[turbofan] Added the optional Float64RoundTiesEven operator to turbofan.

src/compiler/mips64/instruction-selector-mips64.cc

 // 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.
 
 #include "src/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 799 matching lines @@
 void InstructionSelector::VisitFloat64RoundTruncate(Node* node) {
   VisitRR(this, kMips64Float64RoundTruncate, node);
 }
 
 
 void InstructionSelector::VisitFloat64RoundTiesAway(Node* node) {
   UNREACHABLE();
 }
 
 
+void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
+  VisitRR(this, kMips64Float64RoundTiesEven, node);
+}
+
+
 void InstructionSelector::EmitPrepareArguments(NodeVector* arguments,
                                                const CallDescriptor* descriptor,
                                                Node* node) {
   Mips64OperandGenerator g(this);
 
   // Prepare for C function call.
   if (descriptor->IsCFunctionCall()) {
     Emit(kArchPrepareCallCFunction |
              MiscField::encode(static_cast<int>(descriptor->CParameterCount())),
          0, nullptr, 0, nullptr);
@@ skipping 561 matching lines @@
 
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::kFloat64Min |
          MachineOperatorBuilder::kFloat64Max |
          MachineOperatorBuilder::kFloat32Min |
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat64RoundUp |
-         MachineOperatorBuilder::kFloat64RoundTruncate;
+         MachineOperatorBuilder::kFloat64RoundTruncate |
+         MachineOperatorBuilder::kFloat64RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8