MIPS: Fix unaligned read of bytecodes in interpreter.

src/interpreter/bytecodes.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/interpreter/bytecodes.h"
 
 #include "src/frames.h"
 #include "src/interpreter/bytecode-traits.h"
 
 namespace v8 {
@@ skipping 165 matching lines @@
          bytecode == Bytecode::kJumpIfFalseConstant ||
          bytecode == Bytecode::kJumpIfToBooleanTrueConstant ||
          bytecode == Bytecode::kJumpIfToBooleanFalseConstant ||
          bytecode == Bytecode::kJumpIfNull ||
          bytecode == Bytecode::kJumpIfUndefinedConstant;
 }
 
 
 // static
 uint16_t Bytecodes::ShortOperandFromBytes(const uint8_t* bytes) {
-  return *reinterpret_cast<const uint16_t*>(bytes);
+  return ReadShortValue(bytes);

[rmcilroy, 2015/11/05 18:12:01]

Could you call this ReadUnalignedUInt16 and get rid of ShortOperandFromBytes and
just replace all calls with the util method (and same for Write below).

[akos.palfi.imgtec, 2015/11/05 23:18:00]

Done.

 }
 
 
 // static
 void Bytecodes::ShortOperandToBytes(uint16_t operand, uint8_t* bytes_out) {
-  *reinterpret_cast<uint16_t*>(bytes_out) = operand;
+  WriteShortValue(bytes_out, operand);
 }
 
 
 // static
 std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
                                 int parameter_count) {
   Vector<char> buf = Vector<char>::New(50);
 
   Bytecode bytecode = Bytecodes::FromByte(bytecode_start[0]);
   int bytecode_size = Bytecodes::Size(bytecode);
@@ skipping 148 matching lines @@
   }
   if (reg5.is_valid() && reg4.index() + 1 != reg5.index()) {
     return false;
   }
   return true;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8