[turbofan] Add the RoundInt32ToFloat32 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 784 matching lines @@
   Emit(kMips64DmodU, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
        g.UseRegister(m.right().node()));
 }
 
 
 void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
   VisitRR(this, kMips64CvtDS, node);
 }
 
 
+void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
+  VisitRR(this, kMips64CvtSW, node);
+}
+
+
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kMips64CvtDW, node);
 }
 
 
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kMips64CvtDUw, node);
 }
 
 
@@ skipping 1044 matching lines @@
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesEven |
          MachineOperatorBuilder::kFloat32RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8