frm is illegal value , a vector fp inst raise illegal inst but it still will make vs dirty

[xinyuwang-starfive]

for vector fp inst，now spike check require vector first and then require_vector first and then requre frm。
in require vector it will dirty vs。
so if frm is illegal now it will make dirty and will dirty vs。
#define VI_VFP_COMMON \ require_fp; \ require((P.VU.vsew == e16 && p->extension_enabled(EXT_ZVFH)) || \ (P.VU.vsew == e32 && p->extension_enabled('F')) || \ (P.VU.vsew == e64 && p->extension_enabled('D'))); \ require_vector(true); \ require(STATE.frm->read() < 0x5); \
i check spec and not found the detail about how to do it.
can you tell me Whether it meets expectations？

[aswaterman]

I think this is technically not a bug; implementations are allowed to change the state from clean or initial to dirty for any reason. However, I agree it is cleaner not to dirty the state in the event of an illegal-instruction exception. I’ll leave others to comment on the implementation details.