Re: -fdump-passes -fenable-xxx=func_name_list

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

On Tue, Jun 7, 2011 at 10:20 PM, Xinliang David Li <davidxl@google.com> wrote:
> The dump-pass patch with test case.

Ok.

Thanks,
Richard.

> David
>
> On Tue, Jun 7, 2011 at 11:54 AM, Xinliang David Li <davidxl@google.com> wrote:
>> Please review the attached two patches.
>>
>> In the first patch, gate functions are cleaned up. All the per
>> function legality checks are moved into the executor and the
>> optimization heuristic checks (optimize for size) remain in the
>> gators. These allow the the following overriding order:
>>
>>    common flags (O2, -ftree-vrp, -fgcse etc)   <---  compiler
>> heuristic (optimize for size/speed) <--- -fdisable/enable forcing pass
>> options  <--- legality check
>>
>> Testing under going. Ok for trunk?
>>
>> Thanks,
>>
>> David
>>
>> On Tue, Jun 7, 2011 at 9:24 AM, Xinliang David Li <davidxl@google.com> wrote:
>>> Ok -- that sounds good.
>>>
>>> David
>>>
>>> On Tue, Jun 7, 2011 at 3:10 AM, Richard Guenther
>>> <richard.guenther@gmail.com> wrote:
>>>> On Mon, Jun 6, 2011 at 6:00 PM, Xinliang David Li <davidxl@google.com> wrote:
>>>>> On Mon, Jun 6, 2011 at 4:38 AM, Richard Guenther
>>>>> <richard.guenther@gmail.com> wrote:
>>>>>> On Thu, Jun 2, 2011 at 9:12 AM, Xinliang David Li <davidxl@google.com> wrote:
>>>>>>> This is the version of the patch that walks through pass lists.
>>>>>>>
>>>>>>> Ok with this one?
>>>>>>
>>>>>> +/* Dump all optimization passes.  */
>>>>>> +
>>>>>> +void
>>>>>> +dump_passes (void)
>>>>>> +{
>>>>>> +  struct cgraph_node *n, *node = NULL;
>>>>>> +  tree save_fndecl = current_function_decl;
>>>>>> +
>>>>>> +  fprintf (stderr, "MAX_UID = %d\n", cgraph_max_uid);
>>>>>>
>>>>>> this isn't accurate info - cloning can cause more cgraph nodes to
>>>>>> appear (it also looks completely unrelated to dump_passes ...).
>>>>>> Please drop it.
>>>>>
>>>>> Ok.
>>>>>
>>>>>
>>>>>>
>>>>>> +  create_pass_tab();
>>>>>> +  gcc_assert (pass_tab);
>>>>>>
>>>>>> you have quite many asserts of this kind - we don't want them when
>>>>>> the previous stmt as in this case indicates everything is ok.
>>>>>
>>>>> ok.
>>>>>
>>>>>>
>>>>>> +  push_cfun (DECL_STRUCT_FUNCTION (node->decl));
>>>>>>
>>>>>> this has side-effects, I'm not sure we want this here.  Why do you
>>>>>> need it?  Probably because of
>>>>>>
>>>>>> +  is_really_on = override_gate_status (pass, current_function_decl, is_on);
>>>>>>
>>>>>> ?  But that is dependent on the function given which should have no
>>>>>> effect (unless it is overridden globally in which case override_gate_status
>>>>>> and friends should deal with a NULL cfun).
>>>>>
>>>>> As we discussed, currently some pass gate functions depend on per node
>>>>> information -- those checks need to be pushed into execute functions.
>>>>> I would like to clean those up later -- at which time, the push/pop
>>>>> can be removed.
>>>>
>>>> I'd like to do it the other way around, first clean up the gate functions then
>>>> drop in this patch without the cfun push/pop.  The revised patch looks ok
>>>> to me with the cfun push/pop removed.
>>>>
>>>> Thanks,
>>>> Richard.
>>>>
>>>>>>
>>>>>> I don't understand why you need another table mapping pass to name
>>>>>> when pass->name is available and the info is trivially re-constructible.
>>>>>
>>>>> This is needed as the pass->name is not the canonicalized name (i.e.,
>>>>> not with number suffix etc), so the extra mapping from id to
>>>>> normalized name is needed.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> David
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Richard.
>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>> On Wed, Jun 1, 2011 at 12:45 PM, Xinliang David Li <davidxl@google.com> wrote:
