[turbofan] Make an OptionalOperator for MachineOperatorBuilder.

src/compiler/machine-operator.h

 // Copyright 2013 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_MACHINE_OPERATOR_H_
 #define V8_COMPILER_MACHINE_OPERATOR_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/machine-type.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 struct MachineOperatorGlobalCache;
 class Operator;
 
+// For operators that are not supported on all platforms.
+class OptionalOperator {
+ public:
+  explicit OptionalOperator(const Operator* op) : op_(op) {}
+
+  bool IsSupported() const { return op_ != nullptr; }
+  const Operator* op() const {
+    DCHECK_NOT_NULL(op_);
+    return op_;
+  }
+
+ private:
+  const Operator* op_;
+};
 
 // Supported write barrier modes.
 enum WriteBarrierKind { kNoWriteBarrier, kFullWriteBarrier };
 
 std::ostream& operator<<(std::ostream& os, WriteBarrierKind);
 
 
 // A Load needs a MachineType.
 typedef MachineType LoadRepresentation;
 
@@ skipping 47 matching lines @@
     kNoFlags = 0u,
     kFloat32Max = 1u << 0,
     kFloat32Min = 1u << 1,
     kFloat64Max = 1u << 2,
     kFloat64Min = 1u << 3,
     kFloat64RoundDown = 1u << 4,
     kFloat64RoundTruncate = 1u << 5,
     kFloat64RoundTiesAway = 1u << 6,
     kInt32DivIsSafe = 1u << 7,
     kUint32DivIsSafe = 1u << 8,
-    kWord32ShiftIsSafe = 1u << 9
+    kWord32ShiftIsSafe = 1u << 9,
+    kAllOptionalOps = kFloat32Max | kFloat32Min | kFloat64Max | kFloat64Min |
+                      kFloat64RoundDown | kFloat64RoundTruncate |
+                      kFloat64RoundTiesAway
   };
   typedef base::Flags<Flag, unsigned> Flags;
 
   explicit MachineOperatorBuilder(Zone* zone, MachineType word = kMachPtr,
                                   Flags supportedOperators = kNoFlags);
 
   const Operator* Word32And();
   const Operator* Word32Or();
   const Operator* Word32Xor();
   const Operator* Word32Shl();
@@ skipping 82 matching lines @@
   const Operator* Float32Equal();
   const Operator* Float32LessThan();
   const Operator* Float32LessThanOrEqual();
 
   // Floating point comparisons complying to IEEE 754 (double-precision).
   const Operator* Float64Equal();
   const Operator* Float64LessThan();
   const Operator* Float64LessThanOrEqual();
 
   // Floating point min/max complying to IEEE 754 (single-precision).
-  const Operator* Float32Max();
-  const Operator* Float32Min();
-  bool HasFloat32Max() { return flags_ & kFloat32Max; }
-  bool HasFloat32Min() { return flags_ & kFloat32Min; }
+  const OptionalOperator Float32Max();
+  const OptionalOperator Float32Min();
 
   // Floating point min/max complying to IEEE 754 (double-precision).
-  const Operator* Float64Max();
-  const Operator* Float64Min();
-  bool HasFloat64Max() { return flags_ & kFloat64Max; }
-  bool HasFloat64Min() { return flags_ & kFloat64Min; }
+  const OptionalOperator Float64Max();
+  const OptionalOperator Float64Min();
 
   // Floating point abs complying to IEEE 754 (single-precision).
   const Operator* Float32Abs();
 
   // Floating point abs complying to IEEE 754 (double-precision).
   const Operator* Float64Abs();
 
   // Floating point rounding.
-  const Operator* Float64RoundDown();
-  const Operator* Float64RoundTruncate();
-  const Operator* Float64RoundTiesAway();
-  bool HasFloat64RoundDown() { return flags_ & kFloat64RoundDown; }
-  bool HasFloat64RoundTruncate() { return flags_ & kFloat64RoundTruncate; }
-  bool HasFloat64RoundTiesAway() { return flags_ & kFloat64RoundTiesAway; }
+  const OptionalOperator Float64RoundDown();
+  const OptionalOperator Float64RoundTruncate();
+  const OptionalOperator Float64RoundTiesAway();
 
   // Floating point bit representation.
   const Operator* Float64ExtractLowWord32();
   const Operator* Float64ExtractHighWord32();
   const Operator* Float64InsertLowWord32();
   const Operator* Float64InsertHighWord32();
 
   // load [base + index]
   const Operator* Load(LoadRepresentation rep);
 
@@ skipping 53 matching lines @@
 };
 
 
 DEFINE_OPERATORS_FOR_FLAGS(MachineOperatorBuilder::Flags)
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_MACHINE_OPERATOR_H_