Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -435,12 +435,16 @@
 def StringPlusInt : DiagGroup<"string-plus-int">;
 def StringPlusChar : DiagGroup<"string-plus-char">;
 def StrncatSize : DiagGroup<"strncat-size">;
+def TautologicalTypeLimitCompare : DiagGroup<"tautological-type-limit-compare">;
 def TautologicalUnsignedZeroCompare : DiagGroup<"tautological-unsigned-zero-compare">;
 def TautologicalUnsignedEnumZeroCompare : DiagGroup<"tautological-unsigned-enum-zero-compare">;
+def TautologicalRangeCompare : DiagGroup<"tautological-constant-range-compare",
+                                         [TautologicalTypeLimitCompare,
+                                          TautologicalUnsignedZeroCompare,
+                                          TautologicalUnsignedEnumZeroCompare]>;
 def TautologicalOutOfRangeCompare : DiagGroup<"tautological-constant-out-of-range-compare">;
 def TautologicalConstantCompare : DiagGroup<"tautological-constant-compare",
-                                            [TautologicalUnsignedZeroCompare,
-                                             TautologicalUnsignedEnumZeroCompare,
+                                            [TautologicalRangeCompare,
                                              TautologicalOutOfRangeCompare]>;
 def TautologicalPointerCompare : DiagGroup<"tautological-pointer-compare">;
 def TautologicalOverlapCompare : DiagGroup<"tautological-overlap-compare">;
@@ -715,6 +719,7 @@
 def Move : DiagGroup<"move", [PessimizingMove, RedundantMove, SelfMove]>;
 
 def Extra : DiagGroup<"extra", [
+    TautologicalRangeCompare,
     MissingFieldInitializers,
     IgnoredQualifiers,
     InitializerOverrides,
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -5942,15 +5942,15 @@
 def warn_unsigned_always_true_comparison : Warning<
   "result of comparison of %select{%3|unsigned expression}0 %2 "
   "%select{unsigned expression|%3}0 is always %4">,
-  InGroup<TautologicalUnsignedZeroCompare>;
+  InGroup<TautologicalUnsignedZeroCompare>, DefaultIgnore;
 def warn_unsigned_enum_always_true_comparison : Warning<
   "result of comparison of %select{%3|unsigned enum expression}0 %2 "
   "%select{unsigned enum expression|%3}0 is always %4">,
-  InGroup<TautologicalUnsignedEnumZeroCompare>;
+  InGroup<TautologicalUnsignedEnumZeroCompare>, DefaultIgnore;
 def warn_tautological_constant_compare : Warning<
   "result of comparison %select{%3|%1}0 %2 "
   "%select{%1|%3}0 is always %4">,
-  InGroup<TautologicalConstantCompare>;
+  InGroup<TautologicalTypeLimitCompare>, DefaultIgnore;
 
 def warn_mixed_sign_comparison : Warning<
   "comparison of integers of different signs: %0 and %1">,
Index: test/Sema/compare.c
===================================================================
--- test/Sema/compare.c
+++ test/Sema/compare.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -pedantic -verify -Wsign-compare %s -Wno-unreachable-code
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -pedantic -verify -Wsign-compare -Wtautological-constant-range-compare %s -Wno-unreachable-code
 
 int test(char *C) { // nothing here should warn.
   return C != ((void*)0);
Index: test/Sema/tautological-constant-compare.c
===================================================================
--- test/Sema/tautological-constant-compare.c
+++ test/Sema/tautological-constant-compare.c
@@ -1,7 +1,13 @@
-// 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-range-compare -DTEST -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-constant-range-compare -DTEST -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-type-limit-compare -DTEST -verify %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wtautological-type-limit-compare -DTEST -verify -x c++ %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 -Wextra -Wno-sign-compare -DTEST -verify -x c++ %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -Wall -verify %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 %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify -x c++ %s
 
 int value(void);
 
@@ -122,32 +128,6 @@
   if (32767UL >= s)
       return 0;
 
