Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -715,6 +715,7 @@
 def Move : DiagGroup<"move", [PessimizingMove, RedundantMove, SelfMove]>;
 
 def Extra : DiagGroup<"extra", [
+    TautologicalConstantCompare,
     MissingFieldInitializers,
     IgnoredQualifiers,
     InitializerOverrides,
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -5947,7 +5947,7 @@
 def warn_tautological_constant_compare : Warning<
   "result of comparison %select{%3|%1}0 %2 "
   "%select{%1|%3}0 is always %4">,
-  InGroup<TautologicalConstantCompare>;
+  InGroup<TautologicalConstantCompare>, DefaultIgnore;
 
 def warn_mixed_sign_comparison : Warning<
   "comparison of integers of different signs: %0 and %1">,
Index: test/Sema/tautological-constant-compare.c
===================================================================
--- test/Sema/tautological-constant-compare.c
+++ test/Sema/tautological-constant-compare.c
@@ -1,7 +1,11 @@
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -DTEST -verify %s
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wno-tautological-constant-compare -verify %s
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -DTEST -verify -x c++ %s
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wno-tautological-constant-compare -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-constant-compare -DTEST -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wextra -Wno-sign-compare -DTEST -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wall -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-constant-compare -DTEST -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wextra -Wno-sign-compare -DTEST -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wall -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify -x c++ %s
 
 int value(void);
 
@@ -498,7 +502,7 @@
     return 0;
 
 #if __SIZEOF_INT128__
-  __int128 i128;
+  __int128 i128 = value();
   if (i128 == -1) // used to crash
       return 0;
 #endif
@@ -509,7 +513,7 @@
   no,
   maybe
   };
-  enum E e;
+  enum E e = (enum E)value();
 
   if (e == yes)
       return 0;
Index: test/Sema/tautological-constant-enum-compare.c
===================================================================
--- test/Sema/tautological-constant-enum-compare.c
+++ test/Sema/tautological-constant-enum-compare.c
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -DUNSIGNED -verify %s
-// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -DSIGNED -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -DUNSIGNED -Wtautological-constant-compare -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -DSIGNED -Wtautological-constant-compare -verify %s
 // RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -DUNSIGNED -DSILENCE -Wno-tautological-constant-compare -verify %s
 // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -DSIGNED -DSILENCE -Wno-tautological-constant-compare -verify %s
 
Index: test/SemaCXX/compare.cpp
===================================================================
--- test/SemaCXX/compare.cpp
+++ test/SemaCXX/compare.cpp
@@ -1,7 +1,7 @@
 // Force x86-64 because some of our heuristics are actually based
 // on integer sizes.
 
-// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -pedantic -verify -Wsign-compare -std=c++11 %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -pedantic -verify -Wsign-compare -Wtautological-constant-compare -std=c++11 %s
 
 int test0(long a, unsigned long b) {
   enum EnumA {A};