Add a kSimd128 machine type for Turbofan.

src/compiler/representation-change.cc

 // Copyright 2015 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/representation-change.h"
 
 #include <sstream>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 128 matching lines @@
       return GetFloat64RepresentationFor(node, output_rep, output_type,
                                          truncation);
     case MachineRepresentation::kBit:
       return GetBitRepresentationFor(node, output_rep, output_type);
     case MachineRepresentation::kWord8:
     case MachineRepresentation::kWord16:
     case MachineRepresentation::kWord32:
       return GetWord32RepresentationFor(node, output_rep, output_type);
     case MachineRepresentation::kWord64:
       return GetWord64RepresentationFor(node, output_rep, output_type);
+    case MachineRepresentation::kSimd128:  // Fall through.
+    // TODO(bbudge) Handle conversions between tagged and untagged.

[Jarin, 2016/02/17 12:06:46]

Until then, could you DCHECK(output_rep == kSimd128)? (Or just "break;" because
we should not try to convert to the same representation.)

[bbudge, 2016/02/17 18:57:14]

break seems right here. Done.

     case MachineRepresentation::kNone:
       return node;
   }
   UNREACHABLE();
   return nullptr;
 }
 
 
 Node* RepresentationChanger::GetTaggedRepresentationFor(
     Node* node, MachineRepresentation output_rep, Type* output_type) {
@@ skipping 369 matching lines @@
 
 
 Node* RepresentationChanger::InsertChangeTaggedToFloat64(Node* node) {
   return jsgraph()->graph()->NewNode(simplified()->ChangeTaggedToFloat64(),
                                      node);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8