Re: [PATCH] RISC-V: Forbidden fuse vlmax vsetvl to DEMAND_NONZERO_AVL vsetvl

[Robin Dapp via Gcc-patches]

Hi Lehua,

unrelated but I'm seeing a lot of failing gather/scatter tests on
master right now.

>             /* DIRTY -> DIRTY or VALID -> DIRTY.  */
> +           if (block_info.reaching_out.demand_p (DEMAND_NONZERO_AVL)
> +               && vlmax_avl_p (prop.get_avl ()))
> +             continue;
>             vector_insn_info new_info; 

Please add a small comment here which exact situation we're trying
to prevent.

> +asm volatile ("vsetivli x0, 0, e8, m1, ta, ma");

Why is this necessary or rather why is vtype uninitialized?  Is
this the mentioned bug?  If so, why do we still need it with the
vsetvl fix? 

Regards
 Robin