Re: [CHKP, PATCH] Fix instrumented indirect calls with propagated pointers

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

2015-03-25 13:15 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
> On Wed, Mar 25, 2015 at 10:50 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>> On Wed, Mar 25, 2015 at 10:38:56AM +0100, Richard Biener wrote:
>>> --- gcc/passes.c        (revision 221633)
>>> +++ gcc/passes.c        (working copy)
>>> @@ -156,7 +156,8 @@ void
>>>  pass_manager::execute_early_local_passes ()
>>>  {
>>>    execute_pass_list (cfun, pass_build_ssa_passes_1->sub);
>>> -  execute_pass_list (cfun, pass_chkp_instrumentation_passes_1->sub);
>>> +  if (flag_check_pointer_bounds)
>>> +    execute_pass_list (cfun, pass_chkp_instrumentation_passes_1->sub);
>>>    execute_pass_list (cfun, pass_local_optimization_passes_1->sub);
>>>  }
>>>
>>> @@ -424,7 +425,8 @@ public:
>>>    virtual bool gate (function *)
>>>      {
>>>        /* Don't bother doing anything if the program has errors.  */
>>> -      return (!seen_error () && !in_lto_p);
>>> +      return (flag_check_pointer_bounds
>>> +             && !seen_error () && !in_lto_p);
>>>      }
>>>
>>>  }; // class pass_chkp_instrumentation_passes
>>
>> There is still the wasteful pass_fixup_cfg at the start of:
>> PUSH_INSERT_PASSES_WITHIN (pass_local_optimization_passes)
>>   NEXT_PASS (pass_fixup_cfg);
>> which wasn't there before chkp.  Perhaps this should be a different
>> pass with the same execute method, but gate containing
>> flag_check_pointer_bounds?
>
> That's not wasteful but required due to local_pure_const.  The remaining
> wasteful fixup_cfg is the one in pass_build_ssa_passes.  ISTR
> that pass_ipa_chkp_versioning/early_produce_thunks makes that one
> required?  Or EH / CFG cleanup stuff makes it necessary to not
> fail IL checking done by into-SSA.

These two chkp passes don't modify function bodies (mat remove it
though). I don't expect them to require following fixup_cfg.

Ilya

>
> Richard.
>
>>         Jakub