[Sema] Diagnose tautological comparison with type's min/max values

Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak

Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565

Reviewers: rjmccall, rsmith, aaron.ballman

Reviewed By: rsmith

Subscribers: rtrieu, jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D38101

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315614 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 1028 insertions, 294 deletions

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 49c26b449d..293144a832 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -78,6 +78,10 @@ Improvements to Clang's diagnostics
   when the signed integer is coerced to an unsigned type for the comparison.
   ``-Wsign-compare`` was adjusted not to warn in this case.
 
+- ``-Wtautological-constant-compare`` is a new warning that warns on
+  tautological comparisons between integer variable of the type ``T`` and the
+  largest/smallest possible integer constant of that same type.
+
 - ``-Wnull-pointer-arithmetic`` now warns about performing pointer arithmetic
   on a null pointer. Such pointer arithmetic has an undefined behavior if the
   offset is nonzero. It also now warns about arithmetic on a null pointer
diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td
index ae6f51775e..2f4244c98e 100644
--- a/include/clang/Basic/DiagnosticGroups.td
+++ b/include/clang/Basic/DiagnosticGroups.td
@@ -432,13 +432,15 @@ def StrncatSize : DiagGroup<"strncat-size">;
 def TautologicalUnsignedZeroCompare : DiagGroup<"tautological-unsigned-zero-compare">;
 def TautologicalUnsignedEnumZeroCompare : DiagGroup<"tautological-unsigned-enum-zero-compare">;
 def TautologicalOutOfRangeCompare : DiagGroup<"tautological-constant-out-of-range-compare">;
+def TautologicalConstantCompare : DiagGroup<"tautological-constant-compare",
+                                            [TautologicalUnsignedZeroCompare,
+                                             TautologicalUnsignedEnumZeroCompare,
+                                             TautologicalOutOfRangeCompare]>;
 def TautologicalPointerCompare : DiagGroup<"tautological-pointer-compare">;
 def TautologicalOverlapCompare : DiagGroup<"tautological-overlap-compare">;
 def TautologicalUndefinedCompare : DiagGroup<"tautological-undefined-compare">;
 def TautologicalCompare : DiagGroup<"tautological-compare",
-                                    [TautologicalUnsignedZeroCompare,
-                                     TautologicalUnsignedEnumZeroCompare,
-                                     TautologicalOutOfRangeCompare,
+                                    [TautologicalConstantCompare,
                                      TautologicalPointerCompare,
                                      TautologicalOverlapCompare,
                                      TautologicalUndefinedCompare]>;
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 7f20be91df..4a724871d6 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5938,18 +5938,18 @@ def note_typecheck_assign_const : Note<
   "member function %q1 is declared const here|"
   "%select{|nested }1data member %2 declared const here}0">;
 
-def warn_lunsigned_always_true_comparison : Warning<
-  "comparison of unsigned expression %0 is always %select{false|true}1">,
+def warn_unsigned_always_true_comparison : Warning<
+  "comparison of %select{%3|unsigned expression}0 %2 "
+  "%select{unsigned expression|%3}0 is always %select{false|true}4">,
   InGroup<TautologicalUnsignedZeroCompare>;
-def warn_runsigned_always_true_comparison : Warning<
-  "comparison of %0 unsigned expression is always %select{false|true}1">,
-  InGroup<TautologicalUnsignedZeroCompare>;
-def warn_lunsigned_enum_always_true_comparison : Warning<
-  "comparison of unsigned enum expression %0 is always %select{false|true}1">,
-  InGroup<TautologicalUnsignedEnumZeroCompare>;
-def warn_runsigned_enum_always_true_comparison : Warning<
-  "comparison of %0 unsigned enum expression is always %select{false|true}1">,
+def warn_unsigned_enum_always_true_comparison : Warning<
+  "comparison of %select{%3|unsigned enum expression}0 %2 "
+  "%select{unsigned enum expression|%3}0 is always %select{false|true}4">,
   InGroup<TautologicalUnsignedEnumZeroCompare>;
+def warn_tautological_constant_compare : Warning<
+  "comparison %select{%3|%1}0 %2 "
+  "%select{%1|%3}0 is always %select{false|true}4">,
+  InGroup<TautologicalConstantCompare>;
 
 def warn_mixed_sign_comparison : Warning<
   "comparison of integers of different signs: %0 and %1">,
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 9a94900ce2..609426b122 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -8553,19 +8553,71 @@ bool IsSameFloatAfterCast(const APValue &value,
 
 void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
 
-bool IsZero(Sema &S, Expr *E) {
+bool IsEnumConstOrFromMacro(Sema &S, Expr *E) {
   // Suppress cases where we are comparing against an enum constant.
   if (const DeclRefExpr *DR =
       dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
     if (isa<EnumConstantDecl>(DR->getDecl()))
-      return false;
+      return true;
 
   // Suppress cases where the '0' value is expanded from a macro.
   if (E->getLocStart().isMacroID())
-    return false;
+    return true;
 
