A question regarding recognition of nop

[Revital1 Eres]

Hello,

Is there a general way to recognize a nop insn in RTL (using attributes?),
or should I add a target hook for that?

For example, I would like to recognize the following spu insn as a nop:?),

(insn 555 210 203 11 (unspec_volatile [
            (const_int 0 [0x0])
        ] 14) 393 {lnop} (nil))

Thanks,
Revital