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Re: [PATCH] Remove unreachable nodes before IPA profile pass (PR ipa/87706).
On 11/8/18 12:46 PM, Jan Hubicka wrote:
>> On Thu, Nov 8, 2018 at 12:39 PM Martin Liška <mliska@suse.cz> wrote:
>>>
>>> On 11/8/18 12:19 PM, Jan Hubicka wrote:
>>>>> Hi.
>>>>>
>>>>> In order to fix the warnings mentioned in the PR, we need
>>>>> to run remove_unreachable_nodes after early tree passes. That's
>>>>> however possible only within a IPA pass. Thus I'm calling that
>>>>> before the profile PASS.
>>>>>
>>>>> Patch survives regression tests on ppc64le-linux-gnu and majority
>>>>> of warnings are gone in profiledbootstrap.
>>>>>
>>>>> Ready for trunk?
>>>>
>>>> I think we want to do that even with no -fprofile-generate because the
>>>> unreachable code otherwise goes into all other IPA passes for no good
>>>> reason. So perhaps adding it as todo after the early optimization
>>>> metapass?
>>>
>>> That fails due to gcc_assert.
>>> So one needs:
>>>
>>> diff --git a/gcc/passes.c b/gcc/passes.c
>>> index d838d909941..be92a2f3be3 100644
>>> --- a/gcc/passes.c
>>> +++ b/gcc/passes.c
>>> @@ -485,7 +485,7 @@ const pass_data pass_data_all_early_optimizations =
>>> 0, /* properties_provided */
>>> 0, /* properties_destroyed */
>>> 0, /* todo_flags_start */
>>> - 0, /* todo_flags_finish */
>>> + TODO_remove_functions | TODO_rebuild_cgraph_edges, /* todo_flags_finish */
>>> };
>>>
>>> class pass_all_early_optimizations : public gimple_opt_pass
>>> @@ -1989,7 +1989,8 @@ execute_todo (unsigned int flags)
>>> of IPA pass queue. */
>>> if (flags & TODO_remove_functions)
>>> {
>>> - gcc_assert (!cfun);
>>> + gcc_assert (!cfun
>>> + || strcmp (current_pass->name, "early_optimizations") == 0);
>>> symtab->remove_unreachable_nodes (dump_file);
>>> }
>>>
>>>
>>> Or do you prefer to a new pass_remove_functions pass that will be added after
>>> pass_local_optimization_passes ?
>>
>> Can you make it todo_flags_start of pass_ipa_tree_profile instead?
>
> It fails because all_early_optimizations are now gimple pass, so it
> should be TODO after pass_local_optimization_passes?
Unfortunately it does not work. Following file can't be compiled:
./xgcc -B. /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/torture/inline-2.c -O0
/usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /tmp/ccCVFrPv.o: in function `bar1':
inline-2.c:(.text+0x5): undefined reference to `foo2'
/usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /tmp/ccCVFrPv.o: in function `bar2':
inline-2.c:(.text+0x11): undefined reference to `foo1'
collect2: error: ld returned 1 exit status
So it's some interference with einline. Honza?
Thus I'm suggesting to add a new IPA pass.
That survives regression tests on x86_64-linux-gnu and bootstrap works.
Martin
>
> Honza
>>
>>> Martin
>>>
>>>>
>>>> Honza
>>>>> Thanks,
>>>>> Martin
>>>>>
>>>>> gcc/ChangeLog:
>>>>>
>>>>> 2018-11-08 Martin Liska <mliska@suse.cz>
>>>>>
>>>>> * tree-profile.c: Run TODO_remove_functions before "profile"
>>>>> pass in order to remove dead functions that will trigger
>>>>> -Wmissing-profile.
