On Sat, 25 Jun 2011, Jan Hubicka wrote:
> Hi,
> just for those who are interested, this is quick&dirty patch adding another
> pass of local optimization passes at WPA time. I've added early inliner and
> IPA-SRA because I was curious how much of optimization oppurtunities we are
> missing by limiting those to early pass.
At WPA time? I thought we don't have function bodies around.
Richard.
> With Early inlining it seems to be very little. We inline one extra call when
> building Mozilla in LTO mode.
>
> IPA SRA is different story. While we do 579 IPA SRA clones in the early pass,
> the late pass produces 13014 clones (22 times more ;) suggesting that the pass
> might be interesting at IPA level after all.
>
> There are 78686 functions after inlining in Mozilla, so one out of 7 functions
> is touched.
>
> Size difference of libxul is not great, about 100Kb reduction. I will try
> benchmarking it eventually, too.
>
> Honza
>
>
> Index: cgraph.c
> ===================================================================
> *** cgraph.c (revision 175350)
> --- cgraph.c (working copy)
> *************** cgraph_release_function_body (struct cgr
> *** 1389,1396 ****
> }
> if (cfun->cfg)
> {
> ! gcc_assert (dom_computed[0] == DOM_NONE);
> ! gcc_assert (dom_computed[1] == DOM_NONE);
> clear_edges ();
> }
> if (cfun->value_histograms)
> --- 1393,1403 ----
> }
> if (cfun->cfg)
> {
> ! /*gcc_assert (dom_computed[0] == DOM_NONE);
> ! gcc_assert (dom_computed[1] == DOM_NONE);*/
> ! free_dominance_info (CDI_DOMINATORS);
> ! free_dominance_info (CDI_POST_DOMINATORS);
> !
> clear_edges ();
> }
> if (cfun->value_histograms)
> Index: tree-pass.h
> ===================================================================
> *** tree-pass.h (revision 175350)
> --- tree-pass.h (working copy)
> *************** extern struct simple_ipa_opt_pass pass_i
> *** 452,458 ****
> extern struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility;
> extern struct simple_ipa_opt_pass pass_ipa_tree_profile;
>
> ! extern struct simple_ipa_opt_pass pass_early_local_passes;
>
> extern struct ipa_opt_pass_d pass_ipa_whole_program_visibility;
> extern struct ipa_opt_pass_d pass_ipa_lto_gimple_out;
> --- 452,458 ----
> extern struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility;
> extern struct simple_ipa_opt_pass pass_ipa_tree_profile;
>
> ! extern struct simple_ipa_opt_pass pass_early_local_passes,
> pass_late_local_passes, pass_late_local_passes2;
>
> extern struct ipa_opt_pass_d pass_ipa_whole_program_visibility;
> extern struct ipa_opt_pass_d pass_ipa_lto_gimple_out;
> Index: ipa-inline-analysis.c
> ===================================================================
> *** ipa-inline-analysis.c (revision 175350)
> --- ipa-inline-analysis.c (working copy)
> *************** estimate_function_body_sizes (struct cgr
> *** 1535,1542 ****
> edge->call_stmt_cannot_inline_p = true;
> gimple_call_set_cannot_inline (stmt, true);
> }
> ! else
> ! gcc_assert (!gimple_call_cannot_inline_p (stmt));
> }
>
> /* TODO: When conditional jump or swithc is known to be constant, but
> --- 1535,1542 ----
> edge->call_stmt_cannot_inline_p = true;
> gimple_call_set_cannot_inline (stmt, true);
> }
> ! /*else
> ! gcc_assert (!gimple_call_cannot_inline_p (stmt));*/
> }
>
> /* TODO: When conditional jump or swithc is known to be constant, but
> Index: tree-inline.c
> ===================================================================
> *** tree-inline.c (revision 175350)
> --- tree-inline.c (working copy)
> *************** expand_call_inline (basic_block bb, gimp
> *** 3891,3897 ****
> id->src_cfun = DECL_STRUCT_FUNCTION (fn);
> id->gimple_call = stmt;
>
> ! gcc_assert (!id->src_cfun->after_inlining);
>
> id->entry_bb = bb;
> if (lookup_attribute ("cold", DECL_ATTRIBUTES (fn)))
> --- 3891,3897 ----
> id->src_cfun = DECL_STRUCT_FUNCTION (fn);
> id->gimple_call = stmt;
>
> ! /*gcc_assert (!id->src_cfun->after_inlining);*/
>
> id->entry_bb = bb;