-  llvm::APSInt Value;
-  return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
+  return false;
+}
+
+bool isNonBooleanIntegerValue(Expr *E) {
+  return !E->isKnownToHaveBooleanValue() && E->getType()->isIntegerType();
+}
+
+bool isNonBooleanUnsignedValue(Expr *E) {
+  // We are checking that the expression is not known to have boolean value,
+  // is an integer type; and is either unsigned after implicit casts,
+  // or was unsigned before implicit casts.
+  return isNonBooleanIntegerValue(E) &&
+         (!E->getType()->isSignedIntegerType() ||
+          !E->IgnoreParenImpCasts()->getType()->isSignedIntegerType());
+}
+
+enum class LimitType {
+  Max, // e.g. 32767 for short
+  Min  // e.g. -32768 for short
+};
+
+/// Checks whether Expr 'Constant' may be the
+/// std::numeric_limits<>::max() or std::numeric_limits<>::min()
+/// of the Expr 'Other'. If true, then returns the limit type (min or max).
+/// The Value is the evaluation of Constant
+llvm::Optional<LimitType> IsTypeLimit(Sema &S, Expr *Constant, Expr *Other,
+                                      const llvm::APSInt &Value) {
+  if (IsEnumConstOrFromMacro(S, Constant))
+    return llvm::Optional<LimitType>();
+
+  if (isNonBooleanUnsignedValue(Other) && Value == 0)
+    return LimitType::Min;
+
+  // TODO: Investigate using GetExprRange() to get tighter bounds
+  // on the bit ranges.
+  QualType OtherT = Other->IgnoreParenImpCasts()->getType();
+  if (const auto *AT = OtherT->getAs<AtomicType>())
+    OtherT = AT->getValueType();
+
+  IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
+
+  if (llvm::APSInt::isSameValue(
+          llvm::APSInt::getMaxValue(OtherRange.Width,
+                                    OtherT->isUnsignedIntegerType()),
+          Value))
+    return LimitType::Max;
+
+  if (llvm::APSInt::isSameValue(
+          llvm::APSInt::getMinValue(OtherRange.Width,
+                                    OtherT->isUnsignedIntegerType()),
+          Value))
+    return LimitType::Min;
+
+  return llvm::Optional<LimitType>();
 }
 
 bool HasEnumType(Expr *E) {
@@ -8580,63 +8632,59 @@ bool HasEnumType(Expr *E) {
   return E->getType()->isEnumeralType();
 }
 
-bool isNonBooleanUnsignedValue(Expr *E) {
-  // We are checking that the expression is not known to have boolean value,
-  // is an integer type; and is either unsigned after implicit casts,
-  // or was unsigned before implicit casts.
-  return !E->isKnownToHaveBooleanValue() && E->getType()->isIntegerType() &&
-         (!E->getType()->isSignedIntegerType() ||
-          !E->IgnoreParenImpCasts()->getType()->isSignedIntegerType());
-}
-
-bool CheckTautologicalComparisonWithZero(Sema &S, BinaryOperator *E) {
-  // Disable warning in template instantiations.
-  if (S.inTemplateInstantiation())
+bool CheckTautologicalComparison(Sema &S, BinaryOperator *E, Expr *Constant,
+                                 Expr *Other, const llvm::APSInt &Value,
+                                 bool RhsConstant) {
+  // Disable warning in template instantiations
+  // and only analyze <, >, <= and >= operations.
+  if (S.inTemplateInstantiation() || !E->isRelationalOp())
     return false;
 
-  // bool values are handled by DiagnoseOutOfRangeComparison().
-
   BinaryOperatorKind Op = E->getOpcode();
-  if (E->isValueDependent())
+
+  QualType OType = Other->IgnoreParenImpCasts()->getType();
+
+  llvm::Optional<LimitType> ValueType; // Which limit (min/max) is the constant?
+
+  if (!(isNonBooleanIntegerValue(Other) &&
+        (ValueType = IsTypeLimit(S, Constant, Other, Value))))
     return false;
 
-  Expr *LHS = E->getLHS();
-  Expr *RHS = E->getRHS();
+  bool ConstIsLowerBound = (Op == BO_LT || Op == BO_LE) ^ RhsConstant;
+  bool ResultWhenConstEqualsOther = (Op == BO_LE || Op == BO_GE);
+  bool ResultWhenConstNeOther = ConstIsLowerBound ^ ValueType == LimitType::Max;
+  if (ResultWhenConstEqualsOther != ResultWhenConstNeOther)
+    return false; // The comparison is not tautological.
 
-  bool Match = true;
-
-  if (Op == BO_LT && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
-    S.Diag(E->getOperatorLoc(),
-           HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
-                            : diag::warn_lunsigned_always_true_comparison)
-        << "< 0" << false << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_GE && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
-    S.Diag(E->getOperatorLoc(),
-           HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
-                            : diag::warn_lunsigned_always_true_comparison)
-        << ">= 0" << true << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_GT && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
-    S.Diag(E->getOperatorLoc(),
-           HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
-                            : diag::warn_runsigned_always_true_comparison)
-        << "0 >" << false << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_LE && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
-    S.Diag(E->getOperatorLoc(),
-           HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
-                            : diag::warn_runsigned_always_true_comparison)
-        << "0 <=" << true << LHS->getSourceRange() << RHS->getSourceRange();
-  } else
-    Match = false;
+  const bool Result = ResultWhenConstEqualsOther;
+
+  unsigned Diag = (isNonBooleanUnsignedValue(Other) && Value == 0)
+                      ? (HasEnumType(Other)
+                             ? diag::warn_unsigned_enum_always_true_comparison
+                             : diag::warn_unsigned_always_true_comparison)
+                      : diag::warn_tautological_constant_compare;
+
+  // Should be enough for uint128 (39 decimal digits)
+  SmallString<64> PrettySourceValue;
+  llvm::raw_svector_ostream OS(PrettySourceValue);
+  OS << Value;
+
+  S.Diag(E->getOperatorLoc(), Diag)
+      << RhsConstant << OType << E->getOpcodeStr() << OS.str() << Result
+      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
 
-  return Match;
+  return true;
 }
 
-void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
+bool DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
                                   Expr *Other, const llvm::APSInt &Value,
                                   bool RhsConstant) {
   // Disable warning in template instantiations.
   if (S.inTemplateInstantiation())
-    return;
+    return false;
+
+  Constant = Constant->IgnoreParenImpCasts();
+  Other = Other->IgnoreParenImpCasts();
 
