ARM64: Use UntagSmi helpers and clean up assertions.

src/arm64/assembler-arm64-inl.h

 // Copyright 2013 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_ARM64_ASSEMBLER_ARM64_INL_H_
 #define V8_ARM64_ASSEMBLER_ARM64_INL_H_
 
 #include "src/arm64/assembler-arm64.h"
 #include "src/assembler.h"
 #include "src/debug.h"
@@ skipping 412 matching lines @@
 }
 
 
 unsigned Operand::shift_amount() const {
   ASSERT(IsShiftedRegister() || IsExtendedRegister());
   return shift_amount_;
 }
 
 
 Operand Operand::UntagSmi(Register smi) {
+  STATIC_ASSERT((kSmiShift + kSmiValueSize) == kXRegSizeInBits);
   ASSERT(smi.Is64Bits());
   return Operand(smi, ASR, kSmiShift);
 }
 
 
 Operand Operand::UntagSmiAndScale(Register smi, int scale) {
+  STATIC_ASSERT((kSmiShift + kSmiValueSize) == kXRegSizeInBits);
   ASSERT(smi.Is64Bits());
   ASSERT((scale >= 0) && (scale <= (64 - kSmiValueSize)));
   if (scale > kSmiShift) {
     return Operand(smi, LSL, scale - kSmiShift);
   } else if (scale < kSmiShift) {
     return Operand(smi, ASR, kSmiShift - scale);
   }
   return Operand(smi);
 }
 
@@ skipping 806 matching lines @@
 
 
 void Assembler::ClearRecordedAstId() {
   recorded_ast_id_ = TypeFeedbackId::None();
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM64_ASSEMBLER_ARM64_INL_H_