[turbofan] Add the TruncateFloat32ToInt32 operator to turbofan.

src/compiler/mips/instruction-selector-mips.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 495 matching lines @@
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDW, node);
 }
 
 
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDUw, node);
 }
 
 
+void InstructionSelector::VisitTruncateFloat32ToInt32(Node* node) {
+  VisitRR(this, kMipsTruncWS, node);
+}
+
+
 void InstructionSelector::VisitChangeFloat64ToInt32(Node* node) {
   MipsOperandGenerator g(this);
   Node* value = node->InputAt(0);
   // Match ChangeFloat64ToInt32(Float64Round##OP) to corresponding instruction
   // which does rounding and conversion to integer format.
   if (CanCover(node, value)) {
     switch (value->opcode()) {
       case IrOpcode::kFloat64RoundDown:
         Emit(kMipsFloorWD, g.DefineAsRegister(node),
              g.UseRegister(value->InputAt(0)));
@@ skipping 801 matching lines @@
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat32RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8