   // TODO: Investigate using GetExprRange() to get tighter bounds
   // on the bit ranges.
@@ -8648,10 +8696,6 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
 
   bool OtherIsBooleanType = Other->isKnownToHaveBooleanValue();
 
-  // 0 values are handled later by CheckTautologicalComparisonWithZero().
-  if ((Value == 0) && (!OtherIsBooleanType))
-    return;
-
   BinaryOperatorKind op = E->getOpcode();
   bool IsTrue = true;
 
@@ -8667,7 +8711,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
     QualType CommonT = E->getLHS()->getType();
 
     if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
-      return;
+      return false;
     assert((OtherT->isIntegerType() && ConstantT->isIntegerType()) &&
            "comparison with non-integer type");
 
@@ -8682,38 +8726,38 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
         // Check that the constant is representable in type OtherT.
         if (ConstantSigned) {
           if (OtherWidth >= Value.getMinSignedBits())
-            return;
+            return false;
         } else { // !ConstantSigned
           if (OtherWidth >= Value.getActiveBits() + 1)
-            return;
+            return false;
         }
       } else { // !OtherSigned
                // Check that the constant is representable in type OtherT.
         // Negative values are out of range.
         if (ConstantSigned) {
           if (Value.isNonNegative() && OtherWidth >= Value.getActiveBits())
-            return;
+            return false;
         } else { // !ConstantSigned
           if (OtherWidth >= Value.getActiveBits())
-            return;
+            return false;
         }
       }
     } else { // !CommonSigned
       if (OtherRange.NonNegative) {
         if (OtherWidth >= Value.getActiveBits())
-          return;
+          return false;
       } else { // OtherSigned
         assert(!ConstantSigned &&
                "Two signed types converted to unsigned types.");
         // Check to see if the constant is representable in OtherT.
         if (OtherWidth > Value.getActiveBits())
-          return;
+          return false;
         // Check to see if the constant is equivalent to a negative value
         // cast to CommonT.
         if (S.Context.getIntWidth(ConstantT) ==
                 S.Context.getIntWidth(CommonT) &&
             Value.isNegative() && Value.getMinSignedBits() <= OtherWidth)
-          return;
+          return false;
         // The constant value rests between values that OtherT can represent
         // after conversion.  Relational comparison still works, but equality
         // comparisons will be tautological.
@@ -8726,7 +8770,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
     if (op == BO_EQ || op == BO_NE) {
       IsTrue = op == BO_NE;
     } else if (EqualityOnly) {
-      return;
+      return false;
     } else if (RhsConstant) {
       if (op == BO_GT || op == BO_GE)
         IsTrue = !PositiveConstant;
@@ -8814,7 +8858,7 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
     } else if (CmpRes == ATrue) {
       IsTrue = true;
     } else {
-      return;
+      return false;
     }
   }
 
@@ -8837,6 +8881,8 @@ void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
         << OS.str() << LiteralOrBoolConstant
         << OtherT << (OtherIsBooleanType && !OtherT->isBooleanType()) << IsTrue
         << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange());
+
+   return true;
 }
 
 /// Analyze the operands of the given comparison.  Implements the
@@ -8862,44 +8908,48 @@ void AnalyzeComparison(Sema &S, BinaryOperator *E) {
   if (E->isValueDependent())
     return AnalyzeImpConvsInComparison(S, E);
 
-  Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
-  Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
-  
-  bool IsComparisonConstant = false;
-  
-  // Check whether an integer constant comparison results in a value
-  // of 'true' or 'false'.
+  Expr *LHS = E->getLHS();
+  Expr *RHS = E->getRHS();
+
   if (T->isIntegralType(S.Context)) {
     llvm::APSInt RHSValue;
-    bool IsRHSIntegralLiteral = 
-      RHS->isIntegerConstantExpr(RHSValue, S.Context);
     llvm::APSInt LHSValue;
-    bool IsLHSIntegralLiteral = 
-      LHS->isIntegerConstantExpr(LHSValue, S.Context);
-    if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
-        DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
-    else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
-      DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
-    else
-      IsComparisonConstant = 
-        (IsRHSIntegralLiteral && IsLHSIntegralLiteral);
-  } else if (!T->hasUnsignedIntegerRepresentation())
-      IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
-
-  // We don't care about value-dependent expressions or expressions
-  // whose result is a constant.
-  if (IsComparisonConstant)
-    return AnalyzeImpConvsInComparison(S, E);
 
-  // If this is a tautological comparison, suppress -Wsign-compare.
-  if (CheckTautologicalComparisonWithZero(S, E))
-    return AnalyzeImpConvsInComparison(S, E);
+    bool IsRHSIntegralLiteral = RHS->isIntegerConstantExpr(RHSValue, S.Context);
+    bool IsLHSIntegralLiteral = LHS->isIntegerConstantExpr(LHSValue, S.Context);
+
+    // We don't care about expressions whose result is a constant.
+    if (IsRHSIntegralLiteral && IsLHSIntegralLiteral)
+      return AnalyzeImpConvsInComparison(S, E);
+
+    // We only care about expressions where just one side is literal
+    if (IsRHSIntegralLiteral ^ IsLHSIntegralLiteral) {
+      // Is the constant on the RHS or LHS?
+      const bool RhsConstant = IsRHSIntegralLiteral;
+      Expr *Const = RhsConstant ? RHS : LHS;
+      Expr *Other = RhsConstant ? LHS : RHS;
+      const llvm::APSInt &Value = RhsConstant ? RHSValue : LHSValue;
 
