[turbofan] Add support for reinterpreting integers as floating point and vice versa.

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 384 matching lines @@
   switch (TruncationModeOf(node->op())) {
     case TruncationMode::kJavaScript:
       return VisitRR(this, kArchTruncateDoubleToI, node);
     case TruncationMode::kRoundToZero:
       return VisitRR(this, kMipsTruncWD, node);
   }
   UNREACHABLE();
 }
 
 
+void InstructionSelector::VisitBitcastFloat32ToInt32(Node* node) {
+  VisitRR(this, kMipsFloat64ExtractLowWord32, node);
+}
+
+
+void InstructionSelector::VisitBitcastInt32ToFloat32(Node* node) {
+  MipsOperandGenerator g(this);
+  Emit(kMipsFloat64InsertLowWord32, g.DefineAsRegister(node),
+       ImmediateOperand(ImmediateOperand::INLINE, 0),
+       g.UseRegister(node->InputAt(0)));
+}
+
+
 void InstructionSelector::VisitFloat32Add(Node* node) {
   VisitRRR(this, kMipsAddS, node);
 }
 
 
 void InstructionSelector::VisitFloat64Add(Node* node) {
   VisitRRR(this, kMipsAddD, node);
 }
 
 
@@ skipping 698 matching lines @@
       IsFp64Mode()) {
     flags |= MachineOperatorBuilder::kFloat64RoundDown |
              MachineOperatorBuilder::kFloat64RoundTruncate;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8