Re: [PATCH] Prevent TYPE_PRECISION on VECTOR_TYPEs

[Jeff Law <jeffreyalaw@gmail.com>]

On 6/28/23 22:04, Li, Pan2 wrote:
> It seems this patch may result in many test ICE failures on RISC-V backend. Could you help to double confirm about it follow the possible reproduce steps like blow? Thank you!
I've one ICE due to this change as well but it wasn't in the 
tree-ssa-math-opts.code like this one is.  In my case we're in a place 
where it doesn't look like we expect a vector type to show up, but it 
does and we can likely just prune it away.

Anyway, your fault is in here:



divmod_candidate_p:

      if (TYPE_PRECISION (type) <= HOST_BITS_PER_WIDE_INT
           && TYPE_PRECISION (type) <= BITS_PER_WORD)
         return false;

TYPE is almost certainly a vector type.  The question we need to answer 
(and I'm not likely to get to it tomorrow) would be whether or not TYPE 
can legitimately be a vector type here.

The whole point of Richi's change is to detect invalid uses of 
TYPE_PRECISION.  So it's not a big surprise that we're finding a few as 
the change gets wider testing.

jeff