X87: [turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

src/compiler/x87/instruction-selector-x87.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/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
@@ skipping 638 matching lines @@
 
 
 void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
   X87OperandGenerator g(this);
   Emit(kX87Float32ToFloat64, g.DefineAsFixed(node, stX_0),
        g.Use(node->InputAt(0)));
 }
 
 
 void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
-  UNIMPLEMENTED();
+  X87OperandGenerator g(this);
+  Emit(kX87Int32ToFloat32, g.DefineAsFixed(node, stX_0),
+       g.Use(node->InputAt(0)));
 }
 
 
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   X87OperandGenerator g(this);
   Emit(kX87Int32ToFloat64, g.DefineAsFixed(node, stX_0),
        g.Use(node->InputAt(0)));
 }
 
 
@@ skipping 677 matching lines @@
            MachineOperatorBuilder::kFloat32RoundTruncate |
            MachineOperatorBuilder::kFloat64RoundTruncate |
            MachineOperatorBuilder::kFloat32RoundTiesEven |
            MachineOperatorBuilder::kFloat64RoundTiesEven;
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8