[turbofan] Add TruncationMode for TruncateFloat64ToInt32.

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 521 matching lines @@
   Emit(kMips64Ext, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)),
        g.TempImmediate(0), g.TempImmediate(32));
 }
 
 
 void InstructionSelector::VisitTruncateFloat64ToFloat32(Node* node) {
   VisitRR(this, kMips64CvtSD, node);
 }
 
 
+void InstructionSelector::VisitTruncateFloat64ToInt32(Node* node) {
+  switch (TruncationModeOf(node->op())) {
+    case TruncationMode::kJavaScript:
+      return VisitRR(this, kArchTruncateDoubleToI, node);
+    case TruncationMode::kRoundToZero:
+      return VisitRR(this, kMips64TruncWD, node);
+  }
+  UNREACHABLE();
+}
+
+
 void InstructionSelector::VisitFloat32Add(Node* node) {
   VisitRRR(this, kMips64AddS, node);
 }
 
 
 void InstructionSelector::VisitFloat64Add(Node* node) {
   VisitRRR(this, kMips64AddD, node);
 }
 
 
@@ skipping 748 matching lines @@
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat64RoundTruncate;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8