-  if (s == 0UL)
-      return 0;
-  if (s != 0UL)
-      return 0;
-  if (s < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-      return 0;
-  if (s <= 0UL)
-      return 0;
-  if (s > 0UL)
-      return 0;
-  if (s >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-      return 0;
-
-  if (0UL == s)
-      return 0;
-  if (0UL != s)
-      return 0;
-  if (0UL < s)
-      return 0;
-  if (0UL <= s) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-      return 0;
-  if (0UL > s) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-      return 0;
-  if (0UL >= s)
-      return 0;
-
   enum { ULONG_MAX = (2UL * (unsigned long)__LONG_MAX__ + 1UL) };
   if (s == 2UL * (unsigned long)__LONG_MAX__ + 1UL)
       return 0;
@@ -498,7 +478,7 @@
     return 0;
 
 #if __SIZEOF_INT128__
-  __int128 i128;
+  __int128 i128 = value();
   if (i128 == -1) // used to crash
       return 0;
 #endif
@@ -509,7 +489,7 @@
   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-range-compare -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -DSIGNED -Wtautological-constant-range-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/Sema/tautological-unsigned-enum-zero-compare.c
===================================================================
--- test/Sema/tautological-unsigned-enum-zero-compare.c
+++ test/Sema/tautological-unsigned-enum-zero-compare.c
@@ -1,9 +1,10 @@
 // RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only \
+// RUN:            -Wtautological-unsigned-enum-zero-compare \
 // RUN:            -verify=unsigned,unsigned-signed %s
 // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \
+// RUN:            -Wtautological-unsigned-enum-zero-compare \
 // RUN:            -verify=unsigned-signed %s
 // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \
-// RUN:            -Wno-tautological-unsigned-enum-zero-compare \
 // RUN:            -verify=silence %s
 
 // Okay, this is where it gets complicated.
Index: test/Sema/tautological-unsigned-enum-zero-compare.cpp
===================================================================
--- test/Sema/tautological-unsigned-enum-zero-compare.cpp
+++ test/Sema/tautological-unsigned-enum-zero-compare.cpp
@@ -1,9 +1,10 @@
 // RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-linux-gnu -fsyntax-only \
+// RUN:            -Wtautological-unsigned-enum-zero-compare \
 // RUN:            -verify=unsigned,unsigned-signed %s
 // RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \
+// RUN:            -Wtautological-unsigned-enum-zero-compare \
 // RUN:            -verify=unsigned-signed %s
 // RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \
-// RUN:            -Wno-tautological-unsigned-enum-zero-compare \
 // RUN:            -verify=silence %s
 
 // silence-no-diagnostics
Index: test/Sema/tautological-unsigned-zero-compare.c
===================================================================
--- test/Sema/tautological-unsigned-zero-compare.c
+++ test/Sema/tautological-unsigned-zero-compare.c
@@ -1,7 +1,13 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
-// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify=silence %s
-// RUN: %clang_cc1 -fsyntax-only -verify -x c++ %s
-// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify=silence -x c++ %s
+// RUN: %clang_cc1 -fsyntax-only \
+// RUN:            -Wtautological-unsigned-zero-compare \
+// RUN:            -verify %s
+// RUN: %clang_cc1 -fsyntax-only \
+// RUN:            -verify=silence %s
+// RUN: %clang_cc1 -fsyntax-only \
+// RUN:            -Wtautological-unsigned-zero-compare \
+// RUN:            -verify -x c++ %s
+// RUN: %clang_cc1 -fsyntax-only \
+// RUN:            -verify=silence -x c++ %s
 
 unsigned uvalue(void);
 signed int svalue(void);
@@ -32,10 +38,39 @@
   TFunc<unsigned short>();
 #endif
 
+  short s = svalue();
+
   unsigned un = uvalue();
 
   // silence-no-diagnostics
 
+  // Note: both sides are promoted to unsigned long prior to the comparison.
+  if (s == 0UL)
+      return 0;
+  if (s != 0UL)
+      return 0;
+  if (s < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
+      return 0;
+  if (s <= 0UL)
+      return 0;
+  if (s > 0UL)
+      return 0;
+  if (s >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
+      return 0;
+
+  if (0UL == s)
+      return 0;
+  if (0UL != s)
+      return 0;
+  if (0UL < s)
+      return 0;
+  if (0UL <= s) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
+      return 0;
+  if (0UL > s) // expected-warning {{comparison of 0 > unsigned expression is always false}}
+      return 0;
+  if (0UL >= s)
+      return 0;
+
   if (un == 0)
       return 0;
   if (un != 0)
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-range-compare -std=c++11 %s
 
 int test0(long a, unsigned long b) {
   enum EnumA {A};