Re: [PATCH][PUSHED] Fix cfg maintenance after inlining in AutoFDO

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

On Tue, May 9, 2023 at 12:27 AM Eugene Rozenfeld via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Todo from early_inliner needs to be propagated so that
> cleanup_tree_cfg () is called if necessary.
>
> This bug was causing an assert in get_loop_body during
> ipa-sra in autoprofiledbootstrap build since loops weren't
> fixed up and one of the loops had num_nodes set to 0.
>
> Tested on x86_64-pc-linux-gnu.
>
> gcc/ChangeLog:
>
>         * auto-profile.cc (auto_profile): Check todo from early_inline
>         to see if cleanup_tree_vfg needs to be called.

_cfg

>         (early_inline): Return todo from early_inliner.
> ---
>  gcc/auto-profile.cc | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
> index 360c42c4b89..e3af3555e75 100644
> --- a/gcc/auto-profile.cc
> +++ b/gcc/auto-profile.cc
> @@ -1589,13 +1589,14 @@ afdo_annotate_cfg (const stmt_set &promoted_stmts)
>
>  /* Wrapper function to invoke early inliner.  */
>
> -static void
> +static unsigned int
>  early_inline ()
>  {
>    compute_fn_summary (cgraph_node::get (current_function_decl), true);
> -  unsigned todo = early_inliner (cfun);
> +  unsigned int todo = early_inliner (cfun);
>    if (todo & TODO_update_ssa_any)
>      update_ssa (TODO_update_ssa);
> +  return todo;
>  }
>
>  /* Use AutoFDO profile to annoate the control flow graph.
> @@ -1651,20 +1652,22 @@ auto_profile (void)
>         function before annotation, so the profile inside bar@loc_foo2
>         will be useful.  */
>      autofdo::stmt_set promoted_stmts;
> +    unsigned int todo = 0;
>      for (int i = 0; i < 10; i++)
>        {
> -        if (!flag_value_profile_transformations
> -            || !autofdo::afdo_vpt_for_early_inline (&promoted_stmts))
> -          break;
> -        early_inline ();
> +       if (!flag_value_profile_transformations
> +           || !autofdo::afdo_vpt_for_early_inline (&promoted_stmts))
> +         break;
> +       todo |= early_inline ();
>        }
>
> -    early_inline ();
> +    todo |= early_inline ();
>      autofdo::afdo_annotate_cfg (promoted_stmts);
>      compute_function_frequency ();
>
>      /* Local pure-const may imply need to fixup the cfg.  */
> -    if (execute_fixup_cfg () & TODO_cleanup_cfg)
> +    todo |= execute_fixup_cfg ();
> +    if (todo & TODO_cleanup_cfg)
>        cleanup_tree_cfg ();
>
>      free_dominance_info (CDI_DOMINATORS);
> @@ -1674,7 +1677,7 @@ auto_profile (void)
>      pop_cfun ();
>    }
>
> -  return TODO_rebuild_cgraph_edges;
> +  return 0;

This change isn't mentioned - was it accidential?

Otherwise looks OK.

Thanks,
Richard.

>  }
>  } /* namespace autofdo.  */
>
> --
> 2.25.1
>