Re: [PATCH] PHIOPT: Add dump for match and simplify and early phiopt

[Richard Biener <richard.guenther@gmail.com>]

On Sat, Aug 26, 2023 at 4:16 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This adds dump on the full result of the match-and-simplify
> for phiopt and specifically to know if we are rejecting something
> due to being in early phi-opt.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

OK.

Richard.

> gcc/ChangeLog:
>
>         * tree-ssa-phiopt.cc (gimple_simplify_phiopt): Add dump information
>         when resimplify returns true.
>         (match_simplify_replacement): Print only if accepted the match-and-simplify
>         result rather than the full sequence.
> ---
>  gcc/tree-ssa-phiopt.cc | 70 ++++++++++++++++++++++++++----------------
>  1 file changed, 44 insertions(+), 26 deletions(-)
>
> diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
> index 7e63fb115db..9993bbe5b76 100644
> --- a/gcc/tree-ssa-phiopt.cc
> +++ b/gcc/tree-ssa-phiopt.cc
> @@ -499,7 +499,6 @@ gimple_simplify_phiopt (bool early_p, tree type, gimple *comp_stmt,
>                         tree arg0, tree arg1,
>                         gimple_seq *seq)
>  {
> -  tree result;
>    gimple_seq seq1 = NULL;
>    enum tree_code comp_code = gimple_cond_code (comp_stmt);
>    location_t loc = gimple_location (comp_stmt);
> @@ -529,18 +528,29 @@ gimple_simplify_phiopt (bool early_p, tree type, gimple *comp_stmt,
>
>    if (op.resimplify (&seq1, follow_all_ssa_edges))
>      {
> -      /* Early we want only to allow some generated tree codes. */
> -      if (!early_p
> -         || phiopt_early_allow (seq1, op))
> +      bool allowed = !early_p || phiopt_early_allow (seq1, op);
> +      tree result = maybe_push_res_to_seq (&op, &seq1);
> +      if (dump_file && (dump_flags & TDF_FOLDING))
>         {
> -         result = maybe_push_res_to_seq (&op, &seq1);
> +         fprintf (dump_file, "\nphiopt match-simplify back:\n");
> +         if (seq1)
> +           print_gimple_seq (dump_file, seq1, 0, TDF_VOPS|TDF_MEMSYMS);
> +         fprintf (dump_file, "result: ");
>           if (result)
> -           {
> -             if (loc != UNKNOWN_LOCATION)
> -               annotate_all_with_location (seq1, loc);
> -             gimple_seq_add_seq_without_update (seq, seq1);
> -             return result;
> -           }
> +           print_generic_expr (dump_file, result);
> +         else
> +           fprintf (dump_file, " (none)");
> +         fprintf (dump_file, "\n");
> +         if (!allowed)
> +           fprintf (dump_file, "rejected because early\n");
> +       }
> +      /* Early we want only to allow some generated tree codes. */
> +      if (allowed && result)
> +       {
> +         if (loc != UNKNOWN_LOCATION)
> +           annotate_all_with_location (seq1, loc);
> +         gimple_seq_add_seq_without_update (seq, seq1);
> +         return result;
>         }
>      }
>    gimple_seq_discard (seq1);
> @@ -572,18 +582,29 @@ gimple_simplify_phiopt (bool early_p, tree type, gimple *comp_stmt,
>
>    if (op1.resimplify (&seq1, follow_all_ssa_edges))
>      {
> -      /* Early we want only to allow some generated tree codes. */
> -      if (!early_p
> -         || phiopt_early_allow (seq1, op1))
> +      bool allowed = !early_p || phiopt_early_allow (seq1, op1);
> +      tree result = maybe_push_res_to_seq (&op1, &seq1);
> +      if (dump_file && (dump_flags & TDF_FOLDING))
>         {
> -         result = maybe_push_res_to_seq (&op1, &seq1);
> +         fprintf (dump_file, "\nphiopt match-simplify back:\n");
> +         if (seq1)
> +           print_gimple_seq (dump_file, seq1, 0, TDF_VOPS|TDF_MEMSYMS);
> +         fprintf (dump_file, "result: ");
>           if (result)
> -           {
> -             if (loc != UNKNOWN_LOCATION)
> -               annotate_all_with_location (seq1, loc);
> -             gimple_seq_add_seq_without_update (seq, seq1);
> -             return result;
> -           }
> +           print_generic_expr (dump_file, result);
> +         else
> +           fprintf (dump_file, " (none)");
> +         fprintf (dump_file, "\n");
> +         if (!allowed)
> +           fprintf (dump_file, "rejected because early\n");
> +       }
> +      /* Early we want only to allow some generated tree codes. */
> +      if (allowed && result)
> +       {
> +         if (loc != UNKNOWN_LOCATION)
> +           annotate_all_with_location (seq1, loc);
> +         gimple_seq_add_seq_without_update (seq, seq1);
> +         return result;
>         }
>      }
>    gimple_seq_discard (seq1);
> @@ -855,6 +876,8 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb,
>
>    if (!result)
>      return false;
> +  if (dump_file && (dump_flags & TDF_FOLDING))
> +    fprintf (dump_file, "accepted the phiopt match-simplify.\n");
>
>    auto_bitmap exprs_maybe_dce;
>
> @@ -881,11 +904,6 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb,
>           if (name && TREE_CODE (name) == SSA_NAME)
>             bitmap_set_bit (exprs_maybe_dce, SSA_NAME_VERSION (name));
>         }
> -      if (dump_file && (dump_flags & TDF_FOLDING))
> -       {
> -         fprintf (dump_file, "Folded into the sequence:\n");
> -         print_gimple_seq (dump_file, seq, 0, TDF_VOPS|TDF_MEMSYMS);
> -       }
>      gsi_insert_seq_before (&gsi, seq, GSI_CONTINUE_LINKING);
>    }
>
> --
> 2.31.1
>