-  // We don't do anything special if this isn't an unsigned integral
-  // comparison:  we're only interested in integral comparisons, and
-  // signed comparisons only happen in cases we don't care to warn about.
-  if (!T->hasUnsignedIntegerRepresentation())
+      // Check whether an integer constant comparison results in a value
+      // of 'true' or 'false'.
+
+      if (CheckTautologicalComparison(S, E, Const, Other, Value, RhsConstant))
+        return AnalyzeImpConvsInComparison(S, E);
+
+      if (DiagnoseOutOfRangeComparison(S, E, Const, Other, Value, RhsConstant))
+        return AnalyzeImpConvsInComparison(S, E);
+    }
+  }
+
+  if (!T->hasUnsignedIntegerRepresentation()) {
+    // We don't do anything special if this isn't an unsigned integral
+    // comparison:  we're only interested in integral comparisons, and
+    // signed comparisons only happen in cases we don't care to warn about.
     return AnalyzeImpConvsInComparison(S, E);
+  }
+
+  LHS = LHS->IgnoreParenImpCasts();
+  RHS = RHS->IgnoreParenImpCasts();
 
   // Check to see if one of the (unmodified) operands is of different
   // signedness.
diff --git a/test/Sema/outof-range-constant-compare.c b/test/Sema/outof-range-constant-compare.c
index 36b6ff69ca..ccb55e4a16 100644
--- a/test/Sema/outof-range-constant-compare.c
+++ b/test/Sema/outof-range-constant-compare.c
@@ -7,58 +7,6 @@ int main()
 {
     int a = value();
 
-    if (a == 0x0000000000000000L)
-        return 0;
-    if (a != 0x0000000000000000L)
-        return 0;
-    if (a < 0x0000000000000000L)
-        return 0;
-    if (a <= 0x0000000000000000L)
-        return 0;
-    if (a > 0x0000000000000000L)
-        return 0;
-    if (a >= 0x0000000000000000L)
-        return 0;
-
-    if (0x0000000000000000L == a)
-        return 0;
-    if (0x0000000000000000L != a)
-        return 0;
-    if (0x0000000000000000L < a)
-        return 0;
-    if (0x0000000000000000L <= a)
-        return 0;
-    if (0x0000000000000000L > a)
-        return 0;
-    if (0x0000000000000000L >= a)
-        return 0;
-
-    if (a == 0x0000000000000000UL)
-        return 0;
-    if (a != 0x0000000000000000UL)
-        return 0;
-    if (a < 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-        return 0;
-    if (a <= 0x0000000000000000UL)
-        return 0;
-    if (a > 0x0000000000000000UL)
-        return 0;
-    if (a >= 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-        return 0;
-
-    if (0x0000000000000000UL == a)
-        return 0;
-    if (0x0000000000000000UL != a)
-        return 0;
-    if (0x0000000000000000UL < a)
-        return 0;
-    if (0x0000000000000000UL <= a) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-        return 0;
-    if (0x0000000000000000UL > a) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-        return 0;
-    if (0x0000000000000000UL >= a)
-        return 0;
-
     if (a == 0x1234567812345678L) // expected-warning {{comparison of constant 1311768465173141112 with expression of type 'int' is always false}}
         return 0;
     if (a != 0x1234567812345678L) // expected-warning {{comparison of constant 1311768465173141112 with expression of type 'int' is always true}}
@@ -155,113 +103,6 @@ int main()
     if (0x1234567812345678L >= l)
         return 0;
 
