());