First step to cleanup the power-of-2 mess.

src/compiler/representation-change.h

 // 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.
 
 #ifndef V8_COMPILER_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
+#include "src/base/bits.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Contains logic related to changing the representation of values for constants
 // and other nodes, as well as lowering Simplified->Machine operators.
 // Eagerly folds any representation changes for constants.
 class RepresentationChanger {
  public:
   RepresentationChanger(JSGraph* jsgraph, SimplifiedOperatorBuilder* simplified,
                         MachineOperatorBuilder* machine, Isolate* isolate)
       : jsgraph_(jsgraph),
         simplified_(simplified),
         machine_(machine),
         isolate_(isolate),
         testing_type_errors_(false),
         type_error_(false) {}
 
   // TODO(titzer): should Word64 also be implicitly convertable to others?
   static const MachineTypeUnion rWord =
       kRepBit | kRepWord8 | kRepWord16 | kRepWord32;
 
   Node* GetRepresentationFor(Node* node, MachineTypeUnion output_type,
                              MachineTypeUnion use_type) {
-    if (!IsPowerOf2(output_type & kRepMask)) {
+    if (!base::bits::IsPowerOfTwo32(output_type & kRepMask)) {
       // There should be only one output representation.
       return TypeError(node, output_type, use_type);
     }
     if ((use_type & kRepMask) == (output_type & kRepMask)) {
       // Representations are the same. That's a no-op.
       return node;
     }
     if ((use_type & rWord) && (output_type & rWord)) {
       // Both are words less than or equal to 32-bits.
       // Since loads of integers from memory implicitly sign or zero extend the
@@ skipping 290 matching lines @@
   JSGraph* jsgraph() { return jsgraph_; }
   Isolate* isolate() { return isolate_; }
   SimplifiedOperatorBuilder* simplified() { return simplified_; }
   MachineOperatorBuilder* machine() { return machine_; }
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_