[Bug target/111720] RISC-V: Ugly codegen in RVV

["juzhe.zhong at rivai dot ai" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111720

--- Comment #19 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
(In reply to Richard Biener from comment #18)
> With RVV you have intrinsic calls in GIMPLE so nothing to optimize:
> 
> vbool8_t fn ()
> {
>   vbool8_t vmask;
>   vuint8m1_t vand_m;
>   vuint8m1_t varr;
>   uint8_t arr[32];
> 
>   <bb 2> [local count: 1073741824]:
>   arr =
> "\x01\x02\x07\x01\x03\x04\x05\x03\x01\x00\x01\x02\x04\x04\t\t\x01\x02\x07\x01
> \x03\x04\x05\x03\x01\x00\x01\x02\x04\x04\t\t";
>   varr_3 = __riscv_vle8_v_u8m1 (&arr, 32); [return slot optimization]
>   vand_m_4 = __riscv_vand_vx_u8m1 (varr_3, 1, 32); [return slot optimization]
>   vmask_5 = __riscv_vreinterpret_v_u8m1_b8 (vand_m_4); [return slot
> optimization]
>   <retval> = vmask_5;
>   arr ={v} {CLOBBER(eol)};
>   return <retval>;
> 
> and on RTL I see lots of UNSPECs, RTL opts cannot do anything with those.
> 
> This is what Andrew said already.

Ok. I wonder why this issue is gone when I change it into:

arr as static

https://godbolt.org/z/Tdoshdfr6