[patch] Add block debug info to phi_arg_d

[Richard Guenther]

On Thu, Jul 5, 2012 at 11:42 AM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> On Thu, Jul 5, 2012 at 11:23 AM, Richard Guenther
> <richard.guenther@gmail.com> wrote:
>> On Thu, Jul 5, 2012 at 11:08 AM, Dehao Chen <dehao@google.com> wrote:
>>> Hi,
>>>
>>> This patch added block field to phi_arg_d to make sure the associated
>>> source locus is consistent with its block info.
>>>
>>> Bootstrapped and passed gcc regression tests.
>>>
>>> OK for trunk?
>>
>> Hum - makes me want a location like we have on RTL (which maps to
>> location plus block ...).  But oh well ...
>>
>> struct GTY(()) phi_arg_d {
>>   /* imm_use MUST be the first element in struct because we do some
>>      pointer arithmetic with it.  See phi_arg_index_from_use.  */
>>   struct ssa_use_operand_d imm_use;
>> location_t locus;
>> +  tree block;
>>  };
>>
>> please place block before locus though.
>>
>> Ok with that change.
>
> Ehm, wait a moment, please -- does this have to be a tree pointer? Why
> not use BLOCK_NUMBER instead? Adding a pointer to such a
> frequently-used structure should be avoided if an int suffices.

Well, we re-number blocks frequently enough that this won't work.  In
gimple stmts there is also a block tree pointer.  The real solution would
of course be to associate location_t with a block, too, like the source locus
on RTL does.  It will also be fun do deal with during inlining and LTO
streaming.

Richard.

> Ciao!
> Steven