Re: Re: [PATCH] vect: Check that vector factor is a compile-time constant

[<juzhe.zhong@rivai.ai>]

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Currently, upstream GCC is not ready to support auto-vec.
I am building the basic infrastructure of RVV and need more testing.
I can't support auto-vec now since it depends on the infrastructure tha I am building.
I have open source "rvv-next" in RISC-V foundation repo which fully support intrinsic && auto-vec.
You can either wait for the upstream GCC or develop base rvv-next.



juzhe.zhong@rivai.ai
 
From: Michael Collison
Date: 2023-02-23 01:54
To: juzhe.zhong; gcc-patches
CC: kito.cheng; kito.cheng; richard.sandiford; richard.guenther
Subject: Re: [PATCH] vect: Check that vector factor is a compile-time constant
Juzhe,
I disagree with this comment. There are many stakeholders for autovectorization and waiting until GCC 14 is not a viable solution for us as well as other stakeholders ready to begin work on autovectorization.
As we discussed I have been moving forward with patches for autovectorization and am preparing to send them to gcc-patches. This assert is preventing code from compiling and needs to be addressed.
If you have a solution in either the RISCV backend or in this file can you please present it?
On 2/22/23 10:27, juzhe.zhong@rivai.ai wrote:
> gcc/
>
>      * tree-vect-loop-manip.cc (vect_do_peeling): Verify
>      that vectorization factor is a compile-time constant.
>
> ---
>   gcc/tree-vect-loop-manip.cc | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
> index 6aa3d2ed0bf..1ad1961c788 100644
> --- a/gcc/tree-vect-loop-manip.cc
> +++ b/gcc/tree-vect-loop-manip.cc
> @@ -2930,7 +2930,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree
> niters, tree nitersm1,
>         niters = vect_build_loop_niters (loop_vinfo, &new_var_p);
>         /* It's guaranteed that vector loop bound before vectorization is at
>        least VF, so set range information for newly generated var. */
> -      if (new_var_p)
> +      if (new_var_p && vf.is_constant ())
>       {
>         value_range vr (type,
>                 wi::to_wide (build_int_cst (type, vf)),

I don't think we need to apply this limit in case of RVV auto-vectorization.
I have talked with Kito and I have a full solution of supporting RVV solution.

We are going to support RVV auto-vectorization in 3 configuration according to RVV ISA spec:
1. -march=zve32* support QI and HI auto-vectorization by VNx4QImode and VNx2HImode
2. -march=zve64* support QI and HI and SI auto-vectorization by VNx8QImode and VNx4HImode and VNx2SImode
3. -march=v* support QI and HI and SI and DI auto-vectorization by VNx16QImode and VNx8HImode and VNx4SImode and VNx2DImode

I will support them in GCC 14. Current loop vectorizer works well for us no need to fix it. 
Thanks.


juzhe.zhong@rivai.ai