-    unsigned un = 0;
-    if (un == 0x0000000000000000L)
-        return 0;
-    if (un != 0x0000000000000000L)
-        return 0;
-    if (un < 0x0000000000000000L) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-        return 0;
-    if (un <= 0x0000000000000000L)
-        return 0;
-    if (un > 0x0000000000000000L)
-        return 0;
-    if (un >= 0x0000000000000000L) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-        return 0;
-
-    if (0x0000000000000000L == un)
-        return 0;
-    if (0x0000000000000000L != un)
-        return 0;
-    if (0x0000000000000000L < un)
-        return 0;
-    if (0x0000000000000000L <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-        return 0;
-    if (0x0000000000000000L > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-        return 0;
-    if (0x0000000000000000L >= un)
-        return 0;
-
-    if (un == 0x0000000000000000UL)
-        return 0;
-    if (un != 0x0000000000000000UL)
-        return 0;
-    if (un < 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-        return 0;
-    if (un <= 0x0000000000000000UL)
-        return 0;
-    if (un > 0x0000000000000000UL)
-        return 0;
-    if (un >= 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-        return 0;
-
-    if (0x0000000000000000UL == un)
-        return 0;
-    if (0x0000000000000000UL != un)
-        return 0;
-    if (0x0000000000000000UL < un)
-        return 0;
-    if (0x0000000000000000UL <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-        return 0;
-    if (0x0000000000000000UL > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-        return 0;
-    if (0x0000000000000000UL >= un)
-        return 0;
-
-    float fl = 0;
-    if (fl == 0x0000000000000000L)
-        return 0;
-    if (fl != 0x0000000000000000L)
-        return 0;
-    if (fl < 0x0000000000000000L)
-        return 0;
-    if (fl <= 0x0000000000000000L)
-        return 0;
-    if (fl > 0x0000000000000000L)
-        return 0;
-    if (fl >= 0x0000000000000000L)
-        return 0;
-
-    if (0x0000000000000000L == fl)
-        return 0;
-    if (0x0000000000000000L != fl)
-        return 0;
-    if (0x0000000000000000L < fl)
-        return 0;
-    if (0x0000000000000000L <= fl)
-        return 0;
-    if (0x0000000000000000L > fl)
-        return 0;
-    if (0x0000000000000000L >= fl)
-        return 0;
-
-    double dl = 0;
-    if (dl == 0x0000000000000000L)
-        return 0;
-    if (dl != 0x0000000000000000L)
-        return 0;
-    if (dl < 0x0000000000000000L)
-        return 0;
-    if (dl <= 0x0000000000000000L)
-        return 0;
-    if (dl > 0x0000000000000000L)
-        return 0;
-    if (dl >= 0x0000000000000000L)
-        return 0;
-
-    if (0x0000000000000000L == dl)
-        return 0;
-    if (0x0000000000000000L != dl)
-        return 0;
-    if (0x0000000000000000L < dl)
-        return 0;
-    if (0x0000000000000000L <= dl)
-        return 0;
-    if (0x0000000000000000L > dl)
-        return 0;
-    if (0x0000000000000000L >= dl)
-        return 0;
-
     enum E {
     yes,
     no, 
diff --git a/test/Sema/tautological-constant-compare.c b/test/Sema/tautological-constant-compare.c
new file mode 100644
index 0000000000..b9ade2a2db
--- /dev/null
+++ b/test/Sema/tautological-constant-compare.c
@@ -0,0 +1,514 @@
+// 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
+
+int value(void);
+
+#define macro(val) val
+
+#ifdef __cplusplus
+template<typename T>
+void TFunc() {
+  // Make sure that we do warn for normal variables in template functions !
+  unsigned char c = value();
+#ifdef TEST
+  if (c > 255) // expected-warning {{comparison 'unsigned char' > 255 is always false}}
+      return;
+#else
+  if (c > 255)
+      return;
+#endif
+
+  if (c > macro(255))
+      return;
+
+  T v = value();
+  if (v > 255)
+      return;
+  if (v > 32767)
+      return;
+}
+#endif
+
+int main()
+{
+#ifdef __cplusplus
+  TFunc<unsigned char>();
+  TFunc<signed short>();
+#endif
+
+  short s = value();
+
+#ifdef TEST
+  if (s == 32767)
+      return 0;
+  if (s != 32767)
+      return 0;
+  if (s < 32767)
+      return 0;
+  if (s <= 32767) // expected-warning {{comparison 'short' <= 32767 is always true}}
+      return 0;
+  if (s > 32767) // expected-warning {{comparison 'short' > 32767 is always false}}
+      return 0;
+  if (s >= 32767)
+      return 0;
+
+  if (32767 == s)
+      return 0;
+  if (32767 != s)
+      return 0;
+  if (32767 < s) // expected-warning {{comparison 32767 < 'short' is always false}}
+      return 0;
+  if (32767 <= s)
+      return 0;
+  if (32767 > s)
+      return 0;
+  if (32767 >= s) // expected-warning {{comparison 32767 >= 'short' is always true}}
