ARM64: Use the shifter operand to merge in previous shift instructions.

src/hydrogen-instructions.h

 // Copyright 2012 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_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include "v8.h"
 
 #include "allocation.h"
@@ skipping 637 matching lines @@
     HYDROGEN_CONCRETE_INSTRUCTION_LIST(DECLARE_PREDICATE)
   #undef DECLARE_PREDICATE
     bool IsPhi() const { return opcode() == kPhi; }
 
   // Declare virtual predicates for abstract HInstruction or HValue
   #define DECLARE_PREDICATE(type) \
     virtual bool Is##type() const { return false; }
     HYDROGEN_ABSTRACT_INSTRUCTION_LIST(DECLARE_PREDICATE)
   #undef DECLARE_PREDICATE
 
+  bool IsBitwiseBinaryShift() {
+    return IsShl() || IsShr() || IsSar();
+  }
+
   HValue(HType type = HType::Tagged())
       : block_(NULL),
         id_(kNoNumber),
         type_(type),
         use_list_(NULL),
         range_(NULL),
 #ifdef DEBUG
         range_poisoned_(false),
 #endif
         flags_(0) {}
@@ skipping 6888 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_