Clarify precedence of operations involving bitwise and(&) in x64/assembler.

src/x64/assembler-x64-inl.h

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 105 matching lines @@
 }
 
 
 void Assembler::emit_optional_rex_32(Register reg, const Operand& op) {
   byte rex_bits =  (reg.code() & 0x8) >> 1 | op.rex_;
   if (rex_bits != 0) emit(0x40 | rex_bits);
 }
 
 
 void Assembler::emit_optional_rex_32(Register rm_reg) {
-  if (rm_reg.code() & 0x8 != 0) emit(0x41);
+  if (rm_reg.code() > 0x7) emit(0x41);

[Lasse Reichstein, 2009/06/19 09:03:24]

I've used  ">= 0x8" in other places. We really should have has_high_bit() on
Register.

 }
 
 
 void Assembler::emit_optional_rex_32(const Operand& op) {
   if (op.rex_ != 0) emit(0x40 | op.rex_);
 }
 
 
 Address Assembler::target_address_at(Address pc) {
   return Memory::Address_at(pc);
@@ skipping 138 matching lines @@
   ASSERT(len_ == 1 || len_ == 2);
   int32_t* p = reinterpret_cast<int32_t*>(&buf_[len_]);
   *p = disp;
   len_ += sizeof(int32_t);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_INL_H_