> if (lookup_attribute ("cold", DECL_ATTRIBUTES (fn)))
> Index: tree-optimize.c
> ===================================================================
> *** tree-optimize.c (revision 175350)
> --- tree-optimize.c (working copy)
> *************** struct simple_ipa_opt_pass pass_early_lo
> *** 123,128 ****
> --- 123,189 ----
> /* Gate: execute, or not, all of the non-trivial optimizations. */
>
> static bool
> + gate_all_late_local_passes (void)
> + {
> + /* Don't bother doing anything if the program has errors. */
> + return (!seen_error () && optimize);
> + }
> +
> + static unsigned int
> + execute_all_late_local_passes (void)
> + {
> + /* Once this pass (and its sub-passes) are complete, all functions
> + will be in SSA form. Technically this state change is happening
> + a tad late, since the sub-passes have not yet run, but since
> + none of the sub-passes are IPA passes and do not create new
> + functions, this is ok. We're setting this value for the benefit
> + of IPA passes that follow. */
> + if (cgraph_state < CGRAPH_STATE_IPA_SSA)
> + cgraph_state = CGRAPH_STATE_IPA_SSA;
> + return 0;
> + }
> +
> + struct simple_ipa_opt_pass pass_late_local_passes =
> + {
> + {
> + SIMPLE_IPA_PASS,
> + "late_local_cleanups", /* name */
> + gate_all_late_local_passes, /* gate */
> + execute_all_late_local_passes, /* execute */
> + NULL, /* sub */
> + NULL, /* next */
> + 0, /* static_pass_number */
> + TV_EARLY_LOCAL, /* tv_id */
> + 0, /* properties_required */
> + 0, /* properties_provided */
> + 0, /* properties_destroyed */
> + 0, /* todo_flags_start */
> + TODO_remove_functions /* todo_flags_finish */
> + }
> + };
> +
> + struct simple_ipa_opt_pass pass_late_local_passes2 =
> + {
> + {
> + SIMPLE_IPA_PASS,
> + "late_local_cleanups2", /* name */
> + gate_all_late_local_passes, /* gate */
> + execute_all_late_local_passes, /* execute */
> + NULL, /* sub */
> + NULL, /* next */
> + 0, /* static_pass_number */
> + TV_EARLY_LOCAL, /* tv_id */
> + 0, /* properties_required */
> + 0, /* properties_provided */
> + 0, /* properties_destroyed */
> + 0, /* todo_flags_start */
> + TODO_remove_functions /* todo_flags_finish */
> + }
> + };
> +
> + /* Gate: execute, or not, all of the non-trivial optimizations. */
> +
> + static bool
> gate_all_early_optimizations (void)
> {
> return (optimize >= 1
> Index: passes.c
> ===================================================================
> *** passes.c (revision 175350)
> --- passes.c (working copy)
> *************** init_optimization_passes (void)
> *** 1263,1268 ****
> --- 1263,1288 ----
> passes are executed after partitioning and thus see just parts of the
> compiled unit. */
> p = &all_late_ipa_passes;
> + NEXT_PASS (pass_late_local_passes);
> + {
> + struct opt_pass **p = &pass_late_local_passes.pass.sub;
> + NEXT_PASS (pass_inline_parameters);
> + NEXT_PASS (pass_release_ssa_names);
> + }
> + NEXT_PASS (pass_late_local_passes2);
> + {
> + struct opt_pass **p = &pass_late_local_passes2.pass.sub;
> + NEXT_PASS (pass_early_inline);
> + NEXT_PASS (pass_remove_cgraph_callee_edges);
> + NEXT_PASS (pass_ccp);
> + NEXT_PASS (pass_forwprop);
> + NEXT_PASS (pass_fre);
> + NEXT_PASS (pass_cd_dce);
> + NEXT_PASS (pass_early_ipa_sra);
> + NEXT_PASS (pass_release_ssa_names);
> + NEXT_PASS (pass_rebuild_cgraph_edges);
> + NEXT_PASS (pass_inline_parameters);
> + }
> NEXT_PASS (pass_ipa_pta);
> *p = NULL;
> /* These passes are run after IPA passes on every function that is being
> Index: statistics.c
> ===================================================================
> *** statistics.c (revision 175350)
> --- statistics.c (working copy)
> *************** statistics_fini_pass_3 (void **slot, voi
> *** 171,176 ****
> --- 171,178 ----
> void
> statistics_fini_pass (void)
> {
> + if (!current_pass)
> + return;
> if (current_pass->static_pass_number == -1)
> return;
>
>
>
--
Richard Guenther <rguent...@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
