Re: [PATCH] RISC-V: convert the mulh with 0 to mov 0 to the reg.

[Robin Dapp via Gcc-patches]

Hi Yanzhang,

while I appreciate the optimization, I'm a bit wary about just adding a special
case for "0".  Is that so common? Wouldn't we also like to have
  * pow2_p (val) == << val and others?

* 1 should also be covered.

Regards
 Robin