diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4785,6 +4785,8 @@
       : ExplicitCastExpr(BuiltinBitCastExprClass, T, VK, CK, SrcExpr, 0,
                          DstType),
         KWLoc(KWLoc), RParenLoc(RParenLoc) {}
+  BuiltinBitCastExpr(EmptyShell Empty, unsigned PathSize)
+      : ExplicitCastExpr(BuiltinBitCastExprClass, Empty, PathSize) {}
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return KWLoc; }
   SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -1791,6 +1791,9 @@
       /// A CXXFunctionalCastExpr record.
       EXPR_CXX_FUNCTIONAL_CAST,
 
+      /// A BuiltinBitCastExpr record.
+      EXPR_BUILTIN_BIT_CAST,
+
       /// A UserDefinedLiteral record.
       EXPR_USER_DEFINED_LITERAL,
 
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -3593,6 +3593,11 @@
                        /*PathSize*/ Record[ASTStmtReader::NumExprFields]);
       break;
 
+    case EXPR_BUILTIN_BIT_CAST:
+      S = new (Context) BuiltinBitCastExpr(
+          Empty, /*PathSize*/ Record[ASTStmtReader::NumExprFields]);
+      break;
+
     case EXPR_USER_DEFINED_LITERAL:
       S = UserDefinedLiteral::CreateEmpty(
           Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -1635,6 +1635,7 @@
   VisitExplicitCastExpr(E);
   Record.AddSourceLocation(E->getBeginLoc());
   Record.AddSourceLocation(E->getEndLoc());
+  Code = serialization::EXPR_BUILTIN_BIT_CAST;
 }
 
 void ASTStmtWriter::VisitUserDefinedLiteral(UserDefinedLiteral *E) {
diff --git a/clang/test/PCH/builtin-bit-cast.cpp b/clang/test/PCH/builtin-bit-cast.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/PCH/builtin-bit-cast.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -emit-pch -o %t %s
+// RUN: %clang_cc1 -include-pch %t -fsyntax-only -verify %s
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+
+template<class T, class U>
+constexpr T builtin_bit_cast_wrapper(const U& arg) {
+  return __builtin_bit_cast(T, arg);
+}
+
+#else
+
+int main() {
+  builtin_bit_cast_wrapper<int>(0);
+  return 0;
+}
+
+#endif