About opcode!

[libra]

Hello,all:

I have one question about opcode in binutils source directory.
Why have two opcode information(file) in two different location,one is in 
"binutils-2.14/opcodes/xxx-opc.h", the other is in "binutils-
2.14/include/opcode/xxx.h"

For example:
"binutils-2.14/opcodes/arm-opc.h" and "binutils-2.14/include/opcode/arm.h"

Why can not just use one opcode table file? For example, just use "binutils-
2.14/include/opcode/arm.h". What's different purpose between arm-opc.h and 
arm.h?

                                                  thanks a lot!!!