>>>>> ---
>>>>> gcc/tree-profile.c | 2 +-
>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>>
>>>>
>>>>> diff --git a/gcc/tree-profile.c b/gcc/tree-profile.c
>>>>> index d8f2a3b1ba4..c14ebc556a6 100644
>>>>> --- a/gcc/tree-profile.c
>>>>> +++ b/gcc/tree-profile.c
>>>>> @@ -776,7 +776,7 @@ const pass_data pass_data_ipa_tree_profile =
>>>>> 0, /* properties_required */
>>>>> 0, /* properties_provided */
>>>>> 0, /* properties_destroyed */
>>>>> - 0, /* todo_flags_start */
>>>>> + TODO_remove_functions, /* todo_flags_start */
>>>>> TODO_dump_symtab, /* todo_flags_finish */
>>>>> };
>>>>>
>>>>>
>>>>
>>>
>From 00fd2e0870860d5e1b4e599e1f88292982a03efb Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Wed, 7 Nov 2018 13:10:57 +0100
Subject: [PATCH] Remove unreachable nodes before IPA profile pass (PR
ipa/87706).
gcc/ChangeLog:
2018-11-12 Martin Liska <mliska@suse.cz>
PR ipa/87706
* cgraphbuild.c (class pass_ipa_remove_functions): New pass.
(make_pass_remove_functions): Likewise.
* passes.def: Declare the new pass.
* tree-pass.h (make_pass_remove_functions): New.
---
gcc/cgraphbuild.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
gcc/passes.def | 1 +
gcc/tree-pass.h | 1 +
3 files changed, 46 insertions(+)
diff --git a/gcc/cgraphbuild.c b/gcc/cgraphbuild.c
index c2ad5cf2ef7..f903df38c31 100644
--- a/gcc/cgraphbuild.c
+++ b/gcc/cgraphbuild.c
@@ -547,3 +547,47 @@ make_pass_remove_cgraph_callee_edges (gcc::context *ctxt)
{
return new pass_remove_cgraph_callee_edges (ctxt);
}
+
+namespace {
+
+const pass_data pass_data_ipa_remove_functions =
+{
+ IPA_PASS, /* type */
+ "*remove_functions", /* name */
+ OPTGROUP_INLINE, /* optinfo_flags */
+ TV_IPA_FNSUMMARY, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_remove_functions /* todo_flags_finish */
+};
+
+class pass_ipa_remove_functions : public ipa_opt_pass_d
+{
+public:
+ pass_ipa_remove_functions (gcc::context *ctxt)
+ : ipa_opt_pass_d (pass_data_ipa_remove_functions, ctxt,
+ NULL, /* generate_summary */
+ NULL, /* write_summary */
+ NULL, /* read_summary */
+ NULL, /* write_optimization_summary */
+ NULL, /* read_optimization_summary */
+ NULL, /* stmt_fixup */
+ 0, /* function_transform_todo_flags_start */
+ NULL, /* function_transform */
+ NULL) /* variable_transform */
+ {}
+
+ /* opt_pass methods: */
+ virtual unsigned int execute (function *) { return 0; }
+
+}; // class pass_ipa_fn_summary
+
+} // anon namespace
+
+ipa_opt_pass_d *
+make_pass_remove_functions (gcc::context *ctxt)
+{
+ return new pass_ipa_remove_functions (ctxt);
+}
diff --git a/gcc/passes.def b/gcc/passes.def
index 24f212c8e31..f7ebc061721 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -105,6 +105,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_rebuild_cgraph_edges);
NEXT_PASS (pass_local_fn_summary);
POP_INSERT_PASSES ()
+ NEXT_PASS (pass_remove_functions);
NEXT_PASS (pass_ipa_oacc);
PUSH_INSERT_PASSES_WITHIN (pass_ipa_oacc)
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index af15adc8e0c..872d3533b49 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -514,6 +514,7 @@ extern ipa_opt_pass_d *make_pass_ipa_single_use (gcc::context *ctxt);
extern ipa_opt_pass_d *make_pass_ipa_comdats (gcc::context *ctxt);
extern simple_ipa_opt_pass *make_pass_materialize_all_clones (gcc::context *
ctxt);
+extern ipa_opt_pass_d *make_pass_remove_functions (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_cleanup_cfg_post_optimizing (gcc::context
*ctxt);
--
2.19.1