On Sat, Jan 29, 2022 at 12:24 AM Eugene Rozenfeld via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> param_early_inliner_max_iterations specifies the maximum number
> of nested indirect inlining iterations performed by early inliner.
> Normally, the default value is 1.
>
> For AutoFDO this parameter was also used as the number of iteration for
> its indirect call promotion loop and the default value was set to 10.
> While it makes sense to have 10 in the indirect call promotion loop
> (we want to make the IR match the profiled binary before actual annotation)
> there is no reason to have a special default value for the
> regular early inliner.
>
> This change removes the special AutoFDO default value setting for
> param_early_inliner_max_iterations while keeping 10 as the number of
> iterations for the AutoFDO indirect call promotion loop.
>
> This change improves a simple fibonacci benchmark in AutoFDO mode
> by 15% on x86_64-pc-linux-gnu.
>
> Tested on x86_64-pc-linux-gnu.
OK.
Richard.
> gcc/ChangeLog:
> * auto-profile.cc (auto_profile): Hard-code the number of iterations
> (10).
>
> gcc/ChangeLog:
> * opt.cc (common_handle_option): Don't set
> param_early_inliner_max_iterations to 10 for AutoFDO.
> ---
> gcc/auto-profile.cc | 3 +--
> gcc/opts.cc | 2 --
> 2 files changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
> index 0bfaae7b091..c7cee639c85 100644
> --- a/gcc/auto-profile.cc
> +++ b/gcc/auto-profile.cc
> @@ -1644,8 +1644,7 @@ auto_profile (void)
> function before annotation, so the profile inside bar@loc_foo2
> will be useful. */
> autofdo::stmt_set promoted_stmts;
> - for (int i = 0; i < opt_for_fn (node->decl,
> - param_early_inliner_max_iterations); i++)
> + for (int i = 0; i < 10; i++)
> {
> if (!flag_value_profile_transformations
> || !autofdo::afdo_vpt_for_early_inline (&promoted_stmts))
> diff --git a/gcc/opts.cc b/gcc/opts.cc
> index 17e1884f0e4..f6f6a8e1709 100644
> --- a/gcc/opts.cc
> +++ b/gcc/opts.cc
> @@ -2899,8 +2899,6 @@ common_handle_option (struct gcc_options *opts,
> case OPT_fauto_profile:
> enable_fdo_optimizations (opts, opts_set, value);
> SET_OPTION_IF_UNSET (opts, opts_set, flag_profile_correction, value);
> - SET_OPTION_IF_UNSET (opts, opts_set,
> - param_early_inliner_max_iterations, 10);
> break;
>
> case OPT_fprofile_generate_:
> --
> 2.25.1
