[turbofan] Add backend support for Float32Constant.

src/compiler/instruction-selector.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/compiler/instruction-selector.h"
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/pipeline.h"
@@ skipping 458 matching lines @@
       MachineType type = OpParameter<MachineType>(node);
       MarkAsRepresentation(type, node);
       return VisitPhi(node);
     }
     case IrOpcode::kProjection:
       return VisitProjection(node);
     case IrOpcode::kInt32Constant:
     case IrOpcode::kInt64Constant:
     case IrOpcode::kExternalConstant:
       return VisitConstant(node);
+    case IrOpcode::kFloat32Constant:
+      return MarkAsDouble(node), VisitConstant(node);
     case IrOpcode::kFloat64Constant:
       return MarkAsDouble(node), VisitConstant(node);
     case IrOpcode::kHeapConstant:
     case IrOpcode::kNumberConstant:
       // TODO(turbofan): only mark non-smis as references.
       return MarkAsReference(node), VisitConstant(node);
     case IrOpcode::kCall:
       return VisitCall(node, NULL, NULL);
     case IrOpcode::kFrameState:
     case IrOpcode::kStateValues:
@@ skipping 607 matching lines @@
 
 
 void InstructionSelector::VisitCall(Node* call, BasicBlock* continuation,
                                     BasicBlock* deoptimization) {}
 
 #endif  // !V8_TURBOFAN_BACKEND
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8