+      return 0;
+
+  // FIXME: assumes two's complement
+  if (s == -32768)
+      return 0;
+  if (s != -32768)
+      return 0;
+  if (s < -32768) // expected-warning {{comparison 'short' < -32768 is always false}}
+      return 0;
+  if (s <= -32768)
+      return 0;
+  if (s > -32768)
+      return 0;
+  if (s >= -32768) // expected-warning {{comparison 'short' >= -32768 is always true}}
+      return 0;
+
+  if (-32768 == s)
+      return 0;
+  if (-32768 != s)
+      return 0;
+  if (-32768 < s)
+      return 0;
+  if (-32768 <= s) // expected-warning {{comparison -32768 <= 'short' is always true}}
+      return 0;
+  if (-32768 > s) // expected-warning {{comparison -32768 > 'short' is always false}}
+      return 0;
+  if (-32768 >= s)
+      return 0;
+
+  if (s == 32767UL)
+      return 0;
+  if (s != 32767UL)
+      return 0;
+  if (s < 32767UL)
+      return 0;
+  if (s <= 32767UL) // expected-warning {{comparison 'short' <= 32767 is always true}}
+      return 0;
+  if (s > 32767UL) // expected-warning {{comparison 'short' > 32767 is always false}}
+      return 0;
+  if (s >= 32767UL)
+      return 0;
+
+  if (32767UL == s)
+      return 0;
+  if (32767UL != s)
+      return 0;
+  if (32767UL < s) // expected-warning {{comparison 32767 < 'short' is always false}}
+      return 0;
+  if (32767UL <= s)
+      return 0;
+  if (32767UL > s)
+      return 0;
+  if (32767UL >= s) // expected-warning {{comparison 32767 >= 'short' is always true}}
+      return 0;
+
+  // FIXME: assumes two's complement
+  if (s == -32768L)
+      return 0;
+  if (s != -32768L)
+      return 0;
+  if (s < -32768L) // expected-warning {{comparison 'short' < -32768 is always false}}
+      return 0;
+  if (s <= -32768L)
+      return 0;
+  if (s > -32768L)
+      return 0;
+  if (s >= -32768L) // expected-warning {{comparison 'short' >= -32768 is always true}}
+      return 0;
+
+  if (-32768L == s)
+      return 0;
+  if (-32768L != s)
+      return 0;
+  if (-32768L < s)
+      return 0;
+  if (-32768L <= s) // expected-warning {{comparison -32768 <= 'short' is always true}}
+      return 0;
+  if (-32768L > s) // expected-warning {{comparison -32768 > 'short' is always false}}
+      return 0;
+  if (-32768L >= s)
+      return 0;
+#else
+  // expected-no-diagnostics
+  if (s == 32767)
+    return 0;
+  if (s != 32767)
+    return 0;
+  if (s < 32767)
+    return 0;
+  if (s <= 32767)
+    return 0;
+  if (s > 32767)
+    return 0;
+  if (s >= 32767)
+    return 0;
+
+  if (32767 == s)
+    return 0;
+  if (32767 != s)
+    return 0;
+  if (32767 < s)
+    return 0;
+  if (32767 <= s)
+    return 0;
+  if (32767 > s)
+    return 0;
+  if (32767 >= s)
+    return 0;
+
+  // FIXME: assumes two's complement
+  if (s == -32768)
+    return 0;
+  if (s != -32768)
+    return 0;
+  if (s < -32768)
+    return 0;
+  if (s <= -32768)
+    return 0;
+  if (s > -32768)
+    return 0;
+  if (s >= -32768)
+    return 0;
+
+  if (-32768 == s)
+    return 0;
+  if (-32768 != s)
+    return 0;
+  if (-32768 < s)
+    return 0;
+  if (-32768 <= s)
+    return 0;
+  if (-32768 > s)
+    return 0;
+  if (-32768 >= s)
+    return 0;
+
+  if (s == 32767UL)
+    return 0;
+  if (s != 32767UL)
+    return 0;
+  if (s < 32767UL)
+    return 0;
+  if (s <= 32767UL)
+    return 0;
+  if (s > 32767UL)
+    return 0;
+  if (s >= 32767UL)
+    return 0;
+
+  if (32767UL == s)
+    return 0;
+  if (32767UL != s)
+    return 0;
+  if (32767UL < s)
+    return 0;
+  if (32767UL <= s)
+    return 0;
+  if (32767UL > s)
+    return 0;
+  if (32767UL >= s)
+    return 0;
+
+  // FIXME: assumes two's complement
+  if (s == -32768L)
+    return 0;
+  if (s != -32768L)
+    return 0;
+  if (s < -32768L)
+    return 0;
+  if (s <= -32768L)
+    return 0;
+  if (s > -32768L)
+    return 0;
+  if (s >= -32768L)
+    return 0;
+
+  if (-32768L == s)
+    return 0;
+  if (-32768L != s)
+    return 0;
+  if (-32768L < s)
+    return 0;
+  if (-32768L <= s)
+    return 0;
+  if (-32768L > s)
+    return 0;
+  if (-32768L >= s)
+    return 0;
+#endif
+
+  if (s == 0)
+    return 0;
+  if (s != 0)
+    return 0;
+  if (s < 0)
+    return 0;
+  if (s <= 0)
+    return 0;
+  if (s > 0)
+    return 0;
+  if (s >= 0)
+    return 0;
+
+  if (0 == s)
+    return 0;
+  if (0 != s)
+    return 0;
+  if (0 < s)
+    return 0;
+  if (0 <= s)
+    return 0;
+  if (0 > s)
+    return 0;
+  if (0 >= s)
+    return 0;
+
+  // However the comparison with 0U would warn
+
+  unsigned short us = value();
+
+#ifdef TEST
+  if (us == 65535)
+      return 0;
+  if (us != 65535)
+      return 0;
+  if (us < 65535)
+      return 0;
