Re: add dbgcnt and opt-info support for devirtualization

[Xinliang David Li <davidxl at google dot com>]

Sorry about it. Here is the patch.  There is one remaining case where
cgraph_dump_file and dump_enable_p are checked separately --
cgraph_dump_file is set up differently from 'dump_file'.

David



On Mon, May 19, 2014 at 2:21 AM, Richard Biener
<richard.guenther@gmail.com> wrote:
> On Fri, May 16, 2014 at 11:19 PM, Xinliang David Li <davidxl@google.com> wrote:
>> Modified the patch according to yours and Richard's feedback. PTAL.
>
> ENOPATCH.
>
> Btw, I don't see any issue with leaking node order to opt-report.
>
> Richard.
>
>> thanks,
>>
>> David
>>
>> On Fri, May 16, 2014 at 9:03 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>>> Hi, debugging runtime bugs due to devirtualization can be hard for
>>>> very large C++ programs with complicated class hierarchy. This patch
>>>> adds the support to report this high level transformation via
>>>> -fopt-info (not hidden inside dump file) and the ability the do binary
>>>> search with cutoff.
>>>>
>>>> Ok for trunk after build and test?
>>>
>>> Seems resonable to me.
>>>>
>>>> thanks,
>>>>
>>>> David
>>>
>>>> Index: ChangeLog
>>>> ===================================================================
>>>> --- ChangeLog (revision 210479)
>>>> +++ ChangeLog (working copy)
>>>> @@ -1,3 +1,18 @@
>>>> +2014-05-15  Xinliang David Li  <davidxl@google.com>
>>>> +
>>>> +     * cgraphunit.c (walk_polymorphic_call_targets): Add
>>>> +     dbgcnt and fopt-info support.
>>>> +     2014-05-15  Xinliang David Li  <davidxl@google.com>
>>>> +
>>>> +             * cgraphunit.c (walk_polymorphic_call_targets): Add
>>>> +             dbgcnt and fopt-info support.
>>>> +             * ipa-prop.c (ipa_make_edge_direct_to_target): Ditto.
>>>> +             * ipa-devirt.c (ipa_devirt): Ditto.
>>>> +             * ipa.c (walk_polymorphic_call_targets): Ditto.
>>>> +             * gimple-fold.c (fold_gimple_assign): Ditto.
>>>> +             (gimple_fold_call): Ditto.
>>>> +             * dbgcnt.def: New counter.
>>>> +
>>>>  2014-05-15  Martin Jambor  <mjambor@suse.cz>
>>>>
>>>>       PR ipa/61085
>>>> Index: ipa-prop.c
>>>> ===================================================================
>>>> --- ipa-prop.c        (revision 210479)
>>>> +++ ipa-prop.c        (working copy)
>>>> @@ -59,6 +59,7 @@ along with GCC; see the file COPYING3.
>>>>  #include "ipa-utils.h"
>>>>  #include "stringpool.h"
>>>>  #include "tree-ssanames.h"
>>>> +#include "dbgcnt.h"
>>>>
>>>>  /* Intermediate information about a parameter that is only useful during the
>>>>     run of ipa_analyze_node and is not kept afterwards.  */
>>>> @@ -2494,6 +2495,13 @@ ipa_make_edge_direct_to_target (struct c
>>>>           fprintf (dump_file, "ipa-prop: Discovered direct call to non-function"
>>>>                               " in %s/%i, making it unreachable.\n",
>>>>                    ie->caller->name (), ie->caller->order);
>>>> +          else if (dump_enabled_p ())
>>>> +         {
>>>> +           location_t loc = gimple_location (ie->call_stmt);
>>>> +           dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, loc,
>>>> +                            "Discovered direct call to non-function in %s, "
>>>> +                            "making it unreachable\n", ie->caller->name ());
>>>
>>> Perhaps "turning it to __builtin_unreachable call" and similarly in the other cases
>>> we introduce __builtin_unreachable? I think that could be easier for user to work
>>> out.
>>>
>>> What king of problems in devirtualizatoin you are seeing?
>>>
>>>
>>> Honza

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