>>>>>>>> On Wed, Jun 1, 2011 at 12:29 PM, Richard Guenther
>>>>>>>> <richard.guenther@gmail.com> wrote:
>>>>>>>>> On Wed, Jun 1, 2011 at 6:16 PM, Xinliang David Li <davidxl@google.com> wrote:
>>>>>>>>>> On Wed, Jun 1, 2011 at 1:51 AM, Richard Guenther
>>>>>>>>>> <richard.guenther@gmail.com> wrote:
>>>>>>>>>>> On Wed, Jun 1, 2011 at 1:34 AM, Xinliang David Li <davidxl@google.com> wrote:
>>>>>>>>>>>> The following patch implements the a new option that dumps gcc PASS
>>>>>>>>>>>> configuration. The sample output is attached.  There is one
>>>>>>>>>>>> limitation: some placeholder passes that are named with '*xxx' are
>>>>>>>>>>>> note registered thus they are not listed. They are not important as
>>>>>>>>>>>> they can not be turned on/off anyway.
>>>>>>>>>>>>
>>>>>>>>>>>> The patch also enhanced -fenable-xxx and -fdisable-xx to allow a list
>>>>>>>>>>>> of function assembler names to be specified.
>>>>>>>>>>>>
>>>>>>>>>>>> Ok for trunk?
>>>>>>>>>>>
>>>>>>>>>>> Please split the patch.
>>>>>>>>>>>
>>>>>>>>>>> I'm not too happy how you dump the pass configuration.  Why not simply,
>>>>>>>>>>> at a _single_ place, walk the pass tree?  Instead of doing pieces of it
>>>>>>>>>>> at pass execution time when it's not already dumped - that really looks
>>>>>>>>>>> gross.
>>>>>>>>>>
>>>>>>>>>> Yes, that was the original plan -- but it has problems
>>>>>>>>>> 1) the dumper needs to know the root pass lists -- which can change
>>>>>>>>>> frequently -- it can be a long term maintanance burden;
>>>>>>>>>> 2) the centralized dumper needs to be done after option processing
>>>>>>>>>> 3) not sure if gate functions have any side effects or have dependencies on cfun
>>>>>>>>>>
>>>>>>>>>> The proposed solutions IMHO is not that intrusive -- just three hooks
>>>>>>>>>> to do the dumping and tracking indentation.
>>>>>>>>>
>>>>>>>>> Well, if you have a CU that is empty or optimized to nothing at some point
>>>>>>>>> you will not get a complete pass list.  I suppose optimize attributes might
>>>>>>>>> also confuse output.  Your solution might not be that intrusive
>>>>>>>>> but it is still ugly.  I don't see 1) as an issue, for 2) you can just call the
>>>>>>>>> dumping from toplev_main before calling do_compile (), 3) gate functions
>>>>>>>>> shouldn't have side-effects, but as they could gate on optimize_for_speed ()
>>>>>>>>> your option summary output will be bogus anyway.
>>>>>>>>>
>>>>>>>>> So - what is the output intended for if it isn't reliable?
>>>>>>>>
>>>>>>>> This needs to be cleaned up at some point -- the gate function should
>>>>>>>> behave the same for all functions and per-function decisions need to
>>>>>>>> be pushed down to the executor body.  I will try to rework the patch
>>>>>>>> as you suggested to see if there are problems.
>>>>>>>>
>>>>>>>> David
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Richard.
>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> The documentation should also link this option to the -fenable/disable
>>>>>>>>>>> options as obviously the pass names in that dump are those to be
>>>>>>>>>>> used for those flags (and not readily available anywhere else).
>>>>>>>>>>
>>>>>>>>>> Ok.
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> I also think that it would be way more useful to note in the individual
>>>>>>>>>>> dump files the functions (at the place they would usually appear) that
>>>>>>>>>>> have the pass explicitly enabled/disabled.
>>>>>>>>>>
>>>>>>>>>> Ok -- for ipa passes or tree/rtl passes where all functions are
>>>>>>>>>> explicitly disabled.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>>
>>>>>>>>>> David
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Richard.
>>>>>>>>>>>
>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>
>>>>>>>>>>>> David
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>