diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -1469,6 +1469,7 @@
 BUILTIN(__builtin_char_memchr, "c*cC*iz", "n")
 BUILTIN(__builtin_dump_struct, "ivC*v*", "tn")
 BUILTIN(__builtin_preserve_access_index, "v.", "t")
+BUILTIN(__builtin_bitfield_info, "Ui.", "t")
 
 // Safestack builtins
 BUILTIN(__builtin___get_unsafe_stack_start, "v*", "Fn")
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1882,6 +1882,13 @@
     IsInPreservedAIRegion = false;
     return RValue::get(Res);
   }
+  case Builtin::BI__builtin_bitfield_info: {
+    const CGBitFieldInfo &Info = EmitLValue(E->getArg(0)).getBitFieldInfo();
+    uint32_t Val = ((Info.StorageOffset.getQuantity() * 8 + Info.Offset) << 8) |
+                   (Info.IsSigned << 7) |
+                   Info.Size;
+    return RValue::get(ConstantInt::get(Int32Ty, Val));
+  }
 
   case Builtin::BI__builtin_cimag:
   case Builtin::BI__builtin_cimagf:
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1429,6 +1429,19 @@
     if (SemaBuiltinPreserveAI(*this, TheCall))
       return ExprError();
     break;
+  case Builtin::BI__builtin_bitfield_info: {
+    if (checkArgCount(*this, TheCall, 1))
+      return ExprError();
+
+    Expr *Arg = TheCall->getArg(0);
+    if (Arg->getType()->getAsPlaceholderType())
+      return ExprError();
+    if (Arg->IgnoreParens()->getObjectKind() != OK_BitField)
+      return ExprError();
+
+    TheCall->setType(Context.UnsignedIntTy);
+    break;
+  }
   case Builtin::BI__builtin_call_with_static_chain:
     if (SemaBuiltinCallWithStaticChain(*this, TheCall))
       return ExprError();