Re: [PATCH, vec-tails 02/10] Extend _loop_vec_info structure with epilogue related fields

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

2016-06-16 8:11 GMT+03:00 Jeff Law <law@redhat.com>:
> On 05/19/2016 01:38 PM, Ilya Enkovich wrote:
>>
>> Hi,
>>
>> This patch adds new fields to _loop_vec_info structure to support loop
>> epilogue vectorization.
>>
>> Thanks,
>> Ilya
>> --
>> gcc/
>>
>> 2016-05-19  Ilya Enkovich  <ilya.enkovich@intel.com>
>>
>>         * tree-vectorizer.h (struct _loop_vec_info): Add new fields
>>         can_be_masked, required_masks, mask_epilogue, combine_epilogue,
>>         need_masking, orig_loop_info.
>>         (LOOP_VINFO_CAN_BE_MASKED): New.
>>         (LOOP_VINFO_REQUIRED_MASKS): New.
>>         (LOOP_VINFO_COMBINE_EPILOGUE): New.
>>         (LOOP_VINFO_MASK_EPILOGUE): New.
>>         (LOOP_VINFO_NEED_MASKING): New.
>>         (LOOP_VINFO_ORIG_LOOP_INFO): New.
>>         (LOOP_VINFO_EPILOGUE_P): New.
>>         (LOOP_VINFO_ORIG_MASK_EPILOGUE): New.
>>         (LOOP_VINFO_ORIG_VECT_FACTOR): New.
>>         * tree-vect-loop.c (new_loop_vec_info): Initialize new
>>         _loop_vec_info fields.
>
> I don't see anything here that is inherently wrong/bad here; I think this
> would be fine once the whole set is approved.   I also think if you find
> that you need additional similar kinds of fields, that would be OK as well.
>
> The one question I would ask -- do we ever need to copy VINFO data from one
> loop to a duplicate, and if so, ISTM that the code to copy that data would
> be a part of this patch.

AFAIK we currently never copy vectorized loop in vectorizer.  I never saw VINFO
to be copied and I don't see corresponding API in tree-vectorizer.h.
I'll double-check it.

Thanks,
Ilya

>
> jeff
>