committed, thanks.

On Tue, Jan 10, 2023 at 6:40 AM <juzhe.zhong@rivai.ai> wrote:

> From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
>
> gcc/ChangeLog:
>
>         * config/riscv/riscv-vsetvl.cc
> (pass_vsetvl::forward_demand_fusion): Add pre-check for redundant flow.
>
> ---
>  gcc/config/riscv/riscv-vsetvl.cc | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv-vsetvl.cc
> b/gcc/config/riscv/riscv-vsetvl.cc
> index 7800c2ee509..18c6f437db6 100644
> --- a/gcc/config/riscv/riscv-vsetvl.cc
> +++ b/gcc/config/riscv/riscv-vsetvl.cc
> @@ -2140,6 +2140,9 @@ pass_vsetvl::forward_demand_fusion (void)
>        if (!prop.valid_or_dirty_p ())
>         continue;
>
> +      if (cfg_bb == ENTRY_BLOCK_PTR_FOR_FN (cfun))
> +       continue;
> +
>        edge e;
>        edge_iterator ei;
>        /* Forward propagate to each successor.  */
> @@ -2153,6 +2156,11 @@ pass_vsetvl::forward_demand_fusion (void)
>           /* It's quite obvious, we don't need to propagate itself.  */
>           if (e->dest->index == cfg_bb->index)
>             continue;
> +         /* We don't propagate through critical edges.  */
> +         if (e->flags & EDGE_COMPLEX)
> +           continue;
> +         if (e->dest->index == EXIT_BLOCK_PTR_FOR_FN (cfun)->index)
> +           continue;
>
>           /* If there is nothing to propagate, just skip it.  */
>           if (!local_dem.valid_or_dirty_p ())
> --
> 2.36.1
>
>