[PATCH, stage1] Make parloops gate more strict

[Richard Biener]

On Mon, Jun 15, 2015 at 12:38 AM, Tom de Vries <Tom_deVries@mentor.com> wrote:
> On 14/06/15 23:49, Bernhard Reutner-Fischer wrote:
>>
>> On June 14, 2015 10:55:59 AM GMT+02:00, Tom de Vries
>> <Tom_deVries@mentor.com> wrote:
>>>
>>> On 13/03/15 11:36, Richard Biener wrote:
>>>>
>>>> On Fri, Mar 13, 2015 at 11:32 AM, Tom de Vries
>>>
>>> <Tom_deVries@mentor.com> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> this patch moves a bunch of early-out tests from the parloops pass
>>>
>>> to the
>>>>>
>>>>> gate function.
>>>>>
>>>>> The only effect is for functions that we don't consider at all for
>>>>> parallelization in the parloops pass. We no longer dump those in the
>>>>> parloops dump file.
>>>>>
>>>>> Bootstrapped and reg-tested on x86_64.
>>>>>
>>>>> OK for stage1 trunk?
>>>>
>>>>
>>>> Does it work with -fdump-passes?
>>>>
>>>
>>> Hi,
>>>
>>> with -fdump-passes now fixed to work on a dummy function (r222129), I'm
>>>
>>> resubmitting this patch, split up in two patches.
>>>
>>> The first patch moves two trivial early-exit tests to the parloops
>>> gate.
>>>
>>> The second patch moves the number_of_loops test to the parloops gate,
>>> and adds a dummy loops structure in the dummy function for
>>> -fdump-passes.
>>>
>>> Bootstrapped and reg-tested on x86_64.
>>>
>>> Both patches OK for trunk?
>>
>>
>> diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
>> index 02f44eb..a1659a3 100644
>> --- a/gcc/tree-parloops.c
>> +++ b/gcc/tree-parloops.c
>> @@ -2535,10 +2535,6 @@ parallelize_loops (void)
>>     source_location loop_loc;
>>
>>     /* Do not parallelize loops in the functions created by
>> parallelization.  */
>> -  if (parallelized_function_p (cfun->decl))
>> -    return false;
>> -  if (cfun->has_nonlocal_label)
>> -    return false;
>>
>>     gcc_obstack_init (&parloop_obstack);
>>     reduction_info_table_type reduction_list (10);
>>
>> Now stray comment?
>> Stopped reading here.
>>
>
> Fixed in updated patch.
>
> Also:
> - made sure cfun is not used in the gate function
> - added missing update of function header comment for
>   init_loops_structure
> - improved comment in pass_manager::dump_passes.
>
>
> OK for trunk?

For -fdump-passes this doesn't make much sense but I suppose
you are after not getting the untouched functions dumped.  Note
that generally this is undesired for debugging (in my opinion)
as diffs from the pass dump before parloops to parloops will
contain a lot of spurious changes (and if the preceeding pass
is changed similarly the function we run parloops on is maybe
not even dumped there!).

So I question the general idea of the change.

Richard.

> Thanks,
> - Tom
>
>
>