[turbofan] Introduce CheckHole and CheckHoleNaN operators.

src/compiler/simplified-operator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 
 #include <iosfwd>
 
 #include "src/compiler/type-hints.h"
@@ skipping 85 matching lines @@
 
 bool operator==(ElementAccess const&, ElementAccess const&);
 bool operator!=(ElementAccess const&, ElementAccess const&);
 
 size_t hash_value(ElementAccess const&);
 
 std::ostream& operator<<(std::ostream&, ElementAccess const&);
 
 ElementAccess const& ElementAccessOf(const Operator* op) WARN_UNUSED_RESULT;
 
+// Mode of operation for the check-hole operators.
+enum class CheckHoleMode : uint8_t {
+  kAllowReturnHole,  // Allow to return the hole either as NaN or undefined.
+  kNeverReturnHole,  // Never return the hole (deoptimize instead).
+};
+
+size_t hash_value(CheckHoleMode);
+
+std::ostream& operator<<(std::ostream&, CheckHoleMode);
+
+CheckHoleMode CheckHoleModeOf(const Operator*) WARN_UNUSED_RESULT;
+
 Type* TypeOf(const Operator* op) WARN_UNUSED_RESULT;
 
 BinaryOperationHints::Hint BinaryOperationHintOf(const Operator* op);
 
 // Interface for building simplified operators, which represent the
 // medium-level operations of V8, including adding numbers, allocating objects,
 // indexing into objects and arrays, etc.
 // All operators are typed but many are representation independent.
 
 // Number values from JS can be in one of these representations:
@@ skipping 41 matching lines @@
   const Operator* NumberFround();
   const Operator* NumberAtan();
   const Operator* NumberAtan2();
   const Operator* NumberLog();
   const Operator* NumberLog1p();
   const Operator* NumberRound();
   const Operator* NumberSqrt();
   const Operator* NumberTrunc();
   const Operator* NumberToInt32();
   const Operator* NumberToUint32();
-  const Operator* NumberIsHoleNaN();
-  const Operator* NumberConvertHoleNaN();
 
   const Operator* NumberSilenceNaN();
 
   const Operator* SpeculativeNumberAdd(BinaryOperationHints::Hint hint);
   const Operator* SpeculativeNumberSubtract(BinaryOperationHints::Hint hint);
 
   const Operator* ReferenceEqual(Type* type);
 
   const Operator* StringEqual();
   const Operator* StringLessThan();
@@ skipping 16 matching lines @@
   const Operator* ChangeTaggedToBit();
   const Operator* ChangeBitToTagged();
   const Operator* TruncateTaggedToWord32();
   const Operator* TruncateTaggedToFloat64();
 
   const Operator* CheckedUint32ToInt32();
   const Operator* CheckedFloat64ToInt32();
   const Operator* CheckedTaggedToInt32();
   const Operator* CheckedTaggedToFloat64();
 
+  const Operator* CheckHole(CheckHoleMode);
+  const Operator* CheckHoleNaN(CheckHoleMode);
   const Operator* CheckIf();
 
   const Operator* ObjectIsCallable();
   const Operator* ObjectIsNumber();
   const Operator* ObjectIsReceiver();
   const Operator* ObjectIsSmi();
   const Operator* ObjectIsString();
   const Operator* ObjectIsUndetectable();
 
   const Operator* TypeGuard(Type* type);
@@ skipping 22 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_