+  if (us <= 65535) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}}
+      return 0;
+  if (us > 65535) // expected-warning {{comparison 'unsigned short' > 65535 is always false}}
+      return 0;
+  if (us >= 65535)
+      return 0;
+
+  if (65535 == us)
+      return 0;
+  if (65535 != us)
+      return 0;
+  if (65535 < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}}
+      return 0;
+  if (65535 <= us)
+      return 0;
+  if (65535 > us)
+      return 0;
+  if (65535 >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}}
+      return 0;
+
+  if (us == 65535UL)
+      return 0;
+  if (us != 65535UL)
+      return 0;
+  if (us < 65535UL)
+      return 0;
+  if (us <= 65535UL) // expected-warning {{comparison 'unsigned short' <= 65535 is always true}}
+      return 0;
+  if (us > 65535UL) // expected-warning {{comparison 'unsigned short' > 65535 is always false}}
+      return 0;
+  if (us >= 65535UL)
+      return 0;
+
+  if (65535UL == us)
+      return 0;
+  if (65535UL != us)
+      return 0;
+  if (65535UL < us) // expected-warning {{comparison 65535 < 'unsigned short' is always false}}
+      return 0;
+  if (65535UL <= us)
+      return 0;
+  if (65535UL > us)
+      return 0;
+  if (65535UL >= us) // expected-warning {{comparison 65535 >= 'unsigned short' is always true}}
+      return 0;
+#else
+  // expected-no-diagnostics
+  if (us == 65535)
+      return 0;
+  if (us != 65535)
+      return 0;
+  if (us < 65535)
+      return 0;
+  if (us <= 65535)
+      return 0;
+  if (us > 65535)
+      return 0;
+  if (us >= 65535)
+      return 0;
+
+  if (65535 == us)
+      return 0;
+  if (65535 != us)
+      return 0;
+  if (65535 < us)
+      return 0;
+  if (65535 <= us)
+      return 0;
+  if (65535 > us)
+      return 0;
+  if (65535 >= us)
+      return 0;
+
+  if (us == 65535UL)
+      return 0;
+  if (us != 65535UL)
+      return 0;
+  if (us < 65535UL)
+      return 0;
+  if (us <= 65535UL)
+      return 0;
+  if (us > 65535UL)
+      return 0;
+  if (us >= 65535UL)
+      return 0;
+
+  if (65535UL == us)
+      return 0;
+  if (65535UL != us)
+      return 0;
+  if (65535UL < us)
+      return 0;
+  if (65535UL <= us)
+      return 0;
+  if (65535UL > us)
+      return 0;
+  if (65535UL >= us)
+      return 0;
+#endif
+
+  if (us == 32767)
+    return 0;
+  if (us != 32767)
+    return 0;
+  if (us < 32767)
+    return 0;
+  if (us <= 32767)
+    return 0;
+  if (us > 32767)
+    return 0;
+  if (us >= 32767)
+    return 0;
+
+  if (32767 == us)
+    return 0;
+  if (32767 != us)
+    return 0;
+  if (32767 < us)
+    return 0;
+  if (32767 <= us)
+    return 0;
+  if (32767 > us)
+    return 0;
+  if (32767 >= us)
+    return 0;
+
+  if (us == 32767UL)
+    return 0;
+  if (us != 32767UL)
+    return 0;
+  if (us < 32767UL)
+    return 0;
+  if (us <= 32767UL)
+    return 0;
+  if (us > 32767UL)
+    return 0;
+  if (us >= 32767UL)
+    return 0;
+
+  if (32767UL == us)
+    return 0;
+  if (32767UL != us)
+    return 0;
+  if (32767UL < us)
+    return 0;
+  if (32767UL <= us)
+    return 0;
+  if (32767UL > us)
+    return 0;
+  if (32767UL >= us)
+    return 0;
+
+#if __SIZEOF_INT128__
+  __int128 i128;
+  if (i128 == -1) // used to crash
+      return 0;
+#endif
+
+
+  enum E {
+  yes,
+  no,
+  maybe
+  };
+  enum E e;
+
+  if (e == yes)
+      return 0;
+  if (e != yes)
+      return 0;
+  if (e < yes)
+      return 0;
+  if (e <= yes)
+      return 0;
+  if (e > yes)
+      return 0;
+  if (e >= yes)
+      return 0;
+
+  if (yes == e)
+      return 0;
+  if (yes != e)
+      return 0;
+  if (yes < e)
+      return 0;
+  if (yes <= e)
+      return 0;
+  if (yes > e)
+      return 0;
+  if (yes >= e)
+      return 0;
+
+  if (e == maybe)
+      return 0;
+  if (e != maybe)
+      return 0;
+  if (e < maybe)
+      return 0;
+  if (e <= maybe)
+      return 0;
+  if (e > maybe)
+      return 0;
+  if (e >= maybe)
+      return 0;
+
+  if (maybe == e)
+      return 0;
+  if (maybe != e)
+      return 0;
+  if (maybe < e)
+      return 0;
+  if (maybe <= e)
+      return 0;
+  if (maybe > e)
+      return 0;
+  if (maybe >= e)
+      return 0;
+
+  return 1;
+}
diff --git a/test/Sema/tautological-unsigned-zero-compare.c b/test/Sema/tautological-unsigned-zero-compare.c
index 039d8f885e..e0611cb400 100644
--- a/test/Sema/tautological-unsigned-zero-compare.c
+++ b/test/Sema/tautological-unsigned-zero-compare.c
@@ -1,47 +1,370 @@
 // RUN: %clang_cc1 -fsyntax-only -DTEST -verify %s
 // RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify %s
+// RUN: %clang_cc1 -fsyntax-only -DTEST -verify -x c++ %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-zero-compare -verify -x c++ %s
 
