Committed. Thanks kito.
>> I guess you will remove get_all_predecessors once LMUL cost
>> model can use dominator info as well?
Yes. I am trying but there is a failed case for dynamic LMUL.
Not sure whether it can work now.
juzhe.zh...@rivai.ai
From: Kito Cheng
Date: 2023-09-11 15:03
To: Juzhe-Zhong
CC: gcc-patches; kito.cheng
Subject: Re: [PATCH] RISC-V: Use dominance analysis in global vsetvl elimination
LGTM, and I guess you will remove get_all_predecessors once LMUL cost
model can use dominator info as well?
On Mon, Sep 11, 2023 at 11:34 AM Juzhe-Zhong <juzhe.zh...@rivai.ai> wrote:
>
> I found that it's more reasonable to use existing dominance analysis.
>
> gcc/ChangeLog:
>
> * config/riscv/riscv-vsetvl.cc
> (pass_vsetvl::global_eliminate_vsetvl_insn): Use dominance analysis.
> (pass_vsetvl::init): Ditto.
> (pass_vsetvl::done): Ditto.
>
> ---
> gcc/config/riscv/riscv-vsetvl.cc | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config/riscv/riscv-vsetvl.cc
> b/gcc/config/riscv/riscv-vsetvl.cc
> index 134b97737ae..f81361c4ccd 100644
> --- a/gcc/config/riscv/riscv-vsetvl.cc
> +++ b/gcc/config/riscv/riscv-vsetvl.cc
> @@ -4054,7 +4054,7 @@ pass_vsetvl::global_eliminate_vsetvl_insn (const
> bb_info *bb) const
> }
>
> /* Step1: Reshape the VL/VTYPE status to make sure everything compatible.
> */
> - hash_set<basic_block> pred_cfg_bbs = get_all_predecessors (cfg_bb);
> + auto_vec<basic_block> pred_cfg_bbs = get_dominated_by
> (CDI_POST_DOMINATORS, cfg_bb);
> FOR_EACH_EDGE (e, ei, cfg_bb->preds)
> {
> sbitmap avout = m_vector_manager->vector_avout[e->src->index];
> @@ -4243,6 +4243,7 @@ pass_vsetvl::init (void)
> {
> /* Initialization of RTL_SSA. */
> calculate_dominance_info (CDI_DOMINATORS);
> + calculate_dominance_info (CDI_POST_DOMINATORS);
> df_analyze ();
> crtl->ssa = new function_info (cfun);
> }
> @@ -4264,6 +4265,7 @@ pass_vsetvl::done (void)
> {
> /* Finalization of RTL_SSA. */
> free_dominance_info (CDI_DOMINATORS);
> + free_dominance_info (CDI_POST_DOMINATORS);
> if (crtl->ssa->perform_pending_updates ())
> cleanup_cfg (0);
> delete crtl->ssa;
> --
> 2.36.3
>