-unsigned value(void);
+unsigned uvalue(void);
+signed int svalue(void);
 
-int main() {
-  unsigned un = value();
+#define macro(val) val
 
+#ifdef __cplusplus
+template<typename T>
+void TFunc() {
+  // Make sure that we do warn for normal variables in template functions !
+  unsigned char c = svalue();
 #ifdef TEST
+  if (c < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
+      return;
+#else
+  if (c < 0)
+      return;
+#endif
+
+  if (c < macro(0))
+      return;
+
+  T v = svalue();
+  if (v < 0)
+      return;
+}
+#endif
+
+int main()
+{
+#ifdef __cplusplus
+  TFunc<unsigned char>();
+  TFunc<unsigned short>();
+#endif
+
+  unsigned un = uvalue();
+
+#ifdef TEST
+  if (un == 0)
+      return 0;
+  if (un != 0)
+      return 0;
   if (un < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-    return 0;
+      return 0;
+  if (un <= 0)
+      return 0;
+  if (un > 0)
+      return 0;
   if (un >= 0) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-    return 0;
+      return 0;
+
+  if (0 == un)
+      return 0;
+  if (0 != un)
+      return 0;
+  if (0 < un)
+      return 0;
   if (0 <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-    return 0;
+      return 0;
   if (0 > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-    return 0;
-  if (un < 0U) // expected-warning {{comparison of unsigned expression < 0 is always false}}
-    return 0;
-  if (un >= 0U) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
-    return 0;
-  if (0U <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
-    return 0;
-  if (0U > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
-    return 0;
+      return 0;
+  if (0 >= un)
+      return 0;
+
+  if (un == 0UL)
+      return 0;
+  if (un != 0UL)
+      return 0;
+  if (un < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
+      return 0;
+  if (un <= 0UL)
+      return 0;
+  if (un > 0UL)
+      return 0;
+  if (un >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
+      return 0;
+
+  if (0UL == un)
+      return 0;
+  if (0UL != un)
+      return 0;
+  if (0UL < un)
+      return 0;
+  if (0UL <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
+      return 0;
+  if (0UL > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
+      return 0;
+  if (0UL >= un)
+      return 0;
 #else
 // expected-no-diagnostics
+  if (un == 0)
+      return 0;
+  if (un != 0)
+      return 0;
   if (un < 0)
-    return 0;
+      return 0;
+  if (un <= 0)
+      return 0;
+  if (un > 0)
+      return 0;
   if (un >= 0)
-    return 0;
+      return 0;
+
+  if (0 == un)
+      return 0;
+  if (0 != un)
+      return 0;
+  if (0 < un)
+      return 0;
   if (0 <= un)
-    return 0;
+      return 0;
   if (0 > un)
-    return 0;
-  if (un < 0U)
-    return 0;
-  if (un >= 0U)
-    return 0;
-  if (0U <= un)
-    return 0;
-  if (0U > un)
-    return 0;
+      return 0;
+  if (0 >= un)
+      return 0;
+
+  if (un == 0UL)
+      return 0;
+  if (un != 0UL)
+      return 0;
+  if (un < 0UL)
+      return 0;
+  if (un <= 0UL)
+      return 0;
+  if (un > 0UL)
+      return 0;
+  if (un >= 0UL)
+      return 0;
+
+  if (0UL == un)
+      return 0;
+  if (0UL != un)
+      return 0;
+  if (0UL < un)
+      return 0;
+  if (0UL <= un)
+      return 0;
+  if (0UL > un)
+      return 0;
+  if (0UL >= un)
+      return 0;
+#endif
+
+
+  signed int a = svalue();
+
+#ifdef TEST
+  if (a == 0)
+      return 0;
+  if (a != 0)
+      return 0;
+  if (a < 0)
+      return 0;
+  if (a <= 0)
+      return 0;
+  if (a > 0)
+      return 0;
+  if (a >= 0)
+      return 0;
+
+  if (0 == a)
+      return 0;
+  if (0 != a)
+      return 0;
+  if (0 < a)
+      return 0;
+  if (0 <= a)
+      return 0;
+  if (0 > a)
+      return 0;
+  if (0 >= a)
+      return 0;
+
+  if (a == 0UL)
+      return 0;
+  if (a != 0UL)
+      return 0;
+  if (a < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
+      return 0;
+  if (a <= 0UL)
+      return 0;
+  if (a > 0UL)
+      return 0;
+  if (a >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
+      return 0;
+
+  if (0UL == a)
+      return 0;
+  if (0UL != a)
+      return 0;
+  if (0UL < a)
+      return 0;
+  if (0UL <= a) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
+      return 0;
+  if (0UL > a) // expected-warning {{comparison of 0 > unsigned expression is always false}}
+      return 0;
+  if (0UL >= a)
+      return 0;
+#else
+// expected-no-diagnostics
+  if (a == 0)
+      return 0;
+  if (a != 0)
+      return 0;
+  if (a < 0)
+      return 0;
+  if (a <= 0)
+      return 0;
+  if (a > 0)
+      return 0;
+  if (a >= 0)
+      return 0;
+
+  if (0 == a)
+      return 0;
+  if (0 != a)
+      return 0;
+  if (0 < a)
+      return 0;
+  if (0 <= a)
+      return 0;
+  if (0 > a)
+      return 0;
+  if (0 >= a)
+      return 0;
+
+  if (a == 0UL)
+      return 0;
+  if (a != 0UL)
+      return 0;
+  if (a < 0UL)
+      return 0;
+  if (a <= 0UL)
+      return 0;
+  if (a > 0UL)
+      return 0;
+  if (a >= 0UL)
+      return 0;
+
+  if (0UL == a)
+      return 0;
+  if (0UL != a)
+      return 0;
+  if (0UL < a)
+      return 0;
+  if (0UL <= a)
+      return 0;
+  if (0UL > a)
+      return 0;
+  if (0UL >= a)
+      return 0;
 #endif
 
+
+  float fl = 0;
+
+  if (fl == 0)
+      return 0;
+  if (fl != 0)
+      return 0;
+  if (fl < 0)
+      return 0;
+  if (fl <= 0)
+      return 0;
+  if (fl > 0)
+      return 0;
+  if (fl >= 0)
+      return 0;
+
+  if (0 == fl)
+      return 0;
+  if (0 != fl)
+      return 0;
+  if (0 < fl)
+      return 0;
+  if (0 <= fl)
+      return 0;
+  if (0 > fl)
+      return 0;
+  if (0 >= fl)
+      return 0;
+
+  if (fl == 0UL)
+      return 0;
+  if (fl != 0UL)
+      return 0;
+  if (fl < 0UL)
+      return 0;
+  if (fl <= 0UL)
+      return 0;
+  if (fl > 0UL)
+      return 0;
+  if (fl >= 0UL)
+      return 0;
+
+  if (0UL == fl)
+      return 0;
+  if (0UL != fl)
+      return 0;
+  if (0UL < fl)
+      return 0;
+  if (0UL <= fl)
+      return 0;
+  if (0UL > fl)
+      return 0;
+  if (0UL >= fl)
+      return 0;
+
+
+  double dl = 0;
+
+  if (dl == 0)
+      return 0;
+  if (dl != 0)
+      return 0;
+  if (dl < 0)
+      return 0;
+  if (dl <= 0)
+      return 0;
+  if (dl > 0)
+      return 0;
+  if (dl >= 0)
+      return 0;
+
+  if (0 == dl)
+      return 0;
+  if (0 != dl)
+      return 0;
+  if (0 < dl)
+      return 0;
+  if (0 <= dl)
+      return 0;
+  if (0 > dl)
+      return 0;
+  if (0 >= dl)
+      return 0;
+
+  if (dl == 0UL)
+      return 0;
+  if (dl != 0UL)
+      return 0;
+  if (dl < 0UL)
+      return 0;
+  if (dl <= 0UL)
+      return 0;
+  if (dl > 0UL)
+      return 0;
+  if (dl >= 0UL)
+      return 0;
+
+  if (0UL == dl)
+      return 0;
+  if (0UL != dl)
+      return 0;
+  if (0UL < dl)
+      return 0;
+  if (0UL <= dl)
+      return 0;
+  if (0UL > dl)
+      return 0;
+  if (0UL >= dl)
+      return 0;
+
   return 1;
 }